EP4619638A1

EP4619638A1 - Transporter

Info

Publication number: EP4619638A1
Application number: EP23801688.5A
Authority: EP
Inventors: Krishna Chaitanya MUTHYALA; Henrique Daniel LEAL DE OLIVEIRA
Original assignee: Vestas Wind Systems AS
Current assignee: Vestas Wind Systems AS
Priority date: 2022-11-15
Filing date: 2023-11-01
Publication date: 2025-09-24
Also published as: WO2024104536A1

Abstract

The present disclosure relates to a transporter for supporting a tip end of a wind turbine blade. The transporter features a self-levelling mechanism which allows for rotation of the turbine blade about a horizontal axis during transportation to better account for rotational forces which may act on a turbine blade. A biasing arrangement is also provided to return the blade to a neutral position when the external forces causing the table part to rotate are removed.

Description

TRANSPORTER

FIELD OF THE INVENTION

The present invention relates to a transporter for supporting a tip end of a wind turbine blade.

BACKGROUND OF THE INVENTION

As the global demand for clean energy continues to increase, so does the demand for larger capacity wind turbines capable of meeting this demand. However, high capacity (>3MW) wind turbines require very large rotor diameters to allow the wind turbines to sweep greater areas and hence produce larger amounts of electricity. As such, the span lengths of the turbine blades which make up modern wind turbine rotors are also very large which can make transporting modern wind turbine blades a significant challenge.

Due to their significant length, modern turbine blades are often exposed to significant bending or torsional stresses during transportation (for example when cornering or navigating across banked or inclined roadways) which have the potential to damage the composite material of the blades.

As such, it is an aim of the present invention to provide a means for reducing the bending and/or torsional stresses exerted on a given wind turbine blade during transportation.

SUMMARY OF THE INVENTION

According to a first aspect of the present disclosure, there is provided a transporter for supporting a tip end of a wind turbine blade; said transporter having a self-levelling mechanism comprising: a table part configured to support a tip end of a wind turbine blade during use; a supporting part arranged to support the table part, wherein the supporting part is configured to allow for rotation of the table part about a first horizontal axis; and a biasing arrangement configured to return the table part to a neutral position about the first horizontal axis when an external force causing the table part to rotate about the first horizontal axis is removed.

Advantageously, the provision of a self-levelling mechanism which allows for rotation of the table part about a horizontal axis allows the transporter to better account for rotational forces which may act on a turbine blade during transportation. Furthermore, the provision of a biasing arrangement also means that the self-levelling mechanism does not require active adjustment to return the table part (and hence the blade) to a neutral position. Herein the term ‘table part’ can be understood as a supporting part having an upper surface suitable for attachment of one or more interface parts for interfacing to the blade, or for otherwise supporting the blade. The table part may comprise one or more substantially flat surfaces, and/or one or more other surfaces suitable for attachment of interface parts for interfacing to the blade or for directly supporting the blade.

In some examples, the biasing arrangement may comprise a spring and damper arrangement arranged between the table part and the supporting part.

In some examples, the spring and damper arrangement may be oriented at an angle of approximately 10 degrees to the horizontal.

In some examples, the spring and damper arrangement may be connected to an underside of the table part.

In some examples, the self-levelling mechanism may be configured to limit rotation of the table part about the first horizontal axis to an angle of rotation of no more than +/- 10 degrees.

In some examples, the supporting part may be further configured to allow for rotation of the table part about a second horizontal axis.

In some examples, the second horizontal axis may be perpendicular to the first horizontal axis.

In some examples, the supporting part may comprise a weighted, arcuate base configured to return the table part to a neutral position about the second horizontal axis when an external force causing the table part to rotate about the second horizontal axis is removed.

In some examples, the supporting part may comprise a cradle for supporting the weighted, arcuate base.

In some examples, the cradle may comprise a set of rollers configured to engage with the arcuate base so as to substantially prevent translation of the supporting part along the second horizontal axis.

In some examples, the self-levelling mechanism may be further configured to limit rotation of the table part about the second horizontal axis to an angle of rotation of no more than +/- 10 degrees.

In some examples, the table part may be slidably mounted to the supporting part such that the table part is permitted to translate along the first and/or second horizontal axis. In some examples, the self-levelling mechanism may further comprise a first locking mechanism configured to lock the table part relative to the supporting part such that translation of the table part along the first and/or second horizontal axis is substantially prevented.

In some examples, the self-levelling mechanism may be further configured to limit horizontal translation of the table part to a distance of no more than +/- 200mm.

In some examples, the table part may be adjustably mounted to the supporting part so as to permit vertical translation of the table part relative to the supporting part.

In some examples, the table part may be vertically movable between a first vertical position, wherein rotation of the table part about the first horizontal axis is permitted, and a second vertical position, wherein rotation of the table part about the first horizontal axis is not permitted.

In some examples, the self-levelling mechanism may further comprise a second locking mechanism configured to secure the table part in the first vertical position.

In some examples, the self-levelling mechanism may be further configured to limit vertical translation of the table part to a distance of no more than +/- 120mm.

In some examples, the transporter may comprise an upper surface to which the self-levelling mechanism is mounted.

In some examples, when the table part is in the neutral position, an upper surface of the table part may be substantially parallel to the upper surface of the transporter.

In some examples, the transporter may comprise a chassis comprising a rotatable mount coupled between the chassis and the self-levelling mechanism to permit rotation of the self-levelling mechanism about a substantially vertical axis.

