Schaeffler RT Series Guide

Precision strain wave gears
Series RT
Mounting manual

Schaeffler Technologies MON 106 1
Page
Contents
Precision strain wave gears About the mounting manual
Availability........................................................................... 2
Legal guidelines................................................................... 2
Symbols............................................................................... 2
Images................................................................................. 2
General safety guidelines
Usage for the intended purpose............................................ 3
Usage not for the intended purpose ...................................... 3
Selection and qualification of personnel............................... 4
Personal protective equipment ............................................. 4
Safety regulations ................................................................ 4
Scope of delivery
Damage during transit .......................................................... 5
Defects ................................................................................ 5
Strain wave gear RT..-H-..-BHS Preparation for mounting
Cleanliness .......................................................................... 6
Overview.............................................................................. 6
Mounting surfaces ............................................................... 7
Mounting.................................................................................. 8
Running-in process ................................................................... 12
Strain wave gear RT..-H-..-BMS Preparation for mounting
Cleanliness .......................................................................... 14
Overview.............................................................................. 14
Mounting surfaces ............................................................... 15
Mounting.................................................................................. 16
Running-in process ................................................................... 20
Strain wave gear RT..-H-..-UHS Preparation for mounting
Cleanliness .......................................................................... 22
Overview.............................................................................. 22
Mounting surfaces ............................................................... 23
Mounting.................................................................................. 23
Decommissioning and
disposal
................................................................................................ 25

2 MON 106 Schaeffler Technologies
Precision strain wave gears
About the mounting manual This mounting manual serves as an aid in mounting strain wave
gears safely and correctly.
The manual contains important information on:
■ avoiding personal injury or damage to property
■ mounting the strain wave gear correctly to ensure functionality
The original language of the manual is German.
All other languages are translations from the German language.
Availability A current electronic version (PDF) of this manual can be found at
https://www.schaeffler.de/std/1F3F
Legal guidelines The information in this manual reflects the status as of July 2022.
Unauthorised modifications to or improper use of the product are
not permitted. Schaeffler does not assume any liability in this
respect.
The information and instructions contained in this document, in the
catalogue and in the customer delivery drawing must be observed.
Special and customer-specific designs may differ in technical
detail from the designs covered in this publication. It is strongly
recommended that you contact Schaeffler, quoting the type
designation and serial number, if any clarification is required.
Symbols The warning and hazard symbols are defined in accordance with
ANSI Z535.6-2011.
NOTICE
In case of non-compliance, damage or malfunctions in the product
or the adjacent construction may occur.

Images The images in this manual are examples and may differ from
the delivered product.
Further information For any questions relating to mounting, please consult your local
contact at Schaeffler.

Schaeffler Technologies MON 106 3
General safety guidelines
Usage for the intended
purpose
Strain wave gears of series RT are intended for industrial or
commercial applications.
Typical application areas include:
■ robots and handling
■ medical equipment
■ industrial machinery
■ machine tools
The strain wave gears may only be operated within the operating
ranges and environmental conditions specified in the documen-
tation.
Fundamental health and safety requirements were taken into
account during the development, design and production stages.
Under the terms of the EC Machinery Directive, strain wave gears of
series RT are classified as machine components, not incomplete
machines. Machine components do not fall within the scope of the
EC Machinery Directive.
Before commissioning equipment and machinery fitted with strain
wave gears of series RT, the conformity of the equipment or machine
with the EC Machinery Directive must be ensured.
Usage not for the intended
purpose
Use of the strain wave gears outside of the aforementioned
application areas or under operating ranges and environmental
conditions which deviate from those described in the documen-
tation is considered incorrect usage.
Use of the strain wave gears in the following application areas is
considered incorrect use:
■ aviation and aerospace
■ areas with an explosion risk
■ machinery specifically designed or used for nuclear applications,
the failure of which may result in the emission of radioactivity
■ vacuum
■ devices for domestic use
■ medical equipment that comes into direct contact with the
human body
■ machinery or equipment used to transport and lift people
■ special equipment for use in fairgrounds and amusement parks

