Abstract: An unmanned aerial vehicle with deployable components (UAVDC) is disclosed. The UAVDC may comprise a fuselage, at least one wing, and at least one control surface. In some embodiments, the UAVDC may further comprise a propulsion means and/or a modular payload. The UAVDC may be configured in a plurality of arrangements. For example, in a compact arrangement, the UAVDC may comprise the at least one wing stowed against the fuselage and the at least one control surface stowed against the fuselage. In a deployed arrangement, the UAVDC may comprise the at least one wing deployed from the fuselage and the least one control surface deployed from the fuselage. In an expanded arrangement, the UAVDC may comprise the at least one wing telescoped to increase a wingspan of the deployed arrangement. The UAVDC may also comprise a foldable propeller blade with a locking mechanism.

Abstract: Horizontal axis wind turbines are provided that have a rotor including a hub having at least one blade extending therefrom. A first rotatable member is coupled to the rotor and configured to rotate in relation to wind-induced rotation of the rotor. A tower supports the rotor and has a base. A second rotatable member is spaced from the first rotatable member toward the base of the tower. An endless member engages the first rotatable member and the second rotatable member to convey a rotational force therebetween. An electrical generator is coupled to the second rotatable member.

Abstract: Provided herein are a fan assembly having improved cooling and heating performance and an air conditioner having the same. The fan assembly provided in an air conditioner includes a plurality of rotating fans provided to be rotatable about the same rotating shaft and at least one fixed fan fixed between adjacent two rotating fans of the plurality of rotating fans.

Abstract: An axleless blade set includes an annular frame and a driving structure. The driving structure serves to drive the annular frame. Blades extend from an inner wall of the annular frame and an outer wall of the annular frame is formed with a plurality of driving sheets. The driving structure serves to drive the driving sheets so as to drive the annular frame and the blades therein to rotate. As a result, wind blows from one side to another side along an axial direction with a large strength. Therefore defects of wind blowing from prior art fans of low strength and dispersing randomly are resolved.

Abstract: An aircraft has a small high-speed propeller used during take-off, climbing and landing maneuvers, and a large collapsible or foldable propeller used for loitering. The large collapsible or foldable propeller is kept in a folded configuration during take-offs and landings to minimize drag and to avoid ground strikes. During loitering operations, the large collapsible propeller is unfolded and used at a lower rotational speed than the smaller high-speed propeller to permit efficient and quite loitering. During loitering operations, the smaller high-speed propeller may be disengaged so as to spin freely or held in a non-rotational position. One or more foldable propellers may be paired with at least one conventional propeller. The propellers may be arranged as twin tractor, tractor-pusher, or nearly any other type of layout on the fuselage or wings, or on pods of the fuselage or wings.

Abstract: An aircraft includes an airframe having an extending tail, and a counter rotating, coaxial main rotor assembly located at the airframe including an upper rotor assembly and a lower rotor assembly. A translational thrust system is positioned at the extending tail and providing translational thrust to the airframe. An active vibration control (AVC) system is located and the airframe and includes a plurality of AVC actuators configured to generate forces to dampen aircraft component vibration, and an AVC controller configured to transmit control signals to the plurality of AVC actuators thereby triggering force generation by the plurality of AVC actuators. A method of damping vibration of an aircraft includes receiving a vibration signal at an AVC controller, communicating a control signal from the AVC controller to a plurality of AVC actuators, generating a force at the AVC actuators, and damping vibration of the aircraft via the generated force.

Abstract: A rotor balance adjustment method includes: an impeller adjustment process of adjusting, with respect to each of the plurality of impellers, a balance of a position of the center of gravity of the impeller by separately adjusting a weight of the impeller before being attached to the rotor main body; a fixing process of fixing the plurality of impellers to the rotor main body after the impeller adjustment process is performed, wherein the plurality of impellers comprises a large-sized impeller that is larger and heavier than the other impellers; an inclination adjustment process of adjusting an inclination of the large-sized impeller with respect to the rotor main body after the fixing process is performed; and a rotor adjustment process of adjusting a balance of a position of the center of gravity of the rotor.