In some examples, the transporter may comprise a chassis and the self-levelling mechanism may be slidably mounted to said chassis so as to permit translation of the self-levelling mechanism along the first or second horizontal axis.

In some examples, the transporter may comprise a chassis and the self-levelling mechanism may be slidably mounted to said chassis so as to permit longitudinal translation of the self-levelling mechanism along a length of the chassis.

In some examples, the transporter may further comprise a guideway oriented along a longitudinal axis of the chassis and the self-levelling mechanism may further comprise a plurality of rollers configured to engage with the guideway so as to permit translation of the self-levelling mechanism along the length of the chassis.

In some examples, the transporter may further comprise a stopper configured to limit translation of the self-levelling mechanism along the length of the chassis.

In some examples, the transporter may comprise a pair of stoppers configured to limit translation of the self-levelling mechanism to a distance of +/- 180mm from a neutral position.

In some examples, the transporter may be a dolly trailer, preferably a road trailer or a rail dolly.

In some examples, the transporter may be an extendable trailer or a self-propelled modular transporter (SPMT).

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is a front view of a wind turbine;

Figure 2 is a perspective view of a transporter having a self-levelling mechanism according to an aspect of the claimed invention;

Figure 3a is a perspective view of the self-levelling mechanism of the transporter illustrated in Figure 2;

Figure 3b is a front view of the self-levelling mechanism illustrated in Figure 3a;

Figure 3c is another perspective view of the self-levelling mechanism illustrated in Figures 3a and 3b, wherein the table part is in a first vertical position;

Figures 4a is a side view of the biasing arrangement of the self-levelling mechanism illustrated in Figures 3a-c, in which the table part is in a neutral position;

Figures 4b is a side view of the biasing arrangement of the self-levelling mechanism illustrated in Figures 3a-c, in which the table part is in a tilted position;

Figure 5a is a front view of the base of the self-levelling mechanism illustrated in Figures 3a-c, in which the table part is in a neutral position;

Figure 5b is a front view of the base of the self-levelling mechanism illustrated in Figures 3a-c, in which the table part is in a banked position;

Figure 6a is a perspective view of a self-levelling mechanism according to the present disclosure and a mounting which permits translation of the self-levelling mechanism along an upper surface of the transporter;

Figure 6b is an exploded view of the self-levelling mechanism and mounting illustrated in Figure 6a.

Figure 7a is a perspective view of a transporter having a self-levelling mechanism according to an alternative example of the claimed invention, wherein the self-levelling mechanism is rotatably mounted to the transporter; Figure 7b is a perspective view of a transporter according to another example of the claimed invention; Figure 7c is a perspective view of a transporter according to yet another example of the claimed invention; and

Figure 7d is a perspective view of a transporter according to a further example of the claimed invention.

DETAILED DESCRIPTION OF EMBODIMENT(S)

Figure 1 shows a wind turbine 1 including a nacelle 2 supported on a tower 3 that is mounted on a foundation 4. The wind turbine 1 depicted here is an onshore wind turbine such that the foundation 4 is embedded in the ground, but the wind turbine 1 could be an offshore installation in which case the foundation 4 would be provided by a suitable marine platform, such as a monopile or jacket.

The nacelle 2 supports a rotor 5 comprising a hub 6 to which three blades 7 are attached. The blades 7 which make up the rotor 5 of the wind turbine 1 each comprise a tip end, which is located distal from the hub 6, and a root end, which is located proximal to the hub 6. It will be noted that the wind turbine 1 is the common type of horizontal axis wind turbine (HAWT) such that the rotor 5 is mounted at the nacelle 2 to rotate about a substantially horizontal axis defined at the centre at the hub 6. As is known, the blades 7 are acted on by the wind which causes the rotor 5 to rotate about its axis thereby operating generating equipment through a gearbox (not shown) that is housed in the nacelle 2. The generating equipment is not shown in Figure 1 since it is not central to the examples of the invention.

Wind turbine blades, such as those which are displayed in Figure 1 , are typically manufactured from carbon or glass fibre reinforced composite materials and hence can be prone to damage due to bending or torsional forces, particularly when such forces are applied in a direction which is perpendicular to the orientation of the fibre reinforcements within the blade. One of the most common scenarios in which bending ortorsional forces may be applied to a wind turbine blade is during transportation. For example, when cornering or travelling over hilly terrain, there can be a significant difference between the horizontal or vertical position of the root end of the turbine blade relative to the tip end of the turbine blade which can potentially lead to bending stresses being applied to the blade. Similarly, when travelling over banked terrain, there can be a significant difference between the orientation of the root end of the turbine blade relative to the tip end of the turbine blade, which can potentially lead to torsional (or twisting) forces being applied to the blade.

The present disclosure relates to a transporter for supporting the tip end of a wind turbine blade having a self-levelling mechanism configured to allow for rotation of the turbine blade during transportation.

In some examples, the transporter may be provided in the form of a dolly trailer (or road dolly) for use with a road vehicle. In other examples, the transporter may be rail trailer (or rail dolly), forklift dolly or a low-profile dolly. Furthermore, in some examples, the transporter may be an extendable trailer or a self- propelled modular transporter (SPMT). It shall also be appreciated that in some examples, the transporter may be a vehicle, such as a road vehicle (e.g., a flatbed truck) or a rail vehicle (e.g., a locomotive or other form of rolling stock).

In the example illustrated in Figure 2, the transporter 10 is provided in the form of an extendable trailer, although it shall be appreciated that a similar arrangement may be used in examples wherein the trailer is an SPMT.

