Research on Dynamic Sealing Performance of Combined Sealing Structure under Extreme Working Conditions

This study investigates the sealing performance of a combined sealing structure under extremely high and low temperature conditions, considering potential issues like high-temperature aging and low-temperature brittle fracture, which can lead to sealing failure. EPDM rubber underwent uniaxial compression tests at high, low, and normal temperatures, then the sealing performance under extreme working conditions was compared with that under normal temperature conditions. Additionally, the influences of gasket parameters and gas pressure on the sealing performance were analyzed. The result shows that compared with the normal temperature conditions, the maximum von Mises stress is reduced by 65% and the effective sealing length and the maximum contact pressure is reduced by 40% under the high temperature conditions, while the maximum von Mises stress is increased by 7 times and the maximum contact pressure is increased by a remarkable 7 times under the low temperature conditions. In the range of 10–100 MPa, the increase in gas pressure aggravates the O-ring stress concentration and improves the sealing performance relatively. When the thickness of gasket is 0.85–1.05 mm, the stress concentration of the O-ring is lighter and the sealing performance is better.