Wind turbine powertrain

Abstract

The invention describes a wind turbine powertrain comprising: a planetary gearbox (4) for converting rotation of a low speed shaft (2) into rotation of a high speed gearbox output shaft (44); an axial sleeve (42S) extending axially outward from the gearbox (4) and enclosing the gearbox output shaft (44); a generator (6) coaxially mounted to the gearbox (4), the generator (6) comprising a rotor (64) arranged around a cylindrical sleeve (42S); a bearing box (8) arranged between the gearbox (4) and the generator (6), the bearing box (8) comprising a plurality of roller bearings (80) held between a stationary bearing portion (8S) and a swivel bearing portion (8R); and a torque transfer assembly (1) for transferring rotation of the gearbox output shaft (44) to the generator rotor (64), the torque transfer assembly (1) incorporating the swivel bearing portion (8R) and being arranged to extend between the non-driven end of the gearbox output shaft (44) and the generator rotor (64). A method of assembling such a wind turbine powertrain is also described.

Description

Background Technology

[0001] The drivetrain of a wind turbine may include a low-speed shaft rotated by an aerodynamic rotor, a gearbox with a high-speed output shaft, and a generator connected to the high-speed shaft. In known types of medium-speed drivetrains, the gearbox is a multi-stage planetary gearbox, and the generator is coaxially mounted to the gearbox. In this implementation, the low-speed shaft, the planetary gearbox sun shaft, and the generator rotor substantially share a common axis of rotation. Since the low-speed shaft and the gearbox sun shaft can be hollow, coaxial alignment of the drivetrain components can be achieved by arranging hollow tubes within the internal spaces of the low-speed shaft, gearbox, and generator, and using these hollow tubes as cable conduits for electrical cables (e.g., cables from the wind turbine controller to the pitch system of the rotor blades) leading to the hub.

[0002] Instead of fixing the generator housing to the base plate or other fixed structure, the generator housing is cantilevered to the gearbox housing. This cantilever connection between the generator and gearbox has the effect that vibrations from the generator are transmitted to the wind turbine tower via the gearbox. This can amplify certain undesirable frequencies. A relatively long gearbox output shaft can help reduce noise from the powertrain. However, implementing a cantilevered gearbox / generator design with a long output shaft is challenging because the spline connection at the end of the gearbox output shaft requires oil lubrication (including connections to the oil supply and discharge devices), but this spline connection is actually located within the generator space. This is because in tilted powertrains (a common design in large wind turbines), the gearbox-generator bearing between the output shaft and the generator is actually located at the lowest point of the oil lubrication circuit. A longer output shaft shifts this lowest point even further downwards, making it difficult to achieve discharge (which is typically at the lowest point). For these reasons, cantilevered powertrain designs for large wind turbines typically implement short gearbox output shafts.

[0003] In cantilevered gearbox-generator connections, the bearing assembly, primarily used to support the gearbox output shaft, can also be used to center and support the generator rotor. It is advantageous to implement this "gearbox-generator bearing" in the form of a box that can be treated as a single unit. It is desirable to use two parallel roller bearings (e.g., two tapered roller bearings) spaced apart and enclosed in the bearing box to support the weight of the generator rotor and transfer force from the sun gear of the last gearbox planetary gear to the generator rotor. Such a bearing box can have an axial length of 0.5–1 m and a mass of approximately 1,000 kg. In prior art methods, the bearing box housing is typically fixed to the gearbox housing or the generator housing.

[0004] In known cantilever designs, the placement of the gearbox / generator bearings may require complete generator disassembly to access components requiring maintenance. This can involve a complex and time-consuming process of removing and disassembling individual components of the gearbox / generator bearings. Since it is not uncommon for internal components of the generator or gearbox to require maintenance at some point, the cost of a lengthy disassembly and reassembly process can significantly impact the total energy cost.

[0005] Therefore, the object of the present invention is to provide a power transmission system configuration that facilitates simple maintenance of the generator and gearbox output shaft.

