FR2895476A1 - Multiple clutch assembly for motor vehicle, has helical springs deported radially outside braking surface of friction linings on respective support half flanges, and flywheel fixed to circular part which is integrated to plate - Google Patents

Abstract

The assembly (1) has two support half flanges (31a, 31b) forming a support flange. The flanges (31a, 31b) are arranged in friction webs (36a, 36b) carrying friction lining (37a, 37b). A flywheel (7) is fixed to a circular part (13) which is integrated to a plate (15), where the plate and the part form drive washers with helical springs (17). A dampening web (19) is arranged between the washers, and a friction unit (25) is interposed between the washer and the web. The springs are deported radially outside braking surfaces (39a, 39b) of the linings on the respective flanges.

Description

The present invention relates to a multiple clutch assembly

in particular of a motor vehicle.

  A multiple clutch assembly comprises a plurality of clutches, and most often two clutches, as is known in particular from document EP 1 361 102. Such a clutch assembly has the particular advantage of allowing gear shifts without breaking the engine. couple.

  However, such a clutch assembly has the disadvantage of having an axial space greater than that of a single clutch. However, this axial size is critical to be able to implement the clutch assembly between the engine and the gearbox of some vehicles. The present invention is thus particularly intended to provide a multiple clutch assembly having a smaller axial size compared to multiple clutch assemblies currently available on the market. This object of the invention is achieved with a multiple clutch assembly comprising: at least first and second friction, at least one support plate comprising first and second half support plates, at least one first and second pressure plates, capable of pinching said respective friction against said respective half-support plates, - a flywheel for transmitting the driving torque to said clutch assembly, - damping means interposed between said flywheel and said support plate, these damping means comprising: - at least two guide rings, - a plurality of springs disposed between these two guide rings, - at least one damping web disposed between these two guide rings and cooperating with said springs, and - friction means interposed between said guide washers and said web, clutch assembly wherein said springs are deported at least almost completely radially outside the friction tracks of said friction on their respective half-support plates. Deporting the springs radially outside friction friction tracks reduces the total thickness between the friction faces of the two support half-plates without reducing their overall mechanical and thermal resistance, given it is no longer necessary to encroach on their respective volumes to accommodate the guide washers and the springs. This therefore reduces the axial size of the clutch assembly according to the invention. It will be further noted that by deporting the springs radially outside the rub friction tracks, the springs are moved away from said friction tracks, that is to say from areas where, because of friction friction on their respective support half-plates, the temperatures can be very high.

  This protects the springs against such temperatures, which allows to significantly increase the longevity of these springs. Thus, in the end, the offset of the springs outside friction tracks significantly improves the reliability and durability of the clutch according to the invention compared to those of the prior art.

  According to another optional feature of the clutch assembly according to the invention, said springs are deported at least almost completely radially outside said friction tracks. This characteristic makes it possible to increase the angular displacement of the guide washers with respect to the damping veil, and thus to improve the efficiency of the damping means. According to other optional features of the clutch assembly according to the invention: - said guide rings are integral with said flywheel and said web is secured to said two half-plates, - at least one of said guide rings covers a significant part of said web, said friction means being interposed between radially inner portions of said washer and web, said friction means comprise a spring washer and a friction washer, said friction washer being driven by one of said guide washers and rubbing against said web.

  According to another embodiment of the clutch assembly according to the invention, this assembly comprises a first damping assembly comprising: at least two first guide washers, a plurality of first springs disposed between these two first washers; guide, - at least a first damping web disposed between these two first guide rings and cooperating with said first springs, and - first friction means interposed between said first guide rings and said first web, and a second set damping device comprising: - at least two second guide washers, - a plurality of second springs disposed between these two second guide washers, and - at least one second damping veil disposed between these two second guide washers and cooperating with said second springs, and - second friction means interposed between said second guide washers and said web. This other embodiment of the clutch assembly according to the invention, which comprises two damping stages, is particularly advantageous because it allows greater overall angular deflection of the damping means, which improves the vibration filtration. torsion transmitted by the crankshaft. According to another optional feature of the clutch assembly according to the invention, at least one of said guide rings has a relatively large mass concentration at its periphery. This feature allows to play the guide ring the role of a flywheel, in addition (or instead of the steering wheel connected to the crankshaft. According to another optional feature of the clutch assembly according to the invention, said guide washers define closed housings for said spring. This characteristic makes it possible to protect the springs, in particular with regard to the high temperature rises which occur in the areas of the friction tracks of the fictions on their respective half-support plates. According to another optional feature of the clutch assembly according to the invention, seals are arranged in the connection zone between said guide washers and the associated damping web. This characteristic makes it possible to place the springs in sealed compartments, and thus to bathe them in a lubricating substance, which improves their longevity. According to another optional feature of the clutch assembly according to the invention, said friction means are separated from said half-support plates by said guide rings.

