Abstract: A rotor system for a rotary wing aircraft includes a rotor hub including a first beam attachment member and a second beam attachment member. A hub arm including a U-shaped beam member is connected to the rotor hub. The U-shaped beam member includes a first end portion, a second end portion and an intermediate section connecting the first and second end portions. The first end portion is connected at the first beam attachment member. The second end portion is connected at the second beam attachment member. A pitch change bearing is mounted between the first and second beam attachment member through the first end portion and the second end portion.

Abstract: A UAV (unmanned aerial vehicle) arm mechanism includes an arm fixed device, a control device, a limiting device, and an arm connecting device, wherein the control device is adapted for controlling an assembly and disassembly of the arm fixed device and the arm connecting device, the limiting device is adapted for relatively fixing the arm fixed device and the arm connecting device; the control device is adapted for driving the limiting device to be detached from the arm connecting device, so as to achieve that the arm fixed device and the arm connecting device switch among at least three different states through a relative rotation. The UAV and the UAV arm mechanism can be locked up through the positioning pins, and also can be folded and disassembled after pressing the controlling device.

Abstract: A rotor system includes a yoke, a plurality of blade grip assemblies and a plurality of centrifugal force bearings coupling the blade grip assemblies with the yoke. A plurality of rotor blades are coupled to the blade grip assemblies such that each rotor blade has a coincident hinge and such that each rotor blade has three independent degrees of freedom including blade pitch about a pitch change axis, blade flap about a flapping axis and lead-lag about a lead-lag axis. A blade-to-blade damping ring includes a plurality of damper anchors each coupled to one of the blade grip assemblies along the respective pitch change axis and a plurality of lead-lag dampers each coupled between adjacent damper anchors. During blade pitch operations, each blade grip assembly is operable to rotate relative to the respective damper anchor, such that the blade-to-blade damping ring is operable to provide pitch independent lead-lag damping.

Abstract: A rotorcraft rotor comprising a hub made up of a monolithic body of composite material obtained by stacking successive layers of carbon fiber fabric dusted with a thermoplastic resin and compressed while hot. The hub is provided with branches on which respective blades are mounted via hinge systems, each including a strength member bearing radially against a corresponding branch. The strength members are individually received in sockets defined on fabrication so that when the rotor is set into rotation at a predefined operating speed, the radial thrust seat for enabling the strength members to bear against the branches present bearing surfaces that are cylindrical, the radial thrust seats then being of shape complementary to a cylindrical bearing surface of the corresponding strength member.

Abstract: A rotorcraft rotor fitted with a device for damping lead-lag oscillations of the blades (2) of the rotor. The blades (2) are hinge-mounted on a rotary hub (1) of the rotor via respective sleeves (3). The damper device comprises a set of dampers (6), each individually housed in a respective one of said sleeves (3) and deformable between two fastening points (8, 9), one with the sleeve and the other with an engagement member (7) for engaging the hub (1) via a linkage (10). For each of the sleeve (3), the damper (6) housed by a given sleeve (3) is in hinged engagement with the linkage (10) via a lever arm (11) hinged to the sleeve (3).

Abstract: A rotor system includes a lead stop mounted to a spindle and a lead stop plate mounted to a rotor hub arm, the lead stop operable to contact the lead stop plate over a lead angle range.

Abstract: There is described an assembly having a plurality of screws, a propeller and a related method for adjusting the fluid dynamic pitch of the blades of the propeller. The propeller has at least one blade pivoted rotatably to a cylindrical propeller casing, a hub coupled to an engine and mounted coaxially inside the propeller casing, a kinematic mechanism coupled to the hub and/or to the propeller casing, and to the blade for adjusting the fluid dynamic pitch of the propeller. The hub is rotatable with respect to the cylindrical propeller casing, or vice versa, for at least one non-zero angular interval (?) of operation of the kinematic mechanism for adjusting the fluid dynamic pitch and is also integral with a contact surface movable between disengagement from and engagement with, direct or indirect, at least one relative abutment integral with the cylindrical propeller casing which defines a limit stop of the angular interval (?).

Abstract: A hub assembly for a tilt rotor includes a yoke having a plurality of yoke arms located substantially orthogonal to a central axis of the hub assembly. An inboard pitch change bearing assembly substantially surrounds a yoke arm of the plurality of yoke arms. An outboard pitch change bearing assembly is located at the yoke arm. The inboard pitch change bearing assembly and the outboard pitch change bearing assembly are operably connectable with a rotor blade to allow pitch change of the rotor blade relative to the yoke about a pitch change axis.

