FR2752891A1 - ASSEMBLY FORMING A CLUTCH DISC HAVING AXIALLY SHIFTED BUFFER PLATES - Google Patents

Abstract

The present invention relates to a clutch disc assembly 1. This assembly comprises friction liners 15a and 15b, a clutch plate 7 and several buffer plates 16 and 17. The liners 15a and 15b can be pressed against a flywheel 51. Each buffer plate 16 includes a mounting portion 16c on which the liner 15a is mounted, and an elastic link portion 16b which resiliently connects the mounting portion 16c to the plate 7. Each buffer plate 17 includes a mounting portion 17c in which is mounted the cover 15a or 15b, and an elastic connecting part 17b which resiliently connects the mounting part 17c to the plate 7. The parts 17c and 16c are axially offset.

Description

q 2752891 Clutch disc assembly with buffer plates

axially offset

BACKGROUND OF THE INVENTION

  A. Field of the Invention The present invention relates to an assembly forming

Clutch disc.

B. Description of the prior art

  A clutch disc assembly is used to transmit torque between a rotary power input member and a rotary power output member. It generally comprises a clutch disc provided with two parts forming a friction coating fixed to the outer circumference of a power input plate, a power output hub and a damping mechanism which elastically connects the input plate of power to the power output hub, allowing rotation

relative between the two.

  The clutch disc assembly is typically used in a clutch mechanism which includes a flywheel and a clutch housing assembly connected to the flywheel, the clutch disc assembly being placed between the two. . The clutch housing assembly typically includes a pressure plate which contacts one of the friction linings of the housing assembly, urging the other lining

friction against the steering wheel.

  In the clutch disc assembly, when the pressure plate of the housing assembly pushes the friction lining against the flywheel, the clutch disc is held between the flywheel and the pressure plate, and the torque of the flywheel on the engine side is transmitted to the power input plate via the clutch disc. The torque is transmitted via the damping element to the power output hub and then to the power output shaft. Thus, when the clutch is in the coupled position by pressing the clutch disc against the flywheel, the torque

is transmitted.

  A disc assembly often includes a buffer plate between the friction coating portions to reduce any vibration often caused by the clutch coupling. Typically, the buffer tray has a wavy outline. When a clutch disc is pushed against the flywheel, the buffer plate deforms elastically between the parts forming friction coatings. As the elastic deformations act as a spring or a buffer, the shock of the clutch coupling is absorbed. The friction coating parts are designed as annular elements and are fixed to the opposite sides of the buffer plate using

rivets.

  Recent increases in engine power require increased torque transmission capacity by a disc assembly

  clutch, which corresponds to the power of the engine.

  One of the means for increasing the torque transmission capacity of a clutch mechanism consists in increasing the force provided by the pressure plate which pushes the clutch disc device to bring it into contact with a flywheel. A large load of

  pressure requires the buffer plate to be more rigid.

  However, by making the buffer plate more rigid, it reduces its durability to the extent that its repeated compression

causes fatigue.

  A friction coating requires specific properties such as a suitable coefficient of friction, abrasion hardness and impact capacity (ability to withstand repeated impact). It is very difficult to give these properties to a portion forming a satisfactory annular friction coating. As a result, the development and production of a coating portion of

  friction usually represent an expensive effort.

SUMMARY OF THE INVENTION

  The object of the present invention is to improve the durability of a buffer plate and to adjust and modify more easily the specific properties of a friction coating. According to a first aspect of the present invention, a clutch disc assembly comprises a damper disc assembly formed by a hub, and a retaining plate and a clutch plate elastically connected to the hub for the purpose of 'limited relative rotation. The clutch disc assembly also includes several first buffer plates. Each buffer plate is made in one piece and comprises a first mounting part, a first elastic connection part and a first fixing part. The first fixing part is connected to the clutch plate. The first elastic connection part extends between the first fixing part and the first mounting part. The first fixing part and the

  first part of assembly are axially offset.

