Abstract: A device for self-balancing a rotating part, such as a propeller, along a given axis is disclosed. The propeller 102 coupled to, a drive shaft with freedom for linear movement along longitudinal axis L-L; at least one pair of levers 614/616, comprising a first lever 614-1/616-1 and a second lever 614-2/616-2, that are pivotally mounted on mounting plate 606 at two diametrically opposite points 618; and at least one pair of weights 622 fixed at external ends of the levers 614/616. inner ends of levers 614/616 are operatively coupled to the propeller 102 such that when propeller 102 undergoes a linear movement in any direction along the longitudinal, axis L-L due to unbalance, inner ends of levers are, moved to cause the weights 622 to move to provide a balancing force to neutralize the unbalance in the propeller. An embodiment with only one pair of levers is also disclosed.

Abstract: A vibration attenuator for a rotor of an aircraft has a first ring with an eccentric weight, a coaxial second ring with an eccentric weight, and a central ring coaxial with the first and second rings and located therebetween. A first post extends from the first ring toward the central ring and is received in a first arcuate groove formed on the central ring, whereas a second post extends from the second ring toward the central ring and is received in a second groove formed on the central ring. A motor is configured for driving the central ring in rotation about the axis relative to the motor. The grooves are equal in length, and a center of the first groove is located on an opposite side from a center of the second groove. Rotation of the central ring by the motor causes rotation of the first and second rings.

Abstract: A system may detect a vibration being applied to a tuned vibration absorber. The tuned vibration absorber may include a beam, a mass, springs, a sensor, and an actuator. The mass may be disposed on the beam at a current position. The actuator may be configured to adjust a position of the mass on the beam. The system may identify a target position of the mass on the beam based on the detected vibration. The system may generate a drive signal, based on the target position, to control the actuator to adjust the position of the mass on the beam. The system may control the actuator to adjust the position of the mass from the current position on the beam to the target position on the beam to attenuate the vibration.

Abstract: A sealing flange sector for a turbomachine rotor disc includes a radially outer part which is configured to bear at least partly against blades of the turbomachine rotor disc to ensure sealing between the blades and a radially inner part configured to bear on an annular strip mounted on a face of the turbomachine rotor disc, the radially inner part having a first groove disposed radially outwardly of a second groove. The first groove includes at least one foolproofing element.

Abstract: The present invention provides a method of erecting a wind turbine on a wind turbine site. The wind turbine comprises a turbine tower and a nacelle. The method comprises the following steps: providing a plurality of tower sections being arrangeable upon each other in a vertical orientation in a tower structure to form the turbine tower, providing at least two damper units configured to dampen oscillations of the turbine tower, attaching one of the at least two damper units to one of the plurality of the tower sections on an outside thereof, and subsequently arranging said tower section in the tower structure, attaching a subsequent one of the at least two damper units to another one of the plurality of the tower sections on an outside thereof, and subsequently arranging said tower section in the tower structure, while the previous one of the at least two damper units is still attached to the previous one of the plurality of tower sections.

Abstract: A protective cover for a leading-edge of a wind turbine rotor blade is provided. The protective cover is pre-formed into a curved shape to accommodate at least a part of a leading-edge section including the leading-edge of the wind turbine rotor blade to be protected. The protective cover includes a pressure side section, a suction side section and a centerline in-between the pressure side section and the suction side section. The centerline runs in longitudinal direction of the protective cover. Thickness of the protective cover in a cross section of the protective cover in transverse direction has a thickness distribution corresponding to a standardized normal distribution.

Abstract: Rotor blades and turbomachines are provided. The rotor blade includes a main body having a shank, an airfoil extending radially outwardly from the shank, and a platform. The main body further includes a pressure-side slash face and a suction-side slash face. Each of the pressure-side slash face and the suction-side slash face includes a damper land and defines a slot. The damper land is disposed radially inward from the slot.

Abstract: A vibration attenuator for a rotor of an aircraft has a track housing adapted for rotation relative to the rotor and configured for rotation at a second angular velocity greater than a first angular velocity of the rotor. A track is located within the track housing and has a reaction surface, a pair of weights being configured for movement within the track and in contact with the reaction surface. A stop assembly has a pair of stops spaced 180 degrees apart, the stops separating the weights from each other, and each weight being allowed to travel within the track between the stops. A motor rotates the track housing relative to the rotor. The weights are free to travel relative to each other between a minimum-force configuration, in which the weights are positioned 180 degrees apart, and a maximum-force configuration, in which both weights are adjacent one of the stops.

