NACELLE FOR A WIND TURBINE

Abstract

A nacelle for a wind turbine includes: a nacelle housing; a rotor hub; and a rotor bearing for bearing the rotor hub on the nacelle housing, wherein the rotor bearing has at least one inner ring element and at least one outer ring element, wherein at least one oil-lubricated sliding bearing element is formed between the inner ring element and the outer ring element. In the nacelle housing and/or in the rotor hub, a lubricating oil sump is formed in such a manner for receiving a lubricating oil for the sliding bearing element. The lubricating oil sump can be filled with lubricating oil up to a lubricating oil level, wherein at least a section of the rotor bearing is arranged in the lubricating oil sump vertically below the lubricating oil level.

Claims

1. A nacelle (2) for a wind turbine (1), the nacelle (2) comprising: a nacelle housing (4); a rotor hub (6); a rotor bearing (8) for bearing the rotor hub (6) on the nacelle housing (4), wherein the rotor bearing (8) has at least one inner ring element (12) and at least one outer ring element (13), wherein at least one oil-lubricated sliding bearing element (14) is formed between the inner ring element (12) and the outer ring element (13), wherein in the nacelle housing (4) and/or in the rotor hub (6), a lubricating oil sump (18) for receiving a lubricating oil (19) for the sliding bearing element (14) is formed such that the lubricating oil sump (18) can be filled with lubricating oil (19) up to a lubricating oil level (20), wherein at least a section of the rotor hub (8) is arranged in the lubricating oil sump (18) vertically below the lubricating oil level (20).

2. The nacelle (2) according to claim 1, wherein the at least one sliding bearing element (14) is designed as hydrodynamic sliding bearing, which can be lubricated without a pressure-increasing device.

3. The nacelle (2) according to claim 1, wherein at least one lubricating oil bore (22) is arranged in the inner ring element (12) and/or in the outer ring element (13), which lubricating oil bore (22) opens directly into the lubricating oil sump (18).

4. The nacelle (2) according to claim 1, wherein a sealing element (24) is formed between the nacelle housing (4) and the rotor hub (6) and/or between the nacelle housing (4) and a rotor shaft (15).

5. The nacelle (2) according to claim 1, wherein the lubricating oil sump (18) is formed entirely in the nacelle housing (4), wherein the nacelle housing (4) is designed so as to be partible in the region of the lubricating oil sump (18).

6. The nacelle (2) according to claim 5, wherein the nacelle housing (4) has a main part of the housing (35) and a lubricating oil sump lid (36).

7. The nacelle (2) according to claim 1, wherein the inner ring element (12) is coupled with the rotor hub (6) and wherein the at least one sliding bearing element (14) is fastened to the inner ring element (12) and is rotatable relative to the outer ring element (13), wherein a sliding surface (17) is formed between the sliding bearing element (14) and the outer ring element (13).

8. The nacelle (2) according to claim 7, wherein at least one lubricating oil bore (23) is arranged in the outer ring element (13), which lubricating oil bore (23), at a first end, opens into the sliding surface (17) and at a second end opens into the lubricating oil sump (18).

9. The nacelle (2) according to claim 8, wherein a flow channel (27) being circumferential at least in some sections is formed in the outer ring element (13), which flow channel (27) tapers off particularly in the shape of a wedge gap (31) and into which the at least one lubricating oil bore (23) opens.

10. The nacelle (2) according to claim 9, wherein the multiple lubricating oil bores (23) are formed to be distributed across the circumference of the outer ring element (13), wherein multiple of said lubricating oil bores (23) open into the flow channel (27).

11. The nacelle (2) according to claim 1, wherein the lubricating oil level (20) is selected at such a height, that at their lowest-situated cross-section, the sliding surfaces (17) of the rotor bearing (8) are situated entirely below the lubricating oil level (20).

12. The nacelle (2) according to claim 4, wherein the lubricating oil level (20) is selected at such a height that the sealing element (24) is situated above the lubricating oil level (20).

13. The nacelle (2) according to claim 1, wherein the sliding bearing element (14) comprises multiple individual sliding bearing pads (33), which are arranged distributed across the circumference.

14. The nacelle (2) according to claim 13, wherein the sliding bearing pads (33) are each fastened to the inner ring element (12) or outer ring element (13) by means of at least one fastening means (16), in particular a screw connection.

