Hydrodynamic rotor shaft plain bearing for a rotor shaft, in particular of a wind turbine

Abstract

The invention relates to a hydrodynamic rotor shaft plain bearing for a rotor shaft (10), in particular of a wind turbine, the hydrodynamic rotor shaft plain bearing comprising a first and a second radial bearing (2, 3) and an axial bearing (12), wherein the first radial bearing (2) has a first radial bearing housing (4) and the second radial bearing (3) has a second radial bearing housing (5), in each of which a plurality of radial bearing segments (6, 7) are provided, and the axial bearing (12) has a separate axial bearing housing (13) with a plurality of axial bearing segments (15) accommodated therein, wherein the axial bearing (12) is arranged between the two radial bearings (2, 3), and the axial bearing housing (13) consists of a plurality of separate housing segments (14, 14a) on which the axial bearing segments (15, 15a) are arranged, wherein each housing segment (14, 14a) is fastened to the first and the second radial bearing housing (4, 5), thereby connecting them, and can be moved, after detaching the fastening, from a working position in which the axial bearing segment or segments (15, 15a) provided thereon are positioned in a working position on the rotor shaft (10), into a non-working position in which the axial bearing segments (15, 15a) are spaced apart from the rotor shaft (10).

Description

[0001] Hydrodynamic rotor shaft guide bearing for a rotor shaft, particularly of a wind turbine

[0002] The invention relates to a hydrodynamic rotor shaft plain bearing for a rotor shaft, in particular of a wind turbine, comprising a first and a second radial bearing and an axial bearing.

[0003] A wind turbine usually has several rotor blades arranged on a hub. The hub is connected to a rotor shaft, which in turn is coupled to a gearbox, followed by a generator, whose rotor may be connected to an output shaft of the gearbox. Due to the interaction of the rotor blades with the oncoming wind, the rotor shaft, including the hub and the downstream drive train, rotate, so that the generator generates electricity. Inevitably, the rotor shaft also rotates and is mounted accordingly. On the one hand, the rotor shaft is mounted via a radial bearing, which usually consists of two axially spaced radial bearings that radially support the rotor shaft. In addition to the radial bearing, an axial bearing is usually also provided, which preferably allows the rotor shaft to be supported in both directions. Typically, an axial load is applied to the rotor side, resulting from the oncoming wind.Due to changing wind or flow conditions, for example, during a strong gust, the direction of the axial load can be reversed, meaning that the axial load is applied from the gearbox side, meaning the wind load acts from the gearbox side onto the rotor blades. Therefore, axial bearings on both sides are advisable.

[0004] The rotor shaft bearings can be implemented using rolling bearings. Each bearing has several rolling elements. In the case of radial bearings, these are guided in an outer ring and run on an inner ring connected to the rotor shaft. In the case of axial bearings, these are guided on an axial bearing disk and run on a corresponding axial bearing section provided on the rotor shaft. Such rolling bearings are very solid and complex to manufacture and assemble, but are characterized by being largely maintenance-free. Alternatively, a plain bearing for the rotor shaft using hydrodynamic plain bearings is also possible. Such plain bearings have several plain bearing segments. A radial bearing comprises several radial bearing segments, while an axial bearing comprises several axial bearing segments.The bearing is hydrodynamic, whereby a fluid lubricant is introduced by means of a pump during operation of the bearing. Due to the geometry of a lubrication gap into which the lubricant is introduced, a correspondingly high lubricant pressure develops. This leads to the formation of a load-bearing lubricant film, over which the rotor shaft is slide-mounted. With such hydrodynamic slide bearings, the bearing segments must be replaced for maintenance purposes when they wear out. This involves considerable effort because access to the corresponding bearing segments is sometimes difficult. A hydrodynamic rotor shaft bearing for the radial bearing of a shaft is described, for example, in CN 218542962 U, which describes an annular, radially closed radial bearing housing with several radial bearing segments arranged on its inner circumference and projecting radially inward.Another hydrodynamic rotor shaft bearing arrangement is described, for example, in CN 217107882 U, which provides a common bearing housing containing two combined radial-axial bearings, each of which is located at a shaft end. The surfaces of the bearing elements, also called bearing pads, of each combined bearing vary in size around the circumference. The bearing pads are smaller in one circumferential half than in the other to ensure effective support for the actual loads during operation.

