Method and blade lifting yoke for lifting wind turbine rotor blade

Abstract

The invention proposes a blade lifting yoke (1) and a method for lifting a wind turbine rotor blade, in which the blade lifting yoke has at least one crane attachment section (6) for attachment to a crane, in which the blade lifting yoke comprises a base section and at least one retaining device (5), in which the at least one crane attachment section (6) is arranged in the base section, and in which the at least one retaining device (5) is arranged in the at least one crane attachment section (6). The blade lifting yoke comprises first and second upper clamping elements (7) attached to the at least one holding device, first and second lower clamping elements (8), and a support element (9), the upper clamping elements are arranged at a distance from each other above the corresponding lower clamping elements in a direction substantially perpendicular to the longitudinal direction in order to press the rotor blade against the lower clamping elements. At least one holding device comprises a support element (9) adapted to be arranged in contact with the second surface of the wind turbine rotor blade at a predetermined distance from one of the lower clamping elements. A clamping mechanism is configured to contact the upper clamping members and the lower clamping element to clamp the wind turbine rotor blade using at least one clamping pressure between the upper clamping element and the lower clamping element such that during a lift operation, the upper clamping element and the lower clamping element clamp the wind turbine rotor blade. The upper clamping element, the lower clamping element, and the support element provide static stability of the wind turbine rotor blade relative to the blade lift yoke.

Description

Technical Field

[0001] The present invention relates to a blade lifting yoke and a method for lifting a wind turbine rotor blade using a blade lifting yoke. Background Art

[0002] As wind turbine rotor blades become larger and heavier, the demand for lifting equipment, such as blade lifting yokes, is also increasing. The increased size and / or weight of blade lifting yokes has several disadvantages. For example, lifting operations to lift larger loads require cranes with larger capacities. Particularly in the wind turbine industry, lifting operations also require maneuvering wind turbine rotor blades to assemble them into the nacelle, which is located atop the wind turbine tower. Maneuvering these heavy loads is complex and increases the risk of damage to the rotor blades and nacelle.

[0003] For example, EP 3792211 discloses a blade lifting tool, such as a yoke, for lifting a wind turbine rotor blade using a crane for subsequent assembly with the wind turbine. The blade lifting tool has at least one holding device for holding the wind turbine blade. The holding device includes a movable support element for supporting the wind turbine blade and at least one actuator connected to the at least one movable support element. Some of the movable support members are used to clamp the rotor blade. The rotor blade remains firmly clamped, thereby counteracting movement during operation. Other movable support elements can be used to passively support the wind turbine rotor blade, wherein the wind turbine rotor blade rests on the movable support element designed to support the weight of the wind turbine blade so that the wind turbine rotor blade can be securely held in the blade lifting tool. The movable support element, arranged as a cradle-shaped holding area, is configured to adjust the rotor blade so that it can rest in the cradle-shaped lower rest. The movable support element supports the weight of the wind turbine blade but also performs a clamping function. The movable lower support element is arranged below or immediately adjacent to the movable upper support element, with the movable lower and upper support elements serving to clamp the wind turbine rotor blade. This configuration is large and heavy. EP 3792211 proposes a solution for securing the rotor blade against the blade lifting yoke during lifting operations by increasing the clamping pressure.

[0004] The blade lift yoke must be able to hold the rotor blade in a stable position during lifting operations, depending on its shape and weather conditions. To maintain a secure grip on the rotor blade, the blade lift yoke increases the clamping pressure. As rotor blades increase in size and weight, the risk of blade damage due to high clamping pressure also increases.

[0005] Furthermore, as the blade lift yoke becomes larger and heavier, more component material is required, which increases manufacturing costs. Additionally, transportation costs are increased. Summary of the Invention

[0006] The object of the present invention is to overcome these problems by providing a method for lifting large wind turbine rotor blades in a safe, stable and reliable manner without causing any unnecessary damage to the wind turbine rotor blades during lifting. Furthermore, the object of the present invention is also to provide a robust and lightweight blade lifting yoke for lifting wind turbine rotor blades.

[0007] The present invention achieves this object by providing a method for lifting a wind turbine rotor blade using a blade lifting yoke, wherein the blade lifting yoke has at least one crane attachment section for attachment to a crane, wherein the blade lifting yoke comprises a base section and at least one holding device, wherein the blade lifting yoke comprises a first upper clamping element and a first lower clamping element, a second upper clamping element and a second lower clamping element attached to the at least one holding device, and a support element, the at least one holding device comprising an extension member, wherein the extension member extends away from the nearest lower clamping element such that the support element can be moved at a distance from the first lower clamping element or the second lower clamping element. The method further comprises: supporting the lower surface of the rotor blade at a predetermined distance between the first upper clamping element and the second lower clamping element, wherein each of the first upper clamping element and the second upper clamping element is arranged above the corresponding first lower clamping element and the second lower clamping element, and the first upper clamping element and the second upper clamping element are arranged substantially perpendicular to the longitudinal direction of the rotor blade at respective first and second distances, wherein the first upper clamping element and the second upper clamping element are configured to press the rotor blade against the respective first lower clamping element and the second lower clamping element, wherein the method comprises the following actions:

