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.

直接接触式油冷系统设计用于增强电机散热，集成电机冷却系统和齿轮箱冷却系统。考虑到油品的高粘性阻力，提出了一种新的S形通道。S形通道的压力损失仅为直角轴向通道的一半，比圆角轴向通道的压力损失小33%。采用有限元方法优化了S形通道的结构参数和喷油嘴的布置。优化后的圈数、通道宽度和喷嘴数分别为16、18 mm和19。电机最高温度为92.6℃，端部绕组最高温度比定子铁芯高1.5℃。所以，