Study On The Influence Of Spherical Pit Texture On Tribological Properties Of Hydrodynamic Sliding Bearings

Sliding bearing is an important component used to support shaft and other rotary parts.Surface texture,as an effective method to reduce surface friction,reduce wear and improve lubrication and load-carrying performance of friction pairs,has attracted extensive attention of scholars at home and abroad in recent years.At present,there are few theoretical studies on the bearing load and friction characteristics of the spherical pit texture on the inner surface of journal bearing bush.Based on theoretical analysis and experimental verification,the research results of friction reduction design of the textured journal bearing are obtained.Firstly,based on hydrodynamic lubrication theory,the mathematical model of spherical pit texture hydrodynamic sliding bearing is constructed.Secondly,the dimensionless Reynolds equation is obtained by simplifying the three-dimensional Reynolds equation,and the Reynolds boundary conditions are chosen to constrain it.Then the dimensionless Reynolds equation is solved by the finite difference method,the mesh of the solution area is divided,and the appropriate convergence conditions are set.Finally,the corresponding flow chart of program design is given,which lays a theoretical foundation for subsequent simulation analysis.Secondly,the influence of spherical pit texture on the load and friction characteristics of hydrodynamic journal bearings is studied by MATLAB software.The results show that:(1)the number of grids,bearing width-diameter ratio,eccentricity,texture distribution area,texture radius,spacing,depth and area ratio have great influence on the load-bearing and friction characteristics of sliding bearings.(2)The 45-180 degree bearing capacity with texture distribution in the convergence zone of the bearing is the best.(3)When the optimal dimensionless texture spacing is 10 and the texture depth is 0.5,the bearing performance is the best.(4)On the premise of satisfying the load-bearing characteristics,the friction force is minimized.The final eccentricity is 0.8,the ratio of width to diameter is 1.2,the texture radius is 200 ?m,the dimensionless texture spacing is 10,and the dimensionless texture depth is 0.5.(5)When the lubricant viscosity is 0.03 Pa ?s and the journal speed is 5.23m/s,the friction coefficient of sliding bearing is the smallest when the optimum texture area ratio is 78.5%.Finally,the friction tests of the processed specimens were carried out by means of BY-BDB self-made surface laser textile machine and M-2000 friction and wear tester.The results show that the friction force can be significantly reduced when the texture diameter is small,but increased when the diameter is large.For bearing steel specimens,the friction force can be lowered most by selecting texture crossarrangement specimen 4,but for brass specimens,the friction force can be lowered most by selecting texture cross-arrangement specimen 5.Proper texture area ratio can minimize friction of bearings.