The helical gear pair in the reduction box of electric vehicle is in oil lubrication state. The thicker the oil film, the better the meshing performance of the helical gear. As shown in the figure, the oil film thickness curve of No. 0 unmodified gear, No. 1 optimized gear and No. 9 optimized gear is shown. On the whole, the oil film thickness of helical gear pair after No. 1 and No. 9 optimized gear has increased greatly, and the thinnest oil film thickness of gear teeth has increased from 0.17 before the modification μ M increased to 0.20 respectively μ m、0.18 μ m. It increased by about 17.6% and 5.9%.
