Methods and systems for removing and/or installing wind turbine rotor blades

Patent metadata

Field	Value
Publication number	US-9638163-B2
Application number	US-201414185058-A
Country	US
Kind code	B2
Filing date	Feb 20, 2014
Priority date	Feb 20, 2014
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A method for removing a rotor blade from a wind turbine may generally include installing a blade sock around an outer perimeter of the rotor blade, coupling a support cable to the blade root, lowering the rotor blade relative to the hub using the support cable, coupling at least one pulley cable between the rotor blade and a winch using at least one pulley, moving the pulley cable relative to the pulley to lower the rotor blade relative to the hub, applying a force through the blade sock as the pulley cable is moved relative to the pulley in order to control an orientation of the rotor blade and further lowering the rotor blade to a location on or adjacent to the support surface.

First claim

What is claimed is:

1. A method for removing a rotor blade from a wind turbine, the method comprising:
installing a blade sock around an outer perimeter of the rotor blade at an intermediate location defined between a blade root and a blade tip of the rotor blade;
coupling a support cable to the blade root via a threaded rod extending through a root bolt opening defined through a root end of the blade root, wherein the threaded rod extends from the root bolt opening through a corresponding bolt hole defined through a pitch bearing of the wind turbine;
lowering the rotor blade relative to the hub using the support cable such that the rotor blade is spaced apart from the hub by an initial vertical distance;
coupling at least one pulley cable between the rotor blade and a winch located on or adjacent to a support surface of the wind turbine using at least one pulley;
moving the at least one pulley cable relative to the at least one pulley to lower the rotor blade relative to the hub beyond the initial vertical distance;
applying a force through the blade sock as the at least one pulley cable is moved relative to the at least one pulley in order to control an orientation of the rotor blade relative to at least one of a tower of the wind turbine or the support surface; and
further lowering the rotor blade to a location on or adjacent to the support surface.

2. The method of claim 1 , further comprising:
lifting the blade sock relative to the support surface to the intermediate location; and
tightening the blade sock around the rotor blade at the intermediate location using a cable coupled to the blade sock.

3. The method of claim 2 , wherein the blade sock includes a self-tightening sock strap configured to be coupled to the cable, wherein tightening the blade sock around the rotor blade comprises applying a force through the self-tightening sock strap via the cable in order to tighten the blade sock around the rotor blade.

4. The method of claim 1 , wherein a barrel nut is mounted at least partially though the blade root, wherein the threaded rod is coupled to the blade root via the barrel nut.

5. The method of claim 1 , further comprising:
installing a cable translation device within the hub; and
operatively associating the support cable with the cable translation device such that the support cable extends from the threaded rod through a portion of the cable translation device.

6. The method of claim 1 , further comprising:
installing a cable translation device within the hub adjacent to the pitch bearing; and
inserting the support cable through at least a portion of the cable translation device.

7. The method of claim 6 , further comprising operating the cable translation device such that the support cable is incrementally lowered through both the cable translation device and the pitch bearing in order to lower the rotor blade relative to the hub.

8. The method of claim 6 , wherein the cable translation device comprises a fluid-driven actuator including a cylinder and a hollow piston configured to be actuated and retracted relative to the cylinder in order to allow the support cable to be lowered through the hollow piston.

9. The method of claim 6 , wherein the support cable includes a plurality of lugs spaced apart along a length of the support cable, further comprising:
installing a stop block around the support cable directly above, the cable translation device;
lowering the support cable using the cable translation device such that the support cable passes through the stop block;
removing the stop block from the support cable when an adjacent lug of the plurality of lugs is positioned directly above the stop block; and
repositioning the stop block around the support cable at a location above the adjacent lug.

10. The method of claim 1 , wherein the threaded rod defines a length that is the same as or less than a length defined by a plurality of root bolts coupled to the blade root.

11. The method of claim 1 , wherein the at least one pulley comprises at least one blade pulley and at least one up-tower pulley, the method further comprising:
coupling the at least one blade pulley to a blade root of the rotor blade; and
coupling the at least one up-tower pulley to an up-tower component of the wind turbine; and
positioning the pulley cable around the at least one blade pulley and the at least one up-tower pulley.

12. The method of claim 1 , wherein applying the force through the blade sock comprising controlling an amount of tension in a cable coupled to the blade sock in order to control the orientation of the rotor blade relative to the tower or to rotate the rotor blade into a generally horizontal position relative to the support surface.

13. A method for lowering a rotor blade relative to a hub of a wind turbine, the wind turbine including a pitch bearing coupled to the hub, the method comprising:
installing a plurality of cable translation devices within the hub, wherein each of the plurality of cable translation devices comprises a cable hoist;
inserting a plurality of support nuts through a circumferential wall of a blade root of the rotor blade at locations spaced apart from a root end of the blade root;
installing a plurality of support cables in operative association with the plurality of cable translation devices;
coupling each of the plurality of support cables to one of the plurality of support nuts; and
operating the plurality of cable translation devices such that the plurality of support cables are moved relative the plurality of cable translation devices in a manner that causes the rotor blade to be lowered relative to the hub.

14. The method of claim 13 , further comprising:
removing a plurality of barrel nuts from the blade root of the rotor blade; and
replacing each of the plurality of barrel nuts with one of the plurality of support nuts.

15. The method of claim 13 , further comprising coupling a threaded member to each of the plurality of support nuts, the threaded member extending through both a root bolt opening defined through a root end of the blade root and a corresponding bolt hole defined in the pitch bearing.

16. The method of claim 15 , wherein the threaded member comprises one of a threaded cable stud of a secondary support cable, an alignment pin or a root bolt of the wind turbine.

17. A method for removing a rotor blade from a wind turbine, the method comprising:
coupling a support cable to a blade root of the rotor blade, wherein the support cable extends from the blade root and into a hub of the wind turbine;
lowering the rotor blade relative to the hub using the support cable such that the rotor blade is spaced apart from the hub by an initial vertical distance;
coupling a first blade pulley and a second blade pulley to the blade root;
coupling at least one up-tower pulley to an up-tower component of the wind turbine, wherein the at least one up-tower pulley is vertically aligned with at least one of the first blade pulley or the second blade pulley;
coupling at least one pulley cable to the first and second blade pulleys and the at least one up-tower pulley, the at least one pulley cable extending from the rotor blade to a location on or adjacent to a support surface of the wind turbine; and
moving the at least one pulley cable relative to the first and second blade pulleys and the at least one up-tower pulley to lower the rotor blade relative to the hub beyond the initial vertical distance.

18. The method of claim 17 , further comprising:
installing a blade sock around an out

Assignees

• Gen Electric

Inventors

• Holloway Brent Hamilton
• Neumann Ulrich Werner
• Pfeiffer Gaylon Mitchell
• Johnson Michael R
• Hach Forrest Christopher
• Costain Kevin

Classifications

• B66C1/108

  for lifting parts of wind turbines · CPC title

• B66C1/66

  for engaging holes, recesses, or abutments on articles specially provided for facilitating handling thereof · CPC title

• F05B2230/70

  Disassembly methods · CPC title

• F05B2230/61

  using auxiliary equipment for lifting or holding · CPC title

• B66D1/60

  adapted for special purposes · CPC title