FR3108696A1 - HUB ASSEMBLY FOR WET CLUTCH SYSTEM - Google Patents

Abstract

ASSEMBLED HUB FOR WET CLUTCH SYSTEM The invention claims an assembled hub (10) for a wet clutch system (1), comprising: - a torque input disc (3), - a cylindrical hub (7) d axis (X) of rotation, carrying an external spline (70) capable of receiving a drive torque (coming from a driving shaft), - a sealing ring (9) comprising an external cylindrical surface (90) capable to receive the support of a sealing gasket, characterized in that the sealing ring (9) is attached to the inlet veil and/or the cylindrical hub (7), the inlet veil (3 ) and the cylindrical hub (7) being integral in rotation, for example fixed together by welding (50). Figure for abstract: Figure 1

Description

“ASSEMBLED HUB FOR WET CLUTCH SYSTEM”

The present invention relates to an assembled hub for a wet clutch system, as used in the automotive field. The invention also relates to a wet clutch system, such as for example a single, a double or a triple wet clutch, comprising such an assembled hub, as well as a method for assembling such an assembled hub.

A wet clutch system is known, for example a double wet clutch for a motor vehicle, comprising torque input means intended to be coupled to a crankshaft (engine side) via a driving shaft, a first torque output shaft, a second torque output shaft, a first clutch capable of coupling or decoupling the torque input means and the first torque output shaft, a second clutch capable of coupling or decoupling the means torque input shaft and the second torque output shaft.

Each clutch conventionally comprises friction discs linked in rotation to output disc holders, and flanges linked in rotation to a torque input hub via an input disc holder connected to said hub, to form the torque input means. In known manner, the latter are fixed together by several assembly operations, such as the fitting of the inlet veil on an external cylindrical surface of the inlet hub. In some cases, the input hub includes splines connected to the driving shaft in a lubricated environment, for performance and maintaining the mechanical and thermal properties of the clutch system.

Such splines impose complete processing and optimal machining operations on the input hub, with problems of manufacturing tolerances, and with an additional manufacturing cost.

Machining operations also generate pollution (porosity, shavings of material) on the splines of the hub and the surfaces that must seal with the transmission casing. The presence of material shavings could affect the sealing of the clutch system with its close environment.

To effectively ensure the sealing function, a sealing support is generally formed in one piece with the cylindrical bearing surface of the inlet hub. Thus, the sealing support forms a circular bowl all around the hub. Under these conditions, access to the inlet hub to make the splines inside such a cup is made difficult.

The object of the invention is in particular to provide a simple, effective and economical solution to this problem.

For this purpose, the invention proposes, according to a first aspect, an assembled hub for a wet clutch system, comprising:
- a couple entrance veil,
- a cylindrical hub with axis X of rotation, carrying an external spline capable of receiving a drive torque,
- a sealing ring comprising an external cylindrical surface capable of receiving the support of a sealing ring,
characterized in that the sealing ring is attached to the inlet veil and/or the cylindrical hub, the inlet veil and the cylindrical hub being integral in rotation, for example fixed together by welding.

Such an assembled hub receives torque from the drive shaft, seals the wet clutch system to the transmission case, and transmits torque within the wet clutch system. The assembled hub therefore fulfills different functions.

Thanks to such an assembled hub, each of its functions is performed by a component which is specific to it. Thus, each component has a shape, a material, a surface treatment adapted to the function for which the component is assigned. The cylindrical hub receives the torque input transmitted by the motor. The sealing ring seals the crankcase. The entry veil transmits the torque within the clutch system. Therefore, this assembled hub, according to the invention, has the advantage of being simplified and simple to produce, its design and its assembly operations are improved. The entrance veil can for example be stamped. The sealing ring can receive a specific surface treatment.

Preferably, the inlet veil and the cylindrical hub are connected together by a weld.

Advantageously, the weld, connecting said inlet flange to said cylindrical hub, is located radially below the spline of said cylindrical hub. The advantage is to lower the diameter of the weld along the X axis, so as to guarantee a better seal with the transmission casing. Alternatively, the inlet veil can be force-fitted or fitted onto the cylindrical hub.

The assembled hub, in accordance with the first aspect of the invention, advantageously comprises one or more improvements described below, the technical characteristics forming these improvements being able to be taken alone or in combination:

– The weld can be circumferentially continuous around the X axis, to provide additional sealing. As a variant, the weld may be discontinuous around the axis X of rotation, for example formed of a plurality of weld beads distributed angularly around the axis X.

