Wind turbine blade installation system and related methods

Abstract

1. A method, and associated system, for installing a wind turbine blade on a rotor head of a nacelle located at the top of a tower of a wind turbine generator, the method including the step of hoisting the blade on the tower in a substantially vertical orientation, the movement of the blade up the tower being guided by at least one carriage intermediate the blade and the tower, the at least one carriage being removably secured to the blade, the at least one carriage contacting one or more exterior surfaces of the tower as the blade is being hoisted.

Description

[Technical field]

[0001] The present invention relates to a wind turbine blade installation system and an associated wind turbine blade installation method. [Background technology]

[0002] Installation of a wind turbine blade typically requires lifting the wind turbine blade up to the rotor hub or head of the nacelle at the top of the wind turbine tower. Given the height of most wind turbines (approximately 100 meters or more), this can be a dangerous and therefore time-consuming and costly process.

[0003] Known methods may utilize multiple aerial cranes supported at ground level and connecting to various parts of the blade, repeatedly and incrementally lifting the blade until it reaches the nacelle of the wind turbine. This may be a peculiar process in the typically windy conditions at wind turbine installation farms / fields, where high winds may cause dangerous swings of the crane cables and therefore the blades themselves. Furthermore, the swings may sometimes reach resonance, resulting in very high frequency and high amplitude movements of the crane cables / blades. This is dangerous and often makes the final alignment of the blades with the rotor hub or head of the nacelle very difficult. Cranes attached to the tower itself may also require complex and time-consuming assembly and dismantling processes, further increasing costs and construction times.

[0004] Another method may utilize an aircraft such as a helicopter to airlift the blades directly to the nacelle, however this may be very expensive given the required helicopter tonnage required to lift the blades and the resulting fuel consumption, furthermore flying may often be deemed unsafe in high wind conditions making airlift difficult, if not entirely excluded, as an option.

[0005] There is therefore a need to provide a wind turbine blade installation system and corresponding method that at least partially avoids the above-mentioned problems of known methods and systems.

[0006] External sources of information, including patents and other publications, may be referenced herein, typically for the purpose of providing a context for discussing features of the invention. Unless specifically stated, reference to such sources should not be construed as an admission that such sources are prior art in any jurisdiction or form part of the common general knowledge in the art.

[0007] For purposes of this specification, when method steps are described in a sequence, the sequence does not necessarily imply that the steps must be arranged chronologically in that order unless there is another logical way to interpret the sequence. Summary of the Invention [Problem to be solved by the invention]

[0008] It is an object of the present invention to provide a wind turbine blade installation system and / or method that overcomes or at least partially ameliorates some of the above mentioned disadvantages, or at least provides the public with a useful option. [Means for solving the problem]

[0009] In a first aspect, the present invention provides a method for installing wind turbine blades in a rotor head of a nacelle located at the top of a tower of a wind turbine generator, comprising the steps of: hoisting the blade onto the tower with the blade root uppermost and in a substantially vertically extending orientation and guided along the tower by at least one carriage intermediate the blade and the tower, the at least one carriage being removably secured to the blade and contacting one or more exterior surfaces of the tower as the blade is hoisted; Optionally, using at least one carriage to adjust the position of the blade relative to the tower to position the blade root in alignment with a blade mounting flange of the rotor head, whereby the root bolts can be inserted into the root bolt openings; moving the blade to insert the root bolt into the bolt opening; fastening the blade to the rotor head using root bolts; The method can be said to include the following.

[0010] Preferably, at least one carriage is an upper carriage which is secured to the blade at or near the blade root during lifting.

[0011] Preferably, the lifting is by means of support cables or ropes removably attached to the blade and / or to at least one carriage (preferably the upper carriage).

[0012] Preferably, the method further comprises the step of attaching a support cable or rope to the blade (preferably to its anchor, e.g. a lifting anchor) and / or to the at least one carriage, prior to said lifting.

[0013] Preferably, the method includes the step of attaching support cables or ropes to the blade and / or the at least one carriage prior to said lifting, when the blade, with said at least one carriage secured thereto, is in a substantially horizontal position supported by the ground adjacent the tower.

[0014] Preferably the blade is supported by the ground on a support vehicle or support rack prior to said lifting.

[0015] Preferably, the blade is moved from its horizontal position to its hoisted position along its vertical tower by a crane.

[0016] Preferably, the blade is transferred from its horizontal position to a hoisted position along its vertical tower by a crane capable of lifting the blade.

[0017] Preferably, the blade is transferred from its horizontal position to a lifted position along its vertical tower by a crane capable of lifting the blade at a position spaced from the lifting anchor.

[0018] Preferably, the spaced apart positions are defined by lifting anchors on the blades.

[0019] Preferably, the lifting anchor is located closer to the blade tip than where lifting of the blade will then take place.

[0020] Preferably, at least one carriage is an upper carriage that is secured to the blade at or near the blade root during lifting, and the spaced apart position is defined by a second of the at least one carriage that is secured to the blade closer to the blade tip.

[0021] Preferably, the crane includes a lifting boom and a lifting cable or rope extending from the lifting boom to the blade for lifting the blade.

[0022] Preferably the crane is vehicle mounted.

[0023] Preferably, in the horizontal position, the blade and the at least one carriage are spaced away from the tower.

[0024] Preferably, the crane and support cables work together to suspend and move the blade from its horizontal position to its raised position.

[0025] Preferably, the crane and support cables cooperate to suspend and move the blade from its horizontal position to its raised position by contacting at least one carriage with one or more exterior surfaces of the tower.

[0026] Preferably, the crane is disengaged from the blade when the blade is vertical and the at least one carriage is positioned relative to the tower.

[0027] Preferably, the crane is disengaged from the blade once the blade is fully suspended by the lifting cables or ropes only.

[0028] Preferably, in the lifted condition, at least two, preferably three, carriages are removably fixed to the blade at spaced apart positions and are located intermediate the blade and the tower and guided by the tower.

[0029] Preferably, in the lifted condition, the upper carriage is removably secured to the blade at or near the blade root, and the lower carriage is removably secured to the blade near the blade tip and is independent of the upper carriage.

[0030] Preferably, at least one carriage includes wheels or bearings capable of moving on and above one of the tower surfaces during said lifting.

[0031] Preferably, the wheels or bearings help prevent the blade from swinging relative to the tower during lifting.

