DE102022127050A1 - Sealing arrangement, rolling bearing with a sealing arrangement and vehicle - Google Patents

Abstract

A sealing arrangement (1), in particular for a bottom bracket (6), comprises an inner angle ring (24) and an outer angle ring (27), each angle ring (24, 27) having a cylindrical section (25, 28) and an adjoining annular disk-shaped section (26, 32), and a sealing element (34) held on the outer angle ring (27), which has at least two sealing lips (35, 36) contacting the inner angle ring (24) and an annular section (40) projecting in the radial direction beyond the outer angle ring (27). The cylindrical section (28) of the outer angle ring (27) ends at its end face opposite the ring-disk-shaped section (32) of the same angle ring (27) with a tapered section (29) pointing in the axial direction, the annular, flange-like section (40) of the sealing element (34) being free of any metal reinforcement and functioning as a static seal adjoining the latter section (29).

Description

The invention relates to a sealing arrangement according to the preamble of claim 1. The invention also relates to a rolling bearing with a sealing arrangement. In addition, the invention relates to a vehicle with a sealed rolling bearing.

A generic sealing arrangement is known, for example, from EN 10 2016 222 769 A1 It is a cassette-type seal which has two sections, a first section being fixed in a surrounding structure, while a second section is located on a rotating component. A centrifugal disk is provided by the rotating section. Sealing lips are attached to the section held in the surrounding structure. The sealing lips, which are in the EN 10 2016 222 769 A1 generally referred to as a sealing element, merge seamlessly into a casing of an L-shaped metal support profile. The support profile of the first, non-rotatable section deviates from an L-shape in that an outer L-leg, which is referred to as the axial sealing profile leg, is connected to a cover plate section pointing radially outwards, which can be used as an axial stop. The rubber casing vulcanized onto the L-shaped support profile extends into the cover plate section. A section of the rubber casing pointing radially inwards from the cover plate section is designed as a holding element, which secures the centrifugal disc in a form-fitting manner. The sealing arrangement according to the EN 10 2016 222 769 A1 is intended for use in a vehicle roll stabilizer.

Another sealing arrangement, in which a metallic carrier with a basic shape that is L-shaped in cross section has a section that extends radially outwards in the manner of a flange and rests against the front side of a surrounding component, is known, for example, from EN 10 2012 211 853 B4 The flange-like section represents an end piece that can be used to press the seal into the surrounding component.

A radially extending section of a ring that is otherwise approximately L-shaped in cross section is also EN 10 2012 204 620 B4 The radial section is designed as a high flange. The seal according to the EN 10 2012 204 620 B4 additionally has an encoder made of sealing material and is intended for use in a wheel bearing arrangement of a motor vehicle.

Also for use in a wheel bearing is a cassette seal according to the EN 10 2007 057 962 B4 In this case, a labyrinth seal is formed by different sections of elements of the sealing arrangement.

A cassette seal with double labyrinth is in the EN 10 2018 105 832 A1 In addition, in this case there is at least one sealing lip, which is designed as a centrifugal seal. The seal according to the EN 10 2018 105 832 A1 is intended for use in a rolling bearing, in particular in a wheel bearing of a car or truck.

Further seals for rolling bearings, especially ball bearings, are described, for example, in the documents DE 199 16 934 B4 , WO 2019/242810 A1 , JP 000H05272543 A and EN 10 2018 121 558 A1 described.

The EN 103 42 132 A1 discloses a thin-section bearing which is designed as an angular contact roller bearing. In this case, an O-ring is provided as a seal. As regards a possible method for producing a thin-section bearing, reference is made to the EP 0 528 193 B1 pointed out.

The EN 10 2013 215 548 B4 discloses a sensor bottom bracket which is accommodated in a bicycle frame having several frame tubes. The sensor bottom bracket comprises two roller bearings designed as ball bearings, whereby for their sealing in the EN 10 2013 215 548 B4 no statements have been made.

The WO 2009/090120 A2 discloses a seal intended for installation between two rings of a rolling bearing, which has both the function of a static seal and the function of a dynamic seal. In the dynamic sealing area there are two lips which delimit an annular chamber which can be filled with lubricant.

The invention is based on the object of specifying seals which are further developed compared to the cited prior art and are suitable for use in rolling bearings, in particular in two-wheelers, which are characterized by a particular robustness and at the same time require little space.

