FR3034480B1 - TRANSMISSION SYSTEM COMPRISING A WET DOUBLE CLUTCH MECHANISM - Google Patents

Abstract

The invention relates to a transmission system (10), in particular for a motor vehicle, comprising around an axis (o) at least: - a mechanism (20) with a double wet clutch comprising at least a first clutch (E1) and a second clutch (E2) respectively of multi-disk type, - a web (18) of drive to link in rotation said drive shaft to the means (60) of reaction, said multidisk assembly of the first clutch E1 respectively comprising disks (64) of friction and flanges (76) rotatably connected to an inner disk carrier (38) having an external toothing (39), characterized in that the drive web (18) locally defines a projection (80) in the direction of the multi-disk assembly of the first clutch (E1), this projection (80) forming a stop holding the end flange (76) of the multi-disk assembly of the first clutch (E1) alternately to the first piston (30).

Description

The present invention relates to a transmission system comprising a wet double clutch mechanism.

Such a transmission system is intended to form part of a transmission, especially for a motor vehicle or for a so-called industrial vehicle, the latter being for example a truck, a public transport vehicle, or an agricultural vehicle.

The present invention more particularly relates to a transmission system comprising a wet double clutch movable in rotation about a main axis of rotation, which is controlled to selectively couple a drive shaft of a combustion engine to a first driven shaft and to a second driven shaft of a gearbox, said wet double clutch mechanism comprising at least a first clutch and a second clutch respectively multi-disk type, each of said first and second clutches comprising at least one axially movable piston which is driven in displacement at the by means of a control chamber to which is associated a balancing chamber defined at least by a balancing piston, said piston axially clamping in a clutched position a multi-disk assembly against reaction means, said multi-disk assembly comprising flanges and also friction discs bound in tation via a disk carrier to one of said first and second driven trees.

Known from the prior art such transmission systems comprising a double wet clutch mechanism (or "Double Wet Clutch" in English) generally multidisc type, said mechanism being located in the clutch housing of the motor vehicle.

In certain applications, particularly but not exclusively for so-called industrial vehicles, the reliable transmission of large torques is sought while having a radial and axial compactness of the transmission system, for example to allow the implantation between the engine and the gearbox of the vehicle.

The engine torque to be transmitted by the transmission systems has been constantly increasing for several years, reaching values of the order of 4000 Nm. The known architectures of transmission systems comprising a wet double clutch mechanism, as described in the document US2006 / 0086586, do not allow to transmit these torque values and / or do not provide satisfactory reliability in a satisfactory radial and axial dimensions.

In document US2006 / 0086586, the double clutch mechanism comprises two multi-disk assemblies arranged axially on either side of a common reaction means. Each multi-disk assembly comprises respectively friction disks rotatably connected to the shafts driven by external disk carriers. The connection of the outer disk gates on the driven shafts is carried out in an axial plane perpendicular to the axis of rotation and situated outside the axial space used by the two multi-disk assemblies, which is not favorable for the compactness of all.

The transmission system and its associated wet double clutch mechanism is a fragile assembly that needs to be handled with care during transport and assembly operations on the production line.

The document US2006 / 0086586 also describes flanges connected in rotation to inner disk carriers, each of the end flanges being in contact with one of the actuating pistons associated with the two multi-disk assemblies. In the intermediate phase of assembly, when the actuating piston is not present, the end flange engaged on the inner disk carrier is not maintained axially.

Such an assembly is however not without problem. Indeed, there is a risk of disengagement of the end flange of the multi-disk assembly relative to the associated disk-holder during handling of the transmission system until the piston of the array assembly has been assembled on said system. Because of this risk, the manufacturer of the transmission system is obliged to perform a quality control of this assembly at the output of the production line.

The object of the present invention is in particular to provide a torque transmission module comprising a wet double clutch mechanism for solving at least a portion of certain disadvantages of the prior art.

For this purpose, the invention proposes a transmission system, in particular for a motor vehicle, comprising around an axis O at least: a wet double clutch mechanism comprising at least a first clutch and a second clutch respectively of multidisc type and reaction means interposed axially between the first clutch and the second clutch, the mechanism being controlled to selectively couple said drive shaft to a first driven shaft and a second driven shaft, and a drive web to rotatably link. said shaft leading to the reaction means, said first clutch having at least one first piston axially displaceable in one direction to come, in the engaged position, clamping a multi-disk assembly of the first clutch against the reaction means and said second clutch comprising at least a second piston displaceable axially in an opposite direction, to come, in engaged position, s wander a multi-disk assembly of the second clutch against the reaction means, said multi-disk assembly of the first clutch respectively comprising friction disks and flanges, one of which defines an end flange, characterized in that the drive veil defines locally a protrusion in the direction of this end flange, this projection forming a stop holding the end flange alternately to the first piston.

This torque transmission system, according to the invention, has the advantage, thanks to the connection of the drive web to the reaction means, to form a closed assembly subassembly in which the end flange can not disengage from the multi-disk assembly, especially when the piston is not yet mounted on the mounting subassembly. In other words, the projection allows, in the absence of the piston, to maintain the end plate in the multidisk assembly of the first clutch.

Preferably, the end flange is associated with a disk carrier having a toothing. The projection and the free end of the toothing of the disk carrier are separated by an axial distance strictly less than the axial dimension of the end flange of the multi-disk assembly.

During the design of the transmission system, it is easy to define the axial distance between the projection and the free end of the toothing of the disk carrier and to size it according to the axial dimension of the end flange. In this way, the final assembly of the piston on the mounting subassembly can be done automatically, by dispensing with visual control means of good positioning of the end plate on the disk holder of the array assembly. . This avoids an additional control step during assembly of the transmission system. The invention may have any of the features described below combined with one another or taken independently of one another.