[0006] This objective is achieved by the stated wind turbine powertrain and by the stated methods of assembling and disassembling the powertrain. Summary of the Invention

[0007] According to the present invention, a wind turbine power transmission system includes: a planetary gearbox for converting rotation of a low-speed shaft into rotation of a high-speed gearbox output shaft; an axial sleeve extending outward from the non-driving end of the gearbox and enclosing the gearbox output shaft; and a generator coaxially mounted to the gearbox, the generator including a rotor arranged around the axial sleeve. Since the gearbox output shaft also extends from the gearbox in a downwind direction, the axial sleeve effectively surrounds the gearbox output shaft. The power transmission system also includes: a generator coaxially mounted to the planetary gearbox having a rotor arranged around the axial sleeve; a bearing housing disposed between the gearbox and the generator, the bearing housing including a plurality of roller bearings held between a stationary bearing portion and a rotating bearing portion; and a torque transmission assembly including an outer portion extending around the outer side of the axial sleeve and connected to an outer portion of the generator rotor, an inner portion extending around the inner side of the axial sleeve and connected to an inner portion of the gearbox output shaft, and a radial portion extending between the downwind ends of the inner and outer portions. The torque transmission assembly extends between the generator rotor and the gearbox output shaft, incorporating or connecting the rotary bearing portion into it. That is, the external portion of the torque transmission assembly and the rotary bearing portion can be integrated or connected together. In this way, the torque transmission assembly transmits the rotation of the gearbox output shaft to the generator rotor.

[0008] Since the internal portion of the torque transmission assembly is connected to the gearbox output shaft, and the external portion of the torque transmission assembly is connected to the generator rotor, the connection between the gearbox and the generator can be viewed as an arrangement of nested annular components: an axial sleeve, the internal portion of the torque transmission assembly, and the external portion of the torque transmission assembly. The axial sleeve can be formed as an extension of the gearbox housing at its non-drive end, or it can be mounted to the non-drive end of the gearbox housing. In the following text, the terms "axial sleeve," "gearbox housing sleeve," "cylindrical sleeve," and simply "sleeve" are used interchangeably.

[0009] The advantage of the powertrain of this invention is that it allows direct access to powertrain components that were previously difficult to reach. For example, the configuration of this invention allows the gearbox output shaft to be removed without completely disassembling the bearings. This saves the time that would otherwise be required to remove the bearings to access the output shaft for maintenance procedures and to reassemble the bearings after the maintenance procedures are completed.

[0010] Another advantage of this invention is that the novel method of interface between the gearbox and the generator facilitates changing the length of the gearbox output shaft. It is desirable to adjust the length of the gearbox output shaft, thereby adjusting its stiffness to achieve optimal levels of generator vibration and noise. The gearbox output shaft can have a length of approximately 1 m or more (extending to the downwind end of the corresponding long axial sleeve). Therefore, the powertrain of this invention may help reduce wind turbine noise, thereby making it easier for wind turbines to comply with noise regulations at permissible entry points.

[0011] Particularly advantageous embodiments and features of the invention are given by the dependent claims, as disclosed in the following description. Features from different claim classes may be combined as appropriate to give additional embodiments not described herein.

[0012] The hub of an operating wind turbine is typically always aligned so that the aerodynamic rotor faces the wind, and it is generally customary to refer to the front end of the wind turbine's powertrain components as its "drive end" or "upwind end," and the rear end of such components as its "non-drive end" or "downwind end." This convention is followed in this article.

[0013] As explained above, the connection between the gearbox and the generator can be viewed as an arrangement of nested annular components. The overall shape of the torque transmission assembly is annular with a U-shaped cross-section, and the torque transmission assembly essentially "wraps" around the axial sleeve. The torque transmission assembly should be understood to include a rotary bearing portion either by directly incorporating the rotary bearing portion into the torque transmission assembly or by securing the rotary bearing portion to the torque transmission assembly using fasteners.

[0014] For example, the swivel bearing portion can be the outer portion of the torque transmission assembly that extends from the generator rotor to the radial portion of the torque transmission assembly. In this case, both the inner and radial portions of the torque transmission assembly are used to transmit torque from the generator output shaft to the swivel bearing portion, which in turn transmits the torque to the generator rotor.

[0015] In another embodiment, the rotary bearing portion is not directly part of the torque transmission assembly. Instead, the generator rotor may include an internal annular support structure extending from the drive end of the rotor to the radial portion of the torque transmission assembly, such that this annular support structure acts as the outer portion of the torque transmission assembly. The downstream end of the rotary bearing portion may be fixed to the radial portion of the torque transmission assembly. In this case, both the internal and radial portions of the torque transmission assembly are used to transmit torque from the generator output shaft to the generator rotor, while the rotary bearing portion only transmits non-torsional loads.

