Spar cap and production method

Abstract

A spar cap for a rotor blade of a wind power installation, having a longitudinal extent from a first end to a second end, a transverse extent orthogonal to the longitudinal extent, and a thickness orthogonal to the longitudinal extent and to the transverse extent. A method for producing a spar cap as mentioned at the outset. The spar cap has a longitudinal extent from a first end to a second end, a transverse extent orthogonal to the longitudinal extent, and a thickness orthogonal to the longitudinal extent and to the transverse extent, at least two tiers of a first fiber composite material, and at least one tier of a second fiber composite material, wherein the first fiber composite material has a matrix material and/or fibers which is/are different from that/those of the second fiber composite material, the second fiber composite material is disposed in a portion adjacent to the second end, in the direction of the thickness between the at least two tiers of the first fiber composite material, and the at least one tier of the second fiber composite material terminates ahead of the second end.

Claims

1. A rotor blade comprising: a rotor blade root; a rotor blade tip; and a spar cap including: a first end located at a region of the rotor blade root; a second end located in a region of the rotor blade tip; a longitudinal axis extending from the first end to the second end; a transverse axis orthogonal to the longitudinal axis; a thickness orthogonal to the longitudinal axis and to the transverse axis; at least two tiers of a first fiber composite material comprising a matrix material and fibers; and at least one tier of a second fiber composite material comprising a matrix material and fibers, wherein at least one of the matrix material or the fibers of the first fiber composite material are different from the matrix material and the fibers of the second fiber composite material; wherein the second fiber composite material is disposed in a portion adjacent to the second end in a direction of the thickness between the at least two tiers of the first fiber composite material; wherein the at least one tier of the second fiber composite material terminates ahead of the second end, wherein the fibers of the second fiber composite material comprise carbon fibers, and the fibers of the first fiber composite material comprise inorganic fibers, wherein the number of tiers of the first fiber composite material is less at the second end than the number of tiers of the first fiber composite material at the first end, and wherein two external tiers comprising the first fiber composite material are located in a region of the rotor blade that contains a reduction in the tiers of the first fiber composite material.

2. The rotor blade as claimed in claim 1, wherein a region at the second end comprises at least one tier of the first fiber composite material.

3. The rotor blade as claimed in claim 1, comprising: at least two tiers of the second fiber composite material, wherein a number of tiers of the second fiber composite material is reduced toward the second end.

4. The rotor blade as claimed in claim 1, comprising at least one of: at least three or more tiers of the first fiber composite material; or at least three or more tiers of the second fiber composite material.

5. The rotor blade as claimed in claim 1, wherein the at least one tier of the second fiber composite material has two mutually opposite ends, wherein the two mutually opposite ends are formed by a planar expanse of the tiers in the longitudinal axis and the transverse axis, and wherein a same number of tiers of the first fiber composite material is disposed on both ends of the at least one tier of the second fiber composite material.

6. The rotor blade as claimed in claim 1, wherein the matrix material of at least one of: the first fiber composite material or the second fiber composite material includes an insulative material; and wherein the insulative material is at least one of: thermoplastic, thermosetting material, cement, concrete, or ceramic.

7. The rotor blade as claimed in claim 1, wherein the fibers of at least one of: the first fiber composite material or the second fiber composite material extend substantially parallel with a direction of the longitudinal axis.

8. A wind power installation comprising: the rotor blade as claimed in claim 1; and an electrically conductive foil/film tier and a lightning interception installation of a lightning protection system, wherein the electrically conductive foil/film tier is connected to the lightning interception installation by way of an electrically conductive connection.

9. A wind power installation comprising: a tower; a nacelle; and a rotor, wherein the rotor has at least one rotor blade as claimed in claim 1.

