WO2004025307A1

WO2004025307A1 - Instrumented running wheel device

Info

Publication number: WO2004025307A1
Application number: PCT/FR2003/002677
Authority: WO
Inventors: Franck Landrieve
Original assignee: Aktiebolaget Skf
Priority date: 2002-09-13
Filing date: 2003-09-09
Publication date: 2004-03-25
Also published as: FR2844564A1; FR2844564B1; AU2003278289A1

Abstract

The invention concerns an instrumented running wheel comprising a roller (2) mounted rotatable on a shaft (3) via a ball bearing assembly (4) including at least two rows of rolling elements. The device further comprises a housing space (36) defined in the ball bearing assembly (4), and a sensing assembly (37) including an encoder (38) arranged in the housing space (36), and a sensor arranged in the housing space (36) to be opposite the encoder (38), the sensor being designed to be connected via a wire connection (48) to a remote unit, the shaft (3) including a passage (10, 15) for the wire connection (48), the passage (10, 15) emerging on one side of the housing space (36), and on the opposite side outside the housing space (36).

Description

Roller device with instrumented bearing.

The present invention relates to an instrumented roller roller device. A roller generally comprises a fixed part mounted on a support and a mobile part mounted in free rotation on the fixed part and intended to come into contact with an external element while exerting a bearing force on said element. The external part can come into contact for example with a belt, a rail or a drum. The rolling roller device can be used as a tensioning device, for example in the case of a belt, or a guide device.

To control movements of mechanical elements linked to a rolling roller device, a rotation parameter sensor assembly can be placed on the roller, in order to retrieve information relating to the rotation parameters of the roller and to movement parameters ( displacement, rotation, speed, acceleration) of different parts.

An instrumented roller bearing can be brought to bear large radial loads. Furthermore, depending on the environment and the conditions of use, the instrumented roller bearing can be exposed to significant pollution. Furthermore, depending on the application that is made of the instrumented roller bearing, it may be necessary to have a sensor assembly of the parameters of rotation of the roller making it possible to obtain precise measurements of the parameters of rotation of the roller.

The subject of the present invention is an instrumented roller device for recovering signals for measuring precise rotation parameters, while ensuring the protection of a set of sensors, in particular with regard to external pollution, and obtaining a device which can be mounted in a simple and precise manner. The present invention also relates to an instrumented roller roller device capable of supporting large radial loads.

The present invention also relates to an instrumented roller device that can be transported easily, and easy to handle to facilitate its mounting in a mechanical assembly.

The present invention also relates to a compact, simple instrumented roller bearing device with low manufacturing cost.

Such an instrumented roller roller device comprises a roller mounted for rotation on an axis by means of a rolling bearing assembly disposed between a bore of the roller and the axis, the rolling bearing assembly comprising at least two rows of rolling elements, the device further comprising a housing space defined in the rolling bearing assembly, and situated axially between rows of rolling elements and radially between the bore of the roller and the axis, and a sensor assembly. The rolling bearing assembly comprising at least two rolling bearings located radially between the bore of the roller and the axis, and axially spaced to define the housing space, said bearings comprising two inner rings adjusted on the axis to axially distance from each other. The sensor assembly includes an encoder disposed in the housing space, an annular sensor support disposed in the housing space being adjusted on the axis and located axially between the inner rings of the rolling bearing assembly in coming to bear at least on one side on an inner ring, and a sensor arranged in the housing space while being carried by the sensor support so as to be opposite the encoder, the sensor being provided to be connected by means a wired connection to a remote unit, the axis comprising a passage for the wired connection, the passage opening on one side into the housing space, and on the other side out of the housing space. The sensor assembly located in a housing space provided in a rolling bearing assembly is protected, in particular from pollution by external bodies. The rolling bearing assembly comprising at least two rows of rolling elements allows the roller device to withstand large radial loads. Furthermore, the rows of axially distant rolling elements make it possible to support torques exerted on the roller along axes perpendicular to the main axis of rotation of the roller. The inner rings of the rolling bearing assembly attached to the axis facilitate assembly of the device. Likewise, the annular sensor support is simply adjusted on the axis between the inner rings. To do this, one can successively mount an inner bearing ring, the support, then a second inner bearing ring. The mounting of the sensor support, and therefore of the sensor, on the axis does not require carrying out a particular operation on the axis, or a modification of the axis. Furthermore, the positioning of the annular support in contact with a ring makes it possible to precisely position the annular sensor support, and therefore the sensor itself, which improves the final precision of the sensor assembly.

