Hydrodynamic rotor shaft plain bearing for a rotor shaft, especially of a wind turbine

Abstract

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), each containing several radial bearing segments (6, 7), and the axial bearing (12) has a separate axial bearing housing (13) with several 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 several separate housing segments (14, 14a) on which the axial bearing segments (15, 15a) are arranged, wherein each housing segment (14, 14a) is attached to the first and the second radial bearing housings (4, 5). connecting, 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 segment(s) (15, 15a) are displaced from the rotor shaft (10).

Description

[0001] The invention relates to a hydrodynamic rotor shaft sliding bearing for a rotor shaft, in particular of a wind turbine, comprising a first and a second radial bearing as well as an axial bearing.

[0002] A wind turbine typically has several rotor blades arranged around a hub. The hub is connected to a rotor shaft, which in turn is coupled to a gearbox. A generator follows the gearbox, and its 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, along with the hub and the downstream drive train, rotates, causing the generator to produce electricity. This rotation is inevitably accompanied by the rotation of the rotor shaft, which is supported accordingly. The rotor shaft is supported by radial bearings, usually consisting of two axially spaced radial bearings that provide radial support. In addition to the radial bearings, axial bearings are also typically provided, preferably supporting the rotor shaft in both directions. An axial load, resulting from the oncoming wind, is usually present on the rotor side.Due to changing wind or flow conditions, for example during a strong gust, the direction of the axial load can reverse, meaning that the axial load then acts from the gearbox side, i.e., the wind load acts on the rotor blades from the gearbox side. Therefore, axial bearings on both sides are advisable.

[0003] Rotor shaft support can be achieved using rolling bearings. Each bearing has several rolling elements, which, in the case of radial bearings, are guided in an outer ring and run on an inner ring connected to the rotor shaft, and in the case of axial bearings, 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 robust and complex to manufacture and assemble, but are characterized by being virtually maintenance-free.

[0004] Alternatively, the rotor shaft can also be supported by a sliding bearing using hydrodynamic plain bearings. These bearings consist of multiple 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 a pump during operation. Due to the geometry of the lubrication gap into which the lubricant is introduced, a correspondingly high lubricant pressure develops. This results in the formation of a load-bearing lubricant film over which the rotor shaft is supported. With such hydrodynamic plain bearings, the bearing segments must be replaced when worn for maintenance purposes, which is a considerable undertaking, as access to the relevant bearing segments can sometimes be difficult.A hydrodynamic rotor shaft bearing for radial support of a shaft is described, for example, in CN 218542962 U, which describes an annular, radially closed radial bearing housing with several radially inwardly projecting radial bearing segments arranged around its inner circumference. Another hydrodynamic rotor shaft bearing is described, for example, in CN 217107882 U, which describes a common bearing housing containing two combined radial-axial bearings, each combined radial-axial bearing being located at one shaft end. The areas of the bearing elements, also called bearing pads, of each combined bearing are of different sizes around the circumference. Smaller bearing pads are provided in one half of the circumference than in the other half to effectively support the actual loads during operation.

[0005] The invention is based on the problem of providing an improved hydrodynamic rotor shaft sliding bearing for a rotor shaft, in particular for 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, each containing several radial bearing segments, and the axial bearing has a separate axial bearing housing with several axial bearing segments contained therein, wherein the axial bearing is arranged between the two radial bearings and the axial bearing housing consists of several separate housing segments on which the axial bearing segments are arranged, each housing segment being attached to the first and the second radial bearing housing, connecting them, and after releasing the attachment 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 of the rotor shaft are defective, is feasible.

[0007] According to the invention, all three bearings, namely the two radial bearings and the axial bearing, each have a separate bearing housing. That is, the first and second radial bearings each have a first and a separate second radial bearing housing, just as the axial bearing has its own separate axial bearing housing. The arrangement is such that the axial bearing housing is positioned between the two radial bearing housings; that is, axially speaking, the axial bearing is positioned between the two radial bearings.

