Rolling bearing with seals and a segmented spacer ring between said seals

Abstract

A rolling bearing having two seals 38 and an annular spacer ring 52 axially between the two seals 38. The seal has base 44 and sealing lip 46. The shim spacer is formed of three separate segments 62.

Description

The present invention relates to the field of rolling bearings. The invention particularly relates to the field of large-diameter rolling bearings having an inner ring and an outer ring arranged concentrically about an axis of rotation running in an axial direction. Such large-diameter rolling bearings may be used for example in marine applications, for example in a tidal or marine turbine power station, or in a tunnel boring machine, or in a mining extraction machine or in a wind turbine. A large-diameter rolling bearing generally comprises two concentric inner and outer rings, and at least one row of rolling elements, such as rollers or balls, arranged between the rings. The bearing also comprises seals disposed between the inner and outer rings to define a closed space inside which the rolling elements are arranged. Large-diameter rolling bearings are generally used in aggressive environments, in particular in marine applications. Seals prevent exterior elements, such as dust, abrasive particles, water and marine species, for example plankton and algae, from getting inside said bearing and damaging its components. Those exterior elements may also alter the seal itself, leading to a reduction in the seal service life. Generally, a plurality of additional adjacent seals is provided on the bearing front side which is directly in contact with the aggressive environments, for example with the saltwater. These additional seals are fixed to a sealing ring of one of the inner and outer rings and comprise a sealing lip in sliding contact with a running surface of a sealing ring of the other ring. Hence, several adjacent closed outer chambers are delimited between the sealing lips of the adjacent seals. The seals may be separated by an annular spacer ring hardly positioned during the assembly because of his size and his adjustment. It is therefore desirable that a rolling bearing comprises effective sealing elements that prevent the entry of exterior element, of increased service life, particularly in aggressive environment, and easy to implement. One aim of the present invention is to solve the above difficulties. The invention relates to a rolling bearing comprising a first ring and a second ring capable of rotating concentrically relative to one another, and at least one row of rolling elements arranged between first and second raceways of the said first and second rings, the first ring comprising at least one first rolling ring provided with said first raceway, and the second ring comprising at least one second rolling ring provided with said second raceway, the rolling bearing further comprising at least two seals each having an annular heel mounted on a cylindrical surface of the first ring, and at least one sealing lip in frictional contact with the second ring. The rolling bearing also comprises a spacer ring mounted on the first ring and axially arranged between the annular heels of the two seals. According to one aspect of the invention, the spacer ring comprises at least three dissociable segments circumferentially adjacent forming said spacer ring. In other words, the spacer ring is split into at least three successive ring segments. The spacer ring is formed as a slit ring in the circumferential direction. Thus, the segmentation of the spacer ring into multiple segments permits to facilitate the assembly and the disassembly of said spacer ring and of the rolling bearing in general. Advantageously, the spacer ring comprises an annular groove facing said cylindrical surface of the first ring. Preferably, the spacer ring abuts radially against said cylindrical surface of the first ring, as the annular heel of each seal abuts radially again said cylindrical surface. Advantageously, the spacer ring comprises a flange that radially outwardly projects towards the second ring, the flange extending obliquely with a support surface inclined in the same direction as the sealing lip of one of the seals, and an annular axial collar that radially blocks the annular heel of the other seal in a radial outwards direction. Advantageously, each segment has the same size as the other segments. Preferably, each segment comprises at least one axial through hole opening on either side onto one of the seals. Advantageously, each segment comprises only one axial through hole positioned in the middle of the circumferential length of said segments. In another embodiment, each segment comprises at least two axial through holes, each axial through hole being positioned regularly along the circumferential length of each segment. Preferably, the axial through hole comprises a tapping. In one embodiment, the rolling bearing comprises at least three seals and two spacer rings spaced apart from each other by one of the seals which is interposed axially. Preferably, the segments are manufactured by 3D printing, and / or by stamping, and / or by turning, and / or by grinding. In one embodiment, the first ring is the inner ring and the second ring is the outer ring. Alternatively, the first ring is the outer ring and the second ring is the inner ring. The present invention and its advantages will be better understood by studying the detailed description of specific embodiments given by way of non-limiting examples and illustrated by the appended