高速角接触球轴承腔内气液两相流模拟分析

基于轴承腔内气液两相流流动模型,采用VOF方法和MRF模型对高速角接触球轴承简化模型内润滑油的流动特性进行数值计算,获得腔内速度、压力以及润滑油分布情况。分析轴承转速和润滑油进口流量等参数对油液体积分数的影响,以及轴承腔内润滑油的流动轨迹和润滑油进入腔内的影响机理。结果表明:轴承高速转动阶段,润滑油在滚动体和保持架的搅动作用,在腔内局部形成漩涡不利于润滑油的流动；轴承腔内两相流场的环间压力具有周期性特点,喷射润滑油很难穿过环间压力进入腔内；腔内油液体积分数随轴承转速的升高而降低,随供油量的增加而增加,呈非线性关系；喷射角度对环间油液体积分数和滚道油液体积数的影响很大,选择合适的喷射角度能够得到更好的润滑效果。该研究结果对高速轴承润滑设计提供了一定的参考依据。 

Numerical simulation of two-phase air/oil flow in high speed angular contact ball bearing chamber

Based on the model of gas liquid two-phase flow of lubrication oil in bearing chamber, the flow characteristics of the lubricating oil in the simplified model of the high-speed angular contact ball bearing chamber were calculated by volume of fluid (VOF) method and moving reference frame (MRF) model, the velocity, pressure and distribution of lubricant oil were obtained. Then the influence of the rotational speed of the bearing and lubricating oil inlet flow parameters such as the impact on the oil volume fraction were analyzed. The flow path of the lubricating oil in the bearing chamber,and the influence mechanism of the lubricating oil into the cavity were discussed. The results showed that at the bearing high-speed rotating stage, with the agitation of the lubricant and the cage was formed in the chamber. The two phase flow field in the bearing chamber between the bearing rings pressure had the periodic characteristics, spray lubricating oil was difficult to enter the cavity through the pressure between rings. The volume fraction of the oil in the chamber nonliear decreased with the increase of the bearing speed, and increased with oil supply. Injection angles had a great influence on the bearing chamber and bearing raceway of the oil volume fraction, and choosing the appropriate angle can get better lubricating effect. The results of this study provide some reference for the design of high speed bearing oil spray lubrication system.