FR3034480A1 - 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 constitute a part of a transmission, in particular for a motor vehicle or for a so-called industrial vehicle, the latter being for example a heavy vehicle, a public transport vehicle, or an agricultural vehicle. More particularly, the present invention relates to a transmission system having a double wet 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 a second driven shaft of a gearbox, said wet double clutch mechanism comprising at least a first clutch and a second clutch respectively of multidisc type, each of said first and second clutches comprising at least one axially movable piston which is controlled by displacement by means of a control chamber with which is associated a balancing chamber delimited at least by a balancing piston, said piston axially clamping in a clutched position a multi-disk assembly against reaction means, said multi-disc assembly having flanges and also rotat-linked friction discs ion 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 type 3034480 2 multidisc, 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. 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 held axially. Such an assembly is however not without problem. Indeed, there is a risk of disengagement of the end flange of the multi-disc assembly relative to the associated disc holder when handling the transmission system until the piston of the multi-disc 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 propose a torque transmission module comprising a wet double clutch mechanism making it possible to solve at least a part 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 20 0 at least: a wet double clutch mechanism comprising at least a first clutch and a second clutch respectively of type multidiscs, 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 training sail to link in rotation said shaft leading to the reaction means, said first clutch having at least a first piston axially displaceable in one direction to come, in the engaged position, clamp a multidisk assembly of the first clutch 3034480 4 against the reaction means and said second clutch having at least one second piston displaceable axially in an opposite direction, to come into position engaged, 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 and flanges, one of which defines an end flange, characterized in that the training sail defines Locally a projection 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 driving veil to the reaction means, of forming a closed assembly subassembly in which the end flange can not not disengage from the multi-disk assembly, especially when the piston is not yet mounted on the mounting subassembly. In other words, the projection makes it possible, in the absence of the piston, to maintain the end flange in the multi-disk assembly of the first clutch. Preferably, the end flange is associated with a disk carrier having a toothing. The protrusion and the free end of the toothing of the disc holder are separated by an axial distance strictly less than the axial dimension of the end flange of the multi-disc assembly. In designing the transmission system, it is easy to define the axial distance between the protrusion 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 inspection means of good positioning of the end flange on the disk carrier of the multidisk set. 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-plate assembly represents the maximum thickness of the flange 10 along the axis O. Advantageously, the piston comprises an actuating part formed by fingers which extend axially towards the end of the end plate. rear and the driving veil has 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 the fingers extend axially. 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 the end flange in axial position with respect to the toothing of the disk carrier and thus takes over the protrusion of the projection 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 training web. Obtaining the protrusion 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. 5 - The openings are formed in the form stamp. As a variant, the projection is made by a series of shaped stampings circumferentially distributed around the axis O. The projection is in the form of a right-angle return. By means of a fold of material at 90 °, the return 10 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. 15 - The veil has as many embossed form as openings. - The projection has at least one flat bearing area arranged to receive the end plate of the multi-plate assembly. The one or more flat support zones are implanted radially on a diameter between the inside diameter and the outside diameter of the end plate. - The flat bearing area or areas are machined. The flat bearing 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 via 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. In function of the engine torque to be transmitted, the number of friction discs and flanges is adapted to the just necessary. The additional part (s) are therefore dimensionally adjusted to define the adequate axial distance between the projection and the free end 5 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 0 and fixed on the web. Alternatively, the projection is an annular plate attached to the web. - The projection is reported on 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. 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 connected in rotation to the reaction means using 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.

Another object of the invention is, according to another of its aspects, a transmission system, in particular for a motor vehicle, comprising around an axis 0 at least: a wet double clutch mechanism comprising at least one 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 for rotatably connecting said drive shaft to the reaction means, said first clutch having at least one first piston axially displaceable in one direction to come, in the engaged position, to clamp a multi-disc assembly of the first clutch against the reaction means and said second clutch having at least one second piston displaceable axially in a in the opposite position, to come, in the engaged position, clamping a multidisk assembly of the second clutch against the reaction means, said multidisk assembly of the first clutch respectively comprising friction discs rotatably connected to the shaft 20 led by an outer disk carrier forming the output member of the clutch 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 This projection and the free end of the external toothing of the inner disk carrier being separated by an axial distance strictly smaller 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.

Any or all 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 0 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 for rotatably connecting said drive shaft to the reaction means, said first clutch having at least a first piston axially displaceable in one direction to come, in engaged position, to clamp a multi-disk assembly of the first clutch against the means of reaction and said second clutch having at least one second axially displaceable piston 20 in an opposite direction to come, in the engaged position, clamping a multi-disk assembly of the second clutch against the reaction means, said multi-disk assembly of the first clutch comprising respectively friction disks and flanges, one of which defines an end flange, characterized in that the end flange of the multi-disk assembly of the first clutch locally defines a projection towards the drive web, this projection forming a stop holding the end flange alternately to the first piston.

