WO2011002763A1

WO2011002763A1 - Wind generator

Info

Publication number: WO2011002763A1
Application number: PCT/US2010/040375
Authority: WO
Inventors: C. Richard Bacon; Nicholas Richard Bacon; Jacob Bradley Bacon
Original assignee: Via Wind Energy, Llc
Priority date: 2009-07-02
Filing date: 2010-06-29
Publication date: 2011-01-06

Abstract

A wind generator includes a blade-supporting rotor ring formed by alternately staggered accurate segments which inter-fit to provide ease of shipping and assembly resulting in a compact wind generator for shipment from the manufacturer to a location for assembly and use Other features include a shoe mount for securing blades to the rotor in a secure manner which assures a long life for the wind generator Other aspects include a mounting system for supporting a plurality of such wind generators between horizontally extending support cables which allow controlled motion, such that the generator faces the wind direction An array of such wind generators provides a wind farm which can supply energy for use by commercial establishments or a community

Description

WIND GENERATOR

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35 U. S. C. § 119(e) and the benefit of U.S.

Provisional Application No. 61/222,595 entitled WIND GENERATOR, filed on July 2, 2009, by C. Richard Bacon, et al., the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a wind generator and particularly one which employs a circular rotor supporting outwardly extending blades.

[0003] U.S. Patent Nos. 7,215,038, 7,345,377, and 7,358,624, owned by the Assignee of the present invention, disclose wind generators in which a plurality of blades extend from a root ring to an outer ring which is rotatably supported on a frame. The outer ring includes magnets embedded in the inner periphery thereof. The ring rotates the magnets past stator coils on a fixed frame to generate electricity in response to the rotation of the blade-supporting rings. Such a rotor and stator arrangement provides highly efficient wind generation under varying wind speed conditions as compared to a conventional wind generator which has a central hub with blades and a conventional generator coupled to the hub. The disclosure of U.S. Patent Nos. 7,215,038, 7,345,377, and 7,358,624 are incorporated herein by reference.

SUMMARY OF THE INVENTION

[0004] It is one goal of the present invention to improve upon the efficiency of the wind generator of the "038, "377, and "624 patents by providing a single circular rotor and blade support system which places the blades at the outer periphery of the rotor of the wind generator where more efficient use of the force of the wind is obtained.

[0005] According to one aspect of the invention, a ring-shaped blade-supporting rotor for a wind generator is formed of arcuate segments which inter- fit to provide ease of shipping and assembly resulting in a compact wind generator for shipment from the manufacturer to a location for assembly and use. In a preferred embodiment of the rotor design, the arcuate segments comprise overlapping alternately staggered arcuate segments.

[0006] Other features of the invention include a unique lightweight linear blade having an outer skin and foam core. Further, another aspect of this invention is a unique system for mounting blades to the blade-supporting rotor in a secure manner which assures a long life for the wind generator.

[0007] Other aspects of the invention include a mounting system for supporting one or more wind generators between vertically spaced, horizontally extending support cables which allow controlled rotation of the generator(s), such that they face the wind direction.

[0008] Another aspect of the invention is a cable control which includes a pulley system for lowering the vertically spaced horizontal support cables, such that the generators can be lowered to ground level for servicing.

[0009] Another aspect of the invention is a furling system to control the generator position to luff by tilting in high wind conditions and return to an aligned- with-the-wind position when the wind velocity is reduced.

[0010] In yet another aspect of the invention, an array of wind generators is provided to provide a wind farm which can supply energy for use by commercial establishments or a community.

[0011] These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Fig. 1 is a front perspective view of a wind generator embodying the present invention;

[0013] Fig. 2 is an enlarged fragmentary front perspective view of the wind generator shown in Fig. 1;

[0014] Fig. 3 is an enlarged fragmentary rear perspective view of the wind generator shown in Fig. 1;

[0015] Fig. 4 is a greatly enlarged fragmentary rear cross-sectional view of the circled area IV of Fig. 9, showing the rotatable mounting of the rotor ring of the wind generator to the stator beam;

[0016] Fig. 5 is a front elevational view of the wind generator shown in Figs. 1-4;

[0017] Fig. 6 is a greatly enlarged fragmentary perspective and cross-sectional view taken through section line VI-VI in Fig. 5;

[0018] Fig. 7 is a fragmentary perspective vertical cutaway view of the wind generator and its mounting system; [0019] Fig. 8 is an enlarged view of the circled area VIII of Fig. 7;

[0020] Fig. 9 is an enlarged view of the circled area IX of Fig. 7;

[0021] Fig. 10 is an enlarged view of the circled area X of Fig. 7;

[0022] Fig. 11 is an exploded fragmentary view of the mounting tube assembly;

[0023] Fig. 12 is an exploded fragmentary perspective view of the components of rotor 30 shown in Figs. 1-3 and 5;