Abstract: A balance weight assembly for a rotor blade of a rotorcraft. The balance weight assembly includes a balance weight pocket formed by a balance weight tray and a cover. The balance weight tray has an upper surface including a lip region extending outwardly from a projected region with an outboard boss. A balance weight receiving cavity is recessed from the upper surface and contains a plurality of balance weights. The projected region is disposed within an opening in a hollow blade spar such that the outboard boss of the balance weight tray has a contact relationship with an outboard surface of the opening. The cover is coupled to the balance weight tray such that the lip region of the balance weight tray and at least a portion of the cover have a clamping relationship with the blade spar, thereby coupling the balance weight pocket to the blade spar.

Abstract: A blade for a propulsion apparatus. The blade includes a body having opposed pressure and suction sides. The blade extends in span between a root and a tip and the blade extends in chord between a leading edge and a trailing edge. The blade includes a fracture structure that is defined within the body and positioned such that it is spaced-away from the tip. The fracture structure includes at least one chamber. A first fracture wall is disposed between the at least one chamber and the pressure side, and a second fracture wall is disposed between the at least one chamber and the suction side. The fracture structure is configured to fail when a predetermined force is applied to the tip such that the tip separates from the remainder of the body.

Abstract: The present disclosure provides various embodiments of a multicopter-assisted launch and retrieval system generally including: (1) a multi-rotor modular multicopter attachable to (and detachable from) a fixed-wing aircraft to facilitate launch of the fixed-wing aircraft into wing-borne flight; (2) a storage and launch system usable to store the modular multicopter and to facilitate launch of the fixed-wing aircraft into wing-borne flight; and (3) an anchor system usable (along with the multicopter and a flexible capture member) to retrieve the fixed-wing aircraft from wing-borne flight.

Abstract: A method for monitoring the health of propellers in an aircraft is provided. The method includes receiving pressure waves generated by at least one rotating propeller and analysing data corresponding to the received pressure waves to detect tonal noise which is within a selected frequency range. If tonal noise at harmonics of the propeller rotational frequency within the selected frequency range is detected within the selected frequency range, it is established that the health of at least one propeller may be impaired and an alert is created for inspection and maintenance to take place.

Abstract: A flexible damper (24) for turbine blades (10) includes a plurality of segments (32) positioned together in a substantially linear pattern, each segment (32) having a first side (46), a second side (48), a top side (50), a bottom side (52), a length (56), a width (54), and a thickness (58).

Abstract: The present disclosure provides various embodiments of a multicopter-assisted launch and retrieval system generally including: (1) a multi-rotor modular multicopter attachable to (and detachable from) a fixed-wing aircraft to facilitate launch of the fixed-wing aircraft into wing-borne flight; (2) a storage and launch system usable to store the modular multicopter and to facilitate launch of the fixed-wing aircraft into wing-borne flight; and (3) an anchor system usable (along with the multicopter and a flexible capture member) to retrieve the fixed-wing aircraft from wing-borne flight.

Abstract: An assembly of subassemblies having a mating bond interface for a motor vehicle is provided. The assembly includes a first subassembly of molded composite material and a second subassembly of molded composite material. An adjustable mating interface couples the subassemblies together. The interface includes a groove and a flange disposed on the first subassembly and bonded within the groove. The groove is sized and shaped relative to the size and shape of the flange to allow a bonding position of the flange within the groove to be adjusted during assembly of the subassemblies so that the mating interface is adjustable.

Abstract: There is described herein a propeller balancing system and method that selects at least a portion of received propeller vibration data by comparing received aircraft data collected concurrently with the propeller vibration data with at least one customizable flight criterion, and identifying the portion of the vibration data acquired at a time when the aircraft data meets the at least one customizable flight criterion. The selected portion of the propeller vibration data is analyzed to assess a vibration level of the propeller and a balancing need is signaled when the vibration level reaches a threshold.

