Topology Synthesis of Single-DOF Epicyclic Gear Trains Based on Graph Theory *

The research shows that the topology structure of gear kinematic chains can be represented by graphs. The topological synthesis of epicyclic gear trains based on graph theory is an effective system synthesis method. In this paper, a topology synthesis method is developed for single- degree of freedom (DOF) epicyclic gear trains. A new effective identification method Linkage Characteristic Polynomial-Fundamental Circuit Polygon (LCP-FCP) is proposed to solve isomorphism and rotationally isomorphism problem generated in topology synthesis process. The basic idea of proposed topology synthesis is to enumerate all candidate single-DOF gear train kinematic chains first. Then use the LCP-FCP algorithm to identify the isomorphism of the graphs and the rotation graphs respectively, and finally synthesize the kinematic chains that meets the corresponding fundamental requirements. All of the above steps can be automated by a computer program.