Drive train for a wind turbine comprising a torque limiter, wind turbine

Abstract

A drive train for a wind turbine is provided. The drive train includes a torque limiter assembly, which includes a torque limiter. The torque limiter includes: a first clamping disc, a friction disc, a second clamping disc and a preloading device. The clamping disc and the friction disc are configured so that the clamping disc frictionally transmits torque to the friction disc. The torque limiter assembly also includes a torque shaft and a hub shaft. The torque shaft is connected to a rotor of the wind turbine, and the hub shaft is connected to a generator rotor of a generator. The friction disc is bolted to the hub shaft from the downwind side via interface bolts so that the torque limiter can be integrally removed from the hub shaft. A wind turbine is also provided.

Description

Technical Field

[0001] The invention relates to a drive train of a wind turbine and to a wind turbine. Background Art

[0002] Wind is one of the most important renewable energy technologies. Wind turbines (also called wind-driven power plants, wind turbine generators or wind energy converters) are increasingly deployed in large-scale offshore wind farms. There are many technical challenges associated with these offshore wind farms, such as, for example, the assembly and transportation of components, the erection of wind turbines in the sea and the maintenance of wind turbines.

[0003] EP 1 445 484 A1 discloses an overload clutch for a working machine, which has a drive plate, which is connected to the drive shaft of the working machine and is frictionally clamped between two friction plates connected to the drive shaft of the drive machine. For the drive shaft of the working machine, only one radial bearing is provided for centering the friction plate relative to the drive plate. Summary of the invention

[0004] It is an object of the present invention to provide an improved drive train for a wind turbine comprising an easily replaceable / maintainable torque limiter for limiting the maximum torque in the drive train. It is also an object to provide an improved wind turbine.

[0005] According to one aspect, a powertrain includes a torque limiter assembly. The torque limiter assembly includes a torque limiter.

[0006] The torque limiter comprises a first clamping disc and a friction disc. The torque limiter may also comprise a second clamping disc, or even more than two clamping discs. Typically, the number of clamping discs may be equal to the number of friction discs. Alternatively, the number of clamping discs may be one more than the number of friction discs. The torque limiter also comprises a preloading device. For a better understanding, a configuration with two clamping discs and a single friction disc is described below.

[0007] The clamping disk and the friction disk are configured so that the friction disk is frictionally clamped between the clamping disks. The clamping force for frictionally clamping the friction disk between the clamping disks is predetermined by the preload device. Thus, the clamping disk frictionally transmits a torque up to a predetermined maximum torque to the friction disk. However, an over-torque exceeding the predetermined maximum torque causes the friction disk to slip relative to the clamping disk.

[0008] According to another aspect, the torque limiter assembly further comprises a torque shaft and a hub shaft. The torque shaft can be connected to a rotor of a wind turbine. The hub shaft can be connected to a generator rotor of the wind turbine.

[0009] The friction disc can be bolted to the hub shaft from the downwind side via the interface bolts. Therefore, the torque limiter can be removed from the hub shaft as a whole.

[0010] According to an advantageous aspect, the hub shaft may be a hollow shaft. The hub shaft and the torque shaft may be coaxially aligned in the longitudinal direction X. The torque shaft may extend through the hub shaft. Both the hub shaft and the torque shaft may extend from the torque limiter in an upwind direction.

[0011] According to another advantageous aspect, the torque shaft may be connected to the first clamping disc.The torque shaft may comprise a detachable articulated joint at the upwind end.

[0012] The torque shaft assembly may be extracted from the hub shaft assembly by disengaging bolts attaching the friction disk to the generator hub assembly, such that the torque shaft may be removed from the first clamping disk by disengaging / loosening the bolts and / or bolts from the downwind side.

[0013] According to a further advantageous aspect, the torque shaft may be connected to the first clamping disc via an intermediate disc comprised by the torque limiter.According to a further advantageous aspect, the intermediate disc may comprise a through hole providing access to the interface bolts.

[0014] In other words, the intermediate plate may be bolted to the torque shaft and the first clamping plate.The intermediate plate may be bolted to the torque shaft from the downwind side via the intermediate plate interface bolts, such that the torque limiter may be disassembled from the rest of the torque limiter assembly by unscrewing the interface bolts and the intermediate plate interface bolts.

[0015] According to a further advantageous aspect, the intermediate disk may be configured as a brake disk for a holding brake.A brake caliper may be attached to the generator housing and may engage the brake disk.

