牵引电机轴承绝缘涂层绝缘性能与力学性能试验分析

Experimental Analysis on Insulation and Mechanical Properties of Insulation Coating of Traction Motor Bearings

长期承受交变力与热冲击载荷作用的牵引电机轴承绝缘涂层会发生变色、氧化乃至龟裂,导致绝缘涂层的绝缘性能和结合强度等发生改变。以不同型号和涂层厚度的退役绝缘轴承为研究对象,进行温度、湿度交变循环下的轴承绝缘涂层性能试验、划痕试验和热-应力耦合仿真,结果表明:绝缘涂层厚度越大,轴承的整体绝缘性能越好;轴承边缘位置的涂层与基体结合的临界载荷值小于中心位置,边缘位置更容易发生失效,同一型号轴承随着绝缘涂层厚度增加,涂层与基体的临界载荷值减小,涂层与基体的结合强度下降;涂层边缘和中心处内外界面的等效应力差值均随涂层厚度的增加而增大,涂层厚度的增加不利于涂层与基体结合。

The coating of insulated bearings for traction motor under action of alternating force and thermal shock load for a long time will change color,oxidize and even crack,leading to changes in insulation performance and bonding strength of insulation coating.Taking decommissioned insulated bearings with different types and coating thicknesses as research objects,the performance test,scratch test and thermal-stress coupling simulation of insulation coating of the bearings are carried out under alternating cycle of temperature and humidity.The results show that the greater the thickness of insulation coating,the better the overall insulation performance of the bearings;the critical load values of bonding between coating and substrate at edge of the bearings are smaller than that at center,and the failure is more likely to occur at edge position,with the increase of thickness of insulation coating,the critical load values of coating and substrate decrease,and the bonding strength of coating and substrate of same type of the bearings decreases;the equivalent stress difference between inner and outer surfaces at edge and center of coating increases with the increase of coating thickness,which is not conducive to bonding between coating and substrate.