Apparatus and method of forming leading edge protector
By using a robotic arm to deposit fluid polymer materials on wind turbine rotor blades, a continuous leading edge protector is formed, which solves the problem that leading edge protection is difficult to achieve in the existing technology and achieves efficient and economical leading edge protection effects.
Patent Information
- Application Number
- CN202380041451.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-05-20
- Filing Date
- 2023-04-28
- Publication Date
- 2025-01-24
AI Technical Summary
The prior art is difficult to effectively provide leading edge protection for wind turbine rotor blades, especially in complex leading edge curvature and high speed environments, resulting in aerodynamic performance degradation and high maintenance costs.
Use a robotic arm guidance to sedsey the fluid polymer material on the rotor blades to form a continuous front edge protector (LEP) to achieve seamless LEP formation and automated production processes.
A continuous LEP is formed on the long rotor blades, avoiding the defects of the adhesive layer, significantly reducing the cost, and ensuring the consistency of the air dynamic performance of the rotor blades.
Smart Images
Figure CN119365677A_ABST
Abstract
Description
Background Art
[0001] During operation of a wind turbine, the leading edge of a rotor blade may be damaged by impact with airborne particles such as hail, sleet, ice, sand, etc. Since the angular velocity increases with increasing distance from the hub, the risk of impact damage increases towards the rotor blade tip. The tip of a long wind turbine rotor blade may reach speeds in excess of 300 km / h.
[0002] Damage to the leading edge may be in the form of pits, cracks, fissures, etc. The resulting non-uniformity in the surface of the LEP may adversely affect the aerodynamic flow of air over the airfoil. A reduction in aerodynamic performance is associated with a reduction in the annual energy production of the wind turbine. For these reasons, wind turbine rotor blades are typically provided with some form of leading edge protection.
[0003] Since the inboard region of a wind turbine rotor blade is less susceptible to leading edge impact damage due to lower angular velocities, typically the outboard portion of the rotor blade is provided with a LEP, for example along the leading edge in the outer half of the rotor blade.
[0004] Leading edge protectors (LEPs) can be implemented in a variety of different ways and should generally meet a number of conditions. For example, the LEP must adhere reliably to the rotor blade during its lifetime. In addition, the long edge of the LEP should smoothly transition to the pressure and suction side surfaces of the rotor blade. Another requirement is that the LEP should contribute to the overall airfoil shape of the rotor blade.
[0005] These conditions are difficult to meet by known methods of providing leading edge protection for wind turbine rotor blades. For example, in one method, one or more layers of adhesive tape can be applied along the leading edge of the rotor blade. However, it is difficult to apply the tape without any wrinkles or other surface inconsistencies and to ensure that there are no trapped air bubbles under the tape layer. In another method, a suitable polymer can be used to injection mold LEP "shells". One or more LEP shells, each having a length of 1 meter or more, are glued to the leading edge of the rotor blade. However, if these shells are to be properly assembled around the leading edge, several dedicated molds may be required for each rotor blade design. This is particularly a problem where the rotor blade is manufactured to have an upwind curvature or "pre-bend", because the leading edge of such a rotor blade is not straight, but exhibits a certain degree of curvature, especially in the outboard area.
[0006] Another problem with the known technique of mounting a row of pre-made LEP shells to a rotor blade is the need to ensure that there are no gaps between adjacent shells and to avoid "steps" or overlaps between adjacent shells. Achieving satisfactory results is time consuming and expensive, requiring the expertise of a trained technician. Another problem with the known method is that it is difficult to ensure a homogeneous adhesive layer (i.e. an adhesive layer without cavities or trapped air bubbles) between the rotor blade and the LEP shell, as such defects may later lead to partial or complete detachment of the LEP shell. As a result, the known method may lead to expensive repair and maintenance procedures during the lifetime of the wind turbine, with associated downtime and loss of revenue.
[0007] It is therefore an object of the present invention to provide a more economical way of providing satisfactory leading edge protection for a wind turbine rotor blade.
[0008] This object is achieved by the claimed method for depositing a leading edge protector onto a rotor blade and by the claimed deposition device. Summary of the invention
[0009] According to the invention, the method comprises the steps of providing a robot arm adapted to guide a nozzle; providing a supply of fluid polymer material; actuating the robot arm to guide the nozzle along a predefined trajectory within a deposition area while dispensing a predetermined amount of fluid polymer material directly onto a rotor blade within the deposition area. The deposited material is then allowed to solidify, thereby forming a leading edge protector directly on the rotor blade.
