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.