WO1998053225A1

WO1998053225A1 - Hydrokinetic coupling apparatus with tab driving part, in particular for motor vehicles

Info

Publication number: WO1998053225A1
Application number: PCT/FR1998/000983
Authority: WO
Inventors: Luc Thevenon; Rabah Arhab
Original assignee: Valeo
Priority date: 1997-05-16
Filing date: 1998-05-15
Publication date: 1998-11-26
Also published as: JP2000515233A; FR2766894B1; DE19880709T1; FR2766894A1

Abstract

The invention concerns an apparatus comprising a globally transverse-oriented wall (2) carrying a fixed guide ring (6), a piston (9) mounted movable along the guide ring (6) while being linked in rotation to the transverse wall (2) with axial mobility provided by elastic tabs (40) integral with a driving part (44) comprising an inner portion (444) extending radially beneath the piston and linked in rotation to one of the guide ring (6) -transverse wall (2) elements, said inner portion being adjacent to one of the -transverse wall (2)-guide ring (6) elements. The invention is applicable to motor vehicles.

Description

Hydrokinetic coupling device with tongue drive part, in particular for a motor vehicle.

The present invention relates to hydrokinetic coupling devices, in particular for a motor vehicle, as described for example in document WO-A-94/07058.

In this document, the device has a generally transverse orientation wall capable of being linked in rotation to a drive shaft and carrying a guide ring centrally attached, forming a hub.

A piston is mounted movable axially with sealing along the guide ring and defines with the transverse wall and the guide ring a variable volume control chamber delimited externally by a disc and friction linings adapted to be clamped respectively between the piston and the disc and between the disc and the transverse wall.

Each friction lining is integral with one of the disc-piston-transverse wall elements respectively, between which it is intended to be clamped. It has already been proposed in document FR-A-2 634 849 to link the piston in rotation to said transversely fixed transverse wall by means of elastic tongues of tangential orientation fixed to a drive part disposed in the volume chamber variable. In practice, this drive piece is in the form of a disk movable axially with respect to the guide ring carried centrally by said transverse wall and passing through it to form a centering device. This is achieved by means of grooves made on the guide ring and allowing axial movement of the piston - drive part assembly. The rotational connection of the disc to the ring is made by leaving an axial clearance between the wall and the disc. This connection is made on a diameter slightly greater than the diameter of the internal bore of the piston. It follows that the solution is not simple, economical, and is bulky axially due to the grooved mounting of the disc on the guide ring. In addition, the supply of the variable volume chamber must be carried out using inclined channels formed, in a known manner, in said ring, said channels having to be implanted so as to take account of the presence of the disc and the grooves. , which is likely to increase the axial size between the piston and the transverse wall.

In practice, the channels open out between the grooves and the piston so that a distance has to be observed. This increases the axial size. In addition, the disc must be relatively thick.

The object of the present invention is to overcome these drawbacks in a simple and economical manner while continuing to benefit from good ease of sliding of the piston along the guide ring. According to the invention a hydrokinetic coupling device with locking clutch of the above-mentioned type is characterized in that the drive part has an internal portion extending radially below the piston, in that said internal portion is linked in rotation with at least one of the guide ring elements - transverse wall radially below the piston and in that said internal portion is adjacent to one of the guide ring elements - transverse wall.

Thanks to the invention the passage of the fluid is not hindered since the drive part is adjacent to one of the elements transverse wall - guide ring. A large passage therefore exists between the drive part and the piston. In addition the internal portion can abut against the transverse wall or the guide ring because it is adjacent to one of these. As a result, the drive piece may be thin, which promotes the formation of tangential tongues coming directly from the drive piece.

Thanks to the invention, the material falls are reduced since the rotational connection is made radially below the piston.

This connection, moreover, is easy to perform. One can make such a connection at the end of the ring (at the free end thereof). Thus, advantage is taken of the front face of the ring while leaving intact the guide range offered by the ring at its outer periphery.

Thus the internal portion of the drive piece can mesh with the front end of the ring, this drive piece being wedged axially between the ring and the transverse wall, so that the drive piece is integral with the ring assembly - transverse wall.

