Claims:CLAIMS

We claim:

1. A lifting device (20) for a wind turbine (10), said lifting device (20) being constructed to support the lifting of a load (22) to the top of a tower (12) of the wind turbine (10) and/or the lowering of the load (22) from the top of the tower (12) of the wind turbine (10), in particular to or from a hub (15) and/or a nacelle (11) being mounted on top of the tower (12) of the wind turbine (10), characterized in that the lifting device (20) comprises a crane add-on device (30), said crane add-on device (30) being constructed to get, in particular detachably, mounted to a crane device (25) being provided on top of the tower (12) of the wind turbine (10) and having a first crane winch (27), said crane-add-on device (30) comprising an attachment device (31) which is constructed to get, in particular detachably, mounted to said crane device (25), said crane add-on device (30) comprising its own crane winch (32) which is, in particular detachably, attached to a receiving device (35) of the attachment device (31), said crane winch (32) having a crane load capacity which is higher than the crane load capacity of the first crane winch (27) of the crane device (25), said crane add-on device (30) further comprising a crane rope (33), which has a capacity being adapted to the load capacity of the crane winch (32) of the crane add-on device (30).

2. The lifting device (20) according to claim 1, characterized in that the lifting device (20) comprises a crane device (25) being provided on top of the tower (12) of the wind turbine (10) and having a first crane winch (27), said crane device (25) having a crane body (26), which is constructed to get mounted on top of the tower (12) of the wind turbine (10), said first crane winch (27) having a first crane load capacity, said attachment device (31) of the crane add-on device (30) being detachably mounted to the crane body (26) of the crane device (25), said crane winch (32) of the crane add-on device (30) being a second crane winch of the lifting device (20), said second crane winch (32) having a second crane load capacity which is higher than the first crane load capacity of the first crane winch (27).

3. The lifting device (20) according to claim 1 or 2, characterized in that the crane rope (33) of the crane add-on device (30) is stored in a storage container (34).

4. The lifting device (20) according to any one of claims 1 to 3 characterized in that the attachment device (31) of the crane add-on device (30) is constructed as an attachment profile element or as an attachment frame element.

5. The lifting device (20) according to any one of claims 1 to 4, characterized in that the crane device (25) is provided as a bridge crane device, said crane device (25) having a crane body (26) and a trolley (28) being optionally movably attached to the crane body (26), said trolley (28) carrying the first crane winch (27) of the crane device (25), said attachment device (31) of the crane-add-on device (30) being mounted to the crane body (26) or to the trolley (28).

6. A lifting device (20) for a wind turbine (10), said lifting device (20) being constructed to support the lifting of a load (22) to the top of a tower (12) of the wind turbine (10) and/or the lowering of a load (22) from the top of the tower (12) of the wind turbine (10), in particular to or from a hub (15) and/or a nacelle (11) being mounted on top of the tower (12) of the wind turbine (10), in particular a lifting device (20) according to any one of claims 1 to 5, characterized in that the lifting device (20) comprises a guiding device (40), said guiding device (40) being constructed to holding a crane rope (21) of a crane device (25) being provided on top of the tower (12) of the wind turbine (10) in a pre-defined distance to the tower (12) of the wind turbine (10) and/or to guiding said crane rope (21) of said crane device (25), said guiding device (40) comprising an attachment device (43) for attaching the guiding device (40) to the tower (12), in particular to a service platform (13), of the wind turbine (10).

7. The lifting device (20) according to claim 6, characterized in that the guiding device (40) has a first side, said first side comprising the attachment device (43) for attaching the guiding device (40) to the tower (12), and that the guiding device (40) has a second side being spaced apart from said first side, said second side comprising a guiding component (45) for guiding said crane rope (21) of said crane device (25).

8. The lifting device (20) according to claim 6 or 7, characterized in that the attachment device (43) comprises at least one device for generating a pivoting motion of the guiding device (40) in relation to the tower (12) of the wind turbine (10), in particular via a horizontal axis (54) in relation to said tower (12), said attachment device (43) optionally being provided as a joint device.

9. The lifting device (20) according to claim 7 or 8, characterized in that the guiding component (45) comprises a guiding space (46) for receiving said crane rope (21) to be guided, said guiding space (46) being bordered at least partially by a guiding space boundary (47), said guiding space boundary (47) comprising a receiving opening (50) for receiving said crane rope (21) to be guided, and that the guiding component (45) optionally comprises at least one guiding roller (52) being mounted inside the guiding space (46) and/or a locking device (51) for at least temporarily locking the receiving opening (50).

10. The lifting device (20) according to any one of claims 6 to 9, characterized in that the guiding device (40) is provided as an elongated guiding profile element, or that the guiding device (40) comprises a framework having a number of framework components, said framework components being detachably and/or pivotably connected to each other, or that the guiding device (40) is provided at a davit crane (23), said davit crane (23) being mounted on the wind turbine (10), in particular on the service platform (13) thereof.

11. The lifting device (20) according to any one of claims 6 to 10, characterized in that the lifting device (20) comprises at least one actuator device (53) for actuating the guiding device (40), in particular for generating a pivoting motion of the guiding device (40) in relation to the tower (12) of the wind turbine (10).

12. The lifting device (20) according to any one of claims 1 to 11, characterized in that the lifting device (20) comprises a guiding rope (29) for guiding a load (22) to get lifted to the top of the tower (12) of the wind turbine (10) and/or to get lowered from the top of the tower (12) of the wind turbine (10).

13. A wind turbine (10), said wind turbine (10) comprising a tower (12), a nacelle (11) being mounted on top of the tower (12), said nacelle (11) incorporating a drive train (60) of the wind turbine (10), and a rotor (14) being mounted to the nacelle (11) via a hub (15), said rotor (14) comprising a number of rotor blades (16), characterized in that the wind turbine (10) further comprises a lifting device (20), said lifting device (20) being constructed to support the lifting of a load (22) to the top of the tower (12) and/or to support the lowering of a load (22) from the top of the tower (12), in particular to or from the hub (15) and/or the nacelle (11), said lifting device (20) being provided according to any one of claims 1 to 12.

14. A method of lifting a load (22) to the top of a tower (12) of a wind turbine (10) and/or of lowering a load from the top of the tower (12) of the wind turbine (10), in particular to or from a hub (15) and/or a nacelle (11) being mounted on top of the tower (12) of the wind turbine (10), wherein a crane device (25) is provided on top of the tower (12) of the wind turbine, said crane device (25) having a first crane winch (27), characterized by the following steps:
a) by means of said crane device (25), lifting the components of a crane add-on device (30), which comprise an attachment device (31), a second crane winch (32), said second crane winch (32) having a crane load capacity which is higher than the crane load capacity of the first crane winch (27) of the crane device (25), and a crane rope (33), which has a capacity being adapted to the load capacity of the second crane winch (32), to the top of the tower (12) of the wind turbine (10);
b) attaching the attachment device (31) of the crane add-on device (30) to the crane device (25);
c) attaching the second crane winch (32) to the attachment device (31);
d) installing the crane rope (33) of the crane add-on device (30) at the second crane winch (32); and
e) lifting and/or lowering the load (22) by means of said second crane winch (32).

