NL2008227A - Wind turbine having foldable wind engagement surfaces. - Google Patents

Wind turbine having foldable wind engagement surfaces.

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Publication number
NL2008227A
NL2008227A NL2008227A NL2008227A NL2008227A NL 2008227 A NL2008227 A NL 2008227A NL 2008227 A NL2008227 A NL 2008227A NL 2008227 A NL2008227 A NL 2008227A NL 2008227 A NL2008227 A NL 2008227A
Authority
NL
Grant status
Application
Patent type
Prior art keywords
arm
wind
wind turbine
turbine according
substantially
Prior art date
Application number
NL2008227A
Other languages
Dutch (nl)
Other versions
NL2008227C (en )
Inventor
Dick Roest
Original Assignee
Groundtracer B V
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING WEIGHT AND MISCELLANEOUS MOTORS; PRODUCING MECHANICAL POWER; OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D3/00Wind motors with rotation axis substantially perpendicular to the air flow entering the rotor 
    • F03D3/002Wind motors with rotation axis substantially perpendicular to the air flow entering the rotor  axis horizontal
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING WEIGHT AND MISCELLANEOUS MOTORS; PRODUCING MECHANICAL POWER; OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D3/00Wind motors with rotation axis substantially perpendicular to the air flow entering the rotor 
    • F03D3/06Rotors
    • F03D3/062Construction
    • F03D3/067Construction the wind engaging parts having a cyclic movement relative to the rotor during its rotation
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05BINDEXING SCHEME RELATING TO MACHINES OR ENGINES OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, TO WIND MOTORS, TO NON-POSITIVE DISPLACEMENT PUMPS, AND TO GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY
    • F05B2240/00Components
    • F05B2240/20Rotors
    • F05B2240/21Rotors for wind turbines
    • F05B2240/231Rotors for wind turbines driven by aerodynamic lift effects
    • F05B2240/232Rotors for wind turbines driven by aerodynamic lift effects driven by drag
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05BINDEXING SCHEME RELATING TO MACHINES OR ENGINES OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, TO WIND MOTORS, TO NON-POSITIVE DISPLACEMENT PUMPS, AND TO GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY
    • F05B2240/00Components
    • F05B2240/20Rotors
    • F05B2240/30Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
    • F05B2240/31Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor of changeable form or shape
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/70Wind energy
    • Y02E10/74Wind turbines with rotation axis perpendicular to the wind direction

Description

Wind turbine having foldable wind engagement surfacesBACKGROUND

The invention relates to a wind turbine comprisinga hub with arms provided with foldable wind engagementsurfaces. Due to a growing demand for energy worldwide,interest in sustainable energy sources such as wind energyhas peaked. In particular energy service company AllianderB.V. has invested in research in wind turbines forconverting wind energy into rotational energy, and issupporting this invention.

Wind turbines, or wind mills, having foldable windengagement surfaces are known in the art, for instance fromBritish patent no. 4085 which describes a windmillcomprising four collapsible sails adapted for revolvingaround a vertical axis of rotation. Each of the four sailsopens out and collapses alternatively in their rotation asthe force of the wind falls on the front or back of thesail. A drawback of the known windmill is that as the forcesexerted on the axis of rotation due to wind engaging thesails are substantially unbalanced in the horizontal plane,the structure supporting the sails must be of a particularlysolid construction to compensate for this unbalance. As thesize of the sails used increases and thus the torquegenerated by the windmill increases, the significance of drawbacks related to this unbalance, such as the need toprovide a support of a robust construction and the wear ofbearings which support rotation of the sails, increases aswell. It is an object of the present invention to provide awind turbine with foldable wind engagement surfaces, whichis substantially more balanced in the horizontal plane.

SUMMARY OF THE INVENTION

According to a first aspect, the presentinvention provides a wind turbine for converting a stream ofwind blowing in a first direction into rotational energy,comprising a support rotatable around a substantiallyvertical axis, a hub connected to said support and rotatablearound a substantially horizontal axis, a plurality of armsextending substantially radially from said hub; each armprovided with a foldable wind engagement surface comprisinga folding line substantially in a plane normal to thehorizontal axis, wherein said wind engagement surface isadapted for folding about said folding line between anunfolded position when said engagement surface is locatedsubstantially upstream from its arm and a folded positionwhen said engagement surface is located substantiallydownstream from its arm; a wind alignment member adapted forrotating said support around its vertical axis for aligningthe horizontal axis substantially perpendicular to saidfirst direction; and wherein the wind engagement surface ofeach arm is adapted for folding to the unfolded positionwhen said arm is located on a side of the hub facing awayfrom said support.

In the unfolded position, each wind engagementsurface thus forms a wind scoop to be filled with wind andcapable of exerting large amounts of torque on the hub. Thewind alignment member ensures that each wind engagementsurface which is located above the hub and upstream from itsrespective arm with respect to the wind stream, in particular located at a highest position said windengagement surface may reach above the hub, is arranged forat least substantially unfolding due to the force exertedthereon by the wind. Wind drag of the wind engagementsurfaces which move in a direction against the firstdirection is minimized by at least partially folding thesesurfaces. As the wind engages the wind engagement surfacessubstantially head-on, driving rotation of the windengagement surfaces around the horizontal axis of rotation,unbalance of the wind turbine according to the invention isin the horizontal plane of the axis of rotation isminimized, allowing the use of a more light weight supportor more light weight bearings between the support and thehub. Additionally, as the wind engagement surfaces arearranged for folding when located downstream of theircorresponding arms, i.e. when at a lower position, inparticular located below a horizontal plane defined by saidhorizontal axis of rotation, the amount of space required bythese wind engagement surfaces along said horizontal axis atsaid lower position is reduced, reducing the amount of spacerequired by both the support and the wind engagementsurfaces along said horizontal axis.

The folding line of each wind engagement surfaceis preferably oriented substantially parallel to itsrespective arm such that the wind engagement surface may beattached to said arm, with the area or points of attachmentbetween the wind engagement surface and arm defining saidfolding line.

In an embodiment said arms are arranged on the hubat a first distance from the support along the horizontalaxis, and wherein the width along the horizontal axis ofpart of the wind engagement surface located between thefolding line and the support is greater than said firstdistance when the wind engagement surface is in the unfoldedposition, and smaller than said first distance when the windengagement surface is in the folded position.

The arms which are provided with the wind engagement surfaces may thus rotate close to the support, in particularcloser to the support than the width of the wind engagementsurface along the horizontal axis when the wind engagementsurface is in the unfolded position. The shorter distancebetween the arms and the support allows the use of a supportof a light-weight construction and/or the use of lighterbearings between the support and the hub.

