Abstract: An aircraft can include a stacked propeller to generate lift during assent and descent. The stacked propeller includes a first propeller and a second propeller that co-rotate about an axis of rotation. In one embodiment, the blades are coupled to a rotor mast that contains an internal cavity. In one mode of operation, the first propeller and/or the second propeller can be stored in the internal cavity in order to reduce drag during flight. The aircraft can include one or more stacked propellers, such as a port propeller and a starboard propeller, which rotate in opposite directions during one or more modes of flight.

Abstract: Disclosed is an aerial vehicle. The aerial vehicle may include a removable battery. Various embodiments of removable battery assemblies include a pull-bar battery assembly, a latch battery assembly, and a lever battery assembly. The aerial vehicle may also include a propeller locking mechanism to which propellers may be removably coupled. The propeller locking mechanism may obviate the need for tools for coupling or decoupling propellers to the aerial vehicle. Vents in the arm of the aerial vehicle may provide an air pathway, providing convective cooling for the electronics aerial vehicle.

Abstract: A control circuit for changing the angle of propeller blades includes a propeller pitch change mechanism, and a fixed-displacement pump providing the supply of oil from an engine oil return system. A valve has an outlet port to direct oil from a cavity of the valve, and a pitch port in fluid communication with the pitch change mechanism. A spool of the valve is operable between a first position and a second position to respectively open and close the outlet port, and direct oil flow away from or to the pitch change mechanism.

Abstract: A rotorcraft having a fuselage surmounted by a main rotor. The rotorcraft has a first propeller and a second propeller driven in rotation respectively about a first secondary axis of rotation and a second secondary axis of rotation. A mobility system turns the second propeller relative to the fuselage, the mobility system turning the second secondary axis of rotation relative to the fuselage from a first position where the second propeller exerts thrust in a first direction to a second position where the second propeller exerts thrust in a second direction opposite to the first direction.

Abstract: Disclosed is an aerial vehicle. The aerial vehicle may include a removable battery. Various embodiments of removable battery assemblies include a pull-bar battery assembly, a latch battery assembly, and a lever battery assembly. The aerial vehicle may also include a propeller locking mechanism to which propellers may be removably coupled. The propeller locking mechanism may obviate the need for tools for coupling or decoupling propellers to the aerial vehicle. Vents in the arm of the aerial vehicle may provide an air pathway, providing convective cooling for the electronics aerial vehicle.

Abstract: A ram air turbine (RAT) assembly includes a gearbox that supports a gear set with a ring gear that drives a pinion gear. The gear set provides for the transmission of power from the turbine to a generator, pump or other power conversion device. A turbine shaft supports the ring gear and a pinion shaft that rotates about an axis transverse to the turbine shaft supports the pinion gear. A ratio between a face width and a diametrical pitch of the gear set is within a desired ratio that provides sufficient space for supporting bearing assemblies while providing for operation within the physical constraints and desired performance requirements of the RAT.

Abstract: A retention assembly for securing a main rotor shaft in a wind turbine relative to a pillow block is provided. A main rotor shaft extends through a pillow block, and a ring groove is defined in an outer circumferential surface of the main rotor shaft axially offset from the pillow block. A snap ring is engaged within the ring groove, wherein the snap ring and ring groove are designed to achieve a design axial load capacity.

Abstract: A hub for a rotor of a wind turbine is disclosed. The hub includes a hollow body rotatable around a rotation axis. The hollow body includes a blade flange and defines a blade flange area surrounded by the blade flange. The hollow body further includes a main shaft flange defining a first end, and a second end opposite the first end. The hub further includes a stiffening web extending within the blade flange area and defining a web plane. A side profile of the web plane extends from the first end to the second end is oriented at a cone angle to the rotation axis.

Abstract: A propeller governor for controlling blade pitch of a variable pitch propeller has a hydraulic control circuit coupled to the propeller to change blade pitch in response to hydraulic pressure. The hydraulic control circuit has a first pressure path configured to adjust blade pitch within a first range of blade pitch, and a second, different pressure path configured to adjust blade pitch within a second range of blade pitch. An electrohydraulic servo valve of the governor is configured to adjust hydraulic pressure in the first pressure path to adjust blade pitch within the first range and to adjust hydraulic pressure in the second pressure path to adjust blade pitch within the second range.

