Rolling bearings, especially large diameter rolling bearings

Abstract

The rolling bearing comprises a first ring (10) and a second ring (12) which are suitable for rotating concentrically with each other, at least one row of rolling elements (16) arranged radially between the raceways of the rings, at least one row of rolling elements (14) arranged axially between the raceways of the rings, and at least one inner seal (28) which is fixed to one of the two rings (10, 12) and comes into frictional contact with the other of the first and second rings. The rolling bearing further comprises at least one outer seal assembly 32 provided with a seal shield 34 secured to the first ring 10 and in frictional contact with the second ring, the seal shield 32 being disposed outside the inner seal 28 and forming an annular seal chamber together with the inner seal 28.

Description

[0001] The present invention relates to the field of bearings.

[0002] The invention particularly relates to large diameter rolling bearings capable of supporting axial and radial loads and having an inner ring and an outer ring arranged concentrically around an axis of rotation extending in the axial direction.

[0003] Such large-diameter rolling bearings can be used, for example, in a tunnel boring machine, a mining machine or a wind turbine.

[0004] A large diameter rolling bearing generally comprises two concentric inner and outer rings and at least one row of rolling elements arranged between the rings.

[0005] Such rolling bearings are used in aggressive environments and are also equipped with sealing elements to prevent external elements such as dust, metal particles or water from penetrating the bearing and damaging its components.

[0006] Traditionally, the rolling bearing includes an annular seal on each side, which is attached to the outer ring and comes into contact with the inner ring to close the radial space between these rings, which houses the rows of rolling elements. Further details can be found in patent application US 2022 / 0065296 (SKF).

[0007] However, such seals are not sufficient to prevent the ingress of water under high pressure flow, especially during cleaning of the bearings.

[0008] An object of the present invention is to overcome this disadvantage.

[0009] The invention relates to a rolling bearing comprising a first ring and a second ring which are suitable for rotating concentrically with respect to one another, at least one row of rolling elements which are radially inserted between raceways of the rings, and at least one row of rolling elements which are axially inserted between raceways of the rings.

[0010] The rolling bearing includes at least one inner seal attached to one of the first and second rings and in frictional contact with the other of the first and second rings.

[0011] According to a general feature, the rolling bearing further comprises at least one outer sealing arrangement provided with a sealing shield which is fixed to the first ring and is in frictional contact with the second ring, the sealing shield being arranged outside the inner seal and forming, together with the inner seal, an annular sealing chamber.

[0012] The seal shield of the sealing assembly forms a first sealing barrier, and the inner seal forms a second sealing barrier to prevent any residual ingress through the sealing assembly. The seal shield prevents the ingress of high-pressure water and improves the service life of the seal.

[0013] Furthermore, by arranging the seal shield in contact with one of the rings, assembly is simple and reliable. There is no empty space between the shield and the ring. Furthermore, with this arrangement, the expected lubricant volume is low when the sealed chamber is filled with lubricant.

[0014] According to further advantageous, but not mandatory, aspects such a rolling bearing may have one or more of the following features.

[0015] The sealing shield of the outer sealing assembly may have a flat shape in a free state.

[0016] The outer sealing assembly may further be provided with a mounting ring attached to the first ring and mounted against the sealing shield, with the sealing shield sandwiched between the mounting ring and the first ring. Such an arrangement is very compact, reliable, and economical.

[0017] The outer sealing assembly may further include a plurality of bolts extending through the mounting ring and the sealing shield and secured to the first ring.

[0018] The outer sealing assembly may further include a plurality of insert rings each secured in a through-bore on the sealing shield, with each screw extending through one of the insert rings.

[0019] The fixing ring of the outer sealing arrangement can engage in a groove provided on the first ring.

[0020] The second ring may include a shoulder against which the seal shield of the outer seal assembly comes into frictional contact.

[0021] The first ring may include a shoulder to which the sealing shield of the outer sealing assembly is attached.

[0022] The inner seal may be attached to the second ring. The inner seal may come into frictional contact with a surface of the second ring that is offset inwardly relative to the shoulder.

[0023] The inner seal may be attached to the shoulder of the second ring.

[0024] The inner seal may be attached to the first ring.