The transporter 10 may include a chassis 12 which may be supported on a plurality of wheels 14, disposed on either side of the chassis 12 along the chassis’ length. The chassis 12 may define an upper surface 16 to which a self-levelling mechanism 100 is mounted.

The term “self-levelling mechanism” is defined herein as a mechanism coupled to a surface which can return the surface to a stable state at a neutral position without the assistance of a force external to the self-levelling mechanism from an external driving means.

Advantageously, the provision of a self-levelling mechanism allows for rotation of the turbine blade which helps to better account for rotational forces which may act on a turbine blade during transportation. Furthermore, since the mechanism is self-levelling, the mechanism does not require active adjustment to return the turbine blade to a neutral position after it has been rotated.

Figures 3a to 3c show an example of a self-levelling mechanism 100 for use with a transporter such as the transporter 10 illustrated in Figure 2.

The self-levelling mechanism 100 comprises a table part which is designed to support a tip end of a wind turbine blade during transportation. In some examples, the table part may be a fully solid structure. In other examples, the table part may be formed from a mesh or framework to reduce the overall weight of the self-levelling mechanism. It shall also be appreciated that the table part may be square, rectangular, or circular in shape, or may comprise a different shape in some examples.

In the example illustrated in Figure 3a, the table part 110 is provided via a series of members which are arranged to form a substantially rectangular framework. In particular, the table part 110 comprises a pair of substantially parallel lengthwise members 110a,b which define a length of the table part 1 10, and a pair of substantially parallel widthwise members 110c,d which extend perpendicularly between lengthwise members 110a and 110b. A series of crossbeam members 110e may also be provided which extend between the two widthwise members 110c and 110d, in a direction which is substantially parallel to that of the lengthwise members 110a, 110b.

As shown in Figure 3a, the upper surfaces of the respective members 110a-e which make up the table part 110 are substantially flat and coplanar and thereby define a substantially flat upper surface of the table part 110 onto which the tip end of a turbine blade can be received and supported. The table part is mounted to a supporting part. The supporting part may be provided as a single unitary structure or may comprise a plurality of parts which together form the supporting part.

In the example illustrated in Figure 3, the supporting part 120 is provided in two parts and comprises a base portion 130 and a cradle 140. However, it shall be appreciated that in other examples, different constructions may be provided.

The supporting part is configured to allow the table part to rotate about at least one horizontal axis. In the illustrated examples, the table part is supported in a manner which allows for rotation of the table part about a first and a second horizontal axis (as shall be described in greater detail below). However, in other examples, it shall be appreciated that rotation of the table part may only be permitted about the first horizontal axis or may only be permitted about the second horizontal axis.

In the illustrated examples, the first horizontal axis is defined as the axis (X) which extends transversely across a width of the transporter and the second horizontal axis is defined as the axis (Z) which extends longitudinally along a length of the transporter. However, in other examples, it shall be appreciated that the first horizontal axis may be the axis (Z) which extends longitudinally along a length of the transporter and the second horizontal axis may be the axis (X) which extends transversely across a width of the transporter.

The table part may be supported by the supporting part in a manner which allows for clockwise rotation only, counter-clockwise rotation only or rotation in both a clockwise and counter-clockwise direction about the first and/or second horizontal axis.

Advantageously, by allowing the table part to rotate in both a clockwise and counter-clockwise direction, the self-levelling mechanism can help to reduce bending stresses from being applied to the blade when the root end of the turbine blade descends relative to the tip end, for example when travelling over a declined roadway, as well as when the root end of the turbine blade ascends relative to the tip end, for example when travelling over an inclined roadway.

In the example illustrated in Figures 3a to c, the supporting part 120 comprises a pair of support posts 122a, 122b which are mounted an upper surface of the base portion 130.

Support pins 124a and 124b are provided at the distal end of each support post 122a, 122b which are configured to engage with corresponding holes located approximately at the mid-point of the crossbeam members 110e of the table part 1 10. This enables the table part 110 to rotate in both a clockwise and counter-clockwise direction about the first (X) horizontal axis.

As such, when the tip end of the turbine blade is supported on the self-levelling mechanism 100 illustrated in Figures 3a to 3c, the external force generated due to the rotation of the turbine blade about the first horizontal (X) axis will act on a rear portion of the table part 110 (i.e., a portion of the table part 110 located aft of its axis of rotation) thereby causing the table part 110 to tilt upwardly in accordance with the change of orientation of the turbine blade. This rotation of the table part 110 helps to prevent substantial bending stresses from being applied to the blade as would be the case if rotational movement of the tip end of the blade was constrained.

Advantageously, by allowing for rotation about the first horizontal (X) axis, the self-levelling mechanism can allow the table part to tilt, thereby helping to prevent bending forces from being applied to the wind turbine blade as the transporter travels over hilly terrain.

For example, turbine blades for modern wind turbines are typically between 50 and 100 meters in length. As such, when the front end of the transporter (which typically supports the root end of the turbine blade) approaches an inclined road and begins to ascend, the back end of the transporter (which typically supports the tip end) may still be on flat terrain. Therefore, as the root end of the blade continues to ascend relative to the tip end, an equal and opposite force (i.e., an external force) will be applied onto the transporter via the tip end of the blade.

The external force may be the weight of the turbine blade as its centre of gravity shifts fore, aft and side to side during transportation, thereby causing said weight to apply a moment to the table part. However, it shall be appreciated that said external force could also be generated via other factors acting on the turbine blade and so is not solely limited to the force applied to the table part by the weight of the turbine blade as its centre of gravity of the turbine blade shifts.

