TECHNICAL FIELD

[0001] The present disclosure relates to a wind turbine. More particularly, the present disclosure relates to a wind turbine with hinged blades.

BACKGROUND

[0002] Wind turbines convert kinetic energy from wind into rotational energy that can subsequently be converted into electrical energy by a generator. Over the years, various configurations of wind turbines have been developed. Wind turbines with a rotor axis transverse to ground (e.g. vertical axis wind turbines) typically do not require alignment of their rotor with the direction of wind, thereby effectively converting kinetic energy in wind into rotational energy irrespective of the direction of the wind. Further, vertical axis wind turbines can have their drive train positioned closer to ground level in comparison to horizontal axis wind turbines which, conversely, are required to position the drive train at the level of the rotating shaft. Drive trains positioned closer to ground level can be cheaper to install and to maintain. Despite these advantages, horizontal axis wind turbines are still widely used because the entire surface of each of the blades of a horizontal axis wind turbine is exposed to the force of the wind when a horizontal axis wind turbine is positioned in the direction of the wind. As a result, horizontal axis wind turbines typically have greater wind to rotation conversion efficiencies when compared to vertical axis wind turbines.

[0003] Various configurations of vertical axis wind turbines have been developed. For example, United States Patent No. 6,688,842 discloses a vertical axis wind engine which includes a support structure, a rotor mounted rotatably on the support structure for rotation about a vertical axis, and at least one airfoil for causing the rotor to rotate about the vertical axis in response to wind passing the wind engine. The at least one airfoil has vertically extending leading and trailing edges, an angle-of-attack axis extending horizontally through the leading and trailing edges, and a pivotal axis extending vertically intermediate the leading and trailing edges. The airfoil is mounted on the rotor for pivotal movement about the pivotal axis and the rotor includes components for limiting pivotal movement of the airfoil to first and second limits of pivotal movement. The airfoil is free to pivot about the pivotal axis intermediate the first and second limits of pivotal movement as the rotor rotates about the vertical axis to thereby enable the airfoil to align the angle-of-attack axis according to the wind. By providing for air to pass through the centre of the wind engine, this configuration exhibits efficiency problems as the orientation of the airfoils arranged around the rotor create drag as air moves through the centre portion of the rotor.

[0004] United States Patent No. 6,465,899 aims to eliminate back pressure by teaching an omni-directional, vertical-axis wind turbine which includes a rotor/stator combination. The stator section includes a plurality of vertical blades secured between upper and lower conical sails. The blades have a radius fundamentally equal to that of the rotor and a chord length approximately 1.25 times it radius. The rotor has a diameter approximately equal to one-half that of the stator and has a plurality of concave blades secured to a spaced from a vertical spindle, said blades being arranged in stages within the vertical rise of the rotor. Each rotor blade has a chord line equal to twice its radii and a chord length approximately one-third of the diameter of the stator. In aiming to eliminate back pressure on the wind turbine, the configuration provided increases internal pressure within the rotor and, at high wind speeds, air flow across the stator blades stalls and creates back pressure to be self-limiting.

[0005] United States Patent Application No. 2012/0301297 teaches a vertical axis, fluid turbine device comprising a turbine rotor with a rotatable, central shaft and three to six, equally spaces rotor vane sections connected to the central shaft with adjacent vane sections connected to one another in a framework. A generally hexagonal framework funnels wind forces towards the vane sections for transferring wind forces into rotational movement of the device. However, at times some vane panels are not presented to the wind, thereby resulting in some air resistance (e.g. drag). Further, air is permitted to pass through the center of the rotor resulting in additional inefficiency problems. SUMMARY

[0006] It is an object of the present invention to mitigate at least one of the above disadvantages.

[0007] In one embodiment, a wind turbine comprising: a shaft; a plate coupled to the shaft; a plurality of blades, each blade rotatably coupled to the plate such that each blade is rotatable between a closed position and an open position, each blade having an outer surface and an inner surface and positioned about the plate such that: in the closed position, the outer surface of each blade co-operates with the outer surface of an adjacent blade to form a periphery of the wind turbine to direct a flow of wind along the outer surfaces of the adjacent blades away from an interior of the periphery, and during rotation from the closed position to the open position, each blade when extending outwardly from the periphery experiences a drag force due to the flow of wind against the interior surface to contribute to rotation of the plate; and a plurality of abutment surfaces, each abutment surface disposed about a respective blade of the plurality of blades, said each abutment surface positioned to constrain said respective blade from rotating beyond the open position.

