KR102382445B1 - Wet double clutch with centered force transmission mechanisms - Google Patents

Abstract

The present invention relates to a wet double clutch (1) designed to be placed in a transmission chain of a motor vehicle between an engine having a crankshaft and a gearbox comprising two coaxial input shafts (2, 3), said wet double clutch ( 1) comprises first and second clutches (4, 5) capable of transmitting torque from the crankshaft towards one and the other of the two input shafts (2, 3) of the gearbox, respectively,
Each of the first and second clutches 4 and 5,
- input disc holders (8, 9) designed for rotational connection to the crankshaft;
- output disk holders (15, 30) designed for rotational connection to one or the other of the two input shafts of the gearbox;
- a multi-disc assembly (10, 11) moving between the clutch disconnected position and the clutch engaged position; and
- force transmission members (25, 38) for displacing the multidisc assembly (10, 11) from its clutch disconnected position to its clutch engaged position by moving in translation along the axis (X);
The force transmission member is rotationally guided and centered about an axis X.

Description

WET DOUBLE CLUTCH WITH CENTERED FORCE TRANSMISSION MECHANISMS

The present invention relates to the field of transmission of automobiles.

The present invention relates more particularly to a wet double clutch designed to be placed in a transmission chain of a motor vehicle between an engine block and a gearbox comprising two input shafts.

The wet double clutch includes an input hub and two clutches designed to rotate integrally with an engine flywheel fixed to the crankshaft of the engine, the two clutches each having an input disk holder rotationally connected to the input hub, two of the gearbox an output disk holder rotationally connected to one or the other of the input shafts and a multidisk assembly designed to transmit torque between the input disk holder and the output disk holder of the clutch when the clutch is in its clutch engaged position.

One of the input shafts of the gearbox rotationally connected to the output disk holder of one of the clutches corresponds to an odd gear ratio of the gearbox, while the other input shaft rotationally connected to the output disk holder of the other clutch corresponds to an even gear ratio. Accordingly, to effect the gear ratio change, one of the clutches is displaced from its clutch engaged position to its clutch disengaged position, while the other clutch is displaced from its clutch disengaged position to its clutch engaged position. So, with this double clutch, it is possible to change the gear ratio without interruption of torque.

From document DE102014212805 to a hydraulic control system comprising a housing designed to be fixed to a gearbox and having two concentric annular chambers and two annular pistons each axially moving in one and the other of the two annular chambers A wet double clutch actuated by a Each piston has a rotating bearing, which, when the piston moves within its respective annular chamber, cooperates with one or the other of the two clutches to move the clutch between the clutch disengaged position and the clutch engaged position. It is supported against a displacing force transmission member. Such a control system can limit the drag torque and, consequently, provide satisfactory energy compensation performance.

However, the force transmission member is rotationally guided and not centered around the axis X, causing an imbalance to break the balance of the double clutch, affecting the uniformity of the load applied between the rotary bearing and the force transmission member, By changing the radius of application of the load on the multi-disc assembly, the parallelism of the load of the clutch applied to the multi-disc assembly by the force transmitting member may be affected.

Therefore, such a double clutch is not completely satisfactory.

The basic idea of the present invention is to overcome the disadvantages of the prior art by proposing a particularly reliable wet double clutch.

According to one embodiment, the present invention provides a wet dual clutch designed for placement in a transmission chain of a motor vehicle between an engine having a crankshaft and a gearbox comprising two coaxial input shafts extending along an axis (X). , the wet dual clutch comprising first and second clutches capable of transmitting torque from the crankshaft towards one and the other of the two input shafts of the gearbox respectively;

Each of the first and second clutches,

- an input disc holder designed for rotational connection to the crankshaft;

- an output disc holder designed for rotational connection to one or the other of the two input shafts of the gearbox;

- a multi-component comprising at least one friction disk integrally rotating with one of the input and output disk holders and at least two plates respectively disposed on opposite sides of each friction disk and integrally rotating with the other of the input and output disk holders a disc assembly, wherein the friction disk and plates move axially between a clutch disengagement position and a clutch engagement position in which the plates tighten the friction disc to transmit torque between the input disc holder and the output disc holder; and

- a force transmission member capable of displacing the multidisc assembly from its clutch disengaged position to its clutch engaged position by moving in translation along the axis X;

Wet double clutch,

- a housing designed to be fixed to the gearbox;

- further comprising a control system comprising first and second annular pistons mounted to slide axially on the housing and each having first and second rotary bearings;

the first and second rotary bearings cooperate with the force transmitting members of the first and second clutches, respectively, to displace the clutch between its disengaged position and its connected position;

The force transmission member is rotationally guided and centered about an axis (X).

Therefore, the centering of the force transmission member is the equilibration of the wet double clutch; uniformity of the load applied between the rotating bearing and the force transmission member; It is possible to ensure the stability and parallel relationship of the radius of application of the load applied to the multi-disc assembly by the force transmitting member.

In addition, since the hydraulic control system does not require the presence of dynamic joints, it is possible to limit the drag torque and, consequently, to limit the energy consumption of the engine.

According to another advantageous embodiment, such a wet dual clutch may have one or more of the following features.

The first annular piston is positioned radially outward of the second annular piston.

According to one embodiment, each force transmitting member comprises at least one cylindrical centering face, each cylindrical face being circumferentially discontinuous about the axis X. In other words, the centering of the force transmission member is not realized continuously around the axis X. Thus, only the cylindrical centering faces require significant dimensional accuracy, and regions of the force transmitting member other than the cylindrical centering faces can have larger manufacturing tolerances, thereby reducing the manufacturing cost of the force transmitting member.

Also, the geometrical disconnection between the cylindrical centering faces may better circulate the cooling fluid between the force transmission members.

According to one embodiment, the cylindrical centering face is a part of a rotating cylinder whose busbar is the axis (X).

According to one embodiment, the cylinder parts each extend at an angle around the axis X within a value range comprised between 5° and 45°.

According to one embodiment, each force transmitting member has at least three cylindrical portions distributed regularly at an angle around the axis X (eg distributed at 120° all if the member has three cylindrical portions). include

According to one embodiment, the force transmitting member of the first clutch and the force transmitting member of the second clutch are centered with respect to each other.