The table part may be adjustably mounted to the supporting part in a manner which permits vertical translation of the table part relative to the supporting part (i.e., the table part 110 can translate along the vertical (Y) axis). Advantageously, this feature enables the height of the self-levelling mechanism to be adjusted which can be useful when travelling along roadways with limited vertical clearance.

The table part may be vertically movable between a first vertical position, wherein rotation of the table part about the first horizontal (X) axis is permitted, and a second vertical position, wherein rotation of the table part about the first horizontal (X) axis is not permitted. This feature allows the self-levelling mechanism to be used in various applications, including those where rotation of the turbine blade during transportation is not desired.

The self-levelling mechanism may also comprise a locking mechanism configured to secure the table part in the first vertical position to prevent vertical movement of the table part during transportation. It shall be appreciated that many forms of suitable locking mechanism may be used in accordance with examples of the claimed invention. In the example illustrated in Figures 3a to 3c, the support pins 124a, 124b which rotatably support the table part 1 10 are removably mounted to the respective support posts 122a, 122b.

The supports posts 122a, 122b may also include a first slot (not shown) located at a first height and a second slot 126 located at a second height along a length of each support post 122a, 122b, said slots being configured to receive the support pins 124a, 124b.

As the table part 110 is moved in a vertical direction along the vertical (Y) axis, the slots provided in the crossbeam members 110e of the table part 110 will align with the respective slots provided in the support posts 122a, 122b when the table part 110 reaches the first and second heights. Once the slots are aligned, the support pins 124a, 124b can be inserted to secure the table part 1 10 at the first or second height respectively.

As such, in some examples, the support pins 124a, 124b may act as the locking mechanism. In other words, when the support pins 124a, 124b are engaged in the slots, vertical translation of the table part 110 is substantially prevented and when the support pins 124a, 124b are not engaged in the slots, vertical translation the table part 110 may be permitted.

The height of the first slot may be arranged such that when the table part 110 is in the first vertical position (i.e., when the support pins 124a, 124b are engaged in the first slots) sufficient clearance is provided between the table part 110 and base portion 130 to permit rotation of the table part 110 about the first horizontal (X) axis. Meanwhile, the height of the second slot may arranged such that when the table part 110 is in the second position (i.e., when the support pins 124a, 124b are engaged in the second slots), the table part 110 is provided in close contact with the base portion 130 and hence rotation of the table part 110 about the first horizontal (X) axis is not permitted.

In the example illustrated in Figures 3a to c, the first and second slots are spaced apart by a distance of 120mm and hence translation of the table part 110 along the vertical (Y) axis is limited to a distance of +/- 120mm. However, it shall be appreciated that in other examples, the amount of vertical translation which is permitted by the self-levelling mechanism may vary.

It shall be also appreciated this in other embodiments, the table part may be adjustably mounted via a scissor jack arrangement, a vertically oriented hydraulic cylinder or by any other suitable means. Furthermore, it shall be appreciated that in examples wherein the table part is adjustably mounted via a hydraulic cylinder or the like, the locking mechanism may be omitted.

The table part may be slidably mounted to the supporting part such that the table part is permitted to translate along the first or second horizontal axis. This feature enables the centre of gravity of the table part to be better aligned with the centre of gravity of the blade during loading. In some examples, the table part may be slidably mounted to the supporting part such that translation of the table part along the first horizontal (X) axis is permitted. In other examples, the table part may be slidably mounted to the supporting part such that translation of the table part along the second horizontal (Z) axis is permitted. It shall also be appreciated that in some examples, the table part may be fixed relative to the supporting part such that no relative translation between these components is permitted or, in other examples, the table part may be slidably mounted to the supporting part such that translation of the table part along both the first (Z) and second (X) horizontal axes is permitted.

Referring to Figure 3b, in the illustrated example the support post 122a, 122b are coupled to the base portion 130 via a sliding mechanism which permits translation of the support posts 122a, 122b (and hence the table part 110 supported thereon) along the first horizontal (X) axis relative to the base portion 130.

In the example illustrated in Figure 3b, the support posts 122a, 122b are supported on a series of rollers 126a, 126b which are received within corresponding guideways 131 provided in the base portion 130, said guideway being oriented in a direction substantially parallel to the first horizontal (X) axis. However, it shall be appreciated that in other examples other sliding mechanisms may be used.

An associated locking mechanism may also be provided which can be moved between an unlocked state, in which translation of the table part along the first horizontal (X) axis is permitted, and a locked state in which translation of the table part 110 along the first horizontal (X) axis is substantially prevented, so that once the table part 110 has been aligned with the centre of gravity of the blade it can be locked in position ready for transportation.

In the example illustrated in Figure 3b, the locking mechanism is provided as a pair of locking pins 132a, 132b arranged so as to extend across the guideways 131 such that, once inserted, movement of the support posts 122a, 122b along said guideways 131 is substantially prevented. However, it shall be appreciated that in other examples, other suitable locking mechanisms may be used.

A stopper may also be provided such that when the table part 1 10 reaches a position of maximum translation along the first horizontal (X) axis, further translation of the table part 110 in this direction is prevented. In some examples, translation of the table part 110 may be limited to a distance of +/- 200mm from a neutral position. However, it shall be appreciated that in other examples, the amount of translation which is permitted may vary.

