BERTONY, Joseph (59 Ida Street, Hornsby North, New South Wales 2077, 2077, AU)
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CLAIMS
1. A structure for erecting a mast of a vertical axis wind turbine, the structure comprising: a base portion of a vertical axis wind turbine arranged for positioning on a support surface; a pivotable coupling for coupling a mast of the vertical axis wind turbine to the base portion in a manner such that the mast is pivotable to a substantially vertical position whereby the structure is arranged for erecting the mast of the vertical axis wind turbine.
2. The structure of claim 1 wherein the pivotable coupling comprises a bearing for the mast of the vertical axis wind turbine .
3. The structure of claim 2 wherein the bearing is a first bearing arranged to bear the mast at a first portion and wherein the structure further comprises a second bearing arranged to bear the mast also at a second position that is above the first position.
4. The structure of claim 3 wherein the second bearing comprises at last two components, which can be moved from each other prior to erecting the mast and coupled to each other when the mast is erected.
5. The structure of any one of the preceding claims wherein the structure is arranged to pivot the mast from a horizontal to a vertical orientation.
6. The structure of any one of the preceding claims wherein the pivotable coupling is located adjacent a bottom end of the base portion.
7. The structure of any one of the preceding claims comprising the mast of the vertical axis wind turbine. S. The structure of claim 7 comprising a cross-arm arranged as a hoist .
9. A vertical axis wind turbine comprising the structure of any one of the preceding claims and comprising a plurality of airfoils coupled to the erected mast are arranged for rotation with the mast .
10. A method of erecting a mast of a vertical axis wind turbine, the method comprising the steps of: coupling an end-portion of the mast to a pivotable coupling of a base portion; pivoting the mast to a substantially vertical position; and securing the mast in the substantially vertical position so that the mast is rotable about an axis of the vertical axis wind turbine in the substantially vertical position.
11. The method of claim 10 wherein the pivotable coupling comprises a bearing arranged to bear a bottom end of the mast for rotation of the mast about an axis.
12. The method of claim 11 wherein the step of securing the mast in the substantially vertical position comprises moving at least two bearing elements of a second bearing towards each other so that a portion of the mast is surrounded by the bearing elements to bear the mast above the ' bottom end of the mast.
13. The method of any one of claims 10 to 12 wherein the base-portion has a plurality of side-portions and wherein the method comprises assembling side-portions of the base portion except at one least side potion, thereafter pivoting the mast to the substantially vertical position and thereafter assembling the at least one remaining side- portion of the base portion so that the base portion surrounds a portion of the mast.
14. The method of any one of claims 10 to 12 wherein the base portion has side-portions defining an cavity that houses the pivotable coupling and arranged to further house a portion of the mast therein, the base portion further comprising an elongate aperture opening into the cavity, the aperture being arranged for the mast to be pivoted therethrough.
15. A method of erecting a wind turbine comprising the method in accordance with any one of claims 10 - 14 and further comprising connecting a plurality of airfoils to the mast to be rotatable therewith.
16. The method of claim 15 wherein connecting the plurality of airfoils comprises locating a hoist mechanism at an upper end-portion of the mast and using the hoist mechanism to raise the plurality of airfoils. |
A STRUCTURE AND METHOD FOR ERECTING A MAST OF A VERTICAL
AXIS WIND TURBINE
Field of the Invention
The present invention relates generally to structure and method for erecting a mast of a vertical axis wind turbine .
Background
The majority of wind turbines in use to date have a horizontal axis of rotation, but vertical axis wind turbines are now also of gaining interest. The erection of wind turbines can be difficult and the erection of a mast of the wind turbine often requires a crane or the like, which may not be readily accessible in remote locations .
Summary of the Invention
The present invention provides in a first aspect a structure for erecting a mast of a vertical axis wind turbine, the structure comprising: a base portion of a vertical axis wind turbine arranged for positioning on a support surface; a pivotable coupling for coupling a mast of the vertical axis wind turbine to the base portion in a manner such that the mast is pivotable to a substantially vertical position whereby the structure is arranged for erecting the mast of the vertical axis wind turbine.
