Design and analysis of compound stepped planetary gear drives for better transmission performances

This paper aims to propose a systematic approach to design and analyze compound stepped planetary gear drives (CSPG). Six design rules based on equations for the assembly of planets are thus proposed to determine suitable numbers of teeth. A total of six study cases based on design rules without and with profile crowning modification were analyzed by a modified tooth contact analysis model. The influences of the different combinations of tooth numbers on the transmission errors and load sharing were systematically explored. The results show that a compromise but better solution for the smallest transmission error and evener load sharing is that the planets mesh with the sun gear in phase and with the ring gear in sequential phase.