What is a 'bearing race' and why must it be scored or checked during maintenance?

• A. A hole in the housing for mounting.
• B. The inner or outer ring of a bearing that interfaces with rolling elements; scoring indicates wear and may require replacement to prevent failure.
• C. A type of lubricant used for bearings.
• D. A test used to measure bearing temperature.

Answer: (B)

A bearing race is the inner or outer ring of a bearing that provides the smooth contacting surface for the rolling elements. Scoring means scratches or grooves on that race surface. During maintenance, checking for scoring is essential because such damage signals wear, contamination, or lubrication problems. When the race surface is scored, the load is not distributed evenly, creating stress concentrations, increasing friction and heat, and accelerating wear. This can lead to premature failure, including spalling or seizure of the bearing. If scoring is found beyond acceptable limits, the bearing or race should be replaced to prevent a more serious failure in operation. Visual inspection and feel for roughness or grooves, along with measurements if needed, help determine whether the race is still within spec or must be replaced.