The structure in accordance with some embodiments of the present invention has the significant practical advantage that erection of the mast is possible without using a crane .
In an embodiment, the pivotable coupling is located adjacent the bottom end of the base portion. The pivotable coupling may comprise at least one shaft and may be arranged for pivoting about an axis and, if the pivotable coupling comprises the at least one shaft, about the pair of the shafts . The pivotable coupling may comprise a bearing for the mast of the vertical axis wind turbine .
The bearing may be a first bearing arranged to bear the mast at a first portion, which typically is at a bottom end of the mast . The structure may further comprise a second bearing arranged to bear the mast also at a second position that is above the first position. The second bearing typically comprises at last two components, which can be moved from each other prior to erecting the mast and coupled to each other when the mast is erected.
In one embodiment, the structure is arranged to pivot the mast from a horizontal to a vertical orientation. The base portion may comprise a tower. The structure may further comprise a foundation connected to the bottom end of the base portion. The tower may comprise a framework assembly.
The structure may comprise the mast of the vertical axis wind turbine. The mast may comprise a cross-arm arranged as a hoist. The mast may also comprise a collar arranged to rotatably support the mast .
The present invention provides in a second aspect a vertical axis wind turbine comprising the above-defined structure and further comprising a plurality of airfoils coupled to the erected mast and arranged for rotation with the mast .
The present invention provides in a third aspect a method of erecting a mast of a vertical axis wind turbine, the
method comprising the steps of: coupling an end-portion of the mast to a pivotable coupling of a base portion; pivoting the mast to a substantially vertical position; and securing the mast in the substantially vertical position so that the mast is rotable about an axis of the vertical axis wind turbine in the substantially vertical position.
The pivotable coupling may comprise a bearing arranged to bear a bottom end of the mast for rotation of the mast about an axis . The step of securing the mast in the substantially vertical position typically comprises moving at least two bearing elements of a second bearing towards each other so that a portion of the mast is surrounded by the bearing elements to bear the mast above the bottom end of the mast .
In an embodiment, the method comprises constructing the base portion. Constructing the base portion may comprise constructing a part of the base portion arranged to support the mast during erection. Constructing the base portion may comprise completing construction of the base portion after erection of the mast.
For example, the base-portion may have a plurality of side-portions. The method may comprise assembling side- portions of the base portion except at one least side potion, thereafter pivoting the mast to the substantially vertical position and thereafter assembling the at least one remaining side-portion of the base portion so that the base portion surrounds a portion of the mast .
In an embodiment the base portion has side-portions defining a cavity that houses the pivotable coupling and arranged to further house a portion of the mast therein,
- A - the base portion further comprising an elongate aperture opening into the cavity, the aperture being arranged for the mast to be pivoted therethrough. The base portion may not require further construction, and the aperture may be retained, at least in part.
In an embodiment, the method comprises locating the pivotable coupling at a bottom end of the base portion.
The present invention comprises in a third aspect a method of erecting a wind turbine comprising the method in accordance with the second aspect and further comprising connecting a plurality of airfoils to the mast to be rotatable therewith.
Connecting the plurality of airfoils typically comprises locating a hoist mechanism at an upper end-portion of the mast and using the hoist mechanism to raise the plurality of airfoils .
Brief Description of the Figures
Embodiments of the invention will now be described, by way of example only, in order to achieve a better understanding, with reference to the accompanying drawings in which:
Fig. 1 is a side elevation view of an embodiment of a partially completed base tower,
Fig. 2 is a plan view of the partially completed base tower of Fig. 1,
Fig. 3 is a plan view of the base tower of Figs. 1 and 2 showing the addition of one embodiment of a central mast in its initial horizontal position,
Fig. 4 is a side elevation of the base tower of the previous figures showing the mast of Fig. 3 being elevated into its final vertical position,
Fig. 5 is a side elevation of the mast of Fig. 3
being used as a crane to elevate turbine airfoils to form the finished turbine,
Fig. 6 is a side elevation of one embodiment of the finished turbine, Fig. 7 is a side elevation of the mast of Fig. 3 in its vertical position, and
Fig. 8 is a vertical cross-section through the base of the mast of Fig. 3 showing the concrete foundation and the pivotal mast bearing.
