Simulation and Experimental Study on Sealing Characteristics of Hydro-Pneumatic Spring GS Seal Rings

Hydro-pneumatic springs often work under high pressure and alternating load conditions, which can easily cause seal damage, leakage, and serious failure. Relevant studies have shown that the dynamic seal failure of hydro-pneumatic springs is the main cause of hydro-pneumatic spring failure, and the sealing performance of GS sealing rings directly determines the service life of hydro-pneumatic springs. The influence of different sealing structure parameters on the sealing performance of GS sealing of hydro-pneumatic springs has been studied, which can provide effective theoretical guidance for the design of sealing structures related to hydro-pneumatic springs. However, the existing research on hydro-pneumatic springs mainly focuses on the characteristics of damping and stiffness; there is a relative lack of research on sealing performance and sealing structure, and the performance change law of GS seals under different working conditions is unclear. In this paper, a GS seal ring is selected as the main seal of the hydro-pneumatic spring, the material parameters of the GS seal ring are obtained via the single-axis compression test, and the finite element simulation method is used to establish the sealing model under different compression ratios of 10-30% and different pressure impacts of 5-30 MPa. By doing so, the stress nephogram, sealing ring shape, and sealing contact pressure of the GS sealing ring under different simulation parameters are obtained. From the test results, the decrease in compression ratio after the wear of the sealing ring is the main reason for the seal leakage of the hydro-pneumatic spring. The maximum contact stress of the sealing ring occurs at the lip of the step ring, and the maximum sealing pressure of the sealing ring is determined by the contact pressure of sealing surfaces II and III. The sealing performance of the GS-type combination sealing ring is affected by the compression ratio of the sealing ring and the impact pressure; when the compression ratio of the sealing ring is 15%, the sealing ring can meet the sealing work needs below 25 MPa. The research results provide a theoretical basis for the design of GS sealing of hydro-pneumatic springs and the effective improvement of the life and reliability of related equipment.