[0016] In one embodiment of the powertrain of the present invention, the stationary bearing portion is mounted to the outside of the axial sleeve, and the outer portion of the torque transmission assembly includes or is connected to the rotary bearing portion. In such an embodiment, the inner portion of the torque transmission assembly is arranged on the inner side of the axial sleeve and is preferably connected to the gearbox output shaft by a spline arrangement. In this embodiment, a seal is preferably arranged between the rotary bearing portion and the stationary bearing portion at the upwind end of the bearing housing. This seal can be fixed to either the rotary bearing portion or the stationary bearing portion.

[0017] In an alternative embodiment of the powertrain of the present invention, the stationary bearing portion is mounted inside the axial sleeve, and the internal portion of the torque transmission assembly includes or is connected to the rotary bearing portion. The stationary bearing portion is preferably secured to the axial sleeve using a plurality of axially arranged fasteners that can be screwed into axially threaded holes provided in the annular downwind face of the axial sleeve. In an exemplary embodiment, the internal portion of the torque transmission assembly may have a cylindrical shape, fitted between the gearbox output shaft and the rotary bearing portion, and connected to the gearbox output shaft by a spline arrangement. The radial portion of the torque transmission assembly may be secured to the rotary bearing portion by a plurality of axially arranged fasteners that can be screwed into axially threaded holes provided in the downwind face of the rotary bearing portion. In these configurations, a seal between the rotary bearing portion and the stationary bearing portion is preferably arranged at the downwind end of the bearing housing.

[0018] In a preferred embodiment of the invention, the inner, radial, and outer portions of the torque transmission assembly are manufactured as a single component. This implementation of the torque transmission assembly can transmit torque from the gearbox output shaft to the generator rotor particularly efficiently and ensures that only non-torque loads are transmitted to the rotating bearing portion. Therefore, this configuration can extend the bearing's life.

[0019] In a multi-part implementation, the radial portion can be an extension of either the inner or outer portion. The radial portion extends substantially in a radial direction relative to the axis of rotation of the powertrain. As will become clear from the figures, the torque transmission assembly portion shaped to include the radial extension is typically the "non-bearing portion" of the torque transmission assembly.

[0020] In a particularly preferred embodiment of the invention, the bearing housing is connected to the gearbox's lubrication circuit. The fluid lines (oil supply and discharge lines) of the lubrication circuit are arranged to extend from the gearbox through the interior of the generator to the stationary bearing section. The lubrication lines and / or discharge lines may be included in the torque transmission assembly and the rotating bearing section. In a particularly preferred embodiment of the invention, the powertrain includes a splined connection between the gearbox output shaft and the internal portion of the torque transmission assembly. This splined connection requires lubrication and is preferably incorporated into the aforementioned gearbox lubrication circuit. Therefore, the powertrain of the present invention presents a way to overcome the problem described in the introduction (i.e., how to provide lubrication to the splined connection of a long gearbox output shaft).

[0021] In a preferred embodiment of the invention, the powertrain is configured to house a cable conduit or "pitchtube." This cylindrical, hollow cable conduit or tube can be fixed to the planetary carrier of the first stage of the gearbox and rotates at the same speed as the low-speed main shaft of the powertrain. The downwind end of the cable conduit can protrude a certain distance from the downwind end of the gearbox output shaft. Since the rotational speed of the gearbox output shaft is faster than that of the cable conduit (the cable conduit rotates at the same speed as the low-speed shaft), the torque transmission assembly is preferably rotatably isolated from the cable conduit. In a preferred embodiment of the invention, the powertrain includes an additional bearing between the cable conduit and the torque transmission assembly. This cable conduit bearing may be referred to herein as a "support bearing" and may be implemented as a roller bearing or equivalent. This support bearing is also preferably connected to the gearbox lubrication circuit.

[0022] The rigidity of the cable conduit can be locally increased, for example, by arranging a tightly fitted annular bushing or cuff with high rigidity around the cable conduit adjacent to the downwind end of the gearbox output shaft. The form fit between the cable conduit and the annular support cuff ensures that the cuff and the cable conduit rotate as a whole.

