FR3127792A1 - DAMPING MODULE WITH PRE-ASSEMBLED FITTINGS AND METHOD FOR MANUFACTURING SUCH A DAMPING MODULE - Google Patents

Abstract

DAMPING MODULE WITH PRE-ASSEMBLED LININGS AND METHOD FOR MANUFACTURING SUCH A DAMPING MODULE The invention relates to a damping module (4) and its manufacturing method, comprising at least the following steps: a) Hot forming a flange (5) comprising a central body (50), then clean the central body (50), b) Form by indentations in the material, two retaining discs (41, 42), - the indentation (414) of the first disc ( 41) being exempt from cleaning and gluing, - the depression (424) of the second disc (42) being either exempt from cleaning or cleaned to be suitable for receiving gluing, c) Providing and applying a first group of linings (G1 ), along a first friction zone (510) of the cleaned central body, d) Supplying and applying a second group of linings (G2) along a second friction zone (520) of the cleaned central body, or the depression (424) cleaned of the second disc (42), e) Fit the flange (5) between the depressions (414, 424) of the discs (41, 42), before fixing the discs (41, 42). Figure for abstract: FIGURE 3

Description

DAMPING MODULE WITH PRE-ASSEMBLED FITTINGS AND METHOD FOR MANUFACTURING SUCH A DAMPING MODULE

The invention relates to the field of kinematic chains, for mobility devices, such as for example a heavy goods vehicle, an agricultural vehicle, a public transport vehicle or even a hybrid vehicle.

The invention relates to a torque damping module, such as a torque limiter, fitted in particular to a dual mass flywheel. The invention also relates to a method of manufacturing such a damping module.

Torque limiters are known fitted to dual mass flywheels, both for transmitting torque from the engine to the wheels of the vehicle, and for damping the acyclisms generated by a combustion engine.

The document FR2752029 illustrates such a torque limiter, here composed of retaining plates inside which paper-type friction linings are fixed, to tighten a drive web between the two retaining plates. This avoids, thanks to the linings, direct metal-metal contact and premature wear of the parts of the limiter.

The friction linings are cut by press from rolls of paper, in the form of circular rings, but with small and very variable thicknesses, and they are also fixed on the two retaining plates.

The two retaining plates thus each receive a friction lining, and are produced by hot forming before then being cleaned (to remove any impurities before fixing the linings). The losses of material are also important and expensive, with binding manufacturing steps to respect. These same steps are also reproduced for the training veil, in order to guarantee a low surface defect compatible with the plates.

All these hot forming steps are complex and expensive to perform, with a significant logistics flow, and a greater number of specific steps and tools required. Incorrect design or imprecise assembly can damage and prematurely wear the linings (burrs, jamming, geometry of the linings), especially during operation on a vehicle, with jerky movements between the drive veil and the retaining plates ("Stick and Slip", stuck and slipped in English). Hence additional waste, costs and pollutants.

The object of the invention is to respond, at least in large part, to the above problems and also to lead to other advantages, by developing torque limiters that are economical, reliable, simple and quick to fit.

For this purpose, the invention proposes, according to a first aspect, a method of manufacturing a damping module, comprising at least the following steps:
a) Hot forming a drive flange comprising a central body,
then clean the central body so that it is suitable for receiving at least one bonding,
b) Forming by material depressions, a first and a second retaining disc,
- the material depression of the first retaining disc being exempt from cleaning and gluing,
- the depression of the material of the second retaining disc being
is exempt from cleaning and gluing,
is cleaned to be suitable for receiving gluing;
c) Supply and apply a first group of gaskets, glued and lubricated,
along a first friction zone of the cleaned central body,
so as to fix the first group of fittings on the drive flange;
d) Supply and apply a second group of gaskets, glued and lubricated,
along a second friction zone of the cleaned central body, so as to fix the second group of linings on the drive flange, or
along the cleaned material recess of the second retaining disc, so as to fix the second group of gaskets in the material recess of the second retaining disc;
e) Mount the drive flange between the material recesses of the first and second retaining discs,
before fixing the first and second retaining discs solidly together, for example by riveting.

Thanks to these characteristics, the number of cleaning steps for bonding the gaskets is reduced, since certain steps (hot forming and cleaning) associated with the bonding are already carried out to form the drive flange. By gluing at least one of the packing groups to the central body of the drive flange:
- At least one of the retaining discs is exempt from cleaning and sticking. This reduces the number of cleaning steps, or even hot forming (required for the bonding of fittings). Costs are therefore reduced.
- Transport stages and pollutant emissions (particularly CO2) are limited.
- The first retaining disc can be made by a simpler and more optimized process than hot forming, here by cold forming. Manufacturing is then simplified. Errors, rejects and material losses are reduced.

The invention also relates, according to a second aspect, to a method of manufacturing a damping module, comprising at least the following steps:
a) Hot forming a drive flange comprising a central body,
then clean the central body so that it is suitable for receiving at least one bonding,
b) Forming by material depressions, a first and a second retaining disc,
- the material depression of the first retaining disc being exempt from cleaning and from receiving gluing,
- the depression of the material of the second retaining disc being exempted from cleaning and from receiving gluing;
c') Supply and apply a first group of gaskets, glued and lubricated,
along a first friction zone of the cleaned central body,
so as to fix the first group of fittings on the drive flange;
d') Supply and apply a second group of gaskets, glued and lubricated,
along a second friction zone of the cleaned central body,
so as to fix the second group of linings on the drive flange;
e) Mount the drive flange between the material recesses of the first and second retaining discs,
before fixing the first and second retaining discs solidly together, for example by riveting.

Thanks to these characteristics, the number of cleaning steps for bonding the gaskets is reduced, since all the steps (hot forming and cleaning) associated with the bonding are already carried out for the drive flange. By gluing at least one of the packing groups to the central body of the drive flange:
- The two retaining discs no longer include any friction lining. Retaining discs are exempt from cleaning and gluing. This reduces the number of cleaning steps, or even hot forming (required for the bonding of fittings). Costs are therefore reduced.
- Transport stages and pollutant emissions (particularly CO2) are limited.
- The retaining discs can be made by simpler and more optimized processes than hot forming, here by cold forming. Errors, rejects and material losses are reduced. The retaining discs can be designed in a simplified manner, in their most essential form, in order to reduce its bulk, its weight or even to simplify its assembly within such a device.

As an indication, we will prefer cold forming (using a die, punch) to quickly produce parts with complex shapes, without loss of material or energy. Dimensional tolerances are guaranteed by the matrix (stable dimensions, effective interchangeability). The cold forming of retaining disc(s) is more advantageous and simple to carry out, for large production batches.
On the other hand, we will prefer hot forming to quickly produce parts having simplified geometric shapes, but also thicker and more rigid. Thus, hot forming of the drive flange is more advantageous and simple to carry out, for large production batches.
Thus, the steps are simplified, in terms of costs, risk of loss and need for tools.

The invention also relates, according to a third aspect, to a method of manufacturing a damping module, comprising at least the following steps:
a) Hot forming a drive flange comprising a central body,
then clean the central body so that it is suitable for receiving at least one bonding,
b) Forming by material depressions, a first and a second retaining disc,
- the material depression of the first retaining disc being exempt from cleaning and gluing,
- the depression of the material of the second retaining disc being cleaned to be adapted to receive a bonding;
c) Supply and apply a first group of gaskets, glued and lubricated,
along a first friction zone of the cleaned central body,
so as to fix the first group of fittings on the drive flange;
d) Supply and apply a second group of gaskets, glued and lubricated,
along the cleaned material recess of the second retaining disc, so as to fix the second group of gaskets in the material recess of the second retaining disc;
e) Mount the drive flange between the material recesses of the first and second retaining discs,
before fixing the first and second retaining discs solidly together, for example by riveting.

