Ge Appliances Ge752 Users Manual Gek_91584d

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GEK–91584D

VERTICAL DRILLING MOTOR

TYPE GE752

CONTENTS

Page

INTRODUCTION 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GENERAL DESCRIPTION 2. . . . . . . . . . . . . . . . . . . .

DATA 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SPECIAL TOOLS AND EQUIPMENT 8. . . . . . . . . . .

GROUNDING INSTRUCTIONS 8. . . . . . . . . . . . . . . .

GROUNDING PROCEDURES 9. . . . . . . . . . . . . . .

OVERHAUL 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LUBRICATION 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GREASE TUBES AND PIPE PLUGS 9. . . . . . . . .

INSPECTION 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

MONTHLY 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SEMI–ANNUALLY 13. . . . . . . . . . . . . . . . . . . . . . . . .

BASIC REPAIRS 13. . . . . . . . . . . . . . . . . . . . . . . . . . . .

BRUSH REPLACEMENT 13. . . . . . . . . . . . . . . . . . .

BRUSHHOLDER REPLACEMENT 13. . . . . . . . . .

BRUSHHOLDER CLEARANCE

ADJUSTMENT 14. . . . . . . . . . . . . . . . . . . . . . . . . .

COMMUTATOR RESURFACING 14. . . . . . . . . . . .

BASIC OVERHAUL 19. . . . . . . . . . . . . . . . . . . . . . . . .

TESTING BEFORE DISASSEMBLY 19. . . . . . . . .

TABLE 2. DRAWING REFERENCE 20. . . . . . . . . .

DISASSEMBLY 20. . . . . . . . . . . . . . . . . . . . . . . . . . .

CLEANING 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

INSPECTION AND TEST OF

DISASSEMBLED MOTOR 31. . . . . . . . . . . . . . . . . . .

BEARING INSPECTION 31. . . . . . . . . . . . . . . . . . .

ARMATURE 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

COMMUTATOR 32. . . . . . . . . . . . . . . . . . . . . . . . . . .

ARMATURE SHAFT INSPECTION 32. . . . . . . . . .

MOTOR FRAME 32. . . . . . . . . . . . . . . . . . . . . . . . . .

BRUSHHOLDERS 35. . . . . . . . . . . . . . . . . . . . . . . . .

REPAIR 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LUBRICATION OF BOLTS 35. . . . . . . . . . . . . . . . .

Revisions are indicated by margin bars.

CONTENTS (CONT’D)

Page

BRUSHHOLDER SLEEVE REPLACEMENT 36. .

ARMATURE 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TABLE 3. STANDARD BOLT TORQUE

VALUES 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TEST AFTER REPAIR (Armature) 44. . . . . . . . . . .

MOTOR FRAME FIELD COIL

REPLACEMENT 45. . . . . . . . . . . . . . . . . . . . . . . . .

TEST AFTER REPAIR

(Coiled Frame Without Armature) 55. . . . . . . . . .

TABLE 4. VARNISH VISCOSITY CHART

FOR DIPPING COILED FRAME 55. . . . . . . . . . . . .

VARNISH TREATMENT (ARMATURE) 56. . . . . . .

BALANCING ARMATURE 56. . . . . . . . . . . . . . . . . .

REASSEMBLY 56. . . . . . . . . . . . . . . . . . . . . . . . . . . .

BRUSHHOLDER CLEARANCE

ADJUSTMENT 65. . . . . . . . . . . . . . . . . . . . . . . . . .

BRUSH INSTALLATION 65. . . . . . . . . . . . . . . . . . . .

HUB MOUNTING 66. . . . . . . . . . . . . . . . . . . . . . . . .

TESTING AFTER OVERHAUL 67. . . . . . . . . . . . . . .

TESTING SERIES MACHINES

(Models 5GE752AUP, AUT) 67. . . . . . . . . . . . . . .

TESTING SHUNT MACHINES

(Models 5GE752UP and US) 68. . . . . . . . . . . . . .

REMOVING ARMATURE

LOCKING ARRANGEMENT 69. . . . . . . . . . . . . . . . . .

LOCKING THE ARMATURE FOR SHIPMENT 69. .

SHIPPING 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

HANDLING 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CLEANING AND SLUSHING 69. . . . . . . . . . . . . . .

SKIDDING 70. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PROTECTION 70. . . . . . . . . . . . . . . . . . . . . . . . . . . .

ARMATURES 70. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PREPARATION OF BOX 70. . . . . . . . . . . . . . . . . . .

BOXING THE ARMATURE 71. . . . . . . . . . . . . . . . .

STORAGE 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PLACING INTO STORAGE 71. . . . . . . . . . . . . . . . .

REMOVING FROM STORAGE 72. . . . . . . . . . . . .

Copyright 1992, 1993, 2005 General Electric Company. All rights reserved. This copyrighted document may be reproduced free of charge by

General Electric Company customers (OEM’s) and their customers, if such reproduction is used exclusively in connection with equipment used in

those customers’ internal operations.

These instructions do not purport to cover all details or variations in equipment nor to provide for every possible contingency to be met in connection with installation, operation, or mainte-

nance. Should further information be desired or should particular problems arise which are not covered sufficiently for the user’s purposes, the matter should be referred to the General

Electric Company. Any applicable Federal, State or local regulations or company safety or operating rules must take precedence over any instructions given in this material. GE has no

obligation to keep the material up to date after the original publication.

THERE ARE NO WARRANTIES OF ACCURACY, MERCHANTABILITY OR FITNESS FOR PARTICULAR PURPOSE.

Verify numbers for parts, tools, or material by using the Renewal Parts or Tool Catalogs, or contact your General Electric repre-

sentative for assistance.

Do not order from this publication.

GEK–91584D, Vertical Drilling Motor, Type GE752

2

FIG. 1. GE752 VERTICAL DRILLING MOTOR.

E–39088.

INTRODUCTION

GE752 drilling motors designed for vertical opera-

tion, Fig. 1, are available in GE’s UP, AUP, US and AUT

series. This instruction provides inspection, mainte-

nance and basic overhaul procedures for all of these

motors. See Table I (page 3) for the models covered.

These motors have a ball bearing and a reinforced

framehead at the commutator end to support the arma-

ture shaft vertically. They also have a shaft extension at

the commutator end for installation of a brake. Mounting

feet are precision machined to align with the rotational

ovals of the motor.

Refer to GEK–64271C for coverage of GE752 mod-

els designed for horizontal operation.

GENERAL DESCRIPTION

GE752 motors are used by the oil and gas industry to

power offshore and land–based drill rigs. Designed for

vertical operation, they are d–c machines which require

a nominal 750 volt d–c power source.

With suitable switching, they will operate equally well

in either rotational direction. The following provides a

listing of basic features.

The GE752UP and US models are of the “Shunt”

class of motors which means they are separately ex-

cited with shunt wound fields.

The GE752AUP and AUT models are of the “Series”

class of motors which means they are self excited with

series wound fields.

GE752UP and AUP motors are original design mo-

tors introduced in 1983. GE752US and AUT motors are

Hi–Torque motors with:

1. A new shallow slot design and split conductor ar-

rangement reduce heat generating eddy cur-

rents. Kapton insulation and new slot design

allow more copper cross–section and allow the

field windings and armature to operate at in-

creased power levels.

2. The spiral groove commutator provides better

commutator and brush cooling, better commuta-

tion ability, and increased brush life.

3. An additional six exhaust openings in the motor

drive end framehead and revised air flow pas-

sage increases air flow and the motor’s ability to

transfer generated heat.

*Kapton is a registered trademark of E.I. duPont de

Nemours & Co.

Vertical Drilling Motor, Type GE752, GEK–91584D

3

TABLE 1. MODEL DIFFERENCES

Motor Model Differences Superseded By

752UP1 This is a shunt motor with the following distinctions:

– Has internal greasing tubes for both drive end (pinion end)

and commutator–end bearings

– Has a double–ended shaft.

752UP2 Same as UP1 except:

– Has armored cable

– Has no grease tubes at commutator end

Motor Model Differences Superseded By

752UP3 Same as UP2 except:

– Has a single grease tube at drive end which is part of the

framehead/bearing assembly for ease of armature

disassembly.

752UP3A Same as UP3 except:

– Has class H Kapton wrapped exciting coils

752UP4 Same as UP3A except:

– Has an ABS certified shaft.

752UP5 Same as UP3A except:

– Has a thermal sensor embedded in each of its exciting and

commutating coils.

752UP6 Same as UP3A except:

– Has an improved commutator–end bearing assembly and an

ABS–certified armature shaft.

752US1 This is a shunt motor with the following distinctions:

– Same as UP3 except:

– Has an AG type armature with an AF commutator and

a standard AUP flash ring.

– Has AG type commutating coils and poles with brazed

instead of bolted connections.

– Has air vents in the drive–end framehead

– Has a frame specially machined for mounting the

customer gearbox at the drive end.

– Has a different drive–end grease arrangement.

– Has rubber hardtop brushes instead of regular duplex

brushes.

752US2 Same as US1 except:

– Has an improved commutator–end bearing assembly and an

ABS–certified armature shaft.

752AUP1 This is a series motor with the following distinctions:

– Has internal greasing tubes for both drive end and

commutator–end bearings

– Has a double–ended shaft.

752AUP2 Same as AUP1 except:

– Has armored cable

– Has no grease tubes at commutator end

– Mounting feet have dowel holes for vertical mounting.

GEK–91584D, Vertical Drilling Motor, Type GE752

4

TABLE 1 (Cont’d) MODEL DIFFERENCES

Motor Model Differences Superseded By

752AUP3 Same as AUP2 except:

– Has a single grease tube at drive end which is

part of framehead/bearing assembly for ease of

armature disassembly.

752AUP4 Same as AUP3 except:

– Has improved insulation for higher temperatures.

752AUP5 Same as AUP4 except:

– Has an improved commutator–end bearing assembly and an

ABS–certified armature shaft.

752AUT1 This is a series motor with the following distinctions:

– Same as 752AUP3 except:

– Has an AG type armature with an AF commutator and

a standard AUP flash ring.

– Has AG type commutator coils and poles with brazed

instead of bolted connections.

– Has air vents in the drive–end framehead

– Has a frame specially machined for mounting the

customer gearbox at the drive end.

– Has a different drive–end grease arrangement.

– Has rubber hardtop brushes instead of regular duplex

brushes.

752AUT2 Same as AUT1 except:

– Has an improved commutator–end bearing assembly and an

ABS–certified armature shaft.

DATA

Max. Permissible Speed (rpm) 1800. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Max. Permissible Vibration (Commutator End) (in.) 0.002. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

“Resistance at 25 C (Ohms): Min. Max.

Armature

Model 752UP 0.00912 0.00949. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUP 0.00912 0.00949. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752US 0.00749 0.00800. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUT 0.00749 0.00800. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Exciting Field (With Cables)

Model 752UP 1.25 1.33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752UP (After 3/88) 1.13 1.22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUP 0.00512 0.00558. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752US 1.13 1.22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUT 0.00486 0.00535. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutating Field (With Cables)

Model 752UP 0.00508 0.00540. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752UP (After 3/88) 0.00439 0.00534. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUP 0.00439 0.00477. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752US 0.00432 0.00480. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUT 0.00432 0.00480. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Vertical Drilling Motor, Type GE752, GEK–91584D

5

DATA (Cont’d)

Carbon Brushes

Type T900. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Size (in.) 3/4 x 2–1/4 x 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Minimum Brush Length (length at which brush becomes inoperative) (in.) 1–3/32. . . . . . . . . . . . . . . . . . . . . . . . .

(brush is measured on the longest side)

Spring Pressure on Brush, Preset (lb.) 10–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Brushholder

Clearance to Commutator (in.) 1/16–3/32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Clamp Bolt Torque (lb.–ft.) 225–250. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutator

Side Mica Thickness (in.) 0.060. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Slot Depth (in.) 0.047. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Undercutting Saw:

Width (in.) 0.063. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Diameter (in.) 1.000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Diameter: (in.)

New 16.625. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Worn (minimum permissible) 15.375. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Riser Width (minimum permissible) (in.) 0.625. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dust Groove: (in.)

Width 0.250. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Depth 0.125. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutator (Cont’d)

Concentricity – New Commutator (in.)

Total Indicated Runout, TIR 0.001. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Variation of Indicator Runout within (in.)

any Group of 20 Bars 0.0004. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Variation of Indicator Reading between (in.)

any Two Adjacent Bars 0.0001. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Concentricity – Used Commutator (in.)

(Resurface if runout exceeds 0.010 TIR

or 0.003 within any group of 6 bars):

After Resurfacing, TIR (in.) 0.001. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bar–To–Bar Test (500 v) Voltage

Variation Bar–To–Bar +/– 5%. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Armature Balance

Commutator End 12 grams (0.42 oz.). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Drive End 10 grams (0.35 oz.). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Armature Bearings Min. Max.

Diametral Clearance, Assembled (In.)

Drive End 0.005 0.009. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutator End 0.0005 0.0035. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Runout Measured from Shaft to Outer Race (in.):

Drive End 0.004. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutator End 0.003. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GEK–91584D, Vertical Drilling Motor, Type GE752

6

DATA (Cont’d)

Pole Bore Diameter (measured at center of pole) (in.)

Motors: Min. Max.

Exciting Poles (Shunt models) 19.606 19.640. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Exciting Poles (Series models) 19.613 19.640. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutating Poles (Both Shunt and Series models) 19.956 19.998. . . . . . . . . . . . . . . . . . . .

Impedance Test Voltage Drop

(Coiled Frame Without Armature): Min. Max.

Exciting Field (With Cables)

Model 752UP (0.5 Amps @ 60 Hz) 59.0 66.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUP (24 Amps @ 60 Hz) 13.1 15.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752US (0.5 Amps @ 60 Hz)* 59.0 66.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUT (24 Amps @ 60 Hz) 13.1 15.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutating Field (With Cables)

Model 752UP (24 Amps @ 60 Hz) 7.3 8.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUP (24 Amps @ 60 Hz) 7.2 8.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752US (24 Amps @ 60 Hz)** 7.3 8.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model 752AUT (24 Amps @ 60 Hz) 7.7 8.5”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lubrication* – Armature Bearings

Grease Capacities (oz.):

Drive End 39.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commutator End 31.8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lubricant GE–D6A2C10*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

**See Grease Specification at the end of the DATA table.

Weights (lb.) (approx.)

Complete 6720. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Armature Only 2100. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

High–Potential Test

60 Hz, a–c, to ground for one minute (All Windings) (volts):

New or Rewound Armature 3500. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reconditioned 2000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Megger Test Minimum Megohmmeter

Reading (megohms)

Shunt Models

A1–A2 1.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

F1–F2 0.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Series Models

A1–A2 1.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

F1–F2 1.4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

* With Commutating Poles (CP) out.

**Excitation Field in.

Vertical Drilling Motor, Type GE752, GEK–91584D

7

DATA (Cont’d)

Motor Ratings* Continuous

Max. HP

Shunt (UP)

Volts 750. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Armature Amps 1050. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Field Amps 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RPM 1050. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Horsepower 1000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Series (AUP)

Volts 750. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Armature Amps 1050. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Field Amps 100%. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RPM 975. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Horsepower 1000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

*

NOTE: With 2800 SCFM air flow.

Motor Ratings** Continuous Continuous Intermittent

Max. HP Max. Torque Duty Cycle

Shunt (US)

Volts 750 650 750. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Armature Amps 1185 1250 1435. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Field Amps* 60 60 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RPM 1040 900 1065. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Torque 5705 5995 6745. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Horsepower 1130 1030 1365. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Series (AUT)

Volts 750 570 750. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Armature Amps 1150 1250 1400. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Field Strength 100% 100% 100%. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RPM 965 700 920. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Torque 5900 6620 7530. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Horsepower 1085 880 1320. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

**NOTE: With 2800 SCFM air flow and ABS temperature rise standards, 155



C over 40



C ambient.

Grease Specification

D6A2C10 grease is a lithium soap base grease with added antioxidant. It contains an oil of heavy viscosity and is

especially suitable for high speed, high temperature open or shielded bearings in drilling motors.

Specifications:

Worked Consistency, 77 F, MM/10 220–240. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dropping Point, Degrees F (Min) 380. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mineral Oil Viscosity At 100 F, SSU 475–525. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Free Alkali, Percent (Max) 0.50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Free Acid, Percent (Max) Nil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Color Amber. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Base (With Antioxidant) Lithium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Oxidation Resistance Time To Reach 20 psi Drop At 210 F, Hr. (Min) 1000. . . . . . . . . . . . . . . . . . . . . . . . . .

Corrosion Must Pass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Approved Vendor Shell Oil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Brand Name Cyprina RA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GEK–91584D, Vertical Drilling Motor, Type GE752

8

SPECIAL TOOLS

AND EQUIPMENT

CAUTION: This machine is of open splash–proof

construction. It is force–ventilated and requires

an ample supply of cooling air. The cooling air

should not contain combustible gases. If it is

applied in an environment which may contain

combustible gases, an adequate supply of non–

contaminated cooling air must be provided.

The following items are required to maintain, repair

and overhaul the motors:

Part

Megohmmeter (or “Megger”*)

600 volts 111X910 or equivalent. . . . . . . . . . . . . . . .

Voltmeter Simpson Multimeter, Model 260. . . . . . . . . . or equivalent

Puller Tools 41E903423G1. . . . . . . . . . . . . . . . . . . . . . .

Commutator Grinder 427C592G1. . . . . . . . . . . . . . . . .

Resurfacing Stones:

Medium Grade 8828492P11. . . . . . . . . . . . . . . . . . .

Finish Grade 8828492P8. . . . . . . . . . . . . . . . . . . . . .

Brush–Seater Stone (White) 106X98. . . . . . . . . . .

Lifting Eye P9945894P8. . . . . . . . . . . . . . . . . . . . . . . . . .

Crows–Foot Pressing Tool 41C685430G1. . . . . . . . . .

Ball and Socket Tool 41C685080G1. . . . . . . . . . . . . . .

Guide Pins, Three (3) Recommended

for Armature Asm. In Frame 6717114P1. . . . . . . .

Spanner Wrench 8843522G1. . . . . . . . . . . . . . . . . . . . .

Spring Scale (for brush–spring

pressure check) 0–20 lb. capacity. . . . . . . . . . . . . .

Hub Assembly Gauge 41D790941G1. . . . . . . . . . . . . .

Hub Puller (Less Pump) 41B535703G1. . . . . . . . . . . .

Pump (For Above) 8843947G1. . . . . . . . . . . . . . . . . . . .

*Tradename of James G. Biddle Co.

GROUNDING INSTRUCTIONS

Grounding motor frames is required to safeguard

personnel from electric shock in event of an insulation

failure in the machine.

WARNING: Failure to properly ground electrical

equipment may expose personnel to a potentially

hazardous condition in which serious or fatal in-

jury from electrical shock is possible.

Grounding conductors must be provided between

the machine frame and the supporting structure to avoid

hazardous potential difference between the machine

frame and the adjacent surface on which a person may

be standing while touching the machine.

NOTE: This type of ground connection is re-

ferred to in electrical standards as “equipment

grounding” or “enclosure grounding” which is

not to be confused with “system” or “circuit”

grounding. Drilling drive systems normally do

not have intentional circuit ground connec-

tions, except through high impedance detec-

tors.

Grounding conductors must be provided on drilling

units on which the construction of the unit and/or the in-

stallation of the machines do not inherently insure posi-

tive grounding of the equipment. Examples are those

portable (modular) platform rigs and land rigs which do

not already have ground cables to all machinery struc-

tures. Offshore rigs with equipment fastened to the

FIG. 2. DRILLING MOTOR – FRAME GROUNDING

CABLE CONNECTIONS. E–28717.

Vertical Drilling Motor, Type GE752, GEK–91584D

9

decks by bolting or welding should not require additional

grounding. (References: ABS Rules for Building and

Classing Steel Vessels, Section 35.9.6, and IEEE Stan-

dard 45–1977, Recommended Practice for Electrical In-

stallations on Shipboard, Section 21.4.)

GROUNDING PROCEDURES (Fig. 2)

Most GE drilling machines have extra tap blocks on

the frame for mounting of the connection boxes. One of

these may be used for attaching the grounding cable. If

one is not available, use the lower chain case mounting

boss on the end opposite the drive end in accordance

with Step 2.

1. To attach the ground cable to a tap block, obtain

a 0.75–10 bolt with length of 1.0 to 1.5 in. and a

lockwasher. Also obtain a cable lug to fit the

ground cable and large enough for the 0.75 di-

ameter bolt.

2. To attach the cable to the chain case boss, obtain

a 1.25–7 bolt with length of 1.0 to 1.75 in. and a

lockwasher. Prepare a copper plate at least 1/8

in. thick with a 1.25 in. diameter hole for bolting to

the chain case boss, and with enough extra area

for holes to attach a cable lug. Drill hole(s) in

plate for cable lug. Clean all paint, rust and oil

from the chain case boss and bolt the copper

plate to the chain case boss.

3. Prepare a ground conductor* long enough to run

from the motor frame to an existing ground con-

ductor system or to a suitable equipment ground

point as defined by the National Electrical Code

Article 250 or other applicable regulation. Check

that the system ground detector is also con-

nected to the Common ground point for the rig

and make connection if necessary.

4. Install terminal lugs on cable. Remove paint, rust

and oil from the surfaces to which the cables are

to be attached and bolt the lugs securely to these

surfaces.

*Use 4/0 size or larger copper cable for GE752 ma-

chines. (Reference: National Electrical Code, 1978

Edition, Table 250–95.)

5. Use a digital ohmmeter to check that the bolted

connections are solid, low resistance connec-

tions from the cable conductor to the ground

point and to the motor frame. The meter reading

should be 0.2 ohms or less.