[0008] a) determining a first clamping position and a second clamping position of the first upper clamping element and the first lower clamping element and the second upper clamping element and the second lower clamping element, determining a support position of the support element relative to the selected rotor blade when arranged in the blade lifting yoke, and determining a clamping pressure between the first and second upper clamping elements and the corresponding first and second lower clamping elements,

[0009] b) arranging the selected rotor blade relative to at least one holding device such that the first upper clamping element and the second upper clamping element are arranged adjacent to a first surface of the selected rotor blade at a predetermined clamping position of the respective first upper clamping element and second upper clamping element, and the first lower clamping element and the second lower clamping element are arranged adjacent to a second surface of the selected rotor blade relative to the predetermined clamping position of the first lower clamping element and the second lower clamping element,

[0010] c) arranging the support element adjacent to the second surface at a predetermined distance from the first lower clamping element and / or the second lower clamping element, wherein the support element is arranged in a predetermined support position between the center of gravity and the trailing edge of the wind turbine rotor blade,

[0011] d) adjusting, using a clamping mechanism, the clamping pressure between the first and second upper clamping elements and the respective first and second lower clamping elements such that the center of gravity of the wind turbine rotor blade is substantially located in or near a clamping region of the rotor blade, wherein the clamping region is defined by first and second clamping positions of the first and second upper clamping elements and the first and second lower clamping elements,

[0012] Therein, the first and second upper clamping elements, the first and second lower clamping elements, and the support element provide static stability of the wind turbine rotor blade relative to the blade lifting yoke during a lifting operation.

[0013] Rotor blades are becoming larger and heavier, making them more difficult to handle. A lightweight blade lifting yoke construction is needed that avoids the complexity of heavy constructions. Preferably, the total weight of the blade lifting yoke is kept as low as possible. The present invention proposes a simple, robust, and flexible lightweight blade lifting yoke construction that enables handling of large and heavy rotor blades during lifting operations. When handling rotor blades, such as wind turbine rotor blades, during lifting operations, it is crucial to clamp the rotor blade in a fixed position in the blade lifting yoke.

[0014] The blade lifting yoke has a crane attachment section for attaching to a crane, enabling the crane or external lifting equipment to lift the blade lifting yoke, which carries the rotor blade, in a safe, stable, and reliable manner. Lifting operations may involve lifting a heavy wind turbine rotor blade onto and lowering the heavy wind turbine rotor blade from a wind turbine nacelle positioned on a tower. Furthermore, lifting operations may involve holding the rotor blade to and from the wind turbine nacelle during connection. Furthermore, when using the blade lifting yoke to manipulate the rotor blade, issues related to static forces and static moments must be considered.

[0015] The blade lifting yoke includes a base section and at least one retaining device. The blade lifting yoke includes at least two upper clamping elements, for example, at least one first upper clamping element and at least one second upper clamping element. The blade lifting yoke includes at least two lower clamping elements, for example, at least one first lower clamping element and at least one second lower clamping element. The upper clamping elements are configured to press the rotor blade against the respective lower clamping elements so that the rotor blade is in a substantially stable and fixed raised position.

[0016] The support element is arranged relative to the first lower clamping element or the second lower clamping element. The support element is arranged in a supporting position, wherein the support element and the first lower clamping element or the second lower clamping element are located on a section line of the rotor blade. The support element is arranged in a supporting position remote from the clamping area. Each of these upper clamping elements is arranged at a distance above the corresponding lower clamping element in a direction substantially perpendicular to the longitudinal direction. Each of these upper clamping elements is capable of pressing the rotor blade against the lower clamping element, thereby arranging the rotor blade in a substantially fixed position relative to the lifting yoke. It is important to keep the clamping pressure as low as possible to avoid any damage to the rotor blade during the lifting operation.

[0017] The positions of the first upper clamping element and the first lower clamping element, as well as the second upper clamping element and the second lower clamping element, are arranged in clamping positions at a certain distance from each other. The clamping positions of the first upper clamping element and the first lower clamping element, as well as the second upper clamping element and the second lower clamping element, are determined based on the type of rotor blade (e.g., the center of gravity (COG), length, shape, weight, etc. of the rotor blade). The position of the support element is determined based on the first clamping element or the second clamping element and the type of rotor blade (e.g., the center of gravity, length, shape, weight, etc. of the rotor blade). The clamping pressure between these upper clamping elements and the corresponding lower clamping element is determined based on the type of rotor blade (e.g., the center of gravity, length, shape, weight, etc. of the rotor blade). The clamping pressure between the first upper clamping element and the second upper clamping element and the corresponding first lower clamping element and the second lower clamping element can also be determined based on weather conditions existing during the lifting operation.

[0018] The rotor blade is arranged in a clamped position relative to the holding device. A first upper clamping element and a second upper clamping element are arranged adjacent to a first surface of the rotor blade at their respective predetermined clamping positions. The upper clamping elements can be arranged in contact with or relative to the first surface. The first lower clamping element and the second lower clamping element are arranged adjacent to a second surface of the rotor blade at their respective predetermined positions. The lower clamping element can be arranged in contact with or relative to the second surface.

[0019] The support element is arranged in a predetermined position adjacent to the second surface. The support element can be arranged in contact with the second surface or relative to the second surface. The support element is arranged at a predetermined distance from the lower clamping element. The support element is arranged in a predetermined position between the center of gravity and the trailing edge of the wind turbine rotor blade.