As a variant, the internal portion is fixed by gluing, welding, crimping or riveting on the ring.

Many possibilities are offered. Thus the internal portion can be fixed by welding, crimping, gluing or riveting on the transverse wall.

As a variant, the internal portion can be fixed at the end to the transverse wall and to the centralizer of the guide ring, said internal portion then having, for this purpose, at its internal periphery, an annular rim of axial orientation.

In all cases, it is possible to form in advance a sub-assembly comprising at least the drive part coupled by the tongues to the piston.

In all cases, the drive part is integral with the ring - transverse wall assembly with the elimination of axial and circumferential clearances.

The guide ring can be of the standard type. In one embodiment, said internal portion is attached to the transverse wall.

The drive piece is supported by the transverse wall since it is attached to the latter.

The drive piece can thus be even thinner. In addition, this promotes the reduction of the axial size.

The appended figures illustrate the invention with reference to the appended drawings in which FIGS. 1 to 4 are half-views in axial section of a part of the hydrokinetic coupling device showing the locking clutch and the parts d drive according to the invention.

Figure 5 shows part of the torsional damper. As is known, a hydrokinetic coupling device comprises, arranged in the same sealed casing filled with oil and forming a housing, a torque converter and a locking clutch 1. The torque converter comprises a turbine wheel, a impeller wheel and a reaction wheel. The impeller has blades integral with a first half-shell tightly secured with a second drive half-shell capable of being linked in rotation to a driving shaft. The turbine wheel also has blades facing the blades of the impeller wheel. This turbine wheel is secured to a hub capable of being linked in rotation to a driven shaft. The drive half-shell has a generally transversely oriented wall. The turbine wheel is located axially between said transverse wall and the impeller. The locking clutch 1 is located axially between the turbine wheel - turbine hub assembly and this transverse wall.

The half-shells constitute the casing which, by means of its driving half-shell, constitutes the input element of the hydrokinetic coupling device, while the turbine hub constitutes the output element of said device.

As an application for a motor vehicle, the driving shaft is constituted by the crankshaft of the internal combustion engine of the vehicle, while the driven shaft is constituted by the input shaft of the vehicle transmission. This shaft is centrally hollow to form a supply channel for a variable-volume control chamber delimited by parts belonging to the locking clutch comprising a disc linked in rotation disengageably to the turbine wheel assembly. - turbine hub.

When the vehicle starts, the turbine wheel is driven in rotation by the impeller wheel thanks to the circulation of the oil contained in the sealed casing between the blades of the turbine and impeller wheels. The lockup clutch is then disengaged and the torque converter in service.

To avoid a loss of efficiency due in particular to sliding phenomena between the turbine and impeller wheels, the turbine wheel is then secured to the drive half-shell after starting the vehicle by means of the locking clutch which is then engaged, the converter then being out of service.

All this is well known to those skilled in the art and for more details, see for example document O-A-94/07058.

Here for simplicity only the essential elements have been shown and in all the figures the common elements will be assigned the same reference sign.

Thus in these figures, we see at 1 the locking clutch, at 2 the generally transversely oriented wall of the drive half-shell 3, at 4 the turbine wheel and at

5 the turbine hub secured by riveting the turbine wheel

4.

This hub 5, forming the output element of the hydrokinetic coupling device, is internally grooved for its connection in rotation to the driven shaft not shown.

The drive half-shell 3, here in stamped sheet metal, has at its outer periphery an annular rim of axial orientation for its sealingly attachment to the other half-shell (not shown) forming an impeller. This rim extends the transverse wall 2 with a central hole and carrying screws (not referenced) at its external periphery for rotationally connecting the half-shell 3 to the crankshaft of the vehicle engine, in a known manner, by means of a flange. non visible.

The locking clutch 1 is located axially between the turbine wheel 4 - turbine hub 5 assembly and the transverse wall 2.

This clutch 1 comprises a piston 9, drilled centrally and mounted axially movable with sealing along the guide ring

6, forming a hub, inserted axially between the hub 5 and the wall 2. The piston 9 defines with the guide ring 6 and the transverse wall 2 a control chamber 30 with variable volume delimited externally by a disc 10 and friction linings 11 adapted to be clamped respectively between the piston 9 and the disc 10 and between the disc 10 and the transverse wall 2.

