Prediction of Ball Fatigue Life in a Ball/V-Ring Test Rig

Abstract

Standard load and life ratings of ball bearings are based on fatigue failure of the bearing inner and outer raceway surfaces. The rating equations are derived from the mathematical and experimental work of Gustav Lundberg and Arvid Palmgren conducted in Sweden during the 1930s and 1940s; they considered the occurrence of subsurface-initiated, ball fatigue failure highly improbable. In modern ball bearings, this phenomenon occurs occasionally, creating the need for a life prediction means. Ball/v-ring rig fatigue endurance testing is a currently used method to screen ball materials and processing methods, particularly for aircraft applications. As a first step toward predicting ball fatigue life in bearings, the Lundberg-Palmgren and Ioannides-Harris life prediction methods were applied to ball/v-ring test data. The latter method predicted ball fatigue lives which correlated well with the measured ball lives. The Lundberg-Palmgren life prediction method modified using currently accepted material-life and lubrication-life factors did not yield satisfactory correlation.