Thanks to these characteristics, the number of cleaning steps for bonding the fittings is reduced, since certain steps (hot forming and cleaning) associated with the bonding are already carried out for the drive flange. By gluing at least one of the packing groups to the central body of the drive flange:
- The first retaining disc is exempt from cleaning and gluing. The number of hot forming and cleaning steps (required for bonding the first group) is reduced. Costs are therefore reduced.
- Transport stages and pollutant emissions (particularly CO2) are limited.
- The first retaining disc can be made by cold forming, which is a simpler and more optimized process than hot forming. Manufacturing is then simplified. Errors, rejects and material losses are limited.

This first, second and/or third aspect of the invention may have one or other of the characteristics described below combined with each other or taken independently of each other:

– According to step c), the first group of linings can be made by cutting out a plurality of friction segments; The segments of the first group of linings can be spaced apart along the first friction zone of the central body, so as to cover less than 90%, preferably between 30% and 70%, of the first friction zone;

– According to step d), the second group of linings can be produced by cutting out a plurality of friction segments; The segments of the second group of trims can be spaced:
- along the second friction zone of the central body, so as to cover less than 90%, preferably between 30% and 70%, of the second friction zone, or
- Along the recess of the material of the second retaining disc, so as to cover less than 90%, preferably between 30% and 70%, of the second friction zone.

– According to step e), the depressions of the first and second retaining discs can delimit the bottom of a housing inside which the drive flange is mounted, preferably by tight fitting. The tightening of such a flange occurs in particular when fixing all the retaining discs, for example by riveting. We refrain from any drilling or additional fixing means for the assembly of such a flange.

– According to steps e) d), the second group of linings, and in particular its segments, can cover the second friction zone more than the first group of linings covers the first friction zone; In particular, said friction zones, and in particular said groups of linings, can be radially coincident, that is to say that a part of each of the two friction zones are arranged axially opposite each other;

– The segments of the same group of fittings can be arranged according to a regular or uniform distribution;

– The number of segments of the same group of fittings can be between three and fifteen segments;

– The segments of the same group of fittings can be of identical and/or complementary shapes;

– The second friction zone can be arranged radially further inside the housing than the first friction zone. At least one of the first and second friction zones can be defined radially between 25% and 55% of the central body. Thanks to a friction set at 25% or more, the actuating force is exerted on a large support surface and no longer on a linear support. We limit the non-essential parts to the friction of the central body of the bridle. Hence a slipping torque and an improved coefficient of friction for the limiter;

– The first friction zone can be defined radially on 25% to 55% of the central body. Hence a larger contact surface, and greater friction, between the central body and the first disc;

– The second friction zone can extend radially between 25% and 55% of the central body. Hence a larger contact surface, and greater friction, between the central body and the second retaining disc; In all cases, the most important part of the central body is provided for the support of the linings.

– The first and second friction zones may together cover half or more of the central body of the flange. This limits the radial size and the cost of material.

– The friction zones, and in particular the groups of linings, can be offset circumferentially with respect to one another. The friction is then exerted in distinct and spaced zones of the central body;

– The segments of the first trim group can be circumferentially offset from the segments of the second trim group. By way of example, the segments of the first group can be staggered with respect to the segments of the second group;

– The first and second friction zones, and in particular the groups of linings, can be spaced radially with respect to each other, for example according to a predefined separation distance. By way of example, the first friction zone can be arranged radially opposite the second friction zone. By moving them away from each other, a better hold is possible by friction around the central body of the tightly mounted flange;

The invention also relates, according to a fourth aspect, to a damping module for a dual mass flywheel, comprising:
- a drive flange, with axis X of revolution,
comprising a central body of radial elongation delimited between
a first lateral face, on which a first annular friction zone is formed, and
a second lateral face, on which a second annular friction zone is formed,
- first and second retaining discs each comprising a depression of material delimiting a housing, inside which the central body is received,
the drive flange supporting damping means radially beyond the housing,
- two groups of friction linings,
the first group of gaskets being fixedly assembled
on the first friction zone of the central body,
so as to cooperate by friction with the first retaining disk, and
the second group of gaskets being fixedly assembled
on the second friction zone of the central body,
so as to cooperate by friction with the second retaining disc,
Or
on the material depression of the second retaining disc,
so as to cooperate by friction with the second friction zone of the central body.

The manufacture of the damping module is simplified, given that the drive flange comprises at least one group of linings preassembled fixedly on the central body. At least one of the retaining discs is free of friction lining. In other words, by sticking at least one of the two groups of trims on the central body:
- We are freed here, for at least one of the retaining discs, of the associated bonding, cleaning and hot forming constraints. The manufacturing and transport stages are limited.
- Pollutant emissions (particularly CO2) are limited. Costs are therefore reduced.
- The first retaining disc can be made by a simpler and more optimized process than hot forming, here by cold forming. At least one of the discs can be designed in a simplified manner, in its most essential form, in order to reduce its bulk, its weight or even to simplify its assembly within such a device. Errors, rejects and material losses are reduced.

This fourth aspect of the invention may have one or other of the characteristics described below combined with each other or taken independently of each other:

– According to one embodiment of the invention, the second lining group can be fixedly assembled on the second friction zone, so as to cooperate by friction with the second retaining disc.
Here, double bonding is carried out on one and the same part, by pre-assembling the groups of linings only on the drive flange (instead of the retaining discs). The complex hot forming and cleaning steps associated with bonding are limited to one and the same part (drive flange). It is freed from the constraints of hot forming to make the retaining discs, which can be made by simpler and optimized processes, such as for example by cold stamping. The manufacturing steps are optimized.
This embodiment can be realized by the manufacturing method of the first aspect of the invention.

– According to another embodiment of the invention, the second lining group can be preassembled fixedly in a recess of the second retaining disc, so as to cooperate by friction with the second friction zone. It is possible, by keeping a group of lining on one of the retaining discs, to avoid any risk of tearing, shifting, geometric defects or jamming… associated with the transport and assembly of the linings. During the fixing of the second group of lining (by gluing and application), it is advantageously possible to rectify the burrs and to adjust the radial position of the group of lining on the second retaining disc. The manufacturing steps are optimized. This mode can be realized by the manufacturing method of the second aspect of the invention.

– The groups of linings can be segmented, or alternatively continuous angularly around the axis X. At least one of the first and second groups of linings can be formed from a plurality of friction segments;

– The first group of linings can be made of a plurality of friction segments;

– The second group of linings can be made of a plurality of friction segments;

– Each lining group can be formed by a plurality of friction segments. The groups of linings can each be formed of friction segments, for example an identical number of friction segments comprised between three and fifteen segments. The manufacturing and gluing stages are simplified and standardized;

– The friction rings of the same group of linings can be
- contiguous or spaced circumferentially;
- of identical and/or complementary shape;
- made by cutting out the same roller or friction material;
- glued and lubricated beforehand
- Applied spaced circumferentially from each other;
- applied along a corresponding friction zone of the central body of the drive flange;

– At least one of the first and second friction zones may be less than 90% covered by said corresponding group of linings, in particular covered between 30% and 70% by said group of linings:
- The first friction zone may be covered less than 90%, preferably between 30% and 70%, by the first group of lining, and in particular by the friction segments of said first group of lining; and or
- The second friction zone may be covered less than 90%, preferably between 30% and 70%, by the second group of linings, and in particular by the friction segments of said second group of linings;
Friction material (paper type) and liquid assembly resin (bonding type) are saved. Quantities are limited, costs are reduced, without impacting the performance of the damping module.

