Bearings with distance sensor and tapered groove

Abstract

A bearing with a distance sensor and a tapered groove, the bearing comprising a first ring (10) and a second ring (12) which are rotatable concentrically relative to each other. At least one first tapered groove (50) and at least one second tapered groove (52) are formed on the second ring and oriented toward the first ring (10). The bearing further comprises: at least one first distance sensor (24) mounted on the first ring and facing the tapered wall (50a) of the first tapered groove of the second ring; and at least one second distance sensor (25) mounted on the first ring and facing the tapered wall (52a) of the second tapered groove of the second ring, the tapered wall (50a) of the first tapered groove and the tapered wall (52a) of the second tapered groove extending obliquely in opposite directions.

Description

Technical Field

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

[0002] The invention relates in particular to the field of large-diameter rolling bearings which can accommodate axial and radial loads and have an inner ring and an outer ring which are arranged concentrically about an axis of rotation running in the axial direction. Background Art

[0003] Such large-diameter rolling bearings can be used, for example, in tunnel boring machines, mining extraction machines or wind turbines.

[0004] A large diameter rolling bearing comprises two concentric inner and outer rings and at least two rows of rolling elements (such as rollers) arranged between the inner and outer rings. Such rolling bearings are usually subjected to often relatively large loads in the axial direction and in the radial direction. In this case, it is a directional roller bearing or a slew roller bearing.

[0005] Due to the heavy loads, the components of the rolling bearing, more particularly the raceways of the rolling elements, wear. The wear of the raceways and rolling elements leads to a significant increase in the initial bearing clearance. Wear exceeding a certain value can lead to severe bearing failure.

[0006] Measuring bearing wear through the relative axial and radial displacement of the rings due to increased clearance helps predict the remaining life of the bearing.

[0007] This unwanted movement affects the proper functioning of the bearing and the application and carries the risk of the bearing rings coming into contact and colliding. Other elements attached to the bearing rings may also collide.

[0008] Bearings are usually replaced when they are worn. Such maintenance interventions are expensive, especially because the machine or facility needs to be shut down. It is therefore desirable to perform such maintenance interventions in good time, before any contact between the bearing rings occurs, but not too early.

[0009] In order to monitor the bearing condition during its service life, the rolling bearing disclosed in patent application FR-A1-3041396 comprises an annular magnetic target fixed to the inner ring and a sensor mounted on the outer ring and facing the magnetic target. Thus, the axial and angular relative movements between the inner and outer rings can be detected.

[0010] However, this requires that the annular magnetic target be mounted on an inner ring which may be several meters in diameter.

[0011] Furthermore, when using such a magnetic target, the measurement of the axial displacement between the inner and outer rings is affected by the radial displacement. In fact, when measuring the axial displacement of a magnetic target, the gap ( / airgap) between the target and the sensor changes with the radial relative motion between the rings, making the measurement less accurate or even impossible to measure. Summary of the invention

[0012] It is an object of the present invention to overcome these disadvantages.

[0013] The invention relates to a bearing comprising a first ring and a second ring which are rotatable concentrically relative to each other.

[0014] According to a general feature, at least a first tapered groove and at least a second tapered groove are formed on the second turn and are oriented towards the first turn.

[0015] According to another general feature, the bearing further comprises at least one first distance sensor mounted on the first ring and facing a tapered wall of a first tapered groove of the second ring, the tapered wall of the first tapered groove being inclined relative to the axis of the bearing. The longitudinal axis of the first distance sensor is perpendicular to the tapered wall of the first tapered groove.

[0016] According to another general feature, the bearing further comprises at least one second distance sensor mounted on the first ring and facing the conical wall of the second conical groove of the second ring, the conical wall of the second conical groove being inclined relative to the axis of the bearing. The longitudinal axis of the second distance sensor is perpendicular to the conical wall of the second conical groove.

[0017] The tapered wall of the first groove and the tapered wall of the second groove extend obliquely in two opposite directions.

[0018] Thanks to the invention, the axial and radial relative displacements between the rings can be detected accurately. In fact, the combination of the signals of at least two distance sensors allows these axial and radial relative displacements to be calculated. Moreover, since each of the first and second distance sensors detects a surface perpendicular to its longitudinal axis, the sensitivity and linearity of the measurement are improved.

[0019] In addition, there is no need to mount an annular magnetic target on one of the first and second rings. The first groove and the second groove can be easily machined (obtained) on the associated ring.

[0020] The tapered wall of each tapered groove may be the tapered bottom of the groove or any other tapered portion of the groove.

