Plain bearing arrangement

Abstract

A plain bearing arrangement (1) comprises a plain bearing element (2) providing a sliding surface (3) for supporting a shaft, and a housing element (5) supporting the plain bearing element (2) in an at least slightly tiltable manner. The plain bearing element (2) has a mandrel (8) facing away from the sliding surface (3) and facing a surface (6) of the housing element (5). A free space (11) is formed between the surface (9) of the plain bearing element (2) from which the mandrel (8) protrudes and the surface (6) of the housing element (5). Arranged in the free space (11) is an annular disk-shaped, elastic element (7) having a non-cylindrical outer peripheral surface (12) for transmitting forces between the plain bearing element (2) and the housing element (5).

Description

[0001] The invention relates to a plain bearing arrangement suitable, for example, for use in a wind turbine, which comprises a plain bearing element which is supported on a housing in an at least slightly tiltable manner.

[0002] EP 3 662 168 B1 discloses a fluid bearing for a wind turbine. This fluid bearing comprises a plurality of bearing segments arranged in a bearing housing. The individual bearing segments are each supported in the bearing housing by a support structure. The support structures each comprise a plurality of elastomer layers and a plurality of plates made of a non-compressible material, each plate being arranged between two elastomer layers.

[0003] Another bearing assembly designed for use in a wind turbine is disclosed in EP 3 739 224 B1. This bearing assembly comprises a downwind bearing and an upwind bearing, at least one of the two bearings being a radial fluid bearing. The fluid bearing comprises a plurality of radial bearing pads, with adjacent bearing pads being locked in their movement relative to each other and relative to a cylindrical seat by means of press-fitted locking pieces.

[0004] A bearing arrangement for a rotor in a stationary housing described in DE 10 2019 102 430 A1 comprises several housing-side plain bearing segments, each having a sliding surface facing a shaft. Angle adjustment elements are located between the plain bearing segments and the housing, with a surface of the angle adjustment element facing the respective plain bearing segment being convexly or concavely curved.

[0005] The invention is based on the object of specifying a bearing arrangement which is further developed compared to the cited prior art and is particularly suitable for use in a wind turbine, which provides for a tiltability of a plain bearing element with a structurally simple design, wherein the tiltability should be adapted to the conditions given in the individual case.

[0006] This object is achieved according to the invention by a plain bearing arrangement having the features of claim 1. According to claim 10, the plain bearing arrangement can in particular be assigned to a main rotor bearing of a wind turbine.

[0007] The plain bearing assembly according to the application has a plain bearing element providing a sliding surface intended for contacting a shaft or other rotating machine element. The plain bearing element is supported in a housing element in an at least slightly tiltable manner. In numerous applications, the plain bearing assembly serves to radially support the shaft or other machine element. However, it is also possible to use the plain bearing assembly in an axial bearing arrangement or to simultaneously support radial and axial forces, whereby in the latter case, at least a section of the sliding surface must be positioned obliquely to the rotational axis of the mounted element. In all cases, axial forces act by definition between the plain bearing element and the housing element during operation of the plain bearing assembly. The axial direction here refers to the central axis of the plain bearing element.

[0008] Regardless of the application and installation situation, the plain bearing element has a mandrel facing away from the sliding surface and towards a surface of the housing element. The term mandrel is used here for any structure protruding from the surrounding surface of the plain bearing element and oriented essentially perpendicular to both the latter surface and the surface of the housing element. If the mandrel is arranged centrally, its central axis is identical to the central axis of the entire plain bearing element. The mandrel can have a circular cylindrical shape, whereby the length of the mandrel can correspond to its diameter or be larger or smaller than the diameter of the mandrel. In the latter case, the mandrel is shaped like a disc. There are also numerous design options for the end face of the mandrel facing the surface of the housing element.For example, the end face can be flat, optionally with a rounded edge, or spherical or curved in some other way. Unlike the plain bearing element, the surface of the housing element facing the plain bearing element can be either flat or uniformly curved throughout the entire area of ​​the plain bearing arrangement.

[0009] A clearance is formed between the surface of the plain bearing element from which the mandrel protrudes and the surface of the housing element, regardless of the shape of the mandrel. A ring-shaped elastic element with a non-cylindrical outer peripheral surface is arranged in this clearance. It is intended for the transmission of forces, i.e., axial forces, between the plain bearing element and the housing element. The elastic element is made, in particular, of plastic.

[0010] The non-cylindrical outer peripheral surface of the elastic element, which is inserted between the housing element and the plain bearing element, is adapted to the specific requirements of the application. For example, the outer peripheral surface is conical in shape, whereby it can widen either toward the plain bearing element or toward the housing element. Variants of the annular disc-shaped elastic element are also possible, in which its outer peripheral surface describes a convex or concave curved contour.

