SLIDE BEARING, IN PARTICULAR FOR A GEARBOX OF A WIND TURBINE

Abstract

A sliding bearing for a gearbox of a wind turbine, having a support body and a sliding layer which is applied on the support body, and on which a sliding surface is formed, wherein a lubricant distribution groove extending in an axial direction of the sliding surface is formed on the sliding surface. The support body is formed as a bush rolled from a support body strip, wherein a first longitudinal end and a second longitudinal end of the support body strip are connected to one another in a materially bonded manner, in particular by a welding connection, at a joint, wherein the joint is formed in the region of the lubricant distribution groove.

Claims

1. A sliding bearing (22), in particular for a gearbox of a wind turbine, having a support body (27) and a sliding layer (30) which is applied on the support body (27), and on which a sliding surface (17) is formed, wherein a lubricant distribution groove (19) extending in an axial direction (31) of the sliding surface (17) is formed on the sliding surface (17), wherein the support body (27) is formed as a bush (35) rolled from a support body strip (32), wherein a first longitudinal end (33) and a second longitudinal end (34) of the support body strip (32) are connected to one another in a materially bonded manner, in particular by a welding connection, at a joint (23), wherein the joint (23) is formed in the region of the lubricant distribution groove (19).

2. The sliding bearing (22) according to claim 1, wherein a lubricating oil bore (18) opens into the lubricant distribution groove (19).

3. The sliding bearing (22) according to claim 1, wherein the sliding surface (17) is formed on an outer jacket surface (16) of the sliding bearing (22), wherein the lubricant distribution groove (19) is formed by a notch in the form of a flattening.

4. The sliding bearing (22) according to claim 1, wherein the joint (23) comprises a clearance (24) across the entire axial extension (25) of the sliding bearing (22) and an axial extension (26) of the lubricant distribution groove (19) merely extends across a partial section of the axial extension (25) of the sliding bearing (22).

5. The sliding bearing (22) according to claim 1, wherein the lubricant distribution groove (19) has a maximum depth (38) and the sliding layer (30) has a layer thickness (39), wherein the maximum depth (38) of the lubricant distribution groove (19) is equally large or smaller than the layer thickness (39) of the sliding layer (30).

6. The sliding bearing (22) according to claim 1, wherein the clearance (24) has a maximum depth (41), wherein the maximum depth (41) of the clearance (24) is smaller than the maximum depth (38) of the lubricant distribution groove (19).

7. A planetary gearbox (1) for a wind turbine, having at least one sliding bearing (22), in particular a planetary gear radial sliding bearing (14), wherein the sliding bearing (22) is designed according to claim 1.

8. A method for producing a sliding bearing (22), in particular for a gearbox of a wind turbine, wherein the sliding bearing (22) comprises a support body (27) and a sliding layer (30) which is applied on the support body (27), and on which a sliding surface (17) is formed, wherein a lubricant distribution groove (19) extending in an axial direction (31) is formed on the sliding surface (17), comprising the method steps: providing a support body strip (32) having a first longitudinal end (33) and a second longitudinal end (34); rolling the support body strip (32) to a bush (35), which forms the support body (27); establishing a materially bonded connection of the first longitudinal end (33) and the second longitudinal end (34) of the support body strip (32) at a joint (23); inserting the lubricant distribution groove (19) into the sliding layer (30), wherein the lubricant distribution groove (19) is arranged at a location on the sliding bearing (22), at which the joint (23) is formed.

9. The method for producing a sliding bearing (22) according to claim 8, wherein the sliding layer (30) or parts thereof is/are applied to the still flat support body strip (32), in particular that the sliding layer (30) is applied to the support body strip (32) by roll cladding.

10. The method for producing a sliding bearing (22) according to claim 8, wherein the lubricant distribution groove (19) and/or the clearance (24) of the joint (23) is produced by mechanical processing, in particular by milling.

Description

[0025] For the purpose of better understanding of the invention, it will be elucidated in more detail by means of the figures below.

[0026] These show in a respectively very simplified schematic representation:

[0027] FIG. 1 a sectional view of an embodiment variant of the planetary gearbox;

[0028] FIG. 2 a perspective representation of a first exemplary embodiment of a sliding bearing in a first view;

[0029] FIG. 3 a perspective representation of a first exemplary embodiment of a sliding bearing in a second view;

[0030] FIG. 4 a sectional view according to section line IV-IV in FIG. 2;

[0031] FIG. 5 a schematic representation of the sequence of the individual production steps for producing the sliding bearing.

[0032] 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.

