DE102023132976A1 - Rolling bearing arrangement and method for preloading a rolling bearing - Google Patents

Abstract

A rolling bearing arrangement (1), for example in a wind turbine, comprises at least one rolling bearing (4, 5) which has a bearing ring (6, 9) which is supported in the axial direction on a surrounding component (3, 11, 12) via an elastic, three-dimensionally structured thermoset element (10).

Description

The invention relates to a rolling bearing assembly in which a preload force acts in the axial direction of the bearing assembly. Furthermore, the invention relates to a method for preloading a rolling bearing.

The WO 2022/229359 A1 The invention relates to a method for applying a bearing preload to a main bearing unit of a wind turbine. The main bearing unit comprises a bearing ring that is adjustable in the axial direction along a shaft to apply a bearing preload. The shaft, which acts as the ring carrier, has a thread, and a clamping ring designed as a shaft nut can be screwed against the bearing ring to apply the bearing preload.

Another bearing arrangement with preload device is in the DE 10 2009 038 261 A1 In this case, an axial force is generated by means of a disc spring. The bearing arrangement according to the DE 10 2009 038 261 A1 is intended for use in a motor vehicle.

A preload device integrated into a bearing is in the DE 10 2014 204 101 A1 described. In this case, a preload element is arranged in a recess of a bearing ring. Thermosetting elastomer materials are proposed as materials for manufacturing the preload element.

After DE 10 2006 010 655 B4 A roller bearing seal is also designed as a preloading device. For example, it is possible to design a sealing washer as a disc spring that is attached to the inner or outer ring of the rolling bearing, exerting axial pressure on the other bearing ring with its spring force.

One in the DE 10 2010 015 155 A1 The described electrically insulating bearing ring for a rolling bearing comprises polyamide as the insulating material, with the electrically insulating layer having a thickness of approximately 20 to 200 micrometers. Between the electrically insulating layer and a base body of the bearing ring is an intermediate layer, which may be a roughened surface of the base body.

The JP 2007-315585 A proposes the use of a polyamide 9T element to apply a radial force to a bearing ring of a rolling bearing during assembly. The polyamide 9T element is located in an annular groove on the outer peripheral surface of the bearing ring.

From the DE 10 2010 024 582 A1 A rolling bearing with an insulating sleeve is known. The insulating sleeve has radially inwardly folded ribs on both sides, which enclose the outer ring of the rolling bearing. The insulating sleeve serves not only to insulate the rolling bearing electrically but also acoustically.

The DE 11 2016 000 858 T5 focuses specifically on the rust protection capability of a rolling bearing. It proposes the use of a rust protection film designed as a porous film with a sacrificial anode effect.

The DE 10 2012 221 739 A1 describes a bearing assembly intended for use in a wind turbine, which comprises at least one rolling bearing, namely a tapered roller bearing. The rolling bearing has a first bearing ring connected to the rotor of the wind turbine and a second bearing ring connected to a housing. The first bearing ring connected to the rotor has a cylindrical seating surface with which it sits on a section of the rotor. In order to prevent the bearing ring from being susceptible to cracking, DE 10 2012 221 739 A1 It is intended to machine the cylindrical seat surface by means of a hard turning process. Furthermore, it is intended to arrange a ring element made of fiber-reinforced plastic between an end face of the same bearing ring and an end face of a shoulder of the rotor designed for axial engagement.

The object of the invention is to provide possibilities for applying an axial preload force to a rolling bearing that are more advanced than the prior art, whereby a damping effect should also be provided.

This object is achieved according to the invention by a rolling bearing arrangement having the features of claim 1. The object is also achieved by a method for preloading a rolling bearing according to claim 8. The embodiments and advantages of the invention explained below in connection with the method according to the application also apply mutatis mutandis to the device, that is to say rolling bearing arrangement with one or more rolling bearings, and vice versa.

The rolling bearing arrangement comprises at least one rolling bearing having a bearing ring that is supported in the axial direction on a surrounding component via an elastically flexible, three-dimensionally structured thermoset element.

It has been shown that the production of the elastically supporting, three-dimensionally structured element from duroplast offers efficient production possibilities with a sufficiently high geometric mechanical precision and long durability.

The surrounding component could be, for example, a housing cover in which the bearing ring subjected to an axial force is inserted. In this case, the bearing ring is designed as an outer ring. Depending on the dimensions and overall design of the rolling bearing assembly, a screw or an adjusting ring may be present instead of a cover, or the housing itself may form the surrounding component, for example, through a housing shoulder.

