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Title:
WIND TURBINE ROTARY ELECTRIC MACHINE, WIND TURBINE, AND METHOD OF ASSEMBLING A ROTARY ELECTRIC MACHINE TO A WIND TURBINE
Document Type and Number:
WIPO Patent Application WO/2014/016806
Kind Code:
A2
Abstract:
A wind turbine rotary electric machine (3) has an active part (7) having a plurality of axial active segments (8) arranged about an axis of rotation (A); and a tubular structure (9), which extends about the axis of rotation (A), supports the active segments (8), and is divided into a plurality of first sectors (10) connected to one another and designed to fit to a frame (2) of the wind turbine (1).

Inventors:
BUSTREO PAOLO (IT)
TOCCOLI PAOLO (LU)
CASAZZA MATTEO (IT)
Application Number:
PCT/IB2013/056121
Publication Date:
January 30, 2014
Filing Date:
July 25, 2013
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
WILIC SARL (LU)
International Classes:
H02K1/30; H02K1/18; H02K7/18; H02K15/02
Domestic Patent References:
WO2002099950A12002-12-12
WO2004068678A12004-08-12
WO2011031165A12011-03-17
Foreign References:
EP1988282A22008-11-05
EP2169220A22010-03-31
US20120091724A12012-04-19
US20120073118A12012-03-29
Other References:
None
Attorney, Agent or Firm:
BOGGIO, Luigi et al. (Via Viotti 9, Torino, IT)
Download PDF:
Claims:
CLAIMS

1) A rotary electric machine for a wind turbine, the rotary electric machine (3) comprising : a first active part (7) comprising a plurality of axial first active segments (8) arranged about an axis of rotation (A) ; and a first tubular structure (9) , which extends about the axis of rotation (A) , supports the first active segments (8) , and is divided into a plurality of first sectors (10) connected to one another and designed to fit to a frame (2) of the wind turbine (1) .

2) A rotary electric machine as claimed in Claim 1, wherein each first sector (10) is designed to support a plurality of first active segments (8).

3) A rotary electric machine as claimed in Claim 1 or 2, wherein each first sector (10) and each first active segment (8) are designed to form an axially slidable prismatic joint.

4) A rotary electric machine as claimed in any one of the foregoing Claims, wherein each first sector (10) comprises a tubular portion (11) ; and an annular portion (12) preferably ■ integral with the tubular portion (11) .

5) A rotary electric machine as claimed in any one of the foregoing Claims, and comprising a rotary mechanical assembly (17) comprising a sleeve (18) designed to fit to the frame (2) of the wind turbine (1) .

6) A rotary electric machine "as claimed in Claim 5, and comprising a first radial structure (33) extending radially from the sleeve (18) to the first tubular structure (9) to support the first sectors (10) of the first tubular structure (9) .

7) A rotary electric machine as claimed in Claim 6, wherein the first radial structure (33) is adjustable radially.

8) A rotary electric machine as claimed in Claim 6 or 7, wherein the first radial structure (33) comprises a plurality of modules; and each module is independent of the other modules and is associated with a respective sector (10) .

9) A rotary electric machine as claimed in any one of Claims 6 to 8, wherein the first radial structure (33) comprises first tie spokes (34).

10) A rotary electric machine as claimed in Claim

9, wherein the first tie spokes (34) of the first radial structure (33) are tangential spokes.

11) A rotary electric machine as claimed in Claim 9 or 10, wherein the first tie spokes (34) of the first radial structure (33) are arranged in two rows.

12) A rotary electric machine as claimed in Claim 11, wherein the first tie spokes (34) in the two rows cross axially.

13) A rotary electric machine as claimed in any one of Claims 5 to 12, and comprising ""a rotary mechanical assembly (17) comprising a hub (20) designed to fit to the sleeve (18) and rotate about the axis of rotation (A) .

14) A rotary electric machine as claimed in Claim

13, wherein the rotary mechanical assembly (17) comprises a bearing (22) designed to withstand radial and axial forces and located between the hub (20) and the sleeve (18) .

