WHEN LUBRICATION FAILS

Abstract

In most ball bearings, grease functions primarily as a storehouse for the small amount of oil needed to coat ball, raceway and separator surfaces. Bearing life tests indicate that as a grease ages in service, it finally dries to a degree where it fails to provide this lubrication demand when about half the original oil is gone. This condition of dryness which leads to failure is also related to operating factors such as bearing temperature, speed and load.