Investigation on the friction heat generation rate of ball bearings at ultra-high rotation speed

Position and velocity vectors between ball-rings, ball-cage, and cage-ring in space were considered to refine the friction heat generation rate model of ball bearings. The relationship between the position vectors of each part of a bearing in space was analyzed to determine the bearing’s status of contact bearing. Hertz contact theory and Coulomb friction law were employed to calculate the normal and friction forces at the contact points, respectively. The relationship between the velocity vectors of each part in space was analyzed, and the relative sliding velocity between two parts in contact was obtained. Friction heat generation rate of bearings was calculated as the product of friction force and relative velocity. Parameters such as bearing speed, axial load, radial load, and the groove curvature radius coefficient of bearing inner and outer rings were all investigated in the case of ball bearing heat generation. Theoretical calculation and experimental results indicate that the bearing friction heat generation rate is associated with the bearing rotation speed and bearing thrust load at ultra-high rotation speed, whereas the radial load has insignificant effect. Meanwhile, a suitable inner-outer groove curvature radius coefficient can significantly reduce the bearing friction heat generation rate.