FR3034478A1 - TORQUE TRANSMISSION DEVICE FOR A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a torque transmission device for a motor vehicle, comprising a torque input member (6, 7a, 7b), a torque output member (36, 8), elastic members mounted between the torque input member (6, 7a, 7b) and the torque output member (8). The torque output member (36, 8) has a hub (8) having a first cylindrical portion (9) and a second cylindrical portion (10) of larger diameter than the first cylindrical portion (9). torque inlet (6, 7a, 7b) having an annular member (6) comprising a first cylindrical portion (20) mounted around the first cylindrical portion (9) of the hub (8) and a second cylindrical portion (21) mounted around the second cylindrical portion (10) of the hub (8).

Description

The present invention relates to a torque transmission device for a motor vehicle.

Such a device generally comprises a torque input element intended to be coupled directly or indirectly to a crankshaft, a torque output element intended to be coupled to an input shaft of a gearbox, and a first group of resilient members mounted between the input and torque output members and acting against the rotation of one of said input and torque output members relative to the other. When the torque transmission device is LTD (Long Travel Damper) type, it comprises several pairs of elastic members, the elastic members of the same pair being arranged in series via a phasing member so the elastic members of each group deform in phase with each other. In order to allow the damping of large torques, it is known to add to the aforementioned device a second group of elastic members, mounted with clearance between the input and torque output elements, in parallel with the first group of members. resilient and designed to act against the rotation of one of said input or torque output members over a limited angular range, particularly at the end of angular travel. The angular displacement, or the angular offset noted a, of the torque input element with respect to the torque output element, is defined with respect to a rest position (a = 0) in which no torque is transmitted through the device. The second group of elastic members makes it possible to increase the stiffness of the damping device at the end of the angular stroke, that is to say for a significant angular offset of the torque entry element with respect to the torque output element (or vice versa).

The document US 2010/0133063 discloses a LTD type torque transmission device, comprising two groups of elastic members arranged in parallel, the second group being made active only at the end of angular travel a of the input element. torque 5 relative to the torque output member (or vice versa). The torque input element may conventionally comprise two guide washers coupled in rotation to one another and an annular member, such as for example a turbine hub, fixed at the radially inner periphery of the one of the guide washers. The turbine hub 10 has a cylindrical radially inner periphery pivotally mounted about a cylindrical portion of a central hub of the torque output member, said central hub being adapted to be rotatably coupled to an input shaft. a gearbox. The annular turbine hub is generally asymmetrical with respect to the median radial plane so that there is a mounting direction of said turbine hub on the central hub. If an operator mounts the turbine hub upside down on the central hub, this may in particular cause an impossibility of mounting or fixing the device in a gearbox for example and / or a malfunction of the device 20 mounted. It is therefore necessary to avoid such a mounting error. The invention proposes to remedy this drawback simply, efficiently and economically. For this purpose, the invention provides a torque transmission device for a motor vehicle, having a torque input member, a torque output member, resilient members mounted between the torque input member and the torque output member, said resilient members being adapted to act against the rotation of the torque input member with respect to the torque output member, characterized in that the element the torque output member, respectively the torque input member, comprises a hub comprising a first cylindrical portion and a second cylindrical portion of larger diameter than the first cylindrical portion, the torque input member, respectively the torque output member having an annular member comprising, at its radially inner periphery, a first cylindrical portion mounted about the first cylindrical portion of the hub and a second cylindrical portion mounted around the second cylindrical portion of the hub. The differences in diameter of the different portions of the hub and the annular member form keying means 10 preventing the mounting of the annular member on the hub in the wrong direction so that the operator detects and corrects any possible error in mounting. The first cylindrical portion or the second cylindrical portion of the hub may have substantially the same diameter as the first cylindrical portion or the second cylindrical portion of the annular member. Furthermore, the device may comprise at least one first elastic member and at least one second elastic member, arranged in series via a phasing member, so that the first and second elastic members deform in phase with each other, the phasing member being movable relative to the torque input member and with respect to the torque output member, the first resilient member being mounted between the torque element the torque input and the phasing member and being adapted to act against the rotation of the torque input member with respect to the phasing member, the second elastic member being mounted between the phasing member and the torque output member and being adapted to act against the rotation of the torque output member with respect to the phasing member over a first angular range.

In addition, the device may comprise at least a third elastic member mounted with a circumferential clearance between the torque input element and the torque output element, or between the phasing member and the element. torque output, or between the torque input member and the phasing member, in parallel with the first elastic member and / or the second elastic member.