[0020] A clamping mechanism is used to provide a clamping pressure between each of the upper clamping elements and each of the corresponding lower clamping elements. The clamping pressure can substantially maintain the center of gravity of the rotor blade in or near the clamping region of the rotor blade between the upper and lower clamping elements.

[0021] When the selected rotor blade is positioned in the blade lift yoke, the blade lift yoke can be positioned in an open position, allowing the distance between the first and second upper clamping elements and the second lower clamping element to increase. The first and second upper clamping elements are moved away from their clamping positions relative to the first and second lower clamping elements, allowing the rotor blade to be safely positioned in a predetermined position in the blade lift yoke. The rotor blade is positioned in a rest position on the first and second lower clamping elements. The support element can be positioned in a predetermined support position relative to the rotor blade and the lower clamping element.

[0022] The rotor blade can be arranged in a rest position, wherein at least 50% of the weight of the rotor blade rests on the first and second lower clamping elements. Preferably, the rotor blade can be arranged in a rest position, wherein at least 60% of the weight of the rotor blade rests on the first and second lower clamping elements. Most preferably, the rotor blade can be arranged in a rest position, wherein at least 70% of the weight of the rotor blade rests on the first and second lower clamping elements. When the rotor blade is arranged in the rest position in the blade lift yoke, the blade lift yoke can be arranged in a closed position. The distance between the first and second upper clamping elements and the second lower clamping element is reduced, and the blade lift yoke enters a clamping position. The blade lift yoke can be arranged in a releasable locked position, so that the blade lift yoke cannot be inadvertently opened during a lifting operation. The upper clamping element, the lower clamping element, and the support element provide static stability for the wind turbine rotor blade relative to the blade lift yoke.

[0023] In an advantageous method of the invention, the support element is positioned adjacent to the second surface at a predetermined support position at a trailing edge support distance such that more than 70% of the weight of the rotor blade rests on the first and second lower clamping elements.

[0024] The support element is arranged adjacent to the second surface. The support element can be positioned in a predetermined position at a supporting distance from the trailing edge. The predetermined distance between the support element and the first lower clamping element and the second lower clamping element ensures static stability of the rotor blade when arranged in the blade lifting yoke. The static stability is provided by using the three-point principle. Three-point static stability occurs when three forces related to the first lower clamping element and the second lower clamping element and the position of the support element relative to the rotor blade are arranged so that a single main force is applied between two additional reaction forces and the sum of all three forces is equal to zero. The supporting position of the support element is preferably located outside the clamping area of ​​the rotor blade. The support element is not part of the clamping process. The support element is arranged in a predetermined supporting position and applies a force to the second surface, wherein the force is related to the weight of the rotor blade resting on the first lower element and the second lower element.

[0025] The force applied to the predetermined support location on the second surface causes more than 70% of the weight of the rotor blade to rest on the first lower element and the second lower element. Preferably, the predetermined support location causes more than 80% of the weight of the rotor blade to rest on the first lower element and the second lower element. More preferably, the predetermined support location causes more than 90% of the weight of the rotor blade to rest on the first lower element and the second lower element.

[0026] When the majority of the weight of the rotor blade rests on the first and second lower elements, the clamping pressure can be significantly reduced. This ensures optimal handling of the heavy rotor blade during the lifting operation.

[0027] The support distance measured from the trailing edge along the second surface may be within a distance of 10%-50% of the surface distance measured from the leading edge along the second surface to the trailing edge. Preferably, the support distance may be within a distance of 20%-50% of the surface distance measured from the leading edge along the second surface to the trailing edge. More preferably, the support distance may be within a distance of 30%-50% of the surface distance measured from the leading edge along the second surface to the trailing edge.

[0028] The support element is adapted to be arranged in a predetermined position, wherein the support element applies a force to the second surface. By applying the force to the second surface, the center of gravity is maintained at a predetermined COG position relative to the blade lifting yoke, thereby preventing the rotor blade from inadvertently sliding out of the clamped position during a lifting operation. The support element provides increased safety and reduces the need for increased clamping pressure, which could damage the rotor blade.

[0029] In an advantageous method of the invention, a first clamping pressure provided between the first upper clamping element and the first lower clamping element is different from a second clamping pressure provided between the second upper clamping element and the second lower clamping element.

[0030] Weather conditions and other conditions associated with lifting operations may require that the clamping pressure be reduced or increased. To avoid constant high pressure that could damage the rotor blades, the clamping pressure, i.e., both the first clamping pressure and the second clamping pressure, can be predetermined based on the type of rotor blade and / or weather conditions. During lifting operations, the first clamping pressure provided between the first upper clamping element and the first lower clamping element can be different from the second clamping pressure provided between the second upper clamping element and the second lower clamping element. The first and second clamping pressures can be varied to improve stability during lifting operations.

[0031] In another advantageous method of the invention, a first clamping distance between the center of gravity of the rotor blade and the first upper and lower clamping elements is different from a second clamping distance between the center of gravity of the rotor blade and the second upper and lower clamping elements.

