Ball Bearing Mount in Electric Motor

Application: Ball Bearing Mount in Electric Motor (in production since 2015)

Volume: 1MM pieces/year and increasing per 10 year schedule

Customer: Tier 1 Automotive Supplier (Powertrain Division)

Product: Engine Cooling Fan Motor

Background: A customer came to USA Tolerance Rings late in their design cycle due to issues with bearing retention and premature failure in an electric motor. This was in a critical automotive powertrain application that saw extreme temperature swings; resulting in thermal growth. In order to keep an aluminum housing and their component diameters, USA TR designed a variant of the standard AN26X8S ring commonly used with 6000 series bearings. This customization included reducing the wave height and material thickness to accommodate the customer’s bearing internal clearance concerns; avoiding changing the housing ID. Ultimately, this ring was able to save their design, while reducing material costs by using an aluminum housing vs. a precision machined steel alternative.

Case Study Data: The below characteristics of the ring and theoretical performance characteristics are based on component diameters:

  • Inside Member Diameter (OD): 1.0236”
  • Bore Diameter (ID): 1.0984”


Corrugation Height0.950.374
Theoretical Performance Characteristics for AN26X8S5
Compression (Inches)Radial Capacity (lbs)Torque Capacity (in-lbs)
0.0005 (1.3%)913
0.0010 (2.7%)916
0.0015 (4.0%)919
0.0020 (5.3%)9112
0.0025 (6.7%)9115
0.0030 (8.0%)9118
0.0035 (9.4%)721