This object is achieved according to the invention by a sealing arrangement with the features of claim 1. The sealing arrangement can be Part of a rolling bearing according to claim 5. The rolling bearing in turn is particularly suitable for use in a vehicle according to claim 10.

The sealing arrangement comprises, in a basic concept known per se, an inner metal angle ring and an outer, also metal angle ring, each angle ring having a cylindrical section and an annular disk-shaped section adjoining thereto. A sealing element made of an elastomer is held on the outer angle ring, which has at least two sealing lips contacting the inner angle ring and an annular section projecting radially beyond the outer angle ring. According to the application, the cylindrical section of the outer angle ring ends on its end face opposite the annular disk-shaped section of the same angle ring with a tapered section pointing in the axial direction, the annular section of the sealing element, which is free of any metal reinforcement and functions as a static seal, adjoining the latter section.

Overall, a dynamic sealing function provided by the sealing lips is combined with a static sealing function in a space-saving manner. The static seal protects a non-rotating surrounding component adjacent to the sealing arrangement from dirt and moisture, particularly in vehicle applications.

Compared to a conventional sealing arrangement, which does not have a flange-like, radially outward-facing section of an elastomer sealing element, there is only a slightly increased manufacturing effort. The fact that the annular, i.e. flange-like, section of the sealing element made of an elastomer is not reinforced by any metallic elements contributes in particular to limiting the manufacturing effort. The outer angle ring therefore also has a production-friendly shape that is close to a simple L-shape, apart from the tapered end section of the cylindrical section of the angle ring mentioned. The front-side tapering of the cylindrical section contributes to a stable connection of the annular, statically sealing section of the sealing element, since the sealing material in the area of the tapering covers both the inner peripheral surface and the outer peripheral surface of the essentially cylindrical section of the outer angle ring held in a surrounding component.

According to a possible, particularly space-saving design, the annular section of the sealing element, the end face of the same angle ring formed by the tapered section of the outer angle ring, and the annular disk-shaped section of the inner angle ring are arranged in a common plane. An annular gap can be formed between the radially outer edge of the inner angle ring and an inner peripheral surface of the annular, statically sealing section of the sealing element formed by a layer of sealing material on the cylindrical inner surface of the outer angle ring.

The ring-shaped section of the inner angle ring that radially inwards limits the gap represents a centrifugal disk. In the described design, the ring-shaped gap is thus limited inwards by a metallic material and radially outwards by a non-metallic material. Regardless of the choice of material, the gap forms a contour of a labyrinth seal, which complements the effect of the sealing lips, i.e. the contact seal. Dirt and moisture that has entered between the angle rings of the sealing arrangement can be removed again through the gap.

Radially outside the gap there is both a metallic and a non-metallic component of the sealing arrangement. The metallic component is the cylindrical section of the outer angle ring. The aforementioned taper, i.e. the decrease in the wall thickness of the section mentioned towards the front of the sealing arrangement, can be formed by the section tapering towards one end of an L-leg being completely cylindrical on its inner surface, whereas the outer surface of the same section is conical in shape at least in sections. Instead of a conical surface, a surface with a curved cross-section can also be considered. In all cases, the annular disk-shaped front surface of the outer L-leg of the outer angle ring has a width measured in the radial direction that is less than the maximum wall thickness of the L-leg mentioned.

The rolling bearing according to the application is particularly to be attributed to a bottom bracket of a two-wheeler. The rolling bearing generally comprises two bearing rings, namely an inner ring and an outer ring, a plurality of rolling elements arranged between the bearing rings, and a sealing arrangement designed according to claim 1 and inserted between the bearing rings, wherein the annular section of the sealing element forms an end face of the From the point of view of corrosion protection, designs in which the annular section of the sealing element completely covers the end face of the outer ring are particularly advantageous.

For example, the rolling bearing is designed as a single-row ball bearing sealed on one side. The row of rolling elements can be arranged asymmetrically between the end faces of the bearing rings, which makes the best possible use of the space available in the axial direction of the bearing.

As far as the use of space in the radial direction of the rolling bearing is concerned, embodiments are particularly advantageous in which the bearing rings have a reduced wall thickness in the area in which the sealing arrangement is located, compared to a maximum thickness given in the area of bearing shoulders of the ball bearing.

