Shear Web for a Wind Turbine Rotor Blade

Abstract

The present disclosure is directed to a shear web for a rotor blade of a wind turbine and a method of manufacturing and assembling same. The rotor blade generally includes an upper shell member having an upper spar cap configured on an internal surface thereof and a lower shell member having a lower spar cap configured on an internal surface thereof. Further, the shear web extends between the spar caps along a longitudinal length of the blade. In addition, the shear web includes first and second outer pultruded layers at least partially encompassing a core material, wherein end portions of the first and second outer pultruded layers form compressed flanges at opposing ends of the shear web.

Claims

1. A rotor blade assembly for a wind turbine, comprising: an upper shell member having at least one upper spar cap configured on an internal surface thereof; a lower shell member having at least one lower spar cap configured on an internal surface thereof; and, a shear web extending between the spar caps along a longitudinal length of the rotor blade, the shear web comprising first and second outer pultruded layers, wherein end portions of the first and second outer pultruded layers form compressed flanges at opposing ends of the shear web that are bonded to the upper and lower spar caps.

2. The rotor blade assembly of claim 1, wherein the compressed flanges extend generally parallel to a length-wise axis of the shear web.

3. The rotor blade assembly of claim 2, wherein the upper and lower spar caps comprise two spar cap components separated by a gap, the compressed flanges being bonded within the gap of each of the spar caps, respectively.

4. The rotor blade assembly of claim 1, wherein the first and second outer pultruded layers at least partially encompass a core material.

5. The rotor blade assembly of claim 4, wherein the compressed flanges comprise regions containing the core material and regions without the core material.

6. The rotor blade assembly of claim 4, wherein the compressed flanges extend from one side of the core material generally perpendicular to a length-wise axis of the shear web.

7. The rotor blade assembly of claim 4, wherein the compressed flanges extend from opposing sides of the core material generally perpendicular to a length-wise axis of the shear web.

8. The rotor blade assembly of claim 7, wherein the end portions of the first and second outer pultruded layers are separated to form the compressed flanges.

9. The rotor blade assembly of claim 1, further comprising an adhesive configured at interfaces between the compressed flanges and the spar caps, wherein the adhesive comprises one of or a combination of the following: a bond paste, a binder, a tape, a gum, a wax, a plaster, a grout, a resin, an epoxy, a sealant, or glue.

10. The rotor blade assembly of claim 1, wherein the first and second outer pultruded layers are constructed, at least in part, of a reinforced composite laminate material, wherein the reinforced composite laminate material comprises a thermoplastic material.

11. The rotor blade assembly of claim 1, wherein the shear web further comprises a channel.

12. A method for assembling a shear web in a rotor blade of a wind turbine, the method comprising: providing a body shell of the rotor blade having at least one spar cap configured on an internal surface thereof; simultaneously pultruding a first outer layer and a second outer layer so as to form the shear web having compressed flanges at opposing ends thereof, the compressed flanges being formed from at least end portions of the first and second outer layers; and, securing the shear web to the at least one spar cap.

13. The method of claim 12, further comprising inserting at least one of compressed core material or an additional sheet of material between the end portions of the first and second outer layers such that the end portions do not bond together when the compressed flanges are formed.

14. The method of claim 13, further comprising subsequently heating the end portions of the first and second outer layers, separating the end portions of the first and second outer layers, removing at least one of compressed core material or the additional sheet of material, bending the end portions against the core material so as to form the compressed flanges, and securing the shear web to the at least one spar cap via the compressed flanges.

15. The method of claim 12, wherein securing the shear web to the at least one spar cap further comprises bonding the shear web to opposing spar caps via at least one of an adhesive or thermoplastic welding.

16. The method of claim 15, wherein bonding the shear web to opposing spar caps further comprising bonding the compressed flanges of the shear web within a gap of the respective spar caps.

17. The method of claim 12, further comprising subsequently removing the compressed flanges from the shear web and bonding the shear web to the at least one spar cap.