15) A rotary electric machine as claimed in Claim

14, wherein the bearing comprises an inner ring' (23) and an outer ring (24) ; the hub (20) comprising a first annular pocket (25) for housing the inner ring (23) of the bearing (22) ; and the sleeve (18) comprising a second annular pocket (26) for housing the outer ring (24) of the bearing (22) .

16) A rotary electric machine as claimed in any one of Claims 13 to 15, wherein the rotary mechanical assembly (17) comprises a braking system (27) .

17) A rotary electric machine as claimed in Claim 16, wherein the braking system (27) comprises a brake disk (28) fitted to or integral with the hub (20) .

18) A rotary electric machine as claimed in Claim 17, wherein the braking system (27) comprises at least one brake calliper (29) fitted to the sleeve (18) and designed to engage the brake disk (28) .

19) A rotary electric machine as claimed in any one of Claims 13 to 18, wherein the hub (20) comprises an annular flange (21) for forming a connection to a blade assembly (4) of the wind turbine (1) .

20) A rotary electric machine as claimed in any one of Claims' 13 to 19, wherein the rotary mechanical assembly (17) comprises a locking system for locking the hub (20) to the sleeve (18) .

21) A rotary electric machine as claimed in any one of Claims 13 to 20, and comprising a second active part (13) facing the first active part (7) and comprising a plurality of axial second active segments (14) arranged about the axis of rotation (A) ; and a second tubular structure (15) , which extends about the axis of rotation (A) , supports the second active segments (14) , and is divided into a plurality of second sectors (16) connected to one another and designed to fit to the hub (20) .

22) A rotary electric machine as claimed in Claim 21, wherein each second sector (16) is designed to support a plurality of second active segments (14) .

23) A rotary electric machine as claimed in Claim

21 or 22, wherein each second sector (16) and each second active segment (14) are designed to form an axially slidable prismatic joint.

24) A rotary electric machine as claimed in one of Claims 21 to 23, and comprising a second radial structure (37) extending radially from the hub (20) to the second tubular structure (15) to support the second sectors (16) of the second tubular structure (15) .

25) A rotary electric machine as claimed in Claim 24, wherein the second radial structure (37) is adjustable radially.

26) A rotary electric machine as claimed in Claim 24 or 25, wherein the second radial structure (37) is divided into a plurality of second modules; each second module being associated with a respective second sector (16) .

27) A rotary electric machine as claimed in any one of Claims 24 to 26, wherein the second radial structure (37) comprises second tie spokes (38) .

28) A rotary electric machine as claimed in Claim

27, wherein the second tie spokes (38) of the second radial structure (37) are tangential spokes.

29) A rotary electric machine as claimed in Claim 23 or 28, wherein the second tie spokes (38) of the second radial structure (37) are arranged in two rows.

30) A rotary electric machine as claimed in Claim 29, wherein the second tie spokes in the two rows cross axially.

31) A wind turbine for producing electric energy, the wind turbine (1) comprising a frame (2) ; a blade assembly (4) ; and a rotary electric machine (3) as claimed in any one of the foregoing Claims and connected directly to the frame (2) and the blade assembly (4 ) .

32) A method of assembling a rotary electric machine to a wind turbine, the method comprising the steps of assembling a rotary mechanical assembly (17) , designed to rotate about an axis of rotation (A) of the rotary electric machine (3), to a frame (2) of the wind turbine (1) ; and assembling first and second sectors (10, 16), fitted to a first and second radial structure (33, 37), about the axis of rotation and to the rotary mechanical assembly (17) to respectively form a first and second tubular structure (9, 15) coaxial with each other.

33) A method as claimed in Claim 32, and comprising the steps of inserting first and second segments axially into respective seats on the first and second tubular structure (9, 15) respectively, to form a first and second tubular active part (7, 14) facing each other.

Description:
WIND TURBINE ROTARY ELECTRIC MACHINE, WIND TURBINE, AND METHOD OF ASSEMBLING A ROTARY ELECTRIC MACHINE TO A WIND TURBINE TECHNICAL FIELD

The present invention relates to a wind turbine rotary electric machine.

