Numerical Analysis on Seal Structure of High-speed Gearbox Lubrication System

Taking the labyrinth seal at the small-gear motor end of the driving gearbox of the high-speed EMU as the research object,the numerical simulation model of the labyrinth seal with the oil thrower was set up,which was fully compressible,two-dimensional axisymmetric swirl flow.The distribution of flow field within the labyrinth seal cavity and the leakage characteristics were simulated by using the standard k-eturbulence model along with enhanced wall treatment.The Navier-Stokes equation,and energy and turbulence equations were discreted with the finite-volume method and Software Fluent.The SIMPLE algorithm was used for pressure-velocity coupling.The effect of the cavity depth on leakage was studied and the optimum cavity depth was determined.The effects of pressure difference and rotational speed on leakage were also studied.The results show as follows:Along with lengthening of the cavity depth,the leakage firstly falls down and then rises up;the leakage increases with increasing of the pressure difference;without considering the temperature rise,the rotational speed shows no significant influence on leakage,however,raising of the rotational speed improves sealing performance.