18. A method for manufacturing a shear web for a rotor blade of a wind turbine, the method comprising: simultaneously pultruding a first outer layer and a second outer layer around a core material so as to form the shear web; and, compressing end portions of the first and second outer layers and the core material to form compressed flanges at opposing ends of the shear web, wherein the compressed flanges provide a bonding surface for spar caps of the rotor blade.

19. The method of claim 18, wherein the compressed flanges extend generally parallel to a length-wise axis of the shear web.

20. The method of claim 18, wherein the compressed flanges extend from one side of the core material generally perpendicular to a length-wise axis of the shear web.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art is set forth in the specification, which makes reference to the appended figures, in which:

[0021] FIG. 1 illustrates a perspective view of one embodiment of a wind turbine according to the present disclosure;

[0022] FIG. 2 illustrates a perspective view of one embodiment of a rotor blade of a wind turbine according to the present disclosure;

[0023] FIG. 3 illustrates a cross-sectional view of one embodiment of a rotor blade assembly of a wind turbine according to the present disclosure, particularly illustrating a shear web with compressed flanges configured between split spar cap components;

[0024] FIG. 4 illustrates a cross-sectional view of the shear web of FIG. 3;

[0025] FIG. 5 illustrates a cross-sectional view of another embodiment of a rotor blade assembly of a wind turbine according to the present disclosure, particularly illustrating a shear web with compressed flanges configured within a groove of the spar caps;

[0026] FIG. 6 illustrates a cross-sectional view of another embodiment of a rotor blade assembly of a wind turbine according to the present disclosure, particularly illustrating a shear web having compressed flanges extending from opposing sides of a core material of the shear web and bonded to opposing spar caps;

[0027] FIG. 7 illustrates a cross-sectional view the shear web of FIG. 6;

[0028] FIG. 8 illustrates a cross-sectional view of yet another embodiment of a rotor blade assembly of a wind turbine according to the present disclosure, particularly illustrating a shear web having compressed flanges extending from one side of a core material of the shear web and bonded to opposing spar caps;

[0029] FIG. 9 illustrates a cross-sectional view the shear web of FIG. 8;

[0030] FIG. 10 illustrates a top view of one embodiment of a shear web of a wind turbine rotor blade according to the present disclosure, particularly illustrating a shear web constructed of a core material surrounded by pultruded layers that extend past a width of the core material;

[0031] FIG. 11 illustrates a cross-sectional view of the shear web of FIG. 11 along line 11-11;

[0032] FIG. 12 illustrates a top view of one embodiment of a shear web of a wind turbine rotor blade according to the present disclosure, particularly illustrating a shear web constructed of a core material surrounded by folded pultruded layers that extend past a width of the core material;

[0033] FIG. 13 illustrates a cross-sectional view of the shear web of FIG. 12 along line 13-13;

[0034] FIG. 14 illustrates a cross-sectional view of the shear web of FIG. 12 along line 14-14;

[0035] FIG. 15 illustrates a cross-sectional view of the shear web of FIG. 12 along line 15-15;

[0036] FIG. 16 illustrates a cross-sectional view of still another embodiment of a rotor blade assembly of a wind turbine according to the present disclosure, particularly illustrating a shear web having a channel configured within the core material;

[0037] FIG. 17 illustrates a flow diagram of one embodiment of a method for assembling a shear web in a rotor blade of a wind turbine; and,

[0038] FIG. 18 illustrates a flow diagram of one embodiment of a method for manufacturing a shear web for a rotor blade of a wind turbine according to the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0039] Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention include such modifications and variations as come within the scope of the appended claims and their equivalents.