Each friction lining 11 is integral with one of the disc elements 10 respectively piston 9 - transverse wall between which it is intended to be clamped. Thus one of the linings 11 can be fixed, for example by gluing, on the piston 9 and the other lining can be fixed, for example by gluing on the wall 2.

Here the friction linings 11 are fixed to the disc 11 on either side thereof, for example by gluing or brazing. The disc 10 forms the output element of the locking clutch 1. This disc 10 extends radially above the piston 9, here in pressed sheet metal. This piston 9 has at its outer periphery a plane bearing of transverse orientation for the formation of a first friction face for the adjacent friction lining 11. The transverse wall 2 has, opposite this bearing of the piston, also a plane bearing of transverse orientation for the formation of a second friction face for the other friction lining 11.

Of course as a variant, this second friction face can be formed by means of a part which is fixed, for example by welding, to the wall 2.

The piston 9 is inclined from its first external friction face to its internal periphery, provided with a guide sleeve (not referenced) for axial sliding of the piston along the guide ring 6.

Thus, the internal periphery of the piston 9 is in intimate contact with the external periphery of the guide ring 6 with the interposition of a seal 29 mounted in a groove of the ring 6. This ring 6 is provided with a hole centrally blind and has passages for communication from the control chamber 30 with the blind hole of the ring 6. This blind hole is in communication with the driven shaft provided with a supply channel.

The piston 9 delimits by its face facing the wall 2 the chamber 30 and by its face facing the turbine wheel 4 a main control chamber. Thus by varying the pressures in said chambers, the piston 9 is allowed to slide axially along the ring 6 and to approach the wall 2 to tighten the friction linings 11 or to move away from the wall 2 to release said linings. In the first case, the locking clutch 1 is engaged or bridged, while in the second case, the locking clutch 1 is disengaged or disassembled, knowing that the disc 11 is rigidly or resiliently connected to the wheel assembly. turbine 4 - turbine hub 5. It will be noted that a ball bearing 80, of axial orientation, is interposed between the hub 5 and the guide ring 6.

More specifically, the stop 80 is interposed between, on the one hand, the web, which has the hub 5 in one piece at its outer periphery for fixing by riveting, alternatively by welding to the turbine wheel 4 and, d on the other hand, the dorsal face of the ring 6, hollowed out for penetration of the free non-grooved end of the hub 5 inside the ring 6.

A plain bearing 81 is housed in the recess of the ring, being interposed radially between the free end of the hub 5 and the ring 6 as shown in FIG. 1.

When the clutch 1 is tightened, the turbine wheel 4 is coupled to the wall 2 so that no relative movement occurs between the turbine and impeller wheels. When the clutch 1 is disengaged, the turbine wheel 4 is driven by the impeller wheel.

In known manner, the piston 9 is secured in rotation to the transverse wall, rotatable and fixed axially, by means of elastic tongues 40 secured to a drive part 44, so that the piston 9 is linked in rotation to the transverse wall 2 while being able to move axially relative to the latter by sliding axially along the ring 6. By simplicity is meant here, by tongues, either tongues acting in isolation, or tongues resulting from a stacking of elementary tongues.

Here the elastic tongues 40 are of tangential orientation and are fixed by riveting at one of their ends to the piston 9 and at their other end to the drive part 44.

These tabs 40 are regularly distributed circularly in a known manner. Here we see only one tab 40, but in reality four tabs 40, distributed regularly, are provided, as visible for example in document WO 96/14526 to which reference may be made. It will be noted that the piston 9 is stamped locally in the direction of the transverse wall 2 for fixing the elastic tabs 40. The stamping of the piston stiffens it.

These tongues 40 are fixed to the drive part 44 by means of lugs 144, which has said part 44 at its outer periphery.

Thus, clearances are formed between the legs 144 allowing access to the piston 9 for fixing by riveting the tongues 40 to the piston 9. These tongues 40 are here previously fixed by riveting to the legs 144. It is thus possible to form by advance in all the figures a sub-assembly of tongues 40 - piston 9 without having to use fixing means in two parts so as to intervene only on one side of the piston as described in the aforementioned document WO 96/14 526.

