WO2024103098A1

WO2024103098A1 - Plain bearing, a gondola equipped with the plain bearing for a wind turbine, a method for exchanging plain bearing pads in the plain bearing, and a device for exchanging the plain bearing pads

Info

Publication number: WO2024103098A1
Application number: PCT/AT2023/060399
Authority: WO
Inventors: Johannes Sebastian HÖLZL; Patrick Laubichler
Original assignee: Miba Gleitlager Austria Gmbh
Priority date: 2022-11-18
Filing date: 2023-11-17
Publication date: 2024-05-23

Abstract

The invention relates to a plain bearing (9) comprising: - an inner ring element (13); - an outer ring element (14); - at least one plain bearing element (15) arranged between the inner ring element (13) and the outer ring element (14), the plain bearing element (15) comprising a plurality of plain bearing pads (19), wherein the individual plain bearing pads (19) each have a bearing surface (25) which is curved in the axial direction, at least in some sections, wherein a counter-surface (26) interacting with the bearing surface (25) is formed on the inner ring element (13). The individual plain bearing pads (19) are coupled to the outer ring element (14), wherein an axial stop element (24) is formed on the outer ring element (14), wherein between the plain bearing pads (19) and the outer ring element (14) a spacer (20) is arranged in each case, wherein an axial clamping element (23) is formed by means of which the plain bearing pads (19) are clamped in the axial direction between the axial clamping element (23) and the axial stop element (24).

Description

SLIDE BEARING, AS WELL AS A NACELLE EQUIPPED WITH THE SLIDE BEARING FOR A WIND TURBINE,

AS WELL AS A METHOD FOR CHANGING SLIDE BEARING PADS IN THE SLIDE BEARING, AS WELL AS A DEVICE FOR CHANGING THE SLIDE BEARING PADS

The invention relates to a plain bearing, as well as a nacelle equipped with the plain bearing for a wind turbine, a wind turbine, as well as a method for changing plain bearing pads in the plain bearing, as well as a device for changing the plain bearing pads.

From WO 2011/127510 Al a bearing element for supporting the rotor hub of a wind turbine is known.

The object of the present invention was to provide an improved plain bearing.

This object is achieved by a device and a method according to the claims.

According to the invention, a plain bearing is designed. The plain bearing comprises:

- an inner ring element;

- an outer ring element;

- at least one plain bearing element which is arranged between the inner ring element and the outer ring element, wherein the plain bearing element has a plurality of plain bearing pads, wherein the individual plain bearing pads each have a bearing surface which is curved at least in sections in the axial direction, in particular in the form of a spherical cap, wherein a counter surface which interacts with the bearing surface is formed on the inner ring element.

The individual plain bearing pads are coupled to the outer ring element, wherein an axial stop element is formed on the outer ring element, wherein a spacer is arranged between the plain bearing pads and the outer ring element, wherein an axial clamping element is formed, by means of which the plain bearing pads are clamped in the axial direction between the axial clamping element and the axial stop element.

The plain bearing according to the invention has the advantage that the individual plain bearing pads can be easily exchanged and positioned. Furthermore, it can be provided that a first contact bevel is formed on a first end face of the plain bearing pads and that a first counter-contact bevel corresponding to the first contact bevel is formed in the outer ring element and that a second contact bevel is formed on a second end face of the plain bearing pads and that a second counter-contact bevel corresponding to the second contact bevel is formed in the axial clamping element, wherein the plain bearing pads are pressed outwards in the radial direction by clamping the plain bearing pads in the axial direction between the axial clamping element and the axial stop element, wherein the plain bearing pads are pressed radially against the spacers and wherein the spacers are clamped radially between the plain bearing pad and the outer ring element.

Furthermore, it can be expedient if the axial clamping element has a plurality of axial clamping segments distributed in the circumferential direction and/or the axial stop element has a plurality of stop segments distributed in the circumferential direction, with at least one of the axial clamping segments and/or one of the stop segments being assigned to each of the plain bearing pads, with each of the axial clamping segments and/or each of the stop segments being designed to be adjustable independently of one another in the axial direction. This has the advantage that this measure can compensate for dimensional deviations of the plain bearing pads due to dimensional tolerances of the plain bearing pads, so that the plain bearing pads can be arranged exactly centered in the plain bearing in order to achieve smooth functionality of the plain bearing pads.

In particular, it can be provided that the individual axial clamping segments are arranged on the axial clamping element. In this case, it can be provided that the axial clamping segments are adjustable in the axial direction relative to the axial clamping element.

Furthermore, it can be provided that the stop segments are arranged on the axial stop element or are designed to be displaceable relative to the axial stop element.

Furthermore, it can be provided that a first material recess is formed in the axial clamping element and/or that a second material recess is formed in the axial stop element, so that the axial clamping element and/or the axial stop element can be elastically deformed in the axial direction for each of the plain bearing pads. This has the advantage that this measure can ensure that all of the plain bearing pads are adequately clamped. In particular, this can be achieved by Material recesses the individual contact points on the plain bearing pads are elastically deformable due to the elasticity of the material, whereby those contact points which previously rested on the plain bearing pads are elastically deformed so that all of the contact points come into contact with the plain bearing pad.

In addition, it can be provided that a circumferential spacer is formed, wherein the circumferential spacer is arranged in the circumferential direction between two of the plain bearing pads, wherein the circumferential spacer extends in the radial direction over the plain bearing pads and the spacers, wherein both two mutually adjacent plain bearing pads and two mutually adjacent spacers rest on the circumferential spacer. This has the advantage that this measure allows both the plain bearing pads and the spacers assigned to the plain bearing pads to be correctly positioned or held in position. This can be particularly advantageous for changing plain bearing pads. This can be particularly advantageous when changing those plain bearing pads which are located laterally between the top and bottom of the plain bearing, since these could slide downwards due to gravity when the clamping of the plain bearing pads is released.