According to this aspect of the invention, it may be advantageous to define a specific end flange for the multi-disc assembly 3034480 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 sized to retain the end flange on the external toothing of the disk carrier. inside, in the absence of the piston. - The end flange has a friction rear face cooperating with a friction disc and a flat bearing area disposed on the projection. The projection has at least one flat bearing zone arranged to cooperate with the driving veil. Preferably, the axial dimension of the end flange of the multi-disk assembly represents the maximum thickness of the flange measured along the axis 0 between the flat bearing zone 25 and the rear friction face. - The interface surface of the sail 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 control system. transmission according to a preferred embodiment of the invention; FIG. 2 is a perspective and cutaway view of the transmission system of FIG. 1. FIG. 3 is a sectional view on III-III of the transmission system of FIG. 1; FIGS. 4 and 5 are perspective views of the driving veil according to the transmission system of FIG. 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 is 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 axis will be used in a nonlimiting manner and in order to facilitate understanding thereof. 0 main rotation 5 of the transmission of the motor vehicle and the terms "inner / inner" or "outer / outer" with respect to the axis 0 and in a radial orientation, orthogonal to said axial orientation. FIGS. 1 to 3 show a first embodiment of a transmission system 10, in particular for a motor vehicle, having a main axis 0 of rotation. The transmission system 10 comprises around the axis 0 at least one input element which is rotatably connected to a driving shaft (not shown).

Preferably, the input element of the system 10 has 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 radially oriented portion 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 to 25 l. interior of the radial portion, axially rearward, in a direction corresponding to that of the engine. The hub 14 has splines 16, formed in an outer cylindrical 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 fixed together by welding. The inlet hub 14 is, for example, rotatably connected by means of the splines 16 at the outlet of a damping or damping device (such as a double damping flywheel, etc.) whose entry is linked. , in particular via a flywheel, to the driving shaft formed by a crankshaft that rotates a motor fitted to 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 is provided with at its axially oriented outer radial end, the driving veil 18. Rivets 21, distributed circumferentially about the axis 0, are housed in ports 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 mechanical connection 25 rigid. This mechanical link is capable of transmitting significant torque levels. The wet double 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 dual-clutch mechanism 20 comprises at least a first clutch E1 and a second clutch E2, which are respectively multi-disk 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 driven shafts A1, A2 being respectively connected to a box. of gear equipping the motor vehicle.

In the wet dual-clutch mechanism 20, the first clutch E1 serves, for example, both to start and engage the odd gears and the second clutch E2 then supports the even and reverse gears, alternatively the The ratios supported by said first clutch 15 El and second clutch E2 are reversed. The first clutch El 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 (the torque and the speed) of the driving shaft, which receives the input shell 12 of the system 10, to one of the two shafts Al , A2 conducted, depending on the open or closed state of each clutch El 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 move from the open state to the closed state.

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

In order 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 comprising 5 channels 24 for supplying oil. , 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 El 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 El 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 located axially at the back. The first multi-disc type clutch E 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 El. 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 workpiece. 34 closing. The closure piece 34 carries at its outer and inner radial ends 30 sealing means which cooperate respectively with an inner face of an axial portion of the piston 3034480 16 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 stop ring 44 mounted in a groove 45 of the first hub 25A. The piston 30 has at its inner radial end sealing means 46 which cooperate with the outer axial surface 40A of the first hub 25A, when the piston 30 is displaced axially between the disengaged positions and engaged by the pressurization of the chamber. 32 order. 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 El is associated with a balancing chamber 48 delimited at least by a balancing piston 50.

Advantageously, the driving veil 18 constitutes the equilibrium piston 50 of the first clutch El. The driving veil 18 thus provides a dual function, for transmitting the input power on the one hand, and the piston on the other. balancing in the operation of the first clutch El, on the other hand. As illustrated in FIG. 4, the driving veil 18 has a general shape of revolution defining, on its front part 3034480 17, a front face 55 and on its radially external end, an annular wall 53, of axial orientation and of substantially cylindrical shape. The annular wall 53 extends from the outer periphery 5 of the front face 55. A cylindrical wall 57, axially oriented, extends from the radially inner end of the front face 55. 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 10 of the first clutch El is provided mainly by the inner radial portion of said veil 18 drive. The equilibrium chamber 48 of the first clutch E1 is delimited axially by the front radial face of the balancing piston 50 formed by the radially inner portion of the sail 18 and by the rear radial face of the piston 30. The chamber 48 balancing is supplied with oil through the bore 26 that includes the first hub 25A. The sealing 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 El extends radially and is axially disposed between the control chamber 32 situated axially in 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 has, at its outer radial end, an actuating portion formed by fingers 34 which extend axially rearwardly to act on a multi-disk assembly of the first clutch El.

