In the art, sealed rolling elements bearings are known, comprising:

- an inner bearing ring comprising at least one inner raceway, said inner bearing ring having axial end portions;

- an outer bearing ring comprising at least one outer raceway, said outer bearing ring having axial end portions;

- a plurality of rolling elements interposed between a pair of inner and outer raceways;

- an axial sealing assembly stationary fixed to an axial end portion of the inner bearing ring and extending toward the axial end portion of the outer bearing ring, said axial sealing assembly comprising:

o an inside facing the rolling elements and an opposite outside;

o an annular rigid carrier disc having an inner diameter face at an inner perimeter thereof;

o a resilient sealing member having a sealing lip, said resilient sealing member being supported by the carrier disc at an outer perimeter thereof; wherein said sealing lip slidingly and sealingly engages a corresponding sealing surface of the end portion of said outer bearing ring. Such known sealed rolling elements bearings are not satisfactory. In particular, the lifetime is limited, e.g. due to dehydration and corrosion.

From US2015/0316103 a sealed rolling elements bearing is known according to the preamble of claim 1. It comprises an elastic member and a core bar. The elastic member covers the outer circumference of the core bar and of sealing assembly, extending between the inner bearing ring and the outer bearing ring.

It is an aim of the present invention to provide an improved sealed rolling elements bearing. This is achieved according to the present invention in that the outer bearing ring has an inwardly protruding rib axially outward of the corresponding sealing surface of the end portion of said outer bearing ring; wherein the sealing lip has a free end portion remote from the main body of the sealing member, and such that - when seen from the outside, said inwardly protruding rib of the outer bearing ring obscures the free end portion of the sealing lip from view;

wherein the outer perimeter of the carrier disc has a stepped design, with a largest diameter section opposite said inwardly protruding rib of the outer bearing ring, an intermediate diameter section which defines with said sealing member the grease chamber, and with a smallest diameter section defining said groove in which the main body of the sealing member is mounted. This improved sealing rolling elements bearing provides a grease chamber at the outside of the seal, resulting in an improved lifetime. The construction of the grease chamber between the annular carrier disc, the resilient sealing member and the outer bearing ring provides an improved grease retention, and dispenses the need of additional provisions, such as an external cover to form a grease chamber at the outside of the sealing lip.

The invention also relates to a structure provided with a rotatably supported shaft, wherein the structure has a body with opposed end faces and a hole extending between said end faces, wherein a sealed rolling elements bearing according to one or more of the preceding claims is mounted in said hole, so that said outer bearing ring rests against said body of the structure, and wherein the shaft extends through the inner bearing ring.

The improved sealed roller elements bearing is in particular useful in aggressive

circumstances, such as offshore. Structures in which the improved sealed roller elements bearing may be applied include sheaves, tensioners, mud-related activities, soil and sand related activities such as drilling, use in cranes, etc., etc.

Another advantage of the construction of the carrier disc according to the invention is that the resilient member is shielded from external influences such as the aggressive offshore conditions by the carrier disc. The carrier disc is preferably made of metal, in particular steel.

The present invention also relates to a sealed rolling elements bearing comprising:

- an inner bearing ring comprising at least one inner raceway, said inner bearing ring having axial end portions;

- an outer bearing ring comprising at least one outer raceway, said outer bearing ring having axial end portions;

- a plurality of rolling elements interposed between a pair of inner and outer raceways; - an axial sealing assembly stationary fixed to an axial end portion of the inner bearing ring and extending toward the axial end portion of the outer bearing ring, said axial sealing assembly comprising:

o an inside facing the rolling elements and an opposite outside;

o an annular rigid carrier disc having an inner diameter face at an inner

perimeter thereof;

o a resilient sealing member having a main body, mounted on said disc, and an integral conical sealing lip which extends from said main body towards said outer bearing ring as well as towards the outside of the sealing assembly, said sealing lip delimiting a grease chamber for retention of grease therein; wherein said sealing lip slidingly and sealingly engages a corresponding sealing surface of the end portion of said outer bearing ring,

characterised in that,

wherein at its outer perimeter said annular rigid carrier disc is provided with a groove in which said resilient sealing member is mounted;

wherein the sealing lip has a free end portion remote from the main body of the sealing member;

wherein the outer perimeter of the carrier disc has a stepped design, with a largest diameter section at the outside of the axial sealing assembly, opposite the outer bearing ring, an intermediate diameter section which defines with said sealing member the grease chamber, and with a smallest diameter section at the inside of the axial sealing assembly, defining said groove in which the main body of the sealing member is mounted,

wherein a circumferential gap between the largest diameter section of the outer perimeter of the carrier disc and said outer bearing ring is at most 2 millimetres.

Preferably, the outer bearing ring has an inwardly protruding rib axially outward of the corresponding sealing surface of the end portion of said outer bearing ring, said inwardly protruding rib of the outer bearing ring - when seen from the outside - obscuring the free end portion of the sealing lip from view, and wherein said circumferential gap is provided between the largest diameter section of the outer perimeter of the carrier disc and said inwardly protruding rib.

The invention is further elucidated in the drawings, in which:

Fig. 1 is a schematical representation of a structure according to the invention in cross section;

Fig. 2 is a detailed view on a sealed rolling elements bearing according to the invention in cross section; Fig. 3 shows, in cross section, part of the structure of fig. 1 in further detail.

In figs. 1 - 3, a structure 100 is shown, provided with a rotatably supported shaft 50, wherein the structure has a body 55 with opposed end faces 55a; 55b and a hole 55c extending between said end faces. Such a structure is for example a sheave.

