FR3075288B1 - TRANSMISSION DEVICE WITH BALANCING MEANS - Google Patents

Abstract

Torque transmission device (1) for a power unit of a motor vehicle, comprising: - a friction element (2) rotatable about an axis of rotation X, the friction element comprising a friction zone (3) adapted to be gripped by a torque transmission mechanism (50), - a damper (4) comprising a damper input member (5), a damper output member (8), at least one spring ( 10) being arranged between the damper inlet member (5) and the damper outlet member (8) so as to compress to filter the acyclisms, and the friction member (2) being fixed to the damper input member (5), - at least one balancing means (11),

Description

TRANSMISSION DEVICE WITH BALANCING MEANS

Technical area

The invention relates to the field of torque transmission devices, in particular for powertrains of motor vehicles.

The invention also relates to a transmission assembly comprising a torque transmission device and a transmission mechanism.

Technological background

Motor vehicle transmissions are generally equipped with a torsion damper for filtering vibrations upstream of the gearbox so as to avoid shock, noise or noise particularly undesirable. Such damping systems are used in particular dual damping flywheels (DVA) and / or clutch friction, in the case of a manual or robotic transmission, or locking clutches, also called "lock-up" clutches. , fitted to the hydraulic coupling devices, in the case of an automatic transmission.

The damping systems comprise resilient damping means rotatably coupling an input member and an output member so as to allow torque transmission and damping of rotational acyclisms.

In the prior art, it is known to reduce the unbalance phenomenon by using balancing nails which are positioned in the damper at appropriate places to compensate for the unbalance phenomenon, which was observed before the introduction of the balancing nail.

This type of solution is for example described in the document FR2669387. However, the positioning of the nail on the guide rings does not allow to position this nail beyond a certain distance from the axis of rotation, distance imposed by the radius of the guide ring. However, the greater the distance with the axis of rotation to which the balancing nail is implanted, the more efficient the balancing is. Conversely, the closer the balancing nail is positioned near the center, the greater its mass must be, which does not go in the direction of lightening the torque transmission device. Furthermore, circumferentially, the nail can be arranged where desired on the guide washers because some areas of the guide ring are devoted to the attachment of the friction element and it is also difficult to use the zones of the guide washer near the springs to mount a balancing means.

Prior solutions are also known in which certain components of the transmission device have been modified to make them play, in addition to their initial function, the balancing function. This approach does not allow to standardize parts. Finally, using an existing component to play the balancing function does not play on the mass of the device exactly where desired. The balancing possibilities are therefore limited.

In addition, it may be useful to implement the balancing means at the end of assembly according to the intended use for the transmission device, which is not possible when the balancing function is provided by a component providing another function in the transmission device (stop, spacer, assembly of parts)

summary

An idea underlying the invention is to provide a torsion damper having a good balance, with standard components, and with great freedom of implantation of the balancing means, circumferentially.

An idea underlying the invention is also to provide an effective balancing device that does not significantly increase the transmission device.

An idea underlying the invention is to differentiate as late as possible in the manufacturing process the transmission device according to its balancing means.

For this, the invention provides, according to claim 1, a torque transmission device for a powertrain of a motor vehicle, comprising:

a friction element able to rotate about axis of rotation X, the friction element comprising a friction zone that can be gripped by a torque transmission mechanism,

a damper comprising a damper input member, a damper output member, at least one spring being arranged between the damper input member and the damper output member so as to compressing to filter the acyclisms, and the friction member being attached to the damper input member,

at least one balancing means.

In a plane comprising the axis of rotation X and passing through the balancing means, the balancing means is arranged radially between the damper input member and the friction zone.

Thus, the invention offers a great freedom of balancing.

According to other advantageous embodiments, such a transmission device may have one or more of the following characteristics:

The damper input member has an outer contour, and each balancing means is arranged radially outwardly of the outer contour of the damper input member.

The damper has an outer contour and each balancing means is arranged radially outside the outer contour of the damper input member.

The torque transmission device comprises a plurality of balancing means and each balancing means is arranged, in a plane comprising the axis of rotation X and passing through this balancing means, radially between the input element. damper and the friction zone.

