Effect of lubricant viscosity on the performance and damage of high speed ball bearing

Abstract:

To explore the influence of lubricant viscosity on the lubrication condition and performance of bearings under high speed condition, the temperature rise and vibration characteristics of 7014C angular contact ball bearings made of Si₃N₄ ceramic and GCr15 steel under different lubricant viscosities were studied. The results show that the temperature rise and vibration of bearings decrease firstly and then increase with the increasing of lubricant viscosity, and the effect increases with the increasing of rotating speed. At the same time, ceramic bearings show better performance than steel bearings under different lubricant viscosities. By combining the test results with the analysis of lubrication condition, the relationship among lubricant viscosity, lubrication condition and performance of bearing is discussed, which provides important basis for selection of the applicable lubricant viscosity of high speed angular contact ball bearings. In addition, the rolling surface damage under different lubrication conditions was analyzed. The results show that the rolling surface damage of both ceramic bearing and steel bearing is small and with little difference under full oil-film EHL. Under partial oil-film EHL, the surface damage of bearing is serious, with a large number of micro peaks and pits. The surface damage on bearing balls and outer raceway is more serious than that of inner raceway, and the surface scratch on steel balls is denser and deeper than that of ceramic balls.