TRADE STUDY ON DIFFERENT GEAR REDUCTION RATIOS OF THE 5100 HP RDS-21 DEMONSTRATOR GEARBOX

摘要

Sikorsky Aircraft, under a cooperative agreement with AATD (Aviation Applied Technology Directorate), is working on the development of a face gear transmission system, one of the key technologies for RDS-21 (Rotorcraft Drive Systems for the 21st Century). The face gear contact analysis software developed by the Advanced Numerical Solution Company and the face gear geometry generation software developed by Sikorsky researchers were pursued for the design and analysis of face gear. Meanwhile, Sikorsky partnered with Gleason Pfauter Inc on the development of the face gear manufacturing technology. This paper presents the work done on the trade study conducted on the effect of different gear reduction ratios on the system power-to-weight ratio of the two-stage, 5100-HP face gear transmission system. The method for generating the mathematical model of a face gear was introduced in this paper. A finite element analysis software package for gear tooth was used to compute the loads and stresses of gear teeth. Size variations of shaft, bearing and mounting structures with different reduction ratios of the two-stage gear meshes were considered during trade study. Results from the trade study revealed that the optimal reduction ratio of the output stage face gear mesh for achieving the highest power-to-weight ratio was 10.04 when the total gear reduction ratio of the transmission system was 85.3.