Abstract: A lead-lag damper for a rotor assembly has a body mounted to either an inboard portion of a blade assembly or a fixed portion of the rotor assembly. A piston carried within the body is configured to allow for relative motion between the body and the piston. The piston defines opposing chambers within the body, the chambers being in fluid communication through a fluid passage. A link connects the piston to the other of the inboard portion of the blade assembly and the fixed portion of the rotor assembly, and the link engages a central portion of the piston. The piston acts on fluid in the chambers during relative motion between the piston and the body and causes fluid flow between the chambers through the fluid passage. Flow through the passage acts to damp lead-lag motion of the blade assembly relative to the fixed portion of the rotor assembly.

Abstract: A wind mill structure of a lift-type vertical axis wind turbine. The lift-type vertical axis wind turbine includes a vertical shaft and the wind mill includes a plurality of blades and supporting arms. The supporting arms hold the blades, and the blades are connected to the vertical shaft via the supporting arms. A setting angle, formed by a chord of the blades and a tangent line that goes through the center of the blades, ranges from ?12° to 12°. An angle, formed by the chord of the blade and the rotatable supporting arm, ranges from 7° to 100°. The wind mill can maintain relatively stable rotation speeds under wind speeds exceeding the rated wind speed by adjusting the angle of the supporting arms, thereby ensuring stable output from the vertical axis wind turbine.

Abstract: The rotary damper for controlling helicopter motions includes an outer canister with an inner paddle wheel receiving cavity which receives an inner paddle wheel with upper and lower elastomeric tubular intermediate members between the inner paddle wheel and the outer canister. The canister and inner paddle wheel form neighboring variable volume chambers in liquid communication through liquid damping conduits. A clockwise rotation of the inner paddle wheel about the center of rotation axis relative to the outer canister pumps damper liquid from a second variable volume chamber through a first liquid conduit towards a first variable volume chamber, and a counterclockwise rotation of the paddle wheel relative to the outer canister pumps the damper liquid from the first variable volume chamber through the first liquid conduit towards the second variable volume chamber with the elastomeric tubular intermediate members providing for the relative rotation and containing the damper liquid in the damper.

Abstract: A composite transmission housing includes resin transfer molding or vacuum assisted resin transfer molding manufacturing processes combined with discontinuous fiber preforms. The preforms are assembled in a prepared injection and cure mold with additional details and fillers. The preforms are constructed such that the preforms are assembled into the mold in a specific order to assure proper arrangement. Using a combination of vacuum and pressure, a resin is injected into the mold to completely infuse the assembled preforms. At completion, the mold is heated to the resin cure temperature and held at this temperature for sufficient time to insure complete cure.

Abstract: A blade support limb structure of a vertical axis wind power generator includes a fixed support limb (1) and a rotatable support limb (2), one end (21) of the rotatable support limb is connected with one end (22) of the fixed support limb and the rotatable support limb may rotate around it. The structure keeps a wind wheel at stable rotation speed in the case the environmental wind speed exceeds the rated wind speed, thereby to ensure that vertical axis wind power generator outputs constant power. The structure solves a problem of constant power output of the vertical axis wind power generator from hundreds watts to thousands watts, so its applications are wide.

Abstract: A rotor system includes a lead stop mounted to a spindle and a lead stop plate mounted to a rotor hub arm, the lead stop operable to contact the lead stop plate over a lead angle range.

Abstract: A lead-lag damper for a rotor assembly has a body mounted to either an inboard portion of a blade assembly or a fixed portion of the rotor assembly. A piston carried within the body is configured to allow for relative motion between the body and the piston. The piston defines opposing chambers within the body, the chambers being in fluid communication through a fluid passage. A link connects the piston to the other of the inboard portion of the blade assembly and the fixed portion of the rotor assembly, and the link engages a central portion of the piston. The piston acts on fluid in the chambers during relative motion between the piston and the body and causes fluid flow between the chambers through the fluid passage. Flow through the passage acts to damp lead-lag motion of the blade assembly relative to the fixed portion of the rotor assembly.