[0008] A further essential aspect 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 ring-shaped closed housings, mostly 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 rather 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 ring-shaped closed radial bearing housings, and the housing segments are attached to the first and second radial bearing housings, connecting them. That is to say,The individual housing segments are firmly connected to the two radial bearing housings in the assembly 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 rigid 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, according to the invention, 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), to a non-working position, in which the axial bearing segments are spaced away from the rotor shaft (i.e., in a non-working position). Each individual housing segment can therefore be moved relative to the two radial bearing housings after releasing the fixed connection, and the axial bearing segments, which can also be referred to as axial pads, can thereby be moved from their working position close to the rotor shaft to a non-working position further away, in which they are accessible for maintenance or replacement.Because of the segmentation, there is no rigid ring shape; rather, the housing segments are arranged in a ring-like configuration during assembly. However, this arrangement can be modified by the individual mobility of each housing segment. This mobility of each housing segment after releasing the fixed connection also allows for the removal of the respective housing segment from the bearing assembly. In other words, after releasing the fixed connection to the radial bearing housings, the respective housing segment can be pulled radially out of the bearing or housing assembly. In the removed state, the axial bearing segment(s) attached to it can be serviced or replaced. Afterward, the housing segment is inserted radially back into the bearing or housing assembly and reconnected to the two radial bearing housings.

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

[0011] As described above, according to the invention, each individual housing segment is movable relative to the two fixed radial bearing housings, which are firmly bolted to a support such as the base frame of a wind turbine nacelle. This movable movement allows for the complete removal of each housing segment for maintenance purposes, etc. Preferably, however, each housing segment remains in its position between the two radial bearing housings even after the connection is loosened and it is moved into the non-operating position, i.e., a mechanical connection between the respective housing segment and the two radial bearing housings is maintained. The loosening of the connection, as well as the remaining connection, allows the movement of the respective housing segment relative to the two radial bearing housings, while at the same time the bearing housing assembly is not completely disassembled.A particularly advantageous embodiment in this context provides that each housing segment, after the fastening is loosened, can be pivoted about a pivot axis formed between the respective housing segment and the two radial bearing housings. Accordingly, it is possible to pivot each housing segment about a pivot axis still present between the housing segment and the two radial bearing housings after the fixed connection is loosened. This allows the axial bearing to be opened radially by pivoting the respective housing segment. This pivoting action moves or pivots the axial bearing segment(s) or axial pads out of their working position on the rotor shaft, where 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, non-working position.Since the bearing assembly is opened by this pivoting action, it is also possible for maintenance personnel to access the radial bearing segments in the two radial bearings through the opening of the bearing assembly provided by the pivoting action, so that these can also be serviced, at least in the area accessible via the opening.

[0012] As described, each housing segment is firmly connected to the two radial bearing housings in the assembly position, although this connection is, as described, detachable. Preferably, each housing segment is attached to the first and second radial bearing housings by at least two detachable screw connections. These screw connections allow for a sufficiently strong connection of the housing segments to the radial bearing housings and a corresponding stiffening of the entire housing assembly. Conversely, the screw connections also allow for easy detachment for the purpose of opening the axial bearing housing or moving a respective housing segment.

[0013] A particularly advantageous embodiment of the invention provides that the pivot axis is formed by a screw connection. To release the fixed connection, at least two screw connections must be loosened. One screw connection is completely loosened and removed, while the other is only partially loosened, but still connects the respective housing segment to the radial bearing housings to form the pivot axis. By removing the other screw connections (more than two screw connections are, of course, possible) 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. Instead, 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 serves as a fixed connection, i.e., a fastening in the assembly situation, and on the other hand, it forms the pivot axis after the fixed connection is loosened.

[0014] As an alternative to forming the pivot axis via a remaining, but loosened, screw connection, it is also conceivable that the pivot axis is formed by pivot pins projecting axially on both sides of the respective housing segment, which engage in pin 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 pin receptacles at defined positions, for example, cup-shaped recesses into which the pivot pins are inserted and secured by appropriate retaining elements, or axial bores into which the pivot pins engage. The respective housing segment is again fastened to the radial bearing housings via screw connections, which are tightened securely in the assembly position.To open a housing segment, simply remove the screw connections. The pivot axis is defined by the engagement of the pivot pins in the receptacles, allowing the housing segment to be swung open again.

