Damping device for a helicopter rotor blade
AssigneeMesserschmitt-Boelkow-Blohm Gesellschaft mit beschraenkter Haftung
InventorsHubert Frommlet, Ludwig Stangl
Life of this patent
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Abstract
The wing blades of a helicopter rotor each are connected to the rotor hub a connection, e.g. a spar being .fwdarw..rarw. including a hinge which is at least fictitious to permit lead-lag movements of the blades <yielding relative to torsion to permit the blade angle adjustment>. A rod, which is stiff in the lead-lag direction and yielding against torsion, is connected in parallel to the connection between the blade root and the rotor hub. One connection of the rod is rigid, for example the connection to the blade root. The other connection of the rod is elastically yielding substantially only in the plane of the rotor whereby a substantial damping of blade movements in the lead-lag direction is accomplished.
Claims14
An apparatus for damping blade vibrations in the lead-lag direction of the blades of a helicopter rotor, comprising rotor head means and, at least one blade including a blade root, means operatively connecting said blade root to said rotor head means, said connecting means permitting blade angle movements and said blade vibrations, said connecting means including hinge means for permitting lead-lag movements of the blade, torsionally yielding rod means stiff against bending in the lead-lag direction, first securing means operatively connecting said rod means to said blade root means, second securing means operatively connecting said rod means to said rotor head means, one of said first or second securing means providing a substantially rigid connection, the other of said first or second securing means comprising elastic means arranged so as to permit elastically yielding movements of said rod means substantially only in the lead-lag direction for substantially damping vibrations of the respective blade in the lead-lag direction in the plane of rotation of said rotor.
Dependencies are inferred from the claim text.