According to one embodiment, in the plane comprising the axis of rotation X and passing through the balancing means, the support disc has no balancing means on the other side of the axis of rotation X.

The balancing means is arranged on the friction element.

The balancing means is connected only to the friction element.

The balancing means is connected only to the friction element. In other words, the balancing means is not a fastener for assembling two parts of the transmission device.

The balancing means is integrated with the friction element.

The balancing means is a recess in the friction element. Thus the balancing of the transmission device also allows to lighten it.

The balancing means is a recessed or machined area of the friction element.

The balancing means is a hole formed in the friction element.

The balancing means is an element adding mass locally to a portion of the torque transmission device, including a portion of the friction element. This reduces the risk of embrittlement due to the removal of material. The addition of mass makes it easier to balance the transmission device, and gives more maneuvering margins for balancing.

The balancing means is a rivet.

The rivet is attached to the friction element.

The balancing means is a rivet with two heads enclosing the friction element, one of the heads being heavier than the other heads. In particular, the mass of one of the heads is at least twice the mass of the other of the heads. The heavier rivet head is called the balancing head.

The balancing means is a blind rivet or rod break.

The balancing means is a solid rivet.

The balancing means is an element welded or clipped to the friction element.

The friction element comprises a fixing portion, the fixing portion of the friction element being fixed on a radially outer zone of the damper input element.

The fixing portion of the friction element is located on a radially inner region of the friction element.

The friction zone is located on a radially outer zone of the friction element.

The balancing means is arranged on an intermediate zone of the friction element located radially between the fixing portion and the friction zone of the friction element.

The damper input element has, in a plane perpendicular to the X axis, an undulating contour around the X axis, the corrugated contour having at least two ridges arranged circumferentially on either side of a hollow, at least a portion of the balancing means being arranged circumferentially between two peaks of the damper input member.

The ridges have an extremum defining an outer peak diameter and the balancing means may be arranged at least in part within this maximum diameter. Thus, this solution makes it possible to reduce the inertia of the damper input element while maintaining the balancing means quite far from the axis X. Such a corrugated contour is for example useful when it is desired to limit the inertia of the damper input element.

The friction element has an annular shape around the X axis.

Alternatively, the friction element is a pale extending over a limited angular sector around the X axis, especially on a sector of 10 to 45 degrees.

The friction element carries at least one lining, said at least one lining being carried by the friction zone of the friction element.

The lining has an inner contour, and each balancing means is arranged radially inside this inner contour.

The friction element has axial progressivity. In other words, it has deformable portions capable of exerting axial forces of elastic return opposing the clamping forces of the friction element.

The damper input member has at least one guiding guide washer axially retaining the spring.

The damper input element comprises two guide washers arranged axially on either side of the springs.

The two guide washers are arranged at an axial distance fixed from one another.

The two guide washers are mounted integral in rotation.

For example, spacers rotate the two guide rings in rotation and keep them at a fixed distance from one another.

The damper output member is a web arranged axially between the two guide washers.

The torque transmission device comprises a driven member coupled to the damper output member and adapted to drive a gearbox input shaft.

The driven member is a hub comprising internal splines arranged to cooperate with external splines of a gearbox input shaft.

The hub is coupled to the damper output member through a ring gear of the hub.

The driven member is integral in rotation with the damper output member.

The spring is supported on one end, against the two guide rings, and on the other of its ends, against the web.

The axial length of the balancing means is greater than the axial thickness of the web.

The damper input member has a clearance of material or notch, the balancing means occupying at least a portion of the space left by the release of material or indentation. Thus, it is possible to lighten the damper input element while maintaining the balancing means at a satisfactory distance from the axis of rotation.

The guide washers are rotatably mounted around the hub by bearings.

The transmission device comprises a pendulum damper.

The pendulum damper comprises a rotatable rotary support about the axis of rotation.

The pendular support is mounted integral in rotation with the damper output element.

The pendulum damper is centered on the driven member via its pendular support.

The pendular support may be integral in rotation with the driven member, for example by force fitting, or by means of splines.

The pendular support may be mounted integral in rotation with the damper output member. The pendular support can be mounted directly on the damper output member.

