Adjustable support system for main shaft of wind turbine

Abstract

An adjustable support system for supporting and immobilizing a longitudinally extending main shaft in a nacelle of a wind turbine when a gearbox has been dismounted involves: a transverse beam rigidly mounted in the nacelle and extending over the main shaft; a saddle having an arcuate recess to engage with the main shaft from above the main shaft, the saddle movably connected to the transverse beam; a flexible strap that engages the main shaft from below the main shaft to support the main shaft from below; and, a transverse saddle adjuster connected to the saddle and configured to adjust transverse position of the saddle relative to the main shaft.

Description

[0001] ADJUSTABLE SUPPORT SYSTEM FOR MAIN SHAFT OF WIND TURBINE

[0002] Cross-reference to Related Applications

[0003] This application claims the benefit of United States provisional patent application USSN 63 / 512,103 filed July 6, 2023, the entire contents of which is herein incorporated by reference.

[0004] Field

[0005] This application relates to wind turbines, in particular to accessories for use in supporting a main shaft of a wind turbine during replacement or maintenance of a gearbox.

[0006] Background

[0007] Wind turbines comprise a tall tower at the top of which is mounted a rotor having rotor blades and a hub to which the rotor blades are mounted. The hub is mounted at one end of a main shaft, which extends generally horizontally from the hub into a nacelle of the wind turbine. The other end of the main shaft is mounted in a gearbox in the nacelle, with the gearbox connected to a generator. Wind is caught by the rotor blades to turn the hub, which in turn rotates the main shaft, which drives the gears to drive the generator to generate electricity. The main shaft, gearbox and generator are located in the nacelle atop the tower, the nacelle essentially being a compartment in which to house turbine components.

[0008] To efficiently repair or replace a gearbox, it is necessary to dismount the gearbox from the end of the main shaft and lower the gearbox to the ground. After repair, or if replacement is desired, a gearbox is raised back up to the nacelle and remounted on the end of the main shaft.

[0009] However, the gearbox also anchors the end of the main shaft, so when the gearbox is initially dismounted, the weight of the rotor at the other end of the main shaft would cause the main shaft to tilt, which can cause the entire rotor to fall to the ground, or at least cause damage to the main shaft, nacelle and / or the rotor.

[0010] To prevent tilting of the main shaft, one of two strategies is employed. In a first and more elaborate strategy, the rotor is removed from the main shaft before the gearbox is dismounted from the main shaft, and the rotor is lowered to the ground. This requires a large crane and considerable time. In a second strategy, to avoid having to remove the rotor, a ‘main shaft fixture’ is raised up to the nacelle and used to hold the main shaft down prior to dismounting the gearbox. Various main shaft fixtures are known in the art, but generally suffer from one or more problems including being complex to install, being difficult to use including not being simple to properly seat on the main shaft, being useable on only one type of wind turbine and / or only being able to support the main shaft without immobilizing rotation of the main shaft, among others.

[0011] Despite recent advances, there remains a need in the art for a main shaft fixture that solves one or more of the problems with existing main shaft fixtures.

[0012] An adjustable support system for supporting and immobilizing a longitudinally extending main shaft in a nacelle of a wind turbine when a gearbox has been dismounted from the main shaft comprises: a transverse beam rigidly mounted in the nacelle and extending over the main shaft; a saddle having an arcuate recess to engage with the main shaft from above the main shaft, the saddle movably connected to the transverse beam; a flexible strap that engages the main shaft from below the main shaft to support the main shaft from below; and, a transverse saddle adjuster connected to the saddle and configured to adjust transverse position of the saddle relative to the main shaft.

[0013] The adjustable support system is relatively simple to install. Adjustability of the support system permits proper engagement of the saddle with the main shaft so that the main shaft is well-secured and prevented from tipping. The same support system can also be used to tilt the main shaft, for example by about 0.5-1° to facilitate removal and / or reinstallation of a main bearing, the gearbox and the like.