In the example illustrated in Figure 3b, the respective guideways 131 are provided as a recessed portion within an upper surface of the base portion 130 and hence a wall portion (or stopper 133a, 133b) is provided at the ends of the guideway 131 so as to prevent translation of the support posts 122a, 122b (and hence the table part 1 10) past a distance of +/- 200mm from a neutral position. However, it shall be appreciated that in other examples, other suitable stopper types may be used. The self-levelling mechanism also comprises a biasing arrangement configured to return the table part 110 to a neutral position about the first horizontal axis when an external force (which causes the table part to rotate) is removed. The biasing arrangement also provides a secondary function of cushioning the table part as it lowered from the first vertical position to the second vertical position.

As set out above, the first horizontal axis may be the axis (X) which extends transversely across a width of the transporter or in other examples may be the axis (Z) which extends longitudinally along a length of the transporter.

The table part may be mounted to the supporting part such that the neutral position of the table part corresponds to a position wherein the upper surface of the table part is substantially parallel to the first horizontal (X) axis. In other words, when the table part is in a neutral position, the upper surface of the table part may be substantially parallel to an upper surface of the transporter. However, it shall be appreciated that in other examples, the neutral position of the table part may instead be provided at other orientations.

The biasing arrangement may be provided in the form of a coil spring, a spring and damper arrangement, a leaf spring, a resiliently deformable component and/or any other suitable means.

Figures 4a and 4b shows one suitable biasing arrangement which may be used with the self-levelling mechanism 100 illustrated in Figures 3a to c. In the example shown in Figures 4a and 4b, the biasing arrangement is provided as a spring and damper arrangement 150 provided between the table part 110 and the base portion 130 on either side of the axis of rotation of the table part 1 10.

The spring and damper arrangement 150 comprises a spring and corresponding damper having a mount at either end. The first mount is provided between an underside of the table part 110 and a first end of the damper and is configured to permit relative rotation between the first end of the damper and table part 1 10. The second mount is provided between the base portion 130 and a second end of the damper and is also configured to permit relative rotation between the second end of the damper and the base portion 130.

In the example illustrated in Figures 3 and 4, the self-levelling mechanism 100 comprises four spring and damper arrangements, two on either side of the axis of rotation of the table part 110. In the illustrated example, each spring has a spring load of 50kg which provides a biasing arrangement with an overall spring load of 200kg. However, it shall be appreciated that in other examples, a different number of springs I dampers may be used and springs with different spring loads may be utilised. For example, in some examples, the self-levelling mechanism may comprise two springs with each spring having a spring load of 100kg. The overall spring load of the system may also vary depending on the application. As can be seen in Figure 4a, when the table part 110 is in a neutral position, the dampers are elongate and hence the springs are not placed under significant amounts of compression. However, as shown in Figure 4b, as the table part 110 rotates about the first horizontal (X) axis, on one side of the axis of rotation the dampers will become fully elongated whereas on the other side of the axis of rotation the piston of each damper will be pushed into their corresponding cylinder, thereby causing the damper to shorten and hence putting the associated springs into compression. As such, once the force causing the table part 110 to rotate is removed or once the force applied to the table part 110 drops below the spring load of the compressed springs, the spring load stored in each of the compressed springs will act on the damper piston causing it to re-lengthen which will in turn act to return the table part 1 10 to the neutral position.

The self-levelling mechanism may be configured to limit rotation of the table part about the first horizontal axis such that the angle of rotation does not exceed +/- 10 degrees. The degree of rotation is limited to +/- 10 degrees to help prevent causing damage to the blade, since blade damage can occur when the blade is rotated by more than 10 degrees.

The self-levelling arrangement may be configured to limit rotation of the table part about the first horizontal axis via the configuration and/or orientation of the supporting part and biasing arrangement, via selecting a suitable rotatable mounting which only permits the desired degree of rotation and/or via providing a suitable stopper arrangement.

In the example illustrated in Figure 4, the rotation of the table part 110 is limited via orienting the spring and damper arrangement 150 at an angle of approximately 10 degrees to the horizontal. As can be seen in Figure 4b, due to the orientation of the spring and damper arrangement 150, when the table part 110 has been rotated by approximately 10 degrees, the spring and damper arrangement 150 on one side of the axis of rotation of the table part 1 10 will be orientated substantially parallel to the base portion 130. As such, any further rotation of the table part 110 is restricted since further rotation would cause the spring and damper arrangement 150 to contact the base portion 130.

The base portion 130 may also be provided with a pair of stoppers 134a, 134b (shown in Figures 5a and 5b) arranged to contact an underside of the table part 110 when it has been rotated by approximately 10 degrees thereby further preventing any rotation of the table part 1 10 beyond an angle of rotation of +/- 10 degrees. However, it shall be appreciated that in other example, different means for limiting rotation of the table part about the first horizontal axis may be used.

In some examples, the self-levelling mechanism may also be configured to allow rotation of the table part about a second horizontal (Z) axis. Advantageously, by allowing for rotation about the second horizontal (Z) axis, the self-levelling mechanism can allow the table part to roll, thereby helping to prevent torsional forces from being applied to the wind turbine blade as the transporter travels over hilly terrain. For example, when the front end of the transporter (which typically supports the root end of the turbine blade) travels along a banked roadway, the orientation of the transporter (and hence the orientation of the root end of the turbine blade) will also be rotated in accordance with the inclination of the bank along which the transporter is travelling. Meanwhile, the rear end of the transporter (which typically supports the tip end of the turbine blade), which may be yet to reach the inclined bank, may still be in a substantially neutral orientation. As such, in such circumstances where there is a difference in orientation between the root end and tip end of the turbine blade, a torsional (or twisting) force may be applied to the blade. When the turbine blade is supported on a self-levelling mechanism which permits rotation about a horizontal axis, the torsional (or twisting) force acting on the blade will be transferred onto the table part thereby causing it to rotate. In doing so, the self-levelling mechanism enables the tip end of the turbine blade to rotate to match the orientation of the root end of the blade which in turn helps to prevent torsional stresses from being applied to the blade during transportation along banked roadways.

