Beam for a wind turbine blade, wind turbine blade, wind turbine and method for manufacturing a beam for a wind turbine blade

Abstract

Provided is a beam for a wind turbine blade of a wind turbine, whereby the beam is made from a composite material including a matrix and a reinforcement, the beam having a length in a longitudinal direction of the beam, a width in a width direction of the beam and a thickness in a thickness direction of the beam. The beam includes at least one longitudinal recess arranged in the longitudinal direction of the beam, whereby the at least one longitudinal recess separates the beam into adjacent longitudinal beam portions, whereby the longitudinal recess has the width or the thickness of the beam.

Claims

1. A beam for a wind turbine blade of a wind turbine, wherein the beam is made from a composite material comprising a matrix and a reinforcement, the beam having a length in a longitudinal direction of the beam, a width in a width direction of the beam and a thickness in a thickness direction of the beam, wherein the beam includes at least one longitudinal recess arranged in the longitudinal direction of the beam, wherein the at least one longitudinal recess separates the beam into adjacent longitudinal beam portions, wherein the at least one longitudinal recess has the width or the thickness of the beam, wherein the longitudinal beam portions are connected to one another by unrecessed sections of the beam where the at least one longitudinal recess is not provided, and wherein the unrecessed sections are provided at both ends of the beam.

2. The beam according to claim 1, wherein the reinforcement of the composite material comprises unidirectional fibers arranged in the longitudinal direction of the beam.

3. The beam according to claim 1, wherein the composite material is a fiber-reinforced plastic.

4. The beam according to claim 1, wherein the beam is made from at least one pultruded element.

5. The beam according to claim 1, wherein at least one of the at least one longitudinal recess has a length of at least 20% of the length of the beam.

6. The beam according to claim 1, wherein at least one of the at least one longitudinal recess is provided at a distance of at least 20% of the length of the beam from a first end and/or a second end of the beam.

7. The beam according to claim 1, wherein the longitudinal beam portions are electrically connected to each other by at least one electrically conductive element.

8. The beam according to claim 7, wherein the at least one electrically conductive element is wrapped around the beam.

9. The beam according to claim 7, wherein the at least one electrically conductive element is a carbon fiber roving or a copper mesh.

10. A wind turbine blade of a wind turbine, the wind turbine blade comprising a shell and a spar having at least one spar cap, wherein at least one of the at least one spar cap comprises the beam according to claim 1.

11. The wind turbine blade according to claim 10, wherein the at least one of the at least one spar cap comprising the beam is arranged at a trailing edge of the wind turbine blade.

12. A wind turbine comprising the wind turbine blade of claim 10.

13. A method for manufacturing a beam for a wind turbine blade of a wind turbine, wherein the beam is made from a composite material comprising a matrix and a reinforcement, the beam having a length in a longitudinal direction of the beam, a width in a width direction of the beam, and a thickness in a thickness direction of the beam, the method comprising the step of cutting at least one longitudinal recess in the longitudinal direction of the beam, so that the at least one longitudinal recess separates the beam into adjacent longitudinal beam portions and the at least one longitudinal recess has the width or the thickness of the beam and so that the longitudinal beam portions are connected to one another by unrecessed sections of the beam where the at least one longitudinal recess is not provided, and wherein the unrecessed sections are provided at both ends of the beam.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows a side view on an embodiment of a wind turbine according to the invention;

(3) FIG. 2 shows a sectional view along a transversal plane of an embodiment of a wind turbine blade according to the invention and of the wind turbine of FIG. 1;

(4) FIG. 3 shows a side view on an embodiment of an embodiment beam according to the invention and of the wind turbine blade of FIG. 2;

(5) FIG. 4 shows a sectional view along line A-A of a first embodiment of the beam of FIG. 3;

(6) FIG. 5 shows a sectional view of a second embodiment of a beam according to the invention;

(7) FIG. 6 shows a sectional view of a third embodiment of a beam according to the invention; and

(8) FIG. 7 shows a sectional view of a fourth embodiment of abeam according to the invention.

(9) Same objects in FIGS. 1 to 7 are denominated with the same reference number. If there is more than one object of the same kind in one of the figures, the objects are numbered in ascending order with the ascending number of the object being separated from its reference number by a dot.

BRIEF DESCRIPTION

(10) FIG. 1 is a side view on an embodiment of a wind turbine 1 according to embodiments of the invention. The wind turbine 1 is provided with three wind turbine blades 10.1, 10.2, 10.3 attached to a hub 4 of the wind turbine 1, which is connected to a nacelle 3 of the wind turbine 1, the nacelle 3 being supported on a mast 2 of the wind turbine 1.

