Clarifying Bearing Failure Analysis

Rolling-element bearings are complex mechanisms designed to have long, although finite, lifespans. When bearings fail an accurate determination of the failure mechanism and recommendations for eliminating the cause of failure can be determined in large part by accurate assessment of characteristic damage observed in the failed bearing. Features such as smearing, spalling, or fretting all indicate specific failure mechanisms. However, in practice features like these can be hard to differentiate. Smearing and microspalling, for instance, can appear similar even under microscopic analysis. There is also ambiguity between terms used to describe characteristic damage which can lead to differing, sometimes contradictory views on a root cause. This presentation will provide a brief overview of bearing failure mechanisms. Examples of damage that was difficult to visually access and ways to determine the specific type of characteristic damage will be explored. Additional examples of miscommunication with respect to bearing failures will also be discussed.