Abstract: What is provided is a propeller guard apparatus that may be readily configured to a variety of different boat motors. Described embodiments of the propeller guard apparatus comprise a cylindrical housing configured to circumferentially enclose a propeller from all sides in order to protect humans, pets, and aquatic wildlife from being entangled or cut by the propeller. Described embodiments of the propeller guard apparatus also comprise a protective structure, such as a skid plate comprising of at least two pieces of metal attached from the cylindrical housing to an end of the outer casing to form a folded T-shaped configuration. This type of configuration serves to protect the propeller from damage caused by submerged objects and aquatic wildlife found in shallow water. Also, the folded T-shaped configuration may push vegetation, weeds, manatees, and other aquatic wildlife away from the path of the moving boat and its propeller.

Abstract: A drive unit provided with at least one powertrain which is equipped with at least two widely spaced operating points for achieving a high rotational speed spread with a high degree of efficiency. A method for controlling the load speed of a corresponding device, specifically, a wind turbine plant is also disclosed.

Abstract: A horizontal-shaft wind machine having improved low wind speed performance and greater overall efficiency consists of multiple rotors, wherein each successive rotor is larger in diameter than the previous rotor moving from the most windward rotor to the most leeward rotor. Each rotor may be coupled to a shroud/diffuser that is displaced axially downwind from the rotor.

Abstract: A horizontal-shaft wind machine having improved low wind speed performance and greater overall efficiency consists of multiple rotors, wherein each successive rotor is larger in diameter than the previous rotor moving from the most windward rotor to the most leeward rotor. Each rotor may be coupled to a separate concentric shaft, and all rotors may rotate in the same direction with the output shafts of each rotor coupled via an overrunning clutch to a single shaft, the output of which is used to drive the load. Winglets attached to the leading edge and tip of the rotor sails improve low wind startup torque.

Abstract: An exemplary apparatus minimizes an aircraft propeller noise having an associated frequency and a corresponding wavelength. A resonant tone produced on the propeller blade elicits a sound with substantially the same frequency as the associated frequency of the offending source. The resonant tone is powered by an inflow of air in or across an aperture of a resonant structure during the rotation of the blade and the aperture has an opening from which the sound is emitted. The resonant structure is dimensioned to generate a sound with substantially the same frequency as the offending source. The aperture is located on the blade with the opening a distance from a target origin of the noise that is substantially one half of the wavelength of the noise so that the sound arrives at the target origin of the noise substantially 180 degrees out of phase with the noise.

Abstract: Generally, a mechanically self-regulating propeller is described which may have a central hub unit disposed around a shaft member, at least two blades coupled to the central hub unit, at least one timing hub coupled to each of the at least two blades, and a hydraulic unit coupled to the at least one timing hub. The at least one timing hub is slidably engaged to the shaft member. When not in use the blades lay substantially parallel to the central hub unit. When the central hub unit is rotated the blades begin to open or fan out to a position that is substantially perpendicular to the central hub unit. The propeller may be used any number of implementations including vehicles, generators, and any other mechanism requiring a propeller or similarly structured device.

Abstract: A gas turbine engine includes a shaft defining an axis of rotation. An outer turbine rotor directly drives the shaft and includes an outer set of blades. An inner turbine rotor has an inner set of blades interspersed with the outer set of blades. The inner turbine rotor is configured to rotate in an opposite direction about the axis of rotation from the outer turbine rotor. A splitter gear system couples the inner turbine rotor to the shaft and is configured to rotate the inner set of blades at a faster speed than the outer set of blades.

Abstract: A rotor system includes a first rotor located at a rotor axis that imparts a first axial load and a first moment, and a first shaft connected to the first rotor at the axis. A first bearing connects a gearbox to the first shaft, transferring the first axial load from the first shaft to the gearbox. A second rotor located at the axis imparts a second axial load and a second moment. A second shaft is connected to the second rotor at the axis, the second shaft coaxial with the first rotor. A second bearing connects the gearbox to the second shaft, transferring the second axial load from the second shaft to the gearbox. A nonrotating standpipe is located at the axis radially between the first shaft and the second shaft. An intershaft bearing located at the standpipe reacts the first and second moments using the first and second bearings.

Abstract: According to at least one exemplary embodiment, an oil-free contra-rotating transmission is disclosed. The contra-rotating transmission may comprise a lower drive unit; and an upper drive unit, wherein the lower drive unit receives power from a motor and is configured to (i) transfer power from the motor to the upper drive unit, and (ii) rotate a first axial fan in a first direction. The upper drive unit may be configured to rotate the second axial fan in a second direction opposite to the direction of rotation of the first direction.

