Drive Train Simulation Requirements For Development Of Helicopter Overrunning Clutches

This paper discusses the test methodology used to develop helicopter overrunning clutches. It includes: static and fatigue test requirements, functional and environmental simulations required during testing, and a description of the test facility required for representative aircraft drive system simulation. To simulate the aircraft environment, a computer-controlled drive train simulation laboratory was built at Sikorsky Aircraft. This facility includes a motor and hydroviscous drive clutch; a hydroviscous absorber brake; a motor to simulate overrunning; a self-contained hot/ cold gearbox lubrication system; and a dedicated mini-computer for control of five feedback loops with built-in automatic shut down, alarm features, and online monitoring. This paper includes a discussion of these subsystems. This multipurpose facility was designed to permit development of all drive train components, with the clutch development requiring most of the available features.