高速永磁电机转子设计与强度分析

文中介绍了高速永磁电机的设计特点，重点论述了永磁材料和转子结构型式的选取、主要尺寸的确定与转子强度的分析和计算方法。目前永磁电机多采用烧结钕铁硼永磁材料，其抗压强度较大而抗拉强度很小，永磁体难以承受转子高速旋转巨大离心力产生的拉应力，必须在永磁体外设置高强度非导磁防护套，采用过盈配合给永磁体施加一定的预压力。文中介绍了采用解析法和数值分析有限元法进行高速永磁电机转子强度分析的实用技术，并给出了对一台额定转速为60000r／min的高速电机永磁转子强度的分析计算结果。

ROTOR DESIGN AND STRENGTH ANALYSIS OF HIGH SPEED PERMANENT MAGNET MACHINE

In this paper, the design features of high speed permanent magnet machines are introduced. More discussions are paid to the choice of permanent magnet (PM) material and rotor structure, determination of main rotor dimensions, and analysis method of rotor strength. Nowadays, the sintered neodymium-iron-boron (Nd-Fe-B) material is used in most of PM machines. This kind of PM material has large compression strength but small tensile strength, and can not withstand the large centrifugal force due to the high rotation speed. A nonmagnetic steel enclosure is needed to cover the PM material.The tensile press of PM can be reduced by pre-pressure applied to the outer surface of the PM through shrink-fitting into the enclosure. The rotor strength analysis methods of high speed PM machine by means of analytical method as well as finite element analysis are introduced. As an example, the strength analysis results for a high speed PM machine with rated speed of 60000r/min are presented.