WO2024125707A1

WO2024125707A1 - Hydrodynamic or hydrostatic axial sliding bearing

Info

Publication number: WO2024125707A1
Application number: PCT/DE2023/100918
Authority: WO
Inventors: Michael Plogmann; Christoph Hentschke; Tim Leister; Mario Kittsteiner
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2022-12-16
Filing date: 2023-11-27
Publication date: 2024-06-20
Also published as: DE102022133619A1

Abstract

The invention relates to a hydrodynamic or hydrostatic sliding bearing (1) for rotatably bearing a shaft (3), in particular in a wind turbine (2), having at least one first sliding element (4) with a first sliding surface (5), which sliding element is arranged to pivot on a carrier disc (17) via a first pivot element (6), wherein the pivot element (6) is designed as a body elastically deformable in at least one pivot direction, the pivoting elasticity of which body is caused by at least one first slit (7) extending through the pivot element (6), which slit extends from a lateral face (8) of the pivot element (6) into its interior.

Description

HYDRODYNAMIC OR HYDROSTATIC AXIAL SLIDE BEARING

The present invention relates to a hydrodynamic or hydrostatic plain bearing for the rotatable mounting of a shaft, in particular in a wind turbine, with at least one first sliding element with a first sliding surface, which is pivotably arranged on a carrier disk via a first pivot element.

Nowadays, rolling bearings are usually used for rotor bearings in wind turbines. However, the use of plain bearings for such rotors has also been proposed, for example in DE 102 55 745 A1.

The use of plain bearings in the area of transmission gears for wind turbines is also generally known, as shown in EP 1 184 567 A2. Another area of application for plain bearings in wind turbines can also be a slewing ring bearing, as is also known from DE 100 43 936 A1. It is also known to use plain bearings for the bearing of the rotor blades of a wind turbine, as is clear from DE 102005 051 912 A1, for example.

Such a hydrostatic plain bearing has an active lubricant circuit, which is maintained by an external pump and which is guided through the bearing gap between the elements moving relative to one another. A thin hydrostatic support film builds up in the bearing gap, which reduces the friction between elements moving relative to one another.

In addition to hydrostatic plain bearings, hydrodynamic plain bearings are also known, but also hydrodynamic plain bearings, in which the lubricating film is only generated by the movement of the plain bearing. This is usually achieved by a wedge-like lubricating gap, so that the power is transmitted via the lubricant film inserted between the surface of the moving bearing part and into the constriction. The individual sliding elements in such plain bearings are usually elastically supported in order to enable good load distribution in particular in the event of shape deviations.

It is the object of the invention to provide a plain bearing that can provide a cost-effective, easily configurable and wear-resistant elastic bearing for its sliding elements.

This object is achieved by a hydrodynamic or hydrostatic plain bearing for the rotatable mounting of a shaft, in particular in a wind turbine, with at least one first sliding element with a first sliding surface, which is pivotably arranged on a carrier disk via a first pivoting element, wherein the pivoting element is designed as a body which is elastically deformable in at least one pivoting direction, the pivoting elasticity of which is brought about by at least one first slot extending through the pivoting element, which extends from a lateral surface of the pivoting element into its interior.

This provides the advantage that the pivoting or tilting mobility of the pivoting element can be provided by a structure that creates pivoting elasticity. This preferably consists of a simple block (body) into which one or more slots are made. This allows the pivoting elasticity of the pivoting element to be easily adjusted while being inexpensive to manufacture.

Furthermore, compressive forces and tensile forces can be absorbed via the pivoting element, so that the usual problems of holding the sliding element against gravity can also be avoided by means of the pivoting element.

The swivel element also has no internal or external sliding movements that could cause material wear, which means that the swivel element can be designed to be very durable. The swivel or tilting movement is therefore achieved by the elastic deformation of the Swivel element without wear-related relative movement of components to one another. The swivel element can also be configured in such a way that creep of the material forming the swivel element can be avoided.

The swivel element with its slot or slots can also provide elasticity normal to the load direction. This can contribute to better distribution of the load and compensation for height differences between individual sliding elements caused by manufacturing and wear.

Basically, the swivel element makes it possible to design the elasticity of the swivel element using one or more slots on or in the swivel element. The swivel elasticity or rigidity of the swivel element can therefore be individually determined by the dimensions of the swivel element and the slot(s).

Preferably, the slot or slots extend from the outer surface of the pivoting element into its interior, so that under purely normal loading, the pivoting element deflects without tilting.