15. The nacelle (2) according to claim 1, wherein the sliding bearing element (14) comprises a polymer layer, wherein the polymer layer comprises solid lubricant particles and metal oxide particles and as a polymer only a polyimide polymer or a polyamide-imide polymer or a mixture thereof, wherein the metal oxide particles are selected from a group comprising bismuth vanadates, chromium-antimony-rutile and mixtures thereof.

16. A wind turbine (1) having a nacelle (2), the nacelle (2) comprising: a nacelle housing (4); a rotor hub (6) with rotor blades arranged thereon; a rotor bearing (8) for bearing the rotor hub (6) on the nacelle housing (4), wherein the rotor bearing (8) has at least one inner ring element (12) and at least one outer ring element (13), wherein at least one sliding bearing element (14) is formed between the inner ring element (12) and the outer ring element (13), wherein in the nacelle housing (4) and/or in the rotor hub (6), a lubricating oil sump (18) for receiving a lubricating oil (19) for the sliding bearing element (14) is formed, wherein the lubricating oil sump (18) is filled with lubricating oil (19) up to a lubricating oil level (20), wherein at least a section of the rotor hub (8) is arranged in the lubricating oil sump (18) vertically below the lubricating oil level (20), so that said section of the rotor bearing (8) is immersed in the lubricating oil (19) collected in the lubricating oil sump (18).

Description

[0067] These show in a respectively very simplified schematic representation:

[0068] FIG. 1 a schematic representation of a wind turbine;

[0069] FIG. 2 a cross-section of a nacelle in a very schematic representation;

[0070] FIG. 3 a cross-section of the nacelle with a flow channel in the outer ring element;

[0071] FIG. 4 a sectional view of the outer ring element with the flow channel;

[0072] FIG. 5 a cross-section of a nacelle with a parted nacelle housing in a very schematic representation;

[0073] FIG. 6 an exemplary embodiment of a mechanical seal with a sliding surface formed on a sleeve;

[0074] FIG. 7 an exemplary embodiment of a labyrinth seal with an oil drain.

[0075] First of all, it is to be noted that in the different embodiments described, equal parts are provided with equal reference numbers and/or equal component designations, where the disclosures contained in the entire description may be analogously transferred to equal parts with equal reference numbers and/or equal component designations. Moreover, the specifications of location, such as at the top, at the bottom, at the side, chosen in the description refer to the directly described and depicted figure and in case of a change of position, these specifications of location are to be analogously transferred to the new position.

[0076] FIG. 1 shows a schematic representation of a wind turbine 1 for generating electrical energy from wind energy. The wind turbine 1 comprises a nacelle 2, which is rotatably received on a tower 3. The nacelle 2 comprises a nacelle housing 4, which forms the main structure of the nacelle 2. In the nacelle housing 4 of the nacelle 2, the electrotechnical components such as a generator of the wind turbine 1 are arranged.

[0077] Moreover, a rotor 5 is formed, which has a rotor hub 6 with rotor blades 7 arranged thereon. The rotor hub 6 is considered part of the nacelle 2. The rotor hub 6 is received so as to be rotatable on the nacelle housing 4 by means of a rotor bearing 8.

[0078] The rotor bearing 8, which serves for bearing the rotor hub 6 on the nacelle housing 4 of the nacelle 2, is configured for absorbing a radial force 9, an axial force 10 and a tilting torque 11. The axial force 10 is caused by the force of the wind. The radial force 9 is caused by the weight force of the rotor 5 and is effective at the center of gravity of the rotor 5. As the center of gravity of the rotor 5 is outside the rotor bearing 8, the tilting torque 11 is generated in the rotor bearing 8 by the radial force 9. The tilting torque 11 may also be caused by an uneven load of the rotor blades 7.

[0079] The rotor bearing 8 according to the invention can have a diameter of 0.5 m to 5 m, for example. Of course, it is also conceivable that the rotor bearing 8 is smaller or larger.

[0080] FIG. 2 shows the nacelle housing 4 and the rotor hub 6 in a schematic sectional representation, wherein the structure, in particular its dimensions, are highly schematized. As can be seen from FIG. 2, it may be provided that the rotor bearing 8 has at least one inner ring element 12 and least one outer ring element 13. At least one sliding bearing element 14 is arranged between the inner ring element 12 and the outer ring element 13.