15. A method of lifting a load (22) to the top of a tower (12) of a wind turbine (10) and/or of lowering a load (22) from the top of the tower (12) of the wind turbine (10), in particular to or from a hub (15) and/or a nacelle (11) being mounted on top of the tower (12) of the wind turbine (10), wherein a crane device (25) is provided on top of the tower (12) of the wind turbine (10), said crane device (25) having a first crane winch (27), in particular the method according to claim 14, said method being characterized by the following steps:
a) aligning a guiding device (40), which is, by means of an attachment device (43), attached to the tower (12) of the wind turbine (10), in particular to a service platform (13) of the wind turbine (10), in a pre-defined guiding position, in particular in a horizontal guiding position, in relation to the tower (12); and
b) by means of said aligned guiding device (40), holding a crane rope (21) of said crane device (25) in a pre-defined distance to the tower (12) in said pre-defined guiding position during said lifting and/or lowering procedure of the load (22) and/or guiding said crane rope (21) of said crane device (25) in said pre-defined guiding position during said lifting and/or lowering procedure of the load (22).

16. The method according to claim 14 or 15, characterized in that the method is performed by means of a lifting device (20) according to anyone of claims 1 to 12, or that the method is performed in a wind turbine (10) according to claim 13.
, Description:FIELD OF THE INVENTION

The present invention relates to a lifting device for a wind turbine, said lifting device being constructed to support the lifting of a load to the top of a tower of the wind turbine and/or the lowering of a load from the top of the tower of the wind turbine, in particular to or from a hub and/or a nacelle being mounted on top of the tower of the wind turbine. Furthermore, the present invention relates to a wind turbine incorporating such a lifting device. Moreover, the present invention is directed to a method of operating such a lifting device.

BACKGROUND

Wind turbines, in particular wind turbines of horizontal type, which means that the wind turbines comprise a horizontal rotor axis and a rotor being directed towards the wind, are known in the art. Such wind turbines can be used as so-called offshore wind turbines, which means that those wind turbines are situated at sea in some distance from the shore. However, such wind turbines can be used as so-called onshore wind turbines as well, which means that those wind turbines are situated on land.

In both cases, such wind turbines generally comprise a nacelle incorporating a drive train. In general, the drive train comprises at least a generator device. The nacelle is mounted to a tower. The rotor with a number of rotor blades, particularly with three rotor blades, is connected to the drive train via a hub, to which the rotor blades are mounted. The rotor rotates around its rotational rotor axis. According to one type of wind turbines the rotor blades are adjustably mounted to the hub. This is realized by means of respective pitch drives, said pitch drives being part of a pitch system. The pitch system, which is generally known in the prior-art, participates in the control of the rotor speed to given set points. In particular, the rotor speed is controlled by the electrical load of the generator device and by the pitch angle. By means of the pitch drives, the rotor blades may be moved about rotor blade axes into different pitch positions.

In recent years, wind turbines became taller and taller. Nowadays it is common practice, that wind turbines can reach a hub height of more than 100 meters.

In order to lift loads to the top of the tower of the wind turbine, in particular to the hub and/or to the nacelle of the wind turbine, or in order to lower such loads from the top of the tower, wind turbines usually comprise a lifting device. The lifting device mostly comprises a crane device, which is mounted on top of the tower, at the hub or at the nacelle for example (however, not necessarily, e.g. winch only at nacelle). The crane device comprises a crane winch, in order to lift or lower any loads to the top or from the top, of the tower. Due to the big height of the wind turbines and due to the large weight of some of the wind turbine’s components which are to be lifted or lowered (like some components of the drive train for example, such as the high-speed-stage of the gear device), common lifting and lowering procedures of such components go along with a number of drawbacks and problems.

In common wind turbines, one will find crane devices at the top of the tower, so called bridge cranes for example, with 1 to 2 tonnes of load capacity. To lift higher loads, there are concepts like self-hoisting cranes or special devices, in order to lift and lower special parts of the wind turbine which are heavier than the load capacity of the regular crane device. For example, a high-speed-stage of a gear device weighs up to approximately 4 tons which may be beyond the load capacity of the regular crane device. Other options are mobile cranes in the case of onshore wind turbines, or floating cranes in the case of offshore wind turbines. However, such mobile cranes and floating cranes are very expensive to operate.

It is to be further noted that self-hoisting cranes and special lifting devices have high outer dimensions, especially for offshore applications. Therefore, big vessels are required to transport them to the wind turbines. Furthermore, such special devices are mostly designed to do one job only. This means they don’t have such a big versatility, as for instance a self-hoisting crane.

Due to the height of the wind turbines, other problems may arise as well, if components of the wind turbine have to get lifted to the top of the tower or have to get lowered therefrom. Lowering of a load, for example a third stage of a gear box, from an offshore wind turbine hub or a nacelle by use of a crane winch is performed by lowering the component to the service platform of the wind turbine in first step, followed by releasing the load and by parking the load on the platform. In a different, subsequent step, the load is attached to a different crane device, which is mounted on the platform. The load is lifted by the crane and gets swivelled over the handrail of the platform to a position where it then can be lowered down with the crane winch to a transport vessel.

In such a case, a crane device with a high capacity is needed on the platform, in order to swivel, lift and lower relatively heavy components such as the third stage of the gear box from the service platform to the transport vessel. Also, the intermediate parking of the load on the service platform and the manipulation of the load by the crane device requires working space on the service platform, and it takes additional amount of time, which is of high value for offshore turbine operation. Finally, when lifting or lowering the component to or from the top of the tower, the load has to travel large heights. Due to the wind acting on the component during the lifting and/or lowering procedure, there is a risk that the load collides with the tower, thus causing damages to either the load and/or the tower.

OBJECT OF THE INVENTION

Considering the aforementioned prior-art means, it is the object of the present invention to provide solutions in the field of wind turbines which avoid the aforementioned drawbacks. In particular, it is the object of the present invention to provide a lifting device by means of which components with large load can be lifted and lowered and/or by means of which the lifting and lowering procedure of such components can be performed in an easy and safe way.

According to the present invention, the object is solved by the lifting device with the features according to independent claim 1, which is the first aspect of the invention, by the lifting device with the features according to independent claim 6, which is the second aspect of the invention, by the wind turbine with the features according to independent claim 13, which is the third aspect of the present invention, by the method with the features according to independent claim 14, which is the fourth aspect of the invention, and further by the method with the features according to independent claim 15, which is the fifth aspect of the invention. Further features and details of the invention become apparent from the dependent claims, from the description as well as from the drawings. Therein, features and details which are described in connection with one aspect according to the invention also apply with respect to their disclosure in their entirety to the other aspects according to the invention, so that any statements made with respect to one aspect of the invention also apply to their full extent to the other aspects of the invention, and vice versa.

In particular, it is the underlying concept of the present invention according to its different aspects that the lifting device of the wind turbine is provided in a special way such that it is capable of avoiding those drawbacks as mentioned above with respect to the prior-art. The lifting device according to the present invention provides a cheap solution, which can get realized in a constructive simple manner, said lifting device being capable of lifting large loads. Furthermore, the lifting device according to the present invention avoids the risk that the loads may collide with the tower during the lifting/lowering procedure. Further, with the present lifting device there is no need of installing a high capacity crane device on a service platform of the wind turbine.

