IMPROVEMENT OF DOUBLE HUNG VIBRATION ABSORBER FOR HELICOPTER ROTARY WING

摘要

A multibladed helicopter rotor carries at least three bifilar absorbers which are tuned to eliminate in-plane vibrations of the rotor which otherwise would be transmitted to the helicopter fuselage. Improved tuning pin assemblies and cooperating tracking inserts for the absorber reduce the undesirable frictional damping heretofore encountered in bifilar absorbers by centering the pendulous elements of the absorbers relative to their support members and reacting forces normal to centrifugal force by permitting flapping movement of the bifilar mass in the vertical plane.