[0008] According to another embodiment, a trailing edge of each blade is positioned immediately adjacent to a leading edge of the adjacent blade to direct the flow of wind along the outer surfaces of the adjacent blades away from the interior of the periphery.

[0009] According to another embodiment, a trailing edge of each blade is spaced from a leading edge of the adjacent blade by a predefined distance to direct the flow of wind along the outer surfaces of the adjacent blades away from the interior of the periphery.

[0010] According to another embodiment, a trailing edge of each blade overlaps at least a portion of a leading edge of the adjacent blade to direct the flow of wind along the outer surfaces of the adjacent blades away from the interior of the periphery.

[0011] According to another embodiment, each blade couples to the plate at a hinge point, each hinge point coupling one blade to the plate. [0012] According to another embodiment, each blade couples to the plate at a hinge point, each hinge point positioned between two abutment surfaces.

[0013] According to another embodiment, each blade forms a pair of opposed blades with an opposed blade, each pair of opposed blades arranged such that as each blade of the pair of opposed blades is moving from the closed position to the open position, the opposed blade is moving from the open position to the closed position.

[0014] According to another embodiment, each blade couples to the plate at a hinge point, each hinge point spaced from an adjacent hinge point and positioned about the periphery of the plate such that the outer surfaces of the plurality of blades co-operate to form a boundary surrounding the rotation point when each blade is in the closed position.

[0015] Additional aspects and advantages of the present invention will be apparent in view of the description which follows. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0017] Figure 1 shows an isometric view of one embodiment of a wind turbine where a plurality of blades is hingedly coupled to a plate coupled to a shaft. When wind in any direction strikes an outer surface of the plurality of blades, the blades move from a closed position to an open position to convert wind energy to rotational energy.

[0018] Figures 2A and 2B each show a top view of the wind turbine of Figure 1 .

[0019] Figure 3 shows an isometric view of the wind turbine of Figure 1 wherein the base does not extend beyond an edge of the plate. [0020] Figure 4 shows a top view of various states of a blade of the wind turbine of Figure 1 at various locations on the plate, marked A to F, as the plate completes one rotation about the shaft; and

[0021] Figure 5 shows a top view of the wind turbine of Figure 4 illustrating a torque moment created in relation to air flow around the blades at locations A and B.

[0022] Figure 6 shows a top view of one embodiment of Figure 1 of a wind turbine comprising three blades and a hub positioned within the interior.

[0023] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

DETAILED DESCRIPTION

[0024] Embodiments are described below, by way of example, with reference to Figures 1 to 6. The embodiments described and depicted herein provide a wind turbine.

[0025] It will be understood that the terms "top" and "bottom" referred to herein are used in the context of the attached Figures. The terms are not necessarily reflective of the orientation of wind turbine 100 in actual use and are therefore not meant to be limiting in their use herein.

[0026] Described herein are various embodiments for a wind turbine that uses wind energy to rotate a shaft as further described below. This rotation can subsequently be converted into electrical energy by a generator (e.g. a rotor and stator).

[0027] The wind turbine embodiments described herein comprise a shaft, a plate and a plurality of blades coupled to the plate. The shaft is coupled to the plate at a rotation point and each of the blades is coupled to the plate about or within a periphery of the wind turbine. The periphery of the wind turbine is distal to the rotation point and can include an edge of the plate or can be adjacent to (e.g. spaced apart from) the edge of the plate. In one embodiment, the shaft can be coupled to the plate distal (e.g. spaced apart) from a center of the plate. In another embodiment, the shaft can be coupled to the plate at the center of the plate. [0028] Each blade has an inner surface and an outer surface which co-operate to provide each blade with an arcuate (e.g. curved) shape. The inner surface of each blade has a concave shape. The inner surface of each blade is defined as being the surface opposed to and facing the shaft when the blade is in a closed position (further defined below). The inner surface of each blade therefore faces the inner surface of each other blade when each blade is in its closed position. The inner surface of each of the plurality of blades co-operates to form an interior of the wind turbine when each of the blades is in a closed position.