[0081] As can be seen from FIG. 2, it may be provided that the inner ring element 12 is coupled with the rotor hub 6. In particular, it may be provided that a rotor shaft 15 is formed, on which the rotor hub 6 is arranged. The inner ring element 12 can be received directly on the rotor shaft 15.

[0082] In a further exemplary embodiment that is not depicted, it may of course also be provided that the inner ring element 12 is received directly on the rotor hub 6.

[0083] In yet another exemplary embodiment that is not depicted, it may of course also be provided that the inner ring element 12 is fastened to the nacelle housing 4, and that the rotor hub 6 is coupled with the outer ring element 13.

[0084] As can be seen from FIG. 2, it may be provided that both the inner ring element 12 and the outer ring element 13 are V-shaped, and two sliding bearing elements 14 are each formed so as to be spaced apart from each other on the V-shaped flank between the two ring elements 12, 13, which sliding bearing elements 14 are arranged at an angle to one another. As can be seen from FIG. 2, an exemplary embodiment may provide that the sliding bearing elements 14 are fastened to the inner ring element 12 by means of a fastening means 16. Hence, a sliding surface 17 may be formed between the sliding bearing elements 14 and the outer ring element 13. In an arrangement of the sliding bearing elements 14 as it is shown in FIG. 2, the sliding surfaces 17 may also be arranged in a V-shape.

[0085] As can also be seen from FIG. 2, it may be provided that the inner ring element 12 is designed to be parted with regard to its axial extension, in order to make the assembly of the rotor bearing 8 easier.

[0086] In an exemplary embodiment that is not depicted, it is of course also conceivable that the inner ring element 12 does not form a groove as shown in the exemplary embodiment of FIG. 2, but rather that the V-shaped arrangement has a reverse formation, so that a V-shaped projection is formed on the inner ring element 12. In this case, it may be provided for the purpose of an easier assembly that the outer ring element 13 is designed to be parted in its axial extension.

[0087] Both in a design with an inner ring element 12 partible in the axial extension and in a design with an outer ring element 13 partible in the axial extension, it may be provided that the individual parts of the respective partibly designed ring element 12, 13 are formed so as to be axially adjustable relative to one another, in order to be able to compensate for example the wear of the sliding bearing elements 14. In particular, it may be provided that due to the axial adjustability of the individual parts of the ring elements 12, 13 relative to one another, the bearing gap can be adjusted.

[0088] As can further be seen from FIG. 2, it is provided that a lubricating oil sump 18 is formed, which serves for receiving lubricating oil 19. In the operating state, the lubricating oil sump 18 is filled with lubricating oil 19 up to a lubricating oil level 20. In this regard, the lubricating oil level 20 is selected such that the sliding surfaces 17 are at least partially below the lubricating oil level 20 and thus are immersed in the lubricating oil 19 situated in the lubricating oil sump 18.

[0089] The sliding bearing elements 14 are designed as hydrodynamic sliding bearings, whereby a lubricating oil film forms on the sliding surface 17 when the rotor hub 6 rotates about a rotor axis 21, which lubricating oil film serves the hydrodynamic bearing of the sliding bearing element 14.

[0090] For introducing lubricating oil 19 to the sliding surface 17, it may be provided that lubricating oil bores 22 are formed in the inner ring element 12 and/or in the outer ring element 13, which lubricating oil bores 22, depending on the rotation position of the rotor hub 6, open into the lubricating oil sump 18 at a first longitudinal end and end into an intermediate space between the inner ring element 12 and the outer ring element 13 at their second longitudinal end. By this measure, it can be achieved that sufficient lubricating oil 19 can be introduced to the sliding bearing element 14.

[0091] Moreover, it is also possible for lubricating oil bores 23 to be provided which open directly into the sliding surface 17. By means of these lubricating oil bores 23, the sliding surface 17 can be fluidically connected directly to the lubricating oil sump 18, so that sufficient lubricating oil 19 can be introduced to the sliding surface 17. In particular, it may be provided that due to the movement of the sliding bearing element 14 relative to the outer ring element 13, lubricating oil 19 is sucked into the sliding surface 17 via the lubricating oil bore 23 and/or the lubricating oil bore 22 and there, a lubricating oil film for the lubrication and/or bearing of the sliding bearing element 14 is formed.

