Simulation of Hydrodynamic Forces on Passenger Car Synchronizer Rings During Rattling

This paper presents a model to calculate hydrodynamic forces on a rattling synchronizer ring, i.e. a ring which is excited by rotational speed irregularities and therefore moves within its functional clearance. Based on the Reynolds Equation an analytical and a numerical solution for determination of the forces resulting from oil films on the ring are derived. The model is implemented in a user force element for the multi-body simulation environment SIMPACK and sample simulations with a simple experimental transmission are presented. The results show that the model is capable of representing the rattle characteristic of a synchronizer ring.