[0029] Conversely, the outer surface of each blade has a convex shape and is opposed and transverse to a direction of moving fluid (e.g. moving air or wind) when each blade is in its closed position. The outer surface of each blade co-operates with the outer surface of an adjacent blade to form a periphery of the wind turbine. The periphery of the wind turbine can direct a flow of moving fluid along the outer surfaces of the adjacent blades. Each blade can thereby inhibit moving fluid travelling transverse to the outer surface of each of the blades of the wind turbine from entering the interior of the wind turbine. Further, the outer surface of each blade can co-operate with an outer surface of an adjacent blade to surround (e.g. enclose) the rotation point (and at least a portion of the shaft) of the wind turbine and form a periphery of the wind turbine when the blades are in the closed position.

[0030] Each blade is hingedly coupled to a surface of the plate such that each blade can rotate between a first (e.g. closed position) and a second (e.g. open position). The closed position of each blade is a position where the outer surface of the blade inhibits movement of fluid (e.g. air) from entering the interior of the wind turbine. The open position of each blade is a position where the inner surface of the blade is acted upon by moving fluid (e.g. air) to contribute to rotation of the plate and the shaft. The inner surface of each blade can receive energy from a moving fluid (e.g. wind) to contribute to the rotation of the plate and the shaft when in the open position. The moving fluid therefore supplies energy to the wind turbine to contribute to the rotation of the plate and the shaft.

[0031] Turning to the Figures, the wind turbine 100 is described in further detail. [0032] Figure 1 of the drawings shows an isometric view of the main components of one embodiment of wind turbine 100. In this embodiment, wind turbine 100 comprises a base 102 for support, a plate 104 rotatably coupled to a shaft 106 for rotation about an axis X defined by the shaft 106, and a plurality of blades 108 hingedly coupled to plate 104.

[0033] Wind turbine 100 comprises a shaft 106 co-operating at a first end with a generator 130 and coupled at a second end to plate 104 such that rotation of plate 104 can rotate shaft 106. Wind turbine 100 is arranged such that shaft 106 is oriented transverse to ground, where an axis of rotation X of shaft 106 is transverse to a direction of flow of a fluid (e.g. air). Shaft 106 of wind turbine 100 co-operates at a first end with a generator 130 and couples at a second end to plate 104. In the embodiment shown in the Figures, plate 104 is coupled to shaft 106 such that shaft 106 is transverse to plate 104. The shaft is coupled to the plate at a rotation point such that the plate 104 is rotatable about an axis X defined by shaft 106 where axis X is transverse to a flow of fluid. Rotation of plate 104 provides for rotation of shaft 106 about axis X. Wind turbine 100 can also comprise a rotor and a stator (not shown) positioned within an interior (defined below) of the wind turbine 100 to convert wind energy into electrical energy. For example, the rotor and stator configured to rotate with respect to one another, one of the rotor or the stator mounted to the shaft 106 and the other of the rotor or the stator mounted to the plate 104.

[0034] Shaft 106 is coupled to plate 104 at a rotation point 1 10 within a periphery 1 13 of wind turbine 100. Periphery 113 of wind turbine 100 is distal to rotation point 10 and can include an edge 122 of plate 104 or can be adjacent to (e.g. spaced apart from) edge 122 of plate 104. In one embodiment, shaft 106 can be coupled to plate 104 distal (e.g. spaced apart) from edge 122 of plate 104. In another embodiment, shaft 106 can be coupled to plate 104 at a center of plate 104.

[0035] Plate 104 can support each blade 108 of a plurality of blades. Each blade 108 is rotatably coupled to plate 104. In one embodiment, each blade 108 is hingedly coupled to plate 104. A top surface 1 12 of plate 104 can support each blade 108 such that each blade 108 is hingedly coupled to surface 112 of plate 104 at a hinge point 115. It should be understood that each blade 108 couples to surface 112 of plate 104 at a separate hinge point 115. In the embodiments shown in the Figures, each hinge point 115 is positioned on surface 112 of plate 106 about rotation point 110 within periphery 113. For example, each hinge point 115 can disposed about rotation point 110 such that each hinge point 115 co-operates each other hinge point 115 to form a round (e.g. circular) pattern on surface 112 of plate 104.

