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: An aerofoil assembly comprising a plurality of rotatable blades. A damping member is disposed between at least two of the blades, each of the at least two blades having an aerofoil portion, a stem portion and a root portion. A recess is provided on two cooperating stem portions with a first shelf extending from a first end of each recess, and a second shelf extending from a second end of each recess to define a compartment. When the blades are aligned the damping member is held on one side of the shelves within the compartment. The damping member is provided with a projection at one corner and a projection on a diagonally opposite corner, the longitudinal distance between ends of the projections being greater than the distance between edges of the first and second shelf.

Abstract: The present invention relates to an improvement to rotorcraft rotors (1) fitted with inter-blade drag dampers (15) such that for each blade (4), the two joints (16) connecting said blade (4) to two inter-blade drag dampers (15) are disposed on either side of the pitch variation axis (101) of said blade, at least one of the two joints (16) being offset to above the plane P containing the pitch variation axis (101) and the vertical flapping axis (102).

Abstract: According to an embodiment of this invention, a plurality of stops are implemented between metal surfaces that may be reached only in the event of shocks of great violence and in any case following a certain elastic deformation of the shock absorbing resilient inserts of elastomer, which in any case remains partial compared to full compressing of the elastomer beyond its super elastic limit. At the bottom of each circular cavity (15) housing a respective annular insert (16) of elastomer of the flange (14) of a first cylindrical sleeve (13) directly keyed on the drive shaft of the propeller a hole coaxial and of greater diameter than the diameter of the central hole of the annular insert of elastomer and of the relative engaging pin (19) is formed and the pins projecting from the face of the terminal flange of a second circular sleeve extend through the coaxially formed holes at the bottom of the respective circular cavities of the flange of the first sleeve.

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: An elastomeric bearing element having an outer race, an inner race, and at least two elastomeric segments secured between the inner and outer races is provided. The elastomeric segments are spaced from one another by a corresponding number of expansion segments. The elastomeric segments provide a first spring rate when a first force applied to the outer race places the elastomeric segments in compression and a second spring rate when a second force applied to the outer race places the elastomeric segments in shear. The second spring rate is lower than the first spring rate.

Abstract: Disclosed herein is a wind turbine. The wind turbine includes a support unit having a lower base block and a cylindrical protruding part. A rotary cylinder is rotatably supported by the protruding part. A rotating shaft extends from a center of the rotary cylinder to rotate along therewith. An upper bearing is installed on the protruding part to support the rotary cylinder. A lower bearing is installed on the lower base block to support the rotary cylinder. A plurality of vanes is installed along the outer circumference of the rotary cylinder at regular angular intervals, and is opened outwards relative to the rotary cylinder or closed to be in close contact with the outer circumference of the rotary cylinder, according to a position relative to a wind direction. An angle limiting means prevents each vane from being opened beyond a preset angle.

Abstract: The present invention is to provide a vertical axis wind engine comprising at least one arm each having its center rotatably coupled to a vertical axis mounted on a base on the ground, each pair of the upper and lower arms adapted to define an airfoil receiving space for pivotably mounting an airfoil by pivot pins thereof; and at least one elastic stop member each provided on the arm proximate the airfoil and spaced from the pivot pins, each stop member adapted to limit a pivot angle of the airfoil and lift the pivot limitation for allowing the airfoil to pivot when the airfoil experiences a wind force larger than a maximum resistance force thereof, preventing the components of the wind engine from being damaged by strong wind or when the wind engine is operating in high speed.

Abstract: The invention relates to a wind generator of the type with automatic power regulation, comprising at least one propeller having at least two blades (21), whereby the efficiency of one propeller varies inversely to a variation in the wind energy, from a lower wind speed limit. The torque/speed characteristics of each propeller are determined such that the working point begins to move towards the areas of low aerodynamic efficiency when the wind speed approaches the value at which the generator reaches the maximum, safety-compliant power. The inventive wind generator is characterized in that it also comprises: at least one centrifugal counter weight system (24) which is arranged such as to reduce the pitch of at least one part of the blades when the speed of rotation is increasing; and at least one system comprising an end stop (30) and return (15) or compression (25) means which mechanically define the initial working pitch and the optimum working pitch up to the nominal speed.