Abstract: A method and arrangement of controlling blade pitch angle of a set of rotor blades. The method comprises providing a target blade pitch angle to a controller mounted on the rotor; measuring the speed of rotation of the rotor using a rate gyro mounted on the rotor; calculating the blade pitch angle required to match the target blade pitch angle by summing the target blade pitch angle and the measured rotational speed; and actuating the blades to the calculated blade pitch angle.

Abstract: A variable chord morphing helicopter rotor blade is disclosed. The variable chord morphing helicopter rotor blade includes an extensible quasi-static chord section connected to the rotor blade, an adjusted airfoil chord length of the rotor blade corresponding to extension of the quasi-static chord section relative to a baseline airfoil chord length, the adjusted airfoil chord length determined according to helicopter flight conditions.

Abstract: A method for shutdown of a wind turbine having one or more wind turbine blades includes detecting an operational condition of the wind turbine that calls for an expedited or emergency shutdown of the wind turbine by a manner other than normal pitch control shutdown. Upon detection of the operational condition, one or more air brake flaps configured on each of the turbine blades is deployed by removing power to a fail-safe actuator operatively coupled to each of the air brake flaps. The fail-safe actuator is configured to hold the respective air brake flap at a retracted position relative to a suction side of the turbine blade in a powered state of the fail-safe actuator and to release the air brake flap for automatic deployment to an open position upon loss of power to the fail-safe actuator.

Abstract: A variable-diameter rotor comprises a hub with a shaft and rotor blades, wherein each of the rotor blades comprises a radially internal blade part and a radially external blade part. In each of the rotor blades, a jackscrew mechanism is arranged therein and includes a jackscrew arranged in the radially internal blade part and a nut connected with the radially external blade part, the nut cooperating with the jackscrew for radially moving the radially external blade part with respect to the radially internal blade part. The rotor further comprises an energy storage system, including a compressed-gas accumulator. The compressed-gas accumulator comprises a volume of gas and a piston for compressing and expanding the volume of pressurized gas. The energy storage system also includes a means for converting a radial motion of the radially external blade part into a motion of the piston of the compressed-gas accumulator and vice-versa.

Abstract: A method of assembling a pitch assembly for use with a wind turbine. The wind turbine includes a rotor and a plurality of rotor blades coupled to the rotor. The method includes coupling a pitch drive system to at least one of the plurality of rotor blades for rotating the rotor blade about a pitch axis. At least one sensor is coupled in signal communication with the pitch drive system. The pitch drive system rotates the rotor blade when the sensor senses rotor overspeed.

Abstract: An assembly for changing the pitch of fan blades rotatably attached to a hub includes a main drive shaft configured to rotate the hub. The main drive shaft is rotated by a first motor. A secondary drive shaft is coupled to the main drive shaft via a gearing system located within the hub. The secondary drive shaft is also driven by a second motor. When driven by the second motor, the secondary drive shaft manipulates the gearing system to alter the pitch of the fan blades.

Abstract: A wind turbine includes wireless system for receiving a control signal at a hub of the wind turbine.

Abstract: A system adjusts the pitch of a variable pitch propeller having a non-rotating side and a rotating side. The rotating side of the propeller has a hub, a propeller blade mounted to the hub, a propeller shaft that rotates the hub and propeller blade, and an actuation system. The actuation system has a screw and a piston. A motor has a non-rotating component in communication with the non-rotating side of the propeller and a rotating component in communication with the actuation system. When the motor increases speed, the screw rotates and the piston moves laterally in a first axial direction to decrease the pitch of the propeller and, when the motor decreases speed, the screw rotates and the piston moves laterally in a second axial direction to increase the pitch of the propeller.

Abstract: A method for operating a wind turbine having a rotor with a number of wind turbine blades, wherein the rotor's axis of rotation is tilted in relation to the direction of the incoming wind, includes the steps of determining the azimuth angle (A) of the blades and adjusting the pitch angle of the blades in accordance with the azimuth angle (A) to ensure a substantially constant angle of attack (AoA) during at least a full rotation of the rotor. A wind turbine and use of the method are also contemplated.

