Investigation into the influence of stretching on reciprocating rod seals based on a novel 3-D model vs axisymmetric model

Stretching and compression of the seal play essential roles for guaranteeing the function of the actuator. Because of the defect of the axisymmetric element, the simplification to the axisymmetric (2-D) model may cause inevitable errors when stretching is involved. To investigate the influence of stretching more exactly, a novel 3-D model integrating a macro stretching and a mixed lubrication model is brought forward. An LCS boundary condition is applied without the need for a full-scale model. Simulations of the axisymmetric and 3-D models are compared at different stretch ratios. Results indicate that the stretching effects should be considered in the simulation and that the axisymmetric model is feasible for single seals but not for combined seals at large stretch ratios.