Abstract: The invention provides a mechanism for attenuating torque pulsations between an engine (2) and a rotor (1) of a rotorcraft. Torsion means (5) are interposed between the driving and driven shafts and comprise a torsion shaft (6) axially engaged with the drive shaft (3) and the driven shaft (4) an inlet shaft (9) and an outlet shaft (10) respectively engaged with the drive and driven shafts (3, 4) a lever system (7) that extends radially relative to the torsion shaft (6) and that has the inlet and outlet shafts (9, 10) hinged thereto via points (11, 12) that are spaced apart; and a mass (8) carried by said lever arm (7) at its free end (13) radially farthest away from the axis along which the torsion shaft (6) extends.

Abstract: A turbine blade is provided comprising: a root; an airfoil comprising an external wall extending radially from the root and having a radially outermost portion; and a damping structure. The external wall may comprise first and second side walls joined together to define an inner cavity of the airfoil. The damping structure may be positioned within the airfoil inner cavity and coupled to the airfoil so as to define a tuned mass damper.

Abstract: A rotor for a helicopter, having: a hub rotating about an axis and in turn having a number of blades; and an at least partly hollow drive shaft connectable to a drive of the helicopter and connected functionally to the hub to rotate the hub about the axis; the rotor also having vibration damping means in turn having a mass, and an elastically deformable member connected to the mass and supported by the shaft; the member extending at least partly inside the shaft, and being elongated parallel to the axis; and the mass vibrating, in use, at such a frequency as to oppose transmission to the shaft of the vibration produced by rotation of the hub and blades.

Abstract: An airfoil includes an airfoil body that has a leading edge and a trailing edge and a first sidewall and a second sidewall that is spaced apart from the first sidewall. The first sidewall and the second sidewall join the leading edge and the trailing edge and at least partially define a cavity in the airfoil body. A damper member is enclosed in the cavity and is free-floating within the cavity.

Abstract: A wind turbine is provided, comprising a rotor arranged at a nacelle, the nacelle supported by a tower, and a damper including a movable mass. The damper is adapted for variably adjusting a frequency response of the wind turbine.

Abstract: A device (10) for reducing vibration of a main rotor (1) having a support (20) and a plurality of heavy elements (30) and of rollers (50). Each heavy element (30) includes two first openings (31) respectively at least partially in registration with two second openings (22) of the support (20. Each roller (50) passes through a first opening (31) and a second opening (22). The device (10) has link means (60) for connecting the support (20) to the hub (2). A drive shaft (70) and a drive means (80) rotate at a first speed of rotation (V1) greater than a second speed of rotation (V2) of the hub (2). The drive shaft (70) rotates about an axis of rotation (AX1) of the support (20). The link means (60) is connected to the support (20) by a link member (90) enabling the support (20) to rotate about the axis of rotation (AX1) relative to the link means (60).

Abstract: A rotating object dynamic balancing system and method for balancing a rotating object including a shaft by using centrifugal force on a plurality of weighted masses traveling along at least one race. The rotating object dynamic balancing system has an inner body, an outer body, a fastening body or fastening body, and a plurality of weighted masses. The inner body has a hollow interior area and an aperture in communication with the interior area and adapted to receive the shaft. The outer body has a hollow interior area defined therethrough, and at least one radial race defined in the interior area. The outer body is attachable to the inner body. The fastening body has a hollow interior area, and is configured to be received into the interior area of the inner body. The interior area of the fastening body assembly is adapted to engage with the shaft received through the inner body thereby securing the rotating object dynamic balancing system to the rotating object.

Abstract: A balancing assembly for a rotor assembly of a gas turbine engine includes a flange engaging portion defining a flange receiving opening for mating with the flange in a slidable manner. A hole extends through at least part of the flange engaging portion, the hole corresponding in size to a recess and adapted to receive a rivet or other suitable fastener to fix the balancing weight with respect to the disc.

Abstract: A wind turbine is provided including a nacelle housing a power train of the wind turbine. The power train of the wind turbine includes a gearbox, a generator, and one or more rotatable shafts, each including a radial direction and an axial direction. Further, the wind turbine includes a vibration absorbing device being arranged on a shaft of the power train. The vibration absorbing device includes an energy storing arrangement, which includes a flexible element and a mass assembly. The vibration absorbing device is connected to the shaft in an axially symmetric way.

