Study of Injection Method for Maximizing Oil-Cooling Performance of Electric Vehicle Motor with Hairpin Winding

The oil injection method was studied to maximize the cooling performance of an electric vehicle motor with a hairpin winding. The cooling performance of the motor using the oil cooling method is proportional to the contact area of the oil and the coil. A numerical analysis was conducted to examine the effect of the spray nozzle type on the oil flow. The dripping nozzle forms the thickest oil film on the coil, making it the most effective for cooling of hairpin-type motors. Subsequently, an experimental study was conducted to optimize the nozzle diameter and number of nozzles. When the inlet diameter and number was 6.35 mm and 6, the oil film formation rate was 53%, yielding the most uniform oil film. Next, an experiment was performed to investigate the effects of the oil temperature and flow rate on the oil flow. The oil film formation rate was the highest (83%) when the oil temperature was 40 degrees C and the flow rate was 6 LPM.

Automated summary

The study focused on maximizing the cooling performance of an electric vehicle motor with hairpin winding using the oil injection method. Numerical analysis showed that the dripping nozzle was the most effective in forming a thick oil film on the coil for optimal cooling. Experimental results indicated that the highest oil film formation rate of 83% was achieved at an oil temperature of 40 degrees C and flow rate of 6 LPM.