OVERHAUL

Overhaul intervals will depend on the severity of ser

vice seen by the machine. However, General Electric

Co. recommends that an overhaul be performed every

18,000 hours (approximately every two years) on all

machines subjected to normal operation.

The motor should be removed, disassembled,

cleaned, inspected and reconditioned as necessary (in-

cluding varnish treatment of armature and fields). Motor

bearings should be repacked with grease. See the

DATA section for grease type and quantity.

LUBRICATION

Periodic lubrication is required on all GE752 drilling

machines designed for vertical operation between

scheduled overhaul periods. Every six months or 2500

hours, whichever comes first, apply approximately 2 oz.

of grease at each end.

GREASE TUBES AND PIPE PLUGS

The following lists grease tube and pipe plug configu-

rations for all models covered in this publication:

1. UP1 and AUP1 — Four grease tubes with pipe

plugs, two at each end.

2. UP2 and AUP2 — Two grease tubes with pipe

plugs, one at each end.

3. UP3, UP3A, UP4, UP5, UP6, AUP3, AUP4,

AUP5 – One grease tube with a pipe plug at the

drive end, one pipe plug only at the commutator

end.

4. US1, US2, AUT1, AUT2 – One pipe plug only at

each end.

Pipe plugs are provided on bearing caps and on the

ends of all grease tubes to prevent the ingress of dirt or

other contamination.

Remove the pipe plugs and install grease fittings to

facilitate lubrication. Replace the pipe plugs after adding

lubricant. See the DATA section for recommended

grease type.

GEK–91584D, Vertical Drilling Motor, Type GE752

10

INSPECTION

MONTHLY

Inspect the exterior of the machine, including cables,

for damage.

Covers, Seals, Latches

Clean the outside of the machine and remove the in-

spection covers. Use clean, dry compressed air and

blow the dirt and carbon dust from the interior of the ma-

chine.

WARNING: When using compressed air for clean-

ing purposes, flying debris and particles may

present a hazard to personnel in the immediate

area. Personnel should be provided with, and

trained in the use of, personal protective equip-

ment as specified by applicable federal or state

safety regulations.

Check exterior covers to be sure felt seals are intact.

If seals are missing or covers are damaged, replace

seals or covers as necessary. Make sure covers fit prop-

erly and cover latches work properly.

Brushholders (Fig. 5)

Satisfactory operation of the drilling motor requires

the brushholders to be in good condition. Of particular

importance is the inside dimension of the carbonways.

Operation may also be impaired by brushholders which

have been mechanically damaged or sustained dam-

age as the result of motor flashovers.

Inspect the brushholders for damage. If they require

replacement, refer to BASIC REPAIRS, Brushholder

Replacement section for instructions.

When new, brushholder carbonways should mea-

sure 0.753 +/–0.002 in x 2.2575 +/–0.0025 in. If or when

the 0.753 in. dimension exceeds 0.765 in., the brushhol-

der should be scrapped. If it falls between 0.758 and

0.765 in., the carbonway can be restored to its proper

dimension according to the following instructions:

1. Remove the brushholder. Position it as shown in

Fig. 3 and tap the metal ridge with a hammer.

FIG. 3. RESIZING BRUSHHOLDER

CARBONWAYS. E–11281.

Start at one end and work along the ridge to the

other end.

2. Check progress frequently by means of a “Go/

No–Go” gage made to the dimensions shown in

Fig. 4.

FIG. 4. BRUSHHOLDER CARBONWAY

GAGE. E–11283A.

Vertical Drilling Motor, Type GE752, GEK–91584D

11

3. Continue tapping as described in Step 1 until the

0.753 dimension falls between 0.751 and 0.755.

4. If, due to excessive pounding, the inside dimen-

sion becomes less than 0.751 in., file back to size

with a fine mill file.

Additional repairs can be made to restore damaged

brushholder bodies. Brushholder damage is fairly typi-

cal when flashovers have occured, resulting in some

burning or melting of metal at the corners of the brush-

holder. Metal thus removed can be restored according

to the following instruction, unless more than 1/4 in.

buildup of metal is required in the affected area, in which

case the brushholder should be scrapped. Proceed as

follows:

1. Thoroughly clean the affected area by wire

brushing, and grind off any metal flow resulting

from a flashover.

2. Apply a suitable brazing flux such as

GE–A10B15 to the area to be built up.

3. Insert a carbon brush into the brushholder to pre-

vent the brazing material from flowing into the

carbonway.

4. Using a brazing torch and a 1/16 in. diameter

brass brazing rod, puddle in sufficient metal to

restore the metal that had been removed.

5. Check the carbonway for size with the “Go/No–

Go” gage after the brushholder has cooled to

room temperature.

6. Resize as required using the preceding method.

Brushholder Sleeves

Use a clean, lintless cloth and wipe dirt and grease

from the Teflon* brushholder sleeves, Fig. 5. If neces-

sary, use a cleaner such as MEK (methyl ethyl ketone)

to clean the sleeves. Inspect sleeves for cracks and thin

spots caused by flashovers. Replace any damaged

brushholder or one having a damaged sleeve.

WARNING: MEK is a volatile solvent. The fumes

should not be inhaled. Use only in a well–venti-

lated area and take adequate precautions to pro-

tect eyes, skin and hands.

NOTE: Never paint these sleeves. Periodically

wipe them clean with a dry cloth or a cloth

dipped in an approved non–oily cleaning sol-

vent.

Inspect the brushholder cables and make sure all

terminal bolts and all brushholder clamp bolts are tight.

Brush Spring Pressure

Lift the brush pressure fingers to the “toggled–up”

position, Fig. 5, and check for free movement of the

spring assembly.

Inspect the brush springs for obvious failure or dam-

age. Check brush–spring pressure by comparing spring

pressure with a spring known to be good. Refer to the

DATA section for brush spring–pressure value.

FIG. 5. BRUSH SPRING ARRANGEMENT.

E–18963.

TEFLON

SLEEVES

BRUSH PRESSURE FINGER

(IN TOGGLED–UP POSITION)

PRESSURE

SPRING

CARBONWAY

BRUSH–SHUNT

TERMINAL

SCREWS

*Product of E.I. duPont de Nemours Company.

GEK–91584D, Vertical Drilling Motor, Type GE752

12

Brushes

Brush wear is determined by measuring actual brush

length from the top of the carbon. Lift the brush spring,

remove the brush and measure brush length on the

longest side.

NOTE: If brush replacement is not required, be

sure that brushes are of sufficient length to last

until the next inspection.

If one or more brushes are worn to or near the mini-

mum length listed in the DATA section it is generally rec-

ommended that all twelve brushes be replaced at the

same time.

WARNING: To avoid possible electrical shock or

injury from rotating equipment, do not remove or

replace brushes while equipment is energized or

rotating.

If brushes are to be replaced, see the BASIC RE-

PAIRS, Brush Replacement section for brush installa-

tion instructions.

If brushes are not to be replaced, the following brush

inspection should be made:

CAUTION: When replacing brushes, use only the

GE recommended grade. Mixing of brush grades

in the same motor or changing brushes to anoth-

er grade may seriously affect commutation, sur-

face film, commutator and brush life. See the

DATA section for brush grade.

1. Inspect all brushes to be sure they are not

chipped or broken. Make sure brush shunts are

not frayed or broken. Replace any brush which

shows damage of any kind.

NOTE: Chipped, burned or rough–faced

brushes may indicate the commutator needs

resurfacing.

2. Move the brushes up and down in their carbon-

ways to be sure brushes slide freely.

3. Check brush shunts to be sure they are not

twisted or out of position, Fig. 6. Make sure all

brush–shunt terminal connections and all brush-

holder cable connections are tight.

Commutator

Inspect the commutator for possible flashover dam-

age. The commutator should be clean, smooth, glossy

and free of high mica, high bars, flat spots or rough sur-

faces.

If there are indications that the commutator is out–

of–round (as evidenced by variations in width of the

ridge between brush paths), check the concentricity of

the commutator with a dial indicator. Condemning limits

for concentricity are listed in the DATA section.

If the commutator requires grinding, refer to Com-

mutator Resurfacing in the BASIC REPAIRS section of

this manual for instructions.

Creepage Band

Clean the creepage band (located on the commuta-

tor cap) with a clean cloth dipped in an approved sol-

vent. Inspect the band for possible flashover damage.

Make sure the creepage band is tight on the commu-

tator cap.

Flash Ring

Examine the flash ring for possible flashover dam-

age. Wipe the flash ring clean. Keep ring free of dirt and

varnish.

KEEP SHUNTS CLEAR

OF LEVER ARMS

BRUSH

SHUNTS

FIG. 6. CORRECT POSITION OF BRUSH

SHUNTS. E–22568.

Vertical Drilling Motor, Type GE752, GEK–91584D

13

Insulation

Measure the insulation resistance with a meg– ohm-

meter (Megger) to determine the condition of the insula-

tion. If reading is low, make a further inspection to deter-

mine if insulation failure or excessive moisture is caus-

ing the low megohmmeter reading. Correct the cause of

low readings before returning the motor to service.

Inspect all accessible parts of the field coil insulation

for cracking and evidence of overheating.

Power Cables

Inspect the power cables for signs of excessive heat-

ing, poor insulation or mechanical damage. Assure all

terminals are tight. Replace any cables which show low

insulation resistance or will not stand 75% above rated

voltage.

Mounting Bolts

Check all mounting bolts to assure tightness.

SEMI–ANNUALLY

1. Perform inspection operations listed under

Monthly section.

2. Refer to the DATA section for the Brushholder

Clearance dimension, and check the clearance

between the brushholders and the commutator

surface.

If clearance adjustment is required, refer to the BA-

SIC REPAIRS, Brushholder Clearance Adjustment sec-

tion for instructions.

BASIC REPAIRS

BRUSH REPLACEMENT

NOTE: Brush spring pressure is pre–set and

non–adjustable for the brushholders used on

these machines. Any brushholder that is dam-

aged or has a low spring pressure should be re-

placed before installing new brushes. Spring

pressure can be measured with a 20–lb. spring

scale pulling radially on the brush pressure fin-

ger over the center of each brush. See the DATA

section for limits.

1. Remove the commutator inspection covers.

2. Disconnect the brush shunt from the terminal

screw, Fig. 5, located on the brushholder body.

3. Lift the pressure finger away from the brush to

the toggled–up position. Remove the brush.

4. Use dry, compressed air and blow the carbon

dust from the carbonway.

WARNING: When using compressed air for clean-

ing purposes, flying debris and particles may

present a hazard to personnel in the immediate

area. Personnel should be provided with, and

trained in the use of, personal protective equip-

ment as specified by applicable federal or state

safety regulations.

5. Insert a new brush and make sure it slides freely

in the carbonway.

6. Carefully lower the pressure finger on the brush.

Do not allow the finger to snap down on the

brush; this could damage the brush.

7. Bolt the brush shunt terminals to the brushhol-

der(s). Arrange the brush shunt strands so they

clear the pressure fingers, Fig. 6, and tighten the

terminal screw(s). Make sure brush shunts are

not positioned under the pressure fingers. Check

and tighten all brushholder cable connections.

8. Seat the new brushes with a white seater stone.

CAUTION: When replacing brushes, use the GE

recommended grade. Mixing of brush grades in

the same motor or changing brushes to another

grade will seriously affect commutation, surface

film, commutator and brush life. See the DATA

section for brush grade.

BRUSHHOLDER REPLACEMENT

Removal

1. Remove brushes from the brushholders and

cover the commutator with heavy paper.

2. Disconnect the cable from the brushholder(s) in-

volved.

GEK–91584D, Vertical Drilling Motor, Type GE752

14

3. Remove bolt, washer and brushholder clamp.

Lift the brushholder out of the frame.

Installation

1. Position the brushholder in the frame with the

brushholder studs resting in the clamp surfaces

of the brushholder support.

2. Install bolt and washer. Tighten bolt but do not

torque until the brushholder–to–commutator

clearance has been established. Refer to Brush-

holder Clearance Adjustment section for instruc-

tions to adjust brushholder clearance.

3. After brushholder clearance has been set, con-

nect the brushholder cable and remove protec-

tive paper from commutator surface.

4. Check brushes to insure they exceed the mini-

mum brush length dimension and are free of any

damage. If they are long enough and are not

damaged, they can be re–used. If not, replace

with new brushes.

BRUSHHOLDER CLEARANCE

ADJUSTMENT

Refer to the DATA section for the brushholder–to–

commutator clearance dimension and adjust brushhol-

der as follows:

1. Remove the brushes.

CAUTION: Do not allow the brushholder to

touch, bump or rest on the commutator.

2. Insert a fiber gauge (equal in thickness to the

clearance dimension) between the commutator

and the brushholder. (Loosen brushholder first if

below minimum allowable clearance.)

Do NOT use a metallic gauge.

3. Loosen the brushholder support bolt and move

the brushholder against the fiber gauge so clea-

rance–to–commutator is the same as the gauge

thickness.

4. Torque bolt to 225–250 ft.–lb. and recheck the

brushholder clearance gap.

COMMUTATOR RESURFACING

Prior to resurfacing, consider the following:

1. The brush surface diameter of the commutator

must not be less than the minimum permissible

diameter, listed in the DATA section, after resur-

facing operations are completed.

2. The commutator can be resurfaced by sanding,

stoning or grinding. Choose the method to be

used based on the condition of the commutator.

NOTE: Outside power will be required to oper-

ate the motor for the following commutator–re-

surfacing procedure.

1. A second person must be at the auxiliary

power (welder) control station, ready to

shut off power in case of an emergency

during the grinding operation.

2. The grinding operator should wear

goggles and a dust mask when resurfac-

ing or blowing out the commutator.

3. To avoid electrical shock, do not touch

any part of the machine interior during

grinding operations.

WARNING: For the safety of personnel during

resurfacing operations, the following safety

precautions must be adhered to:

Preparation For Operating Series Model

Machines For Commutator Resurfacing

1. Break the coupling (if applicable) so the machine

can be operated from a d–c welding set or other

outside d–c power source.

2. Lift all the brushes except two of opposite polarity

(adjacent brushholders) which are necessary to

operate the motor.

3. Connect the machine to an outside source of

controlled d–c power; such as a 3–5 kw, 100 vdc

welding set which is capable of driving it at a

speed of 900–1000 rpm.

4. Refer to Fig. 7 for diagram of connections to run

a series machine from a welding set. Connect

Vertical Drilling Motor, Type GE752, GEK–91584D

15

FIG. 7. DIAGRAM OF CONNECTIONS TO RUN

A SERIES MACHINE FROM A WELDING SET.

E–28718.

leads so machine will operate as a series motor,

and the armature will rotate counterclockwise

(viewed from the commutator end).

Preparation For Operating Shunt Model

Machines For Commutator Resurfacing

1. Break the coupling (if applicable) so the machine

can be run from a d–c power source.

2. Lift all brushes except two of opposite polarity

(adjacent brushholders) which are necessary to

operate the motor.

3. Connect the machine to an outside source of

controlled d–c power, Fig. 8.

4. Apply power as follows:

a. Increase the field supply (0–50 v) to 32.0 volts

at 25 amps.

b. Increase the armature supply (0–150 v) to

150 volts.

c. Slowly decrease the field supply to bring the

speed up to 1000 rpm.

FIG. 8. CONNECTIONS TO RUN A SHUNT

MACHINE FROM A D–C POWER SOURCE.

E–23930A.

NOTE: When shutting down, increase the field

supply to maximum, and then turn off the arma-

ture supply. After the armature supply has been

shut off, shut down the field supply.

Sanding Procedure

If the commutator is dirty, blackened or slightly

rough, resurface it by sanding with 00 sandpaper, or fin-

er, as follows:

1. Attach the fine sandpaper to a wooden block

shaped to fit the commutator, Fig. 9.

2. Run the machine at approximately 1000 rpm and

hold the block against the commutator with a

light, even pressure. Move the block back and

forth longitudinally to clean the commutator.

3. Use clean, dry compressed air, to remove dust

and sand.

Hand Stoning Procedure

If the commutator surface is mildly grooved,

threaded or burned, and only a small amount of copper

has to be removed to correct the trouble, use a hand

stone. Hand stoning will not correct an out–of–round

commutator. See “Fixture Grinding” section.

1. Use a fine–grade stone ground to fit the commu-

tator curvature, Fig. 10. It should also be of suffi-

cient width to bridge any flat spots; otherwise,

the stone will ride in and out of the flat and will not

correct it.

2. Remove one brushholder for access to the com-

mutator.

WOOD BLOCK

SHAPED TO

COMMUTATOR

FINE

SANDPAPER

WOOD SCREW

AND WASHER

FIG. 9. METHOD OF SANDING COMMUTATOR.

E–18149.

GEK–91584D, Vertical Drilling Motor, Type GE752

16

CAUTION: Never use an emery cloth on this or

any commutator. The abrasive particles on

emery cloth scratch the commutator surface

and lodge in the groves between commutator

segments. The condition creates the possibil-

ity of an eventual flashover which could seri-

ously damage the machine.

WARNING: Do not come into close proximity

of an energized motor during the cleaning pro-

cess. The armature commutator and brush rig-

ging have a high electrical charge which could

cause serious injury or death. Always use a

hose tip that is an electrical non–conductor

when cleaning with air.

WARNING: When using compressed air for

cleaning purposes, flying debris and particles

may present a hazard to personnel in the im-

mediate area. Personnel should be provided

with, and trained in the use of, personal pro-

tective equipment as specified by applicable

federal or state safety regulations.

3. Run the motor at approximately 1000 rpm.

4. Hold the stone firmly against the commutator

surface, and with even pressure, move the stone

back and forth longitudinally across the commu-

tator surface.

5. Blow away dust and sand with clean, dry, com-

pressed air.

FIG. 10. PROPER SHAPE OF

HANDSTONE. E–8779A.

WARNING: Do not come into close proximity

of an energized motor during the cleaning pro-

cess. The armature commutator and brush rig-

ging have a high electrical charge which could

cause serious injury or death. Always use a

hose tip that is an electrical non–conductor

when cleaning with air.

WARNING: When using compressed air for

cleaning purposes, flying debris and particles

may present a hazard to personnel in the im-

mediate area. Personnel should be provided

with, and trained in the use of, personal pro-

tective equipment as specified by applicable

federal or state safety regulations.

Fixture Grinding

Perform fixture–grinding operations to correct a

commutator that is grooved, threaded or out–of–round.

CAUTION: Be sure there is enough material on

the commutator so grinding will not decrease

the commutator diameter below the minimum

permissible diameter listed in the DATA sec-

tion.

Refer to SPECIAL TOOLS AND EQUIPMENT sec-

tion for commutator grinder part number. See Fig. 11 for

grinder nomenclature.

Grinder Installation

NOTE: Inspect the grinder before installing it to

be sure it is reasonably clean. Make sure the tra-

verse slides are free of accumulated dirt and

copper chips; otherwise, the carriage may bind

during the grinding operation.

1. Remove the inspection covers from the ma-

chine.

2. Remove the most accessible brushholder, and

clamp the grinder mounting bracket to the frame.

3. Remove the brushes from one brushholder adja-

cent to grinder in a CCW direction.

4. Install old brushes in remaining brushholders.

5. Bolt the grinder to the mounting bracket.

Vertical Drilling Motor, Type GE752, GEK–91584D

17

FIG. 11. COMMUTATOR GRINDER. E–18249.

NOTE: For most applications, finish–grade

resurfacing stones are recommended. Medium

grade stones can be used for rough grinding a

deeply grooved or threaded commutator, or a

commutator with deep flat spots, followed by fi-

nish–grade stones for the final grinding. If new

stones will be used, they should be contoured

on a Carborundum wheel to approximate the

curvature of the commutator.

Install the stones in the grinder so the entire surface

of the commutator will be resurfaced when the carriage

is traversed from side–to–side. Proceed with alignment

of the grinder as follows:

Install the resurfacing stones in the grinder and pro-

ceed as follows:

1. Traverse the carriage to one end of the commu-

tator and check the clearance between the com-

mutator surface and one stone with a feeler

gauge or a fiber strip (approximately 0.030 in.

thick). Traverse the carriage to the other end of

the commutator and check the clearance under

the same stone. The clearance should be the

same at both ends. If clearance is not equal at

both ends, adjust the mounting bracket by

means of the set screws to obtain equal clear-

ance at both ends.

GEK–91584D, Vertical Drilling Motor, Type GE752

18

2. Turn the feed control to back the stones away

from the commutator before starting the ma-

chine.

NOTE: If possible, use some method of collect-

ing the copper chips and abrasive dust pro-

duced by the grinding operation. For example,

use a vacuum cleaning device with the suction

wand set just behind the trailing edge of the

stones.

Grinding

1. Apply power to the machine and gradually in-

crease speed to 900–1000 rpm.

NOTE: Do not grind the commutator to a depth

where no mica undercut remains, or to a diame-

ter which is smaller than the minimum permis-

sible diameter listed in the DATA section.

2. Begin grinding by radially feeding the stones

lightly against the commutator. Then, slowly

move the carriage back and forth longitudinally

across the surface. When the cutting action of

the stone ceases, again feed the stone lightly

against the commutator and continue grinding.

Use care to make a light cut and to avoid chatter.

Cutting action should take place at the trailing

edge of the stones. Heavy cuts will cause exces-

sive copper drag.

3. Grind the commutator to obtain a uniformly

smooth surface, but do not remove any more

copper than necessary.

4. Lighten the cutting pressure on the stones near

the end of the grinding operation. If medium–

grade stones were used, stop the motor, change

to finish–grade stones and repeat Steps 1, 2, 3

and 4. After the final cut, traverse the stones

back and forth without changing the feed until

cutting action ceases.

5. Remove power from the machine.

6. Check commutator runout with a dial indicator.

Refer to the DATA section for concentricity limits.

FIG. 12. COMMUTATOR SLOT RAKING TOOL.

E–19771A.