SUMMARY OF THE INVENTION

The present invention according to its five aspects is directed to the technical field of wind turbines, in particular to the technical field of horizontal wind turbines. Such wind turbines are generally known in the prior-art.

The present invention is preferably used in connection with offshore wind turbines. Offshore wind turbines are situated at sea in some distance from the shore. Nevertheless, the present invention is applicable with onshore wind turbines as well. Onshore wind turbines are such wind turbines, that are situated on land.

According to a preferred embodiment, the wind turbine, which can be an offshore or onshore wind turbine, comprises a nacelle which incorporates a drive train. The drive train transmits the rotor speed to the generator where it is converted into electric energy. In particular, the drive train is the mechanical energy transmitting line starting from the hub of the rotor right up to the generator. The wind turbine comprises a rotor being connected to said drive train, said rotor preferably comprising a hub and a number of rotor blade, preferably three rotor blades, said rotor blades being mounted to said hub. The rotor, which is directed towards the wind, is pivotally mounted around a rotational rotor axis to the drive train. In order to transform the rotational energy of the rotor into electric energy, the drive train, to which the rotor of the wind turbine is mounted, comprises a number of different components. One of these components is a generator device. The generator device generates electric energy. For this purpose, the generator device preferably comprises a stator component and a rotor component, said rotor component being coupled to the generator shaft. Another component of the drive train can be a gear device, which is preferably located between the hub and the generator device. The nacelle is mounted at the top of a tower of said wind turbine. At its lower base end, the tower is anchored to the ground by means of a foundation.

In particular, each rotor blade is adjustably mounted on the hub. This is realized by means of a pitch drive, said pitch drive being part of a pitch drive unit, which in turn is part of a pitch system. The pitch system, which is generally known in the prior-art, participates in the control of the rotor speed to given set points. In particular, the rotor speed is controlled by the electrical load of the generator device and by the pitch angle. By means of the pitch drives, the rotor blades may be moved about rotor blade axes into different pitch positions, said rotor blade axes extending in an axial direction of the rotor blade. A rotor blade having an adjustable pitch can be particularly understood in such a manner, that the angle of attack of the rotor blade, which may be defined as the pitch angle, can be adjusted or is provided in an adjustable manner, during a pitch-offset for example.

The present invention will now be explained in detail and with reference to the different aspects of the present invention.

According to the first aspect of the present invention, the object is solved by a lifting device comprising the features of independent claim 1.

The lifting device according to the first aspect of the invention can be implemented as a high load crane add-on device. The crane add-on device according to the first aspect comprises a number of different components, which, in particular include an attachment device, a separate crane winch and a crane rope. Therefore, in order to get a cheaper solution to lifting and/or lowering large loads, a common crane device being mounted at the top of the tower of the wind turbine, at the hub or at or in the nacelle for example, such as an on-board bridge crane, gets an additional mobile device to lift/lower larger loads. This additional device preferably consists of an additional high load attachment device, an additional high load frame for example, a high load crane winch and a crane rope with higher capacity. In the initial state, the crane add-on device is some kind of a construction kit, which is independent from the crane device. During the assembling procedure, the crane add-on device is mounted to the crane device. In its operational mode, the crane add-on device is attached, preferably detachably attached, to the crane device. Thus, during its operational mode, the crane add-on device constitutes a part of the crane device.

According to the first aspect, the invention is directed to a lifting device for a wind turbine, said lifting device being constructed to support the lifting of a load to the top of a tower of the wind turbine and/or the lowering of a load from the top of the tower of the wind turbine, in particular to or from a hub and/or a nacelle being mounted on top of the tower of the wind turbine. In the sense of the present invention, the term “supporting” is generally to be understood in the way of “giving assistance to”. According to the first aspect of the invention, the term “supporting” particularly includes that the lifting device is adapted to or capable of guiding and/or holding and/or deflecting a load to the top of the tower or lowering a load from the top of the tower.

According to the first aspect, the lifting device comprises a crane add-on device. Preferably, this crane add-on device is an extension to an existing crane device. The crane add-on device is constructed in such a way that it can be, in particular detachably, mounted to a crane device being provided on top of the tower of the wind turbine and having a first crane winch. This first crane winch has a first crane load capacity. Such a crane device can be provided as a bridge crane for example, said bridge crane being permanently or temporarily mounted at the top of the tower, inside or outside the nacelle of the wind turbine for example.

As a first component, the crane add-on device comprises an attachment device which is constructed to be, in particular detachably, mounted to said crane device, in particular to a crane body of said crane device. During an assembling procedure the different components of the crane add-on device get lifted to the top of the tower, by means of said first crane winch of said crane device for example. If the wind turbine is provided as an offshore wind turbine, the crane add-on device including its different components can get delivered by use of a transport vessel for example. The arrangement of the attachment device as well as the configuration of the attachment device can get realized in different ways. Some preferred embodiments with this regard are described in more detail further below. A detachable arrangement of the attachment device at the crane device can be realised by means of suitable attachment means, by use of attachment bolts or screws for example.

As a second component, the crane add-on device comprises its own crane winch which is, in particular detachably, attached to a receiving device of the attachment device. In its assembled state, where the crane add-on device is mounted to the crane device, the crane winch of the crane add-on device is a second crane winch, which is in addition to the first crane winch of the crane device. During the assembling procedure, the second crane winch gets attached to the crane device via the attachment device. Therefore, in the assembled state, the crane device comprises the first crane winch and the second crane winch. For example, in order to realise a detachable connection between the attachment device and the crane winch of the crane add-on device, the receiving device of the attachment device may comprise a receiving eye. The crane winch of the crane add-on device may comprise a corresponding hook. During the attachment procedure, the hook is inserted into the eye. In order to allow lifting and/or lowering of high loads, said crane winch of the crane-add-on device, the second crane winch preferably has a crane load capacity which is higher than the crane load capacity of the first crane winch of the crane device. For example, the first crane winch may have a crane load capacity of up to 2 tons, whilst the second crane winch may have a crane load capacity of up to 4 or more tons for example. The present invention is not limited to this specific example. According to a preferred embodiment, after the crane add-on device has been installed at the crane device, the use of the first crane winch for support operations for example, is still possible.

As a third component, said crane add-on device further comprises a crane rope which has a capacity adapted to the load capacity of the crane winch of the crane add-on device. By means of the crane rope, a load can be lifted/lowered. The present invention according to all of its different aspects is not limited to specific types of crane ropes. For example, the crane rope can be provided as a cable or as a chain, and the like. At its free end, the crane rope may comprise a receiving device, a receiving hook for example, by means of which the crane rope gets connected to the load to be lifted/lowered.

According to a preferred embodiment, the crane rope of the crane add-on device is stored in a storage container, a bucket for example. Such a storage container can easily get lifted to the top of the tower. When the storage container including the crane rope has been lifted to the top of the tower, by mean of said first crane winch of the crane device for example, the storage container preferably gets placed near the crane winch of the crane add-on device, in order to lead the crane rope of the crane add-on device to its crane winch, via a rope pipe for example. Once the crane rope has been lifted to the top of the tower, into the nacelle for example, the crane rope is brought in connection with the crane winch of the crane add-on device. For example, the crane rope is inserted to or engaged with the crane winch of the crane add-on device.

