Contact mechanics and friction in PTFE coaxial sealing systems

The paper addresses the friction process in coaxial sealing systems of hydraulic cylinders based on studies starting from an analysis of the energy efficiency ensured by these actuators. Notwithstanding the main purpose of a sealing system, namely to prevent fluid leakage, energy related aspects should also be considered, materialised in the efficiency of the hydraulic cylinders. The efficiency of hydraulic cylinders depends on the magnitude of the friction forces caused by the sealing systems. In this respect the paper focuses on discussing studies concerning the types of friction in the sealing tribosystem and on establishing methodologies for the analytical and experimental determination of the friction forces introduced by coaxial sealing systems. The obtained results yield the conclusion that coaxial sealing systems generate friction forces several times smaller than those caused by other sealing types, thus ensuring a higher efficiency to hydraulic cylinders equipped with such sealing elements.