[0024] Fig. 13 is a fragmentary perspective view, partly broken away, of the rotor 30;

[0025] Fig. 14 is an exploded fragmentary perspective view, partly broken away, of a blade mount to the rotor ring;

[0026] Fig. 14A is an enlarged view of the circled area XIVA in Fig. 14;

[0027] Fig. 15 is a fragmentary perspective view of a partially assembled blade and rotor ring;

[0028] Fig. 16 is a front elevational view of a mounting shoe employed for coupling blades to the rotor ring;

[0029] Fig. 17 is a rear elevational view of the shoe shown in Fig. 16;

[0030] Fig. 18 is an end elevational view of the outer end of the mounting shoe;

[0031] Fig. 19 is an end elevational view of the inner end of the shoe;

[0032] Fig. 20 is a front elevational view of one of the blades;

[0033] Fig. 21 is a cross-sectional view of the blade taken along section line XXI-XXI of

Fig. 20;

[0034] Fig. 22 is a cross-sectional view of the blade taken along section line XXII-XXII of

Fig. 20;

[0035] Fig. 23 is a perspective schematic view of an array of wind generators;

[0036] Fig. 24 is a fragmentary perspective view of the circled area XXIV of Fig. 23 showing the mounting of the suspension cables for the wind generators such that they can be lowered for servicing;

[0037] Figs. 25-27 are schematic views illustrating the sequence for lowering wind generators for servicing; and

[0038] Fig. 28 is a plan schematic view of a large wind farm employing the wind generators of this invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0039] Figs. 1-3 and 5 show the overall configuration of a wind generator 10 embodying the present invention. The wind generator 10 can be mounted on a conventional derrick or mast but preferably is part of a group of wind generators forming a wind farm and, as such, are suspended between an upper support such as a cable 12 and a lower support such as a cable 14. Generator 10 is coupled between supports 12 and 14 by telescopic tubes 16, 18 and 20 as described in greater detail below. Generator 10 comprises a blade supporting ring-shaped rotor 30 having a plurality of radially outwardly extending blades 40 coupled thereto. Twelve blades are shown in the figures, although any desired reasonable number of equally spaced blades can be employed. Typically, the blades will be from about 26-48 inches in length and extend radially outwardly from the laminated circular blade- supporting rotor 30, which includes an inner peripheral surface 32 with embedded permanent magnets 39 (Figs. 6 and 12) placed in spaced relationship around the entire inner periphery of the rotor 30 of the wind generator 10.

[0040] Rotor 30 is rotatably coupled to a stationary (with respect to the rotor 30) horizontal beam 50 by a wheel-like structure 60 having a central hub 62 and a plurality of spokes 64 coupled to and extending from the hub 62. The spokes have outer ends coupled to brackets 66 and fasteners 68 couple the wheel-like structure 60 to the front of rotor 30 as best seen in Fig. 2. Hub 62 is rotatably mounted by spaced bearings 70 to a 1" stainless steel axle 72, which extends through the center of stator beam 50 and is secured to tube 18 by a mounting plate 74, as best seen in Figs. 2 and 3. A cap 76 encloses the outer bearing 70. This mounting positions the two opposed stator assemblies 52 at the ends of beam 50 in axial alignment with the magnets 39 on the inner periphery 32 of rotor 30. Stators 52 are spaced a radial distance from surface 32 of rotor 30 leaving an air gap of about .087 inches, as best seen in Fig. 6. The ends of the beam 50 support plates 54 which hold the stator assemblies 52, each comprising a plurality of coils 53 (shown in Fig. 6) wound around ferromagnetic cores 55 and electrically coupled in a conventional manner. The plates 54 are secured to beam 50 by suitable fasteners, such as nuts and bolts. The channel-shaped beam 50 is fixedly mounted by axle 72 to tube mast 18 by a U-shaped bracket 78 and flange 79 (Figs. 2 and 3). Four struts 80, 82, 84, and 86 extend divergently between tube 18 and beam 50 to also mount and stabilize the beam 50 to the tube 18, as best seen in Figs. 2, 3 and 5. The inner ends of the struts are welded to tube 18 while the outer ends are secured to the channel-shaped beam 50 by brackets 81 (Figs. 2-8) and fasteners 83.