– The friction lining groups can be
- chosen from various friction materials, including paper or graphite or resin coating;
- lubricated before assembly, previously bathed in an oil bath.
Thanks to step e) of the first or second aspect of the invention, all the oil not absorbed by the linings will be expelled during the assembly operation. The lubrication of the packing groups is optimized;

– The friction zones, and in particular the groups of linings, can be of different sizes;

– The first and second packing groups may be identical, in at least
- the friction coating, preferably a coating compatible with grease lubrication,
- cutting from the same material,
- the number of segments,
- the shape of the cut, for example
rings of the same thickness or geometric shape,
an identical thickness or contour,
two rings made from the same sheet,

– By way of example, the friction rings of the same group of linings can be
- of identical or different dimensions. The friction segments of the same group of linings can be of complementary shapes. Their manufacture is then standardized, their assembly is simplified;
- distributed equidistantly, or according to a regular angular distribution. For example, two friction segments of the same group of linings can be mounted both spaced apart and nested one inside the other;

– The first and second trim groups can have
- an identical number of friction segments;
- friction segments of identical shapes, to standardize their manufacture;

– The first and second friction zones can be radially offset from each other. Thus the radial position of a group of linings, and in particular of the segments, is allowed within a certain zone (+/- 1 mm in relation to the internal and external diameters), which takes into account dimensioning and bonding errors;

– The drive flange can be housed inside the retaining discs, preferably pinched inside the two retaining discs. The retaining discs are then arranged axially on either side of the flange;

– The retaining discs can delimit a housing receiving the central body of the drive flange;

– The first and second packing groups can be arranged axially on either side of the flange;

– Thus, the first and second friction zones can be formed axially on either side of the flange;

– The housing can be made over 360 degrees around the X axis, to contain the drive flange over 360 degrees;

– Retaining discs can be made as an arch, cup, butt or tenon, or any other form of part with the end prepared for assembly. In particular, the two retaining discs can form the output member of the damping module. This allows both a better resistance of the support constraints and a low inertia generating neither resonance nor noise pollution in operation;

– The retaining discs and the central body of the drive flange, can form an axial stack.

– The two retaining discs can be fixed together by first fixing means, for example by riveting, so that the drive flange is mounted inside the retaining discs;

– The damping module may include at least one sealing washer. Said at least one sealing washer and the first and second retaining discs can be fixed integrally together, by first fixing means. A preassembled unitary subassembly of such components is produced, which is both inexpensive and combines several functions (sealing, torque limitation). The stages of assembly, transport and handling are simplified;

– By way of example, the sealing washer can be elastic or rigid, and/or be a dust-proof element and/or an oil deflector for said primary and secondary flywheels. Better lubrication and concentration of the hydraulic fluid circulation on the groups of seals are guaranteed;

– The retaining discs can each comprise a support means, made in one piece inside said depressions, in particular according to a mounting in abutment, so as to simplify the mounting of the drive flange. These support means can jointly delimit the bottom of the retaining supports, in other words the free space, inside which the drive flange comes into contact, in particular in radial support;

– At least one support means for a retaining disc may be a flat surface produced by folding material, in particular by forming a depression or a shoulder, or by one or more tangential strikes

– The retaining discs can have different external diameters, in order to distinguish them and simplify their assembly (correct positioning) vis-à-vis the primary and secondary flywheels. The inside diameter of the drive flange can be 1.3 times greater than the inside diameter of the first and/or second retaining disc. The difference in diameters guarantees the regular transmission of the engine torque, with a slip torque for example at least 2 times greater than the maximum engine torque;

– The drive flange can support damping means radially beyond the housing. The drive flange may include at least two external fingers supporting damping means;

– The drive flange can be a flexible or elastic washer, Belleville type. The advantage here is to reduce any risk of breakage, deterioration, and to apply a much greater load to prevent it from slipping between the retaining discs before a certain predefined torque.

The invention also relates, according to a fourth aspect, to a dual mass flywheel for a transmission chain, in particular a hybrid kinematic chain, comprising a damping module incorporating all or part of the characteristics described above, intended to transmit a torque and damping rotational acyclisms between a primary flywheel and a secondary flywheel,
the primary flywheel receiving the elastic members, and
the first and second retaining discs being fixedly connected to the secondary flywheel.

According to this aspect of the invention, the retaining discs can be assembled to the secondary flywheel by second fixing means, in particular by a series of fixing screws, bolts or rivets.

Advantageously, said at least one sealing flange can be fixed integrally
to the first and second retaining discs, with first fixing means on the one hand, and
to the secondary flywheel, with second fixing means on the other hand.

Advantageously, the first and second fixing means can be two distinct series of fixing screws, bolts or rivets, in particular spaced apart, along the axis X. Thus, the first and second means fixing can be arranged on implantation circles of different diameters.

According to this aspect of the invention, the dual mass flywheel may further comprise:
- a clutch mechanism; and or
- A torque transmission shaft, which may be a drive shaft coupled in rotation to a motor; and or
- a release bearing;

The invention also relates, according to a fifth aspect, to an assembly kit for a dual mass flywheel, comprising a damping module that can incorporate all or part of the characteristics described above.

According to this aspect of the invention, the assembly kit may further comprise:
- a running gear, a primary flywheel and a secondary flywheel; and or
- a torsion damper assembly, comprising for example springs; and or
- a clutch mechanism; and or
- A torque transmission shaft, which may be a drive shaft coupled in rotation to a motor; and or
- a release bearing;

The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of a particular embodiment of the invention, given solely by way of illustration and not limiting, with reference to the appended figures:
– is an axial section of a dual mass flywheel, comprising in particular a damping module such as a torque limiter, according to a first embodiment of the invention;
– is a perspective of the damping module according to the first mode illustrated in ;
– is a detailed perspective of the damping module according to the first mode illustrated in ;
– describes a method of manufacturing the damping module of the first embodiment;
– is an axial section of a damping module according to the first mode illustrated in ;
– is a perspective of the drive flange according to the first mode illustrated in ;
– To are different perspectives of a drive flange according to a second embodiment;
– is an axial section of the damping module according to a third embodiment of the invention
– are an axial section of the damping module according to a fourth embodiment of the invention;
– is a detailed perspective of the damping module according to the fourth mode illustrated in the ;
– is another axial section of the damping module according to the fourth embodiment;

By "mobility device", we mean any automobile, passenger vehicle, but also industrial vehicles, in particular heavy goods vehicles, public transport vehicles or agricultural vehicles, as well as any transport device making it possible to pass from one point to another a living being and/or an object. The latter may include a hybrid motorization, an electric motorization and/or low mobility.

Unless otherwise specified, “axially” means “parallel to the X axis of rotation of the damping module or dual mass flywheel”; "radially" means "along a transverse axis intersecting the axis of rotation of the damping module or of the dual mass flywheel"; “Angularly” or “circumferentially” means “around the axis X of rotation of the damping module or the dual mass flywheel”.

In the following description and claims, certain elements can be indexed such as: the first and second retaining discs, the first and second fixing means, the primary or secondary flywheels. It is a simple indexing to differentiate and name close but not identical elements. Indexing does not imply a priority of one element over another and one can easily interchange such denominations without departing from the scope of the description.

The terms “inner/internal” or “outer/external” with respect to the X axis and in a radial orientation, orthogonal to said axial orientation will be used without limitation and in order to facilitate understanding thereof; and the terms "rear" AR and "front" AV to define the relative position of one element with respect to another in the axial direction, an element intended to be placed close to the heat engine being designated rear and an element intended to be placed close to the gearbox being designated by front. The thicknesses are measured along the X axis of rotation.