The axial dimension of the end flange of the multi-disk assembly represents the maximum thickness of the flange along the axis O.

Advantageously, the piston comprises an actuating part formed by fingers which extend axially towards the rear and the driving veil comprises openings for the axial passage of said fingers. This architecture has the advantage of reducing the radial size of the torque transmission system.

Advantageously, the circular piston has a front ring from which axially extend the fingers. The projection formed on the drive web is located axially between the front ring of the piston and the end flange. This architecture has the advantage of reducing the axial size of the torque transmission system. Also, when the transmission system is assembled, the piston maintains in axial position the end flange relative to the toothing of the disk carrier and thus takes the relay of the protrusion of the driving veil.

The openings are rectangular or oblong or elliptical in a plane perpendicular to the axis O.

In one embodiment of the invention, the projection is integral with the driving veil. Obtaining the projection coming directly from the material with the web advantageously limits the dimensional tolerances of manufacture which concerns the axial distance between the projection and the free end of the toothing.

The projection is made by a stamp of circumferentially continuous shape.

The openings are formed in shape stamping.

In a variant, the projection is produced by a series of shaped stampings circumferentially distributed around the axis O.

The projection is in the form of a return of squares. By means of a fold of material at 90 °, the return of square advantageously limits the size of the projection.

The stampings of shape are angularly distributed between the openings arranged on the training sail.

The stampings of form surround the openings.

The veil has as many embossed shapes as openings.

The projection has at least one flat bearing area arranged to receive the end flange of the array assembly.

The flat bearing zone or zones are implanted radially on a diameter between the inside diameter and the outside diameter of the end flange.

The flat support zone or zones are machined.

The flat support zone or zones are calibrated by a press operation. Rework operations such as machining or calibration by press operation further reduce manufacturing tolerances.

In another embodiment of the invention, the projection is attached to the web by means of at least one additional piece. Obtaining the projection by adding at least one additional piece allows greater flexibility in terms of manufacturing the double clutch mechanism. Depending on the engine torque to be transmitted, the number of friction discs and flanges is adapted to the necessary. The additional part (s) are therefore dimensionally adjusted to define the adequate axial distance between the projection and the free end of the toothing. In this way, the training veil can become a reusable standard part for several applications.

Preferably, the projection comprises at least three rivets distributed circumferentially around the axis O and fixed on the web.

Alternatively, the projection is an annular plate attached to the web.

The projection is attached to the veil by riveting, welding or gluing.

Advantageously, the end flange of the multidisk assembly is of monobloc structure.

In a variant, the end flange of the multi-plate assembly is of lamellar structure.

The end flange of the multi-disk assembly is annular in shape.

Advantageously, the driving veil has a general shape of revolution defining a front face having the openings and the projection is formed from said front face or attached to said front face.

The driving veil is rotatably connected to the reaction means by means of connecting means made by riveting or welding.

The piston is concentric with the training sail.

The front face of the drive web is located axially between the front ring of the piston and the end flange. The invention also relates, in another of its aspects, to a transmission system, in particular for a motor vehicle, comprising around an axis O at least: a wet double clutch mechanism comprising at least a first clutch and a second clutch respectively multi-disk type, and reaction means interposed axially between the first clutch and the second clutch, the mechanism being controlled to selectively couple said drive shaft to a first driven shaft and a second driven shaft, and - a sail driving means for rotationally connecting said shaft leading to the reaction means, said first clutch comprising at least a first piston displaceable axially in one direction to come, in the engaged position, clamping a multi-disk assembly of the first clutch against the reaction means and said second clutch comprising at least a second piston displaceable axially in an opposite direction, p To come, in the engaged position, tighten a multi-disk assembly of the second clutch against the reaction means, said multi-disk assembly of the first clutch respectively comprising friction discs rotatably connected to the shaft driven by an outer disk carrier forming the element. clutch outlet and flanges rotatably connected to an inner disk carrier having external toothing, characterized in that the drive web locally defines a projection towards the multi-disk assembly of the first clutch, said projection and the free end of the external toothing of the inner disk carrier being separated by an axial distance strictly less than the axial dimension of the end flange of this multi-disk assembly.

Advantageously, the projection is dimensioned so as to retain the end flange on the external toothing of the inner disk carrier in the absence of the piston, in particular during the assembly operation of the wet double clutch mechanism.

All or some of the features mentioned above apply to this other aspect of the invention. The invention also relates, in another of its aspects, to a transmission system, in particular for a motor vehicle, comprising around an axis O at least: a wet double clutch mechanism comprising at least a first clutch and a second clutch respectively multi-disk type, and reaction means interposed axially between the first clutch and the second clutch, the mechanism being controlled to selectively couple said drive shaft to a first driven shaft and a second driven shaft, and - a sail driving means for rotationally connecting said shaft leading to the reaction means, said first clutch comprising at least a first piston displaceable axially in one direction to come, in the engaged position, clamping a multi-disk assembly of the first clutch against the reaction means and said second clutch comprising at least a second piston displaceable axially in an opposite direction, p To come, in the engaged position, tighten a multi-disk assembly of the second clutch against the reaction means, said multi-disk assembly of the first clutch respectively comprising friction disks and flanges, one of which defines an end flange, characterized in that the flange end of the multidisk assembly of the first clutch locally defines a projection towards the drive web, this projection forming a stop holding the end plate alternately to the first piston.

According to this aspect of the invention, it may be advantageous to define a specific end plate for the multi-disk assembly of the first clutch. The training sail can become a reusable standard part for many applications.