– Preferably, said weld can be arranged away from the outer groove, which avoids any risk of pollution and drips. Advantageously, the weld can be placed halfway between the outer spline and the bearing surface of the cylindrical hub;

– Said welding can be laser welding by transparency or by capacitor discharge;

– Said welding can be located radially below the sealing ring;

– The inlet veil may include an axial extension seat adapted to support the sealing ring, the axial extension seat having an outer diameter greater than that of the outer spline;

– Advantageously, the sealing ring can be fitted and/or welded onto the inlet veil. Alternatively, the sealing ring can be fitted and/or welded onto the cylindrical hub;
Alternatively, the sealing ring can be fitted on the inlet veil and the cylindrical hub;
Alternatively, the sealing ring can be welded to the inlet veil and the cylindrical hub;

Therefore, such a ring is adaptable according to the specific architectures and needs of the wet clutch system. Its advantageous arrangement, according to the targeted leak zones, makes it possible to guarantee them a better seal, in particular according to the size of the assembled hub.
In these ways, the sealing ring can be brought closer to the engine side, to limit the access of pollutants. In some cases, the support of the sealing ring is improved due to a large contact surface formed jointly by the cylindrical hub and the inlet veil;

– Said welding can be located inside the sealing ring. In this way, the sealing ring has the advantage of surrounding said weld, delimiting additional sealing of the assembled hub, which avoids any risk of infiltration and pollution of the engine;

– Advantageously, said weld, the external spline and the sealing ring can form a radial stack. In other words, they are arranged radially and closely one after the other, in order to reduce bulk and guarantee a tighter assembled hub. Each part is thus advantageously arranged, to perform its sole function in an optimal manner;

– The sealing ring can extend circumferentially continuously around the X axis;

– The sealing ring can be located radially above the external spline;

– Preferably, the axial dimension of the sealing ring can be greater than that of the external spline. Alternatively, the sealing ring may have an axial dimension substantially equal to that of the outer spline. Alternatively, the sealing ring may have an axial dimension smaller than that of the external spline;

– The input sail may include an external spline suitable for connection to a torque input disc holder;

– Alternatively, the torque input web can include an axial extension seat capable of receiving a multi-disc assembly, the axial extension seat being formed by stamping. Therefore, the number of added parts is reduced. The stamping of the entrance veil allows the realization of complex shapes, of thinner thickness, by eliminating the machining steps. Preferably, the axial extension surface of the inlet veil may comprise an internal spline capable of receiving said multi-disc assembly;

– The inlet veil may include a support face perpendicular to the X axis, said support face being arranged axially opposite the side face of the cylindrical hub. Said bearing face and said lateral face can be fixed together by welding, preferably welded by transparency;

– The external spline of the cylindrical hub can be an added crown. Machining and treatment operations are limited here by concentrating them only on the splined crown, in order to increase hardness, limit wear and ensure the best possible connection to the drive shaft. The rest of the cylindrical hub, known as the hub cylinder, no longer needs these operations or specific treatment. We therefore move from a fully machined and treated hub in the prior art, to a hub or hub cylinder that is largely unmachined and/or untreated in the present invention, the advantage being to reduce the steps and costs Manufacturing ;

– The cylindrical hub may include a bearing surface located radially below the external spline and which is capable of receiving a bearing or a guide bearing;

– For example, the cylindrical hub and/or its cylinder can be made by forging, machining, sintering, flow forming, etc. or by any other process known to those skilled in the art;

– At least two of the parts of the hub assembled among the inlet flange, the sealing ring, the cylindrical hub and the external spline (if fitted) are of different materials and/or hardnesses. Therefore, the surface treatments are not the same, some are no longer necessary;

– Advantageously, said parts of the assembled hub all have different hardnesses from each other. This advantageously allows, for each function, to use the most optimal material, for example among different categories of materials such as steels and aluminum alloys;

– Advantageously, the hardness of the sealing ring can be greater than that of the inlet veil;

– Alternatively or additionally, the hardness of the sealing ring can be greater than that of the cylindrical hub. The hardness of the sealing ring can be higher than that of the outer spline;
The advantage of such hardness of the sealing ring is to optimize its sealing function, resulting from a specific material, a specific shape and a specific treatment.

– The hardness of the external spline can be greater than that of the inlet veil;

– In addition, the hardness of the cylindrical hub can be greater than that of the inlet veil;

– In the particular case of an added external spline, the hardness of the added spline crown may be greater than that of the cylinder of the cylindrical hub;

The advantage of such hardness of the cylindrical hub, in particular of its external spline, is to optimize its torque transmission function from the driving shaft, resulting from a specific material, a specific shape and a specific treatment. By way of example, the external spline can be made of steel, formed for example by quenching and tempering (according to the “quenching and tempering” method).

The invention also relates to a wet clutch system, comprising at least a first clutch of the multi-disc type, controlled to selectively couple a driving shaft to a first driven shaft, characterized in that it comprises an assembled hub or part of the characteristics mentioned above, said assembled hub being coupled in rotation with the multi-disc assembly of the first clutch.

Such a wet clutch system according to the invention has the advantage of ensuring better sealing of its components, or even better transmission of torque from the drive shaft. The assembly steps of such a system are facilitated. Size and weight can be reduced.

– According to a first exemplary embodiment, the clutch system in accordance with the second aspect of the invention may be of the simple clutch type, or even a wet clutch of the hybrid type.

– According to a second embodiment, the system can be of the double clutch type. Advantageously, the clutch system can be of the triple clutch or hybrid clutch type, intended to equip, for example, vehicles with robotic gearboxes;

– Therefore, the clutch system may comprise – according to a first version – two clutches configured according to an axial configuration, a first clutch being located in front of a second clutch, the two clutches of the multi-disc type being located at the same distance radial to the axis of rotation.

