Rolling bearing comprising holes and grooves

Abstract

Rolling bearing 10 having outer ring 12 and inner ring 14 and at least one row of rolling elements therebetween, the rolling bearing 10 having two external axial end faces 16, 18. The outer and inner

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, especially 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. If water starts to enter inside the rolling bearing, by first entering inside the first outer seal chamber, it is desired to prevent the water or pollution to move further inside the bearing until the rolling space. Water ingress can occur in most of the applications, but particularly for immerged applications such as in a tidal turbine. In a general way, the sealing rings are designed to optimize sealing and to facilitate seal maintenance. Accordingly, in certain types of design, all or most sealing rings comprise one or many leakage test channels. Prior to use of the rolling bearing, a leakage test channel enables to introduce a fluid in an area where a seal is located. Hence, the efficiency of the sealing members and the seals may be tested. The introduced fluid may be compressed air, lubricant, coloured liquid, etc. A closing plug may be attached at an inlet orifice and / or at an outlet orifice of the leakage test channel, by any appropriate means, for example by screwing. Preferably, the closing plug is made of transparent material to be able to visually detect the presence of contaminant fluid during an inspection of the rolling bearing. The closing plug may be recovered by potting material and embedded inside this material. Hence, the associated thread of the closing plug is sealed. The rolling bearing presented above works well and gives satisfaction. However, it has some drawbacks. The rolling bearing structure is complex, and its implementation in a device, or between devices, can be complicated. It is difficult to orientate the outer ring with a part of a device, and to orientate the inner ring with another part of a device. Maintenance of the bearing can also be complicated, because it is necessary to precisely position the outer ring or the inner ring with respect to a component, or to precisely position the two rings relative to each other. This results in other disadvantages such as quite a high cost and a fairly long assembly time. The present invention wishes, among other things, to overcome these drawbacks. The invention seeks to optimise the rolling bearing installation by making it simpler. As a corollary, the invention wishes to reduce assembly times and to facilitate maintenance. The invention relates to a rolling bearing comprising an outer ring and an inner ring capable of rotating concentrically relative to one another about a longitudinal axis, at least one row of rolling elements being arranged between said outer and inner rings, the rolling bearing being provided with a first external face and a second external face axially opposite to said first external face which delimit the axial length of the bearing. The outer ring has a longitudinal hole, said hole opening out at the first external face of the rolling bearing, at least one edge of the outer ring having a longitudinal mark, said hole and said mark of the outer ring being separated by an angle a. The inner ring has a longitudinal hole, said hole opening out at the second external face of the rolling bearing, at least one edge of the inner ring having a longitudinal mark, said hole and said mark of the inner ring being separated by an angle p. Said hole of the outer ring and said hole of the inner ring are separated by an angle y when the marks of the outer ring and the inner ring are contained in a same longitudinal plane passing through the longitudinal axis. The angles a and P are measured according to the same direction of rotation, and the angle y is P minus a. Because the angles a and P are known, the angle y is also known. Accordingly, two pins each placed in a hole are separated by said known angle y. In other words, it is enough to place all the marks of the rings in the same plane to adjust the distance between the pins. As a result, the placing of each ring on a part of a device is easier. Effectively, each pin has a protruding part which takes place in a hole of the device. The two holes which receive the protrusions of the pins are offset by an angle value y. This allows easy positioning of the outer and inner rings in a device. Thanks to the holes with pins, the angular position of the outer and inner rings is correct. Among the resulting advantages are easier and faster installation of the rolling bearing, easier maintenance, lower costs. In one embodiment, the outer ring comprises at least a first rolling ring and at least one first sealing ring secured to the first rolling ring, the inner ring comprising at least one second rolling ring and at least one second sealing ring secured to the second rolling ring. This makes it possible to reinforce the sealing of the bearing. The first sealing ring of the outer ring is formed as a split ring and comprises at least two part rings, the part ring farthest from the rolling ring being an end ring, each part ring having a longitudinal through hole located on a first diameter ¢1, an outer peripheral edge of each part ring having a longitudinal mark, said through hole and said mark of the outer peripheral edge being separated by the angle a, the first rolling ring of the outer ring having a longitudinal through hole located on the first diameter ¢1, an outer peripheral edge of the first rolling ring having a longitudinal mark, said through hole and said mark of the outer peripheral edge being separated by the angle a, all of the through holes in the part rings and the through hole in the first rolling ring being aligned and forming the hole opening out at the first face of the rolling bearing, when all the marks of the part rings and the first rolling ring are aligned. As a result, a pin prevents all rings from rotating relative to each other, when said pin is in place in the hole opening out at the first face of the rolling bearing. Two of the part rings are twin rings having the same design, each twin ring having two longitudinal through holes, said two through holes being on the first diameter ¢1 and being separated by the angle y, each twin ring having a first mark at the level