WIND TURBINE

Abstract

Provided is a wind turbine including a rotor with a hub and several rotor blades arranged at the hub with the rotor blades being rotatable around an axis relative to the hub by a pitch bearing arrangement, whereby each rotor blade extends into the hub with a blade section, with the pitch bearing arrangement including a first and a second rolling bearing being spaced apart from each other in the direction of the axis and arranged between the blade sections and the hub.

Claims

1. A wind turbine comprising a rotor with a hub and several rotor blades arranged at the hub with the rotor blades being rotatable around an axis relative to the hub by a pitch bearing arrangement, wherein each rotor blade extends into the hub with a blade section, with the pitch bearing arrangement including a first and a second rolling bearing being spaced apart from each other in the direction of the axis and arranged between the blade sections and the hub.

2. The wind turbine according to claim 1, wherein the first rolling bearing being arranged on a larger diameter of the hub has a greater diameter than the second rolling bearing arranged on a smaller diameter of the hub.

3. The wind turbine according to claim 2, wherein each blade section tapers conically from a first bearing seat carrying the first bearing to a second bearing seat carrying the second bearing.

4. The wind turbine according to claim 2, wherein each blade section tapers in a stepped manner from a first bearing seat carrying the first bearing to a second bearing seat carrying the second bearing.

5. The wind turbine according to claim 1, wherein the hub comprises hub sections extending in the direction of the respective axis, with each hub section comprises a bearing seat for the first bearing in the region of its free end and a second bearing seat for the second bearing at an inner position.

6. The wind turbine according to claim 1, wherein the hub comprises hub sections extending in the direction of the respective axis, with each hub section comprises a bearing seat for the first bearing in the region of its free end and with a second bearing seat for the second bearing being provided at an inner position close to the center of the hub.

7. The wind turbine according to claim 5, wherein the hub comprises one-piece hub sections, or that each hub section is a separate component attached to a central hub component.

8. The wind turbine according to claim 1, wherein the hub comprises three similar hub components each with a hub section and an inner connection section with inclined and abutting connection portions, with each hub component comprises a bearing seat for the first bearing in the region of its free end and a second bearing seat for the second bearing at an inner position.

9. The wind turbine according to claim 8, wherein each hub component comprises an inner component part with the connection portion and a separate hub section fixed to the inner component part, or that each hub component is a one-piece component.

Description

BRIEF DESCRIPTION

[0020] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0021] FIG. 1 is a schematic drawing of an inventive wind turbine, shown in part, according to a first embodiment;

[0022] FIG. 2 is an enlarged cutout view of a part of the arrangement according to FIG. 1;

[0023] FIG. 3 is a schematic drawing of a hub component for making up a wind turbine hub according to a second embodiment;

[0024] FIG. 4 is a schematic drawing of a hub made up by three hub components according to FIG. 3; and

[0025] FIG. 5 is a third embodiment of an inventive wind turbine.

DETAILED DESCRIPTION

[0026] FIG. 1 shows a schematic drawing of an inventive wind turbine 1, from which turbine only the hub 2 and one rotor blade 3 fixed to the hub 2 is shown.

[0027] The rotor blade 3 comprises a blade section 4, which tapers conically to its free end. This tapered blade section 4 extends or is inserted into the hub 2. It is rotatable about its longitudinal axis 5 by means of an appropriate actuation means like an electronic drive motor for pitching the blade. For allowing this rotation a pitch bearing arrangement 6 is provided, comprising a first rolling bearing 7 and a second rolling bearing 8. As this is only a schematic drawing all components are only schematically shown.

[0028] In this embodiment the hub 2 comprises a central hub component 15, to which respective hub sections 9 extending in the respective direction of the respective rotation axis 5 are fixed. The blade 5 extends with its blade section 4, which is also a separate component fixed to the main blade section 10, into the hub section 9 and, as FIG. 1 shows, into the central hub component 15.

[0029] The first rolling bearing 7 is arranged at the free end of the hub section 9. The hub section 9 comprises a first bearing seat 11, while the blade section 4 comprises a second bearing seat 12, on which bearing seats 11, 12 the respective first rolling bearing 7 is arranged.

[0030] As FIG. 2 shows, the blade section 4 extends into the central hub component 15. The second rolling bearing 8 is arranged within this central hub component 15. It is attached to a second bearing seat 13 provided at the hub component 15 and a second bearing seat 14 provided at the blade section 4.

[0031] The respective rolling bearings 7 are only radially loaded pitch bearings. The outer first rolling bearing 7 has a larger diameter than the inner second rolling bearing 8, as can clearly be taken from FIG. 1. This is due to the fact that the outer rolling bearing 7 will carry the larger load compared to the inner rolling bearing 8.

[0032] It is clear that the bearings 7, 8 and the blade sections 4 are inside the hub sections 9, they are shown in the figures in detail only for illustrative purpose.

