Patent Application
20250001447
This application relates generally to wind turbines, and more particularly relates to an applicator tool for use with a robotic device for repairing damage along the leading edge of a wind turbine blade without necessitating removal of the blade from the tower of the wind turbine or manual repairs by rope access technicians.
Wind turbines are used to produce electrical energy using a renewable resource and without combusting a fossil fuel. Generally, a wind turbine converts kinetic energy from the wind into electrical power. A conventional wind turbine installation includes a foundation, a tower supported by the foundation, and an energy generating unit positioned atop of the tower. The energy generating unit typically includes one or more nacelles to house several mechanical and electrical components, such as a generator, gearbox, and main bearing, and the wind turbine also includes a rotor operatively coupled to the components in the nacelle through a main shaft extending from the nacelle. Single rotor wind turbines and multi-rotor wind turbines (which may have multiple nacelles) are known, but for the sake of efficiency, the following description refers primarily to single rotor designs. The rotor, in turn, includes a central hub and a plurality of blades extending radially therefrom and configured to interact with the wind to cause rotation of the rotor. The rotor is supported on the main shaft, which is either directly or indirectly operatively coupled with the generator which is housed inside the nacelle. Consequently, as wind forces the blades to rotate, electrical energy is produced by the generator. Wind power has seen significant growth over the last few decades, with many wind turbine installations being located both on land and offshore.
As noted above, blades interact with the wind to generate mechanical rotation of the rotor, which can then be converted into electrical energy. A wind turbine blade is a complex structure that must be constructed to withstand long-term service in an abusive environment, while also maximizing lift and minimizing drag forces. The blades move at varying speeds through the ambient environment surrounding the wind turbine, but often this movement is at high speed. Consequently, the blades will typically experience erosion and damage over time in operation as a result of friction from the air as well as potential impacts from rain, particulate matter, debris, or other items in the air, especially along the leading edge that is configured to face the direction of movement through the wind. The erosion or damage along the leading edge of the blade adversely affects the aerodynamic qualities of the blade over time, resulting in lower power production for given incoming wind speeds. Such erosion and damage on the blades can be corrected by routine maintenance and repair procedures.
The blades are typically formed from a shell of layered fiber composite, aluminum, or similar material with an outer skin defined by a series of layers of coatings (polymeric elastomers, paint, etc.) surrounding and covering an outer surface of the shell. The shell encloses internal components of the blade and isolates them from the environment, including shear webs and spar caps, for example. The outer skin may be defined by several different layers of material, including at least an outermost topcoat, a second layer underneath the outermost topcoat, and a third layer underneath the second layer. Other layers are typically present underneath the third layer as well, including base materials typically made from fiber composites and the like. Damage to the blade outer skin can be categorized into several different levels of severity based on which layer the damage extends to, e.g., an erosion to the third layer would be a “category 2” level of severity, which would be higher than a cut to the second layer, which would be a “category 1” level of severity. For low levels of damage or erosion, such damage can be repaired by depositing a coating onto the area to fill in the damage and restore the blade to the original condition along the leading edge thereof. One such repair by depositing material can be reviewed in PCT International Patent Publication No. WO2018/113875, owned by the original Applicant of the present application.
Although the '875 Publication referenced above provides one automated device for maintenance and repair, these types of repairs of the wind turbine blades have typically been conducted in three other manners conventionally. First, the blade can be disassembled from the remainder of the wind turbine and lowered to the ground for the repair to be completed. Such a repair process is time-consuming and costly as a result of needing to disassemble, move, and reassemble the blade relative to the top of the tower. Second, a human operator with rope access can rappel along the wind turbine blade while still attached to the rotor hub to evaluate and make repairs as needed to the blade. Once again, such a repair process is time-consuming and costly because of the need for experienced rope access technicians and the time needed to effect the repairs manually. Third, a repair action can be taken by an operator on a platform hoisted into position adjacent the blade on the wind turbine, either extending from the nacelle or hub of the wind turbine or extending from a cherry picker or boom-style lift. In all conventional methods, the wind turbine must be stopped and locked for the time period of repair, and as such, significant power production losses are experienced by wind turbine operators for these necessary maintenance and repair actions. This may lead some operators to delay or procrastinate in making such repairs, which can lead to more significant structural damage and even longer delays when more thorough repairs are necessary on the wind turbine blade.
In recent years, a desire has emerged to allow for some automated or semi-autonomous maintenance of wind turbine blades, to thereby improve the speed and/or precision of such a process. However, such maintenance devices are not always designed for reliable use on a wind turbine blade still connected to the rotor and hub of a wind turbine, and such systems are very slow in operation. Furthermore, such systems may be prone to uneven or misshapen coatings that may not be precisely positioned to assure that the repair remains fully effective and bonded over a long period of time to the previous exterior surface of the blade. Thus, further improvements for maintenance and repair systems are desired.
