Abstract: In this elastic strut incorporating a hydromechanical resonator having a weight/spring system of the type providing a hydraulic amplification of the displacement of the beating weight (7), the weight mounted between two opposed return springs constitutes a double-sided hollow piston slidably mounted on two coaxial opposed cylinders (6) in a closed chamber filled with a liquid (10) in an inner tubular element (1) disposed in an outer tubular element (2) with which it defines, at each end, a chamber (18, 26) filled with liquid onto which opens one of the cylinders (6), the elements (1, 2) constituting the body of the strut being coaxially movable relative to each other and fixed together at each of their ends in a sealed and elastic manner by bearings composed of an elastomer material.

Abstract: 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.

Abstract: A rotary damper comprises a stator and a rotor which are co-axial, circular and cylindrical, two extreme faces substantialy transversal to the axis of the stator and rotor and disposed respectively on either side of the stator and rotor, a main chamber filled with a fluid, defined between the extreme faces and the stator and the rotor, blades disposed on the stator and rotor and dividing the main chamber is a plurality of volumes, the blades laminating the flow of fluid through the different volumes of the main chamber, and an auxiliary chamber which communicates with the main chamber. The auxiliary chamber is at least partly formed by a diaphragm which is elastically deformable and which is designed to compensate for the volume variations of the fluid as a function of its temperature, and to bring in, if necessary, a twisting stiffness in parallel to the damping function. The rotary damper finds application for example in vehicle suspensions.