[0032] Preferably, the at least one carriage includes wheels or bearings capable of moving over the surface of the tower and holding the blade in place where the at least one carriage is fixed to the blade at a predetermined distance from the tower.

[0033] Preferably, the at least one carriage includes wheels or bearings capable of moving over the surface of the tower and holding the blade in place such that the at least one carriage is secured to the blade at a predetermined radial position from the tower.

[0034] Preferably, the at least one carriage includes wheels or bearings capable of moving over the surface of the tower and holding the blade in place such that the at least one carriage is fixed to the blade at a predetermined tangential position from the tower.

[0035] Preferably, the positioning of the blade is achieved by means of at least one carriage.

[0036] Preferably, said at least one carriage (preferably at least said upper carriage) includes a mechanism that allows the relative position of the blade and tower to be adjusted.

[0037] Preferably, the mechanism is an at least two-axis translation mechanism.

[0038] Preferably, said mechanism is an at least two-axis translation mechanism capable of radially and tangentially displacing the blade on said carriage relative to the tower.

[0039] Preferably, the mechanism is operable to move the blade to insert the root bolt into the bolt opening.

[0040] Preferably, at least one carriage is in sliding or rolling contact with the tower during lifting of the blade.

[0041] Preferably, lifting is from a lifting point above the blade.

[0042] Preferably, the lifting point is fixed relative to the tower.

[0043] Preferably, the lifting point is located such that during lifting there is a gravity bias on the blade and its fixed carriage towards the tower face of the surface.

[0044] Preferably, the winch for lifting the blade is supported by the ground on which the tower is supported.

[0045] Preferably, the winch for lifting the blade is secured by the ground on which the tower is supported.

[0046] Preferably, a winch for hoisting the blade is fixed to and above the ground on which the tower is supported.

[0047] Preferably, a support cable or rope extends from the blade or said at least one carriage upwardly to a lifting point during lifting.

[0048] Preferably, during lifting, a support cable or rope extends upwardly from the blade or said at least one carriage to a lifting point and from the lifting point towards the ground to a lifting winch.

[0049] Preferably, after fixing the blade, the at least one carriage is detached from the blade.

[0050] Preferably, after securing the blade, the at least one carriage is detached from the blade and lowered to the ground.

[0051] Preferably, after securing the blade, the at least one carriage is detached from the blade and lowered to the ground by the support cables.

[0052] Preferably the blades are delivered to the wind turbine generator from a remote location by a support vehicle, preferably a road vehicle (eg by a truck, eg on a trailer of the truck).

[0053] Preferably, the blades are delivered to the wind turbine from a remote location by a support vehicle and the crane is attached to said vehicle.

[0054] In a further aspect, the present invention provides a method of removing a wind turbine blade from a rotor head of a nacelle located at the top of a tower of a wind turbine generator, the method comprising the steps of: Releasing the blade root bolts from the rotor head; moving the blade to remove the root bolt from the bolt opening; lowering the blade, with the blade root uppermost and in a substantially vertically extending orientation, down the tower, guided along the tower by at least one carriage intermediate the blade and the tower, the at least one carriage being removably secured to the blade and contacting one or more exterior surfaces of the tower as the blade is lowered; The method can be said to include the following.

[0055] Preferably, at least one carriage is secured to the blade prior to said lowering.

[0056] Preferably, at least one carriage is an upper carriage which is secured to the blade at or near the blade root during descent.

[0057] Preferably, the lowering is by means of a support cable or rope removably attached to the blade and / or to at least one carriage (preferably the upper carriage).

[0058] Preferably, the method further comprises the step of attaching support cables or ropes to the blade (preferably its lifting anchor) and / or to at least one carriage prior to said lowering (and preferably prior to said unlocking).

[0059] Preferably, the blade is lowered onto a support vehicle or rack.

[0060] Preferably, the blade is transferred from a suspended position along a vertical tower to its horizontal position by a crane.

[0061] Preferably, the blade is transferred from a suspended position along a vertical tower to its horizontal position by a crane capable of lifting the blade.

[0062] Preferably, the blade is transferred from a lifted position along a vertical tower to its horizontal position by a crane capable of lifting the blade at a position spaced from the lifting anchor.

[0063] Preferably, the spaced apart positions are defined by lifting anchors on the blades.

[0064] Preferably, the lifting anchor is located closer to the blade tip than where the lowering of the blade will then take place.

[0065] Preferably, in the horizontal position, the blade and the at least one carriage are spaced away from the tower.

[0066] Preferably, the crane and support cables work together to suspend and move the blade from its vertically lowered position to its horizontal position.

[0067] Preferably, the lowering is done from a lifting point above the blade.

[0068] Preferably, the winch for lowering the blade is supported by the ground on which the tower is supported.

[0069] Preferably the winch is secured by the ground on which the tower is supported.

[0070] Preferably the winch is fixed to and above the ground on which the tower is supported.

[0071] In a further aspect, the present invention relates to a system for installing and / or removing turbine blades in or from a rotor head of a nacelle located at the top of a tower of a wind turbine generator, comprising: a. a support cable or rope capable of supporting the blade in a vertical position and lifting and / or lowering the blade from a position above the blade; b. at least one carriage located intermediate the blade and the tower and removably secured to the blade and in contact with one or more exterior surfaces of the tower as the blade is raised and / or lowered by the support cables, the at least one carriage including a mechanism for allowing the relative position of the blade and the tower to be adjusted to position the blade relative to the tower using the at least one carriage to position the blade root in alignment with the blade mounting flange of the rotor head, whereby a root bolt can be inserted into the root bolt opening; The system can be said to include the above.

[0072] In a further aspect, the present invention relates to a system for installing and / or removing wind turbine blades to or from a rotor head of a nacelle located at the top of a tower of a wind turbine generator, comprising: a. a support cable or rope capable of supporting the blade in a vertical position and lifting and / or lowering the blade from a position above the blade; b. at least one carriage located intermediate the blade and the tower and removably secured to the blade and in contact with one or more exterior surfaces of the tower when the blade is raised and / or lowered by the support cables; c. A crane capable of lifting the blade and, in conjunction with the supporting cables, moving the blade between its vertical position parallel and adjacent to the tower and a horizontal position further away from the tower. The system can be said to include the above.

[0073] Preferably, at least one carriage is an upper carriage which is secured to the blade at or near the blade root during lifting.

