ABSTRACT
Multi-carrier planetary gear trains (PGT) are designated those composed of more than two component PGTs—three-carrier, four-carrier. This chapter shows that some cases of different ways of combining the component PGTs and the obtained structural schemes. It presents the simplest and most commonly used case of compound three-carrier PGT. According to the algebraic signs of the compound shaft, the directions of the branched power flows are determined. And the determination of relative power direction is not a problem, as the third carrier HIII is fixed and the speeds of the other two carriers HI and HII are lower than those of the respective sun gears 1 and 4. Determination of relative power directions of all three component gears needs some clarification. In general, the use of the torque method analysis of PGT allows for direct determination of load on all gear train elements without passing through the kinematic analysis of R. Willis’s or Kutschbach’s methods.
