Comparison of performance of hybrid ceramic ball bearing and all-steel bearing coated with polytetrafluoroethylene solid lubricant film

The surface sliding velocity between the bearing ball and the raceway was calculated by with the Heathcote's theory on the lubrication of rolling bearings. The traction force between the ball and the guide-loop of the bearings coated with polytetrafluoroethylene (PTFE) solid lubricant film was determined by taking into account the load-deflection relationship of a solid surface. Moreover, the heat generation, the spin-roll ratio, the contact angle of the PTFE-coated hybrid ceramic ball bearing and the PTFE-coated all-steel ball bearing at high speed were comparatively investigated. As a result, the PTFE-coated hybrid ceramic ball bearing had a heat generation of only 62.6% and the spin-to-roll ratio of only 18% as that of the PTFE-coated all-steel bearing, at a rotational speed of 40000 r/min and the axial load of 3000 N. Thus the PTFE-coated ceramic ball bearing was superior to the PTFE coated all-steel bearing in the high rotational speed. The results in the present work might be used to guide the design and application of hybrid ceramic ball bearings at the special working condition. M50 steel is used as the raw material of the all-steel bearing.