Rotor bearing housing and wind turbine comprising rotor bearing housing - Patents.com

Abstract

A rotor bearing housing (10) for accommodating a rotor (120) of a wind power plant (100), the rotor bearing housing (10) comprising a circular tower connector (20) and a rotor bearing having two sleeve bearings (30, 40) spaced apart from each other for attachment to a rotor shaft (130), the sleeve bearings (30, 40) being configured as tapered roller bearings and being arranged within the tower connector (20) in plan view, and the effective bearing centers of the sleeve bearings (30, 40) being arranged outside the tower connector (20) in plan view. [Selected Figure] Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotor bearing housing for housing a rotor of a wind turbine, the rotor bearing housing comprising a circular tower connection and a rotor bearing comprising two ring bearings spaced apart from each other to house the rotor. The present invention also relates to a wind turbine comprising a tower, a rotor bearing housing arranged on the tower, a rotor mounted in the rotor bearing housing and comprising a rotor shaft, a rotor hub connected to the rotor shaft via a rotor flange, at least one rotor blade connected to the rotor hub, and a generator connected to the rotor. [Background technology]

[0002] The increasing demand for renewable energy, especially wind energy, worldwide, coupled with the rapid decrease in suitable wind turbine sites with sufficient wind speeds, has led to the development of ever larger and more powerful wind turbines. The increased turbine performance has resulted in the transport and assembly of components of ever larger mass and size, presenting significant logistical challenges in many locations. In this regard, the width and height of the nacelle as well as the total weight of such wind turbines increasingly exceed the permissible limits for road transport. Also, the steady increase in turbine performance in offshore areas requires the reduction of the mass and size of the tower head in order to further reduce the costs for the construction and assembly of the wind turbines and the foundations.

[0003] Therefore, one objective of new wind turbine development is to always keep the nacelle measurements and dimensions as small as possible to further reduce manufacturing costs in order to increase the cost-effectiveness of the wind turbine. The use of small gearbox generator units with small gearbox ratios and medium speed generators (hybrid drives) represents the best compromise between the two traditional drive train concepts with direct drive generators and high speed generators with high ratio gearboxes, in terms of size, mass reliability and cost, especially for large wind turbines.

[0004] US Patent No. 5,399,633 already shows a very compact design, but in this case the rotor bearings, gearbox and generator are located between the rotor hub and the tower top in the force flow of the wind turbine, which components can only be replaced in the event of damage by completely dismantling the entire rotor and drive train, which has a negative impact on the maintenance costs of such a turbine, and at the same time the housing of these components has to transmit all the rotor loads, which can lead to undesirable deformations of the abovementioned components and further have a negative impact on their function and service life, so the housing must be designed to be particularly robust.

[0005] Patent document 2 shows a bearing unit connected to a gearbox generator unit, so that the rotor load is not transferred through the gearbox and the generator housing. However, the disadvantage of this solution is that the bearing unit still needs to be connected to the underlying machine carrier by multiple non-circular flange screwing surfaces, thus resulting in an unfavorable shape of the bearing unit and the machine carrier, which leads to stress peaks in the flange surfaces and requires additional machining of the flange surfaces and additional screw connections, which results in an increase in size, weight and manufacturing costs.

[0006] US Patent No. 5,399,633 shows a tubular support structure in which the gearbox support structure and part of the generator support structure are integrated so as to absorb all the rotor forces, and the rotor bearings are placed in a separate housing in front of the tubular support structure, which inconveniently introduces the forces of the rotor load into the cylindrical support structure, increases the manufacturing costs due to the additional flange connections required, and creates the problem of complete dismantling of the nacelle required in case of damage to the gearbox.

[0007] Finally, US Pat. No. 5,399,633 shows by way of example a rotor bearing housing as mentioned at the outset, which is designed in particular as one piece, with a circular tower connection on which a horizontally extending section is arranged, in which two spaced apart ring bearings are adapted to accommodate the rotor shaft of the rotor. A disadvantage of this design is the space-consuming construction associated with it, which prevents the creation of compact wind turbines. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] German Patent Application Publication No. 102007012408 [Patent Document 2] U.S. Patent No. 8,907,517 [Patent Document 3] U.S. Patent No. 4,527,072 [Patent Document 4] China Utility Model No. 201386629 Summary of the Invention [Problem to be solved by the invention]

[0009] The problem addressed by this invention is to create a nacelle that has the most compact and lightweight design possible while at the same time allowing for field replacement of critical drive train components without the need to lift the entire nacelle off the tower and disassemble it. [Means for solving the problem]

[0010] According to the invention, the above problem is solved by a rotor bearing housing having the features of claim 1. The problem is also solved by a wind turbine having the features of claim 8. Each of the dependent claims describes advantageous embodiments of the invention.