[0005] The invention is based on the problem of providing an improved hydrodynamic rotor shaft plain bearing for a rotor shaft, in particular of a wind turbine.

[0006] To solve the problem, in a hydrodynamic rotor shaft plain bearing of the type described above, the invention provides that the first radial bearing has a first radial bearing housing and the second radial bearing has a second radial bearing housing, in each of which a plurality of radial bearing segments are provided, and the axial bearing has a separate axial bearing housing with a plurality of axial bearing segments accommodated therein, wherein the axial bearing is arranged between the two radial bearings and the axial bearing housing consists of a plurality of separate housing segments on which the axial bearing segments are arranged, wherein each housing segment is fastened to the first and the second radial bearing housing, connecting them, and after releasing the fastening from a working position in which the axial bearing segment(s) provided thereon are positioned in a working position on the rotor shaft, into a non-working position,in which the axial bearing segments are objected to by the rotor shaft.

[0007] According to the invention, all three bearings, namely the two radial bearings and the axial bearing, each have a separate bearing housing. This means that the first and second radial bearings have a first and a separate second radial bearing housing, and the axial bearing also has its own separate axial bearing housing. The arrangement is such that the axial bearing housing is located between the two radial bearing housings, meaning that, viewed axially, the axial bearing is positioned between the two radial bearings.

[0008] Another essential feature of the invention is that the axial bearing housing consists of several separate housing segments, i.e. it is a multi-part, segmented bearing housing, unlike previously known bearings and in particular main bearing housings in wind turbines, where such bearing housings are annularly closed housings, usually made of cast metal, which have the corresponding receptacles or seats for the bearing segments. In contrast, according to the invention the axial bearing consists of several individual housing segments that are individually manufactured and assembled. As described, the axial bearing or the axial bearing housing is arranged axially between the two radial bearing housings. Specifically, according to the invention the housing segments of the axial bearing housing are arranged between the two annularly closed radial bearing housings, wherein according to the invention the housing segments are fastened to the first and the second radial bearing housing, connecting them. I.e.The individual housing segments are firmly connected to the two radial bearing housings in the assembled or operating position, resulting in a bearing or housing assembly consisting of the three bearing housings or the two radial bearing housings and the housing segments. This firm connection of the two radial bearing housings via the housing segments stiffens the radial bearing housings, resulting in an extremely rigid bearing assembly.

[0009] Finally, the invention provides that each housing segment can be moved from a working position, in which the axial bearing segment(s) arranged on the respective housing segment are positioned on the rotor shaft, i.e., in a working position axially supporting the rotor shaft, into a non-working position, in which the axial bearing segments are spaced from the rotor shaft, i.e., in a non-working position. Accordingly, after the fixed connection to the two radial bearing housings has been released, each individual housing segment can be moved relative to the two radial bearing housings, and the axial bearing segments, which can also be referred to as axial pads, can be moved from their working position near the rotor shaft to a non-working position remote therefrom, in which they are accessible for maintenance purposes or replacement.This is because the segmentation does not result in a rigid ring shape; rather, the housing segments are only arranged in a ring during assembly, although this can be resolved due to the individual mobility of each housing segment. This mobility of each individual housing segment after the fixed connection has been released can also allow the respective housing segment to be removed from the bearing assembly, i.e. the respective housing segment can be pulled radially out of the bearing or housing assembly after the fixed connection to the radial bearing housings has been released. When pulled out, the axial bearing segment(s) arranged on it can be serviced or replaced accordingly, after which the housing segment is pushed radially back into the bearing or housing assembly and firmly connected again to the two radial bearing housings.

[0010] The segmentation of the thrust bearing housing allows the individual housing segments to be dimensioned accordingly, thus allowing the number and thus the dimensions of the individual housing segments to be adjusted depending on the bearing size. The thrust bearing housing should consist of at least three housing segments, preferably at least four housing segments. However, more than four housing segments can be provided for large bearings, which allows the individual housing segments to be dimensioned accordingly smaller and more manageable for large bearings.