Of course, as described in this document, the elastic tongues 40 can be in one piece with the drive part, being obtained by cutting. As a variant, instead of being metallic, the drive part may be made of composite material while being in one piece with the drive part. The tongues 40 can, as a variant, be inclined.

In all cases, the drive part 44 and the tongues 40 are arranged in the variable-volume control chamber 30, between the piston 9 and the wall 2.

It will be noted that the wall 2 is stamped locally outwards at the level of the tongues 40 and that this wall comprises at its internal periphery an axial orientation sleeve 50 delimiting the central hole of the wall 2 used for mounting the ring 6 in the manner described below.

It will be noted that the guide sleeve of the piston 9 is directed axially towards the wall 2, that is to say in the same direction as the sleeve 50.

The disc 10, located at the outer periphery of the piston 9, has at its outer periphery radial lugs here offset axially in the direction of the turbine wheel 4 relative to the main part of the disc 10 carrying the friction linings 11. These lugs each have a notch into which a lug 14 (FIG. 5) penetrates, which has a part 12 coupled to the wheel 4 and turbine hub 5 assembly.

The disc 10 is thus linked in rotation, with the possibility of axial movement, by a cooperative connection of forms of the tenon-mortise type.

The part 12 can be directly fixed, for example by welding to the turbine wheel 4, in which case the disc 10 is rigidly coupled to the turbine wheel 4. Here the part 12 belongs to a torsion damper 20 so that the disc 10 is coupled elastically to the turbine wheel 4 - turbine hub 5 assembly. This part 12 forms a guide washer.

The torsion damper 20 is here of the type described in document FR 97 04186 filed on March 28, 1997.

Thus the torsion damper comprises two guide washers 12,17 fixed together at their internal periphery by spacers (not referenced) and which hold coil springs 16, the circumferential ends of which bear against the bearing surfaces of the guide washers 12.17.

A flange 19 is interposed between the guide washers 12,17 and carries at its outer periphery radial tabs forming support portions for the circumferential ends of the springs 16. One of the washers, called the first guide washer, namely the washer 12, carries on its outer periphery drive lugs of axial orientation penetrating into the notches aforementioned outer tabs of the disc 10. The other guide washer 17, called the second guide washer, has a transverse portion which, at its outer periphery, has fixing notches in which penetrate pins of axial orientation belonging to a annular portion of axial orientation of the first guide washer 12 for a crimp connection of the tenon-mortise type between the two guide washers, as visible in FIG. 5. The tenons are thus distinct from the drive lugs referenced at 14 in this figure. The flange 19 is fixed to the turbine hub 5, here by welding. The spacers cross the flange through oblong openings thereof.

Of course, the torsion damper can have another shape, for example of the type described in document WO-A-94/07058.

Here, according to a characteristic of the invention, the drive part 44 extends radially below the piston 9 to be linked in rotation to at least one of the elements guide ring 6 - transverse wall 2. The connection in rotation is therefore located radially below the piston 9.

This washer is thus economical because, compared to the solutions described in document WO 96/14526, advantage is taken of the material drop. Material losses are thus reduced. In addition, the drive part 44, here in the form of a tortuous washer, has an external diameter smaller than that of this document WO 96/14526 and is therefore more economical.

It will be noted that the guide ring 6 is provided with a 7-stage centering nose in diameter, projecting axially towards the wall 2 and passing through the central hole of said wall 2.

The ring 6 has in one piece a flange 8 of axial orientation at its outer periphery. The nose 7 is in one piece with the ring 6. The collar 8 is parallel to the nose 7 and is directed towards the wall 2. In this collar 8 it is formed notches or notches (not referenced) for passage of the fluid of command of inside the ring to the control chamber, so that the flange 8 is notched.

To do this, the nose 7 has holes 15 inclined in communication with said scalloped collar 8 of height greater than its width. The notches of the flange 8 are of radial orientation.

The flange 8 is parallel to the nose 7 and extends radially above the latter.

This flange 8 has an outer diameter smaller than that of the ring 6.

Thus, the guide range, which the ring 6 offers at its periphery external to the piston, is of minimum length.