  This characteristic makes it possible to isolate the springs from the zones of high temperatures, the guide washers then forming a kind of heat shield. According to another optional feature of the clutch assembly according to the invention, said half-plates comprise cooling orifices, and said friction means are arranged at least partially in front of these orifices. This feature allows to aerate the friction means, and thus to prevent these means are subjected to too high temperatures. According to another optional feature of the clutch assembly according to the invention, said half-plates comprise cooling orifices, and said springs are arranged at least partly in front of these orifices. This feature allows to ventilate the springs, and thus to prevent these springs from being subjected to too high temperatures. According to still other optional features of the clutch assembly according to the invention: said half-plates are interconnected by spacers in order to limit the cone deformation of these half-plates, said flywheel is flexible. Other features and advantages of the clutch assembly according to the invention will become apparent in the light of the description which follows, and on examining the appended figures, in which: FIG. 1 is an axial sectional view a first embodiment of the clutch assembly according to the invention, - Figure 2 is an axial sectional view of a second embodiment of the clutch assembly according to the invention, and FIG. 3 is a front view of the damping means of the clutch assembly of FIG. 2. The following has been chosen to present the invention on the basis of two embodiments of a double clutch. .

  It should be noted, however, that the present invention is not limited to double clutches, and is applicable to multiple clutches in general, whether normally open or normally closed. Referring now to Figure 1, on which it can be seen that the clutch assembly 1 is disposed within a fixed clutch bell 3.

  This clutch assembly is connected upstream to a crankshaft 5, via a flywheel 7, and downstream to two coaxial gearbox shafts 9, 11. The flywheel 7, which could possibly be flexible , is attached to a substantially circular piece 13 forming a guide ring, having a relatively large mass concentration at its periphery, giving it a high inertia relative to the axis of rotation of the clutch assembly. This piece 13, and a plate 15 which it is integral, form the two guide rings of a plurality of helical springs 17 regularly distributed about the axis of rotation of the clutch assembly.

  More specifically, the two guide washers 13 and 15 are shaped so as to define closed housings for the springs 17. Between these two guide washers extends a substantially circular damping web 19, cooperating with the coil springs 17. As is known per se, the damping web 19 is rotatable relative to the two guide washers 13, 15, against the resistance opposed by the coil springs 17. Preferably, seals 21 are arranged in the connection zone of the guide washers 13, 15 with the damping web 19. It will also be noted that it is advantageous to provide, inside the housings defined by the two guide washers 13, 15, gutters 23 guiding the springs 17. The guide washer 13 covers a significant portion of the damping web 19, and between the radially inner portions, that is to say the parts of these two parts s closest to the axis of rotation of the clutch assembly are disposed friction means 25.

  These friction means, known per se and said hysteresis, typically comprise a spring washer 27 which exerts an axial force on a friction washer 29 which itself bears on the damping web 19. The friction washer 29 is mounted with an angular clearance relative to the guide ring 13 and driven by it after a certain deflection. It is movable in rotation relative to the damping web 19. On either side of the damping web 19 are arranged two half-support plates 31a, 31b, forming together a support plate 31. Two series of rivets 33a and 33b forming spacers, located respectively radially close and at a distance from the axis of rotation of the clutch assembly, connect together in a fixed manner the two half-support plates 31a, 31b and the steering wheel. 19. Between the half-support plate 31a and the damping web 19 is a space allowing the introduction and rotation of the guide washer 13, which has circumferential grooves for the passage of the rivets 33b . It may be noted that the two half-plates 31a, 31b preferably comprise orifices 35a, 35b, regularly distributed, arranged in front of the zone in which the friction means 25 are located.

  On both sides of the support half-plates 31a, 31b are friction webs 36a, 36b carrying at their periphery friction linings 37a, 37b. Friction tracks 39a, 39b will denote the portions of the half-support plates 31a, 31b capable of cooperating with the friction linings 37a, 37b.

  Pressure plates 41a, 41b are capable of sandwiching the friction linings 37a, 37b with the two half-bearing plates 31a, 31b. As is known per se, the pressure plates 41a, 41b can be moved axially under the action of respective diaphragms 43a, 43b themselves respectively actuated by a finger 45 slidably mounted inside the shaft 9, and by a stop 47 movable axially. Note that the coil springs 17 are advantageously placed radially outside the friction tracks 39a, 39b. The mode of operation of the clutch which has just been described and its advantages result directly from the foregoing.

