SPINNER-LESS HUB ACCESS AND LIFTING SYSTEM FOR A WIND TURBINE

• US 20100129216A1
• Filed: 11/21/2008
• Published: 05/27/2010
• Est. Priority Date: 11/21/2008
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Bagepalli, Bharat S., Wambeke, Dustin Jon, Riddell, Scott G.
• Granted Patent: US 8,061,999 B2
• Time in Patent Office: Days
• US Class Current: 416/61
• CPC Class Codes: F03D 1/0691 of the hub
• CPC Class Codes: F03D 80/00 Details, components or accessories not provided for in groups F03D1/00 - F03D17/00
• CPC Class Codes: F03D 80/50 Maintenance or repair
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A simple and safe means is provided to gain entry into the rotor hub of a wind turbine for maintenance operations within the hub. A ladder-like structure is mounted onto the rotor hub using the same bolts attaching a fixed outer race of the pitch bearing for the rotor blades. The ladder-like structure has integral with it a protective cage to the front, forming a basket. Structural elements for grasping are provided to a worker over the full path traversed from the nacelle to the entry hatch of the hub. An expanded area between rungs may be provided to facilitate entry by a service worker into the safety cage area. Lifting ears made also be formed with tubular sections integrated into the ladder-like structure.

Claims

1. An access and lifting system, adapted for gaining entry to a rotor hub for a wind turbine, comprising:

a wind turbine tower with a nacelle including a rotor hub mounted at a forward end, wherein the rotor hub supports a plurality of rotor blades distributed circumferentially around the rotor hub and includes an entry hatch and a pitching mechanism for each rotor blade including a pitch bearing; and

a plurality of ladder-like structures, each structure positioned over a surface of the rotor hub centered between adjacent rotor blades and each structure including a plurality of rungs distributed axially along a length, opposing side-members, and mounting elements on both the opposing side-members, wherein the mounting elements attach the structure to the rotor hub at a junction between the rotor hub and the pitch bearing for the adjacent rotor blade.

2. The access and lifting system according to claim 1, wherein the pitch bearing further includes an outer fixed race with a flange surface, wherein the mounting elements on each individual opposing-member of the ladder-like structure are attached at the flange surface of the outer fixed race of the pitch bearing for the adjacent rotor blade.

3. The access and lifting system according to claim 2, further comprising:

a mounting surface on a flange of the rotor hub flange extending outward radially beyond the flange for the pitch bearing, wherein the mounting elements of the ladder-like structure attach directly to the mounting surface on the flange of the rotor hub.

4. The access and lifting system according to claim 2, further comprising:

a plurality of mounting bolts for the flange surface of the outer fixed race of the pitch bearing, wherein the mounting elements on each individual opposing-member of the ladder-like structure are attached with the mounting bolts to the outer fixed race of the pitch bearing for the adjacent rotor blade.

5. The access and lifting system according to claim 4, wherein the mounting elements comprise arms extending from the ladder-like structure to the mounting bolts.

6. The access and lifting system according to claim 4, wherein the ladder-like structure comprises:

a welded frame.

7. The access and lifting system according to claim 4, wherein the ladder-like structure comprises:

a bolted frame.

8. The access and lifting system according to claim 4, wherein the ladder-like structure comprises:

a combination of a bolted frame and a welded frame.

9. The access and lifting system according to claim 4, wherein the ladder-like structure extends over a surface of the hub from an area adjacent to the nacelle to an area forward of the entry hatch of the hub including a safety cage section in front of the hub and an access to the safety cage section.

10. The access and lifting system according to claim 9, wherein the access to the safety cage section includes an extended space between a pair of adjacent rungs adapted for allowing a service person to enter the safety cage section.

11. The access and lifting system according to claim 10, wherein the extended space between a pair of adjacent rungs includes a bowing of the forward rung of the pair of adjacent rungs, adapted for providing greater access.

12. The access and lifting system according to claim 11, wherein a forward part of the safety cage section for each of the plurality of ladder-like structures on the hub surfaces area between adjacent rotor blades fixedly engages each other at a forward end to form a full enclosure around the entry hatch.

13. The access and lifting system according to claim 12, wherein the forward part of the safety cage for the individual ladder-like structures on the hub surfaces area between adjacent rotor blades fixedly engage at a forward end in a bolted arrangement.

14. The access and lifting system according to claim 12, further comprising:

a shell fixedly attached to the full enclosure around the entry hatch.

15. The access and lifting system according to claim 13, wherein the shell fixedly attached to the full enclosure around the entry hatch is attached on an outer side of the full enclosure.

16. The access and lifting system according to claim 4, further comprising:

a plurality of lifting ears attached fixedly to each of the side-members of the ladder-like structure.

17. A method for accessing an interior of a rotor hub for a wind turbine through an entry hatch at a forward end, the method comprising:

positioning a rotor hub for a wind turbine to locate an exterior climbing surface for a hub ladder at a topmost position of hub rotation with respect to the ground;

climbing over the exterior climbing surface of the hub ladder forward from an area adjacent to a nacelle;

entering between adjacent rungs into a safety cage upon reaching an access opening in the ladder;

opening the entry hatch; and

entering through the entry hatch into the hub.

18. The method for accessing an interior of a rotor hub for a wind turbine according to claim 17, comprising:

protecting the operator at the forward end of the entry hatch by shielding from the elements with a shell attached to a front part of the safety cage.

19. A method for lifting a hub of a rotor for a wind turbine, comprising:

providing lifting ears integral to a ladder-like structure adapted for mounting on the hub between adjacent rotor blades;

bolting the ladder-like-structure to the hub at the rotor pitch bearing;

attaching lifting slings to lifting ears formed integral to a ladder-like structure; and

performing a lift of the hub using the lifting slings to a mounting position at the nacelle.

20. The method for lifting a hub of a rotor for a wind turbine according to claim 19, the step of performing a lift comprising:

lifting the hub with at least one of with blades attached and without blades attached.