Abstract: The present invention relates to a device for directly controlling a blade which comprises a stator (1), at least one blade carrier (7) composed of at least one curved magnet (6), the blade carrier (7) being secured to at least one blade (3) and pivotally coupled to the rotor (8) for varying the alpha angle of said blades with the excitation of the stator (1). The stator (1) is a partially spherical stator, the stator core (1) being the intersection of the blade axis (22) and the rotor axis (20), said stator being radially close to the magnets (3) to control the rotation of the blades (3) around the blade axis (22). A magnetic ring (5) holds the blades (3) in a neutral position, the system can be compared to a cyclically controlled mechanical oscillator, the frequency, phase and amplitude of the oscillation being controlled by said stator. Device providing a compact, lightweight and robust solution for controlling the direction of an aircraft.

Abstract: In one aspect, the present disclosure provides a system for reducing vibrations or stresses in a rotor blade system. The system may include at least three rotor blades configured to be rotated about a main rotor axis, where each of the three rotor blades may be adjusted by at least one electrically-adjustable control rod of a plurality of control rods. The plurality of control rods may include a first number of control rods forming a first group, and the plurality of control rods may include a second number of control rods forming a second group. A first circuit for may activate or deactivate the first group of control rods, and a second circuit may activate or deactivate the second group of control rods.

Abstract: A rotor for a hover-capable aircraft is described that comprises: a drive mast; a hub operatively connected to the drive mast and rotatable about a first axis; and at least two blades hinged to the hub, via a rigid or elastically deformable connection, so as to be able to assume an attitude rotated about and/or translated along at least a second axis with respect to said hub; the aircraft further comprising sensor means configured to detect the attitude of at least one said blade with respect to the hub; the sensor means are configured to acquire an optical image associated with the attitude of the blade with respect to the hub.

Abstract: An example unmanned aerial vehicle includes a power source, a processor module having one or more processors, and a plurality of boom arms, each boom arm being couplable to a printed circuit board (PCB) and a plurality of propellers. In the example UAV, a PCB of each boom arm includes a power hub electrically couplable to the power source and to corresponding propellers of the boom arm, and a signal hub electrically couplable to at least one processor of the processor module and to the corresponding propellers. Further, in the example UAV, the power hub of each PCB is configured to transfer power from the power source to the corresponding propellers, and wherein the signal hub of each PCB is configured to transfer signals from the processor module to the corresponding propellers such that the processor module controls the plurality of propellers.

Abstract: A method for controlling an individually pitched wind turbine during shutdown is disclosed, the wind turbine comprising at least three wind turbine blades (1a, 1b, 1c). In response to a shutdown command for stopping operation of the wind turbine, a blade parameter of each of the wind turbine blades (1a, 1b, 1c), e.g. pitch angle, bending moment or blade acceleration, is determined. The blade parameters of the wind turbine blades (1a, 1b, 1c) are compared, and a shutdown strategy for the wind turbine is selected from a group of two or more predefined shutdown strategies, based on the comparing step. Finally, the wind turbine blades (1a, 1b, 1c) are moved towards a feathered position in accordance with the selected shutdown strategy.

Abstract: Controlling rotor blades of a rotor assembly includes determining an azimuthal position of a rotor assembly and identifying a lateral control command value, a longitudinal control command value and a collective control command value of a rotor assembly control system. A sine value and a cosine value of the azimuthal position are calculated and separate blade commands signals are generated for each separate blade of the rotor assembly to control a position of each blade independent of each other blade. The blade command signals are generated based on combining the sine and cosine values of the azimuthal position with the lateral control command value, the longitudinal control command value and the collective control command value.

