Oil Film Thickness Mechanism of Silicon Nitride Ceramic Ball for Bearing

Aiming at the problem that the lubrication characteristics of silicon nitride hybrid ceramic ball bearings are not clear, an optical measurement method is used to study the variation of oil film thickness and morphology of silicon nitride ceramic balls under different entrainment velocities and load combinations through the ball-disk contact optical interference oil film measurement device, and the influence mechanism of adhesion characteristics of silicon nitride ceramic balls on oil film thickness.

At the same time, a comparative study of oil film thickness with steel balls under the same working conditions is also carried out. The results show that: (1) At high entrainment velocity, there is a lack of oil at the entrance of the contact area, and the thickness of the test film no longer increases with the increase of the speed, so that the thickness of the silicon nitride ceramic ball test film is lower than the theoretical calculation value; however, without considering the high-speed starved oil condition, the test film thickness of the steel ball conforms to the theoretical calculation, and the test film thickness of the silicon nitride ceramic ball is only 70%~87% of the theoretical calculation, which is obviously low, indicating that the traditional theory has limitations in evaluating the oil film thickness of the silicon nitride ceramic ball.