A device for patching wind turbine blade surface

Abstract

The invention relates to the wind turbines and wind turbine blades' maintenance devices, in particular, to the methods and devices for patching wind turbine blade surface. The claimed device comprises: a patching head, comprising: a frame enclosure open on one side; the frame enclosure having a patch placement area designed to be in the form of a UV-transparent membrane, configured to be substantially flat at least in its center and have a border that extends outward; the frame enclosure further comprising suction interface, configured to be applied to a surface of a wind turbine blade and to hold the frame enclosure in the place, in respect to the blade; a curtain with curtain holding arrangement. The curtain is designed to be UV-opaque and configured to be removably attached in front of the membrane, so to close the open side of the frame enclosure and to guard a patch from the ambient UV light exposure, when the patch is placed on the membrane. The frame enclosure further comprising a UV light source configured to expose a patch placed on the patch placement area to the UV light. The device further comprises a pump system, connected to the suction interface of the patching head; a robotic arm, designed to grip and position the patching head, to exert substantially perpendicular pressure onto the blade surface via the frame enclosure during activation of the vacuum pump system.

Description

Field of the invention

[001] The present invention relates to the wind turbines and wind turbine blades’ maintenance devices, in particular, to the methods and devices for patching wind turbine blade surface. Background of the invention

[002] Wind turbine blades are typically void structures generally made from glass or carbon fiber with laminate and sandwich structures. Generally, these turbines have three blades that are all connected to the single hub. Every blade also has one or more drainage holes which serves the purpose of letting out any condensate that has accumulated inside the blade. There can be one or several drainage holes near the tip of the blade as well as closer to the root of the blade.

[003] Wind turbines have seen a lot of development as the need for green energy increases. Also, the size of the turbines has grown. Some turbine model blades have reached the length of more than hundred meters.

[004] As these blades rotate it is important that all blades are balanced. Any imbalance would create vibration for the hub and the nacelle and could damage the tower, bearings, and blades themselves.

[005] Sometimes it is necessary to alter a blade surface to introduce some structural modifications [e.g. counterbalancing, or reinforcement of a wind turbine blade], or to repair impact, fatigue, or erosion damage of a blade surface.

[006] As wind turbine blades are designed for optimal aerodynamics and structural performance, altering a blade surface e.g. by introducing holes or creating non-even surface can influence its performance and longevity. Any roughness or protrusion can cause turbulence, reducing blade efficiency. An unprotected hole can allow moisture and other environmental contaminants to penetrate the blade, leading to further damage, such as delamination or internal corrosion. Also, a consistent and uniform appearance of wind turbines is important for stakeholders and regulatory bodies. Thus, proper patching and painting of these alterations are crucial to maintain the blade's integrity and performance. Any imperfection can lead to reduced efficiency. 2024220884   11 Jun 2026

[007] Wind turbine blades are positioned at great heights. Traditionally wind turbine blade surface repair is performed using rope-access technicians. They would use either ropes or platforms to access the tip and perform the work. Brief summary of the invention

[008] The goal of the invention is to provide a robotic device for effective patching wind turbine blade surface.

[009] Disclosed herein is a device for patching wind turbine blade surface comprising: a patching head, comprising: a frame enclosure open on one side. The frame enclosure having a patch placement area designed to be in the form of a UV-transparent membrane, configured to be substantially flat at least in its center and have a border that extends outward. The frame enclosure further comprising suction interface, configured to be applied to a surface of a wind turbine blade and to hold the frame enclosure in the place, in respect to the blade; a curtain with curtain holding arrangement. The curtain is designed to be UV-opaque and configured to be removably attached in front of the membrane, so to close the open side of the frame enclosure and to guard a patch from the ambient UV light exposure, when the patch is placed on the membrane. The curtain holding arrangement is configured to allow remotely controllable removal of the curtain, so to remove the UV protection from the patch placed on the membrane. The frame enclosure further comprising a UV light source located in the frame enclosure and configured to expose a patch placed on the patch placement area to the UV light. The device further comprises a pump system, connected to the suction interface of the patching head; a robotic arm, designed to grip and position the patching head, to exert substantially perpendicular pressure onto the blade surface via the frame enclosure during activation of the vacuum pump system.

[010] According to the preferred embodiment the frame enclosure is further provided with UV-protected air vents configured to let an air to the frame enclosure, but block light from entering in to the frame enclosure.