[0011] The basic idea of ​​the invention is to design the rotor bearing housing, as known, as the central unit which acts as the rotor bearing unit and at the same time connects all the components of the nacelle to each other, so that the component machine carrier, the second bearing housing and the generator carrier, all of which are used to house the components of the nacelle in other designs, are not necessary.

[0012] According to the invention, the use of only one rotor bearing unit significantly reduces the manufacturing and processing costs of the mechanical parts of the wind turbine in particular and results in a very compact design when compared to known wind turbines, while maintaining modularity and interchangeability of the gearbox-generator unit without dismantling the entire drive train together with the rotor.

[0013] In particular, the arrangement of the two ring bearings on the flange connection surface in an azimuth bearing ensures that the transverse forces transmitted to the bearings are optimally transmitted to the lower structure of the rotor bearing unit. The inter-bearing distance is therefore essentially the same as the diameter of the lower flange connection surface of the rotor bearing housing.

[0014] Due to the shape consisting essentially of intersecting cylinders and cones, which is very favorable for the flow of forces in the rotor bearing housing, the stresses and deformations in the rotor bearing housing are particularly small, thereby resulting in a significant reduction in weight when compared to known conventional solutions.

[0015] Also, the very compact design of the rotor bearing housing according to the invention allows a small distance between the circular rotor surface and the tower wall of the wind turbine. The housing of a self-supporting separate gearbox-generator unit, preferably designed as a hybrid drive, is rigidly screwed to the rotor bearing housing, i.e. neither a further machine carrier or generator carrier bearing the weight load of the two components nor torque supports arranged on both sides of the gearbox housing to absorb the torque of the drive train can be dispensed with.

[0016] The rotor shaft and the gearbox input shaft are connected by a compensating coupling or via a fixed flange connection between the two components. By eliminating the need for a separate machine carrier and torque support, the overall width and length of the drivetrain is significantly reduced when compared to other designs.

[0017] The rotor bearing housing is screwed to the azimuth bearing at the lower flange connection and is connected in a rotatable manner directly to the top part of the tower via the azimuth bearing. In order to minimize the transport width of the nacelle, the diameter of the azimuth bearing should be reduced as much as possible. The small distance between the circular rotor surface and the tower axis, which is brought about by a very compact rotor bearing housing, and the smallest possible diameter of the azimuth bearing can be realized in particular by the downwind configuration of the rotor as a downwind runner (lee-runner) and by the absence of an active yaw system (free yaw or passive yaw system).

[0018] Because in the downwind configuration the rotor blades bend away from the tower due to the wind loads that occur during normal operation, the downwind configuration allows for a much smaller distance between the circular rotor surface and the tower wall than is the case in the normal upwind configuration of the rotor as an upwind runner.

[0019] An upwind configuration with an active yaw system requires the application of a certain torque about the vertical axis of the tower so that the nacelle can actively track the wind direction. The wind forces generated usually react to the direction of movement, i.e. do not support it. In the case of an active yaw system, the required torque must be realized by a suitable number of yaw drives and a sufficiently large diameter azimuth bearing. Thus, an active yaw system prevents the desired minimization of the diameter of the azimuth bearing.

[0020] However, in a particularly preferred downwind configuration with a passive yaw system, there is no need for the yaw system of the nacelle to generate a torque about the vertical axis of the tower, since the nacelle is passively tracked by the wind loads generated on the rotor according to the anemometer principle, so no yaw drive is required and the diameter of the azimuth bearing can be dimensioned and minimized solely as desired based on the bending moment to be transmitted.

[0021] Nevertheless, the azimuth brake is able to apply a braking torque to a brake disk arranged on the rotor bearing housing and thus rigidly connected to the tower. For this purpose, the azimuth brake is designed in such a way that the braking torque can be adjusted between zero and a maximum value. As a result, the azimuth movement of the nacelle can be limited to an acceptable value of rotation speed or rotation acceleration in certain operating states or in the case of errors by the activation of the azimuth brake. This limitation is necessary in particular to avoid unacceptable operating conditions of the turbine due to excessive yaw speed or yaw acceleration, which can lead to overloading and damage of components.

