载流工况下圆柱滚子轴承等效电容计算分析及试验验证

Computational Analysis and Experimental Verification of Equivalent Capacitance of Cylindrical Roller Bearings Under Current-Carrying Condition

电场环境中的高频轴电流直接影响轴承的使用寿命,使轴承出现电蚀,进而影响整个传动系统的工作性能和使用寿命。为更准确地分析载流工况下轴承运行参数对轴承等效电容的影响,基于滚动轴承动力学理论建立了一种圆柱滚子轴承等效电容动力学模型,得到滚子与滚道之间的动态赫兹接触面积和动态油膜厚度并计算出轴承等效电容,实现了圆柱滚子轴承等效电容的动态仿真,分析了轴承转速和径向载荷对圆柱滚子轴承等效电容的影响规律。结果表明:随着轴承转速的增加,轴承等效电容随之减小,但轴承击穿阈值电压随之增大;随着径向载荷的增加,轴承等效电容随之增大,但轴承击穿阈值电压随之减小;当其他条件一定时,适当提高轴承的d_(m)n值、增加轴承宽度和滚子直径可以防止轴承被击穿。通过载流轴承试验机进行试验,试验与仿真结果的最大误差为10.1%,验证了理论计算与模型仿真的合理性。

The high-frequency shaft current directly affects the service life of bearings in electric field,leading to electric corrosion damage of bearings,then affects the working performance and service life of entire transmission system.In order to more accurately analyze the effect of operating parameters on equivalent capacitance of bearings under current-carrying condition.Based on dynamic theory of rolling bearings,a dynamic model of equivalent capacitance of cylindrical roller bearings is established,the dynamic Hertzian contact area and dynamic oil film thickness between rollers and raceways are obtained,and the equivalent capacitance of the bearings is calculated,thus realizing the dynamic simulation of equivalent capacitance of the bearings.The influence law of rotational speed and radial load on equivalent capacitance of the bearings is analyzed.The results show that:with the increase of rotational speed of the bearings,the equivalent capacitance of the bearings decreases,but the breakdown threshold voltage of the bearings increases;with the increase of radial load,the equivalent capacitance of the bearings increases,but the breakdown threshold voltage of the bearings decreases;when other conditions are certain,the breakdown of the bearings can be inhibited by appropriately increasing d_(m)n value,width of the bearings and diameter of rollers.The test is carried out by current-carrying bearing tester,the maximum error between test and simulation results is 10.1%,verifying the rationality of theoretical calculation and model simulation.