The rolling bearing can be designed in particular as a thin-ring bearing. This also applies to multi-row designs of the rolling bearing. Instead of spherical rolling elements, roller-shaped rolling elements can in principle also be used. Different shapes of rolling elements, for example balls on the one hand and rollers or needles on the other, within one and the same rolling bearing are also generally possible.

The vehicle in which the rolling bearing is installed can be, for example, a bicycle, in particular a bicycle with an electric auxiliary drive, i.e. a pedelec or e-bike. The rolling bearing according to the application can be installed in the vehicle in such a way that the ring-shaped section of the sealing element made of an elastomer forms a static seal between the end face of the outer ring of the rolling bearing and an inner housing surface, for example an inner surface of a vehicle frame.

• 1 in schematisierter Darstellung ein in ein Fahrrad mit elektrischem Hilfsantrieb eingebautes Tretlager mit einseitig abgedichteten Wälzlagern,
• 2 ein Detail der Anordnung nach 1.

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

• 1 in a schematic representation of a bottom bracket with one-sided sealed roller bearings installed in a bicycle with electric auxiliary drive,
• 2 a detail of the arrangement according to 1 .

The 1 and 2 show in a more or less simplified representation, partly exaggerated for the purpose of better recognition, features, in particular design features of sealing arrangements 1, of an electrified two-wheeler 10, which is also generally referred to as an e-bike or pedelec. One sealing arrangement 1 is provided for use in a roller bearing 2, 16 of a bottom bracket 6 of the two-wheeler 10. The roller bearings 2, 16 each have an inner ring 3 and an outer ring 4, wherein the two outer rings 4 are arranged in a rotationally fixed manner in a housing 5, which is firmly connected to the frame of the vehicle 10, i.e. two-wheeler, or is provided directly by the vehicle frame. The inner rings 3 of the roller bearings 2, 16 are firmly connected to a shaft 7, i.e. crankshaft. In the case of the first roller bearing 2, which is in the arrangement according to 1 is located on the right and has a larger diameter than the second rolling bearing 16 arranged on the left, an annular component 8 is located between the inner ring 3 and the shaft 7, which rotates together with the shaft 7. Connecting contours of the shaft 7, which extend to its front sides, are designated with 9.

The center axis of the shaft 7 and thus of the bottom bracket 6 is marked MA. In addition to the ring-shaped component 8, 1 Further shaft-side components 11, 14 are indicated, which are located axially between the two roller bearings 2, 16. Various housing-side components are designated 12, 13. The components 11, 12, 13, 14 mentioned, which in particular have drive and/or measurement functions, are located in an interior space 16, which is sealed on both sides by a sealing arrangement 1. Seals of the roller bearings 2, 16 towards the interior space 15 are not provided.

The rolling bearings 2, 16 have balls as rolling elements 17, which are guided in a cage 18. The diameters of the balls 17 of the first rolling bearing 2 on the one hand and the second rolling bearing 16 on the other hand do not match in the present case.

In any case, the balls 17 roll on rolling element raceways 19 of the bearing rings 2, 3. The groove-shaped rolling element raceway 19 of the inner ring 3 is arranged between bearing shoulders 20, 21, with the bearing shoulder 20 facing the interior 15 and the bearing shoulder 21 being arranged next to the sealing arrangement 1, which is located between the bearing rings 3, 4. In an analogous manner, two bearing shoulders 22, 23 are formed by the outer ring 4. The maximum thickness S _maxIR of the inner ring 3, measured in the radial direction of the rolling bearing 2, is determined by the bearing shoulders 20, 21. The minimum thickness S _minIR of the inner ring 3 is given in the area of the sealing arrangement 1. The inner ring 3 therefore has a stepped shape on its outer peripheral surface. A stepped shape is also given on the inner peripheral surface of the outer ring 4. In this case, the maximum thickness of the bearing ring 4 is S _maxAR and the minimum thickness of the bearing ring 4 is designated as S _minAR . The rolling element raceways 19 are arranged off-center in each rolling bearing 2, 16, namely offset towards the interior 15.

