A YAW BRAKING ASSEMBLY OF A WIND TURBINE
FIELD
[0001] The present disclosure relates in general to wind turbines, and more
particularly to systems and methods for braking a yawing rotation of the nacelle of a
wind turbine.
BACKGROUND
[0002] 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, a
generator, a gearbox, a nacelle, and one or more rotor blades. The nacelle includes a
rotor assembly coupled to the gearbox and to the generator. The rotor assembly and
the gearbox are mounted on a bedplate support frame located within the nacelle. The
one or more rotor blades capture kinetic energy of wind using known airfoil
principles. The rotor blades transmit the kinetic energy in the form of rotational
energy so as 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 and the electrical energy may be transmitted to a converter
and/or a transformer housed within the tower and subsequently deployed to a utility
grid. Modern wind power generation systems typically take the form of a wind farm
having multiple such wind turbine generators that are operable to supply power to a
transmission system providing power to an electrical grid.
[0003] In order to efficiently produce electrical energy, it is typically desirable for
the nacelle of the wind turbine to be oriented in aerodynamic alignment with the
winds acting on the wind turbine. This is generally accomplished by rotating the
nacelle relative to the tower. However, once aerodynamic alignment is achieved,
additional rotation of the nacelle relative to the tower must be resisted. The resistance
to additional rotation is typically provided via a yaw braking system.
[0004] The yaw braking systems of modern wind turbines are typically cylindrical
in nature and are inserted through the bedplate support frame. The yaw braking
systems typically utilize the top surface of the yaw bearing as the braking friction
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surface and the bedplate support frame as the mounting structure for the braking load
actuating unit. However, this configuration has several known drawbacks. For
example, during the braking of the nacelle, loads in sheer, axial, torque, and moment
directions are generated and can be transferred to the internal components of the
actuation unit, causing damage. Additionally, the circular nature of the brake pads
often facilitates the spinning of the brake pads during actuation. It is common for the
spinning of the brake pads to result in a decreased braking effectiveness, pad-edge
cracking, loosening, and actuator component wear/damage. Additionally, due to the
likelihood of spinning, the incorporation of wear sensors into the brake pads has
proven quite problematic, which leads to brake pad servicing on a schedule, rather
than when necessitated by actual conditions. Further, because the yaw braking
systems are typically inserted through the bedplate support frame, servicing of the
brake pads requires the disassembly of the yaw braking system in order to remove and
access the brake pads.
[0005] Thus, the art is continuously seeking new and improved systems to control
the yawing rotation of the nacelle of a wind turbine. Accordingly, the present
disclosure is directed to a yaw braking assembly which overcomes the drawbacks of
the previous yaw braking assemblies.
BRIEF DESCRIPTION
[0006] Aspects and advantages of the invention 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 invention.
[0007] In one aspect, the present disclosure is directed to a yaw braking assembly
of a wind turbine. The braking assembly may include a yaw bearing. The yaw
braking assembly may also include a bedplate support frame having an annular flange
arranged adjacent to the yaw bearing. The annular flange may define a plurality of
recesses formed into a lower-most annular surface of the annular flange and extending
at least partially through an axial thickness of the annular flange. Each of the plurality
of recesses may define and open exterior circumferential side. Additionally, the yaw
braking assembly may include a plurality of brake pads positioned within the plurality
of recesses. Each of the plurality of brake pads may be configured to engage at least
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one race of the yaw bearing. Further, the yaw braking assembly may include a
plurality of actuators for driving the plurality of brake pads to engage the at least one
race of the yaw bearing so as to resist a yawing of a nacelle of the wind turbine.
[0008] In an embodiment, the yaw braking assembly may also include a plurality
of arm members positioned within a corresponding plurality of holes through the
annular flange between the plurality of actuators and the plurality of brake pads. The
plurality of arm members may be oriented to transfer a force from the plurality of
actuators to the plurality of brake pads.
[0009] In an embodiment, each of the plurality of brake pads may have a noncircular shape.
[0010] In an additional embodiment, each of the plurality of brake pads may have
at least one of a polygonal a shape, a curvilinear polygonal the shape, or a roundedsquare planform.
[0011] In a further embodiment, each of the plurality of brake pads may define a
maximal length and a maximal width. The maximal length may be greater than the
maximal width.
[0012] In an embodiment, each open, exterior circumferential side of the plurality
of recesses may define a circumferential length which is greater than the maximal
length of the corresponding brake pad.
[0013] In an additional embodiment, only one of the plurality of brake pads may
be positioned within each of the plurality of recesses.
[0014] In an embodiment, the plurality of recesses and corresponding plurality of
brake pads may be distributed circumferentially about the annular flange in a plurality
of adjacent pair sets.
[0015] In an additional embodiment, a single actuator may be operably coupled to
each of the plurality of pair sets.
[0016] In a further embodiment, the plurality of brake pads may be radially
aligned with an outer race of the yaw bearing.
[0017] In an embodiment, the yaw braking assembly may also include a retention
bracket secured to the exterior circumferential side. The retention bracket may
occlude at least one of the circumferential openings.