[0023] The powertrain may also include seals between the torque transmission assembly and the cable conduit, or between the torque transmission assembly and the annular sleeve. These seals can be implemented as double-lip seals to prevent gearbox oil from entering the generator and to prevent contaminants from the generator from entering the confined space. The cable conduit bearings and seals can be attached to relevant portions of the nested torque transmission assembly, for example, to the inner surface of the inner portion.

[0024] After the drive end of the generator housing (already carrying the armature winding) is cantilevered to the non-drive end of the gearbox, the assembly of the wind turbine powertrain of the present invention can be carried out through the following exemplary sequence of steps: the generator rotor (already carrying the field magnet) is positioned around the axial gearbox housing sleeve and temporarily secured to the gearbox housing and / or generator housing using suitable fastening devices. Then, the bearing housing is moved into the generator, and the stationary bearing portion is secured to the sleeve. Depending on the design choice, the rotating bearing portion will be assigned to the internal portion or the external portion of the torque transmission assembly. As explained above, the torque transmission assembly can be a single component or can comprise two or more components secured by fasteners. After this assembly stage is completed, the external portion of the torque transmission assembly (which, depending on the selected design, can be a rotating bearing portion, a cylindrical rotor support structure, or part of a single torque transmission assembly) is secured to the generator rotor (using threaded fasteners); and the internal portion of the torque transmission assembly (which, depending on the selected design, can be a rotating bearing portion or part of a single torque transmission assembly) is secured to the gearbox output shaft (by means of a spline arrangement and threaded fasteners). Assembly is completed as follows: attach the brake disc to the end face of the torque transmission assembly, release the temporary fastening device, and seal the generator housing with a suitable cover or end plate.

[0025] During the lifespan of a wind turbine, it may be necessary to perform maintenance on the gearbox output shaft, gearbox-generator bearings, or another component of this part of the powertrain. According to the invention, maintenance of the aforementioned powertrain can be performed, for example, as follows: after removing the generator housing end plate, temporarily securing the generator rotor as described above, and removing the brake disc, additional components can be removed to access the part requiring maintenance. For example, support sleeves, seals, and bearings can be removed from around the cable conduit to access the axial fasteners from the gearbox output shaft to the torque transmission assembly. Depending on how the torque transmission assembly is constructed (constructed as a single part or comprising several parts), the torque transmission assembly can then be removed after releasing the appropriately axially oriented fasteners.

[0026] During the lifespan of a wind turbine, it may be necessary to replace the generator rotor and / or stator. The maintenance method of this invention can involve a generator replacement procedure, which can be implemented as follows: After removing the generator housing end plate and temporarily securing the generator rotor to the generator housing, remove the fasteners as needed to release the external portion of the torque transmission assembly from the generator rotor. The external portion of the torque transmission assembly can then be removed from inside the generator. Then, another set of fasteners is removed to release the generator housing from the gearbox housing. The generator rotor and stator can then be removed, leaving the bearing housing in place on the axial sleeve. Therefore, the powertrain design of this invention facilitates a favorable, quick, and simple method for replacing the rotor and / or stator without the time-consuming and costly steps of disassembling and reassembling the gearbox-generator bearings.

[0027] During the lifespan of a wind turbine, it may be necessary to replace the gearbox output shaft. The maintenance method of this invention may involve a gearbox output shaft replacement procedure, which can be implemented as follows: After removing the generator housing end plate and the brake disc, other components (e.g., cable conduit support clamps, seals, and bearings) can be removed as described above. Depending on how the torque transmission assembly is constructed (either as a single part or comprising several parts), this torque transmission assembly can then be removed after releasing the appropriate axially oriented fasteners. The gearbox output shaft can then be removed, leaving the bearing housing in place on the axial sleeve.

[0028] If it is desired to remove the gearbox-generator bearing, then remove the additional fasteners to release the bearing housing from the axial sleeve. The bearing housing can then be pulled away from the axial sleeve and removed from inside the generator. Attached Figure Description

[0029] Other objects and features of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. However, it should be understood that the drawings are designed for illustrative purposes only and are not intended to limit the scope of the invention.

