Tip-marking device for wind turbine blade

Abstract

A tip-marking device (6) for making the tip end (2) of a wind turbine blade (1) more clearly visible is disclosed, said tip-marking device (6) comprising a sleeve part (7), which is made from an elastic material and configured to be mounted around the tip end (2) of a wind turbine blade (1) in such a way that at least an edge of the sleeve part (7) at a first end thereof, which is furthest away from the tip end (2) of the wind turbine blade (1), fits tightly around the outer surface of the wind turbine blade (1).

Description

[0001] TIP-MARKING DEVICE FOR WIND TURBINE BLADE

[0002] The present invention relates to a tip-marking device for making the tip end of a wind turbine blade more clearly visible, in particular during transportation and storage of the wind turbine blade.

[0003] Background of the invention

[0004] Due to the increasing length of wind turbine blades being installed on new wind turbines, it is continuously growing problem that the tip end and often a relatively long part of the wind turbine blade protrude from the vehicles, on which the wind turbine blades are transported or temporarily stored.

[0005] This means that the risk of accidents, in which a moving vehicle hits a wind turbine blade during transportation or storage thereof, simply because the driver of the vehicle is not aware of the protruding tip end of the blade, is also increasing. Thus, it has become increasingly important to make the tip end of wind turbine blades more clearly visible during transportation and storage of the blades in order to reduce the risk of damage to wind turbine blades and vehicles and, not least, to reduce the risk of people being hurt or, in severe cases, even killed in such accidents.

[0006] A known solution to this problem is a so-called "tip protection", which is basically a bracket with two arms, both of which have a U-formed cross-section so that they can grab around the leading edge and the trailing edge of the wind turbine blade, respectively, when the bracket is pushed onto the wind turbine blade from the tip end thereof. Fig. 2 shows a schematic illustration of such a tip protection. The tip protection is typically produced in a red foam material, which is neither luminescent nor reflective, so in order to make it more visible, a number of reflective stickers are mounted on the outside surface of the bracket arms and on a body part of the bracket connecting the two arms.

[0007] A number of problems are known to be related to the use of such tip protections. The brackets are prone to deteriorate due to exposure to ultraviolet radiation, weather and birds. Also, the reflective stickers often fall off, and problems with mould formation and discolouring of the surfaces of the wind turbine blades are common. In addition, different tip protections are needed for different types of wind turbine blades, the tip ends of which may not be shaped and dimensioned equally. Furthermore, the tip protections take up a lot of space, leaving only room for maybe five or six of them on a standardised European transportation pallet.

[0008] The most important problem, however, seems to be that such tip protections tend to fall of the wind turbine blades during transportation and storage. The friction between the arms of the tip protection and the surface of the wind turbine blade is not enough to hinder the tip protection from simply sliding over the tip and off the wind turbine blade. It is often attempted to secure the tip protection to the wind turbine blade by wrapping fixation tape around the two arms forcing them towards each other. Due to the material thickness of the two arms, however, this fixation tape is unable to get into contact with and stick to the surface of the wind turbine blade, and it does not solve the problem. Furthermore, the fixation tape will often cover some of the reflective stickers on the arms, thus making the wind turbine blade tip with the tip protection less visible.

[0009] US 2008 / 282590 A1 discloses a wind power installation in the form of a sheath for providing a simple daytime identification which is different from colour marking of wind turbine blades. The installation has fixing means for releasably fixing the sheath to a rotor blade of the wind power installation.

[0010] EP 2 213 587 A1 discloses a packing for wind power turbine blades, which has at least one inflatable annular structure with a flat outer supporting wall, and inner clamping walls for clamping a blade in a given position.

[0011] Brief description of the invention

[0012] It is a purpose of the present invention to provide a solution for making the tip end of wind turbine blades more clearly visible, in particular during transportation and storage thereof, which overcomes the disadvantages of solutions known in the art as described above.

[0013] Thus, the present invention relates to a tip-marking device for making the tip end of a wind turbine blade more clearly visible, said tip-marking device (6) comprising a sleeve part, which is made from an elastic material and configured to be mounted around the tip end of a wind turbine blade in such a way that at least an edge of the sleeve part at a first end thereof, which is furthest away from the tip end of the wind turbine blade, fits tightly around the outer surface of the wind turbine blade.