[0074] Preferably, the lifting and / or lowering is by means of supporting cables or ropes which may be removably attached to the blade and / or at least one carriage (preferably the upper carriage).

[0075] Preferably, a crane is provided which is capable of lifting the blade and, in conjunction with the support cables, transitioning the blade between its vertical position, parallel and adjacent to the tower, and a horizontal position, further away from the tower.

[0076] Preferably, the crane is capable of lifting the blade.

[0077] Preferably, the crane is capable of lifting the blade at a position spaced from the lifting anchor.

[0078] Preferably, the spaced apart positions are defined by lifting anchors on the blades.

[0079] Preferably, the lifting anchor is located closer to the blade tip than where lifting of the blade will then take place.

[0080] Preferably, at least one carriage is an upper carriage which can be secured to the blade at or near the blade root during lifting, and the spaced apart position is defined by a second of the at least one carriage which is secured to the blade closer to the blade tip.

[0081] Preferably, the crane includes a lifting boom and a lifting cable or rope extending from the lifting boom to the blade for lifting the blade.

[0082] Preferably the crane is vehicle mounted.

[0083] Preferably, in the horizontal position, the blade and the at least one carriage are spaced away from the tower.

[0084] Preferably, the crane and support cables work together to suspend and move the blade from its horizontal position to its raised position.

[0085] Preferably, at least two, preferably three, carriages are provided which are removably secured to the blade at spaced apart locations.

[0086] Preferably, at least one carriage includes wheels or bearings capable of moving on and above one of the tower surfaces during said lifting.

[0087] Preferably, the wheels or bearings help prevent the blade from swinging relative to the tower during lifting.

[0088] Preferably, the at least one carriage includes wheels or bearings capable of moving over the surface of the tower and holding the blade in place where the at least one carriage is fixed to the blade at a predetermined distance from the tower.

[0089] Preferably, the at least one carriage includes wheels or bearings capable of moving over the surface of the tower and holding the blade in place such that the at least one carriage is secured to the blade at a predetermined radial position from the tower.

[0090] Preferably, the at least one carriage includes wheels or bearings capable of moving over the surface of the tower and holding the blade in place such that the at least one carriage is fixed to the blade at a predetermined tangential position from the tower.

[0091] Preferably, the at least one carriage includes a mechanism for allowing the relative position of the blade and tower to be adjusted, and for adjusting the position of the blade relative to the tower using the at least one carriage to position the blade root in alignment with the blade mounting flange of the rotor head so that the root bolts can be inserted into the root bolt openings.

[0092] Preferably, the mechanism is an at least two-axis translation mechanism.

[0093] Preferably, said mechanism is an at least two-axis translation mechanism capable of radially and tangentially displacing the blade on said carriage relative to the tower.

[0094] Preferably, the mechanism is operable to move the blade to insert the root bolt into the bolt opening.

[0095] Preferably, at least one carriage is adapted and configured for sliding or rolling contact with the tower during lifting and / or lowering of the blade.

[0096] Preferably, lifting and / or lowering is performed from a lifting point above the blade.

[0097] Preferably, the lifting point is fixed relative to the tower.

[0098] Preferably, the lifting point is located such that during lifting there is a gravity bias on the blade and its fixed carriage towards the tower face of the surface.

[0099] Preferably, a winch for lifting / lowering the blade is supported by the ground on which the tower is supported.

[0100] Preferably, the winch for lifting / lowering the blade is fixed by the ground on which the tower is supported.

[0101] Preferably, a winch for hoisting / lowering the blade is fixed to and above the ground on which the tower is supported.

[0102] Preferably, a support cable or rope extends from the blade or said at least one carriage upwardly to a lifting point during lifting.

[0103] Preferably, during lifting, a support cable or rope extends upwardly from the blade or said at least one carriage to a lifting point and from the lifting point towards the ground to a lifting winch.

[0104] Preferably, the system further includes a support vehicle.

[0105] Preferably, the support vehicle is capable of supporting a blade.

[0106] Preferably, the support vehicle is capable of delivering the blades from a remote location to the wind turbine and from the wind turbine to the remote location.

[0107] Preferably the support vehicle is a road vehicle (eg a truck).

[0108] As used in this specification and claims, the term "comprising" means "consisting at least in part of." When interpreting statements in this specification and claims that include the term "comprising," there may be features present other than those recited preceding the term in each statement. Related words such as "comprise" and "comprised" can be interpreted in the same manner.

[0109] Reference to a range of numerical values ​​disclosed herein (e.g., 1-10) also incorporates a reference to every rational number within that range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, 10) and also any range of rational numbers within that range (e.g., 2-8, 1.5-5.5, 3.1-4.7), and thus all subranges of every range explicitly disclosed herein are intended to be expressly disclosed hereby. These are only a few examples of what is specifically intended, and all possible combinations of numerical values ​​between the lowest and highest values ​​recited are likewise considered to be expressly set forth in this application.

[0110] The present invention may also be broadly stated to include any or all combinations of the parts, elements and features referred to or described in this specification of this application, either individually or collectively, and any two or more of said parts, elements or features, and where a particular integer number having a known equivalent in the art to which the invention pertains is described herein, such known equivalent is also deemed to be incorporated herein as if set forth individually.

[0111] As used herein, the term "(s)" after a noun refers to the plural and / or the singular form of that noun.

[0112] As used herein, the term "and / or" means "and" or "or" or both where the context allows.

[0113] The present invention also contemplates configurations including those mentioned above and those given below merely by way of example.

[0114] The invention will now be described, by way of example only, with reference to the drawings in which: [Brief description of the drawings]

