Elastohydrodynamic lubrication simulation of O-ring and U-cup hydraulic seals

The recent development of an elastohydrodynamic lubrication rod seal model has made possible the simulation of hydraulic seal performance for design and selection purposes. This model consists of coupled fluid mechanics, contact mechanics, deformation, and thermal analyses. The model yields predictions of such characteristics as leakage and the friction force on the rod, as well as film thickness, fluid pressure, and contact pressure distributions. The model has been used in the selection process for the rod seal in a mini-actuator of a fluid power orthosis (orthopaedic device used to improve the function of movable parts of the body). Two alternative seals have been analysed and compared, an O-ring seal and a U-cup, both of polyurethane.