ADJUSTMENT UNIT FOR ADJUSTING THE PITCH OF A ROTOR BLADE, AND WIND TURBINE WITH SUCH AN ADJUSTMENT UNIT

Abstract

The invention relates to wind turbines with variable rotor blades whose pitch angle can be adjusted, wherein an adjustment unit for adjusting the pitch angle of a wind turbine rotor blade with a pivot bearing comprising at least two coaxial bearing rings that are rotatable against each other, at least one adjustment actuator for rotating the two bearing rings against each other, and a supply unit for supplying the adjustment actuator with energy, wherein the at least one adjustment actuator and the supply unit are disposed on opposite sides on a plate-shaped adjustment drive carrier part which is directly or indirectly rotatably connected with one of the bearing rings and comprises a rotatable support bearing for the rotatable support of the adjustment actuator on the carrier part. The supply unit is connected with the adjustment actuator by at least one pressurized-media channel passing through the support bearing.

Claims

1. An adjustment unit comprising a pivot bearing including at least two coaxial bearing rings that are rotatable against each other, at least one adjustment actuator for rotating the two bearing rings against each other, and a supply unit for supplying the adjustment actuator with energy, wherein the at least one adjustment actuator and the supply unit are disposed on an adjustment drive carrier part which is directly or indirectly rotatably connected with one of the bearing rings and comprises a support bearing for rotatably supporting the adjustment actuator, wherein the adjustment unit is connected with the adjustment actuator by means of at least one pressurized-media channel passing through the support bearing.

2. The adjustment unit according to claim 1, wherein the energy supply and/or control connection between the supply unit and the adjustment actuator is without tubes or cables and passes only through the rotatable support bearing for the non-rotatable support of the adjustment actuator on the adjustment drive carrier part.

3. The adjustment unit according to claim 1, wherein the supply unit is rotatably mounted together with the adjustment actuator on the carrier part such that the supply unit and the adjustment actuator are jointly rotatable and/or pivotable in relation to the carrier part without relative rotation to each other.

4. The adjustment unit according to claim 3, wherein the support bearing comprises a bearing journal which passes through the carrier part and is rotatably mounted on the carrier part, wherein on opposite end sections of the bearing journal on the one hand, the adjustment actuator is rotatable mounted on the bearing journal and on the other hand the supply unit is rotatably mounted on the bearing journal.

5. The adjustment unit according to claim 4, wherein the bearing journal comprises at least one pressurized-media channel for hydraulically connecting the supply unit and the adjustment actuator.

6. The adjustment unit according to claim 1, wherein the support bearing comprises a rotatable pressurized-media duct containing two bearing parts rotatable against each other across whose interface a pressurized-media channel extends.

7. The adjustment unit according to claim 6, wherein the rotatable duct comprises a bearing journal and a push rod rotatably mounted on same, wherein at least one pressurized-media channel in the push rod and at least one hydraulic channel in the bearing journal are in flow connection with each other.

8. The adjustment unit according to claim 6, wherein the supply unit is non-rotatably mounted on the carrier part and connected through the rotatable duct with the bearing journal that is rotatable against the same.

9. The adjustment unit according to claim 1, wherein the supply unit with its various component is combined into a pre-assembled module on a mounting support and is mounted as one unit on the carrier part or the support bearing.

10. The adjustment unit according to claim 1, wherein a control device for controlling the adjustment movements of the at least one adjustment actuator comprises a travel measuring system for recording adjustment movements of the at least one adjustment actuator and/or performs rotational movements generated by same, wherein said travel measuring system comprises an angle sensor integrated in the support bearing and/or a travel sensor integrated in the adjustment actuator, wherein a signal line passes from the angle sensor and/or the travel measuring system to the control device disposed on the supply unit through the support bearing.