[0014] Mounting a sleeve part around the tip end of the wind turbine blade is a fast, simple and reliable way of enhancing the visibility of the tip end. The use of an elastic material allows for a "one-size-fits-all" solution and ensures that, in most cases, the sleeve part will fit tightly to the surface of the wind turbine blade along the full inner surface of the sleeve part or at least most thereof. This is an improvement compared to the sheath of US 2008 / 282590 A1 , which requires cables in order for it to be fixed to the wind turbine blade, since the sheath is not made from an elastic material ensuring that the sheath fits tightly around an outer surface of different sizes of wind turbine blades. Likewise, the elastic material ensuring that the sheath fits tightly around an outer surface of different sizes of wind turbine blades is also not disclosed in EP 2 213 587 A1 , where the tip sheath is positioned around the tip by means of inflation.

[0015] Moreover, it is an advantage of tip-marking devices according to the present invention that, when they are not in use, they take up significantly less space than the tip protections known in the art. Thus, hundreds of such tip-marking devices may be transported on a single standardised European transportation pallet.

[0016] In an embodiment of the invention, the tip-marking device further comprises at a second end of the sleeve part opposite the first end thereof an end-marking part, which end-marking part has an end-marking surface, at least a part of which endmarking surface is arranged to be perpendicular to a longitudinal direction of the wind turbine blade and to face away from the tip end of the wind turbine blade, when the sleeve part is mounted around the tip end of the wind turbine blade.

[0017] For increasing the security and for meeting the legal requirements in some countries, the tip-marking device may be provided with an end-marking part providing a visible surface that is substantially perpendicular to the longitudinal direction of the wind turbine blade, in which the outer surface of the sleeve part extends. In an embodiment of the invention, the sleeve part is produced from an elastic fabric or mesh or from an elastic polymer material, such as polyethylene, polypropylene or thermoplastic polyurethane.

[0018] The sleeve-part of the tip-marking device may, in principle, be produced from any elastic material that will allow the sleeve part to be mounted on the tip end of the wind turbine blade and fit tightly to the surface thereof. However, the mentioned materials have been found to be preferable due to weight, cost and strength considerations. Furthermore, such materials are quick-drying and / or water-repellent, which significantly reduces the risk of mould formation and discolouring of the surface of the wind turbine blade.

[0019] In an embodiment of the invention, the material, from which the sleeve part is made, is a high-visible material with luminescent and / or reflective properties and / or a colour that is easily discernible from almost any background.

[0020] The use of high-visible materials, such as for instance fabric as the ones used for producing so-called hi-vis clothing for running and training, is advantageous in that it makes the sleeve part very visible and in that it is a light and takes up very little space.

[0021] In an embodiment of the invention, the sleeve part, before it is mounted around a tip end of a wind turbine blade, is configured as a cylindrical tube or a conical tube.

[0022] Depending on the shape of the tip ends of the wind turbines blades, with which the tip-marking devices is to be used, it may be advantageous to form the sleeve part as a conical tube, the first end of which is wider than the second end thereof.

[0023] In an embodiment of the invention, the sleeve part comprises an adhesive tape along the edge at the first end of the sleeve part for fastening the edge of the sleeve part to the outer surface of the wind turbine blade.

[0024] Adhesive tape is a simple and reliable means for ensuring that the edge at the first end of the sleeve part fits tightly around the outer surface of the wind turbine blade and is kept in place during transportation and storage of the wind turbine blade. In an embodiment of the invention, the sleeve part comprises one or more areas on its inner surface, such as along the edge at the first end of the sleeve part, which are at least partly covered with a friction-enhancing material, such as a rubber material.

[0025] The use of friction-enhancing material on the inner surface of the sleeve part increases the ability of the sleeve part to stay in place during transportation and storage of the wind turbine blade. For instance, small dots of the friction-enhancing material may be glued onto the inner surface of the sleeve part, similar to the solution used in some working gloves.

