Generator stiffener ring

Abstract

To facilitate maintenance and repair of a rotor and a stator.SOLUTION: The present disclosure relates to an electrical machine comprising a rotor (13), a stator (12) and a radial air gap (39) between the rotor (13) and the stator (12), where one of the rotor and the stator comprises an endplate driven on one side of the electrical machine, a central support (32) radially surrounding the other of the rotor (13) and the stator (12), and a stiffener ring (33) on an opposite side of the electrical machine. The stiffener ring comprises an outer ring (34) connected to the central support (32), and an inner ring (35) connected to the outer ring (34). The outer ring (34) comprises a plurality of removably mounted outer segments (44). The present disclosure further relates to wind turbines and to methods for repairing components of the electrical machine.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an electric machine, and more specifically to a generator for a wind turbine and a wind turbine comprising such a generator. The present disclosure further relates to a method for accessing active components of an electric machine, more specifically a wind turbine generator.

Background Art

[0002] Electric machines such as motors and generators generally comprise a rotor structure and a stator structure. A large generator may be, for example, a permanent magnet generator (PMG).

[0003] Such a generator can be used, for example, in a wind turbine. A wind turbine generally comprises a rotor having a rotor hub and a plurality of blades. The rotor is configured to rotate under the influence of wind on the blades. The rotation of the rotor shaft directly drives the generator rotor ("direct drive type") or is driven using a gearbox. Such a direct drive type wind turbine generator can have, for example, a diameter of 6 to 10 meters (236 to  328 inches), a length of, for example, 2 to 3 meters (79 to 118 inches), and can rotate at a low speed in the range of, for example, 2 to 20 rpm (revolutions per minute). Alternatively, the permanent magnet generator may also be coupled to a gearbox that increases the rotational speed of the generator to, for example, 50 to 500 rpm or more.

[0004] An electric machine comprises a rotor that rotates with respect to a stator. The rotor may be an inner structure and the stator may be an outer structure. Thus, in this case the stator surrounds the rotor. Alternatively, the configuration may be the opposite, i.e., the rotor may radially surround the stator.

[0005] In permanent magnet-excited generators (PMGs), the permanent magnets (PMs) are generally located in the rotor (although they can also be arranged alternately in the stator structure), while the winding elements (e.g., coils) are usually contained within the stator (although they can also be arranged alternately in the rotor structure). Permanent magnet generators are generally considered reliable and require less maintenance than other types of generators. This is a key reason why permanent magnet generators are used in offshore wind turbines, particularly direct-drive offshore wind turbines.

[0006] Multiple permanent magnets may be provided in a permanent magnet module, which may be mounted to the rotor as a single component. A permanent magnet module may be defined as a unit having multiple permanent magnets, which can be mounted and dismounted together. Such a module may have a module base having a shape suitable for housing or supporting multiple permanent magnets that can be fixed to a base. The base may be configured to be fixed to a rotor structure, such as a rotor rim, so that the multiple magnets are fixed together to the rotor rim through the module base. The use of a permanent magnet module can facilitate the manufacture of the rotor. Similarly, stator coils may be grouped together in a coil module. The coil module may be fixed to a generator structure, such as a stator rim.

[0007] In larger electromechanical devices, such as direct-drive wind turbines, one side of the electromechanism may be closed by an end plate. The other side of the electromechanism may be partially closed by a stiffening flange. Such a stiffening flange extends partially radially inward but is not supported as a whole. The stiffening flange can be segmented to allow temporary removal of flange segments for maintenance or repair, providing access to active components (permanent magnets and / or coils). [Overview of the project]

[0008] In one aspect of the present disclosure, an electromachine is provided. The electromachine comprises a rotor, a stator, and a radial air gap between the rotor and the stator. One of the rotor and stator comprises an end plate on one side of the generator, and a central support surrounding the other of the rotor and stator, and further comprises a stiffening flange on the opposite side of the generator. The stiffening flange comprises an outer ring connected to the central support and an inner ring connected to the outer ring. The outer ring comprises a plurality of removablely mounted outer annular segments.

[0009] By using the electromechanical apparatus according to this embodiment, maintenance and repair of the rotor and stator can be facilitated. Removable outer segments can be removed to provide access to the rotor and / or stator. The inner ring can provide sufficient rigidity so that the rotor does not deform during such operation and the air gap between the stator and rotor is not compromised. Furthermore, the weight of the structure can be optimized because solutions involving increasing the thickness or width, for example, of a stiffening ring to increase rigidity, can be avoided.