[0040] Generally, the present disclosure is directed to a shear web for a rotor blade of a wind turbine and a method of manufacturing and assembling same. The rotor blade generally includes upper and lower shell members having upper and lower spar caps configured on respective internal surfaces thereof. Further, the shear web extends between the spar caps along a longitudinal length of the blade. In addition, the shear web is formed from first and second outer pultruded layers at least partially encompassing a core material. Further, end portions of the first and second outer pultruded layers and optionally the core material form compressed flanges at opposing ends of the shear web that can be easily bonded or mounted to the upper and lower spar caps. As such, the shear web of the present disclosure can be quickly and easily manufactured so as to provide additional stiffness and/or strength to the rotor blade.

[0041] Referring now to the drawings, FIG. 1 illustrates one embodiment of a wind turbine 10 according to the present disclosure. As shown, the wind turbine 10 includes a tower 12 with a nacelle 14 mounted thereon. A plurality of rotor blades 16 are mounted to a rotor hub 18, which is in turn connected to a main flange that turns a main rotor shaft. The wind turbine power generation and control components are housed within the nacelle 14. The view of FIG. 1 is provided for illustrative purposes only to place the present invention in an exemplary field of use. It should be appreciated that the invention is not limited to any particular type of wind turbine configuration.

[0042] Referring now to FIG. 2, a more detailed view of one of the rotor blades 16 of FIG. 1 is illustrated. As shown, the rotor blade 16 includes an upper shell member 20 and a lower shell member 22. Further, the upper shell member 20 is configured as the suction side surface of the blade 16, while the lower shell member 22 is configured as the pressure side surface of the blade 16. The rotor blade 16 also includes a leading edge 24 and a trailing edge 26, as well as a root portion 28 and a tip portion 30. As is well known in the art, the upper shell member 20 and the lower shell member 22 may be joined together at the leading edge 24 and trailing edge 26 or any other suitable location. The rotor blade 16 also includes an internal cavity 25 (FIG. 3) in which various structural members, such as spar caps 32, 34 and one or more shear webs 30 according to the present disclosure, may be configured.

[0043] Referring now to FIGS. 3-10, various cross-sectional views of the shear web 28 of the rotor blade 16 are illustrated that incorporate various aspects of the present invention. More specifically, as shown in FIGS. 3, 6, 8, and 10, the upper shell member 20 contains an upper spar cap 32 configured on an internal surface thereof. Similarly, the lower shell member 22 contains a lower spar cap 34 configured on an internal surface thereof. As such, the shear web 28 extends between the spar caps 32, 34 along a longitudinal length of the blade 16 in a generally span-wise direction. In addition, the cross-section of the shear web 28 may have any suitable shape. For example, as shown, the cross-sectional shape of the shear web 28 may have a generally square or rectangular shape. It should be appreciated, that as used herein, terms of approximation, such as approximately, substantially, generally, or about, refer to being within a ten percent margin of error.

[0044] Further, as shown generally in the figures, the shear web 28 includes at least one outer layer or sheet (e.g. pultruded outer layers 36, 38) at least partially surrounding or encompassing one or more core materials 30. For example, as shown in FIGS. 4-7, the shear web 28 includes a first outer layer 36 and a second outer layer 38 generally encompassing the core material 30. More specifically, as shown in FIG. 4, the first outer layer 36 is configured on a first side of the core material 30 and the second outer layer 38 is configured on a second, opposite side of the core material 30. As such, the first and second outer layers 36, 38 generally correspond to the outer cross-sectional shape of the core material 30. More specifically, as shown in FIGS. 4 and 9, end portions 46, 48 of the first and second outer layers 36, 38 and compressed portions of the core material 30 (i.e. compressed core flanges 40, 42) form compressed flanges 37, 39 of the shear web 28 at opposing ends of the shear web 28 that may be bonded to their respective spar caps 32, 34, which will be discussed in more detail below.

