Abstract: 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.

Key words: Dynamic supporting stiffness, Electric spindle, Extra high-speed, Numerical calculating method, Spindle bearing