  Several buffer plates are each made in one piece and include a second mounting part, a second elastic connection part and a second fixing part. The second fixing part is connected to the clutch plate while the second elastic connection part extends between the second fixing part and the second mounting part. The second fixing part and the second mounting part are offset axially, so that the second mounting part of each of said second buffer plates is offset axially with respect to the first mounting parts. Several pairs of first friction liners are attached to corresponding opposite axial sides of the first mounting portions. Pairs of first friction liners are also attached to corresponding opposite axial sides of at least one of the

second parts of assembly.

  Preferably, eight of the first buffer plates and eight of the second buffer plates are fixed to the clutch plate. The first buffer plates alternate with the second, and pairs of second friction liners are attached to opposite axial sides of four of the seconds

mounting parts.

  According to another aspect of the present invention, a clutch disc assembly comprises a damper disc assembly formed by a hub, and a retaining plate and a clutch plate elastically connected to the hub for the purpose of 'limited relative rotation. Several first buffer plates are each made in one piece and include a first mounting part, a first elastic connection part and a first fixing part. The first fixing part is connected to the clutch plate. The first elastic connection part extends between the first fixing part and the first mounting part. The first fixing part and the first mounting part are offset axially. Each of the second buffer plates is made in one piece and comprises a second mounting part, a second elastic connection part and a second fixing part. The

  second fixing part is connected to the clutch plate.

  The second elastic connection part extends between the

  second fixing part and the second mounting part.

  The second fixing part and the second mounting part are offset axially, so that the second mounting part of each of the second buffer plates is offset axially with respect to the first mounting parts. A first annular friction coating is attached to an axial side of the first mounting portions. A second annular friction lining is attached to an axial side of the second mounting parts opposite the axial side of the

first parts of assembly.

  According to another aspect of the invention, a clutch disc assembly comprises a damper disc assembly formed by a hub, and a retaining plate and a clutch plate elastically connected to the hub for the purpose of 'limited relative rotation. Each of the trays forming the trays is made in one piece and comprises first and second mounting parts, first and second connecting parts and a fixing part. The fixing part is connected to the clutch plate. The first elastic connection part extends

  between the fixing part and the first mounting part.

  The second elastic connection part extends between the fixing part and the second mounting part. The first and second mounting parts are offset axially. Several pairs of first friction liners are attached to corresponding opposite axial sides

  first and second mounting parts.

  Friction coatings consist of

  preferably a sintered metal material.

  According to another aspect of the present invention, a clutch disc assembly comprises a damper disc assembly formed by a hub, and a retaining plate and a clutch plate elastically connected to the hub for the purpose of 'limited relative rotation. Several buffer plates are each made in one piece and include first and second mounting parts, first and second elastic connecting parts and a fixing part. The fixing part is connected to the clutch plate. The first elastic connection part extends between the fixing part and the first mounting part. The second elastic connection part extends between the fixing part and the second mounting part. The first and second mounting parts are offset axially. A first annular friction coating is attached to an axial side of the first mounting portions while a second friction coating is attached to an axial side of the second mounting portions opposite the axial side of the

first parts of assembly.

  According to another aspect of the invention, a clutch disc assembly comprises a damper disc assembly formed by a hub, and a retaining plate and a clutch plate elastically connected to the hub for the purpose of 'limited relative rotation. Several buffer plates are each made in one piece and include first and second mounting parts, first, second and third elastic connecting parts and first and second fixing parts. The first and second attachment parts are connected to the clutch plate. The first elastic connection part extends between the first fixing part and the first mounting part. The second elastic connection part extends between the second fixing part and the second mounting part. The third elastic connection part extends

  between the first and second mounting parts, and those

  these have an angular offset so that they define a V shape, seen from a radial edge, in a position without compression. Multiple pairs of friction liners are attached to opposite axial sides

  correspondents of the first and second mounting parts.

  In the buffer plates described above, the elastic parts produce a buffer effect. Consequently, from a structural point of view, the stress caused by the elastic deformation is lower than with conventional buffer plates. In addition, the buffer properties can be easily calculated with

correct accuracy.

  These and other objects, features, aspects and advantages of the present invention will become more apparent.

  clearly from the following detailed description of

  the invention with reference to the accompanying drawings, in which identical elements are designated by the same numbers

reference.