[0010] An advantage of the method according to the invention is that the entire LEP is formed seamlessly. With the help of the method according to the invention, a long LEP can be formed on a long rotor blade without any interruptions along the length of the LEP. The procedure can be performed as an automated process, so that significant cost savings can be achieved. Furthermore, by forming the LEP directly on the rotor blade, the method according to the invention avoids the problems known from the prior art, namely problems caused by defects in the adhesive layer. Therefore, the method according to the invention provides a way to achieve consistent aerodynamic performance of rotor blades equipped with leading edge protection.
[0011] According to the invention, the deposition device is suitable for depositing a leading edge protector onto a leading edge region of a wind turbine rotor blade and comprises: a mechanical arm adapted to guide a nozzle; a supply of a fluid polymer material; and a controller configured to actuate the mechanical arm to guide the nozzle along a predefined trajectory within a deposition region and to actuate the dispenser to dispense a predetermined amount of the fluid polymer material onto the deposition region. The term "deposition region" should be understood as a geometrical area onto which a layer of fluid polymer material is to be deposited when constructing a LEP.
[0012] An advantage of the apparatus of the invention is that it can be configured to carry out the method steps in a systematic and methodical manner so as to gradually build up the LEP layer at a suitable rate. Since the robot arm can operate substantially without interruption and since the desired layer thickness can be obtained with very advantageous precision, the resulting protective coating or LEP can be formed to have a very advantageous aerodynamic shape, regardless of the complexity of the leading edge curvature of the rotor blade.
[0013] The object of the invention is also achieved by a computer program product having a computer program which can be directly loaded into the memory of a controller of a deposition device and comprises program elements for implementing the steps of the method of the invention when the program is executed by the controller.
[0014] Particularly advantageous embodiments and features of the invention are given by the dependent claims, as revealed in the following description. Features of different claim categories may be combined as appropriate to give further embodiments not described herein.
[0015] The geometric leading edge of a wind turbine rotor blade is the line or interface between the suction side and the pressure side. In the following, it may be assumed that the leading edge region has the shape of an elongated rectangle extending a certain distance on either side of the leading edge. The length of the leading edge region may comprise any suitable fraction of the rotor blade span, for example up to 40% of the total span. The leading edge region may extend between any two suitable points along the rotor blade span and may extend to the outermost tip of the rotor blade. Likewise, the leading edge region may terminate at a certain distance inwards from the outermost tip.
[0016] The inventive method is essentially a method of "3D printing" of LEP directly onto a wind turbine rotor blade. The terms "3D printing" and "additive manufacturing" should be understood as synonyms and may be used interchangeably herein. In the following, without limiting the invention in any way, it may be assumed that the inventive method utilizes fused filament technology.
[0017] In the molten filament additive manufacturing technology, the fluid polymer material is a filament of a softened or molten thermoplastic raw material. The thermoplastic raw material can be any of the following: aliphatic polyamides such as nylon, high impact polystyrene (HIPS), acrylonitrile butadiene styrene (ABS), thermoplastic polyurethane (TPU), polyethylene terephthalate (PET), polylactic acid (PLA), polyethylene terephthalate glycol (PETG), etc. In an exemplary embodiment of a deposition device for implementing the molten filament additive manufacturing technology, a motor-driven unit pulls the raw material from a reel and pushes the raw material into a liquefier. The liquefier includes a heating chamber that melts the raw material, which then leaves through a nozzle. The deposition rate can be adjusted by adjusting the stepper motor speed and / or adjusting the temperature in the heating chamber and / or selecting an appropriate nozzle thickness.
[0018] Since the LEP is built up in a sequence of layers, and since the shape of the LEP is ideally a continuation of the airfoil shape of the rotor blade, the surface area of a deposition region will generally be smaller than the surface area of the previous deposition region.