Such a transmission system may have one or more of the following other features:

Preferably, the drive web has an interface surface with the end flange and the end flange is associated with a disk carrier having a toothing. The interface surface of the drive web and the free end of the toothing of the disk carrier are separated by an axial distance strictly less than the axial dimension of the end plate of the multi-disk assembly.

Advantageously, the end flange is rotatably connected to an inner disk carrier having an external toothing and the projection of the end flange is dimensioned so as to retain the end flange on the external toothing of the inner disk carrier, in the absence of the piston. the end flange has a friction rear face cooperating with a friction disk and a flat bearing zone disposed on the projection.

The projection has at least one flat bearing area arranged to cooperate with the training sail.

Preferably, the axial dimension of the end flange of the multi-disk assembly represents the maximum thickness of the flange measured along the axis O between the flat bearing zone and the rear friction face.

The interface surface of the web is flat.

The interface surface of the web is annular.

Preferably, the projection of the end flange is made by a protrusion of circumferentially continuous shape.

Alternatively, the projection of the end flange is made by discontinuous growths. The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the appended drawings, in which: FIG. 1 is a front view of a transmission system according to a preferred mode of implementation of the invention; Figure 2 is a perspective and cutaway view of the transmission system of Figure 1. Figure 3 is a sectional view along III - III of the transmission system of Figure 1; Figures 4 and 5 are perspective views of the driving veil according to the transmission system of Figure 1; Figure 6 is a sectional view of a transmission system according to a second embodiment similar to that shown in Figure 1; Figure 7 is a front view of a transmission system according to a third embodiment of the invention; Figure 8 a sectional view along IIX - IIX of the transmission system of Figure 7; Figures 9 and 10 are perspective views of the driving veil according to the transmission system of Figure 7; Figure 11 is a front view of a transmission system according to a fourth embodiment of the invention; Figure 12 a sectional view along XII - XII of the transmission system of Figure 11; Figure 13 is a sectional view of a transmission system according to a fifth embodiment of the invention.

In the remainder of the description and the claims, the terms "before" or "backward" depending on the direction with respect to an axial orientation determined by the principal axis O will be used in a nonlimiting manner and in order to facilitate understanding thereof. of rotation of the transmission of the motor vehicle and the terms "inner / inner" or "outer / outer" with respect to the axis O and in a radial orientation, orthogonal to said axial orientation.

There is shown in Figures 1 to 3 a first embodiment of a transmission system 10, in particular for a motor vehicle, having a main axis O of rotation.

The transmission system 10 comprises around the axis O at least one input element which is rotatably connected to a driving shaft (not shown).

Preferably, the input element of the system 10 comprises at least one input shell 12 which is rotatably connected to an input hub 14.

The inlet shell 12, generally having an "L" shape, has a radially oriented portion and an axially oriented portion.

The hub 14 has a portion of radial orientation and an axially oriented portion, the hub 14 being arranged radially inward with respect to the shell 12.

The axially oriented portion of the hub 14 extends inside the radial portion, axially rearward, in a direction corresponding to that of the motor.

The hub 14 has splines 16, formed in a cylindrical outer surface of the axial portion, for the rotational connection of the input member formed by at least the shell 12 and the hub 14 with the drive shaft. The inner end of the radial portion of the shell 12 and the outer end of the radial portion of the hub 14 input are integral, preferably secured together by welding.

The hub 14 of input is for example linked in rotation through the splines 16 at the output of a damping or damping device (such as a double damping flywheel, etc.) whose input is linked, particularly via a flywheel, the driving shaft formed by a crankshaft that rotates a motor equipping the motor vehicle.

The inlet shell 12 is rotatably connected to a drive veil 18, which drive vane 18 rotates said inlet shell 12 to a wet dual-clutch mechanism 20.

The inlet shell 12 and the driving veil 18 are connected in rotation by a mechanical riveting type connection.

As illustrated in FIG. 2, the inlet shell 12 has radially outwardly extending tabs 17 at its axially-oriented outer radial end, which bear on an annular ring 19 that includes at its radially outer end axially oriented, the veil 18 drive.

Rivets 21, circumferentially distributed around the axis O, are housed in orifices common to the driving veil 18 and to the shell 12, located respectively on the lugs 17 and the annular ring 19 so as to create a rigid mechanical connection . This mechanical link is capable of transmitting significant torque levels.

The wet dual clutch mechanism 20 is controlled to selectively couple said drive shaft to a first driven shaft A1 and a second driven shaft A2.

Preferably, the first driven shaft A1 and the second driven shaft A2 are coaxial.

The wet double clutch mechanism 20 comprises at least a first clutch E1 and a second clutch E2, which are respectively multidisc type.

The first driven shaft A1 is rotated when said first clutch E1 is closed and the second driven shaft A2 is rotated when said second clutch E2 is closed, said first and second shafts A1, A2 being respectively connected to a box of speeds fitted to the motor vehicle.

In the wet dual-clutch mechanism 20, the first clutch E1 serves, for example, both to start and engage the odd reports and the second clutch E2 then supports the even and reverse, alternatively the ratios supported by said first clutch E1 and second clutch E2 are reversed.

The first clutch E1 is for example arranged axially in front of the side of the gearbox and the second clutch E2 is for example arranged axially at the rear of the motor side of the hub 14 input.

The first clutch E1 and the second clutch E2 alternately transmit the input power (torque and speed) of the drive shaft, which receives the input shell 12 of the system 10, to one of the two shafts A1, A2 conducted, depending on the open or closed state of each clutch E1 and E2.

Preferably, the first clutch E1 and the second clutch E2 are in the open state, also called "normally open", and are selectively actuated in operation by a control device (not shown) to go from the open state to the closed state.

The wet dual-clutch mechanism 20 is hydraulically controlled via a pressurized fluid, usually oil.