The sealing arrangement 1 is designed as a cassette seal and comprises two metal angle plates 24, 27, which each have an at least approximately L-shape in cross-section and are also generally referred to as angle rings. The angle ring 24 held on the inner ring 3 has a cylindrical section 25 and an adjoining ring-disk-shaped section 26, the latter section 26 having the function of a centrifugal disk and being located on one end face of the sealing arrangement 1. The ring-disk-shaped section 26 is also referred to as the disk-shaped section for short.

In the case of the outer angle ring 27, a cylindrical section resting on the outer ring 4 is designated with 28. The cylindrical section 28 merges into a tapered end section 29 towards its front side and thus towards the front side of the entire sealing arrangement 1. A cylindrical inner surface 30 of the outer angle ring 27 extends over the entire cylindrical section 28 including the tapered end section 29. In contrast, a conical outer surface 31 is formed on the outer surface of the tapered end section 29. The tapered end section 29 is thus raised from an inner surface of the outer ring 4 which is continuously cylindrical in the area of the sealing arrangement 1. On its side facing away from the tapered end section 29 and facing the rolling elements 17, the cylindrical section 28 merges into a disk-shaped - more precisely: annular disk-shaped - section 32 which is arranged essentially parallel to the centrifugal disk 26. In contrast to the centrifugal disk 26, the disk-shaped section 32 does not have a consistently flat shape. Rather, within the disk-shaped section 32 there is a bend 33 in the form of a ring-shaped step. Overall, the two ring-shaped sections 27, 32 are arranged essentially parallel to one another.

A sealing element 34 made of an elastomer material is vulcanized onto the outer angle ring 27. The sealing element 34 has two sealing lips 35, 36 which contact the centrifugal disk 26 and the cylindrical section 25 of the inner angle ring 24. As can be seen from 2 As can be seen, there is also a sealing material layer 37 on the inner surface 30 of the cylindrical section 28. This sealing material layer 37 extends to the front side of the entire sealing arrangement 1 and is partially opposite the outer peripheral surface of the centrifugal disk 26, so that a gap 38 is formed between the centrifugal disk 26 and the sealing element 34, which gap is attributable to a labyrinth seal 39.

The sealing material layer 37 continues on the front side of the sealing arrangement 1 in the form of a radially outward-facing, annular section 40 of the sealing element 34. The section 40 thus has the shape of a flange of the sealing element 34, wherein the sealing element 34 has no metallic reinforcement in the area of the section 40. The annular section 40, which is made exclusively of an elastomer, rests on the one hand on an end face 42 of the outer ring 4 and on the other hand on an annular disk-shaped inner surface 43 of the housing 5. The extension of the annular section 40, which is to be measured in the radial direction, corresponds to the minimum thickness S _minAR of the outer ring 4. This means that the annular section 40 covers the end face 42 of the outer ring 4 over its entire surface. At the same time, a corrosion protection effect is achieved by the fact that the annular section 40 also rests flat against the inner surface 43.

The front face of the outer angle ring 27 is designated 41 and is significantly narrower than the front face 42 of the outer ring 4. A plane E is applied to the front face 41 of the outer angle ring 27, with the central axis MA representing a surface normal to this plane E. The plane E intersects, as can be seen from 2 , both the annular section 40 of the sealing element 34 and the centrifugal disk 26. Overall, the rolling bearing 2, 16 including the sealing arrangement 1 is characterized by a compact structure in both the radial and axial directions, while at the same time providing a very good sealing effect. The thickness of the annular section 40 measured in the axial direction is in the present case less than the thickness of the centrifugal disk 26 measured in the same direction.