The swivel element also allows the swivel elasticity or the tilting stiffness to be designed differently in different spatial directions.

The elastic sliding element support is specially configured and intended for sliding bearings that serve as the main bearing of a drive shaft of a wind turbine.

The plain bearing can be designed as a radial bearing or axial bearing.

The connection of the swivel element to a sliding element can also be made particularly durable, for example by means of a screw connection or a weld. In principle, it would also be conceivable to provide a distance measuring device that is integrated in or on the swivel element and can be used during assembly work to correctly adjust the height of the sliding element.

It would also be advantageous to arrange a strain gauge on or in the pivoting element in order to provide a measurement of the deflection, so that the load acting on the sliding element or pivoting element to be installed can be measured and the height can be adjusted if necessary to the state of wear of other sliding elements present in the sliding bearing, so that one sliding element is not subjected to a significantly greater load than the other sliding elements.

The swivel element can be positioned in particular in the middle of the center of gravity of the sliding element or only slightly offset from it. Deflection of the sliding element can be reduced by the central or near-central support provided by the swivel element. It would also be conceivable for a stiffening plate to be provided between the swivel element and the sliding element.

It would also be possible to form the sliding element and the swivel element in one piece, in particular monolithically. This allows the sliding element to be designed to be self-retaining on the swivel element in a particularly advantageous manner. Alternatively, if the sliding element and the swivel element are designed as separate components, a connection can be provided by means of screws or welding.

According to an advantageous embodiment of the invention, it can be provided that the pivoting element is formed from a metallic material, in particular steel. The advantage of this embodiment is that steel in particular has good dynamic strength. Alloyed tempering steels are particularly preferred in this context. In principle, it would also be possible to form the pivoting element from aluminum or an aluminum alloy. In particular, the pivoting element can also be welded to the sliding element, in which case the pivoting element and the sliding element are formed from a weldable steel.

Furthermore, the use of a metallic material also eliminates the need for elastomers, which is advantageous due to the need for lubrication with oil in a corresponding wet room.

According to a further preferred development of the invention, it can also be provided that the pivoting element has a plurality of slots to form its pivoting elasticity.

This makes it possible to easily adapt the swivel elasticity of the swivel element to the individual requirements of the respective plain bearing by selecting different dimensions of the swivel element, a different number of slots and/or a different length of the slots.

For example, it would be conceivable to arrange slots on different sides of a cube- or cuboid-shaped swivel element at different heights. Positioning slots at the same height would also be conceivable. It would also be possible to arrange the slots in the circumferential direction and in the width direction.

It may also be advantageous for the slots to be formed on two opposite sides of a cube- or cuboid-shaped pivoting element for each pivoting direction, so that deflection is also possible when force is applied without a moment.

In order to enable the swiveling or tilting movement in two directions, a total of at least four slots are preferably provided. The number of slots for the two swivel directions can be of different sizes, so that the swivel elasticity of a swivel element for the two spatial directions. Pivoting mobility in two directions can be helpful, for example, for adjusting the sliding element in the circumferential direction to achieve a convergent gap and for adjusting against misalignment.

It can be advantageous for all swivel elements to be essentially identical. However, it is also possible to design the swivel elements or their swivel elasticity differently.

Furthermore, according to a likewise advantageous embodiment of the invention, it can be provided that the pivoting element has a first group of slots and at least one second group of slots, wherein the first group of slots is aligned with the second group of slots rotated by an angle to one another, so that the first pivoting element has pivoting elasticity in two different directions.

The advantageous effect of this design is based on the fact that it allows pivoting elasticity to be achieved in two different directions. In this context, it is particularly preferred that the angle is 90° to one another. Furthermore, in this context, it is also preferred that the pivoting element or elements is/are cube-shaped or cuboid-shaped.

According to a further particularly preferred embodiment of the invention, it can be provided that the slots of the first group and the slots of the second group are arranged on different levels in the pivoting element and do not intersect.

Furthermore, the invention can also be further developed in such a way that at least the first slot, preferably a plurality of slots, most preferably all slots each have a radius at their end protruding into the pivoting element. The advantage of this design is that it leads to a reduction in notch stresses and thus to an increase in the fatigue strength of a pivoting element. In a likewise preferred embodiment of the invention, it can also be provided that the slots run essentially parallel to one another. This can result in particularly favorable production and an advantageously designed pivoting elasticity.