[0115] [Figure 1] FIG. 1 is a perspective view of an exemplary horizontally oriented wind turbine blade prior to installation. [Figure 2A]FIG. 1 is a perspective view of an exemplary wind turbine tower awaiting installation of at least one of its blades. [Figure 2B] FIG. 2B is a detailed perspective view of a nacelle of the example wind turbine tower of FIG. 2A. [Figure 3A] FIG. 2 is a perspective view of an exemplary first / upper carriage of an embodiment of a wind turbine installation system. [Figure 3B] FIG. 3B is an exploded perspective view of the exemplary first / upper carriage of FIG. 3A. [Figure 4A] FIG. 2 is a perspective view of an exemplary second carriage of an embodiment of a wind turbine installation system. [Figure 4B] FIG. 4B is an exploded perspective view of the exemplary second carriage of FIG. 4A. [Diagram 5] FIG. 1 is a perspective view of an embodiment of a wind turbine installation system immediately prior to commencing lifting of a horizontally oriented wind turbine blade. [Figure 6] FIG. 6 is a perspective view of the embodiment of the wind turbine mounting system of FIG. 5 with the blades elevated off the ground. [Figure 7] FIG. 7 is a perspective view of the embodiment of the wind turbine mounting system of FIG. 6 with the blades elevated further up. [Figure 8] FIG. 8 is a perspective view of the embodiment of the wind turbine mounting system of FIG. 7 with the blades elevated in a substantially vertical orientation. [Figure 9] FIG. 9 is a perspective view of the embodiment of the wind turbine mounting system of FIG. 8 with the blades raised in a vertical orientation. [Figure 10A] FIG. 10 is a perspective view of the embodiment of the wind turbine mounting system of FIG. 9 with the blade elevated adjacent to the wind turbine rotor head. [Figure 10B] FIG. 10B is a detailed perspective view of the embodiment of the wind turbine mounting system of FIG. 10A with the wind turbine rotor head and nacelle shown in cross-section for clarity. [Figure 11A] FIG. 1 is a side view of an embodiment of a wind turbine mounting system with a force diagram shown. [Figure 11B]11B is a rear view and a cross-sectional view of the wind turbine mounting system according to the embodiment of FIG. 11A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0116] Referring to the above drawings, in which like features are generally designated with like reference numerals, a wind turbine blade mounting system according to a first aspect of the present invention is generally designated with the reference numeral 1000.

[0117] Figure 1 illustrates an exemplary wind turbine blade 10. The shape, length, and configuration of the wind turbine blade 10 illustrated in Figures 1-11B and described herein are merely illustrative of a typical wind turbine blade that is approximately 80 meters in length.

[0118] Similarly, an exemplary wind turbine tower 200 is shown in Figure 2A. The tower 200 is shown with its nacelle 210 and rotor head 220 already installed using known methods of wind turbine tower assembly and construction / erection. The tower 200 is merely an exemplary configuration of a wind turbine tower that may employ the systems and methods described herein to connect its blades to the tower. The tower 200 may be approximately 165 meters tall, by way of example, from the top of the nacelle 210 to its base 230.

[0119] 2B shows rotor head 220 of tower 200 in a transparent state, illustrating three openings or blade mounting flanges 222 corresponding to the three blades to be installed. These blade mounting flanges 222 are shown with annular rings with root bolt openings 224.

[0120] Generally, blade 10 has an uppermost blade root 12, a midsection 14, and a blade tip 16. Root 12 may generally have a substantially cylindrical or tubular configuration, as shown in Figure 1, with an annular ring of root bolt openings 12A extending circumferentially around root 12. Roots of other shapes are known in the art and can be adapted by one of ordinary skill in the art for use with the systems and methods described herein.

[0121] The term "bolt" is used herein only as one example of a means used to fasten the blade mounting flanges 222 of the rotor head 220 of the wind turbine nacelle 210. Other fastening means known to those skilled in the art may also be employed depending on the particular configuration of the overall wind turbine 200, the nacelle 210, its rotor head 220, its blade mounting flanges 220 and / or a given blade 10 root configuration.

[0122] In Figure 1, the blade is shown in a substantially horizontal orientation. Generally, this may be understood as the condition in which the blade 10 arrives at the site, carried by a transport vehicle, for subsequent erection and installation. The blade 10 may arrive at the site using a support vehicle, such as a multi-wheel truck having a flatbed support rack. The blade 10 may be transported to the site near the tower foundation in a substantially horizontal position.

[0123] The blade 10 in FIG. 1 is shown with a number of carriages 1020, 1040 removably secured thereto. These carriages 1020, 1040 may form part of the system 1000 described below, but are merely exemplary of how the system and its carriages may be configured. The carriages may be secured to the blade 10 after the blade 10 arrives at the site while the blade 10 is resting on the support rack / flatbed of the support vehicle / truck, may be secured to the blade 10 before the blade 10 arrives on the support rack / flatbed of the support vehicle / truck (i.e., the blade 10 arrives at the site with the carriages pre-positioned), and / or may be secured to the blade 10 after the blade has been lifted or otherwise removed from the support rack / flatbed of the support vehicle / truck and placed on the ground at / near the tower base.

[0124] Generally, in the systems 1000 described herein, at least one carriage is employed and provided to assist in moving the blade 10 from its substantially horizontal position to a substantially vertical orientation, in which the blade root 12 is oriented upward and higher than the downwardly oriented blade tip 16, as shown and described in connection with Figures 1-11B.

[0125] However, FIG. 1 illustrates an exemplary embodiment of the system 1000 in which two carriages are employed: a first or upper carriage 1020 and a second or middle carriage 1040 .

[0126] Generally, the system 1000 employs at least one upper carriage 1020 at or near the blade root 12, although it may be advantageous to employ a second, third or additional carriages depending on the length or other characteristics of the blade 10 to be installed.

[0127] The second or intermediate carriage 1040, when employed in combination with the first or upper carriage 1020, is typically located at or near the mid-portion 14 of the blade 10, between the root portion 12 and the tip portion 16. More generally, however, the second or intermediate carriage 1040 may be located anywhere along the blade 10 away from the blade root portion 12 where the first carriage 1020 is located, and typically closer to or toward the blade tip portion 16 than said first carriage 1020.

[0128] Also shown in FIG. 1 is a lifting anchor 1100 located at or near the blade tip 16, at a location spaced from the first and second carriages 1020,1040.

[0129] Those skilled in the art will appreciate that the number and location of carriages and lifting anchors 1100 employed in the systems and methods described herein may vary and may depend on many design, installation and engineering considerations, including, among other things, optimizing balance / center of gravity and reducing sway / rotation of the blade 10 during lifting.

[0130] For example, in the illustrated exemplary embodiment in which two carriages are employed, a first or upper carriage 1020 is generally located at the blade root portion 12, a second carriage 1040 is located at the central portion 14, and a lifting anchor 1100 is located at or near the blade tip portion 16.

[0131] However, in another embodiment, only the first carriage 1020 may be employed at the blade root 12 without a second carriage, with the lifting anchor 1100 provided at or near the blade tip 16. In such a case, the location of the first carriage 1020 and lifting anchor 1100 may differ from that shown in FIG.

