FR3081952A1 - ASSEMBLED DISC HOLDER AND WET CLUTCH MECHANISM INCLUDING THIS ASSEMBLED DISC HOLDER - Google Patents

Abstract

The invention relates to an assembled disc holder (30) for a wet clutch mechanism, comprising: - a cylindrical hub (31) with an axis of rotation (O) comprising a bearing face (32) perpendicular to the axis , - a disc support (33) in the form of a revolution around the axis (O) comprising an axial extension (34) arranged to receive the multidisk assembly of the wet clutch, an annular portion (35) delimited by a internal bore (36), extending radially inwards from the axial extension along a plane perpendicular to the axis (O) and partially covering the bearing face of the hub according to a covering zone (37), the hub (31) and the disc support (33) being fixed together by laser welding by transparency at the overlap zone and the internal bore of the disc support and the bearing face of the hub form a cavity (38) able to receive and center an axial bearing.

Description

Assembled disc holder and wet clutch mechanism comprising this assembled disc holder

The present invention relates to an assembled disc holder and a wet clutch mechanism comprising this assembled disc holder. The wet clutch mechanism can be a cut-off clutch for a hybrid transmission or a wet double clutch mechanism.

Such a double clutch mechanism is intended to constitute part of a torque transmission system, in particular for a motor vehicle or for a so-called industrial vehicle, the latter being for example a heavy goods vehicle, a public transport vehicle, or an agricultural vehicle.

Patent application EP 2905492 A2 discloses a wet double clutch mechanism for a motor vehicle, comprising torque input means intended to be coupled to a crankshaft, a first torque output shaft, a second torque output shaft , a first clutch adapted to couple or decouple the torque input means and the first torque output shaft, a second clutch adapted to couple or decouple the torque input means and the second torque output shaft. The first and second clutches of the multidisk type, respectively, are arranged radially one above the other. Each of the multi-plate clutches have flanges linked in rotation to an input disc holder forming the torque input means and friction discs linked in rotation to the output disc holders. Axial bearings are arranged between the torque input disc carrier and the output disc carriers.

When changing gearbox ratios, the torque output shafts move axially due to the axial forces present in the gearbox. The output disc carriers are linked in rotation to the torque output shafts by means of splines. This splined connection has the effect, during the torque transmission phases, of axially securing the shafts with the disc carriers. The axial movement of the gearbox shafts causes displacement of the output disc carriers within the clutch mechanism. The axial bearings then make it possible to transfer the axial forces within the double clutch mechanism while allowing the rotation of the disc carriers between them.

The axial bearings made up of rotating rings and needles are then loaded under load. Centering the axial bearing between the rotating movable disc holders is necessary to guarantee the longevity of this component. It is known from patent application EP 2905492 A2 to center the axial bearing on the oil supply hub of the wet double clutch mechanism using specific centering lugs. The axial bearing is no longer a standard component purchased from the catalog.

Another means for centering the axial bearing consists in machining a cavity integrally in the central hub constituting a part of the output disc holder. The cavity makes it possible to maintain and axially center the axial bearing between the disc carriers of the first and of the second clutch. This machining operation results in an additional manufacturing cost.

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

The object of the present invention is in particular to propose a wet clutch mechanism for a torque transmission system making it possible to solve at least some of the drawbacks of the prior art.

To this end, the invention provides an assembled disc holder for a wet clutch mechanism, comprising:

- a cylindrical hub with an axis of rotation O comprising a bearing face perpendicular to the axis,

- a disc support in the shape of a revolution around the axis O comprising an axial extension arranged to receive the multi-disc assembly of the wet clutch, an annular portion delimited by an internal bore, extending radially inwards from the axial extension along a plane perpendicular to the axis O and partially covering the bearing face of the hub according to an overlap zone, the hub and the disc support being fixed together by laser welding by transparency at the level of the covering and the internal bore of the disc support and the bearing face of the hub forming a cavity capable of receiving and centering an axial bearing.

This assembled disc holder according to the invention has the advantage, thanks to the internal bore of the annular portion, of having a circular centering surface. The application of the disc support on the bearing face of the hub creates a lower-cost cavity in which an axial bearing can be arranged. In this way, the centering of the axial bearing is carried out without any additional manufacturing step. This assembled disc holder also has the advantage of offering a flat overlap zone adapted to the process of laser welding by transparency. Transparent laser welding avoids the use of axially bulky fixing rivets.

Preferably, the overlap zone is arranged radially beyond the cavity. This cavity has the advantage of reducing the outside diameter of the axial bearing.