The sensor connected to a remote unit via a wired link makes it possible to keep a compact sensor assembly to preserve the compactness of the roller device as a whole. The axis provided with a passage allows the routing of the wire connection from the housing space where the sensor is located to the outside.

Preferably, the annular sensor support is in axial contact with each of the inner rings. This improves the positioning of the sensor support which can also act as a spacer between the inner rings to maintain their axial spacing.

Advantageously, the rolling bearing assembly comprises sealing members arranged axially between the rows of rolling elements and the housing space. The sensor assembly must be protected from external pollution and in particular from the introduction dust or external elements. In particular, provision may be made for lubrication of the rolling bearing assembly, for example using grease. The sealing members arranged between the rows of rolling elements and the housing space make it possible to protect the latter from the intrusion of a lubricant from the rows of rolling elements.

To preserve a seal in the housing space, a shutter may be provided closing the passage of the axis on the side opposite to the housing space, while allowing the passage of the wire connection.

To simplify the transport and installation of the instrumented roller roller device, a connector can be provided to which the wire connection is connected, the connector closing the passage of the axis on the side opposite to the housing space. In one embodiment, the axis comprises an axial passage for the wire connection, and a radial passage opening into the axial passage and located axially opposite the housing space.

Preferably, the axial passage opens at one end of the axis. In this case, the axial passage can be a hole crossing the axis or blind.

In one embodiment, the sensor assembly includes an optical encoder and an optical sensor. The use of an optical encoder and an associated optical sensor is particularly recommended in applications which require high accuracy in detecting the parameters of rotation of the roller. These optical detection devices are indeed capable of providing signals having high precision and resolution. However, the optical sensor assemblies are particularly sensitive to pollution. The arrangement of the optical sensor assembly in a protected housing space is therefore an essential condition for ensuring reliable operation of the optical sensor assembly.

Advantageously, provision can be made for identical rolling bearings for standardization and a reduction in the manufacturing cost. In one embodiment, the rolling bearings comprise external rings added and adjusted in the bore of the roller, the encoder being disposed axially between external rings of the rolling bearings while being in contact with at least one of said rings to maintain the '' axial spacing between the outer rings. The encoder can be arranged directly in contact on one side with an outer ring of a rolling bearing, and on the opposite side with an outer ring of another rolling bearing. It can also be provided that the encoder is in direct contact with the outer rings of the two rolling bearings.

The present invention and its advantages will be better understood on studying the detailed description of embodiments taken by way of nonlimiting examples and illustrated by the appended drawings, in which: FIG. 1 is a view in axial section of 'a first embodiment;

FIG 2 is an axial sectional view of a second embodiment;

FIG. 3 is a variant axial section view of the device according to FIG. 2; and

FIG. 4 is a view in axial section of a variant of the device according to FIG. 3.

In FIG. 1, an instrumented roller roller device, referenced 1 as a whole, comprises a roller 2 mounted for free rotation on an axis 3 by means of a rolling bearing assembly 4.

The roller 2 is in the form of a tubular element comprising a bore 5 and a cylindrical external surface 6. The roller 2 can come into contact with an element directly by its external surface 6 or by means of a pulley, not shown in Figure 1, said pulley can be attached to the roller 2 or integrated with celuic-i

The axis 3 comprises a cylindrical axial portion 7 having a cylindrical outer surface 9 and an axial passage 10 opening out at the two ends of the cylindrical axial portion 7. The axial passage 10 has a bore 8.

The axis 3 comprises a flange 11 extending radially outwards from one end of the cylindrical axial portion 7. The flange 11 has a front radial surface 12 oriented on the side opposite to the cylindrical axial portion 7, and an annular radial support surface 13 oriented on the side opposite to the front surface 12. The flange 11 is provided with fixing means in the form of threaded holes 14, two of which are visible in FIG. 1, circumferentially spaced, and located radially at a distance from the axis of revolution of the axis 3 greater than the outside diameter of the cylindrical axial portion 7.