As described below in detail, the wind generator 10 is free to rotate with tube 18 to face the direction of oncoming wind. In order to align the generator with the wind, a tail assembly 90 (Figs. 1-3) is employed and includes a pair of upper and lower vertical stabilizers 92 and 94 which are pivotally coupled by support members 96 and 98 to tube 18, as best seen in Figs. 2 and 3. The ends of members 96 and 98 remote from the tail 90 extend into a pair of clevises 100 and 102 and are pivotally mounted thereto by pivot pins 101 and 103, respectively. The tubular supports 96 and 98 are coupled near the junction with tube 18 by a pair of vertically extending support tubes 104 and 106, to which there is fixedly coupled a mounting plate 108 (Fig. 8). In order to stabilize the tail 90 with respect to the wind generator 10, a furling mechanism, as best seen in Fig. 3, is coupled between the stator beam 50 and the tail section 90. The furling mechanism includes a pneumatic cylinder 110 pivotally coupled at one end to plate 108 by clevis 112 and pivotally coupled to beam 50 at a second end by a clevis 114. Cylinder 110 is coupled to a source of pneumatic pressure, which is controlled by a sensor for the wind speed to extend and retract, thereby pivoting the rotor 30 generally in a direction facing the wind under normal wind conditions. As the detected wind speed increases above a predetermined level (rotating rotor 30 at about 250 RPM), the rod of the pneumatic cylinder 110 is extended to rotate the wind generator 10 in a clockwise direction (as viewed from above) to furl the wind generator, preventing over-speed spinning of the generator. On the opposite side of the pivot points comprising the longitudinal axis of tube 18 are a pair of tension springs 116 and 118, which also tend to rotate the wind generator 10 in a clockwise direction against the holding force of cylinder 110. This provides a failsafe mode of furling the wind generator 10 in the event cylinder 110 should fail. One end of each of the springs 116 and 118 is coupled to plate 108 by fasteners 117, as seen in Fig. 3, and to beam 50 by fasteners 119. Thus, the tail assembly 90, which includes the furling mechanism including cylinder 110 and springs 116 and 118, typically hold the wind generator facing oncoming wind but, in the event of a wind that tends to over-speed the generator, cylinder 110 is controlled to rotate the generator to an off axis direction from the wind in an increasing amount to maintain the generator within the rotational limit of about 250-300 RPMs. The beam 50, wheel 60, and mounting hardware are typically made of a nonferrous material, such as aluminum or stainless steel. [0042] As can be appreciated, wind frequently, with oncoming weather systems, shifts directions through 360° rotation one or more times. In order to accommodate shifting winds and allow the tail assembly 90 to maintain the wind generator 10 facing the oncoming wind, the telescopic mounting tubes 16, 18 and 20 are designed not only to suspend the wind generators 10 between upper and lower support cables 12 and 14, respectively, but also allow the wind generators 10 to rotate over several revolutions to follow a clocking wind. Thus, the mounting system, including the telescopic tubes, will allow, in essence, the wind generator to twist up to eight revolutions before stopping, which typically will accommodate numerous weather patterns. If it reaches eight revolutions, when the wind dies down, the torsion member employed (as described below in connection with the mounting of the wind generators), unwinds allowing the generator to again face the wind and rotate as necessary to be continually facing the wind under varying wind conditions.

[0043] Figs. 7-11 illustrate the unique mounting system which controls the rotation of wind generator 10 in a clocking wind. Referring initially to Fig. 7, there is shown a wind generator 10 and its rotational mounting tube assembly 22 comprising upper tube 16, center tube 18 to which wind generator 10 is attached as discussed above, and a lower telescopic tube 20. Upper tube 16 includes, as best seen in Fig. 8, a cable clamp 17 which secures the upper end of tube 16 to upper cable 12, as seen in Fig. 1. Tube 16 telescopically extends within intermediate tube 18, as seen in Figs. 7 and 8, and includes, as seen in Fig. 11, longitudinally extending polymeric bushings 19 radially spaced at 120° intervals around tube 16 and secured thereto by recessed fasteners to provide a lubricious sliding and rotating interface between tube 16 and outer tube 18. The wind generator 10 is held in place between cables 12 and 14 by a strap 24 anchored at its upper end by a loop

25 extending around a pin 23 extending across and anchored to inner tube 16, as seen in Figs. 8 and 11.

[0044] Strap 24 is made of a flexible material, such as a commercially available industrial woven fabric or belting material. The length of the strap is from about 3 feet to about 4 feet long and it has a width of about 1 inch. Strap 24 includes a loop 25 at its upper end surrounding pin 23 in tube 16 and a second loop 27 at its lower end, which surrounds pin

26 anchored to telescopic outer tube 18 just above the clevis 100, as shown in Figs. 3 and 9. Thus, tube 18 holding wind generator 10 surrounds tube 16 and is suspended from upper cable 12 by strap 24. Tube 18 and wind generator 10 secured thereto is allowed to rotate with strap 24 twisting within upper tube 16 up to eight revolutions before strap 24 tightens sufficiently to provide a counter torque to the rotation of generator 10, which prevents further rotation under clocking wind conditions. Under normal wind conditions, the strap will only rotate one or two complete revolutions before this occurs. Upon diminishing of the wind, the strap will unwind to allow tail assembly 90 to continue to align the wind generator with the wind. Tube 18 receives at its lower end, a seen in Fig. 7, the smaller diameter telescopic lower tube 20, which includes axially spaced longitudinally extending bushings 28 and 29 radially spaced approximately 120° around tube 20 and which are made with a lubricious polymeric material mounted to tube 20 by recessed fasteners to provide a lubricious sliding and rotating interface between tube 20 and the outer tube 18. Tube 20 includes a cable clamp 21 at its lower end for securing the lower end of tube 20 to mounting cable 14 of the mounting system for the wind generator. Tube 18 includes a stop collar (not shown) to prevent tube 20 from withdrawing from tube 18 once installed. Electrical conductors from the stators 52 extend through the hollow tubes 18, 20 and are of sufficient height to twist with strap 24 without fatigue. The conductors are then secured to the lower cable 14 and extend to the electrical circuits coupling power from the generators 10 to the electrical grid employing the wind generated power.