11. The adjustment unit according to claim 1, wherein the at least one adjustment actuator is on the one hand linked in an articulated way to said carrier part which is non-rotatably connected with one of the bearing rings and extends across the middle of a bearing, and on the other hand linked in an articulated way to the other bearing ring wherein said other bearing ring comprises a support part that leaves the middle of the bearing open and is connected to the bearing ring only at the section where the adjustment actuator is linked with it.

12. The adjustment unit according to claim 1, wherein at least two adjustment actuators are configured to act in directions opposite each other, so as to extend one of the adjustment actuators and retract the other to rotate the two bearing rings against each other.

13. The adjustment unit according to claim 1, wherein at least two adjustment actuators are configured to act together in the same direction so that both adjustment actuators are simultaneously extendable and/or both adjustment actuators are simultaneously retractable to rotate the two bearing rings against each other.

14. A wind turbine with a rotor comprising rotor blades with adjustable pitch angles, wherein an adjustment unit is provided for adjusting the pitch angle of the rotor blades, wherein the adjustment unit comprises a pivot bearing including at least two coaxial bearing rings that are rotatable against each other, at least one adjustment actuator for rotating the two bearing rings against each other, and a supply unit for supplying the adjustment actuator with energy, wherein the at least one adjustment actuator and the supply unit are disposed on an adjustment drive carrier part which is directly or indirectly rotatable connected with one of the bearing rings and comprises a support bearing for rotatable supporting the adjustment actuator, wherein the adjustment unit is connected with the adjustment actuator by means of at least one pressurized-media channel passing through the support bearing.

15. The wind turbine according to claim 14, wherein an inner ring of the pivot bearing is non-rotatably connected with a rotor blade and an outer ring of the pivot bearing is non-rotatably connected with a rotor hub, wherein the carrier part on which the at least one adjustment actuator is supported is non-rotatably connected with the outer ring of the pivot bearing, and the at least one adjustment actuator is on the other hand linked in an articulated way to the inner ring of the pivot bearing, wherein the inner ring comprises a support part that leaves the middle of the bearing open and is connected with the inner ring only in the section where the adjustment actuator is linked to it.

16. The adjustment unit according to claim 1, wherein the adjustment unit is for adjusting a pitch angle of a wind turbine rotor blade.

17. The adjustment unit according to claim 1, wherein the adjustment drive carrier part is plate-shaped.

18. The adjustment unit according to claim 9, wherein the various components of the supply unit are one or more of an electric motor, a pump, or a pressure accumulator.

19. The wind turbine according to claim 14, wherein the adjustment drive carrier part is plate-shaped.

Description

[0029] Below, the invention is described in detail by means of preferred embodiments and with reference to the attached drawings where

[0030] FIG. 1 shows a schematic perspective view of a wind turbine with pitch-adjustable rotor blades according to an advantageous embodiment of the invention,

[0031] FIG. 2 shows a perspective schematic view of the pivot bearing and the adjustment drive integrated therein for oppositely rotating the two bearing rings,

[0032] FIG. 3 shows a top view of the pivot bearing with the associated adjustment actuators, as shown in FIG. 2,

[0033] FIG. 4 shows a top view of the supply unit of the adjustment drive arranged on the plate-shaped carrier part, on the side opposite the adjustment actuators,

[0034] FIG. 5 shows a top view of a pivot bearing and the adjustment actuators disposed there, similar to FIG. 2, with the adjustment actuators arranged such that they rotate oppositely,

[0035] FIG. 6 shows a top view of a pivot bearing, similar to FIG. 3 and FIG. 5, wherein the adjustment drive in this version comprises only one adjustment actuator, and the supply unit is rotatably mounted on the plate-shaped carrier part together with the actuator,

[0036] FIG. 7 shows a schematic sectional view of a rotatably mounted bearing journal for supporting the adjustment actuator shown in FIG. 6 on the carrier part, wherein the sectional view shows the hydraulic ducts to the pressurized-media supply of the adjustment actuator through the bearing journal, and

[0037] FIG. 8 shows a schematic sectional view of a bearing journal and the hydraulic rotatable duct integrated therein, with the hydraulic ducts disposed therein, thereby allowing the rotation of the supply unit against the adjustment actuator.