Abstract: A pitch driving unit according to the present invention is equipped with hydraulic actuators that change the pitch angles of wind turbine blades; a hydraulic pump that supplies oil to the hydraulic actuators; a high-pressure oil line that guides the oil discharged from the hydraulic pump to the hydraulic actuators; a low-pressure oil line that returns the oil discharged from the hydraulic actuators to the hydraulic pump; and a pressure control unit that stores a surplus amount of the oil and that refills the low-pressure oil line with the oil so as not to generate negative pressure at an oil intake portion of the hydraulic pump, wherein the hydraulic actuators 15, the hydraulic pump, the high-pressure oil line, the low-pressure oil line, and the pressure control unit constitute a closed hydraulic circuit that does not open to the atmosphere, the closed hydraulic circuit being filled with the oil.

Abstract: Proposed is a redundant hydraulically controlled variable pitch propeller for an air, land or water craft, comprising at least two propeller blades (14) mounted in a propeller hub (12) for variable pitch control by means of a hydraulically powered piston assembly (18). In accordance with the invention the piston assembly (18) comprises two mechanically interconnected servo pistons (20, 22) each assigned an independent hydraulic circuit.

Abstract: A system for actively controlling the span-wise rotational twist of a hollow beam along its longitudinal axis, including a hollow beam structure having a leading edge and a trailing edge region, the beam being split along its length, an actuator arranged between split surfaces of the beam, the actuator adapted to move the split surfaces in a longitudinal direction relative to each other, inducing a twist in the beam. The hollow beam is affixed to an external structure at one or both ends, with only the zero warping displacement points of the beam being attached to the external structure, material or device. In one embodiment, the actuator is a plurality of solid blocks with high thermal expansion coefficients arranged between frames of the split surfaces of the beam, with alternating blocks being heated by resistance heaters to cause expansion in the spanwise longitudinal direction.

Abstract: A hydraulic valve assembly includes a hydraulic valve, a control rod configured to be moved in translation along a first longitudinal axis by flight controls of an aircraft, a servocontrol, and an outlet rod configured to be moved in translation along a second longitudinal axis and configured to transfer a hydraulic fluid between the servocontrol and the hydraulic valve. A blocker device is configured to block a movement of the control rod when a difference between a first movement of the control rod and a second movement of the outlet rod exceeds a predetermined threshold and includes at least one moveable abutment configured to block the movement of the control rod when the predetermined threshold is reached and configured to move in longitudinal translation with the outlet rod, and a differential lever configured to mechanically link the control rod to the outlet rod and to cooperate with the at least one moveable abutment.

Abstract: A system for adjusting the pitch of a variable pitch propeller has a hub assembly, a valve assembly, and a fluid supply assembly. The hub assembly comprises a hub rotatably driven by a propeller shaft, an actuator connected to the hub, and a plurality of propeller blades connected to the actuator with at least one mechanical connection. The valve assembly is in fluid communication with the valve assembly and the actuator. The fluid supply assembly comprises a valve control mechanism that is isolated from the valve assembly and the hub assembly. The valve control mechanism provides a variable hydraulic pressure control signal to the valve assembly, which transfers fluid to the actuator as a function of the variable hydraulic pressure control signal. Based on the fluid pressure in the actuator, the pitch of the propeller blades is adjusted.

Abstract: There is provided a wind turbine generator that includes an improved grease supply and discharge system of lubricant oil used in a blade rotating ring bearing of a wind turbine blade, and can reliably recover discharged grease. The wind turbine generator includes a pitch control mechanism that can adjust a pitch angle of the wind turbine blade via the blade rotating ring bearing provided between the wind turbine blade and a rotor head, a grease supply and discharge device is provided in the rotor head, and the grease supply and discharge device includes a grease supply device that pumps lubricant oil in a supplied grease tank with a grease supply pump and supplies the lubricant oil to the blade rotating ring bearing, and a grease discharge device that forcibly sucks and recovers the discharged grease from the blade rotating ring bearing.

Abstract: A blade actuation system comprises at least one motor coupled to a rotor blade for changing the pitch angle of the rotor blade. The motor is configured to wirelessly communicate with at least one flight control computer to modulate the pitch angle. At least one generator may be mounted on a rotor shaft to generate power during rotation of the rotor shaft. The generator may provide power to the motor. The flight control computer is operative to provide control signals to at least one of the generators and motors for regulation thereof. The flight control computer, motor and generator may be configured to wirelessly communicate with one another.