[0132] Similarly, in another embodiment, the lifting anchor 1100 may not be provided and only the first and second carriages 1020, 1040 may be employed. In such a case, the second carriage 1040 may be moved further towards the blade tip 16, again achieving a different center of gravity when lifting the blade 10.

[0133] 1 also shows two tensioning cables 1200, one running taut from the first carriage 1020 to the second carriage 1040, and the other running from the second carriage 1040 to the lifting anchor 1100. Such tensioning cables 1200 may be employed to help keep the blade 10 generally aligned as it is lifted, i.e., to reduce yaw / rotation about the long axis of the blade 10.

[0134] Figures 3A and 3B show detailed views of an exemplary embodiment of the first carriage 1020. In Figure 3A, the first or upper carriage 1020 is shown connected to the blade 10, while Figure 3B shows an exploded view of the upper carriage 1020 itself.

[0135] The first or upper carriage 1020 includes a mounting structure 1022 generally in the form of a truss 1024 having two mounting flanges 1026 that connect to the root 12 of the blade 10. In particular, the mounting flanges 1026 are configured (shaped / dimensioned) to mate with and thereby connect to the annular rings of the root bolt openings 12A of the blade root 12. Any number of mounting flanges 1026 may be provided and positioned in a variety of manners around the root 12 of the blade 10. However, two mounting flanges 1026 are shown here positioned at opposing ends of the circumference of the root 12.

[0136] FIG. 3B shows at least a two-axis translation mechanism, and in particular a three-axis translation mechanism, of the carriage 1020, which includes: · Fore-aft translation structure 1028. The fore-aft translation structure 1028 allows the mounting structure 1022 to translate fore-aft relative to said fore-aft translation structure 1028, for example by means of rollers 1028A mounted between rails 1028B. Lateral translation structure 1030. The lateral translation structure 1030 allows the front-to-rear translation structure 1028 to translate laterally (side to side) relative to said lateral translation structure 1030, for example, by rollers 1030A mounted between rails 1030B. Guiding structure 1032. Guiding structure 1032 allows lateral translation structure 1030 to translate vertically (up and down) relative to said guiding structure 1032, for example by means of rollers 1032A mounted between rails 1032B.

[0137] The three-axis translation mechanism of this embodiment is merely exemplary and many other structures and means other than rollers / rails can be employed to provide three-axis translation of the carriage 1020 and adjust the position of the blade 10 (i.e., the mounting structure 1022 connecting to the blade 10) relative to the tower 200 (i.e., the guide structure 1032 that contacts the surface of the tower 200, thereby guiding the blade 10 up along the tower 200).

[0138] To that end, the guide structure 1032 includes a number of guide legs 1034 configured to extend generally around the circumference of the tower 200 depending on the expected outer diameter of the tower 200. The guide legs 1034 are thus fitted with a number of rollers 1036 which can contact the circumference / outer surface of the tower 200 to provide rolling or sliding contact, thus allowing the entire carriage 1020 to move up along the tower 200 when the blade 10 is lifted. A lifting point 1038 is attached to the distal end of the forward-most guide leg 1034 to which a support cable or rope 1400 can be removably attached. A lifting point (not shown) is attached to the rear of the guide structure 1032 to which the tensioning cable 1200 described above can be connected.

[0139] 3A also shows support rollers 1027, which may initially contact the periphery / outer surface of tower 200 and thus assist in providing rolling or sliding contact and thus assist in the movement of the entire carriage 1020. In some embodiments, these support rollers 1027 may be driven by a motor or the like to assist in said initial movement of carriage 1020 up along tower 200.

[0140] Figures 4A and 4B show detailed views of an exemplary embodiment of the second carriage 1040. In Figure 4A, the second carriage 1040 is shown connected to the blade 10 at or near the midsection 14, while Figure 4B shows an exploded view of the second carriage 1040 itself.

[0141] The second carriage 1040 generally includes a mounting structure 1042 having mounting legs 1044 that connect to the central portion 14 of the blade 10. This may be by a direct connection (i.e., use of fasteners, etc.), or may be by, for example, ratchet straps, tensioned cables, etc., or by any other suitable means of coupling said mounting legs 1044 to a surface or anchor of the central portion 14 of the blade 10.

[0142] 4B shows the angular pivot mechanism of the carriage 1040, in particular the guide structure 1046, which allows the mounting structure 1042 to translate vertically (up and down) relative to said guide structure 1046, for example by means of rollers 1046A mounted between rails 1046B. Thus, by changing the vertical position of the mounting structure 1042 relative to the guide structure 1046, the overall pitch angle (i.e. the angle of the long axis of the blade 10 relative to the long axis of the tower 200) can be changed.

[0143] The angular pivot mechanism of this embodiment is exemplary only and many other structures and means other than rollers / rails can be employed to provide angular pivoting of the carriage 1040 to adjust the angular pitch / position of the central portion 14 of the blade 10 (i.e., the mounting structure 1042 connecting to the central portion 14) relative to the tower 200 (i.e., the guide structure 1046 that contacts the surface of the tower 200, thereby guiding the blade 10 up along the tower 200).

[0144] To that end, the guide structure 1046 includes a number of guide legs 1048 configured to extend generally around the circumference of the tower 200 depending on the expected outer diameter of the tower 200. Accordingly, the guide legs 1048 are fitted with a number of rollers 1049 which can contact the circumference / outer surface of the tower 200 to provide rolling or sliding contact, thus allowing the entire carriage 1040 to move up along the tower 200 when the blade 10 is lifted. At the rear and front of the guide structure 1046, lifting points 1047 are fitted to which the tensioning cables 1200 described above can be connected.

[0145] A lifting system 1000 and associated exemplary lifting processes and methods will now be described.

[0146] 5 shows the initial start of the lifting, with the blade 10 in its horizontal position. On the foundation 230, opposite the end of the rotor head 220 of the tower nacelle 210, is located a winch device 1300. This winch device may include any suitable lifting means, i.e., two winches as shown. A lifting means, for example its tensioned cable 1400, extends from said winch device 1300 into the interior of the tower 200 and upwards through it to the top of the tower 200.

[0147] The cables 1400 then extend outwardly from the wall of the tower 200 and out adjacent and underneath the nacelle 210 of the tower 200. This is shown in Figure 10B, where the cables 1400 extend from the side of the tower 200 to idler pulleys 1410. These idler pulleys 1410 are positioned such that the lifting cables 1400 extending downwardly therefrom are approximately aligned with the lifting points 1038 on the forward most guide leg 1034 of the first or upper carriage 1020.

