WO2012101123A1

WO2012101123A1 - Belt tensioning roller device and related method of assembly

Info

Publication number: WO2012101123A1
Application number: PCT/EP2012/051052
Authority: WO
Inventors: Romuald Lescorail; Frédéric LIÈGE
Original assignee: Aktiebolaget Skf
Priority date: 2011-01-24
Filing date: 2012-01-24
Publication date: 2012-08-02
Also published as: FR2970755B1; CN103328841A; FR2970755A1

Abstract

Belt or chain tensioning roller device (1) comprising a fixed member (2) intended to hold the device (1) on an external element (3), a moving member (4) that can move angularly with respect to the fixed member (2) and a roller or pulley (5) supported by the moving member (4) and intended to be in contact with the belt or the chain, the fixed member (2) comprising an adjusting eccentric (6) and the moving member (4) comprising a working eccentric (9) mounted to rotate on the adjusting eccentric (6) and a rolling bearing (13), the rolling bearing (13) comprising an external ring (17), an internal ring (16) and at least one row of rolling elements (18) arranged between the internal (16) and external (17) rings. Each row of rolling elements (18) is in contact via two contact zones at least with the internal ring (16), the internal ring (16) being a thin-walled ring produced by pressing or drawing a sheet or a tube.

Description

Belt tensioning roller device and related method of assembly

The present invention relates to the field of automati c tensioning roller devices, notably used for ensuring adequate tension in chains or b elts, for example motor vehicle internal combustion engine timing belts.

A belt or chain tensioning roller devi ce generally compri ses a support intended to be fixed to the engine block, and a moving part capable of angular movement with respect to the support by means of a plain bearing. The moving part is provided with an eccentric or with an articulated arm, and with a rolling bearing on which i s mounted a roller or pulley that is intended to be brought into contact with the belt or the chain. A spring applies permanent tension between the support and the moving part, causing the roller to come into contact with the belt or the chain with suitable b elt tension .

The tensioning roller device thus ensures that the required belt or chain tension i s kept within a certain tolerance band and does so despite dimensional variations in the belt or chain that may be caused by wear or else by temperature variations.

The failure of a belt, particularly a motor vehicle combustion engine timing belt, may cause considerable damage to the engine and impair reliable operation thereof. It is therefore important to ensure that the belt or chain i s kept under tension.

Document FR 2 920 85 1 di sclo ses a b elt tensioning roller device provided with an adj usting eccentric which i s intended to b e fixed to an engine block vi a a baseplate, and with a working eccentric mounted to rotate on the adj usting eccentric. A roller or pulley i s fixed to a rolling bearing mounted on the working eccentric. The said rolling bearing compri ses an external ring, an internal ring, and a row of rolling elements arranged between the said rings. The internal and external rings are one-piece rings .

To adjust the tension in the engine b elt, a screw i s fitted into the bore of the adj usting eccentric but not tightened, so that the adj usting eccentric can be turned with respect to the engine block; the adj usting eccentric is then pivoted, using an appropriate spanner, with respect to the baseplate, so as to bring the roller or pulley into contact with the b elt. Through the reaction of the belt on the roller, the working eccentric i s automatically made to rotate with respect to the baseplate.

However, given the small radial di stance separating the axi s of the adjusting eccentric and the axi s of the working eccentric, the automatic rotation of the working eccentric may not be enough to achieve the desired b elt tension. It then becomes necessary al so to provide for manual adj ustment of thi s tension.

It is therefore an obj ect of the present invention to overcome these di sadvantages.

More particularly, the present invention aim s to provide a tensioning roller device that i s particularly easy to manufacture, to fit, i s of small bulk, i s economical, and does not require manual adj ustment of the tension.

One subj ect of the invention i s a belt or chain tensioning roll er device compri sing a fixed member intended to hold the device on an external el ement, a moving member that can move angularly with respect to the fixed member and a roller or pulley supported by the moving member and intended to be in contact with the belt or the chain, the fixed member comprising an adj usting eccentric and the moving member comprising a working eccentric mounted to rotate on the adjusting eccentric and a rolling bearing, the rolling bearing compri sing an external ring, an internal ring and at least one row of rolling elements arranged between the internal and external rings.