SHORT DESCRIPTION OF THE DRAWINGS

  Figure 1 is a fragmentary side cross section of a clutch disc assembly according to a first embodiment of the invention, Figure 2 is an elevational view of the clutch disc assembly, in the direction of arrow II in FIG. 1, FIG. 3 is an elevation view similar to FIG. 2, which shows a clutch disc assembly according to a second embodiment of the invention, FIG. 4 is a view in an elevation similar to FIGS. 2 and 3, which shows a clutch disc assembly according to a third embodiment of the invention, FIG. 5 is a side view of a part of the clutch disc assembly of the Figure 2, according to the arrows VV, which shows details of a buffer plate according to the first embodiment of the invention, Figure 6 is a side view of a part of the clutch disc assembly of the figure 3, following the arrows VI-VI, which shows e of the details of a buffer plate according to the second embodiment of the invention, FIG. 7 is a side view of a part of the assembly forming the clutch disc of FIG. 4, according to the arrows VII-VII , which shows details of a buffer plate according to the third embodiment of the invention, FIG. 8 is similar to FIG. 5 and shows a fourth embodiment of the invention, in which two annular friction elements are fixed to the buffer plates, which are identical to those of FIG. 5, and FIG. 9 is similar to FIG. 6 and shows a modification of the fourth embodiment in which two annular friction elements are fixed to the plates

  buffers, which are identical to those in Figure 6.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIRST EMBODIMENT

  Figures 1, 2 and 5 show a clutch disc assembly 1 according to a first embodiment. A motor (not shown) intended to supply a torque is arranged on the left of FIG. 1 while a transmission (not shown) intended to receive the torque is arranged on the right. For orientation purposes, the left side of Figure 1 will be called in the following engine side, and the right side transmission side. The clutch disc assembly 1 is a device intended to transmit a torque coming from a flywheel 51, engine side, to a shaft

  main engine 32, transmission side.

  In Figure 1, the line 0-0 indicates the axis of

  rotation of the clutch disc assembly 1.

  At the center of the clutch disc assembly 1 is a splined hub 2 which is connected to the main drive shaft 32. The splined hub 2 has in its center a splined hole 2a which engages in a toothing (not shown) of the main drive shaft 32. The splined hub 2 comprises a flange element 3 which extends radially

  outward from said hub 2.

  On the outer circumference of the hub 2, a retaining plate 6 and a clutch plate 7 each having the shape of an annular disc are arranged around the splined hub 2, the flange element 3 being interposed between the two. The plates 6 and 7 are fixed to each other but they can rotate relative to the splined hub 2. Their outer circumferences are connected by a pin

stop 8.

  Several cut parts 3a are formed on the outer circumference of the flange element 3. The stop pins 8 pass through these cut parts 3a, thus limiting the relative rotation of the plates 6 and 7 relative to the flange element 3. Window holes 3b are formed on the inner circumference of the flange member 3 at predetermined intervals in the circular direction. A torsion spring 4 is housed

  in each window hole 3b.

  According to the window holes 3b of the flange element 3, window holes 6a and 7a are formed respectively in the retaining plate 6 and the clutch plate 7. As shown in FIG. 1, these holes 6a and 7a are cut and formed so as to extend outwards, to cover and to retain axially

torsion springs 4.

  As shown in Figure 2, several buffer plates 16 and 17 are alternately attached to the circumference

  outside of the clutch plate 7 using rivets 9.

  More specifically, eight plates 16 and eight plates 17 are fixed to the clutch plate 7. As shown in FIG. 5, friction linings 15a and 15b are fixed to the sides

  opposite of the buffer plates 16 and 17.

  The friction linings 15a all consist of an organic material which offers relatively good coupling characteristics, and in a preferred embodiment, they are mounted on the eight buffer plates 16 and on four buffer plates 17. Consequently, out of a total of sixteen friction coating positions, twelve of these possible positions are occupied by the friction coatings 15a. The friction liners 15a are mounted using a bonding material or adhesive, or they can be mounted using rivets (not shown). In a preferred embodiment of the invention, rivets, which are heavy, are not used in order to reduce the inertia of the disc assembly.

clutch 1.