[0026] In an embodiment of the invention, the friction-enhancing material is integrated in the material, from which the sleeve part is produced.

[0027] If the elastic material is a fabric or a mesh, stripes of threads of friction-enhancing material may, for instance, be woven into the elastic material, or the two materials may be sewn together.

[0028] In an embodiment of the invention, the end-marking part comprises a plate made from a solid material, such as wood, metal or plastic, and wherein one side of the plate constitutes the end-marking surface.

[0029] In preferred embodiments of the invention, the end-marking surface is a plane surface, which is easily obtained by using one of the sides of a solid plate for this purpose. The outer periphery of the plate may have any shape, such as circular, triangular, square or octagonal (like a stop sign in the traffic).

[0030] In an embodiment of the invention, the end-marking part comprises a plate or a frame made from a solid material, such as wood, metal, plastic or bamboo, and wherein the end-marking surface is constituted by a flexible material covering said plate or frame.

[0031] In an embodiment of the invention, the flexible material is the same material as the elastic material, from which the sleeve part is made. Another advantageous way of obtaining a suitable end-marking surface is to cover a plate or a frame with a flexible material, such as the elastic material, from which the sleeve part is produced. If a frame is used, the mass of the tip-marking device can be reduced significantly. Furthermore, using the same material for the end-marking surface as for the sleeve part means that the elastic material can be used for connecting the sleeve part and the end-marking part and for keeping the two parts in place relative to each other.

[0032] In an embodiment of the invention, the end-marking surface and / or the outer surface of the sleeve part is provided with one or more reflective markers, such as reflective stickers or adhesive reflective tape.

[0033] The use of reflective markers significantly increases the visibility and thereby the security, especially at night time and in other periods without much daylight.

[0034] In an embodiment of the invention, the sleeve part and / or the end-marking surface is made from a fabric or mesh, and wherein reflective markers are woven into or in other ways integrated in the fabric or mesh.

[0035] If the elastic material is a fabric or a mesh, stripes of threads of reflective material may be woven into the elastic material, or the two materials may be sewn together.

[0036] In an embodiment of the invention, the length of the sleeve part from the first end thereof to the second end thereof, when the sleeve part is mounted around a tip end of a wind turbine blade, is between 20 cm and 2 m, preferable between 40 cm and 80 cm.

[0037] Sleeve parts of lengths within these ranges have proven to be sufficient and advantageous when it comes to keeping the tip-marking device in place around the tip end of the wind turbine blade during transportation and storage thereof.

[0038] In an embodiment of the invention, the area of the end-marking surface is between 100 cm2and 5,000 cm2, preferably between 300 cm2and 2,500 cm2, most preferred between 600 cm2and 1 ,500 cm2. End-marking surface of sizes within these ranges have proven to be clearly visible and still not too large to handle.

[0039] Figures

[0040] A few exemplary embodiments of the invention are described in more detail in the following with reference to the figures, of which

[0041] Fig. 1 shows a wind turbine blade as known in the art,

[0042] Fig. 2 shows a tip protection as known in the art,

[0043] Fig. 3 shows a tip-marking device according to a first embodiment of the invention,

[0044] Fig. 4 shows the tip-marking device shown in Fig. 3 when being mounted around the tip end of a wind turbine blade,

[0045] Fig. 5 is an end view of the tip-marking device shown in Fig. 3,

[0046] Fig. 6 is a cross-sectional view of the tip-marking device shown in Fig. 5,

[0047] Fig. 7 shows a tip-marking device according to a second embodiment of the invention,

[0048] Fig. 8 shows a tip-marking device according to a third embodiment of the invention,

[0049] Fig. 9 shows a tip-marking device according to a fourth embodiment of the invention,

[0050] Fig. 10 shows the tip-marking device shown in Fig. 9 when being mounted around the tip end of a wind turbine blade,

[0051] Fig. 11 shows a tip-marking device according to a fifth embodiment of the invention,

[0052] Fig. 12 shows a tip-marking device according to a sixth embodiment of the invention,

[0053] Fig. 13 shows a tip-marking device according to a seventh embodiment of the invention, and

[0054] Fig. 14 shows a tip-marking device according to an eighth embodiment of the invention. Detailed description of the invention

[0055] Fig. 1 shows a wind turbine blade 1 as known in the art with a tip end 2 and a root end 3, the root end 3 being the end that is mounted onto a hub of a wind turbine (not shown). For making the wind turbine blade 1 capable of generating a significant lift when moving through the air, the cross-sectional shape of all modern wind turbine blades 1 is an aerofoil with a leading edge 18 and a trailing edge 19.