Abstract: A rotor hub assembly for a rotary-wing aircraft has a central member and a plurality of blade grips adapted for attaching rotor blades to the central member. The blade grips are pivotally attached to the central member and are capable of pivoting about a pivot axis generally normal to a plane of rotation of the blades. The pivoting allows for in-plane motion of the blades relative to the central member. A damper is operably connected to each blade grip for damping the in-plane motion of the associated blade, each damper being selectively switchable between at least two spring rates.

Abstract: In the absence of centrifugal force produced during rotation of helicopter blades, damage may result if a blade is rotated upward by wind or other forces. Lock units removably appended between the rotor assembly and each blade pitch housing attached to a helicopter blade are usable to restrict upward rotation. A base portion of a lock unit may be configured to be held in position by a removable pin device. An extendible device extending from the base portion to a surface of a blade pitch housing can be adjusted to press the base portion back against a surface of the rotor assembly. The lock unit thereby restricts these surfaces of the blade pitch housing and rotor assembly from moving closer to each other and thereby restricts upward rotation of the blade pitch housing and its attached helicopter blade. The lock units are readily removable in preparation for returning a helicopter to active use.

Abstract: The invention relates to a rotorcraft rotor comprising a hub and at least two blades hinged relative to the hub about respective pitch axes and about respective flap axes, and about respective lag axes; each blade is secured to a respective pitch lever; the rotor includes a respective pitch control rod connected to each pitch lever by a first ball joint, and a common lag damper system centered substantially on the axis of rotation of the rotor and connected to each of the blades; the damper system is secured to a respective lateral projection from each blade via a respective second ball joint that is sufficiently close to the first ball joint connecting the pitch rod to the pitch lever for the lag damper system to be relatively insensitive to flap oscillations of the hinged blades.

Abstract: The present invention relates to problems of maintenance of elastomeric members. According to the invention, the elastomeric member is provided with at least one elastomeric layer 1 disposed between two rigid strength members 2. In addition, the elastomeric member is provided with graduations 5 located on its visible surface 7, presenting an angle of inclination relative to the rigid strength members 2, thus making it possible to evaluate and monitor propagation of a crack 6 merely by inspecting it visually.

Abstract: The present invention relates to a method of controlling a drag damper for a helicopter blade under all operating configurations of the helicopter, the method consisting in: a) measuring the elongation of the damper; b) amplifying the measured signal and filtering out noise; c) isolating the natural response of the blade corresponding to the drag movement of the blade from the forced response imposed by a rotor driving the blades; and d) analyzing in real time the natural response and adjusting the damping as a function of the analysis.

Abstract: Aspects of the invention relate to a compressor system for a turbine engine that not only allows for larger compressor blade tip clearances as the engine passes through non-standard operating conditions, but also minimizes clearances during normal engine operation, thereby increasing efficiency of the compressor. The blade assembly can include an airfoil having a movable tip insert recessed within a pocket in the radially distal end of the airfoil. The tip insert can move radially outward from a predetermined recessed position to a predetermined extended position. An abutment surface can be provided within the pocket for engaging the tip insert and/or other associated components so as to limit the extension of the tip insert to the predetermined extended position such that the tip insert does not impinge on the stationary compressor structure and such that a spring operatively associated with the tip insert does not overextend its operational limits.

Abstract: A drag damper for use on a rotary-wing aircraft rotor comprises a body defining two variable volume chambers linked by a piston. The chambers filled with fluid in the damper are connected by a restrictor port in the piston or between the latter and the body, and via a channel of great length and small cross-section compared with the cross-section of the body, in which elastic means bear against and load the piston-rod assembly towards a neutral position, the anti-resonance frequency of the damper being matched substantially to the nominal rotation frequency of the rotor, and the restrictor port providing effective damping at the natural frequency (??) of the blades in drag, differing by construction from the rotor frequency (?).

Abstract: A multi-bladed tail rotor assembly is disclosed that provides higher aerodynamic performance, damage tolerant design with 10,000-hour life expectancy, and which requires low maintenance through the use of composites and elastomerics. The tail rotor hub assembly includes two stacked yoke assemblies having multi-bladed teetering rotors, each mounted on a single drive mast. Each yoke assembly includes a yoke hub having a transverse bore therethrough, a bearing assembly disposed within the bore, and retention means for aligning and securing the bearing assembly within the bore. Each bearing assembly includes a trunnion portion having trunnion arms that extend outwardly from a trunnion body portion, and an elastomeric bearing disposed about each trunnion arm. The tail rotor assembly utilizes a composite twist strap flexure to accommodate collective pitch control integral with each rotor blade.

