Relating to the mounting of stators in generators for wind turbines
In a first aspect of the invention there is provided a generator for a wind turbine. The generator includes a stator which defines a central axis of the generator, the stator being mounted within a frame by a stator mounting system. The stator mounting system includes a plurality of stator mounting modules, each stator mounting module being removably attached to the stator and removably attached to the frame. The stator mounting system is arranged so that one or more of the stator mounting modules can be replaced or repositioned with the stator mounted in situ within the frame.
1. A generator for a wind turbine, the generator comprising a stator which defines a central axis of the generator, the stator being mounted within a frame by a stator mounting system, wherein the stator mounting system comprises a plurality of stator mounting modules, at least one stator mounting module being removably attached to the stator and removably attached to the frame, wherein the stator mounting system is arranged so that one or more of the stator mounting modules can be replaced with the stator mounted in situ within the frame.
2. The generator for a wind turbine according to claim 1 , wherein said at least one stator mounting module is removably attached to the stator by at least one stator mounting bolt and removably attached to the frame by at least one fixing bolt.
3. The generator for a wind turbine according to claim 1 , wherein each stator mounting module is removably attached to the stator and removably attached to the frame.
4. The generator for a wind turbine according to claim 1 , wherein the frame comprises a frame cover having an access opening through which one or more of the stator mounting modules can be accessed for replacement or repositioning with the stator mounted in situ within the frame.
5. The generator for a wind turbine according to claim 4 , wherein the frame cover comprises an access panel removably fitted within or over the access opening.
6. The generator for a wind turbine according to claim 1 , wherein the frame comprises a plurality of axially extending members with respect to the central axis of the generator, wherein at least some of the mounting modules are connected to and extend between two of the axially extending members.
7. The generator for a wind turbine according to claim 1 , wherein each stator mounting module is adjustably attached to the frame by an adjustable fixture.
8. The generator for a wind turbine according to claim 1 , wherein each stator mounting module comprises a resilient member and a mounting member, wherein the mounting member is removably attached to the stator and the resilient member is removably attached to the frame.
9. The generator for a wind turbine according to claim 8 , wherein the mounting member is removably attached to the resilient member.
10. The generator for a wind turbine according to claim 8 , wherein the resilient member comprises a beam having a first end and a second end, wherein the first and second ends of the beam are directly and removably attached to the frame.
11. The generator for a wind turbine according to claim 10 , wherein the beam extends in a direction substantially perpendicular to a central axis of the stator.
12. The generator for a wind turbine according to claim 8 , wherein the mounting member of a least one of the mounting modules is of laminate construction comprising a plurality of discrete layers arranged in a stack, wherein at least one of the layers comprises a first material, and wherein at least another of the layers comprises a second material, wherein the layers are stacked in a direction substantially parallel to the central axis of the generator.
13. The generator for a wind turbine according to claim 12 , wherein at least one first layer of the mounting member comprises one or more keys, and wherein at least one second layer comprises one or more recesses, wherein the first and second layers are adjacent to one another, and wherein the one or more keys of the first layer engage with the one or more recesses of the second layer.
14. The generator for a wind turbine according to claim 12 , wherein at least one of the layers of the mounting member comprises an electrically insulating material.
15. The generator for a wind turbine according to claim 8 , wherein one or more of the mounting members comprise a key or a keyhole for engagement with a co-operating keyhole or key located on the stator.
16. The generator for a wind turbine according to claim 8 , wherein one or more of the mounting members comprise a key or a keyhole for engagement with a co-operating keyhole or key located on the resilient member.
17. The generator for a wind turbine according to claim 1 , wherein the stator mounting system comprises a plurality of stator mounting bays located equidistantly around an outer circumference of the stator, wherein each stator mounting bay comprises at least one stator mounting module.
18. The generator for a wind turbine according to claim 17 , wherein each stator mounting bay comprises a plurality of stator mounting modules arranged spaced from one another along a direction substantially parallel with the central axis of the generator.
19. The generator for a wind turbine according to claim 18 , wherein the mechanical properties and/or configuration of a first stator mounting module differ from the mechanical properties and/or configuration of a second stator mounting module.
20. A gearbox-generator unit comprising the generator according to claim 1 , further comprising a gearbox and wherein said gearbox and said generator are connected such that an output shaft of the gearbox and a central axis of the stator of the generator are co-axial.
21. A method for maintaining a generator for a wind turbine, the generator having features according to claim 1 , the method comprising:
removing at least a part of the at least one stator mounting module while at least one other stator mounting module remains attached between the frame and the stator; and
installing at least one replacement part of the at least one stator mounting module.
22. A method for adjusting the stator mounting system of a generator for a wind turbine, the generator having features according to claim 1 , the method comprising:
detaching the at least one stator mounting module from a first position while the at least one other stator mounting module remains attached between the frame and the stator; and
reattaching the at least one stator mounting module in a second position.
23. A wind turbine comprising a wind turbine tower, a nacelle rotatably coupled to the tower, a rotating hub mounted to the nacelle, and a plurality of wind turbine blades coupled to the hub, wherein the nacelle comprises a generator according to claim 1 .
24. The wind turbine according to claim 23 , further comprising a gearbox and wherein said gearbox and said generator are connected such that an output shaft of the gearbox and a central axis of the stator of the generator are co-axial.
25. A generator for a wind turbine, the generator comprising a stator which defines a central axis of the generator, the stator being mounted within a frame by a stator mounting system, wherein the stator mounting system comprises a plurality of stator mounting modules, at least one stator mounting module being removably attached to the stator and removably attached to the frame and located between the frame and the stator, wherein the stator mounting system is arranged so that one or more of the stator mounting modules can be replaced or repositioned with the stator mounted in situ within the frame.