WO2014163490A1

WO2014163490A1 - Crane with connector for erecting a structure

Info

Publication number: WO2014163490A1
Application number: PCT/NL2014/050196
Authority: WO
Inventors: Hendrik Lambertus Lagerweij; Aart VAN DE POL; André Heinz PUBANZ; Albertus Waaijenberg
Original assignee: Valley Power B.V.
Priority date: 2013-04-02
Filing date: 2014-04-01
Publication date: 2014-10-09
Also published as: NL2010554C2

Abstract

Crane for erecting a structure (2), such as a wind turbine, comprising a base (4) for support on the ground, a telescopic boom (6) extendable to a predetermined height, and a top assembly (8) comprising a guide (30) for one or more hoist cables (9) connectable to a load. The crane (1) further has at least one connector (10) connected to the telescopic boom (6), the at least one connector (10) comprising a fixing assembly (11) for rigidly connecting the crane (1) to the structure (2) in operation.

Description

Crane with connector for erecting a structure

Field of the invention

The present invention relates to a crane for erecting a structure, such as a wind turbine, more particularly to a crane for erecting a structure such as a wind turbine, comprising a base, a telescopic boom extendable to a predetermined height, and a top assembly comprising a guide for one or more hoist cables connectable to a load.

Prior art

Dutch patent L1032591 discloses a crane for building slender structures such as wind turbines or transmission towers, comprising a base unit having a plurality of telescoping sections that extend in a substantially vertical direction during operation of the crane. The base unit comprises a lateral anchoring structure for anchoring the base unit to the slender structure.

International patent application WO 2010/095283 discloses a crane comprising a plurality of telescoping sections for erecting a structure. The crane comprises a mounting assembly for rigidly connecting the crane to the structure.

German patent publication DE 102005049 606 Al discloses a portable crane on a vehicle comprising a telescopic boom suitable for erecting large structures such as wind turbines. The crane comprises a jib pivotable at a hinge point of the telescopic boom. The stability of the crane is solely provided by the vehicle.

In the art, several cranes and crane structures are known which can be applied for building wind turbines, i.e. which allow to get wind turbine parts in position for the entire build, including attachment of the wind turbine blades. Cranes exist which have a fixed structure, which is put together at the construction site. These types of cranes have the disadvantage that all parts need to be transported to the constructions site, assembled locally, and after use need to be transported to the next site. This leads to considerable costs and time needed. Also cranes exist which are transportable in nature, i.e. they are attached to a vehicle being able to transport the crane to the construction site. To make that possible, these type of cranes are usually fitted with a telescopic boom. To allow sufficient stability, all types of cranes are fitted with a base part, which is usually fitted with extending arms or outrigger jacks for proper lateral support. This of course makes the crane more complex and costly, and also the foot print needed for operating the crane is large.

Summary of the invention

Wind turbines are rapidly growing in size and weight, and installation requirements are subjected to tighter schedules and smaller budgets. The work involved for erecting a structure such as a large wind turbine becomes increasingly complex, dangerous, expensive and tends to require more time and preparatory work for each generation of wind turbines coming on the market. In case large numbers of wind turbines are to be installed in a timely manner, the total cost of erecting these wind turbines at various locations may become financially unattractive in view of e.g.

amortization time.

The present invention seeks to provide a crane having an improved stability allowing erecting tall structures such as a wind turbine, at reasonable cost and time.

According to the present invention, a crane according to the preamble defined above is provided, wherein the crane further comprises at least one connector connected to the telescopic boom, the at least one connector comprising a fixing assembly for rigidly connecting the crane to the structure in operation, wherein the base comprises a plurality of base mounts. This allows to employ the crane in a flexible manner with a minimal foot print, as it can extend using the telescopic boom, and obtain sufficient rigidity and constructional strength using the connectors attached to the structure being erected. Furthermore, the plurality of base mounts allow for e.g. a bolted connection of the base to a foundation of a wind turbine or to another suitable structure of the wind turbine.

According to a further aspect, the present invention provides a vehicle comprising a crane according to any one of the present invention embodiments, wherein the base is attached to the vehicle. The vehicle is e.g. a trailer, attachable to a truck, and allows for transporting and positioning the crane by a driver or operator with minimal effort and minimum handling steps.

Short description of drawings

The present invention will be discussed in further detail hereinafter based on a number of exemplary embodiments with reference to the drawings, wherein: Fig. 1 is a perspective view of an embodiment of a crane according to the present invention.