[0018] In an additional embodiment, at least one of the plurality of brake pads
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may also include at least one sensor configured to generate an alert relating to a wear
level of one or more of the plurality of brake pads.
[0019] In a further embodiment, the sensor(s) may include a continuity sensor.
[0020] In an embodiment, the plurality of brake pads may be accessible from
outside of the bedplate support frame via the corresponding circumferential openings.
[0021] In an additional embodiment, each of the plurality of brake pads may be
formed with at least one extraction feature. The extraction feature may be positioned
so as to facilitate the removal of each of the brake pads from the corresponding
recesses.
[0022] In another aspect, the present disclosure is directed to a wind turbine. The
wind turbine may include a tower. The wind turbine may also include a nacelle
mounted atop the tower. The nacelle may include a bedplate support frame. The
bedplate support frame may include an annular flange. The annular flange may define
a plurality of recesses formed into a lower-most annular surface of the annular flange
and extending at least partially through an axial thickness of the annular flange. Each
of the plurality of recesses may define and open, exterior circumferential side. The
wind turbine may include a yaw bearing arranged adjacent to the annular flange.
Further, the wind turbine may include a rotor mounted to the nacelle. The rotor may
include a rotatable hub having one or more rotor blades secured thereto. Additionally,
the wind turbine may include a plurality of brake pads positioned within the plurality
of recesses. Each of the plurality of brake pads may be configured to engage at least
one race of the yaw bearing. The wind turbine may also include a plurality of
actuators for driving the plurality of brake pads to engage the at least one race of the
yaw bearing so as to resist a yawing of a nacelle of the wind turbine. It should be
understood that the system may further include any of the additional steps and/or
features described herein.
[0023] In another aspect, the present disclosure is directed to a method for
servicing a yaw braking assembly of a wind turbine. The method may include
accessing at least one brake pad of a plurality of brake pads via an open, exterior
circumferential side of a recess defined by at least one of a plurality of recesses
formed into a lower-most annular surface of an annular flange of a bedplate support
frame and extending at least partially through an axial thickness of the annular flange,
6
wherein the lower-most annular surface is disposed adjacent to a yaw bearing of the
wind turbine. The method may also include passing the at least one brake pad
through the open, exterior circumferential side of the recess while retaining a
corresponding actuator of a plurality of actuators in an assembled configuration. It
should be understood that the system may further include any of the additional steps
and/or features described herein.
[0024] These and other features, aspects and advantages of the present invention
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 invention and,
together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] A full and enabling disclosure of the present invention, 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:
[0026] FIG. 1 illustrates a perspective view of one embodiment of a wind turbine
according to the present disclosure;
[0027] FIG. 2 illustrates a perspective, internal view of one embodiment of a
nacelle of a wind turbine according to the present disclosure;
[0028] FIG. 3 illustrates a top view of one embodiment of a yaw bearing of a
wind turbine according to the present disclosure;
[0029] FIG. 4 illustrates a perspective view of a portion of a wind turbine tower
according to the present disclosure;
[0030] FIG. 5 illustrates a perspective view of a bedplate support frame for
utilization with a yaw braking assembly according to the present disclosure;
[0031] FIG. 6 illustrates a perspective view of an assembled portion of the yaw
braking assembly according to the present disclosure;
[0032] FIGS. 7A and 7B illustrate cross-sectional views of a portion of the
bedplate support frame of FIG. 5 according to the present disclosure;
[0033] FIG. 8 illustrates a bottom view of a portion of the lower-most annular
face of the bedplate support frame of FIG. 5 according to the present disclosure;
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[0034] FIG. 9 illustrates an upward perspective view of a portion of an
embodiment of a portion of the yaw braking assembly according to the present
disclosure;
[0035] FIG. 10 illustrates a bottom view of an embodiment of a brake pad of the
yaw brake assembly according to the present disclosure;
[0036] FIG. 11 illustrates a bottom view of an embodiment of a brake pad of the
yaw brake assembly according to the present disclosure;
[0037] FIGS. 12A and 12B illustrate side and perspective views of embodiments
of brake pads for utilization with the yaw braking assembly according to the present
disclosure; and
[0038] FIG. 13 illustrates a flowchart of a method for servicing a yaw braking
assembly according to the present disclosure.
[0039] Repeat use of reference characters in the present specification and
drawings is intended to represent the same or analogous features or elements of the
present invention.
DETAILED DESCRIPTION
[0040] Reference now will be made in detail to embodiments of the invention,
one or more examples of which are illustrated in the drawings. Each example is
provided by way of explanation of the invention, not limitation of the invention. In
fact, it will be apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing from the scope or
spirit of the invention. 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 invention covers such modifications
and variations as come within the scope of the appended claims and their equivalents.
[0041] As used herein, the terms “first”, “second”, and “third” may be used
interchangeably to distinguish one component from another and are not intended to
signify location or importance of the individual components.
[0042] The terms “coupled,” “fixed,” “attached to,” and the like refer to both
direct coupling, fixing, or attaching, as well as indirect coupling, fixing, or attaching
through one or more intermediate components or features, unless otherwise specified
8
herein.