According to a second compatible version, the clutch system comprises two clutches of the multi-disc type configured according to a radial configuration, a first clutch being located radially outside of a second clutch. Alternatively or in addition, the clutch system may comprise a simple wet clutch type clutch and a hybrid type wet clutch;

The invention also relates to a method for assembling an assembled hub incorporating all or part of the characteristics mentioned above, comprising at least the following steps:
a) provide an inlet veil, a cylindrical hub and a sealing ring,
b) put the cylindrical hub in axial support on the inlet veil,
c) fixing together the cylindrical hub and the inlet veil by welding, for example by laser welding by transparency or by capacitor discharge,
d) attach the sealing ring to the cylindrical hub and/or to the inlet veil.

According to this method, the assembly steps are carried out in a simple manner. Mounting the hub with the entry flange, in a single welding operation, reduces the steps, for example by eliminating the fitting. The sealing ring, mounted only after step c) of fixing the hub with the flange, facilitates access to the splined hub for the operator, in order to be fixed with the entrance flange.

– Preferably, the welding according to step c) is carried out from the side remote from the engine, which ensures the sealing of the parts welded or fixed together by any other means of fastening;

– Preferably, the sealing ring can be slipped onto the cylindrical hub before being fitted onto the inlet veil. Therefore, step d) of the assembly process is further simplified.

The invention will be better understood on reading the following description, given solely by way of example and made with reference to the appended drawings in which:
- There is a view in axial section of a clutch system, comprising a hub assembled according to a first embodiment of the invention;
- There is a detailed view of the assembled hub according to the first embodiment illustrated in [Fig. 1];
- There is an exploded perspective view of the assembled hub according to a second embodiment of the invention, substantially close to the first embodiment;
- There is a view in axial section of a clutch system, comprising a hub assembled according to a third embodiment of the invention, substantially close to the first embodiment;

• « avant » ou « arrière » selon la direction par rapport à une orientation axiale déterminée par l’axe principal de rotation du porte-disques, « l’arrière » désignant la partie située à droite des figures, du côté de la transmission, et « l’avant » désignant la partie gauche des figures, du « côté du moteur » ; et
• « intérieur / interne » ou « extérieur / externe » par rapport à l’axe de rotation et suivant une orientation radiale, orthogonale à ladite orientation axiale, « l’intérieur » désignant une partie proximale de l’axe de rotation et « l’extérieur » désignant une partie distale de l’axe de rotation.

In the remainder of the description and in the claims, the terms will be used, without limitation and in order to facilitate understanding thereof:

• "front" or "rear" depending on the direction with respect to an axial orientation determined by the main axis of rotation of the disc carrier, "the rear" designating the part situated to the right of the figures, on the side of the transmission, and “the front” designating the left part of the figures, on the “engine side”; And
• "inside/internal" or "outside/external" with respect to the axis of rotation and following a radial orientation, orthogonal to the said axial orientation, the "inside" designating a proximal part of the axis of rotation and "the exterior” designating a distal part of the axis of rotation.

"Vehicle" means motor vehicles, which include not only passenger vehicles, but also industrial vehicles, which include heavy goods vehicles, public transport vehicles or agricultural vehicles, but also any transport vehicle allowing a living being and/or an object to pass from one point to another.

Unless otherwise stated, "axially" means "parallel to the X axis of rotation of the friction disc or clutch system"; "radially" means "along a transverse axis intersecting the axis of rotation of the friction disc or of the clutch system"; “Angularly” or “circumferentially” means “around the X axis of rotation of the friction disc”. The thickness is here measured along the X axis of rotation. The "depth" is here measured along the X axis of rotation. Unless otherwise indicated, the verbs "include", "present" or "understand" must be interpreted broadly, that is to say not limiting.

In the various figures, identical references are used to designate identical or similar parts. In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view.

There is shown in FIGURES 1 to 2 a first embodiment of an assembled hub 10 for clutch system 1. Clutch system 1 is located between an engine M1 and a gearbox fitted to the motor vehicle (not represented). The motor M1 can for example be an electric or thermal motor. The motor M1 is equipped with a driving shaft A0, associated for example with the rotor of the motor M1, and able to drive the driving shaft A0, for example at speeds greater than or equal to 15,000 revolutions per minute. The clutch system 1 can be of the wet or dry type.

In the examples shown, the clutch system 1 is a wet type double clutch. The clutch system 1 comprises a first clutch E1 and a second clutch E2, respectively of the multi-disc type. In FIGURES 1 and 4, the first clutch E1 is disposed radially above the second clutch E2.

Alternatively, the first and second clutches E1, E2 can be arranged axially next to each other. In a variant not shown, the clutch system 1 can be a simple clutch, a triple clutch or a hybrid clutch, intended to equip automatic, robotised, hybrid and/or electric transmissions of a motor vehicle.

The clutch system 1 comprises, around the axis X, an assembled hub 10 which is connected in rotation to a driving shaft A0. The assembled hub 10 comprises a cylindrical hub 7 of torque input, annular type and X axis of revolution, of simple shape, which forms the central body of the assembled hub, rotatable and supporting other parts. The cylindrical hub 7 is connected in rotation via an external spline 70, to the output of a damping device (such as a double damped flywheel, etc.) whose input is connected, by the intermediary in particular of a flywheel, to the drive shaft A0 formed by a crankshaft which is driven in rotation by an engine fitted to the motor vehicle.

