NL2008228A - Wind turbine having counter rotating blades. - Google Patents

Wind turbine having counter rotating blades.

Info

Publication number
NL2008228A
NL2008228A NL2008228A NL2008228A NL2008228A NL 2008228 A NL2008228 A NL 2008228A NL 2008228 A NL2008228 A NL 2008228A NL 2008228 A NL2008228 A NL 2008228A NL 2008228 A NL2008228 A NL 2008228A
Authority
NL
Grant status
Application
Patent type
Prior art keywords
rotation
wind turbine
rotor
wind
arms
Prior art date
Application number
NL2008228A
Other languages
Dutch (nl)
Other versions
NL2008228C (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
    • F05B2240/211Rotors for wind turbines with vertical axis
    • F05B2240/218Rotors for wind turbines with vertical axis with horizontally hinged vanes
    • 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
    • F05B2240/221Rotors for wind turbines with horizontal axis
    • F05B2240/2212Rotors for wind turbines with horizontal axis perpendicular to wind direction
    • 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
    • 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 counter rotating bladesBACKGROUND

The invention relates to a wind turbine comprisinga rotor having a set of arms provided with foldable windengagement surfaces such as sails. Due to a growing demandfor energy worldwide, interest in sustainable energy sourcessuch as wind energy has peaked. In particular energy servicecompany Alliander B.V. has invested in research in windturbines for converting wind energy into rotational energy,and is supporting 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 useful energyis lost during conversion of wind energy to rotationalenergy. It is an object of the present invention to providea wind turbine with foldable wind engagement surfaces, whichmore efficiently converts wind energy into rotationalenergy.

SUMMARY OF THE INVENTION

According to a first aspect, the present inventionprovides a wind turbine for converting a stream of windblowing in a first direction into rotational energy, saidwind turbine comprising a first rotor rotatable in a firstdirection of rotation around a first axis of rotation; asecond rotor rotatable in a second direction of rotationaround a second axis of rotation substantially parallel tosaid first axis of rotation; wherein said first rotor andsaid second rotor are each provided with a set of armsextending substantially radially relative to its respectiveaxis of rotation, each arm comprising a foldable windengagement surface having a folding line substantially in aplane normal to said axis of rotation; wherein said firstdirection of rotation is opposite to said second directionof rotation; and wherein said sets of arms of said first andsecond rotors are arranged for rotating in a substantiallycommon plane of rotation. Wind blowing between the axes ofrotation thus engages wind engagement surfaces of both thefirst rotor and of the second rotor and is guided over saidwind engagement surfaces substantially along the respectivefolding lines towards edges of the wind engagement surfacesat the respective outer ends of the arms. Wind escaping oversaid edges of a wind engaging surface of the first rotor isthus directed towards its corresponding wind engagementsurface of the second rotor, and vice versa. This increasesthe pressure of the stream of wind the first directionincident on said wind engagement surfaces, which providesadditional force for rotating the first and second rotors.Preferably, the rotors are arranged to rotate in phase, suchthat a first arm of said first rotor and a second arm ofsaid second rotor are at a minimum distance to each otherwhen substantially coinciding with or intersecting a linebetween the first and second axis of rotation. The minimumdistance is preferably substantially less than the length of an arm of said first or second rotor, preferably less than one eighth thereof.

In an embodiment the first and second axes ofrotation are arranged in a common substantially verticalplane perpendicular to said common plane of rotation. Thefirst axis of rotation and said second axis of rotation arethus both oriented either substantially horizontally, or areboth oriented substantially vertically.

In an embodiment each of said engagement surfacesis adapted for folding about its folding line between anunfolded position when said wind engagement surface islocated substantially upstream from its arm and a foldedposition when said wind engagement surface is locatedsubstantially downstream from its arm. Preferably, the windengagement surfaces of first and second rotors substantiallytrail behind their associated arms along the respectivedirection of rotation of said rotor.

In an embodiment said first rotor and/or saidsecond rotor comprises one or more additional sets of armsspaced apart from said set of arms along its respective axisof rotation and extending substantially radially relative tosaid axis of rotation, each of said arms of said additionalsets of arms comprising a foldable wind engagement surfacehaving a folding line substantially in a plane normal tosaid axis of rotation. By providing the rotors withadditional sets of arms which are rotatable around the firstand/or second axis of rotation, the total wind engagementsurface is increased.

In an embodiment each of said foldable windengagement surfaces is arranged for folding about itsfolding line to an unfolded position due to said stream ofwind when said wind engagement surface is located betweensaid first and second axis of rotation, and preferably forfolding about its folding line to an unfolded positionotherwise. The engagement surface presented to the windstream by a wind engagement surface is thus substantiallysmaller when the wind engagement surface is in the folded position than when it is in the unfolded position. Thus,when a first wind engagement surface of the first rotor anda second wind engagement surface of the second rotor are ata minimum distance from each other, the wind stream incidenton the first wind engagement surface is at least partiallyguided towards the second wind engagement surface and viceversa. As a result additional air pressure is exerted onsaid wind engagement surfaces which is at least partiallyconverted into rotational energy.

In an embodiment the wind turbine furthercomprises a support for supporting said first and secondrotors, wherein said rotors are rotatable relative to saidsupport around their respective axes of rotation and whereinsaid support is rotatable around a vertical axis. Byrotating the support around the vertical axis the windturbine may be optimally aligned with the wind stream, i.e.such that the first and second axes of rotation aresubstantially perpendicular to the first direction of thewind stream.

In an embodiment the wind turbine furthercomprises a wind alignment member adapted for aligning thefirst axis of rotation and said second axis of rotation in adirection substantially perpendicular to said firstdirection. A suitable wind alignment member comprises asubstantially rigid surface, such as a wind vane, connectedto the rotatable support. Another suitable alignment membercomprises a motor for driving rotation of the support aroundits vertical axis based on the first direction.