Advantageously, the internal bore of the disc support is cut only by press tools. The manufacture of the disc holder is free from any additional machining operation. This assembled disc holder according to the invention has the advantage of reducing the manufacturing cost of the wet clutch mechanism.

Preferably, the bearing face of the hub and the annular portion are applied to one another along a plane perpendicular to the axis O. This assembled disc holder, according to the invention, has the advantage of reduce the geometric defects of the assembly, in particular the axial flapping of the axial extension relative to the axis O.

The invention may have one or other of the characteristics described below, combined together or taken independently of one another:

- laser welding can be continuous;

- the cylindrical hub and the disc support are separate parts;

- The cylindrical hub can include an internal groove;

- The cylindrical hub can include an external groove;

- The cylindrical hub may include an annular flange of radial extension on which the bearing face is formed;

- the internal bore of the disc support can define a first diameter D1 along the axis O, and the bearing face of the hub can comprise an external periphery defining a second diameter D2 along the axis O, the diameter D1 being smaller at diameter D2;

- the internal bore of the disc support can include circular centering portions;

- the circular centering portions can be distributed angularly around the axis O;

- The axial extension of the disc support can be made of material with the annular portion;

- the axial extension of the disc support can be attached and fixed in rotation with the annular portion;

- the axial extension may include an external or internal groove.

- the cylindrical hub can be connected to a torque input shaft;

- the cylindrical hub can be connected to a torque output shaft;

According to one of its aspects, the invention also relates to a wet clutch mechanism of the multidisc type, controlled to selectively couple a shaft leading to a driven shaft, for example a gearbox shaft, comprising:

- an assembled disc holder incorporating all or part of the characteristics mentioned above;

- A multi-plate clutch comprising flanges linked in rotation to a torque input disk carrier and friction disks linked in rotation to a torque output disk carrier, the assembled disk carrier constituting one or the other record carriers;

- An axial bearing disposed axially between the torque input disc holder and the torque output disc holder, said axial bearing being received and centered by the cavity formed in the assembled disc holder.

The wet clutch mechanism, according to this other aspect of the invention, has the advantage of facilitating the mounting of the axial bearing between the torque input disk carrier and the torque output disk carrier. Transparency laser welding avoids the use of axially bulky fixing rivets and the integration of the axial bearing into the thickness of the disc holder makes it possible to reduce the axial size of the wet clutch mechanism.

All or part of the characteristics mentioned above also applies to this other aspect of the invention.

Another subject of the invention is, according to another of its aspects, a wet double clutch mechanism comprising a first clutch and a second clutch respectively of the multi-disc type, controlled to selectively couple a shaft leading to a first driven shaft and to a second driven shaft, the first and second clutches being arranged radially one above the other, each of the multi-disc clutches having flanges linked in rotation to a torque input disc holder and friction discs linked in rotation to a torque output disc holder, the torque input disc holder being common to the first and second clutch, said double clutch mechanism comprising:

- an assembled disc holder incorporating all or part of the characteristics mentioned above, constituting one or the other of the torque output disc holders;

- An axial bearing disposed axially between the torque output disc carriers of the first and second clutch, said axial bearing being received and centered by the cavity formed in the assembled disk carrier.

The wet double clutch mechanism, according to this other aspect of the invention, has the advantage of facilitating the mounting of the axial bearing between the torque output disc carriers of the first and second clutch. Laser welding by transparency avoids the use of axially bulky fixing rivets and the integration of the axial bearing in the thickness of the disc carrier makes it possible to reduce the axial dimensions of the wet double clutch mechanism.

All or part of the characteristics mentioned above also applies to this other aspect of the invention.

The subject of the invention is also a process for manufacturing an assembled disc holder incorporating all or part of the characteristics mentioned above, comprising at least the following steps:

provide a hub and a disc holder cut only by press tools, apply the disc holder to the hub at an overlap area, then fix the disc holder to the hub together by laser transparency welding at the level of the overlap area.

According to this process, laser welding by transparency avoids the use of axially bulky fixing rivets.

The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the appended drawings in which:

Figure 1 is an axial sectional view of a wet double clutch mechanism comprising a disc holder assembled according to a first embodiment of the invention;

Figure 2 is an axial sectional view of the disc holder assembled according to the first embodiment of the invention of Figure 1;

Figure 3 is an isometric view of the inner disc holder alone according to the first embodiment of the invention of Figure 1;

Figure 4 is a front view of the outer disc holder alone according to a second implementation of the invention;

In the following description and claims, the terms "front" or "rear" depending on the direction relative to an axial orientation determined by the main axis O will be used without limitation and in order to facilitate understanding thereof. of rotation of the transmission of the motor vehicle and the terms "interior / internal" or "exterior / external" with respect to the axis O and in a radial orientation, orthogonal to said axial orientation.