BACKGROUND ART

Wind turbine rotary electric machines, particularly those used on large-diameter wind turbines, must have special characteristics, as compared with ordinary rotary electric machines. For example, they must be relatively lightweight, must be easily accessible for maintenance, and their component parts must be easy to assemble and disassemble, both when installing and servicing the machine . " Moreover, the rotary electric machine must be connectable easily to the main frame and the blade assembly, and must be so designed as not to require excessively large, heavy main frames .

In wind turbine technology, the trend is towards increasingly powerful, i.e. large-diameter, rotary electric machines. This trend, however, poses problems in terms of the weight and size of the rotary electric machine and its component parts, which in turn pose problems both in transporting the rotary electric machine to the wind turbine installation site, and in assembling the rotary electric machine itself. To meet demand for increasingly high output, manufacturers have been forced to produce wind turbines with extremely large-diameter blade assemblies, thus increasing the height at which the rotary electric machines must be installed.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a wind turbine rotary electric machine, in particular a large-diameter rotary electric machine, that is easy to transport, install and maintain.

According to the present invention, there is provided a rotary electric machine for a wind turbine, the rotary electric machine comprising : a fi-rst active part comprising a plurality of axial first active segments arranged about an axis of rotation; and a first tubular structure, which extends about the axis of rotation, supports the first active segments, and is divided into a plurality of first sectors connected to one another and designed to fit to a frame of the wind turbine .

By dividing the first tubular structure into first sectors, and the first active part into first segments, part of the electric machine can be assembled on site, thus solving the problems posed by transporting and assembling large structures.

In the case in hand, the first tubular structure and the relative first active part define a tubular stator of the rotary electric machine. So it is the entire tubular stator that is divided into a plurality of component parts that can be assembled at the wind turbine installation site.

In a preferred embodiment of the present invention, each first sector is designed to support a plurality of first active segments.

In dividing up the tubular stator, the active part is divided up into more parts than the tubular structure. This is because the active segments call for frequent maintenance and sometimes need replacing, whereas the tubular structure is divided up for practical reasons of transport and assembly.

Preferably, each first sector and each first active segment are designed to form an axially slidable prismatic joint.

This ' configuration simplifies assembly and removal of the active segments .

Preferably, each first sector comprises a tubular portion; and an annular portion preferably integral with the tubular portion.

The annular portion also serves for protection.

In a preferred embodiment of the present invention, the rotary electric machine comprises a rotary mechanical assembly.

' Preferably, the rotary mechanical assembly comprises a sleeve designed to fit to the frame of the wind turbine. The sleeve forms part, and represents the fixed part, of the rotary mechanical assembly.

The rotary mechanical assembly is tubular, and is much smaller in diameter than the first tubular structure.

In a preferred embodiment of the present invention, the rotary electric machine comprises a first radial structure extending radially from the sleeve to the first tubular structure to support the first sectors of the first tubular structure.

The first radial structure serves to support the first tubular structure at a given distance from the axis of rotation. Preferably, the first radial structure comprises a plurality of modules; and each module is independent of the other modules and is associated with a respective sector.

The first radial structure is thus also modular, and can be divided into a plurality of component parts for easy transport and assembly.

Preferably, the first radial structure is adjustable radially to adjust the distance between the first and a second active part. Preferably, the first radial structure comprises first tie spokes.

In a preferred embodiment of the present invention, the rotary mechanical assembly comprises a hub designed to fit to the sleeve and rotate about the axis of rotation; and a bearing designed to withstand radial and axial forces and located between the hub and the sleeve.

The hub of the rotary mechanical assembly thus rotates about the axis of rotation with respect to the sleeve.

Preferably, the bearing comprises an inner ring and an outer ring; the hub comprising a first annular pocket for housing the inner ring of the bearing; and the sleeve comprising a second annular pocket for housing the outer ring of the bearing.

This design permits easy removal and/or replacement of the bearing.

Preferably, the rotary mechanical assembly comprises a braking system.

More specifically, the braking system extends between the hub and the sleeve.

Preferably, the braking system comprises a brake disk fitted to or integral with the hub; and at least one brake calliper fitted to the sleeve and designed to engage the brake disk. Preferably, the rotary mechanical assembly comprises a locking system for locking the hub to the sleeve .

