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Title:
A WIND POWER UNIT
Document Type and Number:
WIPO Patent Application WO/2010/085192
Kind Code:
A1
Abstract:
The invention relates to a wind-power unit having a wind turbine with vertical shaft, a supporting pole, a generator and a vertical shaft (4). The shaft (4) is with its upper end connected to the turbine and with its lower end to the generator. According to the invention, between the upper and lower ends, the shaft (4) is supported by at least two axially separated supporting devices (13). Each supporting device (13) has at least three supporting components (15) that abut against the shaft (4) and that are connected to the supporting pole.

Inventors:
MOUSAVI, Saed (Sorögatan 17, Kista, S-164 41, SE)
LEDIN, Filip (Höganäsgatan 4 B, Uppsala, S-753 30, SE)
Application Number:
SE2009/051437
Publication Date:
July 29, 2010
Filing Date:
December 16, 2009
Export Citation:
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Assignee:
Vertical Wind AB (Sylveniusgatan 5 D, Uppsala, S-754 50, SE)
MOUSAVI, Saed (Sorögatan 17, Kista, S-164 41, SE)
LEDIN, Filip (Höganäsgatan 4 B, Uppsala, S-753 30, SE)
International Classes:
F03D11/00; F03D11/04; F16C32/00
Domestic Patent References:
WO1996030647A11996-10-03
WO2008153490A12008-12-18
Foreign References:
EP1491766A12004-12-29
GB2249143A1992-04-29
Attorney, Agent or Firm:
Groth & Co. KB (Box 6107, Stockholm, S-102 32, SE)
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Claims:
CLAIMS

1. Wind-power unit comprising a wind turbine (1) with vertical shaft, a hollow supporting pole (2), an electric generator (3) and a vertical shaft (4) that with its upper end is connected to the turbine (1 ) and with its lower end is connected to the generator (3), characterized in that the shaft (4) between its upper end and its lower end is supported by at least two axially separated supporting devices (13), each supporting device (13) comprising at least three supporting components (15) that abut directly against the shaft (4) and that are connected to the inside of the supporting pole (2).

2. Wind-power unit according to claim 1 , characterized in that the shaft (4) is hollow and that the shaft (4), in the positions where the supporting devices (13) abut, has a greater material thickness than the material thickness that occurs at other parts of the shaft.

3. Wind-power unit according to claim 2, characterized in that the axial distance between the two adjacent supporting devices (13) is in the range of 4-40 m.

4. Wind-power unit according to claim 3, characterized in that the shaft (4) is composed of a plurality of shaft sections (14) interconnected by splices.

5. Wind-power unit according to claim 4, characterized in that each supporting device (13) is arranged to abut against a splice.

6. Wind-power unit according to claim 4 or 5, characterized in that each splice comprises a splice piece (22) that connects the adjacent shaft sections (14).

7. Wind-power unit according to any one of claims 1-6, characterized in that each supporting component (15) comprises at least one roller body (16) arranged to abut against the shaft (4).

8. Wind-power unit according to claim 7, characterized in that each supporting component (15) comprises two roller bodies (16) arranged on a carrying element (17), which carrying element is turnable around a vertical shaft (18) between the two roller bodies (16).

9. Wind-power unit according to claim 7 or 8, characterized in that each supporting component (15) is resiliently pressed against the shaft (4).

10. Wind-power unit according to claim 9, characterized in that a leaf spring (21 ) is arranged between the supporting component (15) and the carrying pole (2).

11. Wind-power unit according to claim 9 or 10, characterized in that a cup spring (20) is arranged between the supporting component (15) and the carrying pole.

12. Wind-power unit according to any one of claims 7-11 , characterized in that each roller body (16) has a rolling surface of a material that is softer than the rest of the roller body (16).

13. Wind-power unit according to any one of claims 1-12, characterized in that the shaft (4) has a diameter in the range of 40-400 cm.

14. Electric mains (10), characterized in that the mains is connected to a wind-power unit according to any one of claims 1-13.

15. Use of a wind-power unit according to any one of claims 1-13 in order to deliver energy to an electric mains (10).

Description:
A WIND-POWER UNIT

Field of the Invention

The present invention relates to a wind-power unit comprising a wind turbine with vertical shaft, a supporting pole, an electric generator and a vertical shaft that with the upper end thereof is connected to the turbine and with the lower end thereof is connected to the generator.

Background of the Invention Wind-power units with vertical shaft have increasingly developed to become a competitive alternative to wind-power units with horizontal shaft and have several advantages in relation to the same. There are different types of wind- power units with vertical shaft, among others, units with a so-called H-rotor where the turbine blades are vertical. The present invention is primarily intended for H- rotor units but can also be applied to other kinds of wind-power units with vertical shaft.