Abstract: A flexbeam rotor system includes an intermediate tube and a torque tube that envelopes a flexbeam in spaced relation thereto. The torque tube is connected to the flexbeam at its radially outer end and articulately connected to the intermediate tube through a snubber-vibration damper system. The torque tube is connected with an aerodynamic rotor blade member. The snubber vibration damper system includes a snubber bearing and an independent lead/lag bearing. The snubber bearing is located between the flexbeam and the intermediate tube along a pitch change axis. A lead/lag bearing is mounted between the intermediate tube and the torque tube on both the leading and trailing portion of blade assembly. Pitch/lag coupling complications are minimized as lead/lag motion takes place between the torque tube and the intermediate tube. As lead/lag motion is accommodated in the independent lead/lag bearing, the snubber bearing is of a greatly reduced height in relation to conventional design.

Abstract: The invention relates to a combined ball-and-damper device for mounting between firstly a flexible spar connecting a helicopter blade to a rotor hub and secondly a torque tube for controlling the pitch of said blade, the device comprising two individual modules each comprising a plane laminated damper and a laminated ball, the laminated damper extending between an outer end and an inner end and presenting at its outer end an element for connection to the torque tube for controlling the pitch of said helicopter blade, and the laminated ball presenting a stack of metal and elastomer layers, the laminated damper being secured at its inner end to an outer end of the ball whose own inner end presents an element for fixing to said flexible spar, the device including at least one connection element providing a stiffening connection between the outer ends of the two balls of the two individual modules making up the combined device.

Abstract: A flexbeam rotor system includes an intermediate tube and a torque tube that envelopes a flexbeam in spaced relation thereto. The torque tube is connected to the flexbeam at its radially outer end and articulately connected to the intermediate tube through a snubber-vibration damper system. The torque tube is connected with an aerodynamic rotor blade member. The snubber vibration damper system includes a snubber bearing and an independent lead/lag bearing. The snubber bearing is located between the flexbeam and the intermediate tube along a pitch change axis. A lead/lag bearing is mounted between the intermediate tube and the torque tube on both the leading and trailing portion of blade assembly. Pitch/lag coupling complications are minimized as lead/lag motion takes place between the torque tube and the intermediate tube. As lead/lag motion is accommodated in the independent lead/lag bearing, the snubber bearing is of a greatly reduced height in relation to conventional design.

Abstract: A multi-bladed tail rotor assembly is disclosed that provides higher aerodynamic performance, damage tolerant design with 10,000-hour life expectancy, and which requires low maintenance through the use of composites and elastomerics. The tail rotor hub assembly includes two stacked yoke assemblies having multi-bladed teetering rotors, each mounted on a single drive mast. Each yoke assembly includes a yoke hub having a transverse bore therethrough, a bearing assembly disposed within the bore, and retention means for aligning and securing the bearing assembly within the bore. Each bearing assembly includes a trunnion portion having trunnion arms that extend outwardly from a trunnion body portion, and an elastomeric bearing disposed about each trunnion arm. The tail rotor assembly utilizes a composite twist strap flexure to accommodate collective pitch control integral with each rotor blade.

Abstract: A magnetic particle damper apparatus is provided for damping motion between two relatively movable members. The damper apparatus comprises first and second conductor members each attachable to one of the relatively movable members. The conductor members are disposed with confronting surfaces having a gap therebetween filled with a quantity of magnetic particles. A magnetic element is attached to one of the conductor members, producing magnetic flux which is substantially confined to a magnetic flux path defined by relatively magnetically permeable regions and relatively magnetically non-permeable regions of the conductor members to flow across the gap and through the magnetic particles. The magnetic field causes the magnetic particles along the flux path to adhere to one another and to the confronting surfaces of the conductor members producing a force opposing relative motion between said movable members and dissipating energy when the conductor members move relative to one another.

Abstract: A hub for the rotor head of a rotary-wing aircraft having a plurality of blades radially linked to the hub by a blade root provided with a rigid hub includes spherical stops associated with the blades, which stops have an inner armature linked to the root of the blade and an outer armature linked to the hub. The hub includes an upper plate and a lower plate formed of two separate components which are assembled with an outer armature of spherical stops being interposed therebetween, so that the spherical stops are housed in the space defined by the plates. The outer armature is arranged at the periphery of the plates so that a hollow hub is obtained without requiring a sidewall with apertures, so as to facilitate the mounting and/or removal of the blades and the spherical stops. The plates may have a triangular shape with cutoff corners wherein a plurality of outer armatures is arranged near the cut-off corner.