[0038] As FIG. 1 shows, rotor 3 of wind turbine 1 can be rotatable about a horizontal rotor axis and mounted on a nacelle 24 which is disposed on a tower 2 and can be rotated about a vertical axis to align rotor 3 in wind direction. The control assemblies, the generator and additional energy converters and auxiliary assemblies can be accommodated in said nacelle 24 in a manner that is state of the art.

[0039] Rotor hub 4, which is rotatably mounted on nacelle 24 about the horizontal rotor axis carries several rotor blades 5 which are rotatably mounted on rotor hub 4 about longitudinal rotor blade axes such that the pitch angle of rotor blades 5 can be adapted to the operating conditions, in particular to the wind velocity and the switch-on status of the wind turbine. For this purpose, as FIG. 1 shows, each rotor blade 5 is mounted on rotor hub 4 by means of a so-called pitch bearing in the form of a pivot bearing 6.

[0040] Each said pitch or pivot bearing 6 comprises at least two oppositely rotatable coaxial bearing rings 7 and 8 whose rotation axis extends about parallel to each longitudinal rotor blade axis and/or radially to the rotor's rotation axis. In principle, said rotational bearing 6 can be constructed in various forms, particularly in the form of a roller bearing in which said bearing rings 7 and 8 can be supported by suitable roller elements such as elements formed as several axial and radial rows of bearings. The outer bearing ring 8 can be rigidly mounted on rotor hub 4, and the rotatable inner bearing ring 7 can carry the associated rotor blade 6 or can be rigidly connected with said rotor blade 5, although the opposite order is possible as well, i.e. inner ring 7 could be fastened on hub 4 and outer ring 8 on rotor blade 5.

[0041] To allow the pitch angle of each rotor blade 5 to be set in the desired manner, bearing rings 7 and 8 are provided with an adjustment unit 10 which advantageously can be disposed in the inner space which is substantially completely surrounded by bearing rings 7 and 8 and can oppositely rotate the two bearing rings 7 and 8.

[0042] The said adjustment unit 10 can be of electrohydraulic nature, wherein at least one preferably linear adjustment actuator 11 can be supplied with pressurized media by a supply unit 12 to activate adjustment actuator 11. The said supply unit 12 can comprise a pump 14 driven by an electric motor to apply a suitable pressurized medium such as hydraulic fluid. The applied pressurized medium could be fed directly onto the at least one adjustment actuator 11 via suitable flow control means such as valves. Advantageously, supply unit 12 can also comprise at least one pressure accumulator 13, in particular also at least one low-pressure accumulator which can be filled or loaded by the pump 14. Pressure can then be applied to adjustment actuator 11 by the at least one pressure accumulator 13.

[0043] Advantageously, the pressure applied to the at least one adjustment actuator 11 is controlled via a control device which comprises suitable flow control means such as one or more valves 17 which advantageously can be combined in a valve block 16 to which the pump 14 and/or at least one pressure accumulator 13 can be connected.

[0044] Advantageously, supply unit 12 can form a hydraulic self-sufficient system which generates the hydraulic pressure that must be provided. Supply unit 12 needs only a power supply plug to provide electric motor 15 with electric power to drive pump 14. The necessary control assemblies, in particular valve actuators which can be electromagnetic, and/or electronic control assemblies such as circuit boards can be integrated in supply unit 12.