[0043] Approximating language, as used herein throughout the specification and
claims, is applied to modify any quantitative representation that could permissibly
vary without resulting in a change in the basic function to which it is related.
Accordingly, a value modified by a term or terms, such as “about”, “approximately”,
and “substantially”, are not to be limited to the precise value specified. In at least
some instances, the approximating language may correspond to the precision of an
instrument for measuring the value, or the precision of the methods or machines for
constructing or manufacturing the components and/or systems. For example, the
approximating language may refer to being within a 10 percent margin.
[0044] Here and throughout the specification and claims, range limitations are
combined and interchanged, such ranges are identified and include all the sub-ranges
contained therein unless context or language indicates otherwise. For example, all
ranges disclosed herein are inclusive of the endpoints, and the endpoints are
independently combinable with each other.
[0045] Generally, the present disclosure is directed to a yaw braking assembly of
a wind turbine. In particular, the yaw braking assembly of the present disclosure may
include a bedplate support frame having an annular flange. The annular flange may
be formed with a plurality of recesses formed into a lower-most annular surface of the
annular flange. The recesses may extend at least partially through an axial thickness
of the flange and may define an opening in the exterior circumferential side of the
annular flange. In other words, each of the recesses may have two open sides through
which a corresponding brake pad may pass. One opening may be in the lower-most
annular surface of the annular flange and may facilitate the brake pad’s engagement
with a braking friction surface, such as a yaw bearing. The second opening may be in
the exterior circumferential side of the annular flange and may facilitate access to the
brake pad without requiring that the yaw braking assembly be disassembled.
[0046] The brake pads inserted into each of the recesses may have a non-circular
shape. For example, the brake pads may have a polygonal shape, a curvilinear
polygonal shape, or a rounded-square planform. Being formed with a non-circular
shape, the brake pads may interface with the recesses so as to transfer loads generated
during braking to the bedplate support frame, rather than to the actuator components
9
of the yaw braking assembly. It should be appreciated that because the brake pads
interface with the recesses, the brake pads may be prevented from spinning during
braking operations. This, in turn, may increase the braking effectiveness of the yaw
braking assembly and may facilitate the inclusion of a wear sensor with the brake
pads.
[0047] Referring now to the drawings, FIG. 1 illustrates a perspective view of one
embodiment of a wind turbine 100 according to the present disclosure. As shown, the
wind turbine 100 generally includes a tower 102 extending from a support surface
104, a nacelle 106, mounted on the tower 102, and a rotor 108 coupled to the nacelle
106. The rotor 108 includes a rotatable hub 110 and at least one rotor blade 112
coupled to and extending outwardly from the hub 110. For example, in the illustrated
embodiment, the rotor 108 includes three rotor blades 112. However, in an alternative
embodiment, the rotor 108 may include more or less than three rotor blades 112.
Each rotor blade 112 may be spaced about the hub 110 to facilitate rotating the rotor
108 to enable kinetic energy to be transferred from the wind into usable mechanical
energy, and subsequently, electrical energy. For instance, the hub 110 may be
rotatably coupled to an electric generator 118 (FIG. 2) positioned within the nacelle
106 to permit electrical energy to be produced.
[0048] The wind turbine 100 may also include a turbine controller 114 centralized
within the nacelle 106. However, in other embodiments, the turbine controller 114
may be located within any other component of the wind turbine 100 or at a location
outside the wind turbine. Further, the turbine controller 114 may be communicatively
coupled to any number of the components of the wind turbine 100 in order to control
the components. As such, the turbine controller 114 may include a computer or other
suitable processing unit. Thus, in several embodiments, the turbine controller 114
may include suitable computer-readable instructions that, when implemented,
configure the turbine controller 114 to perform various different functions, such as
receiving, transmitting and/or executing wind turbine control signals.
[0049] Referring now to FIG. 2, a simplified, internal view of one embodiment of
the nacelle 106 of the wind turbine 100 shown in FIG. 1 is illustrated. As shown, the
generator 118 may be coupled to the rotor 108 for producing electrical power from the
rotational energy generated by the rotor 108. For example, as shown in the illustrated
10
embodiment, the rotor 108 may include a rotor shaft 122 coupled to the hub 110 for
rotation therewith. The rotor shaft 122 may be rotatably supported by a main bearing.
The rotor shaft 122 may, in turn, be rotatably coupled to a high-speed shaft 124 of the
generator 118 through a gearbox 126 connected to a bedplate support frame 136 by
one or more torque arms 142. As is generally understood, the rotor shaft 122 may
provide a low-speed, high-torque input to the gearbox 126 in response to rotation of
the rotor blades 112 and the hub 110. The gearbox 126 may then be configured to
convert the low-speed, high-torque input to a high-speed, low-torque output to drive
the high-speed shaft 124 and, thus, the generator 118. In an embodiment, the gearbox
126 may be configured with multiple gear ratios so as to produce varying rotational
speeds of the high-speed shaft for a given low-speed input, or vice versa.
