In order to further improve the sealing effect of the sealing structure at the bearing end cover of the train gearbox,and effectively prevent the fluid exchange between the inside and outside of the reducer,based on the previously designed sealing structure,the sealing structure parameters,such as the inner diameter of the impellers on both sides,the inclination of both sides of the blade,the inclination of the bottom of the blade,the fillet of the side of the blade and the number of blades in the middle of the impeller,were optimized and analyzed.Combining the hydrodynamic analysis results and the previous experimental data of the sealing structure,the influence of various parameters on sealing effect was explored.The results show that the inner diameter of the impeller blades on both sides and the inclination angle of the blade side have great influence on the sealing effect,while other parameters have little influence on the sealing effect.Compared to the original sealing structure,the average pressure difference on the key plane between the impeller in the middle and the impeller on the opposite sides of the shaft end seal structure after optimization is increased from 22.97 Pa to 357.94 Pa.And it is found from the velocity streamline diagram that an obvious isolation zone is formed in the middle of the seal structure,which can effectively prevent the fluid leakage inside and outside the gearbox and improve the sealing performance of the shaft end.