FIELD OF THE INVENTION
The present invention is directed to wind power systems and in particular to vertical axis wind systems.
BACKGROUND OF THE INVENTION
Vertical axis wind systems (VAWS) are well known. Such systems offer a number of advantages over horizontal axis wind systems (HAWS). One advantage is that the VAWS can harness wind from any direction without having to reorient to such direction such as is required with the HAWS. Another advantage of VAWS is that the blades may be constructed to a much larger scale than HAWS due to the vertical axis orientation. The vertical axis orientation also results in reduced centrifugal stresses on the blade structure. Due to their vertical orientation VAWS also lend themselves to work at higher elevations clear of any obstructions where the wind speeds are higher.
With the growing interest in utilizing wind power systems to replace or supplement power received from the energy grid, or as an alternate source of power to the energy grid, there is a corresponding interest in developing improvements to existing systems.
SUMMARY OF THE INVENTION
The present invention is directed to an improved VAWS and components for such systems.
In one aspect the invention provides a vertical axis wind system comprising:
- a center post assembly adapted to extend in a vertical orientation, said center post assembly including an outer rotor rotatably connected to an inner post;
- a power generation system including a generator rotor rotatably connected to a generator stator, said generator rotor being driveably connected to said outer rotor; and
- a blade assembly including a plurality of blades having first and second ends connected to said outer rotor.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the accompanying drawings, which are meant to be exemplary and not limiting, in which like references are intended to refer to like or corresponding parts, and in which:
FIG. 1 is a side view of a vertical axis wind system (VAWS) in accordance with a first embodiment of the present invention;
FIG. 2 is a vertical sectional view of the center post assembly of the VAWS as viewed along lines 2-2 of FIG. 1;
FIG. 3 is a horizontal sectional view of the center post assembly of the VAWS as viewed along lines 3-3 of FIG. 1;
FIG. 4 is an enlarged sectional view of the power generation system for the VAWS as viewed at region 4 of FIG. 2;
FIG. 5 is an enlarged view of the shroud and electric brush system for the VAWS as viewed at region 5 of FIG. 4;
FIG. 6 is an enlarged sectional view of the upper blade attachment assembly for the VAWS as viewed at region 6 of FIG. 2;
FIG. 7 is an enlarged sectional view of the center post assembly for the VAWS as viewed at region 7 of FIG. 2;
FIG. 8 is a perspective view of one end of the blade attachment assembly for the VAWS of FIG. 1;
FIG. 9 is an end view of the blade attachment assembly of FIG. 8;
FIG. 10 is a side view of the blade attachment assembly of FIG. 8;
FIG. 11 is an enlarged side view of an attachment arm for the blade attachment assembly as viewed at region 11 of FIG. 10;
FIG. 12 is an enlarged side view showing the attachment of a blade assembly to the blade attachment assembly of FIG. 8;
FIG. 13 is a top view of the attachment of the blade assembly to the blade attachment assembly of FIG. 12;
FIG. 14 is a partial perspective view of the blade assembly for the VAWS of FIG. 1;
FIG. 15 is an enlarged perspective view of a portion of the blade assembly of FIG. 14, showing one embodiment of the primary structure;
FIG. 16 is an enlarged perspective view of a portion of the blade assembly of FIG. 14, showing another embodiment of the primary structure;
FIG. 17 is an enlarged perspective view of a portion of the blade assembly of FIG. 14, showing another embodiment of the primary structure;
FIG. 18 is an enlarged perspective view of a portion of the blade assembly of FIG. 14, showing another embodiment of the primary structure;
FIG. 19 is an enlarged perspective view of a portion of the blade assembly of FIG. 14, showing another embodiment of the primary structure;
FIG. 20 is a side view of a VAWS disposed on one embodiment of a foundation in accordance with the present invention and
FIG. 21 is a side view of a VAWS disposed on another embodiment of a foundation in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A vertical axis wind system (VAWS) in accordance with the present invention is shown generally at 50 in FIG. 1. The VAWS includes a center post assembly 100, a power generation system 200, a blade attachment assembly 300 and a blade assembly 400. The VAWS is adapted to be supported by a foundation 500 that extends over and supports a portion of the center post assembly 100 such as depicted in FIGS. 20 and 21. The VAWS may be disposed at a ground or body of water location or on a rooftop.