of one of the through holes and a second mark at the level of the other of the through holes, the twin rings being adjacent and offset. This simplifies the structure of the rolling bearing. The end ring of the first sealing ring has a radial mark contained in a longitudinal plane passing through the longitudinal axis, said longitudinal plane containing the mark of the outer peripheral edge of the end ring. This allows one to see the position of the end ring from several different points of view. The first sealing ring of the outer ring includes five part rings. Very good operation was obtained with this number of rings, in particular for sealing of the rolling bearing. The second sealing ring of the inner ring has one longitudinal mark and the second rolling ring of the inner ring has one longitudinal mark, said longitudinal marks being contained in a longitudinal plane passing through the longitudinal axis, the hole opening out at the second face of the rolling bearing being on a second diameter ¢2, said hole and said two longitudinal marks being separated by the angle p. Accordingly, the position of a pin in place in the hole opening out at the second face is known. The second sealing ring of the inner ring has a radial mark contained in the longitudinal plane which contains the longitudinal marks. This allows one to see the position of the second sealing ring from several different points of view. The angle value a is 0°, the angle value P is 3°, and the angle value y is 3°. With these values, very good results have been obtained. The invention is also directed to a mounting method of a rolling bearing presented above, the method comprising the following steps : placing a pin in the longitudinal hole of the outer ring so that said pin protrudes, placing another pin in the longitudinal hole of the inner ring so that said pin protrudes, positioning the outer ring relative to the inner ring so that their respective marks are contained in a same longitudinal plane passing through the longitudinal axis, securing one of the outer and inner rings to a rotating device, the projecting part of a pin taking place in an orifice of said device, securing the other of the outer and inner rings to another rotating device, the projecting part of the pin tacking place in an orifice of said device. The present invention and its advantages will be better understood by studying the detailed description of specific embodiment given by way of non-limiting example and illustrated by the appended drawings on which: Figure 1 is a partial perspective view from the side of a first external face of a rolling bearing, according to an example of the invention, Figure 2 is a partial perspective view from the side of a second external face of the rolling bearing of Figure 1, the second external face being opposite to the first external face, Figure 3 is a partial perspective view of the rolling bearing of Figures 1 and 2, showing the second external face and inner edges, Figure 4 is a partial sectional view of the rolling bearing of Figures 1, 2 and 3. The rolling bearing 10 as illustrated in figures 1, 2, 3 and 4 is a large diameter rolling bearing comprising a first ring 12 and a second ring 14. In the illustrated example, the first ring 12 is an outer ring whereas the second ring 14 is an inner ring. The rolling bearing 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 12, 14 are concentric and extend axially along the bearing rotation axis, not shown, which runs in an axial direction. In the illustrated example, the rings 12, 14 are of the solid type, and the rolling bearing 10 extends longitudinally between a first external face 16 and a second external face 18 opposite to said first external face 18. The outer ring 12 comprises a rolling ring 20 and a sealing ring 22 secured to the rolling ring 20. The inner ring 14 also comprises a rolling ring 24 and a sealing ring 26 secured to the rolling ring 24. The sealing ring 22 of the outer ring 12 radially surrounds the sealing ring 26 of the inner ring 14. Accordingly, the first external face 16 is delimited partly by the rolling ring 20 of the outer ring 12, and partly by the rolling ring 24 of the inner ring 14. The rolling ring 20 and the rolling ring 24 are optionally flush or offset axially. In the same spirit, the second external face 18 is delimited partly by the sealing ring 22 of the outer ring, and partly by the sealing ring 26 of the inner ring 14. The sealing ring 22 and the sealing ring 26 are optionally flush or offset axially. A plurality of successive seals, not referenced, is radially provided between the sealing rings 22, 26. In the illustrated example, the rolling bearing 10 also comprises two rows of balls, not referenced, which are arranged between first raceways of the rolling ring 20 of the outer ring 12 and second raceways of the rolling ring 24 of the inner ring 14. The sealing ring 22 of the outer ring 12 is mounted axially into contact against the rolling ring 20. The sealing ring 22 protrudes axially with regard to the rolling ring 20. The sealing ring 22 is reversely attached or secured to the rolling ring 20. The sealing ring 22 radially surrounds the sealing ring 26 of the inner ring 14. Each of the sealing rings 22, 26 may be made of stainless steel or treated steel with a painting or anti-corrosion treatment. In the illustrated example, the sealing ring 22 is formed as a split ring and comprises first 30, second 32, third 34, fourth 36 and fifth 38 part rings stacked one relative to the other in the axial direction. Alternatively, the sealing ring 22 can include more or less rings. The fifth part ring 38 is an end ring, and the second 32, the third 34 and the fourth 36 rings are intermediate rings. The first part ring 30 is reversely secured to the rolling ring 20 by screws, not shown, spaced apart in the circumferential direction. The first part ring 30 axially abuts against the rolling ring 20. Similarly, the second part ring 32 is reversely secured to the first part ring 30 by screws, not shown, axially on the side opposite to the rolling ring 20. The third part ring 34 is reversely secured to the second part ring 32 by screws axially on the side opposite to the first part ring 30. The fourth part ring 36 is reversely secured to the third part ring 34 by screws axially on the side opposite to the second part ring 32. The fifth