Claims:
We Claim:

1. A turning arrangement for a wind turbine, the turning arrangement and a rotor shaft being mounted in or on a main frame of the wind turbine, a brake disc being mounted on the rotor shaft, or other part of the drive train, the brake disc or an engagement disc fixedly attached thereto having on the circumferential edge thereof a plurality of teeth, the turning arrangement comprising:
- a turning device movably mounted in or on the main frame, preferably on the gearbox/ gearbox housing 31, the turning device having a ratchet pawl configured to engage a tooth of the plurality of teeth, the turning device being configured to be driven in order to turn the brake disc and thereby turn the rotor shaft; and
- a positioning device attached to the turning device;
- wherein the positioning device is configured to be driven so as to move the turning device between a first position, in which the turning device is spaced apart from the plurality of teeth, and a second position, in which the ratchet pawl of the turning device is positioned to engage and/or push a tooth of the plurality of teeth.

2. A turning arrangement according to claim 1 characterized in that the positioning device includes a first actuator.

3. A turning arrangement according to claim 2 characterized in that the first actuator has at one end thereof a first piston rod configured to move along a first axis.

4. A turning arrangement according to claim 2 or 3 characterized in that the first actuator is configured to be driven so as to move the first piston rod between a third position, corresponding to the first position of the turning device, and a fourth position, corresponding to the second position of the turning device.

5. A turning arrangement according to any of claims 1 to 4 wherein the wind turbine includes a gearbox having a gearbox housing mounted within the main frame and to which the rotor shaft is coupled, and the turning arrangement is characterized in that the positioning device is fixedly mounted to the gearbox housing.

6. A turning arrangement according to claim 5, characterized in that the first actuator is mounted at another end thereof, opposite the first end, to the gearbox housing.

7. A turning arrangement according to any of the preceding claims characterized in that the turning device is an elongate device fixed in or on the main frame and configured for rotation about one end thereof.

8. A turning arrangement according to any of the preceding claims characterized in that the turning device is an elongate device defining a second axis;
wherein when the turning device is in the second position the second axis is substantially aligned in a first orientation, and
wherein the positioning device is an elongate device defining a second axis configured to be aligned in a second orientation, substantially orthogonal to the first orientation.

9. A turning arrangement according to claim 8 characterized in that the first orientation is substantially horizontal and the second orientation is substantially vertical, or vice versa.

10. A turning arrangement according to any of the preceding claims, characterized in that the turning device includes a second actuator.

11. A turning arrangement according to claim 10 characterized in that the second actuator has at one end thereof a second piston rod configured to move along a second axis, the ratchet pawl being disposed on the second piston rod.

12. A turning arrangement according to claim 11 characterized in that the second actuator is configured to be driven so as to move the second piston rod along a second axis so as to cause the ratchet pawl to engage and push a tooth of the plurality of teeth and thereby turn the brake disc.

13. A turning arrangement according to claim 11 or 12, characterized in that an axis of rotation of the turning device is substantially orthogonal to the first orientation and to the second orientation.

14. A turning arrangement according to any of claims 2 to 13 wherein the first actuator and/or the second actuator comprises a hydraulic cylinder.

15. A turning arrangement according to any of claims 5 to 13, when dependent directly upon claim 1, characterized in that the turning device has a sliding member at one end thereof, and in that the positioning device comprises a sliding block configured to be engaged, in use, by the sliding member.

16. A turning arrangement according to claim 15 characterized in that the sliding member comprises a roller or ball configured to roll, in use, along a surface of the sliding block.

17. A turning arrangement according to claim 16 characterized in that the surface of the sliding block is non-linear, whereby, in use, the sliding member is disposed at a first point on the surface when the positioning device is in the first position, and is disposed at a second point on the surface when the positioning device is in the second position.

18. A turning arrangement according to claim 16 characterized in that the surface has an S-shaped profile, in that the sliding block is disposed on an upper side of the brake disc or engagement disc and/or in that the second point is lower than the first point.

19. A turning arrangement according to any of claims 5 to 13 characterized in that the positioning device comprises a first spring defining a third axis and a second spring defining a fourth axis, the fourth axis being substantially orthogonal to the third axis.

20. A turning arrangement according to claim 19 characterized in that the first spring is fixed at one end thereof in or on the main frame, and at the other end thereof to the ratchet pawl or to the second piston rod.

21. A turning arrangement according to claim 19 or 20 characterized in that the second spring is fixed at one end thereof in or on the main frame, and at the other end thereof to a free end of the turning device.