drawings on which: Figure 1 is a cross-section of a rolling bearing according to the invention, Figure 2 is a partial cross-section of the rolling bearing of Figure 1 according to other cutting planes, and - Figure 3 is a schematic view of a segmented spacer ring of the rolling bearing of Figure 1. The rolling bearing 1 as illustrated on Figure 1 is a large-diameter rolling bearing comprising a first ring 10 and a second ring 12. In the illustrated example, the first ring 10 is the outer ring whereas the second ring 12 is the inner ring. The rolling bearing 1 may for example be used in a tidal or marine turbine power station a tunnel boring machine, a wind turbine, a big offshore crane or any other applications using a large diameter rolling bearing. The outer and inner rings 10, 12 are concentric and extend axially along the bearing rotation axis (not shown) which runs in an axial direction. In this illustrated example, the rings 10, 12 are of the solid type. The outer ring 10 comprises a first rolling ring 14 and a sealing ring 16 secured to the first rolling ring 14. The inner ring 12 also comprises a second rolling ring 18 and a sealing ring 20 secured to the second rolling ring 18. Alternatively, the rolling ring 18 and the sealing ring 20 may be made in one part. The sealing ring 16 of the outer ring partially and radially surrounds the sealing ring 20 of the inner ring. In the illustrated example, the rolling bearing also comprises two rows of balls 22, 24 which are arranged between first raceways 26, 28 of the first rolling ring 14 of the outer ring and second raceways 30, 32 of the second rolling ring 18 of the inner ring. The second rolling ring 18 of the inner ring comprises an outer cylindrical surface 18a from which the raceways 30, 32 are formed. The raceways 30, 32 are oriented radially outwards. The second rolling ring 18 also comprises an inner cylindrical surface or bore 18b which is radially opposite to the outer surface 18a. The second rolling ring 18 further comprises two opposite first and second frontal surfaces 18c, 18d which axially delimit the outer surface 18a and the bore 18b. The frontal surfaces 18c, 18d delimit the axial thickness of the second rolling ring 18. The first rolling ring 14 of the outer ring comprises an outer cylindrical surface 14a and a cylindrical surface 14b which is radially opposite to the outer surface 14a and from which the raceways 26, 28 are formed. The raceways 26, 28 are oriented radially inwards. The first rolling ring 14 further comprises two opposite first and second frontal surfaces 14c, 14d which axially delimit the outer surface 14a and the cylindrical surface 14b. The frontal surfaces 14c, 14d delimit the axial thickness of the first rolling ring 14. The rolling bearing further comprises, axially on each side of the rolling rings 14 and 18, an annular seal 34, 36 mounted on the first rolling ring 14 and provided to close the radial space that exists between the rolling rings 14, 18. This radial space is defined between the surface 14b of the first rolling ring 14 and the outer surface 18a of the second rolling ring 18. An annular closed rolling space (not referenced) is defined between the rolling rings 14, 18 and the seals 34, 36 in which the rows of balls 22, 24 are housed. Advantageously, the rolling space is filled with lubricant. Each seal 34, 36 is mounted into a groove (not referenced) formed on the cylindrical surface 14b of the first rolling ring 14 and comes into contact with the second rolling ring 18. The seal 34 comes into contact with the outer surface 18a of the second rolling ring 18. The seal 36 comes into contact with the outer surface 18a of the second rolling ring 18. Alternatively, it could be possible to provide a reversed arrangement for at least one of the seals 34, 36 with said seal mounted on the second rolling ring 18 and coming into friction contact with the first rolling ring 14. The sealing ring 16 of the outer ring is mounted axially into contact against the frontal surface 14d of the first rolling ring 14. The sealing ring 16 protrudes axially with regard to the first rolling ring 14. The sealing ring 16 is reversely attached or secured to the first rolling ring 14. The sealing ring 16 partially and radially surrounds the sealing ring 20 of the inner ring. Each of the sealing rings 16, 20 may be made of stainless steel or treated steel with a painting or anticorrosion treatment. The sealing ring 16 also comprises a seal lip 37 extending from said sealing ring 16 towards the sealing ring 20 in order to prevent sand or particles from entering between the first ring 10 and the second ring 12. As more precisely illustrated on Figure 2, a plurality of successive annular seals are radially provided between the first rolling ring 14 of the outer ring and the sealing ring 20 of the inner ring. In the illustrated example, the rolling bearing is provided with first, second, and third successive seals 38, 40 and 42 supported by the first rolling ring 14 of the outer ring. The seals 38, 40 and 42 are arranged successively in the axial direction. The seals 38, 40 and 42, as well as the annular seals 34 and 36, may be made of elastomeric material, for example polyurethane. The seals are intended to limit the infiltration of liquids, particles and dust from the subsea environment between the inner ring and the outer ring. The first, second, and third successive seals 38, 40 and 42 are axially disposed outwardly with respect to the annular seal 34. Each seal is provided with an annular heel 44 and with a sealing lip 46 projecting