In an embodiment said first rotor and said secondrotor are mirror symmetrical with respect to a planeparallel and equidistant to said first and second axes ofrotation of said rotors. As the first and second rotors thushave substantially equal dimensions and mass the stabilityof the wind turbine, at least along the common plane ofrotation, is improved.

In an embodiment each of said wind engagementsurfaces is adapted to form a substantially concave surface facing said first direction of the wind stream with itsconcave side, at least when unfolded. A wind stream incidenton the concave side of the wind engagement surface willprovide a force on said wind engagement surface to fold tothe unfolded position. Preferably, when a wind stream isincident on a side of the wind engagement surface facingaway from the wind stream, e.g. when the wind engagementsurface is moving against the wind stream, the wind streamwill cause the wind engagement surface to fold to the foldedposition.

In an embodiment said wind engagement surfaces ofsaid arms comprise a flexible material, preferably aflexible sheet. Such sheets provide cost effective windengagement surfaces, similar to a sail.

In an embodiment said wind engagement surfaces ofsaid arms comprise a resilient material. Preferably, when noforce is exerted on the wind engagement surfaces theresiliency of the material causes the wind engagementsurface to at least substantially fold. In particular when awind engagement surface is arranged downstream of its arm,the surface area of the wind engagement surface on which thewind stream is incident is substantially less than when thewind engagement surface is in the unfolded position.

In an embodiment said wind engagement surfaces ofsaid arms further comprise one or more reinforcementelements .

In an embodiment one or more of said windengagement surfaces of an arm of said first and/or secondrotor comprises a first portion adapted for engaging saidwind stream, said first portion foldably connected along afirst edge to said arm; a second portion adapted forengaging said wind stream, said second portion foldablyconnected along a second edge to said arm.

In an embodiment said first and second portionsare hingeably connected to said arm. Preferably, the firstand second portion are substantially rigid, at least to theextend that the material of the first and second portion is not sufficiently flexible to allow folding in that materialbetween a substantially unfolded and folded position.

In an embodiment said first rotor and/or saidsecond rotor further comprises limiting structures forlimiting the opening angle of its wind engagement surfaces.The opening angle of the wind engagement surfaces in theunfolded position is thus limited, preferably to 180 degreesor less, such that the wind engagement surfaces maintain agreater surface are for engaging the wind when unfolded thanwhen folded.

In an embodiment said limiting structures comprisea link connecting sections of a wind engagement surface ofan arm of said wind turbine on opposite sides of said arm toeach other. The link, for instance a flexible link such as awire, preferably connects corner sections of said windengagement surface to each other.

In an embodiment said limiting structures comprisea first link, connected to a first section of a windengagement surface of an arm of said first rotor or saidsecond rotor, and a second link, connected to a secondsection of said wind engagement surface, wherein said firstand second sections are arranged on opposite sides of saidarm, and wherein said first and second links are connectedto an arm neighboring said arm on said rotor in a directioncounter to the direction of rotation of said rotor. Thelimiting structures thus help in forming a wind scoop whenthe wind engagement surface is in the unfolded position.

In an embodiment said wind engagement surfaces ofsaid arms are substantially symmetrical along theirrespective arms. The force exerted by the wind engagementsurfaces will thus typically be symmetrically distributedalong the arm.

In an embodiment said arms each comprise a distalend at a far end from its axis of rotation, said windturbine further comprising one or more connecting elementsconnecting said distal ends of neighboring arms on a rotorto each other. The connecting elements preferably comprise wires, e.g. metal wires or other wires with high tensilestrength. By connecting the far ends of neighboring arms,which far ends are the ends of arms opposite to the ends ofthe arms proximate to their axis of rotation, the structuralstrength of the rotor is increased.

In an embodiment the wind turbine furthercomprises an airlift structure for lifting the windturbine from the ground, said airlift structure preferablycomprising a balloon filed with a lighter-than-airmaterial. When the wind turbine is substantially floatingin the air, the amount of ground surface required forplacing and operating the wind turbine is substantiallyreduced.

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 attacheddependent claims, 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:

Figures 1A and IB schematically show a cross-sectional side view and a front view respectively of a windturbine according to the present invention, figures 2A and 2B schematically show a side viewand a top view respectively of an embodiment of the presentinvention, figure 3 schematically shows a side view of aanother embodiment of the present invention, figures 4A and 4B schematically show a side viewand a top view of another embodiment of the presentinvention, figures 4C and 4D schematically show side views oftwo alternative embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1A schematically shows a cross-sectionalside view of a wind turbine 1 according to the presentinvention. The wind turbine comprises a support 2 supportinga frame 3,5 which in turn supports a first rotor 100 and asecond rotor 200. The support 2 is rotatable around avertical axis of rotation V to align the rotors 100,200 suchthat their axes of rotation L1,L2, which are substantiallyhorizontal, are substantially normal to a wind streamblowing in a first direction W. In the embodiment shown,this alignment of the rotors 100,200 is achieved by means ofa substantially planar wind alignment surface 10 which isoriented substantially parallel to the first direction W andwhich is fixedly connected to the support via a beam 9.

The first rotor 100 is attached to an axle 140which is rotatable relative to the frame 3,5 of the support2 around first axis of rotation LI in direction R1. Thefirst rotor 100 comprises a first set of arms 101,102,103and 104 which comprise foldable wind engagement surfaces

Ill, 112,113 and 114 respectively. The wind engagementsurfaces 111, 112, 113, 114 are foldable about respectivefolding lines substantially in a plane normal to the axis ofrotation LI of the rotor 100. In the embodiment shown, thefolding line of each wind engagement surface 111,112,113,114is substantially parallel to its corresponding arm101,102,103,104. Though the wind engagement surfaces showneach comprise single sheet of a flexible and resilientmaterial, wherein the flexibility of the material allows forthe wind engagement surface to fold or unfold, in analternative embodiment, each of the wind engagement surfacesmay comprise two portions of a plate like material, whichtwo portions are arranged on either side of a correspondingarm and are attached to the arm by means of a hinge.