[0011] As described above, according to the invention, mobility of each individual housing segment relative to the two positionally fixed radial bearing housings which are firmly screwed to a support, such as a base frame of a nacelle of a wind turbine, is provided, which at most comprises complete removal of the respective housing segment for maintenance purposes, etc. However, each housing segment preferably remains in its arrangement between the two radial bearing housings even after the connection has been released and moved into the non-working position, i.e. there is still a mechanical connection between the respective housing segment and the two radial bearing housings. The release and the remaining connection allow the movement of the respective housing segment relative to the two radial bearing housings, but at the same time the bearing housing assembly is not completely dissolved.A particularly advantageous embodiment in this context provides that, after the fastening has been released, each housing segment can be pivoted relative to the two radial bearing housings about a pivot axis that is formed between the respective housing segment and the two radial bearing housings. Accordingly, after the fixed connection has been released, each housing segment can be pivoted open about a pivot axis that still exists between the housing segment and the two radial bearing housings. This allows the axial bearing to be opened locally radially by pivoting the respective housing segment. With this pivoting, the axial bearing segment(s) or axial pad(s) are moved or pivoted out of their working position on the rotor shaft, in which they engage, for example, in a groove formed on the outer circumference of the rotor shaft, so that they are accessible for maintenance purposes in the pivoted-open non-working position.Since the bearing assembly is opened by this pivoting, it is also possible for maintenance personnel to gain access to the radial bearing segments in the two radial bearings through the opening in the bearing assembly created by the pivoting, so that these too can be serviced at least in the area accessible via the opening.

[0012] As stated, each housing segment is firmly connected to the two radial bearing housings in the assembled position, although this connection, as stated, is detachable. Preferably, each housing segment is fastened to the first and second radial bearing housings via at least two detachable screw connections. These screw connections can easily achieve a correspondingly firm connection of the housing segments to the radial bearing housings and a corresponding stiffening of the entire housing assembly. On the other hand, easy detachability is possible for the purpose of opening the axial bearing housing or moving a respective housing segment by loosening the screw connections.

[0013] A particularly advantageous development of the invention provides that the pivot axis is formed by a screw connection. To release the fixed connection, the at least two screw connections must be loosened, with one screw connection being completely loosened and removed, while the other screw connection is only slightly loosened but still connects the respective housing segment to the radial bearing housings to form the pivot axis. By removing the other screw connections (of course, more than two screw connections can also be provided) and loosening the one remaining screw connection, the fixed connection, i.e. the corresponding fastening of the housing segment to the two radial bearing housings, is no longer present; rather, it can be moved radially relative to the two radial bearing housings and pivoted about the remaining screw connection, which forms the pivot axis.This screw connection therefore has a dual function: on the one hand, it is the fixed connection, i.e. the fastening in the assembly situation, and on the other hand, it is the formation of the pivot axis after the fixed connection has been released.

[0014] As an alternative to forming the pivot axis using such a remaining, but loosened or loosened screw connection, it is also conceivable for the pivot axis to be formed by pivot pins projecting axially on both sides of the respective housing segment and engaging in pivot receptacles formed on the first and second radial bearing housings. Each housing segment therefore has two such pivot pins projecting on both sides, while each radial bearing housing has corresponding pivot receptacles at defined positions, for example shell-like recesses into which the pivot pins are inserted and in which they are secured by corresponding retaining means, or axial bores into which the pivot pins engage. The respective housing segment is again attached to the radial bearing housings using screw connections that are firmly tightened in the assembled position.If a housing segment needs to be opened, simply remove the screw connections. The pivot axis is defined by the engagement of the pivot pins in the mounts, allowing the housing segment to be pivoted open again.