[0050] Each rotor blade 112 may also include a pitch control mechanism 120
configured to rotate each rotor blade 112 about its pitch axis 116. The pitch control
mechanism 120 may include a pitch controller configured to receive at least one pitch
setpoint command from the turbine controller 114. Further, each pitch control
mechanism 120 may include a pitch drive motor 128 (e.g., any suitable electric,
hydraulic, or pneumatic motor), a pitch drive gearbox 130, and a pitch drive pinion
132. In such embodiments, the pitch drive motor 128 may be coupled to the pitch
drive gearbox 130 so that the pitch drive motor 128 imparts mechanical force to the
pitch drive gearbox 130. Similarly, the pitch drive gearbox 130 may be coupled to the
pitch drive pinion 132 for rotation therewith. The pitch drive pinion 132 may, in turn,
be in rotational engagement with a pitch bearing 134 coupled between the hub 110
and a corresponding rotor blade 112 such that rotation of the pitch drive pinion 132
causes rotation of the pitch bearing 134. Thus, in such embodiments, rotation of the
pitch drive motor 128 drives the pitch drive gearbox 130 and the pitch drive pinion
132, thereby rotating the pitch bearing 134 and the rotor blade(s) 112 about the pitch
axis 116.
[0051] The wind turbine 100 may also include one or more yaw drive
mechanisms 138 communicatively coupled to the controller 114. Each yaw drive
mechanism(s) 138 may be configured to change the angle of the nacelle 106 relative
to the wind by engaging a yaw bearing 140 of the wind turbine 100. The yaw bearing
140 may couple the tower 102 and nacelle 106 at a yaw bearing interface 146. For
11
example, as shown in FIG. 3, the yaw bearing 140 may include an inner race 148 and
an outer race 150. As such, the inner race 148 of the yaw bearing 140 may be
mounted to the bedplate support frame 136, whereas the outer race 150 of the yaw
bearing 140 may be mounted to the tower 102 or vice versa. Mounting may be
facilitated through the use of suitable mechanical fasteners, such as nut-bolt
combinations, screws, nails, rivets, or other suitable mechanical fastening devices, or
through a suitable adhesive, or through a suitable mounting technique such as welding
or brazing. In an exemplary embodiment, the inner race 148 may have an inner race
hole pattern 152 corresponding to a matching hole pattern in the bedplate support
frame 136. Similarly, the outer race 150 may have an outer race hole pattern 154 that
corresponds to a matching hole pattern atop the tower 102. In exemplary
embodiments, rotation of the yaw bearing 140, such as the rotation of the inner race
148 with respect to the outer race 150, may cause the nacelle 106 to rotate with
respect to the tower 102. It should be appreciated that in at least one embodiment, the
yaw bearing 140 may be formed with a single race 148, 150 and the tower 102 may
serve as the other race.
[0052] As depicted in FIG. 4, in an embodiment, a reference system may be
defined with respect to the wind turbine 100. In such an embodiment, an axis (A)
may be defined which is essentially parallel to a centerline of the tower 102 and
perpendicular to the support surface 104. The axis (A) may define the axial direction
of the wind turbine 100 such that the term “axially” refers to a position, dimension,
translation, or movement along, or in reference to, the axis (A). The axis may be
intersected by a plane (R). The plane (R) may be oriented essentially perpendicular to
the axis (A) and may define a radial direction as used herein. As such, the term
“radially” refers to a position, dimension, translation, or movement along, or in
reference to, a radius relative to the axis (A). Additionally, an arc (C) may be defined
along the plane (R) so as to define a circumferential position, dimension, translation,
or movement.
[0053] Referring now to FIG. 5-12B, wherein multiple embodiments of the yaw
braking assembly 300 are presented. As shown in FIG. 5, the bedplate support frame
136 may include an annular flange 302. The annular flange 302 may, as depicted in
FIG. 2, be arranged adjacent to the yaw bearing 140 along the yaw bearing interface
12
146. As is particularly illustrated in FIG. 7A, in an embodiment, the annular flange
302 may define a plurality of recesses 304 formed into a lower-most annular surface
306 of the annular flange 302. The plurality of recesses 304 may extend at least
partially through an axial thickness (AT) of the annular flange 302. Each of the
plurality of recesses 304 may define an open, exterior circumferential side 308. In
other words, each of the recesses 304 may define an opening in an exterior
circumferential side 310 of the annular flange 302. In an embodiment, the yaw
braking assembly 300 may also include a plurality of brake pads 312 positioned
within the plurality of recesses 304. The plurality of brake pads 312 may be
configured to engage at least one race 148, 150 of the yaw bearing 140. For example,
in at least one embodiment, the plurality of brake pads 312 may be radially aligned
with the outer race 150 of the yaw bearing 140. Additionally, the yaw braking
assembly 300 may include a plurality of actuators 314 for driving plurality of brake
pads 312 to engage the yaw bearing 140 and resist a yawing of the nacelle 106 of the
wind turbine 100.