In comparison to those solutions being known from the prior-art, the number of working steps can get reduced with the lifting device according to the first aspect of the invention.

In its simplest configuration the lifting device according to the first aspect of the invention comprises the different components of the crane add-on device only.

According to a preferred embodiment, the lifting device further comprises a crane device, said crane device being permanently or temporarily provided on top of the tower of the wind turbine at a hub or at/in a nacelle for example. The crane device comprises a crane body which is constructed to get mounted on top of the tower of the wind turbine. In is assembled state, the crane device, in particular the crane body, is mounted to the top of the tower, at the hub, or at or in the nacelle for example. The present invention is not limited to specific configurations for the crane body. According to a preferred embodiment, the crane body is provided as a crane framework, said crane framework comprising a number of components, profile elements for example, which are assembled to each other and which provide in their assembled form the crane framework. Preferably the crane device is provided as a so-called bridge crane, said bridge crane being mounted inside the nacelle. A preferred embodiment of such a crane device is described in more detail further below. At this point, full reference is also made to the respective disclosure further below. Further, the crane device comprises a first crane winch, said first crane having a first crane load capacity, which is different, generally lesser than the crane load capacity of the crane winch of the crane add-on device, which is the second crane winch of the lifting device. The second crane winch has a second crane load capacity which is higher than the first crane load capacity of the first crane winch. In this embodiment, the attachment device of the crane add-on device is detachably mounted to the crane body of the crane device. The second crane winch is detachably attached to the attachment device.

According to a preferred embodiment, the attachment device of the crane add-on device is constructed as an attachment profile element or as an attachment frame element.

Preferably, the crane device is provided as a bridge crane device, said bridge crane device having a crane body, a crane framework for example, by means of which the crane device gets or is, temporarily or permanently, mounted on top of the tower, at the hub, or at or in the nacelle for example. According to a preferred embodiment, the bridge crane is mounted at/on the nacelle. Furthermore, the crane device comprises a trolley, which is optionally movably attached to the crane body. The trolley carries the first crane winch of the crane device. According to a first option, the attachment device of the crane-add-on device is mounted to the crane body. According to this option, the crane add-on device is mounted via its attachment device to the crane body, the crane framework for example. According to this option, a movement of the crane winch of the crane add-on device, which is the second crane winch, along the crane body is not possible. According to a different, second option, the attachment device of the crane add-on device is mounted to the trolley. According to this second option, a movement of the crane winch of the crane add-on device, which is the second crane winch, along the crane body is possible.

The lifting device according to the first aspect of the invention can decrease the overall costs of service over the life of the wind turbine, because only one crane add-on device is needed for a number of wind turbines, for all of the wind turbines of a wind farm for example. The crane add-on device is simple in design, which reduces its costs. The crane add-on device can be installed easily, which reduces the assembly time needed and which further reduces the costs. Additionally, the crane add-on device, which comprises a number of individual components, is easy to transport due to the limited number of components. Moreover, each component itself is relatively less in weight, for example less than 2 tons, such that each component of the crane add-on device can be lifted to the top of the tower or can be lowered from the top of the tower by means of the first crane winch of the crane device being mounted on top of the tower.

According to the second aspect of the present invention, the object is solved by the lifting device according to independent claim 6.

With regard to the configuration, to the performance and to the function of the lifting device according to the second aspect, full reference is also made to the general description of the invention above, and to the description of the other aspects of the invention as disclosed above and further below.

According to this second aspect, the invention is directed to a lifting device as well. The lifting device according to the second aspect of the invention can be implemented as a lifting guiding device, in particular for offshore wind turbines.

In accordance with the first aspect, the lifting device of the second aspect is constructed to support the lifting of a load to the top of a tower of the wind turbine and/or the lowering of a load from the top of the tower of the wind turbine, in particular to or from a hub and/or a nacelle being mounted on top of the tower of the wind turbine.

According to the second aspect of the invention, a different embodiment of the lifting device is provided in comparison to the lifting device according to the first aspect. However, in an alternative embodiment, the lifting device according to the second aspect of the invention represents a preferred embodiment of the lifting device of the first aspect of the invention .

The lifting device according to the second aspect comprises a guiding device. In particular, it is a general function of said guiding device to sufficiently spacing a load being lifted to the top of the tower or being lowered from the top of the tower with regard to the tower of the wind turbine in such a way that there is a sufficient distance between the tower and the load. In this context, the guiding device has the function of a spacer device. However, the guiding device according to the second aspect has additional functions as well. One function is a guiding function so as to safely guide a load along the tower in a sufficient distance. Another function is a deflection function. That means that the load gets deflected from the tower in particular from the edge of a service platform in a sufficient way, such that the load can be lowered to or lifted from the ground, to or from a vessel for example, without any problems.

The guiding device is designed to hold a crane rope or a crane cable or a crane chain of a crane device as provided on top of the tower of the wind turbine in a pre-defined distance to the tower of the wind turbine and/or to guide said crane rope of said crane device. The guiding device can be constructed in different ways. Preferred embodiments of suitable guiding devices are described in more detail further below.

The guiding device comprises an attachment device for attaching, arranging or mounting the guiding device to the tower, in particular to a service platform, of the wind turbine. By means of said attachment device the guiding device gets or is mounted to the tower, in particular to the service platform. In its assembled state, the guiding device is attached to the tower, in particular to the service platform. The present invention is not limited to specific types of attachment devices. Preferred embodiments thereof are described in more detail further below. According to a preferred embodiment, the guiding device is detachably mounted to the tower, in particular to the service platform. In such a case the guiding device can get mounted to the tower only when it is actually needed. In this case, only one guiding device can be used for different wind turbines, for all wind turbines of a wind farm for example. According to a different embodiment, the guiding device can get permanently mounted to the tower and can remain at the wind turbine for its entire life. In such a case, the guiding device can take over different operational functions as well, the function of a crane device for example.

According to a preferred embodiment, the guiding device provides a horizontal or almost horizontal guiding structure in relation to the tower in its operational mode. Therefore, in its operational mode, when the guiding device is attached to the tower, the service platform for example, the guiding device protrudes from the tower, preferably inclined at a defined angle. When the guiding device gets assembled to the tower or to the service platform, the different components of the guiding device may get lifted from the ground, from a transport vessel for example, to the service platform. Preferably, this lifting procedure can be performed by means of a davit crane, which is often permanently installed on every turbine offshore platform.

According to a preferred embodiment, the guiding device has a first side, said first side comprising the attachment device for attaching, arranging or mounting the guiding device to the tower or to the service platform. With regard to the design of the attachment device, this first side can be a first end of the attachment device. Furthermore, the guiding device has a second side being spaced apart from said first side, preferably being opposite thereto. With regard to the design of the attachment device, this second side can be a second end of the attachment device. This second side of the attachment device comprises a guiding component for guiding, said crane rope of said crane device. For example, a portion of the second side of the attachment device can be designed as the guiding component. According to a different embodiment, the guiding component can be provided as an individual component which is or gets attached to the second side of the guiding device. The present invention is not limited to specific types of guiding components. Preferred embodiments thereof are described in more detail further below.

