Abstract: A hydroelastic damper comprising at least a first resilient assembly that is provided with a first inner strength member engaged at least in part in a first outer strength member, a first resilient member providing resilient return for the first outer strength member and the first inner strength member towards a rest position (POSREP). The hydroelastic damper comprises at least one hydraulic assembly provided with a first hydraulic chamber and a second hydraulic chamber in communication with each other via a connection provided in a first wall of the hydraulic assembly. A first floating piston is movable at least in translation along the longitudinal axis relative to the first inner strength member and to the first outer strength member, the first hydraulic chamber being defined at least by the first floating piston and the first wall in order to protect the first resilient member.

Abstract: A hydro-elastic damper comprising at least one elastic assembly comprising an elastic member between two strength members. The elastic assembly including a compression chamber. The hydro-elastic damper includes a damping assembly provided with an expansion chamber that is defined in a transverse direction by an end wall and by a piston. The compression chamber is hydraulically connected to the expansion chamber by three hydraulic connections comprising respectively: a duct; at least one first passage with an overpressure valve; and at least one second passage with a check valve.

Abstract: A hydroelastic damper comprising at least a first resilient assembly that is provided with a first inner strength member engaged at least in part in a first outer strength member, a first resilient member providing resilient return for the first outer strength member and the first inner strength member towards a rest position (POSREP). The hydroelastic damper comprises at least one hydraulic assembly provided with a first hydraulic chamber and a second hydraulic chamber in communication with each other via a connection provided in a first wall of the hydraulic assembly. A first floating piston is movable at least in translation along the longitudinal axis relative to the first inner strength member and to the first outer strength member, the first hydraulic chamber being defined at least by the first floating piston and the first wall in order to protect the first resilient member.

Abstract: A rotor comprising a hub and a plurality of lift assemblies. Each lift assembly is connected to two adjacent lift assemblies respectively by a first damper and a second damper. The first damper is hinged to a lift assembly about a first axis, and the second damper is hinged to said lift assembly about a second axis. A first plane contains a lead-lag axis of the lift assembly and orthogonally to the pitch axis of the lift assembly. The first axis is situated in a volume lying between the first plane and an axis of rotation of the rotor, the second axis being positioned outside said volume.

Abstract: A damper device provided with a first connection member, a second connection member, a resilient member, and a hydraulic system. The hydraulic system includes an outer casing and a rod, the first connection member being fastened in reversible manner to the outer casing, the resilient member being arranged around a projecting portion of the rod, the resilient member comprising at least one resilient means interposed between a first strength member and a second strength member, the first strength member being fastened in reversible manner to the outer casing, the second strength member being constrained to move in translation with the projecting portion, and the connection member being fastened in reversible manner to the projecting portion.

Abstract: A hydro-elastic damper comprising at least one elastic assembly comprising an elastic member between two strength members. The elastic assembly including a compression chamber. The hydro-elastic damper includes a damping assembly provided with an expansion chamber that is defined in a transverse direction by an end wall and by a piston. The compression chamber is hydraulically connected to the expansion chamber by three hydraulic connections comprising respectively: a duct; at least one first passage with an overpressure valve; and at least one second passage with a check valve.

Abstract: A rotor comprising a hub and a plurality of lift assemblies. Each lift assembly is connected to two adjacent lift assemblies respectively by a first damper and a second damper. The first damper is hinged to a lift assembly about a first axis, and the second damper is hinged to said lift assembly about a second axis. A first plane contains a lead-lag axis of the lift assembly and orthogonally to the pitch axis of the lift assembly. The first axis is situated in a volume lying between the first plane and an axis of rotation of the rotor, the second axis being positioned outside said volume.

Abstract: A damper device provided with a first connection member, a second connection member, a resilient member, and a hydraulic system. The hydraulic system includes an outer casing and a rod, the first connection member being fastened in reversible manner to the outer casing, the resilient member being arranged around a projecting portion of the rod, the resilient member comprising at least one resilient means interposed between a first strength member and a second strength member, the first strength member being fastened in reversible manner to the outer casing, the second strength member being constrained to move in translation with the projecting portion, and the connection member being fastened in reversible manner to the projecting portion.

Abstract: A hydraulic valve assembly includes a hydraulic valve, a control rod configured to be moved in translation along a first longitudinal axis by flight controls of an aircraft, a servocontrol, and an outlet rod configured to be moved in translation along a second longitudinal axis and configured to transfer a hydraulic fluid between the servocontrol and the hydraulic valve. A blocker device is configured to block a movement of the control rod when a difference between a first movement of the control rod and a second movement of the outlet rod exceeds a predetermined threshold and includes at least one moveable abutment configured to block the movement of the control rod when the predetermined threshold is reached and configured to move in longitudinal translation with the outlet rod, and a differential lever configured to mechanically link the control rod to the outlet rod and to cooperate with the at least one moveable abutment.

Abstract: A hydraulic valve assembly includes a hydraulic valve, a control rod configured to be moved in translation along a first longitudinal axis by flight controls of an aircraft, a servocontrol, and an outlet rod configured to be moved in translation along a second longitudinal axis and configured to transfer a hydraulic fluid between the servocontrol and the hydraulic valve. A blocker device is configured to block a movement of the control rod when a difference between a first movement of the control rod and a second movement of the outlet rod exceeds a predetermined threshold and includes at least one moveable abutment configured to block the movement of the control rod when the predetermined threshold is reached and configured to move in longitudinal translation with the outlet rod, and a differential lever configured to mechanically link the control rod to the outlet rod and to cooperate with the at least one moveable abutment.