[0025] The present invention and its advantages will be better understood by studying the detailed description of specific embodiments given by way of non-limiting example and illustrated by the accompanying drawings in which: - Fig. 1 is a partial cross-section of a rolling bearing according to an embodiment of the invention, - Fig. 2 a detailed view of Fig. 1 is, - Fig. 3 an exploded view of Fig. 2, and - Fig. 4 is a partial cross-section of a rolling bearing according to another embodiment of the invention.

[0026] The Fig. The rolling bearing shown in Figure 1 is a large-diameter rolling bearing comprising a first ring 10 and a second ring 12. In the example shown, the first ring 10 is the inner ring, while the second ring 12 is the outer ring. In this example, the outer ring 12 is a rotating ring and the inner ring 10 is a non-rotating ring. The rolling bearing can be used, for example, in a tunnel boring machine, a wind turbine, a large offshore crane, mining applications such as a forklift pickup device, or other applications requiring a large-diameter rolling bearing.

[0027] The inner and outer rings 10, 12 are concentric and extend axially along the bearing's rotational axis (not shown), which runs in the axial direction. The rings 10, 12 are of the solid type.

[0028] In the example shown, the rolling bearing comprises a series of rollers 14 and a series of balls 16 arranged between the inner and outer rings 10, 12. The rollers 14 are identical to one another. Each roller 14 has a cylindrical outer raceway. The rotational axis of each roller 14 is perpendicular to the bearing axis. The rollers 14 are axially inserted between annular radial raceways 18, 20 formed on the inner and outer rings 10, 12, respectively. The raceways 18, 20 face each other in the axial direction. The raceway surface of each roller 14 is in axial contact with the raceways 18, 20.

[0029] The balls 16 are radially inserted between toroidal circular raceways 22, 24 formed on the inner and outer rings 10, 12. The raceways 22, 24 face each other in the radial direction.

[0030] The inner ring 10 comprises an outer stepped cylindrical surface 10a, from which the raceways 18, 22 are formed, and an inner cylindrical bore 10b radially opposite the outer surface 10a. The inner ring 10 further comprises two opposing first and second end surfaces 10c, 10d, which axially delimit the outer surface 10a and the bore 10b.

[0031] The outer ring 12 includes an inner stepped surface or bore 12a, from which the raceways 20, 24 are formed, and an outer cylindrical surface 12b radially opposite the bore 12a. In the illustrated example, the outer surface 12b is provided with a gear toothing (not referenced). The outer ring 12 further includes two opposing first and second end surfaces 12c, 12d, which axially define the outer surface 12b and the bore 12a.

[0032] In the example shown, the rolling bearing comprises an annular seal 26, which is fixed to the outer ring 12 and in frictional contact with the inner ring 10. The seal 26 comes into contact with the end surface 10d of the inner ring. The seal 26 is fixed in a groove formed in the bore 12a of the outer ring (not referenced). The seal 26 is provided with a shoulder 26a, which is fixed in the groove of the outer ring 12, and with a lip 26b, which extends from the shoulder and comes into frictional contact with the inner ring 10. The lip 26b extends obliquely inward from the radially extending shoulder 26a.

[0033] Alternatively, a reverse arrangement of the seal 26 could be provided, wherein the seal is attached to the inner ring 10 and comes into frictional contact with the outer ring 12.

[0034] The rolling bearing also includes an annular seal 28, which is attached to the outer ring 12 and comes into frictional contact with the inner ring 10. The seal 28 is axially mounted on the side opposite the seal 26. Thus, the rolling bearing includes a seal 26, 28 on each side.

[0035] The seals 26, 28 seal the radial space between the inner ring and the outer ring 10, 12. This radial space is defined between the bore 12a of the outer ring and the outer surface 10a of the inner ring.

[0036] A closed space 30 is defined between the inner and outer rings 10, 12 and the seals 26, 28, in which the roller rows 14 and the balls 16 are housed. The seals 26, 28 can preferably be made of rubber, in particular nitrile butadiene rubber (NBR).