[0015] Conveniently, radially projecting fastening sections are provided on both axial edges of each housing segment, on which receptacles for connecting screws and, if applicable, the pivot axis are provided. The housing sections are therefore appropriately profiled on the edges or provided with fastening sections in the area in which the connection and fastening to the radial bearing housings takes place. These fastening sections have corresponding receptacles for connecting screws, i.e. simple through-holes through which the connecting screws are inserted, which are then screwed into corresponding internally threaded holes on the two radial bearing housings. If provided, the pivot pins are also provided on the fastening sections. This design provides, on the one hand, defined areas on the respective housing segments in which the fastening to the radial bearing housings and the pivot bearing take place.On the other hand, there remains a sufficiently large free space between the two edge-side fastening sections, through which the connecting screws are easily accessible and which allows the respective housing segment to be designed to be correspondingly less massive.

[0016] As described, the thrust bearing housing should consist of at least three housing segments, preferably four or more. The more housing segments are provided, the smaller and lighter these individual housing segments are, and the easier they are to remove or pivot.

[0017] Particularly preferably, the housing segments have an identical shape and size. This means that the housing segments are identical components, which simplifies and reduces the cost of manufacturing.

[0018] The invention is explained below using exemplary embodiments with reference to the drawings. The drawings are schematic representations and show:

[0019] Figure 1 shows a schematic diagram of a rotor shaft plain bearing according to the invention in a partial view in the operating position with the housing segments in the working position,

[0020] Figure 2 shows the rotor shaft plain bearing from Figure 1 with a housing segment moved into the non-working position, and

[0021] Figure 3 shows a schematic diagram of a rotor shaft plain bearing according to the invention in longitudinal section.

[0022] Figure 1 shows a hydrodynamic rotor shaft plain bearing 1 according to the invention, with Figure 3 also showing such a rotor shaft plain bearing 1, but in a longitudinal section. The rotor shaft plain bearing 1 basically consists of three bearings, namely a first radial bearing 2 and a second radial bearing 3, with only the first radial bearing 2 being shown in principle in Figure 1. Each radial bearing 2, 3 has a separate radial bearing housing, in the case of the first radial bearing 2 the first radial bearing housing 4, and in the case of the second radial bearing 3 the second radial bearing housing 5. These are one-piece, annular housings, preferably made of cast metal. Radial bearing segments 6, 7 are arranged on the inner circumference of each radial bearing housing 4, 5, comprising corresponding segment carriers 8, 9, which are arranged in suitable receptacles on the inner circumference of the respective radial bearing housing 4, 5.The radial bearing segments 6, 7, which can also be referred to as radial pads, support a rotor shaft 10 radially over its outer circumference 11, as Figure 3 clearly shows.

[0023] The rotor shaft plain bearing 1 further comprises an axial bearing 12, which, viewed axially, is arranged between the two radial bearings 2, 3. The axial bearing 2 has an axial bearing housing 13, which, see Figures 1 and 2, consists of several housing segments 14, 4 in the example shown. Each housing segment 14, which is also a metal component, e.g., made of cast metal, has at least one, in the example shown two, axial bearing segments 15, which can also be referred to as axial bearing pads. Each axial bearing segment 15 has two bearing sections directed in opposite directions, which engage in a groove 16, indicated in Figure 1, formed on the outer circumference 11 of the rotor shaft 2. Figure 3 shows two such bearing sections 17 of an axial bearing segment 15 and their engagement in the groove 16, which in the example shown is formed by two annular bearing disks 18 fastened to the rotor shaft 10.This bidirectional axial bearing provides axial support for the rotor shaft 10 in both axial directions, in order to transfer loads that may act from both axial directions to a support (not shown in detail), for example, a base frame of a wind turbine nacelle, to which support the two radial bearing housings 4, 5 are fastened, in particular screwed. The rotor shaft plain bearing 1 thus allows for radial support of the rotor shaft 10 at axially spaced positions via the two radial bearings 2, 3, as well as bidirectional axial support via the axial bearing 12 arranged between the two radial bearings 2, 3.

[0024] As described, the axial bearing housing 13 is not a single-piece, annular bearing housing, but consists of several separate housing segments 14. The housing segments 14 are preferably all identical components, i.e., identical in shape and size. This allows for simple and cost-effective production of the individual housing segments 14, preferably from cast metal.