Abstract: A damper pin for damping adjacent turbine blades coupled to a rotor shaft includes an elongated body having a center portion that is disposed between a first end portion and a second end portion. The first end portion, center portion and second end portion at least partially define a generally arcuate top portion of the elongated body. At least a portion of the top portion may be configured to contact with a groove that is defined between the adjacent turbine blades. The first end portion and the second end portion have substantially semi-cylindrical cross sectional shapes and the center portion has a cylindrical cross sectional shape. A bottom portion of the elongated body diverges radially outwardly from the first end portion to the center portion and from the second end portion to the center portion.

Abstract: A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

Abstract: A turbomachine blade assembly including a turbomachine blade (1), in particular for a gas turbine, and at least one tuning element container including a housing (10) attached to the turbomachine blade and an insert (20) disposed in a recess (11) of this housing. A wall (20; 21) of the insert spaces apart two first cavities (31), which each accommodate at least one tuning element (40) provided for impacting contact with the housing (10) and the insert (20).

Abstract: A rotorcraft tail rotor comprising at least two blade elements, each blade element being suitable for pivoting about a collective pitch variation axis Z in order to vary the collective pitch of each blade element of the tail rotor, each blade element including at least one compensation weight comprising a projection emerging substantially perpendicularly to a main inertia axis of the blade element, the main inertia axis being parallel to a longitudinal direction of the blade element. In the invention, the tail rotor is wherein the compensation weight includes a deformable portion that is movable relative to the projection in a plane P that is parallel to the main inertia axis of the blade element.

Abstract: The present disclosure relates generally a gas turbine engine and a rotor therefor. The rotor may include a symmetric rim thereon to prevent the propagation of induced vibratory responses. The rim may have one or more sloping surfaces to prevent the re-attachment of boundary layer flow.

Abstract: A rotor blade assembly for a rotor of a gas turbine engine having an axis of rotation includes a shank portion formed from a ceramic matrix composite (CMC) material. The rotor blade assembly also includes a platform portion formed from a substantially similar CMC material as that of the shank portion. The platform portion is coupled to the shank portion. The platform portion and the shank portion cooperate to at least partially define two opposing side portions of the rotor blade assembly. The opposing side portions are angularly separated with respect to the axis of rotation. The rotor blade assembly further includes a damper retention apparatus. The damper retention apparatus is coupled to the shank portion. The damper retention apparatus includes at least one angled bracket apparatus extending toward a circumferentially adjacent rotor blade assembly.

Abstract: The present invention relates to the field of grinding machines. In one of its embodiments, this disclosure presents a grinding machine casing (30) for a grinding machine (100). The grinding machine casing (30) comprises a first casing part (10), which is mounted to a second casing part (20). The first casing part (10) is provided with a set of brackets. Each bracket of a set of brackets comprises a hole which is adapted to receive a cylindrical end of a support bar (60) such that the support bar (60) can be releasably connected to the first casing part (10). Still further, one bracket in each set of brackets comprises a hole, the cross-section of which is non-circular.

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 between a radially outer end and a radially inner end. The first sidewall and the second sidewall at least partially define a cavity extending radially in the airfoil body. A damper member has a free radially inner end in the cavity and a free radially outer end in the cavity. The damper member is free-floating in the cavity.

Abstract: A rotor comprises a disk having a rim. The rim has an axial face facing one of a forward or rearward direction. The rim defines a circumferential groove. A damper engages with the rim at both the axial face and the circumferential groove. The disk includes a rotor hub having a hub inner surface facing a longitudinal axis about which the rotor hub rotates. The rim is spaced radially outwardly relative to the hub inner surface. The axial face extends radially inwardly from the rim to the hub inner surface. The circumferential groove is formed within the hub inner surface. The damper comprises a split ring damper with a first leg mounted within the circumferential groove and a second leg that extends from the first leg, surrounds a radial lip of the hub inner surface, and extends radially outwardly to contact the axial face. An integrally bladed rotor is also disclosed.

Abstract: A turbomachine blade having a main body (10) that includes a plane, first attachment surface (100) having a first rim contour (110), a cover (20; 21, 22) that has a plane, second attachment surface (200) having a second rim contour (210) that is welded to the first attachment surface, and a tuning body configuration having at least one tuning body (30; 31-33) for contacting an inner wall (220) of the cover by impact therewith, a gap (s) being formed between the first and the second rim contour.

