Study On Friction And Wear Performance Of Special Pocket Cage Of High Speed Cylindrical Roller Bearings

High-speed cylindrical roller bearing is widely used in aero-engine rotor system and transmission system,high speed and light load is the typical working conditions.Under this condition,the collision between the outer guide surface of the cage and the guide ring,the cage pocket and the roller become more intense,and the friction and wear of the cage become worse.The outer guide surface and the pocket of the cage are the most serious areas of friction and wear of the cage.When the friction and wear are serious,the cage may break and fail,which directly affects the service life of the bearing and the service time of the aero-engine.For the study of friction and wear properties of high-speed cylindrical roller bearing cage,based on the bevel pocket and V-shaped pocket for the special pocket,the influence of the shape and geometry parameters of special pocket on the friction and wear performance of cage was studied,and the influence of different working conditions and structural parameters of cage on the friction and wear performance of special pocket cages were analyzed.The main research work and results are as follows:The lubrication stability of special pocket-roller contact pair was studied.The evaluation method of the lubrication stability of the special pocket-roller contact pair was proposed.CFD software Fluent and post-processing software were used to discuss the influence of different boundary shapes and pocket shapes on the lubrication stability of the special pocket-roller contact pair,providing a basis for the selection of special pocket shapes.The contact model and dynamic analysis model of high-speed cylindrical roller bearing were established.Taking the cage with bevel pocket and the cage with Vshaped pocket as the research object,the mutual motion relationship between the components of cylindrical roller bearing was analyzed,the contact model between the components of cylindrical roller bearing with bevel pocket and cylindrical roller bearing with V-shaped pocket was established,and the theoretical analysis method of bearing dynamic characteristics was obtained.Based on the above contact mechanism analysis,based on the multi-body dynamics software ADAMS and user-defined subroutines,a simulation model of fluid lubrication and multi-body dynamic contact coupling of high-speed cylindrical roller bearings was established.The reliability of the analysis model was verified by experiments.It provides theoretical support and simulation conditions for the research on the friction and wear performance of special pocket cage.The friction and wear properties of the special pocket cage for high-speed cylindrical roller bearings were studied.Taking the time-averaged wear rate as the evaluation index of the friction and wear performance of the cage,the influence of the surface geometry parameters of the pocket on the friction and wear performance of the cage was discussed.The influences of cage clearance ratio(ratio of pocket clearance to guide clearance),inner ring speed and radial load on the friction and wear performance of cage with special pocket were studied.The results show that the geometrical parameters of pocket have significant effects on the friction and wear performance of cage,and the friction and wear performance of cage can be effectively improved by adjusting the geometric parameters of pocket.Pocket clearance and guide clearance have significant influence on the friction and wear performance of special pocket cage,and their values should be reasonably designed.The inner ring speed has significant effect on the friction and wear performance of the special pocket cage.The timeaveraged wear rate of the outer guide surface of cage and the cage pocket increases with the increase of the inner ring rotational speed.The research results can provide reference value for the structural design of bearing cage.