[0016] According to another advantageous aspect, the intermediate disk may include a through hole configured to accommodate a portion of the preloading device extending through the through hole. Preferably, the diameter of the through hole is greater than the maximum diameter of the portion of the preloading device extending through the through hole. This aspect provides an intermediate disk that can be mounted to and removed from the torque limiter assembly without affecting the predetermined clamping force of the preloading device.

[0017] According to another advantageous aspect, a first circumferential seal can be arranged between the first clamping disk and the friction disk, and a second circumferential seal can be arranged between the second clamping disk and the friction disk, so that the first circumferential seal and the second circumferential seal can provide a sealing space for the friction surfaces of the clamping disk and the friction disk.

[0018] According to an advantageous aspect, the drive train may comprise at least one and in particular two sliding rings. The sliding rings may be configured to align the friction disk and the clamping disk relative to each other. This aspect allows the torque shaft to be supported by the generator bearing.

[0019] According to another advantageous aspect, the friction disc and the hub shaft can be configured to be electrically insulated from the rest of the torque limiter assembly. The rest can include at least a clamping disc and a torque shaft.

[0020] The sliding rings and the friction surfaces may comprise one or more electrically insulating materials. The sliding rings and the friction surfaces having different materials may optimize the friction depending on the intended purpose.

[0021] The air gap between the friction disk and the clamping disk outside the insulating friction surfaces and the air gap between the friction disk and / or the hub shaft and the torque shaft can have a sufficient height to provide a robust electrical insulation.

[0022] The torque shaft may include a sealing ring in a downwind flange portion of the torque shaft. The sealing ring may be constructed and arranged to provide a seal between the torque shaft and the friction disk, or to provide a seal between the torque shaft and the hub shaft.

[0023] According to an advantageous aspect, the entire torque limiter assembly 26 may be supported (solely) by the generator bearing assembly with the second hub shaft.The hub shaft may be rigidly connected, ie threadedly connected, to the second hub shaft.

[0024] The torque limiter assembly and drive train may be configured such that the torque limiter may be installed and de-installed from the drive train without first removing the generator.

[0025] The above aspects greatly reduce the work required to replace or readjust the torque limiter. The insulating construction prevents premature wear and damage to the bearings. The torque limiter protects the generator and other parts of the drive train from overload.

[0026] According to an advantageous aspect, the torque limiter assembly and in particular the intermediate disc (holding brake disc) may include a drive interface configured to temporarily attach a driven portion of a single blade installation tool. For example, the drive interface may include a plurality of threaded holes to attach a corresponding flange of a single blade installation tool.

[0027] The drive train, and in particular the generator housing of the generator, may comprise a mounting interface configured to temporarily mount a fixed part of a single blade mounting tool.

[0028] The single blade installation tool may comprise a (preferably hydraulic) motor and a gear transmission.The single blade installation tool may rotate the rotor 6 of a wind turbine by rotating the torque limiter of the drive train, ie for installing blades to a rotor hub or for performing maintenance work on the drive train. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Further aspects and features of the present invention will be apparent from the following description of preferred embodiments of the present invention with reference to the accompanying drawings, in which:

[0030] Figure 1 is a simplified perspective view of a wind farm including a plurality of wind turbines.

[0031] Figure 2 is a simplified perspective view of the drive train of a wind turbine.

[0032] Figure 3 is a cross-sectional view of the downwind portion of the drive train,

[0033] Figure 4 is a cross-sectional view of the torque limiter assembly,

[0034] Figure 5 yes Figure 4 A magnified and detailed view of a portion of

[0035] Figure 6 is a simplified view of a generator with a single blade installation tool attached thereto. DETAILED DESCRIPTION

[0036] Figure 1 A simplified perspective view of a wind farm comprising a plurality of wind turbines 1 is shown. Each wind turbine 1 comprises a nacelle 4 and a rotor 6. The rotor 6 comprises a central rotatable rotor hub 2. To the rotor hub 2 rotor blades 3 are attached.

[0037] The nacelle 4 extends in a vertical direction Z which is substantially parallel to the axial extension of a tower 5 on which the nacelle 4 is mounted. The nacelle also extends in a horizontal plane defined by a longitudinal direction X and a transverse direction Y, the longitudinal direction X being substantially parallel to the drive train to be located in the nacelle 4. Both the longitudinal direction X and the transverse direction Y are perpendicular to the vertical direction Z and to each other. The longitudinal direction X substantially corresponds to the axis of rotation of the rotor 6 and the drive train.