There is shown in Figures 1 to 3 a first embodiment of an assembled disc holder 30, 40 for a wet clutch mechanism of the multi-disc type. In the example illustrated in FIG. 1, the wet clutch mechanism is a wet double clutch mechanism 1 having a main axis of rotation O.

The wet double clutch mechanism 1 for the torque transmission system comprises around the axis O at least one input element 2 which is linked in rotation to a driving shaft (not shown). The input element 2 is located at the rear of the wet double clutch mechanism 1.

In the first embodiment, the input element 2 having an overall “L” shape, comprises an annular portion of radial orientation formed by an entry web 3 and a portion of axial orientation formed by a hub 4. The inlet web 3 and the inlet hub 4 are integral and welded together by laser welding by transparency.

The hub 4 is arranged radially inside with respect to the entry web 3.

The input hub 4 is for example linked in rotation via the grooves 5 to the output of a damping device (such as a double damping flywheel, etc.) whose input is linked, by l 'Intermediate including a flywheel, the drive shaft formed by a crankshaft which rotates an engine fitted to the motor vehicle.

The entry web 3 has, at its outer radial end of axial orientation, teeth 9 which extend radially outwards and which are supported on an entry disc holder 10.

The wet double clutch mechanism 1 is controlled to selectively couple said shaft leading to a first driven shaft A1 and to a second driven shaft A2 connected to a gearbox fitted to the motor vehicle.

Preferably, the first driven shaft A1 and the second driven shaft A2 are coaxial. 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 wet double clutch mechanism 1 comprises a first clutch E1 and a second clutch E2, which are respectively of the multi-disc type, as well as an actuation system 100 arranged to engage or disengage said first and second clutches E1, E2.

The wet double clutch mechanism 1 is hydraulically controlled by means of a pressurized fluid, generally oil. The actuation system 100 includes:

- A first actuator 110 arranged to configure the first clutch E1 in a configuration between the engaged configuration and the disengaged configuration;

- A second actuator 120 arranged to configure the second clutch E2 in a configuration between the engaged configuration and the disengaged configuration;

a housing 130 in which are housed at least (in part) the first or the second actuator 110, 120.

For example, the actuation system may comprise a clutch support 140 integrated in the casing and extending axially in the direction of the input element 2. The clutch support 140 of the actuation system 100 is coupled in rotation with the housing 130.

A ball bearing 150 is arranged between the clutch support 140 and the input disc holder 10. The ball bearing 150 guides the first and second clutches E1, E2 in rotation relative to the actuation system 100. The ball bearing 150 is supported on the input disc holder 10.

As illustrated in FIG. 1, the first clutch E1 is arranged radially above the second clutch E2.

The multi-disc assembly of the first clutch E1 comprises flanges 11 linked in rotation to the input disc holder and friction discs 12 linked in rotation to an output disc holder 30. The friction discs 12 are, axially, axially interposed between two successive flanges 11.

The output disc holder 30 of the first clutch E1 is a disc holder assembled according to the first embodiment of the invention. The assembled disc holder 30 is linked in rotation by meshing with the friction discs 12 and by a splined connection with said first driven shaft A1.

As illustrated in FIG. 2, the assembled disc holder 30 comprises a cylindrical hub 31 of axis of rotation O comprising a bearing face 32 perpendicular to the axis and a disc support 33 of revolution shape around the O axis.

The disc support 33 comprises in particular an axial extension 34 arranged to receive the multidisk assembly of the first clutch E1 and an annular portion 35 delimited by an internal bore 36, extending radially inwards from the axial extension 34 according to a plane perpendicular to the axis O. The annular portion 35 partially covers the bearing face 32 of the hub 31 according to an overlap zone 37.

The hub 31 and the disc support 33 are fixed together by transparency laser welding at the level of the overlap zone 37. The laser welding 39 is continuous.

The internal bore 36 of the disc support and the bearing face 32 of the hub 31 form a cavity 38 which receives and centers n

an axial bearing 51. The axial bearing 51 is interposed axially between the input element 2 and the output disc holder 30.

The axial bearing 51 includes an outer ring, an inner ring and needles interposed axially between the two rings. The needles are distributed angularly along the axis O.