FIGURES 1 to 6 illustrate a first embodiment of the invention. By referring to the , there is a damping system called double mass flywheel 1 of a transmission chain, which comprises:
- a primary flywheel 2 of inertia, intended to be fixed to a driving shaft, such as a crankshaft of a combustion engine, and
- a secondary flywheel 3 of inertia, which is centered and guided on the primary flywheel 2 by means of a rolling member called bearing 6, such as a centering bearing for the secondary flywheel 3, and
- a series of elastic members 40 forming the damping means, both to transmit the torque, to dampen the acyclisms between primary and secondary flywheels (and to reduce the vibrations coming from the engine); And
- a torsion damping module 4, of the torque limiter type, receiving the elastic members 40.

In operation, the elastic members 40 are pressed outwards against the cylindrical portion 23 by the centrifugal force acting on them. These elastic members 40 are curved, with a circumferential effect, such as helical springs, housed in the annular chamber 28 and distributed circumferentially around the axis X.

Therefore, guide members, in the form of chutes 400, are mounted in the annular chamber 28, between the cylindrical portion 23 of the primary flywheel 2 and the outer periphery of the elastic members 40.

The chutes 400 are each formed of a longitudinally and transversely curved sheet.

Furthermore, the primary 2 and secondary 3 inertia flywheels are mounted movable relative to each other, in particular movable around an axis X of rotation. In addition, the primary flywheel 2 of inertia has:
- a primary central hub 25, radially internal, carrying the bearing 6 with the secondary flywheel 3,
- an annular portion 22 called primary mass, extending radially and
- a cylindrical portion 23 extending axially, on the side opposite the engine, from the outer periphery of the annular portion 22. The primary flywheel 2 also comprises an annular cover 24 fixed to the cylindrical portion 23. The annular cover 24 defines with the annular portion 22 and the cylindrical portion 23, an annular chamber 28.

In addition, the cover 24 is fixed integrally to the cylindrical portion 23, in particular by welding 24A.

Furthermore, the primary flywheel 2 carries, on its outer periphery, a ring gear 26 for driving the primary flywheel 2 in rotation, using a starter. On the , orifices 259 are formed on the central hub 25 opposite orifices 229 formed in the radially inner portion of the annular portion 22.

Furthermore, the primary flywheel 2 carries, on its annular portion 22, an added inertia member 26', in order to increase the resulting inertia of the primary flywheel. Alternatively, not shown, this 26′ inertia member may be a crown.

The secondary flywheel 3 may include orifices, intended for the passage of the screws, when mounting the double damped flywheel on the driving shaft. In addition, the primary flywheel 2 comprises through openings 27 for mounting in the annular portion 22, to handle and mount fastening means 72. For this purpose, these through openings 27 are designed as breakthroughs at the level of the fastening means 72 and, after assembly, are sealed by means of sealing plugs 57 pressed into the through openings 27, for optional closure.

Furthermore, the secondary flywheel 3 comprises:
- a hub 35 or secondary flange, radially internal, centering the bearing 6,
- an annular portion 32 called secondary mass, extending radially and
- a cylindrical portion called the outer edge 33 extending axially, on the side opposite the motor, from the outer periphery of the annular portion 32.

Furthermore, the secondary flywheel 3 is intended to form the reaction plate of a clutch, not shown. The dual mass flywheel may also include a clutch mechanism, further comprising:
- a cover, fixed to the outer periphery of the secondary flywheel, and at least one clutch disc, fitted with friction linings and a splined hub connected to the transmission shaft,
- a pressure plate and an annular diaphragm axially urging the pressure plate towards the secondary flywheel. The pressure plate can be connected in rotation to the cover by tangential elastic tabs, with axial action allowing axial movement of the pressure plate relative to the reaction plate; And
- A clutch thrust bearing capable of pivoting the diaphragm to move the clutch towards its disengaged position.

Furthermore, the secondary flywheel 3 has, near its outer edge 33, holes 330 used to mount the cover of the clutch mechanism, by means of studs.

In the examples illustrated, the cover 24 is radially opposite the secondary hub 35 .

Furthermore, the damping module comprises at least:
- a torque input member 4A, here a drive flange 5, capable of cooperating with the elastic members 40,
- a torque output member 4B (also called a phasing member) which is made up of several parts, here a first and a second retaining disc 41, 42, in order to cooperate by friction with the flange 5 of coaching.
- Two groups of friction linings G1, G2 mounted on the input member and/or the output member 4B.

This damping module 4 is pre-assembled, as shown in the , so as to form a unitary subassembly, simple to transport and handle. Furthermore, each curved elastic member 40 may comprise two coaxial springs mounted one inside the other.

In the examples illustrated, the elastic members 40 extend:
- on the one hand, between two support legs 59, called training legs, formed on the drive flange 5, and
- on the other hand, between two support seats 220 carried by the primary steering wheel 2. Each support seat 230 is constituted by a boss formed in the annular portion 22 and by a boss formed in the cover 24.

In operation, the elastic members 40 are supported, at a first end, against a support seat 220 carried by the primary flywheel 2 and, at a second end, against a lug 59 provided on the drive flange 5, to ensure the torque transmission between the primary flywheel 2 and the damping module 4.

Thus, the torque is transmitted by the crankshaft to the primary flywheel 2 which compresses the elastic members 40. The latter, resting on the tabs 59, drive the drive flange 5, compressed, which cooperates by friction with the discs 41, 42 restraint. Furthermore, the output member 4B, and in particular the retaining discs 41, 42 are fixed integrally to the secondary flywheel 3. These retaining discs 41, 42 in turn drive the secondary flywheel 3.

To limit friction between the elastic members 40 and the primary flywheel 2, the annular chamber 28 is filled with a lubricating agent, preferably grease or oil. The damping module 4 further comprises at least one washer 58 ensuring the sealing of the primary and secondary flywheels, to prevent lubricant leaks to the outside of the annular chamber 24. In the examples illustrated, a single washer 58 d The sealing extends radially between the cover 24 and the secondary hub 35.

In addition, this sealing washer 58 extends radially between an inside diameter DF1 and an outside diameter DF2, in a stepped form. In the first mode, the sealing washer 58 further comprises a first and a second sealing sections axially offset from each other,
- A first section resting on the lid 24; And
- a second section inserted axially bearing between the output member 4B and the secondary hub 35

The sealing washer 58 is axially interposed and tightly mounted, in other words sandwiched, between one of the retaining discs and the hub 35, in particular by riveting. The sealing washer 58 is fixed together:
- On the one hand, with the first retaining disc 41, using first fixing means 71; And
- on the other hand, with the secondary steering wheel 3, using second fixing means 72;

In an embodiment not illustrated, the damping module may comprise a plurality of washers 58, for example two sealing washers 58 arranged axially on either side of the cover 24.

On the the damping module is partially illustrated, with the input member which is tightly mounted inside the output member 4B. The retaining discs 41, 42 (constituting the output member 4B) are made from discoidal sheets, in particular by driving in 414, 424 material, so as to produce arcuate shapes (of the cup type or having butts) radially external.

Furthermore, the retaining discs 41, 42 delimit a free space called housing 8, which receives the central body 50.

The housing 8 is jointly delimited by the depressions 414, 424 of material of the two retaining discs 41, 42. The relative rotation between the retaining discs 41, 42 and the drive flange 5 is limited in order to protect the latter in the event of overtorque. In the examples considered, the drive flange 5:
- is made of a material of the elastic or flexible type;
- Is a drive plate, of rotational symmetry, preferably discoidal and of axis X;
- comprises an annular base called the central body 50, and external tabs 59, here two in number, extending radially from a central body 50. The tabs 59 cooperate circumferentially with the elastic members 40, which are supported radially beyond of housing 8.

By way of example, these retaining discs 41, 42 are made of steel.