10. A rotor blade comprising: a spar cap including: a first end; a second end; a longitudinal axis extending from the first end to the second end; a transverse axis orthogonal to the longitudinal axis; a thickness orthogonal to the longitudinal axis and to the transverse axis; at least two tiers of a first fiber composite material; and at least one tier of a second fiber composite material, wherein: the first fiber composite material has a matrix material and/or fibers that are different from a matrix material and fibers of the second fiber composite material; the second fiber composite material is disposed in a portion adjacent to the second end in a direction of the thickness between the at least two tiers of the first fiber composite material; the at least one tier of the second fiber composite material terminates ahead of the second end; and an electrically conductive foil/film tier and a lightning interception installation of a lightning protection system, wherein the electrically conductive foil/film tier is connected to the lightning interception installation by way of an electrically conductive connection, wherein at least one of: the foil/film tier has a longitudinal axis that extends in a direction of a longitudinal axis of the rotor blade, the longitudinal axis of foil/film tier being at most of the longitudinal axis of the rotor blade; the foil/film covers a region in the direction of the longitudinal axis of the rotor blade in which the at least one tier of the second fiber composite material terminates; the foil/film tier is disposed in an external half of a thickness of a rotor blade wall that is measured transversely longitudinal direction of the rotor blade; the foil/film tier is disposed on one or a plurality of tiers of fiber composite material that do not provide structure support for the rotor blade; the foil/film tier is disposed and configured for resisting an expected lightning current load; or the foil/film tier has a plurality of clearances and/or meshes.

11. A method for producing a rotor blade as claimed in claim 1, the method comprising: stacking the at least two tiers of the first fiber composite material; and stacking the at least one tier of the second fiber composite material.

12. The method as claimed in claim 11, wherein the number of tiers of the first fiber composite material is reduced toward the second end.

13. The method as claimed in claim 11, wherein at least two tiers of the second fiber composite material are laid up in such a manner that the number of tiers of the second fiber composite material is reduced toward the second end.

14. The method as claimed in claim 11, further comprising: incorporating an electrically conductive foil/film tier and connecting the foil/film tier to a lightning interception installation of a lightning protection system by way of an electrically conductive connection.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) Preferred embodiments of the invention will be explained in an exemplary manner by means of the appended figures in which:

(2) FIG. 1: shows a schematic illustration of a wind power installation;

(3) FIG. 2: shows a schematic cross-sectional view of a spar cap in the direction of a longitudinal and transverse extent thereof;

(4) FIG. 3: shows a schematic cross-sectional view of a spar cap in the direction of a longitudinal extent and of the thickness thereof;

(5) FIG. 4: shows a schematic cross-sectional view of a spar cap in the direction of a transverse extent and of a thickness thereof;

(6) FIG. 5: shows a schematic cross-sectional view of a spar cap in the region of the reduced coverage, in the direction of a transverse extent and of a thickness of said spar cap;

(7) FIG. 6: shows a schematic illustration of a rotor blade according to the invention; and

(8) FIG. 7: shows an enlarged fragment from a schematic illustration of an electrically conductive foil/film tier of a rotor blade according to FIG. 6.

DETAILED DESCRIPTION

(9) FIG. 1 shows a schematic illustration of a wind power installation. FIG. 1 shows a wind power installation 100 having a tower 102 and a nacelle 104. A rotor 106 having three rotor blades 108 and a spinner 110 is disposed on the nacelle 104. The rotor 106 in operation is set in rotary motion by the wind and on account thereof drives a generator in the nacelle 104.

(10) Spar caps 200 according to the invention are used in particular for the longitudinal reinforcement of the rotor blades 108. For this purpose, at least one spar cap 200, preferably two spar caps 200, are disposed in the interior of the rotor blade 108 and are preferably fastened to a side facing the interior of the rotor blade 108.

(11) FIG. 2 shows a schematic cross-sectional view in the direction of a longitudinal extent L and transverse extent Q of a spar cap 200. The spar cap extends longitudinally along the longitudinal extent L thereof from a first end 210 to a second end 220. The first end 210 preferably represents the end of the spar cap 200, said end being disposed in the region of a rotor blade root. By contrast, the second end 220 represents that end of the spar cap 200 that is disposed in the region of a rotor blade tip. The dimension of the transverse extent Q can decrease in portions along the longitudinal extent L toward the second end 220. The reduction in the dimension of the transverse extent Q can alternatively also be preferably performed in a continuous manner.

