Design and Testing of a New Vibration Suppression System

The performance of a new vibration control system consisting of a prototype Hub Mounted Vibration Suppressor (HMVS) working in tandem with a fuselage based Active Vibration Control system (AVC) is described. Ground tests were performed at a LORD test facility on a CH-3 fuselage. The anti-vibration system incorporated into this rig is designed to completely suppress vibratory motions at the main rotor gearbox thus precluding fuselage vibration due to main rotor vibratory excitation. Tests were conducted to simulate various static and dynamic in-flight loadings and main rotor shaft speed conditions. The test results indicate that the system successfully suppressed virtually all of the vibratory loads applied to the test main rotor hub thus yielding very low fuselage vibrations.