When a wind stream blows in a first direction W,it causes wind engagement surfaces 111,112 locatedsubstantially upstream of their arms 101,102 relative to thewind stream W to unfold to a position in which they formsubstantially concave surfaces facing the first direction Wwith their concave sides. The force of the wind stream onthese wind engagement surfaces 111 and 112 is converted intorotational energy, i.e. causes the first rotor 100 to rotatein direction R1 around its axis of rotation LI. At the sametime, wind engagement surfaces 113 and 114 of the firstrotor 100 rotate against the first direction W of the windstream, causing them to substantially fold along theirfolding lines such that the area with which they oppose thewind stream W is reduced, i.e. substantially less than thearea with which the wind engagement surfaces 111,112 opposethe wind stream. The force exerted by wind engagementsurfaces 111 and 112 for making the rotor 100 rotate in thedirection of rotation R1 is thus larger than the forceexerted by wind engagement surfaces 113 and 114 on the rotor100 in the opposite direction. An opening angle of each windengagement surface 111,112,113,114 is limited by limitingstructures 121a,121b,122a,122b,123a,123b,124a, 124b in theform of wires, such that the wind engagement surfaces retain their substantially concave shape when facing the windstream W with their concave sides. In the embodiment shown,the wires 121a,121b and 122a,122b are substantially taut astheir corresponding wind engagement surfaces 111, 112 are inthe unfolded position due to the wind acting thereon, andwires 123a,123b and 124a,124b are substantially slack astheir corresponding wind engagement surfaces 113, 114 are inthe folded position.

The second rotor 200 is attached to an axle 240rotatable relative to said support 2 around axis of rotationL2, and comprises a first set of arms 201,202,203,204 whichextend radially from said axis of rotation L2 and which areprovided with wind engagement surfaces 211,212,213 and 214respectively. The respective wind engagement surfaces211,212,213 and 214 are foldable between a substantiallyfolded position and a substantially unfolded position, alongfolding lines substantially in a plane normal to the secondaxis of rotation L2. Though the second rotor 200 is of asimilar construction as the first rotor 100, it is arrangedto rotate in a direction of rotation R2 which is counter tothe direction of rotation R1 of the first rotor. The windengagement surfaces of both the first rotor 100 and of thesecond rotor 200 are thus arranged substantially forunfolding when located between the first axis of rotation LIand the second axis of rotation L2. As each arm of the firstrotor 100 is spaced apart by at least its length from thesecond axis of rotation L2, and each arm of the second rotor200 is spaced apart by at least its length from the firstaxis of rotation LI, collisions between arms of the firstrotor and arms of the second rotor are prevented.

At least when in the unfolded position, the windengagement surfaces 211,212,213 and 214 each form asubstantially concave surface. Wires221a,221b,222a,222b,223a,223b,224a,224b act as limitingstructures for limiting the extend to which the windengagement surfaces 211,212,213 and 214 may unfold andfunction in the same manner as wires 121a,121b,122a,122b,123a,123b,124a,124b of the first rotor 100.

When the wind stream W engages the unfolded windengagement surfaces 111 and 211, much of the wind stream isfirst caught in the substantially concave shapes formed bythe unfolded wind engagement surfaces 111,211 and 112,214,and is then guided towards and across the edges of therespective wind engagement surfaces 111,211. As the edges111a,111b and 211a,211b of the wind engagement surfaces 111and 211 at the distal ends of the arms 101 and 201 near lineP are close to each other, the air pressure at the side ofthe wind engagements surfaces 111,211 facing the wind streamW, in particular near edges 111a,111b,211a,211b increases.As a result, a greater amount of wind energy is converted torotational energy than if the wind escaping over edges111a,111b and 211a,211b would not at least partially bereused to drive rotation of said first and second rotors100,200. In the embodiment shown the minimum distancebetween the wind engagement surface 111 of the first rotor100 and the corresponding wind engagement surface 211 of thesecond rotor is less than one tenth the length of an arm.Both the first rotor 100 and the second rotor 200 aresupported by the support 2 which is rotatable around asubstantially vertical axis of rotation V.

The support 2 comprises an alignment member 10 forcorrectly aligning the rotors in the wind, i.e. such thatthe axes of rotation of the rotors are in a direction normalto the first direction of the wind stream W, and such thatthe wind engagement surfaces of the first and second rotorsfold towards the unfolded position when located between thefirst and second axes of rotation. The alignment membershown comprises the substantially planar wind alignmentsurface 10 which extends substantially perpendicular to theaxes of rotation, and which is fixedly connected to thesupport 2 by a beam 9. Though not shown, an alternativealignment member may be used instead, for instancecomprising an electromotor adapted for rotating the support around the vertical axis V based on the first direction ofthe wind. The frame 3,4,5,6 of the support 2 is shown inmore detail in figure IB.

Figure IB schematically shows a front view of thewind turbine 1 of figure 1A to the invention. The axles 140and 240 of first rotor 100 and second rotor 200 respectivelyare supported by the support 2 and frame 3,4,5 for rotatingaround their respective axes of rotation LI and L2. Therotors 100,200 have been aligned using the planar windalignment surface 10 such that their axes of rotation LI andL2 are substantially perpendicular to the first direction ofthe wind stream, and such that the wind engagement surfacesof the rotors are arranged for unfolding when locatedbetween the axes of rotation L1,L2. Though for reasons ofclarity the wind alignment surface 10 and the beam 9 whichconnects the wind alignment surface 10 to the support 2 havebeen shown at an angle behind the support 2, the windalignment surface would typically be at least substantiallybehind the support relative to the first direction of thewind stream.