[0032] Weather conditions and other conditions related to the lifting operation may require that the clamping positions of the first and second upper clamping elements and the second and second lower clamping elements be shifted relative to the center of gravity of the rotor blade to improve stability during the lifting operation.

[0033] In a further advantageous method of the invention, the first clamping pressure and the second clamping pressure are determined based on at least one item of information relating to weather conditions.

[0034] The clamping pressure between the first and second upper clamping elements and the corresponding first and second lower clamping elements can also be determined based on weather conditions present during the lifting operation. As expected, the rotor blades of a wind turbine are subject to the constant effects of wind forces and turbulence. The rotor blades may be affected by wind conditions during the lifting operation. It may be necessary to vary the clamping pressure between each of the upper and lower clamping elements relative to each other. During the lifting operation, the first and second clamping pressures may be equal to each other. Alternatively, the clamping pressures may differ from each other.

[0035] The first clamping pressure and the second clamping pressure may be adjustable. During a lifting operation, the first and second clamping pressures may be independently varied. The first and second clamping pressures may be varied relative to each other to improve stability during the lifting operation. During a lifting operation, the first and second clamping pressures may be varied manually and / or automatically.

[0036] The clamping distance can be varied to enhance the grip management of the rotor blade during the lifting operation and to improve stability during the lifting operation. Thus, the distance between the center of gravity of the wind turbine rotor blade and the first upper clamping element and the first lower clamping element (i.e., the first clamping distance) can be different from the distance between the center of gravity of the wind turbine rotor blade and the second upper clamping element and the second lower clamping element (i.e., the second clamping distance).

[0037] In a second aspect of the invention, a blade lifting yoke for lifting a wind turbine rotor blade is provided, wherein the blade lifting yoke has at least one crane attachment section for attaching to a crane, wherein the blade lifting yoke comprises a base section and at least one holding device, wherein the blade lifting yoke comprises a first upper clamping element and a first lower clamping element, a second upper clamping element and a second lower clamping element attached to the at least one holding device, and a support element, wherein the first upper clamping element and the second upper clamping element are arranged at a distance from each other above the respective first lower clamping element and the second lower clamping element, wherein the first upper clamping element and the second upper clamping element are configured for pressing the rotor blade against the respective first lower clamping element and the second lower clamping element, wherein one of the at least one holding devices comprises a support element, which is adapted to be arranged at a distance from one of the first lower clamping element and / or the second lower clamping element. and a second lower clamping element, wherein the first and second upper clamping elements are in contact with the second surface of the wind turbine rotor blade at a predetermined distance from the lower clamping element, wherein at least one holding device comprises an extension member, wherein the support element is attached to the extension member, wherein the extension member extends away from the nearest lower clamping element so that the support element can support the lower surface of the rotor blade at a predetermined distance from the first lower clamping element or the second lower clamping element, wherein the clamping mechanism is configured to contact the first upper clamping element and the second upper clamping element and the first lower clamping element and the second lower clamping element, wherein the clamping mechanism is configured to clamp the wind turbine rotor blade using at least one clamping pressure between the first upper and second upper clamping elements and the respective first lower and second lower clamping elements, so that during a lifting operation, the first lower and second lower clamping elements and the support element provide static stability of the wind turbine rotor blade relative to the blade lifting yoke.

[0038] The present invention also provides a blade lifting yoke for lifting a wind turbine rotor blade. The blade lifting yoke has a crane attachment section so that the blade lifting yoke can be attached to a crane for lifting operations. The rotor blade is arranged in or relative to the blade lifting yoke so that the rotor blade is fixed during the lifting operation. The holding device includes a first upper clamping element and a second upper clamping element and a first lower clamping element and a second lower clamping element. The first upper clamping element and the second upper clamping element and the first lower clamping element and the second lower clamping element are separately attached to one or more holding devices. The two upper clamping elements are adapted to be arranged in contact with or relative to a first surface of a wind turbine rotor blade. The first lower clamping element and the second lower clamping element are adapted to be arranged in contact with or relative to a second surface of the rotor blade. Each of the upper clamping elements is arranged at an angle to the longitudinal direction of the rotor blade and substantially above the lower clamping element at a distance. Each of these upper clamping elements is configured for pressing the rotor blade against the lower clamping element with a substantially equal clamping pressure or with a predetermined clamping pressure.

[0039] The holding device may comprise a support element adapted to be arranged in contact with or relative to the second surface of the rotor blade at a predetermined distance from a nearest lower clamping element.The support element may be in a raised position relative to a nearest lower clamping element from which the support element extends.

[0040] The clamping mechanism is configured to contact the first upper and second upper clamping elements and the first lower clamping elements and the second upper and second lower clamping elements. The clamping mechanism is configured to clamp the rotor blade using the first upper and first lower clamping elements and the second upper and second lower clamping elements. The clamping mechanism controls each of these clamping elements individually and / or simultaneously so that a first clamping pressure provided by the first upper and first lower clamping elements is different from or equal to a second clamping pressure provided by the second upper and second lower clamping elements. The first upper and second upper clamping elements, the first lower and second lower clamping elements, and the support element provide static stability of the wind turbine rotor blade relative to the blade lift yoke.

[0041] At least one holding device comprises an extension member, wherein the support element is attached to the extension member, wherein the extension member extends away from the nearest lower clamping element such that the support element can support the lower surface of the rotor blade at a predetermined distance from the first and second lower clamping elements.