[0054] As is particularly depicted in FIGS. 7A and 7B, in at least one
embodiment, the yaw braking assembly 300 may include a plurality of arm members
316 positioned within a corresponding plurality of holes 318 through the annular
flange 302. The holes 318 may be positioned between the plurality of actuators 314
and the plurality of brake pads 312. In an embodiment, the plurality of arm members
316 may be oriented to transfer a force from the plurality of actuators 314 to the
plurality of brake pads 312. In other words, the plurality of arm members 316 may
operably couple the plurality of brake pads 312 to the corresponding plurality of
actuators 314.
[0055] In an embodiment, the brake pads 312 may include a wear layer 320
coupled to a backer plate 322. The wear layer 320 may be configured to engage the
yaw bearing 140 and develop a friction therewith. As such, the wear layer 320 may
be any suitable material selected based on wear characteristics and heat tolerance.
The backer plate 322 may be a rigid/semi-rigid material, such as steel, configured to
increase the ability of the wear layer 320 to resist structural loading.
[0056] In at least one embodiment, such as depicted in FIGS. 5 and 8-12B, the
plurality of brake pads 312 may have a non-circular shape. Additionally, in an
13
embodiment, the plurality of recesses 304 may be formed to coincide to the noncircular shape of the plurality of brake pads 312. For example, as is depicted in FIG.
8, the brake pads 312 may be formed with a polygonal shape or rounded-square
planform. In such an embodiment, the linear perimeter edges of the plurality of brake
pads 312 may be configured to engage with corresponding edges of the plurality of
recesses 304. As is depicted in FIGS. 9 and 10, in at least one embodiment, the
plurality of brake pads 312 may be formed with a curvilinear polygonal shape. In
other words, in such an embodiment, the brake pads 312 may be generally rectangular
but may be formed to coincide with the circumference of the plurality of recesses 304.
It should be appreciated that the yaw braking assembly 300 may include brake pads
312 having differing planforms.
[0057] It should also be appreciated that forming the plurality of recesses 304
coincide to the non-circular shape of the plurality of brake pads 312 may facilitate the
transfer of braking loads from the of brake pads 312 to the bedplate support frame 136
by precluding the spin or rotation of the brake pads 312. As such, only one of the
plurality of brake pads 312 may be positioned within each of the plurality of recesses
304. In other words, in at least one embodiment, the number of recesses 304 may
equal the number of brake pads 312.
[0058] In at least one embodiment, such as depicted in FIGS. 5 and 8, the
plurality of recesses 304 and corresponding plurality of brake pads 312 may be
distributed circumferentially about the annular flange 302 in a plurality of adjacent
pair sets. In at least one embodiment, such as depicted in FIGS. 5 and 6, a single
actuator 314 may be operably coupled to each of the plurality of pair sets 324. In
such an embodiment, the number of actuators 314 may be half the number of brake
pads 312 and recesses 304. It should be appreciated that employing a single actuator
314 to drive a pair set 324 may reduce the cost and complexity of the yaw braking
assembly 300. It should be further appreciated that, in at least one embodiment, a mix
of singular brake pads 312 and pair sets 324 may be utilized to develop the required
braking force for the wind turbine 100.
[0059] In an embodiment, each of the plurality of brake pads 312 may define a
maximal length (ML) and a maximal width (MW). In at least one embodiment, such as
depicted in FIG. 10, the maximal length (ML) may be greater than the maximal width
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(MW). In an alternative embodiment, the maximal width (MW) may be greater than
the maximal length (ML). In yet a further embodiment, the maximal length (ML) and
the maximal width (MW) may have the same length.
[0060] In an embodiment, each open, exterior circumferential side 308 of the
plurality of recesses 304 may define a circumferential length (CL) which is sufficient
to permit the passage of the corresponding brake pad 312. The passage of the
corresponding brake pad 312 may be accomplished without requiring that the brake
pad 312 be rotated or disassembled. For example, in at least one embodiment, the
circumferential length (CL) of the opening in the exterior circumferential side 310 of
the annular flange 302 may be greater than the maximal length (ML) of the
corresponding brake pad 312. It should be appreciated that the ability to pass the
brake pad 312 through the open, exterior circumferential side 308 of the recess 304
may facilitate the utilization of brake pads 312 having a pad surface area which may
be larger than an actuator piston area. In other words, the brake pads 312 may be
larger than the holes 318. It should further be appreciated that the utilization of brake
pads 312 having a larger area may facilitate more controlled pad pressure, and thus
may result in more desirable reliability and wear characteristics.
[0061] As depicted in FIGS. 6 and 8, in an embodiment, the yaw braking
assembly 300 may include a retention bracket 326. The retention bracket 326 may be
secured to the exterior circumferential side 310 of the annular flange 302. The
retention bracket 326 may occlude at least one of the open, exterior circumferential
sides 308 of the plurality of recesses 304. In such an embodiment, the retention
bracket(s) 326 may be the only component of the wind turbine 100 which must be
removed in order to access the brake pads 312. In an embodiment, the plurality of
brake pads 312 may be accessible from outside of the bedplate support frame 136 via
the corresponding open, exterior circumferential sides 308 of the plurality of recesses
304. For example, the yaw braking assembly 300 may permit the swapping of the
brake pads 312 uptower, within the nacelle 106. In such an embodiment, this service
may be accomplished without requiring the decoupling of the actuators 314 from the
bedplate support frame 136. It should be appreciated that the ability to service the
yaw braking assembly 300 while the yaw braking assembly 300 remains substantially
installed, may reduce the cost and complexity of service operations.
