Research On Lightweight Design Of Axial Flux Permanent Magnet Synchronous Machine And Related Techniques

Axial flux permanent magnet synchronous machine(AFPMSM)has higher power density and higher torque density than other types of machine,and its plat structure can well adapt to flat space.So it has broad application prospects in the fields such as transport,wind power and aerospace.To further optimize the performance,a lightweight structure design of AFPM synchronous in-wheel machine is proposed in this paper.And some techniques relative to AFPM machine structure are also investigated.The main research contents are as follows:Firstly,the traditional structure design method of the single stator single rotor AFPM(SSSR AFPM)is analyzed based on the given performance index.And assisted by FEA,the optimization method aiming to obtain the best machine dimension with highest torque density is proposed.Then,based on the analysis of the magnetic circuit in yoke,the material utilization rate(MUR)is studied.The lightweight design method is proposed to improve MUR.Secondly,by using the lightweight design method,the SSSR AFPM machine is redesigned.The output performance of SSSR AFPM machine before and after lightweight design is compared.At the same time,the lightweight design of SSDR AFPM and DSSR AFPM is also investigated,and the output performance before and after lightweight design is studied too.Furthermore,the output performances of different types of AFPM machines are analyzed and compared horizontally.Thirdly,because the ratio of machine diameter to length is relatively high,a small assembly error or a slight deformation may result in a dreadful static eccentricity.The static eccentricity(SE)in different types of AFPM machines is studied.The SE magnetic field distribution is analyzed by solving the scalar potential formula and its analytical expression is studied.FEM is applied to verify the accuracy of the analytical result.In addition,the SE magnetic field distribution of multi-stage machine and AFPM machine with slots is investigated.Finally,the mechanical strength of end covers,axis and shell of SSDR AFPM machine and DSSR AFPM machine are studied.The assembly method was given in different types of AFPM machines.The stress condition of mechanical components under the load condition were studied.Corresponding stress models are established to calculate the mechanical strength.By mechanical calculation,the minimum dimensions of mechanical components satisfying mechanical strength are analyzed.