[0036] In the embodiment shown in Figures 1 to 3, each hinge point 115 is positioned on surface 112 of plate 104 adjacent to edge 122. Plate 104 can have any shape so long as it provides a surface 112. For example, in one embodiment, plate 104 can have a round (e.g. circular or disk) shape. Each hinge point 115 is distal to and spaced apart from an adjacent hinge point 115 by a predefined distance. For example, each hinge point 115 can be positioned such that a distance between hinge point 5 and an adjacent hinge point 115 is equal to a chord length of one of the blades 108 coupled to plate 104 at one of the two adjacent hinge points 115. For example, referring to Figure 2, hinge point A can be spaced from hinge point B by a distance substantially the same as a chord length of the blade 108 coupled to surface 112 of plate 104 at hinge point B.

[0037] Each blade 108 has a leading edge 140 and a trailing edge 142 (see Figures 3 and 4). A direction of rotation of plate 104 defines leading edge 140 and trailing edge 142 of each blade 108. Leading edge 140 of each blade 108 is positioned in a direction of rotation of the plate from trailing edge 142 and leading edge 140 is spaced from trailing edge 142 by a predefined distance. As such, for each blade 108, trailing edge 142 is upstream from leading edge 140 and leading edge 140 is downstream from trailing edge 142 when a fluid passes over outer surface 124 surface of blade 108. The term upstream can be defined as direction of fluid flow experienced by (i.e. away from) a position on a flow pathway (i.e. outer surface of blade) relative to the direction experienced by (i.e. towards) another position on the same flow pathway (i.e. outer surface of blade). The term downstream can be defined as direction of fluid flow experienced by (i.e. towards) a position on a flow pathway (i.e. outer surface of blade) relative to the direction experienced by (i.e. away from) another position on the same flow pathway (i.e. outer surface of blade). Each blade 108 has an inner surface 1 18 and an outer surface 124 which co-operate to provide each blade 108 with an arcuate (e.g. curved) shape. The terms inner and outer refer to the orientation of each blade 108 when in its first (e.g. closed) position (described further below). Inner surface 8 of blade 108 has a concave shape and is defined as being opposed and facing shaft 106 when blade 108 is in a closed position (described further below). Inner surface 1 18 of blade 108 therefore faces each other inner surface 1 18 of each other blade 108 when each blade 108 is in its closed position. Conversely, outer surface 124 of each blade 108 has a convex shape and is defined as being opposed and transverse to a direction of moving fluid when each blade 108 is in its closed position. Each blade 108 can thereby direct movement of moving fluid, where periphery 113 can direct a flow of moving fluid along the outer surfaces 124 of the blades 108 away from an interior 152 (defined below) of the periphery 113. Each blade

108 can have a two-dimensional cross sectional shape profile (ignoring material thickness of the blade 108) and is capable of adopting various two-dimensional profiles. In some cases, depending on the materials, structure and processes used, blades 108 with a three-dimensional profile can be adopted. For example, a cross sectional 3D profile of each blade 108 is such that curvature of the outer surface is different from the curvature of the inner surface of the blade 108, for example an airfoil shape. Each blade 108 can actively or passively contribute to rotation of plate 104 (and therefore shaft 106), as described below.

[0038] As shown in Figure 4, a blade 108A can form an adjacent pair of blades 109 with an adjacent blade 108B. Blade 108A is adjacent to an adjacent blade 108B if trailing edge 142 of blade 108A is adjacent (e.g. proximate) to leading edge 140 of adjacent blade 108B. Outer surface 124 of each blade 108A and 108B of an adjacent pair of blades 109 co-operates to surround (e.g. enclose) rotation point 1 10 and periphery 1 13 when each blade 108A and 108B of adjacent pair of blades 109 are in their closed position. Although specific blades 108A and 108B are illustrated and identified in Figure 4, it should be understood that each blade 108 of the plurality of blades can be part of at least one adjacent pair of blades 109.

[0039] Inner surface 1 18 of each blade 108A and 108B of an adjacent pair of blades

109 co-operates to form a boundary 150 of periphery 1 13 when each blade 108A and periphery 113 is shaped by inner surfaces 18 of each blade 108A and 108B when in the closed position. An interior 152 of periphery 113 is formed about shaft 106 by cooperating inner surfaces 8 of each blade 108 when each blade 108 is in its closed position. Interior 152 is a space defined by the inner surfaces 118 of blades 108 when each blade 108 is in its closed position within (e.g. opposed to) periphery 113. Therefore, outer surface 124 of each blade 108A and 108B of an adjacent pair of blades 109 co-operates to surround (e.g. enclose) interior 152 when each blade 108A and 108B of adjacent pair of blades 109 are in their closed position.

