Clamping of components, especially wind turbine blade tips

Abstract

To provide a method and a tool for handling a part of a wind turbine blade, and another component in general.SOLUTION: A tool (10) comprises a first clamp seat (12) for receiving a first surface of a component and second clamp seats (14, 16) for receiving a second surface of the component, the second surface being opposite to the first surface. The tool (10) further comprises an actuator (45) for moving the first clamp seat (12) to clamp the component with predetermined clamping force, and an electric motor (40) for driving the actuator (45). The tool further comprises a control device that controls a current in the electric motor (40) to provide the predetermined clamping force. A method for determining a current level in the electric motor (40) driving the actuator (45) for clamping the component, and a method for controlling clamping force in the tool (10) are also provided.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a tool for handling a component, the component being clamped to the tool. More particularly, the present disclosure relates to a tool for handling wind turbine blades, and in particular wind turbine blade tips. The present disclosure further relates to a method for controlling the clamping force in the tool and a method for determining a desired current level in an electric motor that drives an actuator for clamping the component. [Background technology]

[0002] Modern wind turbines are commonly used to supply electricity to the power grid. This type of wind turbine generally comprises a tower and a rotor disposed on the tower. The rotor, which typically comprises a hub and a number of blades, rotates under the influence of wind on the blades. The rotation typically generates torque that is transmitted via the rotor shaft to a generator, either directly or using a gearbox. In this way, the generator produces electricity that can be supplied to the power grid.

[0003] Over the years, there has been a trend in the industry to increase the size of wind turbines. Both the hub height and the blade length have increased significantly over the years. Today, wind turbines employ blades that are greater than 70 meters, even greater than 80 meters, and even greater than 100 meters in length.

[0004] Blades of such lengths are difficult to manufacture and transport. It is known to manufacture the blade sections, root and tip, separately, particularly for transportation purposes. The root and tip sections can be transported separately to the wind park site. The root and tip sections can then be joined in situ just before installation. The blade sections may have specific elements (e.g., male-female couplings) that allow them to interlock with one another to allow easier assembly. For example, one of the tip and root sections may have an elongated pin that can be inserted into a suitable receptacle in the other section. It is known to provide a portion of the spar that protrudes beyond its edge. The protruding portion of the spar can then be received in and joined to the other section. After assembly of the blade, it can be pulled up towards the hub of the wind turbine, where it is erected.

[0005] For example, a blade having a length of about 77 meters may be divided into a root section having a length of about 65 meters and a tip section having a length of about 12 meters. Such a blade tip may weigh about 1,000 kg. Of course, the exact dimensions of the root and tip sections will vary for different blades. Typically, the tip section may be 5 to 20 meters long. Such a tip section may weigh, for example, about 500 to 2,000 kg.

[0006] When the tip is to be joined to the root, the root may be held or at least partially supported on a support rack. The tip is elevated to bring it into close proximity with the root. For the parts to be properly joined, the tip must be correctly oriented.

[0007] Lifting tools with hydraulic clamps are known in the art for such operations, however, hydraulic mechanisms can be too complex and expensive to lift, manipulate, and orient the tip.

[0008] Examples of the present disclosure provide methods and tools for handling portions of wind turbine blades, and other components in general. The problems described herein primarily relate to handling wind turbine blades, and in particular wind turbine blade tips, although similar challenges exist in different fields. Summary of the Invention

[0009] In a first aspect of the present disclosure, a tool for handling a component is provided, the tool including a first clamping seat for receiving a first surface of the component, a second clamping seat for receiving a second surface of the component, the second surface being opposite the first surface, and an actuator for moving the first clamping seat relative to the second clamping seat to clamp the component between the first and second clamping seats with a predetermined clamping force. The tool further includes an electric motor for driving the actuator, and a controller configured to control the electric motor by determining a current in the electric motor and to control the electric motor to provide the predetermined clamping force based on the determined current.

[0010] According to this aspect, a tool for manipulating components is provided that is driven by an electric motor rather than a hydraulic mechanism. This makes the tool less complex and less expensive. A challenge with using an electric motor or drive rather than a hydraulic mechanism is that it can be difficult to determine the exact clamping force being applied to the component. For proper operation, this force needs to be precisely controlled. If the force is too high, the component may be damaged. If the force is too low, effective clamping may not occur and the component may shift or fall off.

[0011] According to this aspect, the current in the electric motor is measured to determine the actual clamping force being applied, and it has been found that the clamping force can be accurately controlled in this manner, as opposed to using other controls based on, for example, the position of the actuator or the speed of the electric motor.