The outer spline 70 is formed on the outer periphery of the cylindrical hub 7. The outer spline 70 defines a diameter D1 along the axis X. The outer spline 70 is connected to the spline of the driving shaft A0, in order to ensure the passage of a drive torque of the driving shaft A0.

The driving shaft A0 is here located radially outside the cylindrical hub 7. Therefore, the clutch system 1 is controlled to selectively couple the driving shaft A0 to a first driven shaft A1 and to a second driven shaft A2 , via the assembled hub 10. The first and second driven shafts A1, A2 are connected to the gearbox. The first and second driven shafts A1, A2 are coaxial, one of the shafts A2 being hollow and the other shaft A1 extending inside the hollow shaft A2. The first driven shaft A1 is driven in rotation when said first clutch E1 is closed and the second driven shaft A2 is driven in rotation when said second clutch E2 is closed. The clutch system 1 has a main axis of rotation X.

The assembled hub 10 further comprises a radially oriented part formed by a torque input web 3. In the examples illustrated, the assembled hub 10 generally has an “L” shape, comprising an annular portion of radial orientation formed by an inlet veil 3 and an axial orientation part formed by the cylindrical hub 4. The hub assembled 10 is located in front of the wet clutch system 1.

To guarantee optimal operation, the clutch system 1 further comprises three bearings 5, 25, 35:
- a first axial bearing 25 interposed axially between the output disc carrier 13 of the clutch E1 and the output disc carrier 23 of the clutch E2, in order to be able to transmit an axial load between the two output disc carriers 13, 23 which can rotate at different speeds when the first and second clutches E1, E2 are configured in a different configuration;
- A second axial bearing 35 interposed between the output disc carrier 13 of the clutch E2 and the main hub 7;
- A radial bearing 5 interposed in an axially intermediate position between a bearing surface 77 of the cylindrical hub 4 and one of the transmission shafts A1, A2.

In this way, the cylindrical hub 7 can be hollow or hollow, in order to form on its inner bore a bearing surface 77, for example to receive the bearing 5. In this way, said bearing 5 makes it possible to support the radial forces of the hub assembled 10 despite the different speeds of rotation at which the driving shaft A0 and the first transmission shaft A1 can respectively rotate.

Advantageously, the bearings 5, 25, 35 are rolling bearings with a first and second disk between which a plurality of rolling bodies are arranged.

In a variant not shown, the bearing(s) 5, 25, 35 may be ball bearing members.

In another variant, not shown, the radial bearing 10 can be located in an axially intermediate position between said bearing surface 77 of the cylindrical hub 4 and a front axial end AV of the first output hub 31.

A first lateral face 710 of the cylindrical hub 7, perpendicular to the axis X, is delimited radially between the external spline 70 and the bearing surface 77. Preferably, the external spline 70 and the bearing surface 77 are aligned radially, by relative to the same axial level along the X axis.

In the examples illustrated, the cylindrical hub 7 is arranged radially inside with respect to the veil 3 of entry. The inlet veil 3 and the cylindrical hub 7 are integral in rotation and welded together by a weld 50, for example by laser welding by transparency or by capacitor discharge.

Weld 50 connects said inlet veil 3 to said cylindrical hub 7. Weld 50 only connects parts 3, 7 to each other. Preferably, the weld 50 is circumferentially continuous around the axis X, to seal the direct connection of the inlet veil 3 with the cylindrical hub 7.

In a variant not shown, the weld 50 can be discontinuous, in the form of weld beads distributed angularly regularly around the axis X.

Advantageously, the weld 50 is located radially below the outer spline 70 of said cylindrical hub 7. Therefore, the first side face 710 is adapted to receive the weld 50 connecting said inlet web 3 to said cylindrical hub 7. Said Weld 50 is advantageously disposed away from the outer groove 50, to avoid any risk of pollution and drips.

In the examples illustrated, the weld 50 is placed on the first lateral face 710, located on a central zone of said first lateral face 710. By “central zone”, we mean a zone extending over approximately 30% of the length separating the two ends of said edge, or located equidistant from the two ends of said edge. Preferably, the weld 50 is located substantially halfway between the external spline 70 and the bearing surface 77 of the cylindrical hub 7.

Consequently, the cylindrical hub 7 is of simple shape, that is to say without any flange extending beyond the external spline 70, to simplify the assembly operations and not to interfere with the formation of said weld. 50. Furthermore, the cylindrical hub 7 may comprise a protrusion 44, of rounded shape, capable of receiving another bearing surface. This protrusion 44, arranged as close as possible to the axis X and therefore radially below the external groove 50, is formed of an axial extension of material which is oriented opposite the inlet veil 3, towards the front of the cylindrical hub 7.

Preferably, the inlet veil 3 comprises a bearing face 33 perpendicular to the axis X. Said bearing face 33 is arranged axially opposite the side face 710 of the cylindrical hub 7. The welding operation 50 laser by transparency or by capacitor discharge is simplified, given that said support face 33 and lateral face 710 are mutually parallel.

Furthermore, the radially inner end edge of the inlet web 3 and the bearing surface 77 of the cylindrical hub 7 can be aligned axially, without overshoot, in order to further limit the radial bulk.