[0045] For example, the core material 30 may include one or more compressed flanges 40, 42, i.e. flanges made of compressed core material. More specifically, as shown in FIGS. 4, 7, and 9, the core material 30 may include a first compressed flange 40 and a second compressed flange 42 on an opposite end of the core material 30. Further, in certain embodiments, as shown in FIGS. 4 and 7, the core material flanges 40, 42 may extend from opposing ends 33, 35 of the core material 30 in a direction substantially parallel to a length-wise axis 44 of the core material 30. As such, the compressed flanges 37, 39 of the shear web 28 may also extend generally parallel to the length-wise axis 44 of the shear web 28. Further, as shown, the compressed flanges 37, 39 may extend from the opposing ends 33, 35 substantially at the center of the ends 33, 35 (as shown) or may be located more to the left or right of each of the ends 33, 35.

[0046] Alternatively, as shown in FIG. 9, the compressed core material flanges 40, 42 may extend from the opposing ends 33, 35 of the core material 30 in a direction substantially perpendicular to the length-wise axis 44 of the core material 30. In such embodiments, the compressed flanges 37, 39 of the shear web 28 may also extend generally perpendicular to the length-wise axis 44 of the shear web 28. More specifically, as shown in FIGS. 8 and 9, the compressed flanges 37, 39 extend from the same side of the shear web 28. In alternative embodiments, the compressed flanges 37, 39 may extend from opposing sides of the shear web 28, i.e. one from the left side and one from the right side such that the flanges extend in opposite directions with respect to the core material 30.

[0047] In certain embodiments, the shear web 28, and more particularly the first and second outer layers 36, 38, may be formed via a pultrusion process. For example, in one embodiment, the shear web 28 may be formed via a two-dimensional (2D) pultrusion process. Alternatively, the shear webs 28 described herein can be quickly and easily formed via 3D pultrusion. In such embodiments, the pultruded shear web 28 may be constructed, at least in part, of a thermoset material or a thermoplastic material. As used herein, the term pultruded or similar generally describe reinforced materials (e.g. fibers or woven or braided strands) that are impregnated with a resin (e.g. a thermoset or a thermoplastic polymer) and pulled through a stationary die such that the resin cures or undergoes polymerization. As such, the pultrusion process is typically characterized by a continuous process of composite materials that produces composite parts having a constant cross-section. Further, 3D pultrusion is generally characterized by a manufacturing process similar to 2D pultrusion, but that can accommodate three-dimensional curved profiles. In addition, 3D pultrusion processes can be used to generate pultruded components having a variety of non-linear or variable cross-sectional shapes rather than a constant cross-section.

[0048] Further, pultruded components may be constructed of reinforced thermoset or thermoplastic materials. In addition, pultruded components may be produced from rovings, which generally encompass long and narrow bundles of fibers that are not combined until joined by a cured resin.

[0049] A thermoplastic material as described herein generally encompasses a plastic material or polymer that is reversible in nature. For example, thermoplastic materials typically become pliable or moldable when heated to a certain temperature and solidify upon cooling. Further, thermoplastic materials may include amorphous thermoplastic materials and/or semi-crystalline thermoplastic materials. For example, some amorphous thermoplastic materials may generally include, but are not limited to, styrenes, vinyls, cellulosics, polyesters, acrylics, polysulphones, and/or imides. More specifically, exemplary amorphous thermoplastic materials may include polystyrene, acrylonitrile butadiene styrene (ABS), polymethyl methacrylate (PMMA), glycolised polyethylene terephthalate (PET-G), polycarbonate, polyvinyl acetate, amorphous polyamide, polyvinyl chlorides (PVC), polyvinylidene chloride, polyurethane, or any other suitable amorphous thermoplastic material. In addition, exemplary semi-crystalline thermoplastic materials may generally include, but are not limited to polyolefins, polyamides, fluropolymer, ethyl-methyl acrylate, polyesters, polycarbonates, and/or acetals. More specifically, exemplary semi-crystalline thermoplastic materials may include polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene, polyphenyl sulfide, polyethylene, polyamide (nylon), polyetherketone, or any other suitable semi-crystalline thermoplastic material. Further, a thermoset material as described herein generally encompasses a plastic material or polymer that is non-reversible in nature. For example, thermoset materials, once cured, cannot be easily remolded or returned to a liquid state. As such, after initial forming, thermoset materials are generally resistant to heat, corrosion, and/or creep. Example thermoset materials may generally include, but are not limited to, some polyesters, esters, epoxies, or any other suitable thermoset material.