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[0062] In an embodiment, such as depicted in FIGS. 8, 12A, and 12B, at least one
of the plurality of brake pads 312 may include at least one sensor 328 configured to
generate an alert relating to a wear level of one or more of the plurality of brake pads
312. The sensor(s) 328 may be configured to detect when a thickness of the wear
layer 320 may be less than a predetermined threshold. In such an embodiment, the
sensor(s) 328 may generate an alert when the thickness of the wear layer 320 crosses
the threshold. The alert may, include a signal to the controller 114, a light, a sound, or
other suitable device selected to alert an operator of the wear level of one or more of
the plurality of brake pads 312. For example, in at least one embodiment, the
sensor(s) 328 may be a continuity sensor. As the thickness of the wear layer 320
decreases, the sensor(s) 328 may be brought into contact with the yaw bearing 140,
resulting in a disruption of the continuity of the sensor(s) 328. It should be
appreciated that the inclusion of the sensor(s) 328 may permit the performance or
scheduling of maintenance activities based on actual wear of the brake pads 312,
rather than on a predetermined schedule. This may, in turn, preclude the performance
of maintenance activities out of sync with the wear state of the brake pads 312.
[0063] In a further embodiment, each of the plurality of brake pads 312 may be
formed with at least one extraction feature 330. The extraction feature 330 may be
positioned to facilitate the removal of each of the brake pads 312 from the
corresponding recesses 304. For example, as shown in FIG. 10, the backer plate 322
may be formed with at least one protrusion 332. The protrusion 332 may define
suitable features, such as holes, depressions, notches, and/or ridges, which may be
engaged with the tool so as to affect the extraction of the brake pad 312 through the
open, exterior circumferential side 308 of the corresponding recess 304. In an
additional embodiment, such as depicted in FIG. 11, the backer plate 322 may be
formed so as to define a threaded hole 334. In such an embodiment, a tool, fastener,
or other similar implement may be threaded into the threaded hole 334 and utilized to
extract the brake pad 312 through the open, exterior circumferential side 308 of the
corresponding recess 304.
[0064] Referring now to FIG. 13, a flow diagram of one embodiment of a method
400 for servicing a braking assembly of a wind turbine is presented. The method 400
may be implemented using, for instance, the assembly 300 of the present disclosure
16
discussed above with references to FIGS. 1-12B. FIG. 13 depicts steps performed in
a particular order for purposes of illustration and discussion. Those of ordinary skill
in the art, using the disclosures provided herein, will understand that various steps of
the method 400, or any of the methods disclosed herein, may be adapted, modified,
rearranged, performed simultaneously, or modified in various ways without deviating
from the scope of the present disclosure.
[0065] As shown at (402), the method 400 may include accessing at least one
brake pad of a plurality of brake pads via an open, exterior circumferential side of a
recess defined by at least one of a plurality of recesses formed into a lower-most
annular surface of an annular flange of a bedplate support frame and extending at least
partially through an axial thickness of the annular flange. The lower-most annular
surface may be disposed adjacent to a yaw bearing of the wind turbine. As shown at
(404), the method 400 may also include passing the at least one brake pad through the
open, exterior circumferential side of the recess while retaining a corresponding
actuator of a plurality of actuators in an assembled configuration.
[0066] Furthermore, the skilled artisan will recognize the interchangeability of
various features from different embodiments. Similarly, the various method steps and
features described, as well as other known equivalents for each such methods and
feature, can be mixed and matched by one of ordinary skill in this art to construct
additional systems and techniques in accordance with principles of this disclosure. Of
course, it is to be understood that not necessarily all such objects or advantages
described above may be achieved in accordance with any particular embodiment.
Thus, for example, those skilled in the art will recognize that the systems and
techniques described herein may be embodied or carried out in a manner that achieves
or optimizes one advantage or group of advantages as taught herein without
necessarily achieving other objects or advantages as may be taught or suggested
herein.
[0067] This written description uses examples to disclose the invention, including
the best mode, and also to enable any person skilled in the art to practice the
invention, including making and using any devices or systems and performing any
incorporated methods. The patentable scope of the invention is defined by the claims,
and may include other examples that occur to those skilled in the art. Such other
17
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.