Although, in an embodiment, the wind turbinecomprises a single support element substantially arranged onone side of the hub and plurality of arms, in a preferredembodiment the support comprises a first support element anda second support element, wherein the hub is arrangedbetween said first and second support element, and whereinsaid first and second support elements are arranged spacedapart from each other at a distance which is less than amaximum width of the wind engagement surface along saidhorizontal axis of rotation when in the unfolded position.The rotating hub is thus supported one two sides by thefirst and second support structures, forming a substantiallybalanced construction. Preferably, the center of mass of thehub and arms is arranged between the first and secondsupport elements.

In an embodiment the wind engagement surfaces ofsaid arms are arranged for passing between the first andsecond support element in a direction towards the firstdirection in the folded position. The distance between thefirst and second support element may thus be substantiallyless than the width of the wind engagement surfaces alongthe horizontal axis of rotation when unfolded. Preferablythe wind engagement surfaces of said arms are adapted forfolding just prior to passing between the first and secondsupport element.

In an embodiment the wind engagement surfaces ofsaid arms comprise a flexible material, preferably aflexible sheet or sail. Such wind engagement surfaces areeasily manufactured and also easily adapt to form a concavesurface when filled with wind, for instance when the surface is arranged substantially upstream from its respective arm.

In an embodiment the wind engagement surfaces ofsaid arms comprise a resilient material. Thus, the shape ofsuch a wind engagement surface, and in particular themaximum width thereof along the horizontal axis of rotationof the hub during relatively low wind conditions, may bepredetermined. Preferably, the resilient material of a windengagement surface is biased towards a neutral position inwhich the width of the wind engagement surface along thehorizontal axis is less than when the wind engagementsurface is in the unfolded position, in particular in whichsaid width is less than a distance between the first andsecond support elements. The wind engagement surface maythus pass between the first support element and the secondsupport element even in relatively low wind conditions.Preferably each wind engagement surface is substantiallyformed as a single piece.

In an embodiment, when projected onto a verticalplane parallel to the horizontal axis of rotation, said windengagement surfaces of said arms are adapted for having afirst area when at a highest position, and a substantiallysmaller second area when at a position below a horizontalplane defined by the horizontal axis of rotation of the hub.The force which is exerted by the wind on a wind engagementsurface which is in the highest position is thus larger thanthe force exerted by a wind engagement surface located belowsaid horizontal plane, resulting in rotation of the hubaround the horizontal axis.

In an embodiment, at least in the unfoldedposition, the width of the wind engagement surfaces of saidarms along the axis of rotation substantially increases withthe distance from horizontal axis of rotation. The windengagement surfaces are thus adapted for generating largeamounts of torque. Preferably, the wind engagement surfaces,when unfolded and projected onto a vertical plane parallelto the axis of rotation, are substantially triangular inshape, preferably mirror-symmetrical in their corresponding arm, with one corner or corner section of the triangularshape pointing towards the horizontal axis of rotation, andtwo other corners or corner sections defining a line whichis substantially parallel to the horizontal axis ofrotation.

In an embodiment said wind engagement surfaces ofsaid arms further comprise one or more reinforcementelements. Preferably the reinforcement elements extend alongone or more outer edges of the wind engagement surfaces,and/or extend from an arm to one or more outer edges of itsassociated wind engagement surface. In the latter case, thereinforcement elements preferably extend substantiallyperpendicular from said arm. Such reinforcement elements areparticularly advantageous when used in combination with aflexible wind engagement surface, for example a windengagement surface made of sail cloth or made of a foil.

In an embodiment a said wind engagement surface ofan arm of said plurality of arms comprises a first portionand a second portion, wherein said portions are arranged onopposing sides of said arm. Preferably the first and secondportions each are formed from a plate like material and/or aflexible wind engagement surface, for example a windengagement surface made of sail cloth or made of a foil.

In an embodiment said first and second portions,in particular when formed from a substantially rigid platelike material, are hingeably connected to said arm.

In an embodiment the wind turbine furthercomprises limiting structures for limiting the opening angleof a said wind engagement surface when in the unfoldedposition, preferably such that the angle of incidence of thewind stream on said wind engagement surface is less than 90degrees for all or a substantial part of the wind engagementsurface. When an unfolded wind engagement surface forms asubstantially concave surface facing with its concave sidetowards the wind stream, the limiting structures thus helpin maintaining the concave shape. A concave shape, or scoop¬like shape, is particularly desirable, as it substantially traps the wind stream, allowing a relatively high portion ofthe wind force to be converted into a rotational force.

In an embodiment the limiting structures comprisea link connecting sections of a wind engagement surface ofan arm of said plurality of arms to each other, wherein saidsections are arranged on said wind engagement surface onopposite sides of said arm. Preferably the sections comprisea first section at a first corner at an edge of the windengagement surface opposite from the hub, and a secondsection at a second corner at an edge of the wind engagementsurface opposite from the hub. The link may comprise a wireor chain or the like.

In an embodiment the hub is arranged for rotatingin a direction of rotation, wherein said limiting structurescomprise at least two links connecting sections of said windengagement surface of an arm to a neighboring arm arrangedcounter to the direction of rotation on the hub, whereinsaid sections are arranged on opposite sides of said arm. Inthis embodiment the extent to which one of the sections maymove relative to the arm is independent on the extent theother of the sections moves relative to the arm. Instead ofbeing connected to a neighboring arm, the links may beconnected to a beam extending radially from the hub andarranged between the arm and the neighboring arm. The beamis not necessarily provided with wind engagement surfaces.

In an embodiment said wind engagement surfaces ofeach of said arms are substantially mirror-symmetrical alongtheir respective arms. Thus, when the wind stream isdirected substantially perpendicular to the horizontal axisof rotation, the force exerted thereby on the wind turbine,in particular on the first and second support elementthereof is substantially balanced in the horizontal plane.

In an embodiment each arm comprises a first endconnected to said hub, and an opposite second end, whereintwo neighboring arms are connected to each other by aconnecting element connected to the respective second endsof said neighboring arms. By neighboring arms are meant neighboring arms along the circumference of the hub. Theconnecting elements according to this embodiment providefurther stability to the arms.