[0033] FIG. 1 shows an exemplary embodiment of a planetary gearbox 1 in a sectional view according to a cross section along a centerline 2 of the planetary gearbox 1. The view according to FIG. 1 is shown schematically and serves for general explanation of the structure of the planetary gearbox and for showing the components installed in a planetary gearbox.

[0034] As is known, wind turbines comprise a tower on the upper end of which a nacelle is arranged, in which the rotor with the rotor blades is mounted. This rotor is operatively connected to a generator, which is also located in the nacelle, via the planetary gearbox 1, wherein the low rotational frequency of the rotor is translated into a higher rotational frequency of the generator rotor via the planetary gearbox 1. Since such designs of wind turbines are part of the prior art, at this point, reference is made to the relevant literature in this regard.

[0035] The planetary gearbox 1 has a sun gear 3 connected in a motion-coupled manner to a shaft 4 leading to the generator rotor. The sun gear 3 is surrounded by multiple planetary gears 5, for example two, preferably three. Both the sun gear 3 and the planetary gears 5 have outer end toothings, which are engaged in a meshing arrangement, wherein these end toothings are schematically represented in FIG. 1.

[0036] The planetary gears 5 are each accommodated in a planetary carrier 7 by means of a planetary gear bolt 6. Moreover, it may be provided that the planetary gear bolt 6 is fixed and/or accommodated in a first planet carrier cheek 8 and a second planet carrier cheek 9 in a force-fitted or positively locked manner In particular, it may be provided that the planetary gear bolt 6 is secured against rotation via any not explicitly shown securing element. The two planet carrier cheeks 8, 9 are parts of the planetary carrier 7.

[0037] An internal gear 10 is arranged to surround the planetary gears 5, which internal gear has an internal toothing which is engaged in a meshing arrangement with the end toothing of the planetary gears 5. The internal gear 10 may be formed in a single-part or multi-part planetary gearbox housing 11, and/or coupled thereto.

[0038] Moreover, it may be provided that in the planetary gearbox housing 11 at least one planetary carrier radial sliding bearing 12 is arranged, which serves for bearing the planetary carrier 7 in the planetary gearbox housing 11.

[0039] In particular, it may be provided that in the first planet carrier cheek 8, an oil distribution channel section 13 is formed, by means of which the individual sliding surfaces 17 of the individual sliding bearings 12, 14, 21 may be supplied with lubricating oil.

[0040] Moreover, it may be provided that for bearing the planetary gears 5, at least one planetary gear radial sliding bearing 14 is provided on the planetary gear bolts 6 of each planetary gear 5.

[0041] According to a first embodiment variant, the planetary gear radial sliding bearing 14 is mounted on an inner jacket surface 15 on the planetary gear bolt 6. A sliding surface 17 is formed on an outer jacket surface 16 of the planetary gear radial sliding bearing 14. Moreover, it may be provided that in the planetary gear radial sliding bearing 14, a lubricating oil bore 18 is formed which is guided from the inner jacket surface 15 of the planetary gear radial sliding bearing 14 to the outer jacket surface 16 of the planetary gear radial sliding bearing 14.

[0042] Moreover, it may be provided that at least one lubricant distribution groove 19, which is fluidically coupled to the lubricating oil bore 18 in the planetary gear radial sliding bearing 14 is formed on the outer jacket surface 16 of the planetary gear radial sliding bearing 14. In particular, it may be provided that two lubricating oil bores 18 and two lubricant distribution grooves 19 are formed on the planetary gear radial sliding bearing 14 so as to diametrically oppose one another. A detailed exemplary embodiment of the planetary gear radial sliding bearing 14 will be described below in FIG. 2 in more detail.

[0043] As can also be seen from FIG. 1, it may be provided that oil distribution channel sections 20, which open into the lubricating oil bores 18 of the planetary gear radial sliding bearing 14, are formed in the planetary gear bolt 6.

[0044] As can further be seen from FIG. 1, it may be provided that a sun gear radial sliding bearing 21 is formed which serves for bearing the shaft 4 on which the sun gear 3 is mounted. In particular, it may be provided that the first sun gear radial sliding bearing 21 is arranged between a cavity of the first planet carrier cheek 8 and the shaft 4.

[0045] FIGS. 2 and 3 show a further and possibly independent embodiment of the sliding bearing 22, wherein again, equal reference numbers/component designations are used for equal parts as before in FIG. 1. In order to avoid unnecessary repetitions, it is pointed to/reference is made to the detailed description in FIG. 1 preceding it.

[0046] FIG. 2 shows a first exemplary embodiment of the sliding bearing 22 in a first perspective view of its front side.