This makes it possible to- remove the bearing easily, or to insert or remove the first active segments and/or first sectors.

In a preferred embodiment of the present invention, the rotary electric machine comprises a second active part facing the first active part and comprising a plurality of axial second active segments arranged about the axis of rotation; and a second tubular structure, which extends about the axis of rotation, supports the second active segments, and is divided into a plurality of second sectors connected to one another and designed to fit to the hub.

In other words, the modular design is also applied to the second active part and second tubular structure. So the rotor, even when of large diameter, can be transported easily and assembled on site.

In a preferred embodiment of the present invention, the rotary electric machine comprises a second radial structure extending radially from the hub to the second tubular structure to support the second sectors of the second tubular structure.

The second radial structure serves to firmly support the second tubular structure at a given distance from the axis of rotation.

Preferably, the second radial structure is divided into a plurality of second modules; each second module being associated with a respective second sector.

The modular design of the second radial structure makes it easier to transport and assemble.

Preferably, the ' second radial structure is adjustable radially to adjust the distance between the first and second active part.

Preferably, the second radial structure comprises second tie spokes .

The tie spokes greatly reduce the weight of the second radial structure, and make it easy to divide into second modules .

A further object of the present invention is to provide a wind turbine designed to eliminate the drawbacks of the known art .

According to the present ' invention, there is provided a wind turbine for producing electric energy, the wind turbine comprising a frame; a blade assembly; and a rotary electric machine having any one of the above- listed characteristics and connected directly to the frame and the blade assembly.

A further object of the present invention is to provide a method of assembling a rotary electric machine to a wind turbine, designed to eliminate the drawbacks of the known art.

According to the present invention, there is provided a method of assembling a rotary electric machine to a wind turbine, the method comprising the steps of assembling a rotary mechanical assembly, designed to rotate about an axis of rotation of the rotary electric machine, to a frame of the wind turbine; and assembling first and second sectors, fitted to a first and second radial structure, about the axis of rotation and to the rotary mechanical assembly to respectively form a first and second tubular structure coaxial with each other.

In the present invention, the large-diameter component parts are divided into sectors and assembled about the rotary mechanical assembly.

In a preferred embodiment of the present invention, the method comprises inserting first and second segments axially into respective seats on the first and second tubular structure respectively, to form a first and second tubular active part facing each other.

The first and second active part, separated by a small air gap, are thus assembled later, to reduce the risk of contact and damage.

BRIEF DECRIPTION OF THE DRAWINGS A number of non- limiting embodiments of the present invention will be described by way of example with reference to the attached drawings, in which :

Figure 1 shows a section, with parts removed for clarity, of a wind turbine equipped with a rotary electric machine in accordance with the present invention;

Figure 2 shows a larger-scale, partly sectioned side view, with parts removed for clarity, of a detail of the Figure 1 rotary electric machine;

Figure 3 shows a larger-scale view in perspective, with parts removed for clarity, of a component part of the Figure 1 rotary electric machine ;

Figures 4 and 5 show partly sectioned side views, with parts removed for clarity, of a detail of the rotary electric machine in accordance with a variation of the present invention;

Figure 6 shows a larger-scale view in perspective, with parts removed for clarity, of a module of the radial structure shown in Figure 5.

BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figure 1 indicates as a whole a wind turbine for producing electric energy. Wind turbine 1 comprises a main frame 2 ; a rotary electric machine 3 fitted to frame 2; and a blade assembly 4 mounted to rotate about an axis of rotation A of rotary electric machine 3.

Wind turbine 1 is preferably a direct-drive type, i.e. in which blade assembly 4.is connected directly to rotary electric machine 3 with no mechanical transmissions in between.

Rotary electric machine 3 is tubular, and preferably asynchronous with permanent magnets.

Rotary electric machine 3 is interposed between frame 2 and blade assembly 4, and serves to support the blade assembly, and to transmit the stress generated in blade assembly 4 to rotary electric machine 3 itself.

Rotary electric machine 3 comprises a tubular stator 5 and a tubular rotor 6. In the example shown, tubular rotor 6 is located inside tubular stator 5, but the present invention also applies to configurations in which the tubular rotor surrounds the tubular stator.