  The friction coating 15b is made of a metallic material having excellent heat resistance and abrasion resistance, and it is mounted in permanent friction coating positions on the buffer plates 17. In the present embodiment embodiment, the friction linings 15b are mounted using a bonding material. They can also be mounted using a

molding process.

  Each buffer plate 16 comprises a fixing part 16a, an elastic connection part 16b and a mounting part 16c. Likewise, each buffer plate 17 has a fixing part 17a, an elastic connection part 17b and a mounting part 17c. The fixing parts 16a and 17a are fixed to the outer circumference of the clutch plate 7. The friction linings 15a and 15b are fixed to the mounting parts 16c and 17c as described above and as shown in orientation of Figures 2 and 5. The elastic connecting parts 16b, 17b extend from the fixing parts 16a, 17a to the mounting parts 16c, 17c, respectively, and they provide a predetermined degree of elasticity in an axial direction. As shown in FIGS. 1 and 5, the position of the mounting part 16c of the buffer plate 16 is offset with respect to the fixing part 16a in an axial direction which moves it away from the steering wheel 51, while the position of the part mounting 17c of the buffer plate 17 is offset with respect to the fixing part 17a in an axial direction which brings it closer to the flywheel 51. Thus, the position of the mounting part 16c of the buffer plate 16 is different in an axial direction from that of the part of

mounting 17c of the buffer plate 17.

  The operation of this embodiment will

now be described.

  During coupling of the clutch, the friction linings 15a and 15b are pressed against the side of the flywheel 51 by a pressure plate (not shown). During the coupling of the clutch, the pressure plate is first of all in contact with the buffer plate 16 while the flywheel 51 touches the buffer plate 17. Then the elastic connecting parts 16b and 17b are elastically deformed in a axial direction in response to an increase in the pressure exerted by the pressure plate. A buffer effect is caused by the elastic deformation of the elastic connecting parts 16b and 17b and

  absorbs shock during clutch coupling.

  When the friction coatings 15a and 15b are engaged against the flywheel 51, the torque thereof is introduced into said friction coatings 15a and 15b. The torque is transmitted via the buffer plates 16 and 17 to the clutch plate 7 and to the retaining plate 6. It is then transmitted via the torsion spring 4 to the flange element 3, and exits of the latter 3 via the splined hub 2 to be introduced into the main motor shaft 32. Recent increases in the power of the motors and in the weight of automobiles have tended to increase the torque which is transmitted by a clutch. As the transmitted torque increases, so do the temperatures inside a transmission case and on the friction surface. Consequently, the conventional friction coating composed of a purely organic material does not always give a satisfactory service life. In the present embodiment, the friction coating 15a consists of an organic material while the friction coating 15b consists of a metallic material. Thus, whole friction coatings offer both the good coupling of an organic material and the good resistance

  heat and abrasion of metallic material.

  In a clutch disc assembly 1 according to the first embodiment, the friction linings a and 15b can be independently mounted in the mounting portions 16c and 17c, respectively. In addition, it is possible to easily adjust the properties of whole friction coatings by combining several friction coatings composed of materials having

different properties.

SECOND EMBODIMENT

  A second embodiment contains many elements of the first embodiment, such as the hub 2, the plates 6 and 7 and the springs 4. In the second embodiment, however, buffer plates 16 and 17 are used instead. mentioned above, only one type of buffer plate 26 represented in FIGS. 3 and 6. In the first embodiment described above, the buffer plates 16 and 17 provided a buffer effect. In the second, each buffer tray 26 is designed to provide a similar buffer effect. There are eight buffer plates 26 which are fixed with rivets 9 on the outer circumference of the clutch plate 7. Each buffer plate 26 comprises an attachment part 26a, a first and a second elastic connection part 26b, 26c, and a first and a second mounting part 26d, 26e. The fixing part 26a is

  attached to the outer circumference of the clutch plate 7.

