Lightning receptor for a wind turbine blade

Patent metadata

Field	Value
Publication number	US-2016348652-A1
Application number	US-201615149490-A
Country	US
Kind code	A1
Filing date	May 9, 2016
Priority date	May 26, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

The invention provides a lightning receptor arrangement ( 11, 12 ) for a wind turbine blade ( 10 ) comprising at least a self-threading screw ( 21 ) having a head ( 23 ) and a threaded shaft ( 25 ) as a the external metallic receptor element for receiving a lightning strike in one side of the wind turbine blade ( 10 ) and an internal element comprising an electrically conductive block ( 20 ) configured with at least an unthreaded hole ( 41 ) for cooperating with said threaded shaft ( 25 ) and connected to a down conductor ( 18 ) of a grounding arrangement. The internal element is joined to at least a shell ( 17 ) of the wind turbine blade ( 10 ) with an adhesive force capable of withstanding the torque applied to the self-threading screw ( 21 ) for threading it to the unthreaded hole ( 41 ).

First claim

1 . A lightning receptor arrangement ( 11 , 12 ) for a wind turbine blade ( 10 ) comprising at least an external metallic receptor element for receiving a lightning strike in one side of the wind turbine blade ( 10 ) and an internal element joined at least to the internal side of a shell ( 17 ) of the wind turbine blade ( 10 ) and connected to a down conductor ( 18 ) of a grounding arrangement of the wind turbine blade ( 10 ), characterized in hat;
the external metallic receptor element is a self-threading screw ( 21 ) having a head ( 23 ) and a threaded shaft ( 25 ); the internal element comprises an electrically conductive block ( 20 ) configured with at least an unthreaded hole ( 41 ) for cooperating with said threaded shaft ( 25 ); the material of the self-threading screw ( 21 ) has higher hardness and lower ductility than the material of the electrically conductive block ( 20 ) and the threaded shaft ( 25 ) and the unthreaded hole ( 41 ) at dimensioned so that the threaded connection between them can transmit all lightning currents received by the self-threading screw ( 21 ); the internal element is joined to the shell ( 17 ) with an adhesive force capable of withstanding the torque applied to the head ( 23 ) of the self-threading screw ( 21 ) for threading it to the unthreaded hole ( 41 ).

2 . A lightning receptor arrangement ( 11 , 12 ) according to claim 1 , wherein the internal element also comprises an insulating coating ( 27 ) for the electrically conductive block ( 20 ).

3 . A lightning receptor arrangement ( 11 , 12 ) according to claim 1 , wherein the threaded shaft ( 25 ) and the unthreaded hole ( 41 ) are also dimensioned so that its threaded connection can have a length that assures a correct alignment or the head ( 23 ) of the self-treading screw ( 21 ) with the outer surface of the shell ( 17 ) of the wind turbine blade ( 10 ) for aerodynamic continuity purposes.

4 . A lightning receptor arrangement( 11 , 12 ) according to claim 1 , wherein the threaded shaft ( 25 ) and the unthreaded hole ( 41 ) have a cylindrical shape being the ratio between their respective diameters D 1 , D 2 comprised between 1.03-1.60.

5 . A lightning receptor arrangement ( 11 , 12 ) according to claim 1 , wherein:
the self-threading screw ( 21 ) is made of steel stainless steel or tungsten; the electrically conductive block ( 20 ) is made of aluminum, copper or brass

6 . A lightning receptor arrangement ( 12 ) according to claim 1 , further comprising an additional self-threading screw ( 22 ) as a metallic receptor element for receiving a lightning strike in the opposite side of the wind turbine blade ( 10 ) having a head ( 24 ) and a threaded shaft ( 26 ) wherein:
the electrically conductive block ( 20 ) is also configured with an additional unthreaded hole ( 42 ) for cooperating with the threaded shaft ( 26 ) of the additional self-treading screw ( 22 ); the material of the additional self-threading screw ( 22 ) has higher hardness and lower ductility than the material of the electrically conductive block ( 20 ) and the threaded shaft ( 26 ) of the additional self-threading screw ( 22 ) and the additional unthreaded hole ( 42 ) are dimensioned so that the threaded connection between them can transmit 11 lightning currents received by the additional self-threading screw ( 22 ).

7 . A lightning receptor arrangement ( 12 ) according to claim 6 , wherein the threaded shaft ( 26 ) of the additional self-threading screw ( 22 ) and the additional unthreaded hole ( 42 ) are also dimensioned so that the threaded connection between them can have a length that assures a correct alignment of the head ( 24 ) of the additional self-threading screw ( 22 ) with the outer surface of the shell ( 19 ) of the wind turbine blade ( 10 ) for aerodynamic continuity purposes.

8 . A lightning receptor arrangement ( 12 ) according to claim 6 , wherein the threaded shaft ( 26 ) of the additional self-threading screw ( 22 ) and the additional unthreaded hole ( 42 ) have a cylindrical shape being the ratio between their respective diameters D 1 , D 2 comprised between 1.03-1.60.

9 . A lightning receptor arrangement ( 12 ) according to claim 6 , wherein the additional self-threading screw ( 22 ) is made of steel, stainless steel or tungsten.

Assignees

• Gamesa Innovation & Tech Sl

Inventors

• March Nomen Víctor
• Madoz Zabalegui Juan
• MARTINEZ OLMO José Manuel

Classifications

• F05B2240/30

  Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor · CPC title

• F03D80/30 Primary

  Lightning protection · CPC title

• F03D1/0675

  of the blades · CPC title

• F05B2230/60

  Assembly methods · CPC title

• F05B2250/36

  in inner-outer relationship, e.g. shaft-bearing arrangements · CPC title