Claims:We Claim:

1. A rotor turning device for turning a rotor of a wind turbine comprising:
- a shaft-drive wheel (15) mountable to a generator shaft (16) or genera-tor output flange (14),
- two opposite sided motor drives (18) for driving the shaft-drive wheel (15), wherein each motor drive (18) having a drive-wheel (19) and
- wherein each drive-wheel (19) and the shaft-drive wheel (15) are con-nected via at least one endless connection mean (20).

2. The rotor turning device according to claim 1, characterized in that the shaft-drive wheel (15) is dividable into at least two parts.

3. The rotor turning device according to claim 2, characterized in that the shaft-drive wheel (15) is assembled with screws (22) in assembled condition.

4. The rotor turning device according to one of the claims 1 to 3, character-ized in that each motor drive (18) having a worm gear (23), which is con-nected with the drive-wheel (19).

5. The rotor turning device according to one of the claims 1 to 4, character-ized in that the motor drives (18) are speed controlled.

6. The rotor turning device according to one of the claims 1 to 5, character-ized in that a ratio between the drive-wheel (19) and the shaft-drive wheel (15) is in a range between 1 : 7 to 1 : 10, wherein the drive-wheel (19) is smaller than the shaft-drive wheel (15).

7. The rotor turning device according to one of the claims 1 to 6, character-ized in that the shaft-drive wheel (15) is a duplex shaft-drive wheel, where-in each drive-wheel (19) is separately connected with the duplex shaft-drive wheel via one endless connection mean (20).

8. The rotor turning device according to claim 7, characterized in that each of the drive-wheel (19) is a duplex drive-wheel, wherein two endless connec-tion means (20) are connected with the duplex drive-wheel as well as the duplex shaft-drive-wheel.

9. The rotor turning device according to one of the claims 1 to 8, character-ized in that each motor drive (18) has a power of at least 5 kW.

10. The rotor turning device according to one of the claims 1 to 9, character-ized in that the motor drives (18) configured to turn the rotor (5) with 1° to 2° per minute.

11. A rotor turning arrangement for turning a rotor of a wind turbine compris-ing:
- a rotor turning device (17) according to one of the claims 1 to 10 and
- a generator (12) having a generator housing (13) and a generator out-put flange (14) for connecting a generator shaft (16),
- wherein the two motor drives (18) of the rotor turning device (17) are connected on opposite sides to the generator housing (14) and
- wherein the shaft-drive wheel (15) is temporally mounted on the gen-erator output flange (14).

12. A wind turbine having a nacelle comprising
- a generator shaft (16),
- a generator (12) having a generator housing (13) and a generator out-put flange (14) for connecting a generator shaft (16) and
- a rotor turning arrangement (24) according to claim 11.
, Description:TITLE OF INVENTION

Rotor Turning Device

FIELD OF INVENTION

The present invention is directed to a rotor turning device and a wind turbine hav-ing such a rotor turning device.

BACKGROUND

Rotor turning devices are well known in the prior art. According to one embodi-ment, a rotor turning device comprises a turning wheel or turning disk, which is coupled to a driving mean over a force transmission mean. The driving mean com-prises a driving wheel or driving disk. This driving wheel is connected over the force transmission mean with the turning wheel. Preferably the turning wheel is arranged at a high-speed shaft of a wind turbine. The turning wheel is connected to a clutch for coupling or decoupling the turning wheel. The clutch is a slipping clutch for preventing in case of high torque an overload and a damage of the turn-ing wheel.

A disadvantage of the prior art is that because of the slipping clutch an unwanted and danger rotation of the rotor is possible. A secure fixation is not possible with the above described rotor turning device.

OBJECT OF THE INVENTION

One object of the invention is to provide a rotor turning device, which overcomes the disadvantages of the prior art.

SUMMARY OF THE INVENTION

This object is solved by the present rotor turning device, which is described in detail below.

The present rotor turning device for turning a rotor of a wind turbine comprising a shaft-drive-wheel mountable to a rotor shaft or generator output flange, two oppo-site sided motor drives for driving the shaft-drive wheel, wherein each motor drive having a drive-wheel and wherein each drive-wheel and the shaft-drive-wheel are connected via at least one endless connection mean. Due to the opposite positioning of two drives the radial forces to the generator bearing are compen-sated.

Advantageously this embodiment provides a good accessible place/space for tem-porary installation of an auxiliary drive and Torque-Capacity for use during Sin-gle-Blade-Installation.

In a preferred embodiment, the shaft-drive-wheel is dividable into at least two parts.

In a preferred embodiment, the shaft-drive-wheel is assembled with screws in as-sembled condition.

In a preferred embodiment, each motor drive having a worm gear, which is con-nected with the drive-wheel. Advantageously, the worm gears having self-locking properties.

In a preferred embodiment, the motor drives are speed controlled.

In a preferred embodiment, a ratio between drive-wheel and shaft-drive-wheel is a range between 1 : 7 to 1 : 10, wherein the drive-wheel is smaller than the shaft-drive-wheel.
In a preferred embodiment, the shaft-drive-wheel is a duplex shaft-drive-wheel, wherein each drive-wheel is separately connected with the duplex shaft-drive wheel via one endless connection mean.

In a preferred embodiment, each of the drive-wheel is a duplex drive-wheel, wherein two endless connection means are connected with the duplex drive-wheel as well as the duplex shaft-drive-wheel.

In a preferred embodiment, each motor drive has a power of at least 5 kW.

In a preferred embodiment, the motor drives configured to turn the rotor with 1° to 2° per minute.

A further aspect of the invention is directed to a rotor turning arrangement for turning a rotor of a wind turbine comprising a rotor turning device accord-ing to one embodiment described above and a generator having a generator hous-ing and a generator flange for connecting a generator shaft, wherein the two motor drives of the rotor turning device are connected on opposite sides to the generator housing and wherein the shaft drive wheel is temporally mounted on the generator flange.