To selectively control the change of state of the first clutch E1 and the second clutch E2 of the mechanism 20 of the transmission system 10, the control device comprises at least one control shaft 22 having oil supply channels 24, for example four in number as shown in Figure 3.

The mechanism 20 comprises at least one hub having radial bores which are each connected to one of the channels 24 for supplying oil.

Preferably, said at least one hub is made in two parts, a first hub 25A and a second hub 25B respectively associated with the first clutch E1 and the second clutch E2.

The first hub 25A has two bores 26 and 27 which are associated with the control of the first clutch E1 located axially at the front and the second hub 25B also comprises two bores 28 and 29 which are associated with the control of the second clutch E2 situated axially. in back.

The first clutch E1 multi-disk type comprises a piston 30 which is axially movable, here from front to rear, between a disengaged position and an engaged position which respectively correspond to the open and closed states of the first clutch E1.

As represented in FIGS. 2 and 3, the piston 30 is controlled in displacement by means of a control chamber 32 delimited axially by a front face of an internal radial portion of the piston 30 and by the rear radial face of a piston. closing piece 34.

The closure piece 34 carries at its radial outer and inner ends sealing means which cooperate respectively with an inner face of an axial portion of the piston 30 and cooperate with an outer axial surface 40A of the first hub 25A.

Preferably, the closing piece 34 is associated with a bearing piece 42 which is axially locked by a locking ring 44 mounted in a groove 45 of the first hub 25A.

The piston 30 has at its radially inner end sealing means 46 which cooperate with the external axial surface 40A of the first hub 25A, when the piston 30 is displaced axially between the disengaged and engaged positions by the pressurization of the chamber 32. control.

The piece 34 closing the chamber 32 for controlling the piston 30 comprises, between its two radial ends, a convex portion which cooperates with the front radial face of the piston 30 axially vis-à-vis.

The volume of the control chamber 32 comprises an outer portion and an inner portion, located radially on either side of said convex portion of the closure piece 34.

The control chamber 32 is fed with oil through the bore 27 which passes radially through the first hub 25A, the bore 27 placing said control chamber 32 in communication with one of the oil supply channels 24.

The control chamber 32 of the piston 30 of the first clutch E1 is associated with a balancing chamber 48 delimited at least by a balancing piston 50.

Advantageously, the driving veil 18 constitutes the balancing piston 50 of the first clutch E1.

The driving veil 18 thus provides a dual function, transmission of the input power on the one hand, and balancing piston in the operation of the first clutch E1, on the other hand.

As illustrated in FIG. 4, the driving veil 18 has a general shape of revolution defining, on its front part, a front face 55 and on its outer radial end, an annular wall 53, of axial orientation and of substantially cylindrical.

The annular wall 53 extends from the outer periphery of the front face 55. A cylindrical wall 57, axially oriented, extends from the inner radial end of the front face 55.

The balancing piston 50 is formed from the rear end of the cylindrical wall 57 and extends radially towards the axis O. More specifically, the function of the balancing piston 50 of the first clutch E1 is ensured. mainly by the internal radial portion of said veil 18 drive.

The equilibrium chamber 48 of the first clutch E1 is delimited axially by the radial front face of the balancing piston 50 formed by the radially inner portion of the driving veil 18 and by the rear radial face of the piston 30.

The balancing chamber 48 is supplied with oil via the bore 26 that the first hub 25A comprises. The tightness of the equilibration chamber 48 is provided radially outwardly by sealing means 52 which are carried by the piston 30 and which cooperate with the internal face of an axial portion of the balancing piston 50 formed. by the training veil 18.

The piston 30 of the first clutch E1 extends radially and is arranged axially between the control chamber 32, located axially at the front, and the equilibrium chamber 48 located axially at the rear. The piston 30 is concentric with the sail 18 drive.

The piston 30 of the first clutch E1 comprises, at its outer radial end, an actuating portion formed by fingers 34 which extend axially rearwardly to act on a multidisk assembly of the first clutch E1.

Advantageously, the veil 18 includes drive openings 56 for the axial passage of said fingers 34 forming the actuating portion of the piston 30 of the clutch E1.

In this way, the axial and radial size of the torque transmission system is reduced.

The piston 30 is controlled to clamp axially, in the engaged position, said multi-disk assembly of the first clutch E1 against means 60 of reaction.

In the transmission system 10 shown in FIGS. 2 and 3, the first clutch E1 and the second clutch E2 of said wet double clutch mechanism 20 are axially juxtaposed, the first clutch E1 and the second clutch E2 being arranged axially on both sides. other of said reaction means 60.

According to the invention, said reaction means 60 comprise at least a first reaction element 58 and a second reaction element 62 which, respectively associated with the first clutch E1 and with the second clutch E2, are separated axially from one another by axial play.

As described above, said at least one hub is preferably made in two parts, respectively the first hub 25A and the second hub 25B.

As illustrated in FIGS. 2 and 3, the first reaction element 58 is made in one piece with said first hub 25A of the first clutch E1 and the second reaction element 62 is made in one piece with said second hub 25B of the second hub. clutch E2.

The first reaction element 58 comprises at least one convex bearing boss 63 which extends axially towards the multi-disk assembly of the first clutch E1. The bearing boss 63 has a front radial face which constitutes said reaction face 59.

The second reaction element 62 comprises at least one convex bearing boss 65 which extends axially towards the multi-disk assembly of the first clutch E2. The bearing boss 65 has a rear radial face constitutes said reaction face 61.

The bosses 63 and 65 support are for example obtained by stamping said elements 58 and 62 of reaction.

Said at least bearing boss 63 of the first element 58 of reaction and said at least one axial bearing boss 65 of the second element 62 of reaction are located radially on the same radius with respect to the axis O.