The cylindrical axial portion 7 of the axis 3 comprises a radial passage 15 opening on one side into the axial passage 10 and on the opposite side towards the outside. The radial passage 15 is located approximately mid-length of the cylindrical axial portion 7.

The axial passage 10 of the axis 3 is closed on the side of the flange 11 by a sealing plug 16. The bore 8 comprises at one end on the side of the flange 11 a recess forming a cylindrical seat 17 of larger diameter and a radial shoulder

18. The obturator plug 16 is adjusted in the range 17 by coming to bear on the shoulder 18 by one end. The opposite axial end of the plug 16 is flush with the front surface 12 of the flange 11. The rolling bearing assembly 4 comprises first and second identical rolling bearings 19, 20 disposed between the cylindrical outer surface 9 of the axial portion cylindrical 7 of the axis 3 and the bore 5 of the roller 2. The rolling bearings 19; 20 are spaced axially. A rolling bearing 19, 20 comprises an outer ring 21 having a cylindrical outer surface 22, a toroidal raceway 23 formed on an inner surface 24, and radial lateral faces 25a, 25b. A rolling bearing 19, 20 comprises an inner ring 26 having a bore 27, a raceway toroidal 28 formed on an outer surface 29, and radial lateral faces 30a, 30b.

Rolling elements 32, here balls, are arranged between the raceways 22, 28 of the outer 21 and inner 26 rings of the rolling bearing 19, 20, being kept spaced circumferentially evenly by a cage 33.

A rolling bearing 19, 20 also comprises sealing members 34, 35, extending radially between the outer rings

21 and inner 26, being arranged axially on either side of the rolling elements 32, to seal the space between the inner 26 and outer 21 rings.

A sealing member 34, 35 is in the form of a seal comprising a metallic annular reinforcement covered by a portion made of flexible material, said flexible portion comprising in its zone of larger diameter a bead which is received in an annular groove formed on the outer ring 21 of the rolling bearing 19, 20, axially near the lateral face 25a, 25b of the outer ring 21, and said flexible portion comprising in its zone of smaller diameter a sealing lip in contact with the outer surface 29 of the inner ring 26.

Rolling bearings 19, 20 are adjusted in the roller 2 with a tight fit between the outer ring 21 and the bore 5 of the roller

2, and are adjusted on the cylindrical axial portion 7 of the axis 3 with a tight or sliding-just fit between the bore 27 of the inner ring 26 on the outer surface 9.

The first rolling bearing 19 comes to bear by a lateral face 30 of its inner ring 26 on the radial bearing surface 13 of the flange 11 of the axis 3. The second rolling bearing 20 is disposed on the axial cylindrical portion 7 while being axially spaced from the first rolling bearing 19.

A housing space 36 is defined axially between the rolling bearings 19, 20, and radially between the outer surface 9 of the cylindrical axial portion 7 of the axis 3 and the bore 5 of the roller 2. The radial passage 15 of the cylindrical axial portion 7 is located axially opposite the housing space 36, so that it allows communication between the axial passage 10 of the axis 3 and the housing space 36.

A sensor assembly 37, disposed in the housing space 36, comprises an encoder 38 in the form of a ring adjusted in the bore 5 of the roller 2 to be integral in rotation with the roller 2, and coming to bear on one face lateral 25a of the outer ring 21 of the second rolling bearing 20. The encoder 38 comprises a radial coding surface 39 oriented on the side opposite to the second rolling bearing 20, and provided on its portion of smaller diameter, located radially opposite the space between the inner 26 and outer 21 rings of the second rolling bearing 20, of optical coding means, not visible in FIG. 1.

An annular spacer 40, having a bore of diameter substantially equal to or greater than the diameter of the inner surfaces 24 of the outer rings 21 of the rolling bearings 19, 20, is disposed axially between the encoder 38 and the outer ring 21 of the first rolling bearing 19 The spacer 40 and the encoder 38 make it possible to maintain the axial spacing of the outer rings 21 of the rolling bearings 19, 20 and therefore to maintain the axial spacing of the rolling bearings 19, 20.

