Power flow and efficiency analysis of epicyclic gear transmission with split power

The analytical efficiency expression of a compound epicyclic gear train with split power is derived via the approach based on virtual power. New concepts, the split-power ratio and the virtual split-power ratio, are introduced to handle the compound gear train. The efficiency formula is verified by a particular condition. The phenomenon of self-lock is disclosed in this compound gear train. It is observed that the power loss on one planet is dominant. This dominant power loss is caused by the immense virtual power passing through one gear mesh. Based on the analytical results, suggestions on design are given to avoid self-lock and increase the total efficiency.