[0045] The blade mounting rotor 30 is a laminated structure including a plurality of overlapping alternately staggered arcuate segments 34 and 36 (Figs. 12-15), each of which includes a pair of adjacent blades 40 mounted thereto as described below. The segments 34 and 36 are alternately staggered overlapping molded polymeric arcuate sections with ends that abut adjoining segments, such that the junction 33 of segments 34 is angularly offset from the junction 35 of segments 36. The segments 34, 36 are lightweight by the use of integrally molded ribs 31 to reduce the material required. Each of the segments is made of individual arcuate molded polymeric members with front sections 34 (Fig. 12) overlapping and inter- fitting with rear sections 36 at the overlapping junctions 33 and 35. Each of the sections 34, 36 include facing molded pockets 38 for receiving the permanent magnets 39, as seen in Figs. 6, 9, and 12. Magnets 39 are alnico magnets and can be from .5 inches to .75 inches wide to provide different field strengths. The pockets 38 will be shaped to receive the selected magnet size and have a wall thickness of about .060 inches between the magnets 39 and the stator. The pockets 38 and magnets 39 are continuously spaced around the entire inner periphery of rotor 30. It is understood that only a few magnets are shown but each pocket 38 will include a magnet. The magnets 39 are backed by four steel backing rings 37 (Figs. 6, 12, and 13) forming a laminated structure extending in an annular slot 41 (Figs. 6 and 12) extending continuously around rotor 30 to concentrate the magnetic field near the surface 32 of the composite ring. Rings 37 have a width of about ³A inch and a thickness of about .04 inch and also add strength to the rotor 30.

[0046] Sections 34 and 36 include aligned plate-receiving slots 44 (Fig. 14A) formed in ribs 31 for receiving mounting plates 120 for the blades 40, as described below. Sections 34 and 36 also include slots 46 which communicate with and are aligned with plate- receiving slots 44 for receiving an inner end 142 of blade mounting shoes 140 shown in detail and described in conjunction with Figs. 14-19 below. The composite rotor 30, in addition to the alternately staggered and inter-fitting sections 34 and 36 which extend 360° around the rotor 30 once assembled, is overlaid by a plurality of abutting front and rear annular backing supports 130, 132. Supports 130 abut adjacent supports to form a 360° ring and overlap junctions 33 of sections 34. Similarly, backing supports 132 abut each other, form a 360° ring and each support overlaps a junction 35 of sections 36. The supports 130, 132 each include a raised sections 131 which overlay the junction of plates 120 and shoe ends 142 to reinforce the mounting junction of the blades 40 to rotor 30.

[0047] The alternately staggered relationship of members 34, 36 and 130, 132 together with the laminations 37 behind magnets 39 add significant strength and integrity to rotor 30 once assembled, as seen in Figs. 1-3, 5-7, and 9. Rivets 134 extend through apertures 135 around the entire rotor 30 to complete the four layer (from front to back) composite structure of rotor 30. Sections 34 and 36 are molded of a polymeric material, such as glass-filled nylon, polycarbonate, PVC, or the like, while the outer supports 130 and 132, which overlap the junctions 33 and 35 to support the composite ring, are typically made of non-ferrous metal, such a aluminum. The alternately staggered sections 36 and 38 circumscribe an arc of 360° divided by the number of blades of the wind generator and, in the case of the generator shown in the Figs. 1-12, an arc of approximately 30°. Rotor 30 so manufactured typically has a mean diameter of from about 40 inches to about 46 inches, while the blades 40, which are mounted thereto as described below, extend outwardly therefrom a distance of from about 26 inches to about 48 inches. For different installations, these dimensions can be varied to optimize the cost and operational efficiency of a given wind generator size.

[0048] The blade mounting plates 120 are embedded into the rotor 30, as shown, for example, in Figs. 12-15, between sections 34 and 36 and outer supports 130 and 132. The plates 120 are secured in slots 44 formed by reducing the thickness of ribs 31 between arcuate sections 34 and 36 (Fig. 14A). The plates 120 are held between sections 131 of outer supports 130, 132 of rotor 30 by rivets 134 (Figs. 12 and 13). Plates 120 include a radially outwardly extending tab 122 with apertures 124 for securing the tab within a slot 141 (Fig. 19) extending axially and radially in shoe 140. Plate tab 122 is secured to shoe end 142 by cap headed fasteners which extend through apertures 124 in plate 120 and apertures 144 in shoe end 142 to secure plate 120 to shoe 140 and extend through apertures in sections 131 of supports 130, 132 to secure the inner end of each shoe 140 to the to the motor. The outer end 146 of each shoe 140, in turn, is molded into the inner end 43 of each blade 40 as described below.