According to a preferred embodiment, the attachment device comprises at least one device for generating a pivoting motion of the guiding device in relation to the tower of the wind turbine, in particular via a horizontal axis in relation to said tower. That means that the guiding device is pivotally mounted to the tower or to the service platform via its attachment device. Preferably, the guiding device can get swivelled around a rotational axis. According to a preferred embodiment, the attachment device comprises a joint device, or it is designed as a joint device. In particular, a joint connection is a movable connection between two components such that the components can get pivoted or swivelled around a point or axis in relation to each other. Nevertheless, one of the components, the tower or service platform for example, can have a fixed position, whilst the other component, the guiding device for example, is pivotally mounted to said component with the fixed position.

According to a preferred embodiment, the guiding device is pivotally mounted to the tower or service platform in such a way that the guiding device can take a position or alignment with respect to the tower, depending on the mounting position of the joint and the dimension of the guiding device between a position, which is perpendicular to the tower in tower direction, and a position, which is perpendicular to the tower away from the tower. According to a different embodiment, the guiding device is pivotally mounted to the tower or service platform in such a way that the guiding device can take a position or alignment with respect to the tower between a position, which is parallel to the tower wherein the second side of the guiding device is directed to the top of the tower, and a position, which is parallel to the tower wherein the second side of the guiding device is directed to the bottom of the tower, or vice versa.

According to the second aspect, instead of a high capacity crane on the service platform, a guiding device can be used, which guides the crane rope, a steel rope or chain for example, on which the load is lowered from the top of the tower, from the hub or nacelle for example, or lifted respectively, by a crane winch, by a crane winch according to the first aspect of the invention for example, in a way that a collision with the tower or service platform is avoided and the load can be lowered by the same crane winch to the ground, to a transport vessel for example.

Preferably the guiding device is supported by a guiding component, a pulley or similar horizontal guiding structure, which is mounted on the guiding device, which for its part can swivel around a horizontal axis by an attachment device, a joint for example, which is connected to the tower or to the service platform structure. The guiding device is further defined by its capability to redirect a crane rope without damaging the tower or itself.

According to yet another preferred embodiment, the guiding component comprises a guiding space for receiving said crane rope to be guided, said guiding space being bordered or surrounded at least partially by a guiding space boundary, said guiding space boundary comprising a receiving opening for receiving said crane rope to be guided. The present invention is not limited to specific types of guiding space boundaries. Preferred embodiments thereof are explained in more detail further below. During its operational mode the crane rope is received by said guiding space via said receiving opening, said receiving opening being provided for arranging the crane rope inside the guide space. The crane rope is held inside the guiding space due to the guiding space boundary bordering or surrounding the guide space. Therefore, the crane rope cannot uncontrolledly exit the guiding space. For this purpose, the guiding component preferably comprises a locking device for at least temporarily locking the receiving opening. The present invention is not limited to specific types of locking devices. For example, the locking device can be provided as a locking rod or bolt or as a lever device, which, in use, blocks the receiving opening. In order to enhance the guidance of the crane rope inside the guiding space, in particular for avoiding or reducing friction and abrasion while moving the crane rope, the guiding component preferably comprises at least one guiding roller being provided or mounted inside the guiding space. According to a preferred embodiment, the guiding component can be U-shaped, wherein the U-shaped guiding component comprises two legs which are connected to each other at one of their ends via a base. Both legs and the base define the guiding space boundary, which encompasses the guiding space. The guiding roller is preferably arranged at the base of the guiding component, or the guiding roller is provided as the base thereof. The side being opposite to the base remains open and therefore defines the receiving opening. The free ends of the legs, which are opposite to those ends being connected to the base, are preferably inclined outwardly, in order to facilitate the insertion of the crane rope via the receiving opening into the guiding space. According to a different embodiment, the guiding space boundary can be provided as a guiding wall. Preferably the guiding space boundary can have the shape of a fork, in particular a two-teethed fork.

The guiding device according to the second aspect of the invention can be designed in different ways. In the following, some preferred embodiments are described in more detail.

According to a preferred embodiment, the guiding device is provided as an elongated guiding profile element, as a rod element for example. In particular, the elongated profile element is an element having a length which is a multiple of the width of said profile element. At a first end of said elongated profile element, the attachment device is provided, by means of which the guiding device is mounted to the tower or to the service platform. At its second end, the elongated profile element comprises the guiding component for guiding the crane rope.

According to another preferred embodiment, the guiding device comprises a framework having a number of framework components, said framework components preferably being detachably and/or pivotably connected to each other. Thus, the guiding device can get easily transported without consuming to much storage space. According to a preferred embodiment, the guiding device can be U-shaped, wherein the U-shaped guiding device comprise two legs which are connected to each other at one of their ends via a base. The other ends of the legs comprise the attachment devices respectively, by means of which the legs of the guiding device are or get connected to the tower or to the service platform. Preferably, the base comprises the guiding component.

According to yet another preferred embodiment, the guiding device is provided at a davit crane, said davit crane being mounted on the wind turbine, in particular on a service platform thereof. In particular, a davit crane is a crane that projects over the side of the service platform for supporting, raising, and lowering any kind of equipment from/onto a transport vessel. Preferably, the davit crane is pivotally mounted around a vertical axis on the service platform. According to this embodiment, the guiding component can be provided, in particular arranged or mounted, at the free end of the crane arm; or the guiding component is formed by the free end of the crane arm. In this case, the attachment device of the guiding device corresponds to the attachment device by means of which the davit crane is mounted, in particular pivotally mounted, to the service platform.

According to another preferred embodiment, the lifting device comprises at least one actuator device for actuating the guiding device. By means of said actuator device, the guiding device, once it has been connected to the tower or to the service platform, can be moved and can change its position and/or alignment and/or orientation with regard to the tower or to the service platform. Preferably, the actuator device is configured for generating a pivoting motion of the guiding device in relation to the tower of the wind turbine or in relation to the service platform, preferably around a horizontal axis. The present invention is not limited to specific types of actuator devices. According to a preferred embodiment, the actuator device is a hydraulic actuator device, a hydraulic cylinder device for example. Other types of suitable actuator devices can be realised as pneumatic actuator devices or as electric actuator devices. According to yet another preferred embodiment, such an actuator device can be realized by means of the davit crane.

The lifting device according to the second aspect of the invention has a number of advantages. In particular, a special crane for lifting and lowering of heavy components can be replaced by said guiding device, which is a much cheaper structure. The guiding device is preferably adapted to be used to lead a guiding rope, which is preferably used to lift or to lower a load in a save manner.

Preferably, the lifting device according to the first and second aspects of the invention comprises a guiding rope for guiding a load to get lifted to the top of the tower of the wind turbine and/or to get lowered from the top of the tower of the wind turbine. Such a guiding rope is capable of holding the load under tension whilst the load gets lifted or lowered. The guiding rope is connected to the load with its first end. Furthermore, the guiding rope may be connected to the service platform and/or to the transport vessel.

According to the third aspect of the present invention the object is solved by the wind turbine according to independent claim 13.