[0050] In alternative embodiments, the first and second outer pultruded layers 36, 38 of the shear web 28 may be constructed of a reinforced laminate composite material, plastic, metal, or any other suitable material.

[0051] It should also be understood that the core material 30 described herein may be constructed of any suitable materials, including but not limited to low-density foam, cork, composites, balsa wood, composites, or similar. Suitable low-density foam materials may include, but are not limited to, polystyrene foams (e.g., expanded polystyrene foams), polyurethane foams (e.g. polyurethane closed-cell foam), polyethylene terephthalate (PET) foams, other foam rubbers/resin-based foams and various other open cell and closed cell foams.

[0052] Referring generally to the figures, the shear web 28 of the present disclosure may be affixed to respective spar caps 32, 34 by any suitable bonding or attachment means. For example, as shown in FIG. 3, each of the spar caps 32, 34 may be split into two spar cap components (e.g. components 31) such that the compressed flanges 37, 39 of the shear web 28 may be directly bonded within the gap 54 located between the respective split spar cap components 31 via an adhesive such as bond paste. In additional embodiments, rather than splitting the spar caps 32, 34, the spar caps 32, 34 may simply include a groove 56 or similar that is configured to receive the compressed flanges 37, 39 as shown in FIG. 5.

[0053] Alternatively, as shown in FIGS. 6 and 7, the end portions 46, 48 of the first and second outer pultruded layers 36, 38 may be separated or bent into flanges (as indicated by the arrows) that can be directly bonded to the respective spar caps 32, 34 via an adhesive. In such an embodiment, the first and second flanges 40, 42 of the core material 30 may be removed so as to create a flat flange having a larger bonding surface area that can be easily bonded to the spar caps 32, 34. In still another embodiment, as shown in FIGS. 8 and 9, the compressed flanges 37, 39 of the shear web 28 may extend substantially perpendicular to the length-wise axis 44 of the core material 30. In such an embodiment, the compressed flanges 37, 39 of the shear web 28 may be directly bonded to the respective split spar caps 32, 34, e.g. via an adhesive, without having to remove the first and second flanges 40, 42 of the core material 30 and without having to split the spar caps 32, 34. It should be understood that the adhesive described herein may include one of or a combination of the following: a bond paste, a binder, a tape, a gum, a wax, a plaster, a grout, a resin, an epoxy, a sealant, glue, or similar. In addition, the shear web 28 may be mounted to the spar caps 32, 34 via any other suitable means, such as thermoplastic welding where applicable.

[0054] In addition, as shown in FIGS. 8 and 9, the compressed flanges 37, 39 may extend from one side of the core material 30 generally perpendicular to the length-wise axis 44 of the shear web 28. For example, as shown, the compressed flanges 37, 39 both extend from side 45 of the core material 30. In alternative embodiments, as shown in FIGS. 6 and 7, the compressed flanges 37, 39 may extend from opposing sides 43, 45 of the core material 30 generally perpendicular to the length-wise axis 44 of the shear web 28. For example, as mentioned, the end portions 46, 48 of the first and second outer pultruded layers 36, 38 may be separated and bent so as to form compressed flanges 37, 39 that can extend from opposing sides 43, 45 of the core material 30.

