Robotic bearing systems

by Kevin Sweeney
02 May, 2024
8 min read

In this article, I intend to give the reader an introduction to various bearing types and applications along with Drive components used in the manufacturing of robotic automation equipment. I will feature the Schaeffler INA product line for robotic bearings and Precision Strain Wave gears as they are a clear leader in the Bearing Industry for Robotic bearings.

Bearing and Drive solutions for robotic automation

Pacific International Bearing offers Schaeffler Bearing’s extensive portfolio of robotic system components. Schaeffler offers precision gearboxes, pivot bearing supports, drive motors, sensors, and the seventh axis. Schaeffler offers two precision gearbox product ranges, graded by performance to accommodate both standard and higher precision applications. Production processes can be monitored with a torque sensor integrated into the gearbox which does not require any extra space. Pacific International offers a one stop marketplace for every aspect of building robotic functionality. We offer robotic system components as well as all types of bearings applied in robotic applications.

Suggested bearings for Robotic applications

  • INA Angular contact roller bearings

INA SGL angular contact roller bearings are highly popular with precision gearbox manufacturers. INA SGL angular contact roller bearings are rigid, have a compact cross section, and are very accurate. This type of bearing is widely used in servo drives and robotic joints as output bearings in planetary gearboxes.

Fig. 1 INA Angular Contact Roller Bearings

INA Angular Contact Roller Bearing Part numbers are available from Pacific International including F-565223.SGL, F613821.SGL, F-587397.SGL, F-587396.SGL, F-587391.SGL, F-557495.SGL, F-557494.SGL, F-557493.SGL, F-550953.SGL, F-240120.SGL, F-238548.SGL, F238167.SGL, F-238166.SGL

Go to Pacific International Bearing to purchase or contact us at [email protected].


INA classic crossed roller bearings are a good choice for high rigidity joint bearings. Short spacers are used in INA’s XSU series to separate the cylindrical rollers which helps reduce the friction and running noise. This is a widely used and desired design for robotic applications especially due to its thin cross section.

Fig. 2 INA Crossed Roller Bearing

Pacific International Bearing offers INA part numbers XSU080168, XSU080188, XSU081218, XSU080258, XSU080318, XSU140414, XSU140544, XSU140644, XSU140744, XS140844, XSU140944, XSU141094, XS080168-RR, XSU080318, XSU140744-RR.

  • INA XZU Series Angular Contact Needle Roller Bearings

If you need more tilting rigidity than the crossed roller bearing a good alternative is the INA Series XZU angular contact needle roller bearings Both INA XZU and INA XSU have identical external dimensions and are interchangeable. The internal design has two separate raceways which provide a support distance increasing rigidity. The needle rollers are precisely guided on the raceways by cages which reduces friction providing more space for lubricating grease.

Fig. 3 INA XZU Angular Contact Roller Bearing

Pacific International Bearing Sales offer Ina Slewing Ring part numbers XZU-RTW511, XZU-RTWH14, XZU-RTWH17 contact us at [email protected] for price and availability.

INA Ultra Precision Drives Precision strain wave gears

In drive systems for robots, machine tools, and industrial automation, gears are a central component for achieving accurate positioning and repeatability.

Schaeffler (INA) has combined all of its engineering expertise, research, and production know-how creating the Ultra Precision Drives category. In this new category are Precision Strain wave gears and planetary gears.

Engineers have a choice of precision strain wave gears for small cobots or large industrial robots, for secondary main axes in machine tools, and positioning drives for numerous automation jobs.

Pacific International Bearing offers INA precision strain wave gears of both the High Torque RT1 and Standard Torque RT2 series. Both RT1 and RT2  cover a maximum torque range of 18 Nm to 484 Nm.  Precision strain wave gears of the High Torque RT1 series exceed the Standard Torque RT2 series by an average of 30% in terms of torque and 40% in terms of service life. 

Precision Strain Wave Gears RT

Robot transmission

The UHS version consists of a Component Set, variant HAT, and a tilt-resistant, double row angular contact needle roller bearing XZU as the output bearing. The fully sealed version of UHS is suitable for axial or parallel motor attachment and can be integrated into the application with minimal design and assembly work. A particular feature of this version is the central hollow shaft, which permits the passage of a mechanical shaft or the necessary energy supply cables, for example.

Fig.4 INA Part number RT1-H-14-100-UHS-C Robot Transmission

Contact PIB for more information on INA Precision strain wave gears at [email protected].

Pacific International Bearing Sales Inc. offers these INA bearings in both metric and Imperial dimensions. Part numbers start from RT1-H-14-100UHS-C  and include over 129 variations including part numbers like RT1-H-17-100UHS-T, RT1-H-25, RT1H32, and up.

In follow up articles I will discuss other Schaeffler INA bearing products available for Robotics. The next article will be the Complete solutions for articulated arms followed by Modular Precision-Drive-Systems. Other INA products include the PSC Series Precision Planetary Gear Units the Monorail guidance systems the Modular system for the 7th axis and the INA Plug-and-Play Ready Range Extender.

Of course, numerous robotic applications use all sorts of bearings but this article and subsequent follow up ones will focus on the deep offering of Schaefller’s robotic bearings and components.

Generally, Robotic bearings are designed to meet standard as well as high precision requirements. Robotic applications have low and high-speed operation, low friction, and slow and precise movements and must be designed for minimal maintenance. Bearings often specified in robotic applications are hybrid using special materials to enhance performance and extend service life. 

Basics of Robotic Bearing Systems

Robotic bearing systems are customized for each specific application.  The various bearings and Schaeffler components offered through Pacific International Bearing are needed for the successful construction of complex cobots and robots. 


In summary, many types of bearings can and are used in Industrial robots and automation equipment. Companies such as Schaeffler INA offer an extensive product line with proven results. When designing robot movements whether linear, rotary, oscillating, or pivoting Pacific International offers a complete and total offering of high quality products to serve your needs. For more information contact us at [email protected]

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Written by

Kevin Sweeney

Founder and CEO at Pacific International Bearing Sales Inc (PIB)
Education: BS Business and Economics California State University Hayward Ca
CBS (Certified Bearing Specialist)

My role with Pacific International Bearings (PIB) is currently CEO. Since 1976, I have been deeply involved in the bearing industry, working in manufacturing sales at NTN Bearing and subsequently in Bearing Distribution. Before establishing PIB in 1990, I gathered valuable experience in bearing manufacturing and distribution. The last 45 + years in the bearing industry have been both rewarding and challenging, assisting customers across a large number of diverse bearing applications.
Outside of the bearing industry, my interests are family, woodworking, motorcycling, cars, gardening, and golf.
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