Each row of rolling elements i s in contact via two contact zones at least with the internal ring. The internal ring i s produced by pressing or drawing a sheet or a tube.

Thus, the bore of the rolling bearing i s larger, making it possible to increase the radial di stance separating the axi s of the working eccentric from the axi s of the adjusting eccentric while at the same time not changing the size of the adj usting eccentric or of the plain bearing. In addition, when adj usting the belt tension, the working eccentric can pivot automatically with respect to the adj usting eccentric over a greater angular range of values, making it possible to di spense with the need to perform a later manual tension adj ustment operation.

Advantageously, the internal ring consi sts of two half-rings which are symmetric with one another when considering the radial plane passing through the centre of the rolling elements and which are mounted on the working eccentric.

The half-rings are advantageously identical, which makes it possible to reduce the costs of manufacturing the rolling bearing.

The rolling bearing may compri se at least one adj usting shim mounted between one of the internal half-rings and the working eccentric.

In one embodiment, the rolling bearing compri ses two adj usting shims, each associated with one of the internal half-rings.

In another emb odiment, the rolling bearing compri ses two rows of rolling elements arranged between at least one external ring and two internal rings. Each row of rolling elements i s in contact vi a two contact zones with one of the internal rings and via one contact zone with the external ring.

Advantageously, the pulley i s overmoulded on the external ring.

The rolling bearing may compri se two thin-walled external rings produced by pressing or drawing a sheet or a tub e; each row of rolling elements i s in contact via two contact zones with one of the external rings .

For example, each external ring i s made up of two half-ring s that are symmetric with one another when considering the radial plane that passes through the centre of each row of rolling elements.

Advantageously, each internal half-ring i s mounted on a sleeve fixed to the working eccentric. In one embodiment, the rolling bearing compri ses two external adj usting shims, each one mounted between a cap and one of the external half-rings .

The rolling bearing may further compri se two internal adjusting shims, each mounted between the sleeve and one of the internal half- rings.

Advantageously, the adjusting shims are fixed to the working eccentric, the sleeve or the upper cap by welding, upsetting, crimping or force fitting.

A second aspect of the invention relates to a method of assembling a tensioning roller device comprising a fixed member intended to hold the device on an external element, a moving memb er that can move angularly with respect to the fixed member and a roller or pulley supported by the moving member and intended to be in contact with the belt or the chain, the fixed member comprising an adj usting eccentric and the moving member compri sing a working eccentric and a rolling bearing, the rolling bearing compri sing an external ring, an internal ring and at least one row of rolling elements arranged between the internal and external rings, in which :

- the working eccentric i s mounted to rotate on the adj usting eccentric,

- one of the internal half-rings that form the thin-walled internal ring produced by pressing or drawing a sheet or a tube i s fixed to the working eccentric,

- the other internal half-ring, a row of rolling elements in contact via two contact zones at least with the thin-walled internal ring formed of the two internal half-rings, and the external ring are fitted, and

- at least one adj usting shim i s fixed between one of the internal half-rings and the working eccentric.

Other obj ects, features and advantages of the invention will become apparent from reading the following description, given solely by way of nonlimiting example, and made with reference to the attached drawings in which:

- Figure 1 is a view in axial section of a tensioning roller device according to the invention;

- Figure 2 depicts a second embodiment of a rolling bearing associated with the tensioning roller device according to Figure 1;

- Figure 3 depicts a third embodiment of a rolling bearing associated with the tensioning roller device according to Figure 1; and

- Figure 4 depicts a fourth embodiment of a rolling bearing associated with the tensioning roller device according to Figure 1.

As illustrated in Figure 1, the belt or chain (not depicted) tensioning roller device referenced 1 in its entirety comprises a fixed member 2 intended to hold the tensioning roller device 1 on an external element 3, for example an engine block, a moving member 4 that can move angularly with respect to the fixed member 2, and a roller or pulley 5 supported by the moving member 4 and intended to be in contact with the belt or the chain.