(12) The spar cap 200 is produced substantially from fiber composite materials which are processed in the form of so-called tiers and in this form are also present in the spar cap 200 produced. A tier comprises substantially fibers and a matrix material, wherein a tier is in particular configured as a layer. This means that a tier has a planar geometry having a minor thickness. The planar geometry of the tiers is in particular configured by a face in the direction of the longitudinal extent L and the transverse extent Q.

(13) Therefore, the tier, or the tiers, respectively, of a first fiber composite material 300, and the tier, or the tiers, respectively, of a second fiber composite material 400 are depicted in FIG. 2, FIG. 3, FIG. 4, and FIG. 5. The tiers of the first fiber composite material 300 comprise or are preferably glass fibers, and the tiers of the second fiber composite material 400 comprise or are preferably carbon fibers.

(14) A tier of the first fiber composite material 300 and a tier of the second fiber composite material are substantially depicted in FIG. 2. The tiers of the first fiber composite material 300 enclose largely the tiers of the second fiber composite material 400 in the direction of the longitudinal extent L and in the direction of the transverse extent Q.

(15) The spar cap 200 in particular has a region of reduced coverage 410 of the tiers of the second fiber composite material 400. Said region of reduced coverage 410 manifests itself in particular in that the tiers of the second fiber composite material 400 are spaced apart from the second end 220 of the spar cap 200. This spacing reduces the risk of a lightning strike in the case of the first fiber composite material having a slight electrical conductivity, or no electrical conductivity, and the second fiber composite material having a high electrical conductivity as compared to the first fiber composite material. Furthermore, the risk of a flashover in the course of the internal discharge toward the rotor blade flange is minimized on account of an installation of this type.

(16) The schematic illustration of the spar cap 200 in FIG. 2 shows a transverse extent Q of the tiers of the first fiber composite material 300 and of the tiers of the second fiber composite material 400.

(17) FIG. 3 shows a schematic cross-sectional view in the direction of a longitudinal extent L and of a thickness D of a spar cap 200. The schematically illustrated tiers and the number thereof are in particular depicted in this view. The tiers are depicted in a perspective orthogonal to the planar expanse of said tiers, and orthogonal to the longitudinal extent of said tiers. The thickness D of the spar cap is determined by the number of the tiers of the first fiber composite material 300 that are disposed on top of one another, and by the number of tiers of the second fiber composite material 400. The region of reduced coverage 410 of the tiers of the second fiber composite material 400 is likewise illustrated in this perspective.

(18) Furthermore depicted is the longitudinal extent of the individual tiers of the first fiber composite material 300, and the longitudinal extent of the individual tiers of the second fiber composite material 400, wherein the dimensions of the respective longitudinal extent of said fiber composite materials are not identical. On account of the region of reduced coverage of the tiers of the second fiber composite material 400 rigidity jumps are created in the choice of a more rigid material for the second fiber composite material than that for the first fiber composite material. On account of the reduction in tiers of the second fiber composite material 400 at the location along the longitudinal extent L, the tiers of the first fiber composite material 300 in summary can have a higher rigidity than the tiers of the second fiber composite material 400 such that the rigidity jumps can be minimized to the largest extent.

(19) Furthermore, on account of the reduction in the tiers of the second fiber composite material 400 of this type, the number of tiers of the first fiber composite material 300 can also be reduced toward the end 220. In turn, the spar cap 200 on account thereof, in the case of a reducing level of elongation, can be produced overall with fewer tiers disposed on top of one another toward the second end 220. A reduced number of the tiers disposed on top of one another results in a more compact construction mode, lower material costs, and an accelerated production time, and ultimately in a lower weight of the spar cap 200.

(20) It is moreover illustrated that the tiers of the second fiber composite material 400 in the direction of the thickness are disposed between tiers of the first fiber composite material 300. It is furthermore depicted in this special exemplary embodiment that the tiers of the second fiber composite material 400 have two external, mutually opposite, sides which are in each case formed by a planar expanse of the tiers in the longitudinal direction L and transverse direction Q, wherein the same number of tiers of the first fiber composite material 300 are disposed on both external sides of the tiers of the second fiber composite material 400. As for FIG. 3, this means that preferably in each case the same number of tiers of the first fiber composite material 300 is disposed in the vertical direction, above and below the three tiers of the second fiber composite material 400.

