Study On Textured Surface Friction Characteristics Of Sliding Guide Of Machine Tool

Surface texture technology,as a new technology to improve the tribological properties of contact surfaces by arranging micro-structures on the surface of materials,has been proved to be effective in many fields.As a part of the global machinery production,the importance of machine tool is self-evident,the wear phenomenon of machine guideway not only destroys the stability of the system movement,but also seriously restricts the surface quality of the workpiece.The common methods to solve the friction and wear problem of guide rail include surface quenching and surface plasticizing,however,both of them have their disadvantages.In view of the problems faced by guideways,surface texture technology which has been proved to be effective in other fields was innovatively applied in this paper,and then the friction properties of textured guide surface were investigated.Firstly,the textured surface model of the sliding guide of the machine tool was established,and the hydrodynamic lubrication equation was solved by using the finite volume method.Two friction performance parameters,bearing capacity F and oil film stiffness K,were selected as the surface friction performance parameters.Secondly,the friction properties of three different types of micro-porous and grooved textured guides were studied by changing their surface geometric parameters.The results showed that compared with other micro-porous textured guides,the elliptical textured guide had stronger hydrodynamic pressure effect,and the bearing capacity F and oil film stiffness K were also larger.The performance of the rectangular groove textured guide was better in the process of texture depth h_pand texture area ratio S_p.Thirdly,a single elliptical hole texture model,a single rectangular groove texture model and a composite textured guide model were established.The surface friction properties of the three textured guides under different parameters were investigated.The results showed that the groove texture had a good effect on increasing the bearing capacity F and oil film stiffness K.When the deflection angles of rectangular grooves were 60°and 90°,the elliptical hole texture with larger deflection angles can increase the bearing capacity F and the oil film stiffness K.Finally,set up three different arrangement models of complex texture(hole on the groove type,left hole-right slot type,two layer composite groove and hole type),and preliminarily investigated the influence of working condition parameters and structure parameters on the surface friction property parameters of machine tool sliding guide under different arrangement models.The influence of the study showed that the magnitude of bearing capacity F and oil film stiffness K depended on the size of the significance of wedge effect between the friction pair on the guide surface.The more significant the wedge effect was,the greater the dynamic pressure of oil film was,and the greater the bearing capacity F and oil film stiffness K were.The maximum bearing capacity F and oil film stiffness K between the friction pair on the surface of the two layer mixed groove and hole textured guide indicated that it had the best wedge effect.The oil film bearing capacity F and oil film stiffness K can be significantly increased by increasing the guide speed u.