[0047] FIG. 3 shows the first exemplary embodiment of the sliding bearing 22 in a second perspective view of its rear side.

[0048] In a gearbox for wind turbines, in particular in the planetary gearbox 1, the planetary carrier radial sliding bearing 12 and/or the planetary gear radial sliding bearing 14 and/or the sun gear radial sliding bearing 21 may have the structure described in FIG. 2. Of course, other sliding bearings, which are not installed in a wind turbine, may also have the structure according to the invention. Thus, for the sake of simplicity, the entirety of sliding bearings having the structure according to the invention are generally referred to as sliding bearings 22 in the present document. The structure of the sliding bearing 22 described in FIG. 2 may be used particularly for the planetary gear radial sliding bearing 14. Thus, the planetary gear radial sliding bearing 14 is described in detail, while, however, reference is made to the fact that the structure according to the invention may analogously be designed for all sliding bearings 22, in particular sliding bearings 22 used in a gearbox for wind turbines.

[0049] As can be seen in FIGS. 2 and 3, it may be provided that the sliding bearing 22 comprises two diametrically opposing lubricant distribution grooves 19 on its outer jacket surface 16. Of course, merely one lubricant distribution groove 19 or a larger number of lubricant distribution grooves 19 may be formed on the sliding bearing 22, which may be arranged across the circumference so as to be distributed uniformly or irregularly.

[0050] Moreover, it may be provided that the lubricating oil bores 18 each open into the lubricant distribution groove 19. The lubricating oil bores 18 serve for guiding lubricating oil from the inner jacket surface 15 of the sliding bearing 22 to the outer jacket surface 16 of the sliding bearing 22.

[0051] As can be seen particularly from FIG. 2, it may be provided that the sliding bearing 22 is formed as a rolled element, which is connected via a materially bonded connection at a joint 23 and thus forms a bush. The materially bonded connection of the joint 23 may for example be established by means of a welding process.

[0052] As a welding process, for example, laser welding may be used. In particular, it may be provided that in one method step, that side of the joint 23 is welded on which the support body 27 is formed. In this regard, the energy input by the laser beam may be selected such that merely the material of the support body 27, in particular steel, is melted, such that no melt mixture with the material of the bearing metal layer 28 occurs. In a further method step, that side of the joint 23 may be welded on which the bearing metal layer 28 is formed, so as to also melt this layer. In this regard, the energy input by the laser beam may be selected such that merely the material of the bearing metal layer 28 is melted, such that no melt mixture with the material of the support body 27 occurs. This results in a joint 23 with a surprisingly high solidity.

[0053] The described approach may, of course, be applied in both, those sliding bearings 22 in which the support body 27 forms the innermost layer and those sliding bearings 22 in which the support body 27 forms the outermost layer.

[0054] In a further embodiment variant, it may also be provided that electron-beam welding is used as the welding method. Of course, the methodology described above may be used also in this welding method.

[0055] In the alternative to this, it is also conceivable that the materially bonded connection at the joint 23 is established by means of a soldering method.

[0056] As can further be seen from FIG. 2, it may be provided that in the region of the joint 23 a clearance 24 is formed, by means of which it may be achieved that possible protrusions of the weld seam produced by the joining process do not extend into an enveloping cylinder of the sliding surface 17 and thus the sliding properties of the sliding bearing 22 are not impaired.

[0057] As can be seen from FIG. 2, it is provided that the lubricant distribution groove 19 is formed in the region of the joint 23. Hence, it may be achieved that the required clearance 24 and the lubricant distribution groove 19 coincide a least in some sections. The production process of the sliding bearing 22 may thus be facilitated.

[0058] As can further be seen from FIG. 2, it may be provided that the clearance 24 extends across the entire axial extension 25 of the sliding bearing 22. An axial extension 26 of the lubricant distribution groove 19 may be smaller than the axial extension 25 of the sliding bearing 22. In particular, it may be provided that the lubricant distribution groove 19 is arranged on the sliding bearing 22 centrally with respect to the axial extension 25 thereof. Moreover, it may also be provided that the lubricating oil bore 18 is arranged on the sliding bearing 22 centrally with respect to the axial extension 25 thereof. As can be seen from the exemplary embodiment according to FIG. 2, it may be provided that the lubricating oil bore 18 is arranged centrally in the lubricant distribution groove 19 also as viewed in the circumferential direction. Moreover, it may be provided that the joint 23 is arranged centrally to the lubricant distribution groove 19 in the circumferential direction.