[0049] The shoes 140 employed for securing the blades 40 to the rotor 30 are specially configured to bond the outer end 146 of the shoe within the open end 43 of the blade during its forming process as disclosed below. For such purpose, shoes 140 (shown in Figs. 16-19) include a plurality of longitudinally extending channels 147 and 149 on opposite sides of end 146, which allows the foam polymeric material injected to form the core 48 of blades 40 to surround the inner and outer surfaces 150 and 152 of end 146 of shoes 140. In order to securely lock the ends 146 of shoes 140 within the ends of blades 40, orthogonally extending ribs 154 extend across center channel 156 on side 150 of each of the shoes 140. Orthogonally extending ribs 158 extend across the opposite side 152 of end 146 of shoes 140, such that the foam polymeric material surrounds the orthogonally extending ribs 154 and 158 (relative to the longitudinal axis of the blades) to securely bond the shoes in the open ends 43 of the blades. As can be seen particularly with reference to Fig. 18, the ends 146 of shoes 140 are curved to conform to the curvilinear shape of open inner ends 43 of blades 40. The interface zone 160 between end 142 and end 146 of a shoe 140 is smoothly tapered, as best seen in Figs. 16-18, to provide a smooth transition between the junction of the rotor 30 with blades 40.

[0050] The very light weight and strong blades 40 are composites made of a structural foam polymeric core 48 (Figs. 21 and 22) having an outer skin 49 covering the core. The blades are manufactured by initially roll forming a sheet of high tensile strength aluminum skin having a thickness of from about .01 inches to about .015 inches over a mandrel having the desired shape of the blade and gluing the overlapping edge 47 (Fig. 20) with an adhesive, such as a hot melt adhesive. Subsequently, the preformed outer skin is inserted into a heated mold conforming to the outer shape of the blade. Reaction injection molded structural foam such as a two-part structural urethane foam is then injected into the inner end 43 of each of the blade forms and the outer end 146 of shoe 140 is inserted into the open inner end 43 of the blade. During the expansion and curing of the foam, it surrounds the ribbed end 146 of shoe 140 and bonds the shoe to the blade with the longitudinal channels 147, 149 of the shoe 140 allowing the foam material to engage the end of the shoe and surround the orthogonally extending ribs 154, 158 for locking the shoe 140 to blade 40. Any flashing that may have exuded from the junction of the foil skin 49 and shoe 140 is then removed and the tip end 45 of blade 40 is sealed by either a suitable foil tape, pinched closed or roll-formed over. Blades 40 could also be made of a variety of lightweight strong material, including wood (such as spruce), fiberglass, carbon fiber composites, aluminum, or the like.

The blades 40 are initially formed in a typical cross-sectional aerodynamic blade shape and subsequently twisted of from about 1.5° to about 5° along their longitudinal axis to provide the desired pitch for the blade depending upon a particular installation. The formation and twisting of the blade results in a linear blade as defined herein in which a level, straight edge can be laid across any chord, such as chords Ci and C₂, shown in Fig. 20, from the inner end 43 to a corresponding location at the tip 45, and the straight edge and surface of the blade perfectly align. Thus, each of the chords parallel to chords Ci and C₂ from the inner end of the blade to the tip end are straight lines forming a linear blade. The radius of curvature on the leading edge of the blades 40 varies linearly from about .28 inches (Ri) near the inner end 43 to about .06 inches (R₂) near the tip end 45. This variable radii from end to end of the blades also contributes to the formation of the linear blades 40. The lightweight construction (about 400 grams) of blades 40 and rotor 30 coupled to stator beam 50 by the wheel-like spoked mount 60 results in a highly efficient wind generator with a low start-up wind speed requirement. One ten-foot diameter generator provided the following operational characteristics.

[0052] The wind generator is assembled by fitting the segments 34, 36 together with the inner and outer rings 130 and 132 and mounting plates 120 which are secured to the shoes 140 utilizing a plurality of through fasteners, such as rivets or cap head bolts.

[0053] The stator coils 53 are electrically coupled by conductors (not shown) extending along beam 50 and within the hollow supports 18 and 20 in a conventional manner. The conductors couple the power output of the wind generator 10 in a conventional manner to a power grid. The circuitry employed for each wind generator can be of the type disclosed in Fig. 8 of U.S. Patent No. 7,215,038, the disclosure of which is incorporated herein by reference, or other conventional circuitry which converts the voltage pulses from the stator coils 53 to a DC voltage, which is either subsequently stored in battery banks or inverted to a 60 Hz alternating voltage at a level usable by the grid or the installation directly using the power generated. In one installation, an Aurora inverter Part No. PVI-3.6OUTD-US- W was employed to couple energy from the wind generator(s) 10 to the power grid.

