Method for lowering and raising a wind turbine blade

Patent metadata

Field	Value
Publication number	US-9494133-B2
Application number	US-201414296934-A
Country	US
Kind code	B2
Filing date	Jun 5, 2014
Priority date	Jun 5, 2013
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A method of lowering a wind turbine blade after removal from a wind turbine lowers the blade in a vertical position to a point near the ground, and rotates it to a horizontal position for emplacement on a cradle. A winch is situated in the nacelle of the wind turbine. A cable extends downward from the winch to the blade root where it may be secured to a load cell. A tip end shoe is placed around the lower portion of the blade, and includes a crane hook receiving component that is used when the blade orientation is being changed. Tag lines are attached to the root and the tip end shoe, and extend to points on the ground where technicians manipulate them to prevent the blade from being blown into the tower.

First claim

We claim:

1. A method of lowering a blade from a wind turbine comprising the steps of:
removing a blade from a wind turbine supported upon a tower;
affixing a lifting yoke to the root end of said blade;
attaching a hoisting cable to said lifting yoke and providing support for said hoisting cable from a position above said lifting yoke;
attaching a tip end shoe to a portion of said blade between the tip and the midpoint of said blade, said tip end shoe including a crane hook receiving component;
securing said tip end shoe in position along said blade with a cord attached to said tip end shoe and extending to and attached in proximity to said root end;
threading a left tag line through a first tag line support structure attached to said tip end shoe and a second tag line support structure attached to said cord in proximity to said root end such that said left tag line is capable of exerting a force at both said tip and said root end of said blade;
threading a right tag line through the first tag line support structure and the second tag line support structure such that said right tag line is capable of exerting a force at both said tip and said root end of said blade;
attaching a crane cable from a crane to said crane hook receiving component;
attaching said hoisting cable to a winch such that operation of the winch in a first direction releases hoisting cable toward said lifting yoke and operation of the winch in a second direction draws hoisting cable from the direction of said lifting yoke;
operating said winch in said first direction whereby said lifting yoke and said blade are lowered toward the ground;
manipulating said tag lines as necessary to prevent said blade from striking said tower;
tightening said crane cable from a point above said tip end shoe to impart a rotation of said blade to a substantially horizontal position;
lowering said blade using said hoisting cable and said crane cable to support the weight of said blade while manipulating said tag lines to orient said blade to a desired position for emplacement on the ground or on a receiving platform.

2. The method claimed in claim 1 further comprising the steps of attaching a tip sock to the tip end of said blade and attaching said cord to said tip sock whereby said cord holds said tip end shoe and said tip sock from sliding longitudinally along said blade during the lowering of said blade.

3. The method claimed in claim 1 wherein said winch is situated in a nacelle and said blade is lowered from said nacelle.

4. The method claimed in claim 3 further comprising providing a take-up spool whereby the portion of said hoisting cable that is not between said winch and said lifting yoke may be stored on said take-up spool and released as necessary to provide additional lengths of said hoisting cable to said winch.

5. The method claimed in claim 4 further comprising situating said take-up spool near the base of said tower.

6. The method claimed in claim 3 further comprising attaching a pulley to said lifting yoke whereby the attachment of said hoisting cable to said yoke further comprises extending said hoisting cable through said pulley and attaching the end of said hoisting cable to said nacelle.

7. The method claimed in claim 1 wherein said winch is situated on the ground and said hoisting cable extends to a nacelle housing of said wind turbine and is threaded through cable guide pulleys located in said nacelle.

8. The method claimed in claim 1 whereby said crane cable is attached to and manipulated by a pick crane the upper end of which is situated above said tip end shoe.

9. The method claimed in claim 1 whereby manipulation of said tag lines is done by individuals standing on the ground at a distance from the base of said tower.

10. A method of raising a blade to a wind turbine supported upon a tower comprising the steps of:
placing a blade in a horizontal position below a tower supporting a wind turbine;
affixing a lifting yoke to the root end of said blade;
attaching a hoisting cable to said lifting yoke and providing support for said cable from a position in the nacelle of said wind turbine;
attaching a tip end shoe to a portion of said blade between the tip and the midpoint of said blade, said tip end shoe including a crane hook receiving component;
securing said tip end shoe in position along said blade with a cord attached to said tip end shoe and extending to and attached in proximity to said blade root;
threading a left tag line through a first tag line support structure attached to said tip end shoe and a second tag line support structure attached to said cord in proximity to said root end such that said left tag line is capable of exerting a force at both said tip and said root end of said blade;
threading a right tag line through the first tag line support structure and the second tag line support structure such that said right tag line is capable of exerting a force at both said tip and said root end of said blade;
attaching a crane cable from a crane to said crane hook receiving component;
attaching said hoisting cable to a winch such that operation of the winch in a first direction releases hoisting cable toward said lifting yoke and operation of the winch in a second direction draws hoisting cable from the direction of said lifting yoke;
operating said winch in said second direction and operating said crane cable whereby said blade is raised in a substantially horizontal position;
manipulating said tag lines as necessary to prevent said blade from striking said tower;
when said blade is high enough above the ground to clear the ground in a vertical position, loosening said crane cable to impart a rotation of said blade to a substantially vertical position;
raising said blade using said hoisting cable and said crane cable to support the weight of said blade while manipulating said tag lines to orient said blade to a desired position for attachment to said wind turbine.

11. The method claimed in claim 10 further comprising the steps of attaching a tip sock to the tip end of said blade and attaching said cord to said tip sock whereby said cord holds said tip end shoe and said tip sock from sliding longitudinally along said blade during the raising of said blade.

12. The method claimed in claim 10 wherein said winch is situated in a nacelle and said blade is raised from said nacelle.

13. The method claimed in claim 12 further comprising providing a take-up spool whereby the portion of said hoisting cable that is not between said winch and said lifting yoke may be wrapped on said take-up spool and taken up as necessary to take up excess lengths of said hoisting cable from said winch.

14. The method claimed in claim 13 further comprising situating said take-up spool near the base of said tower.

15. The method claimed in claim 12 further comprising attaching a pulley to said lifting yoke whereby the attachment of said hoisting cable to said yoke further comprises extending said hoisting cable through said pulley and attaching the end of said hoisting cable to said nacelle.

16. The method claimed in claim 10 wherein said winch is situated on the ground and said hoisting cable extends to a nacelle housing of said wind turbine and is threaded through cable guide pulleys located in said nacelle.

17. The method claimed in claim 10 whereby said crane cable is attached to and manipulated by a pick crane the upper end of which is suspended above said tip end shoe.

18. The method claimed in claim 10 whereby manipulation of said tag lines is done by indivi

Assignees

• Inventus Holdings Llc

Inventors

• Lohan Martin E
• Pander Henrik
• Brake Daniel M

Classifications

• B66C23/207

  with supporting couples provided by wind turbines · CPC title

• F05B2230/61

  using auxiliary equipment for lifting or holding · CPC title

• Y02E10/721

  Cross-Sectional Technologies · mapped topic

• Y10T29/49318

  Repairing or disassembling · CPC title

• F03D1/0658 Primary

  Arrangements for fixing wind-engaging parts to a hub · CPC title