Theoretical Analysis And Experimental Research About Static Inner Leakage Of Hydraulic Cylinder With Variable Clearance Seal

Variable clearance seal hydraulic cylinder was called the third generation hydraulic cylinder as the advantages of small leakage,low friction,fast frequency response and long service life.While hydraulic cylinder is currently in development and test phase,perfect theory system of the hydraulic cylinder has not been established and many characteristic researches of the hydraulic cylinder,especially in the leakage,were required.Therefore,variable gap sealing hydraulic cylinder was regarded as the research object of the topic and main research work of the static internal leakage is summarized as follows:First,based on related knowledge of fluid mechanics,theoretical mechanics and elastic mechanics,loaded deformable lip mechanical model was built.The lip deformation approximate calculation formula was acquired as a result of the model was simplified and solved.And relationship between the internal leakage and the pressure difference is analyzed.Secondly,the eccentric piston,hydraulic oil compression and hydraulic oil temperature were taken into account to analysis influence of the static internal leakage.And the calculation formula of the static internal leakage of the hydraulic cylinder in the actual working process is obtained.Meanwhile,variable clearance seal hydraulic cylinder three-dimensional static internal leakage domain as a standard for evaluating static internal leakage was put forward.The calculation formula of the upper and lower bounds curve of the two-dimensional static internal leakage domain which can satisfy the engineering application was obtained by means of projection transformation of the three-dimensional static internal leakage domain.Finally,performance test platform of hydraulic cylinder with variable clearance seal was utilized to carry out experimental research on the static internal leakage of two different structural cylinders.The experiment results show that the static leakage volume pressure curves are all located in the two-dimensional theory calculated static internal leakage domain,which proves that theoretical analysis about static internal leakage of variable clearance sealing hydraulic cylinder is reasonable.