[0042] One of the at least one holding devices may include an extension member. Alternatively, the holding device may be an elongated holding device including the extension member. The extension member may be part of the holding device. Alternatively, the extension member may be attached to the holding device and extend away from the holding device. The extension member may extend in a direction away from the lower clamping element. The extension member may be movable and its length may be adjustable. The extension member may be pivotally attached to the holding device. The extension length of the extension member may be varied. A support element may be attached to the extension member. The support element may be movably displaced along the extension member. The extension member extends away from the nearest lower clamping element. The support element may be capable of supporting the lower surface of the rotor blade at a predetermined distance from the lower clamping element, thereby providing static stability of the rotor blade relative to the blade lift yoke.

[0043] In a further advantageous embodiment of the invention, the first upper clamping element and / or the second upper clamping element and / or the first lower clamping element and / or the second lower clamping element are pivotally attached to the at least one holding device.

[0044] The rotor blade can include different shapes and lengths depending on the specific type of rotor blade. The first upper clamping element and / or the second upper clamping element and / or the first lower clamping element and / or the second lower clamping element can be pivotally attached to at least one holding device so that the clamping surface of each clamping element can easily follow the surface of the rotor blade. The first upper clamping element and the second upper clamping element and / or the first lower clamping element and the second lower clamping element are pivotally attached to at least one holding device. Alternatively, the first upper clamping element or the second upper clamping element and / or the first lower clamping element or the second lower clamping element are pivotally attached to at least one holding device. Combinations of pivotal attachments can be provided in many variations. The first upper clamping element or the second upper clamping element can be arranged in a pivot position relative to the first surface so that the clamping surfaces of the first upper clamping element and / or the second upper clamping element contact the first surface of the rotor blade. The first lower clamping element and / or the second lower clamping element may be arranged in a pivoted position relative to the second surface such that the clamping surfaces of the first lower clamping element and / or the second lower clamping element are in contact with the second surface of the rotor blade.

[0045] In another advantageous embodiment of the present invention, the first upper clamping element and the second upper clamping element include a first upper clamping member and a second upper clamping member pivotally attached to the first upper clamping element and / or the second upper clamping element, and / or the first lower clamping element and / or the second lower clamping element include a first lower clamping member and a second lower clamping member pivotally attached to the first lower clamping element and / or the second lower clamping element, and / or the support element includes a first support member and a second support member pivotally attached to the support element.

[0046] The upper clamping elements may comprise a first upper clamping member and a second upper clamping member pivotally attached to the upper clamping element, the first lower clamping element and / or the second lower clamping element may comprise a first lower clamping member and a second lower clamping member pivotally attached to the lower clamping element, and / or the support element may comprise a first support member and a second support member pivotally attached to the support element.

[0047] Each clamping member may include further sub-clamping members that can be pivotally attached in pairs to the preceding clamping member. Further sub-clamping members can be pivotally attached in pairs to the preceding sub-clamping members, and so on. The pivotal attachments may be pivot joints, ball joints, or the like that allow the required movement. The objective is to provide a single point of contact between the at least one retaining device and the respective upper clamping element, lower clamping element, and support element, thereby maintaining the three-point principle for ensuring static stability of the wind turbine rotor blade relative to the blade lifting yoke.

[0048] The control system may include a control device configured to control the clamping pressure between the first and second upper clamping elements relative to the first and second lower clamping elements. The clamping pressure may be derived from the weight of the rotor blade resting on the first and second lower elements. The control device may be configured to control the movement of the rotor blade such that the center of gravity of the rotor blade moves relative to the blade lifting yoke. The center of gravity may be adjusted toward a predetermined position during the lifting operation.

[0049] The invention has now been explained with reference to several embodiments and methods, which have been discussed merely to illustrate the many different possibilities that may be achieved using a battery penetration device according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The embodiments of the present invention are described below with reference to the accompanying drawings:

[0051] Figure 1 : A crane is shown lifting a blade lifting yoke with rotor blades.

[0052] Figure 2a 、 Figure 2b : Two different embodiments of blade lift yokes for lifting rotor blades are shown.

[0053] Figure 3a 、 Figure 3b 、 Figure 3c : Shows a cross-sectional embodiment of a blade lift yoke lifting a rotor blade.

[0054] Figure 4a 、 Figure 4b : Shows the predetermined support position and the predetermined clamping position on the surface of the rotor blade.

[0055] In the explanation of the figures, identical or corresponding elements will have the same reference numerals in different figures. Therefore, an explanation of all details will not be given in conjunction with each individual figure / embodiment. DETAILED DESCRIPTION

[0056] The embodiments of the present invention are explained in the following detailed description. It should be understood that the scope of the present invention is not limited to the following description or shown in the accompanying drawings. The present invention is capable of other embodiments and can be practiced or implemented in different ways.

[0057] Figure 1 : A crane 4 is shown lifting a blade lifting yoke 1 with a rotor blade. The blade lifting yoke 1 holds the rotor blade 2 while being lifted by the crane 4 (e.g., on an offshore installation) to the nacelle 31 of a wind turbine 3. The crane 4 and the wind turbine 3 are both supported on the seabed 51 below sea level 52. However, it should be understood that the present invention is not limited to offshore use and can be used in any operation involving lifting a rotor blade 2.