7. If necessary, continue grinding to meet concen-

tricity values listed in the DATA section.

8. Remove the grinder.

9. See Fig. 12 for slot raking tool. Rake the commu-

tator slots to remove projecting mica fins or cop-

per whiskers.

10. Run the machine again at 1000 rpm and polish

the commutator with 00 sandpaper, crocus cloth

or 400A Triemite* paper. The abrasive sheet

should be mounted on a wooden block curved to

fit the surface of the commutator.

CAUTION: Never use an emery cloth on this or

any commutator. The abrasive particles on

emery cloth scratch the commutator surface

and lodge in the grooves between commuta-

tor segments. This condition creates the pos-

sibility of an eventual flashover which could

seriously damage the machine.

11. Blow the dust from the commutator and the inte-

rior of the motor with dry, compressed air. Hold

the air nozzle one to two inches from the surface

of the commutator and sweep nozzle longitudi-

nally to dislodge copper chips and mica dust.

12. Air cure the commutator. See the following sec-

tion for air curing instructions.

*Product of Minnesota Mining and Manufacturing

Co.

Vertical Drilling Motor, Type GE752, GEK–91584D

19

WARNING: When using compressed air for

cleaning purposes, flying debris and particles

may present a hazard to personnel in the im-

mediate area. Personnel should be provided

with, and trained in the use of, personal pro-

tective equipment as specified by applicable

federal or state safety regulations.

Air Curing Commutator

After the commutator has been sanded, stoned or

ground and blown clean, it should be air cured as fol-

lows:

1. Rotate the armature slowly with the same source

of power used for sanding, stoning or grinding.

2. Use a rubber air–hose with the nozzle removed

and sweep the commutator surface with 70 psi

air pressure.

WARNING: Observe all the following safety

precautions to avoid injury.

1. Remove all metal fittings from the air hose

or, if impossible to remove, insulate the

fitting.

2. Be certain an operator is stationed at the

power–supply control to quickly remove

power from the machine should an emer-

gency arise.

3. Wear rubber–insulated gloves and

goggles while air curing. Stand on an in-

sulated platform.

4. Avoid contact with the cable terminals.

WARNING: Do not come into close proximity

of an energized motor during the cleaning pro-

cess. The armature commutator and brush rig-

ging have a high electrical charge which could

cause serious injury or death. Always use a

hose tip that is an electrical non–conductor

when cleaning with air.

3. Increase the machine speed to approximately

900 rpm and blow air on the commutator until the

sparking stops.

4. Increase the speed until full speed is reached (do

not exceed 1000 rpm) and continue to blow air on

the commutator until all sparking stops.

5. Stop the machine.

6. Disconnect external power supply to machine.

Make all necessary mechanical and electrical

changes to restore the machine to service.

7. Use a clean cloth and wipe off the brushholders,

creepage band and accessible surfaces in the

commutator chamber.

8. Brushholder Clearance – Install the brushholder

previously removed and check and adjust as re-

quired the brushholder–to–commutator clear-

ance on all brushholders. See previous Brush-

holder Replacement and Brushholder Clearance

Adjustment sections for instructions to install the

brushholder, and to adjust brushholder clear-

ance.

9. Installing Brushes – Refer to BASIC REPAIRS,

Brush Replacement section, and install

serviceable or new brushes per instructions

listed.

10. Vacuum interior of commutator chamber.

BASIC OVERHAUL

NOTE: Be sure to use the correct drawings for

the machine being overhauled. Refer to Table 2

on page 20 to determine the correct drawing.

It is recommended that a basic overhaul be per-

formed every two years, or 18,000 hours. The time inter-

val between overhauls may vary, depending on the con-

dition of the machine and the severity of service.

The following basic overhaul procedures include in-

structions to disassemble, clean, inspect, repair, reas-

semble and test the machine.

TESTING BEFORE DISASSEMBLY

Perform the following tests prior to disassembly of

the machine:

GEK–91584D, Vertical Drilling Motor, Type GE752

20

TABLE 2. DRAWING REFERENCE

GE752

Model

Inst.

Book

Longi–

tudinal

Puller Tools

Comm. Pinion

End End

Arm.

Shaft

Connection

Diagram Coiled

Frame As-

sembly

Bearing Grease

Distribution

Drive Comm.

End End

Arm.

Locking

Arrange-

ment Outline

AUP1 Fig. 15 Fig. 16 Fig. 17 Fig. 20 Fig. 22 Fig. 29 Fig. 34 Fig. 38 Fig. 43 Fig. 48

AUP2 Fig. 15 Fig. 16 Fig. 17 ––– Fig. 22 Fig. 29 Fig. 34 Fig. 38 Fig. 43 Fig. 48

AUP3 Fig. 15 Fig. 16 Fig. 17 ––– Fig. 22 Fig. 29 Fig. 35 Fig. 38 Fig. 43 Fig. 48

AUP4 Fig. 15 Fig. 16 Fig. 17 ––– Fig. 22 Fig. 29 Fig. 35 Fig. 38 Fig. 43 Fig. 48

AUP5 Fig. 15 Fig. 16 Fig. 17 ––– Fig. 22 Fig. 29 Fig. 35 Fig. 39 Fig. 43 Fig. 48

AUT1 Fig. 18 Fig. 16 Fig. 17 ––– Fig. 24 Fig. 32 Fig. 36 Fig. 38 Fig. 43 Fig. 49

AUT2 Fig. 18 Fig. 16 Fig. 17 ––– Fig. 24 Fig. 32 Fig. 36 Fig. 39 Fig. 43 Fig. 49

UP1 Fig. 15 Fig. 16 Fig. 17 Fig. 20 Fig. 21 Fig. 30 Fig. 34 Fig. 38 Fig. 43 Fig. 48

UP2 Fig. 15 Fig. 16 Fig. 17 ––– Fig. 21 Fig. 30 Fig. 34 Fig. 38 Fig. 43 Fig. 48

UP3 Fig. 15 Fig. 16 Fig. 17 ––– Fig. 21 Fig. 30 Fig. 35 Fig. 38 Fig. 43 Fig. 48

UP3A Fig. 15 Fig. 16 Fig. 17 ––– Fig. 21 Fig. 30 Fig. 35 Fig. 38 Fig. 43 Fig. 48

UP4 Fig. 15 Fig. 16 Fig. 17 ––– Fig. 21 Fig. 30 Fig. 35 Fig. 38 Fig. 43 Fig. 48

UP5 Fig. 15 Fig. 16 Fig. 17 ––– Fig. 21 Fig. 30 Fig. 35 Fig. 38 Fig. 43 Fig. 48

UP6 Fig. 15 Fig. 16 Fig. 17 ––– Fig. 21 Fig. 30 Fig. 35 Fig. 39 Fig. 43 Fig. 48

US1 Fig. 18 Fig. 16 Fig. 17 ––– Fig. 23 Fig. 31 Fig. 36 Fig. 38 Fig. 43 Fig. 49

US2 Fig. 18 Fig. 16 Fig. 17 ––– Fig. 23 Fig. 31 Fig. 36 Fig. 39 Fig. 43 Fig. 49

Megohmmeter Test

Lift the brushes and perform a megohmmeter test on

the armature windings and field coils to determine the

condition of the insulation. A reading of less than 2

megohms indicates poor insulation, dirt accumulation or

excessive moisture.

Bar–To–Bar Resistance Test

Test for open or short–circuited armature coils.

1. Pass a regulated d–c current through the arma-

ture coils.

2. Read the voltage drop between the commutator

bars with a millivoltmeter. if the reading varies

more than +/– 5% from the average value, a de-

fective or short–circuited coil is indicated.

DISASSEMBLY

Armature Removal From Frame

Models UP, AUP

Before turning the machine from horizontal to verti-

cal (or vice–versa), attach the armature locking ar-

rangement to prevent the armature from moving axially.

Remove the armature locking arrangement before op-

erating the machine.

See Table 2 to determine the correct armature lock-

ing arrangement drawing.

Refer to the longitudinal drawing, Fig. 15, and puller

tool drawings, Figs. 16 and 17.

1. Clean the outside of the frame.

2. Remove the hubs from the shaft if not already re-

moved.

3. Remove the commutator covers. Disconnect

and remove all brushes and brushholders. Wrap

Vertical Drilling Motor, Type GE752, GEK–91584D

21

3

FIG. 13. COMMUTATOR–END BEARING PILOT.

E–18150.

heavy paper around the commutator for protec-

tion during handling.

4. Remove grease tubes from the commutator–

end bearing cap:

a. On UP1 and AUP1 models, there are two

grease tubes (19, 20).

b. On UP2 and AUP2 models, there is one

grease tube (19).

c. On all other models, only a pipe plug is pro-

vided in the bearing cap.

5. Install puller (Part 6751547G4) and pull sleeve

(42) from the shaft at the commutator end. The

sleeve has four tapped holes for applying the

puller. Apply heat to the sleeve with a torch while

pulling to facilitate removal.

6. Remove bolts and washers (52) and remove

bearing cap (4) and gasket (57) from the frame

head.

7. Make sure the armature locking arrangement is

securely installed. Turn the machine on end on a

stand (commutator–end down) and level it so the

armature can be lifted vertically out of the frame

without damaging the bearings, commutator or

brushholders. Remove the armature locking ar-

rangement.

FIG. 14. ARMATURE LIFTING BAIL. E–23932.

GEK–91584D, Vertical Drilling Motor, Type GE752

22

FIG. 15. LONGITUDINAL SECTION (41D732922 CHG. N). E–28621D.

56

57

52

42

43 44 45 46

VIEW OF COMMUTATOR END FOR

VIEW OF PINION END FOR ALL

MODELS EXCEPT UP1, UP2, AUP1

AND AUP2

THIS GREASE TUBE CONFIGURATION

ALL OTHER MODELS

ALL MODELS EXCEPT UP1, UP2, AUP1 AND AUP2

IS APPLICABLE TO MODELS UP1, UP2

AUP1 AND AUP2 ONLY. SEE VIEW ABOVE FOR

Vertical Drilling Motor, Type GE752, GEK–91584D

23

FIG. 15. LONGITUDINAL SECTION (41D732922 CHG. N). E–28621D.

55

54

53

47

51

50 49 48

MODELS

SEE TABLE 2, PAGE 20

VIEW OF COMMUTATOR END

FOR UP6 AND AUP5

NOTE: UP1 AND AUP1

MODELS HAVE 2 TUBE ASSEMBLIES,

UP2 AND AUP2 HAVE ONE.

GEK–91584D, Vertical Drilling Motor, Type GE752

24

FIG. 15. LONGITUDINAL SECTION (41D732922 CHG. N). E–28621D.

REF. DESCRIPTION

1 COILED FRAME

2 COILED FRAME

3 ARMATURE AND BEARING ASSEMBLY

4 OUTER BEARING CAP

5 OUTER BEARING CAP

6 CARBON BRUSH

7 COVER (TOP INSPECTION)

8 COVER (BOTTOM INSPECTION)

9 COVER (HAND HOLE)

10 BOLT (FRAMEHEAD), N22P39032, 1.00–8 X 2.00

11 BOLT (FRAMEHEAD), N22P39036, 1.00–8 X 2.25

12 LOCKWASHER, N405P50P, 1.00 MEDIUM

13 BOLT (COVER) N22P29014B13, 0.50–13 X 0.88

14 LOCKWASHER, N405P45P, 0.50 MEDIUM

15 NAMEPLATE

16 ESCUTCHEON PIN, N532P1106, NO. 12 X 0.38

17 MONOGRAM

18 ESCUTCHEON PIN, N532P1108, NO. 12 X 0.50

19 TUBING

20 TUBING

21 TUBING (SEE NOTE)

22 TUBING (SEE NOTE)

23 PIPE PLUG, N5700P31, 1/4

24 SPACER, 1/4 EXST. PIPE 3/4 LG.

25 CLAMP

26 BOLT, N22P21020B13, 0.25–20 X 1.25

27 LOCKWASHER, N405P41P, 0.25 MEDIUM

28 SEALER, RTV 108

29 1ST TAPING, 12.00 (IT–1/2L), 41A239176P112

30 2ND TAPING, 24.00 (IT–1/2L), 41A239176P18

31 COILED FRAME

32 COILED FRAME

33 TUBING (SEE NOTE)

34 GREASE (SEE NOTE)

35 CAP

36 ARMATURE AND BEARING ASSEMBLY

37 BEARING ASSEMBLY (PE) (SEE NOTE)

38 PLUG

39 COVER (TOP INSPECTION)

40 COVER (BOTTOM INSPECTION)

41 COVER (HAND HOLE)

42 SLEEVE

43 SPACER

44 BALL BEARING

45 SLEEVE

46 BEARING HOUSING

47 SLEEVE

48 ROLLER BEARING

49 FLINGER

50 SLEEVE

51 BEARING HOUSING

52 BOLTS AND WASHERS

53 BOLTS AND WASHERS

54 GASKET

55 FRAMEHEAD

56 FRAMEHEAD

57 GASKET

Vertical Drilling Motor, Type GE752, GEK–91584D

25

FIG. 16. PULLER TOOLS (41D731569 CHG. 0). E–14383C.

REF DESCRIPTION REF DESCRIPTION REF DESCRIPTION

4 CLAMP PLATE 12 NUT, 5/8–11 21 STUD

5 BOLT 18 RING 22 STUD

6 PRESSURE CAP 20 STUD 23 NUT, 7/16–14

8. Reach into the drive–end of the motor and dis-

connect grease tubes.

a. On UP1 and AUP1 models, disconnect two

grease tubes (21 and 22) from the inner bear-

ing cap (51). Pull these tubes out through

their hole in the frame. The sealing RTV in the

hole will separate with sufficient force.

b. On UP2 and AUP2 models, disconnect one

grease tube (21) from the inner bearing cap

(51). Pull this tube out through its hole in the

frame. The sealing RTV in the hole will sepa-

rate with sufficient force.

c. On all other models, only one grease tube is

used, connected between the inner bearing

cap and the framehead. Remove this tube.

9. Place three 0.125 in. spacers (wedge shaped)

around the armature in the air gap between the

armature and the fields to maintain a vertical atti-

tude of the armature and to prevent the armature

from contacting the fields.

10. Remove bolts (10) and lockwashers (12) from

the framehead (55). Insert bolts into the jackout

holes in the framehead.

11. Install a lifting bail, Fig. 14, onto the end of the

shaft.

12. Line up the hoist cable with the centerline of the

armature before engaging the hook in the lifting

bail on the end of the shaft. Engage the hook and

lift slightly. With sufficient strain on the hoist

cable to take the weight of the armature off the

GEK–91584D, Vertical Drilling Motor, Type GE752

26

REF DESCRIPTION REF DESCRIPTION REF DESCRIPTION

4 CLAMP PLATE 17 CLAMP 21 STUD

5 BOLT 18 RING 22 STUD

6 PRESSURE CAP 19 CLAMP 23 NUT, 7/16–14

12 NUT, 5/8–11 20 STUD

FIG. 17. PULLER TOOLS. E–18155A.

framehead, jack the drive–end framehead loose,

and lift the complete armature assembly out of

the frame. DO NOT DAMAGE THE COMMUTA-

TOR.

13. Move the armature to a suitable fixture for further

bearing disassembly or repair.

14. Install puller (Part 6751547G4) and pull sleeve

(47) from the shaft at the drive end. Heat may be

applied.

15. Remove bolts and lockwashers (53) from bear-

ing cap (5). Remove the bearing cap and gasket

(54).

Vertical Drilling Motor, Type GE752, GEK–91584D

27

16. Remove the framehead. It will come with the

bearing outer race and bearing rollers.

17. Pull the inner bearing race off the drive end of the

shaft with puller (Part 6751547G5).

18. Remove flinger (49) and inner bearing cap (51)

with puller (Part 6751547G6) by inserting the

four puller bolts into tapped holes in the inner

bearing cap.

19. If necessary, remove inner sleeve (50) with puller

(Part 6751547G7).

20. Press the outer bearing race and rollers from the

framehead with an arbor press.

NOTE: Before pressing the drive–end outer

bearing race out of the framehead, observe and

record the number on the face of the race which

is opposite the arrow on framehead. After re-

moval, mark the date (with electric pencil) un-

der this number to indicate that this position

has been used. Reassemble the bearing with

another number opposite the arrow. If the bear-

ing has not been previously marked, etch Nos.

1, 2, 3 and 4 (spaced 90 degrees apart) on the

face of race with an electric pencil. Locate No. 1

opposite the arrow on the framehead and mark

it with the date.

21. Install puller (Part 6751547G10) and pull spacer

(43) from the commutator end of shaft.

22. Install puller (Part 6751547G6) and pull bearing

housing (46) with bearing (44) from the shaft.

23. Press ball bearing (44) from bearing housing

(46) using an arbor press.

24. If applied, remove the nilos ring (4), Fig. 39, from

the bearing and discard.

25. If applied, remove the seal ring (5), Fig. 39, from

the sleeve and discard.

26. Install puller (Part 6751547G11) and pull sleeve

(45) from the shaft.

27. If it is necessary to remove the commutator end

framehead (56), place the frame commutator

end up and remove bolts (11) and lockwashers

(12). Use bolts in the framehead jackout holes

to break the fit and remove the framehead.

Armature Removal From Frame

CAUTION: When lifting the armature out of the

frame, proceed slowly so that no damage will

occur to the armature end–windings, bear-

ings, bearing fits or the commutator.

Models US1, AUT

Before turning the machine from horizontal to verti-

cal (or vice–versa), attach the armature locking ar-

rangement to prevent the armature from moving axially.

Remove the armature locking arrangement before op-

erating the machine.

See Table 2 to determine the correct armature lock-

ing arrangement drawing.

Refer to the longitudinal drawing, Fig. 18, and puller

tool drawings, Figs. 16 and 17.

1. Clean the outside of the frame, using com-

pressed air, a steam–jenny or cleaning solvents,

to remove accumulated dirt.

2. Remove the coupling hub from the shaft, if not al-

ready removed.

3. Remove the commutator covers. Disconnect

and remove all brushes, and wrap heavy paper

around the commutator for protection during

handling.

4. Install puller tool (Part 6751547G4) and pull the

sleeve (6) from the commutator end of the shaft.

5. Remove bolts (10) which hold the bearing cap

and the bearing housing to the commutator–end

framehead. Remove the bearing cap (8) and

gasket (11).

6. Turn the machine on end on a stand, commuta-

tor end down, and level it so that the armature

can be lifted vertically out of the frame without

damaging the bearings, commutator or brush-

holders.

7. Screw three guide pins into the commutator–end

bearing housing (3) to help guide the armature

out of the frame.

GEK–91584D, Vertical Drilling Motor, Type GE752

28

FIG. 18. LONGITUDINAL SECTION (41D735357, CHG. A). E–37949B

VIEW OF COMMUTATOR END

9

Vertical Drilling Motor, Type GE752, GEK–91584D

29

TORQUE TABLE

PART NO. SIZE LBS. FT.

1 .50–13 55–60

10,34 .625–11 110–120

17 .875–9 240–260

13,30 1.00–8 440–495

24 1.25–7 900–995

21 1.25–12 435–483

REF. DESCRIPTION

1 SHAFT

2 SLEEVE

3 BEARING HOUSING

4 BALL BEARING

5 SPACER

6 SLEEVE

7 CAP

8 BEARING CAP (OUTER)

9 PIPE PLUG

10 BOLT AND LOCKWASHER

11 GASKET

12 BOLT

13 BOLT AND LOCKWASHER

14 FRAME HEAD

15 FLASH RING

16 BRUSH HOLDER CLAMP

17 BOLT AND LOCKWASHER

18 BRUSH HOLDER

19 CARBON BRUSH

20 COMMUTATING FIELD COIL

21 COMMUTATING POLE BOLT AND

HARDENED WASHER

REF. DESCRIPTION

22 ARMATURE

23 MAGNET FRAME

24 EXCITING POLE BOLT AND

HARDENED WASHER

25 EXCITING FIELD COIL

27 WASHER

28 FITTING

29 FRAME HEAD

30 BOLT AND LOCKWASHER

31 GASKET

32 FITTING

33 FITTING

34 BOLT AND LOCKWASHER

35 GASKET

36 BEARING CAP (OUTER)

37 SLEEVE

38 ROLLER BEARING

39 FLINGER

40 BEARING CAP (INNER)

41 SLEEVE

FIG. 18. LONGITUDINAL SECTION (41D735357, CHG. A). E–37949B.

MODELS

SEE TABLE 2

GEK–91584D, Vertical Drilling Motor, Type GE752

30

8. Screw a lifting bail, Fig. 14, on the drive end of the

shaft.

9. Remove drive–end framehead bolts (30) and in-

sert three jack screws in the threaded holes pro-

vided in the framehead.

10. Line up the hoist cable with the centerline of the

armature before engaging the hook in the lifting

bail on the end of the shaft. Engage the hook and

lift slightly. With sufficient strain on the hoist

cable to take the weight of the armature off the

framehead, jack the drive–end framehead loose,

and lift the complete armature assembly out of

the frame. DO NOT DAMAGE THE COMMUTA-

TOR.

CAUTION: Special precautions should be taken to

avoid damage to the armature end–windings,

bearings or bearing fits, and the commutator

when lifting the armature in the vertical position

or turning the armature to a horizontal position.

11. Place the armature horizontally in an armature

saddle for bearing disassembly.

12. At the drive end, remove the lubricating tube as-

sembly (9, 33, 32 and 28) from the framehead.

13. Using puller tool (Part 6751547G4), pull the out-

er sleeve (37) from the drive end of the shaft. The

sleeve has tapped holes for applying the puller.

Heat may be applied.

14. Remove bolts (34), and then remove outer bear-

ing cap (36) and gasket (35).

15. Slide framehead (29) off the shaft together with

the outer race and rollers of bearing (38). The in-

ner race will remain on the shaft.