Fig. 2 is a view of the embodiment of the crane of Fig. 1 in transport status, allowing transportation on a vehicle.

Detailed description of exemplary embodiments

According to the present invention embodiments, improvements are provided for erecting a structure such as a large wind turbine by means of a crane. The crane of the present invention seeks to further reduce the amount of work, time and cost involved for erecting a wind turbine. One of the cost savings relates to the fact that the crane according to the present invention embodiments can be transported as a single entity using e.g. a trailer and truck or a separate vehicle. Furthermore, the crane can be installed by e.g. a driver or crane operator with minimal effort.

According to an embodiment, Fig. 1 depicts a crane 1 for erecting a structure 2 such as a wind turbine, comprising a base 4 for support on the ground, a telescopic boom 6 extendable to a predetermined height, and a top assembly 8 comprising a guide 30 for one or more hoist cables 9 connectable to a load, wherein the crane 1 further comprises at least one connector 10 connected to the telescopic boom 6, the at least one connector 10 comprising a fixing assembly 11 for rigidly connecting the crane 1 to the structure 2 in operation. In an embodiment, the telescopic boom 6 comprises a plurality of movable boom sections 6a, each comprising a connector 10 with a fixing assembly 11. This allows the crane 1 to service tall structures 1 whilst making the crane 1 collapsible for transportation to and from a site where the structure 2 is to be erected. Also, the telescopic boom 6 may be provided with the at least one connector 10, but one or more of the moveable boom sections 6a may also be provided with a connecter 10, thereby further increasing the stability of the crane 1 for erecting tall structures.

A variety of embodiments exist for connecting the at least one connector 10 to the structure 2 using the fixing assembly 11. In an embodiment, the fixing assembly 11 comprises one or more bolt mounts 11 rigidly connecting the crane 1 to the structure 2 in the loading state. This embodiment allows the at least one connector 10 to be bolted onto the structure 2 (such as a wind turbine tower), which may require that said structure 2 is provided with corresponding mount assemblies before actual construction as well (which seems very well possible during manufacturing of e.g. the tower parts 2).

In a further embodiment, the fixing assembly 11 comprises a clamp assembly 11, rigidly connecting the crane 1 to the structure 2 in the loading state. The clamp assembly allows the crane 1 to be stabilized by clamping the at least one connector 10 at or around parts or sections of the structure 2. In this way a generic and versatile connection is provided for various types of structures 2 during construction of e.g. a wind turbine. That is, the at least one connector 10 of the present invention need not be specifically adapted to one particular structure 2, such as special tower or mast geometries. Also, the structure 2 need not be specifically adapted for accommodating the at least one connector 10 of the present invention. The at least one connector 10 comprising a generic clamping assembly 11 further reduces preparatory work and the overall installation time and cost of the structure 2. Even further, the clamp assembly may be remotely operated, even further reducing time and cost needed for construction work using the present invention crane embodiments.

In an exemplary embodiment, the clamp assembly comprises a plurality of gripper fingers clamping or squeezing the structure 2 at suitable sections in the loading state. For example, the at least one connector 10 may comprise a two-finger clamping assembly that clamps a tower or mast of the structure 2 at the sides in the loading state.

In yet another embodiment, the clamping assembly comprises a belt arranged to be tightly wrapped around a section of a tower or mast of the structure 2 in the loading state. In yet another embodiment, the clamp assembly comprises one or more magnetic pads rigidly connecting the crane 1 to the structure in the loading state. In this embodiment, the magnetic pads may be locked to e.g. the encased reinforcing steel inside a concrete structure 2, or the magnetic pads may be locked to a steel lattice structure 2.

In yet a further embodiment, the at least one connector 10 is linearly moveable along the telescopic boom 6. In this embodiment, the at least one connector 10 is also provided with a suitable locking assembly in order to fix the connector 10 at a specific height onto the telescopic boom 6. This feature provides for a more flexible use of the crane 1, depending on the specific structure 2 being assembled. The at least one connector 10 is pivotable around a longitudinal axis of the telescopic boom 6 in a further embodiment. This may be useful when fixing the fixing assembly 11 to the structure 2.