Abstract: This invention refers to a hydraulic or pneumatic machine with tilting blades, running either as an engine on a fluid flow or on pressure fluid or as a pump or a compressor. The hydraulic or pneumatic machine on a fluid flow according to the invention consists of a cylindrical casing with inlet and outlet openings, radially arranged, diametrically oposed, along the fluid flowing direction, some disk like rotors with tilting blades, hinged over their front faces and provided with driving mechanisms of their own, and some fixed drums located between the rotors, concentrically to them, making inside the machine some channels, symetrically arranged on one or several stages. Flowing through the channels, the fluid drives the tilting blades causing the movement of the rotors, all the rotors moving to one sense being coupled to the same outlet shaft of the machine.

Abstract: A ceiling fan with retractable fan blades includes an electric motor operable to spin a rotor with a plurality of fan blades attached thereto. Each of the fan blades is operable to move between a closed position and an open position. A rotatable center ring is included on the rotor and connecting rods join each fan blade to the center ring. Rotation of the center ring relative to the rotor moves the plurality of connecting rods and fan blades in unison. The fan blades are spring biased toward the closed position. When the rotor rotates, centrifugal forces acting on the fan blades overcome the spring biasing forces and cause the fan blades to move toward the open position. A governor is positioned between the rotor and at least one of the fan blades to limit the speed of movement of the fan blades between the closed position and the open position. The governor may take the form of a fluid cylinder.

Abstract: The present invention provides a prime mover (2) for harnessing energy from a flow of fluid, the prime mover (2) comprising a shaft (4) having a rotational axis, arranged to be rotatably mounted to a substructure, the shaft (4) comprising at leas one arm (6) extending radially from the shaft (4), the or each arm (6) comprising at least one blade (8) wherein the or each blade (8) is oriented such that flow action on the blade (8) effects rotation of the shaft (4), characterized in that the or each blade (8) is movably mounted on an arm (6) and wherein each blade (8) is movable from a first position, having a first drag, to a second position, having a second drag, wherein the first drag is higher than the second drag. The prime mover (2) of the invention provides substantially reduced drag in a flow of fluid, and an increased torque output, compared to prior art prime movers.

Abstract: A monodirectional impeller for centrifugal electric pumps having a permanent-magnet synchronous motor, having vanes which are deformable at least along part of their extension so as to change their curvature, when loaded, in one direction of rotation, so that the power required for rotation in that direction is greater than the maximum power that can be delivered by the motor.

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: An internal combustion engine for an aircraft is described. The internal combustion engine includes a crankshaft defining first and second ends, a propeller, and a transmission disposed between the first end of the crankshaft and the propeller, operatively connecting the propeller to the crankshaft. A torsion bar is disposed between the first end of the crankshaft and the transmission, operatively connecting the crankshaft to the transmission. A torsional vibration damper is operatively connected at one of the first and the second ends of the crankshaft.

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 damper assembly including a spherical elastomer bearing member, wherein the spherical elastomer bearing member is operable for accommodating relative motion and/or vibration, and a flat elastomer bearing member, wherein the flat elastomer bearing member is operable for accommodating relative motion and/or vibration. The damper assembly also including a substantially rigid transition shim disposed between the spherical elastomer bearing member and the flat elastomer bearing member, wherein the substantially rigid transition shim is operable for coupling the spherical elastomer bearing member to the flat elastomer bearing member. The damper assembly further including a tension member attached to the substantially rigid transition shim, wherein the tension member is operable for precompressing the spherical elastomer bearing member and increasing the cocking stiffness of the damper assembly.

Abstract: A wind rotor comprises a base, a rotor frame rotationally supported on the base for movement about a substantially vertical axis in one of a clockwise or counter clockwise direction, and a plurality of wind receiving vanes pivotally disposed on the rotor frame for movement about a substantially vertical axis in a clockwise and counter clockwise direction between a first closed position and a second open position. The movement of each vane from the first closed position to the second open position further being independent of the other vanes. A variable resistance damping mechanism assembly is disposed between each vane and the rotor frame. The variable resistance damping mechanism is configured to provide damping in both the clockwise and the counterclockwise directions, and to dampen a greater amount in one of the clockwise or counterclockwise directions than in the other.

