Influence of Lubrication Viscosity on Dynamic Characteristics of Full-Ceramic Bearings

Abstract

Full-ceramic bearings possess numerous exceptional attributes, such as enhanced rigidity and superior resistance to wear. Nevertheless, full-ceramic bearings consistently encounter elevated temperatures for extended periods of high-speed operation, which easily affect the processing performance of the equipment. Lubrication viscosity has a significant effect on bearing heat generation, so it is meaningful to approach the effect of lubrication viscosity with respect to the dynamics of full-ceramic bearings. Full-ceramic angular contact ball bearings are treated as research objects to analyse their optimal working condition in this article. A coupled fluid–solid simulation model is constructed for analysis of the fluid and solid in the bearing cavity. First, at the conditions of different lubricant viscosity, the oil volume distribution, temperature field distribution in the bearing cavity is analysed. Then, the vibration characteristics of the inner ring is examined by constructing a dynamic model of the inner ring. Meanwhile, temperature and vibration variation of full-ceramic bearings are verified through experiments under different rotational speeds. The results show that the lubricant volume distribution inside the bearing cavity is nonuniformly distributed, which the lubricant is mainly located in the outer ring groove position. Moreover, elevating the lubricant viscosity within a certain range promotes the enhancement of bearing lubrication properties. The maximum error of the bearing temperature between the simulation results and the experiment is 7.592%. Ultimately, the simulation analysis is validated through experiments, and it provides a theoretical foundation for selecting optimal parameters for the oil–air lubrication of full-ceramic bearing.