[0012] In another aspect, a method for controlling a clamping force in a tool is provided. The method includes operating an electric motor to drive a first clamp seat relative to a second clamp seat to clamp a component between the first and second clamp seats and measuring a current in the electric motor. The method further includes operating the electric motor to reach a desired torque level corresponding to a predetermined clamping force. The desired torque level is determined based on an empty current level, the empty current level being a current level required to operate the electric motor to drive the first clamp seat relative to the second clamp seat in the absence of a component.

[0013] According to this aspect, a method for controlling clamping force is provided that can take into account changing internal losses within the tool. As the tool is used, internal friction within the tool may change. For example, parts may wear, and lubrication may become ineffective over the tool's life. Over the tool's life, the internal friction experienced by the clamp seat may change. To precisely control the actual clamping force applied to the component, the method foresees determining the current level required to operate the clamp without the component. In the absence of the component, the measured current substantially corresponds to the electrical torque required to overcome the internal losses in normal operation, i.e., the force (current) required to overcome the internal losses. In this way, a desired clamping force can be applied even if the internal losses change over the tool's life.

[0014] In yet a further aspect, a method is provided for determining a desired current level in an electric motor driving an actuator for clamping a component. The method includes determining a clamp current required to provide a predetermined holding force. The method includes operating the electric motor under test, the test including driving the actuator in the absence of a component, and determining an internal loss current by measuring the current level under test. The desired current level is then determined by adding the clamp current to the internal loss current. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view of an example of a wind turbine. [Figure 2] FIG. 2 is a simplified internal view of an example nacelle of the wind turbine of FIG. 1. [Figure 3] 1 is an isometric view of an example of a tool for clamping portions of a wind turbine blade. FIG. [Figure 4] FIG. 4 is a rear view of the tool of FIG. 3. [Figure 5] FIG. 4 is a side view of the tool of FIG. 3. [Figure 6] 1A-1C illustrate aspects of an example of testing a clamping tool and an electric motor of the clamping tool. DETAILED DESCRIPTION OF THE INVENTION

[0016] Reference will now be made in detail to the embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is presented by way of explanation of the invention, and not as a limitation of the invention. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents.

[0017] FIG. 1 illustrates a perspective view of an example wind turbine 160. As illustrated, the wind turbine 160 includes a tower 170 extending from a support surface 150, a nacelle 161 mounted on the tower 170, and a rotor 115 coupled to the nacelle 161. The rotor 115 includes a rotatable hub 110 and at least one rotor blade 120 coupled to the hub 110 and extending outwardly from the hub 110. For example, in the illustrated embodiment, the rotor 115 includes three rotor blades 120. However, in alternative embodiments, the rotor 115 may include more or fewer than three rotor blades 120. Each rotor blade 120 may be spaced about the hub 110 to facilitate rotation of the rotor 115 so that kinetic energy from the wind can be converted into usable mechanical energy and, subsequently, electrical energy. For example, the hub 110 may be rotatably coupled to a generator 162 ( FIG. 2 ) disposed within the nacelle 161 to enable the generation of electrical energy.

[0018] 2 shows a simplified interior view of an example nacelle 161 of the wind turbine 160 of FIG. 1. As shown, a generator 162 may be disposed within the nacelle 161. In general, the generator 162 may be coupled to the rotor 115 of the wind turbine 160 to generate electrical power from rotational energy generated by the rotor 115. For example, the rotor 115 may include a main rotor shaft 163 coupled to the hub 110 for rotation therewith. The generator 162 may then be coupled to the rotor shaft 163 such that rotation of the rotor shaft 163 drives the generator 162. For example, in the illustrated embodiment, the generator 162 includes a generator shaft 166 rotatably coupled to the rotor shaft 163 via a gearbox 164.

[0019] It should be understood that the rotor shaft 163 , gearbox 164 , and generator 162 may generally be supported within the nacelle 161 by a support frame or bedplate 165 located on top of the wind turbine tower 170 .

[0020] The nacelle 161 is rotatably coupled to the tower 170 by a yaw system 130 such that the nacelle 161 can rotate about a yaw axis YA. The yaw system 130 includes a yaw bearing having two bearing components configured to rotate relative to one another. The tower 170 is coupled to one of the bearing components, and a bedplate or support frame 165 of the nacelle 161 is coupled to the other bearing component. The yaw system 130 includes a ring gear 131, a plurality of yaw drives 132 having motors 133, a gearbox 134, and a pinion 135 for meshing with the ring gear 131 to rotate one of the bearing components relative to the other.