[0148] These lifting means, for example tensioned cables 1400 which lift the first carriage 1020 up along the tower 200, lift the blade 10.

[0149] In some embodiments, the winch device 1300 may be mounted within the tower 200 itself, but still at ground / foundation level, with its lifting means, for example tensioned cable 1400, extending upward to the top of the tower 200.

[0150] In other embodiments, the winch device 1300 may be provided inside the tower 200, directly below the nacelle 210, with its lifting means, such as a tensioned cable 1400, extending down to the aforementioned idler pulley 1410.

[0151] Those skilled in the art will recognize variations in where to position the winch device 1300 and how to route its cable, i.e., the winch could be mounted on the top of the tower 200 instead of on the idler pulley 1410.

[0152] However, it is generally preferred that the cables 1400 extend from near the nacelle 210 so that the blades can be as close as possible to the rotor head 220 of the tower 200 as they are lifted.

[0153] It is also generally preferred that the cables be routed mostly through the interior of the tower 200 to avoid or reduce the swaying that the cables / cranes are typically subjected to in the typically high winds of the wind turbine installation field / farm, thus reducing hazards and can aid in the final alignment of the blades 10 with the rotor head 210.

[0154] 5 also shows an assist crane 1500 provided to lift the rear or tip 16 of the blade 10 by the lifting anchor 1100 previously described. This crane 1500, which is shown as a vehicle-mounted crane but can also be installed independently, is provided to prevent the tip 16 of the blade 10 from pivoting downward too far and contacting / colliding with the ground as the blade 10 tips upward from the lifting of the first carriage 1020 up along the tower 200.

[0155] The lifting anchor 1100 is shown positioned around the periphery of the blade 10 throughout the drawings and has two upper lifting points 1100A above it to which the cables of the crane 1500 connect, and further has a lower lifting point 1100B 1040 (visible in Figures 6 and 7) to which the tensioning cable 1200 mentioned above can connect to a second or intermediate carriage.

[0156] Those skilled in the art will appreciate that in some embodiments, the lifting anchor 1100 may not be required and the second, third, fourth, etc. carriage may simply be moved further towards the blade tip 16 and a crane 1500 may be connected to that carriage to assist in suspending the blade tip 16.

[0157] Additionally, in some embodiments, the lifting anchor 1100 may be provided with a wheeled or roller arrangement to assist in guiding the lifting anchor 1100 upwardly along the surface of the tower 200.

[0158] Generally, however, the extent to which the first carriage 1020 extends "down" (relative to the horizontal state of the blade) from the blade root 12 is such that in many cases the blade tip 16 cannot contact the tower 200 at all during lift.

[0159] Figure 6 shows the blade 10 being lifted upwardly from the position in Figure 5. The angle of the blade 10 is still not such that the rollers 1036 are in contact with the surface of the tower 200, but the support rollers 1027, which are higher and more forward on the carriage 1020, contact the tower 200. It can be seen that the crane 1500 has lifted the tip 16 of the blade 10 (by means of the lifting anchors 1100) to a higher position than in Figure 5.

[0160] In FIG. 7, the blade 10 is taller and the angle (pitch) of the blade 10 relative to the tower 200 is such that at least some of the rollers 1036 of the first or upper carriage 1020 contact the tower 200 .

[0161] In FIG. 8 , the blade 10 is now in an approximately substantially vertical and upright orientation or position, with the blade root 12 substantially above and in alignment (vertically) with the blade tip 16, and all of the rollers 1036 of the first or upper carriage 1020 and all of the rollers 1049 of the second carriage 1040 substantially in contact with the surface of the tower 200.

[0162] 9, the blade 10 is at a sufficient height that it is no longer necessary to employ the crane 1500. Furthermore, the blade 10 is now in a substantially vertical position, with the blade root 12 above and in line (vertically) with the blade tip 16. The lifting means 1400 now lifts the blade 10 through the final section towards the nacelle 210.

[0163] Finally, in FIG. 10A, the blade 10 reaches its end, with the root end 12 of the blade 10 proximate the blade mounting flange 222 of the rotor head 220 of the wind turbine nacelle 210.

[0164] 10B, which takes a cross-section through the front of the turbine nacelle 210 and rotor head 220 and shows workers 1600, one supported on the nacelle interior floor 210A and one supported on a flat deck 12B removably mounted within the root 12 of the blade 10. These workers 1600 (which may be any desired number) may work together inside the blade root 12, nacelle 210 and / or rotor head 220 to align openings 222A in the blade mounting flange 222 of the rotor head 220 with the annular ring of root bolt openings 12A in the blade root 12.

[0165] Once aligned, root bolts may be tightened through both sets of openings 12A, 222A to complete installation of the blade 10 onto the rotor head 210.

[0166] In some cases, minor adjustments to the position of the blade 10 may need to be made to perfectly align both sets of openings 12A, 222A.

[0167] This can be done in several ways. Slack can be given to the lifting cables 1400 to allow for slight movement of the blade 10. Additionally, one winch of the winch arrangement 1300 can be tensioned more or less than the other, correspondingly increasing / decreasing the tension or length of one lifting cable 1400 relative to the other. This can create a slight slack in the blade 10 on one side of the blade 10, allowing for further movement. The movement of the blade 10 in both of these cases can be performed by personnel 1600, since the suspended blade 10 may not require more than human force to move it by small increments at such heights (e.g., personnel 1600 in the nacelle 210 can pull the blade towards them, personnel 1600 in the rotor head 210 and temporarily on deck 12B assist with this operation).

[0168] Those skilled in the art can envision other means to assist in aligning the openings 12A, 222A, such as by locating alignment rails on the blade mounting flanges 222 of the rotor head 220 and corresponding guide rails on the blade roots 12, the alignment rails and guide rails cooperating to maintain proper coaxial alignment of the roots 12 and rotor head 220 as the roots 12 approach the rotor head 220.

[0169] Additionally, in some embodiments, the multiple rollers 1036 of the first or upper carriage 1020 and the multiple rollers 1049 of the second carriage 1040 may be actuable (i.e., their rotational positions may be remotely movable) and may further be driven by motors sufficient to provide only the slight movements required to make required fine adjustments to the position of the blade 10.