16. Pull the inner bearing race off the shaft with puller

(Part 6751547G5).

17. Remove flinger (39) and inner bearing cap (40)

with puller (Part 6751547G6) by inserting the

four puller bolts into the tapped holes in inner

bearing cap (40).

18. Press the outer bearing race and rollers from the

framehead with an arbor press.

NOTE: Before pressing the drive–end outer

bearing race out of the framehead, observe and

record the number on the face of the race which

is opposite the arrow on the framehead. After

removal, mark the date (with electric pencil) un-

der this number to indicate that this position

has been used. Reassemble the bearing with

another number opposite the arrow. If the bear-

ing has not been previously marked, etch Nos.

1, 2, 3 and 4 (spaced 90 degrees apart) on the

face of race with an electric pencil. Locate No. 1

opposite the arrow on the framehead and mark

it with the date.

19. Install puller tool (Part 6751547G10) and pull

spacer (5) from the commutator end of the shaft.

20. Install puller tool (Part 6751547G6) and pull

bearing (4) and bearing housing (3) from the

commutator end of the shaft.

21. Press the bearing from the framehead with an

arbor press.

22. If applied, remove the nilos ring (4), Fig. 39, from

the bearing and discard.

23. If applied, remove the seal ring (5) Fig. 39, from

the sleeve and discard.

24. Install puller tool (Part 6751547G11) and pull

sleeve (2) from the commutator end of the shaft.

25. If necessary to remove the commutator

framehead (14), turn the frame commutator end

up and remove bolts and lockwashers (13). Use

bolts in the framehead jack–out holes to break

the fit and remove.

CLEANING

The two recommended methods for cleaning are

steam cleaning and vapor degreasing.

CAUTION: Do not use caustic soda solution

on the armature or coiled frame.

Steam Cleaning

(Recommended for both insulated and metal parts)

1. Use steam in combination with a commercial

non–caustic cleaner.

Vertical Drilling Motor, Type GE752, GEK–91584D

31

2. Suspend the part in a position accessible from all

directions to a direct flow of steam from the hose.

3. Rinse all residue from parts with a mixture of

clean steam and water.

4. Bake insulated parts for at least 8 hours at 150

C (302 F) to remove all moisture.

Vapor Degreasing

(Recommended for metal parts)

1. Bring the cleaning solution to a boil, and allow the

vapor line in the tank to rise to the condenser

coils at the top of the tank.

2. Keep the vaporized cleaning solution at about

120 C (248 F).

3. Lower the part to be cleaned into the vapor–la-

den atmosphere, so the vapor will condense on

the part.

4. To speed the removal of heavy dirt accumula-

tions, spray hot solution directly from the tank

onto the part being cleaned. The temperature of

the solution must be kept below its boiling point.

5. Remove the cleaned part from the degreaser.

Drain and cool the part.

Anti–Friction Bearings/Shaft

Tapers/Bearing Fits

Use a cleaning solution that leaves an oil film to pro-

tect finished surfaces from rust. Kerosene, petroleum

spirits or other petroleum–base cleaners provide limited

protection for these surfaces.

INSPECTION AND TEST OF

DISASSEMBLED MOTOR

BEARING INSPECTION

1. Clean the bearings. See Cleaning section.

2. Inspect for broken or cracked races, broken or

cracked rollers and balls, broken, cracked or dis-

torted retainers, scored, pitted, scratched or

chipped races, and for indication of excessive

wear on rollers and balls. Replace the bearing if

any of these conditions is found.

3. Look for evidence of smearing caused by inade-

quate lubrication, and corrosion pitting (usually

at roller spacing) caused by moisture or other

corrosive agent. Replace the bearing if any of

these conditions are found.

4. Inspect bearing outer races for indentations

caused by dirt or foreign material having gone

through the bearing. If the indentations are small

and few in quantity, the bearing can be used. If

the indentations are large and numerous, this

may be an indication the rollers or cone are start-

ing to spall out. Examine the rollers and cone

carefully for spalled areas. Replace the bearings

if spalled areas are found.

5. Dip good bearing parts in a light mineral oil

(SAE–10) heated to 90 C (194 F) to avoid cor-

rosion before reassembly.

6. If a bearing will not be mounted immediately,

wrap it in an oil–proof paper.

CAUTION: Do not interchange bearing parts of

different manufacture or mix new and used

bearing parts.

Perform the following inspection and tests to deter-

mine the condition of the armature, coiled motor frame

and brushholders.

After the inspection and test procedures have been

completed and all defects or damage noted, refer to the

REPAIR section for the correct repair procedure.

ARMATURE

Handle the armature carefully during overhaul oper-

ations to avoid damage to the core, banding, end turns,

shaft fits and commutator. Support the armature in a

saddle to protect the commutator and to coil the ends.

Keep the commutator covered with heavy paper.

Armature Test

1. With the armature at room temperature, 25 C

(77 F), use a 500 or 1000 vdc megohmmeter

and make a dielectric test of the armature insula-

GEK–91584D, Vertical Drilling Motor, Type GE752

32

tion. A reading of one megohm or higher should

be obtained. If necessary, perform additional

cleaning and baking operations to obtain this val-

ue before proceeding.

NOTE: If additional cleaning and baking opera-

tions do not increase the resistance value of the

insulation, it may be necessary to replace the

creepage band and rewind the armature.

2. Measure and record armature resistance. See

the DATA section for values.

3. If there are no armature coils grounded, perform

a bar–to–bar comparison test to check for open

or short–circuited armature coils.

a. Pass a regulated d–c current through the ar-

mature coils.

b. Read the voltage drop between the commu-

tator segments with a millivoltmeter. If the

reading varies more than plus or minus 5%, a

defective or short–circuited coil is indicated. If

the armature fails the bar–to–bar test, the ar-

mature must be rewound.

If the armature will not be rewound, proceed

to inspect the following items.

Insulation

Inspect the insulation of armature coils for cracks,

physical damage, burns and deterioration. If minor re-

pairs are required, refer to Fig. 19 for insulation details.

Glass Band, Commutator End

Inspect the glass bands for split, frayed or loose con-

dition.

Wire Band, Drive End

Inspect the wire band for physical damage, loose tie

clips or broken wire.

Creepage Band

Inspect the surface of the Teflon creepage band for

possible flashover damage. Tap the band lightly and

check for movement of the band to determine if loose. If

the band is loose or has deep burns, replace it. See RE-

PAIR section for instructions.

COMMUTATOR

Check the commutator for threading, pitting, groov-

ing, burns, flat spots, high bars and copper drag.

Check the commutator to make sure that it is not

out–of–round. See the DATA section for concentricity

limits.

Resurfacing

For the resurfacing procedure for a commutator, see

REPAIR, Armature section.

Refer to the DATA section for the minimum permissi-

ble commutator diameter dimension and check the di-

ameter of the commutator.

NOTE: If the brush surface diameter will be less

than the minimum permissible diameter after

resurfacing operations are performed, the com-

mutator must be replaced.

Tightening

If the commutator is loose (has high bars), see the

“REPAIR, Commutator Tightening” section for instruc-

tions to tighten the commutator.

ARMATURE SHAFT INSPECTION

Armature shaft bearing fit dimensions can be

checked and compared to armature shaft drawings pro-

vided in Fig. 20. If the bearing fit dimensions are not

within stated tolerances the shaft must be replaced or

repaired. Refer to Table 2 to determine the correct shaft

drawing for the machine being repaired.

MOTOR FRAME

1. Check the connection strap insulation for dam-

age, signs or burning, cracks or discoloration.

2. Check the insulation on the coils for damage,

signs of burning, cracks or discoloration.

3. Check the lead cables for damage, overheating

and signs of deterioration.

Vertical Drilling Motor, Type GE752, GEK–91584D

33

49

48,77

37 61 60,78 49

17,

71

32

70 867 9,65

6,

66

32 352,

76

11

13

3329

7,

69

5,

68

16

1

ASSEMBLE AROUND

BUTTED JOINT OF PT48

ASSEMBLE IN LINE

WITH NO. 1 SLOT

3/4 LAPPED

P70 TO BE APPLIED

OVER P68 TO LEVEL

THE SURFACE

28 ACTIVE TURNS AT

400 50 LB. TENSION

OVER TOP OF EQUALIZERS

EXTEND A THIN COATING

OF PT32 OVER TOP OF

EQUALIZERS BOTH DECKS

1/4

4–1/4

3/4 REF.

+

–

ASSEMBLE AROUND

BUTTED JOINT OF PT48

1/4

NOTE FOR P54:

MATL: 41B537080P1

ALT. MATL: 41A230144P3

NOTE FOR P57:

MATL: 41A230144P40

3/8

REF.

53

57

54

3

5/8

11–1/4 R. 29

TOP COILS BOTTOM COILS

EQUALIZER CONNECTIONS

COMM. SEGMENTS

TO #183

TO #185

TO #1

TO #96 TO #94

TO #92

NUMBERED SEGMENTS ARE FOR

PURPOSE OF INDICATING SPAN OF

EQUALIZER CONNECTIONS AND DO

NOT NECESSARILY CORRESPOND

TO NUMBERED SEGMENTS IN

MAIN CONNECTION DIAGRAM.

30 MAIN WINDING

CONNECTIONS

C

LSLOT #1

ON MICAC

L

SLOT #16

TOP COILS

SLOT #15

ORPHAN

COIL

SLOT #1

BOTTOM COILS

NOTE FOR P62:

APPLY TO SIDES OF CORE SLOT

ON PINION END ONLY.

INSTALL P11.

NOTE FOR P47:

ENCLOSE ONE IDENTIFICATION C–SIZE

PRINT OF 41D730423 IN EACH

CARTON OF SUPPLY INSUL.

NOTE FOR P32:

TAPE OVER RISERS WITH 3/4 WIDE A2L14B GLASS TAPE

LEAVING 1/4 IN. OF RISERS EXPOSED ON THE CORE END. FILL

BETWEEN ARMATURE LEADS BEHIND RISERS AND OVER

BACK 1/4 IN. OF RISER. WRAP OVER PUTTY WITH A16B39B

MYLAR TAPE AND BAKE AS PART OF THE PREHEAT PERIOD

FOR INSTALLING P37.

NOTE FOR P37 (C.E. BINDING):

APPLY THE P37 PERMANET CE BINDING (COLD TAPE TO HOT

125–135 C ARMATURE)

APPLY 77 ACTIVE TURNS OF P37 AT 500 25 LB. TENSION.

+

–

FIG. 19 ARMATURE INSULATION (41D731545 CHG. F). E–18156A.

GEK–91584D, Vertical Drilling Motor, Type GE752

34

APPLY 35 ACTIVE TURNS OF P38 AT 600 20 LB. TENSION

12 18,19,20,75

11

62

1

26

14 15

355

12

4

27

39

38 SEE NOTE

2–5/8 +1/8

–0

25

4–7/8 MAX.

5 REQ’D.

1–1/16 1/16

+

–

39

PT26 TO BE APPLIED

OVER COILS TO LEVEL

THE SURFACE

SATURATE P2 THOROUGHLY

WITH P56

FIRST TURN

2ND DECK

LAST TURN

3RD DECK

FIRST TURN

(LOWER DECK)

LAST TURN

(LOWER DECK)

A

B

A

B

TOP BAND

28

SECTION A–A

LAST TURN

3RD DECK 41

27 SECTION B–B

2ND AND 3RD DECK

CONTINUOUS WIRE

28

NOTE FOR TEMPORARY BINDING:

APPLY TEMPORARY BINDING. 6 TOTAL PASSES WITH 0.102

DIAM. B4Y19B AT 800 LB. TENSION. BAKE IN A 150 C OVEN

FOR 4 HOURS.

NOTE FOR P38 (P.E. BINDING):

APPLY THE P38 PERMANET BINDING.

APPLY 37 ACTIVE TURNS OF P38 AT 650 20 LB. TENSION

AS THE 1ST DECK.

+

–

AS THE 2ND DECK.

APPLY 34 ACTIVE TURNS OF P38 AT 550 20 LB. TENSION

AS THE 3RD DECK

+

–+

–

THE 2ND AND 3RD DECK MUST BE A CONTINUOUS BAND.

REF. DESCRIPTION REF. DESCRIPTION

1 HEAD INSUL. P.E. 40 BINDING CLIP

2 HEAD INSUL. P.E. 41 TIE CLIP

3 FILLER 42 METHOD OF FASTENING

4 ARMATURE COIL BINDING WIRE (P.E.)

5 INSUL. OVER EQUALIZERS 43 METHOD OF SWAGING

6 INSUL. IN EQUALIZER LOOP COMM. RISERS

7 INSUL. OVER EQUALIZER 44 CORE INSUL.

8 EQUALIZER 45 WINDING INSUL.

9 HEAD INSUL. C E 46 BINDING AND BINDING INSUL.

10 SLOT STRIP BOT 47 IDENTIFICATION PRINT

11 U PIECE AT SLOT ENDS 48 BINDING BASE

12 SLOT WEDGE 49 JOINT INSUL.

13 WINDING INSUL. C E 50 PAD

14 INSUL. IN LOOP P.E. 51 SLOT WEDGE

15 INSUL. IN LOOP 52 SLOT STRIP BOTTOM

16 FILLER STRIP 53 TAPE

17 FILLER 54 TEFLON BAND

18 SLOT STRIP (UNDER WEDGE) 55 TEFLON GLASS TAPE

19 FILLER STRIP 56 VARNISH

20 FILLER STRIP 57 TEFLON BAND

21 SLOT STRIP CENTER 58 EQUALIZER

22 RADIUS SPACER C.E. TOP 59 FILLER FOR COMM.

AND BOTTOM STRING BAND

23 BINDER OVER COMM. MICA 60 BINDING BASE

24 SEAL OVER COMM. 61 MYLAR TAPE

MICA AND STRING BAND 62 CEMENT

25 BINDING INSUL. P.E. 63 CEMENT

26 FILLER P.E. 64 CORE INSUL.

27 BINDING BASE 65 HEAD INSUL.

28 TIE CLIP 66 INSUL. IN EQUALIZER LOOP

29 RADIUS SPACER (C.E. BOTT.) 67 BAND FOR EQUALIZERS

30 DIAGRAM 68 INSUL. OVER EQUALIZERS

31 SHIM (IN RISER SLOT) 69 INSUL. OVER EQUALIZERS

32 FILLER PUTTY 70 FILLER

33 WINDING INSUL. C.E. 71 FILLER

34 FILLER FOR COMM. 72 WINDING INSULATION

STRING BAND 73 ASBESTOS ROPE

35 FILLER FOR COMM. 74 ARMATURE COIL

STRING BAND 75 FILLER STRIP

36 BINDING BASE 76 SLOT STRIP BOTTOM

37 BANDING 77 BINDING BASE

38 BINDING WIRE 78 BINDING BASE

39 BINDING CLIP P.E.

FIG. 19. ARMATURE INSULATION (41D731545 CHG. F). E–18156A.

Vertical Drilling Motor, Type GE752, GEK–91584D

35

FIG. 20. ARMATURE SHAFT (334B336 CHG. D). E–39091A.

MODELS

SEE TABLE 2

4. Conduct a 500 volt megohmmeter test on the

coils. A reading of 20 megohms or more is ac-

ceptable.

5. See Figs. 21 thru 24 and measure and record

commutating and exciting–coil resistance. Re-

fer to Table 2 to determine the correct connection

diagram for the machine being repaired.

6. High–potential test the field coils to ground.

WARNING: Electric shock can cause serious

injury or death. Strict safety precautions must

be taken and observed by personnel conduct-

ing a high–potential test.

Apply a high–potential test of 2000 volts, 60 Hz for

one minute.

BRUSHHOLDERS

1. Inspect the brushholder for flashover damage,

cracks and burned or pitted areas.

2. Check the brush springs to be sure they move

freely and do not bind.

3. Insert a new brush in the carbonway and move it

up and down in the carbonway to be sure it

moves freely.

REPAIR

LUBRICATION OF BOLTS

The threads and washer faces of bolts and nuts

should be lubricated to obtain maximum clamping force

(at the nominal or at a recommended torque value)

when bolts and nuts are installed at reassembly. Lubri-

cate all bolts.

Use a High Pressure Lubricant such as; graphite in

oil (1 part graphite to 5 parts machine oil by volume), Lu-

GEK–91584D, Vertical Drilling Motor, Type GE752

36

briplate* (Part 147X1614), Molykote** (Part 147X1143),

Dag*** (Part 147X1613), or anti–seize compound (Part

147X1640) to lubricate bolts.

NOTE: Threads and washer–contact surfaces

must be clean before lubricant is applied.

Where specific torque values are not listed in these

instructions, refer to Table 3 for standard bolt torque val-

ues of lubricated bolts.

*Product of Fisk Bros. Refining Co., Newark, N.J.

**Registered trademark of Dow Corning Corp.

***Acheson Colloids Co., Port Huron, Mich.

BRUSHHOLDER SLEEVE REPLACEMENT

1. Remove the damaged Teflon sleeve from the

brushholder stud. To remove sleeve, heat the

brushholder in an oven to 150 C (302 F) then

peel or cut sleeve from the stud.

2. Thoroughly clean the surface of the stud and re-

move any carbon or dirt build–up.

3. Heat a new Teflon sleeve in a 150 C (302 F)

oven for 15 minutes.

4. Using adequate hand protection, immediately

assemble the hot sleeve on the stud.

FIG. 21. CONNECTION DIAGRAM (493A210 CHG. 4). E–39092B.

UP1

UP2

UP3

MODELS

SEE TABLE 2

TO CHANGE MOTOR DIRECTION:

TO RUN CCW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO POSITIVE

F2 TO NEGATIVE

A1 TO POSITIVE

A2 TO NEGATIVE

TO RUN CW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO NEGATIVE

F2 TO POSITIVE

A1 TO POSITIVE

A2 TO NEGATIVE

Vertical Drilling Motor, Type GE752, GEK–91584D

37

ARMATURE

Creepage Band Replacement

Because of its superior adhesion qualities, the Teflon

creepage band on the outer end of the commutator

should be applied using the “hot bond” process. A copy

of this process is included in each Teflon Band Kit, Part

No. 76518, which can be ordered from the following ad-

dress:

General Electric Company

Insulating Materials Product Section

One Campbell Road

Schenectady, NY 12345

Attn: Customer Service

NOTE: The Teflon band is not included in the

kit, but can be ordered through normal Renewal

Parts channels.

Inspect the Band

1. There should be no gaps at the joint or between

the edge of the Teflon band and the copper bars.

2. The band surface must be smooth, free of var-

nish and bonded to the underlay material. There

must not be any bubbles under the Teflon or

buckling of the band.

3. The surface must be free of damage including

scratches and cuts.

Rewinding Armature

The armature must be rewound if any coils are

shorted or grounded.

Riser Width

During the rewinding procedure, the TIG welds on

the commutator risers are machined to break the arma-

ture coil connections. Machining reduces the width of

the risers 1/32 to 1/16 in. each time, which in turn de-

creases the current–carrying capacity of the risers.

If the calculated width of the risers (after machining)

will be less than the Minimum Permissible Riser Width

listed in the DATA section, a new commutator must be

installed before new armature coils are assembled.

TABLE 3

STANDARD BOLT TORQUE VALUES

USE THE TORQUE VALUES IN THIS TABLE AS A GUIDE TO IN-

SURE SATISFACTORY TIGHTENING OF BOLTS AND NUTS

WHERE A SPECIFIC VALUE IS NOT GIVEN IN THE INSTRUC-

TIONS.

*INCLUDES SOCKET HEAD SCREWS.

1/4 20 5–8 10–12

28 5–8 10–12

5/16 18 12–15 18–21

24 12–15 20–23

3/8 16 20–25 30–36

24 25–28 34–40

7/16 14 35–40 50–56

20 40–45 60–65

1/2 13 55–60 80–90

20 60–70 95–105

9/16 12 75–80 110–123

18 90–100 130–145

5/8 11 105–115 152–169

18 125–140 185–205

3/4 10 185–205 285–315

16 220–245 340–370

7/8 9 300–330 440–490

14 340–380 510–565

1 8 440–490 685–735

12 530–570 790–8665

1–1/8 7 620–690 935–1040

12 750–830 1115–1240

1–1/4 7 890–990 1250–1360

12 1040–1160 1600–1750

1–3/8 6 1160–1290 1745–1940

12 1420–1580 2125–2360

1–1/2 6 1570–1740 2300–2600

12 1800–2000 2600–3020

THREADS

PER

INCH

TORQUE VALUES (LB./FT.)

MEDIUM CARBON

(SAE GRADE 5) ALLOY STEEL

(SAE GRADE 8)*

BOLT

DIAM.

E–38274

(For Lubricated Bolts)

Diameter

Refer to the DATA section for the Minimum Permissi-

ble Commutator Diameter dimension. If the commutator

brush–surface diameter will be less than the minimum

permissible diameter after resurfacing operations are

performed, replace the commutator before the new ar-

mature coils are assembled.

GEK–91584D, Vertical Drilling Motor, Type GE752

38

NOTE: Before rewinding the armature, first

check the shaft pinion and bearing fits to deter-

mine whether or not shaft replacement is re-

quired. See Table 2 to determine the correct

shaft drawings.

The armature can be rewound using a GE Co. Sup-

ply Kit, Part 41D730545G8, and the information

supplied in the kit.

NOTE: After the armature is rewound, the arma-

ture coil leads must be TIG welded to the com-

mutator risers, the armature must be Vacuum

Pressure Impregnated, and the commutator

must be cleaned and polished.

Commutator Tightening

If the commutator requires tightening, commutator

assembly pressure can be restored at overhaul by per-

forming a commutator tightening procedure; however, it

is necessary that spin–seasoning and resurfacing oper-

ations be performed after the commutator is tightened.

Before proceeding to tighten a loose commutator, it

must first be determined whether or not the brush–sur-

face diameter of the commutator will be larger than the

minimum permissible diameter after the commutator is

resurfaced.