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 El. In this way, the axial and radial dimensions of the system 5 of torque transmission is reduced. The piston 30 is controlled to clamp axially, in the engaged position, said multi-disk assembly of the first clutch El against reaction means 60. 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 of the other by axial play.

As previously described, 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 El and the second reaction element 62 is made in one piece with said second hub 25B. second 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 El. The bearing boss 63 comprises a front radial face which constitutes said face 59 of reaction.

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 one bearing boss 63 of the first reaction element 58 and said at least one axial bearing boss 65 of the second reaction element 62 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. rearward forwards against the face 61 by that of the second clutch E2. The multi-disk assembly of the first clutch El comprises at least friction disks 64 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 25 El. 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 comprises each disc 64 of friction 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 output hub 5 which extends axially and has radially inside the axial grooves 72 which mesh with grooves 73 complementary to the first shaft Al led. The outer disk carrier 66 generally has an "L" shape whose inner radial end, opposite 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 El comprises flanges 76 which are provided at their inner radial periphery with a toothing 78 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 toothing 78 of each of the flanges 76 to rotate them in play-free rotation. free end oriented axially 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 linings 74 of one of the friction discs 64 engages in engaged position with one of the radial faces of the flanges 76 arranged axially on either side, forwardly and rearwardly, of said friction disk 64. . As illustrated in FIG. 3, the flanges 76 are substantially identical geometrically. The multi-disk assembly of the first clutch El comprises axially 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. 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 the fingers 34 extend axially. 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 driving veil 18 locally defines a projection 80 in the direction of the multi-disk assembly of the first clutch El. The projection 80 provided on the veil 18 for driving is located axially between the front ring 31 of the piston 30 and the flange 76 end. 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 integral structure. The end flange is made of a single material, usually sheet steel. The end flange 76 of the multi-disk assembly is annular in shape and has along the axis 0 a thickness of between 1 and 5 mm.

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 flange end plate of the lamellar end type represents the maximum thickness of the flange measured along the axis O. The first clutch El comprises elastic return means 84 for automatically returning the piston 30 to 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 the "Onduflex TM" 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 similar in design to that of the first clutch E1, the second clutch E2 being of multidisc type.

Advantageously, reference will be made to the need for the description of the second clutch E2 to the detailed description of the first clutch El given previously. The multi-disk assembly of the second clutch E2 comprises friction disks 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 multi-disk 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 to the front, between a disengaged position 2334480 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 move, 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 closure 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 rearward relative to 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 El. 90 has at its inner radial end sealing means 91 which cooperate with the external surface 40B of the hub 25B, when the piston 90 is moved axially between the disengaged positions and engaged by the pressurization of the control chamber 92. The control chamber 92 is associated with a balancing chamber 49 defined 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. In order to directly transmit the input power, the wet double clutch mechanism 20 comprises connecting means 85 which, for the first clutch El, axially bond without play at least the veil 18 drive, the inner disk carrier 38 and 60 reaction means. 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 E 2, axially link without play at least the balancing piston 99, the door -disc 93 inside the second clutch E2 and 60 reaction means.

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 El 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 circumferentially respectively 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 30 (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 3034480 25 from the balancing chamber 48 in the direction of the multi-disk assembly. The first rivets 85A axially bond without play at least said veil 18 drive, the disk holder 38 inside the first clutch El 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 drive web 18 locally defines a projection 80 towards the multi-disk assembly of the first clutch El. 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 protrusion 80 is integral with the driving veil. 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 25 between the inside diameter and the outside diameter of the end plate 76. Advantageously, the projection 80 is dimensioned so as to retain the end flange 76 on the external teeth 39 of the disk carrier 38 in the absence of the piston 30, in particular during the assembly operation of the 20 to 30 double mechanism. wet clutch. The projection 80 is preferably obtained from a stamping press. This method of obtaining, forming-type stamping, limits the dimensional tolerances of manufacture of the veil 18 drive. 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 web 18. 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 0 on the external teeth 39 of the inner disk carrier 38, especially during the handling movements of the double clutch mechanism 20 15 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 El. The openings 56 are formed in the shaped recess arranged in FIG. from the front face 55. Each finger 34 of the actuating portion 25 of the piston 30 is mounted with a circumferential clearance in the corresponding opening 56 of the veil 18 drive. 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 30 may be oblong or elliptical in a plane perpendicular to the axis O .