[0021] Preferably, each of the first tapered groove and the second tapered groove of the second ring is annular.Therefore, the axial relative displacement and the radial relative displacement between the rings can be detected regardless of the rotational position of the rings.

[0022] In one embodiment, the tapered wall of the second tapered groove is at least partially symmetrical to the tapered wall of the first tapered groove relative to a radial plane of the bearing.

[0023] Advantageously, the second tapered groove may extend axially from the first tapered groove. Thus, machining of the first groove and the second groove may be accomplished in one single operation.

[0024] In one embodiment, the tapered wall of the second tapered groove may extend the tapered wall of the first tapered groove.

[0025] In one embodiment, the first ring comprises a single through-hole, and the first distance sensor and the second distance sensor are at least partially arranged inside the single through-hole. Advantageously, the bearing may further comprise a casing, which supports the first distance sensor and the second distance sensor and is mounted inside the through-hole of the first ring.

[0026] Thus, the first distance sensor and the second distance sensor can first be mounted on the sleeve, then inserted into the associated through-hole and configured in their final position in an easy manner.Preferably, the sleeve seals the through-hole.

[0027] The through hole of the first ring may extend radially from an axial cylindrical surface (located radially on a side opposite to the second ring) and open on an opposite axial cylindrical surface of the first ring (facing radially the second ring).

[0028] Advantageously, the bearing further comprises a control unit connected to the first distance sensor and the second distance sensor and adapted to calculate the values ​​of the relative axial displacement Da and the relative radial displacement Dr between the first ring and the second ring based on the following formula:

[0029]

[0030]

[0031] in:

[0032] ΔS24 is the differential measurement value of the first distance sensor to the tapered wall of the first tapered groove,

[0033] ΔS25 is the differential measurement value of the second distance sensor to the tapered wall of the second tapered groove,

[0034] β is the value of the first taper angle of the tapered wall of the first groove,

[0035] α is the value of the second taper angle of the tapered wall of the second groove, and

[0036] and

[0037] In one embodiment, a first taper angle of the tapered wall of the first groove is different from a second taper angle of the tapered wall of the second groove.

[0038] In an alternative embodiment, the conical wall may have a first cone angle and a second cone angle that are equal. In this case, the relative axial displacement Da and the relative radial displacement Dr between the first circle and the second circle may be calculated based on the following formula:

[0039]

[0040]

[0041] in:

[0042] β is the value of the first taper angle of the tapered wall of the first groove and the value of the second taper angle of the tapered wall of the second groove.

[0043] The control unit may be located remotely from the components of the bearing. As an option, the control unit may be mounted on one of the components of the bearing (eg, the first ring or the second ring).

[0044] In one embodiment, the first distance sensor and the second distance sensor are spaced apart from each other in a circumferential direction.

[0045] In one embodiment, the bearing further comprises at least one row of rolling elements, and the at least one row of rolling elements is arranged between the raceway provided on the first ring and the raceway provided on the second ring.

[0046] The bearing may further include a first seal and a second seal which are arranged between the first ring and the second ring and together define a closed rolling space inside which the row of rolling elements and the first and second distance sensors are accommodated.

[0047] In one embodiment, the bearing may further include at least one additional seal, which is positioned inside the closed rolling space and defines a closed detection space together with one of the first seal and the second seal, and the first conical groove and the second conical groove are open inside the closed detection space.

[0048] In one embodiment, the bearing comprises at least one row of axial rolling elements and at least one row of radial rolling elements, the at least one row of axial rolling elements being arranged between radial raceways provided on the rings, the at least one row of radial rolling elements being arranged between axial raceways provided on the rings, the second ring comprising a protruding nose engaging in an annular groove of the first ring and protruding from an axial surface of the second ring. The axial raceway of the second ring may be formed onto the second axial cylindrical surface.

[0049] Preferably, the first and second tapered grooves are formed into said axial cylindrical surface of the second ring, from which the nose projects.

[0050] The term "axial rolling elements" is understood to mean rolling elements adapted to accommodate axial loads, whereas the term "radial rolling elements" is understood to mean rolling elements adapted to accommodate radial loads.

[0051] The protruding nose of the second ring may also be provided with two opposite radial flanks delimiting the axial cylindrical surface in axial direction, one of the radial flanks at least partially delimiting the radial raceway of the second ring.

[0052] In one embodiment, the bearing comprises at least two rows of axial rolling elements, each axial rolling element being arranged between radial raceways provided on the ring, the two rows of axial rolling elements being arranged axially on both sides of the nose of the second ring.