In all the figures the drive part 44 extends radially inwards towards the inside of the axial axis of symmetry XX of the device, and this radially below the piston 9 and the external periphery of the flange 8 with formation in advance of a sub-assembly comprising at least the piston 9 and the drive part 44 coupled to the piston by the tongues 40.

The drive part 44, generally in the form of a washer, follows the contour of the transverse wall 2 and has, at its internal periphery and at its external periphery, a portion of transverse orientation. These portions 344, 444 are offset axially with respect to each other and are connected to each other by an inclined zone 244. The external portion 344 is provided with fixing lugs 144 or, as a variant, is of in one piece with the tongues 40. This portion 344 is at a distance from the transverse wall 2. The internal portion 444 is adjacent to the transverse wall 2 and is offset axially in the direction of the hub 5 relative to the external portion 344.

In the figures illustrated, the internal portion is attached to the transverse wall.

Thus the drive piece 44 is well supported and may have a small thickness. It is for this reason that the tangential tongues 40 can be in one piece with the drive part. In the embodiment of FIG. 1, the internal portion 444 has internally, at its internal periphery, an annular rim of axial orientation 544 directed axially towards the outside. Thus, during assembly, a sub-assembly is formed comprising the piston 9, the drive part 44 coupled to the piston 9 by the tongues 44 and the guide ring, the larger diameter portion of its nose 7 forming a centralizer for the rim 544, the internal periphery of which is in intimate contact with the external periphery of the larger diameter portion of the centering device 7. After this sub-assembly is fitted into the central sleeve 50 of the transverse wall 2.

The external periphery of the rim 544 then comes into intimate contact with the internal periphery of the sleeve 50. Then the rim 544 is welded to the end 50 then the rim 544 is welded to the nose 7.

Two welding seams 45,145 thus appear at the free ends of the rim 544 and of the sleeve 50. This welding is carried out here with a laser. Thus, the drive part is integral with the ring 6 and the wall 2 by means of its rim 544 and two welds are necessary for the fixing. The rim 544 is interposed radially between the sleeve 50 and the centralizer 7.

The internal portion 444 is interposed axially by clamping between the flange 8 and the transverse wall 2.

As a variant, a sub-assembly comprising the piston and the drive part is mounted on the wall 2 while welding at 45, then the guide ring 6, shaped as a centering device, is threaded into the flange 544 and then proceeds to welding. in 145. In FIG. 2, the number of welds is increased to form a sub-assembly of the guide ring 6 - piston 9 - drive part 44 coupled by the tongues 40 to the piston 9.

This subset is captive. To do this, the internal portion 444 of the drive piece 44 is welded to the end (at the free end facing the wall 2) of the flange 8 using two welding beads 345,445 offset radially. Then we thread this sub-assembly into the sleeve 50 of the wall 2 in finally carrying out a welding in 555 of the centering device at the end of the sleeve 50, the internal periphery of which is then in intimate contact with the external periphery of larger diameter of the centering device 7.

It will be appreciated that the fixing of the drive part 44 is carried out over a larger diameter and is therefore more robust. The internal portion 444 is also sandwiched between the wall 2 and the flange 8.

The drive part is simplified since it has no axial rim at its internal periphery. In this figure, the tongues 40 are fixed after the portion 444 has been fixed to the flange 8.

In FIG. 3, the same subassembly is produced as in FIG. 2 and in final welding in 555 the centralizer 7 at the end of the sleeve 50 of the transverse wall 2. Here the subassembly is not captive because the internal periphery of the internal portion 444 of the drive part is provided with a toothing to mesh with a toothing produced in the flange 8 at the end thereof. The flange 8 is then stepped in diameter to present at its free end a portion of smaller diameter with the aforementioned toothing.

After welding the centering device 7 at 555, the drive part is interposed axially between the portion of larger diameter of the ring 6 and the wall 2, so that it is immobilized axially and that all the play is eliminated. The drive part is therefore linked in rotation to the guide ring 6.

