高速滚动轴承喷油润滑油液穿透机理分析

基于空气动力学研究高速滚动轴承环间气流特性，通过建立气相流数学模型和气液两相流数学模型研究润滑油在轴承环间的穿透过程，探究高DN值时润滑油的穿透机理.利用流体体积（VOF）模型对此状态下的空气和润滑油界面进行动态捕捉，以研究润滑油的运动过程、分布特点以及不同参数对环间油液体积分数的影响，得到了高速滚动轴承环间气相流的特性；润滑油在不同转速下进入轴承环间的运动过程；轴承环间气液两相流场的压力、速度特性；轴承环间初始气流场对润滑油进入的影响.结果表明:在轴承小端面靠近内圈附近喷油可以避免湍流对润滑油的影响和干扰，有利于润滑油进入环间；轴承环间存在有利于润滑油贴滚道运动的气流径向作用力，随着转速的增加，该力呈近似线性增加；气流的初始状态影响着轴承环间润滑油的运动状态，润滑油对气流的运动影响较小；较低转速时，轴承环间周向压力变化很小可忽略，较高转速时，其呈现周期性波动，对润滑油进入的影响不可忽视；在较低转速时通过提高喷油体积流量可以有效提高轴承环间油液体积分数，但是高转速时，通过提高喷油体积流量来提高轴承环间的油液体积分数的效果并不明显. 

Analysis on penetration mechanism of oil jet lubrication for high speed rolling bearing

Based on aerodynamics, the airflow characteristics between bearing rings of high-speed bearings were researched. And the movement process of the lubrication oil between bearing rings was analyzed by establishing the mathematical model of gas phase flow and gas-liquid two-phase flow, so as to explore the penetration mechanism of the lubrication oil at a high DN value. The original data of the gas-liquid two-phase flow between bearing rings were obtained. And then, the VOF (volume of fluid) model was applied to numerical analysis on the gas-liquid two-phase flow of lubrication oil interacting with the airflow between the bearing rings, so as to catch the interface of the oil and airflow for studying the movement process, the distribution characteristics of lubrication oil and the effects of different parameters on oil volume fraction between bearing rings. The characteristics of the gas phase flow between rings of high-speed rolling bearing, the motion of lubrication oil in different speeds, the pressure and velocity characteristics of the gas-liquid two-phase flow and the effects of the initial airflow on the entrance of the lubrication oil were obtained. Results show that the effect and the interference of turbulence on the lubricating oil can be avoided by jetting oil onto the small end face of bearing near bearing inner race, which is conducive to the oil flow into the ring. The radial force of the air flow between bearing rings is beneficial to the movement of the lubricating oil, and with the increase of the speed, the force increases linearly. The initial state of the air flow affects the movement of the oil between bearing rings, and the oil has little effect on the movement of the air flow. At low speed, the pressure around the bearing change is small. When the speed is high, the periodic fluctuation pressure can not be ignored. At low speed, increasing oil volume flow can effectively raise the oil volume fraction between bearing rings , but at high speed, the oil volume fraction increase is not obvious by increasing oil volume flow.