The rotors 100,200 each comprise a respectivefirst set of arms 101,102,103, 104; 201,202,203,204 of whicharms 101,103 and 201,203 have only been shown in figure IBfor reasons of clarity. The arms are attached to theirrespective axle 140 and 240, and extend radially from theirrespective axes of rotation L1,L2, each arm of the firstsets of arms 101,102,103,104; and 201,202,203,204. Besidesthe first set of arms 101,102,103,104, rotor 100 comprisesan additional set of arms spaced apart from the first set ofarms along the axis of rotation LI. For reasons of clarityonly arms 105 and 107 of the additional set of arms areshown, though the person skilled in the art will appreciatethat the additional set of arms typically comprises the samenumber of arms as the first set of arms, and is typically ofa same configuration as the first set of arms. Likewise, thesecond rotor comprises an additional set of arms spacedapart from its first set of arms along the second axis of rotation L2, and of which additional set of arms only arms205 and 207 are shown for reasons of clarity.

The first sets of arms 101, 102, 103, 104; 201,202,203,204 (see figure 1A) of the first and second rotors 100,200 are arranged to rotate in a substantiallycommon plane of rotation VI, which common plane VI issubstantially vertical and extends perpendicular to both thefirst axis of rotation LI and the second axis of rotationL2 .

The additional sets of arms 105, 107; 205,207 ofthe first and second rotors 100,200 are arranged to rotatein a substantially common plane of rotation V2, which commonplane is substantially vertical and extends perpendicular toboth the first axis of rotation LI and the second axis ofrotation L2.

The wind turbine 1 comprises coupling elements51,51a, 52,53, 54, 54a, 55, 56, 57 and 58 for coupling the rotors100,2 00 such that they rotate counter to each other and atsubstantially the same speed. In the embodiment shown thecoupling elements comprise a first wheel 51 fixedlyconnected to the axle 140 of the first rotor 100 andconnected via a belt 51a to second wheel 52. The secondwheel 52 is rotation-fixedly connected to a gear 53 and to adrive axle 57 of a dynamo 58 for converting rotationalenergy of the drive axle 57 into electrical energy. Thecoupling elements further comprise a third wheel 54 fixedlyconnected to axle 240 of the second rotor 200, connected viaa belt 54a to a fourth wheel 55. The fourth wheel isrotation fixedly connected to a gear 55, which gear 55engages said gear 53, such that said gears 53, 55 rotate inopposite directions. The coupling elements rotationallycouple the rotors 100, 200 to each other such that theyrotate at substantially the same speed, and such that at anytime a distance between corresponding arms of the firstrotor 100 and of the second rotor 200 to a line P halfwaybetween the first axis of rotation LI and the second axis L2and parallel thereto, is substantially the same. For instance, corresponding arms 101 and 201 have the sameangular velocity, and at any time during their rotation, adistance between arm 101 and the line P is substantially thesame as a distance between arm 201 and the line P. Thus,when the wind engagement surfaces 111,112 of both arms101,201 are at a location close to said line P as shown infigure IB, a stream of wind engaging said surface 111 may atleast partially escape said surface 111 over edges 111a,111band provide an extra force on wind engagement surface 211.Likewise, wind escaping over edges 211a,211b of windengagement surface 211 provides an extra force on windengagement surface 111.

Figures 2A and 2B schematically show a side viewand a top view respectively of an embodiment of a windturbine 400 according to the present invention. The windturbine comprises 400 a support 402 which is mountedrotatably around a vertical axis of rotation V on a base408. The support 402 comprises a frame 403,404 supporting afirst rotor 500 comprising an axle 540 rotatable around avertical axis of rotation L3, and a second rotor 600comprising an axle 640 rotatable around a vertical axis ofrotation L4. The first rotor 500 comprises a first set ofarms 501,503 attached and a second set of arms 505, 507.Though for reasons of clarity figure 2A shows each set ofarms to comprise only two arms, it will be appreciated thateach set will typically comprise a larger number of armsextending radially from its axis of rotation. Both sets ofarms 501,503; 505, 507 are attached to the axle 540. Thefirst rotor 500 is rotationally coupled with the secondrotor 600, preferably using coupling elements as describedin figure 1A, such that the first rotor 500 rotatessubstantially at the same speed as the second rotor 600, butin a direction of rotation counter to the direction ofrotation of the second rotor 500. A device, e.g. a dynamo ora pump can be arranged in the support 4 02, for convertingrotational energy of the rotors 500,600 into electrical ormechanical energy respectively. Such a device is preferably coupled to the coupling elements instead of directly to theaxles 540 or 640.

Each of the arms 501,503; 505, 507 of the first rotor comprises a foldable wind engagement surface 511,513;515,517, wherein each of said wind engagement surfaces isfoldable around a folding line substantially in a respectiveplane normal to its axis of rotation L3. Likewise, thesecond rotor 600 comprises two sets of arms 601,603;605,607, each arm comprising a foldable wind engagementsurface 611,613,-615,617, wherein each of said windengagement surfaces is foldable around a folding linesubstantially in a respective plane normal to its axis ofrotation L4. The arms of the first sets 501,503; 601,603 arearranged for rotating in a common horizontal plane ofrotation HI, and the arms of the second sets 505,507;605,607 are arranged for rotating in a common horizontalplane of rotation H2.

Wind alignment member 410, comprising asubstantially planar wind alignment surface 410 extendingperpendicular to the axes of rotation L3,L4 and which isfixedly connected to the support 402 by beam 409, is adaptedfor orienting the support 402 such that the vertical axes ofrotation L3,L4 of the first and second rotor 400,500respectively are substantially perpendicular to a firstdirection W in which a wind stream is directed (see figure2B) .

Because the wind engagement surfaces of the firstrotor 500 and second rotor 600 are arranged for folding tothe unfolded position when within the frame 403,404, oralternatively when located between the axes of rotation L3and L4, the wind stream which escapes one rotor providesadditional wind pressure for driving rotation of the otherrotor. For instance, wind escaping across edges 511a,511b ofwind engagement surface 511 farthest from the axle 540 towhich arm 501 of said wind engagement surface 511 isconnected, at least partially flows towards edges 611a,611bof wind engagement surface 611, such that at a point substantially halfway between the axes of rotation L3,L4 theair pressure is increased, providing an additional force onthe wind engagement surfaces 511,611 for driving rotation ofthe respective first and second rotor. The edges 611a,611bare the edges of the wind engagement surface 611 arrangedfarthest from axle 640 to which the arm 601 of the windengagement 611 surface is connected.

