多因素影响下高速电主轴系统动态特性分析

Analysis of Dynamic Characteristics of High-speed Spindle System with Multi-factor Influence

以某大功率高速铣削加工中心电主轴系统为研究对象,采用有限元法,综合考虑高速状态下主轴系统阻尼比、陀螺力矩效应和轴承刚度软化3种因素,建立了高速电主轴系统的动力学方程。得到了主轴系统由转速引起的陀螺力矩效应,轴承刚度变化两种因素影响下的前6阶固有频率,并进一步得到了上述3种因素影响下的刀尖处频率响应。结果表明在高速状态下,轴承刚度的软化对固有频率的影响大于陀螺力矩效应;而主轴系统的结构阻尼比会减弱轴承刚度软化对刀尖处频率响应的影响。

This paper takes a high-speed milling center spindle system as object of study,uses the finite element method and considers the spindle system damping ratio,gyroscopic moments and bearing stiffness softening effect to establishes the dynamic equations of the high-speed spindle system,gets the first six natural frequencies of the spindle system affecting the gyroscopic effect and bearing stiffness change and obtains the frequency response at cutting the edge affected by the three factors. The results show that at high speed,the impact of bearing stiffness softening on the natural frequency is greater than in the gyroscopic effect. And the structural damping ratio of the spindle system can weaken the impact of the bearing stiffness softening on the frequency response of the tip.