  Friction coatings 25 are mounted on the opposite sides of each first and each second mounting part, as shown in FIG. 6. The friction coating 25 consists of a shoe formed by a composite friction element made of sintered alloy, and it is mounted in each mounting part 26d and 26e by assembly or by molding. The first connecting part 26b extends between the fixing part 26a and the first mounting part 26d, while the second connecting part 26c extends between the fixing part 26a and the second mounting part 26e, being axially elastic of the clutch disc assembly 1. As shown in FIG. 6, the fixing part 26a is located axially closer to the flywheel 51 than the first mounting part 26d, and the second mounting part 26e is located axially closer to the steering wheel 51 than the fixing part 26a. Consequently, the first and second mounting parts 26d, 26e are offset axially.

  The operation will be described in the following.

  During coupling of the clutch, the pressure plate (not shown) is in contact with the friction lining 25 and pushes it towards the flywheel 51. During coupling, the pressure plate is first of all in contact with the friction coating 25 mounted in the first mounting portion 26d, while the flywheel 51 comes into contact with the friction coating 25 mounted in the second mounting portion 26e. In reaction to the continued movement of the pressure plate, the first and second elastic connecting portions 26b and 26c are elastically deformed in the axial direction. The buffering effect caused by elastic deformation absorbs a shock produced during

clutch coupling.

  When the friction coating 25 is pressed against the flywheel 51, the torque coming from the latter is introduced into the friction coating 25. It is transmitted via the buffer plate 26 to the clutch plate 7 and to the clutch plate. retainer 6. Then it is transmitted via the torsion spring 4 to the flange element 3, from where it exits via the splined hub 2

  to be introduced into the main drive shaft 32.

  In the second embodiment, the friction coating 25 consists of a composite friction element mass produced from sintered alloy. The conventional clutch disc assembly which uses a friction coating composed of a composite sintered alloy or mass produced metal friction element has no buffering property. The clutch disc assembly 1 according to the second embodiment, wherein each friction lining is independently mounted on a corresponding mounting portion in a similar manner to the first embodiment has a buffering effect and can use a friction coating defined by a shoe composed of a mass-produced composite friction element

made of sintered alloy.

THIRD EMBODIMENT

  The third embodiment shown in Figures 4 and 7 contains many elements of the two previous embodiments, such as the plates 6 and 7 and the springs 4. In this embodiment, however, a buffer plate 36 is used at the place buffer trays

  16 and 17 of the first and, of the buffer plate 26 of the second.

  In the third embodiment, each buffer plate 36 causes a buffer effect similar to that of the buffer plate of the second embodiment described above. However, the deformation of an elastic connecting part 36g which extends between mounting parts 36e and

36f offers a buffer effect.

  As shown in FIG. 4, there are eight buffer plates 36 which are fixed by means of rivets 9 to the external circumference of the clutch plate 7. Each buffer plate 36 comprises a first and a second fixing part 36a, 36b, a first and a second connecting part 36c, 36d, a first and a second mounting part 36e, 36f and finally an elastic connecting part 36g. The first and second fixing parts 36a and 36b are fixed to the outer circumference of the clutch plate 7. Pairs of friction liners 25 are mounted on both sides of each first and second mounting part 36e and 36f, as shown Figure 7. The first connecting portion 36c extends between the first

  fixing part 36a and the first mounting part 36e.

  The second link portion 36d extends between the second

  fixing part 36b and the second mounting part 36f.

  The first and second mounting parts 36e, 36f are produced in one piece with the elastic connection part 36g which is formed between them and which connects them axially. The first and second disassembly parts 36e and 36f are inclined relative to the flywheel 51, as shown in Figure 7, and are inclined relative to each other. Their inclination relative to the steering wheel 51 is symmetrical relative to the elastic connecting part 36g and, as can be seen in FIG. 7, their inclination one relative to

  the other defines an open V shape.

  It will also be noted that according to a preferred configuration, all the different parts of the buffer plate 36 are produced in a single piece from a single piece

  of material, preferably a sheet.

  The operation will now be described.