[0059] In a further exemplary embodiment, which is not shown, it may also be provided that the lubricating oil bore 18 and/or the joint 23 are arranged eccentrically to the lubricant distribution groove 19 as viewed in the circumferential direction. Thereby, it may for example be achieved that the lubricating oil bore 18 is not arranged in the region of the joint 23 but next to the joint 23.

[0060] As can further be seen from FIGS. 2 and 3, the lubricant distribution groove 19 extends in an axial direction 31. The joint 23 also extends in the axial direction 31.

[0061] FIG. 4 shows a detail view of the sliding bearing 22 in a section IV-IV, wherein again, equal reference numbers and/or component designations are used for equal parts as in FIGS. 1 through 3 above. In order to avoid unnecessary repetitions, it is pointed to/reference is made to the detailed description in FIGS. 1 through 3 preceding it.

[0062] As can be seen from FIG. 4, it may be provided that the sliding bearing 22 comprises a support body 27, a bearing metal layer 28 as well as a polymer layer 29. The sliding surface 17 may be formed on the polymer layer 29.

[0063] The support body 27 preferably consists of a metallic material, commonly of steel, may, however, also consist of a material by means of which the same and/or a similar function, namely the provision of the mechanical strength of the sliding bearing 22 may be realized. For example, diverse copper alloys, such as brass, bronzes, may be used.

[0064] The bearing metal layer 28 is formed by a bearing metal alloy. Such bearing metal alloys are known from the prior art. For example, the bearing metal alloy can be formed by an alloy based on tin, bismuth, indium, lead or aluminum as well as alloys based on CuPb, possibly with a high lead content, or on AlSn or AlBi.

[0065] Although the sliding bearing 22 is shown as a three-layer bearing element in FIG. 1, the sliding bearing 22 may also have less or more than three layers. For example, the polymer layer 29 may be applied directly onto the support body 27. Likewise, common intermediate layers, such as at least one bonding layer or at least one diffusion barrier layer, may be arranged if required. The at least one bonding layer may for example be arranged between the support body 27 and the bearing metal layer 28 and/or between the bearing metal layer 28 and the polymer layer 29. The at least one diffusion barrier layer may for example be arranged between the support body 27 and the bearing metal layer 28 and/or between the bearing metal layer 28 and the polymer layer 29.

[0066] For the sake of simplicity, the layer structure applied at the support body 27, which may for example comprise the bearing metal layer 28 and the polymer layer 29, is referred to as sliding layer 30.

[0067] The polymer layer 29 may comprise solid lubricant particles and metal oxide particles and merely a polyimide polymer or a polyamide-imide polymer as its polymer and/or preferably consist of these components.

[0068] The polyimide polymer may for example be selected from a group comprising or consisting of polyimide (PI), polysuccinimide (PSI), polybismaleinimide (PBMI), polybenzimidazole (PBI), polyoxadiazobenzimidazole (PBO), and polyimide sulfone (PISO), and mixtures thereof.

[0069] Preferably, the polymer is a polyamideimide. The polyamideimide may comprise at least partially aromatic groups, preferably it is a fully aromatic polyamideimide.

[0070] FIG. 5 schematically shows the individual method steps for producing the sliding bearing 22. As can be seen in FIG. 5, it may be provided that a support body strip 32 is provided which comprises a first longitudinal end 33 and a second longitudinal end 34. In a first exemplary embodiment, the support body strip 32 may comprise the sliding layer 30 which has already been applied to the support body strip 32. In this regard, the sliding layer 30 may, for example, have been applied to the support body strip 32 by roll cladding.

[0071] In a further embodiment variant, it may also be provided that the sliding layer 30 is applied only to the finished rolled support body 27.

[0072] As can be seen from FIG. 5, it may be provided that the support body strip 32 is rolled to a bush 35 by means of a rolling process, wherein the first longitudinal end 33 and the second longitudinal end 34 of the support body strip 32 are approximated to one another. In the finished rolled bush 35, the first longitudinal end 33 and the second longitudinal end 34 may be adjacent to each other and/or spaced a small distance apart such that the two longitudinal ends 33, 34 can be connected in a materially bonded manner at the joint 23.

[0073] In an embodiment variant in which the sliding layer 30 has already been applied to the support body strip 32, it may be provided that either already in the flat support body strip 32 or only in a rolled bush 35, the sliding layer 30 is removed in the region of the longitudinal ends 33, 34, such that the longitudinal ends 33, 34 of the support body strip 32 are freely accessible for the materially bonded connection. This method step may optionally also be left out.