Tubular stator 5 comprises a tubular active part

7, which extends about axis of rotation A and comprises a. plurality of axial active segments 8.

Tubular stator 5 comprises a tubular structure 9, which extends about axis of rotation A, is designed to support active segments 8, and is divided into a plurality of sectors 10 connected to one another and designed to fit to frame 2 of wind turbine 1.

Sectors 10 are arc-shaped and preferably identical.

Each sector 10 is designed to support a plurality of active . segments 8.

In other words, sectors 10 extend along a wider angle than active segments 8. And, in the example shown, tubular structure 9 comprises two sectors 10, each extending 180° about axis of rotation A.

Each sector 10 and each active segment 8 are designed to form an axially slidable prismatic joint.

Each sector 10 comprises a tubular portion 11; and an annular portion 12 preferably integral with tubular portion 11. Tubular portion 11 serves to support active segments 8, while annular portion 12 acts as a protective casing. 1

Clearly, dividing tubular structure 9 into two sectors is in no way to be intended as limiting the scope of the present invention.

Likewise, tubular rotor 6 comprises a tubular active part 13, which faces active part 7, extends about axis of rotation A, and comprises a plurality of axial active segments 1 .

Tubular rotor 6 comprises a tubular structure 15, which extends about axis of rotation A, is designed to support active segments 14, and is divided into a plurality of sectors 16 connected to one another.

Sectors 16 are arc-shaped and preferably identical.

Each sector 16 is designed to support a plurality of active segments 14.

In other words, sectors 16 extend along a wider angle than active segments 14. And, in the example shown, tubular structure 15 comprises twenty sectors 16, each extending 36° about axis of rotation A. Clearly, dividing tubular structure 15 into twenty sectors is in no way to. be intended as limiting the scope of the present invention.

Each sector 16 and each active segment 14 are designed to form an axially slidable prismatic joint.

Rotary electric machine 3 comprises a rotary mechanical assembly 17 interposed between frame 2 and blade assembly 4, and designed to permit rotation of tubular rotor 6 with respect to tubular stator 5, to brake tubular rotor 5, and to fix tubular rotor 5 to tubular stator 6.

Rotary electric machine 3 - in the example shown, rotary mechanical assembly 17 - comprises a sleeve 18 fixed, preferably bolted, to frame -2. For which purpose,- sleeve 18 comprises a flange 19. Sleeve 18 preferably decreases axially in diameter, from frame 2 towards blade assembly 4. Rotary electric machine 3 - in the example shown, rotary mechanical assembly 17 - comprises a hub 20 designed to fit to sleeve 18 and rotate about axis of rotation A.

Hub 20 is connected directly to blade assembly 4.

For which purpose, hub 20 comprises a flange 21 for connecting, preferably bolting, the hub to blade assembly 4.

Rotary electric machine 3 - in the example shown, rotary mechanical assembly 17 - comprises a bearing 22 for withstanding radial and axial forces and located between hub 20 and sleeve 18. Bearing 22 comprises an inner ring 23 and an outer ring 24.

Hub 20 comprises an annular pocket 25 for housing inner ring 23 of bearing 22.

Sleeve 18 comprises an annular pocket 26 for housing outer ring 24 of bearing 22.

Hub 20 has a substantially C-shaped cross section extending about the free end of sleeve 18.

Hub 20, in fact, is designed to extend inside and outside sleeve 18.

Rotary mechanical assembly 17 comprises a braking system 27 fitted to sleeve 18 and hub 20. Braking system 27 preferably comprises a brake disk 28 fitted to or formed integrally with hub 20; and at least one brake calliper 29 fitted to sleeve 18 and designed to engage the brake disk 28. Brake disk 28 extends about sleeve 18 or at least about an end portion of sleeve 18.

Rotary mechanical assembly 17 comprises a locking system 30 for locking hub 20 to sleeve 18.

More specifically, locking system 30 comprises lock members 31 fitted to sleeve 18; and lock members 32 located along hub 20 and designed to interact with lock members 31.

Rotary mechanical assembly 17, in other words, provides for rotating hub 20 about axis of rotation A with respect to sleeve 18, mechanically braking hub 20 with respect to sleeve 18, and locking hub 20 to sleeve 18.