[0058] Figure 2a 、 Figure 2b : Two different embodiments of the blade lifting yoke 1 lifting the rotor blade 2 are shown. Figure 2a , the blade lifting yoke 1 comprises a base section and two holding devices 51, 52, wherein in this embodiment the holding devices 51, 52 are part of the base section. The blade lifting yoke 1 lifts the rotor blade 2, wherein the rotor blade is in a lifted position with its trailing edge 11 facing away from the holding devices 51, 52. The blade lifting yoke 1 comprises a crane attachment section 6 for attaching to a crane 4. The blade lifting yoke 1 has a crane attachment section 6 which can be attached to, for example, a hook. The crane attachment section 6 can also be movably fastened to the top of the holding devices 51, 52 so that the crane can lift the blade lifting yoke 1. The rotor plate has a longitudinal axis X along the longitudinal direction of the rotor blade 2. The vertical axis Y is substantially perpendicular to the longitudinal axis X and extends from the holding device 5 1 , 5 2 The top portion of the top extends to the bottom portion.

[0059] exist Figure 2b In the embodiment, the blade lifting yoke 1 includes a holding device 5, wherein in this embodiment, the holding device 5 is part of the base section. The blade lifting yoke 1 lifts the rotor blade 2, wherein the rotor blade 2 is in the raised position, with its leading edge 12 facing away from the holding device 5. The blade lifting yoke 1 includes a crane attachment section 6 for attaching to a crane 4. The crane attachment section 6 is also movably fastened to the top of the holding device 5, enabling the crane to lift the blade lifting yoke 1.

[0060] Figure 3a 、 Figure 3b 、 Figure 3c : Shows a cross-sectional embodiment of a blade lifting yoke 1 lifting a rotor blade 2. Figure 3a A blade lifting yoke 1 is shown carrying a rotor blade 2 in a raised position. The blade lifting yoke 1 has a C-shaped holding device 5. The C-shape has a top portion and a bottom portion. The holding device 5 can partially surround the rotor blade 2. The rotor blade 2 has a first surface facing an upper holding element 7 and a second surface facing a lower holding element 8. The rotor blade 2 has a leading edge 12 and a trailing edge 11.

[0061] The upper clamping element 7 is adapted to be arranged in contact with a first surface of the rotor blade 2. The lower clamping element 8 is adapted to be arranged in contact with a second surface of the rotor blade 2. The rotor blade 2 is arranged in the blade lifting yoke 1 in a raised position, between the upper clamping element 8 and the lower clamping element 8. The upper clamping elements 7 are arranged at a distance along the vertical axis Y in a direction substantially perpendicular to the longitudinal direction. The upper clamping elements 7 are arranged substantially above the corresponding lower clamping elements 8. The upper clamping elements 7 enable the rotor blade to be pressed against the lower clamping elements 8 using a clamping device. The rotor blade 2 is in a substantially fixed position relative to the lifting yoke 1. It is important to keep the clamping pressure as low as possible to avoid any damage to the rotor blade 2 during the lifting operation. The upper and lower clamping elements 7 are intended to ensure that the center of gravity 10 of the rotor blade 2 is substantially within or near the clamping area. Securing the rotor blade 2 using only the upper and lower clamping elements 7 and 8 is a difficult task.

[0062] During a lifting operation, the wings may push the trailing edge 11 downward, as indicated by arrow A1. The upper clamping element, which is positioned at a predetermined clamping position relative to the first surface of rotor blade 2, and the lower clamping element, which is positioned at a predetermined clamping position relative to the second surface of rotor blade 2, move away from their respective predetermined clamping positions, as indicated by arrows A2 and A3. This causes the center of gravity to shift outward and away from the geometric center of blade lifting yoke 1. Consequently, rotor blade 2 may be placed in an unsafe and unstable lifted position.

[0063] In order to be able to hold the rotor blade, the clamping pressure must be increased to be able to hold the rotor blade 2. The pressure to which the rotor blade 2 is subjected may eventually lead to damage to the rotor blade 2.

[0064] exist Figure 3b , a C-shaped rotor blade is shown having a top portion and a bottom portion, wherein the bottom portion is an extended bottom portion, such as an extension member 13. A support element 9 is attached to the extension member 13. The support element 9 is capable of supporting the lower surface of the rotor blade at a predetermined distance d from the lower clamping element 8. The support element 9 is arranged in a predetermined position between the center of gravity 10 and the trailing edge 11 of the rotor blade 2. The support element 9 forces the trailing end of the rotor blade upward, as shown by the arrow As. The center of gravity 10 moves in the direction shown by the arrow A° and is essentially in a stable position in or near the clamping area 14 defined by the upper clamping element 7 and the lower clamping element 8. The rotor blade 2 is then positioned in a safe and stable lifting position. The clamping pressure between the upper and lower clamping elements can be reduced to retain the rotor blade 2, as most of the weight of the rotor blade rests on the lower clamping element 8.

[0065] The pressure distribution can be reduced by enlarging the surface area of ​​the clamping location, where the upper clamping element and the lower element exert force on the rotor blade 2. This provides a secure clamp at each clamping location while reducing the pressure on the surface of the clamping area.