22. A turning arrangement according to claim 19, 20 or 21 characterized in that (i) when the positioning device is in the first position, the first spring and the second spring are in equilibrium and/or non-tensioned, and (ii) when the positioning device is in the second position, the first spring is in tension and the second spring is in compression.

23. A turning arrangement according to any of claims 19 to 22 characterized in that the third axis is substantially horizontal and the fourth axis is substantially vertical.

24. A turning arrangement according to any of claims 19 to 23 characterized in that the positioning device is disposed adjacent a lower point on the brake disc or engagement disc.

25. A wind turbine comprising a turning arrangement according to any of the preceding claims.

26. A method of turning a rotor of a wind turbine, the method comprising:
- applying pressure to a rotor brake to prevent the rotor from inadvertent rotary movements
- providing a turning arrangement according to any of claims 1 to 24 mounted in or on a main frame of the wind turbine; and
- driving the positioning device so as to move the turning device with the help of a first actuator and a first piston rod from the first position, in which the turning device is spaced apart from the plurality of teeth, to the second position, in which the ratchet pawl of the turning device is positioned to engage a tooth of the plurality of teeth
- activating a second actuator so as to move a second piston rod so as to cause a ratchet pawl being disposed on the second piston rod to engage and push a tooth of the plurality of teeth and thereby turn the brake disc and the rotor shaft accordingly, whereby the pressure applied to the rotor brake holds the shaft in position during the return stroke of the piston rod but the second actuator is still able to cope with the braking torque.
, Description:TECHNICAL FIELD

The invention relates to components of a wind turbine, and more particularly to a turning arrangement for a rotor of a wind turbine, a wind turbine and a method of turning a rotor of a wind turbine.

BACKGROUND

In the deployment and maintenance of wind turbines it is necessary to be able to turn the rotor or rotor shaft mounted on the main frame, e.g. to engage components in the desired position/orientation for operation and/or to reposition the components for disengagement, e.g. for maintenance/servicing purposes.

As the components concerned (especially the rotor shaft) can be of great weight, and due to their location, careful and accurate turning of the components by an operator can be difficult.

It is known to use a tool assembly for safely rotating a heavy turbine generator rotor for alignment and maintenance purposes. The tool assembly includes a plurality of segments mounted to an outer face of a coupling affixed to an end of a shaft of the rotor, where the segments include a plurality of segment teeth extending beyond an outer edge of the coupling. A tool is positioned adjacent to the coupling and includes a support assembly, a hydraulic ram and a ratcheting pawl. The ratcheting pawl includes a drive pin positioned to engage the teeth of the segments, where extension of a piston rod from the hydraulic ram causes the coupling and shaft to rotate. Tension provided by a spring forces the ratcheting pawl against the notch segment when a piston rod of the hydraulic ram is being retracted into a cylinder, and where the spring tension can be manually adjusted during operation by moving a tension ring up and down on the cylinder.

However, a problem with known techniques is that components (e.g. ratchet pawl) is biased into contact with others (e.g. teeth), potentially causing abrasions leading to corrosion, or other damage that affects the operation or reduces operating life.

OBJECTIVE OF THE INVENTION

The present invention seeks to overcome the aforementioned problems and to provide an improved turning arrangement for a rotor of a wind turbine, a wind turbine and a method of turning a rotor of a wind turbine.

SUMMARY OF THE INVENTION

According to an aspect of the invention there is provided a wind turbine comprising a turning arrangement.

According to another aspect of the invention there is provided a turning arrangement for a wind turbine, the turning arrangement and a rotor shaft being mounted in or on a main frame of the wind turbine, a brake disc being mounted on the rotor shaft or other part of the drive train, the brake disc or an engagement disc fixedly attached thereto having on the circumferential edge thereof a plurality of teeth. The turning arrangement comprises a turning device movably mounted in or on the main frame, preferably on the gearbox/gearbox housing, the turning device having a ratchet pawl configured to engage a tooth of the plurality of teeth, the turning device being configured to be driven in order to turn the brake disc and thereby turn the rotor shaft. The turning arrangement further comprises a positioning device attached to the turning device. The positioning device is configured to be driven so as to move the turning device between a first position, in which the turning device is spaced apart from the plurality of teeth, and a second position, in which the ratchet pawl of the turning device is positioned to engage and/or push a tooth of the plurality of teeth.

Preferably, the positioning device includes a first actuator. Preferably, the first actuator has at one end thereof a first piston rod configured to move along a first axis. Preferably, the first actuator is configured to be driven so as to move the first piston rod between a third position, corresponding to the first position of the turning device, and a fourth position, corresponding to the second position of the turning device.