  The engine torque is transmitted to the steering wheel 7 by the crankshaft 5.

  This flywheel 7 in turn transmits this torque to the guide washers 13, 15, which in turn transmit this torque to the damping veil 19 through the damping means that constitute on the one hand the helical springs 17 and on the other hand the friction means 25.

  These damping means make it possible to filter the torsional vibrations transmitted by the crankshaft 5 to the clutch assembly 1. The respective actuations of the finger 45 and the stop 47 selectively allow the friction linings 37a to be clamped between the half support plate 31a and the pressure plate 41a, or the friction liners 37b between the half support plate 31b and the pressure plate 41b. In this way, it is possible to selectively transmit the driving torque to the shaft 9 or to the shaft 11. The fact of moving the coil springs 17 radially outwardly from the friction tracks 39a, 39b makes it possible to use trays. support 31a, 31b having a more regular average thickness than in devices of the state of the art and therefore a smaller footprint with equivalent mechanical and thermal behavior. Indeed, since in the present invention, the housings in which the coil springs 17 are located no longer encroach on these half support plates 31a, 31b, a lower average thickness of these two half-trays. support is sufficient to give them the necessary mechanical strength. Note further that the radial offset of the coil springs 17 allows to move them away from an area subjected to very high temperature rises caused by the friction of the friction liners 37a, 37b on their respective support plates. It is thus possible to preserve the springs 17 of the drawbacks inherent in the high temperature rises without having to increase the respective thicknesses of the half-support plates 31a, 31b.

  It is thus understood that the clutch according to the invention makes it possible to obtain an axial space saving compared to the devices of the prior art, which makes this clutch assembly compatible with a very compact clutch bell 3. .

  The provision of a guide ring 13 having a high rotational inertia relative to the axis of the clutch assembly makes it possible to play this washer the role of a complementary flywheel. The fact that the two guide washers 13, 15 define housings closed and sealed by the seals 21 makes it possible to bathe the springs 17 in a lubricant. The presence of the gutters 23, which follow the shape of the springs 17, makes it possible to correctly guide these springs inside their respective housings. The fact of providing orifices 35a, 35b in front of the friction means 25 allows to properly cool these friction means. The presence of the spacers 33b which connect the two half-bearing plates 31a, 31b between them makes it possible to limit the cone deformations of these two half-plates under the effect of the rise in temperature caused by the friction of the linings 37a. , 37b on their respective friction tracks.

  Note also that the fact of deporting the helical springs 17 radially outside the friction tracks 39a, 39b makes it possible to obtain a greater angular displacement of the guide washers 13, 15 with respect to the damping veil 19, which which is more favorable for the filtration of the torsional vibrations transmitted by the crankshaft 5 to the clutch assembly 1.

  Reference is now made to the embodiment shown in FIGS. 2 and 3, for which the same reference numerals have been used as previously for the common or similar members. Only the differences of this embodiment with respect to the previous one will be described hereinafter.

  In this embodiment, the damping means comprise in fact two damping assemblies. The first damping assembly comprises two first guide washers 13, 15 fixed on the flywheel 7, a plurality of first springs 17 being evenly distributed between these two first guide rings.

  A first damping veil 19 cooperating with the first springs 17 is disposed between the first two guide washers 13, 15. First friction means 25 (called hysteresis) are interposed between the two first guide washers 13, 15 one side and the first damping veil 19.

  The first two guide rings 13, 15 themselves collect in an extension forming a second damping web 49 forming part of a second damping assembly. This second damping assembly comprises, in addition to this web 49, two second guide washers 51, 53 between which are placed a plurality of second springs 55 cooperating with the damping web 49. Second friction means 57 are interposed between the two second guide washers 51, 53 on the one hand and the second damping veil 49.

  Advantageously, it will be noted that the first friction means 25 are isolated from the two half-support plates 31a, 31b by the first two guide washers 13, 15, and that the second friction means 57 are isolated from each other. these two half support plates by the two second guide washers 51, 53.

  It will also be noted that orifices 61a, 61b are formed in the two support half-plates in front of the second coil springs 55. It will be noted that in this second embodiment, both the first springs 17 and the second springs 55 are deported. almost completely radially out of the friction tracks 39a, 39b, respectively radially outside and radially inside these tracks. The advantages of this second embodiment result directly from the foregoing. The fact of providing two sets of damping makes it possible to cumulate the angular deflections of each of these assemblies, and thus to obtain an even more efficient filtration of the torsional vibrations transmitted by the crankshaft 5. It can be seen in this respect. Figure 3 on which there is shown an example of the angular deflections that can be obtained with each set of damping. In this example, the damping assembly comprising the first springs 17 allows an angular deflection of 18 degrees and 30 minutes of the first damping veil 19 with respect to the first two guide washers 13, 15, and the second springs 55 allow an angular deflection of 22 degrees and 30 minutes of the second two guide washers 51, 53 with respect to the second damping veil 49, a cumulative angular clearance of 31 degrees.