[0021] The blades 120 are coupled to the hub 110 via pitch bearings 100 between the blades 120 and the hub 110. The pitch bearings 100 comprise an inner ring and an outer ring. The wind turbine blades can be mounted on either the inner bearing ring or the outer bearing ring, with the hub connected to the other. The blades 120 can undergo relative rotational movement with respect to the hub 110 when the pitch system 107 is actuated. Thus, the inner bearing ring can undergo rotational movement with respect to the outer bearing ring. The pitch system 107 of FIG. 2 comprises a pinion 108 that meshes with an annular gear 109 provided on the inner bearing ring to rotate the wind turbine blades about the pitch axis PA.

[0022] Figure 3 shows an isometric view of an example of a tool for clamping sections of a wind turbine blade. Figure 4 shows a rear view of the same tool of Figure 3. For ease of understanding, some parts have been omitted from the illustration. Figure 5 shows a side view of the tool of Figure 3.

[0023] FIG. 3 provides a tool 10 for handling a component, the tool comprising a first clamping seat 12 for receiving a first surface of the component and a second clamping seat 14 for receiving a second surface of the component, the second surface being opposite the first surface.

[0024] The tool 10 further includes an actuator 45 for moving the first clamp seat 12 relative to the second clamp seat 14 to clamp the component therebetween with a predetermined clamping force. The tool also includes an electric motor 40 for driving the actuator 45, and a controller configured to control the electric motor 40 by determining a current in the electric motor 40 and to control the electric motor 40 to provide the predetermined clamping force based on the determined current.

[0025] By measuring the current or current level in the motor, the effective clamping force can be determined. The level of current in the motor indicated the level of electric torque required to drive the electric motor and therefore the level of electric torque required to drive the clamp seat. The clamping force can be controlled by appropriately controlling the electric torque in the motor.

[0026] In this particular example, tool 10 may include a third clamping seat 16 for receiving a second surface of a portion of a wind turbine blade. In a not shown example, a fourth clamping seat may be provided. The fourth clamping seat may also be actuated by an actuator and may be configured to contact the same surface as the first clamping seat. Also, in this particular example, tool 10 may be configured to handle a portion of a wind turbine blade, particularly a wind turbine blade tip.

[0027] In this particular example, the suction side of the wind turbine blade section may be engaged by first clamp seat 12. The pressure side of the wind turbine blade section may be engaged by second clamp seat 14 and third clamp seat 16. Clamping the wind turbine blade section between the clamp seats allows the section to be manipulated. In other examples using blade sections, the first clamp seat may instead engage the pressure side, and the second clamp seat (and optionally the third clamp seat) may engage the suction side.

[0028] In the operation of attaching the blade tip to the root, the tool 10 can be lifted by a crane. The tip can be clamped by the tool, and the tool (and with it the tip) can be brought close to the root. Thus, the tip can be firmly supported by the tool during the assembly process. The clamping force must not be too high, as this could damage the wind turbine blade tip. At the same time, the clamping force must be high enough to ensure that the blade tip is effectively clamped and does not fall off the tool.

[0029] In some examples, the controller may be configured to determine the current in the electric motor 40 due to internal friction in the tool 10. By determining the internal friction in the tool 10, the clamping force can be more precisely controlled.

[0030] In some examples, the current in the electric motor due to internal friction within the tool can be determined by operating the electric motor in the absence of a component (in this example, a wind turbine blade tip). In the absence of the component, the current in the motor substantially corresponds to the current required to overcome the resistance and friction in the tool. In normal operation, part of the resistance experienced by the clamping seat (and therefore part of the current measured at the motor) is due to internal losses in the tool rather than due to actually clamping the component. Therefore, to very precisely control the clamping force applied to a wind turbine blade, the current due to internal losses can be subtracted from the measured current to obtain an indication of the applied clamping force.

[0031] In the specifically disclosed example, the actuator for moving the first clamp seat 12 is a threaded spindle 45 disposed on the nut. By rotating the threaded spindle 45, the threaded spindle 45 can be extended from or retracted into the housing 49. Thus, the position of the clamp seat 12 can be determined by driving the threaded spindle. By driving the spindle 45, the relative position of the first clamp seat 12 with respect to the second clamp seat 14 and the third clamp seat 16 can be controlled.

[0032] A spindle may be considered herein as a rod or pin that acts as an axis about which it rotates when in operation, and a nut may be considered herein as a component having a threaded hole.