[0038] The wind farm may be an offshore wind farm, and thus the wind turbines 1 may be installed in the open sea 7 .

[0039] Figure 2 A simplified perspective view of a drive train 8 of a wind turbine 1 is shown.

[0040] To describe the relative arrangement / position of components in the longitudinal direction X, the terms "upwind" (toward the wind) and "downwind" (to the leeward) as well as "front" and "rear" are used. However, these references relate to the wind direction in normal operation, i.e. when the rotor 6 of the wind turbine is directed (turned) towards the wind. Generally speaking, the rotor 6 is located in front of (upwind) the nacelle 4. Comparing the positions of two components of the drive train 8 in the longitudinal direction X, the component closer to the rotor hub 2 is referred to as the upwind / front component and the component further away from the rotor hub 2 (along the longitudinal direction X) is referred to as the downwind / rear component.

[0041] In the downwind direction, the drive train 8 includes a main shaft assembly 9 , a gearbox 10 and a generator 11 .

[0042] The main shaft assembly 9 includes a main shaft housing 13, a main bearing and a main shaft 12. The main bearing is installed in the main shaft housing 13. The main shaft 12 is supported by the main bearing. The rotor hub 2 is attached to and supported by the main shaft 12. The main shaft 12 rotates together with the rotor 6.

[0043] The gearbox 10 is attached to the main shaft assembly 9. The gearbox input shaft is attached to the downwind portion of the main shaft 12. The gearbox input shaft rotates with the main shaft 12.

[0044] The gearbox 10 comprises a multi-stage planetary gear. More precisely, the gearbox 10 comprises a two-stage planetary gear. The planetary gearbox is configured to convert a slow rotational motion of a gearbox input shaft into a faster rotational motion of a gearbox output shaft.

[0045] Figure 3 A cross-sectional view of a downwind portion of the drive train 8 is shown. The downwind portion of the drive train 8 includes the coupling shaft 18, the torque limiter assembly 26, the generator hub assembly 27, the generator bearing assembly 28, the energy tube 15 and the energy tube bearing assembly 29.

[0046] Connecting shaft

[0047] The coupling shaft 18 is a hollow shaft and includes a first (upwind) coupling component 20 and a second (downwind) coupling component 21 .

[0048] The coupling shaft 18 is floatingly supported by the gearbox output shaft 17 and the torque shaft 19 .

[0049] The gearbox output shaft 17 comprises a gearbox output coupling part 22. The first coupling part 20 of the coupling shaft 18 forms together with the gearbox output coupling part 22 a first articulated joint 23.

[0050] The torque shaft 19 comprises a torque shaft input coupling part 24 . The second coupling part 21 of the coupling shaft 18 forms together with the torque shaft input coupling part 24 a second articulated joint 25 .

[0051] The coupling shaft 18 is floatingly mounted between the gearbox output coupling member 22 and the torque shaft input coupling member 24 .

[0052] By means of the first articulated joint 23 and the second articulated joint 25 , the coupling shaft 18 rotates along the gearbox output shaft 17 , and the torque shaft 19 rotates along the coupling shaft 17 .

[0053] The first articulated joint 23 and the second articulated joint 25 compensate for concentricity tolerances and misalignments of the gearbox output shaft 17 and the torque shaft 19 .

[0054] The articulated joints 23, 25 can be based on various functional principles. In the illustrated embodiment, the articulated joints 23, 25 each comprise a splined coupling. A spline is a ridge or tooth on the drive shaft (external spline) that meshes with a groove (internal spline) in a mating part and transmits torque to it, thereby maintaining the angular correspondence between the drive shaft and the mating part. In this embodiment, the coupling shaft 18 comprises external splines on the first and second coupling parts 20, 21. The external splines of the first and second coupling parts 20, 21 match the internal splines of the gearbox output coupling part 22 and the torque shaft input coupling part 24, respectively.

[0055] The spline couplings of the first articulated joint 23 and the second articulated joint 25 are crowned spline couplings. The sides of the equally spaced grooves are preferably involutes. By having a crowned (convex) shape, the male teeth are modified to allow for misalignment (angular movement).