Locking hub 20 to sleeve 18 enables removal and replacement of bearing 22. For which purpose, sleeve 18 and hub 20 are designed to permit removal of bearing 22 from the frame 2 side, once hub 20 is locked to sleeve 18.

Rotary mechanical assembly 17 can be assembled to frame 2 and blade assembly 4 without tubular stator 5 and tubular rotor 6. In other words, tubular rotor 6 and tubular stator 5 can be assembled about rotary mechanical assembly 17 already installed in position. Assembling tubular rotor 6 and tubular stator 5 later is made possible by respective tubular structures 15 and 9 being divided into respective sectors 16 and 10, and by respective active parts 13 and 7 being divided into respective segments 14 and 8.

Tubular stator 5 is connected to sleeve 18. More specifically, rotary electric machine 3 comprises a radial structure 33 extending radially from sleeve 18 to tubular structure 9 to support sectors 10 of tubular structure 9.

Radial structure 33 is preferably divided into modules, each associated with a respective sector 10.

Radial structure 33 is preferably adjustable radially.

Radial structure 33 preferably comprises tie spokes 34. Tie spokes 34 are designed to mainly withstand tensile stress. Tie spokes 34 allow radial structure 33 to be divided easily into modules.

Tie spokes 34 are preferably mounted tangentially with respect to sleeve 18, so as to also withstand moments transmitted by tubular structure 9 to sleeve 18.

Tie spokes 34 of radial structure 33 are arranged in two rows, and cross axially to withstand axial stress .

Tie spokes 34 are connectable to sleeve 18 and tubular structure 9 by means of ball joints 35. Each tie spoke 34 also comprises a nipple 36 for adjusting the pull, and therefore the length, of tie spoke 34.

Tubular rotor 6 is connected to hub 20. More specifically, rotary electric machine 3 comprises a radial structure 37 extending radially from hub 20 to tubular structure 15 to support sectors 16 of tubular structure 15.

Radial structure 37 is preferably adjustable radially.

Radial structure 37 is also preferably divided into modules, each associated with a respective sector 16.

Radial structure 37 preferably comprises tie spokes 38 designed to mainly withstand tensile stress.

Tie spokes 38 are preferably mounted tangentially with respect to hub 20, so as to also withstand moments transmitted by tubular structure 15 to hub 20.

Tie spokes 38 of radial structure 37 are arranged in two rows, and cross axially to withstand axial stress.

Tie spokes 38 are connectable to hub 20 and tubular structure 15 by means of ball joints 39. Each tie spoke 38 also comprises a nipple 40 for adjusting the pull and length of tie spoke 38.

With reference to Figure 2, each sector 16 comprises a base 41 with a seat; and an insert 42 that can be selectively fitted axially inside the seat on base 41. Insert 42 in turn comprises a plurality of seats, into which active segments 14 can be selectively fitted axially. Each active segment 14 is designed to fit inside a respective seat in the insert.

Tubular rotor 6 also comprises expansion plugs 43, each located between two adjacent sectors 16 to transmit circumferential force and eliminate any slack between sectors 16, and so stabilize tubular structure 15.

With reference to Figure 3, each sector 10 of tubular structure 9 has flanges 44 for connecting sector 10 to adjacent sectors 10, or to the adjacent sector 10 in the example shown, in which tubular structure 15 comprises two semicylindrical sectors 10.

Figures 4, 5 and 6 show a variation of radial structure 37, in which tie spokes 38 are arranged in a trellis pattern to support sectors 16, to better withstand axial, radial and tangential stress, and to support each sector 16 with no assistance from adjacent sectors 16.

Radial structure 37 may also have a spoke pattern as shown in Figures 4-6.

In short, the present invention provides for easily and cheaply transporting and installing large- diameter rotary electric machines . According to the present invention, rotary- mechanical assembly 17 can be fitted to the wind turbine frame 2, and the rotary electric machine assembled about rotary mechanical assembly 17.

- Clearly, changes may be made to the rotary electric machine according to the present invention without, however, departing from the scope of the accompanying Claims .