If the brush–surface diameter is calculated to be

smaller (after resurfacing) than the minimum

permissible diameter, listed in the DATA section, the

commutator must be replaced.

After a long period of service, the mica insulation

may relax, due to temperature cycling, and relieve com-

mutator assembly pressure. This could result in a loose

commutator (with raised bars), or an out–of–round com-

mutator.

The assembly pressure can be restored by tighten-

ing the commutator bolts. This must be done before un-

dertaking any resurfacing operation on the commutator.

Procedure

1. Chip the weld from the commutator bolt heads to

free bolts from the cap.

2. Torque the commutator bolts by one of the fol-

lowing methods.

Hydraulic Press (Preferred Method)

1. Clean the front face of the cap and the segments,

Fig. 25. Remove ONE bolt at a time, and lubri-

cate the bolt threads and under the bolt head.

See Lubrication of Bolts section. Follow the se-

quence shown on Fig. 27 for bolt removal. Reas-

semble bolt and tighten to the initial breakaway

torque value.

2. Using a depth micrometer, measure the distance

(X in Fig. 25) between the face of the cap and the

segments at four points, 90 degrees apart. The

face of the cap and the segments should be par-

allel within 0.020 in. If necessary, tighten the ap-

propriate cap bolts to obtain this parallel relation-

ship between the face of cap and the segments.

3. Place the armature in a vertical press. Position

ball and socket tool (Part 41C685080G1) and

crow–foot pressing fixture (Part 41C685430G1)

on the commutator, and apply 70 tons pressure

at the diameter shown on Fig. 26.

4. Tighten the commutator bolts to 145 lb.–ft.

torque in a crisscross sequence, Fig. 27. Tighten

the bolts twice in this sequence, then tighten

bolts once–around at 145 lb.–ft. torque.

NOTE: The specified torque values have no sig-

nificance unless the bolts are lubricated.

5. Check the dimension between cap face and seg-

ments at four locations, 90 degrees apart, to as-

sure surfaces are still parallel within 0.020 in.

Torque Wrench (Acceptable Method)

In the absence of a suitable press, bolts may be tight-

ened with a torque wrench adjusted to apply the indi-

cated torque to each bolt.

1. Clean the front face of the cap and the segments.

Using a depth micrometer, measure the distance

(X in Fig. 25) between the face of the cap and the

segments at four points, 90 degrees apart. The

face of the cap and the segments should be par-

allel within 0.020 in.

Vertical Drilling Motor, Type GE752, GEK–91584D

39

If necessary, tighten the appropriate cap bolts to

obtain this parallel relationship between the face

of the cap and the segments.

2. Remove ONE bolt. Clean and lubricate the bolt

threads under the bolt head. Reassemble bolt,

and torque to 97 lb.–ft.

3. Repeat Step 2 for remaining bolts, following the

crisscross tightening sequence shown on Fig.

27.

4. Repeat the tightening sequence increasing the

torque by 10% each time until a FINAL value of

145 lb.–ft. torque for all bolts is obtained.

5. Check the dimension between face of cap and

segments to assure these surfaces are parallel

within 0.020 in.

NOTE: Do not tack–weld the bolts to the com-

mutator cap before spin seasoning or resurfac-

ing operations are performed.

Refer to following sections for instructions to spin

season and resurface the commutator.

Spin Seasoning

(Commutator Assembled On Armature)

A commutator seasoning cycle is required after com-

mutator tightening operations have been performed.

Prior to spin–seasoning, dynamically balance the ar-

mature to within 12 grams on the commutator end and

10 grams on the drive end. Refer to longitudinal section

for balance weight locations (see Table 2 to determine

the correct drawing).

To spin season the commutator, place the armature

in a spin–seasoning stand and proceed as follows:

1. Heat the commutator to 155–165 C (312–330

F) in 60 minutes at 2940 rpm. Spin at 155–165

C (312–330 F) for 60 minutes at 2940 rpm. Cool

to 50 C (122 F) maximum in 30 minutes at

2940 rpm.

2. Allow the commutator to cool, and grind cold.

See “Commutator Resurfacing” section.

3. Heat the commutator to 155–165 C (312–330

F) in 60 minutes at 2940 rpm. Spin at 155–165

C (312–330 F) for 30 minutes at 2940 rpm. Cool

to 50 C (112 F) maximum in 30 minutes at

2940 rpm. Repeat for a total of 2 cycles.

4. Heat the commutator to 140–150 C (284–302

F) in 60 minutes at 2940 rpm, and check commu-

tator smoothness at 2940 rpm.

5. Allow the commutator to cool, and grind cold.

See the “Commutator Resurfacing” section.

Check commutator runout per the information in

the DATA section. If the commutator is rough or

has high bars, repeat the pressing, tightening,

spin–seasoning and resurfacing procedures un-

til the runout is within the limits specified in the

DATA section.

6. Tack–weld the bolts to the commutator cap with

bronze welding rod, GE–B50E37.

7. Refer to the “Test After Repair (Armature)” sec-

tion for the test voltage, and perform a High–Po-

tential test on the armature windings.

Commutator Resurfacing

Prior to turning or grinding the commutator, be cer-

tain there is sufficient stock so the commutator will not

be turned or ground below the minimum permissible di-

ameter.

Refer to the DATA section for the minimum permissi-

ble commutator diameter dimension.

If the brush surface diameter will be less than the

minimum permissible diameter after the resurfacing op-

erations are performed, the commutator must be re-

placed.

Grinding

1. Prior to grinding, true the shaft centers with re-

spect to the bearing fits by scraping.

2. Place the armature in a lathe equipped with a

grinding attachment or in a grinding machine.

Check the concentricity of the bearing fits. The

TIR should not exceed 0.001 in.

3. Cover the armature windings to prevent entry of

grinding dust and chips.

GEK–91584D, Vertical Drilling Motor, Type GE752

40

FIG. 22. CONNECTION DIAGRAM (41A237276 CHG. 0). E–39093A.

MODELS

SEE TABLE 2

TO CHANGE MOTOR DIRECTION:

TO RUN CCW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO POSITIVE

F2 TO NEGATIVE

A1 TO POSITIVE

A2 TO NEGATIVE

TO RUN CW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO NEGATIVE

F2 TO POSITIVE

A1 TO POSITIVE

A2 TO NEGATIVE

TO CHANGE MOTOR DIRECTION:

TO RUN CCW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO POSITIVE

F2 TO NEGATIVE

A1 TO POSITIVE

A2 TO NEGATIVE

TO RUN CW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO NEGATIVE

F2 TO POSITIVE

A1 TO POSITIVE

A2 TO NEGATIVE

4. Grind the commutator and check commutator

runout with a dial indicator. The maximum com-

mutator runout is 0.001 in.

5. Perform the undercutting, raking and polishing

operations.

Turning

If the surface of the commutator is badly worn,

burned or scarred, turn the commutator in a lathe as fol-

lows:

1. True the shaft centers with respect to the bearing

fits by scraping. Place the armature in a lathe and

check the concentricity of the bearing fits. The

TIR should not exceed 0.001 in.

2. Cover the windings to keep out chips.

3. Set the cutting tool for turning copper, and set

lathe speed to give a commutator surface speed

of 300 feet per minute. Refer to the DATA section

for dust groove dimensions.

4. Make clean, smooth cuts to remove just enough

copper to renew the commutator surface. Do not

allow the cutting tool to chatter.

5. After turning operations have been completed,

check commutator runout with a dial indicator.

The maximum runout is 0.001 in.

6. Perform the undercutting, raking and polishing

operations.

Vertical Drilling Motor, Type GE752, GEK–91584D

41

FIG. 23. CONNECTION DIAGRAM (41A330278, CHG. 0). E–38055B.

MODELS

SEE TABLE 2

TO CHANGE MOTOR DIRECTION:

TO RUN CCW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO POSITIVE

F2 TO NEGATIVE

A1 TO POSITIVE

A2 TO NEGATIVE

TO RUN CW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO NEGATIVE

F2 TO POSITIVE

A1 TO POSITIVE

A2 TO NEGATIVE

Undercutting

See Fig. 28 for a diagram of proper undercut.

A sharp hacksaw blade may be used but caution

must be observed since a dull blade or saw produces

small cracks in the mica into which dirt or moisture may

accumulate and cause a breakdown in the insulation be-

tween the commutator segments.

With practice, hand–held power undercutters can be

used. Follow the tool manufacturer’s instructions and

GEK–91584D, Vertical Drilling Motor, Type GE752

42

FIG. 24. CONNECTION DIAGRAM (41A330179, CHG. A). E–37950A

I

O

N

#1

#46

S

#2 #184

#22

#23

#12

#92

#93 #94

–

–

I

–

–

I

–

–

I

–

–

I

–

–

I

–

–

I

–

–

I

–

–

O

O

OOO

O

O

N

NN

S

S

S

#1

EVERY BAR

EQUALIZED

VIEW AT COMMUTATOR END

A1

A2

F1

F2

MODEL

SEE TABLE 2

TO CHANGE MOTOR DIRECTION:

TO RUN CCW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO POSITIVE

F2 TO NEGATIVE

A1 TO POSITIVE

A2 TO NEGATIVE

TO RUN CW VIEWED FROM COMMUTATOR END,

CONNECT: F1 TO NEGATIVE

F2 TO POSITIVE

A1 TO POSITIVE

A2 TO NEGATIVE

Vertical Drilling Motor, Type GE752, GEK–91584D

43

FIG. 25. COMMUTATOR TIGHTENING.

E–4270B.

WARNING: During resurfacing operations,

eye protection and a respirator should be

worn to protect personnel from dust and fly-

ing particles.

use slot guides and depth gauges for accurate, uniform

cuts. Make a few practice passes over a scrap commu-

tator to get the “feel” of the tool. Care must be taken to

prevent the power undercutter from jumping out of the

slot and across the commutator surface. The high–

speed operation of the blade will quickly gouge the com-

mutator.

1. After a commutator has been resurfaced, the

mica between the bars should be undercut to a

depth of 0.047 in. Undercutting should be done

with a sharp–edged tool with a cutting width of

0.063 in.

2. Blow loose material off the commutator with dry,

compressed air.

FIG. 26. COMMUTATOR PRESSING

DIAMETER. E–18140

WARNING: When using compressed air for

cleaning purposes, flying debris and particles

may present a hazard to personnel in the im-

mediate area. Personnel should be provided

with, and trained in the use of, personal pro-

tective equipment as specified by applicable

federal or state safety regulations.

Raking

Resurfacing usually leaves particles and slivers of

copper hanging on the bar edges or lodged in the under-

cut slots. These must be removed before the motor is

placed in service, or the particles may bridge the side

mica and cause a flashover.

1. Brush out dirt and copper whiskers attached to

the trailing edge of the bars with a stiff–bristle

brush; preferably one with nylon bristles. A new

paint brush or stencil brush with the bristles cut

short for added stiffness may also be satisfacto-

ry. If stoning and undercutting have produced

considerable dragging of copper from the edges

of the bars, use a raking tool to remove the cop-

per fins and ragged edges. Use the tool to rake

the bar edges with the point inserted in the slot so

that sides of the V rake the trailing edge of the

bar. If the tool is ground with flat sides and used

with moderate pressure as a raking tool, it will re-

move ragged copper fins and break the sharp

15

9

3

7

11

2

10

4

8

6

12

FIG. 27. COMMUTATOR BOLT TIGHTENING

SEQUENCE. E–4502.

GEK–91584D, Vertical Drilling Motor, Type GE752

44

edges of the bars. See Fig. 12 for an illustration

of the tool. Another method of removing copper

fins is to rake the slots with a piece of fiberboard

approximately 0.045 in. thick.

2. After slots have been raked with fiberboard or a

raking tool, sand the commutator with fine sand-

paper to remove small pieces of copper sticking

from edges of slots.

3. Thoroughly clean the armature core and com-

mutator with dry, compressed air to remove cop-

per and dust.

1. If the commutator is discolored or smudged, pol-

ishing with canvas, crocus cloth, fine (4/0) sand-

paper or 400A Triemite paper is usually suffi-

cient.

Abrasive paper should be mounted on a wooden

block curved to fit the surface of the commutator.

2. Blow loose material off the commutator with dry,

compressed air.

3. Check commutator concentricity with a dial indi-

cator. Refer to the DATA section for runout limits.

4. Cover the commutator with heavy paper or felt to

protect it from damage.

WARNING: Personal injury may result if prop-

er eye protection is not worn when cleaning

with compressed air.

CAUTION: Never use an emery cloth on this or

any commutator. The abrasive particles on

emery cloth scratch the commutator surface

and lodge in the grooves between commuta-

tor segments. This condition creates the pos-

sibility of an eventual flashover which could

seriously damage the machine.

TEST AFTER REPAIR (Armature)

High Potential Test

Apply test voltage between the commutator (with all

segments shorted) and the shaft.

Used Armature

Apply a high–potential test voltage of 2000 volts, 60

Hz for one minute.

Rewound Armature

Apply a high–potential test voltage of 3500 volts, 60

Hz for one minute.

NOTE: Measure leakage current to ground dur-

ing test 3–85.0 milliamps.

WARNING: Electric shock can cause serious

or fatal injury. To avoid such injury, personnel

should take and observe proper precautions

during the high–potential testing.

Resistance Measurement

Refer to the DATA section for armature the resis-

tance value and measure armature resistance.

NOTE: Insulation Processing (Armature VPI)

After the armature has been cleaned and re-

paired or rewound, it must be vacuum pressure

impregnated. See the Varnish Treatment, “Vac-

uum Pressure Impregnation” section for fur-

ther required processing of the armature.

A. MICA PROPERLY UNDERCUT.

B. UNDERCUTTING TOOL TOO NARROW, LEAVING FIN

AT ONE SIDE OF SLOT.

C.UNDERCUTTING TOOL VERY NARROW, LEAVING

FINS AT BOTH SIDES OF SLOT.

D.SLOT IMPROPERLY INDEXED, PART OF BAR CUT

AWAY AND FIN OF MICA LEFT.

E. TOOL TOO WIDE, PART OF BAR CUT AWAY.

F. UNDERCUTTING TOO SHALLOW, SERVICE LIFE

SHORTENS BEFORE NEXT UNDERCUTTING.

G.UNDERCUTTING TOO DEEP, POCKET COLLECTS

CARBON AND COPPER DUST, SHORT CIRCUITING

BARS.

FIG. 28. COMMON MISTAKES IN

UNDERCUTTING COMMUTATOR SLOTS.

E–5024A.

Vertical Drilling Motor, Type GE752, GEK–91584D

45

MOTOR FRAME FIELD COIL

REPLACEMENT

Refer to Table 2, Page 20, to determine the correct

coiled frame assembly drawing for the machine being

repaired.

Coil Removal

1. Remove terminal insulation and disconnect coil

leads. Use a gas torch or brazing tongs to sepa-

rate brazed connections. When using brazing

tongs use low voltage and high a–c current to

heat coil connections.

WARNING: Safety glasses and leather gloves

must be worn at all times during brazing oper-

ations to protect personnel from physical

harm.

NOTE: If a gas torch is used, coil insulation

must be protected from heat by a non–flam-

mable heat absorbent.

1. Pack absorbent around the insulation near

the connection and over adjacent coils.

2. Make sure all exposed insulation is covered

with a thick layer of absorbent, then heat and

separate the coil connections.

2. Heat the coiled frame in an oven at 150 C (302

F) for four hours to soften the varnish so pole

bolts can be removed.

Remove the pole bolts and the coil–pole assem-

bly from the magnet frame.

3. Mark any shims for reassembly with the corre-

sponding pole when the coil(s) is installed in the

frame.

Coil Installation

Procedure for New Coil–Pole Assembly

NOTE: Install any exciting coils and braze their

connections before installing commutating

coils.

1. Before installing any coil and pole, clean the pole

contact surface on the frame and the pole piece

mounting surface.

2. Install the new pole and coil in the frame with any

shims that were on the damaged coil. Use new

washers under bolt heads. Lubricate the bolt

heads, threads and washers and draw the pole

bolts moderately tight.

3. Refer to Table 2, Page 20, to determine the cor-

rect coiled frame assembly drawings. All coil

connections must be brazed with silver solder,

GE–B20A6. Use two pieces of solder (0.010 x 1

in. x 1 in.) between terminal surfaces and braze

terminals as follows:

GEK–91584D, Vertical Drilling Motor, Type GE752

46

17 15,16

29

37

15,16

10

11,

45

VIEW AT Z OF

BRUSH HOLDER

CONNECTION

15,

16,

17 7

18,

19

54

6

30

62

33,

35

8

16,

17,

54

31

1

22,

49

A2

12,46

A1

11,45

29

26

28

10

15,16

ZE

E

APPLY ONE COAT OF P23

AFTER ALL P18 & P19 TAPINGS.

VIEW OF COMM. END

18,19

9

15,

16,

17

224 SEE NOTE

26

D

3

13,50

F2

13,50

F1

22,

49

32,35,74

2

62

3

1

27

FILL C’BORES

WITH P25

(24 PLACES) VIEW OF PINION END

20 21

BEFORE ASSEMBLING

CONNECTIONS INSULATE

9 O’CLOCK CABLE SUPPORT

AS SHOWN WITH P20 TAPED

WITH P21 (COMM. END)

INSULATE EXCITING & COMMUTATING FIELD COIL

TERMINALS BY FILLING ALL CAVATIES & COVERING

ALL BOLT HEADS WITH P24 THEN INSULATE ENTIRE

TERMINAL ASSEMBLY WITH P18 & P19 AND THOROUGHLY

BRUSH WITH P23.

15,

16,

17

7

18,

19 5

26

6

18,19,24,30

11,47

A1 12,48

A2

22,

49

8

33,35

62

31

1

29

4

15,16 28

10 YEE

D

VIEW OF COMM. END

10

37

17

15,16 30 11,47

15,16,18,19,24

VIEW AT Y OF

BRUSH HOLDER

CONNECTION

18,19 9

15,

16,

17

2

1

24 SEE NOTE

3

62

32,35,74

2

22,

49

13,50

F2

13,50

F1

3

VIEW OF PINION END

27

FIG. 29. COILED FRAME ASSEMBLY (41D732353 CHG. N). E–39094A.

Vertical Drilling Motor, Type GE752, GEK–91584D

47

62

1

VIEW AT A ENLARGED (TYPICAL)

ASSEMBLE FLUSH TO TOP OF INSIDE

WALL WITHIN .25 & TIGHEN UNTIL

PLUG IS EXPANDED & TIGHT IN HOLE

+

–2,

315 16 9

2,3

17

17

VIEW AT B ENLARGED (TYPICAL)

41

42

42,44

SIDE VIEW OF COMM. CHAMBER

SHOWING PLUGS ON SIDE

OPPOSITE CONNECTION BOX.

42,44

P44 FOR PRESSURE SWITCH USAGE

ON CONNECTION BOX SIDE ONLY.

IF NO PRESSURE SWITCH IS

REQUIRED, PLUG HOLE WITH P42

SECTION C–C

CONN. BOX

GROUND ARMOR WITH P52

(G3 & G4 ONLY)

VIEW AT D

STAPLE

10

MAG. FRAME

WALL

SECTION E–E

ATTACH BRUSH HOLDER CABLES

AGAINST INSIDE WALL OF MAG. FRAME

38

34,

36

CARBON

BRUSH

37

VIEW SHOWING

BRUSH HOLDER ASSEMBLY

NOTE FOR P61: ATTACH MARKING BAND (P61) TO

EACH END OF CABLE PTS. 11,12,13,45,46,47,48,

50,56,57,58,64,65,67 & STAMP WITH APPROPRIATE

MARKINGS AT ASSEMBLY.

TORQUE TABLE

PART SIZE TORQUE LB.–FT.

32–74 1.25–7 900–1000

33 1.25–12 435–483

34 .875–9 115–125

LUBRICATE BOLTS

FIG. 29. COILED FRAME ASSEMBLY (41D732353 CHG. N). E–39094A.

MODELS

SEE TABLE 2, PAGE 20

GEK–91584D, Vertical Drilling Motor, Type GE752

48

11,13

50

18

8,60

33

6

11,

13

VIEW AT Z OF

BRUSH HOLDER

CONNECTION

11,13 62,

26 3516,

17 25 SEE NOTE

2

4

48

18

75

39,

41

75

46

35

49

21,64

8 A1,

60

9 A2,

61

13,18,66

50

28

Z

F

F

D

37

6

VIEW OF COMM. END

FILL C’BORES

WITH P25

(24 PLACES)

.19 +

–.06

30

51

75

VIEW OF PINION END

ENLARGED VIEW AT B

FILL C’BORES

WITH P25

(24 PLACES)

71

24 SEE NOTE

7

58

57

22 59

10 F1

45 F2

38,41,76

7

12,14,15

22

AB

22

36

ENLARGED VIEW AT D

75 ASSEMBLE FLUSH TO TOP OF

INSIDE WALL WITHIN .25

AND TIGHTEN UNTIL PLUG IS

EXPANDED AND TIGHT IN HOLE

+

–

.19 +

–.06

29

31

32

30

.12

75

ENLARGED VIEW AT A

ASSEMBLE FLUSH TO TOP OF

INSIDE WALL WITHIN .25

AND TIGHTEN UNTIL PLUG IS

EXPANDED AND TIGHT IN HOLE

+

–

11,

13 2,

26

3

516,

17 25 SEE NOTE

4

16,17,24,48

8 A1,

62

9 A2,

63

21,

64

4635

39,41

75

49

6

50

6

37

11,

13,

18

D

E

Y

F

F

28

VIEW OF COMM. END

11,13

6

38

48

11,13

18

11,13

8,62

VIEW AT Y OF

BRUSH HOLDER

CONNECTION

28 7

1

24 SEE NOTE

7

22

38,41,76

7

45 F2

10 F1

12,14,15

22

59

57

58 36

22

AB

NOTE FOR P74:

ATTACH MARKING BAND (P74) TO EACH END

OF CABLE PTS. 8,9,60,61,62,63,68,69,76,77,78,

81,82,83. STAMP WITH APPROPRIATE MARKING

AT ASSEMBLY.