[0074] In a further method step, subsequently, the first longitudinal end and the second longitudinal end 33, 34 of the support body strip 32 may be welded together at the joint 23. In a subsequent method step, the clearance 24 may be generated by mechanical removal, in particular by milling. In particular, the protruding material of the weld seam is removed in the clearance 24.

[0075] If, as described above, the sliding layer 30 has already been sufficiently removed before welding the two longitudinal ends 33, 34 of the support body strip 32, this can optionally act as the clearance 24 subsequently, which means that no further processing step is required after the welding process.

[0076] In a further processing step, the lubricant distribution groove 19 may be generated by mechanical removal, in particular by milling

[0077] As can be seen from FIG. 4, it may be provided that the lubricant distribution groove 19 comprises a groove base 36 which tapers off into the outer jacket surface 16 of the sliding bearing 22. In such a design, a wedge gap 37 forms at the edge of the lubricant distribution groove 19 as seen in the circumferential direction.

[0078] In an alternative embodiment variant, it may of course also be provided that the groove base 36 of the lubricant distribution groove 19 does not taper off into the outer jacket surface 16 but that the lubricant distribution groove 19 is provided in the form of a recess and the groove base 36 is thus bounded by side walls as seen in the circumferential direction. The lubricant distribution groove 19 has a maximum depth 38 which is measured starting out from an enveloping cylinder of the outer jacket surface 16. The maximum depth 38 of the lubricant distribution groove 19 may extend across a layer thickness 39 of the sliding layer 30.

[0079] The width 40 of the lubricant distribution groove 19 results from the diameter of the outer jacket surface 16 and the maximum depth 38 of the lubricant distribution groove 19.

[0080] The clearance 24 has a maximum depth 41, which is also measured from an enveloping cylinder of the outer jacket surface 16 to a groove base 42 of the clearance 24. As can be seen from FIG. 4, it may be provided that, as viewed in the circumferential direction, a first clearance groove wall 44 and/or a second clearance groove wall 45 are formed, which form a transition between the groove base 42 of the clearance 24 and the outer jacket surface 16 of the sliding bearing 22. This is the case where the maximum depth 41 of the clearance 24 is selected to be so large in relation to the width 43 of the clearance 24 that the groove base 42 of the clearance 24 cannot taper off into the outer jacket surface 16 of the sliding bearing 22.

[0081] As can be seen from FIG. 4, it may be provided that the maximum depth 38 of the lubricant distribution groove 19 is larger than the maximum depth 41 of the clearance 24. The maximum depth 41 of the clearance 24 is selected to be as small as possible such that during the use of the sliding bearing 22 as little as possible of the lubricant guided into the lubricant distribution groove 19 can leak axially via the clearances 24.

[0082] As can be seen from FIG. 4, it may be provided that the width 40 of the lubricant distribution groove 19 is larger than the width 43 of the clearance 24.

[0083] In a further exemplary embodiment, which is not shown, it may of course also be provided that the sliding surface 17 and thus also the lubricant distribution grooves 19 are arranged on the inner jacket surface 15 of the sliding bearing 22. It is within the capabilities of the person skilled in the art to redesign the structure of the sliding bearing accordingly on the basis of the exemplary embodiment described.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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

[0088]

TABLE-US-00001 1 planetary gearbox 2 centerline of planetary gearbox 3 sun gear 4 shaft 5 planetary gear 6 planetary gear bolt 7 planetary carrier 8 first planet carrier cheek 9 second planet carrier cheek 10 internal gear 11 planetary gearbox housing 12 planetary carrier radial sliding bearing 13 oil distribution channel section of the first planet carrier cheek 14 planetary gear radial sliding bearing 15 inner jacket surface of the planetary gear radial sliding bearing 16 outer jacket surface of the planetary gear radial sliding bearing 17 sliding surface of the planetary gear radial sliding bearing 18 lubricating oil bore of the planetary gear radial sliding bearing 19 lubricant distribution groove 20 oil distribution channel section of the planetary gear bolt 21 sun gear radial sliding bearing 22 sliding bearing 23 joint 24 clearance 25 axial extension of the sliding bearing 26 axial extension of the lubricant distribution groove 27 support body 28 bearing metal layer 29 polymer layer 30 sliding layer 31 axial direction 32 support body strip 33 first longitudinal end 34 second longitudinal end 35 bush 36 groove base of the lubricant distribution groove 37 wedge gap 38 maximum depth of the lubricant distribution groove 39 layer thickness of the sliding layer 40 width of the lubricant distribution groove 41 maximum depth of the clearance 42 groove base of the clearance 43 width of the clearance 44 first clearance groove wall 45 second clearance groove wall