List of reference symbols

1

Seal arrangement

2

roller bearing

3

Inner ring

4

Outer ring

5

Housing

6

Bottom bracket

7

Shaft, crankshaft

8th

ring-shaped component

9

Connection contour

10

vehicle, two-wheeler

11

shaft-side component

12

housing-side component

13

housing-side component

14

shaft-side component

15

inner space

16

roller bearing

17

Rolling element, ball

18

Cage

19

Rolling element raceway

20

Bearing shoulder, facing the interior, inner ring

21

Bearing shoulder facing the seal assembly, inner ring

22

Bearing shoulder, facing the interior, outer ring

23

Bearing shoulder facing the seal assembly, outer ring

24

Angle ring on the inner ring

25

cylindrical section of the angle ring 24

26

disc-shaped section of the angle ring 24, centrifugal disc

27

Angle ring on the outer ring

28

cylindrical section of the angle ring 27

29

tapered end section of section 27

30

cylindrical inner surface

31

conical outer surface

32

disc-shaped section of the angle ring 27

33

Offset within the disc-shaped section 32

34

Sealing element

35

Sealing lip

36

Sealing lip

37

Sealing material layer on the cylindrical inner surface

38

gap space

39

Labyrinth seal

40

annular section of the sealing element

41

Front face of the outer angle ring

42

Face of the outer ring

43

annular disc-shaped inner surface of the housing

SmaxAR

maximum thickness of the outer ring

SminAR

minimum thickness of the outer ring

SmaxIR

maximum thickness of the inner ring

SminIR

minimum thickness of the inner ring

E

level

MA

Central axis

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102016222769 A1 [0002]
• DE 102012211853 B4 [0003]
• DE 102012204620 B4 [0004]
• DE 102007057962 B4 [0005]
• DE 102018105832 A1 [0006]
• DE 19916934 B4 [0007]
• WO 2019242810 A1 [0007]
• JP 000H05272543 A [0007]
• DE 102018121558 A1 [0007]
• DE 10342132 A1 [0008]
• EP 0528193 B1 [0008]
• DE 102013215548 B4 [0009]
• WO 2009090120 A2 [0010]

Claims (10)

Sealing arrangement (1) with an inner angle ring (24) and an outer angle ring (27), each angle ring (24, 27) having a cylindrical section (25, 28) and an annular disk-shaped section (26, 32) adjoining thereto, and with a sealing element (34) held on the outer angle ring (27), which has at least two sealing lips (35, 36) contacting the inner angle ring (24) and an annular section (40) projecting radially beyond the outer angle ring (27), characterized in that the cylindrical section (28) of the outer angle ring (27) ends on its end face opposite the annular disk-shaped section (32) of the same angle ring (27) with a tapered section (29) pointing in the axial direction, and the annular section (40) of the sealing element (34), which is free of any metal reinforcement and functions as a static seal, adjoins the latter section (29). Sealing arrangement (1) according to Claim 1 , characterized in that the tapered portion (29) of the outer angle ring (27) has a cylindrical inner surface (30) and a conically tapered outer surface (31). Sealing arrangement (1) according to Claim 2 , characterized in that an annular gap (38) is formed between the radially outer edge of the inner angle ring (24) and an inner peripheral surface of the annular portion (40) of the sealing element (34) formed by a sealing material layer (37) on the cylindrical inner surface (30) of the outer angle ring (27). Sealing arrangement (1) according to one of the Claims 1 until 3 , characterized in that the annular portion (40) of the sealing element (34), the end face (41) of the same angle ring (27) formed by the tapered portion (29) of the outer angle ring (27), and the annular disk-shaped portion (26) of the inner angle ring (24) are arranged in a common plane (E). Rolling bearing (2, 16), comprising two bearing rings (3, 4), namely an inner ring (3) and an outer ring (4), a plurality of rolling elements (17) arranged between the bearing rings (3, 4), and a Claim 1 formed sealing arrangement (1) inserted between the bearing rings (3, 4), wherein the annular portion (40) of the sealing element (34) contacts an end face (42) of the outer ring (4). Rolling bearings (2, 16) according to Claim 5 , characterized in that the annular portion (40) of the sealing element (34) completely covers the end face (42) of the outer ring (4). Rolling bearings (2, 16) according to Claim 5 or 6 , characterized in that it is designed as a single-row ball bearing sealed on one side with a row of rolling elements (17) arranged asymmetrically between the end faces of the bearing rings (3, 4). Rolling bearing (2, 16) according to one of the Claims 5 until 7 , characterized in that it is designed as a thin-ring bearing. Rolling bearing (2, 16) according to one of the Claims 5 until 8th , characterized in that the bearing rings (3, 4) have a reduced wall thickness (S _minIR , S _minAR ) in the region in which the sealing arrangement (1) is located, compared with a maximum thickness (S _maxIR , S _maxAR ) given in the region of bearing shoulders (20, 21, 22, 23). Vehicle (10), in particular a two-wheeler with electric auxiliary drive, with a rolling bearing (2, 16) according to Claim 5 , wherein the annular portion (40) of the sealing element (34) forms a static seal between the end face (42) of the outer ring (4) and a housing inner surface (43).

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