The rotationally fixed mounting of the pendular support relative to the damper output member or to the driven member must be interpreted as being integral in rotation at least up to a certain torque level, the presence of another limiter of torque (to protect the pendulum from over-tweezers) between on the one hand the damper output member or the driven member, and on the other hand, the pendulum support, not being excluded from this invention.

The pendular damper comprises at least one pendular mass, preferably a plurality of pendular masses, able to move freely relative to the pendular support and guided by the same pendular support.

The pendulum mass can be mounted at the outer periphery of the pendular support. The pendulum mass is driven in a pendulum operation and may for example comprise two parts mounted axially on either side of the pendular support and interconnected by one or more spacers each through an opening of the pendular support. A roller can cooperate with a raceway formed in each spacer and with the edge of the corresponding opening of the pendular support.

Alternatively, the roller can cooperate with two raceways, each formed in an opening of a portion of the pendulum mass, and with a third raceway formed by the edge of an opening of the pendulum support different from the openings of the support pendular dedicated to the spacers.

In each of these cases, several rollers may be provided for each pendulum mass.

Preferably, the pendulum mass and the friction zone are offset axially.

According to one embodiment, the balancing means is arranged radially beyond the internal radial edge of the pendular masses.

Preferably, there is an axis parallel to the axis of rotation passing through both the pendulum mass and the balancing means. The balancing means and the pendulum mass can therefore be axially opposite one another.

The friction element comprises an annular disc arranged around the axis X. According to one variant, the friction element comprises a plurality of blades regularly distributed around the axis X.

The friction element comprises a plurality of implantation points, each implantation point being able to receive a balancing means.

The friction element has a plurality of balancing zones, each balancing zone having a plurality of implantation points.

The damper input element has a clearance of material or notch in axial vis-à-vis of each balancing zone.

The implantation points are regularly distributed around the X axis.

The invention also relates to a transmission assembly comprising:

the transmission device according to one of the preceding claims,

- A pressure mechanism arranged to permanently or temporarily pinch the friction element at said at least one friction zone.

According to other advantageous embodiments, such a transmission assembly may have one or more of the following characteristics:

The pressure mechanism is a torque limiter.

The torque limiter comprises a bearing washer, a pressure washer, a reaction washer, the friction element being arranged axially between the pressure washer and the reaction washer, a spring arranged between the support washer and the pressure washer so as to press the pressure washer against the friction zone so that the friction zone is pinched by the pressure washer and the reaction washer;

the torque limiter comprises an annular space axially separating the bearing washer and the reaction washer and in which the pressure washer, the spring and the friction zone of the friction element are arranged, the balancing means being also arranged at least partly in this annular space.

Thus, one can take advantage of this cavity, usually unused, to implement balancing means which is quite effective at this location relatively far from the axis of rotation.

The friction zone of the friction element, the gaskets, the pressure washer, and the spring are housed in this annular space.

The mounting portions of the support washer and the reaction washer are superimposed.

At least one of the support washer and the reaction washer has an axial recess so as to create the annular space accommodating the friction element, the gaskets, the pressure washer, the spring and the pressure means. 'balancing.

The axial recess of the thrust washer is oriented in a direction opposite to the axial direction of the recess of the reaction washer.

The balancing means is arranged radially inside the pressure washer. There is a radial overlap between the pressure washer and the balancing means, in particular between the balancing head of the balancing rivet (when the balancing means is a rivet) and the pressure washer,

In a plane comprising the axis of rotation X and passing through the balancing means, the balancing means is arranged radially between the web and the pressure washer.

The balancing means has an implantation axis, this implantation axis being located in the annular space of the torque limiter.

The transmission assembly may comprise a torque input member, in particular a flywheel mounted integrally in rotation, by means of fasteners such as screws or rivets, the bearing washer and the washer of reaction of the torque limiter.

The bearing washer and the reaction washer each comprise a mounting portion, the mounting portions being assembled to one another and being adapted to be mounted together on a flywheel.

The flywheel is flexible, especially axially.

- For comparison, the axial length of the balancing means may be greater than the axial thickness of the web. The axial length of the balancing means may be greater than the axial thickness of the assembly consisting of the friction element and the gaskets. The axial length of the balancing means may be greater than the minimum axial distance separating the guide washers. The axial length of the balancing means may be greater than the axial thickness of the pendulum in the mass zone. The axial length of the balancing means may be greater than the axial thickness of the assembly consisting of the friction element, the gaskets, and the pressure washer.