In an embodiment each of said arms is providedwith one or more further wind engagement surfaces eachcomprising a folding line substantially in a plane normal tothe horizontal axis, wherein said one or more further windengagement surfaces are adapted for folding about theirrespective folding lines between an unfolded position whensaid one or more further engagement surfaces are locatedsubstantially upstream from its arm and a folded positionwhen said one or more further engagement surfaces arelocated substantially downstream from its arm, wherein saidone or more further wind engagement surfaces of said arm arearranged at different positions along the length of saidarm. Thus each arm comprises multiple smaller windengagement surfaces which may easily fold and unfold, whilemaintaining a large total wind engagement surface.Preferably, the folding lines of all wind engagementsurfaces of an arm are substantially collinear.

In an embodiment said further wind engagementsurfaces of an arm comprise a trailing side for engaging thewind when in the unfolded position, wherein when viewingsaid trailing side a wind engagement surface of said furtherwind engagement surfaces is partially overlapped by aneighboring wind engagement surface of said further windengagement surfaces. Preferably, when viewed from thetrailing side, neighboring wind engagement surfaces of saidfurther wind engagement surfaces which are located fartheraway from the hub are partially in front of a neighboringwind engagement surface of said further wind engagementsurfaces located closer to the hub. Thus, wind engagementsurfaces located father from the hub may unfold when theneighboring wind engagement surface closer to the hubremains in the folded position, without the latter blockingunfolding of the first. Preferably, the further windengagement surface are attached with their trailing side to the arm, wherein the further wind engagement surfaces whichare located farther away from the hub are arranged partiallybetween the arm and a wind engagement surface of saidfurther wind engagement surfaces located closer to the hub.

In an embodiment, at least when in the foldedposition, said wind engagement surfaces of an arm arrangedfarther from the hub are at least partially surrounded bywind engagement surfaces arranged closer to the hub whenviewed in a plane normal to said arm.

In an embodiment said wind engagement surfaces ofsaid am are arranged for at least partially abuttingneighboring wind engagement surfaces of said wind engagementsurfaces when in the unfolded position. Thus, in theunfolded position the wind engagement surfaces together forma substantially contiguous surface.

In an embodiment said one or more further windengagement surfaces or said wind engagement surface withsaid one or more further wind engagement surfaces arearranged for folding and/or unfolding around the arm to forma substantially contiguous concave surface.

In an embodiment said further wind engagementsurfaces of an am of said arms each comprise first andsecond corner sections arranged on opposite sides of saidarm and connected via links to a distal end of a beam,wherein said beam is rotation fixedly coupled to the hub andwherein said distal end of the beam is spaced apart fromsaid arm on a trailing side of said arm. The beam, which mayextend from the hub, or may extend from the arm itself, forinstance from a distal end of said arm, provides a rotationfixed point relative to the arm for attaching the links to.The links, e.g. wires or cables, together with the beamlimit the opening angle of the further wind engagementsurfaces and help in maintaining the concave shapes of thewind engagement surfaces when unfolded.

In an embodiment said wind engagement surface isattached to the arm by means of a clamping element, whereinpreferably said clamping element is arranged on a leading side of the arm. The clamping element may for instance bebolted to or screwed against the arm, with the bolts orscrews extending through holes in the wind engagementsurface. When the wind engagement is arranged on a trailingside of the arm and the clamping element is arranged on aleading side of the arm, the clamping element may easily betightened of loosened from a position outside the volumespanned by the wind engagement surface, facilitatingattaching or detaching a wind engagement surface from itsarm. In a preferred embodiment in which the clamping elementextends along substantially the entire length of said windengagement surface along said arm, no holes in the windengagement surface are required for attaching the windengagement surface to an arm.

In an embodiment the clamping element extendsalong substantially the entire length of said windengagement surface or surfaces along said arm. As theclamping force on the wind engagement surface is distributedover the length of the arm instead of over a single point ora number of single points, tearing of the wind engagementsurface is substantially prevented.

In an embodiment the wind turbine comprises adevice which is driven by rotation of the rotors. The devicepreferably comprises a mechanical device such as a pump,e.g. for pumping water, or an electrical device such asdynamo, e.g. for generating electricity from said rotationalmovement of the rotors. Preferably, the device is comprisedon or within the support of the wind turbine.

According to a second aspect the present inventionprovides a use of a wind turbine according to the invention,for driving a device, preferably a mechanical or electricaldevice. The rotational energy supplied by the wind turbinemay thus be used to drive a mechanical device such as apump, e.g. for pumping water, or an electrical device suchas dynamo, e.g. for generating electricity.

The various aspects and features described andshown in the specification can be applied, individually, wherever possible. These individual aspects, in particularthe aspects and features described in the attached dependentclaims, can be made subject of divisional patentapplications.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis ofan exemplary embodiment shown in the attached drawings, inwhich:

Figure 1 shows a schematic side view of a firstembodiment of a wind turbine according to the present invention, figure 2 shows a schematic front view of the windturbine of figure 1, figure 3 shows a schematic side view of a secondembodiment of a wind turbine according to the present invention, figure 4 shows a schematic front view of the windturbine of figure 3, figures 5A and 5B shows a detail of an arm and awind engagement surface as used in two respective embodiments of the invention, figures 6A, 6B and 6C show a cross-sectional viewof a wind engagement surface as used in an embodiment of theinvention, in a neutral, unfolded and folded position respectively, figures 7A, 7B and 7C show a cross-sectional viewof an alternative wind engagement surface as used in anembodiment of the invention, in a neutral, unfolded andfolded position respectively, figure 8A shows a front view of an arm providedwith multiple wind engagement surfaces as used in anembodiment of the invention, figure 8B shows a cross-sectional side view of thearm of figure 8A along line VIII B - VIII B.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a schematic side view of a firstembodiment of a wind turbine according to the invention. Thewind turbine 1 comprises a support 2 comprising a supportelement 4 and which is rotatably connected to a base 6,which base is arranged on a ground surface 7. At an end ofthe support 2 opposite from the base 6, the wind turbinecomprises a hub 8, which is rotatably connected to thesupport element 4 and has a substantially horizontal axis ofrotation L. A plurality of arms 10,11,12,13 extend radiallyfrom the hub 8 and are provided with respective windengagement surfaces 14,15,16,17. Each arm 10,11,12,13 eachcomprises a first distal end connected to the hub 8, and anopposite, second distal end 10a,11a,12a,13a. The seconddistal ends 10a, 11a, 12a, 13a of neighboring arms 10,11/11,12; 12,13; and 13,10, i.e. neighboring along the direction of rotation D around the horizontal axis orrotation L, are connected to each other by means ofconnecting elements, or wires 21,22,23,24, which provideadditional stability to the arms. The wires also substantially prevent excessive bending of the arms due towind force exerted on their corresponding wind engagementsurfaces, e.g. excessive bending of arm 10 due to wind forceW exerted thereon through wind engagement surface 14 isprevented by means of wire 24 which connects arm 10 to arm13.

