ROTOR BLADE FOR A WIND TURBINE

Abstract

Provide is a rotor blade for a wind turbine, including a hollow blade body with a root and a tip, wherein the blade body is split along a split plane into two body parts, one extending from the root to a first connection section and the other extending from a second connection section to the tip, wherein the first and the second connection sections are adapted to overlap each other in the connected position.

Claims

1. A rotor blade for a wind turbine, comprising a hollow blade body with a root and a tip wherein the hollow blade body is split along a split plane into two body parts, one body part extending from the root to a first connection section and the other body part extending from a second connection section to the tip; wherein the first connection section and the second connection section are configured to overlap each other in a connected position.

2. The rotor blade according to claim 1, wherein the split plane is in an area where the rotor blade has a convex peripheral geometry.

3. The rotor blade according to claim 1, wherein the split plane is in an area where the rotor blade has a single curved cross section seen in a direction from the root to the tip.

4. The rotor blade according to claim 1, wherein the split plane is in an area where the rotor blade has a convex peripheral geometry and where the rotor blade has a single curved cross section seen in a direction from the root to the tip.

5. The rotor blade according to claim 3, wherein the single curved cross section is circular, oval or egg-shaped.

6. The rotor blade according to claim 1, wherein the first connection section and the second connection section have a conical geometry configured to insert one connection section into the other connection section.

7. The rotor blade according to claim 1, wherein at least one connection section of the first connection section and the second connection section has a stepped geometry.

8. The rotor blade according to claim 6, wherein the first connection section and the second connection section are interlocked with a form fit.

9. The rotor blade according to claim 6, wherein the first connection section is inserted into the second connection section.

10. The rotor blade according to claim 6, further comprising, at the first connection section and/or at the second connection section, one or more slits extending from an end edge over at least a part of a length of the first connection section and/or the second connection section.

11. The rotor blade according to claim 1, further comprising a connection or a stiffening means extending at inner surfaces and bridging a transition region from the first connection section to the second connection section.

12. The rotor blade according to claim 11, wherein the connection or the stiffening means comprises one or more webs or sheets attached to the inner surfaces.

13. The rotor blade according to claim 12, wherein the connection or the stiffening means comprises at least one web or sheet extending along an inner circumference for at least 360 degrees.

14. The rotor blade according to claim 12, wherein the connection or the stiffening means comprises several band- or strip-like webs or sheets extending in a longitudinal direction over the transition region and being distanced to each other along the inner circumference.

15. The rotor blade according to claim 12, wherein the webs or sheets are attached by means of a hardened bonding agent, by lamination or by vacuum assisted resin transfer molding.

16. The rotor blade according to claim 1, wherein the split plane is at an inboard section of the hollow blade body.

17. A wind turbine, comprising a rotor with at least one rotor blade according to claim 1.

Description

BRIEF DESCRIPTION

[0022] Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

[0023] FIG. 1 shows a principle sketch of a wind turbine comprising three rotor blades;

[0024] FIG. 2 shows a perspective exploded sketch of a rotor blade of a first embodiment;

[0025] FIG. 3 shows a partial sketch of a cross section of the rotor blade in the connection area of the two body parts with a web-like connection of stiffening means being provided;

[0026] FIG. 4 shows a sketch according to FIG. 3 with further web-like connection or stiffening means being provided; and

[0027] FIG. 5 shows a principle sketch of a rotor blade according to a second embodiment in an exploded view.

DETAILED DESCRIPTION

[0028] FIG. 1 shows an inventive wind turbine 1, comprising a tower 2 with a nacelle 3 and a hub 4, at which hub in this embodiment three inventive rotor blades 5 are attached. As commonly known, the rotor blades 5 interact with the wind making the hub 4 rotate. This rotation drives a generator arranged in the nacelle 3 for producing electric energy.

[0029] FIG. 2 shows a principle sketch in form of an exploded view of a rotor blade 5 according to a first embodiment. In the following several embodiments are described. The same reference numbers will be used for the same or comparable parts of the respective embodiment.