from said heel 44. In the illustrated example, each sealing lip 46 extends inwardly and obliquely from the annular heel 44. Each sealing lip 46 extends obliquely outwards. The sealing lips 46 are flexible in the radial direction. Each sealing lips 46 is elastically deformed and in sliding frictional contact with a sliding contact surface of the second ring 12, preferably a surface from the second sealing ring 20, for example at the same level as the outer surface 18a. The cylindrical surface 14b is more precisely provided with an annular groove 48 open radially towards the outer ring 10. The annular groove 48 is axially bounded between a shoulder 50 of the first rolling ring 14 and the first sealing ring 16. The shoulder 50 is formed when removing material on the cylindrical surface 14b. The seals 34, 38, 40 and 42 are mounted on the cylindrical surface 14b, more precisely in the annular groove 48. The rolling bearing also comprises a first and a second spacer rings 52 are arranged in the annular groove 48. The spacer rings 52 are annular. The first spacer ring 52 is axially mounted between the annular heels 44 of seals 38 and 40 respectively. The second spacer ring 52 is axially mounted between the annular heels 44 of seals 40 and 42 respectively. In the embodiment illustrated, the two spacer rings 52 are similar. Each spacer ring 52 comprises a flange 54 that radially outwardly projects towards the second ring 12. The flange 54 extends obliquely and is provided with a support surface inclined in the same direction as the sealing lip 46 of the one seal, for example the second seal 40, in order to prevent any reversion of the sealing lip 46. The spacer ring 52 further comprises an annular axial collar 56 that radially block the annular heel 44 of one other seal opposed to the seal of the precedent paragraph, so the seal 38, in a radial outwards direction. The annular heels 44 of the axially adjacent seals 38, 40 and 42 are axially maintained between the seal 34, the first sealing ring 16, the different spacer rings 52, and the seal 34, itself maintained by the shoulder 50. Furthermore, the annular heel 44 are radially maintained between the annular axial collar 56 and the cylindrical surface 14b, more precisely the cylindrical surface 14b inside the annular groove 48. As shown partly on Figure 3, the spacer ring 52 is divided in the circumferential direction. The spacer ring 52 is segmented. The spacer ring 52 comprises at least three dissociable successive circumferential segments 62 circumferentially adjacent forming said spacer ring 52. A spacer ring 52 can comprise between 3 and 50 segments 62, preferably between 3 and 25 segments. Each segment 62 is provided with a first end and with a second end which delimit said segment in the circumferential direction. The first end of one segment 62 abuts in the circumferential direction against the second end of one successive segment 62, and the second end of said segment 62 abuts in the circumferential direction against the first end of one other successive segment 62. In one embodiment, the segments 62 may be identical one to another. During the assembly, each segment 62 is positioned against a seal and all segments 62 together are forming the spacer ring 52. The last segment 62 to be positioned can be adjusted in terms of length and position to the free space still available in order to create a keystone and provide the desired rigidity for the spacer ring 52. These segments 62 are easy to be axially installed during assembly of the rolling bearing 1. These segments 62 are also easy to be removed and replaced by new elements during a maintenance operation. Moreover, these segments 62 permit to minimize the impact of a deformation of the spacer ring 52, in particular for big diameter, for example more than one meter. In this embodiment, each segment 62 can comprise an axial hole 58, said axial hole 58 being here positioned in the middle of the circumferential length of said segment 62. The axial hole 58 is provided for handling purpose during assembly or disassembly of the rolling bearing. In one embodiment, each segment 62 may comprise more than two axial holes 62, each axial hole 62 being positioned regularly along the circumferential length of each segment 62. Advantageously, each axial hole 62 comprises a tapping in order to facilitate the insertion of a screw or a bolt and to secure the spacer ring 52 to a lifting machine. Advantageously, the axial hole 62 is a through-hole. Each spacer ring 52 also comprises an annular groove 60 facing the cylindrical surface 14b of the first ring 10. The annular groove 60 is destined to be in fluidic communication with radial channels (not shown) through the spacer ring 52 for sealing testing, for example airleakage test, or lubrication purpose. Alternatively, the rolling bearing 1 may comprise a different number of seals or of spacer rings. Otherwise, as previously mentioned, in the illustrated examples, the first ring of the rolling bearing is the outer ring whereas the second ring is the inner ring. As an alternative, it could be possible to provide a reversed arrangement with the first ring forming the inner 5 ring and the second ring forming the outer ring. In the described examples, the rolling bearing comprises two rows of rolling elements. Alternatively, the rolling bearing may comprise only one row of rolling elements, or three or more rows of rolling elements. In the illustrated example, the rolling elements are 10 balls. The rolling bearing may comprise other types of rolling elements, for example rollers.