According to one advantageous variant, the force transmission members of the first and second clutches each have an inner part cooperating with one of the first and second rotary bearings, an outer part cooperating with one of the multidisc assembly and an inner part cooperating with one of the multidisc assemblies, respectively. and an axially oriented cylindrical centering skirt connecting the outer portion; The cylindrical centering skirts of the force transmitting members of the first clutch and the second clutch cooperate with each other to center the force transmitting members with respect to each other.

According to one embodiment, each input or output disk holder comprises a grooved cylindrical skirt; Each friction disk or plate is installed to move axially on a grooved cylindrical skirt of one of the output or input disk holders and to rotate integrally with one of the output or input disk holders, one of the input disk holders is provided with a control system a support oriented radially inwardly from the edge of the cylindrical skirt having its grooves oriented toward; The support has a radially inner edge that cooperates with the bearing to guide the rotation of the dual clutch around the axis X.

According to one embodiment, the force transmission member of the second clutch is centered on the support. Accordingly, the centering of the force transmitting member of the first clutch is ensured by the support portion and the support portion itself is centered and rotationally guided around the axis X by the bearing guiding the rotation of the dual clutch.

According to one embodiment, the support comprises an outer portion, an inner portion axially offset with respect to the outer portion and disposed inside the multidisc assembly, and an axially oriented cylindrical centering skirt connecting the outer portion and the inner portion. and; The force transmitting member of the second clutch includes an axially oriented cylindrical centering skirt cooperating with the cylindrical centering skirt of the support to center the force transmitting member of the second clutch on the support.

According to one embodiment, the force transmission members are centered with respect to each other and the force transmission member of the second clutch is centered on the support; The force transmitting member of the first clutch and the force transmitting member of the second clutch cooperate with each other through a plurality of cylindrical surfaces regularly distributed around the axis X to center the force transmitting members relative to each other, and The force transmission member comprises a plurality of cylindrically-distributed regularly about the axis X and circumferentially offset about the axis X with respect to the cylindrical faces by which the force transmission members of the first and second clutches cooperate. It is centered on the support through the face.

According to one embodiment, the second rotary bearing comprises a first ring fixed to the second annular piston, a second ring supported against the force transmission device of the second clutch, and inserted between the first ring and the second ring. a rolling element; The force transmitting member of the second clutch is centered on the second ring.

According to one embodiment variant, the force transmitting member of the second clutch comprises a cylindrical centering face cooperating with a complementary cylindrical centering face provided on an edge of the second ring.

According to one embodiment, the first rotary bearing comprises a first ring fixed to the first annular piston, a second ring supported against the force transmission device of the first clutch, and an interposed between the first ring and the second ring. and a rolling element, wherein the force transmission member of the first clutch is centered on the second ring. Accordingly, the centering of the force transmitting member of the first clutch is ensured by the first rotating bearing, which also ensures rotational guidance of the force transmitting member about the axis X.

According to one variant, the force transmission member of the first clutch comprises a cylindrical centering face cooperating with a complementary cylindrical centering face provided on the edge of the second ring of the first rotary bearing.

According to another embodiment, the force transmission member of the first clutch is centered and rotationally guided on the housing of the actuation system.

According to one embodiment variant, the housing of the actuation system comprises radially cylindrical centering surfaces on the outside of the first and second annular pistons, the force transmitting member of the first clutch having an inner part cooperating with the first rotating bearing , an outer portion, and an axially oriented cylindrical centering skirt connecting the inner and outer portions, the cylindrical centering skirt cooperating with a cylindrical centering face of the housing to center the force transmitting member of the first clutch relative to the housing and guide rotation do.

According to one embodiment, the housing of the control system comprises an inner tube extending axially about the axis X and providing an interior space for passing two input shafts of the gearbox, first and second The two annular piston is installed to slide axially on the housing on the outside of the inner tube; The support is rotatably installed on the inner tube by means of a guide bearing.

According to one embodiment, the inner tube extends axially beyond the first and second annular chambers in the direction of the two clutches.

According to one embodiment, the inner tube is made integrally with the housing, ie formed as one piece.

According to one embodiment, the inner tube has at least one cooling fluid passing channel designed to direct the cooling fluid towards the clutch. Therefore, since the cooling circuit of the clutch is integrated into the hydraulic control system of the dual clutch, the number of parts of the wet dual clutch can be reduced, the occupied volume thereof can be reduced, and it can contribute to increase the standardization of the parts.

The cooling fluid passage channel has an outlet orifice that opens axially beyond the rotational bearing of the second annular piston wherever the position of the second annular piston is between its rest position and its active position. Therefore, because of the proper axial positioning of the outlet orifice, the circulation of the cooling fluid is particularly efficient, which can ensure the cooling performance of the dual clutch. In particular, the cooling fluid passage channel is open beyond the stroke of the annular piston between the active and rest positions of the annular piston, so that whatever the piston of the clutch is, especially when the clutch is in the biting point and need for cooling At maximum, efficient cooling of the clutch is ensured.

According to one embodiment, the inner tube may comprise a plurality of cooling fluid passage channels distributed circumferentially around the axis X to ensure efficient and uniform cooling. According to one embodiment, the cooling fluid passage channels are evenly distributed around the axis X.

According to one embodiment, the two clutches can be arranged radially one inside the other, thereby limiting the axial occupied volume of the dual clutch.

According to one embodiment, the input disk holders are arranged radially outwardly of the output disk holders of their respective clutches.

According to one embodiment, the input disk holders of the two clutches are installed to rotate about the axis X on the inner tube of the hydraulic control system by means of bearings. Thus, the input disk holder is supported on a control system designed to be fixed to the gearbox, and the bearing is installed on a stable and rigid element that does not undergo axial and/or radial displacement, thus improving the stability of the dual clutch and the reduction of the bearing. Greater reliability is guaranteed. Further, since the bearing is installed on an inner tube having a relatively small diameter, and the diameter of the bearing is limited, especially in the case of a rolling bearing, the cost can be reduced.

According to one embodiment, the bearing is a rolling bearing.

