多层护套结构高速永磁电机转子机械强度与损耗分析

Analysis of mechanical strength and loss of high-speed permanent magnet motor rotor with multi-layer sleeves structure

针对表贴式高速永磁电机转子护套与永磁体之间过盈配合单一、护套内外表面上作用力跨度较大的问题,提出一种多层护套转子结构,能有效减小护套的总厚度。在满足转子机械性能的前提下,多层护套转子结构通过在每层护套之间施加适当过盈量的方法使护套整体的受力分布更加均匀,提升了护套的使用效率,因此总厚度相比单层护套更薄。为快速分析多层护套转子结构的受力情况,建立了该结构的二维应力场解析计算模型。基于解析模型提出了一种多层护套的设计方法,并用该方法对一台高速永磁电机的转子进行设计,且通过有限元分析验证了该设计方法的准确性。最后,将所设计的多层护套与原单层护套相对比,该结构的护套厚度减小了10%、转子涡流损耗减少了12.6%。

Aiming at the problems that for the surface-mounted high-speed permanent magnet motor, the interference fit between the rotor sleeve and permanent magnet is single and the span of force on the inner and outer surfaces of the sleeve is large, this paper proposes a multi-layer sleeves rotor structure, which can effectively reduce the total thickness of the sleeve. Under the premise of satisfying the mechanical performance of the rotor, the multi-layer sleeves rotor structure makes the overall force distribution of the sleeve more uniform by applying an appropriate interference fits between different layers of sleeves, and improves the efficiency of the sleeve. In order to quickly analyze the force of the multi-layer sleeves rotor structure, an analytical model for calculating the two-dimensional(2 D) rotor stress field was established. Based on the 2 D rotor stress field model, a design method for the multi-layer sleeves was proposed and the rotor of a surface-mounted permanent magnet motor was designed. The accurateness of the design method was verified by the finite element analysis. Finally, comparing the designed multi-layer sleeves rotor structure with the original structure, the total thickness of the multi-layer sleeves is reduced by 10%, and the rotor eddy current loss of the new structure is reduced by 12.6%.