[0054] Wind generator 10 of the present invention can be employed in a small wind farm

200, such as shown in Fig. 23 or a large array wind farm 300, as seen in Fig. 28. In Fig. 23, a plurality of wind generators 10 are mounted, in the example shown, in three vertically spaced rows in an array between support cables 12, 14, 15, and 19, with the wind generators being supported between the vertically spaced support cables in horizontally spaced relationship. The support cables, in turn, are supported by pylons (or towers) 202 and 204 of conventional design supported by guide wires 206 suitably

¹ Electrical power output from an inverter coupled to a power grid is about 88% of the blade power. anchored to the ground. In the example shown, the wind farm 200 includes 15 generators 10 between a pair of the pylons.

[0055] In the larger wind farm illustrated in Fig. 28, the array of wind generators 10 form a series of squares 301-304, although the array can be of any desired configuration. The array 300 supports 60 wind generators for each horizontal level of the array and can include 180 such generators when three levels are employed as seen in Fig. 23. In this system, pylons 305-313 are spaced apart in a horizontal and vertical array (as viewed in plan) and support cables extend along the Y-axis and the X-axis and have ends connected to the pylons, as shown in Fig. 24. One or more vertically spaced lower support cables are positioned below the upper cables for supporting wind generators 10 in a three- dimensional horizontal and vertical array between the pylons 305-313.

[0056] In order to service wind generators 10 in a wind farm environment, such as shown by Figs. 23 and 28, the pulley and cable structure shown in Figs. 24-27 is employed on at least one of the pylons, such as pylon 204. Associated with each string of wind generators 10, there is provided a pair of blocks, including an upper block 170 and a lower block 180 which include cables 172 and 182, which are coupled to the upper cable 12 and a lower cable 14, for example, supporting wind generators 10 therebetween, as seen in Fig. 23. The cables 172 and 182 extend downwardly adjacent the pylon 204 and have ends which can be secured by suitable hooks and pad eyes secured to the pylon 204. This mounting arrangement allows cables 12 and 14 to be selectively lowered to lower the wind generators 10 to ground level for servicing. Cable 14 includes electrical cables coupled thereto at spaced locations by suitable wire ties for coupling power from the generators 10 to the power grid. The sequence of lowering the wind generators 10 on the cables 12 and 14 for servicing is illustrated in Figs. 25-27, now briefly described.

[0057] In Fig. 25, the cables 172 and 182 are taut. They are gradually slackened, typically by the use of a powered winch or other means coupled to the cables 172 and 182 prior to releasing them from the pylon 204. As the cables 172 and 182 are substantially simultaneously lowered, the wind generators 10 are gradually lowered toward the ground, as illustrated in Figs. 26 and 27. They approach ground level and eventually rest on the ground where a workman can easily access the generators for servicing, if necessary. The process is then reversed when it is time for the generators to again be raised into the functional position, as shown in Fig. 25, in which cables 12 and 14 are substantially parallel and horizontally oriented. [0058] Thus, with the wind generators and wind farm system of the present invention, highly efficient, durable, and relatively inexpensive generators are provided. The generators can be mounted on freestanding towers or mounted between suspension cables in a wind farm for supplying relatively large amounts of energy. A typical generator will provide from 2 kw to 4 kw of energy per generator and, when coupled in a wind farm environment, can supply sufficient energy for a commercial establishment, an entire neighborhood, or a small town.

[0059] It will become apparent to those skilled in the art that various modifications to the preferred embodiment of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims.

Claims

The invention claimed is:

1. A wind generator comprising:

a blade supporting rotor ring having a plurality of permanent magnets in radially spaced relationship to an inner annular surface of said rotor ring;

a stator beam with a plurality of induction coils at opposite ends;

a spoked wheel-like mount rotatably coupling said rotor ring to said stator beam with said induction coils positioned closely adjacent said inner annular surface of said rotor for inducing an electrical current in said coils as said rotor rotates with respect to said beam; and

a plurality of composite blades and a mounting structure coupling said blades to an outer side of said rotor ring such that said blades extend outwardly from said rotor ring.

2. The wind generator as defined in claim 1 wherein said stator beam extends in a generally horizontal direction.

3. The wind generator as defined in claim 1 wherein the diameter of said rotor ring is about 40 inches.

4. The wind generator as defined in claim 1 wherein said blades have a length of from about 26 inches to about 48 inches.

5. The wind generator as defined in claim 1 wherein said generator includes about 12 blades.

6. The wind generator as defined in claim 1 wherein said composite blades are lightweight and have a weight of about 400 grams.