Wind-power units of this kind can be of relatively great dimensions with a shaft length of 50-100 m and a shaft diameter in the order of 50-200 cm. A stable bearing mounting of the shaft is required, and with units in the indicated size range, this entails a problem. Conventional bearings become very expensive. As they moreover are arranged at a high height, it becomes complicated to repair a bearing failure or other defects in the bearing mounting.

The object of the present invention is to overcome this problem and thus provide support to the shaft in the radial direction wherein the indicated drawbacks are obviated or at least reduced.

Summary of the Invention

The object set forth is achieved by the invention by the fact that a wind- power unit of the kind mentioned by way of introduction has the special features that the shaft between its upper and lower end is supported by at least two axially separated supporting devices, each supporting device comprising at least three supporting components that abut against the shaft and that are connected to the supporting pole. The supporting devices replace the need of conventional bearings for the bearing mounting of the shaft and eliminate thereby the problems associated with the same at the large dimensions that often are concerned in this context. The supporting devices become considerably more inexpensive than conventional bearings. This constitutes a significant contribution to enhance the economical competitiveness of this kind of wind-power units. The invention also entails an improved operating economy in comparison with if conventional bearings would have been used, thanks to service and repair of possible defects being facilitated. The device for bearing mounting according to the invention has in addition a relatively low weight.

According to a preferred embodiment, the shaft is hollow and has a greater material thickness in the positions where the supporting devices abut than the material thickness that occurs at other parts of the shaft.

For shaft dimensions that are concerned here, it is important to have as thin a material thickness as possible with the purpose of keeping the weight down. The material thickness of the shaft in its entirety is determined by what is required to be able to carry the torsional and bending stresses that can be expected to occur. The material thickness that in that connection is sufficient is however not always sufficient to resist the concentrated compressive forces that occur at the support points. By having a greater material thickness only at these areas, the need to overdimension the shaft in its entirety is avoided. Accordingly, by this embodiment, the weight of the shaft is reduced in comparison with if the material thickness would be constant.

According to an additional preferred embodiment, the axial distance between two adjacent supporting devices is in the range of 4-40 m.

In this range, the distance between the supporting devices is not greater than that a stable and efficient bearing mounting is achieved. Simultaneously, it is naturally desirable to need to use as few supporting devices as possible, and in the given range, the number becomes relatively small. The optimal balance between, on one hand, achieving stable bearing mounting, and on the other hand not using unnecessary many supporting devices, is something that can be decided from case to case based on the conditions in question.

According to an additional preferred embodiment, the shaft is composed of a plurality of shaft sections interconnected by splices. Particularly for large units, this is advantageous for reasons of manufacturing technique and allows transportation without problems.

According to an additional preferred embodiment, each supporting device is arranged to abut against a splice. Thereby, a practical modularization of the shaft and the bearing mounting thereof is achieved by the fact that the length of the shaft sections and the distance between the support points become uniform. In addition, provision of an increased material thickness of the shaft at the support points is facilitated if the thicker material thickness is formed adjacent to the splices in comparison with if it would be made somewhere in the middle of a shaft section.

According to an additional preferred embodiment, each splice comprises a splice piece that connects the adjacent shaft sections.

Thereby, the increased material thickness can be formed on the splice piece. This entails that the shaft sections in themselves do not need to be provided with increased material thickness at their ends, which simplifies the manufacture of the same. In addition, the assembling is facilitated when this is effected by means of special splice pieces.

According to an additional preferred embodiment, each supporting component comprises at least one roller body arranged to abut against the shaft. This entails low friction and little wear. Suitably, the roller body consists of a wheel.

According to an additional preferred embodiment, each supporting component comprises two wheels arranged on a carrying element, which carrying element is turnable around a vertical shaft between the two wheel shafts. Such a boogie-like supporting component provides a good centring of the shaft of the unit between the supporting components and contributes to the fact that the supporting device gets a desired flexibility that allows a certain motion laterally of the shaft without the bearing-mounting stability becoming impaired.

According to an additional preferred embodiment, each supporting component is resiliently pressed against the shaft.

This contributes further to the desirable flexibility and reduces the risk of the building up of large bending stresses in the shaft. The resilient suspension means therefore also lower requirements of precision in the mounting of the unit. According to an additional preferred embodiment, a leaf spring is arranged between the supporting component and the carrying pole.

By this arrangement, the resilient pressing is achieved in a simple, reliable and expedient way. According to an additional preferred embodiment, a cup spring is arranged between the supporting component and the carrying pole.

