Roller element bearings are anti-friction bearings used to reduce wear and friction in high axial and radial load applications. The life of an individual rolling bearing is defined as the number of revolutions bearing endures before the first sign of fatigue (flaking, spalling) occurs on one of its rings or rolling elements. Purpose of this test rig is to determine life by varying the speed, axial load, radial load and lubricating conditions.

Four identical bearings are mounted on a shaft. Axial and radial loads are applied when bearings are running. Failure of a bearing is sensed by abnormal increase of either vibration or temperature. At this point, the rig stops. Number of revolutions to fail is recorded. This data is used in Weibull failure analysis to determine fatigue life L10. This is the life which 90% of the bearings in a sufficiently large group can be expected to attain or exceed.