It may also be advantageous to further develop the invention in such a way that at least the first slot, preferably a plurality of slots, most preferably all slots are each formed as a flat, rectangular material recess in the pivoting element. The advantage that can be achieved in this way is that comparatively cost-effective production can be achieved by using geometrically simple slots. For example, it would be possible for the slots to be introduced into the pivoting element by means of sawing or milling.

According to a further preferred embodiment of the subject matter of the invention, it can be provided that at least the first slot, preferably a plurality of slots, most preferably all slots each have/have at least in sections an intermediate layer which is made of an intermediate layer material that differs from the material of the pivoting element. Since the highest loads on the pivoting element, for example in a wind turbine, only occur for a short time, a travel limit ensures that there is no excessive deflection and no excessive tension at the maximum loads that occur. To implement the travel limit, an intermediate layer is positioned in a slot. This intermediate layer can be made of various materials such as steel, aluminum, bronze or a plastic and can thus elastically spring along and absorb loads. The intermediate layer can be attached over the entire surface of the slot or just part of it.

Finally, the invention can also be advantageously designed such that the first pivoting element is designed as a cylindrical body which is connected on the one hand to the first sliding element and on the other hand to the Carrier disk is connected, wherein the at least first slot extends continuously from the outer surface of the cylindrical body into its interior. The advantage of this design is pivoting elasticity in all directions and a possible low installation height of the pivoting element.

The hydrodynamic plain bearing can preferably have a plurality of sliding elements, each with a sliding surface, which are arranged pivotably on a carrier disk via a pivot element, wherein the pivot elements are essentially identical. The high degree of uniformity allows the manufacturing costs to be further reduced.

The invention will be explained in more detail below with reference to figures without limiting the general inventive concept.

It shows:

Figure 1 shows a plain bearing in a perspective view,

Figure 2 shows a sliding element and a pivoting element in a first embodiment in a schematic sectional view,

Figure 3 shows a sliding element and a pivoting element in a second embodiment in a schematic sectional view,

Figure 4 shows a swivel element in a schematic sectional view,

Figure 5 three views of a cuboid swivel element,

Figure 6 three views of a cylindrical swivel element,

Figure 7 shows a wind turbine with a plain bearing in a schematic representation. Figure 1 shows a hydrodynamic or hydrostatic plain bearing 1 for the rotatable mounting of a shaft 3, in particular in a wind turbine 2, as is also shown by way of example in Figure 7. The plain bearing 1 has at least a first sliding element 4 with a first sliding surface 5, which is arranged pivotably on an annular carrier disk 17 with the inner radius R via a first pivot element 6.

As can be seen from Figure 2, the pivoting element 6 is designed as a body which is elastically deformable in at least one pivoting direction, the pivoting elasticity of which is brought about by at least one first slot 7 extending through the pivoting element 6, which extends from a lateral surface 8 of the pivoting element 6 into its interior.

The pivoting element 6 is on the one hand with the intermediate arrangement of the stiffening plate 20 on the sliding element 4 and on the other hand on the carrier disk 17. In order to create a height compensation, tension and compression screws as well as a height adjustment 16 are used. The screws are not or only slightly stressed by the operating loads, which is advantageous for operation in the wind turbine (durability). The stiffening plate 20 can be used to limit any possible deflection of the sliding element 4. The hydrodynamic pressure curve 15 indicated by the dashed line is established on the sliding surface 5 when the sliding bearing is in operation.

In the example shown, the cuboid-shaped pivot element 6 is formed from a metallic material, in particular steel. The pivot element 6 has a plurality of slots 7 to form its pivot elasticity. In the embodiment shown in Figure 2, the pivot element 6 has a first group of slots 9 and a second group of slots, the first group of slots 9 being aligned with the second group of slots 10 rotated by 90° to one another, so that the first pivot element 6 has pivot elasticity in two different directions. The slots of the first group 9 and the slots of the second group 10 run parallel to one another on different planes in the pivot element 6 and therefore do not intersect. All slots 7 have a radius 13 at their end 12 protruding into the pivot element 6. The slots 7 are each designed as a flat, rectangular material recess in the pivot element 6.

As shown in Figure 4, in a pivoting element 6, a plurality of slots 7, most preferably all slots 7, can each have at least in sections an intermediate layer 14 which is formed from an intermediate layer material that differs from the material of the pivoting element 6.