[0033] In the particular example of Figure 1, the upper clamp seat 12 is actuated while the lower clamp seats 14 and 16 remain fixed in position. However, it will be apparent that in other examples this may be reversed. It will also be apparent that in other examples other mechanisms for controlling the position of one clamp seat relative to the other may be modified.

[0034] In some examples, tool 10 can include frame 18 including one or more lifting gears 31, 32, and 33 for lifting the tool. Lifting gears 31, 32, and 33 can be configured to be lifted by a crane. The lifting gears may include shackles, hooks, eyelets, or any other fasteners for attaching to hooks attached to a crane line. In this particular example of FIG. 1, lifting gears 31 and 32 are eyelets, and lifting gear 33 is a shaft.

[0035] In some examples, at least one of the lifting devices is movable relative to the frame. In this particular example, the lifting device 33 may be a shaft on a movable slide 34. The movable slide 34 may be guided along a longitudinal beam 22 of the top 21 of the frame 18.

[0036] The tool 10 may further include a lifting fixture actuator 36 for controlling the position of the movable lifting fixture 33. In this example, the slide 34 may be driven back and forth by operating a motor 38. The motor 38, via appropriate transmission, may drive a threaded spindle 36. The threaded spindle 36 may be rotatably attached to a nut on the slide 34. By rotating the spindle 36, the position of the slide 34 relative to the beam 22 may be changed.

[0037] Being able to change and control the position of one or more lifting fixtures can have the effect of adapting the position of the lifting fixture relative to the center of gravity. If the tool is lifted without the wind turbine blade tip inside, the center of gravity will be in a different location than if the wind turbine blade tip is supported inside. The center of gravity will change both longitudinally (defined in this case as parallel to the longitudinal beam 22) and laterally (defined in this case as parallel to the lateral beam 24, which substantially coincides with the length of the wind turbine blade tip when attached to the tool). The longitudinal position of the lifting fixture 33 can be changed to accommodate different situations and ensure the tool can be held in a desired, e.g., substantially horizontal, position. The relative displacement of the lifting fixture 33 that may be required will vary with different blades having different sizes.

[0038] The act of adjusting the position of the lifting gear relative to the frame may, in some instances, be performed when the component is barely lifted, i.e., just above ground level. The tool with the component may be carefully lifted, and as the lifting occurs, the tool tends to rotate about its lateral axis. By adjusting the position of the lifting gear 33, such rotation can be controlled and counteracted. In other instances, the adjustment of the position of one or more lifting gears may be performed, for example, after lifting to an operating height, or while the tool is still positioned on the ground.

[0039] During operation, some forward or rearward rotation ("tilt") about the lateral axis may be desired or required for easier assembly of the blade tip to the blade root. A sling fixture 70 may be provided at the rear of the frame 18. A sling may be threaded through the opening, and precise control of tilt may be provided by pulling the sling upward or releasing the sling downward. Alternatively, or in addition, a sling or cable may be attached to shackles 73, 75 located on or near the opposite, i.e., front, side of the tool.

[0040] Additionally or alternatively, pitching of the component (i.e., rotation about its longitudinal axis) may be accomplished by providing a chain hoist suspended from a crane, with the cable of the chain hoist attached to two different points on top of the frame. Optionally, in the case of a blade section, the first point may be located toward or in front of the leading edge of the blade section in use, and the second point may be located toward or behind the trailing edge. By manipulating the chain hoist, the pitch angle of the blade can be changed.

[0041] A further alternative or additional option for providing pitching is provided by actively moving one or more lifting fixtures as the component is held within the tool. In this particular example, lifting fixture 33 may be moved linearly by actuator 36 as previously described. Moving the lifting fixture rotates the tool (and the components therein) to a new equilibrium state.

[0042] The frame 18 may include a base 20 that supports one of the first and second clamp seats and an upper frame 21 that supports a lifting fixture. The tool may further include an intermediate frame 19 that supports the other of the first and second clamp seats. The intermediate frame may include parallel arms 23. Multiple lateral beams 63, 65, 67, and 69 (seen particularly in FIGS. 4 and 5) extend from one side of the tool to the other and may provide sufficient strength and rigidity. A lateral beam 65 extending between the arms 23 may support one of the clamp seats with a corresponding actuator and drive system.

[0043] The upper frame 21 may include a support beam 26 rotatably mounted relative to the base 20, and one or more arms 22, 24 attached to the support beam 26 and supporting a lifting device. The tool may further include an upper frame actuator 54 for controlling the orientation of the support beam 26 relative to the base 20 of the frame.