To these and other ends, embodiments of the invention are directed to an applicator tool configured to be used with a robotic maintenance device for repairing damage around a leading edge of a wind turbine blade on a wind turbine. The applicator tool includes a tool frame configured to be connected at one end of the robotic maintenance device and a spatula supported by the tool frame and configured to be engaged with an exterior surface of the wind turbine blade. The spatula includes a flexible extrusion plate having a front edge, a rear edge facing the robotic maintenance device, an outer surface and an inner surface, wherein the flexible extrusion plate is configured to define a gap between the inner surface thereof and the exterior surface of the wind turbine blade. The applicator tool further includes a first nozzle with a nozzle outlet located under the spatula to deliver a coating material into the gap as the robotic maintenance device moves the spatula along the leading edge of the wind turbine blade. The applicator tool also includes a first chamfer arm and a second chamfer arm operatively coupled to the tool frame. Each chamfer arm engages the outer surface of the extrusion plate of the spatula adjacent the front edge to press the extrusion plate against the exterior surface of the wind turbine blade at two specific engagement locations on opposing sides of the leading edge of the wind turbine blade. In this regard, the spatula is configured to shape the coating material into a shaped coating as the coating material spreads in the gap to thereby fill in and cover the damage on the wind turbine blade, and the first and second chamfer arms are configured to limit spread of the coating material beyond the two specific engagement locations such that the shaped coating applied to the wind turbine blade extends between a first chamfer line and a second chamfer line on opposite sides of the leading edge. For example, the exterior surface of the blade may be sanded or abraded by a tool to prepare for application of the coating, and the use of the first and second chamfer arms advantageously keeps the first and second chamfer lines at the edges of the shaped coating generally aligned with edges of the abrading/sanding done.
Several embodiments are now described in conjunction with the applicator tool of this invention, and it will be understood that each embodiment can stand on its own and/or be combined in any combination with the other features/steps in the following embodiments.
In one embodiment, each of the first and second chamfer arms includes a proximal end and a distal end and the applicator tool further includes first and second drive shafts extending from the tool frame so as to be coupled with the proximal ends of the first and second chamfer arms. The drive shafts are configured to pivotally move the first and second chamfer arms to adjust a position of the two specific engagement locations where the distal ends of the first and second chamfer arms engage the extrusion plate of the spatula.
In another embodiment, the applicator tool includes a gear assembly located on the tool frame and connected to the first and second drive shafts and a drive cylinder that actuates the gear assembly to synchronously rotate the first and second chamfer arms to pivot the distal ends towards or away from the spatula. In one embodiment, the drive cylinder actively applies a driving force to the gear assembly during delivery of the coating material under the spatula to maintain an engagement of the first and second chamfer arms with the extrusion plate as the spatula and the robotic maintenance device move along the leading edge of the wind turbine blade.
In yet another embodiment, the first and second chamfer arms are formed from a rigid material and the distal end of each the first and second chamfer arms further includes a pad to engage with the outer surface of the extrusion plate on the spatula. The pad is at least partially resilient to transfer forces from the first and second chamfer arms to produce the first and second chamfer lines without causing damage to the spatula or to the wind turbine blade.
In a further embodiment, the applicator tool includes a vision system with at least one imaging device configured to image the exterior surface of the wind turbine blade. In this regard, the vision system detects, based on images from the at least one imaging device, a specific location along the exterior surface where the coating terminates to define the first and second chamfer lines. The applicator tool also includes a controller operatively coupled to the vision system and to a drive element of the robotic maintenance device that can vary a supply rate of the coating material delivered to the first nozzle. The controller is programmed to determine, based on information from the vision system, whether the first and second chamfer lines of the shaped coating are located at an expected position defined by a desired size of the shaped coating. The controller is configured to send a signal to the drive element to cause the supply rate of the coating material to the nozzle be varied when the first and second chamfer lines are not located at the expected position. The vision system thereby allows the maintenance device to accurately correct for any overfill or underfill condition that may cause the first and second chamfer lines to not be in desired positions on the wind turbine blade.
In another embodiment, the vision system includes at least one illumination element configured to direct light energy onto the exterior surface of the wind turbine blade such that the at least one imaging device is configured to image the exterior surface of the wind turbine blade when illuminated by the at least one illumination element.
In another embodiment, the expected position is located at the two specific engagement locations where the first and second chamfer arms engage the outer surface of the spatula during operation of the robotic maintenance device. In still another embodiment, when the first and second chamfer lines are not located at the expected position, the controller is programmed to send a signal to the drive element to increase the supply rate of the coating material to the first nozzle, if the first and second chamfer lines are positioned closer to the leading edge than the expected position, indicative of an underfill condition. The controller is also programmed to send a signal to the drive element to decrease the supply rate of the coating material to the first nozzle, if the first and second chamfer lines are positioned farther from the leading edge than the expected position, indicative of an overfill condition.