It will be noted that the toothing of the collar is shorter than that of the internal portion so that the collar 8 is not in contact with the wall 2. In FIGS. 1 to 3 the centering device 7 is used to center the locking clutch 1 on the wall 2. More specifically, the nose 7 serves as a centering device for the piston 9 and as a clamping member for tightening the internal portion 444 in contact with the wall 2.

In all cases, the disc 10 with its linings 11 is inserted axially between the piston and the wall 2 before the final fixing of the centering device 7 is made. As a variant, in FIG. 4, a piston 9 - drive part 44 sub-assembly is formed coupled to the piston 9 by the tongues.

Then the outer periphery of the piston 9 is centered relative to the axial rim of the drive half-shell 3 and then the internal portion 444 of the piece 44 is welded by transparency to the wall 2. This welding is carried out radially below the piston

9 in the vicinity of the internal periphery of the internal portion 444.

In this case the flange 8 is stepped in diameter to come, radially below the drive part 44 of the tongues 40, directly in contact with the wall 2 by its part of smaller diameter. The internal portion 444 is then axially spaced from the portion of larger diameter of the flange 8.

As a variant, the internal portion 444 can be centered directly by the wall 2 and this is the reason why there is shown in FIG. 4 a member making it possible to center the internal periphery of the portion 444.

Of course, the welds can be replaced by bonding. In FIG. 4, the internal portion 444 can be fixed by riveting to the wall 2. The rivets are then obtained by extruding the wall 2 as visible in document WO 96/14526.

In Figures 2 and 3 can be fixed by riveting the internal portion on the flange 8 to form a captive sub-assembly.

Of course it is then necessary to drown the heads of the rivets in the internal portion.

It can be seen in the light of FIG. 4, by inversion of structure, that the internal portion 444 can be fixed by welding or riveting to the flange with the appearance of a clearance between the portion 444 and the wall 2. In this case the portion 444 is adjacent to the wall 2 without being attached to the latter.

All combinations are possible. For example, the rim 544 of the part 44 can be welded in the end on the centering device 7 after having carried out a transparent welding or a riveting of the internal portion 444 on the wall 2 as in FIG. 4. In FIG. 3 the end free of smaller diameter of the collar 8 can be devoid of teeth. The internal portion 444 is then forcibly inserted into the teeth on said end. free forming the part of smaller diameter of the flange 8. During this operation the teeth of the portion 444 size of the grooves in the flange 8 and this is the reason why a groove has been shown in FIG. 3 the connection zone of the part with the smallest diameter of the flange 8 to the part with the largest diameter thereof.

Thus the material of the collar 8 can flow in said groove when the internal portion 444 is force-fitted onto the collar 8. This results in a fixing by crimping of the drive part on the guide ring 6. This embodiment allows to cancel any axial and circumferential play.

As a variant, the internal portion 444 may be adjacent to the guide ring 6 proper. More precisely, this internal portion 444 can be engaged in the bottom of the notches, which the flange 8 presents in the aforementioned manner.

The internal portion 444 then has tabs penetrating the bottom of said notches to be fixed for example by welding or riveting to the ring 6.

In all cases, the internal portion 444 delimits the fluid passages in connection with the flange 8.

The circulation of the fluid is therefore not hampered by the drive part 44. The drive part is therefore linked in rotation to at least one of the elements transverse wall 2 - ring 6. It can be fixed to these two elements (Figure 1), or one of them (Figures 2 and 3). It is then linked in rotation and axially to this element. In all cases, its rotational connection zone is produced radially below the piston, so that the guide range offered by the guide ring to the piston is not affected.

In all the figures, the passage of the fluid from the interior of the ring 6 to the chamber 30 is not hindered since the drive part is adjacent to the wall 2 or to the ring 6.

In FIGS. 1 to 4, the drive piece is inserted without play or with play between the flange 8 and the wall 2. It will be noted that the mounting with grooves of document FR-A-2 634 849 is eliminated. In practice these grooves are longer than the thickness of the drive part so that space is gained in axial dimensions. Thus, despite the insertion of the internal portion between the ring and the wall, the axial size is reduced. This is all the more so as the internal portion can be thin and be attached to the transverse wall which eliminates any axial play at this level. In the present invention, the tongues 40 ensure the axial movement of the piston 9.

