中文摘要：

针对定位预紧的电主轴球轴承,基于球和套圈相互作用模型,推导了球轴承刚度求解模型,使用Newton-Raphson方法求解可到刚度矩阵。基于Riccati传递矩阵法,给出了考虑轴承动刚度的电主轴临界转速计算方法。建立了铣削激振下考虑轴承动刚度的电主轴动力学方程,使用RungeKutta法求解得到电主轴动力学响应。对某铣削高速电主轴计算,结果发现轴承径向刚度随转速增大而减小,采用定位预紧后刚度增大,且随转速增大轴心预紧刚度增大明显。考虑轴承动刚度可得到更为准确的电主轴动特性结果,最后通过高速电主轴动特性实验证明了该模型对动特性预测的准确性。

英文摘要：

For spindle bearings with position preload,bearing stiffness model is presented based on the interactions model between the ball and rings. Newton- Raphson method is used to solve the stiffness matrix. Based on Riccati transfer matrix method,calculation method of critical speed of motorized spindle considering the dynamic stiffness of bearing is presented. The dynamic equation of the motorized spindle considering dynamic stiffness of bearing under milling excitation is given,and the dynamic responses are solved by using Runge- Kutta method. Taking a high speed milling spindle as an example,results show that radial stiffness of the bearing decrease with increase of rotating speed,the bearing stiffness increases with the positioning preload,and the increase becomes obvious with the increases of speed. More accuracy of dynamic responses of the spindle system can be obtained by considering dynamic stiffness. Finally the dynamic characteristic experiment of high- speed electric spindle demonstrates the accuracy of the proposed model.