[0056] Fig. 2 shows a tip protection 4 as known in the art. As described above, the tip protection 4 comprises two arms grapping the leading edge 18 and the trailing edge 19 of the tip end 2 of a wind turbine blade 1 , respectively. The shown tip protection 4 further comprises a number of reflective markers 5 placed on the sides of the tip protection 4. As can be seen from Fig. 2, such a traditional tip protection 4 is simply slid onto the tip end 2 of the wind turbine blade 1 and will easily slide off again.

[0057] Fig. 3 shows a tip-marking device 6 according to a first embodiment of the invention with a sleeve part 7 and an end-marking part 8. The sleeve part 7 is configured as a conical cylinder, the first end, in which there is an opening 9, being wider than the second end, which is closest to the end-marking part 8. Fig. 3 further shows how the sleeve part 7 is provided with reflective markers 5, and how the opening 9 has a width W1. The reflective markers 5 may, for instance, be reflective stickers stuck on the outer surface of the sleeve part, or they may be produced by weaving reflective material into a fabric, from which the sleeve part 7 is produced.

[0058] Fig. 4 shows the tip-marking device 6 shown in Fig. 3 when being mounted around the tip end 2 of a wind turbine blade 1. It is seen how mounting the tip-marking device 6 around the tip end 2 involves a stretching of the elastic material, from which the sleeve part 7 is made, so that the width W2 of the opening 9 in the sleeve part 7 is now larger than the width W1 shown in Fig. 3.

[0059] Fig. 5 is a schematic end view of the tip-marking device 6 shown in Fig. 3. It should be noted that it is not an accurate drawing, which can, for instance be seen from the oval shape of the sleeve part 7. Obviously, in real life, the inner surface 10 of the sleeve part 7, which fits tightly to the outer surface of the wind turbine blade 1 (not shown in this figure), will have a cross-sectional shape corresponding to the aerofoil of the wind turbine blade 1 , cf. the above comments to Fig. 1. Furthermore, Fig. 5 shows the plane A:A, along which the cross-sectional view shown in Fig. 6 is taken.

[0060] Fig. 6 is a cross-sectional view of the tip-marking device 6 shown in Fig. 5. In the illustrated embodiment, the inner surface 10 of the sleeve part 7 is provided with a number of areas, which are completely or partly covered with a friction-enhancing material 11. This serves the purpose of increasing the friction between the sleeve part 7 and the outer surface of the wind turbine blade 1 , thereby reducing the risk that the tip-marking device 6 might slide from its correct position during transportation and storage of the wind turbine blade 1. For the same purpose, the sleeve part 7 is provided with friction-enhancing material 11 and / or an adhesive tape 12 along the edge at the first end of the sleeve part 7.

[0061] Fig. 6 also shows that, in the illustrated embodiment, the end-marking part 8 basically consists of a plate 20, one side of which forms the end-marking surface 13. One or more reflective markers 5 are arranged on the end-marking surface 13 for increasing the visibility of the end-marking part 8, especially during the night time and other periods without much daylight.

[0062] Fig. 7 shows a tip-marking device 6 according to a second embodiment of the invention. In this embodiment, the end-marking part 8 comprises a frame 14, which is covered by the same flexible material as is used for making the sleeve part 7, thus forming an end-marking surface 13, which has the same properties as the outer surface of the sleeve part 7.

