一种磁悬浮永磁直线电动机的电磁力特性

为消除直线电机数控机床进给系统的摩擦阻力,提出一种自身产生磁悬浮力的磁悬浮永磁直线同步电动机.从描述磁介质的分子环流假设出发,用毕奥-萨伐尔定理导出永磁体外部空间磁场分布的解析表达式,并基于由磁荷法和虚位移法给出的永磁体磁力数值积分公式,椎导出电机悬浮力波动的解析模型,说明斜极对电机悬浮力的影响.利用Maxwell 3D软件建立三维有限元瞬态分析模型,结果证明该磁悬浮永磁直线电动机自身可以产生独立并可控的推力和悬浮力.进一步建立斜极结构下电动机的三维有限元模型,分析结果表明采用斜极结构可以有效的减小电机推力和悬浮力的波动.

Electromagnetic force characteristic of magnetic suspension permanent magnet linear motor

In order to eliminate the friction force of linear motor numerical control machine tool feed system,a magnetic suspension permanent magnet linear motor is put forward,which can generate the suspending power by itself.From the molecular current viewpoint,an analytic expression exactly describing magnetic field distribution of rectangular permanent magnets was derived from the Biot-Savart’s law.Based on permanent magnet magnetic force numerical-integral formula which was derived from magnetic charge method and virtual displacement method,got analytical suspension force ripple model for the motor,and the effect of the suspension force ripple after using skewing pole configuration was analyzed.The three-dimensional(3D) transient finite element model of the motor was established.The results show that the motor can respectively generate the suspension force and thrust and the force could be controlled.Furthemore 3D finite element model was established based on skewing pole configuration.The results show that the thrust and suspension force ripple can be reduced by applying skewing pole.