Symmetry Detection and Topological Synthesis of Mechanisms of Powertrains

Abstract

The function of vehicle powertrains (including hybrid powertrains) is to transmit power from the power source (engine or electric machine) to driving wheels. The planetary gear train (PGT) is a core structure of mechanisms of powertrains. The detection of topological symmetry is helpful for improving the efficiency of mechanism design. In this paper, we present a fully automatic and reliable method for detecting symmetry of plane kinematic chains and extend this method to symmetry detection and the topological design of mechanisms of powertrains. First, the topological model and adjacency matrix are introduced to represent various kinds of plane kinematic chains. Then, the moment matrix of the kinematic chain is established to obtain link groups, based on which we propose an algorithm to generate the unique numerical code of each link and precisely detect the symmetry. Our method is applied to synthesize different kinds of plane kinematic chains and mechanisms, which can improve the design efficiency of mechanisms of powertrains and other mechanical devices.

Power Flow in Coupled Three-Row Series-Parallel Planetary Gear System, Part I: Without Power Losses

“…An example may be a gearbox with several gears (Figure 1b) obtained from the transformation of the series-parallel gearbox shown in Figure 1a. Other examples of such gearboxes are presented, for example, in [37,69,89,90,115,122,125,151]. Most series-parallel transmissions are structurally and dynamically coupled.…”