Abstract: 2K-H gear trains are the important aid units in the transmission systems. A systematic method has been presented for the determination of mechanical efficiency of 2K-H gear trains. The method is based on graph theory and the methodology of fundamental circuits for gear trains. First, based on the basic theory of the graph representation of gear trains, the kinematics of the 2K-H gear trains is analyzed. Then, the equations of the mechanical efficiency of 2K-H gear trains constructed. Finally, the mechanical efficiency and the self-lock property of 2K-H gear trains are discussed. The results of this work are used as a tool to design the 2K-H gear trains.

Key words: 2K-H gear trains, Mechanical efficiency, Self-lock, Speed-ratio