Detent Force Reduction in Permanent Magnet Synchronous Linear Motor Based on Arc-teeth

Permanent Magnet Synchronous Linear Motors (PMSLM) has the advantages of high thrust force density, high acceleration, high speed, high precision, high efficiency etc. However, the detent force of PMSLM is an inevitable problem, caused by their inherent end-disconnection structure. Excessive detent force will cause thrust fluctuations and reduce the system’s stability. To resolve the above problems, an improved PMSLM structure based on arc-teeth is proposed to reduce detent force. Firstly, the motor permeability distribution is analyzed at different moments based on the flux-tube method, and the expression of detent force is derived. Second, the finite element model of PMSLM is established to optimize the height of arc-teeth, and the optimal structural parameters of the motor is obtained. Finally, the performance advantages of the proposed PMSLM are verified by comparing with traditional linear motor.