4 MON 106 Schaeffler Technologies
Precision strain wave gears
Selection and qualification
of personnel
Strain wave gears may only be fitted by qualified personnel.
Qualified personnel:
■ are authorised
■ have all the necessary knowledge
■ are familiar with the safety regulations
Personal protective equipment Personal protective equipment protects against health hazards.
For your own safety, always use safety shoes and clean safety
gloves.
Depending on the mounting location and on the machine or equip-
ment, it may be necessary to use additional personal protective
equipment. Further information on this subject can be obtained from
your contact at Schaeffler.
Observe the applicable regulations relating to occupational safety
at the mounting location.
Safety specifications In order to prevent the occurrence of personal injury or damage
to property, observe the following safety specifications.
Fundamental specifications Keep the work area free of trip hazards.
Always carry out all mounting and maintenance work when the
machine or equipment is at a standstill. Do not reach into the work-
ing area of the gear unit while the shafts are still rotating.
Secure the machine or equipment against unintentional start-up
before carrying out mounting or maintenance work.
Observe the safety datasheet for the lubricant. Please address any
questions to your contact at Schaeffler.
Transport, storage, mounting Do not open the strain wave gear packaging until immediately before
mounting.
Cleaning Use volatile cleaning solvents, which allow residue-free cleaning,
to clean the surfaces of the gear unit. The solvents must be
compatible with the gear unit surfaces and with the corrosion
protection used, in order to avoid damage to the gear unit
surfaces.
Disposal Dispose of any cloths soaked with grease or solvents, as well as
excess grease, packaging material and any other waste generated in
connection with mounting, by environmentally acceptable methods.
Observe the applicable legal regulations at the mounting location.

Schaeffler Technologies MON 106 5
Environmental hazards Pay attention to any safety risks that are not associated directly
with the strain wave gear, but are posed by the ambient conditions
at the mounting location. These may include dusts that are
hazardous to health or working at a considerable height.
Furthermore, the machine or equipment may also be a source
of hazards, for example, as a result of moving machine or equipment
parts.
Consult with a local safety engineer before starting mounting work
and observe all safety specifications that are applicable to the
mounting location, the machine or the equipment.
Scope of delivery Please refer to the customer delivery drawing.
The scope of delivery comprises:
■ strain wave gear
■ accessories
–O-rings
– lubricant (for RT..-H-..-BHS and RT..-H-..-BMS)
Damage during transit  Check the delivery immediately upon arrival for any damage
during transit.
 Report any damage during transit promptly as a complaint
to the carrier.
Defects  Check the strain wave gear immediately upon delivery for
externally visible defects.
 Report any defects promptly as a complaint to the distributor
of the strain wave gear.

6 MON 106 Schaeffler Technologies
Strain wave gear RT..-H-..-BHS
Preparation for mounting
Cleanliness
NOTICE
No foreign bodies or mounting aids must be allowed to enter
the gear unit during mounting.
Contaminants and residues from cleaning agents can shorten
the operating life of the strain wave gear.
Only use volatile solvents and lint-free cloths for cleaning.

Measures for ensuring cleanliness are as follows:
 Keep the mounting location, tools and clothing clean and free
from magnetic or magnetisable particles.
 Clean the mounting surfaces on the gear parts.
 Do not remove the strain wave gear from its packaging until
immediately before mounting.
Overview An overview of the components used in the strain wave gear can
be found in the following illustration.
O1, O2 = O-rings
 Flexspline
 Double row angular contact
needle roller bearing
XZU-RTH
 Circular spline
 Wave generator bearing
 Input shaft
 Wave generator
 Retaining screws
Figure 1
Components of RT..-H-..-BHS
3
2
5
4
1
7
6
O2O1
0019F0220019F022

Schaeffler Technologies MON 106 7
Mounting surfaces Observe the following instructions in relation to the mounting
surfaces.
NOTICE
Damage due to anti-corrosion oil.
The gear unit is supplied with anti-corrosion oil.
Remove the anti-corrosion oil prior to mounting.

NOTICE
Damage due to incompatible components.
The main components of the gear unit (flexspline, circular spline,
input shaft and wave generator bearing) are matched to each other.
Do not substitute the components for components from other gear
units.

 Motor shaft
 Adjacent construction
(on the circular spline side)
 Adjacent construction
(on the flexspline side)
Figure 2
Strain wave gear RT..-H-..-BHS
with adjacent construction
1112
10
0019F0240019F024

8 MON 106 Schaeffler Technologies
Strain wave gear RT..-H-..-BHS
Mounting Wear clean gloves when working on the gear unit to prevent
corrosion.
Do not remove the strain wave gear from its packaging until immedi-
ately before mounting.
The gear teeth, wave generator bearing and double row angular
contact needle roller bearing XZU-RTH are supplied ready lubricated.
NOTICE
Damage to property due to removal of individual parts.
Do not remove any screws from the circular spline.