Figure 3 schematically shows a side view of a windturbine 1000 according to the invention, comprising asupport 1002 which is rotatable relative to a ground plane1010 around a vertical axis of rotation V. The support 1002comprises an annular base 1006, which is rotatable aroundthe axis of rotation V relative to the ground plane 1010using a wheel drive comprising wheels 1007,1008 and a motorfor driving rotation of the wheel 1008. The support 1002comprises a first substantially upright support element 1004and a second substantially upright support element 1005,both protruding from the annular base 1006, between whichupright support elements 1004,1005 a first rotor 1100 and asecond rotor 1200 are supported. The first rotor 1100 andsecond rotor 1200 are rotationally coupled for rotatingaround their respective axes of rotation L5, L6 atsubstantially equal speeds but in opposite directions R5 andR4. The rotors 1100, 1200 are arranged such that the windengagement surfaces of their arms substantially unfold whenlocated between the axis of rotation L5 of the first rotor1100 and the axis of rotation L6 of the second rotor, i.e.when located proximate or closest to line P2 which isparallel to the axes of rotation L5,L6 and arranged halfwaybetween those axes. The line P2 lies in an plane which isparallel and equidistant to said axes of rotation L5,L6.

Each rotor comprises multiple sets of arms1101a, 1103a; 1101m, 1103m; HOlv, 1103v, 1201a, 1203a;1201m, 1203m; 1201v, 1203v, wherein the sets of arms of eachrespective rotor 1100,1200 are spaced apart from each otheralong the axis of rotation of the rotor. In the embodimentshown, the first and second rotors each comprise twentytwo sets of arms. The arms of corresponding sets of arms of thefirst and second rotor are adapted for rotation around theirrespective axis of rotation R5,R6 in a vertical plane whichis substantially common for each arm in both sets. Forinstance, arms 1101a, 1103a of a first set of arms of thefirst rotor and arms 1201a, 1203a of a corresponding firstset of arms of the second rotor are arranged for rotating ina substantially common vertical plane.

Though for reasons of clarity each set of arms isshown comprising only two arms, it will be appreciated thateach set of arms will typically comprise more than two arms,e.g. three to six arms in a common plane normal to the axisof rotation. The arms of the set of arms 1201m, 1203m and ofthe set of arms 1101m, 1103m will be described next, thoughthe description holds for the other arms of the first andsecond rotors as well. Arms 1101m,1103m and 1201m, 1203meach comprise a foldable wind engagement surface 1111m,1113m, 1211m and 1213m respectively, of a same constructionas described for the previous embodiments. Wind engagementsurfaces 1111m and 1211m which are located upstream relativeto their arms 1101m, 1201m, in figure 3 shown between theaxes of rotation L5,L6, are in a substantially unfoldedposition in which they form substantially concave surfacesfor facing a stream of wind. The wind engagement surfaces1113m,1213m are substantially downstream of their arms1103m, 1203m and are in a folded position. The windengagement surfaces between the axes of rotation L5,L6, atleast during a part of their rotation, are arranged fortrapping a substantial part of a wind stream which passesbetween the axes of rotation.

A dynamo 1058 is adapted for converting rotationof said rotors 1100,1200 into electrical energy.

Figures 4A and 4B show a schematic side view, anda schematic top view respectively of an embodiment of a windturbine 2000 according to the present invention. The windturbine comprises a support 2003 for supporting a firstrotor 2100 and a second rotor 2200, each comprising multiple sets of arms as described for the previous embodiments. Thefirst rotor 2100 and second rotor 2200 comprise axles 2140and 2240 respectively to which the arms are connected, whichaxles 2140,2240 are rotatably connected to the support 2003for rotating relative to the support 2003 in oppositedirections R7, R8 at substantially equal speeds aroundsubstantially horizontal axes of rotation L7 and L8respectively. The rotors 2100,2200 are arranged such thatthe wind engagement surfaces of their arms substantiallyunfold when located between the axis of rotation L7 of thefirst rotor 2100 and the axis of rotation L8 of the secondrotor 2200, i.e. when located proximate or closest to lineP3 which is parallel to the axes of rotation L7,L8 andarranged halfway between those axes. The line P3 lies in anplane which is parallel and equidistant to said axes ofrotation L7,L8.

The support 2003 comprises a first support element2004 and a second support element 2005, between which thefirst rotor 2100 and the second rotor 2200 are located. Thesupport 2003 further comprises reinforcement rods 2007 and2008 which increase the structural integrity of the support2003.

The wind turbine 2000 further comprises an airliftstructure comprising a zeppelin or blimp 2010 filed with alighter-than-air gas, i.e. a gas having a lower density thanthe air surrounding the zeppelin, e.g. helium or heated air.The zeppelin 2010 comprises a longitudinal axis Lz which isparallel to the first direction of the wind stream W (seefigure 3C) and is provided with wind alignment members inthe form of fins 2011 for aligning the zeppelin with a frontside 2012 into the direction in which the wind stream W isblowing. The axes of rotation L7,L8 of the wind turbine areoriented substantially perpendicular to the longitudinalaxis Lz of the zeppelin. The zeppelin thus forms a windalignment structure for aligning the axis of rotation L7,L8of the wind turbine substantially perpendicular to the firstdirection W.

The support 2003 is suspended from the zeppelin2010 by means of a rigid frame 2006 which rotation fixedlyconnects the support 2003 to the zeppelin 2010. The windturbine 2000 is mechanically connected to the ground 1010 bya wire 2021. The wire 2021 functions to at leastsubstantially fix the location of the wind turbine 2000 withrespect to the ground 1010. Moreover, the wire 2021comprises an electrical conductor for conducting electricitygenerated by dynamo 2 058 of the wind turbine to a locationremote from the wind turbine.