A cup spring is another suitable alternative of the springing that in a simple way guarantees a suitable degree of springing. The cup spring may also be complementary to the leaf spring. According to an additional preferred embodiment, each roller body has a rolling surface of a material that is softer than the rest of the roller body.

With a relatively soft material in the rolling path, the risk of the roller body only abutting against the shaft in certain points decreases. Suitably, the soft material is a plastic such as, e.g., polyurethane and the rest of the roller body may be of metal.

According to an additional preferred embodiment, the shaft has a diameter in the range of 40-400 cm.

It is above all for large shaft dimensions that the advantages of the invention are most notable, and therefore this embodiment is of particular interest. The above-mentioned preferred embodiments of the invention are defined in the claims depending on claim 1. It should be emphasized that additional preferred embodiments naturally may consist of all feasible combinations of the above-mentioned preferred embodiments.

The invention also relates to an electric mains that has the special feature that it is connected to the invented wind-power unit, particularly according to any one of the preferred embodiments of the same.

Furthermore, the invention relates to a use of the invented wind-power unit in order to deliver energy to an electric mains, particularly according to any one of the preferred embodiments of the same. Such an electric mains and such a use entail advantages of the corresponding kinds that are gained with the invented wind-power unit and the preferred embodiments of the same and that have been accounted for above. The invention is explained in more detail by the subsequent detailed description of embodiment examples of the same, reference being made to the appended drawing figures.

Brief Description of the Drawings

Fig. 1 is a schematic side view of a wind-power unit according to the invention.

Fig. 2 is a side view of the shaft of the unit in Fig. 1.

Fig. 3 is a section along the line Ill-Ill in Fig. 2. Fig. 4 is a section along the line IV-IV in Fig. 3.

Description of Embodiment Examples

Fig. 1 illustrates schematically a wind-power unit according to the invention with vertical shaft. The unit has a turbine 1 of the H-rotor type where a number of vertical turbine blades 5, e.g., three, are connected to the turbine shaft 6 via stays 7. The turbine shaft 6 is connected to the shaft 4 of the unit. The shaft 4 of the unit is at its lower end connected to the rotor of a generator 3. A supporting column 2 surrounds the shaft 4 and is stayed by stay wires 8. The supporting column has at its upper end bearings 9 for axial and radial bearing mounting of the turbine 1. The supporting column also serves as radial support to the shaft 4 of the unit. The generator 3 delivers energy to an electric mains 10.

Fig. 2 shows the shaft 4 of the unit in a side view. Its upper end is provided with connection means 11 by which it is connected to the turbine shaft 6, and its lower end is provided with connection means 12 by which it is connected to the shaft of the generator 3.

Along the shaft 4, five supporting devices 13 are arranged. The same are placed mutually axially equidistantly at approx. 6 m. Each supporting device abuts against the shaft 4 and is mounted in the supporting column 2 (see Fig. 1 ). The shaft 4 is composed of six sections that are joined to each other at the respective supporting device 13.

It should, however, be appreciated that the splices do not necessarily need to be situated in such a way. Furthermore, the number of supporting devices 13 and the number of shaft sections 14 may naturally be another than the above- mentioned one. Neither does the distance between the supporting devices necessarily need to be the same along the entire shaft.

Fig. 3 is an enlarged section along the line Ill-Ill in Fig. 2 and illustrates an example of how the supporting device 13 may be formed. The shown supporting device consists of three supporting components 15 uniformly distributed in the circumferential direction around the shaft 4. Each supporting component 15 has two roller bodies 16 formed as wheels and that abut against the shaft 4. The wheels 16 are mounted on a carrying element 17. The carrying element 17 is turnable around a suspension shaft 18 in a holder 19 that via a cup spring 20 is attached to a supporting beam 21. The leaf spring 20 presses the supporting component 15 by a certain bias force against the shaft 4, suitably in the order of 1 kN. The supporting beam 20 is anchored in the supporting column 2 (see Fig. 1 ).

Fig. 4 is a section along the line IV-IV in Fig. 3 and shows one of the wheels 16 abutting against the shaft, at a splice. In the example shown, the two shaft sections 14 are spliced together by means of a special splice piece 22. The joint is suitably a bolted flange joint. The splice piece 22 has a material thickness that is 5-10 times thicker than the thickness of the shaft sections. A normal material thickness of the shaft sections is about 1 cm. On its outside, the splice piece has a groove 23 that forms a rolling path for the wheel 16. The wheel 16 has a coating of polyurethane.

The supporting beam 21 may be dimensioned relatively thin so that it gets resilient properties and thereby work as a leaf spring 21. Thereby, it can replace the cup spring 20 or be complementary to the same.