In this case, the hub and / or the annular member may define an annular housing in which is housed, at least in part, the third elastic member. In addition, the device may comprise two guide rings located axially on either side of an annular web, the guide washers belonging to the torque input element, the annular web belonging to the element of torque output, or conversely, the annular member being attached to one of the guide washers, the hub being attached to the annular web. In this case, the annular web may comprise an annular portion 15 from which tabs extend radially outwards, the first and second elastic members being mounted circumferentially between said tabs of the web. Furthermore, the device may comprise pendular damping means mounted on a movable member of said device.

In this case, the pendular damping means may comprise a support coupled in rotation to the phasing member or formed by said phasing member, and pendular masses mounted movably on the support. The invention further relates to a hydrodynamic torque converter for a motor vehicle, characterized in that it comprises at least one device of the aforementioned type. The device according to the invention may also have at least one of the following features: a splined hub is attached to at least one of the guide washers, said splined hub comprises a fluted cylindrical portion from which a The annular portion extends radially inwardly, said radial annular portion being fixed to one of the guide washers, for example by riveting, the resilient members are curved and / or straight helical compression springs. The invention will be better understood and other details, characteristics and advantages of the invention will become apparent on reading the following description given by way of non-limiting example with reference to the accompanying drawings, in which: FIG. schematic of a torque converter equipped with a torque transmission device according to the invention, Figure 2 is a perspective view of the device, Figure 3 is an exploded view, in perspective, of the device, Figure 4 Fig. 5 is a view corresponding to Fig. 4, showing a mounting error of the turbine hub. A hydrodynamic torque converter according to the invention is shown schematically and partially in FIG. 1. This converter makes it possible to transmit a torque of an output shaft of an internal combustion engine of a motor vehicle, such as for example 25 a crankshaft 1, to an input shaft 2 of a gearbox. The torque converter conventionally comprises an impeller impeller 3, adapted to hydrokinetically drive a turbine blade wheel 4, via a reactor 5. The impeller wheel 3 is coupled to the crankshaft 1 and the turbine wheel 4 is coupled to a turbine hub 6 (Figures 2 to 5), itself coupled to two guide washers 7, referenced 7a and 7b.

As best seen in Figure 2, the guide ring 7b and the turbine hub 6 are rotatably mounted about a splined central hub 8, to be coupled to the input shaft 2 of the box. speeds.

The central hub comprises in particular a first cylindrical portion 9 and a second cylindrical portion 10, located in front of the first portion and of smaller diameter than the first portion 9. The two portions 9, 10 are separated from one another The radial hub 12 is situated directly behind the first cylindrical portion 9. An annular groove 13 is formed directly in front of the second cylindrical portion 10. The central hub 8 has a radial shoulder 11. in addition to an annular recess 14 opening axially towards the front. The turbine hub 6 has an annular recess 15 opening towards the recess 14 of the central hub 8 and radially outwardly. The recesses 14, 15 define an annular housing whose function will be better detailed after. The recess 15 of the turbine hub 6 has a rear-end face 16 extending radially.

The turbine hub 6 further comprises an annular recess opening towards the front, said recess comprising a radially inner annular bearing zone 17 and a radially outer bearing zone 18. The radially inner periphery of the guide washer 7a is intended to bear on said bearing zones 17, 18. A hollow annular zone 19 is thus delimited between the bearing zones 17 and 18, and forms the bottom of the aforementioned recess. The radially inner periphery of the turbine hub 6 comprises a first portion 20 of diameter substantially equal to the diameter of the first portion 9 of the central hub 8 and a second portion 21 whose diameter is slightly greater than the diameter of the second portion 10 3447478 7 second portion 10 the central hub 8, while being smaller than the diameter of the first portion 9 of the central hub 8. The inner portion of the turbine hub 6 has a rear radial face 22 intended to bear against the annular shoulder 12 5 of the central hub 8, and shifted rearwardly with respect to the radial face 16 of the turbine hub, said face 16 bearing on an annular bearing face 23 of the central hub 8, situated radially outside the recess 14 of the hub 8 and shifted forward with respect to the shoulder 12.

It should be noted that, during a good mounting of the turbine hub 6 (FIG. 4), that is to say in particular when the face 22 of the turbine hub 6 bears on the shoulder 12 of the hub central 8, then the groove 13 is accessible from the outside for mounting an elastic ring type circlips for example. Such an elastic ring makes it possible, for example, to fix the device to a gearbox. The guide washer 7a is mounted around the turbine hub 6 and fixed thereto. The two guide washers 7a, 7b extend radially and delimit between them an internal space 24 (FIG. 4) serving in particular for the accommodation of first elastic members 25a and of second elastic members 25b, which are, for example, compression coil springs. . The guide ring 7b has a cylindrical rim 26 at its radially outer periphery, extending towards the guide ring 7a and fixed thereto.