The wind engagement surfaces 14,15,16, and 17 areeach adapted for folding about corresponding a folding linewhich extends in a plane normal to the axis of rotation L,and in the embodiment shown is substantially parallel toarms 10,11,12 and 13 respectively. The wind engagementsurfaces 14,15,16,17 comprise corner sections 14a,14b;15a,15b; 16a,16b; 17a,17b respectively, which are spaced apart from their respective arms 10,11,12 and 13, and located on opposite sides of said arms. In the view shown,corner sections 16b and 17b of wind engagement surfaces 16and 17 are obscured by corner sections 16a,17b as these windengagement surfaces 16,17 are in a substantially closedposition.

Corner sections 14a and 14b are connected viawires 30a,30b respectively to neighboring arm 13. Theneighboring arm 13 is the arm which neighbors arm 14 in adirection counter to the direction of rotation D along thecircumference of the hub 8. Likewise, corner sections15a,15b are connected via wires 31a,31b to neighboring arm10, and wires 32a,32b and 33a,3b connect corner sections16a, 16 and 17a, 17b to neighboring arms 11 and 12 respectively. The wires 30a,30b,31a,31b,32a,32b,33a,33blimit an opening angle, i.e. a maximum folding angle, of thefoldable wind engagement surfaces 14,15,16,17.

The support 2 comprises a wind vane 3 and is arranged rotatably on said base 6 around a vertical axis R.The wind vane 3 is adapted for aligning the support 2 torotate around the vertical axis R such that the horizontalaxis of rotation L of the hub is substantially perpendicularto the first direction W in which the wind stream is blowing, and that wind engagement surfaces are arranged driving the hub 8 to rotate around direction D. In theembodiment shown, the support 2 is aligned such that upperwind engagement surface 14 which faces the first direction Win which the stream of wind is blowing and is arranged substantially upstream relative to the first direction fromits arm 10, is engaged by the wind stream such that the windengagement surface 14 is forced into a substantiallyunfolded position. The force of the wind stream on theunfolded wind engagement surface 14 imparts a rotatingmotion along the direction D on the hub 8.

Figure 2 shows a schematic front view of the windturbine 1 of figure 1 along the first direction W, howeverwith arm 13 left out for reasons of clarity. The manner inwhich the wind engagement surfaces 14, 15, and 16 have folded or unfolded is visible in particular. The support 2comprises two upright support elements 4,5, which are spacedapart from each other and between which the hub 8 supported.Wind engagement surface 14 is shown in an unfolded position,in which it forms a substantially concave surface, or windscoop, facing with its concave side towards direction inwhich the wind is blowing, i.e. first direction W of figure1. Much of the wind caught by the wind engagement surface 14may leave said surface its distal edges 34a and 34b. Whenprojected on a plane normal to the wind direction W, asshown in figure 2, the area of the wind engagement surface14 is substantially larger than the area of wind engagementsurface 16 which is located at a lower position. As aresult, the force exerted by wind engagement surface 14 onthe hub 8 in the direction D (see figure 1) is substantiallylarger than the force exerted by wind engagement surface 16on the hub counter to direction D, and the hub will rotatein direction D. Additionally, though in the projection shownthe width of wind engagement surface 14 in the unfoldedposition is larger that the distance between the first andsecond support elements 4,5, engagement surface 16 hasfolded to a folded position due to force exerted thereon bythe wind, and in this folded position is adapted for easilypassing between the first and second support elements 4,5.In other words, the width of the wind engagement surface 16in the folded position is substantially less than thedistance between the first and second support element 4,5.The triangular shape of the wind engagement surface 14 whenin the unfolded position allows it to generate large amountsof torque, i.e. a substantially larger torque than if asurface having an equal length along the arm 10 and a widthequal to distance between the first and second supportelements were used instead.

Figure 3 shows a schematic side view of a secondembodiment of a wind turbine according to the presentinvention. Like elements as shown in the turbine of figures1 and 2 are indicated using the same reference numerals. The wind turbine 50 of figure 3 differs from the wind turbine 1of figures 1 and 2 in that the opening angle of the windengagement surfaces 14,15,16,17 is limited by means of wires51,52,53,54 respectively. The wires 51,52,53,54 areconnected to corner sections 14a,14b; 15a,15b; 16a,16b;17a,17b which are arranged on engagement surfaces14,15,16,17 on opposite sides of their respective arms10,11,12,13.

Figure 4 shows a schematic front view of the windturbine of figure 3 along the first direction W, in whicharm 13 has been omitted for reasons of clarity. The wires51, 52 are substantially taut and limit the opening angle ofthe wind engagement surfaces 14 and 15 respectively. Thelength of wire 51 is less than the sum of the lengths ofedges 34a,34b which are proximate to the second distal end10a of arm 10. As a result, when the wire 51 is taut and thewind engagement surface 14 is located upstream from its arm10 with respect to the wind stream W, the wind engagementsurface 14 forms a concave surface with its concave sidefacing the first direction W.

Wires 51,52,53,54 limit the maximum opening anglesof the wind engagement surfaces 14,15,16 and 17respectively, in particular to the extend that these anglesdo not exceed 180 degrees. When the wind engagement surfacesare not completely unfolded or are in a substantially foldedposition, as is the case for the wind engagement surfaces 16and 17 of arms 12 and 13 (see figure 3), the wiresconnecting 53,54 the corresponding corner sections aresomewhat slack. In an alternative embodiment, the wires maycomprise an elastic material.

Figure 5A shows a detail of an arm 100 for use inan embodiment of a wind turbine according to the invention,the arm 100 is provided with a wind engagement surface101a, 101b, for use in an embodiment of a wind turbineaccording to the invention. The arm 100 comprises a lightweight material and substantially supports the windengagement surface 101a,101b. The wind engagement surface comprises of a first portion 101a and a second portion 101b,both portions hingeably connected to the arm 100 by means ofhinge 120. Both the first portion 101a and the secondportion 101b are substantially rigid, such that any foldingaction is substantially completely provided by the hinge120. The corner sections 114a, 114b of the first and secondportions 101a,101b which corner sections are spaced apartfrom the arm 100 can be used for attaching wires forlimiting an opening angle, i.e. a maximum folding angle,between the first and second portions 101a,101b. The wiresmay for instance connect the corner sections 114a,114b ofthe wind engagement surface 101a, 101b of the arm 100 to anneighboring arm in the direction counter to the direction ofrotation, in a similar fashion as the wires30a,30b,31a,31b,32a,32b, 33a, 33b of figure 1, and/or thewires may connect the two corner section 114a, 131b of thewind engagement surface 101a,101b to each other, in asimilar fashion as the wires 51,52,53,54 of figure 3.