From the above a skilled person will readily envisage a myriad of arrangements of the at least one connector 10 with respect to the crane 1. For example, only the main boom 6 may be provided with the at least one connector 10, or the main boom 6 as well as one or more boom sections 6a may be provided with the at least one connector 10 and so forth. The main point of the present invention is to provide further stabilization to the crane 1 by means of the at least one connector 10 connecting the crane 1 to the structure 2 to be erected.

In typical embodiments, the one or more hoist cables 9 may be provided with a load connector 20, e.g. a hook, to connect the crane 1 to a load such as tower sections, rotor blades, generator parts, a nacelle and the like via the top assembly 8 and guide 30. The base 4 comprises a winch assembly (not shown) for raising or lowering the load to a desired height by means of the hoist cables 9 that are connected to the winch assembly and the load connector 20. The winch assembly may also be positioned at a different location on the crane 1.

In the embodiment shown, the base 4 comprises a plurality of base mounts 5a for e.g. bolting the base 4 to a structure provided in the ground, such as a (concrete) foundation of a wind turbine tower, which is prepared well before the wind turbine assembly. Firm attachment of the crane 1 using the base mounts 5a can be achieved e.g. using bolt connections, or other structural features allowing to secure the crane 1 to the structure. These other structural features may include, but are not limited to, securing mechanisms, e.g. using clamping elements, fastening elements, etc.

In the embodiment shown, the base 4 also comprises a slewing assembly 5 for rotating the crane 1 around a generally vertical axis. This allows the top assembly 8 of the crane 1 to swing around in a normal manner, allowing pick up of parts in the vicinity of the crane 1. The slewing assembly may be implemented as a bearing, allowing to transfer the forces involved in operation to be transferred to the base mounts 5 a.

According to the present invention, when erecting the structure 2, such as a wind turbine, the crane 1 is advantageously stabilized by the at least one connector 10, which rigidly connects the telescopic boom 6, hence the crane 1, in the loading state. The connector 10 thus stabilizes the crane 1 by utilizing the same structure 2 to be erected, e.g. the tower or mast of a wind turbine. The crane 1 can therefore be deployed for taller structures without increasing the size of the base 4 and the width and weight of the telescopic boom 6. Furthermore, the slewing assembly 5 of the base 4 can still rotate the crane 1 since the at least one connector 10 is rotatably disposed on the telescopic boom 6, i.e. the connector 10 is rotatable around the telescopic boom 6 by means of e.g. a bearing. Therefore, the at least one connector 10 of present invention stabilizes the crane 1 without sacrificing the rotational freedom of the crane 1.

In a further aspect, the present invention relates to a vehicle 3 comprising a crane 1 according to any one of the embodiments of the crane described herein, wherein the base 4 is attached to the vehicle 3. The vehicle is e.g. a trailer 3, attachable to a truck, as shown in Fig. 2, or a dedicated truck.

The vehicle 3 is arranged for transporting and positioning the crane 1 to or from a location at which the structure 2 is to be erected. In this embodiment, a single operator could transport and position the crane 1 with minimum effort and handling steps.

The crane 1 is collapsible and suitable for transportation by road using e.g. a trailer in a further embodiment. For this, the crane 1 further comprises a tilting assembly 3a connected to the trailer and the telescopic boom for rotating the telescopic boom 6 from a first angular position to a second angular position, e.g. from a generally horizontal position the a generally vertical position. This can e.g. be executed to erect the crane 1 after attachment to a foundation using the base mounts 5a.

To allow securing the crane 1 in the upright position, the base 4 and telescopic boom 6 are pivotally connected at one or more hinge elements 7 in a further embodiment. Once positioned in the generally vertical position, the one or more hinge elements 7 are locked, e.g. using corresponding locking elements 7a on the base 4.

The crane 1 of the present invention further comprises a boom tip 32 connecting the top assembly 8 to the telescopic boom 6. The boom tip 32 is generally adapted to withstand downward forces rather than moments imposed by the load connected to the load connector 20.

In an embodiment, the crane 1 comprises one or more boom lines 16 connecting the top assembly 8 to the base 4. The boom lines 16 further minimize the moments imposed on the boom tip 32. In another embodiment, the boom lines 16 can be shortened and lengthened as the height of the boom tip 32 varies according to the deployed length of the main boom 6 and the one or more boom sections 6a.

In an embodiment of the present invention, the top assembly 8 comprises ajib 14 and a counter jib 27, such as a tower crane configuration. In an embodiment, thejib 14 comprises the guide or upper sheave 30 guiding the one or more hoist cables 9. In another embodiment, the jib 14 may comprise ajib trolley moveable parallel to saidjib 14 and guiding the one or more hoist cables 9. In this embodiment the jib 14 may be positioned substantially horizontally and the job trolley is adapted to move the load along the jib 14 to or away from the telescopic boom 6.