[0010] Throughout this disclosure, “removably mounted” means that a removablely mounted component or segment is mounted in such a way that it can be detached or removed without damaging the component or segment or the surrounding structure. The component or segment may be mounted or attached using appropriate fasteners, such as bolts or screws, which allow for the removal of the fasteners, thereby allowing for the disassembly or removal of the component or segment.

[0011] In a further embodiment, a method is provided for repairing components of an electromechanical device having a rotor, a stator, and a radial air gap between the rotor and the stator. The method includes the steps of removing a segment of a stiffening ring located on one side of the generator to form an opening in the stiffening ring, and accessing the rotor and / or stator through the opening in the stiffening ring, wherein the stiffening ring is not supported at its radially inner end. The stiffening ring comprises an outer ring and an inner ring, and the step of removing a segment of the stiffening ring includes the step of removing a segment of the outer ring, while the inner ring is not disassembled.

[0012] In this embodiment, access to the generator rotor and / or stator can be provided to perform repairs. In the example, active components of the rotor and / or stator can be removed and replaced.

[0013] In yet another embodiment, a wind turbine is provided comprising a wind turbine rotor including a plurality of blades, a generator rotor operably connected to the wind turbine rotor, and a generator stator radially arranged within the generator rotor. The generator rotor comprises a radial support rotatably mounted on the main frame at the front, a rotor rim, and a stiffening ring for the generator rotor at the rear. The stiffening ring comprises an outer ring and an inner ring, the outer ring comprising a plurality of removablely mounted outer ring segments. [Brief explanation of the drawing]

[0014] [Figure 1] This diagram schematically shows a perspective view of an example of a wind turbine. [Figure 2] This figure shows an example of a direct-drive wind turbine. [Figure 3] This diagram schematically shows an example of a generator for a direct-drive wind turbine. [Figure 4] This diagram schematically shows the axial view of an example of a generator. [Figure 5]This figure schematically shows the details of an example generator in Figure 4. [Figure 6] Figure 4 is a schematic diagram illustrating an example of a repair method for the active components of a generator. [Figure 7] Figure 4 is a schematic diagram illustrating an example of a repair method for the active components of a generator. [Figure 8] This figure schematically illustrates further examples of electrical machinery as described in this disclosure. [Modes for carrying out the invention]

[0015] The embodiments of the present invention are described in detail below, with one or more examples shown in the drawings. Each example is presented to illustrate the invention and is not intended to limit it. Indeed, it will be apparent to those skilled in the art that various modifications and changes can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can also be used in conjunction with another embodiment to bring about further embodiments. Accordingly, the present invention is intended to encompass such modifications and changes that fall within the scope of the appended claims and their equivalents.

[0016] Figure 1 shows a perspective view of an example of a wind turbine 1. As shown, the wind turbine 1 includes a tower 2 extending from a support surface 3, a nacelle 4 mounted on the tower 2, and a rotor 5 coupled to the nacelle 4. The rotor 5 includes a rotatable hub 6 and at least one rotor blade 7 coupled to the hub 6 and extending outward from the hub 6. For example, in the illustrated example, the rotor 5 includes three rotor blades 7. However, in alternative embodiments, the rotor 5 may include more or fewer rotor blades 7 than three. Each rotor blade 7 may be spaced away from the hub 6 to facilitate the rotation of the rotor 5 and to allow kinetic energy to be converted from wind to usable mechanical energy, and subsequently to electrical energy. For example, the hub 6 can be positioned within the nacelle 4 or rotatably coupled to a generator 10 (Figure 2) that forms part of the nacelle to enable the generation of electrical energy. The rotation of the rotor may be transmitted to a generator, for example, a direct-drive wind turbine, or to a generator by the use of a gearbox.

[0017] Figure 2 shows a simplified internal diagram of an example of a nacelle 4 of a direct-drive wind turbine 1. As shown, the generator 10 may be located inside the nacelle 4 or between the nacelle 4 and the rotor 5. Generally, the generator 10 may be coupled to the rotor 5 of the wind turbine 1 to generate electricity from the rotational energy generated by the rotor 5. For example, the rotor 5 of the wind turbine may include a hub 6 coupled to the rotor 9 of the generator 10 to rotate together with the rotor 9 of the generator 10. Thus, the rotation of the hub 6 can drive the rotor 12 of the generator 10.

