Thermal Analysis and Research of Axial Flux In-wheel Motor

The in-wheel motor for electric vehicles needs to meet the requirements of high power density and efficiency. The heating and heat dissipation of the motor has an impact on the reliability and stability of the vehicle operation. In this paper, an yokeless and segmented armature axial flux in-wheel motor with wound amorphous alloy stator tooth is used as an analysis prototype. Based on the theory of electromagnetic loss, a three-dimensional electromagnetic field finite element model of the motor is established. The electromagnetic losses of the motor under different working conditions are calculated. The heat conduction method of the stator teeth is analyzed. The equivalent thermal conductivity and heat dissipation coefficient of each component are calculated, a three-dimensional temperature field finite element model of the motor is established. the amplitude and distribution of the motor temperature rise are obtained. The prototype is manufactured and the experimental platform is built. The temperature at different positions of the motor is measured by thermocouples and infrared cameras, which is consistent with the calculation results. The effectiveness of the finite element model is verified. The thermal characteristics of the prototype proposed in this paper meet the requirements of electric vehicles and can provide a reference for the thermal design of novel axial flux in-wheel motors.