Abstract: Methods and apparatus are provided for limiting the load on a rotor support structure when a rotationally mounted rotor becomes imbalanced. The rotor is rotationally mounted within a plurality of circumferentially spaced variable volume hydraulic fluid receptacles that at least engage the rotor and have hydraulic fluid disposed therein. Each of the variable volume hydraulic fluid receptacles is fluidly connected to a substantially fixed volume hydraulic fluid receptacle that has hydraulic fluid disposed therein and is coupled to the rotor support structure. When the rotor becomes imbalanced, the hydraulic fluid is continuously moved between the variable volume hydraulic fluid receptacles and the substantially fixed volume hydraulic fluid receptacle.

Abstract: A vibration attenuator for an aircraft has at least one weight mounted in a rotating system of a rotor hub of the aircraft, each weight being rotatable about an axis of rotation of the hub relative to the hub and to each other weight. Drive means are provided for rotating each weight about the axis of rotation at a selected speed for creating oscillatory shear forces that oppose and attenuate rotor-induced vibrations having a selected frequency. A vertically oriented vibration attenuator is configured to oppose and attenuate vertical rotor induced oscillatory forces that would otherwise travel vertical down the rotor mast and into the airframe.

Abstract: A method and device for reducing vibratory noise in a system with an integral rotating member includes independently operable drive systems for controlling the angular velocity of at least two independently rotatable masses. Control signals manipulate the drive system to rotate each mass at optimal speed, direction and phase to reduce noise induced in the system by the rotating member.

Abstract: A vibration attenuator for an aircraft has at least one weight mounted in a rotating system of a rotor hub of the aircraft, each weight being rotatable about an axis of rotation of the hub relative to the hub and to each other weight. Drive means are provided for rotating each weight about the axis of rotation at a selected speed for creating oscillatory shear forces that oppose and attenuate rotor-induced vibrations having a selected frequency.

Abstract: A vibration suppressor system includes an annular electric motor system which independently controls rotation of at least two masses about the axis of rotation to reduce in-plane vibration of the rotating system. A method of reducing vibrations in a rotary-wing aircraft includes independently controlling a relative angular position of a multiple of independently rotatable masses to reduce vibrations of a main rotor system.

Abstract: A rotor assembly for a gas turbine engine including a circumferential array of regularly spaced apart features provided on the disk which are each configured for receiving a balancing weight. The circumferential array of features has an angular orientation relative to the circumferential array of blades such that the features are each located at an at least substantially same offset angle from a stacking line of a respective adjacent blade.

Abstract: An aircraft propeller taper bore insert apparatus includes an outer surface, the outer surface dimensioned and configured to fit within an aircraft propeller taper bore or an aircraft propeller balancing tube, and an inner surface, the inner surface defining an inner cavity configured to receive a balancing medium, the inner surface comprising a plurality of retention formations arranged thereon, and the plurality of retention formations being configured to support the balancing medium.

Abstract: A method of validating a wind turbine including a rotor includes intentionally inducing a loading imbalance to the rotor. The method also includes measuring the loading imbalance induced to the rotor, transmitting a signal representative of the measured loading imbalance to a calibration module, and at least one of detecting an error and calibrating at least one component of the wind turbine based on the signal.

Abstract: A system for balancing an aircraft propeller system receives a vibration signal from the aircraft propeller system and determines whether the vibration signal indicates a transient vibration condition. If it is determined that the vibration signal does not indicate a transient condition, the system enables a balance correction controller. The controller generates a balance correction signal based on the vibration signal, and balances the aircraft propeller system in response to the balance correction signal if the balance correction controller is enabled.

Abstract: A vibration reduction device according to the present invention includes: an elastic body; a dynamic mass; and a controllable mass. The dynamic mass is supported by an object of vibration reduction through the elastic body. The actuator causes the controllable mass to move with respect to the dynamic mass. Such a vibration reduction device can vary the frequency and the amplitude at which the dynamic mass vibrates with respect to the object of vibration reduction by causing the controllable mass to move appropriately with respect to the dynamic mass, thereby enabling the vibration of the object of vibration reduction to be reduced more reliably. In addition, such a vibration reduction device can reduce vibration of a certain frequency of the object of vibration reduction even when the controllable mass is fixed with respect to the dynamic mass.

Abstract: According to the invention, at least one of the counterweights (40, 40.1, 40.2, 40.3, 40.4) is mobile mounted on a guiding slot (24, 34) coaxial to the hub envelope (22, 32) that surrounds the hub (21, 31) of the corresponding propeller (2, 3), the movement of said mobile counterweight (40, 40.1, 40.2, 40., 40.4) along said guiding slot (24, 34) being controlled on the basis of an estimation of the possible unbalance of said propulsive system (1).