[0056] Since the coupling shaft 18 is a floating shaft, the coupling shaft has a degree of freedom in the axial / longitudinal direction X. The coupling shaft 18 is supported only by the first articulated joint 23 and the second articulated joint 25. The coupling shaft 18 is not supported by additional bearings.

[0057] Restraint Devices

[0058] The movement of the floating coupling shaft 18 in the longitudinal direction X is restricted to a predetermined range of movement by the restriction device 30 . In other words, the coupling shaft 18 is axially supported by the torque shaft 19 .

[0059] The restraint device 30 can be based on various functional principles.

[0060] In the embodiment shown, the restraint device 30 comprises a bayonet coupling. More specifically, the restraint device 30 comprises a male bayonet and a female bayonet, wherein one of the male bayonet and the female bayonet is rigidly attached to the coupling shaft 18 or forms a part of the coupling shaft 18, and the respective other of the male bayonet and the female bayonet is rigidly attached to the torque shaft 19 or forms a part of the torque shaft 19. In this case, the female bayonet 31 of the bayonet coupling is rigidly attached (threaded) to the coupling shaft 18; the male bayonet 32 ​​is rigidly attached (threaded) to the torque shaft 19.

[0061] Alternative functional principles of the restraining device 30 may for example be based on a first abutment surface (stop) in / at the interface of the gearbox output shaft 17 and the coupling shaft 18 and a second abutment surface (stop) in / at the interface of the coupling shaft 18 and the torque shaft 19 .

[0062] Torque shafts and torque limiters

[0063] The generator rotor 33 of the generator 11 is directly or indirectly attached to the torque shaft 19. In the present case, the torque shaft 19 is attached to the torque limiter 26, and the torque limiter 26 is attached to the generator hub assembly 27. The generator hub assembly supports the generator rotor 33.

[0064] Under normal operating conditions, the generator rotor 33 rotates along the torque axis 19 .

[0065] However, under abnormal loads, such as extremely high torque peaks in the event of a short circuit in the generator 11, the torque limiter 26 decouples the generator rotor 33 from the torque shaft 19. In other words, the torque limiter disconnects the mechanical (and rotationally rigid) connection between the torque shaft 19 and the generator rotor 33 in the event of an overload.

[0066] The torque limiter (assembly) 26 is a (mechanical) overload clutch. The torque limiter comprises at least a first friction surface and a second friction surface which rub against each other. An adjustable preload device 34 applies an adjustable force which clamps the first friction surface and the second friction surface together to provide an adjustable and predetermined release torque. If the load torque becomes greater than the release torque, the torque limiter 26 at least disengages the connection between the gearbox 10 and the generator 11. In other words, the torque limiter 26 limits the torque in all components of the drive train 8 to a predetermined maximum torque. For example, if the gearbox is a gearbox with a transmission ratio R=n 进 / n 出 The gearbox, in which the transmission ratio R is less than 1 (speed increase ratio), the torque at the upwind side of the gearbox in the transmission system 8 can be the largest (considering an idealized model that ignores additional losses) 逆风 =1 / R*M 释放 .

[0067] In this embodiment, the torque limiter 26 comprises a first clamping disc 35 and a second clamping disc 36 and a friction disc 37, which is clamped mutually by the first clamping disc 35 and the second clamping disc 36. The preloading device 34 comprises a plurality of bolts 39 extending through the first clamping disc 25 and the second clamping disc 26, corresponding nuts 40 and corresponding spring elements 41. The preloading device 34 may also comprise one or more ring washers for each bolt 39. In particular, the preloading device 34 comprises a bolt 39, each bolt extending through the clamping discs 35, 36 and (in this order) further extending through an optional first washer, a spring 41, an optional second washer and a nut 40. The preloading / clamping force is adjusted by tightening or loosening the respective bolt-nut connection of the preloading device 34.

[0068] The first clamping plate 35 includes a first friction surface. The friction plate includes a second friction surface and a third friction surface. The second clamping plate 36 includes a fourth friction surface. The friction force between the first friction surface and the second friction surface and the friction force between the fourth friction surface and the third friction surface transfers the rated maximum torque load (or less) from the torque shaft 19 to the generator hub assembly 27. The magnitude of the preload force determines the friction force.

[0069] The first clamping disc 35 is rigidly attached (directly or indirectly, as well) to the torque shaft 19 or forms part of the torque shaft 19 .