- According to another embodiment not shown, the friction mechanism is a clutch mechanism capable of pinching, in an engaged mode, the friction element and able to release, in a disengaged mode, the friction element.

Brief description of the figures

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly in the course of the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes. with reference to the accompanying drawings.

- Figure 1 is a front view of a transmission device according to a first embodiment of the invention.

- Figure 2 is a sectional view along AA of the torsion damper of Figure 1, the upper part corresponding to a view of the first embodiment in a plane comprising the axis of rotation X and passing through the means of 'balancing.

- Figure 3 is an enlarged sectional view of the torsion damper of Figure 1.

FIG. 4 is an implantation view of balancing means.

in persppective showing an example

- Figure 5 is a front view of a balancing rivet before assembly.

- Figure 6 is a front view of a balancing rivet after assembly.

- Figure 7 is a schematic view of a second embodiment.

- Figure 8 is a perspective view of a third embodiment.

FIG. 9 is a sectional view of a fourth embodiment comprising a pendulum, this sectional view corresponding to a view of the fourth embodiment in a plane comprising the axis of rotation X and passing through the means of FIG. balancing.

Detailed description of embodiments

In the description and the claims, it will be possible to use the external and internal terms as well as the axial and radial orientations to designate, according to the definitions given in the description, elements of the torsion damper.

By convention, the radial orientation is directed orthogonally to the rotational axis X of the torsion damper determining the axial orientation and, from the inside towards the outside away from said axis, the circumferential orientation is directed orthogonally to the axis of the torsion damper and orthogonal to the radial direction. The terms outer and inner are used to define the relative position of one element with respect to another, with reference to the axis X of rotation of the torsion damper, an element close to the axis is thus described as internal as opposed to an outer member located radially periphery.

The remainder of the description is made with reference to the figures in the context of a torque limiter for a motor vehicle, in particular for a hybrid vehicle. This description is not limiting and the invention is applicable by analogy to any other type of torque transmission device comprising a damper coupled to a friction element.

FIGS. 1 to 4 show a torque transmission device 1 for a power unit of a motor vehicle, comprising:

a friction element 2 rotatable around an axis of rotation X, the friction element 2 comprising a friction zone 3 capable of being gripped by a torque transmission mechanism 50,

a damper 4 comprising a damper input element 5, a damper output element 8, springs 10 being arranged between the damper input element 5 and the shock absorber output element 8 so as to compress itself to filter the acyclisms,

The friction element 2 is attached to the damper input element 5.

To correct the unbalance phenomenon, the transmission device comprises balancing means 11.

The damper inlet element comprises two guide washers 5 and 7 arranged axially on either side of the springs 10 and axially retaining the springs 10. The two guide washers 5 and 7 are arranged at a fixed axial distance one from the other. They are mounted integral in rotation by spacers 31 which, moreover, keep them at a fixed distance from one another.

The damper output element is a web 8 arranged axially between the two guide washers 5 and 7.

The torque transmission device 1 further comprises a hub 28 coupled to the web 8 and adapted to drive a gearbox input shaft by means of internal splines 29 arranged to cooperate with external splines of the shaft.

The hub 28 is coupled to the web by means of a ring gear 32 formed in the hub which cooperates with complementary shapes formed in the internal radial contour of the web 8.

The springs 10 bear on one of their ends, against the two guide washers 5 and 7, and on the other of their ends, against the web 8.

A friction device is interposed axially between at least one of the guide washers and the web 8 to dissipate the energy stored in the springs 10.

The guide washers 5 and 7 are rotatably mounted around the hub 28 by means of bearings 33 and 34.

Figures 1 and 2 describe the torque transmission device 1, within a transmission assembly 100 which comprises, in addition to the transmission device 1, a pressure mechanism 50.

The pressure mechanism here is a torque limiter 50 arranged to permanently clamp the friction element 3 at the friction zone 3.