As set out previously, the second horizontal axis may be the axis extending longitudinally along the transporter chassis or in some examples (in which the first horizontal axis extends longitudinally along the transporter chassis) the second horizontal axis may extend transversely across a width of the chassis.

The second horizontal axis may be oriented perpendicular to the first horizontal axis. However, it shall be appreciated that in some examples, the angle formed between the first and second horizontal axes may be more than 90 degrees or less than 90 degrees.

In the example illustrated in Figures 5a and 5b, rotation of the table part 110 about the second horizontal (Z) axis is permitted via supporting the table part 1 10 on a weighted base portion 130 having a substantially arcuate (or bow-like) shape. However, whilst the illustrated example comprises an arcuate base to allow the table part to rotate about the second horizontal axis and return to a neutral position, in other examples other suitable mechanisms (for example a second spring and damper arrangement) may be used.

In the illustrated example, the base portion 130 comprises a pair of elongate sleds 135a, 135b (shown in Figure 3a) which extend in a direction parallel to the first horizontal (X) axis, transversely across the width of the transporter chassis 12. The elongate sleds 135a, 135b are made up of an arcuate portion 136 which forms a bottom surface of each sled 135, and a flat portion 137, which forms an upper surface of each sled 137.

In the illustrated example, the table part 110 is centrally supported on the upper surface of each sled 135 such that the centre of gravity of the table part 110 is coaxial with the centre of gravity of the base portion 130. As such, when an external force is applied to the table part 110 to the left or right of its centre of gravity, said force will be transferred onto the base portion 130 causing the base portion 130 (along with the table part 110 supported thereon) to rock or rotate about the second horizontal (Z) axis, thereby helping to prevent torsional forces from being applied to the turbine blade when travelling over banked terrain. Furthermore, when the external force is removed from the table part 1 10, the arcuate shape of the base portion 130 allows the base portion 130 to return the table part 110 to a neutral position.

In the illustrated example, the self-levelling mechanism is configured such that, when the table part is in the neutral position, the upper surface of the table part 110 is substantially parallel to the horizontal plane defined by an upper surface 16 of the transporter 10. However, in some examples, the neutral position may correspond to a position wherein the table part is not substantially parallel to the upper surface of the transporter.

The self-levelling mechanism may be configured to limit rotation of the table part about the second horizontal (Z) axis such that the angle of rotation does not exceed +/- 10 degrees. As mentioned previously, the degree of rotation is limited to +/- 10 degrees to help prevent causing damage to the blade, since blade damage can occur when the blade is rotated by more than 10 degrees.

The self-levelling arrangement may be configured to limit rotation of the table part about the second horizontal axis via the configuration and/or orientation of the supporting part and biasing arrangement, via selecting a suitable rotatable mounting which only permits the desired degree of rotation and/or via providing a suitable stopper arrangement.

In the example illustrated in Figures 5a and 5b, the arcuate portion 136 is provided having a large radius of curvature such that the central angle (or arc measure) formed by the arcuate portion 136 is approximately 20 degrees. As such, the maximum amount by which the base portion 130 can rotate about the second horizontal (Z) axis is 10 degrees either side of the neutral position. In some examples, the base portion 140 may also be provided with a pair of stopper portions (not shown) at either end of the arcuate portion 136 which are configured to urge against the cradle 140 when base portion 130 (and hence table part 110) is at a position of maximum rotation to prevent any further rotation beyond an angle of rotation of +/- 10 degrees. However, it shall also be appreciated that in alternative examples, other forms of stopper may instead be used or in some examples (such as those illustrated in Figures 5a and 5b), said stoppers may be omitted

In some examples, the base portion 130 of the supporting part 120 may mounted on a cradle 140.

The cradle 140 may include a first set of rollers 142. The base portion 130 may be rested on the cradle 140 such that the first set of rollers 142 contact the arcuate portion 136 of the base 130. This allows the base portion 130 to easily rock (or rotate) about the second horizontal (Z) axis. The cradle 140 may include a second set of rollers 144 configured to engage with the base portion 130 to substantially prevent translation of the supporting part 120 along the second horizontal axis. This feature helps to prevent movements which could cause the base portion 130 to move out of contact with the first set of rollers 142. The second horizontal (Y) axis may be the axis extending longitudinally along the transporter chassis or in some examples (in which the first horizontal axis extends longitudinally along the transporter chassis) the second horizontal axis may extend transversely across a width of the chassis.

In the illustrated example, the second set of rollers 144 engage with a corresponding lip 138 provided on the outer periphery of each sled 135. The engagement between the second set of rollers 144 and the lip 138 permits rotation of the supporting part 120 about the second horizontal (Z) axis but substantially prevents any translation of the supporting part 120 along the second horizontal (Z) axis However, it shall be appreciated that in other examples, other configurations or engagements between the second set of rollers 144 and the base portion 130 may be used.