[0014] The transverse beam is rigidly mounted in the nacelle and extends over the main shaft. The transverse beam may be mounted at any convenient and sufficiently supportive location in the nacelle that permits the transverse beam to extend transversely across the nacelle above the main shaft. In some embodiments, the transverse beam is mounted to longitudinal beams mounted in the nacelle. In some embodiments, the longitudinal beams are situated above the main shaft and mounted on pillow blocks in the nacelle. The longitudinal beams may also be mounted on a main bearing or a bed plate in the nacelle. In some embodiments, the transverse beam comprises mounting flanges to assist with mounting the transverse beam in the nacelle, for example by using pinned connections involving pins inserted through at least one aperture in a mounting flange and at least one corresponding aperture in the structure to which the transverse beam is being mounted. The transverse beam may further comprise connection structures to which other components of the adjustable support system may be connected. The connection structures may also include mechanisms for tightening various components of the adjustable support system. Connection structures include, for example, lugs, rings, buckles, come-alongs and the like.

[0015] The saddle has an arcuate recess to engage with the main shaft from above the main shaft. The arcuate recess is preferably shaped to conform to the curvature of the main shaft. In some embodiments, the arcuate recess has a depth sufficient to impede the main shaft from rolling out of the saddle when the main shaft experiences side loading. In some embodiments, the arcuate recess has a liner that engages the surface of the main shaft. The liner comprises a material (e.g., rubber, other elastomers) that provides more friction to impede rotation of the main shaft when the saddle is engaged with the main shaft. In some embodiments, the liner material is also sufficiently compressible to provide better conformity of the saddle to the surface of the main shaft, which further facilitates immobilization of the main shaft.

[0016] The saddle is movably connected to the transverse beam. Moveable connection permits the saddle to move with degrees of freedom thereby facilitating proper positioning of the saddle in relation to the main shaft for better engagement of the saddle with the main shaft. In some embodiments, the saddle is transversely movable along a transverse axis and rotatable about a vertical axis through the saddle to permit adjusting a position of the saddle in relation to the main shaft. In some embodiments, the saddle is transversely movable along a transverse axis, vertically movable along the vertical axis and / or rotatable about the vertical axis.

[0017] In some embodiments, the moveable connection is provided by rigging between the saddle and the transverse beam. In some embodiments, the saddle is attached to the transverse beam only by rigging. Rigging may comprise any combination of ropes, cables, chains, and the like. In some embodiments, chains are utilized. In some embodiments, the rigging comprises four chains, two forward chains and two rearward chains, extending between the saddle and front and rear faces of the transverse beam.

[0018] With the saddle movably connected to the transverse beam, various saddle position adjusters may be utilized to properly position the saddle in relation to the main shaft for better engagement of the saddle with the main shaft. For this purpose, a transverse saddle adjuster is connected to the saddle. The transverse saddle adjuster is configured to adjust the transverse position of the saddle relative to the main shaft. In some embodiments, the transverse saddle adjuster also stabilizes the saddle against sideloading to help prevent the main shaft from rotating about a vertical axis through a main bearing of the wind turbine. In some embodiments, the transverse saddle adjuster comprises an actuator that applies a transversely directed force to the saddle. Any suitable actuator may be utilized, for example mechanical actuators, hydraulic actuators, electric actuators and the like. In some embodiments, the actuator is a mechanical actuator. Mechanical actuators may comprise, for example, threaded rods, cranks, turnbuckles, linkages and the like. In some embodiments, the mechanical actuator comprises a turnbuckle. Any number of actuators may be utilized, for example 1 , 2, 3, 4, 5 or more actuators. In some embodiments, the transverse saddle adjuster comprises at least two actuators, for example turnbuckles, connecting the saddle to the nacelle from opposite sides of the saddle. Operating the transverse saddle adjuster causes the saddle to shift in one or the other of the transverse directions relative to the main shaft so that the recess can be properly aligned with the main shaft. The transverse saddle adjuster may connect the saddle to any suitable support structure in the nacelle, for example, the longitudinal beam, a crane component and the like. In some embodiments, the transverse saddle adjuster connects the saddle to a longitudinal beam situated above the main shaft.

