Effect of surface texture on tribological performance of crankshaft bearing

The synergistic lubricating effect of grooved texture and dimpled texture was considered, and the compound texture with parabolic grooves and spherical dimples was designed on the surface of crankshaft bearing to improve its lubrication performance. In order to analyze the effect of compound texture on the lubrication performance of crankshaft bearing, a mixed lubrication model of crankshaft bearing was developed based on average Reynolds equation and Greenwood-Tripp micro-convex contact equation, the mass conservation boundary condition was used to deal with the rupture and reformulation of oil film, the tribological performances of crankshaft bearings with grooved texture, dimpled texture and compound groove-dimple texture were analyzed, and the influences of distribution locations and structure parameters of compound groove-dimple texture on the load-carrying capacity and friction force of crankshaft bearing werestudied. Analysis result shows that the compound groove-dimple texture has larger load-carrying capacity than the grooved texture and lower friction force than the dimpled texture. The maximum dimensionless load-carrying capacity is obtained when the optimal groove width is 1.3 mm, the groove area density is 0.7, the maximum groove depth is 25μm, the dimple number is 6, the dimple area density is 0.7, and the maximum dimple depth is 20μm. The minimum dimensionless friction force is also obtained when the optimal groove width is 2.6 mm, the groove area density is 0.7, the maximum groove depth is 30μm, the dimple number is 15, the dimple area density is 0.7, and the maximum dimple depth is 35μm. When the compound groove-dimple texture has optimal distribution location and structural parameters, the load-carrying capacity of textured bearing increases by 4.1% and the friction force reduces by 19.6% compared with the untextured bearing.