Another advantageous embodiment is one in which the circumferential spacer, viewed in cross-section, has a trapezoidal shape that tapers radially inwards and the plain bearing pads have a corresponding trapezoidal shape that tapers radially outwards, so that the plain bearing pads are supported outwards in the radial direction. This has the advantage that the plain bearing pads cannot fall radially outwards even when a spacer is removed. This is particularly advantageous when a lower plain bearing pad is changed when a bearing pad is changed and the spacer assigned to this plain bearing pad is removed in order to change the plain bearing pad in order to be able to remove the plain bearing pad. In an arrangement without the circumferential spacers designed in this way, the lower plain bearing pad would fall downwards due to gravity when removed.

According to a further development, it is possible for the axial clamping element to be coupled to the outer ring element by means of several fastening screws distributed over the circumference, whereby the number of fastening screws corresponds to an integer multiple of the number of plain bearing pads. This has the advantage that for each of the There is a fastening screw at the same relative position for each of the plain bearing pads. This means that all of the plain bearing pads can be loaded with the same clamping situation, which leads to more even wear on the plain bearing pads. In addition, this measure means that a plain bearing pad changing device for changing the plain bearing pads, which can be screwed into the fastening holes of the outer ring element, can assume an exact relative position to the respective plain bearing pad to be changed, whereby this relative position is the same for all of the plain bearing pads to be changed. This simplifies changing the plain bearing pads.

According to the invention, a nacelle is provided for a wind turbine. The nacelle comprises:

- a nacelle housing;

- a rotor hub;

- a rotor bearing for supporting the rotor hub on the nacelle housing.

The rotor bearing comprises a plain bearing according to one of the preceding claims.

Especially in the case of gondolas according to the invention, the sliding bearing according to the invention leads to easy maintenance of the sliding bearing.

The invention also relates to a method for changing plain bearing pads in a plain bearing. The method comprises the following method steps:

- Loosening the axial clamping element and axially removing the axial clamping element from the outer ring element;

- Axial withdrawal of the spacer from the gap between the outer ring element and the plain bearing pad;

- Removing the plain bearing pad by moving the plain bearing pad radially outwards and then pulling the plain bearing pad axially out of the space between the inner ring element and the outer ring element;

- Inserting a new plain bearing pad by axially inserting the plain bearing pad and then moving the plain bearing pad radially inwards;

- Axial insertion of the spacer of the relevant plain bearing pad into the space between the outer ring element and the plain bearing pad;

- Fixing the plain bearing pad by axially clamping the plain bearing pad using the axial clamping element and thereby pressing the plain bearing pad onto the spacer.

The method according to the invention leads to easy maintainability of the plain bearing. Furthermore, it can be provided that the plain bearing pad is coupled to a first manipulation arm of a plain bearing pad changing device and the spacer is coupled to a second manipulation arm of the plain bearing pad changing device, wherein the plain bearing pad is held in position by the first manipulation arm during the axial withdrawal of the spacer by means of the second manipulation arm. This has the advantage that when the spacer is removed, the plain bearing pad does not fall out of position in an uncontrolled manner. This is particularly necessary when a plain bearing pad is changed which is located on the underside of the plain bearing and thus rests on the spacer due to gravity or would fall downwards when the spacer is removed.

According to a particular embodiment, it is possible for the axial clamping element to have a plurality of axial clamping segments distributed in the circumferential direction and/or for the axial stop element to have a plurality of stop segments distributed in the circumferential direction, with at least one of the axial clamping segments and/or one of the stop segments being assigned to each of the plain bearing pads, with each of the axial clamping segments and/or each of the stop segments being designed to be adjustable in the axial direction independently of one another, with the axial clamping segments and/or the axial stop elements being adjusted in the axial direction by means of an adjusting screw and being pressed axially onto the plain bearing pad with a predetermined torque of the adjusting screw in order to achieve a certain axial contact force. This has the advantage that this measure allows the plain bearing pad to be positioned precisely in the plain bearing in order to avoid one-sided wear of the plain bearing pad.

In particular, it can be provided that before adjusting the stop segments, the plain bearing pad, in particular the bearing surface of the plain bearing pad, is pressed against the counter surface of the inner ring element, whereby the plain bearing pad centers itself in the axial direction by pressing the plain bearing pad against the counter surface.

The associated process steps for changing the plain bearing pad can be as follows. The old plain bearing pads are removed one after the other according to the process steps already described and replaced with new plain bearing pads. An old plain bearing pad is removed and then directly replaced with a new plain bearing pad before the adjacent plain bearing pad is removed and replaced. When After inserting the plain bearing pad, it can be pressed radially onto the inner ring element in order to achieve axial centering of the plain bearing pad through the curved plain bearing surface. The respective stop segment can then be pressed onto the plain bearing pad with a predetermined force or, accordingly, with a predetermined torque. In a further process step, the remaining plain bearing pads can then be changed using the same principle. Once all of the plain bearing pads have been changed, the axial clamping element can be coupled to the outer ring element or fastened to it. In a final process step, each of the axial stop elements can now be pressed onto the respective plain bearing pad with a predetermined axial stop force. This measure enables all of the plain bearing pads to have an exact alignment in the plain bearing, regardless of any dimensional deviations caused by production.

According to an advantageous further development, it can be provided that before changing one of the sliding bearing pads located below, the inner ring element is raised in order to relieve the load on the sliding bearing pad to be changed. This has the advantage that this measure also allows the sliding bearing pads located below to be changed easily and without great effort.

In particular, it can be advantageous if the axial clamping element is coupled to the outer ring element by means of several fastening screws distributed over the circumference, with the fastening screws being tightened diagonally opposite one another. This has the surprising advantage that this measure can improve and thus reduce the wear on the individual plain bearing pads, which can improve the overall longevity of the plain bearing.

Plain bearing pad changing device for changing plain bearing pads. The plain bearing pad changing device comprises:

- a base frame;

- a first manipulation arm, wherein the first manipulation arm is displaceable relative to the base frame and wherein the first manipulation arm is designed for coupling with the sliding bearing pad,

- a second manipulation arm, wherein the second manipulation arm is movable relative to the Base frame is displaceable and wherein the second manipulation arm is designed to be coupled to the spacer.