Figure 4C schematically shows yet anotherembodiment according to the invention. The wind turbine 3000according to this embodiment comprises airlift means 3010 inthe form of a balloon filled with a lighter-than-air gas.The wind turbine further comprises a frame3003,3004,3005,3007,3008 for supporting a first rotor 3100and a second rotor 3200, comprises respective axles3140,3240 rotatable relative to the support aroundrespective substantially horizontal axes of rotation L9,L10in opposite directions R9,R10. The rotors 3100,3200 arerotationally coupled in the same manner as described for theprevious embodiments. The first rotor 3100 and the secondrotor 3200 each comprises a plurality of arms with foldablewind engagement surfaces as described for the embodimentsabove. The rotors 3100,3200 are arranged such that the windengagement surfaces of their arms substantially unfold whenlocated between the axis of rotation L9 of the first rotor3100 and the axis of rotation L10 of the second rotor 3200,i.e. when located proximate or closest to line 43 which isparallel to the axes of rotation L9,L10 and arranged halfwaybetween those axes. The line P4 lies in an plane which isparallel and equidistant to said axes of rotation L9,L10.

The wind turbine 3000 is connected to the ground1010 by means of at least two wires or ropes 3021,3022 whichconnect two respective sides of the frame 3005,3004 whichare spaced apart along the axis of rotation L9 to poles1011,1012 embedded into the ground. The wires 3021,3022 are substantially taut, such that they substantially restrainchanges in orientation of the wind turbine 3000 relative tothe ground 1010 around a vertical axis of rotation V of thewind turbine 3000. In case the wind direction changes, oneor both of the wires 3021,3022 is uncoupled from the poles1011,1012 and attached to another pole, for instance to pole1013, such that the wires 3021, 3022 are substantially tautand such that the support 1003 is rotated relative to theground 1010 for changing its orientation to the winddirection. Wire 3021 also comprises an electrical conductorfor conducting electrical energy generated by dynamo 3058 ofthe wind turbine 3000 away from the wind turbine.

Typically the wires 3021,3022 are attached topoles such that the direction of the wind stream issubstantially normal to a vertical plane defined by thefirst and second axes of rotation L9,L10. Though in theembodiment shown the wind turbine is aligned using poles1011,1012,1013,1014 and wires 3021,3022 it will be apparentthat alignment of the wind turbine 3000 by be achieved usingother means .

Figure 4C shows another embodiment of a windturbine according to the invention. The wind turbine 4000comprises airlift means in the form of a kite 4010, which isrotation-freely connected via a wire 4012 to a frame4003,4004,4005. The frame supports a first rotor 4100 and asecond rotor 4200, each of said rotors comprising an axle4140, 4240 to which a plurality of arms with foldable windengagement surfaces is attached. The axles 4140,4240 of therotors 4100,4200 are rotationally coupled for rotatingaround their respective axis of rotation L11,L12 in oppositedirections R11,R12 and at the same velocity.

The foldable wind engagement surfaces are arrangedfor unfolding when located between the axes of rotationL11,L12. For keeping the rotors aligned with their axis ofrotation perpendicular to the wind, two wires 4021,4022 areattached respectively on either side 4005,4004 of the framealong the axis of rotation and connect said frame 4003,4004,4005 to the ground 1010. When the wires 4021,4022are taut, as shown, they limit a change in orientation ofthe frame with respect to the wind. Moreover, the wirecomprises an electrical conductor for conducting electricalenergy generated by dynamo 4 058 away from the wind turbine4000.

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 theinvention. 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. In particular it is envisaged that a wind turbineaccording to the invention is further provided with anelectrical generator, e.g. a dynamo, adapted for convertingrotational movement of said rotors into electrical energy.

Claims (23)