[0044] The support beam 26 may be substantially vertical and may be mounted on a swivel 58 (particularly visible in FIG. 4 ) so that the support beam 26 can rotate about a substantially horizontal axis relative to the base 20. A motor 50 may drive a spindle 54 through an appropriate transmission (gearing) 52. The spindle 54 is threadably attached to a nut 60 attached to the vertical support beam 26. Driving the motor changes the distance of the nut 60 relative to the transmission 52. Changing this distance changes the orientation of the support beam 26 relative to the vertical. Thus, the relative orientation between the base 20 and the upper frame 21 can be changed, and the described configuration can ensure that the blade tip can be held in the appropriate orientation as needed. Additionally, when different sized blades and blade tips are used, controlling the vertical support beam 26 allows it to rotate as needed.

[0045] This form of tool orientation control may also alternatively or additionally utilize a chain hoist suspended from the crane, with active control of the lines from the chain hoist to the various attachment points providing enhanced control of the tool orientation.

[0046] In some examples, one or more of clamp seats 12, 14, and 16 may be removably attached to a tool. Various kits of clamp seats may be provided to accommodate different blades. For example, the length, width, and internal curvature may be varied in different kits to accommodate different curvatures on the pressure and / or suction sides of the wind turbine blade section.

[0047] In some examples, the clamp seats 12, 14, 16 may have pads to avoid damage to the surface of the component being handled and to provide sufficient friction to effectively hold the component. The pads may be made of, for example, polyurethane.

[0048] 3, the upper or first clamping seat 12 is rotatable about two perpendicular axes 57 and 59 relative to a base plate 53 driven by spindle 45. Thus, the clamping seat 12 can accommodate small variations in the component being lifted or the portion of the component being clamped. A spring 55 or alternative elastic element can be provided to provide tension to the clamping seat 12 so that any rotation or movement of the clamping seat 12 is appropriately accommodated.

[0049] The base plate 53 of the first clamp seat 12 in this particular example may be guided by linear guides, such as the two perpendicular linear guides 46 and 48, so that the displacement of the clamp seat 12 can be more accurate and shear loads can be absorbed. Such guides can also prevent free rotation of the base plate 53 and the entire clamp seat.

[0050] It will be appreciated that the base 20 may further comprise a bumper 13 with suitable shock absorption (e.g., protective padding) to avoid damage to the components when placed inside the tool. The bumper 13 may also serve as a reference for correctly placing the components in the tool.

[0051] From the rear view of FIG. 4, it can be seen that the base 20 may further include sleeves 21 for receiving the forks of a forklift. Thus, the tool 20 can be easily transported and moved as needed. Rollers 15 may be provided on the front of the tool to avoid damage to the components being lifted and other nearby objects. For example, wind turbine blade tips may be stacked on top of each other in a frame and may be lifted one after the other from the frame. In operations approaching the blade tips, the rollers or wheels 15 can act as bumpers for shock absorption and avoid damage to the blade tips.

[0052] In one aspect, a method for controlling clamping force in a tool is provided, which can be described, for example, with reference to FIG.

[0053] To control the clamping force in the tool, the electric motor 40 can be operated to drive the first clamp seat 12 relative to the second clamp seat 14, 16 to clamp a component therebetween. During operation, the current in the electric motor 40 can be measured, and the electric motor 40 can be operated to reach a desired current level corresponding to a predetermined clamping force. The desired current level is determined based on an empty current level, which is the current level required to operate the electric motor to drive the first clamp seat relative to the second clamp seat in the absence of a component.

[0054] The empty current level may be determined in a test before operating the electric motor to clamp a component. Optionally, this test may be performed before every operation to clamp a component.

[0055] Tool calibration, which may be performed periodically, for example once a year, may determine the nominal current (i.e., the maximum current in normal operation of the electric motor) as well as the current level in the motor that corresponds to the desired clamping force.

[0056] Before each tool operation, a test may be performed from the tool, in which a first clamping seat is driven toward a second clamping seat without any components attached between them. The current measured at the motor in the text would correspond to the drive energy and torque required to simply displace the clamping seat. The level of torque or current required in this test may vary due to changes in internal losses and internal friction in the tool. Such internal friction and internal losses may occur in the electric motor, in the transmission between the electric motor and the actuator, and also in the actuator, for example. In the illustrated example, the actuator is a spindle. Losses occur both in the spindle driven by the motor and between the spindle and the nut. These losses vary, especially as a result of wear and tear of components.

[0057] Tests to determine the empty current level (the level of current when the tool is empty) can reliably determine the internal losses at each instant. If the internal friction and losses are too high, the electric motor may not be able to provide sufficient clamping force. For example, if the nominal current minus the empty current level is lower than the current level required for clamping force, tool operation may be prevented.