Abstract: A flexbeam (1) having flapping portions (3) and lead-lag and feathering portions (5). Each lead-lag and feathering portion has: a central portion with an elongated and narrow width; middle portions each of which continuously connects to the central portion and branches from both ends of the central portion extending along the longitudinal direction thereof, and extends upward and downward; and edge portions each of which continuously connects to the middle portion and bends from each end of the middle portions and extends almost in parallel with the central portion. At corners formed on branch portions (40, 50) and/or bending portions (60, 70), concaves (41-43, 51-53, 61, 62, 71, 72) each of which has a cross-section of an approximate arc shape and which continuously and smoothly connects to two surfaces forming each of the corners and is formed inside extended planes of the two surfaces.

Abstract: The invention is a system, device and method that captures wind energy and converts it into mechanical or electrical energy. In a system embodiment, the system transfers wind power to rotational energy. The system includes a wind capture means that uses wind to generate a mechanical force, an energy coupling means for transferring the mechanical force to a horizontally mountable wheel having a shaft coupled thereto, and an energy transfer system that couples the mechanical force from the shaft to a machine. In a device embodiment, a wheel capable of receiving wind power is provided. The wheel includes an airfoil support having a center portion, a stop location, and an airfoil location, and an airfoil is coupled to the airfoil support at the airfoil location. A method of driving the wheel uses a mounted airfoil to capture wind energy in an airflow, where the airfoil is mounted to a horizontally mountable wheel.

Abstract: A damper assembly including a spherical elastomer bearing member, wherein the spherical elastomer bearing member is operable for accommodating relative motion and/or vibration, and a flat elastomer bearing member, wherein the flat elastomer bearing member is operable for accommodating relative motion and/or vibration. The damper assembly also including a substantially rigid transition shim disposed between the spherical elastomer bearing member and the flat elastomer bearing member, wherein the substantially rigid transition shim is operable for coupling the spherical elastomer bearing member to the flat elastomer bearing member. The damper assembly further including a tension member attached to the substantially rigid transition shim, wherein the tension member is operable for precompressing the spherical elastomer bearing member and increasing the cocking stiffness of the damper assembly.

Abstract: A redundant fan system for a computer includes two fans installed in series with at least one of the fans having collapsible blades. A fan system of this type reduces the fan inefficiency caused when one fan in a series mounted pair is not operating, either because it is free-wheeling or in a locked rotor condition. When non-operational, the fan blades of the collapsible fan fold inward due to airflow generated by the operational fan over the collapsible blades. The ability of the blades to fold reduces the inefficiency of the operational fan, having less of an effect on fan life. Also, because the flow of air is less restricted, proper airflow can be maintained, thus preventing overheating of the computer.

Abstract: The technology of all weather wind turbine is disclosed by applying it to a savonius design wind turbine although it can be applied to all kinds of windmills based on rotational mechanism in general and specifically in the field of wind turbines. In this current embodiment the art is used to a savonius design rotor. A Savonius rotor assembly includes two blades. Each of the blades has an outer edge and an inner edge with the outer edges of the blades lying on a circle which define the diameter of the rotor. Each of the blades has a linear portion adjacent to the inner edge and a first curved portion which is substantially an arc of a circle tangent to the linear portion and tangent to the circle defining the rotor diameter. A second curved portion is substantially coincident to the circle defining the rotor diameter. In some applications multiple blades or multiple units are mounted in layers for more torque.

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 vertical axis wind engine, also referred to as a vertical axis wind turbine (VAWT) includes a support structure, a rotor mounted rotatably on the support structure for rotation about a vertical axis, and at least one airfoil for causing the rotor to rotate about the vertical axis in response to wind passing the wind engine. The airfoil has vertically extending leading and trailing edges, an angle-of-attack axis extending horizontally through the leading and trailing edges, and a pivotal axis extending vertically intermediate the leading and trailing edges. The airfoil is mounted on the rotor for pivotal movement about the pivotal axis and the rotor includes components for limiting pivotal movement of the airfoil to first and second limits of pivotal movement.

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 are filled with fluid and are connected by a restriction port (35) and by a channel (32) of larger cross-section than the restriction port. A secondary piston slidable and pressure-tight piston is fitted in the channel and loaded by an elastic bias (34). The equivalent mass of this secondary piston (33) and of the fluid which it displaces, and the stiffness of the elastic bias (34) are such that the secondary piston is resonant in the channel (32) at the rotation frequency of the rotor, to filter the dynamic component at this frequency of stresses applied to the damper (20).

