开辅助槽对永磁直线伺服电机法向力波动的影响

Effect of Introducing Auxiliary Slot on Normal Force Ripple of Permanent Magnet Linear Servo Motor

单边平板型有铁心永磁直线伺服电机(PMLSM)由于具有推力大,功率密度高的特点,是目前应用最为广泛的一种直线电机,但由于齿槽效应、端部效应及磁场谐波的影响,电机在运行过程中初、次级之间存在较大的法向力波动,其中齿槽效应引起的法向力波动一方面以摩擦力扰动的形式引起切向推力的波动,另一方会面引起机床的振动。为此,采用Maxwell stress tensor推导初级边齿无限长永磁直线电机空载齿槽法向力的解析表达式,通过对整数槽和分数槽PMLSM法向力波动谐波分量的分析,得出电机初级齿开辅助槽对齿槽法向力波动谐波次数和谐波幅值的影响规律。利用Ansoft Maxwell有限元软件对单边永磁直线电机开辅助槽前后的法向力波动情况进行仿真分析,仿真结果与解析结果基本一致,验证了解析分析方法的正确性,为削弱PMLSM法向力波动提供了理论指导。

Single-side flat-plate core servo-used permanent magnet linear synchronous motor（ PMLSM） with the characteristics of big thrust,high power density,has been the most widely used linear motor at present.However,due to the impact of slot effect,end effect and magnetic field harmonics,there is the large normal force ripple between the mover and stator when the motor is operating,the cogging effect of PMLM is one of the important factors. The cogging effect normal force ripple can cause the feeding table in vibration and produce resonance with other moving components of the servo feeding system. Therefore,the normal force ripple analytical expression of the primary end tooth infinitely long PMLSM can be derived using Maxwell stress tensor method,the further study of the harmonic components of normal force ripples in fractional slot and integer slot PMLSM were done,it can be known that the effect law of introducing auxiliary slot on normal force ripple. Using the Ansoft Maxwell finite element software,the law of the normal force ripple before and after the notching was analyzed. Simulation and analytical results are basically consistent,which demonstrates the validity of the analytical method,which provides theoretical direction for weakening the normal force ripple of PMLSM.