The torque limiter 50 comprises:

a bearing washer 51, a pressure washer 52, a reaction washer 53, the friction element 2 of the transmission device being arranged axially between the pressure washer 52 and the reaction washer 53,

a spring 55 arranged between the bearing washer 51 and the pressure washer 52 so as to press the pressure washer 52 against the friction zone 3 of the friction element 2 so that the friction zone 3 is pinched by the pressure washer 52 and the reaction washer 53.

The bearing washer 51 of the reaction washer 53 of the torque limiter 50 can be mounted integral in rotation with a torque input member, for example a flywheel integral in rotation with the crankshaft of the vehicle. The bearing washer and the reaction washer each comprise a mounting portion 56, 57 which are superimposed on one another. Concentric orifices allow the same fastener such as a screw, to fix both the bearing washer 51 and the reaction washer 53 on the flywheel. If desired, the mounting portions can also be pre-assembled, for example with rivets 92, before mounting them on the flywheel (Figure 2).

The pressure washer 52 is mounted to rotate with the support washer 51 and the reaction washer 53 by means of tabs 64 which cooperate with notches 65 made in the support washer 51.

Thus, when the torque transmitted between the crankshaft and the gearbox input shaft is less than a limit threshold S, the reaction washer 53, the friction element 2 and the pressure washer 52 rotate together.

Conversely, when the transmitted torque reaches the limit threshold S, a sliding occurs at the friction element 2, between the friction zone 3 of the friction element 2 and the pressure washer 52 of a part, and between the friction zone 3 of the friction element 2 and the reaction washer 53 on the other hand. Thus, the torque passing from the crankshaft to the speed shaft is limited to said threshold limit S.

In Figure 1, we see that the torque transmission device 1 comprises a plurality of balancing means 11, here three in number.

Each balancing means is arranged, in a plane comprising the axis of rotation X and passing through this balancing means, radially between the damper inlet element 5 and the friction zone 3 of the element friction 2.

In this embodiment, the friction element comprises four balancing zones Z1, Z2, Z3 and Z4. Each balancing zone comprises three implantation points 88, each implantation point being able to receive a balancing rivet 11. Each implantation point is a hole 88 made in the friction element 2.

In each plane comprising the axis of rotation X and passing through the balancing rivet 11, the support disc does not have a balancing rivet on the other side of the axis of rotation X.

Here, only zone Z1 is provided with balancing rivets. However, the arrangement of Figure 1 allows many combinations of implant rivets.

Here, we see that the balancing means are carried only by the friction element 2.

The balancing rivet 11 adds weight locally to the friction element, which makes it easier to balance the transmission device.

As best seen in Figure 3, which is an enlargement of Figure 2, each balancing means is here formed by a solid rivet 11 fixed on the friction element 2. These balancing rivets have two heads 21 22 enclosing the friction element 2. One of the heads 22 is heavier than the other 21 heads. The heavier rivet head 22 may be called the balancing head.

In FIG. 3, it can be seen that the axial length of the balancing rivet 11, in particular the axial length of its balancing head 22, is greater than the axial thickness of the web 8.

In FIG. 4, which represents the torque transmission device of FIG. 3, without the torque limiter 50, it can be seen that the guide washer 5 has, locally, a clearance of material. Here the circular contour of the washer 5 is gnawed locally in the form of a flat.

The three rivets 11 occupy part of the space left by this flat. Thus, it can lighten the guide washer 5 to reduce its inertia while maintaining the balancing rivets 11 at a satisfactory distance from the axis of rotation X.

According to a variant not shown, the balancing means may be blind or rod break rivets. According to another embodiment not shown, the balancing means 11 is an element welded to the friction element. According to another embodiment not shown, the balancing means 11 may be integrated with the friction element. If necessary, the balancing means may be a recess, for example a hole, or a machining of the friction element 2. Thus the balancing of the transmission device makes it possible to lighten the torque transmission device.

FIG. 3 shows that the friction element 2 comprises a fastening portion 13, the fastening portion 13 of the friction element 2 being fastened to a radially outer zone of the shock absorber inlet element 5 .

The fixing portion 13 of the friction element 2 is located on a radially inner zone of the friction element 2 while the friction zone 3 is located on a radially outer zone of the friction element 2.