In order to avoid any risk of breakage of the flange 5, the housing 8 allows the flange 5 to slip relative to the two discs 41, 42 under overtorque conditions. To do this, the housing 8 defines a final axial difference L0, strictly greater than the thickness of the flange 5, in particular the thickness Ep0 of the central body 50, in order to ensure its sliding.

In the examples considered, the central body 50 of the drive flange 5 can be
- solid in shape (ie exempt from windows or grooves) and flat, linear, contained in a plane P,
- Delimited axially between a first and a second side faces 51, 52;
- Delimited radially between an inner diameter D1 and an outer diameter D2.
- Mounted radially inside the housing 8, in particular mounted tightly in the housing 8;
- mounted perpendicular to the X axis, that is to say here contained in a plane P of symmetry. This plane P is defined for the assembly of symmetrical parts of the module (here the retaining discs);
- Distinguished from a drive sail, in that the central body 50 of the flange is radially thinned, ie having an inside diameter D1 greater than that of a simple drive sail.

In the examples considered, each retaining disc 41, 42 may comprise:
- a solid shape, ie exempt from windows and circumferentially continuous over 360 degrees;
- a radially internal central core 410, 420, intended for the assembly of said module, provided:
- orifices 411, 421 coaxial for the passage of first fixing means 71, here eighteen in number; And
- orifices 412, 422 coaxial for the passage of second fixing means 72, here nine in number;
- A central bore 416, 426 defining the inner diameter D11, D11 of said disc, intended to receive part of the bearing 6 and of the central hub 25;
- a recess 414, 424 of radially outer material, which preferably:
- is made in the form of an arc or about, configured to delimit the housing 8
- Is slightly inclined angularly relative to the central core 410, 420, and laid flat with the drive flange. A better contact surface is then obtained between the groups of linings G1, G2 and the side faces 51, 52 of the drive flange 5, regardless of the dimensioning tolerances.

Furthermore, each central core 410, 420 is equipped with discontinuous bearing surfaces 415, 425, which are
- made by forming, for example by striking material, in one piece with the central core 410, 420,
- Arranged for mounting the drive flange, in particular defining the bottom of the housing 8;
- here shoulders or folds of material, intended to center the inner diameter D1 of the flange 5;
- Here nine in number, angularly spaced around the X axis;

The two retaining discs 41, 42 are preferably produced separately, with different geometries by at least: the radial elongation, the thickness, the inside and outside diameters. In a variant not shown, the retaining discs can be of identical thicknesses and/or shapes, to simplify their manufacture.

Advantageously, the first retaining disc 41 may comprise:
- A radial elongation, which is of greater size than that of the second retaining disc 42;
- A depression 414, which is larger in size than the second retaining disc 42;
- An outer diameter D12 of dimension greater than the outer diameter D22 of the second retaining disc 42;
- A thickness Ep1 which is greater than the thickness Ep2 of the second disc 42. The thickness Ep1, Ep2 of a retaining disc 41, 42 is substantially the same all along said part. The thicknesses Ep1, Ep2 of the retaining discs 41, 42 can be between 0.5 and 2 mm, preferably around 0.8 mm.

In the first mode, the first retaining disc 41 is arranged on the gearbox side, axially closest to the secondary flywheel 3. The second disc 42 is arranged on the engine side, furthest from the secondary flywheel 3.

Furthermore, the sealing washer 58 further comprises:
- Holes 581, here eighteen in number, coaxial with the holes 411, 421 for the first fastening means 71; And
- Holes 582, here nine in number, coaxial with the holes 412, 422 for the second fastening means 72;
Therefore, these openings 411, 421, 581 and 412, 422, 582 are here bores of said parts, at least some of which can be formed in pairs symmetrically with respect to the axis of each opening.

Furthermore, the first fixing means 71 ensure the assembly of the retaining discs and of said sealing washer, so as to form a unitary sub-assembly. Therefore, it is possible that:
- the orifices 411, 421 and the holes 581 are of identical shape, having the same area, here crossing, aligned according to the same implantation circle C1' and coaxial with axes R1. The mounting axes R1 are parallel with respect to the X axis;
- The first fixing means 71 ensure the assembly and tight mounting of the drive flange with the discs 41, 42, during the pre-assembly of the components of the damping module 4;
- the first fastening means 71, here rivets, can be defined by a circle C1' of the openings 411, 421, 581, formed in the central webs 410, 420, which receive said rivets.

Furthermore, the second fixing means 72 ensure the assembly of the damping module on the secondary flywheel 3. As a result, it is possible that:
- the orifices 411, 421 and the holes 581 are of identical shape, having the same area, here crossing, aligned according to the same implantation circle C2' and coaxial with axes R2. The mounting axes R2 are parallel with respect to the X axis;
the secondary hub 35 may comprise a mounting interface receiving the second fixing means 72, also consisting of orifices 352 passing through axes R2;
- the second fastening means 72, here rivets, can be defined by an implantation circle C2' of the openings 412, 422, 582 receiving said rivets, also defined on the central cores 410, 420.

In the examples illustrated, the implantation circles C1', C2' are of different diameters.
In particular, the circle of implantation C1' surrounds the circle of implantation C2'.

To avoid direct metal-metal contact and premature wear, first and second groups of friction linings G1, G2 are arranged between the input and output members 4B, further ensuring the coupling of the parts.

To better dispose of such groups of linings G1, G2, first and second friction zones 510, 520 are previously defined and delimited on parts of the central body 50. In the examples illustrated:
- A first friction zone 510, of the annular type, is delimited along the first side face 51 of the central body, inside which is located radially the first group of friction linings G1; And
- A second friction zone 520, of the annular type, is delimited along the second side face 52 of the central body, inside which the second group of friction linings G2 is located radially.

In particular, the first friction zone 510 is continuous around the axis X and it is delimited radially between an inside diameter D1' and an outside diameter D1''. The first lining group G1 extends radially along a height h1, and it covers in the radial direction the entire first friction zone 510. The height h1 is defined by the space between the inside diameters D1' and outside diameters D1 '' of the friction zone 510.

In particular, the second friction zone 520 is continuous around the axis X and it is delimited radially between an inside diameter D2' and an outside diameter D2''. The second group of lining G2 extends radially according to a height h2, and it covers in the radial direction the entirety of the second friction zone 520. The height h2 is defined by the space between the inner diameters D2' and outer diameters D2 '' of the friction zone 520.

To avoid stict-slip phenomena, groups of friction linings G1, G2 consist of wet friction linings, suitable for bathing in an oil-type fluid. In addition, the prior fixing of the groups of gaskets G1, G2 is carried out by impregnation or application of a liquid resin, here by bonding (resin type adhesive) or by any other means of assembly not illustrated (including riveting). In particular, each group of packing G1, G2 can receive or be impregnated beforehand with a liquid resin, before being applied to another component of the module.