A further aspect of the invention is directed to a wind turbine having a nacelle comprising a generator shaft, a generator having a generator housing and a genera-tor flange for connecting a generator shaft and a rotor turning arrangement described above.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be explained in more detail with respect to exemplary em-bodiments with reference to the enclosed drawings, wherein:

Figure 1 shows a wind turbine (prior art);

Figure 2 shows a rotor turning device and

Figure 3 a rotor turning arrangement having the rotor turning device according to Fig. 2.

The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompany-ing drawing figures.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 depicts a schematic view of a wind turbine 1 with a tower 2 and a nacelle 3. Depending on given requirements the wind turbine 1 can be used for offshore or onshore applications. The nacelle 3 is rotatable mounted on the tower 2. The nacelle 3 incorporates a number of components of a drive train chain 4 comprising a rotor shaft (not shown) for example. The nacelle 3 also incorporates a generator (see Fig. 3) connected with a plurality of electrical components (not shown). Fur-ther the nacelle 3 comprises a yaw system (not shown) for rotating the nacelle 3. Said rotor shaft is connected to a rotor 5. The rotor 5 comprises three rotor blades 6 which are mounted to a hub 7. The hub 7 is connected to the rotor shaft of the drive train chain 4. The rotor blades 6 are adjustably mounted on the hub 7. This is realized by means of pitch drives 8, said pitch drives 8 being part of a pitch system (not shown). The pitch system controls the rotor speed to given set points. By means of pitch-drives 8, the rotor blades 6 may be moved about a rotor blade 6 axes into different pitch positions, said rotor blade 6 axis extending in an axial direction of the rotor blades 6. Each rotor blade 6 is connected to the hub 7 via its pitch-drive 8. The nacelle 3 is covered by a nacelle cover 9, which has a nacelle cover interface 10. The hub 7 is covered by a spinner 11. The generator 12 having a generator housing 13 and a generator output flange 14 for mounting a shaft-drive wheel 15, which is shown in Fig. 3. The generator flange 14 is also connect-ed to a generator shaft 16. Depending on the type of the wind turbine 1 the gener-ator shaft 16 is further connected to a gearbox (not shown) or with the hub 7. In case the generator shaft 16 is connects the generator 12 with the gearbox, the gen-erator shaft 16 can be also called as high speed shaft. In case the generator shaft 16 connects the generator 12 with the hub 7, the generator shaft 16 can be also called as rotor shaft or low speed shaft.

Fig. 2 depicts a rotor turning device 17 for turning the rotor 5 of a wind turbine 1. This rotor turning device 17 comprising a shaft-drive-wheel 15 mountable to a generator shaft 16 or generator output flange 14, two opposite sided motor drives 18 for driving the shaft-drive-wheel 15, wherein each motor drive having a drive-wheel 19 and wherein each drive-wheel 19 and the shaft-drive-wheel 15 are con-nected via at least one endless connection mean like a chain 20. The shaft-drive wheel 15 consist of two parts, which are assembled together at connection points 21 via screws 22 or some else. A ratio between the drive-wheels 19 and the shaft-drive wheel 15 is in a range between 1 : 7 to 1 : 10, wherein the drive-wheels 19 are smaller than the shaft-drive-wheel 15.

Each motor drive 18 having a worm gear 23, which is connected with the drive-wheel 19. Further the motor drives 18 are speed controlled. Therefore the motor drives 18 comprising a speed controller (not shown), which could be arranged at each motor drive 18 or could be arranged centralized for controlling the motor drives 18 together. The motor drives 18, in particular the speed controller(s), are configured such a way that the rotor 5 turns with 1° to 2° per hour. Therefore each motor drive 18 has a power of at least 5 kW.

In a not shown embodiment, the shaft-drive wheel 15 is a duplex shaft-drive wheel, wherein each drive-wheel 19 is separately connected with the duplex shaft-drive wheel via one chain 20. It is also possible that each of the drive-wheel 19 is a duplex drive-wheel, wherein two chains 20 are connected with the duplex drive-wheel as well as the duplex shaft-drive-wheel.

Fig. 3 depicts a rotor turning arrangement 24 for turning a rotor 5 of a wind tur-bine 1 comprising said rotor turning device 17. Further the rotor turning arrange-ment 24 comprises a generator 12 having a generator housing 13 and a generator output flange 14 for connecting a generator shaft 16, wherein the two motor drives 18 of the rotor turning device 17 are connected on opposite sides to the generator housing 13 and wherein the shaft-drive wheel 15 is temporally mounted on the generator output flange 14. Also the motor drives 18 are connected via screws 25 to the generator housing13.

This means that all connected parts are connected via screws. So the rotor turning device 17 can be mount to the generator 12 respectively can be demounting from the generator 12. So the rotor turning device 17 doesn’t have to be mounted per-manently to the generator. Instead of this it can be mounted temporally during the use of the rotor turning device 17. After this the rotor turning device 17 can be demounted for a use in another wind turbine. Therefore all parts are designed in this way that they can be moved by service personnel alone or with help of service cranes if available at the wind turbine. However, an additional crane like a mobile crane is not necessary.

LIST OF REFERENCE SIGNS

1 wind turbine
2 tower
3 nacelle
4 drive train chain
5 rotor
6 rotor blades
7 hub
8 pitch drives
9 nacelle cover
10 nacelle cover interface
11 spinner
12 generator
13 generator housing
14 generator output flange
15 shaft-drive wheel
16 generator shaft
17 rotor turning device
18 motor drives
19 drive-wheel
20 chain
21 connection points
22 screws
23 worm gear
24 rotor turning arrangement
25 screws