高精度永磁直线伺服电动机法向电磁力波分析与计算

Analysis and Calculation of the Normal Electromagnetic Force Wave of Precision Permanent Magnet Linear Servo Motor

永磁直线伺服电动机在运行过程中动、定子之间存在较大的法向电磁力波动,法向力波动引起的振动和摩擦摄动严重影响到高精密机床的定位精度。法向力波动主要由电机气隙磁场作用于动子铁心的法向电磁力波所激发,齿槽效应是影响它的重要因素。为此,采用磁动势磁导法推导出单边平板型永磁直线电机法向电磁力波的解析表达式;分析各阶力波次数和力波幅值对法向力波动的影响。通过对傅里叶分解系数的分析,指出极弧系数和极槽配合是影响法向电磁力波的两个主要因素。利用Ansoft有限元软件对8极12槽单边永磁直线电动机进行仿真分析,仿真结果与解析结果基本一致,验证了法向电磁力波解析分析方法的正确性。

There is the large normal force ripple between the mover and stator when the single-side flat-plate permanent magnet linear motor （PMLM） is operating,and the friction force perturbation and the vibration of the machine tool caused by the normal force ripple will influence the accuracy of machine tool greatly.The normal force ripple can cause the feeding table in vibration and produce resonance with other moving components of the servo feeding system.It is produced by normal electromagnetic force wave acting on iron cores of PMLSM.The cogging effect of PMLM is one of the important factors.Therefore,the analytical expression of normal force wave of single-side PMLSM was deduced using the method of magnetmotive force （MMF） magnetic permeance,the further study of the force wave order and amplitude for the normal force ripple was done.It can be known by analyzing the Fourier decomposition coefficients that the pole and slot matching and pole arc coefficient are the two main parameters impacting the normal electromagnetic force wave.Using the Ansoft finite element software,the law of the normal electromagnetic force wave of a 6 poles 36 slots PMLSM was analyzed.Simulation and analytical results are basically consistent,which demonstrates the validity of the analytical method for the normal electromagnetic force wave.