part ring 38 is reversely secured to the fourth part ring 36 by screws axially on the side opposite to the third part ring 34. The heads of the screws of the first part ring 30 may be recovered by potting material and embedded inside this material. Hence, the associated threads of the screws are sealed. Figure 1 shows that the outer ring 12 has a longitudinal hole 40, said hole 40 opening out at the first face 16 of the rolling bearing 10, at least one edge 42 of the outer ring 12 having a longitudinal mark 44, said hole 40 and said mark 44 of the outer ring 12 being separated by an angle a. The hole 40 is parallel to the longitudinal axis of the rolling bearing 10. The edge 42 can be an outer peripheral surface of the rolling ring 20. The longitudinal mark 44 is a groove but, alternatively, it could be a series of dots, a coloured inscription, or any equivalent. In a non-limiting manner, the value of the angle a is 0°, which means that the hole 40 and the mark 44 are both contained in a same longitudinal plane of the rolling bearing 10 containing the longitudinal axis of rotation. Nevertheless, the value of the angle a could be different, for example a few degrees. In this case the hole 40 and the mark 44 would be offset angularly. Figure 3 shows that the inner ring 14 has a longitudinal hole 50, said hole 50 opening out at the second external face 18 of the rolling bearing 10, at least one edge 52 of the inner ring 14 having a longitudinal mark 54, said hole 50 and said mark 54 of the inner ring 14 being separated by an angle p. The hole 50 is parallel to the longitudinal axis of the rolling bearing 10. The edge 52 can be an inner peripheral surface of the rolling ring 24. The longitudinal mark 54 is a groove but, alternatively, it could be a series of dots, a coloured inscription, or any equivalent. In a non-limiting manner, the value of the angle P is a few degrees, for example three, which means that the hole 50 and the mark 54 are offset. In view of figures 1, 2, 3, the hole 40 of the outer ring 12 and the hole 50 of the inner ring 14 are separated by an angle y when the marks 44, 54 of the outer ring 12 and the inner ring 14 are contained in a same longitudinal plane passing through the longitudinal axis. The angles a and P are measured according to the same direction of rotation, and the angle y is P minus a. Because the angles a and P are known, the angle y is also known. Accordingly, two pins each placed in a hole 40, 50 are separated by said known angle y. For example, in a non-limitative way, the value of angle y can be 3°. As a result, the placing of each ring 12, 14 on a part of a device is easier. Effectively, each pin has a protruding part which takes place in a hole of the device. Said two holes which receive the protrusions of the pins are offset by an angle value y. This allows easy positioning of the outer 12 and inner 14 rings in the device. Thanks to the holes 40, 50 with pins, the angular position of the outer 12 and inner 14 rings is correct. Always in the illustrated example, in view of figures 1 and 2, each part ring 30, 32, 34, 36, 38 has a longitudinal through hole, not shown, located on a first diameter ¢1, each outer peripheral edge 60, 62, 64, 66, 68 of each part ring 30, 32, 34, 36, 38 having respectively a longitudinal mark 70, 72, 74, 76, 78, the through hole and the mark of an outer peripheral edge being separated by the angle a. The first rolling ring 20 of the outer ring 12 has a longitudinal through hole, not shown, located on the first diameter ¢1, the outer peripheral edge 42 of the first rolling ring 20 having the longitudinal mark 44 as seen before, said through hole and said mark 44 of the outer peripheral edge 42 being separated by the angle a. All of the through holes in the part rings 30, 32, 34, 36, 38 and the through hole in the first rolling ring 20 are aligned and form the hole 40 opening out at the first face 16 of the rolling bearing 10, when all the marks 70, 72, 74, 76, 78, 44 of the part rings 30, 32, 34, 36, 38 and the first rolling ring 20 are aligned. As a result, a pin prevents all rings from rotating relative to each other, when said pin is in place in the hole 40 opening out at the first face of the rolling bearing. In a non-limiting manner, two of the intermediate rings 32, 34 are twin rings having the same design. In other words, the twin rings 32, 34, have the same structure. Each twin ring 32, 34 has two longitudinal through holes, said two through holes being on the first diameter ¢1 and being separated by the angle y. Each twin ring 32, 34 respectively has the first mark 72, 74 at the level of one of the through holes and a second mark 82, 84 at the level of the other of the through holes, the twin rings 32, 34 being adjacent and offset. This simplifies the structure of the rolling bearing. Figure 2 shows that the end ring 38 of the first sealing ring 22 has a radial mark 86 contained in a longitudinal plane passing through the longitudinal axis, said longitudinal plane containing the mark 78 of the outer peripheral edge 68 of the end ring 38. Figure 3 shows that the second sealing ring 26 of the inner ring 14 has one longitudinal mark 88 and the second rolling ring 24 of the inner ring 14 has one longitudinal mark 54, said mark 54 being the longitudinal mark of the inner ring 14 seen before. Both longitudinal marks 88, 54 are contained in a longitudinal plane passing through the longitudinal axis, the hole 50 opening out at the second face 18 of the rolling bearing 10 being on a second diameter ¢2, said hole 50 and said two longitudinal marks 88, 54 being separated by the angle p. Accordingly, the position of a pin in place in the hole 50 opening out at the second face 18 is known. The second sealing ring 26 of the inner ring 14 has a radial mark 90 contained in the longitudinal plane which contains the longitudinal marks 88, 54. The angle value a is 0°, the angle value P is 3°, and the angle value y is 3°. With these values, very good results have been obtained. In the described example, the rolling bearing 10 comprises two rows of rolling elements. Alternatively, the rolling bearing 10 may comprise only one row of rolling elements, or three or more rows of rolling elements. The rolling elements can be balls, rollers, or else. All marks are grooves, but could alternately be color marks, ribs, rows of dimples, or whatever.

