Plain bearings with springs and their use

Abstract

The invention relates to a sliding bearing comprising a sliding segment with a sliding surface, wherein the sliding surface rests against a shaft and the sliding segment has a spring element on its rear side, which is arranged between the sliding segment and a support structure, the spring element being held in position by a guide element which surrounds the spring element in order to hold it in a certain position between the sliding segment and the support structure.

Description

Brief description of the invention

[0001] The present invention relates to an improved plain bearing, preferably on a plain-bearing main rotor shaft of a wind turbine.

[0002] The state of the art describes various possibilities for the suspension of segment bearings within wind turbines.

[0003] EP 3 460 270 B1, for example, describes a wind turbine having a support structure and an axial bearing with a bearing segment that includes a piston and is movably connected to the support structure. In addition, it has a spring element that surrounds the piston and includes a disc spring and / or a polymer element and is configured to resiliently support the bearing segment with respect to the support structure. The disadvantage of the described bearing arrangement is that the installation space for the spring element is severely restricted by the guide piston. This requires a spring with larger external dimensions or a spring with a higher spring rate. One disadvantage of such a design is that the load-bearing behavior of the segments is negatively influenced because the mobility of the segment is restricted.

[0004] EP 3 577 356 B1 describes a bearing shell-support connection comprising a bearing shell and a bearing shell support structure, wherein the bearing segment is connected to the support structure via a ball joint. The bearing segment grips the ball head, and the support structure grips the ball from within the ball joint. The bearing segment and the support structure are connected via a spring connection such that a force is exerted between the bearing segment and the support structure, which force presses the ball head movably into the ball socket. This connection comprises a bushing, which in turn at least partially surrounds the spring and has two rings that transfer the spring force to the support structure. Consequently, EP 3 577 356 B1 describes a cohesion of the individual components of the segment that should not impair the mobility of the segment. However, a deflection of the segment does not occur.Furthermore, many components are necessary to ensure proper function; in particular, the ball-and-socket support of the segment is complex and it is difficult to ensure a smooth tilting movement.

[0005] DE 10 2020 108 248 B3 also describes an arrangement of a bearing segment, spring element, and support element that rest loosely on top of one another. This design requires a device for assembling and disassembling the bearing assembly for a wind turbine rotor to join the individual rows and hold them together for the assembly process. The disadvantage of such an arrangement is therefore the need for a complex device for assembling and disassembling a bearing assembly within wind turbines.

[0006] The object of the present invention is therefore to provide a construction that combines several functions. Furthermore, a plain bearing connection is to be provided that enables simple and secure assembly of components that are supposed to lie loosely on top of one another.

[0007] The present invention is intended, on the one hand, to enable the segment to be resilient relative to the support structure and, on the other hand, to firmly connect the spring, the sliding segment and the support structure to one another.

[0008] The present invention therefore relates to a plain bearing in which preferably several guide segments are distributed around the circumference of a shaft, wherein the shaft is preferably a plain-bearing main rotor shaft of a wind turbine. Each sliding segment is arranged such that its sliding surface rests against the shaft. On the back of each sliding segment, a spring element is attached between the sliding segment and a support structure, which spring element is held by a guide element that encloses the spring element, wherein the guide element is fastened to the sliding segment and the support structure. The plain bearing is designed such that a gap is arranged between the spring element and the guide element, which gap allows mobility between the spring element and the guide element.

[0009] In a preferred embodiment, the spring element is made of plastic. In a preferred aspect, the guide element is an elastomer.

[0010] The plain bearing is preferably used as part of the main rotor shaft of a wind turbine. Consequently, the invention also relates to a wind turbine with at least one of the above-described plain bearings or to the use of the above-described plain bearing in a wind turbine.

[0011] Furthermore, the plain bearing according to the invention can also be used in other industrial applications, so that the invention further relates to the use of the previously described plain bearing in gears of industrial applications.

[0012] The present invention is characterized by the embodiments in the claims and described in more detail by the embodiments in the following description, the examples and the drawings. Description of the drawings Fig. 1 Schematic representation of a main rotor shaft with several plain bearing segments Fig. 2 Schematic representation of a plain bearing segment in a) unloaded and b) loaded position Fig. 3 Schematic perspective view of a preferred embodiment of a plain bearing segment according to the invention with guide element Detailed description of the invention

[0013] The present invention relates to a plain bearing, preferably for use in a plain-bearing main rotor shaft of a wind turbine, and to an associated wind turbine.

[0014] In the following, the articles “a” and all derivatives thereof, as used herein, should generally be understood as “one or more”, unless otherwise stated or clear from the context as the singular form.

[0015] Whenever the terms "includes", "has", "possesses" and the like are used in the description or the claims, these terms should be understood in the same way as the term "comprising" or "having" and are not exhaustive unless explicitly stated.