[0019] In order to deposit a uniform layer thickness of fluid polymer material onto the deposition area, the nozzle is preferably maintained at a consistent or uniform distance from the underlying surface and is preferably maintained at right angles to the underlying surface. However, the deposition area may have a complex shape, i.e., a rectangular area curved around the leading edge. In particular, towards the tip of the rotor blade, the radius of curvature at the leading edge is typically very small, requiring the nozzle to change position through almost 180°. Further complexity may result from the pre-bent curvature of the rotor blade or the swept shape in the tip region. As the LEP is built, the surface profile in the leading edge region changes further. The deposition device of the present invention provides a method for depositing fluid polymer material around a complex surface around the leading edge of a rotor blade using additive manufacturing technology by controlling a robotic arm to take into account the initial complex shape and any subsequent changes to the shape. To this end, in a preferred embodiment of the present invention, the deposition device includes a plurality of distance sensors, each of which is directed toward the rotor blade and is arranged to measure the distance between a reference point and the underlying surface. The controller can evaluate the measurements transmitted by the distance sensor, allowing it to "track" the growing leading edge profile. Using this information, the controller can always correctly orient the nozzle relative to the underlying surface.
[0020] In a preparatory step, the controller may cause the robotic arm to "sweep" the entire spanwise length and chordwise width of the deposition zone to obtain an initial map of the deposition zone. This "map" may be used as the basis for all further position adjustments when building the layers. In a preferred embodiment of the invention, such a "map" is initially compiled for a particular type of rotor blade, and then used as the basis for "printing" the LEP onto a series of such rotor blades.
[0021] Preferably, the deposition device comprises a displacement device suitable for achieving displacement of the manipulator relative to the rotor blade. In a preferred embodiment of the present invention, the deposition device is movably mounted to the rotor blade, for example by using a suction foot and / or a clamp arrangement. Such a displacement device may include a motor-driven vacuum device for the suction foot, a motor-driven hydraulic clamp arrangement, or any suitable actuator. Similarly, the displacement device may include an arrangement of wheels, rollers, tracks or other guides to support the deposition device. The displacement device allows the deposition device to move along the relevant area of the rotor blade. In an alternative method, a gantry may be arranged around the rotor blade, and the manipulator may be suspended from the gantry. The displacement device may be configured to allow the manipulator to move back and forth both laterally (i.e., in the chord direction) and longitudinally (i.e., in the span direction). The vertical support of the gantry may be configured to allow vertical displacement of the gantry.
[0022] The fluid material may be completely liquid when it leaves the nozzle and may flow a certain distance under the influence of gravity. Therefore, in a preferred embodiment of the invention, the method comprises an initial step of arranging the wind turbine rotor blade with its leading edge pointing upwards. With the rotor blade held in this way, any spreading of the fluid material is not confined to one side of the airfoil, but may be spread in a more balanced manner.
[0023] In a particularly preferred embodiment of the invention, a wind turbine rotor blade is held with its leading edge pointing substantially upward, but with the chord plane slightly angled to facilitate the flow of molten material toward a particular side of the rotor blade airfoil. For example, it may be desirable to shape the LEP to have a greater thickness toward the front of the pressure side because the rotor blade will be angled slightly upward ("angle of attack") relative to the incoming air flow for most of its operation. A slightly thicker LEP in the area most exposed to the incoming air flow can extend the service life of the rotor blade. The average angle of attack does not have to be the same over the entire length of the rotor blade, but can be a function of the distance (spanwise position) along the rotor blade. Therefore, in a preferred embodiment of the invention, the method includes an initial step of estimating the angle of attack at various spanwise positions along the rotor blade. During the LEP deposition procedure, the rotor blade can be rotated about its longitudinal axis to adjust the orientation of the local chord plane. For this purpose, the root end of the rotor blade can be rotatably mounted in a holding device, and the airfoil of the rotor blade can be supported by one or more rotatably mounted airfoil clamps. Control of these rotatably mounted holding devices is preferably synchronized with the operation of the robotic arm.
[0024] The LEP is preferably constructed by applying continuous layers of thin deposited fluid material. The fluid material leaves the nozzle in the form of a thin stream or "bead", which adheres to the rotor blade surface. Therefore, in a preferred embodiment of the present invention, the predefined trajectory comprises a series of uninterrupted path segments extending between opposite sides of the deposition area. For example, the area to be deposited with the LEP may have the form of an elongated rectangle or ellipse that "wraps" the leading edge of the rotor blade. The length of the deposition area should be understood as extending in the spanwise direction of the rotor blade, while the width of the deposition area extends from the pressure side to the suction side following the curvature on the leading edge of the rotor blade.