[011] According to yet another embodiment, the patching head further comprises a connecting element connected to the frame enclosure and configured to hold the frame enclosure in place and to allow the frame enclosure to maintain consistent contact with the wind turbine blade surface irrespective of the curvature of the blade surface. The 2024220884   11 Jun 2026 connecting element further preferably comprise at least two hinged levers having ends one and two. The ends one of the hinged levers are designed to be located substantially under the frame enclosure; the connecting element being pivotally attached to the frame enclosure at a pivot point, located between the ends one and two of the hinged levers, so to adjust the hinged levers’ angle relative to the frame enclosure during moving of the patching head along the varying curvature of the blade surface; wherein the ends one and two of the hinged levers are provided with a mechanism configured to move or glide across the blade surface without causing it damage. The mechanism configured to move or glide across the blade surface can be rollers, wheels, balls, sliders, skids, pads, tracks, gliders, casters arrangement.

[012] According to yet another embodiment, the connecting element may comprise sequential hinged levers having ends one and two; the sequential hinged levers being pivotally attached to the hinged levers at a pivot point, located between the ends one and two of the sequential hinged levers, so to adjust the sequential hinged levers’ angle relative to the hinged levers during moving of the patching head along the varying curvature of the blade surface; wherein the ends one and two of the sequential hinged levers are provided with a mechanism configured to move or glide across the blade surface without causing it damage. Brief description of the drawings [12a] Preferred embodiments of the present invention will be described by way of examples only, with reference to the accompanying drawings.

[013] Fig. 1 - one embodiment of the toolbox adapted to store a patching head in a closable UV protective box, showing a robotic arm connecting patching head to a vacuum pump system; Fig. 2 shows the patching head releasably fixed to the surface of a wind turbine blade by means of suction interface (in this embodiment - in the form of suction cups); Fig. 3 shows one embodiment of the patching head ready to apply a patch with a UV curable adhesive to the surface of the blade; Fig. 4 shows one embodiment of the frame enclosure with patch accommodated therein and closed by a UV protective curtain; 2024220884   11 Jun 2026 Fig. 5 shows one embodiment of the patching head with patch UV protective curtain holding arrangement and the UV protective curtain rolled-in; Fig. 6 schematically shows a balancing system of a frame of the patching head. Detailed description of the invention

[014] The claimed device for patching wind turbine blade surface comprises: a patching head 10, comprising: a frame enclosure 11 open on one side; the frame enclosure having a patch placement area 21; suction interface 12 [such as suction cups, vacuum pads, suction plates, suction channels in the frame, or equivalent means), configured to be applied to a surface of a wind turbine blade and to hold the frame enclosure 11 in the place, in respect to the blade; a curtain 30 with curtain holding arrangement 32; a UV light source 40 located in the frame enclosure 11 and configured to expose a patch placed on the patch placement area 21 to the UV light [Fig. 1-5). The device further comprises a pump system 20 pump system 20, connected to the suction interface 12 of the patching head 10; a robotic arm 50, designed to grip and position the patching head 10, to exert substantially perpendicular pressure onto the blade surface via the frame enclosure 11 during activation of the vacuum pump system 20.

[015] The patch placement area 21 is designed to be in the form of a UV-transparent membrane 31, configured to be substantially flat at least in its center and have a border that extends outward ensuring a tight seal with the blade's surface when the vacuum pump system 20 is activated through the suction interface 12. According to one embodiment, the membrane 31 acts both as a holding means for the patch, and a vacuum sucker when applied to the blade [i.e. the suction interface 12 can be integrated into the membrane 31). The material of the membrane 31 [e.g. silicone) is flexible and transparent to the UV light spectrum.

[016] The curtain 30 is designed to be UV-opaque and configured to be removably attached in front of the membrane 31, so to close open side of the frame enclosure 11 and to guard a patch from the ambient UV light exposure, when the patch is placed on the membrane 31. The curtain holding arrangement 32 is configured to allow remotely controllable removal of the curtain 30, so to remove the UV protection from the patch placed on the membrane 31. According to one embodiment the curtain holding arrangement 32 has a roller mechanism, where the curtain 30 is attached to a cylindrical rod or tube. When engaged, the curtain 30 is unrolled to cover the open side of the frame enclosure 11. There might be end stops or locking mechanism in place to ensure the curtain 30 stays in its desired position, whether fully unrolled, or fully retracted. When controllably disengaged, the curtain 30 rolls up onto this rod [for instance, located in a curtain storing compartment), retracting it from the open side. To ensure the curtain 30 rolls and unrolls smoothly without deviation, there may be guiding rails or channels on either side of the frame enclosure 11 that the edges of the curtain slide within.

