Research On Drag Reduction Characteristic Of Bionic Non-smooth Sealing Ring For Cylinder

Hydraulic cylinder, as an indispensable actuator in the hydraulic system, whose sealing ring performance and frictional resistance are the key factors to impede the development of hydraulic technique. Therefore, improving of the sealing performance and decreasing of the frictional resistance present a crucial and practical engineering significance for improving life time of the sealing ring and the working efficiency of the cylinder. The theory of bionics and drag reduction technique are utilized to reduce the frictional resistance between the sealing bodies and to save energy, which has turned into a novel research field.Based on the perspective of bionics, non-smooth surface morphology of the body characteristics of the cybister bengalensis etc. was chosen as the biological prototype, and piston cylinder seal was chosen as the research object, the physical model and numerical analysis model of the sealing ring drag reduction of non-smooth surface with bionic pit triangle was established.By using ABAQUS software, sealing performance of rubber seals with smooth and non-smooth surfaces were calculated, the sealing deformation and stress distribution were analysed, under different compression circumstances. Through the calculation result, the effective stress of smooth and non-smooth surfaces seals was 3.5MPa when the compression rate is 20%. 3.5MPa is the working cylinder medium pressure, so that it meets the cylinder seal tightness.After research on drag reduction characteristics of non-smooth surface for sealing ring model with bionic pit by triangle combination, and the kinematic model of the parameters and initial conditions was confirmed. Furthermore, the influence of different pit diameter parameters on drag reduction properties for non-smooth surface was studied, and also the effect of the velocity of different pistons on drag reducing properties was analysed. Through the calculation result, when the pit diameter was 1.5mm reaches the maximum drag reduction rate was reached under the certain piston speed. Under the certain pit diameter, drag reduction rate was increasing when initial velocity became got larger, and the seals had a stable drag reduction rate when the speed reaches 0.6m/s.At last, a ration numerical model was set up by fluid-structure interaction analysis of lubricating oil stored in pits. Meanwhile, using analysis of liquid dynamic on lubricating oil stored in bottom of pits by the LS-DYNA software, the affection of lubrication performance between rubber seal and cylinder surface on oil storage pits was studied.It turned out that the kinetic friction force 'of seal ring is reduced by the reasonable non-smooth contact surface to a certain extent and that the effect of drag reduction isobtained.