In one embodiment, the coating material includes an ultraviolet material additive, and the at least one illumination element is configured to direct ultraviolet light energy onto the exterior surface of the wind turbine blade, such that the vision system detects where the coating terminates based on where the ultraviolet material additive stops when illuminated by the ultraviolet light energy. In yet another embodiment, the at least one illumination element is configured to direct visible spectrum light energy onto the exterior surface of the wind turbine blade, such that the vision system detects where the coating terminates based on a change in reflectivity and/or color observed when illuminated by the visible spectrum light energy.
In a further embodiment, the applicator tool includes a second nozzle adjacent the first nozzle, and a nozzle outlet located under the spatula to deliver a coating material into the gap as the robotic maintenance device moves the spatula along the leading edge of the wind turbine blade. The first and second nozzles are configured for independent connection to respective first and second coating material supply containers, such that the applicator tool applies coating material from the first nozzle until the first coating material supply container is about to be exhausted, at which point the applicator tool begins applying coating material from the second nozzle to thereby maintain a consistent supply rate of the coating material to the spatula. In another embodiment, the applicator tool includes at least three nozzles and the robotic maintenance device includes a coating material supply container for each nozzle. The coating material supply containers are independently connected to a respective one of said at least three nozzles to increase a total amount of coating material applied and/or a total length of the leading edge of the wind turbine blade that can be repaired by the robotic maintenance device. In one embodiment, each of the coating material supply containers is configured to be supported in a shared revolver or storage rack located on a main chassis of the robotic maintenance device, and separate feed hoses are connected between each nozzle at the applicator tool and a corresponding one of the coating material supply containers. In yet another embodiment, the nozzle outlets of each of the nozzles are arranged in side-by-side relationship under the spatula to feed coating material into the gap.
In a further embodiment, the applicator tool includes a repair verification scanner. The repair verification scanner includes a first scanning element and a second scanning element, each of which is configured to detect a profile height of the leading edge of the wind turbine blade defined by a spacing between the leading edge and the corresponding first or second scanning element. The first scanning element is positioned upstream from the spatula to scan the leading edge before the shaped coating is applied, and the second scanning element is positioned downstream from the spatula to scan the leading edge after the shaped coating is applied, thereby to determine a coating layer thickness of the shaped coating applied to the wind turbine blade. The coating layer thickness being a difference between the spacings detected by the first and second scanning elements. In one embodiment, the first and second scanning elements each includes an infrared sensor. In another embodiment, the first and second scanning elements perform continuous line scans of the profile height of the leading edge such that the coating layer thickness is detected over an entire working length where the applicator tool applies the shaped coating to repair damages on the wind turbine blade. The repair verification scanner allows for another verification or check to be provided to confirm the quality and accuracy of repair actions done by the applicator tool.
One embodiment of the invention is directed to a robotic maintenance device for repairing damage around a leading edge of a wind turbine blade on a wind turbine. The robotic maintenance device includes an applicator tool of any previous embodiment and a sander configured to sand the exterior surface around the leading edge of the wind turbine blade at the damage before the coating material is applied. The first and second chamfer arms are adjusted to position the first and second chamfer lines of the shaped coating proximate edges of where the exterior surface has been sanded.
Embodiments of the present invention are also directed to a method for repairing damage around a leading edge of a wind turbine blade on a wind turbine. The method includes providing a robotic maintenance device onto the wind turbine blade, the robotic maintenance device including an applicator tool having a spatula, a first nozzle, and a first chamfer arm and a second chamfer arm located adjacent the spatula. The method includes moving the robotic maintenance device along a working length at the leading edge of the wind turbine blade and discharging a coating material from the first nozzle under the spatula and specifically into a gap defined between an extrusion plate of the spatula and an exterior surface of the wind turbine blade. The method further includes shaping the coating material into a shaped coating with the extrusion plate of the spatula as the coating material spreads in the gap and as the spatula moves along the working length such that the shaped coating fills in and covers the damage on the wind turbine blade. The method also includes engaging the first and second chamfer arms with the spatula to press the extrusion plate against the exterior surface of the wind turbine blade at two specific engagement locations on opposing sides of the leading edge of the wind turbine blade to thereby limit the spread of the coating material beyond the two specific engagement locations such that the shaped coating applied to the wind turbine blade extends between a first chamfer line and a second chamfer line on opposite sides of the leading edge.