Abstract: A method of controlling a wind turbine, where a control signal for a controllable parameter of the wind turbine is determined repeatingly at successive time steps, and a control history including respective control values derived from or included in past control signals is stored. These control values stored in the control history are then used to determine an alert parameter for the controllable parameter, the alert parameter being a function of the variations of the control signals over time. The wind turbine is then controlled according to the most recent control signal only if the alert parameter is below an alert threshold, and otherwise according to a modified control strategy. The control method may be performed on pitch reference signals for controlling the individual and/or collective pitch of the blades. The invention further relates to a control system configured to perform the above control method, and a wind turbine comprising such system.

Abstract: A method for operating a wind turbine having a rotor with a number of wind turbine blades, wherein the rotor's axis of rotation is tilted in relation to the direction of the incoming wind, includes the steps of determining the azimuth angle (A) of the blades and adjusting the pitch angle of the blades in accordance with the azimuth angle (A) to ensure a substantially constant angle of attack (AoA) during at least a full rotation of the rotor. A wind turbine and use of the method are also contemplated.

Abstract: A wind turbine for generating electricity has been developed. The turbine includes a housing for securement to a support. A wheel is mounted within the housing and is rotatable about a horizontal axis. The wheel has an axle assembly and a number of blade assemblies affixed thereto. Each of the blade assemblies has a frame with a spaced-apart pair of uprights and a crosspiece connecting the uprights. Each of the blade assemblies also having a pair of movable blades positioned within the frame with each of the blades being hingedly fastened to a respective one of the uprights. A brake actuator assembly is associated with each of the blades for relieving pressure imparted by strong winds on the blades. A brake operator assembly, disposed principally within said axle assembly, synchronizes the movement of the blades. An electrical current generator is connected to the wheel so as to be powered thereby.

Abstract: A method for condition monitoring a rotor of a wind energy plant includes the steps of measuring activity signals of the blades in the rotor and establishing one or more differential values between the activity signals of different blades. The one or more differential values are used for monitoring the condition of the rotor in the wind energy plant. A wind energy plant, a cluster of wind energy plants and use hereof is also contemplated.

Abstract: A power generating system wherein a turbine is mounted on top of a tower or tethered underwater. The turbine includes a rotor having a main blade connected to a rotor hub and an extender section. An adjusting device positions the extender blade between a retracted position within the main blade and to an extended position to expose more or less of the rotor to the fluid flow. The adjusting device includes a servo-controlled rack and pinion mechanism that converts rotation of the pinion by a servomotor into linear motion of the extender blade. A generator is connected to the turbine for generating electrical energy.

Abstract: A pitch change system includes a yoke assembly which receives a pitch trunnion that extends from each propeller blade assembly. Each pitch trunnion is received within a respective bearing assembly mounted in the yoke assembly. The bearing assemblies are mounted between a forward yoke plate and an aft yoke plate. A spacer is mounted between each adjacent bearing assembly to position and restrain each bearing assembly. Each spacer includes an extension which retains the adjacent bearing assembly on a pitch trunnion pin in a direction generally parallel to axis. Each of the bearing assemblies includes a generally rectilinear outer race and a spherical inner race inside diameter to receive the pitch trunnion pin. The rectilinear outer race reduces contact stresses to acceptable levels for high load applications yet permits blade installation without actuator disassembly.

Abstract: A rotor for a wind power installation having at least one rotor blade. The smaller the surface area on which the wind acts, that is to say in particular the rotor blade area, the correspondingly lower is the load level for which installation has to be designed and the correspondingly more easily can the rotor blade be transported. On the other hand the size of the wind power installation entails minimum dimensions which are unavoidable for operation and below which the installation dimensions may not fall. In order to provide a rotor blade which on the one hand has the aerodynamically required surface area but which on the other hand is so designed that the surface area of the rotor blade and therewith the depth thereof can be reduced in predetermined situations a part of the surface of the rotor blade is deformmable or movable.

Abstract: A method for controlling a wind power installation at very high wind speeds, in which there is predetermined a first wind speed at which the rotor blades of the wind power installation are put into a first predetermined setting. In addition, the method includes controlling the wind power installation during an extreme wind situation where the rotor blades moved to a position to reduce, as far as possible, mechanical loadings on the wind power installation caused by the extreme wind situation.

