Abstract: A bottom abutment device for a rotor having a plurality of lift assemblies. The bottom abutment device comprises at least one abutment track per lift assembly. The bottom abutment device comprises a plate with a ring and one branch per lift assembly. The bottom abutment device has a plurality of supports, each support fastenable to a rotary member of the rotor, each support extending in part in an opening in a branch, the supports giving the plate a restricted degree of freedom to move in translation, the supports giving the plate at least one restricted degree of freedom to move in rotation about the axis of symmetry.

Abstract: A resonator provided with a heavy member comprising a casing fastened a spring blade. The heavy member comprises a set of masses that is movable in translation in said casing along a longitudinal direction. A wormscrew driven by drive means is engaged in a slider nut of said set of masses. The set of masses comprises two masses that are slidable respectively in two cylindrical spaces of the casing. Each mass presents at least two presser means interposed between the mass and the casing, each presser means comprising a groove formed in a circumference of a mass, each presser means comprising at least one resilient member arranged in said groove and a split ring pressed against the casing by said at least one resilient member of the presser means.

Abstract: A resonator provided with a heavy member comprising a casing fastened a spring blade. The heavy member comprises a set of masses that is movable in translation in said casing along a longitudinal direction. A wormscrew driven by drive means is engaged in a slider nut of said set of masses. The set of masses comprises two masses that are slidable respectively in two cylindrical spaces of the casing. Each mass presents at least two presser means interposed between the mass and the casing, each presser means comprising a groove formed in a circumference of a mass, each presser means comprising at least one resilient member arranged in said groove and a split ring pressed against the casing by said at least one resilient member of the presser means.

Abstract: A bottom abutment device for a rotor having a plurality of lift assemblies. The bottom abutment device comprises at least one abutment track per lift assembly. The bottom abutment device comprises a plate with a ring and one branch per lift assembly. The bottom abutment device has a plurality of supports, each support including fastener means for fastening to a rotary member of the rotor, each support extending in part in an opening in a branch, the supports giving the plate a restricted degree of freedom to move in translation, the supports giving the plate at least one restricted degree of freedom to move in rotation about the axis of symmetry.

Abstract: A rotor for a rotorcraft, the rotor having a plurality of lift assemblies, together with a flapping abutment mechanism for each lift assembly. Each abutment mechanism has a projection secured to a lift assembly with an abutment end provided with an inner face and an outer face, and at least one pivotally-mounted lever extending longitudinally from a flyweight to a hook. The hook is provided with two walls in elevation and a bottom wall forming a periphery that defines the groove, a first wall in elevation having an upper bearing zone for blocking the inner face and a second wall in elevation including a lower bearing zone for blocking the outer face.

Abstract: A suspension device (10) provided with at least one suspension means (20) comprising a flapper (21) performing pendulum motion, the flapper (21) being provided with a mass support (25) supporting at least one flapping mass (30). The mass support (25) is hinged to a carrier structure (2) for isolating and to a holder bar (15) for holding said mechanical assembly. The suspension device (10) includes at least one force generator (70), said suspension device (10) having at least one computer (50) connected to a measurement system (55) measuring the levels of vibration, and to said force generator (70) to regulate said amplitude and said phase actively by controlling the force generator (70) as a function of at least one measurement signal coming from said measurement system (55).

Abstract: A rotor for a rotorcraft, the rotor having a plurality of lift assemblies, together with a flapping abutment mechanism for each lift assembly. Each abutment mechanism has a projection secured to a lift assembly with an abutment end provided with an inner face and an outer face, and at least one pivotally-mounted lever extending longitudinally from a flyweight to a hook. The hook is provided with two walls in elevation and a bottom wall forming a periphery that defines the groove, a first wall in elevation having an upper bearing zone for blocking the inner face and a second wall in elevation including a lower bearing zone for blocking the outer face.

Abstract: A suspension device (10) provided with at least one suspension means (20) comprising a flapper (21) performing pendulum motion, the flapper (21) being provided with a mass support (25) supporting at least one flapping mass (30). The mass support (25) is hinged to a carrier structure (2) for isolating and to a holder bar (15) for holding said mechanical assembly. The suspension device (10) includes at least one force generator (70), said suspension device (10) having at least one computer (50) connected to a measurement system (55) measuring the levels of vibration, and to said force generator (70) to regulate said amplitude and said phase actively by controlling the force generator (70) as a function of at least one measurement signal coming from said measurement system (55).

Abstract: The present invention relates to a rotorcraft blade (1) provided with at least one spar (3) and an outer covering (4), said blade (1) including a hollow sleeve (10) with a wall (11) that is provided at least with said outer covering (4) secured to said spar (3). The blade includes a rotary damper (20) provided with an inner tubular strength member (21) and an outer tubular strength member (22) that are coaxial and connected together by a ring (23) of viscoelastic material, said inner tubular strength member (21) being secured to said covering (4), and said outer tubular strength member (22) being provided with a fork (25) possessing first and second tines (26, 27) facing each other so as to be suitable for receiving a first ball joint (41) close to the pitch-variation axis (AX1) of said blade (1).

Abstract: The present invention relates to a method of monitoring the effectiveness of a damper system, wherein the method consists in measuring the relative movements of two strength members, in filtering the measurements in order to isolate those that relate to the lead-lag resonant frequency of the blade, in rectifying the signal, in recording the signal, in comparing the rectified signal (S) with a threshold value (SL), in determining an initial time interval (T0) as soon as the rectified signal exceeds the threshold value (SL), in calculating the integrals of the signal from T0 to T0+? and from T0 to T0+p?, in calculating the ratio R of the integrals, and in comparing the ratio R with a limit value RL, and in activating and delivering an alert signal (V1) if the ratio R is greater than or equal to the limit value RL.

Abstract: The present invention relates to a method of monitoring the effectiveness of a damper system, wherein the method consists in measuring the relative movements of two strength members, in filtering the measurements in order to isolate those that relate to the lead-lag resonant frequency of the blade, in rectifying the signal, in recording the signal, in comparing the rectified signal (S) with a threshold value (SL), in determining an initial time interval (T0) as soon as the rectified signal exceeds the threshold value (SL), in calculating the integrals of the signal from T0 to T0+? and from T0 to T0+p?, in calculating the ratio R of the integrals, and in comparing the ratio R with a limit value RL, and in activating and delivering an alert signal (V1) if the ratio R is greater than or equal to the limit value RL.

Abstract: The present invention relates to a rotorcraft blade (1) provided with at least one spar (3) and an outer covering (4), said blade (1) including a hollow sleeve (10) with a wall (11) that is provided at least with said outer covering (4) secured to said spar (3). The blade includes a rotary damper (20) provided with an inner tubular strength member (21) and an outer tubular strength member (22) that are coaxial and connected together by a ring (23) of viscoelastic material, said inner tubular strength member (21) being secured to said covering (4), and said outer tubular strength member (22) being provided with a fork (25) possessing first and second tines (26, 27) facing each other so as to be suitable for receiving a first ball joint (41) close to the pitch-variation axis (AX1) of said blade (1).