[0018] In Figure 2, the wind turbine rotor 5 may be rotatably mounted to the support frame 9 via rotor bearings 8 in the coupling region or on the front side. The generator 10 may include a rotor 12 and a stator 13. The stator may be rigidly mounted to the support frame 9. The rotor may be rotatably mounted to the stator via generator bearings 14 so that the rotor can rotate relative to the stator about its axis.

[0019] The generator 10 may be electrically coupled to a converter. The wind turbine converter can adapt the output power of the generator to the requirements of the power grid. In some examples, the converter may be installed inside the nacelle 4. However, in other examples, it may be installed at other locations of the wind turbine.

[0020] It should be understood that the rotor 5 and the generator 10 of the wind turbine may be supported by a bedplate or a support frame 9 positioned at the top of the wind turbine tower 2.

[0021] The nacelle 4 is rotatably coupled to the tower 2 via a yaw system 20. The yaw system includes a yaw bearing (not visible in FIG. 2) having two bearing components configured to rotate relative to each other. The tower 2 is coupled to the first bearing component, and the nacelle 4, for example, the bedplate or the support frame 9, is coupled to the second bearing component.

[0022] FIG. 3 schematically shows an example of a generator of a wind turbine. In one aspect of the present disclosure, a wind turbine is provided that includes a wind turbine rotor 5 including a plurality of blades 7 (see FIGS. 1 and 2). The wind turbine also includes a generator rotor 13 operably connected to the wind turbine rotor 5 and a generator stator 12 radially disposed within the generator rotor 13. The generator rotor 13 includes a radial support 31 rotatably mounted to the main frame 9 on the front side, a rotor rim 32, and a stiffening ring 33 on the rear side of the generator rotor. The stiffening ring 33 includes an outer ring 34 and an inner ring 35, and the outer ring 34 includes a plurality of removably mounted outer ring segments 44 (see FIG. 4).

[0023] In the example of FIG. 3, the inner ring 35 is not supported on the inside. In this example, the rotor that radially surrounds the stator is mounted in a cantilevered manner and is supported only on one side of the generator. In the example of FIG. 3, the generator rotor can be directly driven by the wind turbine rotor 5, that is, there is no gearbox arranged between the rotor (shaft) and the generator rotor. In the example of FIG. 3, the rotor shaft 36 may be directly coupled to the hub 6 of the wind turbine, or the rotor shaft 36 may be an extension of the hub of the wind turbine.

[0024] In an example (as can be seen, for example, in FIG. 4), the outer ring may include 10 to 50 segments, specifically 20 to 40 segments. The optimal number of segments may be determined according to the diameter of the generator rotor. The size of the segment may be selected such that a single segment can be removed to provide access to the rotor or stator of the generator. In particular, the segment may be of a shape and size such that active components can be removed through an opening formed by removing the segment. The active component may be a single coil, a single permanent magnet, or a coil module or permanent magnet module. In an example, different outer segments may have different sizes. However, in order to optimize manufacturing and logistics, all outer segments may have the same size and the same configuration.

[0025] In an example, the wind turbine may include a seal between the removably mounted outer ring segments.

[0026] Referring further to Figures 3 and 4, in a further embodiment, the present disclosure provides an electromachine 10 comprising a rotor 13, a stator 12, and a radial air gap 39 between the rotor 13 and the stator 12. In this embodiment, one of the rotor and stator comprises an end plate 31 on one side of the generator 10, a central support 32, and a stiffening flange 33 on the opposite side of the generator 10. The central support 32 is radially outward of the other rotor and stator, or radially surrounds the other rotor and stator. The stiffening ring or stiffening flange 33 comprises an outer ring ("annular flange") 34 connected to the central support 32 and an inner ring ("inner annular flange") 35 connected to the outer ring 34. The outer ring 34 comprises a plurality of removablely mounted outer annular segments 44.

[0027] In the illustrated example, the rotor radially surrounds the stator, and the rotor can form an overhang structure. In other examples, the stator may radially surround the rotor. In such cases, the stator may be cantilevered, with a ring-shaped end plate on one side and a stiffening ring on the other side.

[0028] The end plate may be substantially ring-shaped or annular.