Abstract: A sky turbine, having impeller blades with a plurality of panels that can telescope inward and outward. The pitch of the panels can be adjusted, and the pitch of each panel on a blade, passing from the innermost panel to the outermost panel, differs from the pitch of the previous panel by a certain adjustable amount. The sky turbine is preferably mounted above a city at a sufficiently high elevation that air current will be generally faster than just above the ground. In the preferred embodiments, a wing with two pods is pivotally mounted on a tower. Each pod has front and rear shafts, from which four blades extend. Servomotors cause the wing to turn so that its center of symmetry is parallel to the direction the sky is moving, cause the pitch of the panels of the blades to change, and cause the panels of the blades to telescope.

Abstract: A system and method for providing pressurised oil during non-feathered in-flight shutdown conditions in a variable-pitch aircraft propeller engine. A secondary pump provides pressurised oil substantially independent of an engine main oil circuit.

Abstract: Disclosed is a wind power generating apparatus in which windmill blades are mounted in a multi-stage fashion to a rotating shaft while being spaced apart from one another to efficiently generate wind power. Each windmill blade includes blade bodies mounted to the rotating shaft, and provided with wind pressure adjusting holes, wind pressure adjusting plates coupled to each blade body, and connected together to a wire, each wind pressure adjusting plate being slidable along guides respectively arranged at opposite sides of the associated wind pressure adjusting hole to adjust an opening degree of the wind pressure adjusting hole, elastic members each adapted to connect one end of the associated wire to the associated blade body, and winches each adapted to connect the other end of the associated blade body, the winches being mounted to a single shaft to simultaneously wind or unwind all wire.

Abstract: A pop-off valve that, in one embodiment, provides overboost protection for an aircraft engine, is described. The pop-off valve includes a housing adapted for connection to a portion of a drive device containing a pressure medium. It also includes a pressure body movably disposed in the housing such that, in operation, a first side of the pressure body is exposed to the pressure medium while a second side is exposed to a reference force. In addition, the pop-off valve incorporates a control device adapted to receive at least one signal concerning at least one operating parameter of the drive device and, in response to the operating parameter signal, to control the reference force. As a result of movement of the pressure body within the housing, at least one first opening in the housing is exposed, permitting venting of the pressure medium.

Abstract: A fan blade-hoisting device for ceiling fan comprises a fixed bracket and a revolving unit. Wherein the fixed bracket is fixed to the rotary assembly of the ceiling fan, the revolving unit is connected to the fixed bracket, which is revolvable relative to the fixed bracket, the revolving unit is combined with the fan blade. By such arrangements, the respective fan blade will be drop down in case of stoppage of the ceiling fan, such that enables the user to clean the fan blades easily without damaged caused, while the fan blades will be raised up so as to blow the air in case of the rotation of the ceiling fan.

Abstract: A self-contained variable pitch and/or constant speed propeller including provisions for feathering and reverse pitch operation, wherein no direct contact is required between the fixed engine or airframe and the rotating propeller for effectuation of blade pitch change, therefore eliminating the burdens and complexities general associated with propeller installation, maintenance and blade pitch change operations.

Abstract: An aircraft control system includes a propeller governor in which a stepper motor is used to apply a compression force on a speeder spring, and a turbocharger in which a stepper motor is used to actuate a needle valve associated with a diaphragm cell. An electronic control unit may be used to control the stepper motor in the propeller governor and the stepper motor in the turbocharger. The integration of the propeller governor and the turbocharger into a single control system decreases the number of individual adjustments that must be performed manually by the pilot.

Abstract: A backup governing system for a variable pitch propeller, carried by the propeller hub which is hydraulically interposed between a main control for the propeller and a propeller blade moving, double acting piston, the backup governing system comprising a spool valve including a spool movable between a plurality of metering positions along with first and second opposing springs applying oppositely directed biasing forces to the valve member. A flyweight assembly is connected to the spool and applies a speed dependent valve positioning force to the spool in opposition to a first of the springs and in addition to the second of the springs. A piston valve is operatively associated with the second spring and operable to change the bias applied by the second spring to the spool.