(11) FIG. 2 is a sectional view along the transversal plane of line I-I depicted in FIG. 1 of the wind turbine blade 10.1 of the wind turbine 1 of FIG. 1. The wind turbine blade 10 has a trailing edge 11 and a leading edge 12. The wind turbine blade 10.1 comprises a shell 20 and a spar 30. The spar 30 comprises three spar caps 31.1, 31.2, 31.3. The two spar caps 31.1, 31.2 face each other and are connected to one another by means of a spar web 32. The spar cap 31.3 is arranged at the trailing edge 11 of the wind turbine blade 10. In this particular embodiment, the spar cap 31.3 comprises four beams 40.1, 40.2, 40.3, 40.4. However, any number of beams 40 can be provided in the spar cap 31.3. Moreover, the spar caps 31.1, 31.2 may be provided with beams 40 according to embodiments of the invention.

(12) FIG. 3 is a side view on the beam 40.1 of FIG. 2. The beam has a length L.sub.40 in the longitudinal direction of the beam 40, a width W.sub.40 in the width direction of the beam 40 and a thickness T.sub.40 in the thickness direction of the beam 40. In this particular embodiment, the beam 40 is a pultruded element made from carbon fiber-reinforced plastic. Five longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5 are arranged parallel to one another in the longitudinal direction of the beam 40, whereby the longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5 separate the beam 40 into six adjacent longitudinal beam portions 42.1, 42.2, 42.3, 42.4, 42.5, 42.6. The longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5 and the longitudinal beam portions 42.1, 42.2, 42.3, 42.4, 42.5, 42.6 have the thickness T.sub.40 of the beam. The longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5 are arranged in a recessed portion having the length L.sub.41 of the beam 40. The length L.sub.41 is 50% of the length L.sub.40 of the beam 40 in this particular embodiment. The longitudinal beam portions 42.1, 42.2, 42.3, 42.4, 42.5, 42.6 are connected to each other by means of unrecessed portions arranged towards a first end 44 and towards a second end 45 of the beam 40, respectively. Both unrecessed portions have a length of 25% of the length L.sub.40 of the beam 40 in this particular embodiment. Thereby, the longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5 are provided at a distance of 25% of the length L.sub.40 of the beam 40 from the first end 44 and the second end 45 of the beam 40.

(13) FIG. 4 is a sectional view along line A-A of the beam 40 of FIG. 3. Here, the longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5 separating the longitudinal beam portions 42.1, 42.2, 42.3, 42.4, 42.5, 42.6 from one another can clearly be seen. The longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5 and the longitudinal beam portions 42.1, 42.2, 42.3, 42.4, 42.5, 42.6 have the thickness T.sub.40, which is the thickness of the beam 40. The longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5 have a height of W.sub.41.1, which is provided in the width direction W.sub.40 of the beam 40 and create a space or distance between adjacent longitudinal beam portions 42.1, 42.2, 42.3, 42.4, 42.5, 42.6.

(14) FIG. 5 is a sectional view of a second embodiment of a beam 40 according to embodiments of the invention. Here, an electrically conductive material 43 is wrapped around the beam 40, in particularly around the entire circumference of the beam 40. The electrically conductive material 43 is designed as a sheet material and is flexible in this particular embodiment. Such a wrap is a particularly easy way of electrically connecting the longitudinal beam portions 42.1, 42.2, 42.3, 42.4, 42.5, 42.6.

(15) FIG. 6 is a sectional view of a third embodiment of a beam 40 according to embodiments of the invention. Here, five separate pads of electrically conductive material 43.1, 43.2, 43.3, 43.4, 43.5 are provided in each of the longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5. In particular, these pads of electrically conductive material 43.1, 43.2, 43.3, 43.4, 43.5 are flexible, so that the beam 40 is kept flexible and with its high twisting capabilities at its recessed portion.

(16) FIG. 7 is a sectional view of a fourth embodiment of a beam 40 according to embodiments of the invention. Here, the electrically conductive material 43 is wrapped around the beam 40, in particular around the entire circumference of the beam 40, and additionally provided in each of the longitudinal recesses 41.1, 41.2, 41.3, 41.4, 41.5. Thereby, a large surface area of the electrically conductive material 43 is provided, by means of which the current from a lightning strike intercepted by the beam 40 can be passed on between the longitudinal beam portions 42.1, 42.2, 42.3, 42.4, 42.5, 42.6.

(17) 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.

(18) 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.