[0022] The slip ring unit transfers the power and the necessary control signals from the rotating nacelle to the stationary tower, so that the payout of the power cable, which is necessary in concepts with an active yaw system after a certain maximum allowable number of nacelle rotations, is not necessary when using such a slip ring unit.

[0023] A passive yaw system introduces a certain deviation of the nacelle position from the mean wind direction, depending on the mean wind speed and other wind parameters, which cannot be actively compensated for in a passive yaw system, as is common in the case of active yaw systems. By targeted use of the lateral offset between the rotor axis and the tower vertical axis, as is preferred according to the invention, this deviation can be minimized for the expected wind speed with the greatest percentage of energy yield.

[0024] Therefore, according to the invention, a rotor bearing housing for accommodating a rotor of a wind turbine is proposed, which comprises a circular tower connection part and a rotor bearing with two spaced apart ring bearings for mounting on the rotor shaft, the ring bearings being arranged within the tower connection part, i.e. within the circumference of the tower connection part, as viewed from above. For this, the ring bearing is designed in such a way that its effective bearing centre is arranged outside the tower connection part, as viewed from above. This can be easily achieved in particular by designing the ring bearing as a tapered roller bearing.

[0025] It is further preferred that the rotor bearing housing has an essentially vertically extending section, which is formed on its underside with a circular tower connection and which is integrated with an essentially horizontally extending section which houses the rotor bearing, the vertical section being particularly preferably designed conically and the rotor bearing housing being formed by the meeting of a hollow cone with a hollow cylinder.

[0026] In the vertically extending section, a first manhole is provided for passing through the tower connection into the vertical section of the rotor bearing housing and a second manhole for passing from the vertical section of the rotor bearing housing to an area outside the rotor bearing housing, thereby allowing a compact construction and at the same time providing a passage from the wind turbine tower through the rotor bearing housing into the nacelle formed by the exterior of the nacelle.

[0027] Furthermore, a connection flange extending essentially at a 90 degree angle to the tower connection is preferably provided for fastening the generator housing.

[0028] According to a further preferred embodiment, the imaginary axis passes through the effective bearing centre of the ring bearing and does not pass through the centre point of the tower connection.

[0029] Correspondingly, a wind turbine is also claimed, comprising a tower, a rotor bearing housing of the above-mentioned design arranged on the tower, a rotor mounted in the rotor bearing housing and comprising a rotor shaft, a rotor hub connected to the rotor shaft via a rotor flange, at least one rotor blade connected to the rotor hub, and a generator connected to the rotor shaft.

[0030] The wind turbine is preferably provided with an azimuth system arranged at the upper end of the tower and comprising two bearing members rotatable relative to one another, the rotor bearing housing forming the upper bearing member of the azimuth system.

[0031] The distance between the ring bearings essentially corresponds to the diameter of the upper section of the tower in the area of ​​the azimuth system. In particular, the diameter of the upper section of the tower in the area of ​​the azimuth system is at most 15% larger than the distance between the ring bearings. In particular, the diameter of the upper section of the tower in the area of ​​the azimuth system is at most 10% larger than the distance between the ring bearings.

[0032] According to a further preferred embodiment, the diameter of the rotor flange also essentially corresponds to the distance between the ring bearings and / or essentially corresponds to the diameter of the upper section of the tower in the area of ​​the azimuth system. The diameter of the rotor flange and the diameter of the upper section of the tower in the area of ​​the azimuth system are preferably at most 15% larger or smaller than the distance between the ring bearings. The diameter of the rotor flange and the diameter of the upper section of the tower in the area of ​​the azimuth system are preferably at most 10% larger or smaller than the distance between the ring bearings.

[0033] This preferred embodiment achieves optimal power flow from the rotor to the tower.

[0034] The rotor axis preferably passes outside the centre of the tower to counteract the tilt of the nacelle relative to the wind direction resulting from the passive yaw system due to the selected geometry.

[0035] The connection flange of the rotor bearing housing is preferably connected to a generator housing which houses the generator. The rotor shaft is preferably connected to the generator via a gearbox. The gearbox and the generator are preferably designed as a hybrid drive.

[0036] Also, an azimuth brake is preferably located on the rotor bearing housing.

[0037] Finally, a wind turbine designed according to the present invention is preferably designed as a downwind runner.

[0038] The invention achieves a very compact design, increases the reliability of the wind turbine and at the same time ensures the replacement of components most at risk of failure without a complete dismantling of the nacelle, which gives clear advantages in terms of investment and lifetime costs of a wind turbine designed according to the invention compared to other drive train concepts.