With regard to the configuration, to the performance and to the function of the wind turbine according to the third aspect, full reference is also made to the general description of the invention above, and to the description of the other aspects of the invention as disclosed above and further below.

According to this third aspect, the invention is directed to a wind turbine, said wind turbine comprising a tower, a nacelle being mounted on top of the tower, said nacelle incorporating a drive train of the wind turbine, and a rotor being mounted to the nacelle via a hub, said rotor comprising a number of rotor blades. The wind turbine is characterized in that it further comprises a lifting device, said lifting device being constructed to support the lifting of a load to the top of the tower and/or to support the lowering of a load from the top of the tower, in particular to or from a hub and/or a nacelle, said lifting device being provided according to the first and/or second aspect of the invention as described above. Therefore, at this point, full reference is made to the disclosure of the lifting device according to the first and second aspects of the invention as described above.

According to the fourth aspect of the present invention the object is solved by the method of lifting a load to the top of a tower of a wind turbine and/or of lowering a load from the top of the tower of the wind turbine according to independent claim 14.

With regard to the procedure and to the performance of the method according to the fourth aspect, full reference is also made to the general description of the invention above, and to the description of the other aspects of the invention as disclosed above and further below.

According to this fourth aspect, the invention is directed to a method of lifting a load to the top of a tower of a wind turbine and/or of lowering a load from the top of the tower of the wind turbine, in particular to or from a hub and/or a nacelle being mounted on top of the tower of the wind turbine, wherein a crane device is provided on top of the tower of the wind turbine, said crane device having a first crane winch. In particular, this method is linked to the lifting device according to the first aspect of the Invention.

The method according to the fourth aspect of the invention is characterized by the following steps:
a) By means of said crane device, lifting the components of a crane add-on device, which comprise an attachment device, a second crane winch, said second crane winch having a crane load capacity which is higher than the crane load capacity of the first crane winch of the crane device, and a crane rope, preferably inside a storage container, which has a capacity being adapted to the load capacity of the second crane winch, to the top of the tower of the wind turbine;
b) Attaching the attachment device of the crane add-on device to the crane device;
c) Attaching the second crane winch to the attachment device;
d) Installing the crane rope of the crane add-on device at the second crane winch; and
e) Lifting and/or lowering the load by means of said second crane winch.

Further features and details of the method according to the fourth aspect become particularly apparent from the description of the lifting device according to the first aspect of the invention. Preferably, the method is performed by means of a lifting device according to the first aspect of the invention. Therefore, at this point, full reference to the description of the first aspect is made as well.

According to the fifth aspect of the present invention or as a preferred embodiment of the method according to the fourth aspect, the invention is directed to the method according to independent claim 15.

With regard to the procedure and to the performance of the method according to the fifth aspect, full reference is also made to the general description of the invention above, and to the description of the other aspects of the invention as disclosed above and further below.

According to this fifth aspect, the invention is directed to a method of lifting a load to the top of a tower of a wind turbine and/or of lowering a load from the top of the tower of the wind turbine, in particular to or from a hub and/or a nacelle being mounted on top of the tower of the wind turbine, wherein a crane device is provided on top of the tower of the wind turbine, said crane device having a first crane winch. In particular, this method is linked to the lifting device according to the second aspect of the Invention.

The method according to the fifth aspect of the invention is characterized by the following steps:
a) Aligning a guiding device, which is, by means of an attachment device, attached to the tower of the wind turbine, in particular to a service platform of the wind turbine, in a pre-defined guiding position, in particular in a horizontal guiding position, in relation to the tower; and
b) By means of said aligned guiding device, holding a crane rope of said crane device in a pre-defined distance to the tower in said pre-defined guiding position during said lifting and/or lowering procedure of the load and/or guiding said crane rope of said crane device in said pre-defined guiding position during said lifting and/or lowering procedure of the load.

Further features and details of the method according to the fifth aspect become particularly apparent from the description of the lifting device according to the second aspect of the invention. Preferably, the method is performed by means of a lifting device according to the second aspect of the invention. Therefore, at this point, full reference to the description of the second aspect is made as well.

The invention will now be explained in more detail with respect to exemplary embodiments with reference to the enclosed drawings, wherein the foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE INVENTION

Figure 1 is a schematic view of a wind turbine incorporating the principles of the present invention;
Figures 2 to 14 depict different schematic views of a lifting device for a wind turbine according to the second aspect of the present invention, said lifting device comprising a guiding device;
Figures 15 to 22 depict different schematic views of a lifting device for a wind turbine according to the first aspect of the present invention, said lifting device comprising a crane add-on device;
Figures 23 and 24 depict different schematic views of a wind turbine showing the general principles of a lifting procedure; and
Figures 25 to 35 depict different schematic views explaining the principles of the method according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 depicts an offshore wind turbine (10), which is situated at sea (17) in some distance from the shore. The wind turbine (10) is reached and supplied by a transport vessel (18). The wind turbine (10) is a wind turbine (10) of the horizontal type with a tower (12) having a service platform (13) and a nacelle (11). Nacelle (11) is rotatably mounted to the top of tower (12). At its lower base end, the tower (12) is anchored to the ground by means of a foundation. Nacelle (11) incorporates a drive train (not shown), said drive train being mounted inside the nacelle (11) and being connected to a rotor (14). Rotor (14) comprises three rotor blades (16) which are mounted to a hub (15). In Figure 1, only one rotor blade (16) is depicted. Hub (15) of the rotor (14) is connected to a drive shaft of the drive train. The rotor blades (16) are adjustably mounted on the hub (15). This is realized by means of pitch drives (not shown), said pitch drives being part of a pitch system. The pitch system controls the rotor speed to given set points. By means of the pitch drives, the rotor blades (16) may be moved about rotor blade axes such that the pitch of the rotor blades (16) can be changed. This means that the pitch-angles of the rotor blades (16) can be changed such that the orientation of the rotor blades (16) can be varied. The rotor (14) is rotatably connected to the drive train via its rotational axis. The drive train transmits the rotor speed to a generator device, where it is converted into electric energy. Furthermore, the drive train may comprise a gear device.

Figures 2 to 14 depict different views of a lifting device (20) for said wind turbine (10), said lifting device (20) comprising a guiding device (40).

As particularly evident from Figure 2, the guiding device (40) is pivotally mounted to the service platform (13) of tower (12) of said wind turbine (10). The guiding device (40) is U-shaped and has two legs (41, 42). Each leg (41, 42) comprises an attachment device (43) at one of its ends, by means of which the legs (41, 42) and therefore the entire guiding device (40) are/is pivotably mounted to the service platform (13), by means of a joint connection for example. At the other ends, the legs (41, 42) are connected with each other via a base (44), said base (44) comprising a guiding component (45), said guiding component (45) being capable of guiding a crane rope (21) for lifting and/or lowering a load (22). Due to its U-shaped configuration, the guiding device (40) encompasses a workspace (24), which is depicted in Figures 3 to 8 for example, and which is implemented for lifting the load (22) from, and lowering the load (22) to, the service platform (13). The workspace (24) is depicted in Figures 3 to 8 for example.