[0053] In one embodiment, the first distance sensor and / or the second distance sensor may be a contactless measurement sensor, ie, a proximity sensor, such as an inductive sensor, an ultrasonic sensor, or an optical sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The 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:

[0055] Figure 1 is a partial cross section of a rolling bearing according to a first example of the present invention, and

[0056] Figure 2 yes Figure 1 Detailed view of

[0057] Figure 3 yes Figure 1 Detailed view of a bearing showing schematically the axial displacement of one ring relative to the other.

[0058] Figure 4 yes Figure 1 A detailed view of a bearing schematically showing the radial displacement of one ring relative to the other, and

[0059] Figure 5 is a detailed view of a rolling bearing according to a second example of the present invention. DETAILED DESCRIPTION

[0060] like Figure 1 The rolling bearing shown 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 an outer ring and the second ring 12 is an inner ring. The rolling bearing can be used, for example, in tunnel boring machines, wind turbines or in any other application where large-diameter rolling bearings are used.

[0061] The outer ring 10 and the inner ring 12 are concentric and extend axially along a bearing rotation axis XX' which runs in the axial direction. The rings 10, 12 are of solid type.

[0062] The outer ring 10 is formed as a split ring and includes a first ring 14 and a second ring 16 stacked relative to each other in the axial direction. Each of the first ring 14 and the second ring 16 of the outer ring is provided with a plurality of aligned through holes (not shown) to be engaged by assembly bolts.

[0063] In the example shown, the rolling bearing comprises two rows of axial rollers 18 , 20 arranged between the outer ring 10 and the inner ring 12 to create an axial thrust, and a row of radial rollers 22 arranged between the rings to create a radial thrust.

[0064] As will be described later, the rolling bearing further includes a first distance sensor 24 and a second distance sensor 25 for detecting axial and radial relative displacements between the outer ring 10 and the inner ring 12. In the example shown, the sensors 24 and 25 are mounted on the outer ring 10.

[0065] The rollers 18, 20, 22 of a row are identical to one another. Each roller 18, 20, 22 comprises a cylindrical outer rolling surface and two opposite frontal end surfaces delimiting said outer rolling surface. The axis of rotation of each roller 22 is parallel to the axis XX' of the bearing and perpendicular to the axis of each roller 18, 20. In the example shown, the axial length of the roller 18 is greater than the axial length of the roller 20. As an alternative, the axial length of the roller 18 may be less than or may be equal to the axial length of the roller 20.

[0066] The rollers 18 are axially arranged between an annular radial raceway 26 formed on the inner ring 12 and an annular radial raceway 28 formed on the outer ring 10. Each radial raceway 26, 28 has a straight inner profile in cross section that contacts the rolling surface of the rollers 18. The raceways 26, 28 face each other in the axial direction.

[0067] The rollers 20 are arranged axially between an annular radial raceway 30 formed on the inner ring 12 and an annular radial raceway 32 formed on the outer ring 10. Each radial raceway 30, 32 has a straight inner profile in cross section that contacts the rolling surface of the rollers 20. The raceways 30, 32 face each other in the axial direction. The rows of rollers 18 and the rows of rollers 20 are spaced apart from each other in the axial direction.

[0068] The rollers 22 are arranged radially between an annular axial raceway 34 formed on the inner ring 12 and an annular axial raceway 36 formed on the outer ring 10. Each axial raceway 34, 36 has a straight inner profile in cross section that contacts the rolling surface of the roller 22. The raceways 34, 36 face each other in the radial direction. The row of rollers 22 is offset outwardly in the radial direction relative to the row of rollers 18 and the row of rollers 20. The row of rollers 22 is located between the row of rollers 18 and the row of rollers 20 in the axial direction.

[0069] The outer ring 10 comprises an annular groove 38 which opens radially inwardly towards the inner ring 12. The outer ring 10 comprises a stepped cylindrical inner surface or hole 10a from which the groove 38 is formed. The outer ring 10 also comprises a cylindrical outer surface 10b radially opposite to the hole 10a. The outer ring 10 also comprises two opposite radial front surfaces 10c, 10d which axially delimit the hole 10a and the outer surface 10b of the ring.

[0070] The inner ring 12 comprises an annular protruding nose 40 which engages in the annular groove 38 of the outer ring. The nose 40 extends radially outwards.

[0071] The inner ring 12 comprises a cylindrical inner hole 12a and a stepped cylindrical outer surface 12b radially opposite to the hole 12a. In the example shown, the hole 12a of the inner ring is provided with gear teeth (gear teeth) (not shown). The inner ring 12 also comprises two opposite radial front surfaces 12c, 12d that axially define the hole 12a and the cylindrical outer surface 12b. The protruding nose 40 protrudes radially from the cylindrical outer surface 12b.