[0030] Figure 1 An embodiment of the power transmission system of the present invention is shown; Figure 2 - 9 shows Figure 1 Various gearbox-generator installation configurations and disassembly modes of the power transmission system; Figure 10 This illustrates the installation arrangement of the gearbox and generator in a conventional powertrain.

[0031] In the accompanying drawings, similar reference numerals always refer to similar objects. Objects in the accompanying drawings are not necessarily drawn to scale. Detailed Implementation

[0032] Figure 1An embodiment of the wind turbine power transmission system 1 of the present invention is shown. The power transmission system 1 includes a planetary gearbox 4 for converting the rotation of a low-speed shaft 2 into the rotation of a high-speed gearbox output shaft. It is assumed that the low-speed main shaft of the wind turbine drives the planet carrier in the first stage of the gearbox 4. The gearbox output shaft is connected to or integrated with the sun gear of the last stage of the gearbox. A generator 6 is cantilevered and coaxially mounted to the gearbox 4. The generator rotor is driven by the gearbox output shaft.

[0033] This invention proposes an improvement to the connection between the generator and the gearbox in this powertrain, and Figure 2 -8 shows the various ways in which torque transmission component 1 can be implemented.

[0034] The attached diagram illustrates a cantilever mounting arrangement for connecting the generator housing 62 to the gearbox housing 42. It should be understood that the rotation axis 2R of the powertrain is actually inclined at approximately 6° relative to the horizontal plane H, as shown in the diagram. Figure 2 As indicated in the document.

[0035] In the embodiment shown here, the gearbox housing 42 includes an axial sleeve 42S extending axially into the generator 6 in the downwind direction. In other embodiments, the axial sleeve may be mounted to the gearbox housing 42. The gearbox output shaft 44 extends toward the downwind end of this axial sleeve 42S. The axial sleeve 42S may be formed to enclose a bearing housing 8, or be enclosed by a bearing housing 8. Each figure shows a cross-section at the joint between the gearbox 4 and the generator 6, showing the axial sleeve 42S extending from the non-drive end 4 of the gearbox housing 42. NDE Extending outwards in the downwind direction and into the generator 6. The axial sleeve 42S can engage with the non-drive end 4 of the gearbox housing 42. NDE It is formed as a single piece. Since the gearbox output shaft 44 also extends from the gearbox 4 in the downwind direction, the sleeve 42S actually surrounds the gearbox output shaft 44. Figure 1 In embodiment 5, the gearbox-generator bearing 8 is arranged on the outer side of the axial sleeve 42S. Figures 6 to 9 In one embodiment, the gearbox-generator bearing 8 is arranged inside the axial sleeve 42S.

[0036] The generator rotor 64 may be substantially cylindrical or barrel-shaped, closed at its driving end and open at its non-driving end. The generator rotor 64 may carry the magnet 6F around its outer annular surface, and the windings 6A may be arranged accordingly around the inner annular surface of the generator housing 42.

[0037] The accompanying drawings also show a bearing housing 8, which comprises two tapered roller bearings 80 arranged in parallel between a stationary bearing portion 82 and a rotating bearing portion 84. The bearing housing 8 can be treated as a single component.

[0038] The torque transmission assembly 1 is used to connect the generator rotor 64 to the gearbox output shaft 44 and allows the entire bearing housing 8 to be removed from the generator 6. As will become clear from the figures, the torque transmission assembly 1 includes the rotating portion 84 of the bearing. The torque transmission assembly 1 can be considered as an annular component with a U-shaped cross-section, i.e., two nested cylindrical portions 12, 14 connected by an annular end plate 13, which is assembled around an axial sleeve 42S.

[0039] This torque transmission assembly 1 includes an outer cylindrical portion 12 extending around the outer side of the sleeve 42S and connected to the generator rotor 64, and an inner portion 14 extending around the inner side of the sleeve 42S and connected to the gearbox output shaft 44. In each embodiment, the torque transmission assembly 1 includes portions that can be detached from each other and / or removed from another part of the powertrain, allowing these portions to be removed from the generator, thereby allowing removal of the generator rotor without removing the bearing housing 8, or facilitating access to the gearbox output shaft 44 without removing the bearing housing 8, etc.

[0040] The accompanying drawing also shows the cable conduit 9 extending beyond the axial sleeve 42S. As explained above, during wind turbine operation, the cable conduit 9 rotates at the same speed as the low-speed shaft 2 and is used to carry the cables of the pitch system located at the hub of the wind turbine.