[0068] Further aspects of the invention are provided by the subject matter of the
following clauses:
[0069] Clause 1. A yaw braking assembly of a wind turbine, the yaw braking
assembly comprising: a yaw bearing; a bedplate support frame comprising an annular
flange arranged adjacent to the yaw bearing, the annular flange defining a plurality of
recesses formed into a lower-most annular surface of the annular flange and extending
at least partially through an axial thickness of the annular flange, each of the plurality
of recesses defining an open, exterior circumferential side; a plurality of brake pads
positioned within the plurality of recesses, each of the plurality of brake pads
configured to engage at least one race of the yaw bearing; and a plurality of actuators
for driving the plurality of brake pads to engage the at least one race of the yaw
bearing so as to resist a yawing of a nacelle of the wind turbine.
[0070] Clause 2. The yaw braking assembly of any preceding clause, further
comprising: a plurality of arm members positioned within a corresponding plurality of
holes through the annular flange between the plurality of actuators and the plurality of
brake pads, the plurality of arm members being oriented to transfer a force from the
plurality of actuators to the plurality of brake pads.
[0071] Clause 3. The yaw braking assembly of any preceding clause, wherein
each of the plurality of brake pads has a non-circular shape.
[0072] Clause 4. The yaw braking assembly of any preceding clause, wherein
each of the plurality of brake pads has at least one of a polygonal shape, a curvilinear
polygonal shape, or rounded-square planform.
[0073] Clause 5. The yaw braking assembly of any preceding clause, wherein
each of the plurality of brake pads defines a maximal length and a maximal width, the
maximal length being greater than the maximal width.
[0074] Clause 6. The yaw braking assembly of any preceding clause, wherein
each open, exterior circumferential side of the plurality of recesses defines a
18
circumferential length which is greater than the maximal length of the corresponding
brake pad.
[0075] Clause 7. The yaw braking assembly of any preceding clause, wherein
only one of the plurality of brake pads is positioned within each of the plurality of
recesses.
[0076] Clause 8. The yaw braking assembly of any preceding clause, wherein
the plurality of recesses and corresponding plurality of brake pads are distributed
circumferentially about the annular flange in a plurality of adjacent pair sets.
[0077] Clause 9. The yaw braking assembly of any preceding clause, wherein a
single actuator is operably coupled to each of the plurality of pair sets.
[0078] Clause 10. The yaw braking assembly of any preceding clause, wherein
the plurality of brake pads are radially aligned with an outer race of the yaw bearing.
[0079] Clause 11. The yaw braking assembly of any preceding clause, further
comprising a retention bracket secured to the exterior circumferential side, the
retention bracket occluding at least one of the circumferential openings.
[0080] Clause 12. The yaw braking assembly of any preceding clause, wherein at
least one of the plurality of brake pads further comprises at least one sensor
configured to generate an alert relating to a wear level of one or more of the plurality
of brake pads.
[0081] Clause 13. The yaw braking assembly of any preceding clause, wherein
the at least one sensor comprises a continuity sensor.
[0082] Clause 14. The yaw braking assembly of any preceding clause, wherein
plurality of brake pads are accessible from outside of the bedplate support frame via
the corresponding circumferential openings.
[0083] Clause 15. The yaw braking assembly of any preceding clause, wherein
each of the plurality of brake pads is formed with at least one extraction feature, the
extraction feature being positioned to facilitate the removal of each of the brake pads
from the corresponding recesses.
[0084] Clause 16. A wind turbine, comprising: a tower; a nacelle mounted atop
the tower and comprising a bedplate support frame, the bedplate support frame
comprising a bedplate support frame comprising an annular flange arranged adjacent
to the yaw bearing, the annular flange defining a plurality of recesses formed into a
19
lower-most annular surface of the annular flange and extending at least partially
through an axial thickness of the annular flange, each of the plurality of recesses
defining an open, exterior circumferential side, a yaw bearing arranged adjacent to the
annular flange; a rotor mounted to the nacelle, the rotor comprising a rotatable hub
having one or more rotor blades secured thereto; and a plurality of brake pads
positioned within the plurality of recesses, each of the plurality of brake pads
configured to engage at least one race of the yaw bearing; and a plurality of actuators
for driving the plurality of brake pads to engage the at least one race of the yaw
bearing so as to resist a yawing of a nacelle of the wind turbine.
[0085] Clause 17. The wind turbine of any preceding clause, wherein each of the
plurality of brake pads comprises at least one of a polygonal shape, a curvilinear
polygonal shape, or rounded-square planform.
[0086] Clause 18. The wind turbine of any preceding clause, wherein each of the
plurality of brake pads defines a maximal length and a maximal width, the maximal
length being greater than the maximal width.
[0087] Clause 19. The wind turbine of any preceding clause, wherein each
circumferential opening defines a circumferential length that is greater than the
maximal length of a corresponding brake pad of the plurality of brake pads.