[0025] Initially, one or more thin layers of fluid material are deposited over the entire LEP area. As the LEP is built, successive layers will become successively narrower, i.e. the width of the deposition area gradually decreases. In a preferred embodiment of the invention, the predefined trajectory comprises a series of uninterrupted path segments extending between the long sides of the deposition area, e.g. when the robot arm guides the nozzle over the curved leading edge of the rotor blade, the path segment extends from the long edge of the deposition area on the pressure side to the opposite long edge of the deposition area on the suction side.
[0026] In an alternative approach, the path segments extend from one short edge of the deposition area to the opposite short edge. Thus, each path segment is deposited in the spanwise direction. In this approach, the rotor blade may be slowly rotated from an initial position with the pressure side facing upward to a final position with the suction side facing upward while the robotic arm moves back and forth in the spanwise direction to deposit a long bead of fluid material in the deposition area. Of course, a combination of the above approaches may be preferred, such that the LEP is constructed by depositing layers of alternating bead directions, i.e., one layer is formed by depositing beads in the spanwise direction, followed by a continuous layer by depositing beads in the chordwise direction, followed by a continuous layer by depositing beads in the spanwise direction, and so on.
[0027] The "trajectory" of the nozzle may be understood as a sequence of path segments between the start and the end of the deposited bead. Preferably, the predefined trajectory is programmed to produce a homogenous layer of fluid material in the deposition area, i.e. the number of path segments may depend on the bead thickness, which in turn may depend on the nozzle size, nozzle speed, mixture viscosity or filament viscosity, feedstock or pump motor speed, etc. Preferably, the method comprises the steps of directing the nozzle at a predetermined speed relative to the surface of the rotor blade and selecting the nozzle speed based on the desired bead thickness.
[0028] In a preferred embodiment of the present invention, the robot arm has multiple degrees of freedom, that is, the robot arm is articulated with several joints so that the end effector can be oriented at any desired angle. The robot arm of the deposition device of the present invention can be equipped with a single end effector, which is suitable for holding the nozzle in a desired orientation relative to the rotor blade surface. For example, the end effector can be rotatable, or can be arranged at one end of a rotatable joint. The robot arm can be equipped with several end effectors, each of which holds a nozzle, each nozzle having a different shape and / or a different cross-sectional area. These nozzles can dispense fluid materials in the deposition area at the same time. Similarly, these nozzles can be manipulated separately. One nozzle can be used to apply one or more very thin initial layers over the entire LEP area. Then, this same nozzle or a nozzle with an appropriately sized orifice can be used to apply additional thin layers of reduced width to begin forming the bevel of the LEP. Then, a third nozzle with a larger orifice can be used to build the final layer of the LEP.
[0029] The smoothness of the cured LEP (i.e., the LEP after the deposited material has hardened) may depend to some extent on the bead thickness and nozzle diameter, among other things. Although the apparatus can be configured to deposit very thin layers and produce smooth exterior surfaces on the cured LEP, similar results can be achieved with thicker layers. For example, the deposition apparatus can be equipped with an additional end effector, such as a spreader, which is configured to smooth the "steps" between successive layers along the outer edge of the deposition area. In an alternative embodiment, such an end effector can be a directional heat source that can be aimed at the material extruded from the nozzle. The heat source can reheat the molten material to delay solidification, causing the bead of material to spread out slightly more. In this way, a smoother outer edge of the LEP can be obtained.
[0030] Alternatively, after the LEP has been deposited and has cured, the surface can be optimized by manually directing a heat source along the outer edge to soften the material at the outer surface of the LEP, which becomes smoother as the thermoplastic material yields and spreads.
[0031] The initial layer can be deposited directly onto the surface of the rotor blade. After the rotor blade is molded, its outer surface can be treated by applying one or more protective coatings (such as paint, resin or any suitable polymer). The material to be deposited in the thin fluid layer can be selected according to its ability to adhere to such a surface coating. However, it may be preferred to form the LEP from a material that cannot bond to such a surface coating. Therefore, in a further preferred embodiment of the present invention, the method includes a preparatory step of arranging a thin sheet of thermoplastic material onto the leading edge area before depositing the molten thermoplastic. The sheet of thermoplastic material or "hot melt sheet" can be made of suitable polyester, polyurethane or other adhesive. The hot melt sheet can be softened by a directional heat source (e.g. maintained by the end effector of a robotic arm) immediately before, during or after depositing a bead of fluid material.