[0037] Here, the seal 28 comes into contact with the outer surface 10a of the inner ring near the rollers 14. The seal 28 is secured in a groove (not referenced) formed on the end surface 12c of the outer ring. The seal 28 is provided with a shoulder 28a secured in the groove of the outer ring 12 and with a lip 28b extending from the shoulder and coming into frictional contact with the inner ring 10. The lip 28b extends obliquely inward from the axially extending shoulder 28a.

[0038] Alternatively, a reverse arrangement of the seal 28 could be provided, with the seal being attached to the inner ring 10 and coming into frictional contact with the outer ring 12.

[0039] As in the Fig. 1 and Fig. As shown in Figure 2, the rolling bearing further comprises an annular sealing arrangement 32, which is attached to the inner ring 10 and offset outwardly with respect to the seal 28. The sealing arrangement 32 is offset radially outwardly with respect to the seal 28.

[0040] The seal shield 32 is disposed outside the inner seal 28. The seal assembly 32 forms a first outer sealing barrier, and the seal 28 forms a second sealing barrier to stop any residual ingress passing through the seal assembly 32.

[0041] The sealing assembly 32 is provided with an annular sealing shield 34, which is attached to the first ring 10 and is in frictional contact with the second ring. The sealing shield 34 can preferably be made of rubber, in particular nitrile butadiene rubber (NBR).

[0042] The seal assembly 32 is further provided with an annular mounting ring 36 and a plurality of screws 38 for securing the seal shield 34 and the mounting ring 36 to the inner ring 10. The seal shield 34 is inserted between the mounting ring 36 and the inner ring 10. The seal shield 34 is inserted radially between the mounting ring 36 and the inner ring 10.

[0043] The seal shield 34 is attached to the outer surface 10a of the inner ring. In the example shown, the outer surface 10a of the inner ring is provided with an annular shoulder 40 that extends radially outward. The shoulder 40 is provided for positioning and securing the seal shield 34 to the inner ring 10. The seal shield 34 is attached to the shoulder 40. The seal shield 34 is attached radially to the shoulder 40.

[0044] The seal shield 34 extends toward the outer ring 12 and comes into frictional contact with an annular shoulder 42 provided on the end face 12c of the outer ring. The shoulder 42 extends axially outward. The free end of the seal shield 34 comes into frictional contact with the shoulder 42. A portion of the seal shield 34 is bent outward by contact with the shoulder 42. In the free state, the seal shield 34 has a flat shape, as shown in Fig. 3. The groove in which the seal 28 is secured is provided on the shoulder 42. The contact between the seal 28 and the outer surface 10a of the inner ring is offset radially inward with respect to the shoulder 40.

[0045] The seal 28 is attached to the outer ring 12 and abuts the inner ring 10, while the seal shield 34 is attached to the inner ring 10 and abuts the outer ring 12. These opposing arrangements form a labyrinth that improves sealing. When contaminants pass through the free end of the seal shield 34, the contaminants rest against the lip 28b of the seal.

[0046] Alternatively, a reverse arrangement may be provided, in which the seal shield 34 is attached to the outer ring 12 and abuts the inner ring 10, while the seal 28 is attached to the inner ring 10 and abuts the outer ring 12. In another embodiment, both the seal shield 34 and the seal 28 may be attached to the inner ring 10 or the outer ring 12.

[0047] An annular, sealed chamber 44 is formed between the seal shield 34 and the seal 28. More specifically, the chamber 44 is defined by the seal shield 34, the seal 28, and the inner and outer rings 10, 12. The chamber 44 is defined radially by the seal shield 34, the seal 28, and the outer surface 10a of the inner ring, and axially by the shoulders 40, 42 and the seal 28. The chamber 44 may be provided with lubricants, such as grease.

[0048] The retaining ring 36 of the seal assembly is attached to the seal shield 34 and fixedly connected to the inner ring 10. The retaining ring 36 has an L-shape in cross-section. The retaining ring 36 includes a first portion 36a, which is attached to the seal shield 34, and a second portion 36b, which extends from the first portion 36a and is inserted into a groove (unreferenced) of the shoulder 40 of the inner ring. The first portion 36a extends axially and the second portion 36b extends radially. The retaining ring 36 can be made of steel. The retaining ring 36 can be segmented and formed from a plurality of ring segments that contact one another in the circumferential direction and are connected to one another.