[0072] The rows of rollers 18 and 20 are arranged axially between the nose 40 of the inner ring and the groove 38 of the outer ring. The rows of rollers 18 and 20 are arranged on both sides of the nose 40 of the inner ring. The radial raceway 26 is located on the nose 40 and on the radial portion of the stepped cylindrical outer surface 12b of the inner ring. As an option, the radial raceway 26 can be completely located on the nose 40. The radial raceway 30 is located on the nose 40. The radial raceways 28 and 32 are located on the groove 38 of the outer ring.

[0073] More precisely, the first radial side ( / flank) of the nose 40 partially defines the radial raceway 26 for the roller 18. The first radial side of the groove 38 (the first radial side facing the nose 40 in the axial direction) defines the radial raceway 28 for the roller 18. The second side of the nose 40 and the opposite second side of the groove 38 define the radial raceways 30, 32 for the roller 20, respectively. The opposite first and second sides of the nose 40 define the nose in the axial direction. Similarly, the opposite first and second sides of the groove 38 define the groove in the axial direction. Each of the first and second sides of the nose 40 extends radially from the cylindrical outer surface 12b of the inner ring.

[0074] The rows of rollers 22 are arranged radially between the nose 40 of the inner ring and the groove 38 of the outer ring. The axial raceways 34, 36 are located on the nose 40 and the groove 38, respectively. The cylindrical outer surface of the nose 40 defines the axial raceway 34. The cylindrical outer surface of the nose 40 and the cylindrical outer surface 12b are offset in the radial direction. As a result, the axial raceway 34 and the cylindrical outer surface 12b are also offset in the radial direction. The cylindrical outer surface of the nose 40 extends axially between the opposite radial sides of the nose.

[0075] The axial bottom of the groove 38 defines the axial raceway 36. In the example shown, an annular groove ( / slot) (slot) 41 is formed in the bottom of the groove 38 and defines the axial raceway 36. The axial raceway 36 radially faces the cylindrical outer surface of the nose 40 onto which the axial raceway 34 is formed.

[0076] In the example shown, the inner ring 12 is made in one part. As an alternative, the inner ring 12 can be divided in the axial direction into at least two separate parts fixed together. In another variant, the nose 40 can be made separately from the main part of the inner ring.

[0077] As mentioned before, the outer ring 10 is divided in the axial direction into two separate parts, namely the first ring 14 and the second ring 16. The first ring 14 and the second ring 16 together define the groove 38. The radial raceway 28 is located on the first ring 14 and the radial raceway 32 is located on the second ring 16 of the outer ring.

[0078] The rolling bearing also comprises annular seals 42, 44 on both sides mounted on the inner ring 12 and arranged to close the radial space present between the rings 10, 12. This radial space is defined between the bore 10a of the outer ring and the cylindrical outer surface 12b of the inner ring and the outer surface of the nose 40.

[0079] A closed space 46 is defined between the inner and outer races 12 and 14 and the seals 42 , 44 , and the rows of rolling elements 18 , 20 , and 22 and the first and second distance sensors 24 , 25 are accommodated in the closed space 62 .

[0080] Each seal 42, 44 is mounted in a groove (not shown) formed on the cylindrical outer surface 12b of the inner ring and contacts the outer ring 10. The seal 42 contacts the radial front surface 10c of the outer ring. The seal 44 contacts the hole 10a of the outer ring near the row of rollers 18 in the axial direction. As an option, a reverse arrangement can be provided for at least one of the seals 42, 44, wherein the seal is mounted on the outer ring 10 and in frictional contact with the inner ring 12.

[0081] As mentioned above, the first distance sensor 24 and the second distance sensor 25 are arranged to detect the axial relative displacement and the radial relative displacement between the outer ring 10 and the inner ring 12. To this end, a first annular tapered groove 50 and a second annular tapered groove 52 are also formed on the inner ring 12. In the example shown, the grooves 50, 52 are formed on the cylindrical outer surface 12b of the inner ring.

