Research On Tribological Properties Of Partially Tilting Pad Thrust Bearing With Micro-dimple

Thrust bearing is widely used in the transmission system of mechanical equipment,which is mainly used to support the axial load of rotating shaft,and its mechanical properties determines the working efficiency and service life of the mechanical equipment.Compared with the traditional parallel thrust bearing,the tilting pad thrust bearing can form several convergent wedges around the journal,which has higher bearing capacity and higher stability.However,the tribological performance of tilting-pad thrust bearing is facing more serious challenge.The surface texture technology can effectively improve the tribological performance of the motion pair,and the proper partial texture can effectively improve the load-carrying capacity of the thrust bearing.In this academic dissertation,the effect of partial texture on the tribological properties of thrust bearing is studied by using surface texture technique to process regularly arranged partial dimple on the bearing surface.Based on the formation mechanism of hydrodynamic lubrication and the ’balance wedge effect’ of tilting pad,the mass conservation cavitation boundary condition(JFO)is introduced in this academic dissertation,a two-dimensional hydrodynamic lubrication numerical model of tilting pad thrust bearing with partial dimples is established.In order to reduce the number of independent and dependent variables,the mathematical model is dimensionless.Finally,the pressure distribution of the tilting pad thrust bearing is solved by multi-grid method,and the effect of partial dimples texture on hydrodynamic lubrication performance of tilting pad thrust bearing is analyzed.The results show that the convergence ratio is a key factor for bearing capacity,and the proper partial dimple texture has a positive effect on the bearing capacity of tilting pad thrust bearings.When the convergence ratio is small,the bearing capacity can be maximized by the optimal textured extent and the dimple depth.In order to obtain greater hydrodynamic pressure,the divergent wedge effect of texture should be reduced and partial texture should be arranged in the inlet area.The RTEC MFT-5000 multifunctional friction and wear test machine was used to conduct the friction and wear test of the partial textured thrust bearing,and the effects of the partial texture circumferential extent,radial extent,circumferential position and radial position parameters on the tribological properties of the thrust bearing were investigatived.The results show that the partial dimple texture has good lubrication and anti-friction properties,while the friction factor of the full texture is higher than that of the partial textured sample.With the increase of the texture radial extent and the circumferential extent,the average friction factor of the sample decreases at first and then increases,indicating that the optimal texture radial extent and circumferential extent can optimize the tribology of the thrust bearing.performance.The effect of radial position on the friction factor is almost negligible.The smaller the circumferential position,the smaller the friction factor of the sample,indicating that the pratial texture at the entrance can effectively improve the tribological performance of the thrust bearing.