| About one-third to one-half of the world’s energy consumption is caused by friction and wear,and about 80% of the parts in mechanical equipment fail and scrap due to wear.Reducing the friction resistance of friction pairs and increasing bearing capacity can improve the service performance of mechanical equipment and increase its working life.Surface texture is an effective means to improve the lubrication ability of friction surfaces,reduce friction,and improve the loadbearing capacity of lubricating oil films,which can reduce the premature failure of mechanical equipment and energy consumption caused by friction and wear.Starting from the morphological characteristics and mechanism of surface texture,this article adopts a combination of theoretical analysis and experimental methods to establish a lubricating oil film model for textured friction pairs.The oil film model is simulated and calculated to explore its lubrication mechanism.Select a reasonable friction pair matching material,conduct experimental research on its surface processing texture under different PV values,and explore the reasonable selection of texture parameters to improve the bearing capacity,friction and wear performance,and service life of the friction pair.The main research content of this article is as follows:(1)Physical modeling of the lubricating oil film between textured parallel plane friction pairs was carried out,and CFD numerical calculation method was used to set the boundary conditions for solving the model.FLUENT calculation software was used to solve the standard N-S equation,obtaining the pressure and flow velocity distribution of the lubricating oil film on the textured surface,in order to analyze the impact of surface texture on the performance of the lubricating oil film.After calculation,it was found that the main mechanism for improving the performance of lubricating oil film by texture is the formation of a convergence wedge at the texture outlet due to the combination of texture and friction plane,which leads to an increase in oil pressure and improves the bearing capacity of the oil film;At the inlet of the texture,the oil pressure slightly decreases,forming a pressure drop zone.Together with the pressure rise zone at the inlet,it forms a pressure difference inside the texture,driving the oil to replenish the surrounding non textured area,allowing the area to maintain good lubrication in an under lubricated and lean state,providing a "secondary lubrication" effect;Simultaneously,the oil circulates and flows in the texture to form vortex rings,which is beneficial for storing the oil in the texture and providing continuous lubrication.(2)Due to the numerous texture parameters,combined with the working conditions of the lubricating oil film,the orthogonal experimental design method is used to coordinate and simulate the speed,texture shape,texture diameter to depth ratio,and texture arrangement density.The evaluation index is the lubricating oil film bearing capacity between friction pairs,and the weight of the influence of each parameter on the oil film bearing capacity is ranked from large to small as follows: speed>arrangement density>diameter to depth ratio>shape.Simulate and calculate the effects of surface texture parameters on the performance of lubricating oil films by gradually changing the different levels of each parameter.Among the four parameters studied in the experiment,by comparing the bearing capacity and pressure range of the textured surface lubricating oil film,it was found that the influence of the texture diameter depth ratio on the oil film performance is not clear enough,and further research is needed through actual experiments.(3)Based on theoretical analysis and simulation results,experiments were conducted to verify the lubrication performance of actual textured samples with different aspect ratios under different PV values.Using the friction coefficient curve and the surface microstructure of the sample after the friction experiment as evaluation indicators,this study investigates the wear mechanism of the friction pair surface of samples with different diameter to depth ratios under different PV values,and seeks the most suitable value of the texture diameter to depth ratio under different pressure loads.The experimental results show that the diameter to depth ratio has a slightly lower advantage in reducing the average friction coefficient,and its main advantage lies in maintaining the stability of the friction coefficient.In terms of reducing the wear quality of texture samples,the texture with a diameter to depth ratio of 1.5 performs the best,and has strong adaptability to changes in PV values.The main wear mechanisms of textured surfaces are adhesive wear and abrasive wear.A surface texture with a diameter to depth ratio of 1.5 has a significant advantage in accommodating abrasive debris and reducing abrasive wear,but has no significant advantage in resisting adhesive wear. |
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