Vibration Reduction by Segmented Continuous Variable Width Pole for Rotating Armature Permanent-Magnet Motors

In the present study, to reduce the electromagnetic vibration of rotating armature permanent-magnet motor, a method is proposed by exploiting the magnetic pole with segmented continuous variable pole width. The distribution of flux density and radial force density in air gap is determined by the analytical method. In addition, the analytical solutions of radial exciting force and bending moment on the magnetic pole are yielded. After conducting the analysis, the principle of magnetic pole width adjustment to reduce radial exciting force and bending moment is formulated. With the three-dimensional finite element method, the magnetic field, Maxwell stress, cogging torque, vibration deformation, and acceleration of the motor are determined. To verify the effectiveness of the proposed method, a comparison is drawn between the proposed scheme and the other three conventional schemes. Finally, the experimentally achieved results regarding the four types of motors are compared to verify the proposed method.