[0040] Each blade 108 is coupled to plate 104 such that each blade 108 is moveable between a first (e.g. closed) position and a second (e.g. open) position. The closed position of each blade 108 is a position where outer surface 124 of blade 108 inhibits moving fluid from entering interior 152. When in the closed position, each blade 108 passively contributes to rotation of plate 104 by directing moving fluid around periphery 113 and thus inhibiting excessive drag forces pertaining to the wind from acting on the interior surface 118 of the closed blade 108. For example, in the closed position of blade 610 of Figure 6B, this blade 610 is rotating towards the wind and thus deflects the wind along its outside surface 124 from the windward side to the leeward side of the wind turbine 600. It is recognised that impingement of the wind on the outer surface 124 of the blade 610 counteracts effects of the Bernoulli principle and thus the blade 610 preferably remains in the closed position in order to inhibit opening of the blade 610.

[0041] The open position of each blade 108 is a position where inner surface 118 is acted upon by moving fluid. When acted upon, each inner surface 118 can receive energy from the moving fluid to actively contribute to rotation of plate 104 and shaft 106. In one embodiment, each blade 108 extends radially from surface 112 of plate 104 after rotation about hinge point 115 when in its open position. Each blade 108 actively contributes to rotation of the plate 104 when the blade 108 is one of: moving between the blade's 108 closed position and the blade's 108 open position, in the blade's 108 open position or between the blade's 108 closed position and the blade's 108 open position. Blades 108 actively contribute to rotation of the plate 104 by either directing

10 (e.g. receiving) moving fluid about the periphery of the wind turbine 100 along thie outer surface 124, or deflecting the moving fluid by impingement of the moving fluid on their inner surface 1 18.

[0042] An adjacent pair of blades 109 can be positioned such that each blade 108A and 108B comprising the adjacent pair of blades 109 are coupled to plate 104 on the same side of shaft 106. In this configuration, each outer surface 124 of each blade 108 of the pair of adjacent blades 09 can be arranged such that each blade 08 of the adjacent pair of blades 109 co-operates to inhibit moving fluid from entering interior 152. In one exemplary configuration, trailing edge 142 of a blade 108A of adjacent pair of blades 109 is immediately adjacent to (e.g. contiguous with) leading edge 140 of a second blade 108B. In another exemplary configuration, trailing edge 142 of blade 108A overlaps leading edge 140 of blade 108B, where overlaps refers to at least a portion of inner surface 118 (e.g. trailing edge 142) of blade 108A being opposed to at least a portion of outer surface 142 (e.g. leading edge) of blade 108B. In a third exemplary configuration, trailing edge 142 of blade 108A is spaced apart from leading edge 140 of blade 108B by a predefined distance to inhibit flow of fluid therebetween into interior 152.

[0043] As also shown in Figure 4, a blade 08A can form an opposed pair of blades 1 1 1 with a blade 108C if inner surface 1 18 of each of blades 108A and 108C are positioned opposed to each other around periphery 1 13. An opposed pair of blades 109 is arranged such that inner surfaces 1 18 of each blade 108A and 108C are spaced apart from shaft 106 and positioned about periphery 1 13 such that inner surfaces 1 18 are on opposite sides of shaft 106. In this arrangement, as blade 108A of the pair of opposed blades 1 1 1 is moving from its closed position to its open position, blade 108C is moving from its open position to its closed position. Similarly, as blade 108A of the pair of opposed blades 111 is moving from its open position to its closed position, blade 108C is moving from its closed position to its open position. Again, although specific blades 108A and 108C are illustrated and identified in Figure 4, it should be understood that each blade 108 of the plurality of blades can be part of an opposed pair of blades 1 1 1. [0044] Each blade 108 couples to plate 104 at a separate hinge point 115. In one embodiment, leading edge 140 of blade 108 is proximate to hinge point 115 and trailing edge 142 is distal to hinge point 1 15. Each hinge point 1 15 is positioned in or on periphery 1 13, on surface 1 12 of plate 104, about shaft 106. In one embodiment, each hinge point 115 is positioned on edge 122 of plate 104 about shaft 106. In another embodiment, plate 104 is round (e.g. circular) and each hinge point 1 15 is positioned on periphery 1 13 adjacent to edge 122. Each hinge point 1 15 can be positioned such that a distance between a hinge point 115 and an adjacent hinge point is the same as a chord length of one of the pair of blades coupled to one of the hinge points 115 and one of its adjacent hinge points.