Abstract: A rotor blade arrangement for a bearingless rotor of a helicopter includes a flexbeam connecting an airfoil blade to a rotor head, and a control sleeve surrounding the flexbeam. The control sleeve is relatively stiff, but the flexbeam has portions that are flexible so as form a fictitious flapping hinge, lead-lag hinge, and torsion axis, which respectively enable flapping, lead-lag pivoting, and torsional movements of the airfoil blade. The inboard end of the control sleeve is secured to the root end of the flexbeam near the rotor head to prevent lateral displacements therebetween. Damping elements are arranged within the enclosure of the control sleeve at a location between the fictitious lead-lag hinge of the flexbeam and the transition region at which the flexbeam transitions into the airfoil blade.

Abstract: A centrifugally activated variable damper assembly for a stopped-rotor aircraft is disclosed for adjusting dampening level of teetering motions produced by the rotors during the in-flight conversion process from rotary-wing to fixed-wing flight, or vise versa. The assembly includes a damper valve responsive to centrifugal forces produced by rotational speed of the aircraft rotor. The assembly also includes dampers within the rotor system that operate at variable damping levels in response to centrifugal forces acting upon the damper valve.

Abstract: A semi-articulated stiff-in-plane (SASTIP) rotor hub is provided. The hub includes a cylindrical composite shell (12). A plurality of flexure mount assemblies (16) are positioned around the periphery of the hub shell. Each flexure mount assembly includes both an upper and a lower flexure (64), (66). The outboard ends of the upper and lower flexures attach to an outboard bearing support (34). The inboard end of each flexure is maintained within first and second clamp plates (76), (78) that are mounted within hub flexure openings (38), (40). The flexure clamp plates (76), (78) additionally attach circumferentially to annular CF rings (24), (26), (28), (30) positioned within the hub shell. A blade shaft (14) extends through the outboard bearing (72) and connects to a spindle. The spindle is supported by a spherical bearing that is mounted within the hub shell (12) at a circular spindle hole.

Abstract: The locking device comprises, for each blade, at least one first subassembly with a fork for locking a finger, one of the fork and finger pivoting on a chassis attached laterally to the hub between the linking members of two neighboring blades, the other element being fixed to the linking member and projecting laterally towards the other linking member so that the pivoting element can be moved between a position in which it is engaged over the finger for locking the blade at least in terms of pitch, and a disengaged position for unlocking.

Abstract: A flap lock device for restraining the flapping movement of a main rotor blade assembly on a helicopter. The flap lock device includes an first elongate frame member which extends between a first end and a second end and second elongate frame member which also extends between a first end and a second end. A pivot connection pivotally connects the first end of the first frame member with the first end of the second frame member. An outwardly facing contact pad is coupled to each of the frame members and adapted for contact with various positions on the helicopter. An actuating device interconnects the first and second frame members and is used to forcibly move the contact pads outwardly and into contact with the helicopter. The flap lock device is installed between the main rotor blade assembly and the main rotor assembly to forcibly maintain the main rotor blade assembly against the droop stop mechanism.

Abstract: A helicopter rotor has two or more blades which extend from a hub and has an adjustment mechanism for adjusting the lead/lag variation of the blades which typically occur due to manufacturing tolerance variations or to changes which occur through operation such as softening of the supporting elastomer dampers. One embodiment of the invention incorporates an end plate on an upper damper with a lug positioned adjacent to a lug on the torque tube such that the end plate of the damper can be changed relative to the longitudinal axis of the blade. For example, a .+-.1/2 degree adjustment can be made in the blade angle relative to the hub to insure that lead/lag errors are reduced. In another embodiment, the damper set includes extended metal shims adjacent to the end most laminate plys of the upper and lower dampers such that these shims can be bolted to the end plates of the snubber assemblies for step increasing the stiffness of the assemblies.

