The Research Of The Composite Texture And Lubrication Characteristics On High Speed Hydraulic Cylinder

The friction coefficient of the piston-cylinder friction pair directly affects the efficiency of the whole hydraulic system.So improved the lubrication characteristics of the hydraulic cylinder is especially important for the hydraulic system.Surface texture is a method that can significantly improve the tribological properties of the surface which has been applied to some instruments.In this paper,surface texture technology is applied in the cylinder-piston friction pair on hydraulic cylinder to analysis the dynamic pressure lubrication effect,which can provides a new theoretical and technical basis for realizing the high speed of the hydraulic cylinder.In order to systematically study the friction performance of surface texture and find the optimal texture parameters of hydraulic cylinder under specific working conditions and lubrication conditions,the following works are done:(1)The surface texture is designed,and numerically is solved.The shape of strip,circle,square and zigzag is designed and modeled for surface texture.The Reynolds equation is used to solve the texture of a single pit surface,and the pressure distribution,oil film bearing capacity,friction force and friction coefficient of the different textures are obtained.Compared the dynamic pressure lubrication characteristics of the surface texture of different textures can obtain the optimum shape that is the bar texture.(2)Research on dynamic lubrication characteristics of asymmetric texture.Under certain conditions,asymmetric texture has better hydrodynamic lubrication performance than symmetric pits texture.When the asymmetric texture shape is set,the load capacity is proportional to the velocity.And the bearing capacity increases with the increase of speed.(3)Research on dynamic lubrication performance of textured clearance seal hydraulic cylinder.The surface texture is introduced into the hydraulic cylinder gap seal,then the whole annular gap sealing flow was simulated by the computer.The solution was obtained that when the annular pits texture was in the middle of the cylinder the friction coefficient is the minimum.(4)The friction performance test of the textured cylinder was designed and carried out.Based on the textured hydraulic cylinder platform,four different combinations of cylinder-piston pair are tested and studied.It is concluded that a reasonable combination of cylinder and piston can reduce the friction coefficient by more than 50%.When the same piston is selected,the textured cylinder is obtained a smaller friction coefficient and better lubrication characteristics.