Figure 5B shows an alternative arm 150 for use inan embodiment of a wind turbine according to the invention.The arm 150 comprises a contiguous wind engagement surface151a,151b comprising first and second portions 151a,151bwhich are formed as a single piece and comprise a flexiblesheet material, such as sail cloth or a polymer sheet orfoil. When using a flexible sheet material, the first andsecond portion 151a, 151b need not be hingeably connected,because the folding action can occur in the flexiblematerial.

Reinforcement elements 155a,155b are attached toan end 150a of the arm 150 opposite from the end of the armconnected to the hub, and function to maintain thesubstantially triangular shape of the wind engagement firstand second portions 151a,151b. The shape of the first andsecond portions 151a,151b is further maintained byreinforcement elements 154 which extend substantially fromthe arm 150 towards outer edges 152a and 152b of respectivewind engagement surfaces 151a and 151b.

Figure 6A shows a cross-sectional view of a windengagement surface 201 for use in an embodiment of a windturbine according to the invention, along a plane normal toan arm 200 to which said surface is attached. The windengagement surface comprises a single sheet 201 of aresilient material which is fixedly attached along a foldingline 202 to the arm 200, which folding line is substantiallyparallel to said arm 200. The wind engagement surface isadapted for folding about said line 202. In figure 6A, thewind engagement surface is shown in a neutral position, i.e.the position the wind engagement surface would assume whenthere is substantially no force due to wind and/or gravityacting thereon.

In figure 6B the same wind engagement surface 201is shown in an unfolded position, as would be the case whenthe wind engagement surface 201 is located upstream from itsarm 2 00, such that the wind stream W pushes the windengagement surface 201 to the unfolded position, as shown.The neutral position of the wind engagement surface is shownin dotted lines. When a wind stream W is blowing, thealignment member of the wind turbine according to theinvention cause the horizontal axis of rotation of the hub(see figures 1 and 3) to be substantially perpendicular tosaid wind stream W. As a result, any wind engagement surfacelocated in a relatively high position, i.e. substantiallyabove a horizontal plane defined by the horizontal axis ofrotation of the hub, will be arranged upstream of its armwith respect to the wind stream, and the wind will causesaid wind engagement surface to unfold.

In figure 6C the wind engagement surface 201 isshown in a folded position, as would be the case when thewind engagement surface 201 is located downstream from saidarm 200, such that the wind stream W pushes the windengagement surface 201 to the folded position, as shown.Typically, when a wind turbine according to the invention isproperly aligned to the first direction in which the wind isblowing as described above, the situation shown in figure 6C

occurs when the wind engagement surface is locatedrelatively low, i.e. below a horizontal plane defined by thehorizontal axis of rotation of the hub.

Figures 7A-7C show wind engagement surfaces insimilar positions as the wind engagements surfaces offigures 6A-6C respectively. However, in figures 7A-7C thewind engagement surface 301 is partially folded around thearm 300, and fixed against the arm by means of clamp 311which extends parallel to the arm 300. This has severaladvantages. First, when the clamp 311 extends alongsubstantially the entire length of the wind engagementsurface along the arm, the wind engagement surface 301 ispressed against the arm 300 over substantially the entirelength of the clamp 311 facing the arm, avoiding singlepoints of stress on the wind engagement surface 301.Secondly, the wind engagement surface 301 may be clamped tothe arm 300 without requiring holes in the wind engagementsurface for attaching it to the arm. In case some holes areprovided in the wind engagement surface 301 for fixing theclamp 311 to the arm, the force for fixing the windengagement surface to the arm is exerted along the length ofthe entire clamp 311, instead of just on the holes in thewind engagement surface. Third, the wind engagement surface301 may easily be removed from or attached to the arm 300 byloosening the clamp, removing and/or attaching a windengagement surface, and the tightening the clamp. This maybe done from a side of the wind engagement surface 301facing away from both the arm 300 and the concave side ofthe wind engagement surface 301.

In figure 7A the wind engagement surface 301 isshown in a neutral position, in which it has a substantiallyconcave shape facing the arm 300 with its concave side.

In figure 7B and 7C the wind engagement surface301 is shown in its unfolded and folded positionrespectively. The wind engagement surface 301 is folded fromthe folded position to the unfolded position and vice versaalong fold lines 302 and 303 which are parallel to the arm 300. Thus, in the unfolded position shown in figure 7B thesurface area for engaging the wind W is substantially largerthan in the folded position shown in figure 7C. In bothfigures dotted lines indicate position of the windengagement surface when in the neutral position.

Figures 8A and 8B show a front view and a cross-sectional side view respectively of an arm 910 for use in anembodiment of a wind turbine according to the invention. Thearm 910 comprises multiple wind engagement surfaces921,922,923,924,925,926 arranged at different positionsalong the length of the arm 910. The wind engagementsurfaces are shown in an unfolded position facing a firstdirection for engaging a stream of wind W, and in figure 8Awith only their trailing sides shown. The arm 910 isconnected to a hub 908 which is rotatable in direction D(see figure 8B) around the substantially horizontal axis ofrotation L. The wind engagement surfaces921,922,923, 924,925, 926 are attached to the arm 910 in anoverlapping manner along the length of the arm, such that,when viewed along the direction of rotation D as shown infigure 8B, wind engagement surfaces located closer to thehub 908 are at least partially behind neighboring windengagement surfaces on the arm 910 farther from the hub. Thewind engagement surfaces are substantially mirror-symmetrical in a plane of rotation of the arm 910 around theaxis of rotation L and attached in said plane of rotation tothe arm 910. The wind engagement surfaces 921, ..., 926 eachcomprise two corner sections 921a, 921b;.../926a, 926b, arrangedon either side of the arm 910 and spaced apart there from.The corner sections of the wind engagement surfaces921,..., 926 move relative to the arm 910 when the windengagement surfaces fold or unfold. Respective links931a, 931b; ...; 936a, 936b connect the corner sections921a, 921b; ...; 926a, 926b of the wind engagement surfaces to adistal end 940 of a beam 911 which is rotation fixedlyconnected to the hub 908 and extends radially there from.The links, for instance flexible links such as wires, form limiting structures which limit the opening angle of therespective wind engagement surfaces. In yet anotheralternative embodiment the links are connected to a distalend of a neighboring arm counter to the direction ofrotation D instead, and the beam may be omitted.