The free end of the cylindrical flange 26 has tabs 27 extending axially through orifices 28 of the washer 7a. These tongues 27 are riveted on the outer periphery of the guide washer 7a and can be welded to the latter, so as to ensure the attachment of the two guide rings 7a, 7b.

The guide washers 7a, 7b conventionally comprise windows 29 for accommodating the resilient members 25a, 25b.

A splined hub 30 is also fixed by riveting on the rear face of the guide washer 7b. This fluted hub has a radial portion 31 fixed to said rear face of the guide washer 7b, and a fluted cylindrical flange 32 extending rearwardly from the radially outer periphery of the radial portion 31. A clutch 33 (FIG. 1) makes it possible to transmit a torque from the crankshaft 1 to the guide washers 7, in a determined operating phase, without involving the impeller wheel 3 and the turbine wheel 4. This clutch 33 comprises an input element 34 10 coupled to the crankshaft 1 and an output member 35, including the spline hub 30. A radially extending annular web 36 is mounted in the inner space 24 and is secured to the central hub 8, via rivets or through welding for example.

As best seen in Figure 3, the annular web 36 has a radially inner annular portion 37 from which tabs 38, for example three in number, extend radially outwardly. Each tab 38 has two opposite faces 39 serving to support the elastic members 25a, 25b, inclined relative to each other 20 and relative to the radial direction. Two abutment studs 40 extend circumferentially on either side of each tab 38, at its outer periphery. The resilient members 25a, 25b are circumferentially mounted between the annular web 36 and the guide washers 25a, 7b. More particularly, the elastic members 25a, 25b are arranged in pairs. The elastic members 25a, 25b of the same pair are arranged in series via a common phasing member 41, so that the elastic members 25a, 25b deform in phase with each other. In the embodiment shown in the figures, the torque converter has three pairs of resilient members 25a, 25b. Thus, for each pair of resilient members 25a, 25b, depending on the direction of rotation of the guide washers 7a, 7b with respect to the annular web 36, one of the elastic members (eg 25a) is intended to bear on the one hand, on the corresponding end of the windows 29 of the guide washers 7a, 7b and, on the other hand, on the phasing member 41. The other elastic member (for example 25b) is then intended to bear, on the one hand, on the phasing member 41 and, on the other hand, on one of the faces 39 of the corresponding tab 38 of the annular web 36. Furthermore, the annular housing delimited by the recesses 14, 15 of the central hub 8 and the turbine hub 6 (Figure 4) is intended for the housing of third elastic members 25c (only visible in Figure 1), active only at the end of the angular movement of the input member 15 of torque (including in particular the guide washers 7a, 7b and the turbine hub 6) by rap port to the torque output member (having the annular web 36 and the central hub 8). The phasing member 41 has an outer annular portion 42 from which tabs 43, here three in number, extend radially inwards (Figure 3). Each tab 43 has two opposite faces 44 serving to support the resilient members 25a, 25b, inclined relative to each other and relative to the radial direction. Two abutment zones 45, forming shoulders, extend circumferentially on either side of each tab 43.

The abutment studs 40 of the tabs 38 of the annular web 36 are able to bear respectively on the abutment zones 45 of the phasing member 41. The studs 40 and the zones 45 are positioned and dimensioned so as to limit the compression of the elastic members 25a, 25b and avoid, when it comes to helical springs, that the turns of the springs are contiguous during their compression, both in the sense of rotation in the forward direction and in the direction of rotation; opposite rotation, says retro sense. The forward direction corresponds to the case of operation in which torque is transmitted from the torque input element 6, 7 to the torque output element 36, 8. In certain operating phases, for example when the user abruptly removes his foot from the accelerator, a resistive torque is transmitted from the torque output member 36, 8 to the torque input member 6, 7, which can cause rotation of the actuator member. phasing 41 in the retro direction. The device further comprises pendulum masses 46 movably mounted at the radially outer periphery of an annular support 47, the radially inner periphery of said support 47 being coupled in rotation with the tabs 43 of the phasing member 41 by the The pendulum masses 46 are mounted movably on the support 47 via spacers 49 and rollers 50 (FIG. 4), as is known per se. being intended to improve the filtration of vibrations and rotational acyclisms. FIG. 5 shows a bad mounting of the turbine hub 6 on the central hub 8, as opposed to a correct assembly as illustrated in FIG. 4. In the event of a bad assembly, the front face 51 of the turbine hub 6 is turned towards the rear so that the portion 21 of the turbine hub 6 bears on the shoulder 11 of the central hub 8. The inner periphery of the guide ring 7a then bears on the face 16 of the turbine hub 6.