[0019] In some embodiments, the adjustable support system further comprises a vertical saddle adjuster. In some embodiments, the vertical saddle adjuster is connected to the transverse beam. The vertical saddle adjuster is configured to translate the saddle vertically to immobilize the main shaft between the saddle and the flexible strap and / or change a tilt angle of the main shaft in the nacelle. In some embodiments, the vertical saddle adjuster comprises an actuator that applies a vertically directed force to the saddle. Any suitable actuator may be utilized, for example mechanical actuators, hydraulic actuators, electric actuators and the like. In some embodiments, the actuator is a mechanical actuator. Mechanical actuators may comprise, for example, threaded rods, cranks, turnbuckles, linkages and the like. Any number of actuators may be utilized, for example 1 , 2, 3, 4, 5 or more actuators. In some embodiments, the vertical saddle adjuster comprises at least two actuators, for example threaded rods, situated on opposite longitudinal sides of the transverse beam. In some embodiments, the vertical saddle adjuster comprises a threaded rod. In some embodiments, the threaded rod is threaded through a threaded aperture in the transverse beam whereby an end of the threaded rod engages the saddle as the threaded rod is turned to vertically translate the saddle. In some embodiments, the saddle comprises a depression in which the threaded rod engages the saddle. The depression permits rotation and some transverse translation of the saddle as the threaded rod is contacted with the top of the saddle.

[0020] The adjustable support system further comprises a flexible strap that engages the main shaft from below the main shaft to support the main shaft from below. The flexible strap wraps around underneath the main shaft to support the main shaft from below. The flexible strap may be attached to any suitably located component of the wind turbine in the nacelle or accessory in the nacelle, for example the transverse beam, the bed plate, the longitudinal beams, crane components and the like. In some embodiments, the flexible strap is connected to the transverse beam. In some embodiments, the flexible strap is connected to a longitudinally facing face of the transverse beam. In some embodiments, the flexible strap is connected to connecting rings and / or to tightening mechanisms. Tightening mechanisms, for example come-alongs, buckles (e.g., turnbuckles, belt buckles) and the like, help tighten the flexible strap against the surface of the main shaft. In some embodiments, the flexible strap is made of a material that is sufficiently flexible to conform to the shape of the main shaft when the flexible strap is tightened around the lower portion of the main shaft, while being sufficiently strong to bearthe weight of the main shaft. Such materials include, for example, thermoplastics (e.g., nylon), rubbers, canvas and the like. In some embodiments, more than one flexible strap is utilized, for example 1 , 2, 3, 4 or more flexible straps. In some embodiments, two flexible straps are utilized. In some embodiments, a forward flexible strap is connected to the forward face of the transverse beam on opposite sides of the main shaft. In some embodiments, a rearward flexible strap is connected to the rearward face of the transverse beam on opposite sides of the main shaft. The use of a flexible strap to support the main shaft from underneath is convenient and inexpensive and can be readily adapted to any wind turbine configuration without the need for other more elaborate supporting structures beneath the main shaft.

[0021] In some embodiments, two or more of the flexible strap, moveable saddle, vertical saddle adjuster and transverse saddle adjuster cooperate to simplify the process of immobilizing the main shaft by providing adjustability of the saddle and the flexible strap through several degrees of freedom. Adjustability of the saddle and flexibility of the strap(s) permits proper seating of the saddle and the strap on the main shaft so that the main shaft is well-secured and prevented from tipping. Furthermore, the same support system can be used to tilt the main shaft, for example by about 0.5-1°, to facilitate removal and / or reinstallation of a gearbox, main bearing and the like.

[0022] Further features will be described or will become apparent in the course of the following detailed description. It should be understood that each feature described herein may be utilized in any combination with any one or more of the other described features, and that each feature does not necessarily rely on the presence of another feature except where evident to one of skill in the art.

[0023] Brief Description of the Drawings

[0024] For clearer understanding, preferred embodiments will now be described in detail by way of example, with reference to the accompanying drawings, in which:

[0025] Fig. 1 depicts a rear perspective view of an adjustable support system for supporting and immobilizing a longitudinally extending main shaft in context with other parts of a nacelle of a wind turbine.

