滚珠自转对高速球轴承环下润滑内部流动的影响

Effects of Ball Rotation on Internal Flow of Under-Race Lubrication of High Speed Ball Bearing

关键词:  高速球轴承  环下润滑  滚珠自转  计算流体力学  油气两相流

Key words:  High-speed ball bearing  Under-race lubrication  Ball rotation  Computational fluid dynamics  Oil-gas two-phase flow

摘要:

高速球轴承正常工作时，处于高速旋转状态，此时油相和气相因重力和离心力的作用在轴承环间剧烈运动。为了更准确地分析轴承环间的两相流动，采取VOF模型进行内部流场的模拟，采用多重旋转坐标系描述部件运动。建立球轴承环下润滑计算模型，分析了考虑滚珠自转因素下轴承内部的流动，并在此基础上探究了转速及供油量对轴承工作状态的影响。结果表明，对比整体模型与滚珠自转模型，发现滚珠自转使得轴承内部油体积分数增大，同时也使得滑油穿透间隙达到外环的能力增加；在考虑滚珠自转情况下，转速的不断增大，使得轴承内部的油相体积分数不断减小，在低转速情况下滚珠自转对流体运动影响较为明显，在高转速情况下公转速度对流体运动起到主导作用，滚珠自转对流体运动影响减弱；供油量不断的增大，使得滚珠自转模型内部的油相体积分数也在不断增大，而且滚珠自转运动会加强滑油在轴承内部的分布。

Abstract:

High-speed ball bearings are in high-speed rotation under normal working conditions. At this time， the oil phase and gas phase move violently between the bearing rings due to gravity and centrifugal force. In order to analyze the two-phase flow between the bearing rings more accurately， the volume of fluid（VOF）model is adopted to simulate the internal flow field， and the multiple rotating coordinate system is used to solve the movement of the component. A calculation model for lubrication under the bearing ring of a ball bearing is established， and the flow inside the bearing under consideration of the rotation of the ball is analyzed. On this basis， the influence of speed and oil supply on the working state of the bearing is investigated. The results show that comparing the bearing model with the ball rotation model， it is found that the ball rotation increases the oil volume fraction inside the bearing， and also increases the ability of the oil to penetrate the clearance to reach the outer ring. Considering the rotation of the ball， the continuous increase in speed makes the oil phase volume fraction inside the bearing to continuously decrease. In the case of low speed， the ball rotation has a more obvious influence on the fluid movement. In the case of high speed， the revolution speed plays a leading role in the fluid movement， and the ball rotation has a weaker influence on the fluid movement. The continuous increase in the amount of oil supply makes the oil phase volume fraction inside the ball rotation model also continue to increase， and the ball rotation movement will strengthen the distribution of lubricating oil inside the bearing.