The present disclosure relates generally to wind turbines, and more particularly to a structural assembly for an improved hub-to-shaft connection.
Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades capture kinetic energy from wind using known foil principles and transmit the kinetic energy through rotational energy to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
The uptower components of the wind turbines require periodic maintenance, inspection, and repair, and the safety of personnel conducting such procedures is paramount. The rotating components of the rotor, drivetrain, and yaw system all present risks to personnel, and it is an important safety consideration to prevent the rotation of such components while personnel are performing certain procedures in the nacelle or rotor hub. In various jurisdictions around the world, permits for installation and operation of wind turbines require interlocks between the rotor and yaw systems with the hatches in the nacelle that give access to the respective components/systems.
In this regard, EP 1 291 521 A1 describes a wind turbine having a rotor lock device for locking a rotor disk and fixation means for fixing the rotor disk to the nacelle. The rotor lock device includes an axially movable pin arranged on the nacelle structure and corresponding apertures formed in the rotor disk.
Furthermore, U.S. Patent Publication No. 2010/0232978 describes a rotor lock for locking a hub of a wind turbine against rotational movements relative to a base frame of the nacelle of the wind turbine. Such a locking arrangement is, e.g., required for safety purposes in order to prevent the hub from rotating during maintenance of the wind turbine. The locking arrangement may include a safety system that prevents access to an interior part of the hub when certain components of the locking arrangement are in the release position. The safety system may, e.g., be coupled to a locking system of a hatch or a door arranged across an opening creating access to the hub, wherein the safety system prevents the locking mechanism from being unlocked if the locking components are in the release position, i.e., if the hub is allowed to rotate relative to the base frame. Thereby, it is ensured that maintenance personnel can only gain access to the interior part of the hub if the hub is securely locked to the base frame.
In a typical wind turbine, the load transfer path from the hub to the main shaft goes completely through a bolted joint between these two components. However, the rotor lock disk, which is typically in the vicinity of the bolted connection, is not involved in this load path. Rather, the sole purpose of the rotor lock disk is to receive the Low Speed Rotor Lock (LSRL) shear pin to lock the turbine rotor.
Accordingly, there is a need for an improved structural architecture that engages the rotor lock disk in the load carrying capacity to increase the hub to main shaft joint capacity.
Aspects and advantages of the present disclosure will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the present disclosure.
In one aspect, the present disclosure is directed to a wind turbine. The wind turbine includes a nacelle, a generator housed with the nacelle, a rotor having a rotatable hub with at least one rotor blade mounted thereto, at least one shaft rotatably coupled to the hub for driving the generator, and a rotor lock arranged with the shaft(s) for locking the shaft(s) in a locked position. The wind turbine also includes a bolted-joint connection at an interface between the hub and the shaft(s). The bolted-joint connection includes a first plurality of fasteners extending through the hub, the shaft(s), and the rotor lock. As such, a load transfer path from the hub to the shaft(s) travels through each of the hub, the shaft(s), and the rotor lock so as to increase a load capacity of the interface.
In an embodiment, the wind turbine may also include a gearbox. In such embodiments, the shaft(s) may include a rotor shaft rotatably coupled to the hub for driving the gearbox and a generator shaft rotatably coupled to the gearbox for driving the generator. In another embodiment, the rotor lock may be one of a rotor shaft rotor lock or a generator shaft rotor lock.
In further embodiments, the interface may also include a hub stiffener. In one embodiment, the hub stiffener may be positioned on a rotor side of the rotor lock. In alternative embodiments, the hub stiffener may be positioned on a generator side of the rotor lock. In certain embodiments, the hub stiffener may include a plurality of stiffener segments arranged circumferentially around the rotor lock.
Thus, in particular embodiments, each of the plurality of stiffener segments receives one or more of the first plurality of fasteners therethrough. Furthermore, in such embodiments, each of the plurality of stiffener segments may be positioned within the hub.
In further embodiments, each of the plurality of stiffener segments receives a subset of a second plurality of fasteners therethrough such that the second plurality of fasteners secure the plurality of stiffener segments to the hub between the rotor lock and the hub. In such embodiments, the second plurality of fasteners may be arranged concentric with the first plurality of fasteners.
Furthermore, in an embodiment, one or more of the subset of the second plurality of fasteners received through each of the plurality of stiffener segments may include jacking components, such as jacking fasteners and/or jacking wedges. In such embodiments, the jacking components may be positioned at opposing ends of the each of the plurality of stiffener segments.
In additional embodiments, one or more of the plurality of stiffener segments may include a scalloped portion for reducing weight thereof and/or to enable packaging of the features and/or components required in the assembly process.
