Research On Damage And Crack Propagation Mechanism Of Sealing Ring Of Hydraulic Cylinder

As the main key equipment in modern coal mining,hydraulic supports are mainly used to ensure the safety of personnel and mining and transportation equipment in fully mechanized mining faces.The support of the hydraulic support and the execution of all actions are completed by various hydraulic cylinders that use emulsion as the medium.The damage of the sealing ring between the mating surfaces in the cylinder will cause the failure of the sealing function,which will cause fluid leakage and leakage in the cylinder.The failure of the entire hydraulic support function.The research on the damage and failure mechanism of the sealing ring is of great significance to improve the sealing reliability of the underground hydraulic support.This paper takes the bud seal ring for the piston rod of the hydraulic support as the research object,and conducts an in-depth study on the crack propagation damage of the bud seal ring caused by the particles in the emulsion medium of the hydraulic cylinder.The Mooney-Rivlin model is selected to describe the non-linear characteristics of the rubber material of the bud-shaped sealing ring,and the material mechanical parameters are obtained through uniaxial tensile experiments.Numerical simulations were carried out on the particle-free and particle-free models of the bud-shaped sealing ring with ANSYS finite element software.The results showed that:in the non-particulate model,the maximum stress of the bud-shaped sealing ring is the middle area in contact with the piston rod;In the model,the contact stress is greater when the contact area is below,which is more likely to cause damage to the bud-shaped sealing ring and cause cracks.The contact stress between the bud-shaped seal ring and the piston rod is extracted as the boundary condition of crack propagation.The Abaqus expansion finite element method is used to study the crack propagation mechanism and sealing performance of the bud-shaped sealing ring.The analysis shows that the length and angle of the preformed crack will affect the crack propagation length,expansion angle,and propagation path of the sealing ring.The longer the preformed crack length,The longer the crack propagation length,the greater the pre-crack angle,the more likely it is to cause more cracks in the bud-shaped sealing ring,and the more likely it is to have seal failure.Finally,the sealing performance of the bud-shaped sealing ring with different pre-crack lengths is analyzed after the crack propagation ends.The results show that the sealing performance of the pre-crack model with different lengths is different after the crack propagation.When the length of the pre-crack is small,the maximum contact stress of the bud-shaped seal is greater than the pressure of the emulsion medium,and the sealing performance of the seal is good;when the length of the pre-crack is large,the seal fails.