FACE GEAR TRANSMISSION DEVELOPMENT PROGRAM AT SIKORSKY AIRCRAFT

Sikorsky Aircraft and the U.S. Army's Aviation Applied Technology Directorate (AATD) have initiated a four-year research program to develop advanced face gear based rotorcraft transmissions. This effort, known as Rotorcraft Drive Systems for the 21st Century (RDS-21), is pursuing mechanical power transmission technologies that will enhance the performance and affordability of current and future manned and unmanned rotorcraft. Sikorsky has partnered with The Ohio State University to develop face gear design software and with Gleason Corporation to develop face gear manufacturing technology, partially funded by Army MANTECH. This paper presents an overview of the RDS-21 face gear program and major milestones achieved. The methods developed for face gear design and analysis are covered. A mathematical model facilitates the calculation of parameters such as sliding velocities, contact ratio, tooth loads and stresses. Digital master gears are created for inspection purposes. Preliminary results from a face gear endurance test are presented.