Numerical analysis of heat flow in angular contact ball bearing cavity containing graphene oil-air lubrication

To more effectively reduce the cavity temperature of high-speed angular contact ball bearings for high-power high-speed electric spindles, the effect law of oil-air lubrication containing graphene on the heat flow characteristics of the bearing cavity was analyzed. Based on the conservation equations of fluid mechanics, a mathematical model of thermal flow analysis for the gas-liquid-solid three-phase flow formed by the compressed gas, lubricating oil and graphene particles in the cavity of a high-speed angular contact ball bearing was established. The formation conditions of graphene lubricant annular flow in the oil-gas passage at different velocities of compressed gas state, the velocity of graphene lubricant flow field in the bearing cavity and the relationship between graphene particle distribution and bearing cavity temperature field were numerically simulated. The results showed that an annular flow of graphene lubricant would be formed in the oil-gas channel as a way to achieve good lubrication of the contact ball bearing cavity when the ratio of graphene lubricant velocity to compressed gas velocity was 1: 10; the distribution of graphene in the bearing cavity was affected by both centrifugal force and nign speed spin of the ball, and the temperature was lower in the area having more dense of graphene particles; the greater the graphene lubricant flow rate in the ball to inner ring contact area, the higher the surface heat transfer coefficient, resulting in good heat dissipation, which provided theoretical basis for graphene oil-air lubrication to better reduce the temperature of high-speed angular contact ball bearings and ensure the normal operation of the bearings. © 2024 CIMS. All rights reserved.