  When coupling the clutch, the pressure plate (not shown) presses the friction coating 25 against the flywheel 51. The pressure plate and the flywheel 51 are first of all in contact with the edges of the coverings. friction 25 which are mounted on opposite sides of the mounting parts 36e and 36f. When the coupling continues, the elastic connection part 36g causes the elastic deformation of the buffer plate 36, so that the inclination of the mounting parts 36e and 36f is eliminated. More specifically, the buffer plate 36 is held between the pressure plate and the flywheel 51 by means of the friction coating 25 by the force of the pressure plate, and becomes generally flat or planar. A buffer effect is thus created by the elastic deformation of the elastic connection part 36g and absorbs the shock produced during the coupling of the clutch. In addition, the first and second connecting portions 36c and 36d are also elastically deformed, also providing certain buffer effects. Then the torque is transmitted in the same way as in the embodiments described above.

FOURTH EMBODIMENT

  In the first and second embodiments described above, a friction coating is mounted independently on each mounting part. In a fourth embodiment, however, it is also possible to mount an annular friction coating on the corresponding sides of the buffer plates described above, for example buffer plates 16 and 17, and 26. According to FIG. 8, for example, an annular friction coating 115 is mounted on the transmission side of the mounting portion 16c of the first embodiment, and an annular friction coating 115 'is also mounted on the engine side of the mounting portion 17c. In a variant of the fourth embodiment which is shown in FIG. 9, an annular friction coating 125 is mounted on the transmission side of the first mounting part 26d of the second embodiment, and an annular friction coating 125 'is also mounted on the motor side of the second mounting part 26e. It is therefore possible to use two annular members forming friction coatings with the buffer plates described above for the

  first and second embodiment.

  The other structures and operation of the clutch disc assembly are the same as in

  the first and second embodiments.

  Thus, by using an annular friction coating, it is possible to obtain a clutch disc assembly which has a buffering effect and has reduced stress against a buffer plate as has been

  mentioned in the previous embodiment.

EFFECTS OF THE INVENTION

  The present invention increases the durability of a buffer tray by improving the location and structure of the elastic portion which provides the buffer effect. In addition, when each friction coating is used independently, it is possible to adjust and set the optimal properties of the entire friction coating by

  combining the properties of each friction coating.

  Various details of this clutch disc assembly can be modified without departing from the scope of

  the invention. In addition, the preceding description of the modes of

  realization is given by way of illustration only, but without limiting the invention as defined by the

claims.

Claims (7)