The fixed member 2 comprises an adjusting eccentric 6, of axis Xi, to which a baseplate 7 is fixed at one axial end. The adjusting eccentric 6 is provided with a threaded bore 6a capable of accepting a fastener, such as a screw 8, for securing the adjusting eccentric 6 to the engine block 3. The working eccentric 6 can pivot with respect to the engine block 3 when the screw 8 is slackened off, the tightening of the screw 8 immobilizing the adjusting eccentric 6. The adjusting eccentric 6 comprises a central cylindrical portion 6b and, at the axial end situated on the engine block 3 side, a shoulder 6c of a diameter greater than the diameter of the central portion 6b so as to increase a radial bearing surface 6d via which the adjusting eccentric 6 bears against the engine block 3. The adjusting eccentric 6 also comprises, at the opposite end to the engine block 3, a shoulder 6e of a diameter smaller than the diameter of the central portion 6b and the external surface of which is intended to engage with a bore of a ring 10. The baseplate 7, advantageously made of thin sheet, compri se s a sub stantially axial guide portion 7a, of tubular shape and defining a bore 7b, that comes into contact with the external surface of the adj usting eccentric 6. The axial guide portion 7a i s extended, from a larger-diameter zone consi stent in shape with the shoulder 6c, radially outwards in the form of a radial portion 7c near the engine block 3 . The radi al portion 7c i s extended axially towards the moving memb er 4 in the form of an axial tab 7d. The baseplate 7 i s angularly connected to the engine block 3 by any appropriate means.

The moving member 4 compri ses a working eccentric 9 mounted to rotate on the adj usting eccentric 6 via a plain bearing 1 1 , an actuator compri sing a return spring 12 and a rolling bearing 1 3 mounted on the working eccentric 9 and on which the roller or pull ey 5 i s mounted.

The working eccentric 9 compri ses a bore 9a, a frontal radial surface 9b situated axially at the opposite end to the baseplate 7, a first cylindrical external surface 9c extending over part of its length from the frontal radial surface 9b . The first external cylindri cal surface 9c i s axially connected to a second external cylindrical surface 9d by a sub stantially oblique surface 9e. The second external cylindrical surface 9d i s extended by a radial portion 9f extending outwards from the end of the second cylindrical surface 9d, and a sub stantially axial portion 9g axially on the opposite side to the frontal radial surface 9b . The working eccentric 9 i s a one-piece component.

The radi al portion 9f, the axial portion 9g and the radial bearing portion 7c of the baseplate 7 define a housing 14 in whi ch the spring 12 i s arranged. A protective element 1 5 may al so be arranged in thi s housing, being fixed against the baseplate 7. As illustrated, the protective element 1 5 i s situated radially between the axial portion 7a of the baseplate 7 and the spring 12. One end of the spring 12 i s fastened to the baseplate 7, the other end being secured to the working eccentric 9. Thus, the working eccentric 9 can turn in relation to the adjusting eccentric 7, about the axis Xi, while being subjected to a return torque applied by the said spring 12.

The plain bearing 11 takes the form of an annular bushing comprising an axial portion 11a mounted rigidly by force-fitting in the bore 9a of the working eccentric 9 and is able to slide along the external cylindrical surface of the adjusting eccentric 6. For this purpose, the bore of the axial portion 11a may be coated with a thin layer of polytetrafluoroethylene (PTFE). The axial portion 11a is extended, at one axial end, on the opposite side to the shoulder 6b, by a radial portion lib that extends outwards bearing against the frontal surface 9b of the working eccentric 9.

The rolling bearing 13, of axis X₂, comprises an internal ring 16, an external ring 17 and a row of rolling elements 18, here produced in the form of balls, arranged between the external 17 and internal 16 rings, a cage 21 respectively maintaining the correct circumferential spacing of the rolling elements 18, and two seals or sealing end plates 20 which are symmetric with respect to a radial plane passing between the row of rolling elements 18.