[0092] In order to achieve a good lubricating effect of the sliding bearing element 14, it may be provided that, as shown in FIG. 2, at least a section of the sliding surface 17, with regard to its width, is situated entirely below the lubricating oil level 20.

[0093] Moreover, it may be provided that a sealing element 24 is formed, which serves to seal the rotor hub 6 from the nacelle housing 4. As can be seen from FIG. 2, it may be provided that the sealing element 24 acts between a front side 25 of the nacelle housing 4 and between a front side 26 of the rotor hub 6. In particular, it may be provided that the lubricating oil sump 18 extends over both the nacelle housing 4 and the rotor hub 6 and thus, the sealing element 24 is situated below the lubricating oil level 20 at least in some sections.

[0094] As can further be seen from FIG. 2, it may be provided that the sealing element 24 is accommodated in the nacelle housing 4.

[0095] FIG. 3 shows a further and possibly independent embodiment of the nacelle 2, wherein again, equal reference numbers and/or component designations are used for equal parts as in FIGS. 1 through 2 above. In order to avoid unnecessary repetitions, it is pointed to/reference is made to the detailed description in FIGS. 1 through 2 preceding it.

[0096] As can be seen from FIG. 3, it may be provided that a flow channel 27 is formed in the outer ring element 13, which flow channel 27 is fluidically connected to the lubricating oil bores 23 and serves the improved distribution of lubricating oil 19 in the sliding surface 17.

[0097] FIG. 4 shows a sectional view according to section line IV-IV in FIG. 3. As can be seen from FIG. 4, it may be provided that the flow channel 27 extends over a flow channel angle 28, which is preferably selected such that the flow channel 27 is arranged entirely below the lubricating oil level 20. In particular, it may be provided that the flow channel angle 28 is between 10° and 160°, preferably between 45° and 80°.

[0098] Moreover, it is provided that a flow channel width 29 is selected such that it is smaller than a width 30 of the sliding bearing element 14. As can be seen from FIG. 4, it may be provided that multiple of the lubricating oil bores 23 open into the flow channel 27. Moreover, it may be provided that the flow channel 27 tapers off in the shape of a wedge gap 31. By this measure, a lubrication film can be formed.

[0099] In a first exemplary embodiment, it may be provided that the flow channel 27 on both sides in the circumferential direction tapers off in the shape of a wedge gap 31.

[0100] In a further exemplary embodiment, it may be provided that, viewed in the main direction of rotation 32, the wedge gap 31 is formed only at the end of the flow channel 27.

[0101] As can further be seen from FIG. 4, it may be provided that the sliding bearing element 14 has multiple sliding bearing pads 33, which are arranged on the inner ring element 12 so as to be distributed across the circumference. The sliding bearing pads 33 may in particular be arranged on the inner ring element 12, such that a continuous sliding surface 17 is formed, which can act as a hydrodynamic bearing. In particular, it may be provided that the sliding surface 17 has the shape of a frustum.

[0102] FIG. 5 shows a further and possibly independent embodiment of the nacelle 2, wherein again, equal reference numbers and/or component designations are used for equal parts as in FIGS. 1 through 4 above. In order to avoid unnecessary repetitions, it is pointed to/reference is made to the detailed description in FIGS. 1 through 4 preceding it.

[0103] As can be seen from FIG. 5, it may be provided that the lubricating oil sump 18 is formed entirely in the nacelle housing 4. In this regard, it may in particular be provided that the sealing elements 24, in particular their sealing surface 34, are situated entirely above the lubricating oil level 20. In order to enable and/or facilitate the assembly and/or the maintenance of a nacelle housing 4 and/or rotor bearing 8 constructed in such a manner, it may be provided that the nacelle housing 4 has a main part of the housing 35 and a lubricating oil sump lid 36. In particular, it may be provided that the main part of the housing 35 and the lubricating oil sump lid 36 delimit the lubricating oil sump 18. In this regard, it may be provided that the lubricating oil sump lid 36 is fastened to the main part of the housing 35 by means of a fastening means 37.