In one embodiment, the wind turbine includes a gearbox, a gearbox housing of the gearbox being mounted within the main frame and to which the rotor shaft is coupled; and the positioning device is configured to be fixedly mounted to the gearbox housing.

Preferably, the first actuator is mounted at another end thereof, opposite the first end, to the gearbox housing.

Preferably, the turning device is an elongate device fixed in or on the main frame and configured for rotation about one end thereof.

Preferably, the turning device is an elongate device defining a second axis; wherein when the turning device is in the second position the second axis is substantially aligned in a first orientation, and wherein the positioning device is an elongate device defining a second axis configured to be aligned in a second orientation, substantially orthogonal to the first orientation. The first orientation may be substantially horizontal and the second orientation substantially vertical, or vice versa.

In one embodiment, the turning device includes a second actuator. Preferably, the second actuator has at one end thereof a second piston rod configured to move along a second axis, the ratchet pawl being disposed on the second piston rod. Preferably, the second actuator is configured to be driven so as to move the second piston rod along a second axis so as to cause the ratchet pawl to engage and push a tooth of the plurality of teeth and thereby turn the brake disc. Preferably, an axis of rotation of the turning device is substantially orthogonal to the first orientation and to the second orientation.

In an embodiment, the first actuator and/or the second actuator comprises a hydraulic cylinder.

In an embodiment, the turning device has a sliding member at one end thereof, and in that the positioning device comprises a sliding block configured to be engaged, in use, by the sliding member. Preferably, the sliding member comprises a roller or ball configured to roll, in use, along a surface of the sliding block. Preferably, the surface of the sliding block is non-linear, whereby, in use, the sliding member is disposed at a first point on the surface when the positioning device is in the first position, and is disposed at a second point on the surface when the positioning device is in the second position.

In an embodiment, the surface has an S-shaped profile, in that the sliding block is disposed on an upper side of the brake disc or engagement disc and/or in that the second point is lower than the first point.

In another embodiment, the positioning device comprises a first spring defining a third axis and a second spring defining a fourth axis, the fourth axis being substantially orthogonal to the third axis.

Preferably, the first spring is fixed at one end thereof in or on the main frame, and at the other end thereof to the ratchet pawl or to the second piston rod.

In an embodiment, that the second spring is fixed at one end thereof in or on the main frame, and at the other end thereof to a free end of the turning device.

In an embodiment, (i) when the positioning device is in the first position, the first spring and the second spring are in equilibrium and/or non-tensioned, and (ii) when the positioning device is in the second position, the first spring is in tension and the second spring is in compression.

In an embodiment, the third axis is substantially horizontal and the fourth axis is substantially vertical.

In an embodiment, the positioning device is disposed adjacent a lower point on the brake disc or engagement disc.

According to another aspect of the invention there is provided a method of turning a rotor of a wind turbine, the method comprising: applying pressure to a rotor brake to prevent the rotor from inadvertent rotary movements; providing a turning arrangement mounted in or on a main frame of the wind turbine; and driving the positioning device so as to move the turning device with the help of a first actuator and a first piston rod from the first position, in which the turning device is spaced apart from the plurality of teeth, to the second position, in which the ratchet pawl of the turning device is positioned to engage a tooth of the plurality of teeth; activating a second actuator so as to move a second piston rod so as to cause a ratchet pawl being disposed on the second piston rod to engage and push a tooth of the plurality of teeth and thereby turn the brake disc and the rotor shaft accordingly, whereby the pressure applied to the rotor brake holds the shaft in position during the return stroke of the piston rod but the second actuator is still able to cope with the braking torque.

An advantage of the invention, at least in the embodiments, is to avoid wear of device during operation of the system. In particular, the invention beneficially avoids abrasions or other damage to the teeth, ratchet pawl, etc.

A further advantage is that, when aligning the tooth position on the brake disc, transmission ratio and the holes on the rotor locking disc, the rotor locking bolt and the respective holes may be positioned such that the bolts and holes are exactly flush at the end of the cylinder stroke.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details of the invention will become apparent from the drawings according to the description. In the drawings:

Figure 1 (PRIOR ART) is a perspective view from above of the upper part of a known form of wind turbine;
Figure 2(a) is a lateral view of a turning arrangement used in the turbine of Fig. 1 in a disengaged position, and Fig. 2(b) shows an engaged position, in an embodiment employing an actuator as a positioning device;
Figure 3(a) is a lateral view of a turning arrangement used in the turbine of Fig. 1 in a disengaged position, and Fig. 3(b) shows an engaged position, in an embodiment employing a sliding block as a positioning device; and
Figure 4(a) is a lateral view of a turning arrangement used in the turbine of Fig. 1 in a disengaged position, and Fig. 4(b) shows an engaged position, in an embodiment employing a pair of springs as a positioning device.