Referring to FIGS. 1-7, the center post assembly 100 includes an inner post 102 and outer rotor 104. The outer rotor 104 surrounds inner post 102 and is spaced with bearings 106 (e.g. slewing or turntable bearings as visible in FIG. 4) at appropriate intervals in known manner to facilitate rotation of outer rotor 104 around inner post 102 and to maintain a desired gap 108 between them. The inner post 102 and the outer rotor 104 may each comprise a plurality of sections 110 each having end flanges 112 adapted for securing the sections together end to end using nut and bolt fasteners or other suitable fastening means 114. The sectioned structure for each of the inner post 102 and the outer rotor 104 provides for ease of transport and assembly and also allows for variability in the overall height of the resulting center post assembly.
The inner post 102 and outer rotor 104 may each be formed from standard commercially available steel or aluminum pipes that provide sufficient structural integrity for the operation of the VAWS for its intended purpose and within its intended size parameters. One or both of the inner post 102 and outer rotor 104, or portions thereof, may alternatively be formed of other materials that are suitable for the intended purpose and size parameters. The outer rotor 104 for instance may be formed of lightweight materials of sufficient structural strength for the intended purpose while the inner post 102 may be formed of more robust materials if required to meet the structural support requirements as described herein. The inner post 102 may be constructed from solid or hollow pipes. If hollow pipes are provided, such pipes may optionally be filled prior to or following assembly with concrete, honey comb materials, structural foam or other suitable materials.
It is preferred that the aspect ratio A of width to height of the inner post 102 be sufficient to support the center post assembly without the assistance of guy wires. The aspect ratio A for the currently preferred embodiment is approximately 1 to 100.
In a currently preferred embodiment, for a center post assembly having a height of up to 150 feet, the inner post 102 has a corresponding height of 150 feet and is provided in sections of preferably 18 feet in length and 30 inches in outside diameter (a hollow inner post is presently contemplated). The outer rotor 104 has a height of 80 feet and is provided in sections of preferably 18 feet in length and 42 inches in outside diameter. Foundation 500 thus has a height of approximately 70 feet for surrounding and supporting the remaining portion of inner post 102. Both the outer rotor 104 and inner post 102 have a preferred wall thickness of ⅜ inches leaving a resulting gap 108 of approximately 5⅝ inches on either side of inner post 102.
Referring to FIG. 4, the power generation system 200 includes a power generator 202 that is preferably a direct drive generator having a generator rotor 204 and a generator stator 206 spaced apart by gap 208. The direct drive generator may be a commercially available system such as is available from Danotek™ or may be specifically designed for the present purpose. The generator rotor is directly connected to the flanged end of outer rotor 104 using nut and bolt fasteners or other suitable fasteners 210. A flexible connector 212 such as a rubber coupling may be disposed between outer rotor and generator rotor to accommodate balance variations between both elements. The power generation system may be further modified to provide for one or more of a torque convector assembly, a planetary or other gear system and a mechanical clutch assembly.
A braking system 220 including a brake disc 222 and brake mechanism 224 is also provided for braking rotation of outer rotor 104. An off the shelf system may be used such as one of the electromechanical systems available from Hanning & Kahl™. Power generation system 200 and braking system 220 are encased in a housing 230.
Referring to FIG. 5, a shroud 232 and electric brush system 234 are provided for protecting power generation system 200 from the intrusion of external elements and from external electrical currents due to lightening.
Referring to FIG. 7, the flanges on the inner post and the outer rotor are spaced in a staggered arrangement to allow for ease of assembly and a clearance from the inner wall on each side.
