Effects of raceway surface roughness in an angular contact ball bearing

The friction forces and moments acting on the contact spots between the ball and raceways are key factors to accurately predict the motions of each bearing component in angular contact ball bearing, while the surface roughness could produce significant effect on the friction force and subsurface stresses. The roughness of ball and raceway surfaces is a requisite but difficult factor to be determined during design, so it is desirable for engineering to understand the effect of surface roughness on the motion of ball and subsurface stresses in bearing. In this paper, a dynamic model is developed for angular contact ball bearings to investigate the effect of raceway surface roughness on motions of ball and subsurface stresses, in which the friction coefficient between ball and raceways is evaluated by an engineering approach with consideration of surface roughness and temperature rise due to the sliding. The results show that the surface roughness of raceways can make great effects on the motion state of balls and lubrication performance in an angular contact ball bearing; and together with the effect of surface roughness on the stress in the substrate, the roughness of ball and race surfaces can be optimally determined.