[0015] Advantageously, each housing segment is provided with radially projecting mounting sections on both axial edges, which accommodate connecting screws and, if applicable, the pivot axis. The housing segments are thus appropriately profiled or provided with mounting sections at their edges, in the area where the connection and fastening to the radial bearing housings takes place. These mounting sections have corresponding receptacles for connecting screws, i.e., simple through holes through which the connecting screws are inserted and then screwed into corresponding internal threaded holes in the two radial bearing housings. If provided, pivot pins are also provided on the mounting sections. This design provides, on the one hand, defined areas on the respective housing segments where the fastening to the radial bearing housings and the pivot bearing are located.Secondly, a sufficiently large space remains between the two edge-side mounting sections, allowing easy access to the connecting screws and enabling the respective housing segment to be designed with a correspondingly less massive form.

[0016] As described, the axial 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] Preferably, the housing segments have an identical shape and size. This means that the housing segments are identical components, which simplifies and reduces manufacturing costs.

[0018] The invention is explained below with reference to exemplary embodiments and the drawings. The drawings are schematic representations and show: Fig. 1 A schematic representation of a rotor shaft sliding bearing according to the invention in a partial view in the operating position with housing segments in the working position, Fig. 2 the rotor shaft plain bearing Fig. 1 with a housing segment moved into the non-working position, and Fig. 3 A schematic representation of a rotor shaft sliding bearing according to the invention in longitudinal section.

[0019] Fig. Figure 1 shows a hydrodynamic rotor shaft sliding bearing 1 according to the invention, wherein also Fig. Figure 3 shows 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, wherein in Fig. Figure 1 shows only the first radial bearing 2 in its basic form. 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, preferably annular housings made of scrap 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 adapted 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 shown. Fig. 3 clearly shows.

[0020] The rotor shaft plain bearing 1 further comprises a thrust bearing 12, which is arranged axially between the two radial bearings 2, 3. The thrust bearing 2 has a thrust bearing housing 13, which, see Fig. 1 and Fig. 2, consisting of several, in the example shown 4, housing segments 14. 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 oriented in opposite directions, which are arranged in a Fig. 1 indicated groove 16 formed on the outer circumference 11 of the rotor shaft 2 engage. Fig. 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 attached 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 acting from both directions to a support (not shown in detail), for example, a base frame of a wind turbine nacelle, to which the two radial bearing housings 4, 5 are attached, in particular bolted. The rotor shaft plain bearing 1 thus allows for radial support of the rotor shaft 10 at axially stressed 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.

[0021] As described, the axial bearing housing 13 is not a one-piece, ring-shaped 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 manufacturing of the individual housing segments 14, preferably from cast metal.

[0022] 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, whereby 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 enable the corresponding screw connections 19, the two radial bearing housings 4, 5 have corresponding fastening sections 20, 21 in the form of corresponding edge ribs in which, for example, internal threaded bores are provided. Each housing segment 14 also has edge fastening sections 22, 23 on both edges, these edge fastening sections 22, 23 being shown in the figures. Fig. 3, preferably designed only as local, radially projecting fastening sections. The view according to Fig. Figure 2 shows only the mounting sections 22 positioned adjacent to the first radial bearing housing 4; the mounting sections 23 are not visible in this section plane. Each mounting section 22 is provided, for example, with a through-hole which, in the assembled position, aligns with an internal threaded hole on the mounting section 20, allowing a connecting screw to be inserted and screwed into the internal threaded hole. The same applies, of course, to the design of the mounting sections 23 and their connection to the mounting section 21.

[0023] How Fig. As shown in Figure 1, 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 and to the second radial bearing housing 5 via only two screw connections 19. The respective screw connections 19 are detachable. This allows a correspondingly tight connection, as it exists in the assembly position or operating situation, to be loosened if necessary, thus dissolving 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 side of the segment is completely loosened and removed, while the other screw connection 19 on each side is loosened.The screw connection 19 remains in place to a certain extent, i.e., the connecting screw is not completely unscrewed. This remaining screw connection 19, or rather the connecting screw, is intended to form a pivot axis around which the respective housing segment 14 can be radially disengaged, and thus moved out of the housing assembly, even though the housing segment 14 remains connected to the two radial bearing housings 4 and 5. This can be achieved by loosening the remaining screw connection 19.

