Thermal analysis of surface mounted permanent magnet brushless DC motors with different types of retaining sleeve

In this paper, the transient thermal fields of two permanent magnet brushless DC motors with identical rated power and rated speed have been calculated and analyzed via two-dimensional time step finite element method. One of the motors has stainless steel retaining sleeve, another has carbon fiber retaining sleeve. The influence of the different materials on the temperature rises is compared and analyzed. The study reveals that carbon fiber is superior to stainless steel in terms of reducing rotor losses and depressing temperature rises. Furthermore, simulation results are compared with experimental data to verify the accuracy of the model.