The first set of rollers 142 may comprise four rollers, which are positioned to engage with the base portion 130 at either end of each sled 135. However, it shall be appreciated that in other examples, different numbers of rollers may be used.

The second set of rollers may be located proximal to the first set of rollers or may be located at different positions. The second set of rollers 144 may comprises twelve rollers, with three rollers engaging the peripheral lip 138 at either end of each sled 135. However, it shall be appreciated that in other examples, different numbers of rollers may be used.

As set out previously, the self-levelling mechanism according to aspects of the present disclosure may be used with a variety of different transporter types which may have different blade mobility requirements.

For examples, when a turbine blade is mounted to an extendable trailer or an SPMT, the traction force provided by the pulling vehicle is not applied through the blade itself. Instead, the traction force is applied through the extendable trailer or SPMT.

As such, when transporting a blade using an extendable trailer or SPMT, the blade is not typically exposed to significant bending stresses during cornering and hence it is not typically necessary to provide for rotation of the turbine blade about a vertical axis. However, when using an extendable trailer or SPMT, it is often desirable to allow for translation of the blade in a longitudinal direction along the transporter chassis to help account for compressive and tensile stresses which may be applied to the blade during acceleration or deceleration of the transporter. Therefore, in some examples, the self-levelling mechanism may be slidably mounted to the chassis to permit translation of the self-levelling mechanism along the second horizontal (Z) axis, i.e., along a longitudinal axis of the transporter. In other examples, the self-levelling mechanism may be slidably mounted to permit translation of the self-levelling mechanism along the first horizontal (X) axis, i.e., transversely across a width of the transporter or, in further examples, the self-levelling mechanism may be slidably mounted to permit translation of the self-levelling mechanism in any direction across the horizontal plane defined by the upper surface of the chassis.

The provision of a self-levelling mechanism which is slidably mounted to the chassis also allows the centre of gravity of the blade supported thereon to shift as it tilts I rolls which helps to maintain more even loading on the transporter as the turbine blade rotates. This feature can also be used to adjust the position of the table part 110 during loading to ensure that the centre of the table part is aligned with the centre of gravity of the blade tip.

In the example illustrated in Figure 2, the self-levelling mechanism 100 is slidably mounted to the upper surface 16 of the transporter chassis 12 such that the self-levelling mechanism 100 is permitted to translate longitudinally along a length of the chassis 12 (i.e., along the second horizontal (Z) axis).

Figures 6a and 6b show an example of a slidable mounting which allows for such translation.

In the example illustrated in Figures 6a and 6b, the slidable mounting is provided as a pair of guideways 18a, 18b which extend in a longitudinal direction part way along a length of the chassis 12. However, it shall be appreciated that in some examples, other forms of slidable mounting such as a set of rollers or a set of tracks may instead be used. The slidable mounting may be provided on a base 18 which is secured to the upper surface 16 of the chassis 12 (as is the case in Figures 2 and 6) or in alternative examples may be mounted directly onto the chassis 12.

The self-levelling mechanism 100 may comprise corresponding engaging elements configured to engage with the slidable mounting to allow fortranslation of the self-levelling mechanism 100 along the length of the chassis 12. In the example illustrated in Figures 6a and 6b, the engaging elements are provided in the form of a set of rollers 146 which are provided around a periphery of the cradle 140 and which are configured to engage with the guideways 18a,b so as to allow translation of the self-levelling mechanism along a length of the chassis 12. However, in other examples, the engaging elements may be provided in any other suitable form.

A pair of stoppers may also be provided to prevent further translation of the self-levelling mechanism 100 beyond a predetermined maximum displacement. In the example illustrated in Figures 6a and 6b, the pair of stoppers 17, 19 are provided at each end of the slidable mounting and are positioned to prevent translation of the self-levelling mechanism 200 beyond a distance of +/- 180mm from the neutral position. In the case of Figure 6, the neutral position is defined as a position wherein the self-levelling mechanism is positioned mid-way along the length of each guideway 18a,b. However, it shall be appreciated that in other examples, other amounts of translation may be permitted.

Whilst the mounting illustrated in Figures 6a and 6b is suitable for use with an extendable trailer or SPMT, in some examples vertical rotation of the self-levelling mechanism relative to the transporter may be desirable.

As is known in the art, “dollies” are a category of trailer wherein the trailer (or dolly) is not directly attached to a pulling vehicle (e.g., a motor vehicle or rail vehicle) and hence when using a dolly, all the traction provided by the pulling vehicle is applied to the dolly via the turbine blade. In other words, when mounted on a dolly, the blade itself essentially acts as the connector which connects the dolly to the pulling vehicle. As such, significant bending stresses can be generated in the blade during transportation, particularly when cornering.

An example of a suitable dolly trailer is illustrated in Figure 7a.

As with the transporter 10 illustrated in Figure 2, the transporter 20 of Figure 7a includes a chassis 22 which may be supported on a plurality of wheels 24, disposed on either side of the chassis 22 along the chassis’ length. The chassis 22 may also define an upper surface 26 to which the self-levelling mechanism 100 may be mounted. The self-levelling mechanism 100 shown in Figure 7a is substantially the same as that which has been described above and so, for the sake of conciseness, shall not be described in detail.

In the example illustrated in Figure 7a, to help counteract the bending forces generated during cornering, the self-levelling mechanism 100 may be rotatably mounted to the chassis 22 of the transporter 20 to allow for rotation of the self-levelling mechanism 100 about the vertical (Y) axis, which extends in a direction perpendicular to the upper surface 26 of the transporter 20. In Figure 7a, the rotatable mounting is provided in the form of rotary table 28. However, it shall be appreciated that any other suitable form of rotatable mounting may be used.

