RIVR1041 HTC Apps Guide Hydraulic Torque Coupler Catalog

User Manual: Hydraulic-Torque-Coupler-Catalog

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RIVERHAWK HYDRAULIC TORQUE COUPLER

APPLICATIONS GUIDE

Features and Benefits

• Eliminates keys, splines, and tapered shaft ends

• Allows for use of smaller diameter shafts

• Reduces overhung moment

• Custom designs to fit your envelope and shaft ends

Patented

Eliminates keys, splines and tapered shaft ends.

Keys and splines produce stress concentration in

machine shafts. Tapered shaft ends and bores are expen-

sive to produce and require special tooling. The Hydrau-

lic Torque Coupler shown in Figures 1 and 2 allows

designs using straight, cylindrical, slip fit surfaces

eliminating stress concentrations and reducing costs.

Allows for the use of smaller diameter shafts.

High squeeze capacity of Riverhawk Hydraulic Torque

Couplers translates into smaller shafting requirements.

Smaller shafts translate into smaller bearing require-

ments reducing overall cost and increased design flex-

ibility.

Reduces overhung moment.

In high power density applications it is the total over-

hung moment that impacts rotordynamics. The Hydraulic

Torque Coupler allows for designs with smaller shafts and

shorter interfaces. These factors translate into reduced

overall overhung moment.

Custom designs fit your envelope and shaft

In addition to a standard line, Riverhawk will modify a

standard product or engineer a custom solution for your

particular application.

Slip-Fit Components For Keyless Connections

The Hydraulic Torque Coupler provides high integrity

keyless fit joints using convenient, low cost slip-fit

designs. Our design eliminates heat at assembly as well

as keys, splines, tapered shafts, plug/ring gages, and

hydraulic maintenance equipment. Shaft ends are

simplified therefore reducing design, manufacturing, and

maintenance costs. In addition, maximum axial and

phase adjustment simplifies timing issues.

Hydraulically Applied Clamp Pressure For High

Torque Capacity

Select the Riverhawk Hydraulic Torque Coupler to meet

the high power density requirements of today’s high

performance equipment. Hydraulic coupling provides

ultra-secure clamping of shaft elements with reduced

shaft diameter.

Design, Existing Shaft Ends

Select the Riverhawk Hydraulic Torque Coupler to meet

the high power density requirements of today’s high

performance equipment. Hydraulic coupling provides

ultra-secure clamping of shaft elements with reduced

shaft diameter.

Figure 2 -

Hydraulic torque coupler mounted on high speed gear.

2

Figure 1 -

Cutaway View of HTC Hub Assembly

Dimensional Drawing

Figure 3

APPLICATION DATA

NOTES:

Contact Riverhawk Engineering for assistance in evaluating special

conditions and requirements.

1. Static slip torque values reflect hub and shaft machined with a

slip fit per AGMA 9002 class I fit for sizes up to 6.5 in. See

dimensional chart and Figures 6 and 7 for design clearances.

2. The application torque must always be less than the slip torque

at speed. Slip torque calculations are based on “steel on steel”

fits with a coefficient of friction of 0.15. The actual slip torque

may vary depending on hub & shaft materials and surface

condition.

Motor Torque/

Static

(1)

Speed Speed

Shaft Total Hub Slip Motor Hub Slip Reduction Limit

Size d1 Width OD Weight Torque, Ts Speed Torque, Tss Factor

(3)

, Fs Speed

Model (inches) (inches) (inches) (pounds) (in.-lb.)

(2)

(RPM) (in.-lb.) (in.-lb./krpm

2

)(RPM)

