The Influence Of High Speed Rail Gearbox Cavity Structure On The Lubrication Performance Of Gears And Bearings

The gearbox is the core component of the high-speed rail transmission system,which undergoes complex working conditions such as starting,accelerating,and braking during the driving process.Under different operating conditions,both gears and bearings require good lubrication conditions.Poor lubrication of gears can cause tooth surface wear,pitting,and adhesion;Poor lubrication of bearings can lead to temperature rise,vibration,abnormal noise,and other phenomena,affecting the service life of the gearbox,and even causing safety accidents.Therefore,studying the flow field inside the box and the structure of the box cavity is of great significance for the lubrication performance of gears and bearings.This article studies the distribution of flow field in high-speed railway gearboxes and the influence of box body cavity structure on the lubrication performance of gearboxes through numerical analysis,providing reference for the research and design of gearboxes.Firstly,based on computational fluid dynamics(CFD)theory,a three-dimensional CFD model of high-speed railway gearbox is established based on turbulence model and VOF model.The effectiveness of the CFD model is verified through theoretical verification and literature comparison.Then,the machining and assembly characteristics and structural differences of the integral box and the split box are introduced,and the effects of the internal structural differences of the two boxes on the flow field(speed,pressure,turbulent viscosity,and lubrication performance)in the box are compared.The flow field analysis of the gearbox is the basis for studying the lubrication of the output end bearing.Through the simulation analysis of the flow field of the gearbox,the volume fraction and speed of the lubricating oil at the output end bearing oil collecting box are obtained,and the effects of different box type cavity structures on the lubrication performance of the output end bearing are studied.Finally,the effects of different operating parameters(immersion depth,rotational speed,lubricating oil viscosity)on the flow field in the tank were analyzed.Using the average pressure at the meshing point of the gear teeth as the evaluation index of the gear lubrication performance,and the average volume fraction of the plane lubricating oil in the oil collecting box as the evaluation index of the output end bearing lubrication performance,using the response surface method and variance analysis,the respective regression equations were established,and the impact levels of the cavity structure parameters(radial distance,radial distance,and guide rib width)on the evaluation index were analyzed,The influence of cavity structural parameters on each evaluation index was discussed.A set of box model parameters for optimal lubrication performance is given through RSM prediction in Design-Expert software.