According to one embodiment, the rolling bearing includes an inner ring provided on the periphery of the inner tube, an outer ring installed inside the receiving portion of the input disk holder of one of the clutches, and a rolling element inserted between the inner ring and the outer ring do.

According to one embodiment, the inner ring is held on the inner tube along a direction opposite to the control system by an elastic ring installed on a neck portion provided on the inner tube.

According to another embodiment, the ring is held by a shoulder formed directly on the inner tube.

According to one embodiment, the inner tube is integral with the housing in the axial direction so that the axial load of the clutch applied by the annular piston is directly recovered by the housing.

According to one embodiment, the rolling bearing is of the inclined contact type.

According to one embodiment, the bearing is mounted on a bearing surface of the inner tube, the bearing surface being in the first direction between its rest position and its active position in the direction of the two clutches, at least as long as the friction linings of the multidisc assembly do not wear out. and beyond the stroke of the second annular piston.

According to one embodiment, the output disk holders are fixed to the output hub or formed in one piece with the output hub, the output hub cooperating with a complementary groove provided at one or the other end of the input shaft of the gearbox. Includes grooves.

According to one embodiment, the cylindrical skirt of the output disk holder is connected to its respective output hub by a radial portion extending radially inwardly from the edge of the cylindrical skirt oriented in a direction opposite to the hydraulic control system.

According to one embodiment, the multidisk assembly of one of the clutches is disposed radially inside the multidisk assembly of the other clutch, and the bearing is disposed radially inside the multidisk assembly of the clutch.

According to one embodiment, the multidisk assembly of one of the clutches is disposed radially inside the multidisk assembly of the other clutch, and the bearing supporting the input disc holder is disposed radially inside the multidisk assembly of the clutch; , inside the multidisc assembly, the support has an inner section that folds in a direction opposite to the hydraulic control system.

According to one embodiment, the force transmitting member of each clutch has an outer periphery provided with a plurality of fingers of axial orientation each passing across the support using an opening; The fingers are supported against the multidisc assembly of the clutch.

According to one embodiment, each force transmission member comprises an inner portion having an axial reinforcement in the direction of the two clutches, in which the first and second annular pistons of the control system are at least partially accommodated. This arrangement also contributes to the increased axial compactness of the dual clutch.

According to one embodiment, the dual clutch comprises an input hub comprising a groove designed to cooperate with a complementary groove of an element secured to a crankshaft of an internal combustion engine, such as an engine flywheel. The input disk holders are secured to the input hub by means of an input flywheel, for example.

According to one embodiment, the input disk holders are arranged radially outwardly of the output disk holders of their respective clutches.

According to one embodiment, the present invention also provides a motor vehicle comprising a dual clutch of the type described above.

A better understanding of the present invention and other objects, details, features and advantages of the present invention will become more apparent following the following description of several specific embodiments of the invention, presented only by way of example and non-limiting, with reference to the accompanying drawings. will be done

1 is a partial cross-sectional view of a wet dual clutch according to a first embodiment;
2 is a partial cross-sectional view of a wet dual clutch according to a second embodiment;
3 is a partial cross-sectional view of a wet dual clutch according to a third embodiment;
4 is a partial cross-sectional view of a wet dual clutch according to a third embodiment;
Fig. 5 is a rear view of the wet double clutch of Fig. 1;
Fig. 6 is a partial cross-sectional view in a plane perpendicular to the axis X of the dual clutch of Fig. 3;

In this specification and claims, the terms "outer" and "inner" and "axial" and "radial" orientations are used to refer to the elements of a dual clutch according to the definitions given herein. For convenience, the "radial" orientation is oriented orthogonal to the axis of rotation (X) of the dual clutch, which determines the "axial" orientation, extending the axis from the inside to the outside, and the "circumferential" orientation is orthogonal to the axis (X) and radial oriented orthogonal to the direction. The terms "outer" and "inner" are used to define the position of one element relative to another, with respect to the axis (X), the element close to the axis (X) being the outer element positioned radially around it. It is called the inner side as opposed to . On the other hand, the terms "rear" AR and "front" AV are used to define the relative position of one element to another along the axial direction, the element disposed close to the internal combustion engine is referred to as the front and disposed close to the gearbox The element that becomes the back is referred to as the rear.

Referring to FIG. 1 , there is shown a double clutch 1 designed to be arranged between the engine block and the gearbox. This double clutch 1 aims to transmit torque from the crankshaft of an internal combustion engine selectively towards one or the other of the two coaxial input shafts 2 , 3 of the gearbox. The inner shaft 2 extends longitudinally along an axis X across the housing of the gearbox. The hollow shaft 3 also traverses the housing of the gearbox and surrounds the inner shaft 2 . The double clutch 1 comprises two clutches 4 , 5 each designed to temporarily connect the crankshaft of an internal combustion engine to one of the input shafts 2 , 3 of the gearbox. One of the input shafts 2 , 3 of the gearbox corresponds to a specific gear ratio of the gearbox, eg reverse and odd gear ratio, and the other corresponds to another gear ratio, eg even gear ratio. Accordingly, to effect the gear ratio change, one of the clutches 4, 5 is displaced from its clutch engaged position toward the clutch disengaged position, and the other clutch 4, 5 is displaced from its clutch disengaged position toward the clutch engaged position. Thus, engine torque is gradually transmitted from one of the clutches 4 and 5 to the other. Thus, this double clutch 1 is capable of changing the gear ratio without interruption of torque, ie maintaining engine torque transmission to the wheels.

The dual clutch 1 includes an input hub 6 comprising an external groove designed to cooperate with a complementary groove formed in an element secured to the crankshaft of an internal combustion engine, such as a single or dual engine flywheel, not shown. .

The dual clutch 1 is designed to be accommodated in a clutch housing, not shown, which is fixed to a gearbox. The clutch housing is closed forward by a closure cover, not shown, whose rotation is guided on the cylindrical outer surface of the input hub 6 by a bearing, not shown. Since the closure cover has an annular joint on its outer periphery which cooperates with the inner surface of the housing of the clutch, the sealing of the double clutch 1 is ensured.

The dual clutch 1 also comprises an input flywheel 7 which is welded to or formed as a single member with the input hub 6 . The input flywheel is rotationally connected to the input disk holder of each of the two clutches 4 , 5 .