The plain bearing pad changing device offers the advantage of easy maintenance of the plain bearing.

In addition, it can be provided that the first manipulation arm is designed to be movable in the axial direction and in the radial direction. This has the advantage that the plain bearing pad to be changed or the plain bearing pad to be inserted can be easily manipulated from or into their position.

Furthermore, it can be provided that the first manipulation arm and the second manipulation arm are arranged on a common carriage. The carriage can be arranged on the base frame so that it can be moved in the radial direction by means of a carriage guide. This measure allows the first manipulation arm and the second manipulation arm to be moved together in the radial direction.

Furthermore, it can be provided that a radial adjustment device is formed, by means of which the carriage can be displaced in the radial direction on the carriage guide. The radial adjustment device can be designed in the form of a spindle, whereby a spindle nut can be arranged or formed in the base frame. The radial adjustment device in the form of a spindle can be rotatably mounted on the carriage and coupled to it. By rotating the radial adjustment device, it can thus be displaced together with the carriage in the radial direction.

Furthermore, it can be provided that a torque pin is formed at the end of the radial adjustment device, which can be designed in the form of a spindle, which serves to introduce a torque into the spindle. The torque pin can be coupled to drive it, for example, with a hand crank or with an electric motor drive device, such as a cordless screwdriver.

Furthermore, it can be provided that at least the second manipulation arm is arranged on a swivel device so that it can be swiveled about an axis normal to the axial direction. This measure can make it easier to replace the old, pulled-out plain bearing pad with a new plain bearing pad. In particular, After pulling out the old plain bearing pad using the swivel device, the plain bearing pad can be swiveled outwards to improve accessibility to the plain bearing pad.

Another advantageous embodiment is one in which the base frame can be coupled to a fastening element, the fastening element having through holes, the hole spacing of the through holes in the circumferential direction being the same as the hole spacing of fastening holes in the outer ring element or corresponding to a multiple of the hole spacing of fastening holes in the outer ring element, the fastening element being able to be fastened to the outer ring element by means of fastening screws extending through the through holes. This has the advantage that this measure allows the base frame or the plain bearing pad changing device to be easily fastened to the outer ring element in order to enable the individual plain bearing pads to be changed. In particular, the plain bearing pad changing device can be realigned and positioned for each of the plain bearing pads to be changed. An appropriate hole pattern can be used to achieve exact alignment of the plain bearing pad changing device relative to the respective plain bearing pad to be changed.

In a further embodiment, it is also conceivable that the plain bearing pad changing device has a fastening ring, wherein the fastening ring is fastened to the outer ring element. The fastening ring can also have a circumferential rail. In addition, it can be provided that a running unit is arranged on the base frame, which interacts with the circumferential rail or with the fastening ring, whereby a free positioning of the base frame and thus of the manipulation arms can be achieved all around. The fastening ring therefore only needs to be positioned once on the outer ring element and all of the plain bearing pads can be changed by moving the base frame relative to the fastening ring by the circumference of the plain bearing.

A curvature of the bearing surface in the axial direction can have the same or a different radius as a radius of the bearing surface in the circumferential direction. If the radius in the circumferential direction and the radius in the axial direction are the same size, the bearing surface forms the shape of a spherical cap. If the radius in the axial direction is smaller than the radius in the circumferential direction, the sliding surface can, for example, have the shape of a torus or of a torus segment. In addition, it is also conceivable that the bearing surface has different sections with different curvatures in the axial direction.

A spherical cap is a segment of the surface of a sphere. The bearing surface preferably has the basic shape of an ideal spherical cap. In correspondence with this, the counter surface is of course also designed in the shape of an ideal spherical cap. The radii of these two spherical caps are selected accordingly so that the bearing surface rests on the counter surface over as much of its entire surface as possible. In special applications, it can also be provided that not the entire bearing surface has the shape of an ideal spherical cap, but that, for example, an oil intake wedge is formed, which can be necessary for a hydrodynamic bearing. It is therefore possible that the bearing surface deviates from the shape of the ideal spherical cap, particularly in the circumferential direction. Furthermore, it is also conceivable that the surface of the bearing surface deviates from the ideal spherical cap due to manufacturing tolerances. Such designs also fall within the scope of protection of the independent main claims.

For a better understanding of the invention, it is explained in more detail with reference to the following figures.

They show in a highly simplified, schematic representation:

Fig. 1 is a schematic representation of a wind turbine;

Fig. 2 is a longitudinal sectional view of a first embodiment of a plain bearing of the wind turbine;

Fig. 3 is a cross-sectional view of the first embodiment of the plain bearing;

Fig. 4 is a schematic representation of an embodiment of the process sequence for changing the plain bearing pads;

Fig. 5 is a schematic representation of a first embodiment of a plain bearing pad changing device for changing the plain bearing pads;

Fig. 6 is a perspective view of a second embodiment of the plain bearing pad changing device for changing the plain bearing pads; Fig. 7 is a perspective view of a third embodiment of the plain bearing pad changing device for changing the plain bearing pads;

Fig. 8 is a longitudinal sectional view of a second embodiment of a plain bearing of the wind turbine;

Fig. 9 is a longitudinal sectional view of a third embodiment of a plain bearing of the wind turbine;

Fig. 10 is a cross-sectional view of the further embodiment of the plain bearing with circumferential spacers;

Fig. 11 is a cross-sectional view of another embodiment of the plain bearing with circumferential spacers in trapezoidal shape.

To begin with, it should be noted that in the different embodiments described, identical parts are provided with identical reference symbols or identical component designations, whereby the disclosures contained in the entire description can be transferred analogously to identical parts with identical reference symbols or identical component designations. The position information chosen in the description, such as top, bottom, side, etc., also refers to the figure directly described and shown, and these position information must be transferred analogously to the new position if the position changes.