Abstract: A frame for supporting equipment arranged in a hub of a wind turbine is fixed to the hub at one end and flexibly connected to the hub at another end. The variation of the relative position between the hub and the frame caused by the deformation of the hub associated with a rotation of the wind turbine or the like is absorbed by the flexible connection. A wind turbine whose frame in the hub has high durability against the rotation can be provided.

Abstract: A propeller system includes a propeller hub which supports a multiple of propeller blades. A tailshaft extends from a propeller hub portion of the propeller hub along an axis of rotation with a propeller pitch change yoke mounted within the propeller hub for movement along an axis of rotation to change a pitch of the multiple of propeller blades, the propeller pitch change yoke in sliding engagement with the tailshaft.

Abstract: A method for connecting a tension-torsion strap. The method includes sliding a sleeve into an arm of a hub; aligning holes in the sleeve with holes in the hub; installing a bushing in each aligned hole in the sleeve; sliding a first end of the tension-torsion strap through the sleeve; and placing a pin through the bushings and the tension-torsion strap.

Abstract: A translational thrust system for a high speed rotary-wing aircraft includes a propeller system driven by a propeller gearbox, a hydraulic system, and a mechanical-hydraulic control system. The mechanical-hydraulic control system utilizes a hydraulic fluid which travels to and from a propeller dome via an oil transfer/position feedback tube which translates with a propeller pitch change piston. Translation of the oil transfer/position feedback tube and the propeller pitch change piston pitches the blades between high (coarse) and low (fine) pitch positions.

Abstract: Helicopter blades each have a piston connected to it. The pistons are movable within a cylinder between innermost and outermost positions. The hydraulic fluid of each cylinder is connected to other cylinders by a hydraulic tube or through a manifold. A drive bar moving synchronously with the blades is connects to the cylinders. As the helicopter moves in flight the force of the wind against a blade causes a piston to move inwardly. This causes fluid to be expelled from the cylinder into the another cylinder by way of the hydraulic tube causing other piston to be moved outwardly. Meanwhile the other piston, because it is moving with the wind, is exerting an opposite effect on the other piston. The result is a tendency for the blades to approach an equilibrium condition with respect to the wind forces to minimize the shocks to the overall system.

Abstract: A controllable pitch propeller is provided with a blade that naturally tends to rotate in a direction toward maximum pitch as a result of the hydrodynamic forces on the blade. As a result, the blade will move toward a pitch position of increased pitch magnitude in the event that a control system failure occurs. If the blades of a propeller move naturally toward their maximum pitch position in the event of a hydraulic, mechanical, or electrical failure in the pitch control system, the propeller will be operable and will allow a marine vessel operator to navigate toward port even with a propeller pitch control system that has malfunctioned.

Abstract: A boat propeller has a housing adapted to be fixed to a boat, a hub rotatable about a main axis on the housing, a plurality of generally radially projecting vanes pivotable on the hub, and an operating core shaft coaxially received in the hub, rotatable about the main axis but axially nondisplaceable relative thereto, and having a rear end projecting axially from the hub and a front end. A yoke is fixed to the rear core-shaft end and respective rods fixed to the yoke are connected to the vanes for pivoting the vanes on angular movement of the core shaft about the main axis. A cylinder axially fixed in the housing at the front core-shaft end holds an axially displaceable piston. A nut element having a nonbinding internal screwthread is threaded on a screw element. One of the elements is axially coupled to the piston and the other of the elements is axially coupled to the core-shaft front end.

Abstract: A flap actuation system for a helicopter rotor blade. The rotor blade includes a root end, a tip end, a trailing edge and a flap hinged to at least a portion of the trailing edge about a pivot axis. The flap actuation system includes at least one supply line mounted within the rotor blade and extending outward from the root end. The supply line is adapted to channel pressurized fluid. At least one actuator fluidly connected to the supply line. The actuator includes a displacement member and a head member. The head member is engaged with the flap and is adapted to pivot the flap about its pivot axis when pressurized fluid is conveyed through the supply line. In one embodiment of the invention there are two supply lines, each extending outward from the root end and is adapted to channel pressurized fluid. There is at least one actuator fluidly connected to each supply line.