DETAILED DESCRIPTION

In the following, like reference numerals denote like parts, and any element, design feature or method step of any embodiment may be used in combination with an element, design feature or method step of any other embodiment unless stated otherwise herein.

Figure 1 (PRIOR ART) is a perspective view from above of the upper part of a wind turbine 2. As shown, the wind turbine 2 has a tube tower 3 known from the prior art, a nacelle 4 mounted on the tower 3 and a rotor 5 with a hub 8 and e.g. three rotor blades 6 which are each rotatably mounted about a blade axle. The hub 8 is mounted on a rotor shaft (not shown) which is rotatably mounted on a main frame (not shown) within the nacelle 4. According to this embodiment, the tube tower 3 is formed of multiple tube segments 16.

Figure 2(a) is a lateral view of a turning arrangement 20 used in the turbine of Fig. 1 in a disengaged position, and Fig. 2(b) shows an engaged position, in an embodiment employing an actuator as a positioning device.

In this embodiment, the turning arrangement 20 and a rotor shaft or high speed shaft of the gearbox 7 are mounted in or on a main frame, preferably on the gearbox/ gearbox housing 31 of the wind turbine 2 (Fig. 1), a part of which is schematically indicated by support 21. A brake disc 22 is mounted on the rotor shaft or high speed shaft of the gearbox 7. The brake disc 22 or an engagement disc fixedly attached to the brake disc 22 has on the circumferential edge thereof a plurality of teeth 23; and the brake disc 22 or engagement disc is braked or held, between consecutive movements or rotational advancements of the brake disc 22 or engagement disc, by brake caliper 19. According to the invention, the turning arrangement 20 comprises a turning device 24 movably mounted in or on the main frame (i.e. to support 21 or to the gearbox). The turning device 24 has a ratchet pawl 25 configured to engage a tooth 23-1 (Fig. 2(b) of the plurality of teeth 23 (Fig. 2(a)). For turning the rotor shaft, the turning device 24 is configured to be driven in order to turn the brake disc 22 and thereby turn the rotor shaft or high speed shaft of the gearbox 7.

The turning arrangement 20 further comprises a positioning device 26 attached to the turning device 24. The positioning device 26 is configured to be driven so as to move the turning device 24 between a first position (Fig. 2(a)), in which the turning device 24 is spaced apart from the plurality of teeth 23, and a second position (illustrated in Fig. 2(b)), in which the ratchet pawl 25 of the turning device 24 is positioned to engage a tooth 23-1 of the plurality of teeth 23.

Preferably, the positioning device 26 includes a first actuator 27. Preferably, the first actuator 27 has at one end 28 thereof a first piston rod 29 configured to move along a first axis 30. Preferably, the first actuator 27 is configured to be driven so as to move the first piston rod 29 between a third position (Fig. 2(a)), corresponding to the first position of the turning device 24, and a fourth position (Fig. 2(b), corresponding to the second position of the turning device 24. In this way, the engagement device 26 can move the ratchet pawl 25 into engagement with one of the teeth 23, and moved out of engagement with the teeth 23 (i.e. by being driven in reverse).

In one embodiment, the engagement device 26 is fixedly mounted to a gearbox housing 31 of a gearbox mounted within the main frame and to which the rotor shaft is coupled. For example, the engagement device 26 is mounted to a gearbox housing 31 via bracket 32. Thus, preferably, the first actuator 27 is mounted at another end 33 thereof, opposite the first end 28, to the gearbox housing 31. The engagement device 26 may be coupled to the turning device 24 via a hinged or fixed bracket 34.

Preferably, the turning device 24 is an elongate device fixed in or on the main frame and configured for rotation about one end 35 thereof, e.g. about axis 36 (into the paper). A hinged bracket 41 may be used for this purpose, the hinged bracket 41 being fixedly attached to the turning device 24 and rotatably attached to the support 21 for rotation about the axis 36.

Preferably, the turning device 24 is an elongate device defining a second axis 37. When the turning device 24 is in the first position the second axis 37 is substantially aligned in a first orientation. The engagement device 26 is an elongate device defining the first axis 30 and configured to be aligned in a second orientation, substantially orthogonal to the first orientation. Preferably, the first orientation is substantially horizontal and the second orientation is substantially vertical.