Referring to FIGS. 8-11, the blade attachment assembly 300 for attaching the ends of the blades to the center post assembly 100 is shown. The blade attachment assembly has a hollow cylindrical portion 302 with flanged ends 304 adapted for attaching to upper and lower ends of the center post assembly. A plurality of blade attachment arms 306 extend outwardly from the outer wall 308 of cylindrical portion. Each blade attachment arm has a flanged end 310 and an elongate aperture 312 for securing blade attachment. The blade attachment arms are disposed around the cylindrical portion in positions to facilitate variations on the number of blades that are secured to the blade attachment assembly. As may be seen most clearly in FIG. 9, the arms may be oriented at equally spaced locations for securing two blades, three blades or four blades to the blade attachment assembly. Blade attachment assembly may be formed with additional attachment arms if it is desired to attach more than four blades.
Referring to FIGS. 12 and 13, each blade assembly 400 includes a forked end member 402 that hooks over flanged end 310 of each blade attachment arm 306. The blade assembly 400 is secured and supported at a desired position using a two piece end support 404 that is disposed over the flanged end 310, a gusset plate 406 that engages flanged end 310 along one side and end support 404 along its other sides and two clamping plates 408 and 410 that engage and secure end member 402 using nut and bolt fasteners or other suitable fastening means. Clamping plate 410 is retained within aperture 312.
Referring to FIGS. 14-19, blade assembly further comprises an elongate blade 420 having a primary structure 422 and a secondary structure 424. The primary structure comprises one or more struts 426 extending along its length for supporting a plurality of ribs 428 extending along its width. The ribs and struts are preferably formed of a lightweight material that provides sufficient structural strength for the size and intended purpose of the blade assembly. This material can be steel, aluminum, or composite or a combination. The struts are preferably formed in an airfoil or other aerodynamic shape suitable for wind system power generation. The struts are provided in one of a variety of embodiments. FIG. 15 shows a pair of parallel extending struts, FIG. 16 shows an H-shaped strut, FIG. 17 shows a pair of tubular struts having a rectilinear cross section, FIG. 18 shows a C-shaped strut and FIG. 19 shows a T-shaped strut.
The secondary structure comprises a skin 430 that is disposed over the ribs to define an aerodynamic blade surface suitable for power generation. The skin may be formed of any suitable material including steel, aluminum, wood, plastic, composite fibers using rolled, stamped, extruded, molded, wound, hydro-formed or net shaped manufacturing processes. The skin may be painted, coated or formed from any material that reduces drag and prevents ice build up such as plastic or polyurethane. The skin may be attached to ribs using mechanical fasteners, mig-weld, laser-weld, spot-weld, stitch-weld, rivets, adhesives or any other suitable means of fastening.
It is desirable that the center post assembly be supported by the inner post 102 without the assistance of guy wires. Accordingly, it is preferred that the inner post 102 is supported by a foundation 500 such as the truss structure 502 shown in FIG. 20 or the concrete structure 504 as shown in FIG. 21 (which could be modified to desired architectural dimensions to suit the surrounding functional and aesthetic needs). The inner post 102 may be secured by means of a base plate 506 that is attached by nut and bolt fasteners, or other suitable fasteners 508 (including welds) to the foundation. Base plate may be comprised of gusset plates 510 that are provided with openings 512 to provide means for raising the power generation system using a crane or the like for the purposes of assembly, repair or disassembly.
The inner post 102 preferably extends through the foundation to engage a bottom surface. The foundation may be constructed to define an enclosed structure, having an access door 514, such as is shown in FIG. 21, to house components of the VAWS and related equipment such as the power generation system 200 as well as the VAWS control system, electrical wiring and generator cooling system (not shown).
While the invention has been described and illustrated in connection with preferred embodiments, many variations and modifications, as will be evident to those skilled in the relevant arts, may be made without departing from the spirit and scope of the invention. The invention is thus not to be limited to the precise details of methodology or construction set forth above.
Patent Application
20080008575