Fig. 1 shows a schematic representation of a first embodiment of a wind turbine 1 for generating electrical energy from wind power. The wind turbine 1 comprises a nacelle 2, which is rotatably mounted on a tower 3. The nacelle 2 comprises a nacelle housing 4, which forms the main structure of the nacelle 2. The electrical components, such as a generator of the wind turbine 1, are arranged in the nacelle housing 4 of the nacelle 2.

Furthermore, a rotor 5 is formed, which has a rotor hub 6 with rotor blades 7 arranged thereon. The rotor hub 6 is seen as part of the nacelle 2. The rotor hub 6 is rotatably mounted on the nacelle housing 4 by means of a rotor bearing 8. In particular, it is provided that a plain bearing 9 according to the invention and described in more detail below is used as the rotor bearing 8. The rotor bearing 8, which serves to support the rotor hub 6 on the nacelle housing 4 of the nacelle 2, is designed to absorb a radial force 10 and an axial force 11. The axial force 11 is caused by the force of the wind. The radial force 10 is caused by the weight of the rotor 5 and acts on the center of gravity of the rotor 5. Since the center of gravity of the rotor 5 is outside the rotor bearing 8, a tilting moment 12 is caused in the rotor bearing 8 by the radial force 10. The tilting moment 12 can also be caused by an uneven load on the rotor blades 7. This tilting moment 12 can be absorbed by means of a second plain bearing, which is arranged at a distance from the plain bearing 9 according to the invention.

The rotor bearing 8 according to the invention can, for example, have a diameter of between 0.5 m and 5 m. Of course, it is also conceivable that the rotor bearing 8 is smaller or larger.

Fig. 2 shows a first embodiment of the plain bearing 9 installed in the nacelle 2. Of course, the plain bearing 9 shown in Fig. 2 can also be used in all other industrial applications outside of wind turbines. The plain bearing 9 is shown in Fig. 2 in a half-sectional view.

As can be seen from Fig. 2, it can be provided that the sliding bearing 9 has an inner ring element 13 and an outer ring element 14. The inner ring element 13 and/or the outer ring element 14 can be rotationally symmetrical. In a further development, it is also conceivable that the outer ring element 14 is rotationally symmetrical only on its inner side and has fastening elements on its outer side for fastening to the nacelle 2.

Between the inner ring element 13 and the outer ring element 14 there is arranged a sliding bearing element 15 which serves for the rotational sliding bearing of the inner ring element 13 relative to the outer ring element 14.

In the embodiment shown in Fig. 2, an inner surface 16 is formed on the inner ring element 13, which has a cylindrical shape and serves to accommodate a rotor shaft 17 or another shaft. The rotor shaft 17 is shown schematically in Fig. 2. In an alternative embodiment, it is also conceivable that the inner ring element 13 is formed directly by the rotor shaft 17 or is formed on it. Furthermore, it can be provided that the outer ring element 14 is coupled to the nacelle housing 4. In particular, it can be provided that the outer ring element 14 is designed in the form of a bearing block. The bearing block can be designed in one piece. Furthermore, it is also conceivable that the bearing block is designed in two or more parts. The bearing block can thus have a base and a bearing block cover. Furthermore, it can also be provided that the outer ring element 14 is designed as an annular element which is received in a bearing block or is coupled to a bearing block. Furthermore, it is also conceivable that the outer ring element 14 is formed directly in the nacelle housing 4.

In the embodiment shown in Fig. 2, it is thus provided that the outer ring element 14 is rigidly coupled to the nacelle housing 4 and the inner ring element 13 is rotatable relative to the outer ring element 14 with respect to a rotor axis 18 by means of the sliding bearing element 15.

Since the rotor shaft 17, which is coupled to the rotor hub 6 and thus to the rotor 5, is accommodated in the inner ring element 13, the rotor shaft 17 is thus rotatably accommodated about a rotor axis 18 by means of the plain bearing 9 in the nacelle housing 4.

As can also be seen from Fig. 2, the sliding bearing element 15 comprises a plurality of individual sliding bearing pads 19, which are arranged distributed over the circumference between the inner ring element 13 and the outer ring element 14.

As can also be seen from Fig. 2, it can be provided that a spacer 20 is arranged between each of the individual plain bearing pads 19 and the outer ring element 14. In particular, it can be provided that the spacer 20 is clamped in the radial direction between an inner side 21 of the outer ring element 14 and a rear side 22 of the plain bearing pad 19. The fixing of the plain bearing pad 19 can be achieved by means of an axial clamping element 23, by means of which the plain bearing pad 19 can be pressed in the axial direction against an axial stop element 24 of the outer ring element 14.

The individual plain bearing pads 19 can thus be firmly coupled to the outer ring element in the operational state of the plain bearing. In particular, it can be provided that a bearing surface 25 is formed on the plain bearing pads 19 on an inner side of the plain bearing pads 19 facing the rotor axis 18. Furthermore, it can be provided that on the inner ring element 13 a counter surface 26 is formed, against which the bearing surface 25 rests or which corresponds with the bearing surface 25.

The bearing surface 25 of the plain bearing pad 19 and the counter surface 26 of the outer ring element 14 are designed as sliding surfaces which slide against one another during operation of the plain bearing 9. In particular, it can be provided that the counter surface 26 of the inner ring element 13 is designed as a hard, wear-resistant surface which can be formed, for example, by a hardened steel. The bearing surface 25 of the plain bearing pad 19 can be formed from a plain bearing material which is softer than the counter surface 26. Of course, it is also conceivable that the bearing surface 25 has a sliding coating.

As can be seen particularly well in Fig. 2, the bearing surface 25 is designed in the form of a spherical cap. The design of the bearing surface 25 or the counter surface 26 in the form of a spherical cap has the advantage that the plain bearing pads 19 can be easily rotated about the rotor axis 18. At the same time, the plain bearing pads 19 can be tilted by an angle with respect to the longitudinal extension of the rotor axis 18. The described design of a spherical cap thus makes it possible to compensate for deflections of the rotor shaft 17 in the plain bearing 9 without this leading to an increased surface load on the bearing surface 25.