[017] To prevent pressure imbalances, and unintended movement of the membrane 31 as a result of differential air pressure, the frame enclosure 11 is preferably provided with UV-protected air vents 41 configured to let an air to the frame enclosure 11, but block light from entering in to the frame enclosure 11. These vents 41 may be configured to have baffled design [a series of baffles to create a zigzag pathway for air, blocking direct light paths); or be covered by a UV-protective mesh, designed to block UV light. The vents 41 may be positioned on the bottom or on a side of the frame enclosure 11, facing away from the primary light source. The vents 41 may be also provided by external shading, e.g. protruding over the vents 41.

[018] According to the preferred embodiment the patching head 10 further comprises a balancing system, adaptable to the curative of the blade’s surface [Fig. 6). The balancing system, comprising a connecting element 14 connected to the frame enclosure 11 and configured to hold the frame enclosure 11 in place and to allow the frame enclosure 11 to maintain consistent contact with the wind turbine blade surface irrespective of the curvature of the blade surface. The connecting element 14 may comprise at least two hinged levers 15 having ends one and two; the ends one of the hinged levers 15 are designed to be located substantially under the frame enclosure 11; the connecting element 14 being pivotally attached to the frame enclosure 11 at a pivot point 17, located between the ends one and two of the hinged levers 15, so to adjust the hinged levers’ 15 angle relative to the frame enclosure 11 during moving of the patching head 10 along the varying curvature of the blade surface; wherein the ends one and two of the hinged levers 15 are provided with a mechanism 16 configured to move or glide across the blade surface without causing it damage.

[019] The connecting element 14 may comprise sequential hinged levers 18 having ends one and two. The sequential hinged levers 18 being pivotally attached to the hinged levers 15 at a pivot point 19, located between the ends one and two of the sequential hinged levers 18, so to adjust the sequential hinged levers’ 18 angle relative to the hinged levers 15 during moving of the patching head 10 along the varying curvature of the blade surface; wherein the ends one and two of the sequential hinged levers 18 are provided with a mechanism 16 configured to move or glide across the blade surface without causing it damage. The mechanism 16 can be rollers’, wheels’, balls’, sliders’, skids’, pads’, tracks’, gliders’, or casters’ arrangement.

[020] The claimed device operates as follows. Before elevation of the device to the wind turbine blade's damaged area for patching wind turbine blade surface, the patch is prepared. A suitable patch is be selected. The patch can consist of multiple layers of pre-impregnated fabric. Multiple layers are to be prepared in advance to be held them together as a single patch and to be free of any air bubbles. Each size of multiple fabrics can be different to achieve scarfing. The patch can also have apertures, if necessary. The patch is be pre-impregnated with a UV-curable resin, is placed on the patch placement area 21. UV curable filler material (e.g. UV-curable epoxy resin, acrylic resin, urethane acrylate, polyester resin, gel coat, polyurethane, silicone resin, methacrylate adhesive, thiol-ene system) is applied on the membrane 31 around the edge of the patch to achieve a smooth edge transition when vacuum and UV are activated. Filler can also be applied to the back of the patch between the patch and the membrane 31 to achieve a smoother patch surface.

[021] If desired, a sensor can be placed on or fixed to the patch to attach it to the wind turbine blade together with the patch. A sensor can be a planar electronic circuit board, which may or may not be integrated with a photovoltaic module. The sensor electronic circuit board is preferably encapsulated to avoid air, have smooth edges, and withstand mechanical vacuum application. If the sensor has a photovoltaic module, then the patch may be provided by an aperture, that matches the position of the sensor’s photovoltaic module.

