热网络法和有限元法保护轴承热分析研究

Research on Thermal Analysis of Auxiliary Bearings Based on Thermal Network Method and Finite Element Method

在磁悬浮轴承系统中,悬浮转子会因突然断电而失去磁场力支撑,从而跌落到位于两端的保护轴承上,导致保护轴承内圈瞬间产生大量的摩擦热,使得保护轴承系统温度升高,影响保护轴承转动性能以及磁悬浮轴承的可靠性。根据轴承内部受载,得出轴承发热量,研究了保护轴承零件之间的生热及热传递关系。根据工况设置相应的热边界条件,运用有限元方法与热网络方法,对保护轴承进行热力学分析,获得保护轴承温度场分布,并对结果进行对比分析。结果表明:保护轴承的最高温度在背离开口的内圈端面处,外圈温度小于滚珠温度,滚珠温度小于内圈温度,内外圈温度分布不对称。

In Magnetic bearing system,once the power is cut off and the magnetic field force is not supported,the high-speed levi-tation rotor will fall on the auxiliary bearing and generate a lot of frictional heat,which will cause the temperature of the auxil-iary bearing system to rise and affect the rotation performance of the auxiliary bearing.According to the internal load of the bear-ing,the heat generated by the bearing is obtained,and the relationship between the heat generation and the heat transfer be-tween the auxiliary bearing parts is studied.According to the working conditions,the corresponding thermal boundary conditions are set,and the thermal analysis of the auxiliary bearing is performed using the thermal network method and the finite element method.The temperature field distribution results of the auxiliary bearing are obtained,and the results are compared and ana-lyzed.The results show that the maximum temperature of the auxiliary bearing is at the end face of the inner ring with the back leaving port,the outer ring temperature is less than the ball temperature and the ball temperature is lower than the inner ring tem-perature,and the temperature distribution of the inner and outer rings is asymmetric.