AGMA 11FTM17 PDF

Micropitting occurs in gears and rolling-element bearings that operate in the mixed or micro EHL lubrication regime. It manifests in many different ways depending on the loads, speeds, rolling and sliding velocities, macrogeometry, surface topography, edge effects, metallurgy, and lubricant properties. The failure analyst must discern whether the micropitting is a primary failure mode or a secondary failure that occurs because of prior damage. Understanding the morphology of micropitting is the key to determining the primary failure mode and root cause of failure. Several examples of micropitting in gears and rolling-element bearings are presented to illustrate the morphological variation that can occur in practice.