  1. 1. Windturbine voor het omzetten van eenwindstroom die in een eerste richting blaast naarrotationele energie, waarbij de windturbine omvat: een eerste rotor die draaibaar is in een eerstedraairichting rondom een eerste rotatie-as; 1. A wind turbine for converting eenwindstroom blowing in a first direction naarrotationele energy, wherein the wind turbine comprises: a first rotor which is rotatable in a first rotational direction about a first axis of rotation; een tweede rotor die draaibaar is in een tweededraairichting rondom een tweede rotatie-as in hoofdzaakparallel aan de eerste rotatie-as; a second rotor which is rotatable in a second rotational direction around a second axis of rotation substantially parallel to the first axis of rotation; waarbij de eerste rotor en de tweede rotor elkzijn voorzien van een verzameling van armen die zich inhoofdzaak radiaal ten opzichte van zijn respectievelijkerotatie-as uitstrekken, waarbij elke arm een vouwbaarwindaangrijpoppervlak omvat met een vouwlijn in hoofdzaak ineen vlak normaal aan de rotatie-as; wherein the first rotor and the second rotor elkzijn provided with a set of arms extending inhoofdzaak extend radially with respect to its respectievelijkerotatie-axis, wherein each arm comprises a vouwbaarwindaangrijpoppervlak with a fold line substantially join plane normal to the axis of rotation; waarbij de eerste draairichting tegenovergesteldis aan de tweede draairichting; wherein the first direction of rotation tegenovergesteldis to the second rotational direction; en waarbij de verzamelingen van armen van de eersteen tweede rotors zijn gerangschikt om te draaien in een inhoofdzaak gezamenlijk draaivlak. and wherein the sets of arms of the solder toe second rotors are arranged to run in a common plane of rotation inhoofdzaak.
  2. 2. Windturbine volgens conclusie 1, waarbij deeerste en tweede rotatie-assen zijn gerangschikt in eengezamenlijk in hoofdzaak verticaal vlak loodrecht op hetgezamenlijk draaivlak. 2. Wind turbine according to claim 1, wherein thefirst and second axes of rotation are arranged in eengezamenlijk substantially vertical plane perpendicular to hetgezamenlijk rotation plane.
  3. 3. Windturbine volgens conclusie 1 of conclusie2, waarbij elk van de aangrijpoppervlakken is ingericht omom zijn vouwlijn te vouwen tussen een uitgevouwen positiewanneer het windaangrijpoppervlak in hoofdzaakstroomopwaarts van zijn arm is geplaatst en een gevouwenpositie wanneer het windaangrijpoppervlak in hoofdzaakstroomafwaarts van zijn arm is geplaatst. 3. A wind turbine as claimed in claim 1 or in claim 2, wherein each of the engaging surfaces is adapted OMOM folding its fold line is disposed between a folded-out position when the windaangrijpoppervlak substantially upstream of its arm, and a folded position when the windaangrijpoppervlak is placed in hoofdzaakstroomafwaarts of his arm.
  4. 4. Windturbine volgens één der voorgaandeconclusies, waarbij de eerste rotor en/of de tweede rotor één of meer bijkomstige verzamelingen van armen omvatten dielangs zijn respectievelijke rotatie-as op afstand zijngeplaatst van de verzameling van armen en zich in hoofdzaakradiaal uitstrekken ten opzichte van de rotatie-as, waarbijelk van de armen van de bijkomstige verzamelingen van armeneen vouwbaar windaangrijpoppervlak omvatten met een vouwlijnin hoofdzaak in een vlak normaal aan de rotatie-as. 4. A wind turbine according to any one of the preceding claims, wherein the first rotor and / or the second rotor, one or more secondary sets of arms comprise dielangs its respective rotation axis are spaced from the set of arms, and extend substantially radially with respect to the rotation -axis, waarbijelk of the arms of the secondary sets of poor no foldable windaangrijpoppervlak comprise a vouwlijnin substantially in a plane normal to the axis of rotation.
  5. 5. Windturbine volgens één der voorgaandeconclusies, waarbij elk van de vouwbarewindaangrijpoppervlakken is ingericht om wegens dewindstroom om zijn vouwlijn te vouwen naar een uitgevouwenpositie wanneer het windaangrijpoppervlak tussen de eersteen tweede rotatie-assen is geplaatst. 5. A wind turbine according to any one of the preceding claims, wherein each of the vouwbarewindaangrijpoppervlakken is arranged to dewindstroom due to expand its fold line into a folded-out position when the windaangrijpoppervlak is disposed between the solder toe second axes of rotation.
  6. 6. Windturbine volgens één der voorgaandeconclusies, verder omvattend een ondersteuning voor hetondersteunen van de eerste en tweede rotors, waarbij derotors draaibaar zijn ten opzichte van de ondersteuning rondhun respectievelijke rotatie-assen en waarbij deondersteuning draaibaar is rond een verticale as. 6. A wind turbine according to any one of the preceding claims, further comprising a support for hetondersteunen of the first and second rotors, wherein derotors are rotatable with respect to the support rondhun respective axes of rotation, and wherein deondersteuning is rotatable about a vertical axis.
  7. 7. Windturbine volgens één der voorgaandeconclusies, verder omvattend een winduitlijnelementingericht om de eerste rotatie-as en de tweede rotatie-asuit te lijnen in een richting in hoofdzaak loodrecht op deeerste richting. 7. A wind turbine according to any one of the preceding claims, further comprising a winduitlijnelementingericht to the first rotation axis and the second rotation of ashes to align in a direction substantially perpendicular to the direction of thefirst.
  8. 8. Windturbine volgens één der voorgaandeconclusies, waarbij de eerste rotor en de tweede rotorspiegelsymmetrisch zijn ten opzichte van een vlak parallelaan en op gelijke afstand van de eerste en tweede rotatie-assen van de rotors. 8. A wind turbine according to any one of the preceding claims, wherein the first rotor and the second rotor are mirror symmetrical relative to a plane parallelaan and at an equal distance from the first and second axes of rotation of the rotors.
  9. 9. Windturbine volgens één der voorgaandeconclusies, waarbij, wanneer uitgevouwen, elk van dewindaangrijpoppervlakken is ingericht om een in hoofdzaakhol oppervlak te vormen dat met zijn holle zijde is gerichtnaar de eerste richting van de windstroom. 9. A wind turbine according to any one of the preceding claims, wherein, when unfolded, each of dewi disposed gripping surfaces is arranged to form an in hoofdzaakhol surface which, with its concave side is directed towards the first direction of the wind stream.
  10. 10. Windturbine volgens één der voorgaandeconclusies, waarbij de windaangrijpoppervlakken van de armeneen flexibel materiaal omvatten, bij voorkeur een flexibel vel. 10. A wind turbine according to any one of the preceding claims, wherein the windaangrijpoppervlakken of poor nay comprise a flexible material, preferably a flexible sheet.