[0039] The invention will now be described in more detail by way of specific preferred constructional embodiments illustrated in the accompanying drawings. [Brief description of the drawings]

[0040] [Figure 1] FIG. 2 is a schematic cross-sectional view of a wind turbine in a particularly preferred configuration in the region of the nacelle. [Diagram 2] FIG. 2 is a perspective view of the wind turbine of FIG. 1 without the nacelle exterior. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] FIG. 1 shows a schematic cross-section of a wind turbine according to the invention, particularly preferably configured as a downwind runner, in the region of the nacelle.

[0042] A particularly preferred configuration of wind turbine 100 comprises a tower 110, a rotor bearing housing 10 constructed in accordance with the present invention and positioned on tower 110, a rotor 120 having a rotor shaft 130 mounted within rotor bearing housing 10, a rotor hub 140 connected to rotor shaft 130 via a rotor flange, a plurality of rotor blades 150 connected to rotor hub 140, and a generator housed by a generator housing 160 and connected to rotor shaft 130.

[0043] It can be clearly seen that the rotor bearing housing 10 is designed with a circular tower connection part 20 which forms the upper bearing member of the azimuth system. The rotor bearing housing 10 also accommodates two ring bearings 30, 40 which are spaced apart from each other and designed as tapered roller bearings. As shown in the cross-sectional view, the ring bearings 30, 40 are arranged within the circumference of the tower connection part 20 and the ring bearings 30, 40 are designed such that their effective bearing centres are outside the tower circumference.

[0044] The distance between the ring bearings 30, 40 corresponds approximately to the diameter of the upper section of the tower 110 in the area of ​​the azimuth system. In this case, the difference between the diameter of the upper section of the tower 110 in the area of ​​the azimuth system and the distance between the ring bearings 30, 40 is less than 10% relative to the distance between the ring bearings 30, 40.

[0045] Also, the diameter of the rotor flange essentially corresponds to the distance between the ring bearings 30, 40 and also essentially corresponds to the diameter of the upper section of the tower 110 in the region of the azimuth system. In the illustrated example, the difference between the diameter of the rotor flange and the diameter of the upper section of the tower 110 in the region of the azimuth system relative to the distance between the ring bearings 30, 40 is less than ±10% relative to the distance between the ring bearings.

[0046] Finally, FIG. 2 shows a perspective view of the wind turbine of FIG. 1 without the nacelle exterior.

[0047] It can be clearly seen that the rotor bearing housing 10, which is rotatably arranged on the tower 110 of a wind turbine 100 designed as a downwind runner, forms an essentially vertically extending section 12, on whose underside a circular tower connection 20 is formed, and an essentially horizontally extending section 14, which houses the rotor bearing. In this case, the two sections 12, 14 are designed as one piece, the vertical section 12 being designed conically and the horizontal section being designed cylindrically. In particular, the rotor bearing housing 10 is formed by the meeting of a hollow cone 12 with a hollow cylinder 14.

[0048] A first manhole is arranged in the vertically extending section 12 for entering the vertical section 12 of the rotor bearing housing 10 through the tower connection 20, and a second manhole 50 arranged in the vertically extending wall of the vertical section 12 is provided for moving from the vertical section 12 of the rotor bearing housing 10 to an area outside the rotor bearing housing 10.

[0049] Finally, in FIG. 2 it can also be seen that the wind turbine 100 comprises an azimuth brake 170 arranged on the rotor bearing housing 10 . [Explanation of symbols]

[0050] 10:Rotor bearing housing 12: Section 14: Section 14: Hollow cylinder 12: Hollow cone 20: Circular tower connection 30, 40: Ring bearing 50: Second manhole 100: Wind turbine 110: Tower 120: Rotor 130:Rotor shaft 140:Rotor hub 150:Rotor blade 160: Generator housing 170: Azimuth brake

Claims

1. A rotor bearing housing (10) for housing a rotor (120) of a wind turbine (100), the rotor bearing housing (10) comprising a circular tower connection (20) and a rotor bearing comprising two spaced apart ring bearings (30, 40) for mounting on a rotor shaft (130); 1. A rotor bearing housing, comprising: a ring bearing (30, 40) designed as a tapered roller bearing and arranged in the tower connection part (20) in a plan view from above; and an effective bearing center of the ring bearing (30, 40) arranged outside the tower connection part (20) in a plan view from above.