[0041] exist Figure 2 In the torque transmission assembly 1, the inner cylindrical portion 14 is mounted to the gearbox output shaft 44 by a spline arrangement 78 and a ring arrangement of fasteners 72. The outer cylindrical portion 12 of the torque transmission assembly 1 is mounted to the generator rotor 64 by a ring arrangement of fasteners 74.

[0042] In this embodiment, the stationary portion 82 of the bearing housing 8 extends around the outer side of the sleeve 42S and is mounted to the sleeve 42S by an annular arrangement of fasteners 73. The rotating portion 84 of the bearing housing 8 extends around the stationary portion 82 and is mounted to the generator rotor 64 by an annular arrangement of fasteners 74. Here, the rotating bearing portion 84 is the outer portion 12 of the torque transmission assembly 1. The inner portion 14 and the annular end plate 13 of the torque transmission assembly 1 are implemented as a single part, which is mounted to the rotating bearing portion 84 by an annular arrangement of fasteners 75, i.e., mounted to the outer portion 12 of the torque transmission assembly 1.

[0043] The accompanying drawing shows the entire generator assembly with generator end plate 69 and brake disc 68. The drawing also shows aligned through openings in the gearbox housing 42 and bearing housing 8, providing a fluid passage 50 for connection to the gearbox lubrication system. In this way, the spline joint 78 can be easily integrated into the gearbox lubrication system, even though it is positioned very low due to the long gearbox output shaft and is practically located in the center of the generator.

[0044] In this type of configuration, the seal 8S is arranged at the windward end of the bearing housing 8 between the rotating bearing portion 84 and the stationary bearing portion 82. The seal 8S rotates together with the rotating bearing portion 84.

[0045] Figure 3 Illustration Figure 2 This is part of the disassembly of the configuration. The end plate 69 and brake disc have been removed, and the generator rotor 64 has been temporarily secured to the gearbox housing 42 using an arrangement of axially oriented fasteners 71.

[0046] Next, remove the seal 96 and support bearing 94 from the cable conduit 9. Then, remove the annular end plate 13 of the torque transmission assembly 1 by removing fastener 75. In a subsequent step, the bearing housing 8 can be removed by removing fasteners 73 and 74 and removed as a single piece from inside the generator 6. Alternatively, the bearing 8 can be left in place, and maintenance procedures can be performed on the now accessible gearbox output shaft 44.

[0047] Figure 4 Showing something similar Figure 2 This figure shows an embodiment of the embodiment. It illustrates the support bearing 94 between the internal portion 14 of the torque transmission assembly 1 and the cable conduit 9. The figure also shows the bore 86 that allows the gearbox-generator bearing 8 and the support bearing 94 to connect to the lubrication circuit of the gearbox 4.

[0048] Figure 5 Showing something similar Figure 2 - Another embodiment of the embodiment shown in -4. Here, the annular end plate 13 of the torque transmission assembly 1 is wider than the bearing housing 8 and is fixed to the rotating bearing portion 84 and the non-driving end 6 of the generator. NDE With driver 6 DE The two support structures 64S extend between each other, with the support structure 64S terminating at the generator rotor 64. Here, the annular support structure 64S serves as the outer part 12 of the torque transmission assembly 1.

[0049] This figure also illustrates another preferred embodiment of the invention, wherein, as shown here, the axial sleeve 42S is mounted to the gearbox housing 42 using an annular arrangement of fasteners. The figure also shows aligned through openings in the gearbox housing 42, the axial sleeve 42S, and the bearing housing 8, providing a fluid passage 50 for connection to the gearbox lubrication system.

[0050] In the following embodiment, the gearbox-generator bearing 8 is arranged inside the axial sleeve 42S.

[0051] exist Figure 6 In this configuration, the torque transmission assembly 1 includes an inner cylindrical body 14, a radial portion 13, and an outer cylindrical body 12. These portions can be formed as a single component with a U-shaped cross-section. The rotating portion 84 of the bearing housing 8 is bolted to the inner cylindrical body 14 by an arrangement of axially oriented fasteners 75. In this type of configuration, a seal 8S is arranged at the downwind end of the bearing housing 8 between the rotating bearing portion 84 and the stationary bearing portion 82.