Abstract: A multi-focus elastomeric bearing system provides a plurality of hemi-spherical bearings arranged in series. An inner hemi-spherical bearing rotates about a focal point which is X distance above a pitch change axis while an outer hemi-spherical bearing rotates about a focal point which is X distance below the pitch change axis. The bearing system thus has an effective rotational center along the pitch change axis. The inner hemi-spherical bearing has a greatly reduced radius and high wrap-around angle, while the outer hemi-spherical bearing has an increased radius and reduced wraparound which provides a more requirement tailored bearing system.

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 blade assembly for a windmill includes an output shaft with a first cross-shaft and a second cross-shaft operatively mounted relative to the output shaft. The first cross-shaft and the second cross-shaft include a first end and a distal end. A first blade is mounted on the first end of the first cross-shaft and the first cross-shaft is rotated by the first blade to impart rotation to the output shaft. A second blade is mounted on the distal end of the first cross-shaft and the first cross-shaft is rotated by the second blade to impart rotation to the output shaft. Stops are positioned on the first cross-shaft for limiting the rotation of the first cross-shaft relative to the output shaft. A third blade is mounted on the first end of the second cross-shaft and the second cross-shaft is rotated by the third blade to impart rotation to the output shaft.

Abstract: The invention is a system, device and method that captures wind energy and converts it into mechanical or electrical energy. In a system embodiment, the system transfers wind power to rotational energy. The system includes a wind capture means that uses wind to generate a mechanical force, an energy coupling means for transferring the mechanical force to a horizontally mountable wheel having a shaft coupled thereto, and an energy transfer system that couples the mechanical force from the shaft to a machine. In a device embodiment, a wheel capable of receiving wind power is provided. The wheel includes an airfoil support having a center portion, a stop location, and an airfoil location, and an airfoil is coupled to the airfoil support at the airfoil location. A method of driving the wheel uses a mounted airfoil to capture wind energy in an airflow, where the airfoil is mounted to a horizontally mountable wheel.

Abstract: The present invention 10 discloses a wheel-like member 30 consisting of a central circular body member 18 having a plurality of spokes 22 radiating from its outside perimeter that attach to the inside perimeter of an outer circular body member 24. On the outside perimeter of the outer circular body member a plurality of hinges 26 with paddles 16 are attached thereto that can only open to a pre-determined angle “A” from the wheel 30 that ensures water current 14 is caught by the paddles on only one side of the wheel which causes the wheel to rotate in only one direction. The kinetic energy stored in the wheel 30 while rotating is harnessed through a drive shaft 34 connected to the central circular body member 18 that connects to a generator 36 placed perpendicular to the central circular body member 18.

Abstract: An apparatus for deploying a propeller assembly from a folded configuration to a deployed, operational configuration, the apparatus comprising a propeller assembly hub which in conjunction with a propeller hub nut maintains an aerodynamically efficient shape after the propeller assembly is deployed, the propeller hub nut which is diametrically large enough to allow assembly of a drive shaft and a drive shaft bevel gear and includes a cavity to accept a spring detent, a propeller blade which protrudes from a journal located in the surface of the propeller assembly hub where when in its folded configuration, the propeller blade is in the same parallel axial direction as the drive shaft and when deployed is nutated to a radially outwardly extending operative position in response to rotating of a propeller blade bevel gear, the drive shaft rotated about its axis where one end engages a prime mover and a second distal end engages the hub nut, drive shaft bevel gear fixed to the drive shaft near the distal end whic

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 featherable propeller assembly for fitment to a drive shaft has a blade carrying assembly which is carried by a hub assembly. The blade carrying assembly is rotatable relative to the hub assembly within relative limits of rotation. Blades are pivotally mounted on the blade carrying assembly. The relative rotation of the hub assembly and blade carrying assembly provides for different positions of respective stop abutments, thus allowing the blades to assume each of the following conditions: (a) a forward drive condition under a forward drive rotation of the shaft; (b) a feathering condition when not under drive from the shaft where the blades are substantially free to move into an orientation which is aligned with the flow of water past the propeller; and (c) a reverse driving condition under a reverse drive rotation of the shaft.

