Finite Element Analysis on the Influence of Back-Up Ring on the Sealing Effect of Rubber O-Ring

Based on finite element analysis software ANSYS, the deformation and force condition of the rubber sealing o-ring pre and post with back-up ring under different oil pressure conditions was analyzed. The von mises stress distribution of the o-ring and the change of contact pressure between o-ring and sealing interface pre and post with back-up ring under different oil pressure conditions were discussed. The results show that, the maximum von mises stress of the o-ring is smaller and the maximum von mises stress of the sealing system concentrates on the left top and the right bottom of the back-up ring after using it; the o-ring will not be extruded into the gap of the groove because of the existence of back-up ring which prevents gap-bite and prolongs service life of the o-ring; the contact pressure between o-ring and sealing interface increased, thus the sealing reliability of the system increased.