[0049] Both the mounting ring 36 and the sealing shield 34 are provided with a plurality of aligned through holes 48, 50, which are to be secured to the inner ring 10 with the screws 38. The through holes 48 are provided on the first part 36a of the mounting ring. The through holes 50 extend through the thickness of the sealing shield 34.

[0050] Each screw 38 extends through one of the mounting ring through holes 48 and the corresponding sealing shield through hole 50 and is inserted into a threaded hole (not referenced) extending from the shoulder 40 into the inner ring. The screws 38 are circumferentially spaced, preferably evenly, from each other.

[0051] The sealing assembly 32 further includes a plurality of annular insert rings 52, each secured in one of the through holes 50 of the sealing shield. Each screw 38 extends through one of the insert rings 52. The sealing assembly 32 also includes a plurality of washers 54, each interposed between the head of a screw 38 and the first portion 36a of the mounting ring. The insert rings 52 and the washers 54 may be made of steel.

[0052] The Fig. The example shown in Figure 4, in which identical parts are provided with identical designations, differs from the first example in that the shoulder 42 is an additional part which is fixed to the outer ring 12 by any suitable means, e.g. by screwing or welding.

[0053] In the examples shown, the sealing arrangement 32 is offset radially outward relative to the seal 28. However, the sealing shield 32 can also be arranged outside the inner seal 28 in a different manner. For example, the sealing arrangement 32 can be offset axially outward relative to the seal 28. In another variant, the sealing arrangement can be offset radially inward relative to the seal 28.

[0054] In the previous examples, the first ring of the rolling bearing is the inner ring 10, while the second ring is the outer ring 12.

[0055] Alternatively, a reverse arrangement could be provided, with the first ring forming the outer ring and the second ring forming the inner ring.

[0056] In the examples shown, the rolling bearing is provided with a row of rollers 14 and a row of balls 16. Alternatively, the rolling bearing may also comprise three or more rows of rolling elements, such as rollers and / or balls. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2022 / 0065296

[0006]

Claims

[1] A rolling bearing comprising a first ring (10) and a second ring (12) adapted to rotate concentrically with each other, at least one row of rolling elements (16) radially interposed between the raceways of the rings, at least one row of rolling elements (14) axially interposed between the raceways of the rings, and at least one inner seal (28) mounted on one of the first and second rings (10, 12) and coming into frictional contact with the other of the first and second rings, characterized by in that the rolling bearing at least further comprises an outer seal arrangement (32) provided with a seal shield (34) which is fastened to the first ring (10) and comes into frictional contact with the second ring (12), the seal shield (32) being arranged outside the inner seal (28) and defining, together with the inner seal, an annular sealed chamber (44). [2] Rolling bearing according to claim 1, wherein the seal shield (34) of the outer seal assembly has a flat shape in the free state. [3] Rolling bearing according to claim 1 or 2, wherein the outer seal assembly (32) is further provided with a fixing ring (36) fixed to the first ring (10) and mounted against the seal shield (34), the seal shield (34) being arranged between the fixing ring (36) and the first ring (10). [4] Rolling bearing according to claim 3, wherein the outer seal assembly (32) is further provided with a plurality of screws (38) extending through the fixing ring (36) and the seal shield (34) and being fixed to the first ring (10). [5] Rolling bearing according to claim 3 or 4, wherein the outer seal assembly (32) is further provided with a plurality of insert rings (52) each fixed in a through hole provided on the seal shield (34), each screw (38) extending through one of the insert rings (52). [6] Rolling bearing according to one of the preceding claims 3 to 5, wherein the fixing ring (36) of the outer seal assembly engages in a groove provided on the first ring (10). [7] Rolling bearing according to one of the preceding claims, wherein the second ring (12) comprises a shoulder (42) against which the seal shield (34) of the outer seal assembly comes into frictional contact. [8] Rolling bearing according to one of the preceding claims, wherein the first ring (10) comprises a shoulder (40) to which the sealing shield (34) of the outer sealing arrangement is attached. [9] Rolling bearing according to one of the preceding claims, wherein the inner seal (28) is fixed to the second ring (12). [10] Rolling bearing according to claim 9 when dependent on claim 7, wherein the inner seal (28) is fixed to the shoulder (42) of the second ring (12).

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