[0045] Each blade 108 can rotate between an open position and a closed position, as previously described. As shown in Figure 4, each open position of each blade 108 is determined by a first abutment surface 411 . In one embodiment, first abutment surface 41 1 is disposed about each hinge point 1 15. Similarly, each closed position of each blade 108 is determined by a second abutment surface 412. In one embodiment, a second abutment surface 412 is disposed about each hinge point 115. In one example, an abutment 401 (e.g. a collar) can be positioned about each hinge point 1 15 to provide the first abutment surface 41 1 and second abutment surface 412 for each blade 108. In another example, two abutments 401 can be positioned about the hinge point 1 15 to provide the first abutment surface 41 1 and second abutment surface 412, each abutment 401 providing one of abutment surfaces 41 1 ,412. In another example, the outer surface 124 of an adjacent blade 108B of adjacent pair of blades 109 can provide an abutment surface for blade 108A.

[0046] As moving fluid approaches wind turbine 100 and interacts with the outer surface 124 of at least one blade 108, the moving fluid is inhibited from entering interior 152 by outer surfaces 124 of one of blade 108 or adjacent pair of blades 109. Moving fluid approaching wind turbine 100 either travels through interior 152 or is redirected to travel along outer surface 124 of blade 108 in one of two directions, a rearward direction and a forward direction. Moving fluid travelling through interior 152 is redirected by an inner surface 124 of a blade 108 that is moving from its open position to its closed position to actively contribute to rotation of plate 104. Moving fluid deflected in the forward direction travels towards a forward side 450 of wind turbine 100 where the moving fluid can act to actively rotate each blade 108 of the plurality of blades from its closed position to its open position. Conversely, moving fluid deflected in the rearward direction travels towards a rearward side 451 of wind turbine 100 where it acts to rotate each blade 108 of the plurality of blades from its open position to its closed position and passively contribute to rotation of plate 104 (e.g. wind turbine 100).

[0047] As fluid moves along outer surface 124 of each blade 108, a pressure difference arises between interior 152 and outer surface of the blade 124. A pressure in interior 152, Pstatic, higher than a pressure immediately adjacent to outer surface 124, Plow, generates a torque force on the inner surface of the blade 108 as shown in Figure 5. The torque force contributes to moving (e.g. rotating) each blade 108 from its closed position towards its open position.

[0048] As each blade 108 rotates from its closed position to its open position, inner surface 1 18 of each blade 1 18 becomes exposed to the moving fluid which can directly act on inner surface 8 in a direction transverse to inner surface 1 8. Inner surface 1 18 of each blade 108 can receive energy from moving fluid once each blade 108 has begun to rotate from its closed position to its open position. Energy received from the moving fluid by each blade 108 can complete rotation of each blade 108 to its open position.

[0049] In its open position, at least a portion of outer surface 124 of blade 108 is resting against second abutment surface 412. Each second abutment surface 412 therefore constrains rotation of each blade 108 beyond its second (e.g. open) position. Moving fluid directly acting upon inner surface 1 18 delivers a force to each blade 108 that drives rotation of plate 104 (and subsequently shaft 106) about axis X. The energy (e.g. wind energy) supplied by the moving fluid is therefore converted into rotational energy as the moving fluid is received by the concave inner surface 1 18 of each blade 108.

[0050] As plate 104 rotates about shaft 106, each blade 108A of opposed pair of blades 111 passes behind its opposed blade 108C such that inner surface 118 of blade 108A is no longer acted upon by the moving fluid. A drag force (not shown) can be received by outer surface 124 of blade 108A from moving fluid travelling around rearward side 451 of wind turbine 100 such that blade 108A begins to move (e.g. rotate) from its open position to its closed position. Blade 108A continues to move towards its closed position until at least a portion of inner surface 118 of blade 108A contacts at least a portion of first abutment surface 41 .