The two clutches 4 , 5 each comprise a multidisc assembly 10 , 11 , ie an axial stack of friction discs and plates. One of the two clutches and the other multi-disc assembly 10 , 11 limit the axial footprint of the dual clutch 1 as one is radially disposed inside the other.

The first clutch (4) comprises an input disk holder (8) fixed to an input flywheel (7), the multi-disk assembly (10) of this clutch being radially external to the multi-disc assembly of the other clutch (5). there is. To this end, the input flywheel 7 is provided with an outer toothed portion 12 on its outer periphery, which has an inner toothed portion 13 formed on the inner surface of the input disk holder 8 of the first clutch 4 and Cooperatively rotate the input flywheel 7 in one piece with respect to the input disk holder 8 . On the other hand, the input flywheel 7 is held axially rearward with respect to the input disk holder 8 of the first clutch 4 by the stop ring 14 . The stop ring 14 is, for example, an elastic connecting ring received in a neck portion provided at the front end of the input disk holder 8 of the first clutch 4 .

The first clutch 4 also includes an output disk holder 15 fixed to the output hub 16 or formed in one piece with the output hub. The output hub 16 is grooved and cooperates with a complementary groove provided on the periphery of the end of one of the input shafts of the gearbox, here the inner shaft 2 . Accordingly, the output hub 16 of the output disk holder 15 rotates integrally with the inner shaft 2 . In the front part, the output hub 16 has, on its periphery, a shoulder defining an axial bearing surface for the bearing 17 . The bearing 17 cooperates with a shoulder which defines an axial bearing surface for the bearing 17 and is provided on the inner periphery of the input hub 6 . The bearing 17 can thus ensure the axial positioning of the output disk holder 15 of the first clutch 4 relative to the input flywheel 7 . The bearing 17 is, for example, a rolling bearing.

The input disk holder 8 comprises an axially oriented cylindrical skirt 18 provided with inner teeth, and an annular support 19 extending radially inwardly from the rear end of the cylindrical skirt 18 . . The support 19 and the cylindrical skirt 18 may be formed as one member from the same metal plate as in the illustrated embodiment, or may be formed as two separate members fixed to each other. The input disk holder 8 is rotatably installed on the hydraulic control system 21 via a bearing 20 , which is described in more detail below, on the one hand, the bearing cooperates with the control system 21 on the one hand and on the other hand cooperates with the radially inner edge of the support 19 . Advantageously, in order to limit the axial footprint of the dual clutch, the support 19 of the input disc holder 8 has a radial orientation and the multidisc assembly 10 , 11 of the two clutches 4 , 5 is an outer section 19a disposed at the rear of the , and an inner section 19b that is folded forward and extends radially inside the multi-disc assembly 10 , 11 .

The output disk holder 15 comprises an axially oriented cylindrical skirt 22 arranged radially inside the cylindrical skirt 18 of the input disk holder 8 and provided with external teeth. The output disk holder 15 also includes a radially oriented portion 23 extending radially from the front end of the cylindrical skirt 22 of the output disk holder 15 to the output hub 16 .

The multidisc assembly 10 comprises a plurality of annular plates, for example made of steel, which are installed to rotate integrally with the input disc holder 8 and slide axially relative to the input disc holder 8 . do. To do this, each plate has, on its outer periphery, outer teeth which engage with inner teeth provided on the inner surface of the cylindrical skirt 18 of the input disk holder 8 .

The multidisc assembly 10 further includes a plurality of friction discs each inserted between the two plates and rotating integrally with the output disc holder 15 with degrees of freedom of axial translational motion. To do this, each friction disk has, on its inner periphery, inner teeth which engage with outer teeth provided on the cylindrical skirt 22 of the output disk holder 15 . Each friction disk includes a friction lining disposed on each of its front and rear surfaces.

The multidisc assembly 10 is supported forwardly against the reaction zone formed on the input flywheel 7 . The reaction zone is provided, in the embodiment shown, by an annular flange 24 formed near the outer periphery of the input flywheel 7 . Meanwhile, the plate disposed at the rear end of the multi-disc assembly 10 cooperates with the force transmission member 25 . The force transmission member 25 is installed to slide in the axial direction and cooperates with a hydraulic control system 21 described in more detail below, which hydraulic control system moves the first clutch 4 from its clutch disengaged position. It is possible to slide the force transmitting member 25 forward in the axial direction to displace it into the connected position. Here, the force transmission member 25 is constituted by a metal plate, and the metal plate includes, on its outer periphery, a plurality of fingers 26 of axial orientation regularly distributed around the axis X. As shown in FIG. 3 , each finger 26 passes across the support 19 of the input disk holder 8 using a dedicated opening 27 . Accordingly, turning to FIG. 1 , it is observed that each finger 26 is supported against a plate disposed at the rear end of the multi-disc assembly 10 of the first clutch 4 .

In order to displace the first clutch 4 from its clutch disengaged position to its clutch engaged position, each friction disc is clamped between two plates so that a torque is transmitted between the input disc holder 8 and the output disc holder 15 . and consequently the force transmission member 25 is displaced forward so as to be transmitted between the crankshaft of the internal combustion engine and the inner input shaft 2 of the gearbox.

Conversely, when the force transmission member 25 is no longer constrained forward, the friction disk and plate regain their clutch disengaged position where they axially separate from each other. To facilitate the return of the friction disk and plate towards their clutch disengaged position, a corrugated elastic washer, not shown, is inserted between the plates. In each section between two neighboring plates, an elastic washer is arranged radially outwardly of the friction disk located in the section.

In order to limit the axial volume of the dual clutch 1 , the force transmission member 25 comprises a forward axial reinforcement 28 therein, in which the hydraulic control system 21 is at least partially accepted.

The second clutch 5, that is, the clutch whose multi-disc assembly 11 is disposed inside the multi-disc assembly of the other clutch 4 in the radial direction, has a structure similar to that of the first clutch. The second clutch 5 comprises an input disk holder 9 which rotates integrally with the input flywheel 7 . To do this, the input disk holder 9 of the second clutch 5 is fixed to the support 19 of the input disk holder 8 of the first clutch 4 by welding, for example. The input disk holder 9 comprises an axially oriented cylindrical skirt 29 , which is disposed radially inside the cylindrical skirt 22 of the output disk holder 15 of the first clutch 4 . The cylindrical skirt 29 has inner teeth.