The counter jib 27 is connected to one or more boom lines 16 and arranged for imposing an equal but opposite moment to the boom tip 32. More specifically, in the loading state thejib 14 imposes e.g. a clockwise moment on the boom tip 32, which would in turn impose a clockwise moment on the telescopic boom 6. The counter jib 27 on the other hand provides a generally equal but opposite moment, e.g. counter clockwise, due to the one or more boom lines 16. Hence, the boom tip 32 mainly transfers downward forces (i.e. compression) to the telescopic boom 6.

In an embodiment, the top assembly 8 further comprising one or more jib lines 24, 28, one or more jib struts 26, the one or more jib lines 24, 28 being connected with the jib 14, the counter jib 27 and the one or more jib struts 26. As indicated in the previous paragraph, the top assembly 8 is prevented from subjecting moments on the telescopic boom 6 due to the boom lines 16, which impose a generally equal but opposite moment to the top assembly 8 in e.g. the loading state. Consequently, the boom point 32 and the telescopic boom 6 are mainly subjected to a downward force (i.e. compression).

In an embodiment, the base 4 comprises a counter weight 4a to further balance moments imposed on the crane 1 in the loading state. Typically, the at least one connector 10 rigidly connects the crane 1 to the structure 2, thereby stabilizing the crane 1 and thus the base 4 against moments in the loading state. In an embodiment, the counter weight 4a further stabilizes the crane 1 in the event the at least one connector 10 cannot or need not be connected to the structure 2. This could be the case when the crane 1 is erected but no structure 2 is present yet, or no heavy lifting is needed. In another embodiment, the counter weight 4a may further reduce moments imposed on the slewing assembly 5, e.g. minimizing moments on a slewing ring gear. The present invention embodiments have been described above with reference to a number of exemplary embodiments as shown in and described with reference to the drawings. Modifications and alternative implementations of some parts or elements are possible, and are included in the scope of protection as defined in the appended claims.

Claims

1. Crane for erecting a structure (2) such as a wind turbine, comprising a base (4) for support on the ground, a telescopic boom (6) extendable to a predetermined height, and a top assembly (8) comprising a guide (30) for one or more hoist cables (9) connectable to a load, wherein the crane (1) further comprises at least one connector (10) connected to the telescopic boom (6), the at least one connector (10) comprising a fixing assembly (11) for rigidly connecting the crane (1) to the structure (2) in operation, wherein the base (4) comprises a plurality of base mounts (5a).

2. Crane according to claim 1, wherein the telescopic boom (6) comprises a plurality of movable boom sections (6a), each comprising a connector (10) with a fixing assembly (11).

3. Crane according to claim 1 or 2, wherein the fixing assembly (11) comprises one or more bolt mounts.

4. Crane according to claim 1 or 2, wherein the fixing assembly (11) comprises a clamp assembly.

5. Crane according to any one of claims 1-4, wherein the at least one connector (10) is linearly moveable along the telescopic boom (6).

6. Crane according to any one of claims 1-5, wherein the at least one connector (10) is pivotable around a longitudinal axis of the telescopic boom (6).

7. Crane according to any one of claims 1-6, wherein the base (4) comprises a slewing assembly (5).

8. Crane according to any one of claims 1-7, wherein the base (4) comprises a counter weight (4a).

9. Crane according to any one of claims 1-8, wherein the base (4) and telescopic boom (6) are pivotally connected at one or more hinge elements (7).

10. Crane according to any one of claims 1-9, further comprising one or more boom lines (16) connecting the top assembly (8) to the base (4).

11. Crane according to any one of claims 1-10, wherein the top assembly (8) comprises a jib (14) and a counter jib (27).

12. Crane according to claim 11, the top assembly (8) further comprising one or more jib lines (24, 28), one or more jib struts (26), the one or more jib lines (24, 28) being connected to the jib (14), the counter jib (27) and the one or more jib struts (26).

13. Vehicle comprising a crane (1) according to any one of claims 1-12, wherein the base (4) is attached to the vehicle (3).

14. Vehicle according to claim 13, further comprising a tilting assembly (3a) connected to the vehicle (3) and the telescopic boom (6).