In addition, by designing the bearing surface 25 or the counter surface 26 in the form of a spherical cap, axial bearing forces can also be transmitted in addition to the transmission of radial bearing forces.

Furthermore, it can be provided that a first contact pressure bevel 28 is formed on a first axial end face 27 of the plain bearing pads 19 and that a first counter-contact pressure bevel 29 corresponding to the first contact pressure bevel 28 is formed in the outer ring element 14 in the axial stop element 24.

Furthermore, it can be provided that a second contact pressure bevel 31 is formed on a second axial end face 30 of the plain bearing pads 19. In this case, a second counter-contact pressure bevel 32 corresponding to the second contact pressure bevel 31 can be formed in the axial clamping element 23. In particular, it can be provided that the first contact bevel 28 and the second contact bevel 31 are designed to open outwards in a V-shape when viewed in longitudinal section along the rotor axis 18.

By means of the first pressing bevel 28 and the second pressing bevel 31 it can be achieved that when the plain bearing pads 19 are clamped in the axial direction between the axial clamping element 23 and the axial stop element 24, the plain bearing pads 19 are pressed outwards in the radial direction, wherein the plain bearing pads 19 are pressed radially against the spacers 20 and wherein the spacers 20 are clamped radially between the plain bearing pad 19 and the inner side 21 of the outer ring element 14.

As can also be seen from Fig. 2, it can be provided that the axial clamping element 23 has a shape similar to a loose flange. In particular, it can be provided that the axial clamping element 23 is rotationally symmetrical in its basic shape.

In particular, it can be provided that a plurality of through holes 33 are formed in the axial clamping element 23 distributed over the circumference, wherein fastening screws 34 can be inserted through the through holes 33 and fastened in fastening holes 35 of the outer ring element 14. As can be seen from Fig. 2, it can be provided that the fastening holes 33 in the outer ring element 14 are equipped with a thread and the fastening screws 34 can be screwed directly into the fastening holes 35. In an alternative embodiment not shown, it is also conceivable that the fastening holes 35 in the outer ring element 14 are also formed in the form of through holes and that the fastening screws 34 are screwed with nuts arranged on the back of the outer ring element 14.

As can be seen from Fig. 2, it can be provided that the through holes 33, the fastening screw 34 and the fastening holes 35 are arranged in a regular pattern distributed over the circumference.

Fig. 3 shows the first embodiment of the plain bearing 9 in a cross-sectional view according to the section line III - III from Fig. 2, wherein again the same reference symbols or component designations are used for the same parts as in the previous figures 1 and 2. In order to avoid unnecessary repetition, reference is made to the detailed description in the previous figures 1 and 2. As can be seen from Fig. 3, it can be provided that the individual plain bearing pads 19 and also the individual spacers 20 can abut one another when viewed in the circumferential direction. It can be provided that the individual plain bearing pads 19 and the individual spacers 20 each have contact projections in the circumferential direction, on which they abut one another.

Fig. 4 shows schematically the process sequence for changing the individual plain bearing pads 19, whereby again the same reference symbols or component designations are used for the same parts as in the previous figures 1 to 3. In order to avoid unnecessary repetition, reference is made to the detailed description in the previous figures 1 to 3.

As can be seen from Fig. 4, it can be provided that in a first method step the fastening screws 34 are loosened and removed from the through holes 33 of the axial clamping element 23. The axial clamping element 23 can then be detached and removed from the outer ring element 14 in the axial direction.

In a subsequent method step, the spacer 20 can be removed in the axial direction from its position between the plain bearing pad 19 and the outer ring element 14. The plain bearing pad 19 to be replaced can then be moved outwards in the radial direction and then removed in the axial direction from the outer ring element 14.

A new plain bearing pad 19 can then be inserted axially into the outer ring element 14 and placed radially against the inner ring element 13.

Subsequently, in a further process step, the spacer 20 can be introduced into the free space between the plain bearing pad 19 and the outer ring element 14. The spacer 20 can optionally be replaced by a new spacer 20 or the old spacer 20 can be reused.

The process for changing the plain bearing pads 19 can be carried out for all of the individual plain bearing pads 19 one after the other, whereby of course the axial clamping element 23 is not re-installed between the individual changing processes. After all the sliding bearing pads 19 that need to be replaced have been replaced, the axial clamping element 23 can be reattached to the outer ring element 14 using the fastening screws 34. By axially pressing the axial clamping element 23 onto the outer ring element 14 and by the presence of the first pressing bevel 28 and the second pressing bevel 31, the individual sliding bearing pads 19 can be pressed onto the spacers 20 in the radial direction when the axial clamping element 23 is axially pressed onto the outer ring element 14. The individual sliding bearing pads 19 can thus be fixed in the sliding bearing 9.

To tighten the fastening screws 34, it can be provided that they are tightened one after the other diagonally opposite each other in order to achieve a uniform clamping of the individual plain bearing pads 19.

Fig. 5 shows an embodiment of the plain bearing pad changing device 37 for changing the individual plain bearing pads 19.

By means of the plain bearing pad changing device 37, the process for changing the plain bearing pads 19 can be made considerably easier.

As can be seen from Fig. 5, it can be provided that the plain bearing pad changing device 37 has a fastening element 39. The fastening element 39 can serve to couple the plain bearing pad changing device 37 to the outer ring element 14. In particular, it can be provided that at least two through holes 40 are formed in the fastening element 39 in order to be able to couple the fastening element 39 to the outer ring element 14 by means of fastening screws 34. In particular, it can be provided that the through holes 40 in the fastening element 39 and the fastening holes 35 of the outer ring element 14 have an at least partially overlapping hole pattern so that the plain bearing pad changing device 37 can be easily coupled to the outer ring element 14.