Abstract: Mechanical interfaces in a backup governing system for a variable pitch propeller between stationary and rotatable propeller sections are avoided in a variable pitch propeller system that includes a backup governing system carried by the propeller hub which is hydraulically interposed between a main control for the propeller and a propeller blade moving, double acting piston. The system includes a spool valve including a spool movable between a plurality of metering positions along with first and second opposing springs applying oppositely directed biasing forces to the valve member. A flyweight assembly is connected to the spool and applies a speed dependent valve positioning force to the spool in opposition to a first of the springs and in addition to the second of the springs. A piston valve is operatively associated with the second spring and operable to change the bias applied by the second spring to the spool.

Abstract: A system that allows a boat propeller to maintain a constant blade speed by varying the pitch of the propeller in order to allow the boat's motor to operate at an optimum RPM. The system includes a governor that sends hydraulic fluid to an annular piston, which in turn controls the pitch of the boat propeller blades so that the torque experienced by the engine is kept approximately constant.

Abstract: A variable pitch fan in which the pitch of the fan blades is varied under control of a controller according to the speed of the fan. The controller is programmed to respond to increased fan speed by decreasing pitch of the fan blades. The variable pitch fan has a piston extending axially from a main shaft, about which main shaft a fan blade hub rotates. A pitch shifter is mounted on a cylinder, which itself is mounted on the piston. The pitch shifter is actuated by hydraulic fluid supplied through the main shaft to the cylinder. The piston is preferably axially stationary in relation to the main shaft. The cylinder is secured against rotational movement by cooperating out of round surfaces. Grease for the pitch shifter is supplied through the guide pin. One guide pin may be used for grease supply, while another may be used for excess grease return.

Abstract: An adjustable pitch boat propeller system adapted for mounting on a drive shaft of a marine drive unit of a boat. The propeller includes an hub that has been adapted for mounting over the drive shaft of the boat, the hub having an external surface and internal annular surface. An annular piston is mounted against the internal annular surface and connected to a plurality of blades which are pivotally connected to the external surface of the hub by way of a linkage that allows pivoting the plurality of blades in response to movements of the annular piston.

Abstract: Method and apparatus for controlling an aircraft engine with a single, manually-operable lever includes structure and function for generating a pilot thrust command from the single lever. A processor is coupled to the single lever and (i) receives the generated pilot thrust command, (ii) receives a plurality of detected ambient air flight conditions, (iii) receives a plurality of detected engine performance parameters, (iv) determines first and second engine control commands based on the received pilot thrust command, the detected ambient air flight conditions, and the engine performance parameters, and (v) outputs first and second output signals respectively corresponding to the first and second engine control commands. Preferably, the engine control commands comprise propeller RPM and engine inlet manifold air pressure commands, and the detected ambient air flight conditions comprise air speed and altitude.

Abstract: Method and apparatus for controlling an aircraft engine with a single, manually-operable lever includes structure and function for generating a pilot thrust command from the single lever. A processor is coupled to the single lever and (i) receives the generated pilot thrust command, (ii) receives a plurality of detected ambient air flight conditions, (iii) receives a plurality of detected engine performance parameters, (iv) determines first and second engine control commands based on the received pilot thrust command, the detected ambient air flight conditions, and the engine performance parameters, and (v) outputs first and second output signals respectively corresponding to the first and second engine control commands. Preferably, the engine control commands comprise propeller RPM and engine inlet manifold air pressure commands, and the detected ambient air flight conditions comprise air speed and altitude.

Abstract: A variable pitch fan in which the pitch of the fan blades is varied under control of a controller according to the speed of the fan. The controller is programmed to respond to increased fan speed by decreasing pitch of the fan blades. The variable pitch fan has a piston extending axially from a main shaft, about which main shaft a fan blade hub rotates. A pitch shifter is mounted on a cylinder, which itself is mounted on the piston. The pitch shifter is actuated by hydraulic fluid supplied through the main shaft to the cylinder. The piston is preferably axially stationary in relation to the main shaft. The cylinder is secured against rotational movement by at least one guide pin passing into the main shaft. Grease for the pitch shifter is supplied through the guide pin. One guide pin may be used for grease supply, while another may be used for excess grease return.

Abstract: A fan assembly (10) includes first and second housing sections (70, 72) which, when mated by a first set of fasteners, define a plurality of circumferentially spaced openings (162) that lead to an internal housing chamber (82). The fan assembly (10) also includes a plurality of blade units (140), each of which includes an integral support stem (142) having a journal portion (148) rotatably mounted within a respective one of the openings (162), an enlarged flange portion (144) and a radial post portion (138) rotatably supported by a hub member (106) within the internal chamber (82). Each blade unit (140) preferably has a thrust bearing (156), bushing sleeve (158) and fan blade (152) integrated with the support stem (142), with the fan blade (152) being preferably molded to the support stem (142) following positioning of the thrust bearing (156) and bushing sleeve (158) to form an integral component.