Abstract: It is intended to provide a vibration control apparatus that can be installed in a small pace and can be produced at low cost, as well as a wind turbine generator equipped with the vibration control apparatus and a vibration control method. The vibration control apparatus 7 includes a first vibration system 10 of inverted-pendulum type, second vibration systems 20 of inverted-pendulum type which are provided on both sides of the first vibration system 10, a restraining unit 30 which restrains a first weight 11 of the first vibration system 10 and a second weight 21 of the second vibration system 20 and a damper which damps vibration of the first weight 11 and the second weight 21. The vibration control apparatus 7 is installed on an upper floor 8a of a plurality of floors 8.

Abstract: A balancing system and method for reducing imbalance in a rotatable member of a machine is provided. The system includes a plurality of vibration sensors positioned about a stationary portion of the machine, a controller assembly communitively coupled to the plurality of vibration sensors, and a balancing assembly coupled to the rotatable member, said balancing assembly configured to wirelessly communicate with said controller assembly, said balancing assembly configured to modify the weight distribution of the rotatable member in response to a command wirelessly transmitted from the controller assembly. The controller assembly is configured to receive data from the plurality of vibration sensors and determine an imbalance in the rotatable member using the received data.

Abstract: A blade (10) extending longitudinally from a root (11) of the blade (10) to a free end (12) of the blade (10), the blade (10) having a resonator (13) incorporated therein to reduce the drag movements (F1, F2) of the blade (10), the resonator (13) being provided with a solid and movable heavy element (30) and with resilient retaining element (20) secured to the heavy element (30) and to the blade (10). Furthermore, the resonator (13) includes guide element (40) in which the heavy element (30) is capable of oscillating (F1?, F2?) longitudinally, the guide element (40) being arranged in a longitudinal direction (D1) of the blade.

Abstract: An aircraft system and method with a first counterweight rotating balancing rotor mass concentration, and a second counterweight rotating balancing rotor mass concentration to balance a first aircraft propeller. The system includes an inboard electromagnetic coil driver with a first inboard electromagnetic coil, and a second inboard electromagnetic coil, the inboard electromagnetic coil driver and the first counterweight balancing rotor and the second counterweight balancing rotor centered around the aircraft propeller shaft rotating machine member. The system/method utilizes a first control system controller to control the coils and position the mass concentrations to balance the first aircraft propeller. The system/method includes a third counterweight rotating balancing rotor mass concentration, and a fourth counterweight rotating balancing rotor mass concentration to balance a second aircraft propeller which positioned and controlled by a second control system controller.

Abstract: An apparatus and method for balancing a gas turbine engine rotor includes a plurality of balancing weights adapted to be selectively attached to at least one of inlets or outlets of a cooling passage of the rotor. The weights include cooling access which permits coolant to communicate with the cooling passage.

Abstract: An impeller assembly including a motor that rotationally drives an impeller is balanced. The impeller assembly is balanced without physically indexing the impeller to determine the rotational position of the impeller while impeller is rotated. For example, the system does not employ an optical sensor, a magnetic sensor (e.g., a Hall sensor), a mechanical indexing sensor, and/or other sensors that physically index the impeller.

Abstract: A balance weight for a turbine rotor includes: a block-like centerbody; a pair of resilient spring arms extending laterally from opposite sides of the centerbody, the centerbody and the spring arms collectively defining an arcuate shape; at least one locating structure extending from a radially outer surface of the balance weight; and a limit tab extending radially inward from a distal end of each of the spring arms.

Abstract: Described is a fan with a blade suitable for use as a ceiling fan. The blade may be regarded as a single blade, although shaft is not attached to blade at one end thereof; rather, shaft is attached to blade at a point between first end and second end. Blade is balanced by counterweights located in blade. In one embodiment, blade is connected to shaft by means that permit angular movement, such as a teeter hinge.

Abstract: Described is a blade (10) extending longitudinally from a root (11) of the blade (10) to a free end (12) of the blade (10), the blade (10) being provided with an incorporated resonator (20) for reducing the drag movements (F1, F2) of the blade (10), the resonator (20) being provided with a closed tank (30) that is partially filled with a liquid (50). Furthermore, the resonator (20) includes a central tube (40) immersed inside the tank (30), the tank (30) and the central tube (40) being arranged in a longitudinal direction (Y) of the blade (10), the central tube (40) having first and second ends (41, 42) that communicate with the tank (30) so that the liquid (50) can move from the tank (30) into the central tube (40), and vice versa.