Abstract: A wind turbine station for generating electricity comprising a multi floor structure having open framing. The open framing comprising at least two spaced-apart, open, vertical frames, the frames each made primarily of uncovered beams and columns. The station has a plurality of vertically spaced, horizontal, interior platforms forming the floors of the structure, each interior platform extending between and joined to both of the frames over the length of the frames. Wind turbines are mounted on the structure about the outer periphery of each platform. The wind turbines face outwardly and are each operatively connected to a generator to produce electricity. In a preferred embodiment, the structure has an annular shape with an outer cylindrical or polygonal prism frame and an inner cylindrical or polygonal prism frame spaced from the outer frame. The interior platforms have a flat, ring shape. The invention includes a method for building the station.

Abstract: A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. A speed reduction device such as an epicyclical gear assembly may be utilized to drive the fan section such that the fan section may rotate at a speed different than the turbine section so as to increase the overall propulsive efficiency of the engine. In such engine architectures, a shaft driven by one of the turbine sections provides an input to the epicyclical gear assembly that drives the fan section at a speed different than the turbine section such that both the turbine section and the fan section can rotate at closer to optimal speeds providing increased performance attributes and performance by desirable combinations of the disclosed features of the various components of the described and disclosed gas turbine engine.

Abstract: A coaxial dual-rotor model helicopter system includes a power control mechanism, a transmission mechanism, a control mechanism and a rotor mechanism. The rotor mechanism includes an upper rotor and a lower rotor coaxially installed on an upper side and a lower side of a main shaft and controlled by an inner shaft and an outer shaft for rotating. The control mechanism includes a Bell self-balance mechanism to control the upper rotor and a Bell-Hiller control structure to control the lower rotor. The power control mechanism controls the rotor mechanism through the transmission mechanism and the control mechanism. The present invention achieves balance effect through the upper rotor by employing the Bell self-balance mechanism that has a great stability to provide automatic control. The lower rotor aims to control direction and employs the Bell-Hiller control structure that has a high maneuverability to perform active control.

Abstract: A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. A speed reduction device such as an epicyclical gear assembly may be utilized to drive the fan section such that the fan section may rotate at a speed different than the turbine section so as to increase the overall propulsive efficiency of the engine. In such engine architectures, a shaft driven by one of the turbine sections provides an input to the epicyclical gear assembly that drives the fan section at a speed different than the turbine section such that both the turbine section and the fan section can rotate at closer to optimal speeds providing increased performance attributes and performance by desirable combinations of the disclosed features of the various components of the described and disclosed gas turbine engine.

Abstract: A series fan assembling structure includes a first main body and a second main body. A first reception recess, a first engagement body, a first reception section and a second reception section are respectively disposed in four corners of one end of the first main body. A second reception recess, a second engagement body, a first raised body and a second raised body are respectively disposed in four corners of one end of the second main body. The first and second engagement bodies and the first and second raised bodies are respectively correspondingly latched and engaged with the first and second reception recesses and the first and second reception sections, whereby the series fan can be quickly assembled and the shake can be minimized.

Abstract: An electrical generation system. A floating vessel is anchored in flowing water. Inlets in the hull of the vessel capture flowing water and direct the water to one or more turbines. The system is designed so that all flows are two-dimensional to the extent possible. The latter feature greatly simplifies both design and construction.

Abstract: A rotor assembly includes a yoke operably associated with a rotor blade. The yoke includes a first device and a second device that attach the rotor blade to the yoke. The first device is configured to allow transverse movement of the rotor blade about a chord axis and rotational movement about a pitch-change axis. The second device is configured to allow rotational movement of the rotor blade solely about the pitch-change axis. The method includes rotating rotor assembly about a first plane of rotation, while retaining a relatively stiff out-of-plane rotation and a relatively soft in-plane rotation during flight.

Abstract: A method of producing a turbine engine rotor includes: joining a first rotor disc (25H) and an intermediate member (26) together by electronic beam welding, the first rotor disc (25H) being formed of a precipitation hardened Ni-based superalloy, the intermediate member (26) being formed of a solid solution strengthened Ni-based superalloy; performing age-hardening treatment on the joined body at a first temperature which is a suitable temperature for age-hardening the precipitation hardened Ni-based superalloy; joining the intermediate member (26) and a second rotor disc (25L) together by electronic beam welding, the second rotor disc (25L) being formed of a steel; and performing annealing treatment on the joined body at a second temperature which is a suitable temperature for annealing the steel.