[0070] The friction disc 37 is rigidly attached (directly or indirectly, as well) to or forms part of the generator hub assembly 27 .

[0071] One or more slide rings 62 align and center the clamping disks 35 , 36 relative to the friction disk 37 and / or the first hub shaft 48 .

[0072] The torque limiter 26 is constructed as a module that can be assembled and pre-adjusted at the factory. The torque limiter 26 can be mounted to the drive train 8 as a whole. In other words, the torque limiter 26 (more precisely, the first clamping disc) is bolted (threaded, flanged) to the torque shaft 19 via the brake disc 38 by bolts 43, 42. The torque limiter 26 (more precisely, the friction disc 37) is bolted to the generator hub assembly 27 by bolts 44, respectively. In other words, the bolt 43 rigidly attaches the brake disc 38 to the torque shaft 19. The bolt 42 rigidly attaches the first clamping disc 35 to the brake disc 38. The bolt 44 attaches the friction disc 37 to the generator hub assembly 27.

[0073] Holding brake

[0074] In this embodiment, the drive train 8 also includes a holding brake 47. The holding brake is configured to hold the rotating components of the drive train 8 in a fixed non-rotating position. The holding brake includes a brake disc 38, which is rigidly attached to the generator hub assembly 27 and / or the torque shaft 19. The holding brake also includes one or more brake calipers 45, each having one or more brake pads. The brake caliper is rigidly attached (threaded, bolted) to the generator housing 46.

[0075] The brake disc 38 of the holding brake 47 serves a dual purpose, namely as a component of the holding brake 47 that holds the rotating component of the drive train 8 in a fixed position and provides support for the first clamping disc 35 of the torque limiter 26 .

[0076] In other words, the torque limiter 26 and the holding brake 47 may be constructed as a combined module that may be mounted to the drive train 8 without requiring any type of disassembly (ie, disassembling the generator 11 from the gearbox 10 , or removing components of the generator 11 to access the torque limiter 26 ).

[0077] Generator hub assembly

[0078] The generator hub assembly 27 comprises a first hub shaft 48. The first hub shaft 48 is a hollow shaft. The torque limiter 26 may be rigidly attached (threaded / bolted) to the downwind side of the first hub shaft 48.

[0079] The first hub axle 48 also includes a first upwind flange 50 extending in an inward direction and a second upwind flange 51 extending in an outward direction.

[0080] The generator rotor 33 is rigidly attached (threaded) to the second upwind flange 51 via a spacer ring 52 .

[0081] The first hub axle 48 is rigidly connected (threaded) to and supported by the second hub axle 49 via a first upwind flange 50 .

[0082] The second hub shaft 49 is included in and supported by the generator bearing assembly 28 .

[0083] Generator bearing assembly

[0084] The generator bearing assembly 28 includes an outer bearing bushing 53, which is rigidly attached (threaded) to the bearing wall 47 of the generator housing 46 from the downwind side via a flange. An inner bearing bushing 54 is inserted into and supported by the outer bearing bushing 53. The inner bearing bushing 54 includes an upwind flange, a first annular support surface adjacent to the upwind flange, and a second annular support surface at its distal end (downwind). The first annular support surface and the second annular support surface of the inner bearing bushing 54 abut the inner surface of the outer bearing bushing 53. The inner bearing bushing 54 is rigidly attached (threaded) to the outer bearing bushing 53 at the flange.

[0085] The inner bearing bushing 54 includes an upwind recess and a downwind recess at the ends of the inner bearing bushing 54 to respectively accommodate an upwind generator rolling bearing and a downwind generator rolling bearing supporting the second hub shaft 49. The upwind rolling bearing and the downwind rolling bearing are tapered roller bearings arranged in an "O" shape.

[0086] The second hub shaft 49 comprises a circumferential abutment edge on the downwind side. The inner bearing rings of the upwind and downwind generator rolling bearings 55, 56 are supported and tensioned between the abutment edge 58 and the clamping ring 57. The spacer tube 59 spaces the inner bearing rings of the upwind and downwind generator bearings 55, 56 apart. The clamping ring 57 is bolted to the second hub shaft 49. The bearing preload is determined by tensioning the corresponding bolts / screws connecting the clamping ring 57 to the upwind side of the second hub shaft 49.

[0087] The generator bearing assembly 28 also includes an annular downwind seal cover including a rotating shaft seal 61 in a recess that provides a seal between the stationary outer bearing bushing 53 of the generator bearing shaft assembly 28 and the rotating second hub shaft 49 .