[0011] Particularly in cases where the outer peripheral surface of the mandrel is cylindrical, the inner peripheral surface of the elastic annular disc-shaped element can also be cylindrical. Cross-sectional designs of the mandrel and the inner peripheral surface of the elastic annular disc-shaped element that deviate from a circular shape are also conceivable. Such designs are particularly suitable in cases where individual components of the plain bearing assembly must be mounted in a defined angular position. This can apply, for example, to cases where the outer peripheral surface of the elastic element has a non-circular shape, such as a rectangular shape.

[0012] In many designs, the transfer of axial forces between the mandrel and the elastic annular disc-shaped element is not provided. Likewise, in many cases, the mandrel is lifted from the housing element, at least when the plain bearing element is not subject to mechanical load.

[0013] The diameter of the elastic annular disc-shaped element can be smaller than the width of the plain bearing element. This allows the elastic annular disc-shaped element to expand within the free space formed between the plain bearing element and the housing element when the plain bearing element tilts, without protruding beyond the outline of the plain bearing element.

[0014] The plain bearing assembly is designed, in particular, as part of a hydrodynamic bearing arrangement, particularly in the form of a rotor main bearing or a gearbox bearing in a wind turbine. Optionally, the plain bearing assembly is equipped with sensors, for example, for force and / or temperature measurement.

[0015] Four exemplary embodiments of the invention are explained in more detail below with reference to a drawing. In the drawings: Fig. 1 shows a first embodiment of a plain bearing arrangement, which has an elastic annular disc-shaped element, in this case with a conical outer contour, located between a plain bearing element and a housing element, Fig. 2 a plain bearing arrangement, which comprises an annular disc-shaped element with opposite Fig. 1 modified conical shape, Fig. 3 a variant of a plain bearing arrangement which comprises an elastic annular disc-shaped element with a convex outer contour, Fig. 4 a plain bearing arrangement including an elastic ring-disk-shaped element with a concave outer contour.

[0016] Unless otherwise stated, the following explanations refer to all exemplary embodiments. Corresponding or essentially equivalent parts are identified by the same reference numerals in all figures.

[0017] A plain bearing arrangement, designated overall by reference numeral 1, is intended for use in a rotor main bearing designed as a hydrodynamic bearing in a wind turbine 10. The rotor main bearing comprises a plurality of the Fig. 1 to 4. The center axis of each plain bearing arrangement 1, designated MA, is aligned radially to the shaft (not shown) supported by the rotor main bearing. For each plain bearing arrangement 1, the center axis MA indicates the axial direction of the respective plain bearing arrangement 1. Regarding the basic design and function of segmented plain bearings in wind turbines, reference is made to the prior art cited at the beginning.

[0018] The plain bearing assembly 1 comprises a plain bearing element 2, also referred to as a plain bearing segment. A sliding surface provided for contacting the mounted shaft is designated 3. In the present case, the sliding surface 3 is formed by a sliding lining 4 of the plain bearing element 2. Alternatively, the entire plain bearing element 2 could be constructed from the same material.

[0019] The sliding bearing element 2 is supported on a surface 6 of a housing element 5 by means of an elastic ring-shaped element 7 made of plastic with limited tilting. Deviating from the simplified representations according to the Fig. 1 to 4, the surface 6 can be curved. The same applies to the shape of the sliding surface 3. The base thickness of the plain bearing element 2, including the sliding lining 4, is designated d2. The width of the plain bearing element, measured in the tangential direction of the supported shaft, is designated B2.

[0020] The elastic annular disc-shaped element 7 surrounds a mandrel 8, which is an integral part of the plain bearing element 2 and protrudes from a surface of the plain bearing element 2, designated 9, which faces the housing element 5. The central axis of the mandrel 8 coincides with the central axis of the entire plain bearing element 2.

[0021] A clearance 11 is formed between the surface 9 of the plain bearing element 2 and the surface 6 of the housing element 5. The height of the clearance 11, measured in the axial direction of the plain bearing arrangement 1, i.e. in the longitudinal direction of the central axis MA, corresponds to the thickness of the elastic annular disk-shaped element 7, designated D7, in the mechanically unloaded state of the plain bearing arrangement 1. The length of the mandrel 8, measured in the same direction and designated L8, is less than the thickness D7. This means that the mandrel 8, in the mechanically unloaded state, as in the Fig. 1 to 4, is lifted from the surface 6 of the housing element 5. In the exemplary embodiments, the length L8 of the mandrel 8 corresponds to less than half of the base thickness d2 of the plain bearing element 2, measured without the mandrel 8.

[0022] The maximum diameter of the elastic ring-shaped element 7, measured orthogonally to the central axis MA, is D7 max In none of the embodiments is the diameter of the elastic annular disc-shaped element 7 uniform across its entire thickness. D7 min The minimum outer diameter of the elastic ring-shaped element 7 is indicated. The different diameters D7 min , D7 max are to be measured on an outer circumferential surface 12 of the elastic annular disc-shaped element 7. The minimum outer diameter D7 min and also the maximum outer diameter D7 maxis less than the width B2 of the plain bearing element 2.