[0030] The rotor blade 5 as shown in FIG. 2 comprises a hollow blade body 6 which is split along a split plane 7 into two body parts 8, 9, which can be, as shown by the arrows P, pushed into each other respectively connected to each other. The first blade body 8 extends from a root 10 to a first connection section 11, while the second body part 9 extends from a second connection section 12 to a tip 13.

[0031] In the connected position, as shown in FIG. 3, which shows a partial cross sectional view of the rotor blade 5 of FIG. 2, the body parts 8, 9 are pushed with their respective connection section 11, 12 into each other, wherein in this embodiment the first connection section 11 of the first body part 8 is pushed into the second connection section 12 of the second body part 9. As FIG. 3 shows, both connection sections 11, 12 are conical allowing for a simple alignment and assembly of the connection sections 11, 12 and for attaching them to each other with a form fit as shown in FIG. 3.

[0032] The split plane 7 is arranged in an area of the rotor blade 5, where the blade has, as shown in FIG. 3, a convex peripheral geometry seen from the side of the blade. As can be clearly seen in FIG. 3, the circumference widens from the left to a kind of maximum circumference in the area of the split plane 7 and narrows then again.

[0033] Furthermore, the split plane 7 is arranged in an area where the blade has a single curved cross section, as is shown in the exploded view in FIG. 1. The cross section of the connection sections 11, 12 is circular respectively oval, thus the connection sections have a single curved cross section respectively are convex all around the circumference seen from the inner of the blade. Arranging the split plane 7 in the convex and single curved area as explained above enhances the structural performance and enables a lighter and stronger connection of both body parts 8, 9 together with the form fit connection of the connection sections 11, 12 preferably via the conical geometries of the connection sections 11, 12.

[0034] FIG. 3 shows a connection or stiffening means 22 being provided at the inner surfaces 14, 15 of the respective body parts 8, 9 respectively the respective connection sections 11, 12. This connection or stiffening means 13 comprises a web 16, for example a glass fiber web or carbon fiber web or the like, which has a ring form and extends around at least 360 degrees along the inner circumference covering the transition region 17, where the inner surface 14 changes to the inner surface 15. The web 16 extends in the longitudinal direction into both body parts 8, 9 and overlaps a certain area of the inner surfaces 14, 15, to which it is tightly embedded by means of a hardened bonding agent or by lamination or by vacuum assisted resin transfer molding or the like. This web 16 connects the body parts 8, 9 and stiffens the connection and also transfers the shear loads from one body part to the other body part.

[0035] FIG. 4 shows a view according to FIG. 3, where in addition to the web 16 several further band- or strip-like webs 18 are attached to the respective inner surfaces 14, 15 extending even further into the respective body part 8, 9. They obviously extend over the web 16 and the respective transition region 17 and are used for further improving the connection respectively the stiffening and the shear load transfer.

[0036] Certainly, additional fixation mean may be used for fixing the body parts 8, 9 to each other in the overlapping connection sections, for example bolt-nut-connections or the like, which are not shown in detail. It is clear that the connection of the body parts 8, 9 needs to be as firm as possible due to the forces acting on the rotor blade and thus on the connection area when in motion.

[0037] Finally FIG. 5 shows another embodiment of an inventive rotor blade 5 again comprising a hollow blade body 6 which is split along a split plane 7 into two body parts 8, 9, the one extending from the root 10 to a first connection section 11 and the other one extending from a second connection section 12 to a tip 13. Also in this embodiment the split plane 7 is provided in an area where the rotor blade 5 has a convex peripheral geometry seen from the side of the blade and where it has a single curved cross section seen in the direction from the root to the tip, as already explained with regard to FIG. 1.

[0038] In this embodiment the connection section 11 shows several slits 19 extending from the end edge 20 over at least a part of the length of the connection section 11. These slits 19 are preferably equally distributed around the circumference and define respective flexible fingers 21. These flexible fingers 21 enhance the flexibility of the connection section 11 which is advantageous for the good form fit of the connection sections 11, 12.

[0039] While the fingers 21 are only provided at the first connection section 11, it is also possible to provide the second connection 12 with the respective fingers 21 or to provide both connections 11, 12 with fingers 21.

[0040] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0041] For the sake of clarity, it is to be understood that the use of a or an throughout this application does not exclude a plurality, and comprising does not exclude other steps or elements.