The guiding component (45) will be explained in detail in connection with Figure 5. The guiding component (45) comprises a guide space (46), said guide space (46) being bordered or surrounded or encompassed by a guide space boundary (47). The guiding component (45) is U-shaped, having two legs (48) and a base (49). Opposite to the base (49) a receiving opening (50) for receiving the crane rope (21) is provided. In order to keep the crane rope (21) inside the guide space (46), the receiving opening (50) can get locked by means of a locking device (51), a locking bolt or a locking lever device for example. As shown in Figure 5, the locking device (51) is preferably provided as a locking lever device. For enhancing the guiding procedure of the crane rope (21) inside the guide space (46), a guide roller (52) is provided inside the guide space (46), said guide roller (52) being connected to the base (49) or forming the base (49).

As evident from Figures 3 and 4 for example, a davit crane (23) can be mounted on service platform (13).

As depicted in Figures 6 to 8, an actuator device (53), a hydraulic cylinder for example, is connected to the guiding device (40), in order to change the orientation and the alignment of the guiding device (40) during a lifting and/or lowering procedure of a load to the top of tower (12) or from the top of tower (12).

Referring back to Figure 2, instead of a high capacity crane on the service platform (13), that was used in solutions according to the prior-art, now the guiding device (40) is used, which guides the crane rope (21), on which the load (22) is lowered from the top of tower (12), from the hub or nacelle for example, by a crane winch (not shown), in a way that a collision with the tower (12) and with the service platform (13) will be avoided and the load (22) can be lowered by the same crane winch to the transport vessel (18). The guiding will be achieved by the guiding device (40) having or providing a horizontal guiding structure, which is mounted to the service platform (13), said guiding device (40) being capable to swivel around a horizontal axis (reference number 54 in Figure 10) by means of attachment device (43) in form of a joint, which is connected to the service platform (13) structure. The guiding device (40) is defined by its capability to redirect the crane rope (21) without causing any damage.

Figures 3 and 4 depict a situation, in which the guiding device (40) is directed downwards from the service platform (13), for example, if the guiding device (40) is currently not in use, or if the guiding device (40) gets mounted to the service platform (13), by means of fastening bolts for example.

Figure 5 depicts the situation in which the guiding device (40) is brought into a horizontal position, in which the actuator device (53) which is shown in Figures 6 to 8, can be mounted or is mounted at the guiding device (40). The guiding device (40) is brought into this horizontal position by means of davit crane (23). By use of actuator device (53), which is preferably a hydraulic actuator device, a hydraulic cylinder for example, the guiding device (40) can be brought into different positions, into a vertical position for example, as evident from Figures 6 to 8. In the position according to Figure 8 the guiding device (40) is ready to interact with the load (22).

The use of the guiding device (40) will now be explained in connection with Figures 9 to 14.

As depicted in Figure 9, a first step is to lower the load (22) by a crane winch, which is mounted on top of the tower (12), in or at the nacelle or at the hub for example, using crane rope (21), down to a certain vertical distance to the service platform (13), which is smaller than the highest possible position of the guiding component (45). Since the distance from the top of tower (12) to the service platform (13) is high, for example more than 100 meters, the load (22) is preferably supported by a guiding rope from below, which will be described in connection with Figures 25 to 35 further below. If needed, this guiding rope can be guided by the guiding component (45) of the guiding device (40) as well up to a position, which is above the highest possible position of the guiding component (45). The guiding device (40), which comprises the guiding component (45), leans nearly approximately vertical on the tower (12) structure in this step.

In a second step, as depicted in Figures 10 and 11, the guiding device (40) gets swivelled by the attachment device (43) around the horizontal axis (54) until the guiding component (45), the guiding roller (52) for example, touches the crane rope (21). The guiding device (40) is moved by force applied by the actuator device (53), which is connected to the service platform (13) and to the guiding device (40). Meaningfully the crane rope (21) is locked inside the guide space (46) by means of the locking device (51), a locking lever device for example.

According to a third step which is depicted in Figure 12, the load (22) is moved on the crane rope (21) in horizontal way over the handrail (19) of the service platform (13) by swivelling the guiding device (40) and the guiding component (45) further off the tower (12) structure up to a position, from where a lowering of the load (22) by the crane winch from the top of tower (12), from the nacelle (11) or hub (15) for example, can be achieved within acceptable risk.

According to a fourth step, which is depicted in Figures 13 and 14, the load (22) is lowered down to the transport vessel (18) by the crane winch. The crane rope (21) is guided by the guiding device (40) incorporating the guiding component (45) as described above. In this situation, the guiding device (40) is aligned perpendicular to the tower (12), which means that the guiding device (40) has a horizontal orientation with regard to the tower (12) orientation.

Figures 15 to 20 disclose a lifting device (20) for the wind turbine (10) according to the first aspect of the invention, which can be implemented as a high load crane add-on device (30).

As evident from Figures 21 and 22, the crane add-on device (30) comprises a number of different components, which are carried to the wind turbine (10), which in turn comprises tower (12) and service platform (13), by means of transport vessel (18). The crane add-on device (30) comprises an attachment device (31), which is an attachment profile element, an attachment bar, for example, a separate crane winch (32) and a separate crane rope (33). The separate crane rope (33) is stored in a storage container (34), a bucket for example. Furthermore, the transport vessel (18) may deliver the load (22) to get lifted to the top of the tower (12), to the hub (15) or nacelle (11) for example, a high-speed-stage of a gear box for example.

Coming back to Figures 15 to 20, the lifting device (20) comprises a crane device (25), which is mounted on top of the tower (12), inside the nacelle for example. The crane device (25) is provided as an on-board bridge crane, said crane device (25) comprising a crane body (26) and a first crane winch (27) having a first crane winch load. The crane body (26) is provided as a crane framework having a number of framework components being assembled to each another. Furthermore, the crane device (25) comprises a trolley (28), which is optionally movably attached to the crane body (26). The trolley (28) carries the first crane winch (27) of the crane device (25).

As particularly evident from Figure 16, the crane add-on device (30) comprises the attachment device (31), which is constructed to get, in particular detachably, mounted to said crane device (25), in particular to a crane body (26) of said crane device (25). During an assembling procedure, the different components of the crane add-on device (30) get lifted to the top of the tower (12), by means of said first crane winch (27) of said crane device (25) for example. A detachably attachment of the attachment device (31) at the crane device (25) can get realised by means of suitable attachment means, by use of attachment bolts or screws for example.

Furthermore, the crane add-on device (30) comprises its own crane winch (32), which is, in particular detachably, attached to a receiving device (35) of the attachment device (31). In its assembled state, where the crane add-on device (30) is mounted to the crane device (25), the crane winch (32) of the crane add-on device (30) is a second crane winch (32) in addition to the first crane winch (27) of the crane device (25). During the assembling procedure, the crane winch (32) of the crane add-on device (30) gets attached to the crane device (25) via the attachment device (31). Therefore, in the assembled state, the crane device (25) comprises the first crane winch (27) and the second crane winch (32). For example, in order to realise a detachable connection between the attachment device (31) and the crane winch (32) of the crane add-on device (30), the receiving device (35) of the attachment device (31) may comprise a receiving eye. The crane winch (32) of the crane add-on device (30) may comprise a corresponding hook (36). During the attachment procedure, the hook (36) is inserted into the eye. In order to allow lifting and/or lowering of high loads, said crane winch (32) of the crane-add-on device (30), the second crane winch (32) or example, preferably has a crane load capacity which is higher than the crane load capacity of the first crane winch (27) of the crane- add-on device (30). For example, the first crane winch (27) may have a crane load capacity of up to 2 tons, whilst the second crane winch (32) may have a crane load capacity, which is higher than the crane load capacity of the first crane winch (27), of up to 4 tons for example. According to a preferred embodiment, after the crane add-on device (30) has been installed at the crane device (25), the use of the first crane winch (27), for support operations for example, is still possible.