The second clutch 5 also includes an output disk holder 30 fixed to the output hub 31 or formed in one piece with the output hub. The output hub 31 has an inner groove, which cooperates with a complementary groove provided on the periphery of one of the input shafts of the gearbox, here the end of the inner shaft 3 . In order to ensure the axial positioning of the output disc holder 30 , a first axial bearing 32 is installed between the output hub 16 of the first clutch 4 and the output hub 31 of the second clutch 5 . and the second axial bearing 33 is inserted between the output hub 31 of the second clutch 5 and the inner tube 42 of the hydraulic control system 21 .

The output disk holder 30 comprises an axially oriented cylindrical skirt 34 which is arranged radially inside the cylindrical skirt 29 of the input disk holder 9 and has external teeth. The output disk holder 30 also includes a radially oriented portion 35 extending radially from the front end of the cylindrical skirt 34 of the output disk holder 30 to the output hub 31 .

The multi-disc assembly 11 of the second clutch 5 includes a plurality of annular plates having a structure similar to that of the annular plate of the first clutch 4 . Each plate includes, on its outer periphery, outer teeth which engage with complementary teeth provided on the inner surface of the cylindrical skirt 29 of the input disk holder 9 . The multi-disc assembly 11 has a structure similar to that of the first clutch 4 and further includes a plurality of friction disks installed to rotate integrally with the output disk holder 30 and slide axially thereon. do. To do this, each friction disk has, on its inner periphery, inner teeth which engage with outer teeth provided on the cylindrical skirt 34 of the output disk holder 30 . Each friction disk is inserted between two plates.

A plate disposed at the front end of the multidisc assembly 11 cooperates with the reaction member 36 . The reaction member 36 itself is held forward by a stop ring 37 fixed at the front end of its cylindrical skirt 34 on the input disk holder 9 of the second clutch 5 .

The second clutch 5 is a force transmission member 38 which, on the one hand, cooperates with a plate arranged at the rear end of the multidisc assembly 11 of the second clutch 5 and on the other hand cooperates with the hydraulic control system 21 . ), the hydraulic control system can displace the second clutch 5 from its clutch disconnected position to its clutch engaged position by sliding the force transmitting member axially forward. Here, the force transmission member 38 is constituted by a metal plate, and the metal plate includes, on its outer periphery, a plurality of fingers 39 of axial orientation regularly distributed around the axis X. Each finger 39 passes across a dedicated opening provided in the support 19 of the input disk holder 8 of the first clutch 4 and thereby the rear of the multi-disk assembly 11 of the second clutch 5 . It is supported against a plate disposed at the end.

In order to displace the second clutch 5 from its clutch disconnected position to its clutch engaged position, each friction disk is clamped between two plates so that a torque is transmitted between the input disk holder 9 and the output disk holder 30 . and consequently the force transmission member 38 is displaced forward so as to be transmitted between the crankshaft of the internal combustion engine and the outer input shaft 3 of the gearbox.

In order to limit the axial footprint of the dual clutch, the force transmission member 38 includes a forward-facing axial reinforcement 40 therein in which the hydraulic control system 21 is at least partially accommodated. do.

The dual clutch 1 further comprises a hydraulic control system 21 capable of actuating the two clutches 4 , 5 . The hydraulic control system 21 includes a housing 41 which is fixed against a wall of a gearbox, not shown. The housing 41 has an inner tube 42 which extends axially around the axis X and provides an inner space through which the input shafts 2 , 3 of the gearbox pass. The inner tube 42 is manufactured integrally with the housing 41 . The housing 41 further has first and second concentric annular chambers 43 , 44 disposed radially outside the inner tube 42 . First and second annular pistons 45 , 46 are installed in axial translational movement inside the first and second annular chambers 43 , 44 .

The housing 41 further includes, for each of the first and second annular chambers 43 and 44 , pressurized fluid supply channels 47 , 48 open to the inside of the chambers 43 , 44 to enable fluid supply. be prepared Each channel 47 , 48 is connected to a hydraulic circuit to which a pump is mounted. In this way, the first and second chambers 43 , 44 are designed to receive fluid and cause displacement of the respective pistons 45 , 46 from their resting positions to their active positions towards the front.

Each of the first and second pistons 45 , 46 has a rotating bearing 49 , 50 secured to an end of the piston 45 , 46 . Each of the rotary bearings 49 , 50 has a first ring 59 , 60 fixed to the piston 43 , 44 , and a second ring 61 , 62 supported against one of the force transmission members 25 , 38 . ), and a rolling element such as a bead inserted between two rings.

The inner tube 42 extends axially forward beyond the first and second chambers 43 , 44 . On the other hand, beyond the strokes of the first and second pistons 45 , 46 corresponding to the displacements of the first and second clutches 4 , 5 from their clutch disengaged position towards their clutch connected position, the inner tube 42 . has a cylindrical bearing surface 51 , on which a bearing 20 supporting the input disk holders 8 , 9 of the clutch 4 , 5 is installed. Here, the bearing 20 is an inner ring installed on the periphery of the cylindrical bearing face 51 of the inner tube 42 , the radial inner edge of the support portion 19 of the input disk holder 8 of the first clutch 4 . It includes an outer ring installed in the interior of the receiving portion 52 provided in, and a rolling element such as a bead inserted between the outer ring and the inner ring. Rolling bearings are inclined contact type. Receptacle 52 includes a rearwardly facing shoulder 53 capable of retaining the outer ring towards the rear. On the other hand, the inner ring is held forward by a "circlip" The outer diameter of the cylindrical bearing face 51 is smaller than the inner bore of the force transmission member 38 .

1 , the force transmitting member 38 of the second clutch 5 is centered on the force transmitting member 25 of the first clutch 4 . Meanwhile, the force transmitting member 25 of the first clutch 4 is centered on the second ring 61 of the first rotary bearing 49 .