Therefore, the weld 50 is made opposite the side of the engine M1, that is to say from the bearing face 33 of the inlet veil 3, in other words the face furthest from the engine. The weld 50 extends axially on the first side face 710 of the cylindrical hub, in the direction of the driving shaft A0, more precisely axially towards the side of the motor M1.

The assembled hub 10 further comprises a sealing ring 9 having an outer cylindrical surface 90. The outer cylindrical surface 90, of annular shape, receives the support of a seal (not shown). The sealing ring 9 thus performs the sealing function with the transmission casing 150.

The axial extension surface 30 of the inlet veil 3 is arranged facing the external groove 70. In this way, the sealing ring 9 is arranged radially above the external groove 70. In addition, the ring seal 9 is located radially above weld 50.

In a variant not shown, the sealing ring 9 can be arranged facing the external spline 70.

Preferably, the sealing ring 9 is simple in shape and relatively robust, for example small in size compared to the other parts 3, 7 of the disc carrier, preferably thin.

In the examples illustrated, the sealing ring 9 is substantially of the same axial dimension as the outer spline 50. The sealing ring extends circumferentially continuously around the axis X, as in FIGURE 3.

Preferably, the sealing ring 9 is defined axially with respect to the bearing surface of the stamping of the web 3 supporting it. The advantage being to reduce the axial and/or radial size. The sealing ring 9 can advantageously be spaced from the outer spline 70, for example by a minimum mounting play of the order of a few tenths of a millimeter, so as not to overlap the outer spline in engagement with the driving shaft. A0. The sealing ring 9 is thus supported indirectly by the cylindrical hub 7 via the inlet veil 3.

Alternatively or in addition, the sealing ring 9 can be supported, linked and supported directly by the cylindrical hub 7.

Therefore, the weld 50 is located inside the sealing ring 9. Therefore, the sealing ring 9 surrounds said weld 50, in order to delimit an additional seal with the transmission casing 150. Similarly , the sealing ring 9 surrounds part of the inlet veil 3.

Additionally, the sealing ring 9 can surround a front part AV of the first output hub 31 and/or a part of the bearing 5. In a variant not shown, the sealing ring 9 can comprise a rim or a collar s extending in the direction of the entry veil 3, so as to bear axially on the entry veil 3.

The sealing ring 9 can advantageously be arranged on the inlet veil 3 and/or the cylindrical hub 7, according to several possible variants. In the examples illustrated, the sealing ring 50 is fitted and welded onto the inlet veil 3. To do this, the inlet veil 3 comprises an axial extension surface 30 which is adapted to support the sealing 9. Preferably, the axial extension bearing 30 defines a diameter D2 along the axis X, along its bore. This diameter D2 is greater than the diameter D1 of the external spline 70. This arrangement of the sealing ring 9, of the external spline 70 and of the weld 50 advantageously forms a radial stack; in other words, they 9, 50, 70 follow one another axially one after the other, which reduces the size and guarantees an assembled hub 10 that is more sealed.

In a variant not shown, the sealing ring 9 can be fitted and/or welded onto the cylindrical hub 7. The sealing ring 9 can have a shape complementary to that of the cylindrical hub. For example, the bore of the sealing ring 9 can be smooth, serrated or fluted. In particular, the sealing ring can rest on the end opposite the motor side of the cylindrical hub, in order to be positioned as close as possible to the drive shaft A0 and ensure better sealing.

In another variant, not shown, the sealing ring 9 can be welded together on the inlet veil 3 and the cylindrical hub 7, so as to ensure its centering. For example, the bore of the sealing ring 9 can be circular in shape.

In another variant not shown, the sealing ring 9 can be fitted with the inlet veil 3 and the cylindrical hub 7. For example, the bore of the sealing ring 9 can be circular in shape, around the axis X, adapted to bear, for example in part, on the axial extension surface 30 and on the end opposite the motor side of the cylindrical hub 7.

In the first and second embodiments, the inlet veil 3 comprises, at its outer radial end of axial orientation, teeth or an outer groove 8, extending radially outwards and which rest on a assembled disc carrier 19 input, allowing the transmission of input torque.

In the first and second embodiments, the torque input disc carrier 19 is common to the first and second clutches E1 and E2. The input disc carrier 19 further comprises an outer disc carrier 14 of the first clutch E1 and an inner disc carrier 24 of the second clutch E2.

In the examples illustrated, the multi-disc assembly of the first clutch E1 comprises flanges 11 connected in rotation to the input disk carrier 19 and friction disks 12 connected in rotation to a first output disk carrier 32 of torque. The friction discs 12 are individually axially interposed between two successive flanges 11. The torque output disc carrier 32 of the first clutch E1 is connected in rotation by meshing with the friction discs 12 and by a splined connection with said first driven shaft A1. The output disc carrier 32 includes an output hub 31 connected to the driven shaft A1.

The multi-disc assembly of the second clutch E2 comprises flanges 21 linked in rotation to the input disc holder 19 and friction discs 22 linked in rotation to a second output disc holder 40 of torque. The torque output disc carrier 40 of the second clutch E2 is connected in rotation by meshing with the friction discs 22 and by a splined connection with said second driven shaft A2. Output carrier 40 includes output hub 41 connected to driven shaft A2.