In particular, in the illustrated examples:
- The first group of fittings G1 can be arranged along a different implantation diameter from that of the second group of fittings G2
- The first friction zone 510 is delimited below the outer diameter D2 of the central body 50;
- The first group of linings G1 is arranged below the outer diameter D2 of the central body 50, in particular along a first circle of installation C1 of linings, centered on the axis X. The first group of linings G1 is spaced apart and distant from the inner and outer diameters D1 and D2 of the central body 50;
- As a result, the radial position of the packing group G1 is allowed in a certain zone ΔS1 (+/- 1 mm relative to the outer diameter D2 of the central body), which takes into account errors in dimensions and fixing;
- The second friction zone 520 is delimited below the inside diameter D1 of the central body 50;
- The second group of linings G2 is arranged below the inner diameter D1 of the central body 50, in particular along a second circle of installation C2 of linings, centered on the axis X. The second group of linings G2 is spaced apart and distant from the inner and outer diameters D1 and D2 of the central body 50;
- As a result, the radial position of the packing group G2 is allowed in a certain zone ΔS2 (+/- 1 mm relative to the internal diameter D1 of the central body), which takes into account errors in dimensions and fixing;
- The second group of linings G2 is closer to the X axis than the first group of linings G1;
- The implantation circles C1, C2 are of different diameters;
- The first circle C1 for installing the linings is formed in the first friction zone 510;
- The implantation circle C1, and in particular the inner diameters D1' and outer diameters D1'' of the friction zone 510, are radially distant from the inner diameters D1 and outer diameters D2 of the central body;
- The second implantation circle C2, and in particular the inner diameter D2' and outer diameter D2''' of the second friction zone 520, are radially distant from the inner diameter D1 and outer diameter D2 of the central body.

The second friction zone 520 is disposed radially further inside the housing 8 than the first friction zone 510. In a variant not shown, the second friction zone can surround the first friction zone.

Furthermore, the groups of linings G1, G2 can be arranged radially contiguous or spaced apart.

In the first mode, the drive flange 5 is remarkable in that it is hot formed. The retaining discs 41, 42 are remarkable in that they are, conversely, cold formed. By stages we mean:
- hot or cold "forming": any operation of crushing, plastic deformation of material, carried out by impact or pressure, using appropriate tools, to make it fit a given shape, without breaking the fibers of the metal, in particular on the radially outer and/or inner periphery. In the examples shown:
- The forming of the retaining discs 41, 42 produces the depressions 414, 424 and/or the additional end 90;
- The forming of the drive flange 5 produces the central body 50 and/or the legs 59;
- "cold" forming: stamping, bending, cold forging, extrusion, cold stamping, drawing, drawing (for example of stainless steel fibres), bending-rolling, hammering, etc.;
- "hot" forming: stamping, stamping, stamping, forging, hot shrinkage;

Furthermore, the first group of lining G1 is remarkable in that it is preassembled fixedly on the central body 50 of the flange 5, here on the first friction zone 510. The first group of lining G1 is arranged so as to cooperate with the first retaining disc 41, in particular with the interior of the depression 414.

Incidentally, the second trim group G2 is remarkable in that it is fixedly pre-assembled:
- either on the central body 50, here on the second friction zone 520. Thus fixed, the second group of lining G2 is intended to cooperate with the second retaining disc 42, here with the interior of the depression 424 of the disc 42.
- Either within the recess 424 of material of the second retaining disk 42. Thus fixed, the second group of lining G2 can cooperate with the second friction zone 520, in particular here covering it.
In FIGURES 6-10 and 15, the second implantation circle C2 is formed in the second friction zone 520. In FIGURES 11-13, the implantation circle C2 is formed inside the depression 424 of material

In order to save quantities of friction materials and resin, it is possible that
- the first group of linings G1 covers in the circumferential direction part of the first friction zone 510, in particular less than 90% of the first friction zone 510 (see FIGURES 3, 7-9, 12, 15); and or
- the second group of linings G2 covers in the circumferential direction part of the second friction zone 520, in particular less than 90% of the second friction zone 520 (see FIGURES 3, 7-9, 12, 15).

By “covering” a friction zone, is meant any lining that can be assembled or that can cooperate with said friction zone. We can then define by
- “surface n1” the sum of the parts of the first friction zone 510 covered by the first group of linings G1, the surface n1 thus being less than 320 degrees around the axis X;
- “surface n2” the sum of the parts of the second friction zone 520 covered by the second group of linings G2, the surface n2 thus being less than 320 degrees around the axis X;

To do this, the first group of linings G1 can advantageously be formed of a series of segments 100 over which the friction linings are distributed. Similarly, the second group of linings G2 can be formed from a series of segments 200 over which the friction linings are distributed.

Advantageously, the friction segments 100 can be contiguous or spaced apart circumferentially around the axis X, according to a regular or uniform distribution. The friction segments 200 can be contiguous or spaced apart circumferentially around the X axis, according to a regular or uniform distribution.

The friction segments 100, 200 are made by cutting out from the same material, from the same sheet or roll. The segments 100, 200 can then include at least one of the following characteristics:
- the same friction lining, preferably a wet friction lining. In particular, the segments 100, 200 can be made from the same paper impregnated with a resin and compatible with grease lubrication;
- the same thickness, substantially constant, of the order of 0.5 mm (+/- 0.05);
- the same geometric outline, by cutting out identical geometric shapes (same pattern).

By way of example, each segment 100, 200 comprises the same circumferential elongation L1, L2, and/or the same radial elongation called height h1, h2. As a variant not shown, the circumferential elongations L1, L2 and/or the heights h1, h2 of the segments can be of different dimensions.

In the first mode, the packing groups G1, G2 are radially spaced from each other. For this reason:
- The segments 100 can be circumferentially offset from the segments 200;
- By way of example, the segments 100, 200 can be arranged in quincunx;
- The radial difference between the groups of linings G1, G2 is allowed in a certain zone ΔS (+/- 1 mm with respect to the friction zones 510, 520), which takes into account errors in dimensions and fixing;
- The first friction zone 520 can surround the second friction zone. Home circle C1 surrounds home circle C2. The second group of linings can then surround the first group of linings;
- The area n2 can be larger than the area n2. In other words, the second group of linings G2 can cover the second friction zone 520 more than the first group of linings G1 covers the first friction zone 510.

In the first mode, we observe that:
- The packing groups G1, G2 can be circumferentially offset from each other. For this reason:
- The first group of linings G1 covers substantially 40% to 50% of the first friction zone 510, preferably half of the first friction zone 510. Consequently, the surface n1 extends over 144 to 180 degrees around the X axis. The packing group G1 may extend discontinuously in the circumferential direction.
- The segments 100, here seven in number, are arranged along the implantation circle C1, here according to a regular angular distribution of approximately 50 degrees.
- The second lining C implantation circle is formed in the second friction zone 520;
- The second group of linings G2 covers substantially 40% to 50% of the second friction zone 510, preferably half of the second friction zone 520. Consequently, the surface n2 extends over 144 to 180 degrees around the X axis. The packing group G2 can extend discontinuously in the circumferential direction
- The segments 200, here seven in number, are arranged along the implantation circle C2, according to a regular angular distribution of approximately 50 degrees.

Furthermore, the support and the axial holding of the inner ring 61 of the bearing 6 are done directly:
- By an annular bead of material 250 of the primary flywheel 2 on the one hand, serving to support the inner ring 61 of the bearing 6 and retaining the end face of said inner ring, in the direction of the engine;
- By a support disc 7 on the other hand, serving to support the inner ring 61 of the bearing 6 and retaining the end face of said outer ring, in the opposite direction to the motor;

Such a bead of material 250 is formed on the outer periphery of the central hub 25 of the primary flywheel 2. This bead of material 250 may for example be a collar, a flange, a collar or a base. Thus, the inner diameter of the bearing 6 is fixedly mounted between the primary flywheel 2 and the support disc 7.

Furthermore, the support and the axial holding of the outer ring 62 of the bearing 6 are done directly:
- By a shoulder 350 of the secondary flywheel 3 on the one hand, serving to support the outer ring 62 of the bearing 6 and retaining the outer diameter of said outer ring, in the opposite direction to the engine;
- by an axial stop component 9 of the damping module 4 on the other hand, serving to support the outer ring 62 of the bearing 6 and retaining the outer diameter of said outer ring, in the direction of the motor;

Such a shoulder 350 is formed on the inner periphery of the hub 35 of the secondary flywheel 3. Thus, the outer diameter of the bearing 6 is fixedly mounted between the secondary flywheel 3 and the damping module 4.
In the examples illustrated, the torque output member 4B and the bearing 6 are arranged radially one above the other. In a variant not shown, the rolling member can be replaced by a plain bearing.

