Physically Motivated Simulation of Dynamic Hydraulic Seals

Abstract

Seals are crucial machine elements, for example in hydraulic cylinders. However, especially in regard to dynamic seals, the theoretical understanding of the sealing mechanism is still insufficient. A physically motivated simulation can help to gain a more detailed understanding. In this contribution a elastohydrodynamic (EHD) seal simulation is presented. It is directly implemented in the commercial Software ABAQUS. The fluid film is considered by implementing the Reynolds equation. For a physically motivated simulation Persson’s theory of contact mechanics and rubber friction is used to calculate the solid contribution to the total friction of a hydraulic seal. Simulations for an oscillating motion of a cylinder rod, sealed by an O-ring seal, are carried out for different velocities and pressures. A qualitative comparison between measurement and simulation is provided. Hysteresis effects and the contributions from both, adhesive and viscoelastic friction to the total solid friction are investigated. The physical origin of these effects is discussed in order to provide a detailed understanding of the dynamic sealing mechanism.