Figure 8B shows a cross-sectional side view of thearm 910 along line VIII-B - VIII-BB of figure 8A. The links931a, 932a, 933a, 934a, 935a, 936a connect the corner sections ofthe wind engagement surfaces to the distal end 940 of beam911, which distal end 94 0 is spaced apart from the hub 908.The links limit the extent to which the wind engagementsurfaces 921,922,923,924,925,926 can unfold, and togetherwith the links 931b, 932b, 933b, 934b, 935b, 936b shown in figure8A ensure that said wind engagement surfaces 921,..., 926 eachmaintain a substantially convex shape when engaged by a windstream directed in the first direction W.

When a stream of wind W engages the windengagement surfaces 921,...92 6, which are shown arrangedsubstantially upstream of the arm 910, each wind engagementsurface forms a convex surface, or scoop, for catching thewind, and the links 931a, 931b; ...; 936a, 936b become taut tolimit the extent to which the wind engagement surfacesunfold. When the wind engagement surfaces921,922,923,924,925,926 are located substantially downstreamof the arm 910, i.e. downstream of the wind stream which isdirected in the first direction W, the wind engagementsurfaces fold to a folded position, and the links may becomeslack. Though in the embodiment shown, the beam 911 extendsradially from the hub, it will be appreciated that the beammay alternatively extend from the arm 910, preferably in adirection substantially perpendicular to said arm, as longas the beam to provides a point of attachment for the links931a, 931b;...; 936a, 936b which is rotationally fixed relativeto the hub 908.

It is to be understood that the above descriptionis included to illustrate the operation of the preferredembodiments and is not meant to limit the scope of the invention. From the above discussion, many variations willbe apparent to one skilled in the art that would yet beencompassed by the spirit and scope of the presentinvention.

Claims (26)