[0082] like Figure 2 As shown more clearly in FIG. 1 , the first groove 50 extends radially inwardly from the cylindrical outer surface 12 b of the inner ring. The groove 50 includes an annular tapered portion or wall 50 a extending obliquely inwardly. The tapered wall 50 a has a frustoconical shape. The tapered wall 50 a is oriented with respect to the axis XX′ ( Figure 1) is inclined. In other words, the tapered wall 50a is formed to be inclined relative to the axis XX'. The tapered wall 50a is inclined relative to the axial cylindrical surface 12b of the inner ring. Figure 2 In the radial plane of the rolling bearing shown, a first taper angle β is formed between the tapered wall 50a of the groove and the axial cylindrical surface 12b. For example, the value of the first taper angle β may preferably be comprised between 15° and 30°.

[0083] In the example shown, the groove 50 is provided with an annular radial side wall 50b, which extends radially inwardly from the cylindrical outer surface 12b and from which the tapered wall 50a extends. As an alternative, the groove 50 may not have such a side wall 50b. In this case, the tapered wall 50a extends directly from the axial cylindrical surface 12b of the inner ring.

[0084] The second groove 52 extends radially inward from the cylindrical outer surface 12 b of the inner ring. In the example shown, the second groove 52 extends axially from the first groove 50 .

[0085] The groove 52 includes an annular tapered portion or wall 52a extending obliquely inwardly. The tapered wall 52a has a frustoconical shape. The tapered wall 52a is oriented relative to the axis XX' ( Figure 1 ) is inclined. The tapered wall 52a is inclined relative to the axial cylindrical surface 12b of the inner ring. A second taper angle α is formed between the tapered wall 52a and the axial cylindrical surface 12b. In the example shown, the value of the second taper angle α is equal to the value of the first taper angle β formed between the tapered wall 50a of the first groove and the axial cylindrical surface 12b.

[0086] In the example shown, the second groove 52 is provided with an annular radial side wall 52b, which extends radially inwardly from the cylindrical outer surface 12b and from which the tapered wall 52a extends. As an alternative, the groove 52 may not have such a side wall 52b. In this case, the tapered wall 52a extends directly from the axial cylindrical surface 12b of the inner ring.

[0087] As mentioned above, in the example shown, the second groove 52 extends axially from the first groove 50. Here, the tapered wall 52a of the second groove extends from the tapered wall 50a of the first groove. As an option, the cylindrical bottom can connect the tapered walls 50a, 52a to each other.

[0088] From the cylindrical outer surface 12 b of the inner race, the tapered wall 50 a of the groove 50 extends obliquely inwardly in a first direction, and the tapered wall 52 a of the groove 52 extends obliquely inwardly in a second direction opposite to the first direction.

[0089] In the example shown, the tapered wall 50a extends from the cylindrical outer surface 12b of the inner ring to the front surface 12d ( Figure 1 ) extends obliquely, while the tapered wall 52a extends obliquely toward the front surface 12c.

[0090] In the example shown, the tapered wall 52a of the groove 52 is symmetrical to the tapered wall 50a of the groove 50 with respect to a radial plane passing through the edge between said walls. More generally, the groove 52 is symmetrical to the groove 50 with respect to said radial plane.

[0091] The first distance sensor 24 faces the first groove 50. The sensor 24 faces the tapered wall 50a of the groove. The sensor 24 measures the distance to the tapered wall 50a. The second distance sensor 25 faces the second groove 52. The sensor 25 faces the tapered wall 52a of the groove. The sensor 25 measures the distance to the tapered wall 52a.

[0092] Refer again Figure 1 The outer ring 14 is provided with a radial through hole ( / through hole) 54, and the first distance sensor 24 and the second distance sensor 25 are located inside the radial through hole 54. The through hole 54 extends from the outer surface 10b of the outer ring and opens on the hole 10a. The through hole 54 faces the first groove 50 and the second groove 52 of the inner ring in the radial direction.

[0093] In the example shown, each of the sensors 24, 25 is mounted into the through hole 54 and radially protrudes into the radial space provided between the outer ring 10 and the inner ring 12. The sensor 24 also protrudes into the first groove 50. The sensor 24 remains spaced apart from the tapered wall 50a of the groove. Similarly, the sensor 25 also protrudes into the second groove 52. The sensor 25 remains spaced apart from the tapered wall 52a of the groove. As an alternative, the sensors 24, 25 may be completely located inside the through hole 54.

[0094] The outer ring 10 also includes a casing 56 that closes and seals the through hole 54. The casing 56 also supports the sensors 24, 25. The sensors 24, 25 are fixed to the casing 56 by any suitable means. The casing 56 is radially positioned into the through hole 54. The casing 56 is fixed inside the through hole 54 by any suitable means, for example, the casing 56 is fixed inside the through hole 54 by force-fitting. The casing 56 is flush with the cylindrical outer surface 10b of the outer ring.