7. The wind generator as defined in claim 1 wherein said rotor ring is made of overlapping opposed facing alternately staggered arcuate segments; and

arcuate front and rear support members coupled to said segments and overlapping junctions between said segments for securing said segments to form a unitary ring-shaped rotor.

8. The wind generator as defined in claim 7 wherein said arcuate segments include recesses for receiving blade-mounting plates secured to said arcuate segments and support members by fasteners, said plates including ends extending radially outwardly from said ring.

9. The wind generator as defined in claim 8 and further including a plurality of mounting shoes for coupling to and receiving an extending end of said mounting plates coupled to said ring, wherein each of said aerodynamic blades include a blade body coupled to said mounting shoe.

10. The wind generator as defined in claim 9 wherein said blade body is molded onto said shoe.

11. The wind generator as defined in claim 10 wherein said composite blades include an inner end for receiving said shoe and has a molded foam polymeric core and an outer metal skin.

12. The wind generator as defined in claim 11 wherein said shoe is molded of a polymeric material and has an end which extends into said inner end of said blade, and wherein said end of said shoe has channels aligned with a longitudinal axis of said blade for allowing said foam material of said blade to surround and bond to said shoe.

13. The wind generator as defined in claim 12 wherein said end of said shoe has ribs extending in a direction orthogonal to the axis of said blade for locking said inner end of said blade onto said end of said shoe.

14. The wind generator as defined in claim 13 wherein said outer skin of said blade is aluminum.

15. The wind generator as defined in claim 14 wherein said arcuate segments are molded of a polymeric material.

16. The wind generator as defined in claim 1 wherein said composite blades are linear blades having an aerodynamic cross section formed to provide a straight line chord between locations at the inner end of the blade and corresponding locations at the tips of the blade.

17. The wind generator as defined in claim 1 wherein said composite blades have a structural foam core covered by an aluminum skin.

18. The wind generator as defined in claim 1 and further including a mounting system for said wind generator for suspending said wind generator between horizontally extending vertically spaced support cables, said mounting system comprising:

a first tube coupled at one end to an upper cable;

a second tube telescopically mounted to said first tube from an end opposite said upper cable;

a flexible torsion member extending between said first and second tubes;

a bushing extending between said first and second tubes, wherein said second tube has an end remote from said first tube, which is coupled to the lower cable; and

said beam is coupled to one of said first and second tubes, whereby said torsion member allows said first and second tubes to rotate in a controlled manner with respect to each other, such that said wind generator rotates to face the oncoming wind.

19. The wind generator as defined in claim 18 wherein said flexible torsion member comprises a strap having one end fixed to said first tube and an opposite end fixed to said second tube.

20. The wind generator as defined in claim 19 wherein said strap has a length of from about 3 feet to about 4 feet.

21. The wind generator as defined in claim 20 wherein said beam is coupled to said second tube.

22. The wind generator as defined in claim 21 wherein said torsion member allows said wind generator to rotate through a plurality of revolutions in shifting wind conditions.

23. The wind generator as defined in claim 22 and further including a third tube telescopically mounted to said second tube for coupling said second tube to said lower cable.

24. A wind farm comprising an array of wind generators as defined in claim 1.

25. The wind farm as defined in claim 22 wherein said wind generators are mounted between vertically spaced, horizontally extending support cables for lowering the generators to ground level for servicing, said system including:

spaced-apart support pylons;

upper and lower support cables extending between adjacent pylons;

a mount for coupling wind generators between said upper and lower cables; and a pulley system coupled to at least one of the adjacent pylons and to said upper and lower cables for lowering and raising said upper and lower cables to lower and raise wind generators for servicing.

26. A blade supporting rotor ring for a wind generator comprising:

a rotor made of arcuate segments, said segments having arcuately spaced recesses formed therein for receiving permanent magnets in spaced relationship to a surface of said rotor; and

27. The rotor as defined in claim 26 wherein said rotor is comprised of overlapping opposed facing alternately staggered arcuate segments.

28. The rotor as defined in claim 27 wherein said arcuate segments include recesses for receiving blade -mounting plates secured to said arcuate segments and support members by fasteners, said plates including ends extending radially outwardly from said rotor.

29. The rotor as defined in claim 28 and further including a plurality of aerodynamic blades and a mounting shoe for coupling to and receiving an extending end of said mounting plate coupled to said rotor, wherein each of said aerodynamic blades include a blade body coupled to its respective mounting shoe.

30. The rotor as defined in claim 29 wherein said blade body is molded onto said shoe.

31. The rotor as defined in claim 30 wherein said blade body includes an inner end for receiving said shoe and has a molded foam polymeric core and an outer skin.

32. The rotor as defined in claim 31 wherein said shoe is molded of a polymeric material and has an end which extends into said inner end of said blade, and wherein said end of said shoe has channels aligned with a longitudinal axis of said blade for allowing said foam material of said blade to surround and bond to said shoe.