If the hole pattern of the fastening holes 35 on the outer ring element 14 corresponds to an integer multiple of the pitch of the individual plain bearing elements 15, the plain bearing pad changing device 37 can simply be offset by a corresponding angle in order to be able to reposition it for each of the plain bearing pads 19 to be changed. In such an embodiment, a base frame 38 of the plain bearing pad changing device 37 can be firmly coupled to the fastening element 39, as shown in Fig. 4.

In a further embodiment not shown, it can also be provided that the fastening element 39 is designed in a flange- or ring-shaped, rotationally symmetrical manner. In this case, it can be provided that the base frame 38 is arranged on the fastening element 39 so that it can be moved in the circumferential direction. This allows the base frame 38 to be repositioned relative to the fastening element 39 in order to change the individual plain bearing pads distributed over the circumference.

As can be further seen from the embodiment of Fig. 5, it can be provided that a first manipulation arm 41 and a second manipulation arm 42 are arranged displaceably relative to the base frame 38.

The first manipulation arm 41 can be used for coupling with the spacer 20. The second manipulation arm 42 can be used for coupling with the plain bearing pad 19. In particular, it can be provided that the first manipulation arm 41 is designed to be displaceable in the axial direction in order to be able to pull the spacer 20 out of the outer ring element 14 in the axial direction. Optionally, it can also be provided that the first manipulation arm 41 is displaceable in the radial direction in order to be able to remove the spacer from the required working space in order to be able to remove the plain bearing pad 19 from the outer ring element 14.

As can be seen from Fig. 5, it can be provided that the second manipulation arm 42 is arranged on the base frame 38 of the plain bearing pad changing device 37 so that it can be displaced in the axial direction and also in the radial direction. The ability of the second manipulation arm 42 to be displaced in the radial direction is necessary in order to be able to radially displace the plain bearing pad 19 for removal from the plain bearing 9.

Fig. 6 shows a further embodiment of the plain bearing pad changing device 37, wherein again the same reference numerals or component designations are used for the same parts as in the previous figures 1 to 5. In order to avoid unnecessary repetition, reference is made to the detailed description in the previous figures 1 to 5. As can be seen from Fig. 6, it can be provided that the first manipulation arm 41 and the second manipulation arm 42 are arranged on a common carriage 43. The carriage 43 can be arranged on the base frame 38 so as to be displaceable in the radial direction by means of a carriage guide 44.

In particular, it can be provided that a radial adjustment device 45 is formed, by means of which the carriage 43 can be displaced in the radial direction on the carriage guide 44. The radial adjustment device 45 can be designed in the form of a spindle, wherein a spindle nut can be arranged or formed in the base frame 38. The radial adjustment device 45 in the form of a spindle can be rotatably mounted on the carriage 43 and coupled to it. By rotating the radial adjustment device 45, it can thus be displaced together with the carriage 43 in the radial direction.

As can also be seen from Fig. 6, it can be provided that a torque pin is formed at the end of the radial adjustment device 45, which can be designed in the form of a spindle, which serves to introduce a torque into the spindle. The torque pin can be coupled to drive it, for example, with a hand crank or with an electric motor drive device, such as a cordless screwdriver.

In an alternative embodiment not shown, it is of course also conceivable that the radial adjustment device 45 is designed in the form of another drive.

As can also be seen from Fig. 6, it can be provided that the first manipulation arm 41 and the second manipulation arm 42 can also each be designed in the form of adjusting spindles. It can also be provided that a torque pin is formed at the end of the adjusting spindles, which serves to introduce a torque into the respective spindle.

Furthermore, it can be provided that the spindle nuts corresponding to the first manipulation arm 41 or the second manipulation arm 42 can be arranged or formed in the carriage 43.

As can be seen from Fig. 6, it can be provided that a first coupling element 46 is arranged on the first manipulation arm 41. Furthermore, it can be provided that a second coupling element 47 is arranged on the second manipulation arm 42. The first Manipulation arm 41 in the form of an adjusting spindle can be rotatably coupled to the first coupling element 46. The second manipulation arm 42 in the form of an adjusting spindle can be rotatably coupled to the second coupling element 47. The first coupling element 46 can serve for coupling to the spacer 20. The second coupling element 47 can serve for coupling to the sliding bearing pad 19.

In the following, a plain bearing pad change is explained using a plain bearing pad changing device 37 as shown in Fig. 6.

In a first method step, the first coupling element 46 can be guided to the spacer 20 and coupled thereto. Furthermore, the second coupling element 47 can be guided to the plain bearing pad 19 and coupled thereto.

Subsequently, by rotating the first manipulation arm 41, which is in the form of a spindle, it can be moved in the axial direction in order to be able to remove the spacer 20 from the outer ring element 14. Subsequently, the carriage 43 can be displaced outwards in the radial direction by rotating the radial adjustment device 45, which is in the form of a spindle, in order to be able to displace the plain bearing pad 19 outwards in the radial direction. At the same time, the spacer 20 can be displaced outwards. As can be seen in Fig. 4, the spacer 20 can be displaced into a spacer groove 48 by being pushed outwards. Subsequently, the second coupling element 47, together with the coupled plain bearing pad 19, can be displaced in the axial direction by rotating the second manipulation arm 42.

When the plain bearing pad 19 is completely removed from the outer ring element 14 by axial movement, it can be detached from the second coupling element 47 and replaced with a new plain bearing pad. The new plain bearing pad can be inserted in the reverse order to removing the old plain bearing pad.

Fig. 7 shows a further embodiment of the plain bearing pad changing device 37, wherein again the same reference numerals or component designations are used for the same parts as in the previous figures 1 to 6. In order to avoid unnecessary repetition, reference is made to the detailed description in the previous figures 1 to 6. As can be seen from Fig. 7, it can be provided that the slide guide 44 is arranged on a pivoting device 49 so that the slide 43 can be pivoted about a vertical axis relative to the base frame 38. This measure can make it easier to replace the pulled out, old plain bearing pad 19 with a new plain bearing pad 19. In particular, after pulling out the old plain bearing pad 19 by means of the pivoting device 49, the plain bearing pad 19 can be pivoted outwards in order to improve the accessibility of the plain bearing pad 19.