In another aspect, the present disclosure is directed to a method of increasing a load capacity of an interface between a hub and a rotor shaft of a wind turbine. The method includes providing a first plurality of fasteners through the hub, the rotor shaft, and a rotor lock of the wind turbine. The rotor lock includes a first plurality of through holes. The method further includes machining a second plurality of through holes through the rotor lock and through the hub. Further, the method includes arranging a plurality of stiffener segments circumferentially between the rotor lock and the hub to form a hub stiffener, each of the plurality of stiffener segments comprising a plurality of through holes that align with a subset of the second plurality of through holes. Moreover, the method includes securing the hub stiffener between the rotor lock and the hub via a plurality of second fasteners that extend through the plurality of through holes of each of the stiffener segments and the second plurality of through holes of the rotor lock.
In an embodiment, the method includes removing a shroud of the rotor lock before machining the second plurality of through holes through the rotor lock.
In further embodiments, the method may include adjusting a height of the hub stiffener via one or more jacking components arranged with one or more of the plurality of stiffener segments to match a gap between the hub and the rotor lock.
In another embodiment, the method may include installing a segmented rain cover at the interface.
In additional embodiments, the method may include machining the second plurality of through holes through the rotor lock from outside of the hub. Alternatively, the method may include machining the second plurality of through holes through the rotor lock from within the hub.
These and other features, aspects and advantages of the present disclosure will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
A full and enabling disclosure of the present disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
Reference now will be made in detail to embodiments of the present disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the present disclosure, not limitation of the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope of the present disclosure. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents.
Referring now to the drawings,
The wind turbine 10 may also include a turbine control system or controller 26 centralized within the nacelle 16. In general, the controller 26 may comprise a computer or other suitable processing unit. Thus, in several embodiments, the controller 26 may include suitable computer-readable instructions that, when implemented, configure the controller 26 to perform various different functions, such as receiving, transmitting and/or executing wind turbine control signals (e.g., pitch commands). As such, the controller 26 may generally be configured to control the various operating modes (e.g., start-up or shut-down sequences) and/or components of the wind turbine 10. For example, the controller 26 may be configured to adjust the blade pitch or pitch angle of each rotor blade 22 (i.e., an angle that determines a perspective of the blade 22 with respect to the direction of the wind) about its pitch axis 28 in order to control the rotational speed of the rotor blade 22 as well as the loads acting on the rotor blade 22. For example, the controller 26 may individually control the pitch angle of each rotor blade 22 by transmitting suitable pitch commands to a pitch system 30 (
Referring now to
As shown in
The operation of the pitch adjustment mechanism 37 for each rotor blade 22 may generally be controlled by the controller 26 via the individual pitch controller 38 for that rotor blade 22.
Similarly, the wind turbine 10 may include one or more yaw drive mechanisms 56 communicatively coupled to the controller 26, with each yaw drive mechanism(s) 56 being configured to change the angle of the nacelle 16 relative to the wind (e.g., by engaging a yaw bearing 58 of the wind turbine 10). The yaw system may include a yaw brake 55, such as a conventional piston/cylinder brake system, as well as a yaw lock (not depicted in
Referring to
Referring now to
It should be understood that the wind turbine 10 may include any conventional configuration of a rotor lock, rotor brake, yaw lock, and/or yaw brake. For example,
Referring now to
In particular,
More particularly, as shown in
Furthermore, as shown in
For example, in an embodiment, as shown in
In additional embodiments, as shown in
In further embodiments, as shown in
More specifically, as shown in
In another embodiment, as shown in
In alternative embodiments, as shown in
Referring now to
In an embodiment, as shown at (202), the method 200 may include positioning the wind turbine 10 in a desired rotor position, such as in a rabbit-eared position and locking the rotor 18 in the desired position. As shown at (204), the method 200 includes optionally include removing a shroud of cover of the rotor lock 68 so as to expose the rotor lock 68. Similarly, if needed, a rain cover of the wind turbine 10 may also be removed to provide access to the rotor lock 68. As shown at (206), the method 200 includes providing a first plurality of fasteners 104 through the hub 20, the rotor shaft 32, and the rotor lock 68 of the wind turbine 10. Further, as generally shown in the figures, the rotor lock 68 includes a first plurality of through holes.
Thus, as shown at (208), the method 200 may further include positioning a machining template on the rotor lock 68. Further, as shown at (210), the method 200 includes machining a second plurality of through holes through the rotor lock 68. For example, in an embodiment, the second plurality of through holes may be machined using any suitable cutting tool, such as a drill. Moreover, as part of the machining process, the method 200 may also include grinding, painting, coating, or similar. For example, in an embodiment, one or more areas within the hub 20 may be grinded such that the various fasteners described herein can lay flat.
