The hydrodynamic phase of gearbox synchromesh operation: The influence of radial and circumferential grooves

Abstract

An earlier brief phenomenological study (1) allowed the authors to divide the period of synchronization into three distinct stages of operation. Each stage corresponded to different types of friction. Expressions establishing estimations of pressure, axial stress, torque and coefficient of friction were made for the case of a smooth synchromesh ring. These all depend upon the film thickness and angular velocities whose variations in time are unknown. The dynamical study presented here permits the solution to this problem. The influence of circumferential and radial grooves on different parameters (distribution of pressure on the contact area, the load borne by the film, torque transmitted by viscous friction and coefficient of friction) is presented and a comparison of the efficiencies of these two types of grooves is made. This study allows the determination of the initial values necessary for the study of the second stage, which takes place in the presence of a variable friction.