The outer disc carrier 14 of the first clutch E1 notably comprises an axial extension arranged to receive the multi-disc assembly of the first clutch. The axial extension forms an internal groove receiving the flanges 11 of the multi-disc assembly of the first clutch E1.

The inner disc carrier 24 of the second clutch E2 comprises an axial extension arranged to receive the multi-disc assembly of the second clutch. The axial extension forms an internal groove receiving the flanges 21 of the multi-disc assembly of the second clutch E2.

The wet clutch system 1 comprises a control system 100 arranged to engage or disengage said first and second clutches E1, E2. The control system 100 is attached to a transmission housing 150. The clutch system 1 is hydraulically controlled via a pressurized fluid, generally oil. Control System 100 includes:
- a first actuating piston 110 arranged to configure the first clutch E1 in a configuration between the engaged configuration and the disengaged configuration;
- a second actuating piston 120 arranged to configure the second clutch E2 in a configuration between the engaged configuration and the disengaged configuration;
– a casing 130 in which are housed at least (in part) the first or the second actuating piston 110, 120.

The two clutches E1, E2 bear on the control system 100 via force transmission members 90, 75. For example, the actuation system can comprise an axial extension bearing 140 integrated in the casing 130 and extending axially in the direction of the input element 2. The axial extension bearing 140 is arranged to support the two clutches E1, E2.

A guide bearing 80 is arranged between the axial extension bearing 140 and the input disc holder 19. The guide bearing 80 is of the ball bearing type and guides the first and second clutches E1, E2 in rotation with respect to to the control system 100. The guide bearing 80 bears axially on the input disc carrier 19. On its internal periphery, the input disc carrier 19 comprises a cylindrical support portion 13 in which is inserted the outer ring of the guide bearing 80. The integration of the guide bearing within the input disc carrier 19 allows the axial forces to be taken up without altering the axial size of the clutch system 1. The guide bearing 80 is common to the first and second clutches E1 and E2. For example, guide bearing 80 is an angular contact ball bearing. In a variant not shown, the guide bearing may be a needle bearing.

In the examples illustrated, the clutch system 1 comprises a first elastic return device 60 for the first actuation piston 110 and a second elastic return device 70 for the second actuation piston 120. The two elastic return devices 60, 70 are supported on the input disc carrier 19 and housed in a recess 15. The depression 15 formed in the input disc carrier 19 is arranged over a diameter located beyond the bearing portion bearing surface cylindrical 13.

Each of the elastic return devices 60, 70 makes it possible to generate an axial force sufficient to restore the actuating piston and the corresponding clutch to the initial so-called disengaged configuration.

The first elastic return device 60 comprises a first series of helical springs 61 distributed angularly around the axis X arranged to bear on a first force transmission member 65. The first force transmission member 90 is interposed axially between the first clutch E1 and the first actuating piston 110.

The second elastic return device 70 comprises a second series of helical springs 71 distributed angularly around the axis X arranged to bear against a second force transmission member 75. The second force transmission member 75 is interposed axially between the first clutch E1 and the first actuating piston 120.

In the examples illustrated, the second elastic return device 70 is arranged radially beyond the first elastic return device 60. The first series of helical springs 61 rests on the first force transmission member 90 via a first annular plate 62. The second series of coil springs 71 rests on the second force transmission member 75 via a second annular plate 72.

A common support plate 17 secures together the first and second series of coil springs 61, 71. The common support plate 17 rests on the inlet disc carrier 19.

In order to reduce the axial size of the wet clutch system 1, the first and second clutches E1, E2, the first and second elastic return devices 60, 70 and the guide bearing 80 are concentric and are nested radially within the input disc carrier 19. Thus, a plane orthogonal to the X axis, geometrically crosses the guide bearing 80, the first and second clutches E1, E2 as well as the first and second elastic return devices 60,70. Said plane passes through the center of the balls of the guide bearing 80.

In order to reduce the axial compactness, the first force transmission member 90 passes through orifices 76 made in the second force transmission member 75 to press on the first elastic return device. The first force transmission member 90 is assembled by means of an actuating part 91 and a reinforcing part 92. This assembly makes it possible to obtain a first assembled force transmission member 90 having improved axial stiffness.

The clutch system 1 also comprises a lubricating ring 55 is also arranged radially between the axial extension bearing 140 and the input disc carrier 10. The lubricating ring 55 is in axial support on the guide bearing 80 The lubricating ring 55 is retained axially by a split ring fitted in a groove provided on the axial extension surface 140 of the casing 130.

Advantageously, the lubricating ring 55 comprises lubricating pipes 51 passing radially right through the ring and opening onto the outer periphery. The lubrication lines 51 are oriented radially in the direction of the clutches E1 and E2.

The housing 130 of the control system 100 comprises cooling fluid supply lines 131 which communicate directly with the lubrication lines 51. The lubrication ring 55 thus channels the cooling fluid coming from the actuation system in the direction of the first and second clutches E1, E2 and promotes their lubrication.

The parts of the assembled hub 10 generally have an “L” shape.