Preferably, the first reaction element 58 and the second reaction element 62 are circumferentially continuous, so as to form a disk.

The first clutch E1 and the second clutch E2 of said wet double clutch mechanism 20 are axially actuated in opposite directions, axially from front to rear against the face 59 by the piston 30 of the first clutch E1 and axially of the clutch. rearwardly against the face 61 by that of the second clutch E2. The multi-disk assembly of the first clutch E1 comprises at least friction discs 64 which are rotatably connected to said first shaft A1 driven by an outer disk carrier 66. The outer disk carrier 66 forms the output element of the first clutch E1.

The outer disk carrier 66 comprises at the outer radial periphery an axial portion which is provided with an internal toothing 67 intended to cooperate with a complementary toothing 68 that each friction disk 64 has at its outer radial periphery. The internal toothing 67 has a free end oriented axially towards the front of the transmission system 10.

The outer disk carrier 66 is rotatably linked by meshing with the friction discs 64 and a spline connection with said first driven shaft A1.

The outer disk carrier 66 has an axially extending outlet hub 70 which has radially inside the axial grooves 72 which mesh with grooves 73 complementary to the first driven shaft A1.

The outer disk carrier 66 generally has an "L" shape whose inner radial end, opposite to the toothing 67, is integral with the outlet hub 70.

Preferably, the outer disk carrier 66 and the outlet hub 70 are fastened together by welding, alternatively by riveting.

The friction discs 64 each comprise on their axially opposite radial faces, respectively front and rear, a friction lining 74. The multi-disk assembly of the first clutch E1 comprises flanges 76 which are provided at their inner radial periphery with a toothing 78 to link them in rotation with an inner disk carrier 38.

The inner disk carrier 38 has at its outer radial end an axial portion having an external toothing 39 which, complementary, meshes with the internal toothing 78 of each of the flanges 76 to bind them in rotation without play. The external toothing 39 has one end. free axially oriented towards the front of the transmission system 10. During assembly of the array assembly, the flanges 76 are assembled on the disk carrier 38 by introducing the flanges 76 from the free end of the external toothing 39.

The friction discs 64 are, unitarily, axially interposed between two successive flanges 76. Each of the friction lining 74 of one of the friction discs 64 cooperates in the engaged position with one of the radial faces of the flanges 76 arranged axially on either side, in front and rear, of said friction disc 64. As illustrated in FIG. 3, the flanges 76 are substantially identical geometrically. The multi-disk assembly of the first clutch E1 axially comprises a flange 76 at each of its ends, respectively a front end flange 76 whose front radial face is intended to cooperate in the engaged position with the fingers 34 forming the actuating portion of the piston 30 and a rear end flange 76 whose rear radial face is intended to cooperate with the face 59 of the reaction element 58 of the reaction means 60.

Advantageously, the piston 30 of circular shape has a front ring 31 from which axially extend the fingers 34. Due to the architecture of the transmission system 10, the piston 30 is positioned on the front part of said transmission system and the front face 55 of the web is located axially between the front ring 31 of the piston 30 and the end flange 76 before. The veil 18 drive locally defines a projection 80 towards the multiisque assembly of the first clutch E1. The projection 80 formed on the veil 18 drive is located axially between the front ring 31 of the piston 30 and the flange end 76. Such an architecture makes it possible to reduce the axial and radial dimensions of the transmission system.

As illustrated in FIGS. 2 and 3, the end flange 76 of the multi-disk assembly is of one-piece structure. The end flange is made of a single material, usually sheet steel. The end flange 76 of the multi-plate assembly is annular in shape and has a thickness of between 1 and 5 mm along the axis O.

The axial dimension of the end flange 76 of the multi-disk assembly represents the maximum thickness of the flange measured along the axis O.

According to a variant not shown, the end flange 76 of the multi-plate assembly is of lamellar structure. In this case, the end plate has a layer superposition of different materials. The axial dimension of the end flange 76 of lamellar type represents the maximum thickness of the flange measured along the axis O.

The first clutch E1 comprises elastic return means 84 for automatically returning the piston 30 in the disengaged position, corresponding to an open state of the clutch.

Preferably, the elastic return means 84 of the piston 30 are formed by spring washers, such as wave washers of "Onduflex ™" type.

The spring washers 84 are interposed axially between the flanges 76 and arranged radially inside the friction discs 64, below the friction linings 74.

The second clutch E2 of the wet double clutch mechanism 20 of the transmission system 10 is of similar design to that of the first clutch E1, the second clutch E2 being of multidisc type.

Advantageously, reference is made to the need for the description of the second clutch E2 to the detailed description of the first clutch E1 given previously. The multidisk assembly of the second clutch E2 comprises friction discs 97 which are rotatably connected to the second shaft A2 led by an outer disk carrier 98 forming the output element of the clutch E2. The multidisk assembly of the second clutch E2 comprises flanges 95 which are provided at their inner radial periphery with a set of teeth 96 to rotate them with an inner disk carrier 93.

The second clutch E2 comprises a piston 90 which is axially movable, here from the rear towards the front, between a disengaged position and an engaged position respectively corresponding to the open and closed states of the second clutch E2 of the mechanism 20.

The piston 30 of the first clutch E1 and the piston 90 of the second clutch E2 of said wet double clutch mechanism 20 move axially in opposite directions to pass for example from the disengaged position to the engaged position.

The piston 90 of the second clutch E2 is controlled in displacement by means of a control chamber 92 delimited axially by a rear face of an inner radial portion of the piston 90 and by the radial front face of a closure piece 94.

The control chamber 92 is selectively supplied with oil by the bore 29 passing radially through the hub 25B and connected to one of the channels 24 for supplying the control shaft 22.