Abstract: One embodiment comprising a motoring propeller (21) attached to a rotatable motoring shaft (22) which in turn is connected to a motor (26) and a generating propeller (23) attached to a rotatable generating shaft (24) which in turn is connected to a generator (25). Operation of the motor (26) results in the motoring propeller (21) to rotate and generate an accelerating slipstream towards the generating propeller (23) which results in the generator (25) rotating to convert recovered rotational energy into other forms of useable energy. The motoring propeller (21) may also be represented as rotating spokes of a wheel rim with the generating propeller (23) situated inside or near the wheel rim space where it freely rotates as a result of the slipstream impacting its blades. The motor (26) may be an electric motor or an internal combustion engine. The generator (25) output is available for charging batteries or powering electrical loads.

Abstract: A series-connected fan frame module includes a plurality of frames, an engaging assembly and an anti-rotation assembly. The frames are arranged in series. The engaging assembly is arranged on each of the frames to couple the frames in series. The anti-rotation assembly is arranged on each of the frames and includes at least one position-fixing member and at least one blocking member arranged on portions of adjacent two of the frames where the adjacent two of the frames are coupled together. The at least one position-fixing member is engaged with the at least one blocking member to prevent relative radial rotation between the adjacent two of the frames.

Abstract: An air vehicle propulsion system incorporates an engine core with a power shaft to drive an outer blade row. The power shaft extends through and is supported by a counter rotation transmission unit which drives an inner blade row in counter rotational motion to the outer blade row. The counter rotation transmission unit exchanges power from the engine core with the shaft. An actuator engages the shaft for translation from a first retracted position to a second extended position.

Abstract: A power generation apparatus for generating power from water flows is described. The power generation apparatus includes: a generator; a first blade set operatively mounted to the generator for rotation in a selected direction in response to flowing water from a selected direction; a second blade set operatively mounted to the generator for rotation and operatively connected to the first blade set, the second blade set being disposed coaxially with, and downstream of or in a wake zone of, the first blade set; wherein the generator is adapted to be driven by at least one of the blade sets, the generator being disposed generally coaxially between the first and second blade sets.

Abstract: A cross flow fan achieves low power input and low noise level by preventing flow separation on an air inlet side and reducing a maximum air velocity in the gap between the blades. At least one of units constituting a cross flow fan is an appearance unit configured such that when the unit is sequentially cut in a direction from one of rings to the other ring along a plane whose normal coincides with a rotation axis, a region S and a region C appear, the radius of a second circle, serving as an inner circumferencial circle (having a radius), in the region S being a first radius of predetermined length, the radius of the second circle, serving as the inner circumferencial circle, in the region C being a second radius shorter than the first radius.

Abstract: A self-starting Savonius wind turbine includes a frame, a rotor assembly that is rotatable about a central axis of rotation and an energy utilizing device operably connected to the rotor assembly. The rotor assembly has at least two rotors, each rotor having at least two rotor blades. Rotation of the rotor assembly is initiated by wind coming from any direction blowing on any one of the plurality of blades. The rotors are configured in a stacked orientation with the blades fixed at a rotated angular position relative to one another to start rotation of the rotor assembly in variable wind conditions. The rotor assembly is made of a composite laminate and the frame is made of a durable, lightweight material. The frame and the rotor assembly are assembled into a single unit for transportation and utilization.

Abstract: A wind power turbine includes a frame, a drag-type fan unit and a lift-type fan unit. The frame has a base, a shaft, an electricity generator and a plurality of air-guiding plates. The air-guiding plates are disposed on the base, and the shaft has one end connected to the electricity generator. The drag-type fan unit has a plurality of drag-type blades coupled to an outer circumference of the shaft. The lift-type fan unit has a plurality of lift-type blades disposed around the drag-type blades. Each of the air-guiding plates has a first side and a second side, and the first and second sides are parallel to the shaft. An air inlet is formed between the first sides of adjacent two of the air-guiding plates, and an air outlet is formed between the second sides of adjacent two of the air-guiding plates. The air inlet is larger than the air outlet.

