RIVR1041 HTC Apps Guide Hydraulic Torque Coupler Catalog

User Manual: Hydraulic-Torque-Coupler-Catalog

Open the PDF directly: View PDF .
Page Count: 8

Download
Open PDF In Browser	View PDF

RIVERHAWK HYDRAULIC TORQUE COUPLER
APPLICATIONS GUIDE

Patented

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

Figure 1 Cutaway View of HTC Hub Assembly

Figure 2 Hydraulic torque coupler mounted on high speed gear.

Eliminates keys, splines and tapered shaft ends.
Keys and splines produce stress concentration in
machine shafts. Tapered shaft ends and bores are expensive to produce and require special tooling. The Hydraulic Torque Coupler shown in Figures 1 and 2 allows
designs using straight, cylindrical, slip fit surfaces
eliminating stress concentrations and reducing costs.

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.

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 requirements reducing overall cost and increased design flexibility.

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.

Reduces overhung moment.
In high power density applications it is the total overhung 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.

Dimensional Drawing

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.
Figure 3

2

APPLICATION DATA

Model
HTC020

HTC025

HTC030

HTC040

HTC050

HTC060

HTC075

HTC095

HTC120

HTC150

Shaft
Total
Size d1 Width
(inches) (inches)
1.500
1.750
1.875
2.000
2.125
2.250
2.375
2.500
2.625
2.750
2.875
3.000
3.250
3.500
3.750
4.000
4.250
4.500
4.750
5.000
5.250
5.500
5.750
6.000
6.500
7.000
7.500
8.000
8.500
9.000
9.500
10.000
10.500
11.000
12.000
13.000
14.000
15.000

OD
(inches)

Weight
(pounds)

1.640

4.250

3.5

2.070

5.313

7.1

2.430

6.375

12.1

3.200

8.500

28.9

4.000

10.625

56.7

4.800

12.750

96.8

6.000

15.938

189.1

7.500

20.188

383.2

9.500

25.500

774.7

11.800

31.875

1513.2

Static (1)
Hub Slip
Torque, Ts
(in.-lb.) (2)
15,100
23,000
27,700
32,900
41,900
48,900
56,600
64,900
78,000
88,500
99,700
111,700
151,400
185,400
223,400
265,500
334,900
391,300
452,700
519,300
624,100
707,900
797,600
893,500
1,187,800
1,451,200
1,745,100
2,230,100
2,629,400
3,066,800
3,542,700
4,371,600
4,993,200
5,662,800
7,148,000
9,502,000
11,609,900
13,960,900

Motor
Speed
(RPM)
3,600
3,600
3,600
3,600
3,600
3,600
3,600
3,600
3,600
3,600
3,600
3,600
3,600
3,600
3,600
3,600
1,800
1,800
1,800
1,800
1,800
1,800
1,800
1,800
1,800
1,800
1,800
1,800
1,800
1,800
1,800
1,200
1,200
1,200
1,200
1,200
1,200
1,200

Motor
Speed
Hub Slip
Torque, Tss
(in.-lb.)
15,000
22,800
27,500
32,700
41,400
48,400
56,100
64,300
76,800
87,200
98,300
110,000
147,000
180,000
218,000
259,000
331,200
387,300
448,300
514,600
614,600
697,700
786,700
881,900
1,159,000
1,419,000
1,710,000
2,142,000
2,532,000
2,961,000
3,428,000
4,247,000
4,859,000
5,518,000
6,982,000
9,097,000
11,160,000
13,460,000

Torque/
Speed
Reduction
Factor (3), Fs
(in.-lb./krpm2)
9.2
11.8
13.2
14.5
35.5
38.9
42.2
45.5
91.3
98.2
105
110
340
380
430
470
1,135
1,243
1,350
1,456
2,922
3,143
3,360
3,580
8,780
9,860
10,920
27,250
30,030
32,800
35,500
86,400
93,500
100,600
114,500
281,100
315,600
349,400

Limit
Speed
(RPM)
23,900

20,700

19,500

15,500

13,800

10,800

8,800

7,200

5,500

4,700

NOTES:

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

Contact Riverhawk Engineering for assistance in evaluating special
conditions and requirements.

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

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.

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.

