FR3034483A1 - TORQUE TRANSMISSION DEVICE FOR A MOTOR VEHICLE - Google Patents

Abstract

A torque transmission device for a motor vehicle having a torque input member (7b) for coupling to a motor shaft, and a torque output member (8) for coupling to an input shaft of a gearbox, elastic members acting against rotation of one of the input and output elements relative to the other and pendulum damping means comprising a mobile support (31) on which pendulum masses (30) are mounted in a mobile manner, characterized in that said support (31) comprises stop means (34) able to cooperate with complementary abutment means (18) of the torque input member (7b), respectively of the torque output member, so as to limit the relative rotation of said carrier (31) relative to the torque input member (7b), respectively the relative rotation of said support (31) with respect to the torque output element.

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 adapted to act against the rotation of one of said input elements over a limited angular range, particularly at the end of the angular stroke. 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). An internal combustion engine generates acyclisms because of the successive explosions in the cylinders of the engine, these acyclisms varying in particular as a function of the number of cylinders. A damping device is generally equipped with friction elements which, in combination with the circumferential action springs, filter out the vibrations due to motor rotation acyclisms. This prevents such vibrations pass into the gearbox and cause shock, noise and unwanted noise.

In order to further improve filtration, it is known to use a pendulum damping device in addition to the usual damping system. The patent application FR 2 981 714, in the name of the Applicant, discloses a pendular damping device 20 comprising an annular support intended to be rotated about its axis and pendular masses mounted at the outer periphery of the support. Each mass is driven in a pendulum operation and has two parts, mounted axially on either side of the support and connected by three spacers each through an opening of the support. A roller is mounted between a raceway formed in each spacer and the edge of the corresponding opening of the support. The spacers are attached to both parts of the mass by riveting. In response to rotational irregularities or acyclisms, each mass moves so that its center of gravity oscillates pendulum. The oscillation frequency of each mass is proportional to the speed of rotation of the drive shaft, the corresponding multiple may for example take a value close to the rank of the overriding harmonic of the vibrations responsible for the large irregularities of rotation in the vicinity. slow motion.

Because of the large mass of the assembly formed by the support and the associated masses, this assembly has a significant inertia. This support can be connected to the torque input element, to the torque output element or to the phasing member of a LTD type damping device, a high inertia of the assembly. aforementioned can fully compress all or part of the elastic members, both in the direction of rotation said forward direction in the opposite direction of rotation, said retro direction. The forward direction corresponds to the operating case in which torque is transmitted from the torque input member to the torque output member. 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 to the torque input member, which may cause a loss of torque. rotation of the phasing member in the retro direction. When the elastic members are helical compression springs, excessive compression of these springs can cause the turns to contact each other. The turns are then called joined. If the transmitted torque is large, the turns are crushed causing fatigue and premature wear of the springs. In general, it is necessary to be able to limit the angular deflections between all or part of the moving elements of the torque transmission device. For this purpose, it has been envisaged to provide complementary abutment means 30 between the phasing member and guide washers belonging to the torque input element, these complementary abutment means being located radially at a distance from one another. outside the different elastic members. There is currently a need to reduce the radial size of such a torque transmission device.

The object of the invention is in particular to provide a simple, effective and economical solution to this problem. For this purpose, the invention provides a torque transmission device for a motor vehicle, having a torque input member for coupling to a motor shaft, and a torque output member for coupling to an input shaft of a gearbox, elastic members acting against the rotation of one of the input and output elements relative to the other and pendular damping means comprising a mobile support on which pendulum masses are movably mounted, characterized in that said support comprises stop means capable of cooperating with abutment means complementary to the torque input element, respectively of the element of torque output, so as to limit the relative rotation of said carrier relative to the torque input member, respectively the relative rotation of said carrier relative to the torque output member. The abutment means being located on the movable support, they can be located radially opposite the elastic members for example. The radial size of the device can be reduced. In addition, the device may comprise at least one group 25 of elastic members mounted between the input and torque output members, the elastic members of this group being arranged in series via a phasing member, so that the elastic members of each group deform in phase with each other.

The torque transmission device is then LTD (Long Travel Damper) type.

The support may be rotatably coupled to the phasing member. Moreover, the resilient members of the or each group may bear, on the one hand, on an annular web and, on the other hand, on two guide washers which extend radially on either side of the annular sail and which are rotatable relative to the latter. In this case, the guide washers may belong to the torque input element, the annular web belonging to the torque output member. In addition, at least one of the guide washers may comprise at least one circumferentially located window facing at least one elastic member, the complementary stop means being formed by at least one of the circumferential ends of said window. The support of the moving masses may then comprise an annular portion from which at least one abutment zone extends radially inwards, said abutment zone being able to bear on at least one of the circumferential ends. of said window. In addition, at least one of the guide washers may comprise a radially inner annular portion and a radially outer annular portion, axially offset relative to one another, the window being located radially between said inner annular portions and external. According to one embodiment of the invention, the torque input means or the torque output means may comprise a hub comprising a radially extending annular portion in which at least one oblong shaped opening is provided. arc of circle, the support pendular masses comprising at least one axially extending pin engaged in said opening, the angular displacement of said support relative to the hub being limited by abutment of said stud on the circumferential ends of the oblong opening. Said stud may be formed by a rivet.