VIEW OF PINION END

FIG. 30. COILED FRAME ASSEMBLY (41D732345 CHG. V). E–39095A.

Vertical Drilling Motor, Type GE752, GEK–91584D

49

22

VIEW SHOWING METHOD

OF ASSEMBLING CABLES

THRU STAPLES.

(PINION END)

20 19

BEFORE ASSEMBLING

CONNECTIONS, INSULATE

CABLE SUPPORTS AS SHOWN

WITH P19 TAPED WITH P20

(COMM. END)

MAG. FRAME

WALL

STAPLE

6

SECTION F–F

ATTACH BRUSH HOLDER

CABLES AGAINST INSIDE

WALL OF MAG. FRAME.

12 7,10,45

14

15

COIL TERM.

OR

CABLE TERM.

VIEW SHOWING METHOD

OF CONNECTING SHUNT

CABLES.

54

51

27,

51

P27 FOR PRESSURE SWITCH

USAGE ON OPPOSITE SIDE

ONLY, IF NO PRESSURE SWITCH

REQUIRED PLUG HOLE WITH P51

SECTION C–C

SIDE VIEW OF COMM. CHAMBER

SHOWING PLUGS OPPOSITE SIDE

OF CONNECTION BOX.

C

C

CARBON

BRUSH

34

40,

42

33

VIEW SHOWING BRUSH HOLDER ASSEMBLY

NOTE FOR P10 AND P15:

INSTALL P10 AND P45 WITH LARGER

TERMINAL ON EXC. COIL CONNECTION.

NOTE FOR P52 AND P53:

INSTALL P52 AND P53 ON CONNECTION

BOX END OF P10 AND P45.

61,64

60,

63

A2 A1

CONNECTION

BOX

VIEW AT E

GROUND A1 AND A2

CABLES WITH P65

(G3 AND G4)

FIG. 30. COILED FRAME ASSEMBLY (41D732345 CHG. V). E–39095A.

MODELS

SEE TABLE 2, PAGE 20

GEK–91584D, Vertical Drilling Motor, Type GE752

50

FIG. 31. COILED FRAME ASSEMBLY (41D735440, CHG. A). E–38056B

NOTE FOR PARTS 37,38,39:

INSULATE EXCITING AND COMMUTATING FIELD COIL TERMINALS BY FILLING ALL CAVITIES

AND COVERING ALL BOLT HEADS WITH P37 THEN INSULATE ENTIRE TERMINAL ASSEMBLY

WITH 1T–1/2 L. OF P38 AND 1T–1/2 L. OF P39.

NOTE FOR P40:

ASSEMBLE P40 FLUSH TO TOP OF INSIDE WALL OF MAGNET FRAME WITHIN .25 AND

TIGHTEN UNTIL PLUG P40 IS EXPANDED AND TIGHT IN HOLE (1–PLACE SEE ENLARGED VIEW

@ ”A”).

V.P.I. COILED FRAME, ONE COAT STATIONARY BAKE, FOLLOWED BY ONE SPRAY COAT ON

THE COMM. CHAMBER.

TORQUE TABLE

PART SIZE TORQUE LBS.–FT.

4 1.25–12 435–483

6 1.25–7 900–995

21 .875–9 240–260

23 .4375–14 25–35

28 .25–20 6–8

MODEL US1

MODELS

SEE TABLE 2, PAGE 20

Vertical Drilling Motor, Type GE752, GEK–91584D

51

FIG. 31. COILED FRAME ASSEMBLY (41D735440, CHG. A). E–38056B.

REF. DESCRIPTION

1 MAGNET FRAME

4 BOLT(NON–MAGNETIC), 1 1/4–12X4

5 HARD WASHER, 1 1/4

6 BOLT, 1 1/4–7X3 3/4

7 EXCITING COIL AND POLE

8 BUSHING

9 CABLE

10 CABLE

11 CABLE

12 CABLES

13 CABLES

14 CABLE

15 CABLE

16 MARKER

17 MARKER

18 TAG

19 BRUSHHOLDER ASSEMBLY

20 BRUSHHOLDER SUPPORT

21 BOLT, 7/8–9X3 1/4

22 LOCKWASHER, 7/8

REF. DESCRIPTION

23 BOLT, 7/16–14X1

24 LOCKWASHER, 7/16

25 BRAZING STRIP, 1X1

26 BRAZING ROD

27 PIPE PLUG, 1/2 NPT

28 BOLT/WASHER, 1/4–20X1/2

29 BELL WASHER, 1/4

30 NUT, 1/4–20

31 REDUCER

32 FITTING

33 SEALER #1473, SILMATE

34 PAD

35 PAD

36 TWINE

37 PUTTY

38 1ST TAPING

39 2ND TAPING

40 PLUG

41 COMMUTATOR POLE AND COIL

GEK–91584D, Vertical Drilling Motor, Type GE752

52

FIG. 32. COILED FRAME ASSEMBLY (41D735343, CHG. C). E–37951C

FILL C’BORES WITH P31

(12–PLACES)

38 36,

38 15

17

16

36,38

1,

39

24

19

32

18

37,38

11

20,21

8,

9

8,9

22,

23

38

38

38

1538

36,

38

38

32

24

7,10

FOR FILLETS

8–PLACES

TYPICAL 20,

21

11

8,9

8,9 11 20,21

20,

21

11

COMMUTATOR END

A1

A2

FILL C’BORES WITH P31

(12–PLACES)

22,

23 FOR FILLETS

8–PLACES

TYPICAL

28

6,

7

.09 MIN. TYP.

24

29 32

PINION END

F1

F2

28

32

29

24

1,

39

28

3,4,5

2,

4,

5

3,4,5

2,

4,

5

1,39

13,

14

12

11

CARBON

BRUSH

VIEW SHOWING BRUSH

HOLDER ASSEMBLY

(COMMUTATOR END)

1,39

25

26

SIDE VIEW OF COMMUTATOR

CHAMBER SHOWING PIPE PLUG

LOCATIONS (BOTH SIDES)

Vertical Drilling Motor, Type GE752, GEK–91584D

53

FIG. 32. COILED FRAME ASSEMBLY (41D735343, CHG. C). E–37951C

+

–5

NOTE FOR PTS. 33, 34, AND 35

INSULATE EXCITING AND COMMUTATING FIELD COIL TERMINALS BY

FILLING ALL VAVITIES WITH P33 THEN INSULATE ENTIRE TERMINAL

ASSEMBLY WITH 2T–1/2L. OF P34 AND 2T–1/2L. OF P35.

V.P.I. COILED FRAME ONE COAT. STATIONARY BAKE, SPRAY PAINT

THE COMMUTATOR CHAMBER INNER SURFACES AND THE FRAME

EXTERIOR. DO NOT SPRAY THE EXCITING AND COMMUTATING COILS.

REF. DESCRIPTION

1 MAGNET FRAME

2 EXCITING COIL

3 EXCITING COIL

4 EXCITING POLE

5 SPRING COLLAR

6 BOLT 1 1/4–7 X 3 3/4

7 HARDENED WASHER 1 1/4

8 COMMUTATING COIL

9 COMMUTATING POLE

10 BOLT 1 1/4–12 X 4

11 BRUSH HOLDER ASSEMBLY

12 BRUSH HOLDER SUPPORT

13 BOLT 7/8–9 X 3 1/4 N22P37052

14 LOCKWASHER 7/8 N405P49P

15 CABLE

16 CABLE

17 CABLE

18 CABLES

19 CABLES

REF. DESCRIPTION

20 BOLT 7/16–14 X 1 N22P27016B13

21 LOCKWASHER 7/16 N405P44P

22 BRAZING STRIP 1 X 1

23 ROD

24 BUSHING

25 PIPE PLUG 1/2 NPT N5700P51

26 PIPE PLUG 3/4 NPT N5700P63

28 CONNECTION STRAP

29 CABLES

31 SEALER NO. 1473 SILMATE 497A806P60

32 TAG

33 PUTTY 41A239176P443

34 1 ST TAPING 41D735343P34

35 2 ND TAPING 41D735343P35

36 PAD

37 PAD

38 CORD 41D735343P38

39 MAGNET FRAME

TORQUE TABLE

PART SIZE TORQUE LBS. FT.

6 1.25–7 900–995

10 1.25–12 435–483

13 .875–9 240–260

20 .4375–14 30

MODELS

SEE TABLE 2, PAGE 20

GEK–91584D, Vertical Drilling Motor, Type GE752

54

NOTE: If a gas torch is used, coil insulation

must be protected from heat by a non–flam-

mable heat absorbent.

1. Pack absorbent around the insulation near

the connection and over adjacent coils.

2. Make sure all exposed insulation is covered

with a thick layer of absorbent, then heat and

separate the coil connections.

2. Heat the coiled frame in an oven at 150 C (302

F) for four hours to soften the varnish so pole

bolts can be removed.

Remove the pole bolts and the coil–pole assem-

bly from the magnet frame.

3. Mark any shims for reassembly with the corre-

sponding pole when the coil(s) is installed in the

frame.

Coil Installation

Procedure for New Coil–Pole Assembly

NOTE: Install any exciting coils and braze their

connections before installing commutating

coils.

1. Before installing any coil and pole, clean the pole

contact surface on the frame and the pole piece

mounting surface.

2. Install the new pole and coil in the frame with any

shims that were on the damaged coil. Use new

washers under bolt heads. Lubricate the bolt

heads, threads and washers and draw the pole

bolts moderately tight.

3. Refer to Table 2, Page 20, to determine the cor-

rect coiled frame assembly drawings. All coil

connections must be brazed with silver solder,

GE–B20A6. Use two pieces of solder (0.010 x 1

in. x 1 in.) between terminal surfaces and braze

terminals as follows:

Brazing Coil Terminals

Braze the coil terminals by one of the following meth-

ods:

Machine Brazing

1. The recommended brazing current is 10,800

amperes at 1.6 volts. With silver–solder brazing

strips inserted between connections, clamp the

brazing tongs on the connection and braze the

joint. If necessary, add additional solder to fill the

joint and form a level surface.

2. Braze all exciting–coil connections before install-

ing the commutating coils.

Gas Torch Brazing

1. Pack the coil insulation with non–flammable heat

absorbent material; e.g., interwoven glass cloth.

2. Insert the brazing strips and use a C–clamp or vi-

se–grip pliers to clamp the connection surfaces

tightly together.

3. Use a torch tip with a 0.1 in. orifice and adjust the

torch to obtain a slightly reduced flame. As the

brazing strips melt, add more solder to fill the

joint and form a level surface.

4. Remove heat absorbent packing from insulation.

Use dry, compressed air and blow out the inside

of the frame.

WARNING: Personal injury may result if prop-

er eye protection is not worn when cleaning

with compressed air.

5. Torque the pole bolts to the values listed in Table

3, Page 37, Standard Bolt Torque Values.

6. Check the polarity of the field poles:

Energize the field circuit with a battery and check

pole polarity with a compass, Fig. 33.

7. Insulate the connections with silicone putty and

wrap connections with Mylar film (30). Apply

glass tape and extend each taping 1/2 in. beyond

the bare area of the connection. Brush the con-

nections with air–drying alkyd varnish GE–8001.

8. Install and connect any cables previously re-

moved.

NOTE: Do not flood–dip the coiled frame before

the cables are installed and the connections are

insulated.

Vertical Drilling Motor, Type GE752, GEK–91584D

55

Flood Dipping Coiled Frame

After field coils have been repaired or replaced and

electrical tests completed, insulate the coiled frame by

flood dipping in GE–8001 varnish. See Table 4, Page

55, for varnish viscosity limits.

Varnish may be thinned, as necessary, with Solves-

so* No. 100 thinner. Agitate varnish for 15 minutes be-

fore dipping frame.

1. Be sure all coil connections are made and insu-

lated, and all cables and ties for cables and con-

nection straps are in place. Tie cable ends above

the varnish level.

2. Coat all machine–fit surfaces with GE–271 black

varnish or stripping compound and plug bolt

holes with dummy bolts.

3. Heat the coiled frame to 40–80 C (104–176 F)

and dip the frame drive end down (with all coil

connections covered) for at least 15 seconds.

Drain and remove the frame from the varnish. Al-

low the frame to drain for at least 5 minutes in a

vertical position, drive end down.

4. Bake the frame in a pre–heated oven at 150 C

(302 F) for 30 minutes, minimum.

5. Clean the varnish from machined surfaces and

unplug the tapped holes.

TEST AFTER REPAIR

(Coiled Frame Without Armature)

1. Pass 24.0 amperes(60 Hz current) through the

exciting (series) field and read the voltage drop.

Minimum Volts 13.1. . . . . . . . . . . . . . . . . . . . . .

Maximum Volts 15.6. . . . . . . . . . . . . . . . . . . . . .

2. Pass 24.0 amperes (60 Hz current) through the

commutating (CP) field and read the voltage

drop.

For Non–Magnetic retainers:

*Standard Oil Co. of Pa.

0

10

20

30

40

50

60

70

0 102030405060

TABLE 4

VARNISH VISCOSITY CHART FOR

DIPPING COILED FRAME

NOTE: When necessary, use Solvesso No. 100 to thin var-

nish.

GE NO. 8001 VARNISH

NO. 3 ZAHN CUP

TIME – SECONDS

TEMP. DEGREES C

FIG. 33. FIELD COIL POLARITY CHECK. E–888A.

GEK–91584D, Vertical Drilling Motor, Type GE752

56

Minimum Volts 7.3. . . . . . . . . . . . . . . . . . . . . . .

Maximum Volts 8.5. . . . . . . . . . . . . . . . . . . . . . .

For Magnetic retainers:

Minimum Volts 0.7. . . . . . . . . . . . . . . . . . . . . . .

Maximum Volts 12.4. . . . . . . . . . . . . . . . . . . . . .

High–Potential Test

Frame With Used Coils

Apply a high–potential test voltage of 2000 volts, 60

Hz for one minute.

Frame With All New Coils

Apply a high–potential test voltage of 3500 volts, 60

Hz for one minute.

Measure leakage current to ground during this test.

5.0 milliamps is maximum.

WARNING: Electric shock can cause serious

or fatal injury. To avoid such injury, personnel

should take and observe proper precautions

during the high–potential testing.

Resistance Measurement

Refer to the DATA section for values and measure

the resistance of the exciting and commutating fields.

VARNISH TREATMENT (ARMATURE)

Vacuum Pressure Impregnation (VPI)

After all repairs have been completed, the armature

must be vacuum pressure impregnated in GE–702C

polyester varnish.

Refer to GEK–101183 for VPI procedure.

Following the VPI processing, the armature must be

given a varnish immersion treatment.

NOTE: Do NOT clean previously protected ma-

chined surfaces, threads and tapped holes be-

fore varnish treating the armature.

Varnish Immersion Treatment After VPI

(Armature)

The following immersion process must be performed

on the armature assembly after the VPI process.

1. Preheat the armature in an oven at 140 C for at

least five hours.

2. The temperature of the armature must not be

less than 90 C, or above 120 C, before im-

mersing. Immerse the armature in a vertical po-

sition (commutator end up) in the varnish (GE

Spec. No. A15B53A) for at least one minute.

NOTE: One minute is the minimum time to in-

sure adequate varnish penetration.

3. Lift the armature out of the varnish and spin until

the excess varnish is removed. Clean the shaft

with Xylene (GE Spec. No. D5B9).

4. Bake at 140 C in an oven for at least eight

hours.

BALANCING ARMATURE

Refer to the appropriate longitudinal section (see

Table 2, Page 20, to determine the correct drawing) for

balance weight locations. Dynamically balance the ar-

mature within 10 grams (0.35 oz.) on the drive end and

12 grams (0.42 oz.) on the commutator end by adding

weights on the commutator cap and the armature head.

REASSEMBLY

Brushholders

1. Using a bolt and washer, attach the brushholder

clamp to the frame mount. Position the studs of

the brushholder in the clamp, and move the

brushholder radially outward as far as possible.

2. Tighten the brushholder clamp bolt but do not

torque. Install all brushholders.

3. Connect the brushholder cables. Refer to Table

2, Page 20, to determine the correct connection

diagram.

Vertical Drilling Motor, Type GE752, GEK–91584D

57

Armature Bearings

NOTE: Parts that will be shrink–fitted should be

heated in an oven and assembled hot. Make

sure shrink–fitted parts are tight against adja-

cent parts after they have cooled.

Drive–End Bearing

(Figs. 34, 35, 36 and 37)

1. Place the armature in a saddle.

2. If the inner sleeve was removed, heat it to 110 C

(230 F) and shrink it tight on the shaft against

the shoulder.

3. Spread 0.5 oz. of grease onto the seals on the

inner and outer bearing caps and the inner

sleeve.

4. Pack 4.8 oz. of grease in the outer circumference

of the inner bearing cap as shown by the shaded

area in the bearing cap.

5. Install the inner bearing cap on the sleeve.

6. Heat and install the flinger tight against the

sleeve.

7. Heat and install the inner race of the roller bear-

ing tight against the flinger.

8. Install the outer race of the bearing in the

framehead.

9. Fill the roller bearing completely with 29.0 oz. of

grease.

10. Install the gasket onto the inner bearing cap.

11. Install guide pins into the inner bearing cap to

guide the framehead into position.

12. Assemble the framehead/bearing assembly

onto the shaft, over the guide pins until seated

against the bearing cap. Remove the guide pins.

NOTE: Orient the inner bearing cap on UP, AUP,

US and AUT models to facilitate grease tube as-

sembly.

13. Assemble the grease tubes to the inner bearing

cap:

a. On UP1 and AUP1 models, there are two

grease tubes, assembled to the inner bearing

cap and protrude through a hole in the frame.

b. On UP2 and AUP2 models, there is one

grease tube, assembled to the inner bearing

cap and protrudes through a hole in the

frame.

c. On all other models, there is one grease tube

assembled to the inner bearing cap and pro-

trudes through a hole in the framehead.

14. Pack 4.8 oz. of grease in the outer circumference

of the outer bearing cap and install the bearing

cap to the framehead. Secure the assembly with

bolts and lockwashers. Torque to the appropriate

value in Table 3, Page 37.

Commutator–End Bearing

(All Models Except US2, UP6, AUT2 and AUP5)

Refer to Fig. 38.

1. Clean and inspect the bearing and the shaft

bearing fit. Remove nicks and burrs.

2. If sleeve (16) was removed, heat it to 110 C

(230 F) and shrink it tight onto the shaft against

the shoulder.

3. Pack 5.25 oz. grease into the outer circumfer-

ence of the cavity of bearing housing (8).

4. Heat bearing housing (8) in an oven to 100 C

(212 F). While hot, assemble ball bearing (3)

into the housing firmly against the shoulder at the

bottom of the bearing fit.

5. Fill all voids in the ball bearing completely with

approximately 20.8 oz. of grease, Fig. 38. Smear

0.5 oz. of grease on the bearing housing and the

bearing cap seals.

6. Heat the bearing and housing assembly in an

oven to 100 C (212 F). While hot, assemble it

onto the shaft, with the inner race tight against

sleeve (16).

GEK–91584D, Vertical Drilling Motor, Type GE752

58

FIG. 34. DRIVE–END BEARING ASSEMBLY. E–18166E.

SMEAR 0.50 OZ. OF

GREASE

ON GREASE SEALS.

MODELS

SEE TABLE 2, PAGE 20

NOTE: Do not heat the bearing and housing as-

sembly above 100



C (212



F). Higher tempera-

tures may cause the oil to “bleed” from the

grease.

7. Heat spacer (9) to 110 C (230 F) and shrink it

onto the shaft tight against the inner race of ball

bearing (3).

Vertical Drilling Motor, Type GE752, GEK–91584D

59

FIG. 35. DRIVE–END BEARING ASSEMBLY. E–39301.

MODELS

SEE TABLE 2, PAGE 20

The bearing assembly will be completed when the

armature is assembled into the frame.

Commutator–End Bearing

(Models US2, UP6, AUT2 and AUP5)

Refer to Fig. 39.

1. Clean and inspect the bearing and the shaft

bearing fit. Remove nicks and burrs.

2. If sleeve (13) was removed, heat it to 110 C

(230 F) and shrink it tight onto the shaft against

the shoulder.

3. When sleeve (13) has cooled, assemble a new

seal ring (5) onto the sleeve, oriented as shown

in Fig. 40.

4. Pack 5.20 oz. grease into the outer circumfer-

ence of the cavity of bearing housing (8).

GEK–91584D, Vertical Drilling Motor, Type GE752

60

FIG. 36. DRIVE–END BEARING ASSEMBLY (41B537821, CHG. B). E–37952B

13

12

17

2

4,5

20

3

6

14 ASSEMBLED TO EITHER P13

OR P17, DEPENDING ON MODEL.

NOT INCLUDED ON ALL MODELS

NOT INCLUDED ON ALL MODELS

APPLY P15 TO THREADS

AT BOTH ENDS OF P12

USE IF NECESSARY TO

ADJUST FOR PROPER

ASSEMBLY OF PARTS

17, 18 AND 19

TORQUE TO

110–120 FT. LBS.