The external ring 17 is a one-piece ring comprising an internal surface 17a having a raceway 17b and an external surface 17c intended to collaborate with a roller or pulley 5. For this purpose, a groove 17d may be provided to make it easier for the pulley 5 to be overmoulded on the external ring 17.

The internal ring 16 is a thin-walled ring produced by pressing or drawing a sheet or a tube and comprises two half-rings 16a, 16b which are symmetric with one another when considering the radial plane that passes through the centre of the rolling elements 18. The internal half-rings 16a, 16b are mounted on the working eccentric 9. As illustrated in Figure 1, the row of rolling elements 18 is in contact via two contact zones with the internal ring 16 and via one contact zone with the one-piece external ring 17.

Each internal half-ring 16a, 16b comprises an axial portion 21a, 21b extending towards the inside in the form of a radial portion 22a, 22b via a substantially oblique portion 23a, 23b. The internal surfaces of the oblique portions 23a, 23b form raceways for the rolling elements 18.

The axial portion 21a of the first internal half-ring 16a situated towards the engine block 3 is in contact with the second external cylindrical surface 9d of the working eccentric 9 and the axial portion 21b of the second internal half-ring 16b is in contact with the first external cylindrical surface 9c of the working eccentric 9.

The substantially oblique portion 23a of the first internal half- ring 16a is in contact with the oblique surface 9e of the working eccentric 9. Thus, the first internal half-ring 16a is consistent in shape with the working eccentric 9.

The axis X₂ of the rolling bearing 13 is radially offset from the axis Xi of the adjusting eccentric 6.

The rolling bearing 13 also comprises an internal adjusting shim 24 arranged between one of the internal half-rings 16b and the working eccentric 9. The internal adjusting shim 24 comprises an upper surface 24a connected to a lower surface 24b by a rounded surface 24c consistent in shape with the substantially oblique portion 23b of the internal half-ring 16b.

One half-ring 16b of the internal ring 16 is mounted, for example, by force fitting onto the second external cylindrical surface 9d of the working eccentric 9 and comes into contact with the radial portion 9f of the eccentric 9. The rolling elements 18, the one-piece external ring 17 and the second internal half-ring 16b are then mounted on the working eccentric 9. Finally, the internal adjusting shim 24 is fixed to the working eccentric 9 by upsetting, welding or crimping so as to hold the two internal half-rings 16a, 16b in place axially. The rolling bearing 13 also comprises seals 20 mounted radially between one of the internal half-rings 16a, 16b and the external ring 17 and which are symmetric with respect to a radial plane that passes through the centre of the rolling elements 18. The rolling bearing 13 ensures that the roller or pulley 5 i s free to rotate with respect to the working eccentric 9 and al so reacts radial load.

When the belt tensioner device 1 i s being fitted, a first step involves adj usting the belt tension. To do thi s, the screw 8 i s fitted without tightening it, so that the adj usting eccentric 6 i s able to move in term s of rotating with respect to the engine block 3 , and with respect to the baseplate 7. A suitable operating spanner (not depicted) collaborating with the ring 10 is used to pivot the adj usting eccentric 6 with respect to the b aseplate 7. In thi s way, the roller or pulley 5 i s brought into contact with the belt (not depicted) . The adj usting eccentric 6 continues to be turned and thi s, via reaction of the belt on the roller 5 , causes the working eccentric 9 to rotate with respect to the baseplate 7 with an increase in the tension in of the spring 12, which applies a resi stive torque between the b aseplate 7 and the working eccentric 9 that has a tendency constantly to push the roller 5 against the belt. The device 1 i s designed so that the roller 5 appli es to the b elt a force that generates suitable tension in the said belt. The baseplate 7 i s then immobilized on the engine block 3 using the screw 8. As the belt wears, the working eccentric 9 will automatically move angularly with respect to the adj usting eccentric 6.

