Effects of micron-sized iron particles on friction and wear behaviors of seals used in a magnetorheological damper: analysis and experiment

This study investigates friction and wear properties of rod seals used to prevent leakage of base oil in magnetorheological (MR) dampers. As the first step, a non-piston MR damper (MRD) model is considered for the analysis of both the frictional force and three-body abrasive wear of seals in MRD. Three different seals; O-ring, step ring, and glyd ring seals are adopted for the analysis and experimental tests. In order to conduct the friction and wear testing, a new type of in-house experimental apparatus consisting of an electrical cylinder, pressure sensor and gravity sensor is established. Subsequently, the friction coefficients and wear losses of the seals are evaluated as a function of operation time to validate the feasibility of the derived friction and wear models. To investigate the variation of the seals within MR fluid domain, morphological scanning electron microscopy images such as contacting and worn surfaces are observed and discussed. In addition, the energy-dispersive spectroscopy images are investigated after wearing the seal to observe the changes in size and shape of iron particles which are randomly distributed in MR fluid. (paper)