HTC020 1.500 1.640 4.250 3.5 15,100 3,600 15,000 9.2 23,900

1.750 23,000 3,600 22,800 11.8

1.875 27,700 3,600 27,500 13.2

2.000 32,900 3,600 32,700 14.5

HTC025 2.125 2.070 5.313 7.1 41,900 3,600 41,400 35.5 20,700

2.250 48,900 3,600 48,400 38.9

2.375 56,600 3,600 56,100 42.2

2.500 64,900 3,600 64,300 45.5

HTC030 2.625 2.430 6.375 12.1 78,000 3,600 76,800 91.3 19,500

2.750 88,500 3,600 87,200 98.2

2.875 99,700 3,600 98,300 105

3.000 111,700 3,600 110,000 110

HTC040 3.250 3.200 8.500 28.9 151,400 3,600 147,000 340 15,500

3.500 185,400 3,600 180,000 380

3.750 223,400 3,600 218,000 430

4.000 265,500 3,600 259,000 470

HTC050 4.250 4.000 10.625 56.7 334,900 1,800 331,200 1,135 13,800

4.500 391,300 1,800 387,300 1,243

4.750 452,700 1,800 448,300 1,350

5.000 519,300 1,800 514,600 1,456

HTC060 5.250 4.800 12.750 96.8 624,100 1,800 614,600 2,922 10,800

5.500 707,900 1,800 697,700 3,143

5.750 797,600 1,800 786,700 3,360

6.000 893,500 1,800 881,900 3,580

HTC075 6.500 6.000 15.938 189.1 1,187,800 1,800 1,159,000 8,780 8,800

7.000 1,451,200 1,800 1,419,000 9,860

7.500 1,745,100 1,800 1,710,000 10,920

HTC095 8.000 7.500 20.188 383.2 2,230,100 1,800 2,142,000 27,250 7,200

8.500 2,629,400 1,800 2,532,000 30,030

9.000 3,066,800 1,800 2,961,000 32,800

9.500 3,542,700 1,800 3,428,000 35,500

HTC120 10.000 9.500 25.500 774.7 4,371,600 1,200 4,247,000 86,400 5,500

10.500 4,993,200 1,200 4,859,000 93,500

11.000 5,662,800 1,200 5,518,000 100,600

12.000 7,148,000 1,200 6,982,000 114,500

HTC150 13.000 11.800 31.875 1513.2 9,502,000 1,200 9,097,000 281,100 4,700

14.000 11,609,900 1,200 11,160,000 315,600

15.000 13,960,900 1,200 13,460,000 349,400

3

3. There are three ways to calculate slip torque at speed (Tss):

A. For motor speeds you can read Tss directly off the above table.

B. To estimate slip torque at any speed read Ts & Fs from the

Application Data table and “Speedfactor” from the graph

Figures 4 and 5. Calculate using the formula:

C. For precise slip torque calculation apply the formula:

At Riverhawk we always strive to improve the products we produce. For that reason the dimensions and specifications contained in this

catalog are subject to change without notice. Certified dimensions of ordered material can be furnished upon request.

Speed Factor For Low Speeds

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

600 900 1200 1500 1800 2100 2400 2700 3000 3300 3600

RPM

Speed Factor

Speed Factor For High Speeds

0

100

200

300

400

500

600

700

0 5000 10000 15000 20000 25000

RPM

Speed Factor

4

Figure 5

Figure 4

1. Establish the loading requirements for your applica-

tion. Loading includes the application torque (Ta) and

axial force (Fa).

2. Establish service factors to account for uncertainties of

the application.

3. Calculate the total equivalent application torque (Te)

using the loading requirements and service factors you

have established.

SELECTION PROCEDURE

HP is the application horse power.

RPM is the application speed.

Application Torque

Equivalent Torque

At Speed Slip Torque

Ta is the application torque. (in-lb)

Kt is the service factor on torque

Fa is the application axial force. (lbf)

Kf is the service factor on axial force.

d1 is the shaft diameter.

Tss is the joint slip torque at speed (in-lb)

Ts is the static slip torque from the application data

chart (in-lb)

Fs is the torque/speed reduction factor from the applica-

tion data chart (in-lb)

4. Compare the calculated Te with Ts from the applica-

tion data chart to obtain the candidate selection.

5. For final size selection you will need to adjust the Ts

value of the candidate selection using the rotational

speed of your application. To do this, calculate the at

speed slip torque (Tss) using the formula below.

Important Note: Service Factor

The application torque Ta and application axial force Fa should be

the greatest values which the system is expected to transmit.

Establishing these may require evaluating several loading combi-

nations as dictated by the application.

The slip torque values supplied in the application chart are

limiting values. Exceeding these values will result in slip. The

application loading must always be below the slip capacity of the

joint. The selecting engineer is advised to apply a service factor to

the application loads to account for factors such as, start-up

conditions, peak loading conditions and service uncertainty.

5

Example Application

A fan is to be mounted on 5” shaft. It is to be powered

by an 9,000 HP, 3,560 RPM induction motor. The motor

can produce a peak torque of 2.5 times its rated torque

during start up. The fan can produce an axial force of

15,000 lbf. A factor of 1.25 will be added to both the

start up torque and the axial force to account for pos-

sible surges and vibration caused by wind gusts at the

intake.

