| The reasonable surface texture on the friction pair can effectively improve the lubrication performance of the friction pair.However,the current research on the influence of surface microtexture on the lubrication performance of friction pair under the condition of cavitation effect is imperfect,and there are few theoretical and experimental studies.Therefore,the paper uses numerical simulation and experimental methods to systematically analyze the influence of the microtexture structure parameters,distribution position,spacing,angle and speed on the lubrication performance of the friction pair,so as to reveal the microtexture on the cavitation phenomenon of the friction pair and mechanism of load-bearing characteristics.In terms of numerical simulation,Fluent software is used to simulate the lubricating characteristics of friction pairs with surface microtexture.The target parameters are rotational speed,texture width,depth(height),distribution position,angle,and morphology.The oil film pressure distribution map and cavitation effect map for single or multiple texture are obtained by simulation.The cavitation occurrence mode and mechanism are analyzed by observing the cavitation phenomenon at the microtexture.Study the influence of cavitation effect on hydrodynamic lubrication of friction pair.In terms of experiments,using a visualized experimental platform,through changing the parameters such as speed and load,bearing capacity and friction under different texture parameters are obtained,and cavitation effect diagrams under different conditions are collected.Obtaining the influence of different working condition parameters and texture parameters on cavitation effect and its influence of the lubrication characteristics of the sliding friction pair,finally these experimental results are used to compare with the numerical simulation results.The simulation results show that for flat friction pair with micro-convex texture on the surface,increasing the relative motion speed between the surfaces,the width or height,the angle of the front and rear ends of the micro-texture can all lead to increase the area of the cavitation and make the cavitation phenomenon more obvious.The appearance of the cavitation effect suppresses the decrease of the pressure in the negative pressure zone at the rear end of the micro-convex body and the bearing capacity of the friction pair is increased.At the same time,due to the cavitation effect,the interface is changed from liquid lubrication to local gas lubrication,the value of the friction coefficient between the interfaces is significantly reduced.For sliding bearing with micro-textured surface,no matter the texture is arranged in the entrance area,the minimum oil film thickness or the exit area,the cavitation phenomenon only occurs in the exit area.When the micro-texture is arranged in the middle area,the bearing capacity is reduced and the friction force is increased compared to the case without texture.When the micro-texture is arranged in the entrance area or the exit area,it can effectively improve the bearing capacity,reduce the friction force and coefficient of friction which works best in the exit area.Properly increasing the speed and the depth and width of the texture will make the cavitation phenomenon more.obvious,meanwhile will improve the bearing capacity and reduce the friction.There is an optimal texture spacing(the spacing is 4 times the texture width)which makes the sliding bearing exhibit the best lubrication performance.The experimental research results show the same trend as simulation results,appropriately increasing the speed and load can increase the cavitation area and make the cavitation phenomenon more obvious;increasing the texture width can reduce the friction coefficient of the friction pair.The distribution position of the texture has an important influence on the lubrication performance of the friction pair and the effect is best when the texture is arranged in the exit area. |
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