Numerical Simulation Study On Lubrication Performance Of Water Lubricated Ceramic Sliding Bearing

The physical and chemical properties of water are different from traditional lubrication,its viscosity is low,and the bearing capacity of water lubricated bearing is low,therefore it is necessary to choose the appropriate bearing material when the water was used as lubricant.In this paper,caremic was selected as bearing material,its high temperature resistance,corrosion resistance,and wear resistance.An infinite line contact elastohydrodynamic lubrication model was established to solve the question of water lubricated ceramic sliding bearing.Based on the theory of elastohydrodynamic lubrication,soft elastohydrodynamic lubrication,multigrid method and multigrid integration method,the elastohydrodynamic lubrication problem of ceramic bearing with water lubrication was analyzed,and the numerical solution of the lubrication under different conditions was obtained.The main factors considered in this paper including inertial force,transient load,surface micro pits,time-varying,roughness,mixed lubrication and other factors.First of all,the thermal effect and surface roughness of the continuous wave were considered,The numerical solution of the sliding bearing under the action of inertia force was obtained when the water had been used as lubricant,and the change of the lubricant film pressure and film thickness were compared when there was no force,in addition,the effects considering the inertial force with different speed,different slip ratio and different roughness magnitudes on the lubrication perfomance were analyzed.Secondly,considering the thermal effect and time-varying effect,changes of pressure and film thickness of water lubrication ceramic bearing under the step,rectangular pulse,sinusoidal pulse and Gaussian pulse four different forms of transient load were obtained by numerical simulation,furthermore,the tendency of the center pressure,the center film thickness and the minimum film thickness change in the water was obtained,and the change of the minimum film thickness of four kinds of transient loads were compared.Third,considering the influence of heat effect,the rectangular and spherical crater model of suiface texture bearing was set up,the pressure and film thickness of thelubricating film under the micro-pit of rectangular and spherical crowns were analyzed,and the numerical solution of the ceramic sliding bearing were obtained by numerical analysis.Then,pressure and film thickness under the effect of two kinds of micro pit situation with different depth,micro pit width,number of micro pits and slip were compared,to obtain the lubrication performance of water lubricated ceramic bearing.Finally,considering the the time varying roughness on two solid contact surface,the mathematical model of line contact in mixed lubrication was set up,the water pressure and water film thickness of ceramic sliding bearing in different instantaneous wrer obtained,and effects of different sliding ratio,different film thickness ratio,different speed and different roughness amplitude on the lubrication performance were compared.