[0051] One embodiment of wind turbine 100 is shown in Figures 2A and 2B, where top views of wind turbine 100 of Figure 1 at two positions, respectively, are presented. Figure 2A shows an embodiment with six blades 108, positions of each blade 108 identified by reference letters A-F. As described above, each blade 108 is positioned adjacent to edge 122 of plate 104. In this embodiment, each blade 108 is configured to rotate in a counterclockwise direction about its respective hinge point 1 15 (as shown by the rotation of positions A-F in Figure 2B). Correspondingly, plate 104 and shaft 106 are also configured to rotate in a counterclockwise direction in the embodiments shown. It should be noted that the wind turbine 100 can also be configured to rotate in a clockwise direction by reversing the position of each of blade 108 hingedly coupled to plate 104. For example, as shown in Figures 2A and 2B, the blade 108 shown hingedly coupled at position B is shown extending towards position A. In a reverse configuration, the blade 108 hingedly coupled at position B would extend towards position C.

[0052] Although Figures 1 and 2 show an isometric and top view, respectively, of one embodiment of a wind turbine 100 with a plate 104 rotatably coupled to a shaft 106, it should be understood that wind turbine 100 could also comprise more than one plate 104 rotatably coupled to shaft 106 (e.g. plate 104 with blades 108 hingedly coupled thereupon are stackable) as a series of stacked plates 104 on top of one another. In this embodiment, each plate 104 is rotatably coupled to a shaft 106 and comprises a plurality of blades 108 hingedly coupled to each top surface 12 of each plate 104, each blade 108 rotatable between a closed position and an open position. Each plate 104 could be oriented as shown in Figures 1 and 2, where each plate 104 is separated by a distance approximately greater than or equal to a height of blades 108, thus providing for the stacked configuration. Conversely, plates 104 could be coupled to shaft 106 such that the plates 104 are proximate to each other and have opposite orientations (e.g. one of plates 104 is upside-down with respect to the other plate 104), thus providing a stacked configuration.

[0053] Figure 3 shows an isometric view of wind turbine 100. In this embodiment, base 102 is rectangular shaped and does not extend beyond edge 122 of plate 104.

[0054] Figure 4 illustrates various states of each blade 108 at various locations (identified by reference letters A through F) on plate 104 during one revolution of plate 104 about axis X. At any time during rotation of plate 104, each blade 108 contributes to rotation of plate 104. Each blade 108 is hingedly coupled to surface 112 of plate 104 such that each blade 108 rotates between a first position (e.g. a closed position) and a second position (e.g. an open position). In this embodiment, the closed position and the open position of each blade 108 is governed by an abutment (e.g. a collar) 401 disposed about each hinge point 115. It should be understood that abutment 401 can be any mechanism positioned to govern rotation of each blade 108 about hinge point 1 15. In the embodiment of Figure 4, each abutment 401 provides two resting surfaces for each blade 108, first abutment surface 411 and second abutment surface 412. In the closed position, inner surface 1 18 of blade 108 rests against first abutment surface 411 of abutment 401 , thereby constraining clockwise rotation of the blade 108 about hinge point 1 15. Conversely, in the open position, outer surface 124 of blade 108 rests against second abutment surface 412 of abutment 401 , thereby constraining counterclockwise rotation of blade 108 about hinge point 1 15.

[0055] As moving fluid approaches wind turbine 100 from any direction, moving fluid engages outer surface 124 of each blade 108 and is redirected around the arcuate (e.g. curved) outer surface 124 provided by one of blade 108 or adjacent pair of blades 109. An area of low pressure Plow adjacent (e.g. proximate) to outer surface 124 of blade 108 (see Figure 5) relative to Pstatic of interior 152 forms. As Pstatic is greater than Plow, a torque acting in a direction transverse to inner surface 118 of blade 108 (as shown in Figure 5) drives blade 108 at location B to begin to move (e.g. rotate) about hinge point 1 15 from its closed position towards its open position. The torque resulting from (e.g. created by) the pressure differential between Pstatic and Plo across blade 108 of wind turbine 100 is shown in Figure 5. [0056] As blade 108 rotates towards its open position (as shown at location C of Figure 4), subsequent rotation of plate 104 (and shaft 106) exposes inner surface 1 18 of blade 108 directly to the force of moving air deflecting off of the outer surface 124 of blade 108 at position B. Energy in the moving fluid redirected by outer surface 124 of blade 108 at position B can contribute to rotation of blade 108 at position C further towards its open position. Inner surface 118 of blade 108 at position C can directly receive kinetic (e.g. wind) energy from the moving fluid once blade 108 has begun to rotate from its closed position to its open position. Receipt of energy by inner surface 1 18 from moving fluid can contribute to moving (e.g. rotating) blade 108 from its closed position to its open position.