[0033] FIG. 2 shows a schematic cutout view of the central hub component 15, the hub section 9 and the blade section 4. As can be clearly seen the blade section 4, which is attached or fixed in an appropriate manner to the main blade section 10, is encompassed by the hub section 9 and, with its inner end, by the central hub component 15. It is provided with a first outer bearing seat 12 and a second inner bearing seat 14, on which the respective first and second rolling bearings 7, 8 are arranged. As shown in FIG. 2, the hub section 9 is provided at its free end with a first bearing seat 11 for carrying the first rolling bearing 7. Finally the central hub component 15 is provided with the second bearing seat 13 for the second rolling bearing 8.

[0034] Apart from the blade section 4 tapering in the way shown in FIG. 2 it is possible that the blade section 4 may change its diameter in a stepwise manner, with a first cylindrical part providing the first bearing seat 12 and with a second cylindrical part providing the second bearing seat 14 with a smaller diameter.

[0035] FIG. 3 shows an embodiment of a hub component 16, with identical parts being denoted with identical reference numbers.

[0036] The hub component 16 is a one-piece component and comprises a hub section 9 and an inner connection section 17 with two inclined connection portions 18 used for interconnecting three of these hub components 16 for building a hub 2.

[0037] In FIG. 3 also the inserted blade section 4 is shown, together with the respective first and second rolling bearings 7, 8, with all components are shown in a schematic way. No need to say that the respective bearings 7, 8 and the blade section 4 are certainly inside of the hub component 16 and are not visible, while the respective bearings 7, 8 are certainly arranged on respective bearing seats etc. FIG. 3 is intended to only show the design or make up of such a hub component 16 used for building a hub, which hub is shown in FIG. 4.

[0038] FIG. 4 shows an arrangement of three identical hub components 16 building a respective hub 2. The hub components 16 are arranged with their inclined connection portions 18 abutting each other. Each angle between two respective inclined connection portions 18 is 120. At these abutting connection portions 18 the respective hub components 16 are fixed to each other.

[0039] While only one rotor blade 3 and the respective first and second bearings 7, 8 are shown, there is no need to explain that also the other hub components 16 are provided with these respective elements for building a wind turbine with a rotor comprising three rotor blades.

[0040] Finally, FIG. 5 shows another embodiment of an inventive wind turbine 1 with a hub 2, which hub 2 is made up by three separate hub components 16. Each hub component 16 comprises an inner component part 19 with respective inner connection sections 17 with inclined connection portions 18 with an angle between the respective inclined portions 18 of 120. In the mounted position the connection portions 18 abut each other as is clearly shown in FIG. 5, with the hub components 16 being fixed to each other at these connection portions 17.

[0041] Attached to these inner component parts 19 are respective cylindrical hub sections 9 extending in the direction of the respective axis of the respective rotor blades 5. Each rotor blade 3 is also in this embodiment provided with a respective blade section 4 which is inserted into the respective hub component 16, i.e. the cylindrical hub section 9 and, as shown in FIG. 5, the respective inner component part 19, which certainly is also a hollow body.

[0042] For pitching the respective rotor blade 3 also in this embodiment a respective pitch bearing arrangement is provided comprising the first pitch rolling bearing 7 and the second pitch rolling bearing 8. While the first pitch rolling bearing 7 is provided at the free end of the respective hub section 9, the second rolling bearing 8 is provided in the inner hub component 19 at respective bearing seats. The blade section 4 is provided with bearing seats, to which the bearing 7, 8 is attached.

[0043] When building the wind turbine it is possible to premanufacture the hub 2 or at least parts of the hub.

[0044] With reference to FIG. 1 it is possible to attach the hub sections 9 to the central hub component 15 and to insert both the respective rolling bearings 7, 8 and the extending blade section 4. The blade section 4 is not connected to the main blade section 10. This hub can then be mounted by means of a crane at an elevated position. After mounting this premanufactured hub it is only necessary to fix the respective main blade sections 10 to the respective blade sections 4.

[0045] A similar process is possible for building the wind turbine shown in FIG. 4. It is possible to provide each hub component 16 with the rolling bearings 7, 8 and the hub sections 4. Afterwards the hub components 16 are fixed to each other for building the hub 2. After mounting the hub 2 at an elevated position it is only necessary to attach the respective main blade sections 10 to the blade sections 4 already provided at the hub 2.

[0046] When building the wind turbine 1 according to FIG. 5 a similar process is possible. The hub components 16 may also be free manufactured by attaching the inner component parts 19 to the hub section 9 and by providing the respective bearings 7, 8. Also the blade sections 4 can also be inserted into the respective hub components 16. When building the hub, it is only necessary to attach the respective hub components 16 to each other and to mount it to the turbine at an elevated position. Afterwards only the respective main blade sections 10 need to be fixed to the already inserted blade sections 4.

[0047] Although the present invention has been described in detail with reference to the preferred embodiment, the present invention is not limited by the disclosed examples from which the skilled person is able to derive other variations without departing from the scope of the invention.