Abstract: A rotary wing vehicle includes a body structure having an elongated tubular backbone or core, and a counter-rotating coaxial rotor system having rotors with each rotor having a separate motor to drive the rotors about a common rotor axis of rotation. The rotor system is used to move the rotary wing vehicle in directional flight.

Abstract: A turboprop propulsion unit includes at least one pusher propeller 5, 6 driven by an aircraft gas-turbine engine, with the aircraft gas-turbine engine being arranged in front of the pusher propeller 5, 6 in a direction of flight. A turbine outlet area 9 is arranged at the front in the direction of flight and a compressor area 14 faces towards the pusher propeller 5, 6.

Abstract: A rotor stack assembly for a gas turbine engine includes a first rotor assembly and a second rotor assembly axially downstream from the first rotor assembly. The first rotor assembly and the second rotor assembly include a rim, a bore and a web that extends between the rim and the bore. A tie shaft is positioned radially inward of the bores. The tie shaft maintains a compressive load on the first rotor assembly and the second rotor assembly. The compressive load is communicated through a first load path of the first rotor assembly and a second load path of the second rotor assembly. At least one of the first load path and the second load path is radially inboard of the rims.

Abstract: A gas turbine engine includes a spool, a turbine coupled to drive the spool, a propulsor coupled to be driven at a at a design speed by the turbine through the spool, and a gear assembly coupled between the propulsor and the spool. Rotation of the turbine drives the propulsor at a different speed than the spool. The propulsor includes a hub and a row of propulsor blades that extend from the hub. Each of the propulsor blades includes an airfoil body. The leading edge of the airfoil body has a swept profile such that, at the design speed, a component of a relative velocity vector of a working gas that is normal to the leading edge is subsonic along the entire radial span.

Abstract: A rotor structure is provided. The rotor structure includes a plurality of wheels, a main axial tie rod passing through the plurality of wheels and a first shaft and a second shaft each attached to one extremity of the main tie rod, wherein the main tie rod and the bore of an end wheel in contact with one of the first and second shafts delimit a hydraulic chamber configured to receive a hydraulic fluid, and wherein the main tie rod, the hydraulic chamber and the end wheel form an internal hydraulic tension device configured to preload the main tie rod.

Abstract: A centrifugal pump has impellers that are not connected by a central shaft. More specifically, each of the impellers has a separate hub segment that interlocks with an adjacent hub segment from another impeller. The hub segments are rotated in unison with each other to rotate the impellers.

Abstract: A hydraulic turbine engine comprises, between a seat and a succession of turbine stages associated with at least one generator, a guiding block secured to the lower stage of the turbine engine and nested on the seat, said guiding block containing winders for guiding cables, the ends of which are secured to the seat.

Abstract: A counter-rotatable low pressure turbine includes counter-rotatable outer and inner drum rotors. The outer drum rotor is connected to a sole shaft for transmitting torque and power out of the low pressure turbine. Low pressure outer drum turbine blade rows extend radially inwardly from an outer shell of the outer drum rotor. Low pressure inner drum turbine blade rows extend radially outwardly from the low pressure inner drum rotor. The outer drum turbine blade rows are interdigitated with the inner drum turbine blade rows. The drum rotors are geared together through an epicyclic gearbox for transmitting all the torque and power produced by the drum rotors to the shaft. The gearbox may be located aft of the drum rotors. A differential thrust bearing is disposed between the drum rotors. A single stage fan section of an engine is connected to the turbine by the shaft.

Abstract: According to some embodiments, a method and system are provided to receive an airflow at a blower fan via an axial fan, and expel the airflow via a blower fan. The blower fan comprises a hub associated with an axis of rotation, and the axial fan comprises the hub.

Abstract: A fan structure comprises a first impeller and a second impeller, wherein the first impeller is composed of a first annular substrate, a plurality of first ribs and a plurality of first blades. The first ribs and the first blades are formed on the first annular substrate, each of the first ribs comprises an engaging hole, and a first accommodating space is formed between each of the adjacent first blades. The second impeller is composed of a hub, a second annular substrate, a plurality of second ribs, a plurality of second blades and at least one engaging member formed on the second ribs. The second ribs and the second blades are formed on the second annular substrate, and a second accommodating space is formed between each of the adjacent second blades. The first blades and the second blades are arranged in a staggered relationship.

