飞轮用轴承组件热-结构耦合特性分析

Analysis on Thermal- Structural Coupling Property of Bearing Assembly for Flywheel

针对飞轮高速转子转速提高引起的轴承温升和疲劳失效问题,建立了轴承组件热-结构耦合有限元模型。将轴承摩擦功耗和电动机功率作为温度分析的边界条件,利用材料的S-N曲线计算轴承的疲劳寿命。以某型号飞轮用轴承组件为例,分析各工况条件对计算结果的影响。结果表明:轴承组件中电动机温度最高,轮体温度最低,轴承中钢球与套圈的接触区温度较高,且钢球接触表面温度最高,内、外圈次之;温度对轴承组件的应力场和轴承的疲劳寿命影响较大;径向力、转速、环境温度以及电动机功率对轴承的温度、应力和疲劳寿命均有所影响,但径向力和电动机功率的影响较小,而转速和环境温度的影响较大。

Aiming at temperature rise and fatigue failure caused by the increase of rotating speed of high speed rotor for flywheel, a thermal -structural coupling finite element model is built for bearing assembly. The frictional power con- sumption of bearings and power of motor are taken as boundary condition for temperature analysis, the fatigue life of bearings is calculated by using S - N curve of material. Taking one model of bearing assembly for flywheel as an exam- ple, the effects of different operating conditions on calculation result are analyzed. The results show that the tempera- ture of motor is the highest in the bearing assembly and the temperature of wheel body is the lowest. The temperature of contact zone between steel balls and rings of bearings is higher, and the temperature of contact surface of steel balls is the highest, inner and outer rings in the second place. The temperature has greater effect on stress field of bearing as- sembly and fatigue life of bearings. The radial force, rotating speed, ambient temperature and power of motor have effect on temperature, stress and fatigue life of bearings, but the rotating speed and ambient temperature have much greater influence than radial force and power of motor.