超高速时电主轴轴承的动态支承刚度分析

ANALYSES OF DYNAMIC SUPPORTING STIFFNESS ABOUT SPINDLE BEARINGS AT EXTRA HIGH-SPEED IN ELECTRIC SPINDLES

基于滚动轴承受力分析的拟静力学和拟动力学模型,利用数值计算方法对超高速时电主轴轴承的内部动力学状态进行计算机模拟仿真,在求解每一个球滚动体动力学基本参量的基础上,计算电主轴轴承对转子支承的动态刚度,并结合具体算例,分析转速、轴承预载荷、径向外载荷等工况条件,以及套圈滚道曲率半径、球滚动体的直径和数量等轴承的内部结构尺寸、球材料的物理性能等方面的因素对轴承动态支承刚度的影响。分析结果表明,外部工况条件以及轴承内部的结构尺寸、球材料的物理性能等方面的因素对超高速时电主轴轴承的动态支承刚度影响较大,超高速时电主轴轴承的动刚度较静态和低速情况有着显著的变化。

Based on the models of imitating statics and imitating dynamics, the dynamic states in the bearings rotating at extra high-speed in electric spindles are simulated by computer and the dynamic supporting stiffness of the bearings can be gained through calculating the dynamics parameters of every ball rolling element by numerical method. Combined a bearing as an example, the influences on its dynamic stiffness acted by the working conditions such as the running speed, the axial preload, the outside loads and the internal makeup parameters of the bearing and also the material, the number, the diameter of the balls are analyzed. The result shows that these factors affect the dynamic supporting stiffness of the bearing heavily, and the dynamic stiffness of a spindle bearing when operating at extra high-speed is greatly different from that of those bearings in static and low speed.