[0032] The controller of the deposition apparatus preferably comprises a number of suitable control modules configured to synchronize at least: control of the displacement device to move the robot arm to the desired position; material feed rate; temperature and / or viscosity of the fluid material; movement of the nozzle along the bead trajectory; nozzle replacement according to the desired bead thickness, etc. If the apparatus utilizes a directed heat source to soften the cured edge of the hot melt sheet or LEP, the controller preferably synchronizes the operation of such heat source as well. If the rotor blade is rotatably mounted at its root end, the controller also preferably synchronizes the rotation of the rotor blade about its longitudinal axis according to the LEP deposition phase. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It should be understood, however, that the drawings are designed for illustration purposes only and not as a definition of the limits of the present invention.
[0034] Figure 1 A simplified schematic diagram showing an embodiment of a deposition apparatus 1 according to the present invention;
[0035] Figure 2 Another embodiment of the deposition device 1 of the present invention is shown;
[0036] Figure 3 and Figure 4 illustrates the stages in an embodiment of the method of the present invention;
[0037] Figure 5 and Figure 6 illustrates the stages in an embodiment of the method of the present invention;
[0038] Figure 7 Another exemplary embodiment of the deposition apparatus of the present invention is shown;
[0039] Figure 8 and Fig. 9 An embodiment of a leading edge protector obtained by the method of the present invention is shown;
[0040] Fig.10 Further exemplary embodiments are illustrated.
[0041] In the drawings, like reference numerals refer to like objects throughout. Objects in the drawings are not necessarily drawn to scale. DETAILED DESCRIPTION
[0042] Figure 1 A simplified schematic diagram of an embodiment of the deposition apparatus 1 of the present invention is shown in position above a wind turbine rotor blade 2. The deposition apparatus 1 is to be operated to deposit a leading edge protector onto a leading edge region R0 using additive manufacturing techniques. The figure shows a robotic arm 10 having a plurality of arm joints 10A, and an end effector 10E adapted to hold and guide a nozzle 10N. The figure also shows a dispensing assembly comprising a stepper motor 10M and a heater 10H, and a thermoplastic material feedstock M. The motor may, for example, rotate a spool to push the filament feedstock M into the heater 10H. The heater heats the thermoplastic material to soften it so that it can pass through the nozzle 10N as a bead M bead Push out or extrude.
[0043] The controller 11 (here conceptually shown as a block) actuates the robot 10 to guide the nozzle 10N along a predefined trajectory within the deposition region R0 and actuates the components of the dispensing assembly so that the molten polymer material M molten A continuous bead of material is deposited onto the rotor blade surface 200. To this end, the control module of the controller 11 sends a control signal 111 to the dispensing assembly; a control signal 112 to the arm joint 10A, the end effector 10E and the nozzle 10N; and a control signal 113 to the displacement device 13.
[0044] The figure also shows a number of distance sensors 10S. In this exemplary embodiment, the sensors 10S are arranged in line with the nozzles 10N to monitor the distance of the nozzles 10N to the rotor blade surface 200. Of course, the sensors may be arranged at any suitable location. The controller 11 evaluates the measurement results S from one or more distance sensors 10S. in , the controller 11 can adjust the position of the robot arm 10, the orientation of the end effector 10E holding the nozzle 10N, the movement rate of the nozzle 10N, and the like.
[0045] In this embodiment, the deposition device 1 is mounted on a rotor blade 2 and is fixed to the rotor blade surface 200 using an arrangement of articulated suction feet of displacement devices 13. These can be operated by a controller 11 to move the robot arm 10 in the spanwise direction and / or chordwise direction as required. Such position adjustment may be required each time the robot arm 10 completes material deposition within its radius of action. The assembly of such an articulated device is known to the skilled person and does not need to be discussed in detail herein. During the deposition of the molten feedstock, the robot arm 10 is actuated to maintain a vertical orientation of the nozzle 10N relative to the surface 200 of the rotor blade 2. The advantageous precise movement of the robot arm can be achieved by an appropriate number of rotational joints between the arm segments 10A.
