Diamond-like Coating Technology And Reliability Analysis Of Hydraulic Seal Ring

Hydraulic seal ring is widely used in the hydraulic system of construction machinery,aerospace,automobile,ship and other major engineering equipment because of its excellent high elastic properties and sealing performance.However,due to the viscoelastic properties between rubber and metal,the hydraulic seal ring is easy to wear and fail,which seriously affects the reliability and safety of the hydraulic system.Diamond like carbon(DLC)film not only has ultra-high hardness and low friction coefficient,but also has good compatibility with rubber since its main composition is similar to rubber.Therefore,the deposition of DLC film on the surface of hydraulic seal ring can reduce the friction force between hydraulic seal ring and metal parts,improve the wear resistance and service life of hydraulic seal ring,and it is of great significance to improve the reliability of hydraulic system.This paper focuses on the diamond-like carbon(DLC)coating and reliability of hydraulic seal ring.It intends to use the method of combining theory,simulation and experiment to study the film forming mechanism of hydraulic seal ring,research and development of experimental device,coating process and reliability analysis,so as to provide theoretical and technical basis for reducing the friction coefficient of hydraulic seals and improving its wear resistance and life.Study on the forming mechanism of diamond-like carbon film for hydraulic seal ring.Based on the emission principle of cathode spot plasma,the motion model of vacuum plasma is established.The excitation principle of large current pulsed arc plasma is studied by finite volume method.Through the vacuum ion beam zero-dimensional model and the radiation collision model,the principle and motion characteristics of ion beam formed by plasma in vacuum are analyzed.According to the energy distribution of carbon ions,the growth model of diamond-like carbon(DLC)films is established.Based on the motion law of sputtered particles in vacuum physics,the forming stress of DLC film is calculated,and the theoretical results are verified by curvature index of experimental samples.Research on experimental device of diamond-like carbon coating for hydraulic sealing ring.The process flow of diamond-like carbon coating for hydraulic seals is analyzed,the overall design of diamond-like carbon coating experimental device is formulated;A pulse ion source structure combining high-current arc ignition and squirrel-cage anodes is proposed to enhance the uniformity of the strong electric field between the cathode and anode,and extend the acceleration time of carbon ions;vacuum chamber structure made of304 stainless steel is designed,which has high strength and strong corrosion resistance,and meets the requirements of coating reliability;A secondary air extraction system is built to shorten the vacuum acquisition time and improve the working efficiency of the coating experiment device.Study on diamond-like carbon coating process of hydraulic seal ring.The pretreatment method of coating process on the surface of hydraulic seal ring was studied.By adding perchloroethylene to clean,the plasticizer on the rubber surface was precipitated,and the bonding force between the film and the substrate was strengthened.Using cathodic pulse arc technology,the technology of nitrile rubber and polyurethane diamond-like carbon coating is studied,and the preparation method of fluorine-doped diamond-like carbon film is proposed to improve the abrasion resistance and hydrophobicity of hydraulic seal ring and increase the service life of seal ring.Reliability analysis of diamond-like carbon coating hydraulic seal ring.The structure of the nitrile rubber and polyurethane hydraulic sealing ring after coating is modeled by parameterization,considering the real working state of the hydraulic seal ring in the cylinder,the structure is simulated and analyzed,according to the structure-strength interference theory,the reliability and sensitivity of the coating seal ring are analyzed;The pulse and reciprocating test bench is built to carry out the reliability test of the hydraulic seal ring,which verifies the correctness of the simulation model and the effectiveness of the diamondlike carbon film.