[0024] Fig. 2 shows, starting from Fig. 1. This situation. Shown are the four housing segments 14, with three housing segments 14 still in their working position, in which the axial bearing segments 15 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. For this purpose, starting from Fig. 1, the lower left screw connection 19 shown there, which is in Fig. 1, designated 19a, was removed from both sides, i.e., the connecting screw was completely unscrewed on each side. At the same time, the upper screw connection 19, which is in Fig. 1 and Fig. 2, designated 19b, is loosened on both sides, i.e., somewhat detached, although the connecting screws remain in position, i.e., still screwed into the internal threaded holes on the mounting sections 20, 21. The fastening is, however, loosened to the extent that the connecting screws 19b can now form a pivot axis around which the housing segment 14a can be pivoted radially, as shown. Fig. Figure 2 shows. In this non-working position, the axial bearing segments 15 of this pivoted housing segment 14a are visible, which axial bearing segments in Fig. The two axial bearing housings, designated 15a, are accessible and can be serviced or replaced by maintenance personnel. Simultaneously, a corresponding radial opening 24 is formed between the two axial bearing housings 4, 5 as a result of the pivoting of the housing segment 14a, allowing maintenance personnel access to the radial bearing segments 6, 7 located in this area via this opening 24.

[0025] After maintenance, the pivoted housing segment 14a is pivoted back into its operating position, in which the two axial bearing segments 15a are again in their working position, i.e., engaging in the groove 16. The screw connections 19b are then tightened, and the screw connections 19a are also reinstalled and tightened, so that the housing segment 14a is once again secured in the bearing assembly and stiffened.

[0026] While Fig. 1 and Fig.2 only showing the pivoting of the upper left housing segment 14a, it is of course also possible to pivot the three other housing segments 14 in the same way after loosening the corresponding screw connections 19, i.e., each housing segment 14 can be pivoted from a working position to a non-working position in the manner described.

[0027] 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 completely remove it from the housing assembly and pull it out radially by loosening and removing the screw connections 19, which connect a housing segment 14 to the radial bearing housings 4, 5, and to completely remove it and, after maintenance has been carried out, to reinsert it in the same way and reattach it via the screw connections 19 that have been reinstalled. Reference symbol list 1 Rotor shaft plain bearing 2 radial bearings 3 radial bearings 4 radial bearing housings 5 radial bearing housings 6 radial bearing segment 7 radial bearing segment 8 Segment beams 9 Segment beams 10 Rotor shaft 11 External circumference 12 axial bearings 13 axial bearing housings 14 14a Housing segment 15 15a Axial bearing segment 16 Nut 17 Situation section 18 bearing disc 19 19a, 19b Screw connection 20 Fastening section 21 Fastening section 22 Fastening section 23 Fastening section 24-hour opening

Claims

[1] Hydrodynamic rotor shaft 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 by, 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), each containing several radial bearing segments (6, 7), and the axial bearing (12) has a separate axial bearing housing (13) containing several axial bearing segments (15), the axial bearing (12) being arranged between the two radial bearings (2, 3), and the axial bearing housing (13) consisting of several separate housing segments (14, 14a) to which the axial bearing segments (15, 15a) are arranged, each housing segment (14, 14a) being attached to the first and second radial bearing housings (4, 5), connecting them, and after releasing the attachment from a working position in which the axial bearing segment(s) (15, 15a) provided thereon are in a working position on the rotor shaft (10) are positioned in a non-working position in which the axial bearing segments (15,15a) are defective from the rotor shaft (10), is remediable. [2] Hydrodynamic rotor shaft plain bearing according to claim 1, characterized by , that each housing segment (14, 14a) can be pivoted relative to the two radial bearing housings (4, 5) about a pivot axis formed between the respective housing segment (14, 14a) and the two radial bearing housings (4, 5) after loosening the fastening. [3] Hydrodynamic rotor shaft bearing according to claim 1 or 2, characterized by , that each housing segment (14, 14a) is attached 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 claims 2 and 3, characterized by , that the pivot axis is formed via a screw connection (19). [5] Hydrodynamic rotor shaft plain bearing according to claims 2 and 3, characterized by, 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 housing (4, 5). [6] Hydrodynamic rotor shaft plain bearing according to claim 4 or 5, characterized by , that on each housing segment (14, 14a) radially projecting fastening sections (22, 23) are provided on both axial edges, on which receptacles for connecting screws and, if applicable, the pivot pins are provided. [7] Hydrodynamic rotor shaft bearing according to one of the preceding claims, characterized by , 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 by , that the case segments (14, 14a) have an identical shape and size. [9] Hydrodynamic rotor shaft bearing according to one of the preceding claims, characterized by , that the housing segments (14, 14a) are metal cast components.

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