The shape design of interior type permanent magnet BLDC motor for minimization of mechanical vibration

This paper presents a rotor shape optimization of interior type permanent magnet (IPM) motor for vibration minimization. The vibration of permanent magnet motor is generated by cogging torque, radial force and commutation torque ripple which are electromagnetic source of vibration. In order to minimize the vibration, the optimal notches are put on the rotor pole face and the arc type pole face is applied. The variations of cogging torque and radial force of each model vibration frequency are computation by finite element method (FEM) and the validity of the analysis and rotor shape design is confirmed by vibration experiments.