In one embodiment, the turning device 24 includes a second actuator 38. Preferably, the second actuator 38 has at one end 39 thereof a second piston rod 40 configured to move along the second axis 37, and the ratchet pawl 25 is disposed on the second piston rod 40. Preferably, the second actuator 38 is configured to be driven so as to move the second piston rod 40 along a second axis 37 so as to cause the ratchet pawl 25 to engage and push a tooth 23-1 of the plurality of teeth 23 and thereby turn the brake disc 22. Preferably, the axis of rotation 36 of the turning device 24 is substantially orthogonal to the first orientation and to the second orientation, e.g. also horizontal.

Figure 3(a) is a lateral view of a turning arrangement 20’ used in the turbine of Fig. 1 in a disengaged position, and Fig. 3(b) shows an engaged position, in an embodiment employing a sliding block 50 as a positioning device 26’. This is the same as the embodiment of Figs 2(a) and 2(b), except as described in the following; and like numerals are used to denote like elements.

In this embodiment, the turning device 24 has a sliding member 51 at one end thereof, and the positioning device 26’ comprises the sliding block 50 configured to be engaged, in use, by the sliding member.

In an embodiment, the sliding member 51 comprises a roller or ball configured to roll, in use, along a surface 52 of the sliding block 50. In an embodiment, the surface 52 of the sliding block is non-linear, whereby, in use, the sliding member 51 is disposed at a first point (Fig. 3(a); disengaged) on the surface 52 when the positioning device 26’ is in the first position, and is disposed at a second point (Fig. 3(b); engaged) on the surface when the positioning device 26’ is in the second position.

In an embodiment, the surface has an S-shaped profile, and the sliding block 50 is disposed on an upper side of the brake disc 22 or engagement disc and/or the second point is lower than the first point. Thus, the sliding member 51 can slide over the surface 52 under gravity or positive guided.

Figure 4(a) is a lateral view of a turning arrangement used in the turbine of Fig. 1 in a disengaged position, and Fig. 4(b) shows an engaged position, in an embodiment employing a pair of springs as a positioning device 26’’. This is the same as the embodiment of Figs 2(a) and 2(b), except as described in the following; and like numerals are used to denote like elements.

In this embodiment, the positioning device 26’’ comprises a first spring 60 defining a third axis 61 and a second spring 62 defining a fourth axis 63, the fourth axis 63 being substantially orthogonal to the third axis 61.

In an embodiment, the first spring 60 is fixed at one end thereof in or on the main frame 31’’, and at the other end thereof to the ratchet pawl 25 or to the second piston rod 40. In an embodiment, the second spring 62 is fixed at one end thereof in or on the main frame 31’’, and at the other end thereof to a free end of the turning device 24.

In an embodiment, when the positioning device 26’’ is in the first position, the first spring 60 and the second spring 62 are in equilibrium and/or non-tensioned (Fig. 4(a)). In an embodiment, when the positioning device 26 is in the second position, the first spring 60 is in tension and the second spring 62 is in compression (Fig. 4(b)).

In an embodiment, the third axis 61 is substantially horizontal and the fourth axis 62 is substantially vertical. In an embodiment, the positioning device 26’’ is disposed adjacent a lower point on the brake disc 22 or engagement disc.

A method of turning a rotor of a wind turbine 2 will now be briefly described. It is assumed that the wind turbine 2 is in situ. The method comprises providing the turning arrangement 20 as described and illustrated herein, and the turning arrangement 20 and a rotor shaft are mounted in or on a main frame of the wind turbine 2, a brake disc 22 being mounted on the rotor shaft or high speed shaft of the gearbox, the brake disc 22 or an engagement disc fixedly attached thereto having on the circumferential edge thereof a plurality of teeth 23. Then the engagement device 26 is driven so as to move the turning device 24 from the first position, in which the turning device 24 is spaced apart from the plurality of teeth 23, to the second position, in which the ratchet pawl 25 of the turning device is positioned to engage and/or push a tooth 23-1 of the plurality of teeth 23.

Thus, in an embodiment, asymmetric external toothing 23 is applied to the brake disc 22, allowing the rotor to be turned in one direction of rotation with a ratchet pawl 25 reset by means of gravity or spring force and an actuator 24 in the rotor. To hold the shaft in position during the return stroke of the cylinder 24 and prevent the rotor from turning more quickly than dictated by the actuator, pressure may be applied to the rotor brake so that the rotor cannot perform any inadvertent rotary movements but the actuator 24 is still able to cope with the braking torque.

In an embodiment, to prevent wear, the actuator 24 is actively (e.g. hydraulically or electrically) pushed (i.e. by engagement device 26) away from the brake disc 22 when not in use so that the ratchet pawl 25 and the toothing 23 of the brake disc 22 cannot come into contact with each other.

While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It is to be understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.