永磁球形电动机转矩特性的数值计算与分析

提出了一种新型永磁球形电动机的基本结构与运行机理，建立了其三维有限元分析模型；针对驱动电机自转的转矩进行了数值仿真，得到了永磁球形电动机的电磁转矩特性曲线和磁阻转矩特性曲线．通过比较分析球形电机不同转子极充磁方式、定子线圈铁心磁导率以及定子外壳是否采用铁磁材料时电磁转矩特性的变化，得出了提高球形电机输出转矩的有效途径．系统地分析了球形电机主要参数的变化对电机转矩的影响，得到了永磁球形电动机最大静转矩随定子极高度、定子铁心半径、永磁含量系数、线圈安匝数以及气隙长度等参数的变化规律．分析结果为永磁球形电动机的优化设计提供了依据．

Calculation and Analysis of Torque Characteristics of a Permanent Magnet Spherical Motor

The mechanical structure and operation principle of a novel permanent magnet （PM） spherical motor were proposed in this paper. An effective 3-D electromagnetic torque finite element model of the PM spherical motor was established. Based on the model ,the numerical simulation was made about the torque which can drive the motor rotating. The electromagnetic torque characteristics and reluctance torque characteristics of the motor were derived. Through comparing and analyzing the variation of the torque characteristics of the spherical motor with different magnetizing methods of rotor poles, different stator iron core permeabilities and different materials applied in the stator shell respectively,an effective way which can enhance the output torque of the spherical motor was obtained. Effects of the variation of main parameters of the spherical motor on the electromagnetic torque were analyzed,and the variation rules of the maximum static torque （MST） of the motor with the length of stator poles,the radius of the stator iron core ,PM content coefficient,ampere turns of windings and the air gap length were obtained respectively. The analysis results provide a basis for the optimization design of the PM spherical motor.