Abstract: An actuation system for pivoting a flap on a helicopter rotor blade to reduce the interaction of the blade with the preceding blade vortex. The actuation system includes a fluid supply which is connected to first and second fluid supply lines. The fluid supply lines convey flows of pressurized fluid from the fluid supply to an actuator. The actuator includes a housing mounted within the rotor blade and having a channel formed in it. A butterfly shaft is pivotally mounted within the channel and has laterally extending arms which separate the channel into four lobes. A first port connects the first fluid supply line with two diametrically opposed lobes in the channel. A second port connects the second fluid supply line with the other two diametrically opposed lobes in the channel. A torque coupling is attached to the butterfly shaft and engaged with the flap such that rotation of the torque coupling produces concomitant rotation of the flap.

Abstract: The invention provides for a cycloidal propeller, in strictly rudder operation, accessory apparatuses that mesh with a gear drive connected to a shaft of the respective wing. The invention accomplishes relatively small actuation movements of the accessory apparatuses, sufficient to achieve a large pivoting movement of the wings, so that the wings can be adjusted over large angles without impediment. Therefore, wings having normal profiles may be utilized.

Abstract: A cycloidal propeller to achieve strictly a rudder operation includes accessory apparatuses containing accessory drives. Clutches are used to couple the accessory drives to the propeller shafts, and additional clutches are provided to disengage the fixed connection of the normal propeller mechanism to the wing shafts in cruising operation.

Abstract: A variable-pitch mechanism, for use in an airplane, a ship, or the like, for adjusting the pitch of a plurality of blades of a propeller in which attachment shafts of a plurality of radial blades of a propeller are rotatably mounted on a tubular hub which can be driven by a drive shaft, and eccentric pins projecting from ends of the attachment shafts are held in an annular groove defined in the outer periphery of an adjusting ring which is disposed concentrically in the hub and axially movable. The attachment shafts can be turned about their own axes through the eccentric pins in response to axial displacement of the adjusting ring for adjusting the pitch of the propeller blades.

Abstract: The invention relates to a connection system for connecting a ring which carries aircraft propeller blades to a turbine which the ring surrounds. Brackets extend between the ring and the turbine and accommodate thermal expansion of the turbine without significant deformation.

Abstract: An omnidirectional variable thrust propeller for a vehicle includes a hub, plurality of blades, and a plurality of shafts. Each shaft is coaxially rotatably connected to a respective blade and extends through the hub at an acute angle to a hub longitudinal axis. Each shaft has a lever arm and an inner end portion which terminates inside the hub. A reciprocably moveable device engages the inner end portions of the blade shafts to uniformly rotate the blades in one direction when the device moves longitudinally in one direction and uniformly rotate the blades in an opposite direction when the device moves in an opposite direction to enable a change of thrust. Another device pivotally supports the reciprocably movable device at a variable acute angle to the longitudinal axis. Another device selectively move the reciprocably movable device about the pivot point to nonuniformly change the rotation or pitch of the blade that alters the propeller's thrust direction.

Abstract: A hydraulic device for the individual control of the pitch of a helicopter rotor blade by a rotary hydraulic jack, the stator vanes of which are integral with a sleeve fitted on the hub. The jack rotor carries rotor vanes movable relative to the stator vanes and delimiting with these chambers of variable volume fed by a servo-distributor controlled as a function of pilot signals and signals from a detector of the angular position of the blade about its pitch axis. The jack is integrated in a pitch bearing and in an elastic ball joint integrated in a rotary hydroelastic shock absorber with vanes for lamination of a viscous fluid. The shock-absorber rotor is connected rigidly in terms of rotation about the pitch axis to the rotor of the jack and is connected to the blade by a rigid cuff.