Applying this data to the formulas above:

• The normal torque for the application is:

159,333 (in-lb)

• The start up torque is:

398,332 (in-lb)

• From these, Te becomes:

500,117 (in-lb)

• Comparing Te to the rating chart yields HTC050 as a

preliminary selection.

• Applying the operating speed to the static rating in

the table. The “at speed” slip torque Tss of HTC050

becomes:

500,847 (in-lb)

• Tss>Te, the HTC050 shrink disc meets the applica-

tion requirements as defined.

Design, Dimensions, and Fits

The Hydraulic Torque Coupler (HTC) design allows hub/

shaft fits to be designed with cylindrical slip fits. The

Suggested Fit Dimensions table provides suggested hub

bore and shaft outside dimensions (OD.) These fits were

derived from AGMA 9002 class 1. Larger sizes were

extrapolated. The HTC can accommodate hub/shaft fits

other than those supplied here such as cylindrical

interference fits and taper fits. In general, tighter fits

are preferable. Contact Riverhawk engineering for

assistance in evaluation of fits that are not listed here.

Surface finishes on hub and shaft diameters of 64

microinches or better are recommended. In general,

smoother surfaces are preferable. Rough surface finishes

tend to mask profile variations and other detrimental

defects.

A fillet as shown in Figures 6 and 7 between the hub OD

and the flange is recommended. The HTC can accommo-

date a fillet up to the values listed in the dimensional

chart.

When the HTC is activated, the material directly under it

is squeezed into a heavy interference with the shaft.

Other areas, such as that below the flange, will still have

a clearance. Machinery misalignment can cause a micro-

scopic rocking motion between the flange and the shaft.

A slight clearance under the flange such as shown in

Figures 6 and 7 will prevent the possibility of fretting in

this area.

A redundant mechanical stop, such as a shaft step or

shaft nut, should be considered in cases where the

equipment must accommodate large thrust loads, espe-

cially where axial slip would affect safe or reliable

operation.

Figures 6 and 7 show options where the HTC is mounted

with hardware and hydraulic access areas located away

from the flange. Access holes can be drilled in the flange

in cases that require the HTC to be mounted with the

hardware against the flange. Contact Riverhawk engi-

neering for recommendations for access solutions.

Design, Hub & Shaft Stress

Keyways, splines, and pins produce stress concentrations

in shafts. Stress concentrations greatly reduce a shaft’s

ability to endure varying loads such as bending and

varying torques. This fact forces the machinery designer

to design larger, heavier shafts than would otherwise be

needed. The Riverhawk Hydraulic Torque Coupler virtu-

ally eliminates these stress concentrations allowing for

more efficient machinery designs.

The hub and shaft material must be capable of accommo-

dating the clamping, torque, and bending loads produced

by the application. For the joint to be capable of trans-

mitting the full rated slip torque, the hub and shaft

material should have a yield strength of at least 45,000

psi, which represents 1040 steel as commonly used in

shafting. The Hydraulic Torque Coupler can be used for

applications with weaker materials by reducing the

clamping load. Contact Riverhawk engineering for

assistance with evaluating shaft and hub stresses.

Design, Balance

Balance level is an issue for high speed applications

utilizing machinery that is sensitive to vibration. River-

hawk Hydraulic Torque Couplers are designed and manu-

factured to tight tolerances in order to produce “as built”

balance level better than required by AGMA 9000 class 8.

Tighter balance requirements can be met with addition of

an assembly balance. Balanced and match-marked

assemblies can achieve balance repeatability levels per

AGMA 9000 class 10 and API 671.