[0046] Figure 2 Another embodiment of the present invention is shown. The deposition device 1 is similar to Figure 1 Here, instead of unwinding the thermoplastic raw material and melting it, the material to be deposited is mixed by combining two components M1, M2 of epoxy resin, polyurethane or any other two-component coating. These components are provided in a reservoir, and the mixing unit 14 is configured to mix the appropriate amounts and feed the mixture to the nozzle 10N. It can be assumed that the nozzle 10N is held by the end effector of a robot arm (not shown), such as Figure 1 As explained in .
[0047] Figure 3 An exemplary trajectory T during a deposition process is shown. Here, within an elongated rectangular deposition region R, the trajectory T comprises a continuous chordal path segment P CW1 , P CW2 , i.e., directing the nozzle 10N back and forth in the chordwise direction between the pressure side 10P and the suction side 20S, thereby forming parallel beads M extending in the chordwise direction on either side of the leading edge 20LE CW1 、M CW2 layer. Figure 4 Showing parallel beads M CW1 、M CW2 The resulting layer L (the bead thickness is greatly exaggerated in this figure).
[0048] An elongated rectangular deposition region R may define any one LEP layer. The deposition region R may have a length of several meters, for example 25 m in the case of a 100 m rotor blade. The width of the widest deposition region (i.e. the width of the first LEP layer) may be about 10 cm on either side of the leading edge (i.e. on either side of the interface between the pressure side and the suction side). In an exemplary embodiment, the thickness of the "printed" or deposited LEP may vary from less than 0.1 mm along the outer edge to a height of 3 mm along the interface between the pressure side and the suction side. Thus, in the first layer, each bead M may have a thickness of 100 m. CW1 、M CW2Each extends a length of about 20 cm, and each bead is at most 0.1 mm thick. As the layers are built up, the bead length becomes shorter, and the bead thickness can be gradually increased (by appropriate choice of nozzle orifice).
[0049] Of course, the shape and form of the deposited LEP can be planned according to the rotor blade geometry and meteorological conditions at the intended installation site.
[0050] Figure 5 A further exemplary trajectory T during a deposition procedure is shown. Here, the trajectory T comprises consecutive spanwise path segments P SW1 , P SW2 , that is, the nozzle 10N is guided back and forth in the spanwise direction parallel to the leading edge 20LE, thereby forming a long parallel bead M SW1 、M SW2 Layer L. Figure 6 The resulting layer L is shown (again, the bead thickness is greatly exaggerated in this figure).
[0051] Figure 7 A further exemplary embodiment is shown. Here, the displacement device of the deposition device 1 includes a gantry 15 in an appropriate position above the rotor blade 2. The gantry can be moved in the span direction. The robot arm 10 can be moved laterally along the viaduct of the gantry. The figure also shows a holding arrangement 50, 51 for holding the rotor blade during the deposition procedure. Here, the rotor blade airfoil 20 is supported by one or more rotatable airfoil clamps 50, while the circular root end 21 is held by a rotatable root end frame 51. This holding arrangement allows the rotor blade 2 to rotate about its longitudinal axis 2A, so that even when the leading edge has a relatively small radius of curvature, a portion of the deposition area can be optimally presented to the robot arm. Of course, instead of rotating the rotor blade 2, the deposition device 1 and the displacement device can be configured to allow the robot arm 10 to move so that the nozzle 10N can be guided around the leading edge curvature.
[0052] Figure 8 A cured leading edge protector 3 is shown, and two cross sections are shown, each from opposite ends of the LEP 3. These cross sections show the different shapes of the LEP depending on the spanwise position along the rotor blade. In the more inboard regions, the LEP 3 may have an asymmetric shape, since the pressure side receives more exposure from the impact of airborne particles. The LEP 3 comprises a number of thin layers L0, L1, ..., Ln of cured material, such as Fig. 9. Each layer thickness substantially corresponds to the thickness of the bead dispensed by the nozzle 10N during the deposition process. The width of the successive layers L0, L1, ..., Ln depends on the spanwise position. The width of the successive layers L0, L1, ..., Ln gradually decreases as a function of the distance outward from the rotor blade surface 200. Here, the outer edge of the LEP 3 may exhibit small "steps" between successive layers. These steps can be smoothed by reheating the plastic material and allowing it to spread, thereby flattening them.