  1. 1. Windturbine voor het omzetten van een windstroom die in een eerste richting blaast naarrotationele energie, omvattend: een ondersteuning draaibaar rond een in hoofdzaakverticale as; 1. A wind turbine for converting wind a current flowing in a first direction blows naarrotationele energy, comprising: a support rotatable about a substantially vertical axis; een naaf verbonden met de ondersteuning endraaibaar rondom een in hoofdzaak horizontale as; a hub connected to the support endraaibaar about a substantially horizontal axis; een veelvoud aan armen die zich in hoofdzaakradiaal vanuit de naaf uitstrekken, waarbij elke arm isvoorzien van een vouwbaar windaangrijpoppervlak omvattendeen vouwlijn in hoofdzaak in een vlak normaal aan dehorizontale as, waarbij het windaangrijpoppervlak is ingericht om te vouwen om de vouwlijn tussen een uitgevouwenpositie wanneer het aangrijpoppervlak in hoofdzaak geplaatstis stroomopwaarts van zijn arm en een gevouwen positiewanneer het aangrijpoppervlak geplaatst is in hoofdzaakstroomafwaarts van zijn arm; a plurality of arms that extend substantially radially from the hub, wherein each arm isvoorzien of a foldable windaangrijpoppervlak include dane fold line is substantially in a plane normal to dehorizontale axis, the windaangrijpoppervlak is adapted to fold about the fold line between an unfolded position where the engaging surface geplaatstis substantially upstream of its arm, and a folded position when the engaging surface is disposed in hoofdzaakstroomafwaarts of its arm; een winduitlijnelement ingericht om de ondersteuning te draaien rond zijn verticale as om dehorizontale as in hoofdzaak loodrecht op de eerste richtinguit te lijnen; a winduitlijnelement adapted to rotate the support about its vertical axis to dehorizontale axis substantially perpendicular to the first lines to richtinguit; en waarbij het windaangri jpoppervlak van elke arm isingericht om te vouwen naar de uitgevouwen positie wanneerde arm is geplaatst aan een zijde van de naaf die van deondersteuning is afgekeerd. and wherein the windaangri jpoppervlak isingericht of each arm to fold is placed into the folded-out position wanneerde arm to a side of the hub which faces away from deondersteuning.
  2. 2. Windturbine volgens conclusie 1, waarbij de armen op de naaf zijn gerangschikt op een eerste afstand tot de ondersteuning langs de horizontale as, en waarbij debreedte langs de horizontale as van deel van het windaangrijpoppervlak dat tussen de vouwlijn en deondersteuning is geplaatst groter is dan de eerste afstandwanneer het windaangrijpoppervlak in de uitgevouwen positie is, en kleiner dan de eerste afstand wanneer hetwindaangrijpoppervlak in de gevouwen positie is. 2. Wind turbine according to claim 1, wherein the arms on the hub are arranged at a first distance from the support along the horizontal axis, and wherein debreedte along the horizontal axis of portion of the windaangrijpoppervlak which is disposed between the fold line and deondersteuning is greater than the first distance when the windaangrijpoppervlak is in the deployed position, and smaller than the first distance when hetwindaangrijpoppervlak is in the folded position.
  3. 3. Windturbine volgens conclusie 1, waarbij deondersteuning een eerste ondersteuningselement en een tweedeondersteuningselement omvat, waarbij de naaf gerangschikt istussen het eerste en tweede ondersteuningselement, enwaarbij het eerste en tweede ondersteuningselement afstandvan elkaar zijn gerangschikt op een afstand die kleiner isdan een maximale breedte van het windaangrijpoppervlaklangs de horizontale rotatie-as wanneer in de uitgevouwenpositie. 3. Wind turbine according to claim 1, wherein deondersteuning comprises a first support element and a second support member, wherein the hub arranged istussen the first and the second supporting element, andin the first and the second supporting member are arranged afstandvan each other by a distance being less than a maximum width of the windaangrijpoppervlaklangs the horizontal axis of rotation when in the deployed position.
  4. 4. Windturbine volgens conclusie 3, waarbij dewindaangrijpoppervlakken van elk van de armen zijngerangschikt om tussen het eerste en tweedeondersteuningselement te passeren in een richting naar deeerste richting in een gevouwen positie. 4. A wind turbine according to claim 3, wherein dewi disposed gripping surfaces of each of the arms zijngerangschikt to pass between the first and the second support element in a direction towards thefirst direction in a folded position.
  5. 5. Windturbine volgens één der voorgaandeconclusies, waarbij de windaangrijpoppervlakken van de armeneen flexibel materiaal omvatten, bij voorkeur een flexibelvel. 5. A wind turbine according to any one of the preceding claims, wherein the windaangrijpoppervlakken of poor nay comprise a flexible material, preferably a flexibelvel.
  6. 6. Windturbine volgens één der voorgaandeconclusies, waarbij de windaangrijpoppervlakken van de armeneen veerkrachtig materiaal omvatten. 6. A wind turbine according to any one of the preceding claims, wherein the poor no windaangrijpoppervlakken comprise resilient material.
  7. 7. Windturbine volgens één der voorgaandeconclusies, waarbij wanneer geprojecteerd op een verticaalvlak parallel aan de horizontale rotatie-as, dewindaangrijpoppervlakken van de armen zijn ingericht om eeneerste oppervlak te hebben wanneer op een hoogste positie,en een in hoofdzaak kleiner tweede oppervlak wanneer op eenpositie onder een horizontaal vlak gedefinieerd door dehorizontale rotatie-as van de naaf. 7. A wind turbine according to any one of the preceding claims, wherein, when projected onto a vertical plane parallel to the horizontal axis of rotation, dewi disposed gripping surfaces of the arms are adapted to have one erste surface when at a highest position, and a substantially smaller second surface when at eenpositie under a horizontal plane defined by dehorizontale axis of rotation of the hub.
  8. 8. Windturbine volgens één der voorgaandeconclusies, waarbij ten minste in de uitgevouwen positie, debreedte van de windaangrijpoppervlakken van de armen langsde rotatie-as in hoofdzaak toeneemt met de afstand tot dehorizontale rotatie-as. 8. A wind turbine according to any one of the preceding claims, wherein at least increased in the unfolded position, of the debreedte windaangrijpoppervlakken of the arms langsde axis of rotation corresponds essentially to the distance to dehorizontale axis of rotation.
  9. 9. Windturbine volgens één der voorgaande conclusies, waarbij de windaangrijpoppervlakken van de armenverder één of meer versterkingselementen omvatten. 9. The wind turbine of any one of the preceding claims, wherein the windaangrijpoppervlakken of the arms further comprises one or more reinforcing elements.
  10. 10. Windturbine volgens één der voorgaandeconclusies, waarbij een genoemd windaangrijpoppervlak vaneen arm van het veelvoud aan armen een eerste gedeelte eneen tweede gedeelte omvat, waarbij de gedeelten aantegenover gelegen zijden van de arm zijn gerangschikt. 10. A wind turbine according to any one of the preceding claims, wherein a said windaangrijpoppervlak asunder arm of the plurality of arms, a first portion, anda second portion, the portions being arranged as they walked on sides of said arm.
  11. 11. Windturbine volgens conclusie 10, waarbij deeerste en tweede gedeelten scharnierbaar zijn verbonden metde arm. 11. A wind turbine according to claim 10, wherein thefirst and second portions are hingedly connected withthe arm.
  12. 12. Windturbine volgens één der voorgaandeconclusies, verder omvattend beperkingstructuren voor hetbeperken van de openingshoek van een genoemdwindaangrijpoppervlak wanneer in de uitgevouwen positie. 12. A wind turbine according to any one of the preceding claims, further comprising limiting structures for hetbeperken of the opening angle of a genoemdwindaangrijpoppervlak when in the deployed position.
  13. 13. Windturbine volgens conclusie 12, waarbij debeperkingstructuren een link omvatten die secties van eenwindaangrijpoppervlak van een arm van het veelvoud aan armenmet elkaar verbindt, waarbij de secties op hetwindaangrijpoppervlak zijn gerangschikt aan tegenovergelegen zijden van de arm. 13. A wind turbine according to claim 12, wherein a link debeperkingstructuren include those sections of eenwindaangrijpoppervlak of an arm of the plurality of armenmet connects to each other, wherein the sections on hetwindaangrijpoppervlak are arranged on opposite sides of the arm.
  14. 14. Windturbine volgens conclusie 12 of conclusie13, waarbij de naaf is gerangschikt om te draaien in eendraairichting, waarbij de beperkingstructuren ten minstetwee links omvatten die secties van hetwindaangrijpoppervlak van een arm verbinden met een naburigearm die tegen de richting van draaiing van de naaf in isgerangschikt, waarbij de secties zijn gerangschikt aantegenover gelegen zijden van de arm. 14. A wind turbine according to claim 12 or to claim 13, wherein the hub is arranged to rotate in duck-rotating direction, wherein the restricting structures at least two links include those sections of hetwindaangrijpoppervlak of an arm connecting to a naburigearm which against the direction of rotation of the hub in isgerangschikt, wherein the sections are arranged as they walked on sides of said arm.
  15. 15. Windturbine volgens één der voorgaandeconclusies, waarbij de windaangrijpoppervlakken van de armenin hoofdzaak spiegelsymmetrisch zijn langs hunrespectievelijke armen. 15. A wind turbine according to any one of the preceding claims, wherein the windaangrijpoppervlakken of the armenin substantially mirror-symmetrical along hunrespectievelijke arms.
  16. 16. Windturbine volgens één der voorgaandeconclusies, waarbij elke arm een eerste einde verbonden metde naaf, en een tegenovergesteld tweede einde omvat, waarbijtwee naburige armen met elkaar zijn verbonden door eenverbindingselement dat is verbonden met de respectievelijke tweede einden van de naburige armen. 16. A wind turbine according to any one of the preceding claims, wherein each arm has a first end connected withthe hub, and includes an opposite second end, wherein two adjacent arms are joined together by eenverbindingselement which is connected to the respective second ends of the adjacent arms.
  17. 17. Windturbine volgens één der voorgaandeconclusies, waarbij elk van de armen is voorzien van één ofmeer verdere windaangrijpoppervlakken elk omvattend eenvouwlijn in hoofdzaak in een vlak normaal aan de horizontaleas, waarbij de één of meer verdere windaangrijpoppervlakkenzijn ingericht om te vouwen om hun respectievelijkevouwlijnen tussen een uitgevouwen positie wanneer de één ofmeer verdere aangrijpingsoppervlakken in hoofdzaakstroomopwaarts van zijn arm zijn geplaatst en een gevouwenpositie wanneer de één of meer verdereaangrijpingsoppervlakken in hoofdzaak stroomafwaarts vanzijn arm zijn geplaatst, waarbij de één of meer verderewindaangrijpoppervlakken van de arm op verschillendeposities langs de lengte van de arm zijn gerangschikt. 17. A wind turbine according to any one of the preceding claims, wherein each of the arms is provided with one ofmeer further windaangrijpoppervlakken each comprising eenvouwlijn substantially in a plane normal to the horizontaleas, wherein the one or more further windaangrijpoppervlakkenzijn adapted to fold to their respectievelijkevouwlijnen between a folded- position when the one ofmeer further engagement surfaces are disposed substantially upstream of its arm, and a folded position when the one or more verdereaangrijpingsoppervlakken be disposed substantially downstream vanzijn arm, the are arranged in one or more distribution rewinders disposed gripping surfaces of the arm at different positions along the length of the arm .
  18. 18. Windturbine volgens conclusie 17, waarbij dewindaangrijpoppervlakken van de arm zijn gerangschikt om tenminste ten dele aan te liggen tegen naburigewindaangrijpoppervlakken van de windaangrijpoppervlakkenwanneer in de uitgevouwen positie. 18. A wind turbine according to claim 17, wherein dewi disposed gripping surfaces of the arm are arranged in order at least partly to abut against naburigewindaangrijpoppervlakken of the windaangrijpoppervlakkenwanneer in the deployed position.
  19. 19. Windturbine volgens conclusie 17 of conclusie18, waarbij de verdere windaangrijpoppervlakken van een armeen volgzijde omvatten voor het aangrijpen van de windwanneer in de uitgevouwen positie, waarbij, wanneer devolgzijde wordt bezien, een windaangrijpoppervlak van deverdere windaangrijpoppervlakken ten dele wordt overlaptdoor een naburig windaangrijpoppervlak van de verderewindaangrijpoppervlakken. 19. The wind turbine according to claim 17 or to claim 18, wherein the further windaangrijpoppervlakken of a armeen slave side includes means for engaging the wind, when in the unfolded position, wherein, when devolgzijde is viewed, a partially windaangrijpoppervlak of Dever more windaangrijpoppervlakken is overlapped by an adjacent windaangrijpoppervlak of the verde rewinding dismissed gripping surfaces.
  20. 20. Windturbine volgens één der conclusies 17-19,waarbij de één of meer verdere windaangrijpoppervlakken ofhet windaangri jpoppervlak met de één of meer verderewindaangrijpoppervlakken zijn gerangschikt om rond de arm tevouwen en/of uit te vouwen om een in hoofdzaakaaneengesloten hol oppervlak te vormen. 20. The wind turbine according to any one of claims 17-19, wherein the one or more further windaangrijpoppervlakken ofhet windaangri jpoppervlak with the one or more distribution rewinders disposed gripping surfaces are arranged to tevouwen around the arm and / or to expand to form a substantially continuous concave surface.
  21. 21. Windturbine volgens één der conclusies 17-20,waarbij de verdere windaangrijpoppervlakken van een arm vande armen elk eerste en tweede hoeksecties omvatten die zijn gerangschikt aan tegenover gelegen zijden van de arm enverbonden via links aan een distaai einde van een balk,waarbij de balk rotatievast is verbonden met de naaf enwaarbij het distale einde van de balk op afstand is gelegenvan de arm aan een volgzijde van de arm. 21. The wind turbine according to any one of claims 17-20, wherein the further windaangrijpoppervlakken of an arm Vande arms each comprise first and second angular sections, which are arranged on opposite sides of the arm Enver bound via links to a distaai end of a beam, wherein the beam is rotation-fixedly connected to the hub andin which the distal end of the distance beam is gelegenvan the arm to a follower side of the arm.
  22. 22. Windturbine volgens één der voorgaandeconclusies, waarbij het windaangrijpoppervlak aan de arm isbevestigd door middel van een klemelement, waarbij hetklemelement aan een leidende zijde van de arm isgerangschikt. 22. The wind turbine according to any one of the preceding claims, wherein the windaangrijpoppervlak isbevestigd to the arm by means of a clamping element, wherein hetklemelement isgerangschikt at a leading side of the arm.
  23. 23. Windturbine volgens conclusie 22, waarbij hetklemelement zich in hoofdzaak langs de gehele lengte van hetwindaangrijpoppervlak langs de arm uitstrekt. 23. The wind turbine according to claim 22, wherein hetklemelement extends substantially along the entire length of hetwindaangrijpoppervlak along the arm.
  24. 24. Windturbine volgens één der voorgaandeconclusies, verder omvattend een inrichting die wordtaangedreven door draaiing van de rotors. 24. The wind turbine according to any one of the preceding claims, further comprising a device which is driven by rotation of the rotors.
  25. 25. Gebruik van een windturbine volgens één dervoorgaande conclusies voor het aandrijven van eeninrichting. 25. Use of a wind turbine according to any one dervoorgaande claims for driving eeninrichting.
  26. 26. Gebruik volgens conclusie 25, waarbij deinrichting een pomp of een dynamo omvat. 26. The use according to claim 25, wherein heaving device comprises a pump or a dynamo.
NL2008227A 2012-02-03 2012-02-03 Wind turbine having foldable wind engagement surfaces. NL2008227C (en)