[0088] Clause 20. A method for servicing a yaw braking assembly of a wind
turbine, the method comprising: accessing at least one brake pad of a plurality of
brake pads via an open, exterior circumferential side of a recess defined by at least
one of a plurality of recesses formed into a lower-most annular surface of an annular
flange of a bedplate support frame and extending at least partially through an axial
thickness of the annular flange, wherein the lower-most annular surface is disposed
adjacent to a yaw bearing of the wind turbine; and passing the at least one brake pad
through the open, exterior circumferential side of the recess while retaining a
corresponding actuator of a plurality of actuators in an assembled configuration

WHAT IS CLAIMED IS:
1. A yaw braking assembly of a wind turbine, the yaw braking assembly
comprising:
a yaw bearing;
a bedplate support frame comprising an annular flange arranged adjacent to
the yaw bearing, the annular flange defining a plurality of recesses formed into a
lower-most annular surface of the annular flange and extending at least partially
through an axial thickness of the annular flange, each of the plurality of recesses
defining an open, exterior circumferential side;
a plurality of brake pads positioned within the plurality of recesses, each of the
plurality of brake pads configured to engage at least one race of the yaw bearing; and
a plurality of actuators for driving the plurality of brake pads to engage the at
least one race of the yaw bearing so as to resist a yawing of a nacelle of the wind
turbine.
2. The yaw braking assembly of claim 1, further comprising:
a plurality of arm members positioned within a corresponding plurality of
holes through the annular flange between the plurality of actuators and the plurality of
brake pads, the plurality of arm members being oriented to transfer a force from the
plurality of actuators to the plurality of brake pads.
3. The yaw braking assembly of claim 1, wherein each of the plurality of
brake pads has a non-circular shape.
4. The yaw braking assembly of claim 1, wherein each of the plurality of
brake pads has at least one of a polygonal shape, a curvilinear polygonal shape, or
rounded-square planform.
5. The yaw braking assembly of claim 1, wherein each of the plurality of
brake pads defines a maximal length and a maximal width, the maximal length being
greater than the maximal width.
6. The yaw braking assembly of claim 1, wherein each open, exterior
circumferential side of the plurality of recesses defines a circumferential length which
is greater than a maximal length of the corresponding brake pad.
7. The yaw braking assembly of claim 1, wherein only one of the
plurality of brake pads is positioned within each of the plurality of recesses.
21
8. The yaw braking assembly of claim 7, wherein the plurality of recesses
and corresponding plurality of brake pads are distributed circumferentially about the
annular flange in a plurality of adjacent pair sets.
9. The yaw braking assembly of claim 8, wherein a single actuator is
operably coupled to each of the plurality of pair sets.
10. The yaw braking assembly of claim 1, wherein the plurality of brake
pads are radially aligned with an outer race of the yaw bearing.
11. The yaw braking assembly of claim 1, further comprising:
a retention bracket secured to the exterior circumferential side, the retention
bracket occluding at least one of the circumferential openings.
12. The yaw braking assembly of claim 1, wherein at least one of the
plurality of brake pads further comprises at least one sensor configured to generate an
alert relating to a wear level of one or more of the plurality of brake pads.
13. The yaw braking assembly of claim 12, wherein the at least one sensor
comprises a continuity sensor.
14. The yaw braking assembly of claim 1, wherein plurality of brake pads
are accessible from outside of the bedplate support frame via the corresponding
circumferential openings.
15. The yaw braking assembly of claim 1, wherein each of the plurality of
brake pads is formed with at least one extraction feature, the extraction feature being
positioned to facilitate the removal of each of the brake pads from the corresponding
recesses.
16. A wind turbine, comprising:
a tower;
a nacelle mounted atop the tower and comprising a bedplate support frame, the
bedplate support frame comprising a bedplate support frame comprising an annular
flange, the annular flange defining a plurality of recesses formed into a lower-most
annular surface of the annular flange and extending at least partially through an axial
thickness of the annular flange, each of the plurality of recesses defining an open,
exterior circumferential side,
a yaw bearing arranged adjacent to the annular flange;
22
a rotor mounted to the nacelle, the rotor comprising a rotatable hub having one
or more rotor blades secured thereto; and
a plurality of brake pads positioned within the plurality of recesses, each of the
plurality of brake pads configured to engage at least one race of the yaw bearing; and
a plurality of actuators for driving the plurality of brake pads to engage the at
least one race of the yaw bearing so as to resist a yawing of a nacelle of the wind
turbine.
17. The wind turbine of claim 16, wherein each of the plurality of brake
pads comprises at least one of a polygonal shape, a curvilinear polygonal shape, or
rounded-square planform.
18. The wind turbine of claim 16, wherein each of the plurality of brake
pads defines a maximal length and a maximal width, the maximal length being greater
than the maximal width.
19. The wind turbine of claim 18, wherein each circumferential opening
defines a circumferential length that is greater than the maximal length of a
corresponding brake pad of the plurality of brake pads.
20. A method for servicing a yaw braking assembly of a wind turbine, the
method comprising:
accessing at least one brake pad of a plurality of brake pads via an open,
exterior circumferential side of a recess defined by at least one of a plurality of
recesses formed into a lower-most annular surface of an annular flange of a bedplate
support frame and extending at least partially through an axial thickness of the
annular flange, wherein the lower-most annular surface is disposed adjacent to a yaw
bearing of the wind turbine; and
passing the at least one brake pad through the open, exterior circumferential
side of the recess while retaining a corresponding actuator of a plurality of actuators
in an assembled configuration