To do this, the force transmission members 25 and 38 have cylindrical centering skirts 63 and 64, respectively, with an axial orientation. Cylindrical centering skirts 63 and 64 connect the inner and outer portions of their respective force transmission members 25 and 38, respectively, and direct the shaft reinforcements 28 and 40 toward the front of the inner portion. Cylindrical centering skirts 63 , 64 cooperate with each other so that the force transmission members 25 , 38 center with respect to each other. The cylindrical centering skirt 63 of the force transmitting member 25 of the first clutch 4 is radially arranged outside the cylindrical centering skirt 64 of the force transmitting member 38 of the second clutch 4, The inner surface of the cylindrical centering skirt 63 and the outer surface of the cylindrical centering skirt 64 cooperate.

According to one embodiment, the cylindrical centering skirts 63 , 64 are cylindrical in rotation about the axis X. In other words, the cylindrical centering skirts 63 , 64 cooperate with each other continuously around the axis X.

According to another embodiment, the cylindrical centering skirts 63 , 64 cooperate with one another in dedicated cylindrical centering faces that are discontinuous around the perimeter of X and are regularly distributed about the axis X. This embodiment will be disclosed in more detail later with reference to FIGS. 3 and 6 .

Accordingly, the axial dimensions of the cylindrical centering skirts 63 and 64 and their relative positioning are as follows:

- On the one hand, the first piston 45 can be displaced to its active position corresponding to the connected state of the first clutch 4 and the second piston 46 is connected to the force transmitting member 25 of the first clutch 4 . ) stays in its rest position which is not axially supported with respect to the force transmission member 38 of the second clutch 5 ;

- on the other hand, the second piston 46 can be displaced to its active position corresponding to the connected state of the second clutch 5 and the first piston 45 is positioned between the two cylindrical centering skirts 63 , 64 . It remains in its resting position where no guidance device is interposed.

On the other hand, the force transmitting member 25 of the first clutch 4 includes an annular projection 65 provided on its inner portion and projecting rearward. Accordingly, a cylindrical centering surface is provided on the radially inner periphery of the annular projection 65 . This cylindrical centering face cooperates with a complementary cylindrical centering face formed by the radially outwardly oriented end of the second ring 61 of the first rotary bearing 49 . The annular projection 65 may be provided continuously around the entire perimeter of the axis X or may consist of a plurality of annular segments regularly distributed around the axis X and spaced apart from each other in the circumferential direction.

According to another embodiment, not shown, the centering of the force transmission member 25 of the first clutch 4 on the second ring 61 of the first rotary bearing 49 is ensured by means of different types. can be

In this embodiment, the rotation guidance of the two force transmission members 25 , 38 about the axis X is ensured by the rotary bearing 49 of the first clutch 4 .

In this embodiment, in operation, the two force transmission members 25 , 38 and the second ring 61 of the first rotary bearing 49 have the same speed, ie the speed of the crankshaft, without generating additional frictional torque. It is particularly advantageous in that it is possible to limit the drag torque and reduce energy consumption since rotational induction of the two force transmission members 25 , 38 is ensured.

Figure 2 shows another embodiment in which each of the force transmission members 25, 38 is centered on a rotating bearing 49, 50 with which it cooperates. The force transmission member 25 of the first clutch 4 is embodied according to what has been previously disclosed in connection with FIG. 1 . In FIG. 2 , the force transmitting member 38 of the second clutch 5 also includes an annular projection 66 projecting rearwardly. The annular projection 66 is, on its inner periphery, a cylinder cooperating with a complementary cylindrical centering face formed by an outwardly oriented end of the second annulus 62 of the radially second rotary bearing 60 . It includes a centering face.

3 and 6 show that the force transmission member 38 of the second clutch 5 is centered on the support 19 and the force transmission member 25 , 38 of the two clutches 4 , 5 is centered relative to each other. Another embodiment is shown.

As in the embodiment of FIG. 1 , the force transmission members 25 , 38 are provided with cylindrical centering skirts 63 , 64 respectively, and the cylindrical centering skirts 63 , 64 cooperate with one another to form the force transmission members 25 , 38 . center with respect to each other.

On the other hand, the support portion 19 includes an axially oriented cylindrical centering skirt 67 connecting the outer portion 19a and the inner portion 19b of the support portion 19 . The cylindrical centering skirt 67 has an inner surface, which cooperates with the outer surface of the cylindrical centering skirt 64 of the force transmission member 38 of the second clutch 5 to ensure centering of the member.

In this embodiment, in addition to the defined axial dimensioning and relative positioning of the cylindrical centering skirts 63 , 64 of the force transmission members 25 , 38 , the axial dimensions of the cylindrical centering skirts 67 of the support 19 . and the relative positioning is such that the force transmitting members 25 , 38 of the second clutch 5 are not bearing bearing against the support 19 and the second piston 46 can be displaced to its active position.

Referring to the cross-sectional view of FIG. 6 , the structure of the cylindrical centering skirts 63 , 64 and 67 according to one embodiment is observed. The cylindrical centering skirt 67 comprises three centering legs 69a, 69b, 69c which are oriented radially inwardly and around which the axis X is regularly distributed. The faces of the centering legs 69a, 69b, 69c, which are oriented inward, have the form of a rotating cylinder part whose busbar is the axis X and have a cylindrical centering skirt of the force transmitting member 38 of the first clutch 5 ( 64) and cooperating with the exterior. Each centering leg 69a, 69b, 69c extends circumferentially on an angular sector comprised between 5 and 45 degrees.

On the other hand, the cylindrical centering skirt 64 of the force transmission member 38 also comprises three centering legs 70a, 70b, 70c which are oriented radially inwardly and around which the axis X is regularly distributed. . Each centering leg 70a, 70b, 70c extends circumferentially on an angular sector Y comprised between 5 and 45° and includes a centering leg 69a, 69b, of the cylindrical centering skirt 67 of the support 19 , 69c) circumferentially offset by an angle Z for each sector. On the other hand, the cylindrical centering skirt 63 of the force transmitting member 25 of the first clutch 4 also includes three centering legs 71a, 71b, 71c oriented radially outward. The face of the inwardly oriented centering leg 70a, 70b, 70c cooperates with the face of the outwardly oriented centering leg 71a, 71b, 71c so as to attach the force transmission members 25, 38 to each other. center against The opposing centering legs 70a, 70b, 70c and 71a, 71b, 71c cooperate with each other via faces in the form of a rotating cylinder whose busbar is the axis X.