[0016] The term "shaft" describes an elongated, cylindrical machine element that is designed to be movable for transmitting rotary motion and torque. In a preferred embodiment, this is at least one steel shaft of a wind turbine gearbox. Although the present invention is described below with reference to main drive shafts of wind turbines, it is also fundamentally possible for the plain bearing to be used in other applications. These include, but are not limited to, hydraulic pistons, sleeve guides, support bearings, worm gear racks, screws, guide rails, bearing rings, and other components.

[0017] In the following, “sliding bearing”, “bearing”, “sliding bearing”, “sliding bearing” and “bearing” are used interchangeably and describe at least one component that enables components that can move relative to one another to be guided. Slide bearings are typically used in larger machines, which then have slide bearing segments (1) with a sliding surface (2). These slide bearing segments (1) or bearing segments are flexible, movable and / or inclinable relative to the bearing ring on which they are arranged, so that they are somewhat adaptable to tolerances and / or deformations due to operational changes in the slide bearing. Consequently, the sliding surface (2) arranged on the slide segment (1) also adapts to the surface of the counterpart to be supported to a certain extent. For this reason, the slide bearing segments (1) require a certain freedom of movement.Although the plain bearing according to the invention, as described above, can be used in various machines, a preferred application is in the rotor of a wind turbine. The plain bearing can be used as a main bearing, secondary bearing, pitch bearing, or yaw bearing. The plain bearing is particularly preferably used within a plain-bearing main rotor shaft of a wind turbine. Dynamic events, such as strong winds, which act on a wind turbine and thus the bearing, can lead to undesired movements within the plain bearing, which can lead to increased wear in the bearing. The present invention provides plain bearings that enable an improved connection of the bearing segment to a bearing ring.

[0018] For this purpose, in the plain bearing according to the invention, several sliding segments (1) are distributed around the circumference of a shaft (11). Each sliding segment (1) is arranged such that its sliding surface (2) rests against the shaft (11) and a spring element (3) is attached to its rear side, which spring element is located between the sliding segment (1) and a support structure (5). Consequently, the sliding segment (1) has a sliding surface (2) on its surface and a spring element (3) on the side opposite the sliding surface (2), i.e. the rear side. The spring element (3) also enables a certain movement of the sliding segment (1) relative to the support structure (5). In particular, the spring element (3) enables a tilting movement of the sliding segment (1) and / or a deflection under a bearing load. The spring element (3) can be made of different materials or combinations thereof, such as, for example, metal and / or plastic.In a preferred embodiment, however, the spring element (3) is made of plastic. The spring element (3) serves to firmly connect the support structure (5) to the sliding segment (1) and to hold the spring element (3) in place, but the spring element (3) is not attached to either the support structure (5) or the sliding segment (1).

[0019] The deflection of the spring element (3) causes the spring element (3) to exert force between the sliding segment (1) and the support structure (5). The spring element (3) is further held by a guide element (4). The guide element (4) consequently ensures that the spring element (3) does not change its position, for example by slipping out. The guide element (4) is therefore designed to have a certain mobility. In one aspect of the present invention, this mobility can be generated due to the material used for the guide element (4). In a preferred embodiment, the guide element (4) is made of an elastomer. In order to hold the spring element (3) in a certain position, the guide element (4) encloses the spring element (3), thereby preventing the spring element (3) from leaving its position between the sliding segment (1) and the support structure (5).The guide element (4) is fastened in the sliding bearing on the sliding segment (1) and the support structure (5). The fastening can be achieved using a detachable, non-detachable, and / or partially detachable connection. This connection is preferably flexible, but at least partially flexible. To provide the strongest possible hold despite the at least partially flexible fastening, the fastening is preferably located within the support structure (5) and the sliding segment (1), such as the . Fig. 2 a). The partially flexible fastening indicates that the guide element (4) has a flexible fastening in a region facing the spring element (3) and a fixed fastening to the support structure (5) or the sliding segment is provided on the side facing away from the spring element (3).

[0020] In order to achieve a certain mobility between the sliding segment (1) and the support structure (5) in order to be able to react to dynamic events, a gap (10) is arranged between the spring element (3) and the guide element (4). The gap forms a distance between the spring element (3) and the guide element (4), whereby they are not in direct contact with each other. This gap (10) allows a certain mobility between the spring element (3) and the guide element (4). The spring element (3) and the guide element (4) are matched to one another in terms of their mobility, i.e. their elasticity is matched to one another in order to be able to perform their respective functions. As shown in the Fig. As shown in Figure 2 b), the spring element (3') is compressed in the loaded state and thus exhibits a bulge, so that the guide element (4') must follow this movement without negatively influencing the spring action of the spring element (3). In order for the guide element (4) to allow such a movement, a flexible connection (7, 9) to the sliding segment and the support structure must be present.