In one embodiment, the method 200 may include machining the second plurality of through holes through the rotor lock 68 from outside of the hub 20. Alternatively, the method 200 may include machining the second plurality of through holes through the rotor lock 68 from within the hub 20.
Referring still
In another embodiment, the method 200 may include re-installing the rain cover or installing a new segmented rain cover at the interface 102.
Various aspects and embodiments of the present invention are defined by the following numbered clauses:
Clause 1. A wind turbine, comprising:
a nacelle;
a generator housed with the nacelle;
a rotor comprising a rotatable hub with at least one rotor blade mounted thereto;
at least one shaft rotatably coupled to the hub for driving the generator; and
a rotor lock arranged with the at least one shaft for locking the at least one shaft in a locked position; and
a bolted-joint connection at an interface between the hub and the at least one shaft comprising a first plurality of fasteners extending through the hub, the at least one shaft, and the rotor lock,
wherein a load transfer path from the hub to the at least one shaft travels through each of the hub, the at least one shaft, and the rotor lock so as to increase a load capacity of the interface.
Clause 2. The wind turbine of clause 1, further comprising a gearbox, wherein the at least one shaft comprises a rotor shaft rotatably coupled to the rotatable hub for driving the gearbox and a generator shaft rotatably coupled to the gearbox for driving the generator.
Clause 3. The wind turbine of any of the preceding clauses, wherein the rotor lock is one of a rotor shaft rotor lock or a generator shaft rotor lock.
Clause 4. The wind turbine of any of the preceding clauses, wherein the interface further comprises a hub stiffener.
Clause 5. The wind turbine of any of the preceding clauses, wherein the hub stiffener is positioned on a rotor side of the rotor lock.
Clause 6. The wind turbine of any of the preceding clauses, wherein the hub stiffener is positioned on a generator side of the rotor lock.
Clause 7. The wind turbine of any of the preceding clauses, wherein the hub stiffener comprises a plurality of stiffener segments arranged circumferentially around the rotor lock.
Clause 8. The wind turbine of any of the preceding clauses, wherein each of the plurality of stiffener segments receives one or more of the first plurality of fasteners therethrough.
Clause 9. The wind turbine of any of the preceding clauses, wherein each of the plurality of stiffener segments is positioned within the rotatable hub.
Clause 10. The wind turbine of any of the preceding clauses, wherein each of the plurality of stiffener segments receives a subset of a second plurality of fasteners therethrough such that the second plurality of fasteners secure the plurality of stiffener segments to the rotatable hub between the rotor lock and the hub, wherein the second plurality of fasteners is arranged concentric with the first plurality of fasteners.
Clause 11. The wind turbine of any of the preceding clauses, wherein one or more of the subset of the second plurality of fasteners received through each of the plurality of stiffener segments comprises jacking components.
Clause 12. The wind turbine of any of the preceding clauses, wherein the jacking components are positioned at opposing ends of the each of the plurality of stiffener segments.
Clause 13. The wind turbine of any of the preceding clauses, wherein one or more of the plurality of stiffener segments comprises a scalloped portion for reducing weight thereof.
Clause 14. A method of increasing a load capacity of an interface between a hub and a rotor shaft of a wind turbine, the method comprising:
providing a first plurality of fasteners through the hub, the rotor shaft, and a rotor lock of the wind turbine, the rotor lock comprising a first plurality of through holes;
machining a second plurality of through holes through the rotor lock and through the hub;
arranging a plurality of stiffener segments circumferentially between the rotor lock and the hub to form a hub stiffener, each of the plurality of stiffener segments comprising a plurality of through holes that align with a subset of the second plurality of through holes; and securing the hub stiffener between the rotor lock and the hub via a plurality of second fasteners that extend through the plurality of through holes of each of the stiffener segments and the second plurality of through holes of the rotor lock.
Clause 15. The method of clause 14, further comprising removing a shroud of the rotor lock before machining the second plurality of through holes through the rotor lock.
Clause 16. The method of clauses 14-15, further comprising adjusting a height of the hub stiffener via one or more jacking components arranged with one or more of the plurality of stiffener segments to match a gap between the hub and the rotor lock.
Clause 17. The method of clauses 14-16, further comprising installing a segmented rain cover at the interface.
Clause 18. The method of clauses 14-17, further comprising machining the second plurality of through holes through the rotor lock from outside of the hub.
Clause 19. The method of clauses 14-18, further comprising machining the second plurality of through holes through the rotor lock from within the hub.
Clause 20. The method of clauses 14-19, wherein the second plurality of fasteners is arranged concentric with the first plurality of fasteners.
This written description uses examples to disclose the present disclosure, including the best mode, and also to enable any person skilled in the art to practice the present disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the present disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.