Abstract: A self-locking pitch change actuator is configured to fit within an annular hub (34). A ring gear (40) is driven circumferentially by a tangentially oriented ballscrew (42) and traveler (44). The ballscrew (42) is driven by a hydraulic motor (50) controlled responsive to an electric pitch change motor (74). A pitchlock (62) is positioned by the collective actions of the ballscrew (42) and pitch change motor (74), with any movement relative to a preselected null position driving the hydraulic motor beta control valve (60) into an operative position.

Abstract: A novel electro-hydraulic control system for use with a helicopter includes a plurality of electro-hydraulic modules which provide control signals to corresponding blade actuators. A controller receives helicopter parameter input signals as well as pilot command signals and generates the control signals in accordance with preestablished algorithms. The system is characterized by a hydraulic slip ring that transmits the hydraulic control signals from the fuselage to the rotating assembly. Consequently, the present system provides "fly by wire" operation with individually addressable helicopter blades.

Abstract: A pitch arrangement for a variable pitch fan assembly of a turbofan gas turbine engine comprises a plurality of fan blades, each of which has a root portion rotatably mounted, in a thrust bearing on a fan rotor. A control ring is arranged coaxially with and is rotatably mounted on the fan rotor, and each of the fan blades is connected to the control ring by a lever arm. The pitch of the fan blades is varied by rotation of the control ring in either direction. A plurality of hydraulic rams are arranged to drive the control ring through a plurality of bell cranks. The hydraulic rams are mounted on the fan rotor so that the pistons and shafts move in a radial direction such that the centrifugal force of the pistons and shafts is applied to the bell cranks so that a counter turning movement is applied to the control ring to oppose the centrifugal turning moment of the fan blades.

Abstract: In a variable pitch wind turbine system, pitch angle is determined by a pneumatically pressurized hydraulic actuator connected between crank arms on the blade pitch axles. The hydraulic line extends coaxially through the rotor drive shaft via a rotary union to a gas charged accumulator on the yaw carriage. The pitch axes are positively coupled for 1:1 counter-rotation by a gear train, preferably lying on the opposite side of the rotor axis from the hydraulic actuator.

Abstract: An apparatus for varying the pitch of propulsor blades of a gas turbine engine by eccentrically driven gears. The gas turbine engine includes a rotating structure, an annular gas flowpath coaxial with the rotating structure, a plurality of rotor blades coupled to the rotating structure and extending into the gas flowpath such that a gas stream flowing through the flowpath causes the rotating structure to rotate with respect to the stationary member and a plurality of variable pitch propulsor blades coupled to and disposed radially outwardly of the rotating structure. The pitch of the blade is varied by a pinion gear coaxially coupled to one of the propulsor blades and an internal gear radially disposed about the pinion gear for driving the pinion gear. Annular displacement of the pinion gear causes angular displacement of the propulsor blade with respect to the rotating structure.

Abstract: A control and actuating system for adjusting the cyclic pitch of the blades of a helicopter automatically and independently in response to the blade gyrating angular position and to the helicopter forward velocity. This action is also independent of the control and adjustment of the collective pitch. The actuation of the blade pitch is performed by means of cams and followers. A hydraulic force-amplifying system is used between the follower/cam assemblies and the blade pitch actuator so as to isolate the follower/cam assemblies from the load carrying components of the system. The displacement signals generated by two cams are combined into a single linear displacement signal which causes a corresponding rotational movement of the blade. The axial position of one cam is determined by the pilot's action and the axial position of the other cam is defined by the helicopter forward speed.

Abstract: A swashplate control system (10) has a first gimbal ring (26) pivotally mounted at (32) along a longitudinal axis. A second gimbal ring (24) is pivotally attached at (28) to the first gimbal ring (26) along a lateral axis. A longitudinal cyclic actuator (14) pivots the first gimbal ring (26) along the longitudinal axis. A lateral cyclic actuator (16) pivots the second gimbal ring (24) along the lateral axis. The lateral cyclic actuator (16) is mounted on the first gimbal ring (26). A swashplate (12) is rotatably mounted on the second gimbal ring (24).

