Investigation of friction in rectangular Nitrile-Butadiene Rubber (NBR) hydraulic rod seals for defence applications

Contact based FE simulations have been carried out to estimate the contact pressure distribution at seal/rod interface at sealed oil pressures of 10, 20 and 30 MPa and constant rod velocity of 0.12 m/s. Oil film thickness at the interface was then computed analytically at various combinations of oil pressures and rod velocities. Seal contact pressure and oil film thickness data along with surface roughness, intermolecular interaction between seal/rod interfaces has been perused to estimate the friction in Nitrile-Butadiene Rubber (NBR) rectangular hydraulic rod seals using theoretical models such as Inverse hydrodynamic lubrication (IHL), Greenwood-Williamson (GW) and Wassink’s models. The friction at seal/rod interface was also measured experimentally using a specially designed test rig. The comparison of theoretical and experimental data revealed that, friction computed from GW and Wassink’s models had good agreement with the experimental results.