• Forschungsbericht FVA 479 IV, IGF-Nr. 16985 BR, Forschungsvereinigung Antriebstechnik e.V., Abhilfemaßnahmen Wälzlagerwandern, Definition und Auslegung von konstruktiven und tribologischen Abhilfemaßnahmen gegen tangentiale Wanderbewegungen von Wälzlagerringen, 2015

The invention is based on the idea that damping elements incorporated into a bearing arrangement represent a fundamentally suitable measure against bearing ring creep. Bearing ring creep, i.e., movements of the bearing ring relative to a component that is essentially rigidly connected to the bearing ring, can be attributed in particular to micromovements of the bearing ring and/or the component connected to the bearing ring. Such micromovements are caused, for example, by mechanical loads that act on the bearing ring via the rolling elements during bearing operation. The following publication provides background information on the topic of rolling bearing ring creep:

• Research Report FVA 479 IV, IGF No. 16985 BR, Research Association for Drive Technology, Remedial Measures for Rolling Bearing Migration, Definition and Design of Structural and Tribological Remedial Measures Against Tangential Migration of Rolling Bearing Rings, 2015

As part of the research project, various solutions, including form-fitting ones, were developed and their effectiveness was investigated experimentally and using complex 3D FE analyses. A steel intermediate ring placed between a bearing ring and a surrounding structure was investigated both experimentally and experimentally.

Further on, the DE 10 2019 118 810 A1 , which addresses the issue of bearing ring creep in the direction of rotation around the bearing's axis of rotation. As a countermeasure against such bearing ring creep, which could lead to premature wear, the use of positive-locking components is recommended, which prevent both rotation and axial displacement of a bearing ring.

Deviating from this known approach, the solution according to the application provides for a frictional engagement between an element, which in this case is made of a thermosetting plastic, and a bearing ring of a rolling bearing, for example a ball, needle or roller bearing.

According to various possible embodiments, the thermoset element of the rolling bearing assembly comprises an elastic stop ring that contacts the bearing ring over its entire surface, while the side of the stop ring facing away from the bearing ring and contacting the surrounding component is structured. The stop ring can either be present as a separate element or be integrally connected to other volume regions of the thermoset element, in particular a cylindrically shaped region that surrounds a circumferential surface of the bearing ring.

The structure of the stop ring is, for example, in the form of webs designed as spring elements. Such webs, which are integral components of the stop ring, can be aligned in particular in the radial direction of the bearing ring and thus describe an overall star shape.

The aforementioned webs, which are essentially located in a common plane perpendicular to the centerline of the rolling bearing assembly, can, optionally together with a cavity-free area of the stop ring, functionally act as a replica of a disc spring. The general advantage of disc springs is that they can transmit considerable axial forces while requiring little space. This advantage is achieved in this case to a sufficient degree for the intended application, despite the manufacture of the spring-acting webs from a non-metallic material.

An additional benefit of manufacturing the thermoset element from a non-metallic material, which transmits axial forces similar to a disc spring and simultaneously provides length compensation, compared to commercially available disc springs lies in the electrically insulating properties of the thermoset material. This applies particularly to designs in which the thermoset element is at least partially formed as a casing that contacts a cylindrical circumferential surface of the bearing ring, thus functioning as an overall electrically insulating element.

The method according to the application for preloading a rolling bearing is generally characterized in that a bearing ring of the rolling bearing is provided with a three-dimensionally structured, elastically provided with a flexible thermoset element and then subjected to an axial force via this thermoset element.

Regarding the structuring of the thermoset element during the manufacturing process, various process variants exist. Firstly, it is possible to structure the thermoset layer during the manufacturing phases that are associated with the application of this layer. These manufacturing phases include the coating process and the layer curing. During these phases, masking can be used, for example. It is also possible to emboss structures during curing.

Another option is to process the thermoset layer only after curing. This type of processing can be performed, for example, by machining with a geometrically defined or non-geometrically defined cutting edge. It is also possible to combine shaping during the coating process with subsequent machining to achieve greater geometric precision.

In all cases, the elastic, damping structure provided by the thermoset element not only represents an effective measure against bearing ring creep, but also against damage caused by standstill vibrations. The rolling bearing arrangement comprises, for example, at least one adjusted bearing, in particular in the form of an angular contact roller bearing.

Possible applications for the rolling bearing assembly include motor and generator systems, for example, in wind turbines. Mobile applications of the rolling bearing assembly are also possible, for example, in motor vehicles or rail vehicles.