Abstract: Apparatus for adjusting and locking the pitch of a variable pitch propeller. Within a propeller shaft, a hydraulic piston is provided which drives a rod, a plate, and levers to rotate the propeller blades in, and with respect to, the hub of the propeller. The root of the propeller within the hub has a conical portion which has a mating conical ring thereabout. This conical ring is engaged and locked into place with the conical portion of the propeller root and the propeller hub by hydraulic oil pressure, once the optimum pitch of the propeller blades is determined.

Abstract: A wind turbine having the tips of the blades pivotable to a position in which they act as brakes to slow the turbine down. The pivoting is caused by relative axial movement of the tip and main blade portions which is caused by the action of a spring. The spring action is normally overcome by a hydraulic actuator 16. When the hydraulic pressure exceeds a threshold value corresponding to a desired limit rotational speed of the turbine a pressure switch 83 causes a pressure release valve 84 to dump the fluid pressure in the hydraulic actuator 16, thus allowing the spring to operate and cause the pivoting of the tip.

Abstract: A rotor having airfoil section shaped blades is set into a fluid stream. Over a connection or transmission means a propeller is connected to the rotor. The fluid stream whereinto the rotor is set gives airflow energy to the rotor and revolves the rotor. The propeller is driven by the rotor over the connection or transmission means. Since the propeller is revolved by the rotor in the fluid stream, the propeller provides a thrust. The thrust may be used to lift a weight or to drive a member. A suitable application of the arrangement is for example, to transform a multibladed helicopter into a gliding craft which descends under a gliding angle towards the surface of the earth, when the helicopter has a complete engine failure. Auto-rotation accidents can thereby become prevented. The device is also applicable to drive a vehicle or to lift a weight. Variable means can be applied to obtain variable thrusts in flying craft to improve their efficiencies or change from one flight system to another flight system.

Abstract: In hydrostatic pumps, motors and transmissions; faces, which slide and seal along adjacent faces, commonly have recesses for hydrostatic lubrication or for control of flow through ports.The invention provides additional arrangements on such faces for the provision of additional functions, for example, for the control of hydrodynamic flow into spaces between faces, the control of an additional control flow through the faces and the sealing therof or it provides recesses or seal inserts of specific locations or configurations for the improvement of the efficiency of the faces or for assurance of additional actions by the faces.

Abstract: Blade collective pitch control is provided for a rotor system by rotary actuators located between adjacent blades. Each actuator is connected to the leading edge of one adjacent blade and the trailing edge of the other adjacent blade.

Abstract: The adjustable propeller has an adjusting mechanism for adjusting the pitch of the individual propeller blades. The adjusting mechanism comprises an actuator and a correction mechanism for each propeller blade for cyclically adjusting the pitch angle of a related propeller blade under the control of a control device.

Abstract: A rotor control system for a helicopter in which the conventional swashplate is eliminated and the rotor hub is integrated to include an actuator for each rotor blade. Two arrangements are employed, each of which utilizes a hydraulic circuit. One arrangement is a hydromechanical arrangement with stick control, while the other arrangement is an electro-hydraulic fly by wire arrangement. The latter does not employ a swashplate, while the former employs a modified swashplate. The controls, like the actuators, are mounted in the rotor hub, and the hydraulic lines and fiber optics pass through the rotor drive shaft to the rotor hub.

Abstract: A helicopter rotor having a rotor hub and a plurality of rotor blades includes for each blade a blade fold mechanism comprising a reversible rotary power source and a rack and pinion mechanism adapted to operate one or more lock pins and to fold the blades between an operational spread position and a folded position. Two embodiments of the invention are described and illustrated.