In the embodiment of FIG. 4 , the force transmitting members 25 , 38 of the first clutch 4 are centered on the housing 41 of the actuation system 21 and the rotation is guided while the force of the two clutches 4 , 5 . The transfer members 25 , 38 are centered relative to each other.

1 and 3, the force transmission members 25 and 38 each have axially oriented cylindrical centering skirts 63 and 64 and the cylindrical centering skirts 63 and 64 cooperate with one another to form the force transmission members ( 25, 38) center with respect to each other.

On the other hand, the housing 41 has, on its radial outer periphery, a cylindrical centering face 68 cooperating with the inner surface of the cylindrical centering skirt 63 of the force transmitting member 25 of the first clutch 4 to provide the force transmitting member Center (25) about axis (X) and guide rotation. In order to guide the rotation of the force transmission member 25 with respect to the housing 41 , the cylindrical centering face 68 has the form of a rotating cylinder whose busbar is the axis X. In an embodiment not shown, an annular sliding bearing is arranged between the force transmission member 25 and the housing 41 to limit friction. Such annular bearings may in particular be made of a plastics material, for example polytetrafluoroethylene (PTFE).

Of course, other arrangements for ensuring the centering and rotational guidance of the force transmission members 25 , 38 about the axis X are possible. In particular, it is possible to combine the features of the above four embodiments.

Also, in another alternative embodiment, not shown, the force transmitting member 38 of the second clutch 5 is centered on the second ring 62 of the second rotary bearing 50 and the force transmitting member of the two clutches. (25, 38) are centered with respect to each other.

In another embodiment, the force transmitting member 38 of the second clutch 5 is centered on the second ring 62 of the second rotating bearing 50 and the force transmitting member 25 of the first clutch 4 is It is centered on the housing 41 of the actuation system 21 and the rotation is guided.

In another embodiment, the force transmitting member 38 of the first clutch 4 is centered on the second ring 61 of the first rotary bearing 49 and the force transmitting member of the second clutch 4 is centered on the support 19 . do.

In another embodiment, the force transmitting member 38 of the first clutch 4 is centered and rotationally guided on the housing 41 of the actuation system and the force transmitting member 38 of the second clutch 5 is connected to the support 19 ) is centered on the

1 , the inner tube 42 of the hydraulic control system 21 is a passage channel 55 for a cooling fluid, such as oil of a gearbox, to ensure lubrication and cooling of the multi-disc assembly 10 , 11 . ) is observed to contain a plurality. Channels 55 are evenly distributed around axis X.

Each channel 55 extends axially between an inlet orifice 56 open at the rear of the housing 41 of the hydraulic control system and an outlet orifice 57 open at the front end of the inner tube 42 . . The inlet orifice 55 is connected to the hydraulic circuit to which the pump is mounted. The outlet orifices 57 are distributed regularly around the axis X and open radially inside the multidisc assembly 10 , 11 . The outlet orifices 57 are oriented radially outward to guide the cooling fluid in the radially outward direction of the multidisc assembly 10 , 11 . In the embodiment shown, the outlet orifice 57 is axially open in the portion of the inner tube extending beyond the cylindrical bearing face 51 and the bearing 20 is installed in the cylindrical bearing face. Accordingly, the cooling fluid passes between the input disk holder (8, 9) and the output disk holder (15, 30).

Cylindrical shape of the input and output disk holders 9, 30 of the second clutch 5, so as to be able to circulate oil from the outlet orifice towards the outside of the dual clutch by passing it across the multi-disk assembly 10, 11 The skirts 29 , 34 and the cylindrical skirts 18 , 22 of the input and output disk holders 8 , 15 of the first clutch 4 have radial orifices 58 . In FIG. 1 only the orifice 58 of the output disk holder 30 of the second clutch 5 is shown.

While the present invention has been disclosed in connection with a plurality of specific embodiments, it is to be understood that the invention is in no way limited thereto and includes all technical equivalents of the disclosed means and combinations thereof provided they fall within the scope of the invention.

The use of the verbs "comprise", "include" or "include" and their conjugations does not exclude the presence of elements or steps other than those described in a claim.

In the claims, any reference signs placed between parentheses should not be construed as limitations of the claim.

Claims (18)