[0170] In other words, modifications can be made to the rollers of the carriage such that they do not only passively provide sliding or rolling contact between the carriage and the surface of the tower 200, but also provide actuatable and controllable movement, such as by a motor driving said rollers. An actuation jack can also be provided extending from the carriage and configured to press against the surface of the tower 200, to adjust the pitch angle of the blade 10 as required.

[0171] Furthermore, the roller and rail configurations of the three-axis translation mechanism of the first or upper carriage 1020 and the angular pivot mechanism of the second carriage 1020 may be passive and therefore loose to allow free movement of the various sub-structures of the carriage, but alternatively, the carriages may be actuated or driven so that small movements of the blade 10 can be made from a remote location to assist in the final alignment of the openings 12A, 222A.

[0172] Note that Figure 10B also shows a forward positioned idler pulley 1410A, which (as the tensioned cable 1400 of the winch device 1300 is routed therethrough) can be used to couple to the coupling point between the support rollers 1027 of the first or upper carriage 1020 at the earliest stage of lifting of the blade 10 (i.e., at or before the position shown in Figure 5).

[0173] It should be appreciated that this can be done in combination with routing additional cables 1400 through lateral idler pulleys 1410. Any number of lifting cables 1400 and any number of idler pulleys 1410 can be used at various circumferential positions below the nacelle 210 to lift the first or upper carriage 1020.

[0174] It should also be appreciated that prior to final coupling / tightening of the root bolts through the openings 12A, 222A, the attachment flange 1026 connecting to the root 12 of the blade 10 must be at least partially decoupled therefrom, so as not to impede the final press-together of the root 12 and the blade attachment flange 222. For example, some of the root bolts can be partially tightened first, then the attachment flange 1026 connecting to the root 12 can be decoupled, after which the blade is supported by the partially tightened root bolts, and then all of the root bolts are positioned and fully tightened to complete the installation of the blade 10.

[0175] The overall dimensions and geometry of the carriages can be adjusted for each situation to assist in the proper distance and alignment of the blade root 12 and tip 16 relative to the tower 200. For example, for the first carriage 1020, the distance between the lifting point 1038 (where the lifting cable 1400 connects) and the mounting flange 1026 (and / or other means to which the blade root 12 connects) can determine the offset distance of the blade root 12 relative to the surface of the tower 200 as the blade root 12 approaches its final aligned and installed position.

[0176] 11A and 11B illustrate at least some of the force considerations that one of ordinary skill in the art may make when employing the systems and methods described herein.

[0177] FIG. 11A shows a schematic force diagram of various forces that may need to be overcome during lifting of the blade 10 before it reaches its substantially vertical state of FIG. 9. A first vertical lifting force FY1 extends upward from the lifting point 1038 where the lifting cable 1400 connects to the first or upper carriage 1020. Similarly, a second vertical lifting force FY2 extends upward from the lifting point 1100A of the lifting anchor 1100 to which the crane 1500 may connect. These two upward vertical lifting forces must counteract the downward gravitational force due to the weight of the blade acting near its center of gravity COG (the location of the center of gravity in FIGS. 11A and 11B is merely exemplary). There is also a horizontal force component (denoted as FX) generated by the angular pitch of the blade 10, and therefore the angular component of the resultant force can be denoted as FT.

[0178] All of these various forces FX, COG, FT, FY1 and FY2 must be resolved by the proper configuration of tension / lifting forces applied by the lifting cables 1400 and, in some embodiments, the crane 1500. In some cases, the crane 1500 may not be a large contributor to the upward vertical lifting force and may therefore be considered negligible. However, in general, most of these forces must be balanced to gradually and smoothly transition the blade 10 from the substantially horizontal state of FIG. 5 to the substantially vertical state of FIG. 9.

[0179] It should also be noted that a moment may be generated about the center of gravity COG of the blade 10 because, depending on the distance therefrom, the first and second vertical lift forces FY1, FY2 may act to rotate the blade in opposite directions (i.e., with respect to FIG. 11A, FY1 may rotate the blade 10 clockwise and FY2 may rotate the blade 10 counterclockwise). Thus, one skilled in the art may also need to consider how the vertical lift forces FY1, FY2 change the pitch angle of the blade 10 itself.

[0180] To that end, as will be appreciated by those skilled in the art, the change in position of the blade 10 effected by the three-axis translation mechanism of the first or upper carriage 1020 and the angular pivot mechanism of the second carriage 1040 can be used to carefully adjust the position of the blade 10 during the transition from the substantially horizontal state of FIG. 5 to the substantially vertical state of FIG. 9 to alleviate at least some of these force and moment considerations.

[0181] 11B also illustrates how changes in tension in each lifting cable 1400 (in an embodiment where two cables run down from an idler pulley 1410 on the side of the tower 200 and connect to a lifting point 1038 on the carriage 1020) can be made to compensate for the typically offset center of gravity COG of the wind turbine blade 10. As can be seen, the COG may not necessarily be located at the center of the blade (i.e. directly through its long axis) and may be biased towards the thicker leading edge of the blade 10.

[0182] Thus, the F1 and F2 vertical lifting forces of each lifting cable 1400 may need to be adjusted to account for the moments caused by the different distances to the offset center of gravity COG. Section AA also shows these differences in the distances of F1 and F2 to COG, shown as D1 and D2 when viewed in a section extending across the lifting point 1038 of the carriage 1020 to which the lifting cables 1400 connect and lift the blade 10.

[0183] It should be noted that the foregoing examples of various aspects of the systems and methods described herein can be configured to adjust the position of the blades during final alignment of both sets of openings 12A, 222A and can be similarly employed by one of ordinary skill in the art when addressing the force considerations discussed above in connection with Figures 11A and 11B.

[0184] Thus, the system 1000 and methods described herein can provide a safe and cost-effective means of lifting and installing wind turbine blades, The cables 1400 involved in lifting the blade are routed internally and fed from an idler pulley 1410 located just below the nacelle, reducing the sway problems associated with high altitude cranes (often multiple) supported at ground level. Guiding the blade 10 up along the surface of the tower 200 via a releasably fixed carriage (positioned midway between the blade 10 and the tower 200) facilitates keeping the centre of gravity of the blade as close as possible to the tower 200 at all times and to the primary lifting means (the lifting cable 1400) as possible, compared to the cumbersome aerial cranes or purely horizontal airlift methods previously employed. Sometimes only a low elevation crane 1500 may be needed to keep the blade tip 16 from contacting the ground during angle changes, which, together with the use of carriages, significantly reduces costs compared to using multiple high elevation cranes or airlift vehicles.