The embodiment illustrated in Figure 2, in whi ch the same elements have the same references, depicts a rolling bearing 13 intended to be mounted on the working eccentric 9 of Figure 1 . The rolling bearing 13 , of axi s X₂, compri ses two thin-walled internal half- rings 16a, 16b produced by pressing or drawing a sheet or a tube, one external ring 17 and one row of rolling elements 1 8, here produced in the form of ball s, arranged between the external 17 and internal 1 6 rings, a cage 21 respectively maintaining the correct circumferential spacing of the rolling elements 1 8, and two seal s or sealing end plates 20 which are symmetric with respect to a radi al plane that passes between the row of rolling elements 1 8. The rolling bearing 13 al so compri ses two internal adjusting shims 24, 25 which are sub stantially identical and symmetric in relation to a radial plane that passes through the centre of the row of rolling elements. Each internal adjusting shim 24, 25 is arranged between one of the internal half- rings 16a, 16b and the working eccentric 9. Since the internal adjusting shims 24, 25 are identical, detail regarding the adjusting shim 25 will not be given.

The embodiment illustrated in Figure 3, in which the same elements have the same references, depicts a rolling bearing 13 intended to be fitted on a working eccentric 9 of the tensioning roller device 1 illustrated in Figure 1.

The rolling bearing 13, of axis X₂, comprises two rows of rolling elements 18a, 18b which are arranged between a single external ring 30 and two thin-walled internal rings 31, 32 produced by pressing or drawing, such that each row of rolling elements 18a, 18b is in contact with one contact zone 30a, 30b of the external ring and two contact zones 31a, 31b and 32a, 32b of each of the internal rings 31, 32.

Each internal ring 31, 32 comprises two thin-walled internal half-rings 33, 34 and 35, 36 produced by pressing or drawing a sheet or a tube. The internal half-rings 33, 34 and 35, 36 are respectively symmetric in relation to a plane that passes through the centre of each row of rolling elements 18a, 18b and are identical to the internal half- rings 16a, 16b illustrated in Figures 1 and 2.

The rolling bearing 13 further comprises two cages 37, 38 that respectively maintain the correct circumferential spacing of the rolling elements 18a, 18b, and two seals or sealing end plates 39 which are symmetric in relation to a radial plane that passes between the rows of rolling elements 18a, 18b. Each of the sealing end plates 39 comprises an upper portion 39a mounted in the external ring 30, extended by an axial portion 39b that extends beyond the radial portion of one of the internal half-rings 33, 36. The axial portion 39b has a lip 39c positioned axially above the radial portion of the internal half-ring 33, 36. The rolling bearing 13 also comprises two internal adjusting shims 40, 41 which are substantially identical and symmetric in relation to a radial plane that passes through the centre of the rows of rolling elements. Each internal adjusting shim 40, 41 is arranged between one of the internal half-rings 33, 36 and a sleeve 42 which is intended to be fitted onto the working eccentric 9. Since the internal adjusting shims 40, 41 are identical to the adjusting shims 24, 25 illustrated in Figure 2, details thereof will not be given. The sleeve 42 comprises a central portion 42a the external surface of which is consistent in terms of shape with the internal half-rings 34, 35 and two lateral portions 42b the external bore of which engages with the internal shims 40, 41. A pulley or a roller can be directly overmoulded on the external ring 30.

The embodiment illustrated in Figure 4, in which the same elements have the same references, depicts a rolling bearing 13 intended to be mounted on a working eccentric 9 of the tensioning roller device 1 illustrated in Figure 1.

The rolling bearing 13, of axis X₂, differs from the rolling bearing illustrated in Figure 3 in that it comprises two external rings 43, 44. Each of the external rings 43, 44 is a thin-walled ring produced by pressing or drawing a sheet or a tube. Each of the rows of rolling elements 18a, 18b is arranged between two external rings 43, 44 and two thin-walled internal rings 31, 32 produced by pressing or drawing, so that each row of rolling elements 18a, 18b is in contact with two contact zones 33a, 33b and 34a, 34b with each of the external rings 33, 34 and two contact zones 31a, 31b and 32a, 32b with each of the internal rings 31, 32.