[0026] Fig. 2 depicts another rear perspective view showing the adjustable support system shown in Fig. 1.

[0027] Fig. 3 depicts a rear perspective view of the adjustable support system shown in Fig. 1 with various components of the system and the nacelle removed.

[0028] Fig. 4 depicts another rear perspective view showing the adjustable support system shown in Fig. 3.

[0029] Fig. 5 depicts a front view showing the adjustable support system shown in Fig. 3.

[0030] Fig. 6 depicts a rear view showing the adjustable support system shown in Fig. 3.

[0031] Fig. 7 depicts a side view showing the adjustable support system shown in Fig. 3.

[0032] Fig. 8 depicts a front perspective view showing the adjustable support system shown in Fig. 3.

[0033] Fig. 9 depicts a rear perspective view showing the adjustable support system shown in

[0034] Fig. 3. Fig. 10 depicts a rear perspective view of the adjustable support system without a flexible strap.

[0035] Fig. 11 depicts a rear view of the adjustable support system shown in Fig. 10.

[0036] Fig. 12 depicts a side view of the adjustable support system shown in Fig. 10.

[0037] Fig. 13 depicts a front view of the adjustable support system shown in Fig. 10.

[0038] Detailed Description

[0039] The Figures show an adjustable support system 1 for supporting and immobilizing a longitudinally extending main shaft 101 in a nacelle of a wind turbine when a gearbox has been dismounted from a rear end of the main shaft 101. The main shaft 101 has a rotor hub flange 102 mounted on a front end thereof, the rotor hub flange 102 configured to have a rotor hub (not shown) mounted thereon, the rotor hub having rotor blades mounted thereon. The nacelle comprises a bed plate 103 on which various components of the nacelle are mounted, the bed plate 103 being mountable atop a tower of the wind turbine. Mounted on the bed plate 103 are gearbox pillow blocks 104.

[0040] During a maintenance exercise on a wind turbine, one or more cranes are typically mounted in the nacelle of the wind turbine. The gearbox pillow blocks 104 are one of the few places that such cranes can be supported. As such, the maintenance exercise may involve removing upper portions of the pillow blocks 104 and replacing the upper portion with pillow block mounts 90 on which various other structures such as two longitudinal beams 91 may be mounted. The longitudinal beams 91 are used to support crane components but can also be utilized to support components of other fixtures, for example the adjustable support system 1.

[0041] The adjustable support system 1 comprises a transverse beam 5 rigidly mounted to the longitudinal beams 91 and extending transversely in the nacelle between the longitudinal beams 91 and over the main shaft 101. The transverse beam 5 is pinned to one of the longitudinal beams 91 through a first mounting flange 6 at a first end of the transverse beam 5 and pinned to the other of the longitudinal beams 91 through a pair of second mounting flanges 7 at a second end of the transverse beam 5.

[0042] Situated beneath and movably attached to the transverse beam 5 is a saddle 10 having an arcuate recess 11 shaped to snugly fit over the main shaft 101 when the saddle 10 engages a top portion of the main shaft 101 . The arcuate recess 11 preferably has a depth sufficient to restrain the main shaft 101 against side loading from wind and other forces so that the main shaft 101 is impeded from rolling out of the saddle 10. The surface of the recess 11 is equipped with rubber pads to protect the main shaft 101 from damage when the saddle 10 is engaged with the main shaft 101. The saddle 10 is attached to the transverse beam 5 by rigging 15. The rigging may comprise any combination of ropes, cables, chains, and the like but is shown in the Figures as comprising four chains, two forward chains and two rearward chains extending between the saddle 10 and front and rear faces of the transverse beam 5. Due to the flexibility of the rigging 15, the rigging 15 affords a range of motion for the saddle 10. The rigging 15 also allows the saddle 10 to be hoisted with the transverse beam 5.