[0029] In the illustrated example, the electromachine is a generator, more specifically, a wind turbine generator. In this example, the rotor is driven by a wind turbine rotor. In other examples, the electromachine may be a motor.

[0030] The ring-shaped end plate 31 can close one side of the generator, in the example of Figure 3, the front side of the generator, i.e., the side of the generator to which the rotor hub of the upstream wind turbine is mounted. The end plate 31 may be attached to the flange of the rotor shaft using appropriate fasteners 37. The rotor shaft 36 is supported on the main frame 9. In the example of Figure 3, the rotor shaft 36 may be rotatably mounted on the main frame 9 using a front bearing 8 and a rear bearing 14. In the example of Figure 3, the front bearing 8 and the rear bearing 14 may be a single tapered roller bearing.

[0031] The stator may be mounted on the main frame 9. The inner support 22 may be formed integrally with the main frame 9. The inner support 22 extends radially outward. The stator rim may be mounted on the inner support 22. In this particular example, the stator rim forms part of the central stator structure. The stator rim can support the stator coils 26. Sets of stator coils may be grouped within coil modules.

[0032] The end plate 31 and the central support structure 32 may be formed integrally as shown in the figure. The central support structure may form an external rotary rim that supports the permanent magnets 37. The set of permanent magnets 37 may be grouped together within a permanent magnet module.

[0033] Within the radially inward direction of the stiffening ring 33, elements of the cooling system may be arranged as cooling air ducts that supply cooling air toward the generator and extract that air after it has been heated by cooling the active components. Further space is occupied by electrical cables connected to the generator. Appropriate sealing may be provided to control the atmosphere inside the generator and to isolate the generator from the rest of the nacelle.

[0034] The generator 10 may further include a suitable cover for protecting and closing the generator (not shown in Figure 3).

[0035] Figure 4 shows a rear view of an example of a generator 10. In Figure 4, the inner support 22 and stator rim can be seen. Part of the stator central structure with the rim and the active components of the generator are closed by a stiffening ring comprising an outer ring or outer flange 34 and an inner ring or inner flange 35.

[0036] As shown in Figures 4 and 5, the removable outer annular segments 44, 44' may be mounted on the central support 32 and the inner annular flange 35. The removable annular segments 44, 44' may be mounted using removable fasteners such as bolts or screws. The central support or rotary rim 32 may be provided with appropriate fastening holes.

[0037] The inner ring 35 comprises multiple inner annular segments 49, 49' and a connecting plate 45, the connecting plate 45 being connected to the inner annular segments 49, 49'. The inner ring may be constructed from several segments. A segmented construction of the inner annular flange can be used to improve ergonomics, manufacturability, and transportability.

[0038] Each individual segment 49, 49' may have concave regions at both ends. The connecting plate 45 may be positioned in these concave regions and may be fixed to adjacent inner annular segments 49, 49' via bolts or similar fasteners.

[0039] In the examples in Figures 3 and 4, the inner ring is not supported at its radially inner end. That is, on the non-driven side of the generator rotor, the stiffener is not supported by a bearing or the like. As can be seen, the end plate on the other side of the generator is supported at its radially inner end. The main functions of the stiffener in these examples include providing rigidity, allowing access for repairs, and protecting the inside of the generator from the external environment.

[0040] As seen in Figure 6 with one of the outer annular segments 44' removed, the outer annular segments 44, 44' may be positioned above the recess or concave region 47 at the outer end of the inner annular segment 49. Although not shown in Figures 4-6, the space between the outer annular segments 44, 44' may be sealed to maintain a protected environment inside the generator. Such spaces may be sealed using silicone.

[0041] In some examples, the outer annular segments 44, 44' may be configured to accommodate a tool for removing the outer annular segment. Similarly, the inner ring may be configured to accommodate a tool for removing the outer annular segment.

[0042] The annular outer segment may be removed from the support 32 and inner annular flange 35 using a robot or other tool. For this purpose, the outer annular segment and / or the inner ring or flange 35 may be provided with suitable mounting holes 49 or fittings so that a robot or other tool can be attached. Once attached, the robot or other tool can remove fasteners such as screws or bolts to release the outer annular segment and disassemble the outer ring.

[0043] Referring particularly to Figures 6 and 7, the present disclosure further provides a method 100 for repairing components of an electromachine 10 having a rotor 13, a stator 12, and a radial air gap 39 between the rotor 13 and the stator 12. The method includes the step of removing a segment 44' of a stiffening ring 33 located on one side of the generator 10 in order to form an opening in the stiffening ring 33. The stiffening ring is not supported at its radially inner end.