Abstract: In order to protect a hinge, an elastomer confinement structure is provided presenting: upstream and downstream openings; a static cap; an upstream collar; and a hinge bellows. Each opening has a ring for rigidly anchoring to a downstream member of the hinge, and each opening has a ring acting as a rigid receiver. The collar is movable and releasably secured by resilient fastening inspection means.

Abstract: In order to protect a hinge, an elastomer confinement structure is provided presenting: upstream and downstream openings; a static cap; an upstream collar; and a hinge bellows. Each opening has a ring for rigidly anchoring to a downstream member of the hinge, and each opening has a ring acting as a rigid receiver. The collar is movable and releasably secured by resilient fastening inspection means.

Abstract: The rolling bearing 1 of this bearing assembly is of the relubricatable type and is mounted tightly on the shaft 4 by its inner race 2 in such a way as to be prevented from rotating and translating on the shaft, the latter for this purpose comprising a thrust shoulder 3. The outer race 6 of the rolling bearing is housed in a ball swivel with a spherical outer peripheral surface consisting of two half ball swivels 7 back to back and this ball swivel is itself mounted in the spherical housing 8 of a support consisting of two flanges 9, 10 arranged facing one another and slightly separated from one another in the axial direction prior to clamping. One 9 of these flanges may be fixed by lugs 11 to the structure of the craft and the other flange 10 may be fixed to the previous one using screws 12.

Abstract: The rolling bearing 1 of this bearing assembly is of the relubricatable type and is mounted tightly on the shaft 4 by its inner race 2 in such a way as to be prevented from rotating and translating on the shaft, the latter for this purpose comprising a thrust shoulder 3. The outer race 6 of the rolling bearing is housed in a ball swivel with a spherical outer peripheral surface consisting of two half ball swivels 7 back to back and this ball swivel is itself mounted in the spherical housing 8 of a support consisting of two flanges 9, 10 arranged facing one another and slightly separated from one another in the axial direction prior to clamping. One 9 of these flanges may be fixed by lugs 11 to the structure of the craft and the other flange 10 may be fixed to the previous one using screws 12.

Abstract: The annular cushion 25 interposed between the fixed housing 22, 23 and a swiveling exterior surface 27 in the shape of a spherical sector with relatively large radius of curvature of the bearing block 12, 15, 16, is in a relatively rigid and incompressible material, with low coefficient of friction surface, and has a transverse section wholly adapted to the section of the annular space arranged between the inner surface of the fixed housing 22, 23 and the swiveling exterior surface of the bearing block 12, 15, 16, this annular cushion consisting of two rings 25 spaced apart and arranged on each side of the transverse median plane of the swiveling exterior surface.

Abstract: Each blade of the rotor has a rigid root oversleeve connected to a torsionable and flexible root strip by two laminated, spherical support half bearings, fixed by their outer frame with double rigid horns the lateral ends of which facing each other on each side of the strip and half bearings are clamped towards each other and against struts so as to allow a significant, calibrated pre-compression of the half bearings. The double horns and/or struts are fixed axially to the oversleeves by fixing elements distinct from the compression means of the double horns on the struts and perpendicular to these compression horns on the struts and perpendicular to these compression elements. One of the struts, possibly in a single piece with one double horn, is also in a single piece with a pitch lever.

Abstract: The device comprises a detachable distance-piece (19') with a pivot (20) retained in a pivoting way in the yoke (7b) of a member (7) connecting a blade (4) to the hub, by one of the two blade pins (15) and a distance-piece yoke (22') in which the blade root (6) is retained pivoting by a fitting pin (18'). The blade (4) is folded by pivoting its root (6) with respect to the distance piece (19') and pivoting the latter with respect to the yoke (7b), with a lateral shift with respect to the conventional folding without a detachable distance-piece (19'), and with a fitting pin (18') which can be inclined with respect to the blade pin (15).

Abstract: A variable-pitch multi-blade rotor for use as the anti-torque rear rotor of a rotating wing aircraft has a rotor with a central shaft rotated about a central axis, a hub constrained to rotate with the central shaft about the central axis, blades distributed around the central axis with each blade being connected to the central shaft by a twistable element, a pitch control disk for the blades which is constrained to rotate with the central shaft but free to slide axially relative to the central shaft, and a member for controlling the sliding of the pitch control disk along the central shaft. Each blade root is secured to a transverse thrust and pitch control lever forming a yoke having one end hinged to the hub and another end hinged to the pitch control disk.

Abstract: A variable pitch multi-blade propeller suitable for use on a helicopter is constructed of a foam preform joined with a fibrous spar enclosed in resin-impregnated foils and fitted with a metal leading edge. Various components are assembled in a mold and the resins, then cured. The structure may further include a reinforcing yoke of carbon fiber fabrics preimpregnated with a polymerizable synthetic resin. The process may further include a heat treating step to effect polymerization.

Abstract: Each blade is fixed to the hub by the root part of the spar, arranged in the form of a loop surrounding a connection element bolted on the hub, with the interposition of rigid rings by a pin simultaneously fixing the hub on a drive sleeve transmitting thereto the driving torque of the central shaft. The hub comprises two coaxial cylindrical walls in each of which is pierced, for each blade, a circular opening in which the member for controlling the angle of attach which is fast with the blade root is mounted to rotate via self-lubricating rings. The invention is particularly applicable to helicopters.