The balancing means 11 is arranged on an intermediate zone 16 of the friction element situated radially between the fastening portion 13 and the friction zone 3 of the friction element 2.

In the embodiment shown in FIGS. 1 to 4, the friction element is a friction disc 2 which has an annular shape around the axis X. As a variant, the friction element 2 may comprise a plurality of circumferentially distributed blades. around the X axis.

The friction disk 2 carries two liners 18, 19, carried by the friction zone 3 of the friction disc 2. The two linings are arranged on either side of the friction disc. If desired, this friction disk may have an axial progressivity capable of exerting axial forces of elastic return opposing the clamping forces of the friction element.

The liners 18, 19 have an inner contour C3, and each balancing rivet 11 is arranged, in a plane comprising the axis of rotation X and passing through the balancing rivet, radially inside this interior contour C3. .

The bearing washer 51 and the reaction washer 53 have an inner contour C4, and a portion of each balancing rivet 11 is arranged in a plane comprising the axis of rotation X and passing through the balancing rivet, radially outside this inner contour C4.

FIG. 3 shows the location of the balancing means within the assembly composed of the torque limiter 50, the friction disk 2 and the damper 4.

It can be seen in particular that the inner part of the bearing washer 51 and the inner part of the reaction washer 53 are axially separated by an annular space 58. The friction zone 3 of the friction element 2, the gaskets 18 and 19, the pressure washer 52, and the spring 55 are housed in this annular space 58. The bearing washer 51 and the reaction washer 53 each comprise an axial recess which creates this annular space 58. The axial recess of the bearing washer 51 and the recess of the reaction washer 53 are oriented in two opposite axial directions so that the cavity is formed by these two axial recesses. The bearing washer 51 and the reaction washer 53 form somehow two covers axially vis-à-vis one another and defining this annular space or cavity 58.

The balancing rivet 11 is also arranged partly in this annular space 58. Thus, it is possible to take advantage of this cavity 58, which is usually not used, to implement a balancing means which is fairly effective at this relatively remote location of the X axis of rotation

As seen in FIG. 3, the balancing rivet 11 is arranged radially inside the pressure washer 52. There is a radial overlap between the pressure washer 52 and the balancing rivet 11, particular between the balancing head 22 of the balancing rivet 11.

In a plane comprising the axis of rotation X and passing through the balancing rivet 11, the balancing rivet 11 is arranged radially between the web 8 and the pressure washer 52.

The balancing rivet 11 has an implantation axis A. This implantation axis A is located in the annular space 58 of the torque limiter 50.

The guide washer 5 has an outer contour C1, and in a plane P comprising the axis of rotation X and passing through the balancing rivet 11, the balancing rivet 11 is arranged radially outside the outer contour C1 of the guide washer 5.

The damper 4 has an outer contour C2, defined here by the outer contour of the web 8 and the balancing rivet 11 is arranged in a plane P comprising the axis of rotation X and passing through the balancing rivet 11, radially outside this contour C2.

This implantation balancing means offers, in addition to its radial distance with the X axis, great freedom of form for the balancing means, particularly with respect to the axial length of the balancing means.

Thus, by way of comparison, the axial length of the balancing rivet 11, and in particular its balancing head 22, may be greater than the axial thickness of the web 8. The axial length of the balancing rivet 11, and including its balancing head 22, may be larger than the axial thickness of the assembly consisting of the friction element 2 and the lining 18 and 19. The axial length of the balancing rivet 11 may be greater than the axial thickness of the assembly consisting of the friction element 2, the gaskets 18 and 19, and the pressure washer 52.

Figures 5 and 6 illustrate an example balancing rivet presented before assembly (Figure 5) and in mounted state (Figure 6). It can be seen that the entire mass of the balancing rivet 11 can be placed essentially on one of the two heads, in particular on the head 22 which is not deformed during assembly.

FIG. 7 is a schematic view of another embodiment in which the guide ring 5 has, in a plane perpendicular to the X axis, an undulating contour around the X axis.

The corrugated contour has a plurality of circumferentially arranged peaks 68, a depression 69 being arranged between two adjacent peaks 68.