  11. 11. Windturbine volgens één der voorgaandeconclusies, waarbij de windaangrijpoppervlakken van de armeneen veerkrachtig materiaal omvatten. 11. A wind turbine according to any one of the preceding claims, wherein the poor no windaangrijpoppervlakken comprise resilient material.
  12. 12. Windturbine volgens één der voorgaandeconclusies, waarbij de windaangrijpoppervlakken van de armenverder één of meer versterkingselementen omvatten. 12. The wind turbine of any one of the preceding claims, wherein the windaangrijpoppervlakken of the arms further comprises one or more reinforcing elements.
  13. 13. Windturbine volgens één der voorgaandeconclusies, waarbij één of meer van dewindaangrijpoppervlakken van een arm van de eerste en/oftweede rotor omvat: een eerste gedeelte ingericht om de windstroom aante grijpen, waarbij het eerste gedeelte langs een eersterand vouwbaar is verbonden met de arm; 13. A wind turbine according to any one of the preceding claims, wherein one or more of dewi disposed gripping surfaces of an arm of the first and / oftweede rotor: decorated a first portion for gripping the wind power aante, wherein said first portion along a first edge foldably connected to the arm; een tweede gedeelte ingericht om de windstroom aante grijpen, waarbij het tweede gedeelte langs een tweederand vouwbaar is verbonden met de arm. a second portion configured to engage the wind stream aante, wherein the second portion along a second edge foldably connected to the arm.
  14. 14. Windturbine volgens conclusie 13, waarbij deeerste en tweede gedeelten scharnierbaar zijn verbonden metde arm. 14. A wind turbine according to claim 13, wherein thefirst and second portions are hingedly connected withthe arm.
  15. 15. Windturbine volgens één der voorgaandeconclusies, waarbij de eerste rotor en/of de tweede rotorverder beperkingstructuren omvat voor het beperken van deopeningshoek van zijn windaangrijpoppervlakken. 15. A wind turbine according to any one of the preceding claims, wherein the first rotor and / or rotor further comprises the second restricting structure for restricting deopeningshoek of its windaangrijpoppervlakken.
  16. 16. Windturbine volgens conclusie 15, waarbij debeperkingstructuren een link omvatten die secties van eenwindaangri jpoppervlak van een arm van de windturbine aantegenovergelegen zijden van de arm met elkaar verbindt. 16. A wind turbine according to claim 15, wherein a link debeperkingstructuren include those sections of eenwindaangri jpoppervlak of an arm of the wind turbine as they walked on sides of the arm connects with each other.
  17. 17. Windturbine volgens conclusie 15 of conclusie16, waarbij de beperkingstructuren omvatten: een eerste link, verbonden met een eerste sectievan een windaangri jpoppervlak van een arm van de eersterotor of de tweede rotor, en een tweede link, verbonden meteen tweede sectie van het windaangrijpoppervlak, waarbij deeerste en tweede secties zijn gerangschikt aantegenovergelegen zijden van de arm, en waarbij de eerste entweede links zijn verbonden met een arm die naburig is aan de arm van de rotor in een richting tegenovergesteld aan dedraairichting van rotor. 17. A wind turbine according to claim 15 or claim 16, wherein the restriction structure comprises: a first link connected to a first sectievan a windaangri jpoppervlak of an arm of the first rotor or the second rotor, and a second link, connected immediately second section of the windaangrijpoppervlak, wherein thefirst and second sections are arranged as they walked on sides of said arm, and wherein the first entweede links are connected to an arm which is adjacent to the arm of the rotor in a direction opposite to dedraairichting of rotor.
  18. 18. Windturbine volgens één der voorgaandeconclusies, waarbij de windaangrijpoppervlakken van de armenin hoofdzaak symmetrisch zijn langs hun respectievelijkearmen. 18. A wind turbine according to any one of the preceding claims, wherein the windaangrijpoppervlakken of the armenin are substantially symmetrical along their respectievelijkearmen.
  19. 19. Windturbine volgens één der voorgaandeconclusies, waarbij de armen een distaai einde aan hun verreeinde van de rotatie-as omvatten, waarbij de windturbineverder één of meer verbindingselementen omvat die de distaleeinden van naburige armen op een rotor met elkaar verbindt. 19. The wind turbine according to any one of the preceding claims, wherein the arms comprise a distaai end to their distal end of the rotary shaft, wherein the wind turbine further comprises one or more connection elements connecting the distaleeinden of adjacent arms on a rotor with each other.
  20. 20. Windturbine volgens één der voorgaandeconclusies, verder omvattend een in de luchthefstructuurvoor het van de grond af heffen van de windturbine, waarbijde in de luchthefstructuur bij voorkeur een ballon omvat diegevuld is met een materiaal dat lichter is dan lucht. 20. The wind turbine according to any one of the preceding claims, further comprising an in the luchthefstructuurvoor lift it from the ground of the wind turbine, where bijde in the luchthefstructuur preferably comprises a balloon diegevuld with a material which is lighter than air.
  21. 21. Windturbine volgens één der voorgaandeconclusies, verder omvattend een inrichting die wordtaangedreven door draaiing van de rotors. 21. The wind turbine according to any one of the preceding claims, further comprising a device which is driven by rotation of the rotors.
  22. 22. Gebruik van een windturbine volgens één dervoorgaande conclusies voor het aandrijven van eeninrichting. 22. Use of a wind turbine according to any one dervoorgaande claims for driving eeninrichting.
  23. 23. Gebruik volgens conclusie 22, waarbij deinrichting een pomp of een dynamo omvat. 23. Use according to claim 22, wherein heaving device comprises a pump or a dynamo.
NL2008228A 2012-02-03 2012-02-03 Wind turbine having counter rotating blades. NL2008228C (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5570997A (en) * 1995-07-17 1996-11-05 Pratt; Charles W. Horizontal windmill with folding blades
WO2009118427A1 (en) * 2008-03-26 2009-10-01 Munoz Saiz Manuel System for the collection of wind energy using elevated turbines
WO2010062273A2 (en) * 2008-09-22 2010-06-03 Kavlak Ahmet Dr Wind turbine with air motor and vertical axis controlled with air pressure
US20100181777A1 (en) * 2009-01-16 2010-07-22 Charles Grigg Wind turbine generator and motor
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
US5570997A (en) * 1995-07-17 1996-11-05 Pratt; Charles W. Horizontal windmill with folding blades
WO2009118427A1 (en) * 2008-03-26 2009-10-01 Munoz Saiz Manuel System for the collection of wind energy using elevated turbines
WO2010062273A2 (en) * 2008-09-22 2010-06-03 Kavlak Ahmet Dr Wind turbine with air motor and vertical axis controlled with air pressure
US20100181777A1 (en) * 2009-01-16 2010-07-22 Charles Grigg Wind turbine generator and motor
WO2011116440A1 (en) * 2010-03-23 2011-09-29 Dulcetti Filho Flavio Francisco Vertical wind turbine with articulated blades

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