Furthermore, the hub may comprise a grooved cylindrical portion from which the annular portion comprising the oblong opening extends radially inwards. In addition, the hub can be fixed, for example by riveting, to one of the guide washers. The angular displacement between the pendular mass support on the one hand, and the torque input element, respectively the torque output element, on the other hand, can be between 1 and 30 °, preferably between 5 and 300.

The torque transmission device may also comprise at least one of the following features: the pendulum masses are mounted at the radially outer periphery of the support. the support is coupled in rotation to the phasing member, by means of spacers, said spacers are riveted to the support and to the phasing member, the device comprises a hub, radially internal, intended for be coupled to an input shaft of a gearbox, - said hub is rotatably coupled to the annular web, - the device comprises a first group of resilient members mounted between the input and output members of torque designed to counteract the rotation of one of said torque input or output members upon rotation of one of said input or torque output members with respect to the another on a first predetermined angular range, and a second group of resilient members, mounted with clearance between the input and torque output members, in parallel with the first group of resilient members and arranged to act against the rotation of one of said elements s of torque input or output, over a second defined angular range, lower than the first angular range. - The elastic members of the second group are housed, at least in part, in a housing of the first radially inner hub. 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 appended drawings, in which: FIGS. 1 to 6 represent a torque transmission device according to a first embodiment of the invention, in which: - Figure 1 is a schematic view of a torque converter equipped with a torque transmission device according to the invention; FIG. 2 is a perspective view from the front of the device; FIG. 3 is a perspective view from the rear of the device; FIG. 4 is a view corresponding to FIG. 3, in which FIG. grooved hub is not shown, Figure 5 is a front view of the device, in a rest position, Figure 6 is a view corresponding to Figure 5, in an abutment position, - Figures 7 to 9 represent an arrangement Torque transmission according to a second embodiment of the invention, in which: FIG. 7 is a front view of the device, in a rest position, FIG. 8 is a half-sectional view according to FIG. VIN-VIN line of Figure 7, Figure 9 is a perspective view from the rear of the device.

Figures 1 to 8 show a torque transmission device according to a first embodiment of the invention. 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 example a crankshaft 1, an input shaft 2 of a gearbox. The torque converter conventionally comprises an impeller impeller 3, adapted to hydrokinetically drive a wheel with turbine blades 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, itself coupled to two guide washers 7, respectively called hereinafter rear guide washer 7a and front guide washer 7b.

As best seen in FIGS. 2 to 6 illustrating a first embodiment of the invention, the front guide washer 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 gearbox. The front guide ring 7a is mounted around the hub 20 of turbine 6 and fixed thereto via pins 6a (Figure 2). The two guide washers 7a, 7b extend radially and delimit between them an internal space 9 (Figure 8) accommodating elastic members 10a, 10b of a first group, which are for example helical compression springs. Each member 10a, 10b may be composed of two concentric helical springs. The rear guide washer 7b has a cylindrical rim 11 at its radially outer periphery, extending towards the front guide washer 7a and fixed thereto. The free end of the cylindrical flange 11 comprises tongues 12 (Figure 2) extending axially, before fixing the two guide rings 7a, 7b therebetween. These tongues 12 are engaged 3034483 9 in openings 13 of the front guide ring 7a and are folded during a riveting operation, and can be welded thereto, so as to ensure the attachment of the two guide rings 7a, 7b.

The guide washers 7a, 7b conventionally comprise windows 14 for accommodating the resilient members 10a, 10b. More particularly, each guide washer 7a, 7b has a radially inner portion 15 and a radially outer portion 16 connected to each other by radial tabs 17, the lateral edges of said radial tabs 17 forming the circumferential ends 18 of the Windows. With particular reference to the rear guide washer 7b, the radially inner and outer portions 15, 16 are axially offset from one another, each tab 17 being axially curved so as to connect the two aforesaid portions 15, 16. The radially inner portions 15 of the two guide washers 7a, 7b are further spaced apart from each other than the radially outer portions 16 of said guide washers 7a, 7b. In particular, each lug 17 has, at its end connected to the radially inner portion, a flat zone 19 located substantially in the radial plane of the radially inner portion 15. A splined hub 20 is also fixed by riveting on the rear face of the rear guide washer 7b. This splined hub 20 has a radial portion 21 fixed to said rear face of the rear guide washer 7b, and a fluted cylindrical flange 22 extending rearwardly from the radially outer periphery of the radial portion 21. A clutch 23 (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 23 comprises an input element 24 coupled to the crankshaft 1 and an output member 25, including the splined hub 20.