[0063] Obviously, some means are needed for keeping the elastic material in the shape illustrated in Fig. 7. Fig. 8 schematically illustrates a tip-marking device 6 according to a third embodiment of the invention, in which this is obtained by means of a non- stretchable sewing 15 at the second end of the sleeve part 7. Other means for obtaining the shape of the elastic material as shown in Fig. 7 could be a tight rubber band or the like, which is arranged around the transition between the sleeve part 7 and the end-marking part 8. Fig. 9 shows a tip-marking device 6 according to a fourth embodiment of the invention. In this embodiment, the tip-marking device 6 consists of a sleeve part 7 only, on the outer surface of which are arranged a number of reflective markers 5. The configuration of the sleeve part 7, when it is not mounted around a tip end 2 of a wind turbine blade 1 is a simple cylindrical tube.

[0064] Fig. 10 shows the tip-marking device 6 shown in Fig. 9 when being mounted around the tip end 2 of a wind turbine blade 1 . It illustrates how the elastic material of the sleeve part 7 is stretched, especially at its first end, while fitting tight against the outer surface of the wind turbine blade 1. The outermost tip of the wind turbine blade 1 is covered by the tip-marking device 6 from all sides around a longitudinal axis of the wind turbine blade 1 , but not on the tip side thereof.

[0065] Fig. 11 shows a tip-marking device 6 according to a fifth embodiment of the invention, which is similar to the embodiment shown in Figs. 9 and 10 with the exception that the sleeve part 7 is closed with a semi-spherical part at its second end, thus covering also the tip side of the tip end 2 of the wind turbine blade 1 when the tip-marking device 6 is mounted around it.

[0066] Fig. 12 shows a tip-marking device 6 according to a sixth embodiment of the invention. In this embodiment, the sleeve part 7 is closed at its second end by gathering the elastic material, for instance by sewing, gluing or binding it together.

[0067] Fig. 13 shows a tip-marking device 6 according to a seventh embodiment of the invention, which is similar to the embodiment shown in Figs. 3 and 4. In this embodiment, the sleeve part 7 is provided with a number of security straps 16, which may be fastened to the outer surface of the wind turbine blade 1 , for instance by means of adhesive tape 12 for securing even further that the tip-marking device 6 stays in place during transportation and storage of the wind turbine blade 1.

[0068] Fig. 14 shows a tip-marking device 6 according to an eighth embodiment of the invention, which is very similar to the embodiment shown in Fig. 13, the exception being that the security straps 17 are adhesive and therefore sticks to the outer surface of the wind turbine blade 1 without the need of any further adhesive tape 12. As an alternative to the security straps shown in Figs. 13 and 14, a clamping mechanism, e.g. in the form of one or more loop straps, may be used. The clamping mechanism may be positioned around the sleeve part 7, possibly close to the sleeve part opening 9.

[0069] It is to be understood that the details and features of the different embodiments described above can be combined in many other ways than illustrated in the given examples, which will easily be appreciated by the skilled person within the art.

[0070] List of references

[0071] 1. Wind turbine blade

[0072] 2. Tip end of wind turbine blade

[0073] 3. Root end of wind turbine blade

[0074] 4. Tip protection (prior art)

[0075] 5. Reflective marker

[0076] 6. Tip-marking device

[0077] 7. Sleeve part

[0078] 8. End-marking part

[0079] 9. Sleeve part opening

[0080] 10 Inner surface of sleeve part

[0081] 11. Friction-enhancing material

[0082] 12. Adhesive tape

[0083] 13. End-marking surface

[0084] 14. Frame of end-marking part

[0085] 15. Sewing

[0086] 16. Security strap

[0087] 17. Adhesive security strap

[0088] 18. Leading edge of wind turbine blade

[0089] 19. T railing edge of wind turbine blade

[0090] 20. Plate of end-marking part

[0091] W1 . First width of sleeve part opening

[0092] W2. Second width of sleeve part opening

Claims

Claims1. A tip-marking device (6) for making the tip end (2) of a wind turbine blade (1) more clearly visible, said tip-marking device (6) comprising a sleeve part (7), which is made from an elastic material and configured to be mounted around the tip end (2) of a wind turbine blade (1) in such a way that at least an edge of the sleeve part (7) at a first end thereof, which is furthest away from the tip end (2) of the wind turbine blade (1), fits tightly around the outer surface of the wind turbine blade (1).