In said hole, a sealed rolling elements bearing 1 is mounted. The sealed rolling elements bearing is shown in further detail in fig. 2. The sealed rolling elements bearing 1 comprises an inner bearing ring 2, comprising at least one inner raceway, said inner bearing ring having axial end portions 2a; 2b. In the shown embodiment, the inner bearing ring 2 is composed of two bearing ring body members 2c, 2d arranged side by side. Bearing ring body member 2c comprises axial end portion 2a, and bearing ring body member 2d comprises axial end portion 2b. Each ring body member 2c, 2d has a single inner raceway 3a, 3b. Said bearing ring body members 2c, 2d are axially interconnected by a connector member 22, e.g. a clip.

In the embodiments of fig. 1 and 3, the shaft 50 of structure 100 extends through the inner bearing ring 2. The sealed rolling elements bearing 1 further comprises an outer bearing ring 5 comprising at least one outer raceway 6, said outer bearing ring having axial end portions 5a; 5b. In the embodiments of fig. 1 and 3, the outer bearing ring 5 rests against said body 55 of the structure 100. The outer bearing ring 5 has a single outer bearing ring body with two raceways 6a, 6b.

In the shown embodiment, the outer bearing ring 5 is axial clamped between two opposed retaining rings 58 that are mounted with bolts 59 onto a respective end face 55a; 55b of the body 55 of the structure. Furthermore, the shown outer bearing ring 5 is provided with a stepped shoulder 5x at each of its axial end portions 5a, which stepped shoulder lies outward of the respective end face of the body 55a of the structure, and wherein each retaining ring 58 has a mating stepped portion 58x that engages said stepped shoulder. The sealed rolling elements bearing 1 comprises a plurality of rolling elements 8 interposed between a pair of inner and outer raceways. In particular, in the shown embodiment, one set of rolling elements 8 is positioned between a pair of inner and outer raceways. The rolling elements are preferably cylindrical rolling elements.

In embodiments, not shown, at least one rolling elements cage is provided, wherein a plurality of rolling elements are retained at circumferential spaced locations.

In embodiments, the outer bearing ring raceway has a diameter of between 300 - 800 millimetres, preferably 400-600 millimetres. In embodiments, the inner bearing ring raceway has a diameter of between 200 - 500 millimetres, preferably 300-400 millimetres.

The sealed rolling elements bearing further comprises an axial sealing assembly 10, stationary fixed to an axial end portion 2a of the inner bearing ring and extending toward the axial end portion 5a of the outer bearing ring.

Said axial sealing assembly 10 comprises an inside 1 1 facing the rolling elements 8 and an opposite outside 12. It has an annular rigid carrier disc 13 having an inner diameter face 14 at an inner perimeter thereof and a resilient sealing member 15 having a sealing lip 16, said resilient sealing member being supported by the carrier disc at an outer perimeter thereof. The sealing lip 16 slidingly and sealingly engages a corresponding sealing surface 7 of the end portion 5a of said outer bearing ring.

Preferably, the inner diameter face 14 of the annular rigid carrier disc 13, preferably the majority of the annular rigid carrier disc, has a width of at least 5 millimetres, e.g. 5-10 millimetres.

Preferably, said inner diameter face 14 is shrunk radially onto a corresponding shrink fit face 2f of the axial end portion 2a of the inner bearing ring. In the shown embodiment, the inner bearing ring 2 has a shoulder 2g delimiting an inner axial end of said corresponding shrink fit face 2f, against which said carrier disc 13 is mounted. Advantageously, wherein said shrink fit forms the sole fixation of said carrier disc 13 onto the inner bearing ring 2.

Alternative mounting techniques are also conceivable, such as via bolts or welding. According to the present invention, the outer bearing ring 5 has an inwardly protruding rib 9 axially outward of the corresponding sealing surface 7 of the end portion of said outer bearing ring. In embodiments, said rib has a width of 2-5 millimetres. Said annular rigid carrier disc 13 is at its outer perimeter provided with a groove 17 in which said resilient sealing member 15 is mounted.

In the shown embodiment, as is preferred, said groove 17 is formed at a corner between an outer perimeter face of the carrier disc and the inside 1 1 of the carrier disc, so that the carrier disc, seen from the outside, covers a majority of the resilient sealing member 15.

The sealing member 15 has a main body 18, mounted in said groove 17, and an integral conical sealing lip 16 which extends from said main body towards said outer bearing ring 5 as well as towards the outside 12 of the sealing assembly.

The sealing lip 16 has a free end portion 16a remote from the main body 18 of the sealing member, and such that - when seen from the outside - said inwardly protruding rib 9 of the outer bearing ring obscures the free end portion 16a of the sealing lip from view. The outer perimeter of the carrier disc 13 has a stepped design, with a largest diameter section 13a opposite said inwardly protruding rib 9 of the outer bearing ring, an intermediate diameter section 13b which defines with said sealing member 15 a grease chamber 20 for retention of grease therein, and with a smallest diameter section 13c defining said groove 17 in which the main body 18 of the sealing member is mounted.

Preferably, a circumferential gap 21 between the largest diameter section 13a of the outer perimeter of the carrier disc 13 and said inwardly protruding rib 9 of the outer bearing ring is at most 2 millimetres, more preferably 1 millimetre. Preferably, a circumferential gap 21 between the largest diameter section 13a of the outer perimeter of the carrier disc 13 and said inwardly protruding rib 9 of the outer bearing ring is at most 3-4 millimetres, more preferably 1-2 millimetres.

Grease chamber 20 is provided between the intermediate diameter section 13b and the opposed sealing surface of the end portion of the outer bearing ring, which defines with said sealing member 15 said grease chamber 20. The circumferential dimension of the grease chamber is advantageously 5-8 times as large as the circumferential gap 21 , hence in the order of 5 - 20 millimetres.