Fig. 8 shows a further embodiment of the plain bearing 9, wherein again the same reference symbols or component designations are used for the same parts as in the previous figures 1 to 7. In order to avoid unnecessary repetition, reference is made to the detailed description in the previous figures 1 to 7.

As can be seen from Fig. 8, a first material recess 50 can be provided in the axial clamping element 23. The first material recess 50 can be arranged in the vicinity of the first contact bevel 28.

Furthermore, it can be provided that a second material recess 51 is formed on the axial stop element 24.

The material recesses 50, 51 can each be designed in such a way that they are circumferential. Furthermore, the material recesses 50, 51 can also be designed in such a way that they also interrupt the axial clamping element 23 or the axial stop element 24 in the circumferential direction, so that for each of the plain bearing pads 19 there is an independently designed flexible wing on which the first contact bevel 28 or the second contact bevel 31 is formed.

Fig. 9 shows a further embodiment of the plain bearing 9, wherein again the same reference symbols or component designations are used for the same parts as in the previous figures 1 to 8. In order to avoid unnecessary repetition, reference is made to the detailed description in the previous figures 1 to 8. As can be seen from Fig. 9, it can be provided that axial clamping segments 52 are formed on the axial clamping element 23, which are adjustable in the axial direction. In particular, it can be provided that one of the axial clamping segments 52 is formed for each sliding bearing pad 19.

Furthermore, it can be provided that stop segments 53 are formed in the axial stop element 24. In particular, it can be provided that one stop segment 53 is formed for each plain bearing pad 19. The axial clamping segments 52 and the stop segments 53 can each be designed to be adjustable in the axial direction by means of an adjusting device.

Fig. 10 shows a further embodiment of the plain bearing 9, wherein again the same reference symbols or component designations are used for the same parts as in the previous figures 1 to 9. In order to avoid unnecessary repetition, reference is made to the detailed description in the previous figures 1 to 9.

As can be seen from Fig. 10, it can be provided that a circumferential spacer 36 is formed, wherein the circumferential spacer 36 is arranged in the circumferential direction between two of the plain bearing pads 19, wherein the circumferential spacer 36 extends in the radial direction over the plain bearing pads 19 and the spacers 20. Furthermore, it can be provided that both two mutually adjacent plain bearing pads 19 and two mutually adjacent spacers 20 rest on the circumferential spacer 36.

Fig. 11 shows a further embodiment of the plain bearing 9, wherein again the same reference symbols or component designations are used for the same parts as in the previous figures 1 to 10. In order to avoid unnecessary repetition, reference is made to the detailed description in the previous figures 1 to 10.

As can be seen from Fig. 11, it can be provided that the circumferential spacer 36, seen in a cross section, has a trapezoidal shape tapering radially inwards and that the plain bearing pads 19 have a corresponding trapezoidal shape tapering radially outwards, so that the plain bearing pads 19 are supported outwards in the radial direction. The embodiments show possible embodiment variants, whereby it should be noted at this point that the invention is not restricted to the specifically illustrated embodiment variants thereof, but rather various combinations of the individual embodiment variants with each other are also possible and this possibility of variation lies within the skill of the person skilled in the art in this technical field due to the teaching of technical action through objective invention.

The scope of protection is determined by the claims. However, the description and the drawings must be used to interpret the claims. Individual features or combinations of features from the different embodiments shown and described can represent independent inventive solutions in themselves. The task underlying the independent inventive solutions can be taken from the description.

All information on value ranges in the description in question is to be understood as including any range and all subranges thereof, e.g. the information 1 to 10 is to be understood as including all subranges starting from the lower limit 1 and the upper limit 10, i.e. all subranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

Finally, for the sake of clarity, it should be noted that in order to better understand the structure, some elements have been shown not to scale and/or enlarged and/or reduced.

Reference number s t a t i o n

Wind turbine 31 second contact slope nacelle 32 second counter contact slope

Tower 33 through hole axial clamping element

Nacelle housing ment

Rotor 34 fastening screw

Rotomabe 35 mounting hole outer ring

Rotor blade gelement

Rotor bearing 36 Circumference spacer

Plain bearing 37 Plain bearing pad changing device Radial force 38 Base frame

Axial force 39 Fastener

Tilting moment 40 Through hole Fastening element Inner ring element Outer ring element 41 First manipulation arm Slide bearing element 42 Second manipulation arm Inner surface Inner ring element 43 Slide element 44 Slide guide

Rotor shaft 45 Radial adjustment device

Rotor axis 46 first coupling element

Plain bearing pad 47 second coupling element

Spacer 48 Spacer niche

Inner side of outer ring element 49 Pivoting device Rear side of plain bearing pad 50 First material recess of axial clamping element 51 Second material recess of axial stop element 52 Axial clamping segment

Bearing area 53 stop segment

Counter surface first axial face first contact bevel first counter contact bevel second axial face

Claims

Patent claims

1. Plain bearing (9) comprising:

- an inner ring element (13);

- an outer ring element (14);

- at least one plain bearing element (15) which is arranged between the inner ring element (13) and the outer ring element (14), wherein the plain bearing element (15) has a plurality of plain bearing pads (19), wherein the individual plain bearing pads (19) each have a bearing surface (25) which is curved at least in sections in the axial direction, wherein a counter surface (26) cooperating with the bearing surface (25) is formed on the inner ring element (13), characterized in that the individual plain bearing pads (19) are coupled to the outer ring element (14), wherein an axial stop element (24) is formed on the outer ring element (14), wherein a spacer (20) is arranged between the plain bearing pads (19) and the outer ring element (14), wherein an axial clamping element (23) is formed, by means of which the plain bearing pads (19) are clamped in the axial direction between the axial clamping element (23) and the axial stop element (24) are clamped.