[0021] In a preferred aspect of the present invention, a plurality of guide elements (4) are arranged between the sliding segment (1) and the support structure (5), wherein particularly preferably at least one guide element (4) is arranged at a respective edge region of the spring element (3), such as the Fig. 2 and Fig. 3 can be found.

[0022] The plain bearing is preferably used as part of the main rotor shaft of a wind turbine. Consequently, the invention also relates to a wind turbine with at least one previously described plain bearing. The rotor of a wind turbine is usually mounted on a tower and can have different shapes and numbers of rotor blades; the task of the rotor is to convert the kinetic energy of the wind into rotational energy. In one aspect, the wind turbine therefore comprises a rotor, a tower, and a gearbox, wherein the rotor is connected via a shaft in a torque-transmitting manner to the gearbox, which has at least one previously described plain bearing. The gearbox, in turn, is connected to a power generator. The power generator can be any technical device that converts mechanical, chemical, thermal, or electromagnetic energy directly into electrical energy and vice versa.Since the present invention is preferably designed for use within wind turbines, the power generator in this case preferably refers to a generator in which energy is transferred from kinetic energy to electrical energy.

[0023] Since the present plain bearing can also be used in other industrial applications, such as in water turbines or gas turbines, where power is generated by a power generator having a torque-transmitting connection to a gearbox, the plain bearing of the present invention can also be arranged in at least one component of the gearbox. The gearbox in an industrial application would then have a torque-transmitting connection to other mechanical components that can, for example, transmit the power and / or drive components. The power generator in this application would then preferably be a technical device that outputs mechanical energy, with the energy being supplied, for example, by means of electrical, chemical, thermal, or electromagnetic energy.Examples of such a power generator would be, but are not limited to, a generator, motor, or a turbomachine such as a turbine.

[0024] These and other embodiments of the present invention are disclosed in, and encompassed by, the specification and examples. Further literature concerning known materials, methods, and applications that can be used in accordance with the present invention can be accessed from public libraries and databases, for example, using electronic devices. A more complete understanding of the invention can be obtained by reference to the figures, which are provided for the purpose of illustration and are not intended to limit the scope of the invention. List of reference symbols 1 sliding segment 2 sliding surface 3 spring element 4 Guide element 5 Support structure 6 Fastening in the segment 7 Flexible connection 8 Fastening in the support structure 9 Flexible connection 10 Gap between spring element and guide element 11 Wave 3' spring element, compressed 4' guide element in compressed state QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 3 460 270 B1

[0003] EP 3 577 356 B1

[0004] DE 10 2020 108 248 B3

[0005]

Claims

[1] Plain bearing comprising a sliding segment (1) with a sliding surface (2), wherein the sliding surface (2) rests against a shaft and the sliding segment (1) has on its rear side a spring element (3) which is arranged between the sliding segment (1) and a support structure (5), the spring element (3) is held in position by a guide element (4) which encloses the spring element (3) in order to hold it in a certain position between the sliding segment (1) and the support structure (5). [2] Plain bearing according to claim 1, wherein the spring element (3) is made of plastic. [3] Plain bearing according to claim 1 or 2, wherein a gap (10) is arranged between the spring element (3) and the guide element (4), which gap allows a certain mobility of the spring element (3). [4] Plain bearing according to one of claims 1 to 3, the guide element (4) is designed such that it has a certain mobility, wherein the guide element (4) is preferably made of an elastomer. [5] Plain bearing according to one of claims 1 to 4, wherein the guide element (4) is fastened to the sliding segment (1) and the support structure (5), wherein the fastening is preferably carried out by means of at least partially flexible connection. [6] Plain bearing according to one of claims 1 to 5, wherein the guide element (4) is fastened within the support structure (5) and the sliding segment (1). [7] Plain bearing according to one of claims 1 to 6, wherein a plurality of guide elements (4) are arranged between the sliding segment (1) and the support structure (5) and hold the at least one spring element (3) in position. [8] Plain bearing according to one of claims 1 to 7 for the movable arrangement of plain bearing segments (1) within plain bearings, wherein the spring element (3) is arranged surrounded by at least one guide element (4) between a sliding segment (1) in a support structure (5) and wherein the spring element (3) is compressed (3') in the loaded state and can have a bulge which the guide element (4) follows without negatively influencing the spring action of the spring element (3). [9] Wind turbine comprising a rotor, a tower and a gearbox, wherein the rotor is connected to the gearbox via a shaft in a torque-transmitting manner and the gearbox is connected to a power generator, wherein at least one plain bearing according to one of claims 1 to 8 is arranged within the gearbox; is included in the wind turbine, preferably the gearbox thereof. [10] Use of the plain bearing according to one of claims 1 to 8 in a drive shaft of a wind turbine, preferably a main drive shaft of a wind turbine, and / or in a gearbox of other industrial applications.

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