It will also be noted that thanks to the invention, all the axial and circumferential clearances are eliminated. Indeed in the embodiment of Figure 3, we just tighten the portion 444 between the wall 2 and the flange 8 so that we remove all the games.

In the other figures, the games are eliminated since a fixing is carried out.

It is the same in the variant in which the internal portion 444 is fixed in the bottom of the notches of the collar 8 in the form of notches or notches as mentioned above.

Of course, the guide ring can have the shape of that described in document FR-A-2 634 849.

In all cases, the guide ring 6 passes centrally through the transverse wall 2 and the internal portion is, radially beyond the centering nose of the ring 6, axially interposed with or without clamping between, on the one hand, the face front of the ring 6, facing the wall 2 and forming the end or the free end of the said ring and, on the other hand, the transverse wall 2. Of course, means are provided to avoid pollution, in particular when the welding operations are carried out.

This is facilitated by the location of the rotating link below the guide surface offered by the ring at its outer periphery to the piston.

Claims

1- hydrokinetic coupling device, in particular for a motor vehicle, comprising a wall of generally transverse orientation (2) suitable for being linked in rotation to a driving shaft and carrying centrally fixed a guide ring (6) passing through said wall for form a centralizer (7), a piston (9) mounted axially movable with sealing along the guide ring (6) and defining with said ring (6) and said transverse wall (2) a variable volume control chamber ( 30) delimited externally by a disc (10) and friction linings (11) adapted to be clamped respectively between the piston (9) and the disc (10) and between the disc (10) and the transverse wall (2), each friction lining (11) being integral with one of the disc elements (10) respectively piston (9) - transverse wall (2) between which it is intended to be tightened, in which the piston (9) is linked in rotation to the wall transve rsale (2) with axial mobility, by means of tangential elastic tongues (40) integral with a drive part (44), characterized in that the drive part (44) has an internal portion (444) extending radially below the piston (9), in that said internal portion (444) is connected in rotation to at least one of the elements guide ring (6) - transverse wall (2) radially below the piston (9) and in that said internal portion (444) is adjacent to one of the transverse wall elements (2) - guide ring (6).

2- Apparatus according to claim 1, characterized in that said internal wall (444) is adjacent to the transverse wall (2), so that it is interposed axially between the guide ring (6) and the wall (2) .

3- Apparatus according to claim 1, characterized in that the internal portion (444) of the drive part (44) is interposed axially between the transverse wall (2) and a flange (8) which has the ring protruding axially guide (6) in the direction of the transverse wall (2) and in that said flange (8) is provided with notches for passage of the fluid supply to the variable volume control chamber (30) and extends parallel to the centralizer (7).

4- Apparatus according to claim 3, characterized in that the internal portion (444) has tabs engaged in the bottom of the notches of the collar (8) while being fixed to the ring (6).

5- Apparatus according to claim 1, characterized in that the internal portion (444) of the drive piece (44) is connected in rotation and axially to at least one of the guide ring elements (6) - transverse wall (2) radially below the piston (9).

6- Apparatus according to claim 5, characterized in that said internal portion (444) has at its internal periphery an annular flange (544) of axial orientation fixed at the end, on the one hand, on a central sleeve (50) d axial orientation which the transverse wall (2) has centrally and, on the other hand, on the centralizer (7) of the guide ring (6), said flange (544) being inserted radially between said sleeve (50) and said centralizer (7).

7- Apparatus according to claim 6, characterized in that the fixing is carried out by welding.

8- Apparatus according to claim 5, characterized in that said internal portion (444) is fixed to said transverse wall radially below the piston (9).

9- Apparatus according to claim 5, characterized in that said internal portion is fixed at the end of the collar (8).

10- Apparatus according to claim 3, characterized in that the collar (8) of the guide piece (6) is stepped in diameter and in that the portion of smaller diameter of the collar has a toothing to mesh with a toothing presented by the drive part (44) at its internal periphery.

11- Apparatus according to claim 3, characterized in that the flange (8) of the guide piece (6) is stepped in diameter and in that the drive piece (44) has at its internal periphery a toothing for cutting grooves in the smaller diameter portion of the flange (8), so that the drive piece (44) is fixed by crimping to the guide ring.