In one embodiment, the applicator tool further includes a vision system with at least one imaging device. In this embodiment, the method further includes, imaging the exterior surface of the wind turbine blade following repair actions performed by the applicator tool with the at least one imaging device and detecting, based on images from the at least one imaging device, a specific location along the exterior surface where the coating material terminates to define the first and second chamfer lines. The method also includes comparing the specific location of the first and second chamfer lines to an expected position defined by a desired size of the shaped coating and varying a supply rate of the coating material to the nozzle when the first and second chamfer lines are not located at the expected position to thereby change the specific location of the first and second chamfer lines to correct for any underfill or overfill condition at the shaped coating.
In another embodiment, the vision system includes at least one illumination element and the method includes directing light energy with the at least one illumination element onto the exterior surface of the wind turbine blade following repair actions performed by the applicator tool. The method also includes imaging the exterior surface of the wind turbine blade with the at least one imaging device when illuminated by the at least one illumination element.
In another embodiment, the applicator tool further includes at least two nozzles and the robotic maintenance device further includes a coating material supply container for each nozzle, said coating material supply containers independently connected to a respective one of said at least two nozzles. In this embodiment, the method further includes, applying coating material through the first nozzle from the first coating material supply container until the first coating material supply container is about to be exhausted and thereafter applying coating material through one of the at least two nozzles from the respective coating material supply containers to continue discharging the coating material under the spatula and into the gap at a consistent supply rate.
In yet another embodiment, the applicator tool further includes a repair verification scanner including a first scanning element and a second scanning element. In this embodiment, the method further includes, scanning the leading edge of the wind turbine blade with the first scanning element before repair actions are performed by the applicator tool, thereby detecting a profile height of the leading edge defined by a spacing between the leading edge and the first scanning element. The method also includes scanning the leading edge of the wind turbine blade with the second scanning element after repair actions are performed by the applicator tool, thereby detecting a profile height of the leading edge defined by a spacing between the leading edge and the second scanning element and determining a coating layer thickness of the shaped coating applied to the wind turbine blade, the coating layer thickness being a difference between the spacings detected by the first and second scanning elements.
The elements and steps described herein can be reconfigured and combined in many different combinations to achieve the desired technical effects for different styles of wind turbines and different repair systems, as may be needed in the art.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.
With reference to
To repair damage around a leading edge of a wind turbine blade, the spatula and one or more chamfer arms are configured to apply a generally uniform coating of material that in cross section is typically thickest adjacent the leading edge of the blade and then decreases in thickness in a generally continuous and smooth manner along the upper and lower surfaces of the blade and in a direction toward a trailing edge of the blade. In this way, the coating may smoothly merge with the existing blade surfaces at locations away from the leading edge. Localized variations in coating thickness will occur where damage to be filled/fixed is deeper into the surface of the blade, but the outer profile of the coating following the shaping should be generally uniform. The shape of the coating material applied by the applicator tool is configured to adequately repair the damaged area of the blade while also minimizing aerodynamic disruptions of the air flow over the blade. Thus, a repair is achieved with minimal impact on the aerodynamic performance of the blade. A method of using the applicator tool may include scanning the blade to image the damaged area, sanding down a surface of the blade around the damaged area and cleaning the same, and then applying one or more layers of coating with the applicator tool to repair the damage. The chamfer arms on the maintenance device are specifically configured to limit flow and spread of the coating material such that the first and second chamfer lines at the edges of the shaped coating follow the edges of the region that has been sanded/abraded when preparing for the repair actions. The applicator tool and associated method thus produce a high quality and precise repair of the damaged area of the wind turbine blade that overcomes many of the drawbacks of existing repair devices and processes. Other advantages and effects of the embodiments of this invention will be evident from the following description.
Throughout this application, the correction of erosion damage on wind turbine blades is typically referred to as a “repair” of those damages. In some contexts, “damage” refers to more significant damages to the blade (perhaps beyond what is described as “category-1” and “category-2” damage herein), and so the operation of the applicator tool may be deemed a routine maintenance action that occurs before a blade is “damaged” in such contexts. In this regard, it will be understood that within the context of this application, the applicator tool is capable of providing preventative maintenance to remove wear and erosion effects before such effects cause “damage” that must be repaired on the wind turbine blade, and the applicator tool is also capable of providing more thorough repairs after damage is caused on the blade.
Turning with reference to
With continued reference to
As the wind turbine 10 ages, one or more of the wind turbine blades 20 may experience erosion from prolonged, continuous exposure to the environment. One example of such erosion damage 26 is shown in
Erosion damage 26 is generally characterized as a loss of material from the wind turbine blade 20. Material loss may be uniformly distributed but is often non-uniform across the leading edge 22 or any other surface of the wind turbine blade 20. Rather than losing a uniform skin of material from a surface, erosion may include localized surface imperfections, such as random pitting and shallow gouges or crack-like features that may be a result of localized, connected pitting (as a result of impacts with debris or other matter in the environment). In any case, if erosion damage 26 is not repaired in a timely fashion, the wind turbine blade 20 may become less efficient at rotating the rotor 16 and, ultimately, the structural integrity of the wind turbine blade 20 may be significantly impaired. With reference to the detailed view of in
With continued reference to
In an exemplary embodiment, the coating 30 may be formed from an epoxy or a polyurethane, but other materials may also be possible. The applicator tool in accordance with embodiments of the invention aids in providing a precise and high-quality coating 30 on the leading edge 22 of the wind turbine blade 20 having the shape and features as described above.