[0095] like Figure 2As more clearly shown above, the first sensor 24 includes a sensor body 58 mounted inside the outer ring sleeve 56. The sensor body 58 faces the tapered wall 50a of the first groove. The sensor body 58 protrudes into the groove 50. The sensor body 58 is kept spaced apart from the tapered wall 50a.

[0096] In the disclosed example, the sensor 24 also includes an output connecting cable 60 for transmitting the sensed data, the output connecting cable 60 extending outward relative to the sensor body 58. The output cable 60 extends radially outward. The sleeve 56 is provided with a through-opening (not shown), wherein the output cable 60 can pass through the through-opening. The output cable 60 connects the sensor 24 to a control unit (not shown) of the rolling bearing to transmit the sensed measurement value. As an option, in the case of a wireless sensor, the sensor 24 may not have such an output cable.

[0097] The sensor body 58 of the first sensor has an obliquely extending longitudinal axis 62. The axis 62 also forms the longitudinal axis of the sensor 24. The axis 62 is perpendicular to the tapered wall 50a of the first groove.

[0098] The second sensor 25 includes a sensor body 64 installed inside the sleeve 56. The sensor body 64 faces the tapered wall 52a of the second groove. The sensor body 64 protrudes into the groove 52. The sensor body 64 is kept spaced apart from the tapered wall 52a.

[0099] In the disclosed example, the sensor 25 also includes an output connection cable 66 for transmitting sensed data, the output connection cable 66 extending outwardly relative to the sensor body 64. The output cable 66 passes through the opening of the sleeve 56. The output cable 66 connects the sensor 25 to the control unit to transmit the sensed measurement values. As an option, in the case of a wireless sensor, the sensor 25 may not have such an output cable.

[0100] The sensor body 64 of the second sensor has an obliquely extending longitudinal axis 68. The axis 68 also forms the longitudinal axis of the sensor 25. The axis 68 is perpendicular to the tapered wall 52a of the second groove.

[0101] Each of the sensors 24, 25 may be an inductive distance sensor, an ultrasonic distance sensor, or an optical distance sensor. Alternatively, each of the sensors 24, 25 may be a mechanical distance sensor provided with a stylus ( / contact stylus). In the latter case, the mechanical sensor faces the tapered wall 50a or 52a of the groove and contacts the tapered wall.

[0102] As mentioned previously, sensor 24 measures the distance to the tapered wall 50a of the first groove of the inner race. The distance is measured along the longitudinal axis 62 of sensor 24. Sensor 25 measures the distance to the tapered wall 52a of the second groove of the inner race. The distance is measured along the longitudinal axis 68 of sensor 25.

[0103] Figure 3 The pure axial displacement of the inner ring 12 relative to the outer ring 10 is schematically and partially shown above. The grooves 50, 52 shown in dashed lines show the position of the inner ring 12 after the axial displacement. The axial displacement Da of the inner ring 12 relative to the outer ring 10 is shown by the arrow referenced 70.

[0104] The arrow labeled 72 shows a first distance from the tapered wall 50a of the groove measured by the sensor 24 before the axial displacement of the inner ring 12 relative to the outer ring 10. The second distance from the tapered wall 50a of the groove measured by the sensor 24 after the axial displacement is shown by the arrow labeled 74.

[0105] The displacement ΔM of the tapered wall 50a of the groove relative to the outer ring 10 detected by the sensor 24 is indicated by the arrow referenced 76. The value of the relative displacement ΔM is equal to the differential measurement of the sensor 24, ie the difference between the second distance measured by the sensor 24 and the first distance.

[0106] In the case of pure axial displacement of the inner ring 12 relative to the outer ring 10 (eg Figure 3 As shown), the displacement ΔM of the conical wall 50a of the groove relative to the outer ring 10 is also equal to:

[0107] ΔM=Da×sinβ, wherein Da is the value of the axial displacement of the inner ring 12 relative to the outer ring 10, and β is the value of the first taper angle of the tapered wall 50a of the first groove.

[0108] Figure 4 Schematically and partially shown above is a pure radial displacement of the inner ring 12 relative to the outer ring 10 . The radial displacement Dr of the inner ring 12 relative to the outer ring 10 is shown by the arrow referenced 80 .

[0109] The arrow labeled 82 shows a first distance from the tapered wall 50a of the groove measured by the sensor 24 before the radial displacement of the inner ring 12 relative to the outer ring 10. A second distance from the tapered wall 50a of the groove measured by the sensor 24 after the radial displacement is shown by the arrow labeled 84.