[0045] As a comparison between FIGS. 2 and 3 with FIG. 4 shows, supply unit 12 on the one hand and the at least one adjustment actuator 11 are arranged on different sides of a carrier part 9 which has the shape of a plate and can extend substantially across the rotation axis of pivot bearing 6. Advantageously, said carrier part 9 can be rigidly connected with the bearing ring which is rigidly fastened to rotor hub 4 and form a stiffening element for stiffening this bearing ring. The said carrier part 9 can, for example, form a kind of lid or wall which can substantially close bearing ring 8 completely, wherein a maintenance access hole can be provided in carrier part 9 to allow access to the inside of rotor blade 5 from rotor hub 4, wherein said maintenance access hole may also be lockable by a lid or a door.

[0046] Advantageously, the at least one adjustment actuator 11 is disposed on the rotor blade side of carrier part 9 and supply unit 12 is disposed on the hub side of carrier part 9, wherein supply unit 12 and the at least one adjustment actuator 11 have an overall flat, longitudinal configuration and can be disposed with their longitudinally extending axis across the rotation axis of pivot bearing 6 and/or arranged parallel to the carrier part 9; see FIGS. 2 to 6.

[0047] As FIGS. 2 and 3 show, according to an embodiment of the invention, two adjustment actuators 11 in the form of cylinder units can be provided which are eccentrically disposed toward the rotation axis of pivot bearing 8 to facilitate the rotational movement. On the one hand, adjustment actuators 11 have a linking point 25 on carrier part 9 and on the other hand a linking point 26 on bearing ring 7 connected with rotor blade 5, wherein said linking points 25 and 26 can be formed by pivotable or articulated support bearings which support adjustment actuators 11 directly or indirectly on carrier part 9 and on bearing ring 7.

[0048] As FIG. 3 shows, each adjustment actuator 11 is supported by a support bearing 18 on carrier part 9, wherein said support bearing 18 is articulated and/or rotatable and has at least one bearing rotation axis parallel to the rotation axis of pivot bearing 6.

[0049] Advantageously, the other linking point 26 on bearing ring 7 is also formed by a support bearing which can be appropriately disposed parallel to the pivot bearing, namely articulated and/or rotatable with at least one rotation axis. It can be linked to bearing ring 7 by means of a linking bracket 28 that is rigidly connected with bearing ring 7.

[0050] When linear adjustment actuators 11 are formed as cylinder units, the cylinder is advantageously supported on support bearing 18 provided on carrier part 9 such that the hydraulic supply passing through adjustment actuator 18 can be conducted directly into the cylinder. However, in principle, a reverse arrangement of adjustment actuators 11 would also be possible wherein pressurized fluid could be introduced via the piston rod.

[0051] The multiple adjustment actuators 11 can be arranged to rotate alike such that to oppositely rotate the two bearing rings 7 and 8, both adjustment actuators 11 can be simultaneously extended and/or retracted, as shown in FIG. 3. However, as shown in FIG. 5, at least two adjustment actuators 11 can also be disposed which rotate in opposite direction such that to oppositely rotate the two bearing rings 7 and 8, one of the adjustment actuators is extendable and the other is retractable.

[0052] As FIG. 6 shows, in principle only one adjustment actuator can also be sufficient, especially when only fairly small rotor blades must be rotated or if generally only fairly small adjustment forces or torques have to be mastered or applied.

[0053] If according to FIGS. 2 and 3 or FIG. 5, several adjustment actuators are provided, supply unit 12 can be rotatably connected to carrier part 9 together with one of the adjustment actuators. To compensate for the angular misalignment that occurs with adjustment movements between adjustment unit 10 and adjustment actuator 11, the respective support bearing 18 or the energy supply integrated therein can be designed as rotatable duct 29, as shown in FIG. 8.

