Abstract:Taking the labyrinth seal structure of the gear motor end of a highspeed EMU gearbox as the research object,the twodimensional axisymmetric rotational flow model of the labyrinth seal with a diffusion cavity was established by using Fluent to simulate the leakage of labyrinth seals.The structural deficiencies of this labyrinth seal,such as a slightly larger seal gap,a larger tip angle,and a shallower cavity depth,were pointed out.A simulation program was designed by using Designexpert 80 software to analyze the effects of seal gap,tooth angle,number of seal teeth,depth of sealed cavity,and rotation speed of the drive shaft on the leakage of labyrinth seal,and a set of optimal parameters were obtained to minimize leakage.The results show that the order of the influence of single factor on the leakage of labyrinth seal is seal gap,depth of cavity,number of teeth,and angle.Rotational speed has almost no effect on leakage.Among the influencing factors of interaction,the influence of seal clearance and cavity depth on leakage is greater than that of seal clearance and tooth number.Through remodelling and simulation,it is verified that it is feasible to use DesignExpert 80 software to design the simulation test scheme of labyrinth seal leakage and optimize the parameters of labyrinth seal.