22 FILL BEARING COMPLETELY

WITH 29 OZ. OF P7

24

NOT INCLUDED ON

ALL MODELS

SMEAR .5 OZ. OF

P7 ON SEALS

USE 4.8 OZ. OF

P7 IN EACH CAVITY

23

2

18

19

16,21

REF. DESCRIPTION

1 FRAME HEAD

2 GASKET

3 BEARING CAP

4 LOCKWASHER 5/8 N405P47P

5 BOLT 5/8–11 X 3 1/2 N22P33056

6 SLEEVE

7 GREASE

12 PIPE 1/4 X 6 IN.

13 COUPLING 1/4 NPT

14 PIPE PLUG 1/4 N5700P31

REF. DESCRIPTION

15 LOCK–TITE 497A806P36

16 FRAME HEAD

17 FITTING 90 ELBOW

18 FITTING 90 ELBOW

19 FITTING BULKHEAD

20 WASHER 9/16 N402P46B13

21 FRAME HEAD

22 ROLLER BEARING

23 BEARING CAP

24 FLINGER

MODELS

SEE TABLE 2, PAGE 20

Vertical Drilling Motor, Type GE752, GEK–91584D

61

5. Heat bearing housing (2) in an oven to 100 C

(212 F). While hot, assemble nilos ring (4) (ori-

ented as shown in Fig. 40), and the ball bearing

(3) into the housing firmly against the shoulder at

the bottom of the bearing fit.

6. Fill all voids in the ball bearing completely with

approximately 20.8 oz. of grease. Smear 0.5 oz.

of grease on the bearing housing and bearing

cap seals, and on the seal ring wear surface on

the nilos ring (4).

7. Heat the bearing and housing assembly in an

oven to 100 C (212 F). While hot, assemble it

onto the shaft, with the inner race tight against

sleeve (13).

CAUTION: Be sure that the nilos ring is assembled

over sleeve (13), not pinched between the sleeve

and the bearing.

NOTE: Do not heat the bearing and housing as-

sembly above 100



C (212



F). Higher tempera-

tures may cause the oil to “bleed” from the

grease.

INNER BEARING

RACE

DIAL INDICATOR

POINTER RESTS

AGAINST OUTER

BEARING RACE

FRAMEHEAD

OUTER BEARING

RACE WITH

ROLLERS

SUPPORT FOR

INDICATOR ON

ARMATURE SHAFT

FIG. 37. CHECK ALIGNMENT OF BEARING

AFTER ASSEMBLY. A–120402.

8. Heat spacer (6) to 110 C (230 F) and shrink it

onto the shaft tight against the inner race of ball

bearing (3).

The bearing assembly will be completed when the

armature is assembled into the frame.

Armature Assembly Into Frame

Models UP and AUP

Refer to Fig. 15.

1. Assemble the brushholders into the frame. Move

them well back from commutator to avoid inter-

ference when installing the armature. Fasten

and insulate the connections and install outgoing

cables.

2. Block and level the frame in a vertical position,

commutator–end down, on a heavy duty stand.

Be sure there is clearance for the commutator–

end shaft extension when the armature is low-

ered into the frame.

3. Install three guide studs in the commutator–end

bearing housing bolt circle to guide the housing

into the framehead fit.

4. Pack 5.25 oz. of grease in the outer circumfer-

ence of bearing cap (4).

5. Lift the armature with the hoist and lifting bail at

the drive end. Line up the hoist directly over the

center of the cavity in the frame.

6. Lower the armature slowly into the frame, being

careful not to damage the commutator. When

the armature is almost fully inserted, use the

guide studs to align bearing housing (46) and

framehead bolt holes (56). (Position the bearing

cap to accommodate the grease tubes in UP1

and AUP1 models.)

7. When the armature has reached its limit of travel,

remove the guide studs and install bearing cap

(4) with a new gasket (57) using bolts and wash-

ers (52). Draw the bearing housing into

framehead (56). Torque bolts to 105–115 ft.lbs.

GEK–91584D, Vertical Drilling Motor, Type GE752

62

FIG. 38. COMMUTATOR–END BEARING ASSEMBLY (41B532745 CHG. F). E–39090A.

MODELS

SEE TABLE 2, PAGE 20

8. Install framehead bolts (10) and lockwashers

(12). Torque to 440–495 lb.–ft.

CAUTION: Alternate tightening of commu-

tator–end bearing housing and drive–end

framehead bolts. Uneven tightening of bolts

could damage bearings or related fitted sur-

faces.

NOTE: Be sure framehead bolt holes are

aligned with bolt holes in inner bearing cap be-

fore assembling bolts (10) and lockwashers

(12).

9. Install grease tubes at the drive end:

a. On UP1 and AUP1 models, two grease tubes

are required. Clean all residual sealing RTV

from the grease tube clearance hole in the

frame. Then, reach into the cavity of the ma-

chine, around the drive–end inner bearing

cap (51), and install these tubes to the bear-

ing cap so that they protrude through a hole in

the frame. Seal around the grease tubes at

their hole in the frame with RTV.

b. On UP2 and AUP2 models, one grease tube

is required. The procedure is the same as in-

dicated in Step 9a.

c. On all other models, one grease tube is re-

quired. This tube connects the inner bearing

cap with the framehead, and should have

been assembled with the drive–end bearing

assembly.

NOTE: Insure that all grease tubes are packed

full of grease.

10. Use a feeler gauge and check the radial clear-

ance on the drive–end bearing between each

bearing roller and the inner race, at the top of the

bearing, Fig. 40. Place the feeler gauge between

the top roller and the inner race.

Vertical Drilling Motor, Type GE752, GEK–91584D

63

FIG. 39. COMMUTATOR-END BEARING ASSEMBLY (41B538068 CHG. 0). E-39300.

1

12

9,10

8

7

6

USE 5.2 OZ. OF P11

IN THIS CAVITY

FILL BEARING COMPLETELY

WITH 20.8 OZ. OF P11

2

3

4

5

13

USE 5.2 OZ. OF P11

IN THIS CAVITY

APPLY NALCO RC TO BORE

OF P7 AND SHAFT

HEAT P7 TO 180 C. (356 F)

RISE AND ASSEMBLE AS SHOWN

REFER TO ASSEMBLY INSTRUCTIONS

FOR DETAILS

SMEAR 0.80 OZ. OF P11 ON GREASE

SEALS AND SEAL SURFACE

oo

2

4

5

13

MODELS

US2, UP6, AUT2 AND AUP5

REF. DESCRIPTION

1 FRAME HEAD

2 BEARING HOUSING

3 BALL BEARING

4 NILOS RING

5 SEAL RING

6 SPACER

7 SLEEVE

8 BEARING CAP

9 BOLT, 5/8-11 X 2 3/4 N22P33044

10 LOCKWASHER, N405P47B13

11 GREASE

12 GASKET

13 SLEEVE

GEK–91584D, Vertical Drilling Motor, Type GE752

64

OUTER BEARING

RACE WITH

ROLLERS

BEARING

CAGE

INNER BEARING

RACE

FRAMEHEAD

SHAFT

FEELERS

FIG. 40. CHECKING INTERNAL CLEARANCE OF

BEARING. A-120403.

11. The clearance between the rollers and the inner

race should measure between 0.0012 and 0.004

in. Try various gauge thicknesses until clearance

can be determined by the feel of the gauge as the

gauge is slowly pulled from between the roller

and the inner race.

12. Pack 4.8 oz. of grease in the outer circumference

of outer bearing cap (5).

13. Install a new gasket (54) and bearing cap (5) with

bolts and lockwashers (53).

14. Smear seals on bearing cap (5) and sleeve (47)

with grease.

15. Heat sleeve (47) to 110 C (230 F) rise and

shrink it onto the shaft tight against the roller

bearing inner race (48).

16. Seal the grease tubes which protrude through

the hole in the frame with RTV–108.

17. At the commutator end, smear the seals on bear-

ing cap (4) and sleeve (42) with grease.

NOTE: Prior to heating sleeve (42), apply NAL-

CO RC* “Rail Conditioner” to the inside diame-

ter of the sleeve and to the mating surface on

the shaft. Apply the NALCO with a Scott–150

white paper towel only and allow it to dry to a

thin white film on both surfaces before pro-

ceeding with Step 18.

18. Heat sleeve (42) to 180 C (356 F) rise and

shrink it onto the shaft tight against the spacer

(43).

19. Assemble the grease tubes to the bearing cap

(4) (UP1 and AUP1 models only). Install pipe

plugs in tubes and tube fittings as indicated in

Fig. 15.

NOTE: Insure that grease tubes are packed full

of grease.

Armature Assembly Into Frame

Models US1, AUT

Refer to Fig. 18.

1. Assemble the brushholders into the frame. Move

them well back from the commutator to avoid in-

terference when installing the armature. Fasten

and insulate the connections and install outgoing

cables.

2. Block and level the frame in a vertical position,

commutator–end down, on a heavy duty stand.

Be sure there is clearance for the commutator–

end shaft extension when the armature is low-

ered into the frame.

3. Install three guide studs in the commutator–end

bearing housing bolt circle to guide the housing

into the framehead fit.

4. Pack 5.25 oz. of grease in the outer circumfer-

ence of bearing cap (8).

5. Lift the armature with the hoist and lifting bail at

the drive end. Line up the hoist directly over the

center of the cavity in the frame.

*Product of NALCO Chemical Co.

Vertical Drilling Motor, Type GE752, GEK–91584D

65

6. Lower the armature slowly into the frame, being

careful not to damage the commutator. When

the armature is almost fully inserted, use the

guide studs to align bearing housing (3) and

framehead bolt holes (14).

7. When the armature has reached its limit of travel,

remove the guide studs and install bearing cap

(8) with a new gasket (11) using bolts and wash-

ers (10). Draw the bearing housing into

framehead (14). Torque bolts to 110–120 ft.lbs.

8. Install framehead bolts and lockwashers(30).

Torque to 440–495 lb.–ft.

CAUTION: Alternate tightening of commu-

tator–end bearing housing and drive–end

framehead bolts. Uneven tightening of bolts

could damage bearings or related fitted sur-

faces.

NOTE: Be sure drive–end framehead bolt holes

are aligned with holes in inner bearing cap be-

fore assembling bolts and lockwashers (30).

9. Use a feeler gauge and check the radial clear-

ance on the drive–end bearing between each

bearing roller and the inner race, at the top of the

bearing, Fig. 40. Place the feeler gauge between

the top roller and the inner race.

10. The clearance between the rollers and the inner

race should measure between 0.0012 and 0.004

in. Try various gauge thicknesses until clearance

can be determined by the feel of the gauge as the

gauge is slowly pulled from between the roller

and the inner race.

11. Pack 4.8 oz. of grease in the outer circumference

of outer bearing cap (36).

12. Install a new gasket (35) and bearing cap (36)

with bolts and lockwashers (34). Torque bolts to

110–120 ft.lbs.

13. Smear seals on bearing cap (36) and sleeve (37)

with grease.

14. Heat sleeve (37) to 110 C (230 F) rise and

shrink it onto the shaft tight against the roller

bearing inner race (38).

15. Finish the assembly of grease tube fittings and

washer (27) where it passes through the

framehead. Tighten all fittings and hardware.

16. At the commutator end, smear the seals on bear-

ing cap (8) and sleeve (6) with grease.

NOTE: Prior to heating sleeve (6), apply NALCO

RC “Rail Conditioner” to the inside diameter of

the sleeve and to the mating surface on the

shaft. Apply the NALCO with a Scott–150 white

paper towel only and allow it to dry to a thin

white film on both surfaces before proceeding

with Step 18.

17. Heat sleeve (6) to 180 C (356 F) rise and

shrink it onto the shaft tight against the spacer

(5).

18. Install pipe plugs in grease tubes and tube fit-

tings as indicated in Fig. 18.

NOTE: Insure that grease tubes are packed full

of grease.

BRUSHHOLDER CLEARANCE

ADJUSTMENT

1. Remove the protective covering from the com-

mutator. Place a 1/16 in. fiber spacer between

the bottom of the brushholder and commutator.

Loosen the brushholder clamp bolts and move

the brushholders so they touch the fiber spacer.

Tighten the clamp bolts to 225–250 lb.–ft. torque

and remove the spacer.

2. Connect the cable leads to the brushholder ter-

minals and tighten the terminal bolts.

BRUSH INSTALLATION

1. Install new brushes.

CAUTION: When replacing brushes, use only

the GE recommended grade. Mixing of brush

grades in the same motor or changing

brushes to another grade will seriously affect

commutation, surface film, commutator and

brush life. See the DATA section for brush

grade.

2. Carefully lower the spring–loaded brush lever on

each brush. Do not allow the lever to snap

against the brush, as the brush may chip.

GEK–91584D, Vertical Drilling Motor, Type GE752

66

3. Attach the brush–shunt terminals to the brush-

holder body under the screws provided.

4. Inspect the interior of the machine for foreign ob-

jects. Install the commutator covers on the motor

and check for proper fit and latch operation.

5. Clean the terminals.

HUB MOUNTING

Hub Fitting

NOTE: GE does not supply the hub for vertical

drill motors. This procedure is included for cus-

tomer use as a reference when installing the

hub.

To prevent a hub from slipping, it should have at least

75 percent fit on the shaft; i.e., at least 75 percent of the

tapered bore of the hub should be in contact with the ta-

pered fit on the shaft. Before mounting a hub, check and

correct the fit as follows:

1. Lightly cover the bore of the hub with a blueing

compound such as Prussian Blue.

2. Snap the cold hub forcefully onto the shaft.

3. Mark the relative angular position of hub with re-

spect to the shaft.

4. Remove the hub from the shaft. A convenient

method of removal is by the use of two finely ta-

pered steel wedges (hardened and ground)

which are carefully driven between the hub and

the bearing outer sleeve on the shaft.

5. Inspect the taper fit of the shaft; blueing of the

hub bore should now show on the shaft. If at least

75 percent of shaft surface shows traces of blue-

ing, the fit is satisfactory. If, however, only a few

spots of blueing show on the shaft, the fit is not

satisfactory.

6. Dress down the blue spots on the shaft very light-

ly with a fine emery cloth such as No. 400A Trie-

mite.

7. Blue the hub bore again (see Step 1) and repeat

Steps 2, 4, 5 and 6. Be sure to place the hub onto

the shaft in the same position as marked.

Generally, the fit will be improved, but the forego-

ing procedure may have to be repeated several

times to obtain a 75 percent fit.

Under no circumstances use a lapping com-

pound since lapping will produce a shoulder at

the large end of the tapered fit. A shoulder will

prevent a perfect fit when the hub is mounted

hot; i.e., when it is mounted in the advanced posi-

tion.

8. After a good fit has been obtained, thoroughly

clean the shaft and the hub bore to remove all

blueing, oil or grease. Then mount the hub.

Hub Mounting

1. Thoroughly clean the hub fit on the shaft and

bore of the hub (see the procedure in the Clean-

ing section). Remove any scoring on the shaft or

hub bore.

2. Spot the cold hub on the shaft by hand and check

for at least 75 percent fit. See the “Hub Fitting”

section. If necessary, dress the shaft to obtain

this fit.

3. Trial mount the cold hub onto the shaft. Measure

and record the position of the hub with respect to

the end of the shaft. Take measurements with a

micrometer advance gauge similar to that shown

in Fig. 41. Zero the gauge.

Mark points of measurement, and mark across

the end of shaft and hub face so that the hub,

when heated, can be mounted in exactly the

same angular position, and so the advance mea-

surement can be made from the same point.

4. Mount the hub hot onto the shaft so as to secure

an advance from the cold position to the hot posi-

tion along the axis of the shaft as indicated in this

section. The ESTIMATED difference between

shaft temperature and hub temperature (temper-

ature rise) which will provide this advance is also

given. The temperature difference is only an esti-

mate and should be adjusted (if necessary) to

provide the advance within prescribed limits.

Vertical Drilling Motor, Type GE752, GEK–91584D

67

CAUTION: Zero settings of advance gauge

must not be disturbed until all readings on the

hub are completed.

Heat the hub in an oven until it has reached a uni-

form temperature (the desired number of de-

grees above shaft temperature). For example, if

shaft temperature is 25 C (77 F), heat hub to

25 C (77 F) +171 C (339 F) = 196 C (385

F). This procedure should provide an advance of

approximately 0.085 in.

An accurate method must be provided for mea-

suring hub and shaft temperatures quickly be-

fore mounting the hub. This can best be done

with a hand pyrometer. In using the pyrometer,

place points of the gauge inside the bore of the

hub, Fig. 42.

NOTE: The part must be left in the oven long

enough for the heat to penetrate throughout the

part.

Measure the temperature of the shaft and the

hub with the same instrument.

5. Insure that the hub bore and the shaft taper are

clean. Then, using adequate hand protection,

quickly mount the hot hub on the shaft in the

same angular position as when cold. When the

FIG. 41. METHOD OF USING ADVANCE

GAUGE. E–5975A.

hub is nearly in engagement with the taper fit (not

in actual contact), snap it forcibly into place with a

quick push. It is important that the hot hub be in-

stantly snapped into position before it has

cooled; otherwise, it will freeze to the shaft and

cannot be adjusted further.

6. Check the hot or shrunk–on position of the hub

on the shaft. The advance from cold to hot posi-

tion along the axis of the shaft must be held with-

in the limits indicated. Check the actual advance

with an indicator gauge, located in the same rela-

tive position as used to measure the cold position

in Step 3, Fig. 41.

If the advance is not within specified limits, re-

move the hub and repeat the assembly proce-

dure.

TESTING AFTER OVERHAUL

TESTING SERIES MACHINES

(Models 5GE752AUP, AUT)

After the motor has been reconditioned and reas-

sembled, make the following tests to assure it will oper-

ate satisfactorily.

Connect the motor to a d–c arc–welding generator,

Fig. 7. Refer to connection diagrams, Figs. 22 and 24,

for connections. Run the machine series–connected

without load at 900 rpm and measure bearing tempera-

tures.

1. Use Duxseal* putty to hold the thermometers on

the drive end and commutator–end outer bear-

PLACE PYROMETER

POINTS IN BORE

OF HUB

FIG. 42. MEASURING TEMPERATURE OF

COUPLING HUB WITH PYROMETER. E–5976.

GEK–91584D, Vertical Drilling Motor, Type GE752

68

ing caps. Thermometers should contact the

bearing caps for best results.

2. Seat the brushes and run for ten minutes at 900

rpm.

Frame temperature should not exceed 25 C rise.

3. With machine running up to speed, measure vi-

bration. Vibration should not exceed 0.002 on

commutator end. If vibration exceeds this

amount, rebalance the armature.

4. Check the commutator for roughness and make

sure the brushes are riding properly.

5. Use a listening rod to check for noisy bearings.

6. Stop the machine and mount an indicator on the

frame. While turning the armature by hand, mea-

sure commutator runout. It should not exceed

0.001 in.

7. Measure field impedance. With 60 Hz a–c and 24

amperes through each field, measure the volt-

age drop across total exciting and commutating

fields. See the DATA section for voltage limits.

8. Apply a high–potential test to the windings of the

assembled machine, as specified in the DATA

section.

WARNING: Electric shock can cause serious

or fatal injury. Proper precautions should be

taken and observed by personnel performing

testing to avoid such injury.

TESTING SHUNT MACHINES

(Models 5GE752UP and US)

After the motor has been reconditioned and reas-

sembled for service, make the following tests to be sure

it will operate satisfactorily.

Connect the motor to a d–c welding generator. Refer

to connection diagrams (Figs. 21 and 23) for connec-

*Product of Johns Manville Co.

tions. Run the machine by separately exciting the shunt

field from a 125 vdc source. From another source of

power, apply voltage to the armature circuit until the de-

sired speed is obtained.

Motor Operation

Ventilated (2300 cfm at 7.6 in. H2O

at Commutator Chamber)

Hold separate field excitation at 50.5 amperes. Vary

the armature voltage to obtain the required rpm. At ap-

proximately 700 terminal volts (no load), the speed will

be 900 rpm.

Unventilated

Hold the separate field excitation at 10 to 15 am-

peres. Vary the armature voltage to obtain the required

rpm. At approximately 338 terminal volts (no load), the

speed will be 900 rpm.

1. Run the motor for five minutes at 450 rpm. In-

crease the speed to 900 rpm and run for two

hours. Bearing temperatures should not exceed

70 C (158 F). Run until the bearing tempera-

ture remains constant for 30 minutes. Increase

the speed to 1300 rpm and hold it while perform-

ing Steps 2, 3 and 4. Then shut down the motor.

Do not exceed 1300 rpm.

2. Measure vibration when running the motor up to

speed. Vibration should not exceed 0.004 in. If

excessive, rebalance the armature.

3. Check the commutator for roughness. Be sure

brushes are riding properly.

4. Listen for noisy bearings with a listening rod.

5. Stop the motor and mount an indicator on the

frame. Turn the armature by hand and measure

commutator runout. Runout should not exceed

0.001 in.

6. Measure the insulation resistance of the wind-

ings with a megohmmeter. If the resistance mea-

sures not less than one megohm, apply an a–c

high–potential test to ground for one minute as

outlined in the DATA section.

Vertical Drilling Motor, Type GE752, GEK–91584D

69

WARNING: Electric shock can cause serious

or fatal injury. To avoid such injury, personnel

should take and observe proper precautions

during the high–potential testing.

REMOVING ARMATURE

LOCKING ARRANGEMENT

(See Fig. 43)

1. Remove the two shipping bolts (1) from the bear-

ing cap. These bolts are longer and can be identi-

fied from the factory by their yellow heads.

2. Install the two regular bolts which are in a bag at-

tached to one of the shipping bolts.

3. Torque the regular bolts to 115 lb.–ft.

NOTE: The shipping bolts and bag should be

saved for future armature locking require-

ments.

FIG. 43. ARMATURE LOCKING ARRANGEMENT

(41B535748 CHG. 0). E–28735A.

LOCKING THE ARMATURE

FOR SHIPMENT

(See Fig. 43)

1. Remove two diametrically opposite bolts in the

commutator end bearing cap.

2. Install shipping bolts (1) (painted yellow) with jam

nuts (2) applied. Torque bolts to 30 lb.–ft. and

tighten the jam nuts.

CAUTION: Do not rotate the armature when

the locking bolts are in place. Bearing and

commutator damage may result.