[0052] Alternatively, as shown in 7, the torque transmission assembly 1 includes a rotating bearing portion 84 as its internal portion 14. The rotating portion 84 of the bearing housing 8 is bolted to the radial portion 13 of the torque transmission assembly 1 by an arrangement of axially oriented fasteners 75.

[0053] In both embodiments, the outer cylindrical body 12 is bolted to the generator rotor 64 by an arrangement of axially oriented fasteners 74. In this way, during operation of the wind turbine, rotation of the gearbox output shaft 44 is transmitted to the torque transmission assembly 1 and the generator rotor 64. The stationary portion 82 of the bearing housing 8 extends around the rotating portion 84 and is mounted to the inside of the sleeve 42S by an annular arrangement of axially oriented fasteners 73. Figure 7 The diagram also shows a through opening 50 in the gearbox housing 42 and aligned through openings 52 in the axial sleeve 42S and the stationary bearing portion 82. Thus, a fluid supply line 51 extending through the interior of the generator to the gearbox lubrication system connects the interior of the bearing housing 8 to the gearbox lubrication system. Similarly, a through opening 54 allows lubricating oil to return to the gearbox lubrication system via a fluid discharge line 55.

[0054] Figure 8A similar embodiment is shown. Here, instead of providing the torque transmission assembly 1 as a single part, the inner cylindrical body 14 and the radial portion 13 are formed as a single piece and connected to the outer cylindrical body 12 by axially oriented fasteners 76. When assembled, these portions 12, 13, and 14 form a component with a substantially U-shaped cross-section. Here, the rotating portion 84 of the bearing housing 8 is also bolted to the inner cylindrical body 14 by an arrangement of axially oriented fasteners 75. The outer cylindrical body 12 is bolted to the generator rotor 64 by an arrangement of axially oriented fasteners 74. The stationary portion 82 of the bearing housing 8 extends around the rotating portion 84 and is mounted to the inside of the sleeve 42S by an annular arrangement of axially oriented fasteners 73. This figure also shows how the generator rotor 64 can be kept stationary for maintenance procedures. Here, the generator transport mounting bracket 62F secures the rotor 64 to the generator housing 62.

[0055] Figure 9 Illustration Figure 8 This is another stage in the disassembly of the configuration. The outer part 12 of the torque transmission assembly 1 is removed from the inner part 14 by removing fastener 76. Then, after releasing fastener 74, the outer part 12 can be pulled out of the generator 6. After releasing the appropriate fasteners, the generator rotor 64 and generator housing 62 (including the field 6F and armature 6A) are removed.

[0056] In subsequent steps, the seal 96, support sleeve 92, and support bearing 94 of the cable conduit 9 can be removed. Then, the axial fastener 79 for securing the inner cylindrical body 14 of the torque transmission assembly 1 to the gearbox output shaft 44 can be accessed and released, thereby allowing the removal of the radial portion 13 and the inner cylindrical body 14 of the torque transmission assembly.

[0057] In a subsequent step, the bearing housing 8 can be released by removing fastener 73, thereby allowing removal of the bearing housing 8 from inside the generator 6. Alternatively, the bearing housing 8 can be removed together with the torque transmission assembly components 12, 13, and 14. Of course, when performing maintenance procedures on the gearbox output shaft 44, the bearing 8 can remain in the appropriate position on the axial sleeve 42S.

[0058] Figure 10 The mounting arrangement of the gearbox 400 and generator 350 in a prior art powertrain is shown. Here, in order to access the output shaft 414, it is necessary to disassemble the generator, that is, to remove the generator rotor 360 together with the inner hub 480. Since the roller bearings 385A and 385B are not included between the stationary and rotating structures but are separate components, the disassembly and assembly phases involve handling the roller bearings 385A and 385B separately, thus making any maintenance procedures complex and time-consuming.

[0059] Although the invention has been disclosed in the form of preferred embodiments and variations thereof, it will be understood that many additional modifications and changes can be made thereto without departing from the scope of the invention.

[0060] For clarity, it should be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “including” does not exclude other steps or elements.

