| In recent years,with the increasing environmental pollution and the pressure of energy shortage,traditional automobiles have been questioned more and more due to their fuel consumption and exhaust emissions.Electric vehicles with various driving modes have developed rapidly because of their advantages of energy saving and environmental protection.Among them,electric vehicles driven by hub motors have received extensive attention and research.Hub motor drive system integrates transmission,differential,motor and so on into the wheel,and eliminates transmission devices.It has great advantages in chassis layout and improves transmission efficiency.But at the same time,there are also some shortcomings.Integrating each component into the space of the wheel increases the quality of the non-spring load,which affects the ride comfort and other automotive dynamic characteristics.Therefore,it is important to optimize the structure of hub motor based on electromagnetic field and temperature field.The main contents of this paper are as follows:(1)Structural optimization design of hub motor based on electromagnetic field.The model of hub motor is established,the electromagnetic field is analyzed,and the results are compared with the existing data to verify the correctness of the finite element model.Then,with the objective of minimizing the volume,the topology optimization model under the boundary condition of electromagnetic field is established,and the topology optimization of different parts of hub motor is carried out,and the results of electromagnetic field calculation before and after optimization are compared and analyzed.(2)Structural optimization design of hub motor based on temperature field.The temperature field analysis model of hub motor is established.Based on the calculation of electromagnetic field loss in Chapter 2,the temperature field results of hub motor are analyzed.On the basis of deepen understanding of the temperature field distribution,the optimal design objective is to minimize the volume of hub motor,and the temperature distribution is the boundary condition,The topology optimization design of each part of hub motor is carried out.By comparing and analyzing the results of temperature field calculation before and after optimization,the optimization results are verified.(3)Research of coupling method and characteristic analysis of electromagnetic field and temperature field.The coupling factors between electromagnetic field and temperature field and the influence trend of the two fields are analyzed.According to the analysis results,the coupling analysis model of electromagnetic field and temperature field is established,ignoring the influence factors of weak coupling.On this basis,based on the solution methods of unidirectional and bidirectional coupling of electromagnetic-temperature field of hub motor,the multi-field coupling calculation is solved,and the results are compared and analyzed to verify the accuracy of the multi-field coupling analysis,at the same time,it lays a foundation for the following topology optimization design of hub motor under multi-field coupling.(4)Structural optimization design of hub motor under the coupling of electromagnetic field and temperature field.Taking volume minimization as the objective of optimization design and considering the boundary conditions of electromagnetic field and temperature field,the topology optimization models in different optimization design domains are established.Based on the above-mentioned multi-field coupling analysis model,the topology optimization design of hub motor under multi-field coupling is carried out.By comparing the results of multi-field coupling calculation before and after optimization,the optimization results are verified. |
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