As a third component, said crane add-on device (30) further comprises the additional crane rope (33), which has a capacity being adapted to the load capacity of the crane winch (32) of the crane add-on device (30).

According to a first option, which is depicted in Figures 17 and 18, the attachment device (31) of the crane-add-on device (30) is mounted to the crane body (26). According to this first option, a movement of the crane winch (27) of the crane add-on device (30), which is the second crane winch, along the crane body (26) is not possible. According to a different, second option, which is depicted in Figures 19 and 20, the attachment device (31) of the crane add-on device (30) is mounted to the trolley (28). According to this second option, a movement of the crane winch (32) of the crane add-on device (30), which is the second crane winch, along the crane body (26) is possible.

Figures 23 and 24 depict two different schematic views of the wind turbine (10) according to Figure 1, showing the general principles of a lifting or lowering procedure. In addition to Figure 1, both Figures show the guiding device (40) being mounted to service platform (13) and the crane device (25) for lifting and/or lowering heavy loads (22). Figure 23 depicts the situation, where the load (22) is completely lifted to nacelle (11). Figure 24 depicts the situation, where the load (22) is in progress of being lifted or lowered by means of crane device (25). The load (22) is lifted or lowered by means of crane rope (21). Furthermore, the load (22) is guided by means of a guiding rope (29).

A method of lowering a load (22), a high-speed-stage of a gear box for example, from the top of the tower (12), from the nacelle (11) for example, down to the transport vessel (18) will now be explained in connection with Figures 25 to 35.

Before such a heavy load (22) can get lowered from the nacelle (11) on-board of the transport vessel (18), the crane add-on device (30) gets mounted to crane device (25). Once the transport vessel (18) carrying the required components has landed at the tower (12) of the wind turbine (10), the crane add-on device (30) gets lifted to nacelle (11) by means of the first crane winch (27) of the crane device (25). Next, the crane add-on device (30) gets mounted to the crane device (25). This procedure has been explained in detail above. Furthermore, the guiding device (40) gets pivotably mounted to the service platform (13) of tower (12). This as well has been explained in detail above. Once the guiding device (40) and the crane-add-on device (30) have been installed, a heavy load (22), a high-speed-stage of the gearbox for example, can get lowered from the nacelle (11) to the transport vessel (18). The load (22) gets disassembled from the drive train inside nacelle (11) and gets lowered by means of the crane winch (32) of the crane add-on device (30).

According to Figures 25 and 26, the load (22), which is lowered by means of crane rope (21), is additionally supported by means of a guiding rope (29), in order to prevent clashing to the tower (12). By means of actuator device (53), the guiding device (40) comprising guiding component (45) is brought into a horizontal direction with regard to tower (12), thus providing enough space between load (22) and tower (12). The guiding rope (29) is guided by guiding component (45) of guiding device (40), and it is fixed on service platform (13) by means of a guiding rope support device (29a).

Once the load (22) approaches the service platform (13), the guiding device (40) is brought into an orientation, in which the guiding device (40) and in particular the guiding component (45) is oriented in the direction of the tower (12). This is shown in connection with Figures 27 to 29. The movement of guiding device (40) is performed by means of actuator device (53). In this situation, the guiding rope (29) comes free from the guiding component (45).

In a next step, as depicted in Figure 30, the guiding device (40), by means of actuator device (53), starts getting swivelled back from the orientation in the direction of the tower (12) into a horizontal direction perpendicular to the tower (12). Since the guiding component (45) of guiding device (40) is located above from the load (22), the crane rope (21) can now come in contact with guiding component (45). In the preferred embodiment, the crane rope (21) is received inside the guide space of guiding component (45). In this situation, the guiding rope (29) is disengaged from the guiding rope support device (29a). Instead the end of guiding rope (29) is transferred from the service platform (13) to transport vessel (18) and fixed on-board thereof, as evident from Figure 35.

Now, as depicted in Figures 31 to 33, the guiding device (40) is brought, by means of actuator device (53), into a horizontal guiding position with regard to the tower (12), such that the load (22) gets swivelled out over the outer edge of service platform (13). Thus, the load (22) cannot come in contact with service platform (13). This stage of the procedure is supported by the guiding rope (29).

Once the load (22) has passed service platform (13), as depicted in Figures 34 and 35, the load (22) is positioned on-board of transport vessel (18). When the lowering procedure of load (22) has been completed, the crane add-on device (30) and/or the guiding device (40) can get demounted again, if desired. The different components can be loaded on-board of transport vessel (18), and the transport vessel (18) leaves the tower (12) of wind turbine (10).

To summarize the present invention, the present invention is, among other aspects, directed to a lifting device (20) for a wind turbine (10), said lifting device (20) being constructed to support the lifting of a load (22) to the top of a tower (12) of the wind turbine (10) and/or the lowering of a load (22) from the top of the tower (12) of the wind turbine (10), in particular to or from a hub (15) and/or a nacelle (11) being mounted on top of the tower (12) of the wind turbine (10). In order to provide an inexpensive solution, which can get realized in a constructive simple manner, the lifting device (20) is capable of lifting high loads (22). According to a first aspect of the invention, this goal is achieved by means of a crane add-on device (30), which is, preferably detachably, mounted to a crane device (25). Alternatively, or in addition, the lifting device (20) according to the present invention avoids the risk that the loads (22) may collide with the tower (12) during the lifting/lowering procedure. According to a second aspect, this goal is achieved by a guiding device (40), which is mouthed to the tower (12), in particular to a service platform (13) thereof.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles described herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is to be understood that the description and drawings presented herein represent a presently preferred embodiment of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further understood that the scope of the present invention fully encompasses other embodiments that may become obvious to those skilled in the art and that the scope of the present invention is accordingly not limited.
LIST OF REFERENCE NUMERALS

10 Wind turbine
11 Nacelle
12 Tower
13 Service platform
14 Rotor
15 Hub
16 Rotor blade
17 Sea
18 Transport vessel
19 Handrail of service platform

20 Lifting device
21 Crane rope
22 Load
23 Davit crane
24 Workspace
25 Crane device (Bridge crane)
26 Crane body
27 First crane winch
28 Trolley
29 Guiding rope
29a Guiding rope support device

30 Crane add-on device
31 Attachment device
32 Crane winch (second crane winch)
33 Crane rope
34 Storage container
35 Receiving device
36 Hook

40 Guiding device
41 Leg
42 Leg
43 Attachment device
44 Base
45 Guiding component
46 Guide space
47 Guide space boundary
48 Leg
49 Base
50 Receiving opening
51 Locking device
52 Guide roller
53 Actuator device
54 Horizontal axis