[0054] In this case, a bearing journal 19 supporting adjustment actuator 11 passing through carrier part 9 can be rotatably mounted to carrier part 9 about said bearing rotation axis 27, for example by means of one or more pivot bearings formed as roller bearings 30 and supporting bearing journal 19 on carrier part 9 (see FIG. 8). A rotating part, for example in the shape of a push rod 21 can be rotatably engaged in bearing journal 19 and be arranged coaxially to said bearing journal 19 or its longitudinal rotation axis 27. For example, a substantially cylindrical push rod 21 can be accommodated in a journal bore inside bearing journal 19, which protrudes in the front from bearing journal 19 toward the hub side and is rotatable related to bearing journal 19, such that push rod 21 can be connected with supply unit 12, in particular with its valve block 16. In this case, said supply unit 12 can be rigidly, i.e. non-rotatably mounted on carrier part 9. Due to rotatable duct 29, bearing journal 19 can rotate in relation to the non-rotatably mounted supply unit 12 and still conduct hydraulic fluid to adjustment actuators 11.

[0055] As shown in FIG. 8, hydraulic channels 23 provided in the rotating part or push rod 21 communicate with hydraulic channels 22 in bearing journal 19, independently of the rotational position, such that adjustment actuators 11 are supplied with pressurized fluid through support bearing 18.

[0056] When adjustment unit 10 has only one adjustment actuator 11 for oppositely rotating bearing rings 7 and 8, as shown in FIG. 6, adjustment actuator 11 can similarly be directly or indirectly supported eccentrically on bearing ring 7 and have appropriate linking points 25 and 26 which are of either articulated or rotatable design.

[0057] In this case, support bearing 18 for supporting adjustment actuator 11 on carrier part 9 also has an integrated energy conduit in the form of pressurized-media channels. As FIG. 7 shows in comparison with FIG. 8, no rotatable duct is necessary, and supply unit 12 can be directly connected to bearing journal 19, thus providing an energy connection, in particular a hydraulic connection.

[0058] Advantageously, adjustment unit 10 can be non-rotatably fastened to the rotatably mounted bearing journal 19, such that the supply unit 12 can be rotated together with adjustment actuator 11 relative to carrier part 9. This means that there are no angular or rotational movements between supply unit 12 and adjustment actuator 11, such that supply unit 12 can be non-rotatably, i.e. rigidly disposed on bearing journal 10. Valve block 16 can be connected directly to hydraulic channels 22 in bearing journal 19.

[0059] For this purpose, supply unit 12 can be combined with its various components such as pressure accumulator 13 and/or pump 14 and/or electric motor 15 into a pre-assembled module that can be mounted as a unit on bearing journal 19, for example by means of a mounting bracket 31 that can be designed as a plate (see FIG. 4) and on the one hand carries supply unit 12 and on the other hand can be fastened to bearing journal 19.

[0060] To be able to exactly regulate the adjustment movements of the at least one adjustment actuator 11, adjustment unit 10 can be integrated in a suitable measuring system 32 with which the adjustment movement generated by adjustment actuator 11 and/or the associated oppositely rotational movement of bearing rings 7 and 8 can be recorded. This is how the relevant travel measuring system can verify by means of feedback control and/or regulation whether a control signal transmitted to valve block 16 has produced an appropriate adjustment movement or whether it has to be readjusted.

[0061] As shown in FIG. 2, said travel measuring system 32 advantageously comprises one or more sensors which can be integrated in the at least one adjustment actuator 11 and/or in its support bearing 18. In particular, a linear travel sensor 33 can be provided on adjustment actuator 11, in particular integrated in its cylinder unit, to directly record the adjustment movement of adjustment actuator 11. Alternatively or additionally, an angle detection sensor 34 can be integrated which records a rotation of the bearing journal 19 and/or the adjustment actuator 11 related to carrier part 9 to record a rotation of adjustment actuator 11 coinciding with an adjustment movement of adjustment actuator 11 related to carrier part 9, which rotation in turn is a measure for the opposite rotation of the bearing rings.

[0062] Alternatively or additionally, an angle sensor 35 can also directly measure the opposite rotation of bearing rings 7 and 8, and for that purpose, said angle sensor 35 is assigned to the two bearing rings 7 and 8, for example integrated in one of the bearing rings.