[0185] It should also be appreciated that the reversal or reverse sequence of the methods / systems described above may be employed to remove or de-install the blades 10 from the rotor head 210. For example, The carriage can be lifted to the top of the nacelle by the winch arrangement as described above. The carriage can be aligned with and connected to the blade 10. · The blade root 12 is disconnected from the rotor head 210 (eg, by a worker 1600 stationed thereon), transferring the weight of the blade 10 from the rotor head 210 to the carriage and lifting cables 1400. Next, following a similar movement as shown in Figures 5-10, but in reverse, the blade 10 is lowered and the assist crane 1500 is positioned at ground level, ready to connect at or near the tip 16 of the blade 10. · The crane connects to the tip 16 of the blade 10 and the lifting cable 1400 lowers the carriage, returning the blade from its substantially vertical position back to the substantially horizontal position as in FIG. The blade 10 is lowered to the ground for maintenance / repair and / or onto a flatbed or the like of a support vehicle for transport off-site as required.

[0186] In the above description, where reference is made to elements or integers that have known equivalents, such equivalents are also included as if they were individually set forth.

[0187] Although the invention has been described by way of example and with reference to specific embodiments, it will be understood that modifications and / or improvements can be made without departing from the scope or spirit of the invention.

[0188] Furthermore, when features or aspects of the invention are described in terms of a Markush group, those skilled in the art will recognize that the invention is also described in terms of each individual member or subgroup of members of the Markush group.

Claims

1. 1. A method for installing wind turbine blades on a rotor head of a nacelle located at the top of a tower of a wind turbine generator, comprising: lifting the blade along the tower in a substantially vertical orientation to present a blade root portion at the top of the blade, the blade being guided along the tower by at least one carriage removably secured to a portion of the blade intermediate the blade and the tower at or near the blade root portion and removably secured to contact one or more exterior surfaces of the tower as the blade is lifted, the at least one carriage including a three-axis translation mechanism configured to displace the blade radially, tangentially, and longitudinally relative to the tower to adjust the position of the blade relative to the tower; b) adjusting the position of the blade relative to the tower using the three-axis translation mechanism of the at least one carriage to position the blade root of the blade in alignment with a blade mounting flange of the rotor head; c. fastening the blade to the rotor head; A method comprising:

2. The method of claim 1 , wherein the at least one carriage comprises an upper carriage removably secured to the blade at or near the blade root during lifting.

3. The method of claim 1 , wherein the lifting is by support cables removably attached to the blade and / or the at least one carriage.

4. 4. The method of claim 3, including the step of, prior to the lifting, providing the blade in a substantially horizontal orientation supported adjacent to the tower by the ground, a support vehicle, or a support rack, and attaching support cables to lifting anchors of the at least one carriage and / or of the blade that are removably secured to the blade.

5. 5. The method of claim 4, wherein the blade is transitioned from its substantially horizontal orientation to its substantially vertical orientation by the support cables and by an assist crane secured to a lifting anchor of the blade.

6. The method described in claim 5, wherein the lifting anchor for the crane is closer to the tip of the blade than the lifting anchor.

7. The method of claim 2 , wherein the at least one carriage further comprises a second carriage removably secured to the blade and closer to the tip of the blade than the upper carriage.

8. The method described in claim 5, wherein the crane and the support cable work together to suspend and move the blade from the substantially horizontal orientation to the substantially vertical orientation.

9. A method as described in claim 8, comprising a step of suspending and moving the blade from the substantially horizontal orientation to the substantially vertical orientation via the crane and the support cable, the step including contacting the at least one carriage with one or more outer surfaces of the tower.

10. The method of claim 9, further comprising disconnecting the crane from the blade when the blade is in the substantially vertical orientation and the at least one carriage contacts the tower.

11. The method described in claim 2, wherein the at least one carriage further has a lower carriage removably fixed to the blade near the tip of the blade, the lower carriage being removably fixed to the blade independently of the upper carriage.

12. The method described in claim 2, wherein the upper carriage includes the three-axis translation mechanism.

13. A method described in any one of claims 1 to 12, further comprising moving the blade by the three-axis translation mechanism to insert the root bolt of the blade root into the bolt opening of the rotor head.

14. The method described in claim 3, wherein during lifting, the support cable extends upward from the blade and / or the at least one carriage to a lifting point located adjacent to and below the nacelle.

15. The method described in claim 14, wherein the lifting point is positioned so that during lifting, the blade and the at least one carriage are biased toward the one or more outer surfaces of the tower.

16. 15. The method of claim 14, wherein the support cables extend from a lifting winch into, through, and up into the interior of the tower to the top of the tower, where they exit outward from the tower to the lifting point adjacent and below the nacelle.

17. 4. The method of claim 3, further comprising, after securing the blades to the rotor head, removing the at least one carriage from the blades and lowering the at least one carriage to the ground by the support cables.

18. 1. A method of removing a wind turbine blade from a rotor head of a nacelle located at the top of a tower of a wind turbine generator, comprising: adjusting the position of the blade relative to the tower to unlock a blade root of the blade from a blade mounting flange of the rotor head and remove the blade from the rotor head; (b) lowering the blade in a substantially vertical orientation along the tower to present the blade root as an uppermost portion, the blade being guided along the tower by at least one carriage removably secured to a portion of the blade intermediate the blade and the tower at or near the blade root and removably secured to contact one or more exterior surfaces of the tower as the blade is lowered, the at least one carriage including a three-axis translation mechanism configured to displace the blade radially, tangentially, and longitudinally relative to the tower to adjust the position of the blade relative to the tower.

19. 1. A system for installing and / or removing wind turbine blades in or from a rotor head of a nacelle located at the top of a tower of a wind turbine generator, comprising: a support cable for supporting the blade in a substantially vertical orientation and for lifting and / or lowering the blade from a position above the blade; at least one carriage removably secured to a portion of the blade intermediate the blade and the tower at or near the blade root and arranged to contact one or more exterior surfaces of the tower as the blade is raised and / or lowered by the support cables, the at least one carriage comprising a three-axis translation mechanism configured to radially, tangentially, and longitudinally displace the blade relative to the tower, thereby enabling the at least one carriage to position a blade root of the blade in alignment with a blade mounting flange of the rotor head for securing the blade relative to the rotor head; A system comprising:

Images