Fatigue Failure Progression in Ball Bearings

Typically, the life of a component containing rolling contacts is defined as the time to the initiation of a fatigue spall. Initiation of a spall does not always cause the component to stop performing its designed function. Operating the component past the initiation of a spall increases the heat generation rates and vibrations, eventually leading to total failure. A ball/v-ring test rig was used to initiate and progress spalls on bearing balls where spall progression was measured as a function of time, and vibrations monitored using accelerometers. A spall progression life mathematical model for balls endurance tested in the v-ring rig was created by extending the Ioannides–Harris fatigue life theory. Also, excessive vibratory loading was determined to be the major cause of total component failure.