[0044] The method includes the step of accessing the rotor 13 and / or stator 12 through an opening in the stiffening ring 33. The stiffening ring 33 comprises an outer ring 34 and an inner ring 35, and the step of removing a segment 44' of the stiffening ring 33 includes the step of removing a segment of the outer ring 34, while the inner ring 35 is not disassembled. Thus, an opening is formed in the stiffening ring, at least partially demarcated by the inner ring. In this example, the opening is demarcated by the rim 32 or central support, the components of the inner ring, and the adjacent outer annular segment.

[0045] In this example, the electrical machine 10 is a generator.

[0046] In some examples, one or more active components of the generator 10 may be removed through an opening in the stiffening ring 33. Stator coils or coil modules, or permanent magnets or permanent magnet modules, may be removed through the opening. These active components may be replaced with new active components.

[0047] In some examples, the inner ring may not be disassembled, while two or more segments of the outer ring may be removed. In some examples, multiple segments may be removed to access different sections of the generator simultaneously. Specifically, non-adjacent segments may be removed simultaneously to avoid localized rigidity loss.

[0048] In some examples, the step of removing a segment of the outer ring may include mounting a tool onto the stiffening ring and using the tool to separate the segment of the outer ring from the other segments of the outer ring. The tool may be a robot or other automated device that can be used to separate the segment, specifically to remove bolts or other fasteners from the segment. In some examples, mounting the tool may include mounting the tool onto the segments of the inner ring and / or outer ring, at least in part.

[0049] An example of method 100 for repairing the generator is shown in the block diagram of Figure 7. In block 110, a tool may be attached to the stiffening ring of the generator. In block 120, the outer ring segment of the stiffening ring may be removed using a tool, while the inner ring of the stiffener is disassembled in block 130, i.e., maintained intact. Thus, the inner ring can provide sufficient rigidity and strength so that the generator rotor does not deform and the air gap is not compromised.

[0050] After one or more segments of the outer ring are removed, block 140 provides access to the inside of the generator. In this example, the operator can reach inside the generator to inspect its components, specifically the active components. In this example, minor repairs can be performed without removing the active components.

[0051] In another example, in block 150, one or more active components may be removed through an opening formed by the removal of the outer ring segment. Next, in block 160, the removed active component may be replaced with a new component. The same opening may be used to introduce the new component and mount them to the stator or rotor. Finally, in block 170, the outer ring segment may be reattached. The segment may be assembled together with the inner ring and rotor rim. The space between a segment and an adjacent segment may be sealed. Once the repair or inspection is complete, the wind turbine can resume normal operation.

[0052] In this example, the stiffening ring may cover 20-60% of the generator rotor diameter. That is, 40-80% of the inner diameter of the generator is not covered by the stiffening ring.

[0053] In the example, the outer segment of the stiffening ring may have a (radial) width of 50-150% of the radial width of the inner segment. Specifically, the width may be 75-125% of the width of the inner segment. In the examples in Figures 4-6, the outer segment has approximately the same radial width as the inner segment, but the outer segment partially overlaps the inner segment.

[0054] Figure 8 shows a further example of an electromachine. In this example, the electromachine is a generator. The generator comprises a rotor 13 and a stator 12. The stator 13 radially surrounds the rotor 12, forming an overhang structure. The overhang structure is supported on one side of the rotor (downstream of the generator rotor 13) and not on the other side (upstream of the generator rotor 13).

[0055] The rotor 12 is operably connected to a wind turbine rotor (not shown, located on the left upstream side in Figure 8). The rotor 12 is supported by a stator 13 via one or more bearings 14. The rotor 12 may carry permanent magnets 37 on its rim. The stator may include a plurality of electrical coils 26. A radial air gap 39 is located between the rotor and the stator.

[0056] On the unsupported side of the stator 12, the stiffening ring comprises an outer ring 34 and an inner ring 35. On the supported side of the stator 12, an end plate 22 closes the generator. The stator 12 further comprises a central support 24 that bears the coils.

[0057] With respect to the rotor in Figure 4, the outer ring 34 of the stiffening ring comprises several removable outer segments. If it is necessary to access the inside of the generator to inspect, repair, or replace the active components of the generator, one or more segments of the outer ring can be removed. Thus, an opening is formed in the stiffening ring. The inner ring 35 remains intact and can partition the opening to provide the necessary rigidity to prevent deformation of the partially disassembled stator.