[0023] In contrast to the outer peripheral surface 12 of the elastic annular disc-shaped element 7, the inner peripheral surface of the same element 7, designated 13, is cylindrical in all illustrated embodiments. Likewise, the outer surface of the mandrel 8, designated 14 and surrounded by the elastic element 7, is cylindrical. The end face of the mandrel 8, designated 15 and spaced parallel to the surface 6, is flat in the present case. Alternatively, a spherical shape of the end face 15 is also possible.

[0024] In the examples according to the Fig. 1 and Fig. 2, the outer peripheral surface 12 of the elastic annular disc-shaped element 7 is conical. In the case of Fig. 1, the outer peripheral surface 12 tapers from the plain bearing element 2 towards the housing element 5. A reverse conicity is in the case of Fig. 2: Here the elastic ring-shaped element 7 lies with its wider end face, that is, with the side on which the maximum diameter D7 min is present, on the surface 6 of the housing element 5.

[0025] The examples of implementation according to the Fig. 3 and Fig. 4 differ from the embodiments according to the Fig. 1 and Fig. 2 in that the outer peripheral surface 12 of the elastic annular disc-shaped element 7, as can be seen from the two sectional views, is convexly or concavely curved.

[0026] In the case of the concave curvature, as shown in the example according to Fig. 4, an axial force acting eccentrically to the central axis MA on the plain bearing element 2 ensures that the section of the outer peripheral surface 12 which is closest to the point of application of the axial force is compressed in such a way that in the corresponding section the concave contour of the outer peripheral surface 12 approaches a straight, cylindrical contour.

[0027] In each of the embodiments according to the Fig.1 to 4, the elastic properties of the annular disc-shaped element 7 are matched to its shape and the maximum tilt angle of the plain bearing element 2 in such a way that, during any conceivable tilting of the plain bearing element 2 during normal operation of the plain bearing arrangement 1, the full-surface contact between the elastic element 7, on the one hand, and the plain bearing element 2 or the surface 6 of the housing element 5, on the other hand, is maintained. In all cases, the free space 11 offers sufficient possibilities for expansion of the elastic element 7, which can be a polymer or elastomer element. List of reference symbols 1 plain bearing arrangement 2 plain bearing element 3 Sliding surface 4 Sliding coating 5 Housing element 6 Surface of the housing element 7 elastic ring-shaped element 8 Thorn 9 Surface of the plain bearing element, facing the housing element 10 wind turbines 11 Free space 12 Outer peripheral surface of the elastic ring-shaped element 13 Inner peripheral surface of the elastic ring-shaped element 14 Shell surface 15 Frontal surface B2 Width of the plain bearing element d2 Base thickness of the plain bearing element d7 Thickness of the elastic ring-shaped element D7 max maximum diameter of the elastic ring-shaped element D7 min minimum diameter of the elastic ring-shaped element L8 Length of the mandrel MA central axis 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 3 662 168 B1

[0002] EP 3 739 224 B1

[0003] DE 10 2019 102 430 A1

[0004]

Claims

[1] Plain bearing arrangement (1), with a plain bearing element (2) having a sliding surface (3), and with a housing element (5) supporting the plain bearing element (2) in an at least slightly tiltable manner, wherein - the sliding bearing element (2) has a mandrel (8) facing away from the sliding surface (3) and facing a surface (6) of the housing element (5), - a free space (11) is formed between the surface (9) of the plain bearing element (2) from which the mandrel (8) protrudes and the surface (6) of the housing element (5), - an annular disc-shaped elastic element (7) with a non-cylindrical outer peripheral surface (12) is arranged in the free space (11) and is provided for transmitting forces between the plain bearing element (2) and the housing element (5). [2] Plain bearing arrangement (1) according to claim 1, characterized by that the outer peripheral surface (12) of the annular disc-shaped element (7) is conical. [3] Plain bearing arrangement (1) according to claim 2, characterized by that the outer peripheral surface (12) of the annular disc-shaped element (7) widens towards the plain bearing element (2). [4] Plain bearing arrangement (1) according to claim 2, characterized by that the outer peripheral surface (12) of the annular disc-shaped element (7) widens towards the housing element (5). [5] Plain bearing arrangement (1) according to claim 1, characterized by that the outer peripheral surface (12) of the annular disc-shaped element (7) has a convex curvature. [6] Plain bearing arrangement (1) according to claim 1, characterized by that the outer peripheral surface (12) of the annular disc-shaped element (7) has a concave curvature. [7] Plain bearing arrangement (1) according to one of claims 1 to 6, characterized by that the outer surface (14) of the mandrel (8) and the inner peripheral surface (13) of the elastic annular disc-shaped element (7) are cylindrical. [8] Plain bearing arrangement (1) according to one of claims 1 to 7, characterized by that the mandrel (8) is lifted from the housing element (5) at least in the mechanically unloaded state of the plain bearing element (2). [9] Plain bearing arrangement (1) according to one of claims 1 to 8, characterized by that the maximum diameter (D7 max ) of the elastic annular disc-shaped element (7) is smaller than the width (B2) of the plain bearing element (2). [10] Use of a plain bearing arrangement (1) according to claim 1 in a rotor main bearing of a wind turbine (10).

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