The Influence of Debris on Bearing Performance: Chapter II

In an earlier paper the primary factors that relate debris to bearing fatigue performance were discussed. It was recognized that it is the largest debris particles in a lubricant system that can influence fatigue life by the denting they produce. Some recent tests are described that provide an approximate relationship of particle size to dent size. An additional analysis of dent shape (primarily slope of the side wall) indicates that the severity of slope is a measure of the dent as a surface stress riser and thus its influence on bearing fatigue life. Comments concerning debris accessibility to a contact and a method to evaluate material differences in tolerating debris are also included.