The maintenance device 40 also includes a control system 52 shown schematically in
The drive system is located on the underside of the body 44 of the maintenance device 40 and is configured to engage with the leading edge 22 of the wind turbine blade 20 (or a portion of the blade 20 proximate the leading edge 22) to move the maintenance device 40 along the leading edge 22. In this regard, the drive system may include a plurality of continuous tread drives, each having a continuous tread independently driven by at least one motor. Each continuous tread may be generally U-shaped to conform to the shape of the leading edge 22 of the wind turbine blade 20. That way, the treads grip the leading edge 22 to move the maintenance device 40. The treads may be formed from rubber, plastics, or other suitable moderate to high friction material for gripping the wind turbine blade 20, for example. To this end, as the treads are driven, the maintenance device 40 is moved at a steady pace along the leading edge 22 of the wind turbine blade 20 during repair operations.
To stabilize the maintenance device 40 as it moves along the leading edge 22 during repair operations, the maintenance device 40 also includes two or more wheels 56 connected to the main body 44 of the maintenance device 40, as shown in
Additionally, a power supply 60 such as a battery pack may be mounted on the maintenance device 40 for supplying power to components of the maintenance device 40 such as the controller 52, the drive system, and the applicator tool 42, for example.
The power supply 60 may be configured to power those components and systems so that the maintenance device 40 can repair an entire leading edge 22 of a wind turbine blade 20, for example. The power supply 60 is shown schematically in
Further examples of robotic maintenance devices are, for example, disclosed in DK Application Nos. PA 201970789 and PA 201970790, which are owned by the same Assignee as the present invention, and such robotic maintenance devices may be used in other embodiments with the applicator tool of the present invention. Further details of any exemplary robotic maintenance device can be understood from those prior patent applications in combination with the description provided herein.
With continued reference to
The support arms 90 are configured to press the extrusion plate 78 against the outer surfaces 34 of the wind turbine blade 20. More particularly, the extrusion plate 78 is held against the wind turbine blade 20 such that a central axis A1 of the extrusion plate 78 is aligned with the leading edge 22 of the blade 20. To press the extrusion plate 78 against the blade 20, the side edges 98 of the extrusion plate 78 are received within and retained by corresponding plates 92 of each support arm 90. The plates 92 include one or more fasteners 104 configured to secure the extrusion plate 78 in place to each corresponding plate 92. More particularly, the fasteners 104 are positioned through corresponding apertures in the plate 92 and extrusion plate 78 which are aligned to receive part of the fastener 104 therethrough to thereby couple each corresponding portion of the extrusion plate 78 to the corresponding plate 92. The fasteners 104 may be a quick lock mechanism such as a quick release push lock pin, for example.
To engage the extrusion plate 78 with the surfaces 34 of the blade 20, each support arm 90 includes a piston 106 and an actuator 108 configured to drive the piston 106 up and down. As shown, each piston 106 extends between the corresponding actuator 108 and plate 92 to position the plate 92 and corresponding side edge 98 of the extrusion plate 78 downward along the respective sides of the wind turbine blade 20. As shown, the support arms 90 are hingeably coupled to the front support 72 of the frame 70 and are configured to pivot about respective joints 110. In this regard, as the pistons 106 are driven downward or raised by the actuators 108, each support arm 90 is permitted to freely pivot about the frame 70 at the corresponding joint 110. Thus, when the pistons 106 are in an extended position, as shown in
The robotic maintenance device 40 is configured to support the applicator tool 42, and more particularly position the spatula 76 and extrusion plate 78 over the leading edge 22 of the blade 20 during repair operations. In this regard, the frame 70 may be supported from the tool head 50 of the maintenance device 40 with two or more piston arrangements (not shown), for example. The pistons may be comprise a gas or hydraulic cylinder and actuator and be configured to raise, lower, and tilt the frame 70 and applicator tool 42 relative to the leading edge 22 of the blade 20, as shown in
In one embodiment, the spatula 76 may include a spacer configured to maintain the gap 112 between the outer surface 34 of the blade 20 and the inner surface 102 of the extrusion plate 78. The one or more spacers may include a rigid blade or spine disposed beneath the inner surface 102 of the extrusion plate 78. The rigid spine may shaped similarly to the desired shape of the gap 112 (e.g., triangular or funnel shaped) and is configured to engage with the leading edge 22 of the wind turbine blade 20 during use. In this regard, the configuration of the spine maintains the gap 112 between the outer surface 34 of the blade 20 and the inner surface 102 of the extrusion plate 78. In this embodiment, the nozzle 84 may be coupled to the spine at one end thereof. In one embodiment, the spine may be integrally formed with the end of the feed tube 88. In an alternative embodiment, these elements may be separate and subsequently coupled together.
