Patent ID: 8764396
Filing Date: 2014-07-01
Classification: B64C,F16F

Abstract:
1. A damper for damping chordwise lead-lag motion about a lead-lag axis of a blade of a rotor assembly, the rotor assembly comprising a yoke and blade assemblies carried by the yoke, the yoke attached to a mast for being driven in rotation by the mast, the damper comprising: a body adapted to be mounted to one of an inboard portion of a blade assembly and a fixed portion of the rotor assembly, the body being located inboard of a lead-lag axis, the inboard portion of the blade assembly being rotatable about the lead-lag axis relative to a yoke; a piston slidably engaged within the body and configured to allow for relative motion between the body and the piston, the piston being configured to form a seal between an inner surface of the body and an outer surface of the piston and configured to define opposing chambers within the body, the chambers being in fluid communication through a fluid passage extending through a thickness of the body; an adjustable flow-restriction device configured to adjustably restrict fluid passing through the fluid passage; and a link adapted to connect the piston to the other of the inboard portion of the blade assembly and the fixed portion of the rotor assembly, the link engaging a central portion of the piston; wherein fluid carried within the chambers is acted on by the piston during relative motion between the piston and the body, the piston causing fluid to flow between the chambers through the fluid passage; and wherein fluid flow through the fluid passage acts to damp relative motion between the body and the piston and damp relative lead-lag motion between the inboard portion of the blade assembly and the fixed portion of the rotor assembly.