[0025] In the assembled position, as shown in the figures, each housing segment 14 is firmly connected to the two radial bearing housings 4, 5 via screw connections 19. This results in a bearing or housing assembly, wherein the two radial bearing housings 4, 5 are correspondingly stiffened as a result of the screw connection to the axial bearing housing 13 or the housing segments 14. In order to be able to set the corresponding screw connections 19, the two radial bearing housings 4, 5 have corresponding fastening sections 20, 21 in the form of corresponding edge webs, in which, for example, internally threaded holes are introduced. Each housing segment 14 also has fastening sections 22, 23 on the two edges, wherein these edge fastening sections 22, 23, see Figure 3, are preferably designed only as local, radially projecting fastening sections.The view according to Figure 2 shows only the fastening sections 22 positioned adjacent to the first radial bearing housing 4; the fastening sections 23 are not visible in this sectional plane. Each fastening section 22 is provided, for example, with a through-hole that, in the assembled position, is aligned with an internally threaded hole on the fastening section 20, so that a connecting screw can be passed through and screwed into the internally threaded hole. The same naturally applies to the design of the fastening sections 23 and the connection to the fastening section 21.

[0026] As Figure 1 shows, each housing segment 14 has only two fastening sections 22, 23 and consequently only two screw connections 19 per side. This means that each housing segment 14 is connected to the first radial bearing housing 4 via only two screw connections 19 and to the second radial bearing housing 5 via only two screw connections 19. The respective screw connections 19 are detachable. This makes it possible to release a correspondingly tight connection, such as that present in the assembled position or operating situation, if necessary, and thus to break the tight connection of a housing segment 14 with the two radial bearing housings 4, 5. This occurs when maintenance personnel need access to the axial bearing segments 15 of a housing segment 14 for maintenance purposes. In this case, one screw connection 19 on each segment side is completely loosened and removed, while the other screw connection 19 on each segment side is loosened.The screw connection 19 remains intact, i.e., the connecting screw is not completely unscrewed. This is because this remaining screw connection 19 or the connecting screw is intended to subsequently form a pivot axis around which the respective housing segment 14 can be radially pivoted, thus being able to be moved out of the housing assembly, although the housing segment 14 still remains connected to the two radial bearing housings 4, 5. This can be achieved via the remaining screw connection 19 if it is simply loosened.

[0027] Figure 2 shows this situation, based on Figure 1. It shows the four housing segments 14, with three housing segments 14 still in their working position, in which the axial bearing segments 15, in their working position, engage in the groove 16 of the rotor shaft 10. However, one of the housing segments 14, here the housing segment designated 14a, has been pivoted into a non-working position.

[0028] For this purpose, starting from Figure 1, the lower left screw connection 19 shown there, which is designated 19a in Figure 1, was removed on both sides, i.e. the connecting screw was completely unscrewed in each case. At the same time, the upper screw connection 19, which is designated 19b in Figures 1 and 2, was loosened on both sides, i.e. slightly loosened, although the connecting screws still remain in position, i.e. are still screwed into the internally threaded holes on the fastening sections 20, 21. However, the fastening is loosened to such an extent that the connecting screws 19b can now form a pivot axis around which the housing segment 14a can be pivoted radially, as Figure 2 shows.In this non-operating position, the axial bearing segments 15 of this pivoted-out housing segment 14a, which are designated 15a in Figure 2, are clearly accessible and can be serviced or replaced by maintenance personnel. At the same time, a corresponding radial opening 24 naturally forms between the two axial bearing housings 4, 5 as a result of the pivoting-out of the housing segment 14a, so that maintenance personnel can also access the radial bearing segments 6, 7 located in this area via this opening 24.

[0029] After maintenance has been carried out, the pivoted-out housing segment 14a is pivoted back into place and into the operating position, in which the two axial bearing segments 15a are once again in their working position, i.e., they engage in the groove 16. The screw connections 19b are then tightened again, and the screw connections 19a are also reinserted and tightened again, so that the housing segment 14a is once again fastened in the bearing assembly and is rigidly integrated. While Figures 1 and 2 only show the pivoting-out of the upper left housing segment 14a, the three other housing segments 14 can, of course, also be pivoted in the same way after the corresponding screw connections 19 have been loosened or loosened, i.e., each housing segment 14 can be pivoted from a working position into a non-working position in the manner described.