In the illustrated example, the rotatable mounting is configured to allow for 360-degree rotation of the self-levelling mechanism about the vertical (Y) axis, although it shall be appreciated that in some examples the amount of rotation permitted by the mounting may be less than 360 degrees.

Furthermore, whilst the transporter illustrated in Figure 7a is designed for use on a road, in other examples (such as those illustrated in Figures 7b, 7c and 7d) the transporter could instead be provided in the form of a forklift dolly 30 or a low-profile dolly 40, which are typically used in warehouses, or may be provided as a rail dolly 50 for use with a locomotive or other rail-based pulling vehicles. In each of these examples, the self-levelling mechanism 100 may be rotatably mounted to the transporter 30, 40, 50 via a rotational table or the like so as to permit rotation of the self-leveling mechanism about the vertical (Y) axis.

Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1 . A transporter for supporting a tip end of a wind turbine blade; said transporter having a self-levelling mechanism comprising: a table part configured to support a tip end of a wind turbine blade during use; a supporting part arranged to support the table part, wherein the supporting part is configured to allow for rotation of the table part about a first horizontal axis; and a biasing arrangement configured to return the table part to a neutral position about the first horizontal axis when an external force causing the table part to rotate about the first horizontal axis is removed.

2. The transporter according to claim 1 or 2, wherein the biasing arrangement comprises a spring and damper arrangement arranged between the table part and the supporting part.

3. The transporter according to claim 3, wherein the spring and damper arrangement is oriented at an angle of approximately 10 degrees to the horizontal, and optionally wherein the spring and damper arrangement is connected to an underside of the table part.

4. The transporter according to any preceding claim, wherein the self-levelling mechanism is configured to limit rotation of the table part about the first horizontal axis to an angle of rotation of no more than +/- 10 degrees.

5. The transporter according to any preceding claim, wherein the supporting part is further configured to allow for rotation of the table part about a second horizontal axis.

6. The transporter according to claim 5, wherein the second horizontal axis is perpendicular to the first horizontal axis.

7. The transporter according to claim 5 or 6, wherein the supporting part comprises a weighted, arcuate base configured to return the table part to a neutral position about the second horizontal axis when an external force causing the table part to rotate about the second horizontal axis is removed.

8. The transporter according to claim 7, wherein the supporting part comprises a cradle for supporting the weighted, arcuate base, said cradle having a set of rollers configured to engage with the arcuate base so as to substantially prevent translation of the supporting part along the second horizontal axis.

9. The transporter according to claim 7 or 8, wherein the self-levelling mechanism is further configured to limit rotation of the table part about the second horizontal axis to an angle of rotation of no more than +/- 10 degrees.

10. The transporter according to any preceding claim, wherein the table part is slidably mounted to the supporting part such that the table part is permitted to translate along the first and/or second horizontal axis, and optionally wherein the self-levelling mechanism further comprises a first locking mechanism configured to lock the table part relative to the supporting part such that translation of the table part along the first and/or second horizontal axis is substantially prevented.

11 . The transporter according to any preceding claim, wherein the table part is adjustably mounted to the supporting part so as to permit vertical translation of the table part relative to the supporting part.

12. The transporter according to claim 11 , wherein the table part is vertically movable between a first vertical position, wherein rotation of the table part about the first horizontal axis is permitted, and a second vertical position, wherein rotation of the table part about the first horizontal axis is not permitted, and optionally wherein the self-levelling mechanism further comprises a second locking mechanism configured to secure the table part in the first vertical position.

13. The transporter according to any preceding claim, wherein the transporter comprises an upper surface to which the self-levelling mechanism is mounted, and wherein, when the table part is in the neutral position, an upper surface of the table part is substantially parallel to the upper surface of the transporter.

14. The transporter according to any preceding claim, wherein the transporter comprises a chassis, and wherein the chassis comprises a rotatable mount coupled between the chassis and the self-levelling mechanism to permit rotation of the self-levelling mechanism about a substantially vertical axis.

15. The transporter according to any preceding claim, wherein the transporter comprises a chassis, and wherein the self-levelling mechanism is slidably mounted to said chassis so as to permit translation of the self-levelling mechanism along the first or second horizontal axis.

16. The transporter according to any preceding claim, wherein the transporter comprises a chassis, and wherein the self-levelling mechanism is slidably mounted to said chassis so as to permit longitudinal translation of the self-levelling mechanism along a length of the chassis.

17. The transporter according to claim 16, wherein the transporter further comprises a guideway oriented along a longitudinal axis of the chassis and wherein the self-levelling mechanism further comprises a plurality of rollers configured to engage with the guideway so as to permit translation of the self-levelling mechanism along the length of the chassis.

18. The transporter according to claim 16 or 17, wherein the self-levelling mechanism further comprises a stopper configured to limit translation of the self-levelling mechanism along the length of the chassis, and optionally wherein the self-levelling mechanism comprises a pair of stoppers configured to limit translation of the self-levelling mechanism to a distance of +/- 180mm from a neutral position.

19. The transporter according to any preceding claim, wherein the transporter is a dolly trailer, preferably a road trailer or a rail dolly.

20. The transporter according to any of claims 1 to 18, wherein the transporter is an extendable trailer or a self-propelled modular transporter (SPMT).