[0057] In its open position, as shown at location C of Figure 4, outer surface 124 of blade 108 is resting against the second abutment surface 412 of abutment 401. Abutment 401 therefore constrains rotation of blade 108 beyond its open position, resulting in the kinetic energy of the moving fluid received by inner surface 118 of the blade 08 driving rotation of plate 104 (and subsequently shaft 106) about axis X. The kinetic energy of the moving fluid is therefore converted into rotational energy as the moving fluid is received by the inner surface 118 of each blade 108.

[0058] At location D, moving fluid is inhibited by the adjacent blades 109 at positions A and B and can no longer act on inner surface 118 of blade 108 at location D. Plate 106 continues to rotate clockwise because of the aforementioned force exerted by the movement of fluid on the blades 108 at locations B and C. As such, the blade 108 at location D begins to experience a drag force from the moving fluid travelling around rearward side 451 of wind turbine 100 and begins to rotate clockwise about hinge point 1 15 from its open position towards its closed position. At locations E and F, blade 108 continues to experience drag from moving fluid directed away from interior 152 around rearward side 451 of wind turbine 100 and has returned to its closed position. At location A, blade 108 remains in its closed position.

[0059] Figure 5 is a graphical representation depicting a direction of wind, as indicated by the lined arrows, as it flows around two blades 08 positioned at locations A and B of Figure 4. Figure 5 also illustrates a direction of torque resulting from (e.g. created by) a pressure differential between Pstatic and Plow across blade 108 of wind turbine 100 of Figure 1.

[0060] Figures 6A and 6B show a top view of an embodiment of a wind turbine 600 comprising three blades 610, 61 1 and 612. Figure 6A shows all three of blades 610, 61 1 and 612 in their respective closed positions, for example when the wind turbine 600 is stationary (e.g. not rotating about a hub 604). In this embodiment wind turbine 600 further comprises the hub 604 positioned within interior 613 (e.g. about rotation point 605). In Figure 6B, during rotation of the wind turbine 600 due to impingement of the wind, blade 610 is shown in its closed position, blade 61 1 is shown in its open position and blade 612 is shown at a position between its open position and its closed position. Each of blades 610, 611 and 612 contributes to rotation of plate 601 and shaft 602 (not shown), as further described below.

[0061] While in its closed position, blade 610 directs moving fluid (e.g. wind) around wind turbine 600 and away from interior 613. Blade 610 is biased to its closed position and passively contributes to rotation of plate 601 (and shaft 602), such that fluid moving across an outer surface of blade 610 can create a pressure difference between the interior 613 and the outer surface of blade 610 (e.g. according to Bernoulli's principle). As previously described, this pressure difference drives blade 610 to open as wind turbine 600 rotations counterclockwise, however the blade 610 preferably remains closed due to impingement of the wind on the outer surface of the blade 610 as the blade 610 tries to open as the blade 610 would open "against" the wind (i.e. open in a direction opposite to the direction of the wind). When in its open position, blade 611 receives moving fluid directed towards wind turbine 600. Blade 611 is biased towards its open position (i.e. opens "into" the wind - open in a direction with the direction of the wind) and actively contributes to rotation of plate 601 (and shaft 602). Blade 612 is shown at a position between its open position and its closed position. Blade 612 deflects moving fluid passing through interior 613 of wind turbine 600 and acting thereupon as shown in Figure 6B against the inner surface 118. Blade 612 is biased towards its open position by impingement of the wind against the inner surface 118 and thus actively contributes to rotation of plate 601 (and shaft 602). [0062] The present invention is described in the preceding Examples, which are set forth to aid in the understanding of the invention, and should not be construed to limit in any way the scope of the invention as defined in the claims which follow thereafter.

[0063] While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be appreciated by one skilled in the art, from a reading of the disclosure, that various changes in form and detail can be made without departing from the true scope of the invention in the appended claims.