The stop component 9 of the bearing is remarkable in that it:
- Can be chosen from the components of the damping module 4, except the drive flange 5, or here from one of the retaining discs 41, 42 and the at least one sealing washer 58. In the first mode, the stop component 9 is formed by the retaining disc furthest from the secondary flywheel, here disc 42.
- comprises an additional radially internal end 90, which is modified beforehand, by deformation of material and/or shrinkage of material for better retention of the bearing. In addition, the additional end 90 delimits with the other components of the damping module 4, an internal housing 93, inside which the bearing 6 is received at least in part.

We will now describe the method of manufacturing a damping module 4, as illustrated for example in the first embodiment (see steps ). This production includes, among other things, the following steps:

According to a first step a), the drive flange 5 is produced (step 12) by hot forming, for example by stamping or stamping sheet metal 10. Thus a flange 5 is produced comprising a central body 50.
The drive flange 5 (newly hot-formed) is then cleaned (step 13) so that it is adapted to receive at least one bonding, in other words, to guarantee correct adhesion with the fittings to be bonded.

According to a second step b), a first and a second retaining disc 41, 42 are formed by indentations in the material, in the first mode by cold forming (step 11), for example by stamping sheets 10'.
During this step 11, an additional end 90 can be made on the second disc 42. The additional end 90 can then be made (according to at least one of the following characteristics):
- in an angularly discontinuous manner, or in a continuous variant around the X axis, in particular over 360 degrees;
- by a material deformation from the radially inner periphery of the disc 52, here by stamping;
- By an axial depression of material which is greater than the thickness Ep2 of the second retaining disk 52;
- Under a depressed and/or curved portion, here of a collar 95, in particular by producing a radius of curvature;
- in the form of a stop (for the bearing 6), consisting of an axial bearing surface 931 and a centering surface 932. The axial bearing surface 931 and the centering surface 932 delimit a housing 93 receiving at least partly the bearing, preferably part of the bearing 6 and of the hub 35 of the secondary flywheel.

In the first embodiment,
- The depression 414 of material of the first disc 41 is exempt from filling, cleaning and gluing.
- The depression 424 of material of the second disc 42 is exempt from filling, cleaning and gluing.

According to a third step c), a first group of linings G1, glued and lubricated, is provided.

According to a fourth step d), a second group of linings G2, glued and lubricated, is provided.
Such groups of linings G1, G2 are advantageously formed:
- a coating previously glued or impregnated with a fixing resin (here glue);
- A coating compatible with grease lubrication, in particular a paper impregnated with lubricant;

To do this, the manufacture of the fittings may contain the following steps:
- Formation of the friction material, in particular by: mixing powder, impregnation;
- Cutting (phase 15) during which a single friction material G is cut, here a continuous roll of friction material. These cutouts can advantageously form series of segments 100, 200, or alternatively not shown continuous rings; Any drilling in view of the fixing passage is here excluded;
- Deburring and grinding;
- Lubrication (phase 14) during which the groups of linings G1, G2 are lubricated before assembly, for example by bathing them beforehand in an oil bath. The oil is distributed over the entire surface of the linings (evenly), for example a minimum quantity of 0.4 g per group of linings G1, G2. Furthermore, all excess oil was removed during the assembly process of the fourth step d).

Each group of linings G1, G2 can then be glued, lubricated, before being applied (by axial support) to a support part, said group of linings then being fixedly assembled, thanks to mechanical gluing. Since then :
- According to a third step c), the cleaned central body 50 is applied along a first friction zone 510, fixing it solidly on the central body 50, in particular by pressure or by heat (phase 16). The group of fittings G1 and the central body 50 are then pressed against each other, before the fixing resin (here glue) deploys its adhesive force, in order to attach the first group of fittings G1 to the central body 50; And
- According to a fourth step d), the cleaned central body 50 is applied along a second friction zone 510, fixing it solidly on the central body 50, in particular by pressure or by heat (phase 16). The group of linings G2 and the central body 50 are then pressed against each other, before the fixing resin (here glue) deploys its adhesive force, in order to attach the second group of linings G2 to the central body 50.

Finally, according to a fifth step e), the drive flange 5 is mounted between the recesses 414, 424 of material of the retaining discs 41, 42, in particular by tight fitting. Such an arrangement includes:
- a first phase during which the two retaining discs 41, 42 are arranged first of all axially spaced apart, on either side of a plane P, in order to delimit a housing 8. The recesses 414, 424 are then axially spaced apart, and arranged in opposition, i.e. symmetrically with respect to the plane P.
- a second phase during which the flange 5 is housed inside the housing 8:
- In particular by pivoting (pivot supports) of the central body 50 on one and/or the other of the discs 41, 42;
- In particular by support in the bottom of the housing 8, in particular on the bearing surfaces 415, 425;
- A third phase during which the two retaining discs 41, 42 are then joined from the inside at the level of the central cores 410, 420, to reduce and adjust the space of the housing 8. In doing so, the depressions 414, 424 of material are axially close together, and the central body 50 is clamped inside the discs 41, 42;
- A fourth phase during which only the two retaining discs 41, 42 are connected using first fastening means 71, here a series of rivets, in order to form a unitary sub-assembly. In doing so, flange 5 is
- exempt from any additional means of attachment.
- Tight fit inside the retaining discs 41, 42, and in particular between the depressions 414, 424.
Advantageously, these fixing means 71 are inserted axially through the coaxial orifices 411, 421, 581, which are formed respectively in the supports 41, 42 and in the sealing washer 58.

There has been described in FIGURES 7 to 9, a second embodiment of the invention substantially similar to the first mode, with the exception of the fact that:
- Each segment 100, 200 is circumferentially continuous, and extends substantially in a C or annular O shape, that is to say (in particular for the elongation L1, L2) between 150 and 360 degrees around the x-axis;
- The first group of trims G1 is formed by a single segment ( to 8) or two segments 100 ( );
- The second group of trims G2 is formed by a single segment ( to 8) or two segments 200 ( );
Each group of linings G1, G2 can cover from 40% to the totality of the corresponding friction zone 510, 520.
In the example of the , the elongation L1, L2 of the segment 100, 200 is approximately 360 degrees.
In the alternative of , the elongation L1, L2 of a segment 100, 200 is approximately equal to 290 degrees.
In the alternative of , the elongation L1, L2 of a segment 100, 200 is approximately equal to 170 degrees.

It has been described on the , a third embodiment of the invention substantially similar to the first mode, except that the friction zones 510, 520, and in particular the groups of linings G1, G2:
- are radially merged. Thus a part of these friction zones 510, 520, and in particular of the groups of linings G1, G2, are arranged axially opposite one another;
- Overlap radially, in particular along a common zone ΔS' of the central body 50;
- Are arranged radially in the center of the central body 50 of the flange;

There has been described in FIGURES 11 to 13, a fourth embodiment of the invention substantially similar to the first mode, with the exception of the fact that:
- The second disc 42, and in particular the recess 424, is cleaned and receives the second group of trim G2;
- The drive flange 5 and the second retaining disc 42 are hot-formed;
- The second group of trim G2 is intended to cooperate with the second friction zone 520.
- In FIGURES 11-13, the implantation circle C2 is formed inside the depression 424 of the disc 42.
- In FIGURES 11-12, the second disc 42 is located on the engine side, furthest from the secondary flywheel 3.
- In the alternative of the , the first retaining disc 41 is arranged on the engine side, axially furthest from the secondary flywheel 3. The second disc 42 can then be arranged on the gearbox side, axially closest to the secondary flywheel 3. The radial elongation of the first disc 41, and in particular the recess 414, is of smaller size than that of the second retaining disc 42, and in particular the recess 424.