[0030] While the figures show the movement of a housing segment 14 by radial pivoting about a pivot axis, it is also possible, in principle, to remove the housing segment 14 entirely from the housing assembly by loosening and removing the screw connections 19 via which it is connected to the radial bearing housings 4, 5, and to pull it out radially as a whole, i.e. to remove it completely, and to reinsert it in the same way after maintenance has been carried out and to fasten it again via the newly inserted screw connections 19.

[0031] List of reference symbols

[0032] Rotor shaft plain bearing

[0033] Radial bearings

[0034] Radial bearings

[0035] Radial bearing housing

[0036] Radial bearing housing

[0037] Radial bearing segment

[0038] Radial bearing segment

[0039] Segment carrier

[0040] Segment carrier

[0041] rotor shaft

[0042] Outer circumference

[0043] Thrust bearing

[0044] Thrust bearing housing

[0045] 14a Housing segment

[0046] 15a Thrust bearing segment

[0047] Nut

[0048] Location section

[0049] bearing disc

[0050] 19a, 19b screw connection

[0051] Fastening section

[0052] Fastening section

[0053] Fastening section

[0054] Mounting section opening

Claims

Patent claims 1 . Hydrodynamic rotor shaft plain bearing for a rotor shaft (10), in particular of a wind turbine, comprising a first and a second radial bearing (2, 3) and an axial bearing (12), characterized in that the first radial bearing (2) has a first radial bearing housing (4) and the second radial bearing (3) has a second radial bearing housing (5), in each of which a plurality of radial bearing segments (6, 7) are provided, and the axial bearing (12) has a separate axial bearing housing (13) with a plurality of axial bearing segments (15) received therein, wherein the axial bearing (12) is arranged between the two radial bearings (2, 3) and the axial bearing housing (13) consists of a plurality of separate housing segments (14, 14a) on which the axial bearing segments (15, 15a) are arranged, wherein each housing segment (14, 14a) is fixed to the first and the second radial bearing housing (4, 5), connecting them, is fastened and after releasing the fastening from a working position,in which the axial bearing segment(s) (15, 15a) provided thereon are positioned in a working position on the rotor shaft (10), can be brought into a non-working position in which the axial bearing segments (15, 15a) are spaced apart from the rotor shaft (10).

2. Hydrodynamic rotor shaft plain bearing according to claim 1, characterized in that each housing segment (14, 14a) is pivotable relative to the two radial bearing housings (4, 5) about a pivot axis which is formed between the respective housing segment (14, 14a) and the two radial bearing housings (4, 5) after the fastening has been released.

3. Hydrodynamic rotor shaft plain bearing according to claim 1 or 2, characterized in that each housing segment (14, 14a) is fastened to the first and second radial bearing housings (4, 5) via at least two detachable screw connections (19).

4. Hydrodynamic rotor shaft plain bearing according to claim 2 and 3, characterized in that the pivot axis is formed by a screw connection (19).

5. Hydrodynamic rotor shaft plain bearing according to claim 2 and 3, characterized in that the pivot axis is formed by pivot pins projecting axially on both sides of the respective housing segment (14, 14a) which engage in pin receptacles formed on the first and second radial bearing housings (4, 5).

6. Hydrodynamic rotor shaft plain bearing according to claim 4 or 5, characterized in that radially projecting fastening sections (22, 23) are provided on each housing segment (14, 14a) on both axial edges, on which receptacles for connecting screws and, if applicable, the pivot pins are provided.

7. Hydrodynamic rotor shaft plain bearing according to one of the preceding claims, characterized in that at least three housing segments (14, 14a) are provided.

8. Hydrodynamic rotor bearing shaft plain bearing according to one of the preceding claims, characterized in that the housing segments (14, 14a) have an identical shape and size.

9. Hydrodynamic rotor shaft plain bearing according to one of the preceding claims, characterized in that the housing segments (14, 14a) are metal cast components.

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