[0066] The rotor blade is arranged in a rest position on the lower holding element 8. The support element 9 can be arranged in a predetermined support position relative to the rotor blade 2 and the lower holding element 8. The rotor blade 2 can be arranged in a rest position, wherein more than 50% of the weight of the rotor blade 2 rests on the lower holding element 8. Preferably, more than 60% of the weight of the rotor blade rests on the lower holding element. Most preferably, more than 70% of the weight of the rotor blade rests on the lower holding element. The rotor blade is arranged in a rest position in the blade lifting yoke 1, wherein the blade lifting yoke 1 is arranged in a closed position. The blade lifting yoke 1 can be arranged in a releasable locking position so that the blade lifting yoke 1 cannot be accidentally opened during a lifting operation.

[0067] exist Figure 3c, which shows a C-shaped rotor blade having a top portion and a bottom portion, wherein the bottom portion is an extended bottom portion 13. Depending on the specific type of rotor blade 2, the rotor blade 2 has different shapes and lengths. An upper clamping element 7 and a second, lower clamping element 8 can be pivotally attached to the holding device 5 so that each clamping element can easily follow the surface of the rotor blade 2. The upper clamping element 7 can be arranged in a pivoted position relative to a first surface, so that the clamping surface of the upper clamping element 7 is in contact with the first surface of the rotor blade 2. The lower clamping element 8 can be arranged in a pivoted position relative to the second surface, so that the clamping surface of the lower clamping element is in contact with the second surface of the rotor blade 2. The support element 9 can be arranged in a pivoted position relative to the second surface, so that the support surface of the support element 9 is in contact with the second surface of the rotor blade 2.

[0068] The upper clamping element 7 may include a first upper clamping member and a second upper clamping member 71 pivotally attached to the upper clamping element 7. +2 The lower clamping element 8 comprises a first lower clamping member and a second lower clamping member 81 pivotally attached to the lower clamping element 8 + 2. The support element 9 comprises a first support member and a second support member 91 pivotally attached to the support element + 2. A greater number of components connected to these elements can be used to increase the area subjected to pressure, so that the three-point principle still ensures the static stability of the wind turbine rotor blade relative to the blade lifting yoke.

[0069] Figure 4a 、 Figure 4b The predetermined support position and the predetermined clamping position 13 on the surface of the rotor blade 2 are shown 1 , 13 2 、14 1 、14 2 , 15. The support position 15 of the support element can have a support distance extending from the center of gravity 10 of the rotor blade 2 to the trailing edge 11. When the rotor blade 2 is arranged in the blade lifting yoke 1, for example during a lifting operation, the support element influences the position of the center of gravity 10. The predetermined support position 15 associated with the second surface can be located at a predetermined support distance from the trailing edge 11. When the rotor blade 2 is arranged in the blade lifting yoke 1 using the three-point principle, the clamping position 14 of the first or second lower clamping element 1 、14 2The distance from the support element's support point 15 ensures the static stability of the rotor blade 2. The three forces applied to the predetermined clamping points 141, 142 of the first and second lower clamping elements and the support element's support point 15 are calculated so that a single primary force is applied between the two additional reaction forces. The sum of all three forces is essentially zero. The support distance is determined for each selected rotor blade 2 type.

[0070] Figure 4b It is shown that a first clamping distance d1 between the center of gravity of the rotor blade and the first upper clamping element and the first lower clamping element at the first upper clamping position 131 and the first lower clamping position 141 can be different from a second clamping distance d2 between the center of gravity of the rotor blade and the second upper clamping element and the second lower clamping element at the second upper clamping position 132 and the second lower clamping position 142. 2 In the first upper clamping position 13 1 The first upper clamping element at the first lower clamping position 14 1 The first clamping pressure provided between the first lower clamping element at the second upper clamping location 132 and the second lower clamping element at the second upper clamping location 144 may be equal to or different from the first clamping pressure provided between the first lower clamping element at the second upper clamping location 132 and the second lower clamping element at the second upper clamping location 144. 2 A second clamping pressure is provided between the second lower clamping elements.

[0071] The support element may be in contact with the second surface. The support element may be located at a support distance from the trailing edge. The distance between the first lower clamping element or the second lower clamping element ensures static stability of the wind turbine rotor blade when arranged in the blade lifting yoke according to the three-point principle. The three forces applied to the positions of the first lower clamping element, the second lower clamping element, and the support element are calculated so that a single primary force is applied between the two additional reaction forces. The sum of all three forces is substantially equal to zero. The support distance is determined for each type of rotor blade selected for lifting.

[0072] The support elements can be arranged at a support distance, which can be defined when calculating the support distance. The support distance can extend from the center of gravity of the rotor blade to its trailing edge. The support elements influence the position of the center of gravity when the rotor blade is positioned in the blade lifting yoke, for example during a lifting operation.

