Experimental And Theoretical Study On Damage Mechanism Of Thrust Ball Bearing Induced By Solid Particle Foreign Matter

Outside foreign particles into the rolling bearing is the phenomena of a engineering practice,because outside of pollutants into the rolling bearing lubrication system and cause premature bearing failure has become the main causes of bearing failure,on some special engineering equipment working conditions,bearing replacement and the maintenance cost is relatively high.Therefore,it is very necessary to explore the wear mechanism of rolling bearings under the condition of external foreign particle pollution.This paper simulates the situation of external sand particles entering the thrust ball bearing.Using testing machine combined with a variety of observation and analysis methods,the wear mechanism of bearing raceway and ball is deeply studied.By using finite element analysis method,the process of foreign matter particles being squeezed by raceway and ball is tentatively explored.Firstly,this paper systematically designs the test of simulating sand particles entering the thrust ball bearing.It includes the selection of testing machine,vibration and acoustic emission acquisition system selection,fixture structure design,test material selection,test material preparation,silica particle selection and characteristic determination,test results analysis observation instrument selection,test scheme design and detailed preparation of test steps.Second,to carry out a series of thrust ball bearing wear test,by changing the test time,contact load of silica particles,particle size,the concentration of silica particles,and other parameters,and collected the vibration and acoustic emission signal in the experiment,combining with test at the end of the bearing raceway and ball optical micrograph observation and analysis of the three-dimensional topography parameters,The wear mechanism of the rolling bearing after the outer sand particles enter the inner part of the bearing is studied deeply.The following conclusions are drawn: the surface damage of bearing raceway is composed of small indentation and large peeling area.With the increase of time,the indentation changes to peeling and eventually leads to large area wear on the surface of the raceway.The bearing raceway ball damage mainly occurs in the running-in zone,which is a gray non-metallic strip area,which is composed of a large number of pits.Indentation pits are mainly in the form of uplift around the middle sag,while larger spalling pits are uneven and irregular in shape.The silica particles enter the contact interface between the raceway and the ball,and produce dents and material spalling on the raceway.With the increase of time,these spalling materials will enter the contact interface and continue to destroy the raceway.Vibration and acoustic emission signal detection can also be used as a nondestructive monitoring method to detect bearing wear.Finally,using the finite element simulation software of raceway particles-ball model are simulated,for foreign particles and the deformation and stress of raceway are analyzed,and the simulation result in the ball over the particles,particles and raceway all have a certain degree of deformation,foreign particle material is different,different degree of deformation and stress conditions.