Dynamics and pareto optimization of a generic synchronizer mechanism

Abstract

Transmission systems for passenger cars and trucks are equipped with synchronizer mechanism. It has a great impact on driving comfort and transmission efficiency. A synchronizer mechanism as a key component of a transmission system must be able to prevent gears from shocking and reduce the noise. Gear shifting improvement with respect to smooth, quick and energy efficient synchronizer’s performance is still an important issue for automotive industry. This contribution studies the kinematics and dynamics of a generic synchronizer consisting of sleeve, blocker ring and gearwheel constituting a mechanical system with a set of time-varying constraints describing frictional contacts between system’s components. The dynamic response is modelled using constrained Lagrangian formalism. Pareto optimization problem is stated and optimized the rate of the applied sleeve force, coefficient of friction and cone angle are found to attain a minimal synchronization time as well as speed difference between sleeve and gearwheel. One outcome of the study is that the obtained Pareto solution is characterized by the minimal admissible value of the cone angle of the synchronizer.