[0043] The adjustable support system 1 also comprises two flexible straps 50 including a forward flexible strap 50a and a rearward flexible strap 50b, although one flexible strap or more than two flexible straps could be utilized. The flexible straps 50 wrap around underneath the main shaft 101 to support the main shaft 101 from below. The flexible straps 50 are connected to transverse beam 5. The forward flexible strap 50a is connected to the forward face of the transverse beam 5 on opposite sides of the main shaft 101. Likewise, the rearward flexible strap 50b is connected to the rearward face of the transverse beam 5 on opposite sides of the main shaft 101. The flexible straps 50 may be connected to connecting rings 51 and / or to tightening mechanisms 52 (see. Fig. 1 and Fig. 2) on the faces of the transverse beam 5. Tightening mechanisms 52, for example come-alongs, buckles (e.g. , turnbuckles, belt buckles) and the like, help tighten the flexible straps 50 against the surface of the main shaft 101. While the flexible straps 50 are shown attached to the transverse beam 5, the flexible straps could be attached to any suitably located component of the wind turbine in the nacelle or accessory in the nacelle, for example the bed plate, longitudinal beams, crane components and the like. The flexible straps 50 are preferably made of a material that is sufficiently flexible to conform to the shape of the main shaft 101 when the flexible straps 50 are tightened against the main shaft 101 , while being sufficiently strong to bear the weight of the main shaft 101. Such materials include, for example, thermoplastics (e.g., nylon), rubbers, canvas and the like. The use of flexible straps to support the main shaft from underneath is convenient and inexpensive and can be readily adapted to any wind turbine configuration without the need for other more elaborate supporting structures beneath the main shaft. The flexible straps help prevent the man shaft from escaping the saddle in unique high wind events. Situated on a bottom edge of the transverse beam 5 is a vertical saddle adjuster 20 comprising a plate 21 having a front end and a rear end, extending forward and rearward, respectively, from the transverse beam 5. The vertical saddle adjuster 20 further comprises front and rear threaded bosses 22a and 22b, respectively through which front and rear threaded rods 23a and 23b, respectively are threaded. Bottom ends of the threaded rods 23a and 23b are seated in respective depressions in top surfaces of respective front and rear abutment blocks 12a and 12b on an upper surface of the saddle 10. When the arcuate recess 11 of the saddle 10 is engaged with the main shaft 101 , adjustment of the threaded rods 23a and 23b pushes the saddle 10 more snugly into main shaft 101 thereby immobilizing the main shaft 101 . Further adjustment of the threaded rods 23a and 23b can be done to push the main shaft 101 downward thereby changing a tilt angle of the main shaft 101. Reversal of the adjustment allows the main shaft to tilt 101 back.

[0044] To better align the saddle 10 with the main shaft 101 in a transverse direction, the adjustable support system 1 further comprises a transverse saddle adjuster 30. The transverse saddle adjuster 30 is connected to the saddle 10 and configured to adjust the transverse position of the saddle 10 relative to the main shaft 101 . The transverse saddle adjuster 30 also helps stabilize the saddle 10 against sideloading to help prevent the main shaft 101 from rotating about a vertical axis through the main bearing, for example under the effect of high side winds. In various embodiments, the transverse saddle adjuster may comprise any number and type of actuator, for example mechanical actuators, hydraulic actuators, electric actuators and the like. Mechanical actuators may comprise cranks, turnbuckles, linkages and the like. The transverse saddle adjuster applies a transversely directed force to the saddle to move the saddle transversely. In the illustrated embodiment, the transverse saddle adjuster 30 comprises two turnbuckles 31 situate at opposite transverse edges of the saddle 10 and connected through pinned connections 32 to the longitudinal beams 91 and through pinned connections 33 to the saddle 10. Operating the turnbuckles 31 causes the saddle 10 to shift in one or the other of the transverse directions relative to the main shaft 101 so that the recess 11 can be properly aligned with the main shaft 101. Operating the turnbuckles 31 is also needed to help raise and lower the saddle 10.

