The Role of Residual Stress in the Performance of Gears and Bearings

Residual stresses are an inevitable consequence of the manufacturer and service conditions to which mechanical components are subjected. In this paper, a wide range of evidence is presented to show the decisive effect of residual stress, both pre-existing and service induced, on the performance of gears and rolling element bearings. The results of measurement of residual stresses arising from a range of manufacturing procedures are presented, particular emphasis being placed on carburized steels. The effect of such stresses on fatigue performance is demonstrated. Possible cause of residual stress change during service are reviewed and the results of new experimental and theoretical work on the role of residual contact stress in a number of relevant tribological failure modes are presented.