  1. Clutch disc assembly (1), characterized in that it comprises: - a damper disc assembly formed by a hub (2), and a retaining plate (6) and a plate clutch (7) elastically connected to the hub (2) for a limited relative rotation, several first buffer plates (16) which are each made in one piece and which include a first mounting part (16c), a first elastic connecting part (16b) and a first fixing part (16a), it being specified that the first fixing part (16a) is connected to the clutch plate (7), than the first elastic connecting part (16b ) extends between the fixing part (16a) and the mounting part (16c), and that the fixing part (16a) and the mounting part (16c) are axially offset, - several second buffer plates (17) which are each made in one piece and which include a second mounting part (17c), a second part e of elastic connection (17b) and a second fixing part (17a), it being specified that the second fixing part (17a) is connected to the clutch plate (7), that the second elastic connecting part (17b) s extends between the fixing part (17a) and the mounting part (17c), and that the fixing part (17a) and the mounting part (17c) are axially offset so that said mounting part (17c) of each of the second buffer plates (17) is axially offset with respect to the first mounting part (16c), and - several first friction coatings (15a), pairs of these coatings (15a) being fixed to the corresponding opposite axial sides first mounting parts (16c), and other pairs of these covers (15a) being attached to the corresponding opposite axial sides of   at least one of the second mounting parts (17c).   2. Clutch disc assembly (1) according to claim 1, characterized in that eight of the first buffer plates (16) and eight of the second buffer plates (17) are fixed to the clutch plate (7), the first plates (16) alternating with the second ones (17), and in that pairs of second friction linings (15b) are fixed to the opposite axial sides of four of the seconds mounting parts (17c).   3. Clutch disc assembly (1), characterized in that it comprises: - a damper disc assembly formed by a hub (2), and a retaining plate (6) and a plate clutch (7) elastically connected to the hub (2) for a limited relative rotation, several first buffer plates (16) which are each made in one piece and which include a first mounting part (16c), a first elastic connecting part (16b) and a first fixing part (16a), it being specified that the first fixing part (16a) is connected to the clutch plate (7), than the first elastic connecting part (16b ) extends between the fixing part (16a) and the mounting part (16c), and that the fixing part (16a) and the mounting part (16c) are axially offset, - several second buffer plates (17) which are each made in one piece and which include a second mounting part (17c), a second part e of elastic connection (17b) and a second fixing part (17a), it being specified that the second fixing part (17a) is connected to the clutch plate (7), that the second elastic connecting part (17b) s extends between the fixing part (17a) and the mounting part (17c), and that the fixing part (17a) and the mounting part (17c) are axially offset so that said mounting part (17c) of each of the second buffer plates (17) is axially offset with respect to the first mounting part (16c), - a first annular friction coating (115) fixed to an axial side of the first mounting parts (16c), and - a second annular friction coating (115 ') attached to an axial side of the second mounting portions (17c) opposite the axial side of the first mounting portions (16c). 4. Clutch disc assembly (1), characterized in that it comprises: - a damper disc assembly formed by a hub (2), and a retaining plate (6) and a plate clutch (7) elastically connected to the hub (2) for a limited relative rotation, several buffer plates (26) which are each made in one piece and which include a first and a second mounting part (26d , 26e), a first and a second elastic connection part (26b, 26c) and a fixing part (26a), it being specified that the fixing part (26a) is connected to the clutch plate (7), that the first elastic connecting part (26b) extends between the fixing part (26a) and the first mounting part (26d), that the second elastic connecting part (26c) extends between the fixing part (26a) and the second mounting part (26e), and that the first and second mounting parts (26d, 26e) are offset axially, and - plus ur first friction coatings (25), pairs of these first friction elements (25) being fixed to corresponding opposite axial sides of the first and second mounting parts (26d, 26e).   5. assembly forming assembly disc (1) according to claim 1, characterized in that the coatings   friction consist of a sintered metal material.   6. Clutch disc assembly (1), characterized in that it comprises: - a damper disc assembly formed by a hub (2), and a retaining plate (6) and a plate clutch (7) elastically connected to the hub (2) for a limited relative rotation, several buffer plates (26) which are each made in one piece and which include first and second mounting parts (26d, 26e), first and second elastic connecting parts (26b, 26c) and a fixing part (26a), it being specified that the fixing part (26a) is connected to the clutch plate (7), that the first part of elastic connection (26b) extends between the fixing part (26a) and the first mounting part (26d), that the second elastic connecting part (26c) extends between the fixing part (26a) and the second mounting part (26e), and that the first and second mounting parts (26d, 26e) are axially offset, - a first rev annular friction element (125) fixed to an axial side of the first mounting parts (26d), and - a second annular friction lining (125 ') fixed to an axial side of the second mounting parts (26e) opposite to the   axial side of the first mounting parts (26d).   7. Clutch disc assembly (1), characterized in that it comprises: - a damper disc assembly formed by a hub (2), and a retaining plate (6) and a plate clutch (7) elastically connected to the hub (2) for a limited relative rotation, several buffer plates (36) which are each made in one piece and which include first and second mounting parts (36e, 36f), first, second and third elastic connecting parts (36c, 36d, 36g) and first and second fixing parts (36a, 36b), it being specified that the first and second fixing parts (36a, 36b) are connected to the clutch plate (7), that the first elastic connection part (36c) extends between the first fixing part (36a) and the first mounting part (36e), that the second elastic connection part ( 36d) extends between the second fixing part (36b) and the second mounting part (36f), that the three isth elastic part (36g) extends between the first and second mounting parts (36e, 36f), and that the first and second mounting parts (36e, 36f) have an angular offset so that they define a shape V-shaped, viewed from a radial edge, in a position without compression, and a plurality of friction liners (25), pairs of these friction liners (25) being attached to corresponding opposite axial sides of the first and second parts of editing (36e, 36f).