Abstract: A rotor system for a rotorcraft includes a rotor hub having a plurality of rotor blade pairs mechanically coupled to a rotor mast. A pitch link assembly is mechanically coupled to each rotor blade pair for controlling the pitch angle of each rotor blade pair in tandem. Each rotor blade pair has an upper rotor blade and a lower rotor blade. The plurality of rotor blade pairs rotor in a single direction and about a single axis of rotation.

Abstract: This invention provides a vertical axis wind turbine for utilization of wind power for electric generator and mechanical power source which enables big reduction of noise, by supporting a guide vane which section are wing section of aircraft shape to a rotation axis freely for rotation to reduce noise especially when in a condition of strong wind is blowing, by arranging a fixing mechanism to fix the guide vane, and rotors when they become parallel to each other, by adding mechanism to pull down all the wind turbine devices to bottom of a pole-like support, by arranging silencer mechanism composed of flexible member at trailing edge.

Abstract: A mechanical arrangement for an engine having two propeller stages, including: a first epicyclic gear stage including a sun gear, a planet gear, a planet carrier and an annulus, wherein the sun gear is driven by a shaft of the engine, the planet carrier is stationary and thereby permits static structure to be located there through, and the annulus outputs torque and/or drive; a second epicyclic gear stage including a second sun gear, a second planet gear, a second planet carrier and a second annulus, wherein the second sun gear is driven by the annulus of the first epicyclic gear stage and is annular to accommodate the static structure, the second planet carrier includes the output to one of the propeller stages and the second annulus includes the output to the other of the propeller stages; wherein the static structure provides mounting for static components on one or both sides of each epicyclic gear stage.

Abstract: A turbine (5) having at least two sets of co-axially mounted, rotatable blades (10, 15) arranged so that one set cannot eclipse another. Preferably, the sets of blades (10, 15) are contra-rotatable. Each set of blades (10, 15) may be operable to extract similar amounts of energy, thereby to minimise the net reactive torque.

Abstract: Provided is a turbine having a first impingement-type turbine portion and a second impingement-type turbine portion integrated into a rotatable disk, wherein the first impulse-type turbine portion has a plurality chutes and a high contact surface for contacting a working fluid and wherein the second impingement-type turbine portion has a plurality of ducts in an upstream rotor and a plurality of vanes in downstream rotor.

Abstract: A wind turbine for harvesting energy from both horizontal and vertical wind currents having an open frame structure and a central passage through the structure with at least three wind energy harvesting generally vertically disposed and rotatably mounted blades positioned about the central passage and at least three wind energy harvesting generally horizontal blades projecting radially from the central vertical axis of the device. The open frame structure includes a unique rod and cable central structure offset from the periphery of the frame. In one embodiment, the frame structure is suspended from a rotatable hub at the top of a stationary mast.

Abstract: An exemplary fan module includes a main fan and an assist fan. The main and assist fans each include a rotor which includes a hub and a plurality of blades around the hub. The assist fan is located below the hub of the main fan. Inner sides of the blades of the assist fan adjacent to the hub of the assist fan are located within a range of a radius of the hub of the main fan along a radial direction of the rotor of the main fan. Outer sides of the blades of the assist fan away from the hub of the assist fan are located beyond the hub of the main fan along the radial direction of the rotor of the main fan. The blades of the assist fan are pushed to rotate by airflow from the main fan to produce airflow towards a heat sink.

Abstract: A helicopter rotor assembly with vertically staggered blades is disclosed. Each blade travels in a rotational path which does not cross the rotational paths of the other blades. This arrangement reduces noise because each blade travels in a path which avoids turbulent or disturbed air from the preceding blades. In one embodiment, the blades are arranged from the lowermost blade to the uppermost blade such that each blade following the lowermost blade will be above the blade in front of it. Since each blade pushes air down to create lift, this vertically staggered arrangement allows the blades to travel through less disturbed air.

Abstract: The invention relates to a wind power plant, comprising a rotor that can be rotated about a vertical axis, said rotor between two horizontal bearing planes disposed at a distance on top of each other comprising a plurality of rotor blades, which are disposed distributed on a circumferential circle, can each be pivoted about a vertical pivot axis, and the pivot range of which is delimited on both sides by a stop. In such a wind power plant, an improvement in the energy yield, while simultaneously ensuring another operation, is enabled in that the width of the rotor blades is smaller than approximately ? the radius of the circumferential circle.