Pole-shape optimization and thermal analysis of PM spherical stepper motor

This paper presents the optimum rotor and stator pole-shape design for a PM spherical stepper motor by experimental design method and the thermal analysis is performed using 3-D FEM. Based on the torque characteristics analysis and full factorial design, three main control factors are selected and their effects on the torque characteristics are discussed in detail. As for the steady-state thermal analysis, the relationships between the stator materials, thickness, and cooling modes with the temperature rise are presented and the computation results are given. The results provide the theoretical guide for the further design, optimization and control research of the spherical stepper motor.