Claims

1. Rolling bearing (10) comprising an outer ring (12) and an inner ring (14) capable of rotating concentrically relative to one another about a longitudinal axis, at least one row of rolling elements being arranged between said outer (12) and inner (14) rings, the rolling bearing (10) being provided with a first external face (16) and a second external face (18) axially opposite to said first external face (16) which delimit the axial length of the bearing, characterized in that:- the outer ring (12) has a longitudinal hole (40), said hole (40) opening out at the first external face (16) of the rolling bearing (10),- at least one edge (42, 60, 62, 64, 66, 68) of the outer ring (12) has a longitudinal mark (44, 70, 72, 74, 76, 78),- said hole (40) and said mark (44, 70, 72, 74, 76, 78) of the outer ring (12) are separated by an angle a,- the inner ring (14) has a longitudinal hole (50), said hole (50) opening out at the second external face (18) of the rolling bearing (10),- at least one edge (52) of the inner ring (14) has a longitudinal mark (54),- said hole (50) and said mark (54) of the inner ring (14) are separated by an angle p,- said hole (40) of the outer ring (12) and said hole (50) of the inner ring (14) are separated by an angle y when the marks (44, 54, 70, 72, 74, 76, 78) of the outer ring (12) and the inner ring (14) are contained in a same longitudinal plane passing through the longitudinal axis.