[0058] Threshold for preventing operation (I threshold ) has the following formula: I threshold =I nom -I clamp wherein Inom is the nominal current of the electric motor, and I clamp is the level of current required to provide a given clamping force.

[0059] If the tool operation is not inhibited (i.e., sufficient clamping force can be provided), the desired current level corresponding to a given clamping force can be determined for each operation, taking into account the empty current level.

[0060] Referring to FIG. 6, I0 may correspond to the empty current level at the beginning of the tool's life. As the tool is used and components wear, the empty current level may increase. At any point in time, the nominal current I nom and I empty The margin between I and I is the motor's margin for providing sufficient clamping force. This margin can be highest at t=0. Therefore, the maximum clamping force can be provided at this point. empty I threshold When the level of I is reached, the motor is no longer clamp and operation may be prevented. In this case, the tool may be at the end of its life or may require some repair or maintenance to reduce internal losses.

[0061] Described herein is a method for determining a desired current level in an electric motor that drives an actuator for clamping a component. The method may include determining a clamping current required to provide a predetermined holding force. Such clamping current may be determined, for example, during tool calibration.

[0062] The method may include operating the electric motor under test, the test including driving an actuator in the absence of a component, and determining an internal loss current by measuring a current level under test. A desired current level (in normal operation) may then be determined by adding a clamp current to the internal loss current.

[0063] The present disclosure also relates to a method of handling a component, in particular a wind turbine blade section, using a tool according to any of the examples disclosed herein, where handling may include holding, and / or moving, and / or orienting, and / or lifting.

[0064] The present disclosure also relates to a method of assembling wind turbine blades, the method including placing a blade root, optionally on a rack. The method may then include lifting and holding a wind turbine blade tip using a tool according to any of the examples disclosed herein. The method may further include bringing the blade tip into proximity with the blade root while the blade tip is held in such a tool. The method may then include joining the blade tip to the blade root. In some examples, the blade tip and blade root may include male and female connectors for joining the blade tip and blade root. In some examples, the method may include rotating the blade tip relative to the blade root before joining. The rotation may occur about the blade's longitudinal axis (i.e., "pitching"), or a lateral axis, or a substantially vertical axis. The rotation may be performed according to any of the examples disclosed herein and may be performed before, during, or after approaching the blade root. The lifting may include lifting by a crane.

[0065] The present disclosure also relates to a kit for handling wind turbine blade sections. The kit may include a tool according to any of the examples disclosed herein and one or more sets of clamp seats for removably mounting on the tool. The set of clamp seats may include at least a first clamp seat for clamping a first blade surface and a second clamp seat for clamping a second, opposing blade surface. The set of clamp seats may also include a third clamp seat as previously disclosed herein. The first clamp seat and the second clamp seat may be configured to clamp a tip of a particular wind turbine blade. The kit may further include sets of clamp seats configured to clamp a tip of a different wind turbine blade. The clamp seats attached to the tool may be replaced by other clamp seats whenever a different blade (tip) is being handled.

[0066] For completeness, various aspects of the disclosure are set forth in the following numbered clauses.

[0067] Article 1. Tools for working with components, a first clamp seat for receiving a first surface of the component; a second clamping seat for receiving a second surface of the component, the second surface being opposite the first surface; an actuator for moving the first clamp seat relative to the second clamp seat to clamp the component between the first and second clamp seats with a predetermined clamping force; an electric motor for driving the actuator; a controller configured to determine a current in the electric motor and to control the electric motor to provide a predetermined clamping force based on the determined current; Provided with a tool.

[0068] Clause 2. The tool of clause 1, wherein the controller is further configured to determine a current in the electric motor due to internal friction within the tool.

[0069] Clause 3. The tool of clause 2, wherein the control device is configured to determine current in the electric motor due to internal friction within the tool by operating the electric motor in the absence of the component.

[0070] Clause 4. A tool as described in any one of clauses 1 to 3, wherein the actuator for moving the first clamping seat is a threaded spindle disposed in the nut.

[0071] Clause 5. The tool of any one of clauses 1 to 4, comprising a third clamping seat for receiving a second surface of the portion of the wind turbine blade.

[0072] Clause 6. A tool according to any one of clauses 1 to 5, further comprising a frame, the frame including one or more lifting devices for lifting the tool.

[0073] Clause 7. The tool of clause 6, wherein at least one of the lifting devices is movable relative to the frame.