[0058] While only a few examples are disclosed herein, other substitutions, modifications, uses, and / or equivalents are possible. Furthermore, all possible combinations of the examples described are also covered. Therefore, the scope of this disclosure should not be limited by any particular example, but should be determined solely by a fair reading of the appended claims. [Explanation of Symbols]

[0059] 1 Wind Turbine 2 Wind Turbine Towers 3 Support surface 4 Nasser 5 Wind turbine rotor 6 hubs 7 rotor blades 8. Front bearing, rotor bearing 9. Bed plate or support frame, main frame, rotor 10. Generators, electrical machinery 12. Generator stator, rotor 13 Generator Rotor 14 Rear bearing, generator bearing 20 Yaw System 22 End plates, inner supports 24 Central support 26 Stator coil, electrical coil 31 End plate, radial support 32 Central support, central rim, rim, central support structure 33. Stiffening rings, stiffening flanges 34 Outer ring, outer flange 35 Inner ring, inner flange, inner annular flange 36 Rotor Shaft 37 Permanent magnets, fasteners 39 Radial air gap 44 Outer ring segment, outer annular segment 44' Outer annular segment 45 Joining plate 47 Concave area 49 Inner annular segment, mounting hole 49' Inner annular segment 100 ways

Claims

1. An electric machine (10) comprising a rotor (13), a stator (12) and a radial air gap (39) between said rotor (13) and said stator (12), one of the rotor (13) and the stator (12) comprises an end plate (31) on one side of the electric machine (10), a central support (32) radially surrounding the rotor (13) and the stator (12), and further comprises a stiffening ring (33) on the opposite side of the electric machine (10); The stiffening ring (33) is unsupported at its radially inner end, The stiffening ring (33) comprises an outer ring (34) connected to the central support (32) and an inner ring (35) connected to the outer ring (34); The outer ring (34) comprises a plurality of removably attached outer annular segments (44). An electric machine (10).

2. The electric machine (10) of claim 1, wherein the removably mounted outer annular segment (44) is mounted to the central support (32) and the inner ring (35).

3. The electric machine (10) of claim 1, wherein the inner ring (35) comprises a plurality of inner annular segments (49, 49') and a joining plate (45), the joining plate (45) being connected to the inner annular segments (49, 49').

4. The electric machine (10) of claim 1, wherein the outer annular segment (44) is configured to receive a tool for removing the outer annular segment (44).

5. The electric machine (10) of claim 1, wherein the inner ring (35) is configured to receive a tool for removing the annular outer segment (44).

6. The electric machine (10) of claim 1, which is a generator (10).

7. The generator (10) of claim 6, wherein the end plate (31) is connected to a rotor shaft (36).

8. The generator (10) of claim 7, wherein the rotor shaft (36) is supported on a main frame (9).

9. The generator (10) of claim 6, wherein the rotor shaft (36) is supported by a front bearing (8) and an aft bearing (14).

10. 7. The generator (10) of claim 6, wherein the stator (12) radially surrounds the rotor (13), and the end plate (22) of the stator (12) is arranged on a side of the rotor (13) on which a wind turbine rotor (5) is arranged.

11. A wind turbine (1) comprising a generator (10) according to any one of claims 6 to 10.

12. A method (100) for repairing a component of an electric machine (10) according to any one of claims 1 to 10, comprising: removing a segment (44) of the stiffening ring (33) on one side of the electric machine (10) to form an opening in the stiffening ring (33); accessing the rotor (13) and / or the stator (12) through the openings in the stiffening ring (33); Including, The method (100), wherein removing the segments (44) of the stiffening ring (33) comprises removing the segments (44) of the outer ring (34) while the inner ring (35) is not disassembled.

13. The method (100) of claim 12, comprising removing two or more segments (44) of the outer ring (34) while the inner ring (35) is not disassembled.

14. The method (100) of claim 12, further comprising removing one or more active components (26, 37) of the generator (10) through the opening in the stiffening ring (33).

15. 13. The method (100) of claim 12, wherein removing the segments (44) of the outer ring (34) comprises attaching a tool to the stiffening ring (33) and disassembling the segments (44) of the outer ring (34) using the tool.

Images