高速永磁同步电机转子强度分析

为了对转子进行有效的冷却,在满足电机电磁性能的前提下,可通过减小保护套的厚度来尽可能增大定转子之间的气隙,因而必须对保护套和永磁体进行强度校核。将转子受力状况简化为平面应变问题,在此基础上推导出了两层过盈配合、三层过盈配合转子的应力场、应变场、位移场的解析公式,并利用有限元方法验证了解析公式的正确性。归纳了高速情况下热套式永磁转子强度设计准则,为转子的优化设计提供了理论依据。以一台额定转速120 kr/min、10 kW的高速永磁同步电机为例,给出了两种常用过盈配合高速电机转子的强度设计方法。

Rotor Strength Analysis of High-speed Permanent Magnet Synchronous Motors

In order to cool rotors effectively,the air gap of motors should be increased as much as possible by decreasing the sleeve thickness,and the motor performance must be effectively fulfilled,the strength of sleeve and the permanent magnet must be checked.In this paper,analytical formulas of stresses,strains and displacements of two the ply composite rotor and the three ply composite rotor are deduced based on that rotor stress conditions,which can be reduced to a plane strain problem.The validity of the theoretic analysis are verified by the 3D finite element method(FEM) model.Design guidelines of the high speed interference fit rotor that offers theory base for optimal design was generalized.The strength design method of the high speed interference fit rotor is presented by taking a high speed PM motor rating 120 kr/min at 10 kW for example.