A wet double clutch (1) designed to be placed in a transmission chain of a motor vehicle between an engine having a crankshaft and a gearbox comprising two coaxial input shafts (2, 3) extending along an axis (X),
The wet double clutch (1) comprises first and second clutches (4, 5) capable of transmitting torque from the crankshaft towards one and the other of the two input shafts (2, 3) of the gearbox, respectively, and ,
Each of the first and second clutches 4 and 5,
input disc holders (8, 9) designed for rotational connection to the crankshaft;
an output disk holder (15, 30) designed for rotational connection to one or the other of the two input shafts of the gearbox;
at least one friction disk rotating integrally with one of the input and output disk holders 8, 9, 15, 30 and respectively disposed on opposite sides of each friction disk and the input and output disk holder 8, 9, 15 . the multi-disc assembly (10, 11) moving axially between an input disk holder (8, 9) and a clutch connection position transmitting torque between the output disk holder (15, 30); and
a force transmission member (25, 38) which moves in translation along the axis (X) to displace the multidisc assembly (10, 11) from its clutch disengaged position to its clutch engaged position;
The wet double clutch (1) further comprises a control system (21),
The control system is
a housing 41 designed to be fixed to the gearbox;
first and second annular pistons (45, 46) mounted to slide axially on said housing and having first and second rotary bearings (49, 50), respectively;
The first and second rotary bearings 49 and 50 cooperate with the force transmission members 25 and 38 of the first and second clutches 4 and 5 respectively to disengage the clutches 4 and 5 from their clutches. displace between a position and its clutch engagement position;
The force transmission members 25, 38 are rotationally guided and centered about an axis X.
Wet double clutch. The method of claim 1,
Each force transmission member 25 , 38 comprises at least one cylindrical centering face, which is each circumferentially discontinuous about the axis X.
Wet double clutch. 3. The method of claim 2,
The cylindrical centering surface is a cylinder part
Wet double clutch. 4. The method of claim 3,
The cylinder parts extend at an angle in a numerical range included in each of 5 ° to 45 ° around the axis (X).
Wet double clutch. 4. The method of claim 3,
Each force transmission member 25 , 38 comprises at least three cylindrical portions regularly distributed at an angle about an axis X.
Wet double clutch. According to claim 1,
The force transmitting member 25 of the first clutch 4 and the force transmitting member 38 of the second clutch 5 are centered relative to each other.
Wet double clutch. 7. The method of claim 6,
The force transmitting members 25 , 38 of the first clutch 4 and the second clutch 5 are, respectively, an inner part cooperating with one of the first and second rotary bearings 49 , 50 , the multi an outer portion cooperating with one of the disc assemblies (10, 11) and an axially oriented cylindrical centering skirt (63, 64) connecting the inner portion and the outer portion, the first clutch (4) and the The cylindrical centering skirts 63 , 64 of the force transmission members 25 , 38 of the second clutch 5 cooperate with each other to center the force transmission members 25 , 38 relative to each other.
Wet double clutch. The method of claim 1,
each input or output disc holder 8 , 9 , 15 , 30 comprises a grooved cylindrical skirt 18 , 22 , 29 , 34 ; Each friction disk or plate is installed to move axially on a cylindrical skirt grooved in one of said output or input disk holders and to rotate integrally with one of said output or input disk holder, said input disk holder (8). , 9) one of which comprises a support 19 oriented radially inwardly from the edge of its grooved cylindrical skirt oriented towards the control system; The support 19 has a radially inner edge cooperating with a bearing 20 guiding the rotation of the dual clutch about the axis X, the force transmitting member 38 of the second clutch 5 being centered on the support 19
Wet double clutch. 9. The method of claim 8,
The support portion 19 comprises an outer portion 19a, an inner portion 19b axially offset with respect to the outer portion 19a and disposed inside the multi-disc assembly 10, 11, and the outer portion 19b. and an axially oriented cylindrical centering skirt (67) connecting the part (19a) and the inner part (19b), the force transmitting member (38) of the second clutch (5) is the cylindrical centering of the support part (19) centering the force transmission member 38 of the second clutch 5 on the support 19 , comprising an axially oriented cylindrical centering skirt 64 cooperating with the skirt 67 .
Wet double clutch. 9. The method of claim 8,
The force transmitting member 25 of the first clutch 4 and the force transmitting member 38 of the second clutch 5 cooperate with each other via a plurality of cylindrical surfaces regularly distributed around the axis X. Centering the force transmitting members 25 , 38 with respect to each other, the force transmitting member 38 of the second clutch 5 being regularly distributed around the axis X and the first and second clutches Centering on the support 19 via a plurality of cylindrical faces circumferentially offset about the axis X with respect to the cylindrical faces by which the force transmission members 25 , 38 of ( 4 , 5 ) cooperate felled
Wet double clutch. The method of claim 1,
The second rotary bearing 50 includes a first ring 60 fixed to the second annular piston 46 , and a second ring 62 supported against the force transmission member 38 of the second clutch 5 . ), and a rolling element inserted between the first ring and the second ring, wherein the force transmitting member of the second clutch (5) is centered on the second ring (62)
Wet double clutch. 12. The method of claim 11,
The force transmission member 38 of the second clutch 5 comprises a cylindrical centering face 66 cooperating with a complementary cylindrical centering face provided on the edge of the second ring 62 .
Wet double clutch. The method of claim 1,
each input or output disc holder 8 , 9 , 15 , 30 comprises a grooved cylindrical skirt 18 , 22 , 29 , 34 ; Each friction disk or plate is installed to move axially on a cylindrical skirt grooved with one of the output or input disk holders and to rotate integrally with one of the output or input disk holders, the input disk holder ( one of 8, 9) comprises a support 19 oriented radially inwardly from the edge of its grooved cylindrical skirt oriented towards the control system; The support (19) has a radially inner edge cooperating with a bearing (20) guiding the rotation of the dual clutch about an axis (X), the force transmitting member (38) of the second clutch (5) is centered on the support 19
Wet double clutch. 14. The method of claim 13,
The support portion 19 comprises an outer portion 19a, an inner portion 19a offset axially with respect to the outer portion 19a and disposed inside the multi-disc assembly 10, 11, and the outer portion 19a. an axially oriented cylindrical centering skirt (67) connecting the part (19a) and the inner part (19b), the force transmitting member (38) of the second clutch (5) is the cylindrical centering of the support part (19) centering the force transmission member 38 of the second clutch 5 on the support 19 , comprising an axially oriented cylindrical centering skirt 64 cooperating with the skirt 67 .
Wet double clutch. 15. The method according to any one of claims 1 to 14,
The first rotary bearing 49 includes a first ring 59 fixed to the first annular piston 45 , and a second ring 61 supported against the force transmission member 25 of the first clutch 4 . ), and a rolling element inserted between the first ring (59) and the second ring (61), wherein the force transmitting member (25) of the first clutch (4) is the second ring (61) centered on
Wet double clutch. 16. The method of claim 15,
The force transmission member 25 of the first clutch 4 has a cylindrical centering face 65 cooperating with a complementary cylindrical centering face provided on the edge of the second ring 61 of the first rotary bearing 49 . containing
Wet double clutch. 15. The method according to any one of claims 1 to 14,
The force transmission member 25 of the first clutch 4 is centered and rotationally guided on the housing 41 of the actuation system 21 .
Wet double clutch. 18. The method of claim 17,
The housing 41 of the actuation system 21 comprises a cylindrical centering face 68 on the outside of the first and second annular pistons 45 , 46 radially, the force of the first clutch 4 . The transmission member (25) comprises an inner portion cooperating with the first rotary bearing (49), an outer portion, and an axially oriented cylindrical centering skirt (63) connecting the inner portion and the outer portion, the cylindrical The centering skirt 63 cooperates with the cylindrical centering face 68 of the housing 41 to center and rotationally guide the force transmitting member 25 of the first clutch 4 with respect to the housing 41 .
Wet double clutch.

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