The sensor assembly 37 also comprises a sensor support 41, of generally annular shape, and comprising a ring 42 having a bore 43a fitted to the exterior surface of the cylindrical axial portion 7 of the axis 3, and a cylindrical exterior surface 43b of diameter less than the bore diameter of the spacer 40. The crown 42 comes to bear by a first radial surface 44 on the inner ring 26 of the first rolling bearing 19 and has on the opposite side a second radial surface 45. The crown 42 is of axial length substantially less than the spacer 40.

The support 41 includes an axial extension 46 extending from the zone of smaller diameter of the crown 42, in the direction of the inner ring 26 of the second rolling bearing 20 coming in contact with or near the inner ring 26. The axial extension 46 has an outside diameter smaller than the inside diameter of the encoder 38. The axial extension 46 allows the support 41 to be maintained between the inner rings 26 of the rolling bearings 19, 20 while forming an annular recess in the support 41 allowing the encoder 38 to pass axially between the crown 42 and the second rolling bearing 20, so that the radial coding surface 39 of the encoder 38 comes radially opposite the zone of plus large diameter of the second radial surface 45 of the crown 42. A sensor 47 is embedded in the crown 42 by being flush with the second radial surface 45, and being oriented towards the coding surface 39 of the encoder 38. A sensor can advantageously be provided 47 optics. In this case, provision is made, for example, for the coding surface 39 to be a succession of reflecting zones and non-reflecting zones, for example in the form of graduations.

The first radial surface 44 of the crown 2 bearing on the first rolling bearing 19 is provided in its zone of smaller diameter with a radial notch 49. The crown 42 is oriented so that the notch 49 is located radially opposite of the radial passage 15 of the axis 3. The radial passage 15 opens into the housing space 36 by being flush with the lateral face 30a of the first rolling bearing 19. In this way, the notch 49 is located axially opposite the passage 15.

A wire connection 48 for connection is connected in a manner not shown to the sensor 47. The wire connection 48 exits from the crown 42 by a bottom surface of the notch 49. The radial passage 15 allows the passage of the wire connection 48 from the 'notch 49 towards the axial passage 10. Next, the link 48 passes through the obturator plug 16, and is connected at its end opposite to the sensor 47 to a remote unit not shown.

On the side opposite the encoder 38, the second rolling bearing 20 is held axially on the axis 3 by means of an elastic ring, of the circlip type, referenced 50, and housed in an annular groove formed on the axial end of the outer surface 9 of the axial cylindrical portion 7.

A sealed closure cover 51 closes the bore of the roller 2, on the side opposite the flange 11 of the axis 3. The sealed cover 51 comprises a disc 52 of diameter greater than the diameter of the bore

5 of the roller 2, and coming to bear by its zone of larger diameter on a radial end face 53 of the roller 2, and an axial rib 54 extending axially from the disc 52, having in the free state a outer diameter slightly greater than that of the bore 5 of the roller 2. The axial rib 54 is adjusted in the bore 5 with a slight tightening, until the disc 52 comes into contact with the roller 2.

The housing space 36 is located axially between the first and second rolling bearings 19, 20. The sealing members 34, 35 of the first and second rolling bearings 19, located axially between the rolling elements 32 of the rolling bearings 19 , 20 and the housing space 36, that is to say between the spaces defined between the inner and outer rings of the rolling bearings 19, 20 and the housing space 36, prevent the intrusion of external elements pollutants in the housing space 36. The plug 16 prevents the intrusion of external elements through the axial passage 10 of the axis 3 and the radial passage 15. Similarly, the cover 51 closing the interior space of the roller 2 on the side opposite the plug 16 prevents the intrusion of external elements into the passage 10 on the side opposite the plug 16. Consequently, the sensor assembly 37 is protected in a sealed housing space 36. Obtaining a sealed sealed accommodation space 36 facilitates the use of an optical sensor assembly 37, comprising an optical encoder 38 and optical sensor 47 disposed in the housing space 36, since the optical sensor assemblies are sensitive to outdoor pollution.