Lubricate the flexspline and
adjacent construction
 Lubricate the interior of the flexspline  using the lubricant
provided.
For the amount of lubricant required, please refer to the customer
delivery drawing.
 Distribute the lubricant evenly.
 Apply the lubricant provided to surface A of the adjacent
construction
 .
For the amount of lubricant required, please refer to the customer
delivery drawing.
Figure 3
Lubricate the flexspline
1
0019F0260019F026
Figure 4
Lubricate the adjacent construction
A
11
0019F0280019F028

Schaeffler Technologies MON 106 9
Fit the wave generator  Fit the wave generator  in the flexspline  in the direction
of the arrow.
To facilitate fitting, turn and slide the input shaft
 at the same
time.
Check the position Correct positioning of the wave generator bearing  is crucial
to the functionality and durability of the strain wave gear.
 Measure the position of the wave generator bearing 
(dimension a) and compare this with the target distance a
(see customer delivery drawing).
Figure 5
Fit the wave generator
in the flexspline
5 1
5
1
6
6
0019F0290019F029
Figure 6
Check the position
of the wave generator bearing
a
1
4
0019F02A0019F02A

10 MON 106 Schaeffler Technologies
Strain wave gear RT..-H-..-BHS
Check alignment If the circular spline  is not fitted concentrically to the
flexspline
 , the service life and gear accuracy will be reduced.
Torque fluctuations can also be attributed to incorrect fitting.
 Ensure that the circular spline  is fitted concentrically.
The strain wave gear should turn very easily when the circular
spline  is correctly aligned.
 If the circular spline  is not correctly aligned, repeat the
mounting process for the wave generator
 , see page 9.
Remove the retaining screws  If necessary, remove the retaining screws  from the
flexspline
 .
Figure 7
Check alignment
of the circular spline
3
1
3
1
0019F02C0019F02C
Figure 8
Remove the retaining screws
from the flexspline
1
7
0019F02E0019F02E

Schaeffler Technologies MON 106 11
Mount the input shaft
on the motor shaft
 Slide the motor shaft  into the input shaft  .
 Tighten the screws in the motor shaft  and ensure that the
required preload force is achieved. For information on the
required preload force, please refer to the customer delivery
drawing.
Size 14 to 17 radial
Size 20 to 32 axial
Mount the flexspline
on the adjacent construction
 Insert the appropriate O-ring into the groove in the adjacent
construction
 .
 Mount the flexspline  on the adjacent construction  .
 Tighten the screws in a crosswise sequence and ensure that
the required preload force is achieved. For information on
the required preload force, please refer to the customer delivery
drawing.
Figure 9
Connect the input shaft
to the motor shaft
10 10
5
0019F05A0019F05A
Figure 10
Mount O-ring O1 and the flexspline
on the adjacent construction
O1
12 12
1
0019F05B0019F05B

12 MON 106 Schaeffler Technologies
Strain wave gear RT..-H-..-BHS
Mount the circular spline
on the adjacent construction
 Insert the appropriate O-ring into the groove in the adjacent
construction
 .
 Mount the circular spline  on the adjacent construction  .
 Tighten the screws in a crosswise sequence and ensure that
the required preload force is achieved. For information on
the required preload force, please refer to the customer delivery
drawing.
 The strain wave gear is mounted.
 Carry out a running-in process before fully loading the strain wave
gear for the first time, see section
Running-in process .
Running-in process In order to achieve the best possible performance from the strain
wave gear, a running-in process is required before the gear is fully
loaded:
 Operate the strain wave gear under zero load in a clockwise and
anti-clockwise direction with a large rotation angle on the output
side.
Input speed: 1 000 min
–1
to 2 000 min
–1
Duration: approx. 20 min
 Clean the strain wave gear and relubricate the relevant points,
Figure 3 and Figure 4 , page 8.
Observe the stipulated lubricant quantities (see customer
delivery drawing).
 The strain wave gear is now ready for operation.
Figure 11
Mount O-ring O2 and the circular
spline on the adjacent construction
O2
11 11
3
0019F05C0019F05C

Schaeffler Technologies MON 106 13

14 MON 106 Schaeffler Technologies
Strain wave gear RT..-H-..-BMS
Preparation for mounting
Cleanliness
NOTICE
No foreign bodies or mounting aids must be allowed to enter
the gear unit during mounting.
Contaminants and residues from cleaning agents can shorten
the operating life of the strain wave gear.
Only use volatile solvents and lint-free cloths for cleaning.

