Modelling and simulation of synchronization and engagement for self-energizing synchronizer with multibody dynamics

Abstract

A multibody dynamic model of the self-energizing synchronizer in a 14-speed manual transmission gearbox is presented. While the contact forces between the engaged splines/teeth and friction torques between the synchro rings are hardly observed by conventional experiments, detailed contact and friction models in consideration of lubrication are established to simulate these contact/friction forces during shifting. The space motion of the sleeve is considered; thus, the differences in the contact forces between the engaged teeth can be simulated and observed. A pneumatic model is established to model the varying shift force acting on the synchronizer. An experiment is conducted for the self-energizing synchronizer to validate the presented synchronizer model. Moreover, to demonstrate the self-energizing function of the synchronizer, a synchronizer without self-energizing mechanism is modelled and compared with the original one.

Gearshift performance improvement for an electromagnetic gearshift system based on optimized active disturbance rejection control method

“…20 Chen and Tian 21 divide the gear engagement process into two phases so that different control strategies can be implemented, and the speed variations caused by contact of synchronization components are deduced using Poisson coefficient of restitution. Since the contact forces are difficult to observe, contact and friction models are developed in Li et al 22 to obtain the characteristics of the contact forces during the gearshift process. However, the influence of the characteristics of the contact forces to the shift quality is not analyzed.…”

“…From equations (22) and 23, it is obvious that the optimal control law u * (t) is decided by the state variables x 1 and x 2 , and as a result it can be realized by state feedback control. Since the actual value of u * (t) is the boundary value r or -r, and it changes from one boundary value to another, the TO method is a typical example of Bang-Bang control.…”

Minimizing synchronization time of a gear shifting mechanism by optimizing its structural design parameters

“…For a synchronizer, a multibody dynamic model is presented. 15 The model is based upon 14-speed gearbox. Friction models and model to capture the contact forces are also implemented in the model.…”