The friction element is made here by a plurality of blades 2 distributed around the axis X. The blades 2 are fixed on the guide ring 5 by rivets 67 disposed at these ridges 68 which have been previously drilled. To do this, each pale 2 has a pale foot 2a which axially covers two ridges 68 of the guide washer 5.

The balancing means is fixed on the light foot 2a and part of the balancing means 11 is arranged circumferentially between two peaks 68 adjacent to the guide washer 5. As previously the balancing means 11 may be a rivet. Several balancing rivets can be used if needed.

The ridges 68 have an extremum defining an outer peak diameter DC and the balancing means 11 may be arranged at least partly within this DC diameter. Thus, this solution reduces the inertia of the guide ring 5 while maintaining the balancing means far enough from the axis X.

FIG. 8 is a perspective view of a third embodiment that differs from the first embodiment in that the balancing means 11 can be located on the periphery of the friction disc 2. The friction disc 2 comprises implantation holes 88 regularly distributed around the axis of rotation X. Depending on the balancing requirements, particularly as a function of the unbalance phenomena observed, a hole 88 or some holes 88 will be provided with balancing means such as balancing rivet 11.

The invention is particularly advantageous when it is desired to have uniformly distributed implantation points, in particular in comparison with the solutions of the prior art in which the implantation points are on the guide washer because a regular distribution of implantation points on the guide washers is difficult because of the presence of the spacers 31, the springs 10 ...

Figure 9 is a sectional view of another embodiment having an assembly as previously described mounted on a flywheel.

As before, the bearing washer 51 and the reaction washer 53 each comprise a mounting portion 56 and 57. These mounting portions 56 and 57 are each provided with orifices. The orifices of the mounting portions 56 and 57 of the bearing washer 51 and the reaction washer 53 are concentric so that the same screw is inserted into both the bearing washer and the reaction washer. These screws thus allow the attachment of the assembly composed of the torque transmission device 1 and the torque limiter 50 to the flywheel. This is a flexible flywheel 90, especially axially.

The bearing washer 51 and the reaction washer 53 are preferably preassembled, in particular by means of rivets 92 arranged on the mounting portions 56, 57 of the bearing washer 51 and the reaction washer 53.

The transmission assembly 100 further comprises a pendulum damper 70. The use of a balancing means 11 is particularly useful when a pendulum damper 70 is used because the pendulum damper 70 can generate a phenomenon of unbalance .

The pendular damper 70 comprises a pendular support 71 rotatable about the axis of rotation. The pendular damper 70 is centered on the hub 28 by means of its pendular support 71. The pendular support 71 may be mounted to rotate with the hub 28, for example by force fitting, or by means of splines.

The pendular damper 70 comprises a plurality of pendular masses 72, able to move freely in a plane perpendicular to the axis X with respect to the pendular support 71 and guided by the same pendulum support 71.

Each pendulum mass 72 is mounted at the outer periphery of the pendular support 71 and has two parts 72a and 72b mounted axially on either side of the pendular support 71 and interconnected by one or more spacers 73 each passing through an opening of the pendular support 71 A roller (not visible in FIG. 9) co-operates with a raceway formed in each spacer 73 and with the edge of the corresponding opening of the pendular support 71. This type of swinging damper is already known.

Thus, in response to torsional oscillations or rotational acyclisms, each pendulum mass 72 moves so that its center of gravity oscillates pendulum. Each pendulum mass 72 is thus animated in operation by a pendulum movement.

It can be seen in FIG. 7 that the pendulum masses 72 and the friction zone of the friction disk 2 are axially offset.

In the plane P of FIG. 9 comprising the axis of rotation X and passing through the balancing means 11, the balancing means is arranged radially beyond the internal radial edge b1 of the pendular masses 72.

Preferably, there is an axis parallel to the axis of rotation passing through both the pendulum mass 72 and the balancing means 11. The balancing means 11 and the pendulum mass 72 are therefore axially opposite one of the other.

By way of comparison, the axial length of the balancing means is greater than the axial thickness of the pendulum 70 in the mass zone 72.

In the three embodiments described above, the damper input member is a guide washer. The invention also applies to an inverted architecture in which the damper input member would be the web and the damper output output member would be the guide washer (s).

Although the invention has been described in connection with several particular embodiments, it is obvious that it is not limited thereto and that it comprises all the technical equivalents of the means described and their combinations if they are within the scope of the invention.

