Finite Element Analysis And Research Of Hydraulic Sealing Ring

Sealing ring is an important component in hydraulic system which can prevent leakage,improve the volume efficiency and ensure the system work normally, also modern hydrauliccontrol technology puts forward higher request to seal. The failure reasons and forms ofsealing ring at work were analyzed. Simulation hydraulic sealing ring models of differentshapes were established. The performances of sealing ring were analyzed, in which thenon-linear properties, material properties, and state properties of geometric were consideredinto account. Various factors which influence seal performance of sealing ring were discussed,and the structure optimization program was put forward. The temperature field and thermalstress coupling field of hydraulic sealing ring were researched, and the influence oftemperature rise to the sealing ring life was concluded. The research content and conclusionsare as follows:1、Finite element analysis of Yx shape hydraulic sealing ring.Application of super elasticity theory and nonlinear theory, and finite element method forperformance of Yx shape hydraulic sealing ring were simulated, obtained the contour ofsealing ring deformation, the contact pressure and stress, analyzes its failure position andpatterns, and studies the effect of parameters on sealing performance, puts forward structureoptimization model.Results show that: The biggest stress appears in the lips interchange. The largestdeformation occurs in Yx shape openings near lip place; The roots have a larger contactpressure, and possible bites phenomenon. The shear stress will increase significantly when thepressure increases. The maximum contact pressure increases linearly with the increase ofmedium pressure. The maximum deformation increases linearly with the increase of initialcompression ratio; Maximum shear reaches to the maximal when the compression rate is 20%.Notch fillet radius of Yx shape sealing ring has the little effect on seal performance. Troughfriction coefficient increases, the maximum shear stress significantly increases, but themaximum deformation and maximum contact pressure decrease. After structure sizeoptimization, sealing performance is enhanced, contact width is decreased greatly, root wearis improved, friction is decreased, and the service life of sealing is improved.2、Finite element analysis of O shape hydraulic sealing ring.Results show that the largest deformation appears in the root of sealing ring and thecontact region between sealing ring and the piston, the largest Mises press occurs in sealingring root. The maximum deformation and equivalent stress increase obviously with theincrease of medium pressure, and the contact press increases linearly at the same time. Thedeformation, shear stress, Mises stress and the largest contact press increase with the increaseof initial compression ratio. The contact press and Mises press increase with the increase of friction coefficient, so choosing the right compression ratio is very important when installed.Joining block ring can prevent bite phenomenon and stress concentration phenomenon in theseal slot, and the service life of sealing is improved.3、Finite element analysis on temperature field of O and Yx shape hydraulic sealing ring.The mechanism of heat generation by friction and mechanical hysteresis of rubber sealring was analyzed based on hyperelasticity theory and heat transfer principle. The coupledfield simulation of thermal and structure of Yx shape hydraulic seals ring were implementedby finite element method and the temperature distribution was obtained. The effect andregularity of working parameters on temperature rise were studied. The results show thatfrictional heat mainly leads to temperature rise on the area where the seal ring and the pistonrod contact, mechanical hysteresis leads to high temperature filed in the central part of sealring, and the temperature rise is obviously higher than that by friction. Seal ring has hightemperature filed under two kinds of heat source. The temperature rise of seal ring evidentlyincreases when oil pressure, relative slide speed and oil temperature increase to the samerubber material. Therefore, limiting the working pressure，relative slide speed and better heatdissipation condition are beneficial to improving sealing performance and service life.4、Finite element analysis on thermal-structure couple field of sealing ringThe rubber hardness decreases with the temperature rises. The maximum shear stress andthe contact stress decrease, and the largest Mises press decreases obviously with thetemperature rises. The oxidation phenomenon makes materials accelerate aging with thetemperature rises which leads to the rubber material hardness, hyperelasticity and tensionstrength weakened significantly and prone to permanent deformation, therefore to ensure thesealing ring working in certain temperature range is important.