6

SUGGESTED FIT DIMENSIONS

7

Figure 6 Figure 7

Shaft Suggested Suggested Net Model Hub OD d2 Hub OD Machined Maximum

Size d1 Shaft Bore Size Maximum Tolerance Hub OD Fillet R

Tolerance Tolerance Clearance Width W

1.5000 0.002 HTC020 2.440

1.750 +.001 0.002 2.440 1.650 0.062

1.875 +.000 0.002 2.440

2.000 0.002 2.440

2.125 0.0025 HTC025 3.050

2.250 0.0025 3.050 2.070 0.094

2.375 0.0025 3.050

2.500 0.0025 3.050

2.625 0.0025 HTC030 3.660 +.000

2.750 0.0025 3.660 -0.001 2.430 0.094

2.875 0.0025 3.660

3.000 0.0025 3.660

3.250 0.0025 HTC040 4.880

3.500 0.0025 4.880 3.200 0.156

3.750 +.000 0.0025 4.880

4.000 -.0010 0.0025 4.880

4.250 0.0025 HTC050 6.100

4.500 +.0015 0.0025 6.100 4.000 0.156

4.750 +.000 0.0025 6.100

5.000 0.0025 6.100

5.250 0.0025 HTC060 7.320

5.500 0.0025 7.320 4.800 0.188

5.750 0.0025 7.320 +.000

6.000 0.0025 7.320 -0.0015

6.500 0.0025 HTC075 9.150

7.000 0.003 9.150 6.000 0.250

7.500 0.003 9.150

8.000 0.003 HTC095 11.590 +.000

8.500 0.003 11.590 -0.002 7.500 0.313

9.000 0.003 11.590

9.500 0.003 11.590

10.000 +.000 0.003 HTC120 14.640

10.500 -.0015 0.004 14.640 +.000 9.500 0.375

11.000 +.0025 0.004 14.640 -0.0025

12.000 +.000 0.004 14.640

13.000 0.004 HTC150 18.300 +.000

14.000 0.004 18.300 -0.003 11.800 0.500

15.000 0.004 18.300

Installation Overview

1. Inspect hub and shaft to insure that they have been

machined to proper tolerances.

2. Clean the hub bore, hub OD and shaft OD. Make sure

that they are free of any debris or coatings. Clean

surfaces are essential for torque transmission.

3. Slide the HTC on to the hub. Take care to insure that

the screws and hydraulic ports are accessible.

4. Slide hub/HTC assembly on to the shaft and set axial

position. Rotate the HTC so that the ports are at the

12:00 and 6:00 positions.

5. Remove retraction screws but leave the retention

screws (socket set screws).

6. Attach hydraulic pressure source to the fitting located

at 6:00 and remove the plug at 12:00.

7. Bleed air out of hydraulics.

8. Apply 200 psi hydraulic pressure to HTC. This step

takes up assembly clearances. At this point the HTC and

hub should be lightly gripping the shaft.

9. Measure and record the gap at clamp outside diameter.

This becomes the initial gap. See Figure 3.

10. Refer to installation instructions for recommended

expansion.

11. Add the initial measured gap from step nine to the

recommended expansion gap from step ten to arrive at a

total gap necessary for proper installation.

12. In steps, apply hydraulic pressure and measure gap.

Stop pumping when the actual gap meets the number

calculated in step eleven. Stop pumping if either the pins

become flush with the torque coupler face OR you exceed

7,500 psi hydraulic pressure.

13. While holding hydraulic pressure, turn retaining

screws in until lightly seated and then release pressure.

14. Allow oil to drain and plug both hydraulic ports.

NOTE: Please refer to the formal installation and removal

manual for additional instructions.

Removal

1. Attach hydraulic pressure source to fitting.

2. Bleed air out of hydraulics. Plug upper port after

bleeding.

3. Slowly add hydraulic pressure, simultaneously apply

removal torque to the retaining screws.

4. Increase hydraulic pressure until retaining screws can

be turned. Screws should be free to rotate at a pressure

between 4,500 psi and 7,500 psi. Once the retaining

screws are free, stop increasing pressure and back off all

screws.

5. Release hydraulic pressure and clamp should retract

by itself. If it does not, retracting screws can be inserted

and turned to retract unit.

NOTE: Care should be taken to tighten jacking screws in

several stages by using approximate one-half turns

following either a clockwise or counterclockwise se-

quence.

6. Once closed, the parts will be free to be disassembled.

NOTE: Please refer to the formal installation and removal

manual for additional instructions.

Disclaimer

The information contained within this document is based upon certain

assumptions about equipment design and operation as foreseen at the

time of publication. The equipment designer is assumed to be familiar

with the equipment and its operation. For this reason the equipment

designer must assume responsibility for the proper application of the

Riverhawk HTC to the subject equipment.

We invite you to visit our web site at www.riverhawk.com

215 Clinton Road

New Hartford, NY 13413

Phone: 315-768-4855

Fax: 315-768-4941

E-mail: sales@riverhawk.com

Installation Accessories

Riverhawk provides pressure kits complete with flexible

hoses as shown in Figure 8.

Figure 8 -Hydraulic Hand Pump

8Release date - 08/01 (1041)