Hub-mounted Vibration System under Test

Lord and Sikorsky are developing a lightweight, self-contained hub-mounted vibration system (HMVS) for the Connecticut manufacturer’s future medium and heavy-lift helicopters as part of Sikorsky’s “High Performance, Low Vibration and Low Noise Enabling Technologies Program” in cooperation with the U.S. Army. The HMVS system features motorized imbalanced rotors that rotate at the blade-pass frequency to create centrifugal forces. By phasing the two rotors, the magnitude and orientation of the centrifugal forces can cancel lateral hub vibration. System components include force generator, controller, sensors and power electronics. Ground testing is scheduled to begin next year.