Abstract: An engine plant for aircraft comprising a multicylinder internal combustion engine (1) whose crankshaft drives an adjustable pitch propeller (5), mechanisms for adjusting the engine speed and a common power stick (4) that controls the operation of the engine and of the adjustment mechanisms, characterized in that said engine is a compression ignition engine (1) that cooperates with an electronic control system (3) controlling the quantity of the fuel injected.

Abstract: A propeller is controlled to change pitch at at least two different rates. In one embodiment, an electric motor is provided with a high or low voltage for driving a pitch change mechanism at a high or low change rate. Preferably the rate is selected automatically. Preferably, the high rate is not used unless the current pitch is below a threshold.

Abstract: A system for controlling functions of a propeller having a plurality of blades is disclosed. The system comprises an electronic control for controlling the functions of the propeller. A plurality of backup devices are provided for backing up the electronic control upon the occurrence of conditions. These conditions include at least one of testing, manual override, and a malfunction in the electronic control causing at least one of the functions to endanger safety. The system further includes a bypass device for bypassing the electronic control and for invoking at least one of the plurality of backup devices to acquire control over at least one of the functions. The bypass devices include a mechanism for determining the occurrence of at least one of the conditions and for actuating electronic control override.

Abstract: A marine drive has a propeller rotatable about a drive axis and having a plurality of blades themselves pivotable about respective blade axes projecting generally radially from the drive axis and each movable between a low-pitch end position extending generally parallel to a plane perpendicular to the drive axis and a high-pitch end position extending at a large acute angle to the plane. An engine rotates the propeller about the drive axis at a variable drive speed in a forward rotation direction. The blade axes are so positioned relative to the respective blades that on forward rotation of the propeller the blades are urged into one of their end positions. A single-acting hydraulic actuator connected to the blades has a compartment pressurizable to displace the blades into the other of the end positions.

Abstract: A control for a hydraulic propeller pitch actuator includes a low power pilot valve responsive to digital electronic input signals to control movement of a hydraulic servomotor driving a higher power servovalve. Negative feedback motion is delivered from the servomotor to both the pilot valve and the servovalve.

Abstract: The present invention discloses a main rotor collective pitch control assly for rotary wing aircraft. The assembly uses segmented rotor blades. The collective pitch of each movable segment may be independently varied, or may be adjusted in unison with one or more other segments on the same or different rotor blades. Control inputs may be made manually by the pilot or may be made by a computer which interprets data pertaining to the vibrational level and velocity of each rotor span. The pilot may override the computer in the event of system failure or if otherwise desired.

Abstract: The present invention relates to a ram air turbine which is preferably used in conjunction with a refueling pod on an aircraft for purposes of operating a fuel pump and/or reeling mechanism for paying in and paying out a fuel line. The turbine generally comprises a rotatable housing having a main turbine output shaft disposed therein and rigidly connect thereto. A plurality of variable pitch turbine blades extend outwardly from and are cooperatively engaged to the housing such that rotation of the turbine blades causes simultaneous rotation of the housing and output shaft. Means are provided within the housing for establishing a preset reference rotational speed for the output shaft. Additionally, a control means cooperatively engaged between the turbine blades and the reference means is provided for adjusting the pitch of the turbine blades in response to a difference in the rotational speed of the output shaft and the preset reference rotational speed.

Abstract: A pitch change actuation system is disclosed for adjusting the pitch of a variable pitch propeller blades (120) operatively connected for pitch change to a pitch change actuator piston (140). A pitch change control system (10) is operatively connected to the pitch change actuator piston (140) for selectively pressuring the pitch change actuator piston to effectuate a desired change in the pitch of the propeller blades (120). The pitch change control system (10) comprises a primary electrohydraulic valve (30), a protection valve (60), an electronic controller (20) and a protection solenoid (50). During normal operation, the primary electrohydraulic valve (30) is modulated under control of the electronic controller (20) to effect pitch change.