Claims

1. A power transmission system for a wind turbine, comprising: - A planetary gearbox (4) for converting the rotation of the low-speed shaft (2) into the rotation of the high-speed gearbox output shaft (44); - An axial sleeve (42S) extending axially outward from the gearbox (4) and enclosing the gearbox output shaft (44); - A generator (6) coaxially mounted to the gearbox (4), the generator (6) including a rotor (64) arranged around the cylindrical sleeve (42S); - A bearing housing (8) disposed between the gearbox (4) and the generator (6), the bearing housing (8) comprising a plurality of roller bearings (80) held between a stationary bearing portion (8S) and a rotating bearing portion (8R); and - A torque transmission assembly (1) for transmitting rotation of the gearbox output shaft (44) to the generator rotor (64), the torque transmission assembly (1) incorporating the rotary bearing portion (8R) and being arranged to extend between the non-drive end of the gearbox output shaft (44) and the generator rotor (64).

2. The wind turbine power transmission system according to the preceding claim, wherein, The torque transmission component (1) includes - An outer portion (12) extending around the outer side of the cylindrical sleeve (42S) and connected to the outer portion of the generator rotor (64); - An inner portion (14) extending around the inner side of the cylindrical sleeve (42S) and connected to the inner portion (14) of the gearbox output shaft (44); and - The radial portion (13) between the outer portion (12) and the inner portion (14).

3. The wind turbine power transmission system according to any one of the preceding claims, wherein, The torque transmission assembly (1) includes two or more structurally separate parts (12, 13, 14).

4. The wind turbine power transmission system according to claim 1 or claim 2, wherein, The torque transmission component (1) is a single-piece structure.

5. The wind turbine power transmission system according to any one of the preceding claims, wherein, The bearing housing (8) is arranged around the outside of the cylindrical sleeve (42S) or around the inside of the cylindrical sleeve (42S).

6. The wind turbine power transmission system according to any of the preceding claims, comprising a spline connection (78) between the gearbox output shaft (44) and the internal portion (14) of the torque transmission assembly (1).

7. The wind turbine power transmission system according to any of the preceding claims, wherein the bearing housing (8) is connected to the lubrication circuit of the gearbox (4).

8. The wind turbine power transmission system according to the preceding claim, comprising fluid lines (51, 55) and passages (50, 52, 54) arranged to connect the lubrication circuit of the gearbox (4) to the interior of the bearing housing (8).

9. A wind turbine powertrain according to any of the preceding claims, comprising a cable conduit (9) extending through the powertrain and arranged to protrude from the gearbox output shaft (44).

10. The wind turbine power transmission system according to claim 9, comprising a support sleeve (92) and / or a bearing (94) and / or a seal (96) disposed between the cable conduit (9) and the torque transmission assembly (1).

11. A method for assembling a wind turbine powertrain according to any one of claims 1 to 10, the method comprising the steps of: - Install the bearing housing (8) onto the cylindrical sleeve (42S); - Connect the internal portion (14) of the torque transmission assembly (1) to the gearbox output shaft (44); - The generator rotor (64) is arranged around the cylindrical sleeve (42S); - The rotary bearing portion (8R) is incorporated into the torque transmission assembly (1); as well as - Connect the torque transmission assembly (1) to the generator rotor (64).

12. The method according to the preceding claim, wherein, The powertrain includes a cable conduit (9), and the assembly of the powertrain includes the steps of providing a support sleeve (92) and / or a bearing (94) and / or a seal (96) between the cable conduit (9) and the torque transmission assembly (1).

13. The method according to claim 11 or claim 12, comprising the step of connecting the bearing housing (8) to the lubrication circuit of the gearbox (4).

14. A method for maintaining the power transmission system of a wind turbine according to any one of claims 1 to 10, the method comprising the following steps: - The generator rotor (64) is fixed to the power transmission housing (42, 62); - Remove the torque transmission assembly (1); - Separate the torque transmission assembly (1) from the rotary bearing portion (8R); as well as - Remove the bearing housing (8) from the generator (6); and / or - Remove the torque transmission assembly (1) from the generator (6); and / or - Remove the generator rotor (64).

15. The method according to the preceding claim, wherein, The generator rotor (64) is fixed to the generator housing (62), and the step of removing the generator rotor (64) includes removing the entire generator (6) while leaving the bearing housing (8) in the proper position on the cylindrical sleeve (42S).

Images