With reference to
The first and second chamfer arms 80, 82 are configured to synchronously rotate about the frame 70 of the applicator tool 42 to simultaneously engage the extrusion plate 78 on opposing sides of the leading edge 22 of the blade 20. In this regard, the frame 70 includes a first and second drive shaft 116, 118, each extending a length of the frame 70 from the rear support 74 to the front support 72. More particularly, the first and second drive shafts 116, 118 each extend from a driven end located at the rear support 74 of the frame 70 to an operative end located at the front support 72 of the frame 70. The operative end of each drive shaft is configured to couple with each corresponding chamfer arm 80, 82. As shown, a proximal end 120 of the first chamfer arm 80 is coupled with the operative end of the first drive shaft 116 and a proximal end 122 of the second chamfer arm 82 is coupled with the operative end of the second drive shaft 118. Thus, the drive shafts 116, 118 are configured to pivotally move the first and second chamfer arms 80, 82 about the frame 70 to engage a distal end 124 of the first chamfer arm 80 and a distal end 126 of the second chamfer arm 82 with the extrusion plate 78 at specific engagement locations along the surfaces 34 of the wind turbine blade 20.
The first and second chamfer arms 80, 82 may be formed from a rigid material and the distal end 124, 126 of each of the first and second chamfer arms 80, 82 may include a compression pad 128 to engage with the outer surface 100 of the extrusion plate 78. The pads 128 may be formed of at least partially resilient material configured to transfer forces from the first and second chamfer arms 80, 82 to produce the first and second chamfer lines 36, 38 without causing damage to the extrusion plate 78 or to the wind turbine blade 20.
The applicator tool 42 further includes a drive cylinder 140 configured to rotate the first and second drive shafts 116, 118 to thereby engage the respective chamfer arms 80, 82 with the extrusion plate 78. The drive cylinder 140 is operatively coupled to a gear assembly 142 located on the applicator tool frame 70 and connected to the driven ends of the first and second drive shafts 116, 118. As shown, the driven ends of the first and second drive shafts 116, 118 each include a gear with the teeth of the gears being in contact with each other to ensure synchronous movement of the first and second chamfer arms 80, 82 as the drive shafts 116, 118 are driven by the drive cylinder 140. The drive cylinder 140 is located on the frame 70 adjacent to the rear support 74 and includes a piston tube 144 and a piston rod 146. The piston tube 144 includes a first leg 148 operatively coupled to the driven end of the first drive shaft 116 with a series of movable linkages 150, and further includes a second leg 152 operatively coupled to the driven end of the second drive shaft 118 with a series of movable linkages 150. Each corresponding linkage 150 is interconnected using a pin 154, nut and bolt combination, or other suitable structure to permit movement of the linkages 150 relative to one another as the piston tube 144 moves up and down the piston rod 146. More particularly, as the piston tube 144 moves down the piston rod 146, the drive shafts 116, 118 are rotated counterclockwise through transferred movement by the linkages 150 to thereby engage the distal ends 124, 126 of the first and second chamfer arms 80, 82 with the extrusion plate 78, as shown in
As will be explained in detail below, the applicator tool 42 may be moved along the leading edge 22 of the wind turbine blade 20 to apply the coating 30 to the blade 20. In this regard, the spatula 76, and more particularly the extrusion plate 78, is configured to engage with the wind turbine blade 20 and extrude coating material applied to the blade 20 immediately behind the extrusion plate 78 of the spatula 76 such that after the spatula 76 passes over the deposited coating material 30, the coating 30 has the desired smoothness and shape. As noted above, the frame 70 of the applicator tool 42 is angled relative to the leading edge 22 to form the gap 112 between the outer surfaces 34 of the wind turbine blade 20 and the inner surface 102 of the extrusion plate 78. After positioning the spatula 76 into a desired position, the gap 112 directly corresponds to the desired shape of the coating 30, and as the applicator tool 42 is moved along the leading edge 22 of the blade 20, the coating material 30 is essentially extruded from the opening 114 of the gap 112 to ultimately define the coating 30. In this regard, the opening 114 of the gap 112 defines a height profile that generally corresponds to the shape of the coating 30 from the applicator tool 42. By way of example, the height profile may have a maximum adjacent the central axis A1 of the extrusion plate 78 and decay to substantially zero adjacent the first and second chamfer lines 36, 38. The first and second chamfer arms 80, 82 engage the extrusion plate 78 proximate the opening 114 of the gap 112 to maintain the shape of the opening 114 and overall shape of the coating material 30 exiting the opening 114, as well as prevent the spread of coating material 30 beyond the first and second chamfer lines 36, 38. Thus, it is the chamfer arms 80, 82 in combination with the extrusion plate 78 that defines the shape and thickness of the shaped coating 30 applied to the leading edge 22 of the blade 20.