Abstract: A method for balancing blades of a wind turbine comprises several steps. First, vibration sensor readings are taken while wind turbine blades are in a pre-balancing configuration. These vibration sensor readings are used to determine initial blade imbalance. Next, vibration sensor readings are taken while wind turbine blades are in a first and a second pitch offset configuration. These vibration sensor readings are used to determine system response to the first and second pitch offset configurations. A correction pitch configuration is determined from the initial blade imbalance and the system response. Finally, blades of the wind turbine are pitched according to the correction pitch configuration.

Abstract: This invention provides convenient airframe vibration and tracking improvements of a helicopter rotor blade by use of an elastomer profile system that is attached through an adhesive system that allows convenient removal and relocation for use by the helicopter manufacturer or by the helicopter operator in a field environment.

Abstract: A balance weight for a rotor includes: (a) an arcuate body including a front wall and a rear wall interconnected by an end wall, the front, rear, and end walls collectively defining a generally U-shaped cross-sectional shape; and (b) a projection extending outwardly from the rear wall, the projection being adapted to engage an aperture extending through a flange of the rotor.

Abstract: A rotating machine includes a stationary member and a rotating member moveable relative to the stationary member. The rotating member includes at least one balancing member assembly receiving portion having a plurality of internal threads. The rotating machine also includes a balancing member assembly including first and second interlocking balancing members. The balancing member assembly also includes a plurality of external threads that are operatively connected to the internal threads of the balancing member assembly receiving portion. With this arrangement, the balancing member assembly provides a dynamic balance for the rotating member.

Abstract: The invention relates to an adjustment device (30) for a rotating body (10; 21; 22), in particular a fan (10) of a cooling fan for a combustion engine, or a shaft (21) or a rotor (22) of an electric motor (20), comprising a rotation axis (R), wherein a mass (311; 10; 11; 14) that rotates around the rotation axis (R) can be dislocated relative to the rotation axis (R) by means of the adjustment device (30). The invention further relates to a rotating body (10; 22), in particular a fan (10) of a cooler blower for a combustion engine, or a shaft (21) or a rotor (22) of an electric motor (20), comprising an adjustment device (30) according to the invention.

Abstract: A system (40) for damping motion of a wind turbine (10a) is provided. The system (40) includes a sensor (42), a movable mass (44), an actuator (58), and a controller (46). The sensor (44) is operable to provide a signal representative of a motion of the wind turbine (10a) in one or more degree of freedoms. The movable mass (44) is associated with the actuator (58) and is disposed on a blade (24a) of the wind turbine (10a) and is configured for movement along a length of the blade. In response to the sensor (42), the controller (46) is operable to direct the actuator (58) to move the movable mass (48) along a length (50) of the blade (24) to a degree effective to dampen motion of the wind turbine (10a) in one or more degree of freedoms.

Abstract: A cooling fan includes a frame and a rotor received in the frame. The rotor includes a hub, blades extending outwardly and radially from the hub, and a cover plate connected with the hub. The hub includes a top wall and a sidewall extending from a circumference of the top wall. The top wall of the hub defines a plurality of blind holes on an outer surface thereof, and the blind holes are shaded by the cover plate.

Abstract: A wind turbine includes a tower, a nacelle located adjacent a top of the tower, a rotor coupled to the nacelle, and a dynamic vibration damper coupled to the tower and configured to dampen vibrations induced in the tower in a torsional direction while negligibly effecting vibrations induced in the tower in bending directions. The dynamic vibration damper may be tuned to a resonant frequency of the wind turbine in the torsional direction. A method of retrofitting a wind turbine with a vibration damper is also disclosed.

Abstract: The present invention relates to a turbomachine rotor balancing system comprising a balancing flange (52) provided with through-passageways (78), the system further comprising balance weights (54) each mounted fixedly on the flange (52) by means of a first and a second screw/nut assembly (56a, 56b) having a first and a second screw (84, 84) passing through a first and a second passageway (78, 78). According to the invention, said first screw is pressing against a first tangential end side (116) of the first through-passageway, and at a distance from a second tangential end side, and the second screw is pressing against a second tangential end side (118) of the second through-passageway, and at a distance from the first tangential end side.

Abstract: A vertical-axis wind turbine for use with an electrical generator for producing power by converting the energy of wind currents into mechanical rotational energy which is then used to operate the electrical generator. In an embodiment, a rotor is responsive to wind currents by imparting rotation upon a central vertical shaft. Preferably, the rotor is designed with functional curved surfaces for efficient operation.