Abstract: A submersible magnetic motor having improved rotary blades comprising a magnetic motor body, a magnetic rotor and a rotary impeller wherein the rotary impeller comprises a rotary hub provided with a plurality of blades which are uniformly distributed and extend outwardly around the periphery of the hub. The rotary hub is provided with an axial hole centrally formed therethrough for positioning an end of a central shaft of the magnetic rotor. The present invention is characterized in that the blades are each provided at the outer end edge with two stoppers and a fin freely pivoted therebetween, so as to be adjacent to the inner surface of the wall of the receiving chamber of the submersible motor. When the magnetic rotor is actuated to rotate, the fins each pivots to contact one of the two stoppers due to the resistance of the water such that the submersible motor can be maintained at a constant rotation speed, and the water pumping efficacy can be substantially improved.

Abstract: The device comprises, between two blades and their members linking them to the hub, three levers articulated by ball joints to the members and to the hub, the two levers pivoting on the third one about axes of pivoting parallel to each other and perpendicular to the common plane passing through the centres of the ball joints. At least one of the levers comprises at least one drag damper.

Abstract: A hollow rotor hub is provided at the top of the rotor shaft for a multi-bladed helicopter. The blades being mounted to the rotor hub on spherical elastomeric bearings which provide for coincident rotor blade hinges for blade pitch, flap and lead-lag motions. The invention discloses a lead-lag damper contained in a housing at the center of the hollow rotor hub. The damper consists of a series of damping plates, each plate being connected to one of the rotor blades. The damping plates are separated from each other and from the damper housing by elastomeric layers bonded to the plates and to the housing. Lead-lag damping is provided by the shear in the elastomeric layers. The damper may be fastened to the air frame in a conventional manner, it may be mounted on a spindle for rotation about the rotor axis independent of rotor shaft rotation or may be free-floating and attached only to the rotor blades and not to the rotor shaft.

Abstract: Gyrocraft rotor hub body (1) in which each blade (2) is linked to the body (1) by articulations and linking members the body includes two strong elements (7, 8) whose planes are substantially parallel to each other and perpendicular to the axis of the mast (3) of the rotor. The two elements (7, 8) are separated from each other by a space which is of sufficient size to permit the housing of the articulations which are advantageously embodied in the form of laminated spherical stops (5), one of the armatures (16) of which moves integrally with the (17) is fixed with respect to the two elements of the hub body and is arranged in the vicinity of the periphery of these elements so as to constitute a rigid bracing.

Abstract: The invention relates to a drag elastic-return and damping device (28) for a blade, and a rotor head including it.The device (28) comprises a connecting rod (30) connected to the blade and transmitting its drag movements to a rotary member (29) for elastic return with incorporated damping whose outer armature (32) it causes to rotate about a coaxial inner armature (31) in order to shear at least one thin collar (33) of a viscoelastic elastomer about its axis (B). The connecting rod (30) is coupled by way of rotational joints (43, 44) to a sleeve (15) for attaching the blade to the hub (1), and to a lever (34) of the outer armature (32). The member (29) is supported at the periphery of the hub (1), between two adjacent blades, or in the sleeve for attaching an adjacent blade such that the corresponding connecting rod is mounted as an inter-blade tie. On the rotor head, each blade is articulated with the hub (1) by a spherical laminated thrust block (5).

Abstract: A device of retractable stops for the blades of articulated rotors for giroplanes, which includes a stationary stop 20 with a finger 22 radially converging towards the exterior and externally radially protruding on the external spar 9 of the articulation means 7 of each blade on the hub 3, as well as a movable stop 21 with a receptacle 36 resiliently returned by a return device 45 in a position fit around the finger, but disengaged from the finger by centrifugal force when the rotation speed of the blades is higher than a set value. The invention therefore provides absolute stops in flapping and drag in the "ground" position and sharp stops in the flight position. One advantageous application is for helicopter rotors.

Abstract: The invention relates to a flapping restrainer device for the blades of a rotorcraft main rotor, and a rotor head comprising the same. The lower restrainers comprise a reciprocal star-shaped plate (32), having as many radial branches (33) as blades, and each one of the branches being engaged into a radial opening (6) of the hub (3). Outside the latter, the star-shaped plate (32) cooperates with supporting runners (47) integral with the blades. The upper restrainers comprise, for each blade, a stop which is retractable by the effect of the centrifugal force and which is composed of a lever (52), pivoting on a pivot (53) carried by the hub (3), and a first arm (55) of which constitutes a stop finger directed towards an upper supporting component (60) integral with the blade, while a second arm (56) carries a governor weight (57) and a nose (58) for support against a shoulder (59) integral with the hub (3).