As the coating material fills the gap 112, the applicator tool 42 may be moved along the leading edge 22 of the blade 20 as demonstrated by arrow A in
As the robotic maintenance device 40 moves along the leading edge of the wind turbine blade 20, the drive cylinder 140 continues to apply a driving force on the first and second chamfer arms 80, 82 to maintain their engagement with the extrusion plate 78. As described above, the engagement between the distal ends 124, 126 of the first and second chamfer arms 80, 82 at specific engagement locations on opposing sides of the leading edge 22 of the blade 20 form the first and second chamfer lines 36, 38. The coating 30 applied to the wind turbine blade 20 extends between the first and second chamfer lines 36, 38 to cover and fill in the erosion damage 26, as shown in
As described above, the maintenance device 40 includes a coating supply source having at least one supply container containing a predetermined quantity of coating material 30. The nozzle 84 may be operatively connected to the supply container with the feed tube 88 or pipe to supply the coating material 30 to the nozzle 84 and applicator tool 42. In one embodiment, the coating material 30 contained in the supply container may be a 2-component mixture that is pushed through a static mixer or some other mixing element before flow through the feed tube 88, with the resulting coating material 30 having a suitable viscosity that allows the material 30 to flow under the influence of gravity and surface tension effects to form a smooth and continuous coating. The supply container may be pressurized to discharge the coating material 30 or the maintenance device 40 may be equipped with a drive element operatively engaged with the supply container to deliver the coating material 30 from the supply container to the nozzle 84. It will be understood that the coating material 30 is not discharged from the supply container (the components thereof) until repair actions are to be done, as the mixed coating material 30 can solidify in the feed tube 88 and/or the nozzle 84 after being mixed for a period of time.
In accordance with another embodiment of the invention shown in
The one or multiple coating material supply containers for each corresponding nozzle 84, 84a may be supported on the robotic maintenance device 40 in a multi-cartridge supply or storage rack 156, which is shown schematically in
By including multiple independent supply containers at the multi-cartridge supply 156, the overall length of the wind turbine blade 20 on which the coating 30 can be applied can be increased accordingly, e.g., without requiring the supply containers to be made so large that the forces needed to dispense the coating material successfully through a mixer, through the feed tube 88, and into the nozzle 84 is not made too large for the dispense drive components of the maintenance device 40, or made so large that the coating material is likely to solidify in the feed tube 88 or in the nozzle 84 during a normal repair action operation. In one particular example, each supply container may be supplied with enough coating material to apply the shaped coating 30 to about 12 meters of longitudinal length along the leading edge 22 of the blade 20, and typical repairs for a 60 meter long blade 20 can extend over 20 meters, thereby requiring supply from at least two supply containers.
As illustrated in
With reference to
In any event, the vision system 160 is configured to detect an underfill condition or an overfill condition and cause a variation of the supply rate of the coating material 30 to correct for such conditions accordingly, as will be described in further detail below. By underfill condition, it is meant that the detected chamfer line 36, 38 fails to reach the expected termination position 172 for the coating material 30. That is, the detected chamfer line 36, 38 is located between the expected termination position 172 and the leading edge 22 of the wind turbine blade 20. An underfill condition is illustrated in
To vary the supply rate of the coating material 30 to the spatula 76, the vision system 160 and drive element for the coating material supply container used to deliver the coating material 30 from the supply container to the nozzle 84 are operatively coupled to a controller, which may be the control system 52 of the maintenance device 40. Based on input received from the vision system 160, the controller is configured to increase or decrease a driving force exerted by the drive element on the material supply container to thereby increase or decrease the supply rate of the coating material 30 to the spatula 76. More particularly, if the chamfer line 36, 38 is detected to be in an underfill condition (
It may be possible for the imaging device 162 to accurately detect the position of the chamfer line 36, 38 using just ambient light available in the external environment. To this end, the applied coating 30 will typically have a different (e.g., more shiny or reflective) reflectivity as compared to the pre-existing exterior surface 34 of blade 20. The applied coating 30 may also be a slightly distinct color upon initial application from the remainder of the blade 20. Thus, the imaging device 162 typically uses a distinction in reflectivity or color to identify where the coating 30 terminates on the blade 20, which defines where the chamfer line 36, 38 is actually positioned.