In particular in the first embodiment, the external spline 70 of the cylindrical hub 7 is an added crown 700. The cylindrical hub is thus formed of a crown 700 of the splined type, forming the external spline 70, and of a cylinder 4 forming the rest of the cylindrical hub 7. The advantage is to concentrate the machining and processing operations only on the 700 fluted crown.

Therefore, the assembled hub 10 consists of four parts 3, 4, 70, 9 assembled. Preferably, each of the four parts comprises a shape and a material which corresponds to it, being different from the others, for the realization of its own associated function.

For example, the cylinder 4 is made by sintering, while the splined crown 700 is made by machining, with a quenching and tempering treatment. Consequently, the material of the splined crown 700 is of a higher hardness than that of the cylinder 4 of the cylindrical hub 7. The advantage of such a material for the cylinder 4 is to use no heat or surface treatment, its associated function not needing it to transmit the rotational torque and to support the other parts of the assembled hub 10.

By "hardness" of a material, we generally mean the resistance offered by the surface and/or the body of a material, for example to the penetration of a foreign element, i.e. for example here the average between the hardness of surface and core hardness. Note that a part will generally have a surface hardness greater than its core hardness, in particular for the sealing ring 9 and/or for the cylindrical hub 7.

By way of example, the sealing ring 9 has a surface hardness of 580 HV10 and a core hardness of 550 HV1. In the examples shown, the material of the sealing ring 9 is steel, press formed and treated. As a variant, the sealing ring 9 can be made of bronze, or of another metal alloy having a hardness greater than that of the inlet web.

By way of example, the inlet veil 3 is formed by stamping and/or bending of sheet metal, in particular at the level of its axial extension surface 30, or more generally from its central bore of axis X. As a variant not illustrated, the ring can be made by forging or machining.

Therefore, the hardness of the sealing ring 9 is greater than that of the inlet veil 3. Preferably, the hardness of the sealing ring 9 is greater than those of the splined ring 700 and of the cylinder 4 of the cylindrical hub 7.

There has been described in FIGURE 3, a second embodiment of the invention substantially similar to the first embodiment, except that the outer spline 70 and the cylindrical hub 7 are formed from a single piece. , one-piece type. Therefore, the assembled hub 10 consists of three parts 3, 7, 9 assembled. Similarly, each of the three parts of the assembled hub 10 comprises a shape and a material which corresponds to it, being different from the others, for the performance of its associated function.

• Selon une première étape, on fournit un voile d’entrée 3, un moyeu cylindrique 7 et une bague d’étanchéité 9 ;
• Selon une deuxième étape, on met en appui axial appui axial 710, 33 le moyeu cylindrique 7 sur le voile d’entrée 3 ;
• Selon une troisième étape, on fixe ensemble le moyeu cylindrique 7 et le voile d’entrée 3 par soudure 50, par exemple par soudure laser par transparence ou par décharge de condensateur ;
• Selon une quatrième étape, on rapporte la bague d’étanchéité 9 sur le voile d’entrée 3 ;

We will now describe the method of assembling an assembled hub, as illustrated in the second embodiment of FIGURE 3. The assembly comprises, among other things, the following steps:

• According to a first step, an inlet veil 3, a cylindrical hub 7 and a sealing ring 9 are provided;
• According to a second step, the cylindrical hub 7 is placed in axial support axial support 710, 33 on the inlet web 3;
• According to a third step, the cylindrical hub 7 and the inlet veil 3 are fixed together by welding 50, for example by laser welding by transparency or by capacitor discharge;
• According to a fourth step, the sealing ring 9 is attached to the inlet veil 3;

The advantage of this fourth step after the third step, in other words the mounting of the sealing ring 9 after the step of fixing the cylindrical hub 7 with the inlet veil 3, is to facilitate access to the cylindrical hub 7 for the operator so as to attach it to the entrance veil 3.

According to the third fixing step, the weld 50 is preferably made from the side remote from the motor M1, in other words, from the rear rear side of the assembled hub 10, this thus ensures the sealing of the parts of the assembled hub 10.

According to the fourth step, the sealing ring 9 is preferably threaded onto the cylindrical hub 7 before being fitted onto the inlet veil 3. Consequently, the fourth step of the assembly process is further simplified. By "threading" or "threaded ring", is meant for example the fact of sliding the sealing ring 9, on or around the cylindrical hub 7. Therefore, the threading step can be carried out without it there is no physical contact between said sealing ring 9 and said cylindrical hub 7. In such a situation, there is then a minimum difference between the diameters D1, D2 must be sufficient to allow the sealing ring to be put on 9 on the cylindrical hub 7 without the latter being in contact with each other.

Advantageously, it is possible, according to an additional step, to add, by welding and/or fitting, a splined crown 700 to the cylinder 4 of the cylindrical hub 7. Said additional step can be carried out either after the third step mentioned, or just after the cited fourth step of said previously described assembly method, as described in the first and third embodiments.

• D’un côté, un appui plan, formé par exemple par la face latérale 710 du moyeu cylindrique 7, et
• De l’autre côté, un cordon formé sur l’autre face d’appui, par exemple la face d’appui 33 du moyeu cylindrique 7, ou inversement.