2. The tip-marking device (6) according to claim 1 , further comprising at a second end of the sleeve part (7) opposite the first end thereof an end-marking part (8), which end-marking part (8) has an end-marking surface (13), at least a part of which endmarking surface (13) is arranged to be perpendicular to a longitudinal direction of the wind turbine blade (1) and to face away from the tip end (2) of the wind turbine blade (1), when the sleeve part (7) is mounted around the tip end (2) of the wind turbine blade (1).

3. The tip-marking device (6) according to claim 1 or 2, wherein the sleeve part (7) is produced from an elastic fabric or mesh or from an elastic polymer material, such as polyethylene, polypropylene or thermoplastic polyurethane.

4. The tip-marking device (6) according to any of the preceding claims, wherein the material, from which the sleeve part (7) is made, is a high-visible material with luminescent and / or reflective properties and / or a colour that is easily discernible from almost any background.

5. The tip-marking device (6) according to any of the preceding claims, wherein the sleeve part (7), before it is mounted around a tip end (2) of a wind turbine blade (1), is configured as a cylindrical tube or a conical tube.

6. The tip-marking device (6) according to any of the preceding claims, wherein the sleeve part (7) comprises an adhesive tape (12) along the edge at the first end of the sleeve part (7) for fastening the edge of the sleeve part (7) to the outer surface of the wind turbine blade (1).

7. The tip-marking device (6) according to any of the preceding claims, wherein the sleeve part (7) comprises one or more areas on its inner surface (10), such as along the edge at the first end of the sleeve part (7), which are at least partly covered with a friction-enhancing material (11), such as a rubber material.

8. The tip-marking device (6) according to claim 7, wherein the friction-enhancing material (11) is integrated in the material, from which the sleeve part (7) is produced.

9. The tip-marking device (6) according to any of the preceding claims, wherein the end-marking part (8) comprises a plate (20) made from a solid material, such as wood, metal or plastic, and wherein one side of the plate constitutes the end-marking surface (13).

10. The tip-marking device (6) according to any of claims 1-8, wherein the endmarking part (8) comprises a plate (20) or a frame (14) made from a solid material, such as wood, metal, plastic or bamboo, and wherein the end-marking surface (13) is constituted by a flexible material covering said plate (20) or frame (14).

11. The tip-marking device (6) according to claim 10, wherein the flexible material is the same material as the elastic material, from which the sleeve part (7) is made.

12. The tip-marking device (6) according to any of the preceding claims, wherein the end-marking surface (13) and / or the outer surface of the sleeve part (7) is provided with one or more reflective markers (5), such as reflective stickers or adhesive reflective tape.

13. The tip-marking device (6) according to any of the preceding claims, wherein the sleeve part (7) and / or the end-marking surface (13) is made from a fabric or mesh, and wherein reflective markers (5) are woven into or in other ways integrated in the fabric or mesh.

14. The tip-marking device (6) according to any of the preceding claims, wherein the sleeve part (7) is provided with a number of security straps (16, 17) configured for being fastened to the outer surface of the wind turbine blade (1).

15. The tip-marking device (6) according to claim 14, wherein the number of security straps (16) is configured for being fastened to the outer surface of the wind turbine blade (1) by means of adhesive tape (12).

16. The tip-marking device (6) according to claim 14, wherein the number of security straps (17) are adhesive and configured for adhering to the outer surface of the wind turbine blade (1) without the need of any further adhesive tape (12).

17. The tip-marking device (6) according to any of the preceding claims, wherein the length of the sleeve part (7) from the first end thereof to the second end thereof, when the sleeve part (7) is mounted around a tip end (2) of a wind turbine blade (1), is between 20 cm and 2 m, preferable between 40 cm and 80 cm.

18. The tip-marking device (6) according to any of the preceding claims, wherein the area of the end-marking surface (13) is between 100 cm2and 5,000 cm2, preferably between 300 cm2and 2,500 cm2, most preferred between 600 cm2and 1 ,500 cm2.

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