The outer ring of the bearing 51 is received in the cavity 38 of the assembled disc holder 30. The centering is done on the inner bore 36 of the annular portion 35, said bore being cut only by press tools. The manufacture of the disc holder 33 is free of additional steps such as machining.

The thickness of the axial bearing 51 is slightly greater than the depth of the cavity 38 measured along the axis O. Thus, the combination of laser welding by transparency and the placement of the axial bearing within the cavity makes it possible to reduce the axial dimensions of the wet double clutch mechanism.

The bearing face 32 of the hub and the annular portion 35 are applied one on the other along a plane perpendicular to the axis O.

The cylindrical hub 31 comprises an annular flange of radial extension on which the bearing face 32 is formed. The annular flange may include openings for the passage of oil passage.

The internal bore 36 of the disc support 33 defines a first diameter D1 along the axis O, and the bearing face 32 of the hub comprises an external periphery defining a second diameter D2 along the axis O. The diameter D1 is less at diameter D2 so that the overlap zone 37 is disposed radially beyond the cavity 38.

The overlap zone 37 is radially between the diameters D1 and D2.

The multi-disc assembly of the second clutch E2 comprises flanges 21 linked in rotation to the assembled disc holder and friction discs 22 linked in rotation to an output disc holder 40.

The output disc holder 40 of the second clutch E2 is a disc holder assembled according to the first embodiment of the invention. The assembled disc holder 40 is linked in rotation by meshing with the friction discs 22 and by a splined connection with said second driven shaft A2.

The assembled disc holder 40 comprises a cylindrical hub 41 of axis of rotation O comprising a bearing face 42 perpendicular to the axis and a disc support 43 of revolution shape around the axis O

The disk support 43 comprises in particular an axial extension 44 arranged to receive the multidisk assembly of the second clutch E2 and an annular portion 45 delimited by an internal bore 46, extending radially inwards from the axial extension 44 according to a plane perpendicular to the axis O. The annular portion 45 partially covers the bearing face 42 of the hub 41 according to an overlap zone 47. In the present case, the axial extension 44 of the disc support 43 which receives the discs of friction 22 is formed directly from material with the annular portion 45.

The hub 41 and the disc support 43 are fixed together by transparency laser welding at the overlap area 47. The laser welding 49 is continuous.

The internal bore 46 of the disc support 43 and the bearing face 42 of the hub form a cavity 48 which receives and centers a second axial bearing 52. The second axial bearing 52 is interposed axially between the outlet disc holder 30 of the first clutch E1 and the output disc holder 40 of the second clutch E2.

A third axial bearing 53 is interposed between the outlet disk 40 and a spacer block 54. The spacer block 54, centered on the clutch support 140, is supported on the inner ring of the ball bearing 150.

The input disc holder 10 is common to the first and second clutch E1 and E2. The input disc holder 10 further comprises an outer disc holder 14 of the first clutch E1 and an inner disc holder 24 of the second clutch E2.

The external disc holder 14 of the first clutch E1 notably comprises an axial extension 15 arranged to receive the multidisk assembly of the first clutch and an annular portion extending radially inwards from the axial extension 15 in a plane perpendicular to the 'O axis.

The axial extension 15 forms an internal groove receiving the flanges 11 of the multidisk assembly of the first clutch E1.

The inner disc holder 24 of the second clutch E2 comprises an axial extension 25 arranged to receive the multi-disc assembly of the second clutch. The inner disc holder 24 has an annular shape.

The axial extension 25 forms an internal groove receiving the flanges 21 of the multidisk assembly of the second clutch E2.

We will now describe with reference to FIG. 4, an assembled disc holder 30 according to a second embodiment of the invention substantially similar to the first embodiment except that the internal bore 36 of the disc support 33 comprises circular portions 36a for centering.

The circular centering portions 36a are angularly distributed around the axis O, for example at an angle of 120 degrees. The circular portions extend at an angle between 10 and 60 degrees.

To ensure proper centering of the axial bearing 51, at least three circular portions are provided. The centering of the axial bearing 51 is done in this case by portions cut only by press tools. The precision of the cut is concentrated here on three zones instead of a circumference extending over 360 degrees. The manufacturing cost of this assembled disc holder is further reduced.

We will now describe the manufacture of the assembled disc holder 30, 40 according to the first embodiment of the invention as illustrated in FIGS. 1 to 3. The manufacture comprises, among other things, the following steps:

According to a first step, the hub 31, 41 and the disc support 33, 43 are manufactured separately, the disc support being only cut by a press tool.