[0110] The displacement ΔM of the tapered wall 50a of the groove relative to the outer ring 10 detected by the sensor 24 is represented by the arrow referenced 86. The value of the relative displacement ΔM is equal to the differential measurement of the sensor 24.

[0111] In the case of pure radial displacement of the inner ring 12 relative to the outer ring 10 (eg Figure 4 As shown), the displacement ΔM of the conical wall 50a of the groove relative to the outer ring 10 is also equal to:

[0112] ΔM=Dr×cosβ, wherein Dr is the value of the radial displacement of the inner ring 12 relative to the outer ring 10, and β is the value of the first taper angle of the wall 50a of the first groove.

[0113] In the case of a combined axial and radial displacement of the inner ring 12 relative to the outer ring 10 and taking into account the signal S emitted by the first sensor 24 24 is a linear function of the distance measured by the sensor, so the differential measurement of the sensor ΔS 24 By ΔS 24 =Dr×cosβ+Da×sinβ definition.

[0114] Similarly, regarding the second sensor 25 facing the tapered wall 52a of the second groove, the differential measurement value ΔS of the second sensor is 25 By ΔS 25 =Dr×cosα-Da×sinα, where α is the value of the second taper angle of the groove wall 52a.

[0115] As mentioned previously, in the example shown, the value of this second cone angle α is equal to the value of the first cone angle β formed between the conical wall 50a of the first groove and the axial cylindrical surface 12b.

[0116] Thus, in this particular example, the differential measurement value ΔS of the second sensor 25 25 Also by ΔS 25 =Dr×cosβ-Da×sinβ definition.

[0117] Therefore, the axial displacement Da and radial displacement Dr of the inner ring 12 relative to the outer ring 10 are equal to:

[0118]

[0119]

[0120] Thus, the axial and radial displacements of the inner ring 12 relative to the outer ring 10 can be calculated from the displacements measured by the sensors 24, 25. Advantageously, the control unit of the rolling bearing calculates these axial and radial displacements of the inner ring 12 relative to the outer ring 10.

[0121] Refer again Figure 1 and Figure 2In the example shown, the rolling bearing further comprises an additional seal 90, which is arranged inside the closed space 46 defined by the seals 42 and 44. The seal 90 is positioned near the seal 42 in the axial direction. The seal 90 is arranged axially between the seal 42 and the axial roller 20 row. In the example shown, the seal 90 is installed in a groove (not shown) formed on the cylindrical outer surface 12b of the inner ring and is in contact with the outer ring 10. The seal 90 is in contact with the hole 10a of the outer ring near the through hole 54. As an option, the seal 90 can be installed on the outer ring 14 and in friction contact with the inner ring 12.

[0122] Located radially between the outer ring 10 and the inner ring 12, the seal 90 defines a closed detection space (not shown) together with the seal 42, inside which the first groove 50 and the second groove 52 of the inner ring and the through hole 54 of the outer ring open. Only the grooves 50, 52, the through hole 54 and the sensors 24, 25 are positioned inside the detection space. There are no rows of rollers inside the detection space. This reduces the risk of contaminants such as grease, dust, and water reaching the sensors 24, 25.

[0123] Figure 5 The example shown (in which like parts are given like reference numerals) differs from the first example only in that the value of the first taper angle β (formed between the tapered wall 50a of the first groove and the axial cylindrical surface 12b) is different from the value of the second taper angle α (formed between the tapered wall 52a of the second groove and the axial cylindrical surface 12b).

[0124] Therefore, in this case, the axial displacement Da and radial displacement Dr of the inner ring 12 relative to the outer ring 10 are equal to:

[0125]

[0126]

[0127] in:

[0128] and

[0129] In the example shown, the tapered grooves 50, 52 are formed on the cylindrical outer surface 12b of the inner ring, axially between the axial roller row 20 and the seal 42. As an alternative, depending on the design of the rolling bearing, the grooves 50, 52 may be provided on another region of the cylindrical outer surface 12b or on the cylindrical outer surface of the nose of the inner ring.

[0130] In the example shown, the tapered grooves 50, 52 are connected together. In other words, the second groove 52 extends axially from the first groove 50. In another variation, the tapered grooves 50, 52 can be spaced axially relative to each other. The tapered grooves 50, 52 can be arranged on the same cylindrical outer surface of the inner ring, or on two different axial cylindrical surfaces of the inner ring (e.g., the cylindrical outer surface 12b of the inner ring and the cylindrical outer surface of the nose).