[0088] Energy tube and energy tube bearing assembly

[0089] The central energy tube 15 extends axially through the drive train 8 in the longitudinal direction X. The energy tube 15 rotates along the gearbox input shaft 16 and the main shaft 12. The energy tube 15 houses hydraulic and / or electrical wires to supply energy and / or to transmit signals to the rotor hub 2, in particular to devices in the rotor 2, such as pitch drives, actuators and / or sensors.

[0090] The energy tube 15 is rotatably supported by an energy tube bearing 63 on the downwind side of the drive train 8. The energy tube bearing 63 includes an energy tube bearing bushing 64. The energy tube bearing bushing 64 is rigidly attached (threaded) to the torque limiter 26, in particular to the brake disc 38.

[0091] The energy tube bearing assembly 28 (which may also be referred to as the energy tube bearing cartridge 28) includes a cartridge mandrel 65 and a cartridge sleeve 66. The cartridge mandrel 66 is a hollow shaft. The energy tube bearing is sandwiched between the cartridge mandrel 65 and the energy tube bearing sleeve 64. The energy tube bearing sleeve 64 is at least partially inserted into the cartridge sleeve 66 and abuts against the cartridge sleeve 66.

[0092] An inner labyrinth seal ring 67 is push-fit onto the upwind end of the barrel mandrel 65. A corresponding outer labyrinth seal ring 68 is partially inserted into and abuts against the upwind end face of the barrel jacket 66. The inner labyrinth seal ring 67 and the outer labyrinth seal ring 68 are arranged so that they cooperatively form a labyrinth seal adjacent the interface (spline connection) of the coupling shaft 18 and the torque shaft 19. The labyrinth seal is arranged on the downwind side of the interface.

[0093] Figure 4 shows a cross-sectional view of a torque limiter assembly; Figure 5 Shows Figure 4The torque limiter assembly 26 ′ is comprised in the drive train 8 of the wind turbine 1 . The torque limiter assembly 26 ′ comprises the torque limiter 26 .

[0094] The torque limiter 26 includes a first clamping disk 35 , a friction disk 37 , a second clamping disk 36 and a preloading device 34 .

[0095] The clamping plates 35, 36 and the friction plates 37 are configured so that the friction plates 37 are frictionally clamped between the clamping plates 35, 36. The clamping force for frictionally clamping the friction plates 37 between the clamping plates 35, 36 is predetermined by the preload device 34 so that the clamping plates 35, 36 frictionally transmit torque up to a predetermined maximum torque to the friction plates 37, and an over-torque above the predetermined maximum torque causes the friction plates 37 to slip relative to the clamping plates 35, 36.

[0096] The torque limiter assembly 26' further comprises a torque shaft 19 and a hub shaft 48. The torque shaft is connected to the rotor 6 of the wind turbine 1. The hub shaft 48 is connected to the generator rotor 33 of the generator 11 of the wind turbine 1.

[0097] The friction plate 37 is bolted to the hub shaft 48 from the downwind side by the interface bolts 44. Therefore, the torque limiter 26 can be removed from the hub shaft 48 as a whole.

[0098] The hub shaft 48 is a hollow shaft. The hub shaft 48 and the torque shaft 19 are coaxially aligned in the longitudinal direction X. The hub shaft 48 and the torque shaft 19 extend from the torque limiter 26 in the upwind direction.

[0099] The torque shaft 19 is connected to the first clamping disc 35. The torque shaft 19 includes a detachable articulated joint 24 at the upwind end so that the torque shaft assembly 26' can be extracted from the hub shaft assembly by disengaging the bolts 44 attaching the friction disc 37 to the generator hub assembly. In addition, the torque shaft 19 can be disassembled from the first clamping disc 35 from the downwind side by disengaging / loosening the bolts 43 and / or the bolts 44.

[0100] The torque shaft 19 is connected to the first clamping disc 35 via an intermediate disc 38 included in the torque limiter 26. The intermediate disc 38 comprises through holes providing access to the interface bolts 44.

[0101] In other words, the intermediate plate 38 is bolted to the torque shaft 19 and the first clamping plate 35. The intermediate plate 38 is bolted to the torque shaft 19 from the downwind side via the intermediate plate interface bolts 43, so that the torque limiter 19 can be removed from the rest of the torque limiter assembly 26' by unscrewing the interface bolts 44 and the intermediate plate interface bolts 43.