• 1 eine Wälzlageranordnung mit zwei Wälzlagern, nämlich Kugellagern,
• 2 ein elastisches, dreidimensional strukturiertes, in Axialrichtung abstützendes Duroplast-Element der Anordnung nach 1 zusammen mit einem gehäusefesten Element,
• 3 in einer Schnittdarstellung die Anordnung nach 2 zusammen mit einem Lagerring eines der beiden Kugellager, wobei zwischen dem Lagerring und der gehäusefesten Komponente höchstens eine geringe Axialkraft wirkt,
• 4 in einer Darstellung analog 3 die gleiche Anordnung unter höherer axialer Belastung.

An embodiment of the invention is explained in more detail below with reference to a drawing. In the drawings:

• 1 a rolling bearing arrangement with two rolling bearings, namely ball bearings,
• 2 an elastic, three-dimensionally structured, axially supporting thermoset element arranged according to 1 together with a housing-fixed element,
• 3 in a sectional view the arrangement according to 2 together with a bearing ring of one of the two ball bearings, whereby at most a small axial force acts between the bearing ring and the housing-fixed component,
• 4 in a representation analogous 3 the same arrangement under higher axial load.

A rolling bearing assembly, designated overall by reference numeral 1, intended for use in a wind turbine comprises a shaft 2 supported by two rolling bearings 4, 5, namely ball bearings, in a housing 3 as the surrounding component. Each rolling bearing 4, 5 has an inner ring 6, an outer ring 9, and rolling elements 8, i.e., balls, rolling between the bearing rings 6, 9. The inner ring 6 of each rolling bearing 4, 5 is supported on an annular, circumferential shoulder 7 of the shaft 2. The rolling bearing assembly 1 is thus designed as a double-row bearing in an X arrangement.

Each outer ring 9 has a thermoset coating 10, which is generally referred to as a thermoset element and covers the outer circumferential surface of the respective bearing ring 9 and, for the most part, also its end faces. In cross section, the thermoset coating 10 thus describes, as shown in 1 can be seen, a flat U-shape.

In the design according to 1 The two thermoset covers 10, each of which is assigned to one of the rolling bearings 4, 5, are not identical or mirror-imaged to each other. The thermoset cover 10 of the 1 The rolling bearing 4 arranged on the left has a uniform wall thickness on the cylindrical circumferential surface as well as on the two end faces of the outer ring 9. In the case of the arrangement according to 1 In the case of the rolling bearing 5 located on the right, the wall thickness of the left end region of the thermoset casing 10, that is to say the annular disc-shaped section of the thermoset casing 10 which faces the other rolling bearing 4, is designed in the same wall thickness as the cylindrical section of the thermoset casing 10, whereas the second end-side, outwardly facing annular disc-shaped section of the thermoset casing 10 of the rolling bearing 5 is designed as a structured stop ring 15, which will be discussed in more detail below.

Both outer rings 9 are each held in the housing 3 by a cover 11, 12. The covers 11, 12, which, like the housing 3, are surrounding components, provide annular disk-shaped stop surfaces 13, 14, on which, in the case of the 1 left rolling bearing 4, a likewise annular disc-shaped, unstructured section of the thermoset casing 10, and in the case of the right rolling bearing 5 in the same illustration, the aforementioned, comparatively thick structured stop ring 15, strikes. Optionally, an axial adjustability of at least one cover 11, 12 is provided, for example by means of a screw connection. In the embodiment according to 1 the left cover 11 represents a closed frontal cover of the rolling bearing arrangement 1, whereas the right cover 12 surrounds the shaft 2 in the shape of an annular disc.

The 2 shows a schematic, partially sectioned representation of the structures of the structured stop ring 15 and the contours of the stop surface 14. The stop ring 15, which is an annular disk-shaped overall and is an integral component of the thermoset casing 10, has numerous webs 14 aligned in a star shape around the central axis of the rolling bearing arrangement 1, between each of which a space 17 is formed. Each of these webs 14 acts as a resilient element effective in the axial direction, with the adjoining, solid area of the stop ring 15 also having a resilient effect to a lesser extent.

In the arrangement according to 3 A minimal axial force F _ax acts between the cover 12 and the outer ring 9. The webs 16 are practically not compressed in this state. Depending on the desired design of the rolling bearing arrangement 1 and, if applicable, the variable positioning of the covers 11, 12, there may be play or a slight preload of the rolling bearings 4, 5 in this state.