Abstract: The present invention relates to a blade or vane for a turbomachine, having at least one impulse element housing with a first impact cavity, in which an impulse element is arranged with play of movement, wherein the impulse element housing has at least one second impact cavity, which is in alignment with the first impact cavity in a first matrix direction and in which an impulse element is arranged with play of movement, and has at least one third impact cavity, which is in alignment with the first impact cavity in a second matrix direction crosswise to the first matrix direction and in which an impulse element is arranged with play of movement.

Abstract: A rotorcraft may include an airframe and a rotor connected to the airframe. The rotor may include a hub and a rotor blade connected to the hub to extend radially away therefrom. The rotor blade may include biasing fibers, oriented to increase the twist of the rotor blade in response to an increase in the speed of rotation of the rotor corresponding to a mission, task, or maneuver.

Abstract: A wind turbine comprises a wind-driven rotor for converting wind energy to a mechanical driving force, a power converter for converting the driving force to exploitable power, and a drive train for rotatably transmitting the driving force from the wind-driven rotor to the power converter. The drive train includes: at least one rotatable driving element configured to provide at least one torsional resonance frequency in the drive train; a first detuner having at least one first mass element with a first mass inertia and at least one first elastic element with first elastic properties; and a second detuner having at least one second mass element with a second mass inertia and at least one second elastic element with second elastic properties. The first and second mass elements and first and second elastic elements are arranged to rotate during operation of the wind turbine. The torsional resonance frequency is influenced by the first and second mass inertias and the first and second first elastic properties.

Abstract: A turbine-blade retaining structure in which deformation of end portions of locking pieces exposed through an insertion window portion in the axial direction is prevented, and the occurrence of a crack in a welded portion is prevented. At least one of the end portions of adjacent locking pieces exposed through the insertion window portion is provided with a thick-plate portion that expands in the disc-thickness direction so as to be inside the insertion window portion.

Abstract: In a moving blade system for a turbomachine, in particular a gas turbine, having at least one moving blade (1), the moving blade system having at least one cavity (3) in which at least one tuning mass (2) is movably situated, the tuning mass and/or the cavity is/are adapted in such a way that the tuning mass rests against an inner wall (3.1) of the cavity in a predefined first operating state of the turbomachine and at least temporarily moves away from the inner wall in a second predefined operating state of the turbomachine.

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: A vehicle wheel is provided with a plurality of tube's distributed at various radial angles from the center and oriented generally transversely of the central plane of the wheel and generally parallel to the wheel's axis of rotation. The azimuthal and longitudinal imbalance of a mounted tire including the wheel is determined. To balance the mounted tire both azimuthally and longitudinally, one or more weights are inserted into one or more tubes disposed on the wheel at appropriate azimuthal locations. The weights are placed longitudinally of the tubes in the plane of central mass of the mounted tire, and are secured in that position within the tube by any of a variety of means such as thread locking fluid, friction, or plugs.

Abstract: An airfoil includes an airfoil body that defines a longitudinal axis. The airfoil body includes 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 at least one longitudinally elongated cavity in the airfoil body. A plurality of loose particles is enclosed in the at least one longitudinally elongated cavity.

Abstract: A damping system for damping vibrations of a rotor blade of a rotor of a turbomachine is disclosed. A damping element is guided on a support such that the damping element is radially outwardly movable during a rotation of the rotor and is contactable with a lower platform area of a rotor blade. A circumferential contact surface is formed by an elevation on the lower platform area, where the circumferential contact surface is a limit stop for a movement of the damping element.

Abstract: A balancing apparatus for a rotary element is provided and includes a central hub portion and radial elements extending outwardly from the central hub portion. The balancing apparatus includes a conduit extending along the radial elements via the central hub portion, a mass movable within the conduit between the radial elements via the central hub portion and a mass balancing system which directs a movement of the mass within the conduit into and out of the central hub portion and along the radial elements.

Abstract: A balancing apparatus for a rotary element is provided and includes a central hub portion and radial elements extending outwardly from the central hub portion. The balancing apparatus includes a conduit extending along the radial elements via the central hub portion, a mass movable within the conduit between the radial elements via the central hub portion and a mass balancing system which directs a movement of the mass within the conduit into and out of the central hub portion and along the radial elements.