In this case, the axial distance between the faces 51 and 16 of the turbine hub 6 is such that it prevents the insertion of the tongues 27 of the guide washer 7b into the orifices 28 of the guide washer 7a or that it prevents said tabs 27 opening outwards beyond said orifices 28. The crimping of the two guide washers 30 7a, 7b with the aid of the tongues 27 is thus made impossible and an error of 3034478 11 mounting of the hub of turbine 6 can be detected easily and quickly by an operator. Moreover, in case of mounting error, the groove 13 is covered and made inaccessible by the turbine hub 6, so that it is impossible to mount the device according to the invention on other elements of a gearbox for example.

Claims (10)

REVENDICATIONS1. Torque transmission device for a motor vehicle, comprising a torque input member (6, 7), a torque output member (36, 8), resilient members (25a, 25b) mounted between the torque element torque input (6, 7) and the torque output member (8), said resilient members (25a, 25b) being adapted to act against rotation of the torque input member ( 6, 7) relative to the torque output member (36, 8), characterized in that the torque output member (36, 8), respectively the torque input member (6, 7) ), comprises a hub (8) comprising a first cylindrical portion (9) and a second cylindrical portion (10) of greater diameter than the first cylindrical portion (9), the torque entry element (6, 7) respectively the torque output member (36, 8) having an annular member (6) comprising, at its radially inner periphery, a first cylindrical portion (20) m a second cylindrical portion (21) mounted around the second cylindrical portion (10) of the hub (8). 2. Device according to claim 1, characterized in that the first cylindrical portion (9) or the second cylindrical portion (10) of the hub (8) has substantially the same diameter as the first cylindrical portion (20) or the second portion cylindrical (21) of the annular member (6). 3. Device according to claim 1 or 2, characterized in that it comprises at least one first elastic member (25a) and at least one second elastic member (25b), arranged in series via a phasing member (41), so that the first and second elastic members (25a, 25b) deform in phase with each other, the phasing member (41) being movable relative to the element of torque input (6, 7) and relative to the torque output member (34, 8), the first resilient member (25a) being mounted between the torque input member (6, 7). and the phasing member (41) and being adapted to act against the rotation of the torque input member (6, 7) relative to the phasing member (41), the second member elastic member (25b) being mounted between the phasing member (41) and the torque output member (36, 8) and being adapted to act against rotation of the blow-out member (36, 8) relative to the phasing member (41), on a first angular range. 4. Device according to claim 3, characterized in that it comprises at least a third elastic member (25c) mounted with a circumferential clearance 10 between the torque input member (6, 7) and the output member. torque (36, 8), or between the phasing member (41) and the torque output member (36, 8), or between the torque input member (6, 7) and the phasing member (41), in parallel with the first elastic member (25a) and / or the second elastic member (25b). 15 5. Device according to claim 4, characterized in that the hub (8) and / or the annular member (6) define an annular housing (14, 15) in which is housed, at least in part, the third elastic member. (25c). 6. Device according to one of claims 1 to 5, characterized in that it comprises two guide washers (7a, 7b) located axially on either side of an annular web (36), the washers of guide (7a, 7b) belonging to the torque input member, the annular web (36) belonging to the torque output member, or vice versa, the annular member (6) being attached to one ( 7a) guide washers (7a, 7b), the hub (8) being attached to the annular web (36). 7. Device according to claim 6, characterized in that the annular web (36) comprises an annular portion (37) from which lugs (38) extend radially outwardly, the first and second elastic members ( 25a, 25b) being circumferentially mounted between said tabs (38) of the web (36). 3034478 14 8. Device according to one of claims 1 to 7, characterized in that it comprises pendular damping means (46, 47) mounted on a movable member (41) of said device. 9. Device according to claims 3 and 8, characterized in that the pendulum damping means comprise a support (47) coupled in rotation to the phasing member (41) or formed by said phasing member (41), and pendulum masses (46) movably mounted on the support (47). 10. Hydrodynamic torque converter for a motor vehicle, characterized in that it comprises at least one device according to one of claims 1 to 9.