The Research Of Locomotive Traction Gear Box Sealing Device Internal Flow Field And Structure Optimization Design

In this paper, combining the theory of fluid dynamics,studies of locomotive driving gear box case cover seal. In the locomotive gear transmission, gear teeth immerse in the lubricating oil. Due to the agitation of high-speed gear, part of the lubricating oil will splash and broken into tiny oil mist particles, mix with air, even spread to seal and leak out of gear box under high temperature and high pressure. Therefore, Locomotive gear boxes generally use labyrinth seal for their case cover sealing. In order to reveal the fluid distribution characteristics inside locomotive gear box seal veritably, further understand what factors determine the performance of labyrinth seal, and explore the best labyrinth seal structure, based on the comprehensive consideration of gear box sealing fluid is not pure and complete ideal air, it’s lubricating oil mist and air mixed two-phase fluid. In combination with fluid dynamics analysis software, this paper studies flow field inside gear box labyrinth seal, analyzed the internal flow field characteristics of sealing devices.First, drew two-dimensional axisymmetric staggered teeth shape axial and radial labyrinth seal models, established their grid models; based on fluid dynamics, Simulated oil-air two phase fluid flow in two kinds of seals respectively, verified grid size effects on leakage and found the best size, concluded sealing mechanism. Then, studied and contrasted several factors that influence the performances of seal, axial seal includes number of cavity, pressure ratio, rotating speed of rotor, clearance and cavity sizes; radial seal includes clearance and cavity sizes, isosceles triangle teeth angle, isosceles trapezoid teeth angle, right-angle trapezoid teeth angle, circular teeth top radius; combined seal includes the tendency, position and angle of helical gear. Finally, referred to the research results and experience values, and optimized axial and radial seal structure, showed reasonable structure parameters, combined the optimized axial seal with the radial one into one model and simulated again, verified the validity of the optimization to improve sealing performance.