高速滚珠轴承电主轴热态特性分析

摘要

为研究高速滚珠轴承电主轴的热特性对其性能的影响,计算轴承的热源生热并进行热特性仿真.研究轴向载荷和转速对接触角的影响规律,进而采用局部热计算方法计算轴承的热损耗.结果发现,轴承的旋转速度对其热损耗的影响比轴向载荷作用更明显,并且滚珠的自旋摩擦是轴承生热的主要形式.结合热源生热计算结果,运用ANSYS对一定转速的空载电主轴分别进行稳态热分析和瞬态热分析,发现电主轴的最高温度点出现在内置电机转子的中心区域.将稳态热分析结果加载到有限元模型进行热-结构耦合分析,发现最大轴向位移出现在主轴的最前端,最大轴向应力则出现在前轴承球与外滚道的接触区域.设计空载电主轴温升测定实验,验证仿真结果的正确性.%To study the influence of the thermal characteristics of the motorized spindle of ball bearings on its performance,the heat source calculation and the thermal characteristic simulation of the bearing were performed.The heating consumption of the bearing was analyzed by the local heat calculation method.It is found that the influence of the bearing speed on thermal consumption is greater than that of axial load,and the ball's spin is the main form of the ball bearing heating.Based on the calculation results of heat source,the steady-state and transient-state analysis were performed respectively by ANSYS under a certain speed with no load.The result shows that the highest temperature appears in the iron core of the motor rotor.The thermal-structure coupling analysis was carried out by loading the steady-state thermal analysis results to the finite element model.The results show that the maximum axial displacement appears at the front of the spindle,and the maximum axial stress appears on the contact point between the ball and the outer ring of the front bearing.An experiment of temperature rise measurement was performed by a no load spindle,the measuring results verified the accuracy of the simulation results.