3. Attach the two regular bolts and bag–tag (5) to

one of the locking bolts (1).

SHIPPING

Whenever drilling motors are to be shipped, they

must be properly skidded and secured to prevent any

damage in transit. The photographs and drawings which

follow illustrate a proven method of skidding these ma-

chines for handing and shipment.

HANDLING

To avoid damage to the machine during handling, re-

view the following cautionary statements:

1. Do not lift motors by the shaft extension of the ar-

mature.

2. Do not allow the armature to bump another ob-

ject.

3. Do not tighten coupling assembly bolts with an

air wrench or by pounding.

4. Do not remove armature end–play by any other

means than axial blocking.

5. Do not load the armature radially (strap down) for

shipment.

CLEANING AND SLUSHING

Before skidding the machine for shipment, all ex-

posed finished surfaces not already painted should be

cleaned and slushed as follows:

GEK–91584D, Vertical Drilling Motor, Type GE752

70

1. Remove all corrosion.

2. Wipe off the surface with clean rags and wet with

petroleum spirits GE–D5B8.

3. Follow with a clean rag wet with methanol, then

wipe dry. DO NOT touch the cleaned surface

with bare hands.

4. Slush immediately after cleaning with

GE–D6C6A1 slushing compound.

SKIDDING

Use yellow pine timbers large enough to support the

weight of the machine. The recommended size is illus-

trated in Fig. 44.

PROTECTION

When any apparatus is shipped in the open, it should

be fully protected from rain, snow, dirt, etc., by covering

with some suitable weatherproof material.

ARMATURES

To prepare drilling motor armatures for shipment or

storage, clean, slush and wrap the armature. Then, se-

FIG. 44. CONSTRUCTION DETAILS. E–7754.

3/4” DIA. (4 HOLES)

7–1/2”

25–1/4” 23–1/2”

2” X 6”

11–1/2”

25–1/4” 62–1/4”

48”

3” X 8”

3” X 6”

7–1/2”

2” X 6”

33”

3” X 8”

3” X 6”

curely support and enclose the armature in a totally en-

closed wooden box of sufficient strength to protect the it

from damage.

1. Clean the armature by removing dirt, oil or

grease from its surface.

2. Treat all unpainted, exposed finished surfaces

as follows:

a. Remove any corrosion.

b. Wipe off the surface with a clean cloth dipped

in petroleum spirits, GE–D5B8.

c. Wipe off the surface with a clean rag, dipped

in methanol, and wipe dry. DO NOT touch the

cleaned surfaces with bare hands.

d. Immediately after cleaning, slush the cleaned

surface with GE–D6C6A1 shushing com-

pound.

3. Wrap heavy paper or cardboard around the com-

mutator for protection.

4. Wrap and secure waterproof paper around ar-

mature punchings. This will prevent saddle tim-

ber moisture from condensing on the core

punchings.

5. Wrap both ends of the shaft with Grade C, Type

1, wax treated cloth and tape it securely into

place.

NOTE: Wherever metal parts come in contact

with the wood, insert a good grade of water-

proof paper between metal and wood. This will

prevent rust formation from the condensation

of moisture on the metal.

PREPARATION OF BOX

1. Make a suitable box from yellow–pine lumber us-

ing timbers of proper size to support the weight of

each armature. See Fig. 45.

2. Make 4 saddle blocks of 3 by 6 in. timber cut out

to fit circumference of armature core. Nail two to

the bottom of the box in the proper position to

Vertical Drilling Motor, Type GE752, GEK–91584D

71

FIG. 45. BOX FOR SHIPPING

ARMATURES. E–3782A.

50–1/2

2 X 6 X 20–1/2

(8 PIECES)

ALL DIMENSIONS IN INCHES

9–1/2

1 X 6 X 22

(NO HOLE)

3 X 6

1 X 6 X 57–1/2

(18 PIECES)

1 X 6 X 22

(2 PIECES)

WITH HOLES

2 X 6 X 24

(4 PIECES) 1 X 6 X 22

(18 PIECES) 2 SKIDS –

3 X 6 X 57–1/2

support the armature on core punchings.

CAUTION: Locate the saddle blocks so they

do not project beyond the punchings; other-

wise, scuffing of coil insulation could occur.

3. Support the commutator–end of the shaft by two

1 X 6 in. boards nailed to the end of the box. Drill a

hole in the two boards just large enough for the

end of the shaft. See Fig. 45. The end of the shaft

will fit in this hole against the end of the box to

prevent movement.

4. After the armature has been placed in the box,

insert a board of proper thickness between the

end of the shaft and the end of the box. Securely

nail it in place. This will prevent any lateral move-

ment of the armature in the box.

BOXING THE ARMATURE

1. Prepare the armature as specified in the forego-

ing.

2. Place it in the box. Support it on two saddle

blocks under the punchings and secure it against

lateral movement. See Fig. 46.

FIG. 46. ARMATURE PLACED IN

SHIPPING BOX. E–3783.

WRAP WATERPROOF

PAPER AROUND

PUNCHINGS

WRAP HEAVY

PAPER AROUND

COMMUTATOR

3 X 6

ADJUST THICKNESS

OF END BOARD TO

SUIT LENGTH OF

SHAFT

3. Place two saddle blocks over the core punch-

ings, as shown in Fig. 46, and nail them to the

side boards. If the box is the correct size, the top

of the saddles will be flush with the top of the side

boards. See Fig. 47.

4. Nail the top cover in place. Also nail through to

the top saddle blocks to prevent them from mov-

ing.

STORAGE

PLACING INTO STORAGE

When placing GE drilling motors into storage, the fol-

lowing preparations should be performed to prevent

damage to the equipment as a result of the storage.

1. Machines should be placed on a pallet and

stored indoors if possible. A clean, dry ambient of

60 F is preferred. In a high humidity environ-

ment, an ambient of 70 F is recommended. Ev-

ery attempt should be made to avoid widely vary-

ing temperatures and high humidity.

2. If it is necessary to store outdoors, a protective

cover should be used to prevent entrance of rain,

dust, etc.

3. All exposed machined steel parts and surfaces

should be slushed. These areas are slushed

prior to shipment from the factory, but should be

GEK–91584D, Vertical Drilling Motor, Type GE752

72

examined for rust. Any rust found should be re-

moved using fine abrasive paper, after the old

slushing compound has been removed with min-

eral spirits (GE–D5B8). Methanol should be

used to remove all residue.

WARNING: Cleaning solvents may be toxic and/

or inflammable. They can cause serious or fatal

injury if used without proper precautions. For

safety:

1. Do not inhale solvent fumes.

2. Use solvents only in adequately ventilated

areas.

3. Avoid contact of solvent with the skin.

4. Do not expose solvent to flame or sparks.

5. Observe caution statements issued by the

manufacturer of the solvent.

Extreme care should be exercised not to dam-

age critical machined surfaces such as the ta-

pered shaft surface while removing rust. The

surfaces should be reslushed with GE–D6C6A1

FIG. 47. SHIPPING BOX WITH ARMATURE,

LESS COVER. E–3784.

slush compound, Kendell Grade 5, or the equiva-

lent.

4. Brushes should be removed from their holders

and clamped under the spring clips to prevent

corrosion of the commutator surface as a result

of moisture absorption by the carbon.

5. Do not completely seal the motor, but cover ma-

jor vent areas with a waterproof shipping tape.

Leave enough opening so the machine can

breathe – i.e., moist air is not trapped. The inten-

tion is to prevent entrance of water, dust, small

animals, etc., but not to seal airtight. GE does not

recommend the use of a silica gel or dehydrating

agent.

6. Since the lubricant drains from the top half of

bearings during storage, this area is subject to

corrosion. The shaft should be rotated periodi-

cally to redistribute a protective film. If stored in-

side, rotate every three months. If outside, every

month. Before placing the machine back into

service after prolonged storage (1 year or more)

bearings should be inspected and repacked with

new grease meeting the recommended GE lubri-

cation specification.

7. The machine should be meggered when placed

into storage and periodically while in storage

(3–month intervals). Keep a record of these

megger readings as a rapid decrease in insula-

tion resistance indicates the machine condition

is deteriorating and the storage conditions inade-

quate.

Before placing a stored motor back into service, refer

to the applicable instruction “Removing Motors From

Storage”.

REMOVING FROM STORAGE

Before placing a stored motor in service, perform the

following:

1. Blow dust and dirt accumulation out of the wind-

ings with clean, dry air.

2. Visually inspect for spring corrosion, sticking

brushes in brushholders and general defects.

Vertical Drilling Motor, Type GE752, GEK–91584D

73

3. Check winding insulation continuity to ground

with a 500 volt megger. If the megger reading is

less than 2 megohms, the winding should be

baked or dried until the moisture content is suffi-

ciently reduced to raise the megger reading to 2

megohms.

4. An electrical source of heat is best for drying as it

can be easily regulated and is clean. Proceed as

follows:

NOTE: Before drying windings, consideration

must be given to bearings and lubricants. Not

only can bearing lubricants be damaged by

heat, but they can also deteriorate with age. For

this reason, it us usually best to remove bear-

ings before drying and repack with new grease

before reassembly.

a. Remove the armature from the frame and re-

move bearings from the armature shaft.

b. Heat the frame and armature until dried suffi-

ciently to obtain the 2 megohm reading.

c. Pack bearings with new grease. Refer to the

DATA table for the proper grease. Refer to the

appropriate bearing illustration for the proper

amount of grease.

d. Reassemble the motor.

e. If facilities are available, give the reas-

sembled machine a running test to check the

bearings.

Refer to Figs. 48 and 49 for outline drawings.

GEK–91584D, Vertical Drilling Motor, Type GE752

74

FIG. 48. OUTLINE, UP AND AUP (41E903631 CHG. H). E–28755B.

15.09

16.82

+

–.25

15.53

16.656

+.000

–.010

15.09

16.82

+

–.25

1.72

18.00 14.78

36.000

+.000

–.010

AIR OUT

(4 CORNERS)

.50–13 TAP X 1.00 DEEP

8 HOLES

F1

F2

ONE .25 PIPE PLUG–REPLACE

WITH GREASE FITTING FOR

2.25 DIA. (3 HOLES)

FOR LIFTING

.375–24 THD.

VIEW SHOWING HYDRAULIC

PUMP OFF FOR HUB

BOTH ENDS

.06 THICK TERMINALS FOR

NO. 10 SCREW ON 37/24 CABLES

EXTENDING 10 FEET FROM FRAME

FIG. 1

GE–752–UP

SAME AS GE–752–AUP EXCEPT

F1 AND F2 CABLES AS SHOWN

–A– –B– –C– .004R

+

–.002

.000

F1

F2

MODEL ”E” ”F” ”G”

UP1 .75–10 22.12 16.50

AUP1 THRU .04R .01R

UP2, 3 & 4 1.005 22.124 16.500

AUP2, & 3 DIA. THRU 22.116

REGREASING (ALL MODELS EXCEPT UP1, UP2, AUP1 AND AUP2)

Vertical Drilling Motor, Type GE752, GEK–91584D

75

FIG. 48. OUTLINE, UP AND AUP (41E903631 CHG. H). E–28755B.

58.50

AIR OUT

9.56

13.43

+

–.06

9.24

F

10.50

23.12

1.38

1.74

8.25 6.50

G

3.19

2.38

–.12

1.00 R.

3.62

7.88

1.06

1.06

+

–.06

G+

+

–.005

11.375

DIA.

C ARMATURE

L

.50 NPT FOR

AIR PRESSURE

MEASUREMENT

A1

F2

F1

ONE .25 PIPE PLUG–REPLACE

WITH GREASE FITTING FOR

1.56 DIA. THRU

(4 HOLES)

E HOLE

.75–10 TAP THRU

(2 HOLES)

FOR JACKING FOOT

DIMENSIONS

C MOTOR

L

.562 DIA.

2 HOLES

ARMATURE LOCK

ARRANGEMENT

SEE NOTE

E HOLE

G

A2

NOTE FOR ARMATURE LOCKING ARRANGEMENT

LOCATED ON COMMUTATOR END

TO BE IN PLACE DURING MOUNTING OF MOTOR

BUT TO BE REMOVED BEFORE OPERATION OF

MOTOR

GE–752–AUP SHOWN IN MAIN VIEWS

GE–752–UP SHOWN IN FIG. 1

APPROXIMATE WEIGHTS

GE–752–UP 6750 POUNDS

GE–752–AUP 6850 POUNDS

AIR FLOW REQUIREMENTS

2300 CFM OF STANDARD AIR

MINIMUM 900 HP

2800 CFM OF STANDARD AIR

MINIMUM 1000 HP

IMPORTANT

THE ELECTRICAL EQUIPMENT SHOULD BE

LOCATED IN A SPACE WHICH

(1) PROVIDES SUFFICIENT ACCESSIBILTY

FOR BRUSH INSPECTION

(2) ALLOWS REMOVAL OF ALL THE BRUSHES

AND PIGTAIL FASTENERS

(3) ALLOWS MAINTENANCE PERSONNEL TO

COMPLY TO THE GE MAINTENANCE

INSTRUCTION SPECIAL REQUIREMENTS

REGREASING (ALL MODELS EXCEPT

UP1, UP2, AUP1 AND AUP2)

GEK–91584D, Vertical Drilling Motor, Type GE752

76

FIG. 48. OUTLINE, UP AND AUP (41E903631 CHG. H). E–28755B.

+

–.005

11.375

DIA.

GREASE VENT TUBE

FITTING ”A”

SEE TABLE 1

GREASE TUBE

FITTING ”B”

SEE TABLE 1 2.00 DIA.

4 BOSSES

.50 NPT THRU

2 HOLES

GREASE TUBE

FITTING ”C”

SEE TABLE 1

.562 DIA. THRU

2 HOLES

1.25 TAPER IN DIA.

PER FOOT IN LENGTH

(BOTH ENDS)

AIR INLET

3.125–8 NS–2A THREADS

(BOTH ENDS)

.50–13 TAP X 1.00 DEEP

6 HOLES

GREASE VENT TUBE

FITTING ”D”

SEE TABLE 1

.656 DIA. DRILL X 2.12 DEEP

.75–10 TAP X 1.50 DEEP

4 HOLES AS SHOWN

13.50

9.50

H H

1.25

REF.

.20

1.50

.390 DIA. DRILL THRU

.578 DIA. DRILL X 1.50 DEEP

1.25 DIA. C’BORE X .20 DEEP

.4375–20 TAP THRU AND .375 NPT

SECTION H–H

ENLARGED

VIEW AT G

TABLE 1

FURNISHED ON MODELS

SHOWN IN TABLE 1 FURNISHED ON MODELS

SHOWN IN TABLE 1

FURNISHED ON MODELS

SHOWN IN TABLE 1

FITTING MODELS MODELS MODELS

UP1, AUP1 UP2, AUP2 (SEE NOTE)

”A” .25 PIPE .NOT NOT

PLUG FURNISHED FURNISHED

”B” .25 MALE .25 PIPE NOT

NPT PLUG FURNISHED

”C” .25 MALE NOT NOT

NPT FURNISHED FURNISHED

”D” .25 PIPE .25 PIPE NOT

PLUG PLUG FURNISHED

NOTE: ALL MODELS EXCEPT UP1, UP2, AUP1 AND AUP2)

Vertical Drilling Motor, Type GE752, GEK–91584D

77

FIG. 48. OUTLINE, UP AND AUP (41E903631 CHG. H). E–28755B.

21.00

TOP INSPECTION

COVER

MINIMUM REQUIRED

TO REMOVE COVER

.812 DIA. X 1.94 DEEP

8 HOLES EQ. SPACED

ON 25.00 DIA. B.C.

.50 NPT

2 HOLES REF.

1.00–8 UNC–2B THREAD X 1.50 DEEP

8 HOLES EQ. SPACED ON 25.00 DIA. B.C.

.562 DIA.

2 HOLES REF.

BOTTOM INSPECTION

COVER

.687 DIA. IN 1325/24 CABLES

EXTENDING 10 FEET FROM

FRAME

1.12

1.00

2.50

.56

AIR INLET FLANGE

A

B

F

8.00

1.12

11.00

8.00 1.12

3.25

8.00

1.12

10.25

1.12

8.00

VIEW AT F

SHOWING FLANGE

WITH COVER REMOVED VIEW AT A

SHOWING FLANGE

WITH COVER REMOVED

VIEW AT B

SHOWING FLANGE

WITH COVER REMOVED

A1

A2

COMMUTATOR END

GEK–91584D, Vertical Drilling Motor, Type GE752

78

FIG. 49. OUTLINE, US1, AUT (41E903745, CHG. A). E–37954B

+

–.25

16.82 15.53

16.656

.000

.010

36.000

.000

.010

.50–13 TAP 1.00 DEEP

(8HOLES)

.25 NPT FOR

REGREASING 2.25 DIA. (3 HOLES)

FOR LIFTING

AIR OUT

(4 CORNERS)

AIR OUT

+

–

+

–

1.72

THIS AREA OF FOOT FLUSH

WITH FRAME FACE.

BOTH SIDES

FI

F2

.375–24 THREAD

VIEW SHOWING HYDRAULIC

PUMP OFF FOR HUB

BOTH ENDS

1.12 8.00 .50

FLAT

10.25

1.12 VIEW AT ”C”

SHOWING FLANGE

WITH COVER

REMOVED

1.12

11.00

.75

FLAT 8.00 1.12

.75

FLAT

VIEW AT ”A”

SHOWING FLANGE

WITH COVER

REMOVED

VIEW AT ”B”

SHOWING FLANGE

WITH COVER

REMOVED

.50–13 TAP THRU

(4 HOLES) 1.12 8.00 .75

FLAT

1.12

8.00

.50–13 TAP THRU

(4 HOLES)

.50–13 TAP THRU

(4 HOLES)

IMPORTANT:

THE ELECTRICAL EQUIPMENT SHOULD

BE LOCATED IN A SPACE WHICH–

(1) PROVIDES SUFFICIENT ACCESSIBILITY

FOR BRUSH INSPECTION.

(2) ALLOWS REMOVAL OF ALL THE

BRUSHES AND PIGTAIL FASTENERS.

(3) ALLOWS MAINTENANCE PERSONNEL

TO COMPLY TO THE GE MAINTENANCE

INSTRUCTION SPECIAL REQUIREMENTS

APPROX. WEIGHT:

GE–752–AUT = 7035 LBS.

AIR FLOW REQUIREMENTS:

2300 CFM OF STANDARD AIR

MINIMUM, 900 HP.

2800 CFM OF STANDARD AIR

MINIMUM, 1000 HP.

GE752AUT AND US1 SHOWN IN

MAIN VIEWS.

Vertical Drilling Motor, Type GE752, GEK–91584D

79

FIG. 49. OUTLINE, US1, AUT (41E903745, CHG. A). E–37954B

58.50

AIR OUT

8.55

1.06

4.63

7.88

6.37

5.69

1.06

+

–

11.375

DIA.

.005

13.44

+

–.078

.059 5.25

4.25

23.12

1.74 10.50

1.38

8.25 6.50

16.500

16.500

22.120

2.38

+

–.12

3.19 1.00 R.

3.62

5.25

.75–10 TAP

THRU

(2 HOLES)

1.005 DIA. THRU

(2 HOLES)

+

–.002

.000

ARMATURE LOCK

ARRANGEMENT

SEE NOTE

1.56 DIA. THRU

(4 HOLES)

1/2 NPT (2 HOLES)

FOR PRESSURE TAPS

.25 NPT

2 INTERCONNECTED

HOLES

”D”

F2

F1

A1

A2

NOTE FOR ARMATURE LOCKING

ARRANGEMENT LOCATED ON

COMMUTATOR END:

TO BE IN PLACE DURING MOUNTING

OF MOTOR BUT TO BE REMOVED

BEFORE OPERATION OF MOTOR.

4.89 0.05

GEK–91584D, Vertical Drilling Motor, Type GE752

80

FIG. 49. OUTLINE, US1, AUT (41E903745, CHG. A). E–37954B

11.375

+

–.005

5.31

.562 DIA.

THRU

(2 HOLES)

9.50

13.50

1.25 TAPER IN DIA.

PER FT. IN LENGTH

(BOTH ENDS)

3.125–8 NS–2A

THREADS

(BOTH ENDS)

AIR INLET

.50–13 TAP 1.00 DEEP

(6 HOLES)

VIEW AT ”D”

AIR INLET FLANGE TOP INSPECTION COVER

2.00

.25 NPT (2 HOLES)

FOR REGREASING

.50 NPT (2 HOLES) REF.

1.00–8 UNC–2B THREAD

1.50 DEEP (8 HOLES EQ.

SP. ON 25.00 DIA. B.C.

.812 DIA. 1.94 DEEP

(8 HOLES EQ. SP. ON

25.00 DIA. B.C.

.562 DIA. (2 HOLES) REF.

COMMUTATOR END

BOTTOM INSPECTION

COVER

1325/24 ARMORED

CABLES EXTENDING

10 FEET FROM

FRAME

A1

A2

”A”

”B”

”C”

0.656 DIA. DRILL X 2.12 DEEP

0.750–10 TAP X 1.50 DEEP

4 HOLES AS SHOWN

DD

.390 DIA. DRILL THRU

.578 DIA. DRILL X 1.50 DEEP

1.25 DIA. C’BORE X .20 DEEP

.4375–20 TAP THRU AND .375 NPT

SECTION D–D

(ENLARGED)

1.25

REF

.20

1.50

Vertical Drilling Motor, Type GE752, GEK–91584D

81

GEK–91584D, Vertical Drilling Motor, Type GE752

82

PRINTED

IN

U.S.A.

E

GE Transportation Systems

2901 East Lake Road

Erie, Pennsylvania 16531

NEW 5–90, WLF

REVISED 10–90, WLF

REVISED 8–92, WLF

REVISED 11–93, WLF

REVISED 02–05, NBS