The closing piece 94 has at its radial outer and inner ends sealing means which cooperate respectively with an inner face of an axial portion of the piston 90 and which cooperate with an outer surface 40B of the hub 25B.

The surface 40B associated with the second clutch E2 is located axially behind the reaction means 60 arranged between said clutches E1 and E2, axially opposite the surface 40 associated with the piston 30 of the first clutch E1.

The piston 90 has, at its radially inner end, sealing means 91 which cooperate with the external surface 40B of the hub 25B, when the piston 90 is displaced axially between the disengaged and engaged positions by the pressurization of the control chamber 92 .

The control chamber 92 is associated with a balancing chamber 49 delimited by at least one balancing piston 99.

The balancing piston 99 of the second clutch E2 is an insert on the inner disk carrier 93.

The balancing chamber 49 is delimited axially by the rear radial face of the balancing piston 99 and by the front radial face of the piston 90.

To directly transmit the input power, the wet dual-clutch mechanism 20 comprises connecting means 85 which, for the first clutch E1, axially link without play at least the veil 18 drive, the inner disk carrier 38 and the reaction means 60.

Similarly, in order to directly transmit the input power, the wet double clutch mechanism 20 also comprises connecting means 85 which, for the second clutch E2, axially link without play at least the balancing piston 99, the carrier disc 93 inside the second clutch E2 and the reaction means 60.

The connecting means 85 are preferably made by riveting. As illustrated in Figures 2 and 3, said connecting means 85 comprises a series of first rivets 85A associated with the first clutch E1 and a series of second rivets 85B (not shown) associated with the second clutch E2.

Said first rivets 85A and the second rivets 85B are respectively circumferentially distributed alternately around the axis O.

Alternatively, the connecting means 85 may be made by welding, in particular by laser welding by transparency.

The veil 18 includes drive stampings (not shown) which, circumferentially distributed, project axially rearwardly relative to the rear radial face of the veil 18 forming the equilibrium piston 50. The stampings (not shown) each surround a hole 88 to be traversed axially by one of the rivets 85A, 85B forming said connecting means. The stampings ensure the passage of the oil from the balancing chamber 48 towards the multi-disk assembly.

The first rivets 85A axially bond without play at least said veil 18 drive, the inner disc holder 38 of the first clutch E1 and the reaction means 60.

The second rivets 85B axially link without play at least the balancing piston 99 of the second clutch E2, the inner disc holder 93 of the second clutch E2 and the reaction means 60.

FIGS. 4 and 5 show a driving veil 18 according to the first embodiment.

As previously described, the training veil 18 has a general shape of revolution defining, on its front part, a front face 55 in the form of a crown. The veil 18 drive locally defines a projection 80 towards the multiisque assembly of the first clutch E1. The projection 80 is formed from said front face 55 and extends axially rearwardly of the transmission system. The projection 80 is made by a stamp of circumferentially continuous shape.

In this embodiment of the invention, the projection 80 is integral with the veil 18 drive. The projection 80 also has a flat bearing area 81 arranged to receive the end flange 76 of the multi-plate assembly. The flat bearing zone 81 is implanted radially on a diameter between the inside diameter and the outside diameter of the end flange 76. Advantageously, the projection 80 is dimensioned so as to retain the end flange 76 on the external teeth of the disk carrier 38 in the absence of the piston 30, in particular during the assembly operation of the double clutch mechanism 20. wet.

The projection 80 is preferably obtained from a stamping press. This method of obtaining, of the forming-drawing type, makes it possible to limit the dimensional tolerances of manufacture of the driving veil. Depending on the diametral dimensions of the space of the sail 18 drive, a complementary calibration operation may be sometimes necessary.

Alternatively, the flat bearing area 81 may be machined to further reduce the dimensional tolerances of the training web.

In this way, during the final assembly of the transmission system, that is to say when the piston 30 is not yet assembled, the projection 80 limits the axial displacements of the end flange 76. In the absence of the piston 30, the end flange 76 has the ability to move freely along the axis O on the outer teeth 39 of the inner disk carrier 38, especially during the handling movements of the double clutch mechanism 20 wet on assembly line. The end flange 76 can not leave the external teeth 39 because the projection 80 and the free end of the external teeth 39 of the disk carrier 38 are separated by an axial distance strictly less than the axial dimension of the flange 76 of FIG. end of the array.

The front face 55 of the driving veil 18 comprises the openings 56 for the axial passage of said fingers 34 forming the actuating portion of the piston 30 of the clutch E1. The apertures 56 are formed in the shaped recess formed from the front face 55. Each finger 34 of the actuating portion of the piston 30 is mounted with a circumferential clearance in the corresponding aperture 56 of the training veil. .

As illustrated in FIG. 4, the openings 56 are rectangular in a plane perpendicular to the axis O.

According to other possible embodiments, the openings may be oblong or elliptical in a plane perpendicular to the axis O.

FIG. 6 shows a second embodiment of a transmission system substantially similar to the first embodiment.

The second embodiment will be described below in comparison with the first embodiment, the same reference numerals denote identical parts or parts having similar functions.

This second embodiment differs in that the multi-disk assembly of the first clutch E1 respectively comprises flanges 176 rotatably connected to the shaft A1 led by an outer disk carrier 66. As illustrated in FIG. 6, the flanges 176 are substantially identical geometrically. The multi-disk assembly of the first clutch E1 comprises flanges 176 which are rotatably connected to said first shaft A1 led by an outer disk carrier 66. The outer disk carrier 66 forms the output element of the first clutch E1.

The outer disk carrier 66 comprises at the outer radial periphery an axial portion which is provided with an internal toothing 67 intended to cooperate with a complementary toothing 178 that each flange 176 comprises at its outer radial periphery. The internal toothing 67 has a free end oriented axially towards the front of the transmission system 10.