We will now describe the method of manufacturing a damping module 4, as illustrated for example in this fourth embodiment of FIGURES 11-13. This process includes, among other things, the following steps:
a) Hot forming a drive flange 5 comprising a central body 50,
then clean the central body 50 so that it is adapted to receive at least one bonding,
b) Forming by material depressions, a first and a second retaining discs 41, 42,
- the depression 414 of material of the first retaining disc 41 being exempt from cleaning and gluing,
- The recess 424 of material of the second retaining disk 42 being cleaned to receive a bonding;
c) Supply and apply a first group of G1 seals, glued and lubricated,
along a first friction zone 510 of the cleaned central body 50,
so as to fix the first group of fittings G1 on the drive flange;
d) Supply and apply a second group of G2 seals, glued and lubricated,
along the depression 424 of the cleaned material of the second disc 42 of retention, so as to fix the second group of linings G2 in the depression 424 of material of the second disc 42 of retention;
e) Mount, in particular in tight assembly, the drive flange 5
between the recesses 414, 424 of material of the first and second retaining discs 41, 42,
then fix together the first and second retaining discs 41, 42 integrally, for example by riveting.

The use of the verb "to comprise", "to understand" or "to include" and of its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim. In the claims, any reference sign in parentheses cannot be interpreted as a claim limitation.

The dimensions indicated or illustrated may not be to scale and correspond only to a particular model of torque limiter developed by the applicant. The manufacturing method according to the invention will be adapted as much as necessary to other nominal diameters of the damping module and to other thicknesses of its components.

Claims (13)

Method of manufacturing a damping module (4), comprising at least the following steps:
a) Hot forming a drive flange (5) comprising a central body (50),
then clean the central body (50) so that it is adapted to receive at least one bonding,
b) Forming by indentations of material, a first and a second retaining disc (41, 42),
- the depression (414) of material of the first retaining disc (41) being exempt from cleaning and gluing,
- the depression (424) of material of the second retaining disc (42) being
either cleaned to be suitable for gluing,
is exempt from cleaning and gluing;
c) Supply and apply a first group of gaskets (G1), glued and lubricated,
along a first friction zone (510) of the cleaned central body (50),
so as to fix the first group of linings (G1) on the drive flange;
d) Supply and apply a second group of gaskets (G2), glued and lubricated,
along a second friction zone (520) of the cleaned central body (50), so as to fix the second group of linings (G2) on the drive flange, or
along the cleaned material recess (424) of the second retaining disc (42) so as to fix the second group of gaskets (G2) in the material recess (424) of the second retaining disc (42) ;
e) Fit the drive flange (5) between the recesses (414, 424) of the material of the first and second retaining discs (41, 42), before fixing the first and second retaining discs (41, 42) solidly together. detention,
for example by riveting. A method of manufacturing a damping module (4) according to claim 1, wherein
the first friction zone (510) is defined radially over 25% to 55% of the central body (50) of the flange (5), and
the second friction zone (520) is defined radially at 25% to 55%
of the central body (50) of the flange (5), or
of the depression (424) of material of the second disc (42) for retaining. Method of manufacturing a damping module (4) according to claim 1 or 2, in which
the first group of linings (G1) is produced by cutting out a plurality of friction segments (100) and/or
the second group of linings (G2) is produced by cutting out a plurality of friction segments (200),
the segments (100, 200) of the same group of linings being arranged according to a regular or uniform distribution,
preferably to the number between three and fifteen segments,
for example of identical and/or complementary shapes. A method of manufacturing a damping module (4) according to claim 3, wherein
the segments (100) of the first group of linings (G1) are spaced apart
along the first friction zone (510) of the central body (50), so as to cover less than 90%, preferably between 30% and 70%, of the first friction zone (510), and/or
the segments (200) of the second group of linings (G2) are spaced
either along the second friction zone (520) of the central body (50), so as to cover less than 90%, preferably between 30% and 70%, of the second friction zone (520),
either along the depression (424) of material of the second retaining disc (42), so as to cover less than 90%, preferably between 30% and 70%, of the second friction zone (520). Damping module (4) for a dual mass flywheel, comprising:
- a flange (5) drive, axis (X) of revolution,
comprising a central body (50) of radial elongation delimited between
a first lateral face (51), on which a first annular friction zone (510) is formed, and
a second lateral face (51, 52), on which a second annular friction zone (520) is formed,
- first and second retaining discs (41, 42) each comprising a recess (414, 424) of material delimiting a housing (8), inside which the central body (50) is received,
the drive flange (5) supporting damping means (40) radially beyond the housing (8),
- two groups of friction linings (G1, G2),
the first group of fittings (G1) being fixedly assembled
on the first friction zone (510) of the central body (50),
so as to cooperate by friction with the first retaining disc (41), and
the second group of gaskets (G2) being fixedly assembled
on the second friction zone (520) of the central body (50),
so as to cooperate by friction with the second retaining disc (42),
Or
on the depression (424) of material of the second retaining disc (42),
so as to cooperate by friction with the second friction zone (520) of the central body (50). Damping module (4) according to claim 5, in which the second friction zone (520) is disposed radially further inside the housing (8) than the first friction zone (510),
at least one of the first and second friction zones (510, 520) being notably defined radially between 25% and 55% of the central body (50). Damping module (4) according to Claim 5 or 6, in which
- the first friction zone (510) is less than 90% covered by the first group of linings (G1), preferably the first group of linings (G1) covers between 30% and 70% of the first friction zone ( 510), and/or
- the second friction zone (520) is covered less than 90% by the second group of linings (G2), preferably the second group of linings (G2) covers between 30% and 70% of the second friction zone ( 520). Damping module (4) according to any one of Claims 5 to 7, in which the first and second groups (G1, G2) of lining are identical, in at least
- the friction coating, preferably compatible with grease lubrication,
- cutting within the same friction material, preferably from the same sheet or friction roller,
- the specific shape of the cut, for example rings of the same thickness or geometric shape. Damping module (4) according to any one of Claims 5 to 8, in which
the groups (G1, G2) of linings are offset circumferentially with respect to one another, and/or
the groups (G1, G2) of linings are radially spaced with respect to each other. Damping module (4) according to any one of claims 5 to 9, in which at least one of the first and second groups of linings (G1, G2) is formed of a plurality of segments (100, 200) friction, preferably the segments of the same group being
contiguous or spaced apart circumferentially, and/or
of identical shapes and/or complementary shapes. Damping module (4) according to the preceding claim, in which the first and second groups of linings (G1, G2) are each formed of friction segments (100, 200), for example an identical number of segments (100, 200 ) of friction between three and fifteen segments. Double damped flywheel (1) for a transmission chain, comprising
a damping module (4) according to any one of Claims 5 to 11, intended to transmit a torque and to dampen rotational acyclisms between a primary flywheel (2) of inertia and a secondary flywheel (3) of inertia ,
the primary flywheel (2) of inertia receiving the elastic members (40), and
the first and second retaining discs (41, 42) being fixedly connected to the secondary flywheel (3) of inertia. Double mass flywheel (1) according to the preceding claim, in which
the damping module (4) comprises at least one sealing washer (58),
said at least one sealing washer (58) being preferably fixed integrally
to the first and second retaining discs (41, 42), with first fixing means (71) on the one hand, and
to the flywheel (3) secondary, with second fixing means (72) on the other hand.
the first and second fixing means (71, 72) being in particular two distinct series of fixing screws, bolts or rivets, for example spaced from each other