NOMENCLATURE

A numerical model of reciprocating fluid power seals has been developed. It has been applied to a variety of hydraulic rod seals, although it could also be used to simulate hydraulic piston seals as well as pneumatic seals. The model is soft elastohydrodynamic and consists of coupled fluid mechanics, contact mechanics, deformation mechanics and thermal analyses. Results for typical rod seals show that these seals operate with mixed lubrication between the rod and seal surfaces, and that the roughness of the seal plays a major role in determining the leakage characteristics of the seal. For a given seal design and set of operating conditions there is a critical seal roughness, below which there will be zero net leakage per cycle and above which the seal will leak