33. The rotor as defined in claim 32 wherein said end of said shoe has ribs extending in a direction orthogonal to the axis of said blade for locking said inner end of said blade onto said end of said shoe.

34. The rotor as defined in claim 33 wherein said outer skin of said blade is aluminum.

35. The rotor as defined in claim 26 wherein said arcuate segments are molded of a polymeric material.

36. A system for mounting a wind generator between vertically spaced, upper and lower horizontally extending supports comprising:

a first tube coupled at one end to an upper support;

a second tube telescopically mounted to said first tube from an end opposite said upper support;

a flexible torsion member extending between said first and second tubes;

a bushing extending between said first and second tubes, wherein said second tube has an end remote from said first tube, which is coupled to the lower support; and

a mount for coupling a wind generator to one of said first and second tubes, whereby said torsion member allows said first and second tubes to rotate in a controlled manner with respect to each other, such that said wind generator rotates to face the oncoming wind.

37. The system as defined in claim 36 wherein said flexible torsion member comprises a strap having one end fixed to said first tube and an opposite end fixed to said second tube.

38. The system as defined in claim 37 wherein said strap has a length of from about 3 feet to about 4 feet.

39. The system as defined in claim 37 wherein said wind generator is coupled to said second tube.

40. The system as defined in claim 36 wherein said torsion member allows said wind generator to rotate through a plurality of revolutions in shifting wind conditions.

41. The system as defined in claim 36 and further including a third tube telescopically mounted to said second tube for coupling said second tube to said lower support.

42. A wind farm including a plurality of wind generators comprising:

a plurality of spaced apart support pylons forming a grid in orthogonal directions; a plurality of supports extending between said support pylons in vertically spaced relationship; and

a plurality of wind generators mounted between said vertically spaced supports in horizontally spaced relationship to present a three-dimensional array of wind generators.

43. The wind farm as defined in claim 42 wherein each wind generator is coupled between said support cables by structure comprising:

a mounting clamp attached to an upper cable;

a first tube coupled to said mounting clamp;

a flexible torsion member extending from said mounting clamp into said first tube and having an end opposite said mounting clamp coupled to said first tube;

a second tube telescopically mounted to said first tube from an end opposite said mounting clamp; and

a bushing extending between said first and second tubes, wherein said second tube has an end remote from said first tube, which is coupled to the lower cable.

44. A wind generator comprising:

a blade supporting annular rotor having a core made of opposed facing alternately staggered arcuate segments having arcuately spaced recesses formed therein for receiving permanent magnets in spaced relationship to an inner surface of said rotor;

a plurality of permanent magnets positioned in said spaced recesses;

arcuate front and rear support members coupled to said segments and overlapping junctions between said segments for securing said segments to form a unitary rotor;

a plurality of spokes extending from said annular rotor to a center hub; and a beam with a plurality of induction coils at opposite ends, said hub rotatably coupled to said beam with said induction coils positioned closely adjacent said inner surface of said rotor for inducing an electrical current in said coils as said rotor rotates with respect to said beam.

45. The wind generator as defined in claim 44 wherein a bearing extends between said beam and said hub to align said magnets of said rotor with said adjacent induction coils.

46. The wind generator as defined in claim 45 wherein said beam is linear and extends in a generally horizontal direction.

47. The wind generator as defined in claim 44 wherein the diameter of said rotor is about 40 inches.

48. The wind generator as defined in claim 47 wherein said rotor supports a plurality of radially outwardly extending blades spaced at substantially equal intervals around said rotor.

49. The wind generator as defined in claim 48 wherein said blades have a length of from about 26 inches to about 48 inches.

50. The wind generator as defined in claim 49 wherein said generator includes about 12 blades.

51. A wind generator kit for assembly comprising; a plurality of arcuate segments of molded polymeric material, said segments having arcuately spaced recesses formed therein for receiving permanent magnets in spaced relationship to a surface of said segments, said segments shaped to overlap one another in alternately staggered relationship and including at least one blade associated therewith;

a plurality of permanent magnets positioned in said spaced recesses;

a plurality of arcuate front and rear support members for coupling to said segments in overlapping junctions between said segments for securing said segments to form a unitary annular rotor; and

a beam and a plurality of induction coils on opposite ends of said beam; and a rotatable mount coupling said rotor to said beam such that, when assembled, said induction coils are positioned closely adjacent said surface of said rotor for inducing an electrical current in said coils as said rotor rotates with respect to said beam.

52. A system for mounting wind generators between vertically spaced, horizontally extending support cables and lowering the generators to ground level for servicing comprising:

spaced-apart support pylons;

upper and lower support cables extending between adjacent pylons;

53. For use in connection with a wind generator, a linear blade comprising:

a blade configuration having an aerodynamic cross section and formed to provide a straight line chord between the inner end and tips of the blade for each corresponding location.