초록 ▼

A hydraulic device for the individual control of the pitch of a helicopter rotor blade by a rotary hydraulic jack, the stator vanes of which are integral with a sleeve fitted on the hub. The jack rotor carries rotor vanes movable relative to the stator vanes and delimiting with these chambers of var

A hydraulic device for the individual control of the pitch of a helicopter rotor blade by a rotary hydraulic jack, the stator vanes of which are integral with a sleeve fitted on the hub. The jack rotor carries rotor vanes movable relative to the stator vanes and delimiting with these chambers of variable volume fed by a servo-distributor controlled as a function of pilot signals and signals from a detector of the angular position of the blade about its pitch axis. The jack is integrated in a pitch bearing and in an elastic ball joint integrated in a rotary hydroelastic shock absorber with vanes for lamination of a viscous fluid. The shock-absorber rotor is connected rigidly in terms of rotation about the pitch axis to the rotor of the jack and is connected to the blade by a rigid cuff.

대표청구항 ▼

A hydraulic device for individual control of the pitch of a blade of an aerodyne rotor, said device comprising (a) at least one double-acting rotary hydraulic jack (18-20, 21-24) adapted to be mounted on said rotor and to be driven in rotation with said rotor, said at least one jack having an axis o

A hydraulic device for individual control of the pitch of a blade of an aerodyne rotor, said device comprising (a) at least one double-acting rotary hydraulic jack (18-20, 21-24) adapted to be mounted on said rotor and to be driven in rotation with said rotor, said at least one jack having an axis of rotation coinciding with a longitudinal pitch-changing axis of said blade; (b) at least one servo-distributor rotating with said rotor and controlling a supply of pressurized hydraulic fluid to said at least one jack, said servo-distributor connecting said jack to at least one hydraulic power circuit and being adapted to receive control signals indicating a state of at least one blade emanating from at least one detector means; (c) said jack comprising a substantially tubular stator fixed to a central part of a hub of a head of said rotor and a substantially tubular rotor coaxial with said stator and being rotatably connected to said blade and comprising at least one inner chamber of variable volume delimited at least partially between said rotor and said stator and connected to at least one said servo-distributor; (d) said stator and said rotor being coaxial about said pitch axis of said blade and having opposing lateral surfaces of revolution about their common axis, a first one of said lateral surfaces being a cylindrical surface of circular cross-section, and a second one of said lateral surfaces having the form of a spherical cap, at least one jack vane diametrically opposed relative to said common axis projecting from each of said lateral surfaces and extending to the immediate vicinity of the respective opposite lateral surface, each of said at least one jack having a convex shape facing toward said opposite lateral surface, said at least one jack vane projecting from said second lateral surface having the shape of a spherical segment connected by a convex face thereof to said spherical cap and having a face in the shape of a portion of a circular cylinder opposite said cylindrical surface, said at least one jack vane projecting from one of said lateral surfaces being circumferentially offset about said pitch axis relative to said at least one jack vane projecting from said opposite lateral surface, so as to delimit at least two chambers of variable volume with a small leakage flow from one said chamber to the other via a small radial play between said jack vanes and said opposite surfaces of revolution; (e) there being at least one axial stack, substantially concentric with said pitch axis, of at least one said rotary hydraulic jack and of at least one cylindrical pivot bearing for the pitch of said blade and for attachment on said hub enabling said blade to rotate about said pitch axis relative to said hub, said rotor of at least one jack being mounted for rotation relative to a corresponding stator by means of at least one said cylindrical pivot bearing, said bearing comprising two axially spaced pairs of facing cylindrical bearing surfaces, a rotor and a stator of at least one rotary hydraulic jack being integrated between said pairs of bearing surfaces; and (f) a ball joint centered substantially on said pitch axis comprising at least one element of elastic material which element is at least partly in the form of at least a portion of at least one spherical cap retained between two rigid supports, one of said supports being integral with said blade in terms of torsion about said pitch axis of said blade, the other of said supports being integral in terms of rotation with the rotor of at least one said rotary hydraulic jack about said pitch axis, said ball joint being rigid circumferentially about said pitch axis while permitting, about a center of said ball joint, relative freedom of angular movement of said blade under flapping and drag as a result of shearing of said elastic material.