Claims

1. Rolling bearing (1) comprising a first ring (10) and a second ring (12) capable of rotating concentrically relative to one another, and at least one row of rolling elements (22) arranged between first and second raceways (26, 30) of the said first and second rings, the first ring (10) comprising at least one first rolling ring (14) provided with said first raceway (26), and the second ring (12) comprising at least one second rolling ring (18) provided with said second raceway (30), the rolling bearing (1) further comprising at least two seals (38, 40) each having an annular heel (44) mounted on a cylindrical surface (14b) of the first ring (10) and a sealing lip (46) in frictional contact with the second ring (12), and at least one spacer ring (52) mounted on the first ring (10) and axially arranged between the annular heels (44) of the two seals (38, 40), characterized in that the spacer ring (52) comprises at least three dissociable segments (62) circumferentially adjacent forming said spacer ring (52).

2. Rolling bearing (1) according to claim 1, wherein the spacer ring (52) comprises an annular groove (60) facing said cylindrical surface (14b) of the first ring (10).

3. Rolling bearing (1) according to claim 1 or 2, wherein the spacer ring (52) comprises a flange (54) that radially outwardly projects towards the second ring (12), the flange (54) extending obliquely with a support surface inclined in the same direction as the sealing lip (46) of one of the seals (40), and an annular axial collar (56) that radially blocks the annular heel (44) of the other seal (38) in a radial outwards direction.

4. Rolling bearing (1) according to any of the preceding claims 1 to 3, wherein each segment (62) has the same size as the other segments (62).

5. Rolling bearing (1) according to any of the preceding claims 1 to 4, wherein each segment (62) comprises at least one axial through hole (58) opening on either side onto one of the seals (38, 40, 42).

6. Rolling bearing (1) according to claim 5, wherein each segment (62) comprises only one axial through hole (58) positioned in the middle of the circumferential length of said segments (62).

7. Rolling bearing (1) according to claim 5, wherein each 5 segment (62) comprises at least two axial through holes (58), each axial through hole (58) being positioned regularly along the circumferential length of each segment (62).

8. Rolling bearing (1) according to any of the preceding claims 5 to 7, wherein the axial through hole (58) comprises a tapping.10 9. Rolling bearing (1) according to any of the precedingclaims 1 to 8, comprising at least three seals (38, 40, 42) and two spacer rings (52) spaced apart from each other by one of the seals (38, 40, 42) which is interposed axially.

10. Rolling bearing (1) according to any of the preceding 15 claims 1 to 9, wherein the segments (62) are manufactured by 3D printing, and / or by stamping, and / or by turning, and / or by grinding.

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