The outer disk carrier 66 generally has an "L" shape whose inner radial end, opposite to the toothing 67, is integral with the outlet hub 70. The multi-disk assembly of the first clutch E1 comprises friction disks 164 which are provided at their inner radial periphery with a toothing 168 to rotate them with an inner disk carrier 38.

The inner disk carrier 38 has at its outer radial end an axial portion having an external toothing 39 which, complementary, meshes with the internal teeth 168 of each of the friction discs 164 to rotate them without play.

The friction disks 164 are, unitarily, axially interposed between two successive flanges 176.

As for the first embodiment, the multi-disk assembly of the first clutch E1 axially comprises a flange 176 at each of its ends, respectively a flange 176 of the front end whose front radial face is intended to cooperate in the engaged position with the fingers 34 forming the actuating portion of the piston 30 and a rear end flange 176 whose rear radial face is intended to cooperate with the face 59 of the reaction element 58 of the reaction means 60.

In this second embodiment, the driving veil 18 locally defines a projection 80 in the direction of the multi-disk assembly of the first clutch E1. The projection 80 and the free end of the internal toothing 67 of the outer disk carrier 66 are separated by an axial distance strictly less than the axial dimension of the end flange 176 of this multi-disk assembly.

Advantageously, the projection 80 is dimensioned so as to retain the end flange 176 on the internal teeth 67 of the outer disk carrier 66 in the absence of the piston 30, in particular during the assembly operation of the double-acting mechanism 20. wet clutch.

FIGS. 7 to 10 show a third embodiment of the invention of a transmission system comprising a mechanism 20 with a double wet clutch.

The description of the transmission system 10 according to the first embodiment illustrated in FIGS. 1 to 5 and in particular that of the wet double clutch mechanism 20 applies to the third embodiment shown in FIGS. 7 to 10.

This third embodiment differs in that the projection 80 of the training web 280 is made by a series of stampings of shape 82 distributed circumferentially around the axis O. The training web 280 has a general shape of revolution defining, on its front portion, a front face 55 shaped crown. The front face 55 has openings 56 for the axial passage of said fingers 34 forming the actuating portion of the piston 30 of the clutch E1. The shaped stampings 82 of the protrusion 80 are formed from said front face 55 and extend axially rearwards of the transmission system. The circumferential distribution of the shaped moldings 82 improves the torsional rigidity of the training web 280 along the axis O.

In this third embodiment, the projection 80 is in the form of a right angle. That is to say, the stampings of form 82 comprise a fold of material obtained from the openings 56. By means of a fold of material at 90 °, the return of angle advantageously limits the congestion of the protrusion 80.

The shaped stampings 82 are angularly distributed between the openings 56. The shaped stampings 82 surround the openings 56.

As illustrated in FIG. 10, the openings 56 are rectangular in a plane perpendicular to the axis O.

According to other possible embodiments, the openings 56 may be oblong or elliptical in a plane perpendicular to the axis O.

Preferably, the web 280 has as many stampings of shape 82 as openings 56. As a variant, the training web 280 can comprise a number of stampings of shape 82 that is smaller than the number of openings 56 made on the face. before 55.

The projection 80 of the training sail 280 according to the third embodiment has a series of flat bearing areas 81 arranged to receive the end flange 76 of the multi-disc assembly. The series of flat bearing regions 81 is implanted radially on a diameter between the inside diameter and the outside diameter of the end flange 76.

The flat bearing areas 81 may be machined to further reduce the dimensional tolerances of the training web 280. Alternatively, the flat bearing areas 81 can be calibrated by a press operation. Rework operations such as machining or press-operation calibration also reduce manufacturing dimensional tolerances.

FIGS. 11 and 12 show a fourth embodiment of the invention of a transmission system comprising a mechanism 20 with a double wet clutch.

The description of the transmission system 10 according to the first embodiment illustrated in FIGS. 1 to 5 and in particular that of the wet double clutch mechanism 20 applies to the fourth embodiment shown in FIGS. 11 and 12.

This fourth embodiment differs in that the projection 80 is attached to the veil 18 by means of at least one additional piece 83. The veil 380 has a general shape of revolution defining, on its front part, a front face 55 in the form of a crown. The front face 55 has openings 56 for the axial passage of said fingers 34 forming the actuating portion of the piston 30 of the clutch E1. The projection 80 is attached to the front face 55 of the training sail 380 towards the multi-disk assembly of the first clutch E1 as illustrated in FIG. 12. The projection 80 is obtained by adding at least one additional piece 83 allows greater flexibility in manufacturing the double clutch mechanism. Depending on the engine torque to be transmitted, the number of friction disks 64 and flanges 76 is adapted to the necessary. The additional piece (s) 83 are therefore dimensionally adapted to define an axial distance between the projection 80 and the free end of the toothing 39 which is strictly smaller than the axial dimension of the end flange 76 of this multi-disk assembly.

According to the fourth embodiment shown in FIG. 11, the projection 80 comprises three rivets distributed circumferentially around the axis O and riveted on the web 380.

In variant not shown, the projection 80 can be obtained by adding an annular plate fixed on the web 380. In this case, the projection 80 also includes said openings coming axially opposite the openings 56 made on the front face 55 training sail 380.

Preferably, the projection 80 is attached to the riveting veil 380. Alternatively, the projection 80 is attached to the training sail 380 by welding or gluing.

FIG. 13 shows a fifth embodiment of the invention of a transmission system comprising a mechanism 20 with a double wet clutch.