[0104] As can be seen from FIG. 5, it may be provided that, one sealing element 24 each is arranged on either side of the lubricating oil sump 18, when viewed in the axial direction of the rotor axis 21. In particular, it may be provided that the sealing elements 24 are formed as a radial seal ring. One of the sealing elements 24 can, in this regard, be arranged in the main part of the housing 35, the second of the sealing elements 24 may be arranged in the lubricating oil sump lid 36.

[0105] Moreover, it may be provided that the sealing elements 24 cooperate with the rotor shaft 15. In particular, it may be provided here that the sliding surface 17 is formed on the rotor shaft 15. In particular, it may be provided that for this purpose, the rotor shaft 15 locally has a particularly formed surface, which is formed for example by a sliding lacquer coating. Such a sliding lacquer coating may particularly be provided when using mechanical seals.

[0106] Moreover, it may be provided that an oil drip element 38 is formed on the rotor shaft 15, which oil drip element 38 serves to prevent lubricating oil 19 from reaching the sealing element 24 along the rotor shaft 15 in the axial direction. The oil drip element 38 may for example be designed in the form of a plunge-cut groove. In an alternative embodiment variant, it may also be provided that the oil drip element 38 is designed, for example, in the form of a circumferential elevation on the rotor shaft 15.

[0107] FIG. 6 shows a further exemplary embodiment of the arrangement of the sealing element 24 in a detailed view. As can be seen from FIG. 6, it may be provided that a sliding sleeve 39 is arranged on the rotor shaft 15, on which sliding sleeve 39 the sealing surface 34 is formed. Such an arrangement may particularly be useful when using mechanical seals.

[0108] In a further exemplary embodiment that is not depicted, it may also be provided that the sliding sleeve 39 is received directly on the rotor hub 6, and the sealing element 24 thus serves to seal the rotor hub 6.

[0109] FIG. 7 shows a further exemplary embodiment of sealing element 24. As can be seen from FIG. 7, it may be provided that the sealing element 24 is designed in the form of a labyrinth seal, which for example cooperates with the lubricating oil sump lid 36. In particular, it may be provided that a return line 40 is formed, which serves to return the lubricating oil 19 into the lubricating oil sump 18. As can be seen in FIG. 7, the return line may be designed in the form of a bore, which starts at the lowest point of the labyrinth seal and leads into the lubricating oil sump 18.

[0110] The exemplary embodiments show possible embodiment variants, and it should be noted in this respect that the invention is not restricted to these particular illustrated embodiment variants of it, but that rather also various combinations of the individual embodiment variants are possible and that this possibility of variation owing to the teaching for technical action provided by the present invention lies within the ability of the person skilled in the art in this technical field.

[0111] The scope of protection is determined by the claims. However, the description and the drawings are to be adduced for construing the claims. Individual features or feature combinations from the different exemplary embodiments shown and described may represent independent inventive solutions. The object underlying the independent inventive solutions may be gathered from the description.

[0112] All indications regarding ranges of values in the present description are to be understood such that these also comprise random and all partial ranges from it, for example, the indication 1 to 10 is to be understood such that it comprises all partial ranges based on the lower limit 1 and the upper limit 10, i.e. all partial ranges start with a lower limit of 1 or larger and end with an upper limit of 10 or less, for example 1 through 1.7, or 3.2 through 8.1, or 5.5 through 10.

[0113] Finally, as a matter of form, it should be noted that for ease of understanding of the structure, elements are partially not depicted to scale and/or are enlarged and/or are reduced in size.

LIST OF REFERENCE NUMBERS

[0114]

TABLE-US-00001  1 wind turbine  2 nacelle  3 tower  4 nacelle housing  5 rotor  6 rotor hub  7 rotor blade  8 rotor bearing  9 radial force 10 axial force 11 tilting torque 12 inner ring element 13 outer ring element 14 sliding bearing element 15 rotor shaft 16 fastening means 17 sliding surface 18 lubricating oil sump 19 lubricating oil 20 lubricating oil level 21 rotor axis 22 lubricating oil bore of the ring element 23 lubricating oil bore 24 sealing element 25 front side of the nacelle housing 26 front side of the rotor hub 27 flow channel 28 flow channel angle 29 flow channel width 30 width of the sliding bearing element 31 wedge gap 32 main direction of rotation 33 sliding bearing pad 34 sealing surface 35 main part of the housing 36 lubricating oil sump lid 37 fastening element 38 oil drip element 39 sliding sleeve 40 return line