永磁球形电动机定子线圈座的应变分析

Strain analysis of stator coil holders for permanent magnet spherical motors

利用气隙磁通密度解析模型和洛仑兹力公式建立了球坐标系下空心定子线圈所受切向电磁力和径向电磁力的解析模型.利用定子壳体和线圈座的有限元模型计算定子线圈座在电磁力作用下的应变,分析了定子壳体厚度、线圈座连接杆长度和直径对应变的影响.最后利用有限元法和解析法对样机进行分析并对结果进行比较,验证了解析模型的正确性和准确性.分析表明,当定子壳体厚度和连接杆直径线性减小而连接杆长度线性增大时,定子线圈座在电磁力作用下产生的应变量在一定范围内线性增加,然后显著增加.

An analytical model of air-gap flux density and the Lorenz force law were used to establish radial and tangential electro- magnetic force models in the spherical coordinate system for the stator coils. Then, a finite element model of the stator casing and coil holder was applied to compute the strain of the coil holder caused by electromagnetic force, and the influences of the stator casing＇ s thickness, the diameter and the length of the coil holder＇ s connecting rod on this strain were analyzed. Finally, the finite element method and the analytical method were used to analyze a prototype motor and their results were compared, which verified the validity and accuracy of the analytical models. This analysis shows that when the stator casing becomes thin or the connecting rod slenderizes, the strain of the stator coil holder produced by electromagnetic force increases linearly within a certain range and then grows significantly.