2. Rolling bearing (10) according to claim 1, wherein the outer ring (12) comprises at least a first rolling ring (20) and at least one first sealing ring (22) secured to the first rolling ring (20), the inner ring (14) comprising at least one second rolling ring (24) and at least one second sealing ring (26) secured to the second rolling ring (24).

3. Rolling bearing (10) according to claim 2, wherein the first sealing ring (22) of the outer ring (12) is formed as a split ring and comprises at least two part rings (30, 32, 34, 36, 38), the part ring (38) farthest from the rolling ring (20) being an end ring, each part ring (30, 32, 34, 36, 38) having a longitudinal through hole located on a first diameter (¢1), an outer peripheral edge (60, 62, 64, 66, 68) of each part ring (30, 32, 34, 36, 38) having a longitudinal mark (70, 72, 74, 76, 78), said through hole and said mark (70, 72, 74, 76, 78) of the outer peripheral edge (60, 62, 64, 66, 68) being separated by the angle a, the first rolling ring (20) of the outer ring (12) having a longitudinal through hole located on the first diameter (¢1), an outer peripheral edge (42) of the first rolling ring (20) having a longitudinal mark (44), said through hole and said mark (44) of the outer peripheral edge (42) being separated by the angle a, all of the through holes in the part rings (30, 32, 34, 36, 38) and the through hole in the first rolling ring (20) being aligned and forming the hole (40) opening out at the first face (16) of the rolling bearing (10), when all the marks (70, 72, 74, 76, 78, 44) of the part rings (30, 32, 34, 36, 38) and the first rolling ring (20) are aligned.

4. Rolling bearing (10) according to claim 3, wherein two (32, 34) of the part rings (30, 32, 34, 36, 38) are twin rings having the same design, each twin ring (32, 34) having two longitudinal through holes, said two through holes being on the first diameter (¢1) and being separated by the angle y, each twin ring (32, 34) having a first mark (72, 74) at the level of one of the through holes and a second mark (82, 84) at the level of the other of the through holes, the twin rings (32, 34) being adjacent and offset.

5. Rolling bearing (10) according to any of claims 2 to 4, wherein the end ring (38) of the first sealing ring (22) has a radial mark (86) contained in a longitudinal plane passing through the longitudinal axis, said longitudinal plane containing the mark (78) of the outer peripheral edge (68) of the end ring (38).

6. Rolling bearing (10) according to any of claims 2 to 5, wherein the first sealing ring (22) of the outer ring (12) includes five part rings (30, 32, 34, 36, 38).

7. Rolling bearing (10) according to any of claims 2 to 6, wherein the second sealing ring (26) of the inner ring (14) has one longitudinal mark (88) and the second rolling ring (24) of the inner ring (14) has one longitudinal mark (54), said longitudinal marks (88, 54) being contained in a longitudinal plane passing through the longitudinal axis, the hole (50) opening out at the second face (18) of the rolling bearing (10) being on a second diameter (¢2), said hole (50) and said two longitudinal marks (88, 54) being separated by the angle p.

8. Rolling bearing (10) according to claim 7, wherein the second sealing ring (26) of the inner ring (14) has a radial mark (90) contained in the longitudinal plane which contains the longitudinal marks.

9. Rolling bearing (10) according to any of the preceding claims, wherein the angle value (a) is 0°, the angle value (P) is 3°, and the angle value (y) is 3°.

10. Mounting method of a rolling bearing (10) according to any of the preceding claims, the method comprising the following steps :- placing a pin in the longitudinal hole (40) of the outer ring (12) so that said pin protrudes,- placing another pin in the longitudinal hole (50) of the inner ring (14) so that said pin protrudes,- positioning the outer ring (12) relative to the inner ring (14) so that their respective marks (44, 54, 70, 72, 76, 78, 84, 86, 88, 90) are contained in a same longitudinal plane passing through the longitudinal axis,- securing one of the outer (12) and inner (14) rings to a rotating device, the projecting part of a pin taking place in an orifice of said device,- securing the other of the outer (12) and inner (14) rings to another rotating device, the projecting part of the pin taking place in an orifice of said device.

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