[0102] The intermediate disk 38 is configured as a brake disk for a holding brake. A brake caliper 45 is attached to the generator housing and can engage the brake disk 38 .

[0103] The intermediate disk 38 includes a through hole configured to accommodate a portion of the preload device 34 extending therethrough. The diameter of the through hole is greater than the maximum diameter of the portion of the preload device extending therethrough. Thus, the intermediate disk 38 can be installed to and removed from the torque limiter assembly 26' without affecting the predetermined clamping force of the preload device 34.

[0104] The first circumferential seal 205 is arranged between the first clamping disk 35 and the friction disk 37 , and the second circumferential seal 206 is arranged between the second clamping disk 36 and the friction disk 37 , so that the first circumferential seal 205 and the second circumferential seal 206 provide a sealing space for the friction surfaces of the clamping disks 35 , 36 and the friction disk 37 .

[0105] The drive train comprises at least one and in particular two sliding rings 62, 207. The sliding rings 62, 207 are configured to align the friction disk 37 and the clamping disks 35, 36 relative to each other.

[0106] The friction disc 37 and the hub shaft 48 are configured to be electrically insulated from the rest of the torque limiter assembly 26 ′, which includes at least the clamping discs 35 , 36 and the torque shaft 19 .

[0107] The slide rings 62, 207 and the friction surfaces 201-204 include one or more electrically insulating materials.

[0108] The air gaps 208 , 209 between the friction disks 37 and the clamping disks 35 , 36 outside the insulating friction surfaces 201 - 204 and between the friction disks 37 and / or the hub shaft 48 and the torque shaft 19 have a sufficient height to provide electrical insulation.

[0109] The torque shaft includes a sealing ring 210 located in a downwind flange portion of the torque shaft. The sealing ring is constructed and arranged to provide a seal between the torque shaft 19 and the friction disc 37, or between the torque shaft 19 and the hub shaft 48.

[0110] The entire torque limiter assembly 26' is supported (solely) by the generator bearing assembly 28 with the second hub shaft 49. The hub shaft 48 is rigidly connected, ie threadedly connected, to the second hub shaft 49.

[0111] The torque limiter assembly 26 ′ and the drive train 8 are configured such that the torque limiter 26 can be installed and disconnected from the drive train 8 without first removing the generator 11 .

[0112] Figure 6A simplified view of a generator with a single blade installation tool attached thereto is shown. The outer generator housing is not shown. The generator 11 comprises a generator stator. The generator stator may be considered to form part of the generator housing.

[0113] The torque limiter assembly 26' and in particular the intermediate disk 38 comprises a drive interface 212 configured to temporarily attach a driven portion 213 of a single blade installation tool 211. The drive interface 212 comprises, for example, a plurality of threaded holes to attach corresponding flanges of the single blade installation tool 211.

[0114] The drive train 8 , and in particular the generator housing of the generator 11 , comprises a mounting interface 214 which is configured to temporarily mount a fixing portion 215 of a single blade mounting tool 211 .

[0115] The single blade installation tool 211 comprises a (preferably hydraulic) motor 216 and a gear transmission 217. The single blade installation tool 211 may rotate the rotor 6 of the wind turbine 1 by rotating the torque limiter 26 of the drive train 8.

[0116] Although the invention has been described above with reference to specific embodiments, it is not limited to these embodiments and those skilled in the art will no doubt think of further alternatives within the scope of the claimed invention.

Claims

1. A drive train for a wind turbine, comprising a torque limiter assembly (26'), the torque limiter assembly comprising a torque limiter (26), in, The torque limiter comprises: a first clamping disc (35), a friction disc (37), a second clamping disc (36) and a preloading device (34). wherein the clamping disk and the friction disk are configured such that the friction disk is frictionally clamped between the clamping disks, and wherein a clamping force for frictionally clamping the friction disk between the clamping disks is predetermined by the preloading device such that the clamping disk frictionally transmits a torque up to a predetermined maximum torque to the friction disk, and an overtorque above the predetermined maximum torque causes the friction disk to slip relative to the clamping disk, Characterized in that the torque limiter assembly further comprises a torque shaft (19) and a hub shaft (48), wherein the torque shaft is connected to a rotor of the wind turbine, and wherein the hub shaft is connected to a generator rotor of a generator of the wind turbine, The friction disc is bolted to the hub shaft from the downwind side via interface bolts (44), so that the torque limiter can be integrally removed from the hub shaft.