If, however, the axial force F _ax acting on the outer ring 9 of the rolling bearing 5 is increased, the result is 4 visualized state. Here, the webs 16 are significantly compressed, while the spaces 17, which are kept free between the webs 16 and are present as grooves, are correspondingly reduced in size. The compression of the webs 16 is reversible. Thus, the thermoset casing 10, including the structured stop ring 15, exerts an axially supporting and simultaneously damping effect in every operating state of the rolling bearing arrangement 1. This effect contributes significantly to reducing movements of the outer ring 9 relative to the housing 3 in the circumferential direction.

In the example according to the 1 to 4 The structuring of the stop ring 15, visible in the form of webs 16 and gaps 17, is subsequently created by machining the thermoset casing 10. It is also possible to create the structuring during the application of the thermoset material to the outer ring 9, with the curing of the thermoset casing 10 optionally being followed by post-processing, for example, in the form of grinding. In any case, the finished, structured stop ring 15 integrated into the thermoset casing 10 acts like a disc spring, which is preloaded by the cover 12, with the damping effect being significantly improved compared to a disc spring.

List of reference symbols

1

Rolling bearing arrangement

2

Wave

3

Housing, surrounding component

4

Rolling bearings

5

Rolling bearings

6

inner ring

7

Heel on the wave

8

Rolling element, ball

9

Outer ring

10

Duroplast covering, Duroplast element

11

Cover, surrounding component

12

Cover, surrounding component

13

Stop surface on the lid 11

14

Stop surface on the lid 12

15

structured stop ring

16

web

17

space

fax

axial force

QUOTES CONTAINED IN THE DESCRIPTION

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

• WO 2022/229359 A1 [0002]
• DE 10 2009 038 261 A1 [0003]
• DE 10 2014 204 101 A1 [0004]
• DE 10 2006 010 655 B4 [0005]
• DE 10 2010 015 155 A1 [0006]
• JP 2007-315585 A [0007]
• DE 10 2010 024 582 A1 [0008]
• DE 11 2016 000 858 T5 [0009]
• DE 10 2012 221 739 A1 [0010]
• DE 10 2019 118 810 A1 [0018]

Cited non-patent literature

• Research report FVA 479 IV, IGF No. 16985 BR, Research Association for Drive Technology, Remedial measures for rolling bearing creep, definition and design of structural and tribological remedial measures against tangential creep of rolling bearing rings, 2015 [0016]

Claims (10)

Rolling bearing arrangement (1), comprising at least one rolling bearing (4, 5) which has a bearing ring (6, 9) which is supported in the axial direction on a surrounding component (3, 11, 12) via an elastic, three-dimensionally structured thermoset element (10). Rolling bearing arrangement (1) according to Claim 1 , characterized in that the surrounding component (11, 12) is designed as a cover of a housing (3) in which the bearing ring (9), namely the outer ring, loaded with an axial force is inserted. Rolling bearing arrangement (1) according to Claim 1 or 2 , characterized in that the thermosetting plastic element (10) comprises an elastic stop ring (15) which contacts the bearing ring (6, 9) over its entire surface, whereas the side of the stop ring (15) facing away from the bearing ring (6, 9) is structured. Rolling bearing arrangement (1) according to Claim 3 , characterized in that the structuring of the stop ring (15) is in the form of webs (16) which are designed as spring elements. Rolling bearing arrangement (1) according to Claim 4 , characterized in that the webs (16) are aligned in the radial direction of the bearing ring (6, 9). Rolling bearing arrangement (1) according to Claim 4 or 5 , characterized in that the webs (16) together with a region of the stop ring (15) which is free of cavities are functionally designed as a replica of a disc spring. Rolling bearing arrangement (1) according to one of the Claims 1 until 5 , characterized in that the thermosetting plastic element (10) comprises a casing which contacts a cylindrical peripheral surface of the bearing ring and is designed as an electrically insulating element. Method for preloading a rolling bearing (4, 5), wherein a bearing ring (6, 9) of the rolling bearing (4, 5) is provided with a three-dimensionally structured, elastically flexible thermoset element (10) and is then loaded with an axial force via this thermoset element (10). Procedure according to Claim 8 , characterized in that the structuring of the thermoset element (10), which is used to transmit an axial force to the bearing ring (6, 9), is produced in the course of applying the thermoset layer to the bearing ring (6, 9). Procedure according to Claim 8 , characterized in that the thermoset element (10) is only structured by machining after the thermoset has been applied and cured.

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