The description of the transmission system 10 according to the first embodiment illustrated in FIGS. 1 to 5 and in particular that of the wet double clutch mechanism 20 applies to the fifth embodiment shown in FIG. 13. multidisc of the first clutch E1 comprises flanges 76 which are provided at their inner radial periphery with a toothing 78 to rotate them with an inner disk carrier 38.

This fifth embodiment differs in that the multi-disk assembly of the first clutch E1 has on its front end, a flange 476 end geometrically different from the other flanges 76 of the array of the first clutch E1. The end flange 476 is located on the front end of the multi-disc assembly of the first clutch E1.

The end flange 476 of the multi-disk assembly of the first clutch E1 locally defines a projection 80 in the direction of the sail 480 drive. The projection 80 of the end flange 476 forms a stop holding said end flange 476 of the multi-disc assembly of the first clutch E1 alternately to the first piston 30.

The projection 80 of the drive flange 476 has a flat bearing area 479 arranged to cooperate with the sail 480 drive.

The end flange 476 is associated with an inner disk carrier 38 having an external toothing 39. The end flange 476 is rotatably connected to the inner disk carrier 38. The projection 80 of the end plate 476 is sized to retain the end flange 476 on the outer teeth 39 of the inner disk carrier 38, in the absence of the piston 30.

The end flange 476 also has a front radial face 478 intended to cooperate in the engaged position with the fingers 34 forming the actuating portion of the piston 30.

According to a variant not shown, the front radial face 478 and the flat bearing zone 479 of the projection 80 may be merged.

As illustrated in FIG. 13, the training sail 480 comprises an interface surface 481 designed to cooperate with the end flange 476. The interface surface 481 of the web is flat and annular.

The interface surface 481 of the entrainment web 480 and the free end of the toothing 39 of the disk carrier 38 are separated by an axial distance strictly smaller than the axial dimension of the end flange 476 of the end of the array assembly.

The end flange 476 has a friction rear face 477 which cooperates with an adjacent friction disc 64.

The axial dimension of the end flange of the multi-disk assembly represents the maximum thickness of the flange measured along the axis O between the flat bearing zone 479 and the friction rear face 477.

As illustrated in FIG. 13, the end flange 476 of the multi-disk assembly is of monobloc structure. The end flange 476 is made of a single material, usually machined from a steel block. The end flange 476 of the multi-disk assembly is annular in shape. The projection 80 of the end flange 476 is formed by a protrusion of circumferentially continuous shape. Alternatively, the projection 80 of the end flange 476 can be made by discontinuous growths. The invention is not limited only to the embodiments which have just been described.

In an unspecified example, resulting from the combination of the fifth embodiment with one of the first four described embodiments, each of the drive veil and the end flange defines a projection one towards the other so as to retain the end flange on the toothing of the disk carrier in the absence of the piston.

Claims (10)

Transmission system (10), in particular for a motor vehicle, comprising around an axis (O) at least: a mechanism (20) with a double wet clutch comprising at least a first clutch (E1) and a second clutch; (E2) respectively multi-disk type, and means (60) of reaction interposed axially between the first clutch (E1) and the second clutch (E2), the mechanism (20) being controlled to selectively couple said drive shaft to a first shaft (A1) driven and a second shaft (A2) driven, and - a web (280) for driving rotatably said shaft leading to the means (60) of reaction, said first clutch (E1) comprising at least a first piston (30) axially displaceable in one direction to come, in the engaged position, tighten a multidisk assembly of the first clutch (E1) against the means (60) of reaction and said second clutch (E2) having at least a second piston (90) axially displaceable in an opposite direction, to come, in the engaged position, clamping a multidisk assembly of the second clutch (E2) against the means (60) of reaction, said multidisc assembly of the first clutch E1 respectively comprising friction discs (64, 164) and flanges (76, 176), one of which defines an end plate (76, 176), characterized in that the web (280) for driving locally defines a projection (80) in the direction of the flange (76, 176). end projection, this projection (80) forming an abutment retaining the end flange (76, 176) alternately to the first piston (30), and in that the projection (80) is made by a series of e-mboutis of shape (82) distributed circumferentially about the axis (O). 2. System (10) according to claim 1, characterized in that the end flange (76, 176) is associated with a disk carrier (66, 38) having a toothing (67, .39) and in that the protrusion (80) and the free end of the toothing (67,39) of the disk carrier (66,38) are separated by an axial distance strictly smaller than the axial dimension of the end plate (76, 176) of the multidisk set. 3. System (10), according to claim 2 characterized in that the axial dimension of the flange (76, 176) end of the multi-plate assembly represents the maximum thickness of the flange along the axis (O). 4. System (10) according to any one of claims 1 to 3, characterized in that the piston (30) comprises an actuating portion formed by fingers (34) which extend axially rearwards and in the drive web (280) has openings (56) for the axial passage of said fingers (34). 5. System (10) according to claim 4, characterized in that the circular piston (30) has a front ring (31) from which the fingers (34) extend axially and that the projection ( 80) arranged on a sail (280) drive is located axially between the front ring (31) of the piston (30) and the flange (76, 176) end. 6. System (10) according to any one of claims 1 to 5, characterized in that the projection (80) has at least one flat bearing area (81) arranged to receive the flange (76, 176). end of the array. 7. System (10) according to claim 6, characterized in that the one or more flat bearing areas (81) are implanted radially on a diameter between the inner diameter and the outer diameter of the flange (76, 176) of end. 8. System (10) according to any one of claims 1 to 7, characterized in that the projection (80) is integral with the web (280) drive. 9. System (10) according to claim 1, characterized in that the shaped recesses (82) are angularly distributed between the openings (56) provided on the web (280) drive. 10. System (10) according to claim 9, characterized in that the shaped recesses (82) surround the openings (56).