In particular, although the invention is described above in relation to a torque limiter, the invention is not limited to such an embodiment and the friction mechanism can also be a clutch mechanism suitable for pinching, in an engaged mode the friction element and able to release, in a disengaged mode, the friction element.

Similarly, the pendular support can be mounted directly on the damper output element, including the web. This pendulum support can be fixed to the torque output element so that the pendular support and the torque output member are rotationally fixed at least to a certain torque value.

The use of the verb "to include", "to understand" or "to include" and its conjugated forms does not exclude the presence of other elements or steps other than those set forth in a claim.

In the claims, any reference sign in parentheses can not be interpreted as a limitation of the claim.

Claims (13)

A torque transmitting device (1) for a motor vehicle power train, comprising: - a friction element (2) rotatable about axis of rotation X, the friction element comprising a friction zone (3) adapted to be gripped by a torque transmission mechanism (50), a damper (4) comprising a damper input member (5), a damper output member (8), at least one spring (10) being arranged between the damper input member ( 5) and the damper output member (8) to compress to filter the acyclisms, and the friction member (2) being attached to the damper input member (5), - At least one balancing means (11), characterized in that, in a plane (P) comprising the axis of rotation X and passing through the balancing means, the balancing means (11) is arranged radially. between the damper inlet member (5) and the friction zone (3). Torque transmission device according to claim 1, in which the torque transmission device comprises a plurality of balancing means (11) and each balancing means is arranged in a plane comprising the axis of rotation X and passing through this balancing means, radially between the damper input member (5) and the friction zone (3). 3. Torque transmission device according to one of the preceding claims wherein the balancing means (11) is arranged on the friction element (2). 4. Torque transmission device according to the preceding claim wherein the balancing means (11) is connected only to the friction element (2). 5. Torque transmission device according to one of claims 1 to 4 wherein the balancing means (11) is integrated with the friction element (2). 6. Torque transmission device according to the preceding claim wherein the balancing means is a recess in the friction element (2). Torque transmission device according to one of claims 1 to 5 wherein the balancing means (11) is an element locally adding mass to a part of the torque transmission device (1), in particular a part of the friction element (2). 8. Torque transmission device according to the preceding claim wherein the balancing means is a rivet (11). 9. Torque transmission device according to the preceding claim wherein the balancing means is a rivet with two heads (21, 22) enclosing the friction element (2), one of the heads (22) being heavier than the other (21) heads. Torque transmission device according to one of the preceding claims, in which the damper inlet element (5) has, in a plane perpendicular to the axis X, a corrugated contour around the axis X, the corrugated contour having at least two ridges (68) arranged circumferentially on either side of a recess (95), at least a part of the balancing means (11) being arranged circumferentially between two ridges (68) of the damper input member (5). 11. torque transmission device according to one of the preceding claims wherein the friction element (2) carries at least one lining (18, 19)), said at least one lining (18, 19) being carried by the friction zone (3) of the friction element (2), said at least one lining (18, 19) having an inner contour (C3), and each balancing means (11) is arranged radially on the inside of this inner contour (C2). 12. Transmission device according to one of claims 1 to 11 comprising a pendulum damper (70), the pendulum damper comprising a pendular support (71) mounted to rotate with the damper output member (8). A transmission assembly (100) comprising: a transmission device (1) according to one of the preceding claims, - A pressure mechanism (50) arranged to permanently or temporarily pinch the friction element (3) at said at least one friction zone (3). the pressure mechanism being a torque limiter (50) comprising: a support washer (51), a pressure washer (52), a reaction washer (53), the friction element (2) being arranged axially between the pressure washer (52) and the reaction washer (53), a spring (55) arranged between the bearing washer (51) and the pressure washer (52) so as to press the pressure washer (52) against the friction zone (3) so that the friction zone (3) is pinched by the pressure washer (52) and the reaction washer (53). the torque limiter (50) having an annular space (58) axially separating the bearing washer (51) and the reaction washer (53) and wherein the pressure washer (52), the spring (53) and the friction zone (3) of the friction element (2) are arranged, the balancing means (11) being also arranged at least partly in this annular space (58).