Thermal Design of High Power Density Motors with Excellent Efficient Cooling Structure

A structure that includes teeth cooling, yoke cooling and end winding cooling to realize high power density and low temperature of motors was proposed in this paper. The cooling channels are specifically designed to provide more cooling areas compared to the conventional flooded motors. The yoke cooling channels adopts an axial and circumferential series connection structure. A nozzle at the end of the tooth oil channel is designed to cool the end windings. Computational Fluid Dynamics (CFD) is applied to predict the temperature and flow. The results indicate that the winding temperature has decreased by $45^{\circ}\mathrm{C}$ compared the conventional flooded motor.