[022] The UV light protective curtain 30 is removably attached to close open side of the frame enclosure 11 and to guard the patch from the ambient UV light exposure. Further the device is brought up to the wind turbine blade to be repaired. The robotic arm 50 positions the patching head 10 over the damaged area of the wind turbine blade, ensuring that the patch placement area 21 directly aligns with the damage on the wind turbine blade surface. Initially, the robotic arm 50 ensures the patching head 10 hovers just above the desired blade surface position without making contact. After removing the curtain 30, the arm 50 advances the patching head 10 perpendicularly until the patch touches the blade surface. Furthermore, the arm 50 exerts perpendicular pressure onto the blade during vacuum activation to assist with optimal sealing. Once the patching head 10 is properly positioned, the suction interface 12 are activated, creating a vacuum seal against the blade's surface. The vacuum pump system 20 ensures that the patching head 10 firmly adheres to the blade's surface, preventing any movement or slippage.

[023] The design of the membrane 31 ensures that the outer edges of the membrane 31 create a tight seal against the blade's surface. The membrane’s 31 substantial flatness in the center ensures a consistent pressure and fit over the patch, which aids in the effective bonding of the patch to the surface to be patched.

[024] The UV light source 40 is activated, emitting UV rays onto the patch. This causes the UV-curable resin within the patch to harden and adhere to the blade's surface. The duration and intensity of the UV exposure would depend on the specific resin being used and the extent of the damage. After curing, the robotic arm 50 retracts the patching head 10 from the blade's surface. The patch should now be securely bonded to the blade's surface. A final inspection is preferably carried out to ensure that the patch has been properly applied and that there are no imperfections or bubbles trapped underneath. Further the negative pressure established by the pump system 20 is alleviated, and the patching head 10 can be moved to another location if there are multiple damages on the blade.

Claims

1. A device for patching wind turbine blade surface comprising:- a patching head, comprising: a frame enclosure open on one side; the frame enclosure having a patch placement area; a suction interface, configured to be applied to a surface of a wind turbine blade and to hold the frame enclosure in the place, in respect to the blade; a curtain with curtain holding arrangement; a UV light source located in the frame enclosure and configured to expose a patch placed on the patch placement area to the UV light;- a pump system , connected to the suction interface of the patching head;- a robotic arm, designed to grip and position the patching head, to exert substantially perpendicular pressure onto the blade surface via the frame enclosure during activation of the vacuum pump system;wherein the patch placement area is designed to be in the form of a UV-transparent membrane, configured to be substantially flat at least in its center and have a border that extends outward ensuring a tight seal with the blade's surface when the vacuum pump system is activated through the suction interface;the curtain is designed to be UV - opaque and configured to be removably attached in front of the membrane, so to close open side of the frame enclosure and to guard a patch from the ambient UV light exposure, when the patch is placed on the membrane; wherein the curtain holding arrangement is configured to allow remotely controllable removal of the curtain, so to remove the UV protection from the patch placed on the membrane.

2. The device according to claim 1, wherein the frame enclosure is provided with UV-protected air vents configured to let an air to the frame enclosure, but block light from entering in to the frame enclosure.

3. The device according to any preceding claims, wherein the suction interface is integrated into the membrane.2024220884   11 Jul 20254. The device according to any preceding claims, wherein the patching head further comprises a connecting element connected to the frame enclosure and configured to hold the frame enclosure in place and to allow the frame enclosure to maintain consistent contact with the wind turbine blade surface irrespective of the curvature of the blade surface.

5. The device according to claim 4, wherein the connecting element comprises at least two hinged levers having ends one and two; the ends one of the hinged levers are designed to be located substantially under the frame enclosure; the connecting element being pivotally attached to the frame enclosure at a pivot point, located between the ends one and two of the hinged levers, so to adjust the hinged levers’ angle relative to the frame enclosure during moving of the patching head along the varying curvature of the blade surface; wherein the ends one and two of the hinged levers are provided with a mechanism configured to move or glide across the blade surface without causing it damage.

6. The device according to claim 5, wherein the connecting element comprise sequential hinged levers having ends one and two; the sequential hinged levers being pivotally attached to the hinged levers at a pivot point, located between the ends one and two of the sequential hinged levers, so to adjust the sequential hinged levers’ angle relative to the hinged levers during moving of the patching head along the varying curvature of the blade surface; wherein the ends one and two of the sequential hinged levers are provided with a mechanism configured to move or glide across the blade surface without causing it damage.

7. The device according to claim 5 or 6, wherein the mechanism configured to move or glide across the blade surface is selected from the group consisting of rollers, wheels, balls, sliders, skids, pads, tracks, gliders and casters.

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