FIG. 6 shows a second embodiment of a transmission system 10 substantially similar to the first embodiment. The second embodiment will be described below in comparison with the first embodiment, the same reference numerals denote like parts or parts having similar functions. This second embodiment differs in that the multi-disk assembly of the first clutch El comprises respectively flanges 176 rotatably connected to the shaft Al 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 El comprises flanges 176 which are rotatably connected to said first shaft Al 15 driven by an outer disk carrier 66. The outer disk carrier 66 forms the output element of the first clutch El. The outer disk carrier 66 comprises at the outer radial periphery an axial portion which is provided with an internal set of teeth 67 intended to cooperate with complementary toothing 178 that 20 comprises each flange 176 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 the toothing 67, is integral with the outlet hub 70. The multi-disk assembly of the first clutch El comprises friction disks 164 which are provided at their inner radial periphery with a set of teeth 168 for rotationally connecting them with an internal disk carrier 38.

The inner disk carrier 38 has at its outer radial end an axial portion having an external toothing 39 which, in addition, meshes with the internal toothing 168 of each of the friction discs 164 to rotate them in play-free rotation. 164 of friction are, unitarily, axially interposed between two flanges 176 successive.

As for the first embodiment, the multi-disk assembly of the first clutch El comprises axially a flange 176 at each of its ends, respectively a front end flange 176 whose front radial face is intended to cooperate in the engaged position with the fingers 34 forming the actuating portion 10 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 towards the multi-disk assembly of the first clutch El. The projection 80 and the free end of the internal teeth 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 mechanism 20 to double 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 3034480 applies to the third embodiment shown in FIGS. 7 to 10. The third embodiment differs in that the protrusion 80 of the driving veil 280 is produced by a series of stampings 82 of shape 82 distributed circumferentially about the axis O. The training veil 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 10 of the piston 30 of the clutch El. The shaped stampings 82 of the projection 80 are formed from said front face 55 and extend axially towards the rear 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 FIG. 20 of the projection 80. The shaped stampings 82 are distributed angularly between the openings 56. The shaped stampings 82 surround the openings 56. As illustrated in FIG. 10, the openings 56 are of rectangular shapes 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. In a variant, the driving veil 280 may comprise a number of stampings of shape 82 smaller than the number of openings 56 made on the front face 55.

The protrusion 80 of the driving veil 280 according to the third embodiment has a series of flat bearing regions 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 may 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 The embodiment differs in that the projection 80 is attached to the driving veil 18 via at least one additional piece 83. The veil 380 has a general shape of revolution defining, on its part before, 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 El. The projection 80 is attached to the front face 30 of the training sail 380 in the direction of the multi-disk assembly of the first clutch El as illustrated in FIG.

Obtaining the projection 80 by adding at least one additional piece 83 allows greater flexibility in terms of manufacturing the double clutch mechanism. Depending on the engine torque to be transmitted, the number of discs 64 friction and 5 flanges 76 is adapted to just 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 circumferentially distributed about the axis 0 and riveted on the web 380. As a variant not shown, the projection 80 can be obtained by adding a Annular plate fixed on the web 380. In this case, the reported projection 80 also has openings coming axially opposite the openings 56 formed on the front face 55 of the 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 25 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. multi-disk assembly of the first clutch El 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 of end geometrically different from the other flanges 76 of the multi-disk assembly of the first clutch El. 476 end flange is located on the front end of the multi-disc assembly of the first clutch El.

The end flange 476 of the multi-disc assembly of the first clutch E1 locally defines a projection 80 towards the driving veil 480. The projection 80 of the end flange 476 forms a stop holding said end flange 476 of the end of the multi-disk assembly of the first clutch El, alternately with the first piston 30. The projection 80 of the drive flange 476 has a flat zone of support 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 planar zone d Support 479 of protrusion 80 can be confused. As illustrated in FIG. 13, the training sail 480 has 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 less than the axial dimension of the end plate 476 of the end of the array . 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-disc assembly represents the maximum thickness of the flange measured along the axis 0 between the flat bearing zone 479 and the friction rear face 477. As illustrated in FIG. the end flange 476 of the multi-disk assembly is of monoblock structure. The end flange 476 is made of a single material, generally 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 a non-described 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 protrusion, one toward the other. other so as to retain the end flange on the toothing of the disk carrier in the absence of the piston. 30

Claims (18)