Each external ring 43, 44 comprises two thin-walled internal half-rings 45, 46 and 47, 48 produced by pressing or drawing a sheet or a tube. The internal half-rings 45, 46 and 47, 48 are respectively symmetric in relation to a plane that passes through the centre of each row of rolling elements 18a, 18b and are identical to the internal half- rings 16a, 16b illustrated in Figures 1 and 2.

The rolling bearing 13 further comprises two cages 37, 38 which respectively maintain the correct circumferential spacing of the rolling elements 1 8a, 1 8b, and two seal s or sealing end plates 39 which are symmetric in relation to a radial plane that passes between the rows of rolling elements 1 8a, 1 8b .

The rolling bearing 13 al so compri ses two internal adj usting shims 40, 41 that are sub stantially identical and symmetric in relation to a radi al pl ane that passes through the centre of the rows of rolling elements and two external adj usting shims 49, 50. Each external adj usting shim 49, 50 i s arranged between one of the external half- rings 45 , 48 and an upper cap 5 1 intended to engage with a pull ey or roller 5. Since the external adj usting shims 49, 50 are identical to the adj usting shims 24, 25 illustrated in Figure 2, further detail s thereof will not be given. The upper cap 5 1 compri ses a central portion 5 1 a the external surface of whi ch i s consi stent in terms of shape with the internal half-rings 46, 47 and two lateral portions 5 1 b the internal bore of which collaborates with the external shims 49, 50.

Each of the sealing end plates 39 compri ses an upper portion 39a mounted in one of the external shims 49, 50, extended by a radial portion 39b which extends beyond the axial portion of one of the internal half-rings 33 , 36. The radial portion 39b has a lip 39c positioned radially above the axial portion of the internal half-ring 33 , 36. In thi s embodiment, the pulley or roller i s overmoulded on the upper cap 5 1 .

In all the embodiments described, the adj usting shims are axially retained by any appropriate means, for example by crimping, welding, bonding or force fitting. As an alternative, provi sion could be made for the bore of the shim to be threaded so that it collab orates with a corresponding screw thread on either the working eccentric, the sleeve, or the upper cap .

The invention i s not restricted to the embodiments described and can be varied in a number of ways.

Thanks to the internal and/or external half-rings which are produced by pressing or drawing a sheet or a tube, the bore of the rolling bearing can be greater than when the rings are made as one- piece components, and thi s makes it po ssible to increase the radial di stance separating the axi s of the working eccentric from the axis of the adjusting eccentric while at the same time not changing the size of the adjusting eccentric or of the plain bearing. In addition, when adj usting the belt tension, the working eccentric can pivot automatically with respect to the adj usting eccentric over a greater angular range of values, making it possible to dispense with the need to perform a later manual tension adj ustment operation.

In addition, the radially fitted adj usting shims allow the play in the rolling bearing to b e adj usted. The axial positioning of each shim i s therefore determined according to the desired operating play in the rolling bearing. The shims al so perform a function of stiffening the associated half-ring.

Such a tensioning roller device makes it possible to reduce the costs of manufacture and di spense with the need for a later manual tension adj ustment operation.

Claims

1. Belt or chain tensioning roller device (1) comprising a fixed member (2) intended to hold the device (1) on an external element (3), a moving member (4) that can move angularly with respect to the fixed member (2) and a roller or pulley (5) supported by the moving member (4) and intended to be in contact with the belt or the chain, the fixed member (2) comprising an adjusting eccentric (6) and the moving member (4) comprising a working eccentric (9) mounted to rotate on the adjusting eccentric (6) and a rolling bearing (13), the rolling bearing (13) comprising an external ring (17, 30, 43, 44), an internal ring (16, 31, 32) and at least one row of rolling elements (18, 18a, 18b) arranged between the internal (16, 31, 32) and external (17, 30, 43, 44) rings, characterized in that each row of rolling elements (18, 18a, 18b) is in contact via two contact zones at least with the internal ring (16, 31 32), the internal ring (16, 31, 32) being a thin-walled ring produced by pressing or drawing a sheet or a tube.