[0053] Fig.10 A further exemplary embodiment is illustrated in which a hot melt sheet 4 is initially applied to the leading edge region R0. The first LEP layer L0 is deposited as described above, for example along short path segments extending on either side of the leading edge 20LE. Here, the robot arm 10 is equipped with a further end effector 10E configured to aim a directional heat source at the hot melt sheet, which melts to bond the deposited layer L0 to the rotor blade surface 200. The remaining LEP layers L0, L1, ..., Ln are constructed as described above.
[0054] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.
[0055] For the sake of clarity, it should be understood that the use of "a" or "an" throughout this application does not exclude a plurality, and "comprising" does not exclude other steps or elements. References to a "unit" or a "module" do not exclude the use of more than one unit or module.
Claims
1. A method for depositing a leading edge protector (3) onto a leading edge region (R0) of a wind turbine rotor blade (2), the method comprising the following steps: - providing a robotic arm (10) suitable for guiding the nozzle (10N); -Provide fluid polymer material (M fluid ) supply device; - actuating the robot arm (10) to guide the nozzle (10N) along a predefined trajectory (T) within a deposition area (R0, R1, ..., Rn) while dispensing a predetermined amount of fluid polymer material (M) within the deposition area (R0, R1, ..., Rn) fluid ), the deposited fluid polymer material (M fluid ) is then cured to form the leading edge protector (3).
2. Method according to the preceding claim, wherein the predefined trajectory (T) is programmed to produce a homogeneous layer (L0, L1, ..., Ln) of deposited material in the deposition region (R0, R1, ..., Rn).
3. The method according to any one of the preceding claims, wherein the path segment (P SW1 , P SW2 ;P CW1 , P CW2 ) extends between a suction side (20S) of the rotor blade and a pressure side (20P) of the rotor blade.
4. The method according to any of the preceding claims, comprising the steps of: calculating a nozzle speed (v_10N) to achieve a desired material deposition; and moving the nozzle (10N) at the calculated speed (v_10N) relative to the surface (200) of the rotor blade (2).
5. Method according to any of the preceding claims, wherein the robot arm (10) comprises a rotatable end effector (10E) suitable for holding a nozzle (10N).
6. The method according to any of the preceding claims, wherein the robot arm (10) is actuated to maintain a vertical orientation of the nozzle (10N) relative to a surface (200) of the rotor blade (2).
7. A method according to any one of the preceding claims, wherein the fluid polymer material (M fluid ) is provided as filaments of a softened thermoplastic raw material (M).
8. A method according to any one of the preceding claims, comprising depositing the fluid polymer material (M fluid ) before arranging a sheet (4) of thermoplastic material onto the leading edge region (R0).
9. A method according to the preceding claim, wherein the predefined trajectory (T) comprises a series of uninterrupted path segments (P SW1 , P SW2 ;P CW1 , P CW2 ).
10. Method according to any of the preceding claims, comprising the step of rotating the rotor blade (2) about its longitudinal axis (2A) during the material deposition procedure.
11. A deposition device (1) suitable for depositing a leading edge protector (3) onto a leading edge region (R0) of a wind turbine rotor blade (2), the deposition device (1) comprising - a mechanical arm (10) suitable for guiding the nozzle (10N); - Fluid polymer material (M fluid ) supply device; and a controller (11) configured to actuate the robot arm (10) to guide the nozzle (10N) along a predefined trajectory (T) within a deposition area (R0, ..., Rn), and to actuate the dispensing components (10M, 10H) to dispense a predetermined amount of fluid polymer material (M fluid ) is dispensed onto the deposition areas (R0, R1, ..., Rn).
12. Deposition device according to the preceding claim, comprising a plurality of distance sensors (10S) arranged to measure the distance to the rotor blade surface (200).
13. The deposition device according to claim 11 or claim 12, comprising a displacement device (13) suitable for achieving displacement of the robot arm (10) and / or the nozzle (10N).
14. The deposition apparatus according to any one of claims 11 to 13, wherein the controller (11) is configured to control the displacement device (13).
15. A computer program product comprising a computer program, which can be directly loaded into the memory of a controller (11) of a deposition device (1) according to any one of claims 11 to 14, and comprises program elements for implementing the steps of the method according to any one of claims 1 to 10 when the computer program is executed by the controller (11).