ABSTRACT
This chapter demonstrates the capabilities of the torque method in the kinematic and efficiency analysis of complex compound planetary gear trains, in particular change-gears. The importance of accurate analysis of all gear trains is determined by the fact that errors in defining the correct speed ratio or in the direction of rotation of the output shaft of the train in some cases may be fatal. The input and output shafts’ coaxiality make them suitable for wind turbines, but they are particularly suited to automatic transmissions because, unlike non-planetary gear trains, all gear wheels are in mesh in all cases of operating and no-switching. The main advantage of the graphical method is the clarity. It is lost for complex compound planetary gear trains because of the tangle of lines obtained. The idea of using the torques of the outer shafts of a gear to determine its gear ratio is not a new one.