Measures for ensuring cleanliness are as follows:
 Keep the mounting location, tools and clothing clean and free
from magnetic or magnetisable particles.
 Clean the mounting surfaces on the gear parts.
 Do not remove the strain wave gear from its packaging until
immediately before mounting.
Overview An overview of the components used in the strain wave gear can
be found in the following illustration.
O1, O2 = O-rings
 Flexspline
 Double row angular contact
needle roller bearing
XZU-RTH
 Circular spline
 Wave generator bearing
 Input shaft
 Wave generator
 Retaining screws
 Clamping element
Figure 1
Components of RT..-H-..-BMS
3
2
5
8
4
1
7
6
O2O1
0019F05E0019F05E

Schaeffler Technologies MON 106 15
Mounting surfaces Observe the following instructions in relation to the mounting
surfaces.
NOTICE
Damage due to anti-corrosion oil.
The gear unit is supplied with anti-corrosion oil.
Remove the anti-corrosion oil prior to mounting.

NOTICE
Damage due to incompatible components.
The main components of the gear unit (flexspline, circular spline,
input shaft and wave generator bearing) are matched to each other.
Do not substitute the components for components from other gear
units.

 Motor shaft
 Adjacent construction
(on the circular spline side)
 Adjacent construction
(on the flexspline side)
Figure 2
Strain wave gear RT..-H-..-BMS
with adjacent construction
11
10
12
0019F0600019F060

16 MON 106 Schaeffler Technologies
Strain wave gear RT..-H-..-BMS
Mounting Wear clean gloves when working on the gear unit to prevent
corrosion.
Do not remove the strain wave gear from its packaging until immedi-
ately before mounting.
The gear teeth, wave generator bearing and double row angular
contact needle roller bearing XZU-RTH are supplied ready lubricated.
NOTICE
Damage to property due to removal of individual parts.
Do not remove any screws from the circular spline.

Lubricate the flexspline and
adjacent construction
 Lubricate the interior of the flexspline  using the lubricant
provided.
For the amount of lubricant required, please refer to the customer
delivery drawing.
 Distribute the lubricant evenly.
 Apply the lubricant provided to surface A of the adjacent
construction
 .
For the amount of lubricant required, please refer to the customer
delivery drawing.
Figure 3
Lubricate the flexspline
1
0019F0260019F026
Figure 4
Lubricate the adjacent construction
A
11
0019F0280019F028

Schaeffler Technologies MON 106 17
Fit the wave generator  Fit the wave generator  in the flexspline  in the direction
of the arrow.
To facilitate fitting, turn and slide the input shaft
 at the same
time.
Check the position Correct positioning of the wave generator bearing  is crucial
to the functionality and durability of the strain wave gear.
 Measure the position of the wave generator bearing 
(dimension a) and compare this with the target distance a
(see customer delivery drawing).
Figure 5
Fit the wave generator
in the flexspline
5
5 11
6
6
0019F0640019F064
Figure 6
Check the position
of the wave generator bearing
a
1
4
0019F0660019F066

18 MON 106 Schaeffler Technologies
Strain wave gear RT..-H-..-BMS
Check alignment If the circular spline  is not fitted concentrically to the
flexspline
 , the service life and gear accuracy will be reduced.
Torque fluctuations can also be attributed to incorrect fitting.
 Ensure that the circular spline  is fitted concentrically.
The strain wave gear should turn very easily when the circular
spline  is correctly aligned.
 If the circular spine  is not correctly aligned, repeat the mount-
ing process for the wave generator
 , page 17.
Mount the input shaft
on the motor shaft
 Slide the motor shaft  into the input shaft  .
 Tighten the screws in the clamping element  and ensure that
the required preload force is achieved. For information on
the required preload force, please refer to the customer delivery
drawing.
Figure 7
Check alignment
of the circular spline
3
1
3
1
0019F02C0019F02C
Figure 8
Connect the input shaft
to the motor shaft
10
5
8
8
0019F0980019F098