油气润滑角接触球轴承腔内空气压力分布数值分析

基于轴承腔内油气两相流流动模型,采用VOF方法和MRF模型对高速角接触球轴承腔内油气两相流的流动情况进行数值计算,重点分析轴承腔内和滚珠表面的压力分布,以及转速、初始空气压力等参数对压力分布的影响。结果表明:轴承腔内的压力因滚珠与保持架的搅动作用,整体处于负值,并且在局部区域形成漩涡;随着转速的增加,腔内压力在负方向上逐渐增大,内外圈之间的压差也随之增大;沿着滚珠自旋方向,压力在负方向上逐渐增大,到滚珠与内圈接触点附近达到最大值,这有利于将润滑油吸附到滚珠表面,从而得到更好的润滑效果;初始压力越大,腔内压力在数值上也越大,分布不均匀性程度随之加剧,初始压力的选取对轴承润滑有很大影响。

Numerical Analysis of Air Pressure Distribution inside the Chamber of Oil-Air Lubricated Angular Contact Ball Bearings

Based on the oil-air two-phase flow model inside the bearing chamber,the VOF method and the MRF model were used to numerically calculate the flow of oil-gas two-phase flow inside the high-speed angular contact ball bearing chamber. The pressure distribution inside the bearing chamber and on the surface of the ball,and the influence of rotational speed,initial air pressure and other parameters on the pressure distribution were analyzed. The results show that the pres- sure distribution inside the bearing chamber is negative as a whole,because of the stirring effect of the ball and cage,and the whirlpool is formed in some areas. With the increase of rotational speed,the pressure inside the chamber is increased gradually in the negative direction,and the pressure difference between the inner and outer rings is also increased. Along the direction of ball spinning,the pressure is increased gradually in the negative direction,it reaches the maximum near the contact point between the ball and the inner ring,which is conducive to adsorbing lubricating oil to the ball surface and obtain better lubrication effect. The higher the initial pressure,the greater the pressure in the chamber in numerical value, but the degree of uneven distribution is also intensified. The choosing of initial pressure has a great influence on the lubri- cation of bearings.