[0045] The flexible strap(s), moveable saddle, vertical saddle adjuster and transverse saddle adjuster all cooperate to simplify the process of immobilizing the main shaft with a main shaft fixture by providing adjustability of the saddle and the flexible strap through several degrees of freedom. Adjustability (vertically, transversely and rotationally) of the saddle and flexibility of the strap(s) permits proper seating of the saddle and the strap(s) on the main shaft so that the main shaft is well-secured and prevented from tipping. Furthermore, the same support system can be used to tilt the main shaft, for example by about 0.5-1°, to facilitate removal and / or reinstallation of a gearbox, main bearing and the like. The novel features will become apparent to those of skill in the art upon examination of the description. It should be understood, however, that the scope of the claims should not be limited by the embodiments but should be given the broadest interpretation consistent with the wording of the claims and the specification as a whole.

Claims

Claims:

1. An adjustable support system for supporting and immobilizing a longitudinally extending main shaft in a nacelle of a wind turbine when a gearbox has been dismounted from the main shaft, the support system comprising: a transverse beam rigidly mounted in the nacelle and extending over the main shaft; a saddle having an arcuate recess to engage with the main shaft from above the main shaft, the saddle movably connected to the transverse beam; a flexible strap that engages the main shaft from below the main shaft to support the main shaft from below; and, a transverse saddle adjuster connected to the saddle and configured to adjust transverse position of the saddle relative to the main shaft.

2. The adjustable support of claim 1 , wherein the transverse saddle adjuster also stabilizes the saddle against sideloading to help prevent the main shaft from rotating about a vertical axis through a main bearing of the wind turbine.

3. The adjustable support system of claim 1 or claim 2, wherein the transverse saddle adjuster comprises an actuator that applies a transversely directed force to the saddle.

4. The adjustable support system of claim 3, wherein the actuator comprises a mechanical actuator.

5. The adjustable support system of claim 4, wherein the mechanical actuator comprises a turnbuckle.

6. The adjustable support system of claim 1 or claim 2, wherein the transverse saddle adjuster comprises at least two turnbuckles connecting the saddle to the nacelle from opposite sides of the saddle.

7. The adjustable support system of any one of claims 1 to 6, wherein the transverse saddle adjuster connects the saddle to a longitudinal beam situated above the main shaft.

8. The adjustable support system of any one of claims 1 to 7, further comprising a vertical saddle adjuster connected to the transverse beam, the vertical saddle adjuster configured to translate the saddle vertically to immobilize the main shaft between the saddle and the flexible strap and / or change a tilt angle of the main shaft in the nacelle.

9. The adjustable support system of claim 8, wherein the vertical saddle adjuster comprises a threaded rod threaded through a threaded aperture in the transverse beam whereby an end of the threaded rod engages the saddle as the threaded rod is turned to vertically translate the saddle.

10. The adjustable support system of claim 9, wherein the saddle comprises a depression in which the threaded rod engages the saddle.

11. The adjustable support system of any one of claims 1 to 10, wherein the saddle is movably connected to the transverse beam by rigging.

12. The adjustable support system of any one of claims 1 to 11 , wherein the saddle is transversely movable along a transverse axis and rotatable about a vertical axis through the saddle to permit adjusting a position of the saddle in relation to the main shaft.13 The adjustable support system of any one of claims 1 to 12, wherein the flexible strap is connected to the transverse beam.

14. The adjustable support system of claim 1 , wherein: the transverse beam is mounted to longitudinal beams mounted in the nacelle, the longitudinal beams situated above the main shaft and mounted on pillow blocks in the nacelle; the saddle is transversely movable along a transverse axis, vertically movable along a vertical axis through the saddle and rotatable about the vertical axis; the transverse saddle adjuster is connected to the saddle and at least one of the longitudinal beams; and, the flexible strap is connected to the transverse beam.

15. The adjustable support system of claim 14, further comprising a vertical saddle adjuster connected to the transverse beam, the vertical saddle adjuster configured to translate thesaddle vertically to immobilize the main shaft between the saddle and the flexible strap and / or change a tilt angle of the main shaft in the nacelle.

16. The adjustable support system of any one of claims 1 to 15, wherein the arcuate recess has a depth sufficient to impede the main shaft from rolling out of the saddle when the main shaft experiences side loading.

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