Dès lors, c’est ledit cordon que l’on vient faire fondre lors de la troisième étape du procédé d’assemblage, de préférence par outillage depuis le côté éloigné du moteur, et qui donnera ainsi ladite section de soudure par décharge de condensateur.In the case of welding by capacitor discharge, there is, before welding, the pressing according to the second step of the assembly process, with:

• On one side, a flat support, formed for example by the side face 710 of the cylindrical hub 7, and
• On the other side, a bead formed on the other bearing face, for example the bearing face 33 of the cylindrical hub 7, or vice versa.

Therefore, it is said bead that is melted during the third step of the assembly process, preferably by tooling from the side remote from the motor, and which will thus give said weld section by capacitor discharge.

There has been described in FIGURE 4, a third embodiment of the invention substantially similar to the first embodiment, except that the torque input web 3 comprises an axial extension bearing 140 which receives a multi-disc clutch assembly. In other words, the inlet veil 3 comprises, at its outer radial end of axial orientation, an internal groove 80, extending radially inwards. In other words, the assembled hub 10 forms the outer disc carrier 14.

More specifically, the outer disc carrier 14 is formed by an axial extension bearing 140 input sail 3 of torque. Therefore, the assembled hub 10 has the advantage of also supporting the discs 11 of a multi-disc assembly, here those of the first clutch E1.

In this third embodiment, the torque input disc carrier 19 further comprises the inner disc carrier 24 of the second clutch E2, as well as teeth or an external spline 8, extending radially towards the outside and which rely on the input veil 3, more precisely on the axial extension bearing 140 in order to receive the transmission of the input torque.

Preferably, the axial extension bearing 140 is formed by stamping the inlet web 3. In a variant not shown, said axial extending bearing may be capable of receiving a multi-disc assembly of the second clutch E2.

Of course, the present invention is not limited to the embodiments described and represented, provided by way of illustrative and non-limiting example.

Claims (15)

Assembled hub (10) for a wet clutch system (1), comprising:
- a torque entrance veil (3),
- a cylindrical hub (7) with axis (X) of rotation, carrying an external spline (70) able to receive a drive torque (from a driving shaft),
- a sealing ring (9) comprising an external cylindrical surface (90) capable of receiving the support of a sealing gasket,
characterized in that the sealing ring (9) is attached to the entry plate and/or the cylindrical hub (7), the entry plate (3) and the cylindrical hub (7) being integral in rotation, for example fixed together by welding (50). Assembled hub (10) according to claim 1, in which a weld (50), connecting said inlet flange (3) to said cylindrical hub (7), is located radially below the external spline (70) of said cylindrical hub ( 7). Hub assembly (10) according to Claim 2, in which the cylindrical hub (7) comprises on its internal bore a bearing surface (77) and a lateral face (710) disposed radially between the external spline (70) and the bearing surface. bearing (77), said side face (710) being adapted to receive the solder (50). Assembled hub (10) according to the preceding claim, in which the entry flange (3) comprises a bearing face (33) perpendicular to the axis (X), said bearing face (33) being disposed axially in next to the side face (710) of the cylindrical hub (7). Hub assembly (10) according to any one of Claims 2 to 4, in which the said weld (50) is located inside the sealing ring (9). Hub assembly (10) according to any one of Claims 1 to 5, in which the external spline (70) of the cylindrical hub (7) is an insert ring. Assembled hub (10) according to any one of Claims 1 to 6, in which the sealing ring (9) is fitted and/or welded onto the entry flange (3). Hub assembly (10) according to any one of Claims 1 to 6, in which the sealing ring (9) is press-fitted and/or welded to the cylindrical hub (7). Assembled hub (10) according to any one of Claims 1 to 6, in which the sealing ring (9) is fitted onto the inlet flange (3) and the cylindrical hub (7). Hub assembly (10) according to any one of Claims 1 to 6, in which the sealing ring (9) is welded to the inlet flange (3) and the cylindrical hub (7). Hub assembly (10) according to any one of the preceding claims, in which the inlet web (3) comprises an axial extension seat (30) adapted to support the sealing ring (9), the axial extension (30) having an outer diameter greater than that of the outer spline (70). Hub assembly (10) according to any one of the preceding claims, in which the torque input plate comprises an axial extension seat capable of receiving a multi-disc assembly, the axial extension seat being formed by stamping. Wet clutch system, comprising at least a first clutch (E1) of the multi-disc type, controlled to selectively couple a driving shaft to a first driven shaft, characterized in that it comprises an assembled hub (10) according to any of the preceding claims, said assembled hub (10) being rotationally coupled with the multi-disc assembly of the first clutch (E1). Method of assembling an assembled hub (10) according to any one of claims 1 to 13, comprising at least the following steps:
a) provide an inlet veil (3), a cylindrical hub (7) and a sealing ring (9),
b) bring the cylindrical hub (7) into axial support (710, 33) on the entry plate (3),
c) fixing together the cylindrical hub (7) and the inlet veil (3) by welding (50), for example by laser welding by transparency or by capacitor discharge,
d) attach the sealing ring (9) to the cylindrical hub (7) and/or to the inlet veil (3). Assembly method according to claim 14, in which the sealing ring (9) is threaded onto the cylindrical hub (7) before being fitted onto the inlet veil (3).