数控蜗杆砂轮磨齿机主轴系统模态与谐响应分析

Modal and harmonic response analysis of spindle system on CNC worm wheel gear grinding machine

针对数控蜗杆砂轮磨齿机磨削过程中具有简谐振动的特点,建立其主轴系统的三维有限元模型。利用有限元分析软件ANSYS进行模态分析和谐响应分析。通过模态分析求解获得了主轴系统的固有频率和振型,并研究了角接触球轴承支承刚度对其固有频率的影响;通过谐响应分析获得了主轴系统的变形—频率响应曲线,最后通过计算临界转速来验证主轴系统是否发生共振。研究结果表明:增大角接触球轴承的支承刚度有利于提高主轴系统的固有频率。磨削激振力的频率在600Hz附近时,变形—频率响应曲线出现了最大的峰值响应为6.56μm。为了避免共振,主轴系统的工作转速应尽量避开一阶临界转速。

Based on the characteristics of simple harmonic vibration of CNC worm wheel gear grinding machine in the process of grinding, a three-dimensional finite element model of the spindle system was established. Modal analysis and harmonic response analysis were carried out through finite element software ANSYS. The natural frequencies and modes of the spindle system were obtained by the modal analysis. The effect of supporting stiffness of ball bearings to the natural frequencies was evaluated. The deformation-frequency response curve was obtained by analyzing the harmonic response of the spindle system. Lastly, the resonance vibration was verified by the critical speed. The results showed that the increasing supporting stiffness of the ball bearing was conducive to the improvement of the spindle system＇ s natural frequencies. When the frequency of grinding exciting force was in the vicinity of 600 Hz, deformation-frequency response curve showed a peak response to 6.56 μm. In order to avoid resonance vibration, the operating speed of the spindle system should avoid the first-order critical speed.