2. Tensioning roller device according to Claim 1, in which the internal ring (16) consists of two half-rings (16a, 16b) which are symmetric with one another when considering the radial plane that passes through the centre of the rolling elements (18) and which are mounted on the working eccentric (9).

3. Tensioning roller device according to Claim 2, in which the rolling bearing (13) comprises at least one adjusting shim (24) mounted between one of the internal half-rings (16b) and the working eccentric (9).

4. Tensioning roller device according to Claim 3, in which the rolling bearing (13) comprises two adjusting shims (24, 25), each associated with one of the internal half-rings (16a, 16b).

5. Tensioning roller device according to Claim 1, in which the rolling bearing (13) comprises two rows of rolling elements (18a, 18b) arranged between at least one external ring (30, 43, 44) and two internal rings (31, 32), each row of rolling elements (18a, 18b) being in contact via two contact zones (31a, 31b, 32a, 32b) with one of the internal rings (31, 32) and via one contact zone (30a, 30b) with the external ring (30).

6. Tensioning roller device according to one of Claims 1 to 5, in which the pulley (5) is overmoulded on the external ring (30).

7. Tensioning roller device according to Claim 5, in which the rolling bearing (13) comprises two thin-walled external rings (43, 44) produced by pressing or drawing a sheet or a tube, each row of rolling elements (18a, 18b) being in contact via two contact zones (43a, 43b, 44a, 44b) with one of the external rings (43, 44).

8. Tensioning roller device according to Claim 7, in which each external ring (43, 44) is made up of two half-rings (45, 46, 47, 48) that are symmetric with one another when considering the radial plane that passes through the centre of each row of rolling elements (18a, 18b).

9. Tensioning roller device according to one of Claims 5 to 8, in which each internal half-ring (45, 46, 47, 48) is mounted on a sleeve (42), the said sleeve (42) being fixed to the working eccentric (9).

10. Tensioning roller device according to Claim 8 or 9, in which the rolling bearing (13) comprises two external adjusting shims

(49, 50), each one mounted between a cap (51) and one of the external half-rings (45, 48).

11. Tensioning roller device according to one of Claims 5 to 10, in which the rolling bearing (13) comprises two internal adjusting shims (40, 41), each mounted between the sleeve (42) and one of the internal half-rings (33, 36).

12. Tensioning roller device according to one of the preceding claims, in which the adjusting shims (24, 25, 40, 41, 49, 50) are fixed to the working eccentric (9), the sleeve (42) or the upper cap (51) by welding, upsetting, crimping or force fitting.

13. Method of assembling a tensioning roller device (1) comprising a fixed member (2) intended to hold the device (1) on an external element (3), a moving member (4) that can move angularly with respect to the fixed member (2) and a roller or pulley (5) supported by the moving member (4) and intended to be in contact with the belt or the chain, the fixed member (2) comprising an adjusting eccentric (6) and the moving member (4) comprising a working eccentric (9) and a rolling bearing (13), the rolling bearing (13) comprising an external ring (17, 30, 43, 44), an internal ring (16, 31, 32) and at least one row of rolling elements (18, 18a, 18b) arranged between the internal (16, 31, 32) and external (17, 30, 43, 44) rings, characterized in that:

- the working eccentric (9) is mounted to rotate on the adjusting eccentric (6),

- one of the internal half-rings (16a) that form the thin-walled internal ring (16) produced by pressing or drawing a sheet or a tube is fixed to the working eccentric (9),

- the other internal half-ring (16b), a row of rolling elements (18) in contact via two contact zones at least with the thin-walled internal ring (16) formed of the two internal half-rings (16a, 16b), and the external ring (17) are fitted, and

- at least one adjusting shim (24) is fixed between one of the internal half-rings (16b) and the working eccentric (9).