In addition, the sensor assembly 37 is compact and can be arranged in a housing space 36 of small dimensions, in particular axially and radially. The spacer 40 and the ring encoder 38 participate in the axial positioning of the rolling bearings 19, which avoids the use of additional parts.

The annular sensor support 41, in axial contact with an inner ring, is thus positioned with improved precision. In the case where the annular sensor support 41 comes to bear axially on each side on the inner rings, this also makes it possible to improve the position accuracy of the sensor support 41 and to maintain an axial spacing between the inner rings.

The annular sensor support 41 which carries the sensor 47 and is simply adjusted on the axis allows a simple assembly of the sensor assembly between the rolling bearings defining between them and with the axis and the bore of the roller a space of sheltered housing.

The use of two identical rolling bearings 19, 20 allows standardization and therefore a reduction in the manufacturing cost of the rolling roller device 2. The axial spacing of the two rolling bearings 19, 20 further allows the roller device with instrumented bearing 1 to support large radial loads and moments acting along an axis perpendicular to a main axis of axis 3. The use of a wire link 48 to connect the sensor 47 to a remote unit, not shown, allows good data transmission and avoids the use of non-wired non-compact transmission means which could affect the compactness of the sensor assembly 37. In FIG. 2, the references to elements similar to those of FIG. 1 have been retained. The axis 3 is devoid of a flange on the side of the plug 16, but comprises a flange 11 extending radially outward from the end of the cylindrical axial portion 7 opposite the plug 16. The flange 11 is devoid of fixing means in its larger diameter area. However, the bore 8 of the axial passage 10 has on the side of the collar 11 a thread 55 extending axially over a limited portion of the bore 8, substantially up to the radial plane passing through the center of the rolling elements 32 of the second rolling bearing 20. On the side of the plug 16, an elastic ring 50 is housed in an annular groove formed on the outer surface 9 of the axial cylindrical portion 7 for axially retaining the inner ring 26 of the first rolling bearing 19, on the side opposite to the second rolling bearing 20.

The thread 55 allows the axis 3 to be fixed on a support, using a screw. Once fixed on its support, the screw makes it possible to seal the axial passage 10, axially on the side opposite the plug 16. In FIG. 3, the elements similar to those of FIG. 1 have been taken up. The obturator plug is replaced by a connector 56 tightly fitted in the bore 8 of the tubular axial portion 7 of the axis 3 while being axially blocked by an internal shoulder of the bore 8 as well as by a flange 57 of the connector. 56, extending radially outward and bearing on the axial end of the axis 3. The connector 56 comprises pins 58, here two in number. The wire connection 48 coming from the crown 42 of the sensor support 41 crosses the radial passage 15, then the axial passage 10 as far as the connector 56. The wire connection 48 is connected in a manner not shown to the pins 58.

This embodiment makes it possible to supply the instrumented roller roller device 1 in the form of a compact modular assembly without a wired connection projecting and which may interfere with the handling of the device by an operator during the mounting of the instrumented roller roller device. in a mechanical assembly. During assembly, provision is simply made to fix the roller with an instrumented roller, then to connect the sensor assembly 37 to a remote unit, not shown, using a connection cable provided with a connector corresponding to the connector 56, and in which it can be inserted.

In FIG. 4, where the elements similar to those of FIG. 3 have been repeated, the encoder 38 is in the form of an annular spacer having a bore 60 of diameter greater than the outside diameter of the crown 42 of the sensor support 41. The encoder 38 is disposed axially between the outer rings 20 of the first and second rolling bearings 19, 20 coming to bear directly on the outer rings 21. The encoder 38 thus alone ensures the maintenance of an axial spacing between the first and second rolling bearings 19, 20.

The encoder 38 comprises, on its bore 60, coding means capable of cooperating with an optical sensor, and which may be in the form of an alternation of reflecting zones and non-reflecting zones. The optical sensor 47 is embedded in the ring 42 by being flush with the external surface 43 a of the ring 42, and by being oriented radially towards the outside facing the bore 60 of the encoder 38.

In the embodiments described, the sensor assembly comprises an optical encoder and an associated optical sensor. The optical sensor assemblies make it possible to obtain highly precise measurements. The instrumented roller device according to the invention is particularly suitable for optical sensor assemblies insofar as the protected housing space of the optical sensor assembly allows improved protection of these optical sensor assemblies sensitive to pollution.