2. 2. A rotor bearing housing (10) according to claim 1, characterized in that it comprises a vertically extending section (12) on whose underside the circular tower connection (20) is formed and which is integrated with a horizontally extending section (14) which houses the rotor bearing.

3. 3. A rotor bearing housing (10) according to claim 2, characterized in that the vertically extending section (12) is of conical design.

4. 4. A rotor bearing housing (10) as claimed in claim 2 or 3, characterized in that the rotor bearing housing (10) is formed by the intersection of the vertically extending section (12) with the horizontally extending section (14), the vertically extending section (12) being a hollow cone and the horizontally extending section (14) being a hollow cylinder.

5. 5. The rotor bearing housing (10) according to claim 2, characterized in that in the vertically extending section (12) a first manhole is arranged for entering the vertically extending section (12) of the rotor bearing housing (10) through the tower connection (20) and a second manhole (50) is provided in the wall of the vertically extending section (12) for passing from the vertically extending section (12) of the rotor bearing housing (10) to an area outside the rotor bearing housing (10).

6. 6. The rotor bearing housing (10) according to any one of claims 1 to 5, characterized in that the rotor bearing housing (10) has a connection flange extending at an angle of 90 degrees to the tower connection part (20) and fastening the generator housing.

7. A rotor bearing housing (10) according to any one of claims 1 to 6, characterized in that, in a planar view from above, a virtual axis passing through the effective bearing center of the ring bearing (30, 40) does not pass through the center point of the tower connection portion (20).

8. 8. A wind turbine (100), comprising: a tower (110); a rotor bearing housing (10) according to any one of claims 1 to 7 arranged on the tower (110); a rotor (120) mounted in the rotor bearing housing (10) and comprising a rotor shaft (130); a rotor hub (140) connected to the rotor shaft (130) via a rotor flange; at least one rotor blade (150) connected to the rotor hub (140); and a generator connected to the rotor shaft (130).

9. 9. The wind turbine (100) according to claim 8, characterized in that the orientation system comprises two bearing members arranged at the upper end of the tower (110) and rotatable relative to each other, and the rotor bearing housing (10) forms the upper bearing member of the orientation system.

10. 10. The wind turbine (100) according to claim 8 or 9, characterized in that the distance between the ring bearings (30, 40) corresponds to the diameter of the upper section of the tower (110) in the area of ​​the azimuth system.

11. 11. The wind turbine (100) according to claim 10, characterized in that the diameter of the upper section of the tower (110) in the area of ​​the azimuth system is at most 15% greater than the distance between the ring bearings (30, 40).

12. 12. The wind turbine (100) according to claim 10 or 11, characterized in that the diameter of the upper section of the tower (110) in the area of ​​the azimuth system is at most 10% greater than the distance between the ring bearings (30, 40).

13. 13. The wind turbine (100) according to any one of claims 8 to 12, characterized in that the diameter of the rotor flange corresponds to the distance between the ring bearings (30, 40) and / or corresponds to the diameter of the upper section of the tower (110) in the area of ​​the azimuth system.

14. 14. Wind turbine according to any one of claims 8 to 13, characterized in that the diameter of the rotor flange and the diameter of the upper section of the tower (110) in the area of ​​the azimuth system are at most 15% larger or smaller than the distance between the ring bearings (30, 40).

15. 15. Wind turbine according to any one of claims 8 to 14, characterized in that the diameter of the rotor flange and the diameter of the upper section of the tower (110) in the area of ​​the azimuth system are at most 10% larger or smaller than the distance between the ring bearings (30, 40).

16. A wind turbine (100) according to any one of claims 8 to 15, characterised in that in a plan view from above, a rotor axis passes outside the centre of the tower.

17. A wind turbine (100) according to any one of claims 8 to 16, characterized in that a connection flange of the rotor bearing housing (10) is connected to a generator housing (160) which houses the generator.

18. 18. The wind turbine (100) according to any one of claims 8 to 17, characterized in that the rotor shaft (130) is connected to the generator via a gearbox.

19. 19. Wind turbine (100) according to claim 18, characterized in that the gearbox and the generator are designed as a hybrid drive.

20. A wind turbine (100) according to any one of claims 8 to 19, characterized by an azimuth brake (170) arranged on the rotor bearing housing (10).

21. Wind turbine (100) according to any one of claims 8 to 20, characterized in that the wind turbine (100) is designed as a downwind runner.

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