An annular radially extending web 26 is mounted in the inner space 9 delimited between the guide washers 7a, 7b and is fixed to the central hub 8, for example by means of rivets. The annular web 26 comprises for example a radially inner annular portion 5 from which tabs, for example three in number, extend radially outwards. Each lug comprises two opposite faces serving to support the resilient members 10a, 10b, inclined with respect to each other and with respect to the radial direction. The elastic members of the first group 10a, 10b are circumferentially mounted between the annular web 26 and the guide washers 7a, 7b. More particularly, the elastic members 10a, 10b are arranged in pairs. The elastic members 10a, 10b of the same pair are arranged in series via a common phasing member 27, so that the elastic members 10a, 10b deform in phase with each other. In the embodiment shown in the figures, the torque converter comprises three pairs of elastic members 10a, 10b. Thus, for each pair of elastic members 10a, 10b, as a function of the direction of rotation of the guide washers 7a, 7b with respect to the annular web 26, one of the elastic members (for example 10a) is intended to bear on the one hand, on the corresponding end 18 of the windows 14 of the guide washers 7a, 7b and, on the other hand, on the phasing member 27. The other elastic member (for example 10b) is then intended to 25 on the one hand, on the one hand, on the phasing member 27 and, on the other hand, on one of the faces of the corresponding tab of the annular web 26. The phasing member 27 is visible only partially and has an annular portion from which lugs 28 extend radially inward (Figure 2). Each lug 28 has two opposite faces 29 serving to support the resilient members 10a, 10b, inclined with respect to each other and with respect to the radial direction.

The device further comprises pendular masses 30 movably mounted at the radially outer periphery of an annular support 31. Said support 31 comprises an annular portion 32 from which abutment zones 33, here three in number , extend radially inwards. Each abutment zone 33 is located facing one of the windows 14 of the rear guide washer 7b and has two lateral edges equipped with studs 34 of rounded section, able to bear against the circumferential ends 18 of the window 10 In particular, the studs 34 are able to bear on the lateral edges 18 of the plane zones 19 of the radial tabs 17 of the guide ring 7b. The pads 34 extend in the plane of the support 31. The abutment zones 33 are also connected to the phasing member 27 via spacers 35, which can be riveted.

The pendulum masses 30 are movably mounted on the support 31 by means of rollers 36 (partially visible in FIG. 5) and spacers 37, as is known per se, these masses being intended to improve filtration of vibrations and rotational acyclisms.

The device further comprises a second group of elastic members 38 (FIGS. 1 and 8) in the form of helical compression springs and partly mounted in an annular recess 39 of the hub 8 and, partly, in an annular housing 40 of the hub 6. The housing 39 of the hub 8 opens axially towards the rear and the housing 40 of the hub 6 opens axially forwardly. Each elastic member 38 of the second group comprises a first end intended to bear against an abutment of the hub 6 and a second end intended to bear against an abutment of the hub 8, or vice versa, depending on the direction of rotation of the torque input member 30 (including in particular the guide washers 3034483 12 7a, 7b and the hub 6) relative to the torque output member (including in particular the web 26 and the hub 8). The elastic members 38 of the second group are mounted with a circumferential clearance located between the ends of said elastic members 38 and the abutments of the hubs 6, 8. This circumferential clearance is noted j in FIG. 1. In operation, the guide washers 7a , 7b and the hub 6 pivot relatively relative to the web and the hub 8, an angle a (in the forward direction or in the retro direction).

As long as this angle α is smaller than the angular clearance j, i.e. at an angle α1, then only the elastic members 10a and 10b of the first group are active, i.e. against rotation of the torque input member (washers 7a, 7b and hub 6) relative to the torque output member (web and hub 8).

When the entire game j is caught, that is to say when the angle a is greater than or equal to ai, then the elastic members 38 of the second group act in parallel elastic members 10a, 10b of the first group . The position a = 0 is defined by the home position of the device in which no torque is transmitted through said device. Such a position is illustrated in FIG. 5. It can be seen that, in this position, the pads 34 of the abutment zones 33 do not bear against the circumferential ends 18 of the windows 14 of the guide washer 7b. The abutment zones 33, the pads 34 and the windows 14 are positioned and dimensioned so as to limit the compression of the elastic members 10a, 10b and avoid, when it comes to coil springs, that the turns of the springs are contiguous when of their compression, both in the direction of rotation said direct direction in the opposite direction of rotation, said retro direction. The forward direction corresponds to the operating case in which torque is transmitted from the torque input member to the torque output member. In certain phases of operation, for example when the user abruptly removes his foot from the accelerator, a resisting torque is transmitted from the torque output member to the torque input member, which may cause a rotation of the phasing member 27 in the retro direction. The total angular displacement of the support 31 and the phasing member 27 relative to the guide washers 7a, 7b is for example between 1 and 30 °, preferably between 5 and 30 °.

