Design of an oil-cooling-system of new energy vehicle drive motor

Abstract

A direct contact oil-cooling-system is designed for enhancing motor heat dissipation and integrating motor cooling system and gearbox cooling system. Considering the high viscous resistance of oil, a new S-shaped channel is proposed. The pressure loss along the S-shaped channel is only half of that of the axis-oriented channel with right turn angle and is 33% less than that of the axis-oriented channel with fillet. The structure parameters of the S-shaped channel and the layout of the oil spray nozzles are optimized by finite element method. The optimized turn number, channel width and nozzle number of are 16, 18 mm, and 19 respectively. The highest temperature of the motor is 92.6 °C and the highest temperature of the end winding is 1.5 °C higher than that of the stator core. Therefore, lower flow resistance and better temperature uniformity in the motor with the direct contact oil-cooling-system is realized.