Abstract: Hub flexures affording beamwise flapping (i.e. flapping perpendicular to the original tip-path plane), mount aircraft propellers through a hub assembly to a drive shaft of a fixed wing aircraft for increasing propulsive efficiency. The hub flexures permit the propeller blades of the fixed wing aircraft to exhibit advantageous beamwise flapping and reach equilibrium positions in response to loading conditions which would otherwise result in efficiency loss. The flexures permit only flapping perpendicular to the original tip-path plane and provide blade rigidity in radial, in-plane and torsional loading. The propeller blades may also be of the variable pitch variety wherein the flexures are advantageously inboard of the blade pitch change bearings. The flexures further facilitate both passive, or responsive flapping in response to actively induced cylic pitch to achieve maximum propulsive efficiency under any given loading conditions.

Abstract: Individual blade control of a helicopter rotor is accomplished by rotation of a mast (10) about a standpipe (12) where an individual blade (16) is coupled to the mast through a hub (18). Pilot input signals are transmitted by fly-by-optic transmission lines (14) through a fiber optic slip ring (40,42) to signal generators (134, 136, 138) for each of three sections of triplex actuators (76-79) coupled to individual rotor blades. Hydraulic fluid for positioning each of the actuators (76-79) is provided by electrohydraulic power packages (88, 90 and 92) where each package includes a pump and alternator. As each blade rotates about the mast (76) the pitch angle changes by individualizing the output of the signal generators (134-138) for each actuator.

Abstract: Blade pitch actuation system wherein the blades are hydraulically maintained in phase with one another. The system comprises hydraulic actuators each adapted to drive a single blade in a pitch change mode of operation. Fluid flow to the actuators is controlled by a blade actuator control valve in fluid communication with the actuators and an hydraulic fluid source and drain. An input member of the control valve is provided with passages which provide selected communication between the hydraulic fluid source and drain and passages in cooperating control valve feedback members each operated by, and in fluid communication with one of the blade actuators. The input and feedback members are positionable along one another such that selective positioning of the input member causes simultaneous selected pressurization and draining of the blade actuators through the feedback members thereby effecting a desired, phased blade pitch setting.

Abstract: A pitch control system for a multibladed variable pitch wind turbine. Each of the turbine blades is pivotally driven about the longitudinal axis thereof independently of the other blades by at least a pair of hydraulic actuators. The actuators are supplied with pressurized hydraulic fluid from a first source thereof under conditions of normal pitch change adjustment. Under conditions wherein feathering of the blades is required, the actuators are supplied with hydraulic fluid from second sources thereof such that one of the actuators associated with each of the blades is supplied with fluid from one second source and a second actuator is provided with fluid from a redundant second source whereby blade feathering may be effected despite a malfunction of one of the redundant sources or one of the actuators.

Abstract: A wind operated generator is disclosed herein having a stationary frame or base rotatably supporting at least four sets of pivotal blades intended to be driven by impinging wind currents. Each set of blades operate in unison for opening and closing air passageways between adjacent ones of the blades as the sets of blades rotate about a common vertical axis. A wind direction sensor is provided which moves into the direction of the wind and electro-mechanical or electrical interface networks operably couple the wind direction sensor to the respective sets of blades whereby the blades are responsive to wind direction so as to be properly feathered to propel the sets of blades. By employment of the interface network, those blades that are in position to actuate or rotate the windmill will receive the full force of the wind while other blades which are not in a position to accomplish the proper operation will be turned to permit passage of the wind thereby.

Abstract: A windmill blade that has a rigid leading edge, a rigid root portion and a movable blade tip. Control of the geometric twist of the windmill blade is accomplished through proper selection of the axis of rotation for the movable blade tip and by controlling the position of the windmill blade tip with a servo motor or by controlling the position of the windmill blade tip with a spring and a weight. The ability to vary the geometric twist of the blade enables the frequency of rotation of the blade to be controlled to reduce wind drags upon the blade. This improved windmill blade eliminates the need for current complicated and expensive rotor hubs which are used to vary the blade pitch angle at the root end of the blade to reduce wind drag upon the blade. Processes related to the windmill blade are also presented.