2. The transmission system according to claim 1, wherein: The hub shaft is a hollow shaft, and wherein the hub shaft and the torque shaft are coaxially aligned along a longitudinal direction X and extend from the torque limiter in an upwind direction.

3. A drive train according to claim 1 or 2, wherein the torque shaft is connected to the first clamping disc; and in, The torque shaft comprises a detachable articulated joint (24), or The torque shaft is detachable from the first clamping disc from the downwind side.

4. A drive train according to claim 1 or 2, wherein the torque shaft is connected to the first clamping disc via an intermediate disc (38) comprised by the torque limiter, and wherein the intermediate disc comprises a through hole providing access to the interface bolt (44).

5. The transmission system according to claim 4, wherein: The intermediate disk is bolted to the torque shaft from the downwind side via intermediate disk interface bolts (43) so that the torque limiter can be removed from the rest of the torque limiter assembly by unscrewing the interface bolts and the intermediate disk interface bolts.

6. The powertrain according to claim 4, wherein: The intermediate disk is designed as a brake disk for a holding brake.

7. The transmission system according to claim 6, wherein: The intermediate disk includes a through hole configured to accommodate a portion of the preload device extending through the through hole, the through hole having a diameter greater than a maximum diameter of the portion extending through the through hole, so that the intermediate disk can be mounted to and removed from the torque limiter assembly without affecting a predetermined clamping force of the preload device.

8. The transmission system according to claim 1 or 2, wherein: A first circumferential seal is arranged between the first clamping disk and the friction disk, and a second circumferential seal is arranged between the second clamping disk and the friction disk, so that the first circumferential seal and the second circumferential seal provide a sealing space for the friction surfaces of the clamping disk and the friction disk.

9. The power train of claim 1 or 2, further comprising at least one sliding ring (62, 207) configured to align the friction disk and the clamping disk relative to each other.

10. The powertrain according to claim 9, wherein: The friction plate and the hub shaft are configured to be electrically insulated from a remaining portion of the torque limiter assembly including at least the clamping plate and the torque shaft.

11. The powertrain according to claim 1 or 2, wherein: The torque shaft includes a sealing ring (210) in a downwind flange portion of the torque shaft, wherein the sealing ring is constructed and arranged to provide a seal between the torque shaft and the friction disk, or to provide a seal between the torque shaft and the hub shaft.

12. The powertrain according to claim 1 or 2, wherein: The entire torque limiter assembly is supported by a generator bearing assembly having a second hub shaft (49) to which the hub shaft (48) is rigidly connected.

13. The powertrain according to claim 1 or 2, wherein: The torque limiter assembly and the drive train are configured such that the torque limiter can be installed and disconnected from the drive train without first removing the generator.

14. The powertrain according to claim 1 or 2, wherein: The torque limiter assembly includes a drive interface configured to temporarily attach a driven portion of a single blade installation tool, wherein the drive train comprises a mounting interface configured to temporarily mount a fixed portion of the single blade mounting tool, The single blade installation tool comprising a motor and a gear transmission is enabled to rotate the rotor of the wind turbine by rotating the torque limiter of the drive train.

15. The powertrain according to claim 4, wherein: The intermediate plate is bolted to the torque shaft and the first clamping plate.

16. The powertrain according to claim 9, wherein: The at least one sliding ring (62, 207) is two sliding rings.

17. The powertrain according to claim 10, wherein: The sliding rings and friction surfaces comprise electrically insulating material, and the air gaps (208, 209) between the friction disk and the clamping disk and between the friction disk / the hub shaft and the torque shaft are of sufficient height to provide electrical insulation.

18. The powertrain of claim 14, wherein: A generator housing of the generator comprises the mounting interface.

19. The powertrain of claim 4, wherein: The intermediate disk includes a drive interface configured to temporarily attach a driven portion of a single blade installation tool, wherein the drive train comprises a mounting interface configured to temporarily mount a fixed portion of the single blade mounting tool, The single blade installation tool comprising a motor and a gear transmission is enabled to rotate the rotor of the wind turbine by rotating the torque limiter of the drive train.

20. A wind turbine comprising a drive train according to any one of claims 1 to 19.

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