Abstract: The invention relates to a rotor head having interblade ties with resilient return in lag and with built-in damping, wherein each tie is connected, to each of the two rotor blades joined by it, by articulation means comprising a main ball retained on a member connecting a blade to the hub and centered on or in immediate proximity to the pitch change axis of the corresponding blade.A single main ball may be connected to the adjacent ends of two neighboring ties by a connection member having the shape of a V open towards the hub, or else each tie is connected to a connection member by a respective one of two main balls offset transversely in relation to the pitch change axis of the blade and/or radially along said axis.Application to the main and/or auxiliary rotors of helicopters.

Abstract: Helicopter rotor on which each blade is connected in articulated manner to a center hub by means of a forkthe vertical plane movement of which, at rotor speeds below a given set value, is limited by a pair of limit rocker arms located between the hub and a ring nut mounted in rotary manner on the forkand rendered angularly integral with the hub by means of a compass drive.

Abstract: Helicopter rotor on which a number of blades are each connected to a perimetrical bridge element on a hub by means of a fork element extending round the said bridge element and connected to it by means of two elastomer supports, arranged in series, of which one is designed to dampen at least operation of the blade in the hub plane.

Abstract: A bearingless helicopter rotor includes an integral damper and pitch change assembly (16) adapted to damp lead/lag movements of a rotor blade and to change the pitch of the rotor blade. In described embodiments, the assembly includes a generally tubular body portion (17, 27) closed at one end and attached by torque transmitting means (18, 28) to a flexure member blade attachment and a rod (20, 29) protruding axially from the other end of the body portion and attached adjacent the rotor hub. Pitch change movements are effected by rotation of the body portion about its longitudinal axis and damping of lead/lag movements either by metering of an incompressible medium across a piston (23) in a chamber (24) formed internally of the body portion or by an annular body of elastomer material (34) bonded to the outside diameter of the rod and the inside diameter of the body portion.

Abstract: The water turbine of the present invention includes a housing defining a generally cylindrical chamber therein defining a laterally extending opening. Rotatably positioned within the chamber is a rotor including a plurality of folding wings or vanes extending outwardly therefrom. Each vane includes a first blade section which is immovably fixed with respect to the rotor hub and a second blade section which is pivotally secured with respect to the first blade section. This pivotal movement of the second blade toward the nonpropelling side of the vane is restricted by a stop whereas pivotal movement of the second blade section toward the propelling side of the vane is made possible. A biasing device is included to urge the second blade section into contact with the stop which is the propulsion of the vane. To protect the joined connection between the first and second blade sections a covering means preferably including an expandable and contractable baffle section may be included.

Abstract: The multi-blade articulated rotor for helicopters, comprises a hub connected to a shaft rotatable substantially about a vertical axis, the hub being in the form of a plate comprising a plurality of perforations, each of which defines a bridge of material of said plate between a part of the edge of said perforation and a part of the edge of said plate; a plurality of yokes, each of which is substantially of U shape and comprises a pair of substantially parallel arms and a base element which connects together one end of said arms, the other end of the arms being connected to one of said blades, said base element being inserted into one of said perforations in the hub; a plurality of elastomer bearings, each of which is disposed between said base element of a yoke and the corresponding hub bridge; and means for limiting the amplitude of the swivel movement which each of said yokes can make substantially in a vertical plane.

Abstract: A variable pitch marine propeller having a plurality of circumferentially spaced apart blades mounted on axles at the root portion of the blades in a hub to permit independent movement of each of the blades about an axis of rotation substantially parallel to the axis of the hub between a first nested position adjacent the hub and a second extended position. Each of the blades includes leading and trailing striking surfaces or root segments on the root portion of the blades which are hub engageable upon initial rotation of the blade in either direction. Intermediate the leading and trailing segments of the blades are positioned cushioning means which may be mounted in either the hub or the blade root segments for inhibiting the shock of engagement of the blades and the hub upon initial start up of rotation of the hub or upon a sudden reversal of rotation of the hub.

Abstract: A helicopter rotor having at least one blade projecting from the central hub and mounted for pitch change, flapping and lead-lag motion and including a lead-lag damper mounted to be pivotally movable in a selected plane and connected to the blade through a pivotal link connection to avoid the adverse effects of pitch and flap coupling.