Of course, other types of detection assemblies can be provided, for example a magnetic sensor / encoder assembly comprising a magnetic encoder and a magnetosensitive sensor. In this case also, the housing space allows improved protection of the sensor assembly. In addition, the sensor can be placed directly opposite and close to the encoder, which improves the accuracy of the measurements. The wire connection also makes it possible to preserve the compactness of the instrumented roller roller device. Furthermore, the invention is not limited to the embodiments described above, but can be, for example, a combination of these embodiments.

Thanks to the instrumented roller device, a roller can be provided with a sensor assembly allowing the recovery of data concerning the parameters of rotation of the roller with improved precision, while ensuring satisfactory protection of the sensor assembly. The rolling bearing assembly comprising two rows of rolling elements allows the roller device to withstand significant forces. The sensor assembly disposed in a housing formed in the rolling bearing assembly makes it possible to preserve the compactness of the rolling roller device. The optical sensor assembly benefits from improved protection. The rolling roller device is adapted to allow the establishment of a wire connection between the sensor assembly and a remote unit, while preserving the protection of the optical sensor assembly.

Claims

1. Roller bearing instrumented instrument comprising a roller (2) rotatably mounted on an axis (3) by means of a rolling bearing assembly (4) disposed between a bore (5) of the roller (2) and the axis (3), the rolling bearing assembly (4) comprising at least two rows of rolling elements, the device further comprising a housing space (36) defined in the rolling bearing assembly ( 4), and located axially between rows of rolling elements and radially between the bore (5) of the roller (2) and the axis (3), and a sensor assembly (37) comprising an encoder (38) arranged in the housing space (36), characterized in that the rolling bearing assembly (4) comprises at least two rolling bearings (19, 20) situated radially between the bore of the roller and the axis, and axially spaced to define the housing space, said bearings comprising two inner rings adjusted on the axis being spaced axially ement, the sensor assembly (37) comprising an annular sensor support (41) disposed in the housing space being adjusted on the axis and located axially between the inner rings by bearing at least on one side on an inner ring, and a sensor (47) arranged in the housing space (36) while being carried by the sensor support so as to be opposite the encoder (38), the sensor being designed to be connected via '' a wired connection (48) to a remote unit, the axis (3) comprising a passage (10, 15) for the wired connection (48), the passage (10, 15) opening on one side into space housing (36), and on the other hand out of the housing space (36).

2. Device according to claim 1, characterized in that the sensor support (41) is in axial contact with each of the inner rings.

3. Device according to any one of claims 1 or 2, the rolling bearing assembly (4) comprises sealing members (34, 35) arranged axially between the rows of rolling elements and the housing space .

4. Device according to any one of the preceding claims, characterized in that it comprises a shutter (16) closing the passage of the axis on the side opposite to the housing space, the shutter allowing the passage of the wired connection (48).

5. Device according to any one of claims 1 or 2, characterized in that it comprises a connector (56) to which is connected the wire connection (48), the connector closing the passage (10, 15) of the axis (3) on the side opposite the housing space (36).

6. Device according to any one of the preceding claims, characterized in that the axis (3) comprises an axial passage (10) for the wire connection (48).

7. Device according to claim 5, characterized in that the axial passage (10) opens at one end of the axis (3).

8. Device according to any one of claims 5 or 6, characterized in that the axis comprises a radial passage (15) opening into the axial passage (10), and located axially opposite the housing space ( 36).

9. Device according to any one of the preceding claims, characterized in that the sensor assembly comprises an optical encoder (38) and an optical sensor (47).

1 0 Device according to any one of the preceding claims, characterized in that the rolling bearings (19, 20) are identical.

1 1 Device according to any one of the preceding claims, characterized in that the rolling bearings include external reported rings fitted in the bore of the roller, the encoder (38) being disposed axially between the outer rings (21) of the rolling bearings (19, 20) while being in contact with at least one of said rings to maintain the axial spacing between the outer rings (21) .

12. Device according to claim 11, characterized in that the encoder is in direct contact with the outer rings (21) of the two rolling bearings (19, 20).