3

Speed Factor

Speed Factor For Low Speeds
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
600

900

1200

1500

1800

2100

2400

2700

3000

3300

3600

RPM
Figure 4

Speed Factor For High Speeds
700
600

Speed Factor

500
400
300
200
100
0
0

5000

10000

15000

RPM
Figure 5

4

20000

25000

SELECTION PROCEDURE
1. Establish the loading requirements for your application. 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.

4. Compare the calculated Te with Ts from the application 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.

Application Torque
HP is the application horse power.
RPM is the application speed.

Equivalent 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.

At Speed Slip Torque
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 application data chart (in-lb)

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 combinations 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 possible 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 application 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 accommodate 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.

6

Other areas, such as that below the flange, will still have
a clearance. Machinery misalignment can cause a microscopic 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, especially 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 engineering 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 virtually eliminates these stress concentrations allowing for
more efficient machinery designs.
The hub and shaft material must be capable of accommodating the clamping, torque, and bending loads produced
by the application. For the joint to be capable of transmitting 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. Riverhawk Hydraulic Torque Couplers are designed and manufactured 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.

SUGGESTED FIT DIMENSIONS
Shaft Suggested Suggested
Net
Size d1
Shaft
Bore Size Maximum
Tolerance Tolerance Clearance
1.5000
1.750
1.875
2.000
2.125
2.250
2.375
2.500
2.625
2.750
2.875
3.000
3.250
3.500
3.750
4.000
4.250
4.500
4.750
5.000
5.250
5.500
5.750
6.000
6.500
7.000
7.500
8.000
8.500
9.000
9.500
10.000
10.500
11.000
12.000
13.000
14.000
15.000

+.001
+.000

+.000
-.0010
+.0015
+.000

+.000
-.0015
+.0025
+.000

0.002
0.002
0.002
0.002
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.003
0.003
0.003
0.003
0.003
0.003
0.003
0.004
0.004
0.004
0.004
0.004
0.004

Figure 6

Model

Hub OD d2

HTC020

2.440
2.440
2.440
2.440
3.050
3.050
3.050
3.050
3.660
3.660
3.660
3.660
4.880
4.880
4.880
4.880
6.100
6.100
6.100
6.100
7.320
7.320
7.320
7.320
9.150
9.150
9.150
11.590
11.590
11.590
11.590
14.640
14.640
14.640
14.640
18.300
18.300
18.300

HTC025

HTC030

HTC040

HTC050

HTC060

HTC075

HTC095

HTC120

HTC150

Hub OD Machined Maximum
Tolerance Hub OD
Fillet R
Width W

+.000
-0.001

1.650

0.062

2.070

0.094

2.430

0.094

3.200

0.156

4.000

0.156

4.800

0.188

6.000

0.250

7.500

0.313

9.500

0.375

11.800

0.500

+.000
-0.0015

+.000
-0.002

+.000
-0.0025
+.000
-0.003

Figure 7

7

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.

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 sequence.
6. Once closed, the parts will be free to be disassembled.
NOTE: Please refer to the formal installation and removal
manual for additional instructions.

Installation Accessories
Riverhawk provides pressure kits complete with flexible
hoses as shown in Figure 8.

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.

Figure 8 -Hydraulic Hand Pump

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

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.

8

215 Clinton Road
New Hartford, NY 13413
Phone: 315-768-4855
Fax: 315-768-4941
E-mail: sales@riverhawk.com
Release date - 08/01 (1041)



---

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.2
Linearized                      : Yes
Create Date                     : 2001:10:04 13:41:46-04:00
Modify Date                     : 2002:11:26 08:55:59-08:00
Subject                         : RIVR1041 HTC Apps Guide
Page Count                      : 8
Creation Date                   : 2001:10:04 17:41:46Z
Mod Date                        : 2001:10:04 17:41:46Z
Producer                        : Acrobat Distiller 5.0.2 for Macintosh
Author                          : E-Boy
Keywords                        : 
Metadata Date                   : 2001:10:04 17:41:46Z
Creator                         : E-Boy
Title                           : RIVR1041 HTC Apps Guide
Description                     : RIVR1041 HTC Apps Guide

EXIF Metadata provided by EXIF.tools