[0131] Furthermore, as mentioned previously, in the example shown, the first ring of the rolling bearing is the outer ring 10 and the second ring is the inner ring 12 .

[0132] As an alternative, a reverse arrangement can be provided, in which the first ring forms the inner ring and the second ring forms the outer ring. In this case, each of the tapered grooves 50, 52 is formed on the axial cylindrical inner surface of the outer ring (which forms the bore of the outer ring), and the sensors 24, 25 are mounted on the inner ring.

[0133] In the example described, the rolling bearing is provided with three rows of rolling elements. As an alternative, the rolling bearing may comprise only one row of rolling elements, or two rows of rolling elements, or four or more rows of rolling elements. In the example shown, the rolling elements are rollers. The rolling bearing may comprise other types of rolling elements, for example, balls. In another variant, the bearing may also be a sliding bearing without rolling elements.

Claims

1. A bearing comprising a first ring (10) and a second ring (12) which are rotatable concentrically relative to each other, characterized in that: At least one first tapered groove (50) and at least one second tapered groove (52) are formed on the second ring and are oriented toward the first ring (10), and the bearing further comprises: at least one first distance sensor (24) mounted on the first ring and facing the conical wall (50a) of the first conical groove of the second ring, the conical wall (50a) of the first conical groove being inclined relative to the axis (XX') of the bearing, the longitudinal axis (62) of the first distance sensor (24) being perpendicular to the conical wall (50a) of the first conical groove; and at least one second distance sensor (25) mounted on the first ring and facing the conical wall (52a) of the second conical groove of the second ring, the conical wall (52a) of the second conical groove being inclined relative to the axis (XX') of the bearing, the longitudinal axis (68) of the second distance sensor (25) being perpendicular to the conical wall (52a) of the second conical groove, The tapered wall (50a) of the first tapered groove and the tapered wall (52a) of the second tapered groove extend obliquely in two opposite directions.

2. The bearing according to claim 1, characterized in that: Each of the first tapered groove (50) and the second tapered groove (52) of the second ring is annular.

3. The bearing according to claim 1 or 2, characterized in that: The tapered wall (52a) of the second tapered groove is at least partially symmetrical to the tapered wall (50a) of the first tapered groove relative to a radial plane of the bearing.

4. The bearing according to claim 1 or 2, characterized in that: The second tapered groove (52) extends from the first tapered groove (50) in the axial direction.

5. The bearing according to claim 4, characterized in that: The tapered wall (52a) of the second tapered groove extends the tapered wall (50a) of the first tapered groove.

6. The bearing according to claim 1 or 2, characterized in that: The first ring (10) comprises a single through hole (54), and the first distance sensor (24) and the second distance sensor (25) are at least partially arranged inside the single through hole (54).

7. The bearing according to claim 6, characterized in that The bearing further comprises a sleeve (56) which supports the first distance sensor (24) and the second distance sensor (25) and is mounted inside the through hole (54) of the first ring.

8. The bearing according to claim 1 or 2, characterized in that: The bearing further comprises a control unit connected to the first distance sensor (24) and the second distance sensor (25) and adapted to calculate the values ​​of the relative axial displacement (Da) and the relative radial displacement (Dr) between the first ring and the second ring based on the following formula: in: ΔS 24 is a differential measurement value of the first distance sensor (24) to the tapered wall (50a) of the first tapered groove, ΔS 25 is the differential measurement value of the second distance sensor (25) to the tapered wall (52a) of the second tapered groove, β is the value of the first taper angle of the tapered wall (50a) of the first tapered groove, α is the value of the second taper angle of the tapered wall (52a) of the second tapered groove, and and 9. The bearing according to claim 1 or 2, characterized in that: The bearing further comprises at least one row of rolling elements (18; 22), the at least one row of rolling elements (18; 22) being arranged between raceways (28, 26; 36, 34) provided on the first ring and the second ring.

10. The bearing according to claim 1 or 2, characterized in that: The bearing comprises at least one row of axial rolling elements (18) and at least one row of radial rolling elements (22), the at least one row of axial rolling elements (18) being arranged between a radial raceway (28) provided on the first ring (10) and a radial raceway (26) provided on the second ring (12), the at least one row of radial rolling elements (22) being arranged between an axial raceway (36) provided on the first ring (10) and an axial raceway (34) provided on the second ring (12), the second ring (12) comprising a protruding nose (40), the protruding nose (40) being engaged in an annular groove (38) of the first ring and protruding radially from an axial cylindrical surface (12b) of the second ring, the first tapered groove (50) and the second tapered groove (52) being formed on the axial cylindrical surface (12b).

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