FIG. 6 shows an abutment position of the support 31 with respect to the guide washer 7b, in the case where the support 31 pivots in the direct direction with respect to the guide washers 7a, 7b. In this case, the pads 34 bear against the corresponding circumferential ends 18 of the windows 14 of the guide washer 7b.

Figures 7 to 9 show a second embodiment of the invention. In this embodiment, the support 31 of the pendular masses 30 is, as previously, rotatably coupled to the phasing member 27, the radially inner periphery of said support comprising studs 41, formed for example by rivets, here at the number Of three and extending axially. The pads 41 are engaged in oblong apertures 42 in the shape of a circular arc formed in the radial portion 21 of the corrugated hub 20. The studs 41 and the openings 42 are positioned and dimensioned so as to limit the angular displacement of the support 31 and 25 of the phasing member 27, on the one hand, with respect to the splined hub 20 and the guide washers 7a, 7b, on the other hand, by abutment or support of said pads 41 on the circumferential ends 43 of the oblong openings 42 As before, the total angular displacement of the support 31 and the phasing member 27 with respect to the guide washers 7a, 7b and the corrugated hub 20 is, for example, between 1 and 30 °, preferably between 5 and 30 °. and 30 °. In these two embodiments, taking into account the position of the abovementioned abutment means, it is possible to reduce the radial size of the torque transmission device and / or to increase the implantation radius of the elastic members 10a, 10b so as to further improve the filtration quality obtained.

Claims (10)

REVENDICATIONS1. Torque transmission device for a motor vehicle having a torque input member (7a, 7b, 6) for coupling to a motor shaft (1), and a torque output member (26, 8), intended to be coupled to an input shaft (2) of a gearbox, resilient members (10a, 10b) acting against the rotation of one of the input and output elements relative to to the other and pendular damping means comprising a movable support (31) on which pendulum masses (30) are mounted in a movable manner, characterized in that said support (31) comprises stop means (34) suitable cooperating with complementary stop means (18) of the torque input member (7a, 7b, 6), respectively of the torque output member (26, 8), so as to limit the relative rotation said support (31) relative to the torque input member (7a, 7b, 6), respectively the relative rotation of said support (31) with respect to the torque output member (26, 8). 2. Device according to claim 1, characterized in that it comprises at least one group of elastic members (10a, 10b) mounted between the input and torque output members, the elastic members (10a, 10b) of this group being arranged in series via a phasing member (27), so that the elastic members (10a, 10b) of each group deform in phase with each other. 3. Device according to claim 2, characterized in that the support (31) is rotatably coupled to the phasing member (27). 4. Torque transmission device according to one of claims 1 to 3, characterized in that the elastic members (10a, 10b) of the or each group are supported, on the one hand, on an annular web (26) and on the other hand, on two guide washers (7a, 7b) which extend radially on either side of the annular web (26) and which are rotatable relative thereto. 3034483 16 Torque transmission device according to claim 4, characterized in that the guide washers (7a, 7b) belong to the torque input element, the annular web (26) belonging to the output element of couple. 5 6. Device according to claim 4 or 5, characterized in that one (7b) at least guide washers (7a, 7b) comprises at least one window (14) circumferentially located facing at least one elastic member. (10a, 10b), the complementary abutment means being formed by at least one of the circumferential ends (18) of said window (14). 7. Device according to claim 6, characterized in that the support (31) of the movable masses (30) comprises an annular portion (32) from which at least one abutment zone (33) extends radially towards the interior, said abutment zone (33) being able to bear on at least one of the circumferential ends (18) of said window (14). 8. Device according to claim 6 or 7, characterized in that at least one of the guide washers (7a, 7b) comprises a radially inner annular portion (15) and a radially outer annular portion (16), axially offset. one with respect to the other, the window (14) being located radially between said inner and outer annular portions (15, 16). 9. Device according to one of claims 1 to 8, characterized in that the torque input means or the torque output means comprise a hub (20) comprising an annular portion 25 extending radially (21) in which is provided at least one oblong opening (42) in the form of a circular arc, the support (31) of the pendulum masses (30) comprising at least one stud (41) extending axially, engaged in said opening (42) , the angular displacement of said support (31) relative to the hub (20) being limited by abutment of said stud (41) on the circumferential ends (43) of the oblong opening (42). 3034483 17 10. Device according to one of claims 1 to 9, characterized in that the angular displacement between the support (31) of the pendulum masses (30) on the one hand, and the torque input element, respectively the The torque output element, on the other hand, is between 1 and 30 °, preferably between 5 and 30 °.