[0074] Clause 8. The tool of clause 7, further comprising a sling actuator for controlling the position of the movable sling.

[0075] Article 9. Frames a base supporting one of the first clamp seat and the second clamp seat; The upper frame that supports the lifting equipment 9. The tool of any one of clauses 6 to 8, comprising:

[0076] Clause 10. The tool of clause 9, further comprising an intermediate frame supporting the other of the first clamp seat and the second clamp seat.

[0077] Clause 11. The tool of clause 10, wherein the upper frame includes a support beam rotatably mounted relative to the base, and one or more arms attached to the support beam and supporting the lifting device.

[0078] Clause 12. The tool of clause 11, further comprising an upper frame actuator for controlling the orientation of the support beam relative to the base of the frame.

[0079] Clause 13. A tool according to any one of clauses 1 to 12, wherein the tool is configured for handling portions of a wind turbine blade, optionally configured for handling a wind turbine blade tip.

[0080] Clause 14. A method for controlling clamping force in a tool, comprising: operating the electric motor to drive the first clamp seat relative to the second clamp seat to clamp the component between the first clamp seat and the second clamp seat; measuring the current in the electric motor; operating the electric motor to reach a desired electric torque level corresponding to a predetermined clamping force; Including, The method, wherein a desired electric torque level is determined based on an empty current level, the empty current level being a current level required to operate the electric motor to drive the first clamp seat relative to the second clamp seat in the absence of the component.

[0081] Clause 15. The method of clause 14, wherein the empty current level is determined in a test before operating the electric motor to clamp the component.

[0082] Clause 16. The method of clause 15, wherein the test is performed before every operation of clamping the component.

[0083] Clause 17. The method of any one of clauses 14 to 16, wherein operation of the electric motor is prevented if the empty current level is above a predetermined threshold.

[0084] Article 18. Prescribed thresholds I threshold is represented by the following formula: threshold =I nom -I clamp where I is determined by nom is the nominal current of the electric motor, and I clamp 18. The method of claim 17, wherein V is the level of current required to provide a predetermined clamping force.

[0085] Clause 19. A method for determining a desired current level in an electric motor driving an actuator for clamping a component, comprising: Determining the clamp current required to provide a predetermined holding force; operating the electric motor under test, the test including driving the actuator in the absence of the component; determining the internal loss current by measuring the current level under test; The clamp current is added to the internal loss current to determine the desired current level. A method comprising:

[0086] Clause 20. The method of clause 19, wherein the clamp current is determined in a calibration phase.

[0087] Clause 21. A method for handling components, in particular wind turbine blade sections, comprising: 14. A method comprising using a tool according to any one of clauses 1 to 13 to clamp a component.

[0088] Clause 22. The method of clause 21, further comprising lifting and moving the component.

[0089] Clause 23. The method of clause 21 or 22, further comprising rotating the component about one or more axes of rotation.

[0090] Clause 24. The method of clause 23, wherein the component is a wind turbine blade tip and rotating about one or more axes of rotation comprises rotating the wind turbine blade tip about a longitudinal axis of the wind turbine blade tip and / or rotating the wind turbine blade tip about an axis perpendicular to the longitudinal axis.

[0091] Clause 25. A method of assembling a wind turbine blade, comprising: Optionally, placing blade roots on a rack; - lifting and holding a wind turbine blade tip using a tool according to any one of clauses 1 to 13; bringing a wind turbine blade tip into proximity with a blade root; Joining the blade tip to the blade root A method comprising:

[0092] Clause 26. The method of clause 25, wherein the blade tip and blade root are provided with male and female connectors for joining the blade tip and blade root.

[0093] Clause 27. The method of clause 25 or 26, including rotating the blade tip relative to the blade root prior to joining.

[0094] Clause 28. The method of any one of clauses 25 to 27, wherein lifting comprises lifting with a crane.

[0095] Article 29. A kit for treating wind turbine blade parts, in particular wind turbine blade tips, comprising: a tool according to any one of clauses 1 to 13; One or more pairs of removable clamp seats A kit comprising:

[0096] This specification uses examples to disclose the invention, including preferred embodiments, and also enables one skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims. Those skilled in the art will be able to mix and match aspects from the various embodiments described above, as well as other known equivalents for each such aspect, to construct further embodiments and techniques consistent with the principles of the present application. Where reference signs relating to the drawings are placed within parentheses in the claims, these reference signs are merely to enhance the clarity of the claims and should not be construed as limiting the scope of the claims. [Explanation of symbols]