According to a second step, the disc support 33, 43 is applied to the hub 31, 41 at the level of the overlap zone 37, 47.

According to a third step, the hub and the disc support are fixed together by laser welding by transparency at the overlap zone.

According to this process, laser welding by transparency avoids the use of axially bulky fixing rivets. The laser weld 39, 49 is continuous and extends circumferentially along the flange of the hub 31, 41.

The invention is not limited to the exemplary embodiments which have just been described. The disc holder assembled according to the invention may also be suitable for the cut-out clutch mechanism, of the KO type, used in hybrid transmissions to couple the heat engine to the electric motor after the vehicle has started up.

Claims (11)

1. Assembled disc holder (30, 40) for wet clutch mechanism, comprising: - a cylindrical hub (31, 41) of axis of rotation (O) comprising a bearing face (32, 42) perpendicular to the axis, - a disc support (33, 43) of revolution shape around the axis O comprising an axial extension (34, 44) arranged to receive the multidisk assembly of the wet clutch, an annular portion (35, 45) delimited by an internal bore (36, 46), extending radially inwards from the axial extension along a plane perpendicular to the axis (O) and partially covering the bearing face of the hub according to an overlap zone (37, 47), characterized in that the hub (31, 31) and the disc support (33, 43) are fixed together by laser welding by transparency at the level of the overlap zone and the internal bore (36, 46) of the disc support and the bearing face of the hub form a cavity (38, 48) capable of receiving and centering an axial bearing. 2. An assembled disc holder according to claim 1, wherein the inner bore (36, 46) of the disc holder is cut only by press tools. 3. An assembled disc holder according to claim 1 or 2, in which the hub (31, 41) comprises an annular flange of radial extension on which the bearing face (32, 42) is formed. 4. An assembled disc holder according to any one of claims 1 to 3, in which the internal bore (36, 46) of the disc holder defines a first diameter D1 along the axis O, and the bearing face ( 32, 42) of the hub comprises an external periphery defining a second diameter D2 along the axis O, the diameter D1 being less than the diameter D2. 5. An assembled disc holder according to any one of the preceding claims, wherein the inner bore (36, 46) of the disc holder comprises circular portions (36a, 46a) for centering. 6. An assembled disc holder according to the preceding claim, in which the circular portions (36a, 46a) for centering are distributed angularly around the axis O. 7. An assembled disc holder according to any one of the preceding claims, in which the axial extension (34, 44) of the disc holder (33, 43) is formed integrally with the annular portion (35, 45). 8. An assembled disc holder according to any one of claims 1 to 6, in which the axial extension (34, 44) of the disc support (33, 43) is attached and fixed in rotation with the annular portion (35 , 45). 9. Multidisk type wet clutch mechanism, controlled to selectively couple a shaft leading to a driven shaft, for example a gearbox shaft, comprising: - an assembled disc holder (30, 40) according to any one of the preceding claims; - a multi-plate clutch comprising flanges (11, 21) linked in rotation to a torque input disc holder and friction discs (12, 22) linked in rotation to a torque output disc holder, the holder - assembled disc (30, 40) constituting one or the other of the disc carriers; - an axial bearing (51) disposed axially between the torque input disc holder and the torque output disc holder characterized in that the axial bearing (51) is received and centered by the cavity (38, 48) formed in the assembled disc holder (30, 40). 10. Double wet clutch mechanism comprising a first clutch (E1) and a second clutch (E2) respectively of the multi-disc type, controlled to selectively couple a drive shaft to a first driven shaft and to a second driven shaft, the first and second clutches (E1, E2) being arranged radially one above the other, each of the multi-plate clutches comprising flanges (11, 21) linked in rotation to a torque input disc holder and friction discs (12 , 22) linked in rotation to a torque output disc carrier, the torque input disc carrier being common to the first and second clutch, characterized in that it comprises: - an assembled disc holder (30, 40) according to any one of the preceding claims, constituting one or the other of the torque output disc holders; - an axial bearing (52) disposed axially between the torque outlet discs of the first and second clutch, said axial bearing (52) being received and centered by the cavity (38, 48) formed in the assembled disc holder (30 , 40). 11. Method for manufacturing an assembled disc holder (30, 40) according to any one of claims 1 to 8, comprising at least the following steps: provide a hub (31, 41) and a disc support (33, 43) cut only by press tools, apply the disc support to the hub at an overlap area (37, 47), 5 - then fix the disc support (33, 43) together on the hub (31, 41) by laser welding by transparency at the level of the overlap zone.