Wind turbine blade having a root region with elongated fastening members provided with metal fibres

Patent metadata

Field	Value
Publication number	US-10309369-B2
Application number	US-201214110890-A
Country	US
Kind code	B2
Filing date	Apr 11, 2012
Priority date	Apr 11, 2011
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A wind turbine blade for a wind turbine is a shell structure of a fibre-reinforced composite and comprises a root region and an airfoil region. The root region has ring-shaped cross section and comprises a plurality of elongated bushings 7 with an inner thread 22 and embedded interspaced in the fibre-reinforced polymer so as to substantially follow the circumference of the root region and allow access from the outside to the inner threads. Each fastening member 7 is provided with a notch 60′ in the periphery 11 thereof. A rod-shaped locking element 61 passes through the notch 60′ in engagement therewith. The locking element 61 is fixedly and tightly fitting arranged in a through-going circular bore 65 extending through the wall of the root region.

First claim

The invention claimed is:

1. A wind turbine blade for a wind turbine rotor comprising a hub from which the wind turbine blade extends when mounted to the hub, the wind turbine blade including a shell structure of a fibre-reinforced composite material comprising fibres embedded in a polymer matrix, the wind turbine blade extending in a longitudinal direction and having a profiled contour including a pressure side and a suction side as well as a leading edge and a trailing edge, said edges defining a chord plane therebetween, when seen in the longitudinal direction the profiled contour comprising a root region with a root end face, an airfoil region and optionally a transition region between the root region and the airfoil region,
the root region having a ring-shaped cross section with an outer surface and an inner surface,
the root region comprising a plurality of elongated fastening members provided with fastening means and embedded mutually spaced apart in the fibre-reinforced polymer matrix so as to substantially follow a circumference of the root region and allow access from the outside to the fastening means used for mounting the blade to the hub,
the elongated fastening members each comprising an outer surface, a first end arranged at the root end face, a second end opposite the first end thereof, a first lateral face, and an opposite second lateral face,
wherein at least one of the elongated fastening members comprises metal fibres, a first end thereof being firmly fixed to the fastening member and the remaining portion thereof extending outwardly from the fastening member and being embedded in the polymer matrix of the fibre-reinforced composite material, the metal fibres extending from the fastening members so as to be arranged in at least one separate layer of the fibre-reinforced composite material, wherein the remaining portion of each said metal fibre extends through, and is surrounded by, the polymer matrix, adjacent ones of the remaining portions of the metal fibres being separated from one another by a portion of the polymer matrix.

2. The wind turbine blade according to claim 1 , wherein the metal fibres extend from the fastening members so as to be arranged in an at least one separate layer of the fibre-reinforced composite material.

3. The wind turbine blade according to claim 1 , wherein the outwardly extending portion of the metal fibres end in a second fibre end.

4. The wind turbine blade according to claim 1 , wherein the metal fibres are firmly fixed to the second end of the fastening member.

5. The wind turbine blade according to claim 1 , wherein the metal fibres are firmly fixed to an outer peripheral surface of the fastening member.

6. The wind turbine blade according to claim 1 , wherein the metal fibres are firmly fixed to the fastening member by casting, gluing, soldering, or brazing.

7. The wind turbine blade according to claim 1 , wherein at least 50% of the fastening members are provided with firmly fixed metal fibres.

8. The wind turbine blade according to claim 7 , wherein at least 60% of the fastening members are provided with firmly fixed metal fibres.

9. The wind turbine blade according to claim 8 , wherein at least 70% of the fastening members are provided with firmly fixed metal fibres.

10. The wind turbine blade according to claim 9 , wherein at least 80% of the fastening members are provided with firmly fixed metal fibres.

11. The wind turbine blade according to claim 10 , wherein at least 90% of the fastening members are provided with firmly fixed metal fibres.

12. The wind turbine blade according to claim 11 , wherein 100% of the fastening members are provided with firmly fixed metal fibres.

13. The wind turbine blade according to claim 1 , wherein an E-modulus of the metal fibres is at least twice an E-modulus of glass fibres.

14. The wind turbine blade according to claim 13 , wherein the E-modulus of the metal fibres is thrice the E-modulus of glass fibres.

15. The wind turbine blade according to claim 13 , wherein the metal fibres comprise steel fibres.

16. The wind turbine blade according to claim 1 , wherein the metal fibres have a cross section in a range between 0.04 mm and 1.0 mm.

17. The wind turbine blade according to claim 16 , wherein the range is between 0.07 and 0.75 mm.

18. The wind turbine blade according to claim 17 , wherein the range is between 0.1 and 0.5 mm.

19. The wind turbine blade according to claim 1 , wherein the metal fibres are fixed to the fastening member as a bundle of fibres.

20. The wind turbine blade according to claim 1 , wherein the metal fibres extend outwards from the fastening members in a mutually diverging manner.

21. The wind turbine blade according to claim 1 , wherein the fastening members are bushings, and the fastening means is a thread in a bore in the bushing.

22. The wind turbine blade according to claim 21 , wherein the bushings comprise a uniform cross section.

23. The wind turbine blade according to claim 1 , wherein the fastening members are made of metal.

24. The wind turbine blade according to claim 23 , wherein the metal comprises steel.

25. The wind turbine blade according to claim 1 , wherein the root region further comprises intermediate retaining means comprising metal fibres and arranged in regions between adjacent interspaced lateral surfaces of the fastening members, preferably in each region between adjacent fastening members, and preferably extending at least from the first to the second end of the fastening members when seen in the longitudinal direction of the blade.

26. The wind turbine blade according to claim 25 , wherein the metal fibres comprise steel fibres.

27. The wind turbine blade according to claim 25 , wherein the intermediate retaining means are in each region between adjacent fastening members and extend at least from the first to the second end of the fastening members when seen in the longitudinal direction of the blade.

28. The wind turbine blade according to claim 25 , wherein the intermediate retaining means comprises a number of first layers comprising metal fibres.

29. The wind turbine blade according to claim 28 , wherein the intermediate retaining means comprises a number of intermediate second layers comprising a different type of fibres than metal fibres.

30. The wind turbine blade according to claim 28 , wherein the different type of fibres comprises glass and/or carbon fibres.

Assignees

• Dahl Martin
• Mortensen Bjarne Krab
• Hornblow Benjamin
• Lm Wp Patent Holding As

Inventors

• Dahl Martin
• Mortensen Bjarne Krab
• Hornblow Benjamin

Classifications

• B29C70/885 Primary

  with incorporated metallic wires, nets, films or plates (as lost heating elements B29C35/0272, B29C61/0625) · CPC title

• F05B2230/238

  Soldering · CPC title

• F05B2280/702

  Reinforcements · CPC title

• F05B2280/4003

  Synthetic polymers, e.g. plastics · CPC title

• F05B2280/6013

  Fibres · CPC title