REVENDICATIONS1. Transmission system (10), in particular for a motor vehicle, comprising around an axis (0) at least: - a mechanism (20) with a double wet clutch comprising at least a first clutch (El) and a second clutch (E2 ) respectively of multidisc type, and means (60) of reaction interposed axially between the first clutch (El) and the second clutch (E2), the mechanism (20) being controlled to selectively couple said drive shaft to a first shaft (A1 ) led to a driven second shaft (A2), and - a driving veil (18, 280, 380, 480) for rotatingly connecting said drive shaft to the reaction means (60), said first clutch (E1) comprising at least one first piston (30) axially displaceable in one direction to come, in the engaged position, clamping a multidisk assembly of the first clutch (El) against the means (60) of reaction and said second clutch (E2) comprising at least a second piston (90) displaceable axia in an opposite direction, to come, in the engaged position, to tighten a multi-disk assembly of the second clutch (E2) against the reaction means (60), said multi-disc assembly of the first clutch E1 respectively comprising friction discs (64, 164). and flanges (76, 176), one of which defines a flange (76, 176 and 476) end, characterized in that the web (18, 280, 380) drive, respectively the flange (476) of end of the multi-disc assembly of the first clutch (El) locally defines a protrusion (80) in the direction of this end flange (76, 176), respectively of the training web (480), this projection (80). forming a stop holding the flange (76, 176, 476) end alternately to the first piston (30). 3034480 35 2. System (10) according to claim 1, characterized in that the web (18, 280, 380) drive locally defines a projection (80) towards the end flange (76, 176), this 5 protrusion (80) forming a stop holding said end flange (76, 176) alternately to the first piston (30). 3. System (10) according to claim 2, 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. 15 4. System (10) according to claim 2 or 3 characterized in that the axial dimension of the end flange (76, 176) of the multi-plate assembly represents the maximum thickness of the flange along the axis (0). 20 5. System (10) according to any one of claims 2 to 4, characterized in that the piston (30) comprises an actuating portion formed by fingers (34) which extend axially rearwardly and in the drive web (18, 280, 380) has openings (56) for axial passage of said fingers (34). 6. System (10) according to claim 5, characterized in that the piston (30) of circular shape has a front ring (31) from which the fingers (34) extend axially and that the protrusion ( 80) arranged on a sail (18, 280, 380) 3034480 36 drive is located axially between the front ring (31) of the piston (30) and the flange (76, 176) end. 7. System (10) according to any one of claims 2 5 to 6, 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. 8. System (10) according to claim 7, characterized in that the one or more bearing plane regions (81) are implanted radially on a diameter between the inner diameter and the outer diameter of the flange (76, 176) of 'end. 9. System (10) according to any one of claims 2 to 8, characterized in that the projection (80) is integral with the web (18, 280) drive. 10. System (10) according to claim 9, characterized in that the projection (80) is formed by a stamping of circumferentially continuous shape. 11. System (10) according to any one of claims 2 to 9, characterized in that the projection (80) is formed by a series of shaped stampings (82) distributed circumferentially around the axis (0) . 12. System (10) according to claim 11, characterized in that the moldings (82) are angularly distributed between the openings (56) provided on the web (280) drive. 30 13. System (10) according to claim 12, characterized in that the shaped recesses (82) surround the openings (56). 3034480 37 14. System (10) according to any one of claims 2 to 9, characterized in that the projection (80) is attached to the web (380) via at least one additional piece (83). 5 15. System (10) according to claim 14, characterized in that the projection (80) comprises at least three rivets (83) distributed circumferentially around the axis (0) and fixed on the web (18). 10 16. System (10) according to claim 1, characterized in that the end flange (476) of the multiisque assembly of the first clutch (El) locally defines a projection (80) towards the web (480) of this projection (80) forming an abutment retaining the end flange (476) alternately with the first piston (30). 17. System (10) according to claim 16, characterized in that the web (480) drive comprises a surface (481) interface with the flange (476) end, said flange (476) 20 of end being associated with a disk carrier (38) having a toothing (39) and in that the surface (481) interface of the web (480) drive and the free end of the toothing (39) of the door and (38) are separated by an axial distance strictly less than the axial dimension of the end flange (476) of the multi-disc assembly. 18. System (10) according to claim 17, characterized in that the end flange (476) has a rear friction face (477) cooperating with a friction disk (64) and a flat bearing zone ( 479) disposed on the projection (80) so that the axial dimension of the end plate of the multi-disk assembly represents the maximum thickness of the flange measured along the axis 0 3034480 38 between the flat bearing area (479). and the friction back face (477). 5