  Providing that the two groups of springs 17 and 55 are located almost completely radially out of the friction tracks 39a, 39b provides advantages similar to those of the previous embodiment in terms of axial size and protection of these springs. vis-à-vis the high temperature rises. The fact of placing the friction means 25 and 57 respectively between the first two guide washers 13, 15 and the second two guide washers 51, 53 makes it possible to protect these friction means from the high temperature rises of the two half-plates support 31a, 31b.

  The fact of providing orifices 61a, 61b in these two support half-plates makes it possible to aerate the springs 55, and thus to preserve them against the high temperature rises. Of course, the present is not limited to the embodiments described and shown, provided by way of illustrative and non-limiting example.

Claims (14)

  1. Multiple clutch assembly (1), comprising: - at least first and second friction (37a, 37b), - at least one support plate comprising first (31a) and second (31b) half-trays d support, - at least first (41a) and second (41b) pressure plates, able to pinch said respective friction (37a, 37b) against said respective half-support plates (31a, 31b), - a flywheel ( 7) of transmission of the engine torque to said clutch assembly (1), - damping means interposed between said flywheel (7) and said support plate (31 a, 31 b), these damping means comprising: at least two guide washers (13, 15, 51, 53), a plurality of springs (17; 55) arranged between these two guide washers, at least one damping web (19, 49) arranged between these two guide washers and cooperating with said springs, and - friction means (25; 57) interposed between said guide washers and said veil, ens clutch gear in which said springs are offset at least almost completely radially out of the friction tracks (39a, 39b) of said friction (37a, 37b) on their respective bearing half-plates (31a, 31b).   2. The clutch assembly (1) according to claim 1, wherein said springs (17) are offset at least almost completely radially outwardly of said friction tracks (39a, 39b).   3. clutch assembly (1) according to claim 2, wherein said guide washers (13, 15) are integral with said flywheel (7) and said web (19) is integral with said two half-plates (31a, 31b). .   4. clutch assembly (1) according to claim 3, wherein said friction means (25) comprises a spring washer (27) and a friction washer (29), the friction washer (29) being driven by the one (13) of said guide washers and rubbing against said web (19).   Clutch assembly (1) according to claim 3 or 4, wherein at least one (13) of said guide washers (13, 15) covers a significant portion of said sail (19), said friction means (25) ) being interposed between radially inner portions of this washer and this web.   6. clutch assembly (1) according to claim 1, comprising a first damping assembly comprising: - at least two first guide washers (13, 15), - a plurality of first springs (17) arranged between these two first guide rings, - at least one first damping web (19) arranged between these two first guide rings (13, 15) and cooperating with said first springs (17), and - first friction means (25) interposed between said first guide washers (13, 15) and said first web (19), and a second damping assembly comprising: - at least two second guide washers (51, 53), - a plurality of second springs ( 55) arranged between these two second guide washers (51, 53), and - at least one second damping web (49) disposed between these two second guide rings (51, 53) and cooperating with said second springs (55 ) and - second means s of friction (57) interposed between said second guide washers (51, 53) and said web (49).   7. clutch assembly (1) according to any one of the preceding claims, wherein at least one (13) of said guide rings has a relatively large mass concentration at its periphery. 25   The clutch assembly (1) according to any one of the preceding claims, wherein said guide washers (13, 15) define closed housings for said springs (17).   The clutch assembly (1) according to claim 8, wherein seals (21) are disposed in the connection zone between said guide washers (13, 30) and the associated damping web (19).   10. clutch assembly (1) according to any one of the preceding claims, wherein said friction means (25, 57) are separated from said half-support plates (31a, 31b) by said guide rings (13). , 15, 51, 53).   11. A clutch assembly (1) according to any one of the preceding claims, wherein said half-plates (31a, 31b) comprise cooling orifices (35a, 35b), and said friction means (25a, 31b). ) are arranged at least partly in front of these orifices (61a, 61b).   The clutch assembly (1) according to any one of the preceding claims, wherein said half-plates (31a, 31b) comprise cooling orifices (61a, 61b), and said springs (55) are arranged at least partly in front of these orifices.   13. clutch assembly (1) according to any one of the preceding claims, wherein said half-plates (31a, 31b) are interconnected by spacers (33b) in order to limit the cone deformation of these halves trays.   14. clutch assembly (1) according to any one of the preceding claims, wherein said wheel (7) is flexible.