[0097] 10 Tools 12, 14, 16 Clamp seat 13 Bumper 15 Wheels, rollers 18 frames 19 Intermediate Frame 20 base 21 Sleeve 21 Upper frame 22 Longitudinal beam 23, 24 Arms 24, 63, 65, 67, 69 Transverse beam 26 Support beam 31, 32, 33 Lifting equipment 34 Movable slide 36, 45 Actuator, Threaded Spindle 38, 50, 133 motors 40 Electric Motor 46, 48 Linear guide 49 Housing 52 Transmission 53 Base Plate 54 Upper frame actuator, spindle 55 Spring 57, 59 Vertical axis 58 Swivel 60 nuts 70 Sling Fixture 73, 75 Shackles 100 pitch bearing 107 Pitch System 109, 131 Annular gear 108 Pinion 110 Hub 115 rotor 120 rotor blades 130 Yaw System 132 Yaw drive unit 134, 164 gearbox 135 Pinion 150 Support surface 160 wind turbines 161 Nacelle 162 Generator 163 rotor shaft 165 bed plate 165 Support Frame 166 Generator shaft 170 Wind Turbine Tower PA pitch axis YA Yaw axis

Claims

1. A tool (10) for handling components, said tool (10) comprising: a first clamp seat (12) for receiving a first surface of the component; a second clamp seat (14) for receiving a second surface of the component, the second surface being opposite the first surface, and wherein linear movement of the first clamp seat (12) relative to the second clamp seat (14) can change the separation distance between the first clamp seat (12) and the second clamp seat (14); an actuator (45) for linearly moving the first clamp seat (12) toward the second clamp seat (14) to clamp the component between the first clamp seat (12) and the second clamp seat (14) with a predetermined clamping force; an electric motor (40) for driving said actuator (45); a controller configured to determine a current in the electric motor (40) and to control the electric motor (40) to provide the predetermined clamping force based on the determined current; a frame (18) including one or more lifting devices (31, 32, 33) for lifting the tool (10); and the frame (18) comprises: a base (20) supporting one of the first clamp seat (12) and the second clamp seat (14); an intermediate frame (19) supporting the other of the first clamp seat (12) and the second clamp seat (14); An upper frame (21) that supports the suspenders (31, 32, 33); It is equipped with The tool (10) includes an upper frame (21) including a support beam (26) rotatably mounted relative to the base (20), and one or more arms (22, 24) attached to the support beam (26) and supporting the lifting device (31, 32, 33).

2. 2. The tool (10) of claim 1, wherein the actuator (45) comprises a threaded spindle disposed in a nut, the threaded spindle (45) configured to control the relative position of the first clamping seat (12) with respect to the second clamping seat (14).

3. 3. The tool (10) of claim 2, further comprising a base plate (53) driven by the threaded spindle (45), the first clamping seat (12) being coupled to the base plate (53) such that the first clamping seat (12) can rotate about two perpendicular axes (57, 59) relative to the base plate (53).

4. The tool (10) of claim 1 or claim 2, comprising a third clamping seat (16) for receiving the second surface of a portion of a wind turbine blade.

5. 2. The tool (10) of claim 1, wherein at least one (33) of the lifting tools (31, 32, 33) is movable relative to the frame (18), and the tool (10) further comprises a lifting tool actuator (36) for controlling the position of the movable lifting tool (33).

6. The tool (10) of claim 1, further comprising an upper frame actuator (54) for controlling the orientation of the support beam (26) relative to the base (20) of the frame (18).

7. The tool (10) of any one of claims 1 to 6, wherein the tool (10) is configured to handle portions of a wind turbine blade.

8. A method for controlling a clamping force in a tool (10) according to any one of claims 1 to 6, said method comprising: operating an electric motor (40) to drive the first clamp seat (12) toward the second clamp seat (14) to clamp a component between the first clamp seat (12) and the second clamp seat (14); measuring the current in the electric motor (40); operating the electric motor (40) to reach a desired electric torque level corresponding to a predetermined clamping force; It contains The method, wherein the desired electric torque level is determined based on an empty current level, the empty current level being the current level required to operate the electric motor (40) to drive the first clamp seat (12) toward the second clamp seat (14) in the absence of the component.

9. 9. The method of claim 8, wherein the empty current level is determined in a test prior to operating the electric motor (40) to clamp the component.

10. The method of claim 9 , wherein the test is performed before every operation of clamping the component.

11. The empty current level is a predetermined threshold (I ｔｈｒｅｓｈｏｌｄ 11. The method according to claim 8, wherein operation of the electric motor (40) is prevented if the difference between the first and second voltages is greater than the first voltage.

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