Abstract: Method and apparatus for vibration-based automatic condition monitoring of a wind turbine, comprising the steps of: determining a set of vibration measurement values of the wind turbine; calculating a frequency spectrum of the set of vibration measurement values; calculating a cepstrum of the frequency spectrum; selecting at least one quefrency in the cepstrum, and detecting an alarm condition based upon an amplitude of the cepstrum at the selected quefrency, and a wind turbine therefor.

Abstract: A device (10) for reducing the vibration of a rotorcraft main rotor (1) provided with a hub (2) and a plurality of blades, said device having a support (20) together with at least one weight element (30). Said weight element (30) is fastened to said support (20) by connection means (40), and said weight element (30) is connected to said connection means (40) by guide means (50) for guiding said weight element (30) in movement in circular translation in a filter plane (P1) that is movable perpendicularly to an elevation axis (AX) of said device (10), said connection means (40) including resilient return means (41) serving to allow said filter plane (P1) to move in elevation while keeping the filter plane (P1) perpendicular to said elevation axis (AX) under the effect of said vibration.

Abstract: In one embodiment, a rotor blade balancing apparatus may include a tube member defining an inner cavity, a plurality of weights, and a biasing member. The tube member may be for the insertion into a cavity of a rotor blade. Each of the weights may be adapted to be slide-ably inserted into the inner cavity of the tube member within a cavity of a rotor blade, and slide-ably removed from the inner cavity of the tube member within a cavity of a rotor blade in order to balance a rotor blade. The biasing member may be for biasing weights, which have been slide-ably inserted into the inner cavity of the tube member within a cavity of a rotor blade, towards an end of the tube member.

Abstract: A method and device for reducing vibratory noise in a system with an integral rotating member includes independently operable drive systems for controlling the angular velocity of at least two independently rotatable masses. Control signals manipulate the drive system to rotate each mass at optimal speed, direction and phase to reduce noise induced in the system by the rotating member.

Abstract: A method and device for reducing vibratory noise in a system with an integral rotating member includes independently operable drive systems for controlling the angular velocity of at least two independently rotatable masses. Control signals manipulate the drive system to rotate each mass at optimal speed, direction and phase to reduce noise induced in the system by the rotating member.

Abstract: An aircraft system/method for propeller balancing.

Abstract: A vibration attenuator for an aircraft has at least one weight mounted in a rotating system of a rotor hub of the aircraft, each weight being rotatable about an axis of rotation of the hub relative to the hub and to each other weight. Drive means are provided for rotating each weight about the axis of rotation at a selected speed for creating oscillatory shear forces that oppose and attenuate rotor-induced vibrations having a selected frequency. A vertically oriented vibration attenuator is configured to oppose and attenuate vertical rotor induced oscillatory forces that would otherwise travel vertical down the rotor mast and into the airframe.

Abstract: A blade for a wind turbine generally comprises a shell body defined by first and second shells extending between a leading edge and a trailing edge, an inner spar supporting at least a portion of the shell body, and a damping element coupled to at least one of the shell body or inner spar. The damping element is configured to move relative to the shell body to dissipate vibrations of the blade, and has a greater degree of freedom in a flapwise direction between the first and second shells than in an edgewise direction between the leading and trailing edges.

Abstract: A vertical axis wind turbine having a vertical rotating axle and a plurality of blades each attached to an upper portion to the rotating axle and at the bottom portion to a convex base dome attached to and rotable with the vertical axle. Each blade wraps around the vertical axle and has a radial width that increases from its upper portion to its lower portion while supporting an open brow section forming a cup-like space and a wedge-like stiffener section.

Abstract: The present invention provides a mechanism (90) for damping vibrations to prevent coupling of vibration modes of the carrier structure (106) with vibration modes of a rotor (100) secured to said carrier structure (106). The mechanism comprises a support (3) suitable for being fastened to said rotor (100) and at least one resonator (1) including a mass (5) carried by said support (3) via mobile mounting means (6) for mounting said mass (5) to move on said support (3), said mechanism (90) including damper means (8) for damping the resonator (1), which means are interposed between the resonator (1) and an engagement member (9) on said support (3).

Abstract: An apparatus and method for a turbine wheel assembly for a pneumatic rotary vibrator that provides a selectable force output while being removably retained on a vibrator shaft member. The turbine wheel assembly is mounted inside of a generally circular interior chamber of a pneumatic vibrator housing. The turbine wheel assembly includes: (1) a turbine ring that has an outside diameter, an inside diameter and a face width, (2) a sleeve member that is round and tubular, (3) an intermediate weight ring assembly that has an outer circumference, an inner circumference, and a predetermined face width, The weight ring assembly is formed by a plurality of wedge shaped segments.