Claims

1. A method for lifting a wind turbine rotor blade using a blade lifting yoke, wherein: The blade lifting yoke has at least one crane attachment section for attachment to a crane, wherein the blade lifting yoke comprises a base section and at least one holding device, wherein the blade lifting yoke comprises a first upper clamping element and a first lower clamping element, a second upper clamping element and a second lower clamping element attached to the at least one holding device, and a support element, the at least one holding device comprising an extension member, wherein the extension member extends away from a nearest lower clamping element such that the support element can support the lower surface of the rotor blade at a predetermined distance from the first lower clamping element or the second lower clamping element. , wherein each of the first upper clamping element and the second upper clamping element is arranged above the respective first lower clamping element and the second lower clamping element, the first upper clamping element and the second upper clamping element being arranged substantially perpendicular to the longitudinal direction of the rotor blade at respective first and second distances above the respective first lower clamping element and the second lower clamping element, wherein the first upper clamping element and the second upper clamping element are configured for pressing the rotor blade against the respective first lower clamping element and the second lower clamping element, wherein the method comprises the following actions: a) determining a first clamping position and a second clamping position of the first upper clamping element and the first lower clamping element and the second upper clamping element and the second lower clamping element, and determining a support position of the support element relative to the selected rotor blade when arranged in the blade lifting yoke, and determining a clamping pressure between the first upper clamping element and the second upper clamping element and the corresponding first lower clamping element and the second lower clamping element, b) arranging the selected rotor blade relative to the at least one holding device such that the first upper clamping element and the second upper clamping element are arranged adjacent to a first surface of the selected rotor blade at a predetermined clamping position of the respective first upper clamping element and the second upper clamping element, and the first lower clamping element and the second lower clamping element are arranged adjacent to a second surface of the selected rotor blade relative to the predetermined clamping position of the first lower clamping element and the second lower clamping element, c) arranging the support element adjacent to the second surface at a predetermined distance from the first lower clamping element and / or the second lower clamping element, wherein the support element is arranged in a predetermined support position between the center of gravity and the trailing edge of the wind turbine rotor blade, d) adjusting the clamping pressure between the first and second upper clamping elements and the respective first and second lower clamping elements using a clamping mechanism such that the center of gravity of the wind turbine rotor blade is substantially located in or near a clamping region of the rotor blade, wherein the clamping region is defined by a first clamping position and a second clamping position of the first and second upper clamping elements and the first and second lower clamping elements, Wherein, during a lifting operation, the first and second upper clamping elements, the first and second lower clamping elements, and the support element provide static stability of the wind turbine rotor blade relative to the blade lifting yoke.

2. The method according to claim 1, wherein The support element is positioned adjacent the second surface at a predetermined support location a support distance from the trailing edge such that more than 70% of the weight of the rotor blade rests on the first lower clamping element and the second lower clamping element.

3. The method according to claim 1 or 2, wherein: A first clamping pressure provided between the first upper clamping element and the first lower clamping element is different from a second clamping pressure provided between the second upper clamping element and the second lower clamping element.

4. The method according to claim 1, 2 or 3, wherein: A first clamping distance between the center of gravity of the wind turbine rotor blade and the first upper clamping element and the first lower clamping element is different from a second clamping distance between the center of gravity of the wind turbine rotor blade and the second upper clamping element and the second lower clamping element.

5. A method according to any one of the preceding claims, wherein The clamping pressure is determined based on at least one item of information related to weather conditions.

6. A blade lifting yoke for lifting a wind turbine rotor blade, wherein: A blade lifting yoke for lifting a wind turbine rotor blade, wherein the blade lifting yoke has at least one crane attachment section for attaching to a crane, wherein the blade lifting yoke comprises a base section and at least one holding device, wherein the blade lifting yoke comprises a first upper clamping element and a first lower clamping element, a second upper clamping element and a second lower clamping element attached to the at least one holding device, and a support element, wherein the first upper clamping element and the second upper clamping element are arranged at a distance from each other above the respective first lower clamping element and the second lower clamping element, wherein the first upper clamping element and the second upper clamping element are configured to press the rotor blade against the respective first lower clamping element and the second lower clamping element, wherein one of the at least one holding device comprises a support element, which is adapted to be arranged to contact the wind turbine at a predetermined distance from one of the first lower clamping element and / or the second lower clamping element. and a second lower clamping element.

7. The blade lifting yoke according to claim 6, wherein: The first upper clamping element and / or the second upper clamping element and / or the first lower clamping element and / or the second lower clamping element are pivotally attached to the at least one holding device.

8. The blade lifting yoke according to claim 6 or 7, wherein: The first upper clamping element or the second upper clamping element includes a first upper clamping member and a second upper clamping member pivotally attached to the first upper clamping element or the second upper clamping element, and / or the first lower clamping element or the second lower clamping element includes a first lower clamping member and a second lower clamping member pivotally attached to the first lower clamping element or the second lower clamping element, and preferably, the support element includes a first support member and a second support member pivotally attached to the support element.

9. The blade lifting yoke according to claim 6 or 7, wherein: The first upper clamping element and the second upper clamping element include a first upper clamping member and a second upper clamping member pivotally attached to the first upper clamping element and the second upper clamping element, and / or the first lower clamping element and the second lower clamping element include a first lower clamping member and a second lower clamping member pivotally attached to the first lower clamping element and the second lower clamping element, and preferably, the support element includes a first support member and a second support member pivotally attached to the support element.

10. The blade lifting yoke according to claim 8 or 9, wherein: A first clamping sub-member and a second clamping sub-member are pivotally attached to each of the clamping members.

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