Abstract: A method for controlling helicopter ground resonance and air resonance motions as well as centrifugal force switching dampers are disclosed. A helicopter lead-lag damper (30) has a first ground resonance motion damping rate stage (FDR) and a second air resonance motion damping rate stage (SDR). The damper (30) includes a centrifugal force switch (52). The damper (30) is oriented relative to the rotary wing rotation axis (26) and helicopter blade (24). An in-flight rotation rate of the centrifugal force switching damper (30) actuates the centrifugal force switch (52) with the damper switching from the first ground resonance motion damping rate stage (FDR) to the second air resonance motion damping rate stage (SDR).

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 aircraft system/method for propeller balancing.

Abstract: A rotating assembly includes a shaft having a driven end and a driving end. At least one rotating member coupled to the driven end. A support member is operatively connected to the at least one rotating member. A dynamic balancing system is operatively coupled to the support member. The dynamic balancing system includes a first balancing weight rotatably mounted to the support member. The first balancing weight is operatively connected to a first motor. A second balancing weight is rotatably mounted to the support member. The second balancing weight is operatively connected to a second motor. A controller is operatively connected to the first and second motors. The controller is configured and disposed to signal each of the first and second motors to rotate and to establish a desired position of the first balancing weight and the second balancing weight relative to at least one rotating member.

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: An aircraft propeller taper bore insert apparatus includes a tapered outer surface, the outer surface dimensioned and configured to fit within and be of substantially a same size and shape as 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 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 propeller rotor has a hub mounting a plurality of blades and a drive shaft for driving the hub and the blades about a central axis. A motor to change its position is operably connected to drive at least one counterweight. A sensor senses vibration on the propeller rotor and communicates with a controller. The controller controls the motor to change a position of the counterweight in response to a sensed imbalance. A method of operating a propeller rotor is also disclosed.

Abstract: An enclosure for carrying an adjustable payload. The enclosure is beneficially used on a rotorcraft blade or other similar structure. The enclosure has a first element having a first flange and an upper element. The first element has an upper surface which has a first angle with respect to a lower surface of the first flange in a direction extending from an inboard direction to an outboard direction. The upper element has a lower surface which has a second angle with respect to an upper surface of said upper element in a direction extending from an inboard direction to an outboard direction, the lower surface being in contact with the upper surface of said first element, the second angle being in a direction which is opposite to the direction of said first angle. The first element and the upper element define a cavity for holding a payload.

Abstract: A vibration-resistant wind turbine and process for operation is provided. The wind turbine has a rotor with at least two blades, each of which includes an inclinometer arrangement with at least two axes, and an evaluating unit. The evaluating unit determines the bending and/or twisting of the blade relative to the longitudinal axis of the blade on the basis of signals from the inclinometer arrangement for each blade during operation. Each rotor blade further has at least one liquid tank which is capable of receiving or transferring liquid from or to a liquid reservoir via a transfer mechanism in response to the determined bending and/or twisting of the rotor blades to reduce vibration caused by imbalances, thereby extending the service life of the wind turbine.

Abstract: A trim balance for a gas turbine engine having a hollow rotatable rotor shaft includes an elongate support rod adapted for longitudinal accommodation within and mounting on an interior surface of the rotor shaft and one or more apertured balance weights supported on the support rod which extends through the weight apertures and a weight retainer for retaining the weights on the support rod.

Abstract: A balancing weight clip with a mass adapted to balance a rotor assembly of a gas turbine engine, includes a weight portion, a first flange engaging portion and a second flange engaging portion extending from the weight portion, each being engageable with a sidewall of at least one recess located on an edge of a flange of a disc of the rotor assembly. Each flange engaging portion is provided with a hook engageable with a mating groove provided on a face of the flange. At least one of the first and second flange engaging portions is resiliently biased so that the first and second flange engaging portions are elastically moveable away from one another to removably secure the balancing weight clip to the flange and engage each hook with the mating groove.

Abstract: Rotary wing system with a rotating blade rotating about a rotation axis. The system includes a fluid damper with a damper fluid for controlling a troublesome motion. The fluid damper has an inboard end and an outboard end, the damper inboard end attached to a first rotary wing system inboard member proximate the rotation axis and the outboard end attached to a second rotary wing system outboard member distal from the rotation axis. The fluid damper contains a damper fluid volume in at least a first working chamber which is worked by a relative motion between said first rotary wing system inboard member and said second rotary wing system outboard member to control the troublesome motion.