(21) FIG. 4 shows a schematic cross-sectional view in the direction of a transverse extent Q and of a thickness D of a spar cap 200. The cross section shown is in particular from a region along the longitudinal extent L in which region the tiers of the first fiber composite material 300 and tiers of the second fiber composite material 400 are not reduced in a manner analogous to the description of FIG. 3. Therefore, three tiers of the second fiber composite material 400 are disposed in the interior, and in each case two tiers of the first fiber composite material are disposed on the planar external sides of said tiers of the second fiber composite material 400. The tiers of the first fiber composite material 300 and of the tiers of the second fiber composite material 400 furthermore preferably extend completely along the transverse extent Q.

(22) FIG. 5 shows a schematic cross-sectional view in the direction of a transverse extent and of a thickness of a spar cap. The cross section shown is in particular from a region of reduced coverage 410 along the longitudinal extent L, in which region the tiers of the first fiber composite material 300 and tiers of the second fiber composite material 400 are reduced, in a manner analogous to the description of FIG. 3, since only tiers of the first fiber composite material 300 are depicted here. A region of reduced coverage 410 which, in a manner adjacent to the second end 220 and not having tiers of the second fiber composite material 400, is composed substantially of tiers of the first fiber composite material 300 or comprises the latter, is furthermore depicted.

(23) FIG. 6 shows a schematic illustration of a rotor blade 108 having a rotor blade tip 510 and two lightning interception installations in the form of a first and of a second receptor 501, 502, the latter being part of a lightning protection system (not illustrated in more detail). An electrically conductive foil/film tier 530 is connected in an electrically conductive manner to the second receptor 502. Said electrically conductive foil/film tier 530 does not extend across the entire longitudinal extent of the rotor blade, but has an extent E of a few meters, preferably approximately 1 to 5 m, in the direction of the longitudinal extent of the rotor blade. The foil/film tier 530 in particular covers a region in the direction of a longitudinal extent of the rotor blade in which the at least one tier of the second fiber composite material of the spar cap terminates. This region in FIG. 6 can be seen at the transition from the spar cap having the first and the second fiber composite material 522 to the spar cap having only the first fiber composite material 521. The foil/film tier 530 is furthermore preferably disposed as far out as possible in the direction transverse to the longitudinal extent of the rotor blade 108.

(24) FIG. 7 shows an enlarged fragment from a schematic illustration of an electrically conductive foil/film tier 530 of a rotor blade according to FIG. 6. The foil/film tier 530 has diamond-shaped meshes 531 which are separated by webs 532. The webs 532 between the meshes 531 preferably have a thickness T of 0.3 mm and a width R of 0.5 mm. The meshes 531 preferably have a length LM of 3.5 mm and a width TM of 2.5 mm.

LIST OF REFERENCE SIGNS

(25) 100 Wind power installation

(26) 102 Tower

(27) 104 Nacelle

(28) 106 Rotor

(29) 108 Rotor blades

(30) 110 Spinner

(31) 200 Spar cap

(32) 210 First end

(33) 220 Second end

(34) 300 Tier(s) of first fiber composite material

(35) 400 Tier(s) of second fiber composite material

(36) 410 Region of reduced coverage

(37) 501, Receptors

(38) 502

(39) 510 Rotor blade tip

(40) 521 Spar cap having the first fiber composite material

(41) 522 Spar cap having the first and the second fiber composite material

(42) 530 Electrically conductive foil/film tier

(43) 531 Mesh

(44) 532 Web

(45) L Longitudinal extent

(46) Q Transverse extent

(47) D Thickness

(48) E Extent of the foil/film tier in the direction of the longitudinal extent of the rotor blade

(49) TM Width of the mesh

(50) LM Length of the mesh

(51) R Width of the web

(52) T Thickness of the web