Abstract: The rotor comprises, for each blade, an inner and an outer flap stop which are fixed to the blade and have a bearing surface which is planar with a cylindrical portion, facing an inner and an outer flap stop fixed to the hub and with torus-shaped bearing surfaces with their convexness facing towards the flap stops of the blade and in the shape of an arc of a circle centered on the axis of drag of the 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: A fluid and elastomer damper includes a first and second members and an elastomer section flexibly mounting the second member to the first member and allowing lateral movement therebetween. The elastomer section includes an inner wall forming a portion of a cavity defined within the damper and a damping fluid disposed within the cavity. A flexible damping plate separates the cavity into first and second chambers. At least one passageway is formed between the damping plate and the inner wall, the passageway exhibiting a gap dimension between the wall and the damping plate. When lateral movement occurs between the first and second members, the gap dimension is maintained substantially constant by flexing of the damping plate along the lateral direction.

Abstract: A multi-blade rotor arrangement free of flapping hinges, for a rotary wing aircraft, includes a rotor head plate (2) made of fiber-reinforced composite material. The head plate (2) includes a plurality of blade connection arms (4) that are elastically flexibly bendable in the blade flapping direction, and at least one plate segment (16, 18) that holds each blade connection arm on two sides thereof radially spaced away from the rotor center in a manner that allows elastic bending in the blade flapping direction. The plate segment is rigidly connected to the rotor mast (122, 222) at mounting locations (20) that are offset in the circumferential direction from the blade connection arms. In this manner, the elastically yielding flapping connection between the rotor blades and the rotor mast is provided by both the elastic bending of the blade connection arms and the elastic deformation of the plate segment portions between the blade connection arms and the mast mounting locations.

Abstract: The non-rotating plate of the device is stopped from rotating around the rotor axis by a stop arm with at least one rigid stop track extending substantially axially and secured to the structure of the rotor aircraft. The track works together with a stop pin, integral with the non-rotating plate to stop the latter from rotating. The track has two flanges between which the pin is engaged so as to follow on this track a straight trajectory, parallel to the rotor axis and a circular arc trajectory centered on this axis, in the case of variation in the collective and cyclic pitch respectively. The stop pin includes a pad sliding between the two flanges of a slide constituting the said track and hinged around its fastening axis on the non-rotating plate.

Abstract: A fan blade mounting system for large air-moving fans includes a radially extending hub strut, a blade root member pivotally coupled to an end of the hub strut for receiving a blade skin, and a tube end located between the blade root member and the hub strut. A pair of resilient mounts are utilized in the blade root member to effectively pivotally couple the blades to the hub, thus relieving most of the vertical bending moment transferred to the hub and eliminating critical frequencies associated with the fan. The hub strut is connected to the hub of the fan by a stud having right- and left-handed threads and a wall thickness adjacent to the threads sufficient for distributing the stresses substantially uniformly on the threads, thereby improving fatigue resistance. The resilient mounts comprise a metal core and metal sleeve with a resilient elastomeric layer between the core and sleeve. The sleeves are connected to the blade root member and the cores of the two mounts are clamped to the tube end.

Abstract: A method of modifying the vibration resonance characteristics of a workpiece includes the steps of determining a vibratory resonance condition frequency of the workpiece, determining the mode shape of said vibratory resonance condition, locating an area on the workpiece that includes a maximum curvature for the determined mode shape and vibratory resonance condition frequency; then laser shock peening the located area to create residual compressive stresses within the workpiece to shift the determined vibratory resonance condition frequency. A workpiece such as a gas turbine engine blade is also disclosed.

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: 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 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: A self-adjusting, variable pitch propeller comprising: a central hub defining a propeller rotation axis; a plurality of blade assemblies symmetrically disposed about the hub, each assembly having a substantially cylindrical segment with a propeller blade fast therewith and defining a leading blade edge, each blade assembly being pivotally attached to the hub adjacent the leading edge of the blade of that assembly, a support means interconnecting each assembly and the hub at a location remote from the pivotal attachment to permit controlled blade pitch adjustment to occur as a function of the magnitude of opposed hydrodynamic and centrifugal forces acting on the assemblies by pivotal movement of each assembly, about its the pivotal attachment, both circumferentially and radially relative to the axis.