Research On Tribological Performance Of Bearing Grease And Simulation Calculation Of Bearing Thermal Stress

The most common tribological components required in electrical vehicles(EVs)to operate as similar as possible to ICEVs can be seen in the review gives an understanding of the most recent achievement in term of tribological solution apply to components and the identification of research gaps for further work and developments according to the improvement of efficiency of EVs.Roller bearing are significant components of supply EV motor and play critical role in normal operation of the motor,although many factors can lead to failures of a roller,failure of lubricating grease may be predominant cause of failure,the failed greases generally suffered from physical,chemical and thermal degradations during bearing operation,and the degradation brought about the loss of lubricating capacities,capacities,especially under high temperature and high velocity condition.Ionic liquids usually have the advantages of good thermal stability,lower pressure,wider electrochemical window,better anti-friction and anti-wear performance and conductivity,and the types and combination of anions and cation are adjustable.Lubricating greases composite preparation for this research is lithium-base grease with different ionic liquids as additives.Among them[C5mim][NTf2],[C5mim][PF6],[C8mim][NTf2],[C8mim][PF6],[C12mim][NTf2]and[C12mim][PF6]as an additive,the contents are 0.5%,1%and 2%,and the loads are 50 N and 100 N.The results show that ionic liquids have excellent anti-friction and anti-wear properties as grease additives.Graphene and graphene oxide have big effect of an important role in some self-lubrication composites.As additive in certain liquid lubricant to improve anti-friction and anti-wear property.In this paper examiner the effect of few layer graphene(FLG)additive on the lubrication efficiency of lithium grease.FLG can effectively improve the anti-friction and anti-wear properties of lithium grease.Grease sample containing 0.10 wt%FLG show the best performance in reducing the friction coefficients and WSD at a large load and low rotary.The proceeding state of traction motors in high-speed EMU(Electric Multiple Unit)are anxiety problems.To generate heat inside the bearing under high load and severe friction.It is necessary to study thermal performance and temperature distribution of ball bearing in traction motors of high-speed EMU.In this paper the application of the relevant mathematical model is extended,and thermal performance and temperature distribution of a grease lubricated bearing under different working condition are studied.Bearing are operate under boundary and mixed lubrication conditions.Boundary lubrication regime is generally observed for thin thickness(λ≤3)which induces the wear and the worn-out particles are contaminating the lubricant.The contaminated lubricant effect of the rolling element bearing is discussed in this paper work with various experimental and numerical analysis.The two Si3N4 balls removed the protrude portion of the artificial pit on the track surface,which in-turn improve the bearing life.