Figure 5 shows a cuboid-shaped swivel element 6 in three different views. The upper figure shows a top view of the swivel element 6. The course of the slot 7 is indicated by the dashed line. The cross-sectional shape of the slot 7 can be seen from the section plane A-A, which can be seen in the middle figure. The lower figure shows the outer surface 8 from the side view, which results from the viewing direction indicated by the arrow B.

Figure 6 shows an embodiment of the pivoting element 6 in three views, in which the pivoting element 6 is designed as a cylindrical body which is connected on the one hand to the first sliding element 4 and on the other hand to the carrier disk 17, wherein the at least first slot 7 extends in a closed manner from the outer surface of the cylindrical body into its interior.

Figure 3 shows a plain bearing 1 in which the pivoting element 6 is penetrated by a sleeve 19 so that a hydraulic fluid 18 can flow through the sleeve 19 and the pivoting element 6. This makes it possible to provide a hydraulic connection between the sliding surface 5 and the carrier disk 17.

The invention is not limited to the embodiments shown in the figures. The above description is therefore not to be regarded as restrictive, but as explanatory. The following patent claims are to be interpreted as understand that a named feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. If the patent claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a ranking.

List of reference symbols

1 plain bearing

2 wind turbine

3 Wave

4 Sliding element

5 Sliding surface

6 Swivel element

7 Slot

8 Shell surface

9 slots

10 slots

12 End

13 Radii

14 Intermediate layer

15 hydrodynamic pressure curve

16 Height adjustment

17 Carrier disc

18 Hydraulic fluid

19 Sleeve

20 Stiffening plate

R Radius

Claims

Claims Hydrodynamic or hydrostatic plain bearing (1 ) for the rotatable mounting of a shaft

(3), in particular in a wind turbine (2), with at least one first sliding element

(4) with a first sliding surface (5), which is arranged pivotably on a carrier disk (17) via a first pivot element (6), characterized in that the pivot element (6) is designed as a body which is elastically deformable in at least one pivot direction, the pivot elasticity of which is brought about by at least one first slot (7) extending through the pivot element (6), which extends from a lateral surface (8) of the pivot element (6) into its interior. Hydrodynamic or hydrostatic plain bearing (1) according to claim 1, characterized in that the pivot element (6) is formed from a metallic material, in particular a steel. Hydrodynamic or hydrostatic plain bearing (1) according to claim 1 or 2, characterized in that the pivot element (6) has a plurality of slots (7) to form its pivot elasticity. Hydrodynamic or hydrostatic plain bearing (1) according to one of the preceding claims, characterized in that the pivoting element (6) has a first group of slots (9) and at least a second group of slots (10), wherein the first group of slots (9) is aligned with the second group of slots (10) rotated by an angle to one another, so that the first pivoting element (6) has pivoting elasticity in two different directions.

5. Hydrodynamic or hydrostatic plain bearing (1) according to claim 4, characterized in that the slots of the first group (9) and the slots of the second group (10) are arranged on different planes in the pivot element (6) and do not intersect.

6. Hydrodynamic or hydrostatic plain bearing (1) according to one of the preceding claims, characterized in that at least the first slot (7), preferably a plurality of slots, most preferably all slots (7) each have a radius (13) at their end (12) projecting into the pivot element.

7. Hydrodynamic or hydrostatic plain bearing (1) according to one of the preceding claims 3-6, characterized in that the slots (7) run substantially parallel to each other

8. Hydrodynamic or hydrostatic plain bearing (1) according to one of the preceding claims, characterized in that at least the first slot (7), preferably a plurality of slots, most preferably all slots (7) is/are each formed as a flat, rectangular material recess in the pivot element (6). Hydrodynamic or hydrostatic plain bearing (1) according to one of the preceding claims, characterized in that at least the first slot (7), preferably a plurality of slots, most preferably all slots (7) each have/have at least in sections an intermediate layer (14) which is formed from an intermediate layer material that differs from the material of the pivot element (6). Hydrodynamic or hydrostatic plain bearing (1) according to one of the preceding claims, characterized in that the first pivot element (6) is designed as a cylindrical body which is connected on the end face to the first sliding element (4) on the one hand and to the carrier disk (17) on the other hand, wherein the at least first slot (7) extends in a closed manner from the outer surface of the cylindrical body into its interior. Hydrodynamic or hydrostatic plain bearing (1) according to one of the preceding claims, characterized in that the hydrodynamic plain bearing (1) has a plurality of sliding elements (4), each with a sliding surface (5), which are arranged pivotably on a carrier disk (17) via a respective pivot element (6), wherein the pivot elements (6) are designed essentially identically.