[0055] Referring now to FIGS. 10-15, the compressed flanges 37, 39 of the shear web 28 may include a region 58 with core material 30 and a region 60 without core material 30. More specifically, as shown, the core material 30 has a fixed width (as described here, width means height in reference to the shear web 28) with the first and second outer pultruded layers 36, 38 on the top and bottom. Further, as shown in FIG. 11, the first and second outer pultruded layers 36, 38 may extend past the width of the core material 30 in either direction or both directions. As shown in FIG. 12, since the shear web 28 tapers in height along the span, the end regions of the core/glass are compressed (FIGS. 13-15); however, some regions of the resulting compressed flanges 37, 39 may contain the pultruded layers 36, 38 and the core material 30 and others only the pultruded layers 36, 38.

[0056] Referring now to FIG. 16, the shear web 28 as described herein may also be configured to accommodate one or more cables, such as a down conductor cable 50 of a lightning protection system (not shown) of the wind turbine 10. More specifically, as shown, the shear web 28 may include a channel 52 (e.g. located in the core material 30) that is configured to receive the down conductor cable 50. As such, the down conductor cable 50 or any other suitable cable or wire may be configured within the hollow cross-section of the channel 52. For example, as shown in FIG. 16, the down conductor cable 50 may be inserted into the channel 52 at the blade root portion 28 and pulled through the rotor blade 16 from the blade tip 30. In alternative embodiments, the down conductor cable 50 may be inserted into the channel 52 at the blade tip 30 and pulled through the rotor blade 16 from the blade root portion 28. As such, the down conductor cable 50 can be easily installed, replaced, and/or repaired.

[0057] Referring now to FIG. 17, a flow diagram of a method 100 for assembling the shear web 28 of the rotor blade 16 of the wind turbine 10 according to the present disclosure is illustrated. As shown at 102, the method 100 includes providing a body shell of a rotor blade 16 having at least one spar cap 32, 34 configured on an internal surface thereof. In one embodiment, as mentioned, the body shell may include an upper shell member 20 having at least one spar cap 32 configured on an internal surface thereof and a lower shell member 22 having at least one spar cap 34 configured on an internal surface thereof.

[0058] As shown at 104, the method 100 includes simultaneously pultruding first and second outer layers 36, 38 around a core material 30 so as to form the shear web 28 having compressed flanges 37, 39 at opposing ends thereof. Further, as shown in FIGS. 4, 7, and 9, the compressed flanges 37, 39 may be formed from compressed core material 40, 42 and end portions 46, 48 of the first and second outer layers 36, 38. In addition, as shown at 106, the method 100 includes securing the shear web 28 to at least one spar cap via the compressed flanges 37, 39. For example, in one embodiment, the method 100 may include bonding the shear web 28 between the opposing spar caps 32, 34 via at least one of an adhesive. More specifically, in certain embodiments as shown in FIG. 3, the step of bonding the shear web 28 to opposing spar caps 32, 34 may include bonding the compressed flanges 37, 39 of the shear web within a gap of the respective spar caps 32, 34.

[0059] In further embodiments, as shown in FIG. 7, the method 100 may further include separating and bending the end portions 46, 48 of the first and second outer layers 36, 38 and removing the compressed core material (i.e. flanges 40, 42) so as to form the compressed flanges 37, 39. More specifically, in one embodiment, the end portions 46, 48 may be subsequently heated such that the portions 46, 48 can be easily formed into the compressed flanges 37, 39.

[0060] Referring now to FIG. 18, a flow diagram of a method 200 for manufacturing the shear web 28 of the rotor blade 16 of the wind turbine 10 according to the present disclosure is illustrated. As shown at 202, the method 200 includes simultaneously pultruding first and second outer layers 36, 38 around a core material 30 so as to form the shear web 28. As shown at 204, the method 200 also includes compressing end portions 46, 48 of the first and second outer layers 36, 38 and the core material 30 to form compressed flanges 37, 39 at opposing ends of the shear web 28. As such, the compressed flanges 37, 39 are configured to provide a bonding surface for the spar caps 32, 34 of the rotor blade 16.

[0061] While the present subject matter has been described in detail with respect to specific exemplary embodiments and methods thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.