In embodiments including the illumination element 164, the illumination element 164 of the vision system 160 is configured to direct light energy onto the exterior surface 34 of the wind turbine blade 20, proximate a location where the chamfer arms 80, 82 press the extrusion plate 78 against the exterior surface 34 of the wind turbine blade 20 to form the chamfer lines 36, 38, to thereby illuminate the surface 34 when the imaging device 162 images the exterior surface 34 of the wind turbine blade 20. The illumination device 164 may be useful in certain situations where the vision system 160 is unable to detect the chamfer lines 36, 38 using ambient light, or where sufficient ambient light is unavailable to allow for an accurate read of the chamfer lines 36, 38. The illumination device 164 may be configured to direct visible spectrum light energy onto the exterior surface 34 of the blade 20 such that the vision system 160 detects where the coating terminates based on a change in reflectivity and/or color observed by the imaging device 162 when illuminated by the visible spectrum light energy, in a similar manner as set forth above.
In an alternative embodiment that may be preferred in some circumstances, the coating material 30 may include an ultraviolet material additive to improve detectability of the chamfer lines 36, 38 by the vision system 160. The illumination device 164 may then be configured to direct ultraviolet light energy onto the exterior surface 34 of the wind turbine blade 20. The ultraviolet material additive will provide a clear contrast between the coating material 30 and the remainder of the exterior surface 34 of the blade 20, thereby enhancing the ability of the vision system 160 to identify where the chamfer lines 36, 38 are and whether adjustments are needed to the coating supply rate. Regardless of the particular form in which the vision system 160 is provided, including the vision system 160 in the maintenance device allows for better adjustments to be made in real time during repair actions on the blade 20 to correct for any overfill or underfill conditions.
The repair verification scanner 180 includes a first scanning element 182 located at the second end 48 of the maintenance device 40 and a second scanning element 184 located at the first end 46 of the maintenance device 40. The second scanning element 184 may be located on the tool head 50, for example. As shown, the first and second scanning elements 182, 184 are spaced apart along the leading edge 22 of the wind turbine blade 20 when the maintenance device 40 is positioned thereon. More particularly, the first scanning element 182 is positioned upstream from the applicator tool 42 and over the erosion damage 26 to the leading edge 22. The second scanning 184 element is positioned downstream from the applicator tool 42 and over the shaped coating 30 recently applied to the leading edge 22. In this regard, the first scanning element 182 scans the leading edge 22 at a point 188 before the shaped coating 30 is applied to detect a first profile height 190. The second scanning element 184 scans the leading edge 22 at a point 192 after the shaped coating 30 is applied to detect a second profile height 194. It will be understood that the specific positions of the first and second scanning element 182, 184 may be modified from the positions shown in
In the exemplary embodiment, the first and second scanning elements 182, 184 perform continuous line scans of the leading edge 22 to detect continuous first and second profile heights 190, 194 over an entire working length of the leading edge 22 of the blade 20. That way, the thickness of the applied coating 30 can be determined for the entire length of the leading edge 22 where the applicator tool 42 applies the shaped coating 30 to repair the erosion damage 26. In an alternative embodiment, the scanning elements 182, 184 may scan the leading edge 22 intermittently at predetermined intervals or locations.
In one embodiment and as briefly alluded to in several places above, the maintenance device may also include a cleaning/abrading tool 200 that is configured to sand down the surface of the wind turbine blade 20 containing damage 26 and then clean that surface to prepare it for repair. The cleaning/abrading tool 200 is shown in
The embodiments of the applicator tool 42 described above improve maintenance and repairs for erosion damage 26 at the leading edge 22 of the wind turbine blade 20. More particularly, the applicator tool 42 provides an apparatus and method for applying a coating 30 over the damage 26 at the leading edge 22 so as to arrest further deterioration of the wind turbine blade 20. Additionally, the applicator tool 42 provides a coating 30 that has a desirable profile, i.e., having a maximum thickness at the leading edge 22 of the blade 20 and then decaying in thickness to substantially zero thickness away from the leading edge 22 so as to smoothly merge into the outer surfaces 34 of the wind turbine blade 20. The profile provided by the applicator tool 42 minimizes disruptions of the airflow over the blade 20 and any resulting reduction in aerodynamic performance as a result of those disruptions. The applicator tool 42 is particularly advantageous when repairing wind turbine blades 20 in field conditions when, for example, the blades 20 remain attached to the rotor hub 18 at the top of the tower 12 of the wind turbine 10, which helps minimize operational downtime that is caused to conduct the maintenance and repair actions. Thus, even in less than ideal field conditions, the applicator tool 42 is able to provide a high quality and precise repair of the damaged area 26 of the wind turbine blade 20.
While the present invention has been illustrated by a description of various preferred embodiments and while these embodiments have been described in some detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Moreover, the various features of the invention may be used alone or in any combination depending on the needs and preferences of the user, and the features described in the different embodiments are not dependent on one another for operation of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| PA202170373 | Jul 2021 | DK | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DK2022/050147 | 6/24/2022 | WO |