2. Plain bearing (9) according to claim 1, characterized in that the axial clamping element (23) has a plurality of axial clamping segments (52) distributed in the circumferential direction and/or the axial stop element (24) has a plurality of stop segments (53) distributed in the circumferential direction, wherein each of the plain bearing pads (19) is assigned at least one of the axial clamping segments (52) and/or one of the stop segments (53), wherein each of the axial clamping segments (52) and/or each of the stop segments (53) are designed to be adjustable in the axial direction independently of one another.

3. Plain bearing (9) according to claim 1 or 2, characterized in that a first material recess (50) is formed in the axial clamping element (23) and/or that a second material recess is formed in the axial stop element (24), so that the axial clamping element (23) and/or the axial stop element (24) is elastically deformable in the axial direction for each of the plain bearing pads (19).

4. Plain bearing (9) according to claim 1 or 2, characterized in that a circumferential spacer (36) is formed, wherein the circumferential spacer (36) is arranged in the circumferential direction between two of the plain bearing pads (19), wherein the circumferential spacer (36) extends in the radial direction over the plain bearing pads (19) and the spacers (20), wherein both two mutually adjacent plain bearing pads (19) and two mutually adjacent spacers (20) abut on the circumferential spacer (36).

5. Plain bearing (9) according to claim 4, characterized in that the circumferential spacer (36) has a trapezoidal shape tapering radially inwards when viewed in a cross section and that the plain bearing pads (19) have a corresponding trapezoidal shape tapering radially outwards, so that the plain bearing pads (19) are supported outwards in the radial direction.

6. Plain bearing (9) according to one of the preceding claims, characterized in that the axial clamping element (23) is coupled to the outer ring element (14) by means of a plurality of fastening screws (34) distributed over the circumference, wherein the number of fastening screws (34) corresponds to an integer multiple of the number of plain bearing pads (19).

7. Nacelle (2) for a wind turbine (1), the nacelle (2) comprising:

- a nacelle housing (4);

- a rotor hub (6);

- a rotor bearing (8) for supporting the rotor hub (6) on the nacelle housing (4), characterized in that the rotor bearing (8) comprises a plain bearing (9) according to one of the preceding claims.

8. Method for changing plain bearing pads (19) in a plain bearing (9) according to one of claims 1 to 6, characterized by the method steps:

- loosening the axial clamping element (23) and axially removing the axial clamping element (23) from the outer ring element (14);

- axially pulling out the spacer (20) from the space between the outer ring element (14) and the plain bearing pad (19); - removing the plain bearing pad (19) by radially moving the plain bearing pad (19) outwards and then axially pulling the plain bearing pad (19) out of the space between the inner ring element (13) and the outer ring element (14);

- Inserting a new plain bearing pad (19) by axially inserting the plain bearing pad (19) and then radially moving the plain bearing pad (19) inwards;

- axially pushing the spacer (20) of the respective plain bearing pad (19) into the space between the outer ring element (14) and the plain bearing pad (19);

- Fixing the plain bearing pad (19) by axially clamping the plain bearing pad (19) by means of the axial clamping element (23) and thereby pressing the plain bearing pad (19) onto the spacer (20).

9. Method according to claim 8, characterized in that the plain bearing pad (19) is coupled to a first manipulation arm (41) of a plain bearing pad changing device (37) and the spacer (20) is coupled to a second manipulation arm (42) of the plain bearing pad changing device (37), wherein during the axial withdrawal of the spacer (20) by means of the second manipulation arm (42), the plain bearing pad (19) is held in position by the first manipulation arm (41).

10. Method according to claim 8 or 9, characterized in that the axial clamping element (23) has a plurality of axial clamping segments (52) distributed in the circumferential direction and/or the axial stop element (24) has a plurality of stop segments (53) distributed in the circumferential direction, wherein each of the plain bearing pads (19) is assigned at least one of the axial clamping segments (52) and/or one of the stop segments (53), wherein each of the axial clamping segments (52) and/or each of the stop segments (53) are designed to be adjustable in the axial direction independently of one another, wherein the axial clamping segments (52) and/or the axial stop elements (24) are adjusted in the axial direction by means of an adjusting screw and are pressed axially onto the plain bearing pad (19) with a predetermined torque of the adjusting screw in order to achieve a certain axial contact force.

11. Method according to one of claims 8 to 10, characterized in that before changing one of the underlying plain bearing pads (19), the inner ring element (13) is raised in order to relieve the plain bearing pad (19) to be changed.

12. Method according to one of claims 8 to 11, characterized in that the axial clamping element (23) is coupled to the outer ring element (14) by means of a plurality of fastening screws (34) distributed over the circumference, wherein the fastening screws (34) are tightened one after the other diagonally opposite one another.

13. Plain bearing pad changing device (37) for changing plain bearing pads (19) in a plain bearing (9) according to one of claims 1 to 6, the plain bearing pad changing device (37) comprising:

- a base frame (38);

- a first manipulation arm (41), wherein the first manipulation arm (41) is displaceable relative to the base frame (38) and wherein the first manipulation arm (41) is designed for coupling to the sliding bearing pad (19),

- a second manipulation arm (42), wherein the second manipulation arm (42) is displaceable relative to the base frame (38) and wherein the second manipulation arm (42) is designed for coupling to the spacer (20).

14. Plain bearing pad changing device (37) according to claim 13, characterized in that the first manipulation arm (41) is designed to be displaceable in the axial direction and in the radial direction.

15. Plain bearing pad changing device (37) according to claim 13 or 14, characterized in that the base frame (38) is coupled to a fastening element (39), wherein the fastening element (39) has through holes (40), wherein a hole spacing of the through holes (40) in the circumferential direction is the same size as a hole spacing of fastening holes (35) in the outer ring element (14) or corresponds to a multiple of a hole spacing of fastening holes (35) in the outer ring element (14), wherein the fastening element (39) can be fastened to the outer ring element (14) by means of fastening screws (34) extending through the through holes (40).