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US20160061184A1 (en) * 2014-09-02 2016-03-03 Nelson Prathish SAGAYANATHAN Wind turbine system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1915689A (en) * 1932-08-26 1933-06-27 Irwin T Moore Windmill
US5570997A (en) * 1995-07-17 1996-11-05 Pratt; Charles W. Horizontal windmill with folding blades
FR2817593A1 (en) * 2000-12-06 2002-06-07 Robert Mazenq Wind-powered turbine for generating electricity has corrugated triangular-section vanes on horizontal shaft with lower halves covered
WO2010062273A2 (en) * 2008-09-22 2010-06-03 Kavlak Ahmet Dr Wind turbine with air motor and vertical axis controlled with air pressure
WO2011116440A1 (en) * 2010-03-23 2011-09-29 Dulcetti Filho Flavio Francisco Vertical wind turbine with articulated blades

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1915689A (en) * 1932-08-26 1933-06-27 Irwin T Moore Windmill
US5570997A (en) * 1995-07-17 1996-11-05 Pratt; Charles W. Horizontal windmill with folding blades
FR2817593A1 (en) * 2000-12-06 2002-06-07 Robert Mazenq Wind-powered turbine for generating electricity has corrugated triangular-section vanes on horizontal shaft with lower halves covered
WO2010062273A2 (en) * 2008-09-22 2010-06-03 Kavlak Ahmet Dr Wind turbine with air motor and vertical axis controlled with air pressure
WO2011116440A1 (en) * 2010-03-23 2011-09-29 Dulcetti Filho Flavio Francisco Vertical wind turbine with articulated blades

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