Detailed Description of Embodiments of the Invention
A structure for erecting a mast of a vertical axis wind turbine 1 in accordance with an embodiment of the present invention is now described with reference to Figures 1 - 8. The completed vertical axis turbine is illustrated in Fig. 6 from which will be seen that the turbine 1, at least in this embodiment, is made up from a base portion, in the form of a supporting structure on a foundation 2, a rotatable mast 3 and a number of airfoils (aerofoils) 4. The airfoils 4 may be similar or identical to those disclosed in International Patent Application No. PCT/AU02/01295 published under No. WO 03/058061 or International Patent Application No. PCT/AU2005/ 001621 published under No. WO 2006/063380 but the airfoils may be different to those disclosed therein. Vertical axis wind turbines having airfoils of other configurations may be used. The airfoils may be in the form of blades, sheets or sails.
As seen in Figs. 1 and 2, the first step is the partial erection of a supporting structure, in this embodiment in the form of three sides of the four sided tower 2 so as to provide a semi- finished tower which is sufficiently strong for the erection procedure. The structure 2 is erected over a supporting surface such as the ground, building roof, etc. A two part upper bearing 16 is located at the
top of the tower. As seen in Figs 2 and 3, at the bottom of the tower 2 is located a pivotable coupling, in this embodiment in the form of a pivotable bearing 6. The bearing has a mast receiving feature in the form of an annulus 29, at least in this embodiment, arranged to receive a base end of the mast 3.
As seen in Figs. 3 - 5 the mast 3 has its bottom or lower end positioned in the pivotable bearing 6 with the mast 3 substantially horizontal as indicated in Fig. 4. At its top the mast 3 has a cross-arm 8 which is to function as a hoist and is provided with a collar 9 which will rotatably support the mast. Also located on the mast 3 are rungs 10 which form a ladder 11.
As seen in Fig. 4 and utilizing the semi -complete tower 2, the mast 3 is pivoted from its initial substantially horizontal position to its final substantially vertical position utilizing cables 13 and a winch 14. Once the mast 3 has reached this position, as seen in Fig. 2 the second half of the two part upper bearing 16 is connected to the top of the base tower 2. Then the un-erected side of the base tower 2 is completed.
Thereafter, as illustrated in Fig. 5, the cross-arm 8 on the mast 3 can be used as a hoist which together with cables 23 enables the individual airfoils 4 to be raised into their final position and connected to the mast 3 to rotate therewith. In this embodiment, the interconnection between the airfoils 4 takes the form of horizontally extending structural members which extend between a longitudinally extending internal truss located within each airfoil 4, in this embodiment at 3 or 4 vertically spaced apart locations . This results in the completed arrangement illustrated in Fig. 6.
As seen in Fig. 7, the cross-arm 8 is positioned above an
upper disc 25 to which the upper end of each sail 4 is connected. Similarly a lower disc 26 is connected to the mast 3 above the collar 9 and the lower ends of the airfoils 4 are connected to the lower disc 26. The collar 9 rotates within the upper bearing 16 and therefore rotatably supports the centre section of the mast 3.
The lower end or bottom of the mast 3 is received within the bearing 6 illustrated in Fig. 8. The bearing 6 is pivotable by virtue of two shafts, in this embodiment trunnions 28, which rotatably support an annulus 29 which is horizontal in Fig. 8 and which in turn supports a thrust bearing 30 which receives the lower end or bottom 33 of the mast 3. The bearing 6 is supported by a concrete foundation 36. As seen in Fig.6 the concrete foundation 36 also supports an equipment shed 38 which houses the bearing 6 and various items of ancillary equipment. The shed 38 is erected within the tower 2 as a final step in the construction process and the mast 3 passes through the roof of the equipment shed 38.
It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention.
Prior publication to which reference is being made does not constitute an admission that the prior publication forms a part of the common knowledge of a skilled person in Australia or any other country.
In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further
features in various embodiments of the invention.