SPRING ARRANGEMENT AND TORQUE TRANSMISSION DEVICE

Description

[0001] The invention relates to the field of spring arrangements, torsion dampers and torque transmission devices for motor vehicle powertrains.

[0002] Motor vehicles may be equipped with a torsion damping device on their drive train. Such a damping device may be included, for example, in a clutch disc or a torque limiter arranged between the engine and the gearbox of a vehicle. Such a torsion damping device allows the filtering of engine acyclisms and other torsional oscillations. These torsion damping devices allow, during the transmission of torque, a relative rotational movement of a first rotating element and a second rotating element, thanks to one or more springs acting circumferentially between them. These springs may be grouped together. These groups of springs may be referred to as a spring arrangement.

[0003] There are spring arrangements comprising three coil springs mounted one inside the other and in which the seats are devoid of means for centering the intermediate spring. The intermediate spring can then move and rub against the inner spring and the outer spring, which impairs the damping quality of the shock absorber. There is also patent application DE102015222660 which describes a spring arrangement comprising three coil springs mounted one inside the other with seats arranged at the ends of the springs. The shape of these seats is such that there is a significant loss of space between the inner spring and the intermediate spring. In a spring arrangement, the space not occupied by the springs is a "lost" space from the filtration point of view. Document EP3026293 also discloses a spring arrangement comprising three coil springs mounted one inside the other.

[0004] The invention aims to improve the spring arrangements of the prior art.

[0005] To this end, the invention relates to a spring arrangement for a motor vehicle torque transmission device comprising: an inner coil spring, an intermediate coil spring, inside which the inner coil spring is housed, an outer coil spring, inside which the intermediate coil spring and the inner coil spring are housed, a first seat comprising an inner bearing surface on which a first end of the inner coil spring can bear and an outer bearing surface on which a first end of the outer coil spring can bear, the first seat further comprising a centering device projecting relative to the inner bearing surface and relative to the outer bearing surface;the centering device of the first seat having on the one hand an external contour outside of which the first end of the external helical spring is arranged and on the other hand an internal contour inside of which the first end of the internal helical spring is arranged, the centering device of the first seat also having an intermediate bearing face on which a first end of the intermediate helical spring can bear; the first end of the intermediate coil spring comprising a chamfer and the centering device of the first seat comprising a centering rim arranged to cooperate with the chamfer of the intermediate coil spring to center the intermediate coil spring, wherein: for a distance L1 separating the outer coil spring from the inner coil spring, and for a coil diameter D of the intermediate coil spring, the coil diameter and the centering device are arranged so that 0.75 < D / L1 < 0.97, and for a distance L2 separating the inner contour and the outer contour of the centering device of the first seat, the distance L2 is such that 0.8 <D / L2<1.

[0006] Here, a seat is a support member inserted between the springs and the elements on which they rest. The term seat also includes the support members sometimes called "cups".

[0007] Thus, for a given size of the spring arrangement, it is possible to reduce the stiffness of the spring arrangement compared to the prior art.

[0008] The damping device may further include the following additional features, alone or in combination: The flange projects from the intermediate bearing face of the intermediate coil spring. The coil diameter and the centering device are arranged so that 0.75 <D / L1<0,9. Le diamètre de spire et le centreur sont agencés de sorte que 0,8<D / L1<0,97, de préférence 0,8<D / L1<0,90 par exemple D / L1=0,85. Le ressort hélicoïdal intérieur, le ressort hélicoïdal intermédiaire et le ressort hélicoïdal extérieur sont sensiblement coaxiaux. Le ressort hélicoïdal intermédiaire s'étend le long d'un axe (Y) Les spires du ressort hélicoïdal intermédiaire sont enroulées autour de l'axe (Y). Le ratio D / L1 peut être pris dans tout plan passant par l'axe (Y) et par le centreur. Le centreur s'étend circonférentiellement tout autour de l'axe (Y).According to one variant, the centering device comprises a plurality of pads spaced apart from each other, at least some of the pads having an inner edge facing the axis of the intermediate helical spring and forming the inner contour of the centering device, and at least some of the pads having an outer edge facing the side opposite the axis of the intermediate helical spring and forming the outer contour of the centering device. The inner contour of the centering device is discontinuous. The outer contour of the centering device is discontinuous. Each pad has an inner edge facing the axis (Y) and forming a part of the inner contour of the centering device. Each pad has an outer edge facing the side opposite the axis (Y) and forming a part of the outer contour of the centering device. The centering rim has an inclined wall pressed against the chamfer of the intermediate helical spring, the inclined wall of the rim being arranged on one end of the centering device axially opposite the inner and outer bearing surfaces of the first seat.The inclined wall of the centering device connects the intermediate bearing face of the centering device to the outer contour of the centering device. The inclined wall thus cooperates with a chamfer provided on a radially outer edge of the first end of the intermediate helical spring. The inclined wall of the centering device connects the intermediate bearing face of the centering device to the inner contour of the centering device. The inclined wall thus cooperates with a chamfer provided on a radially inner edge of the first end of the intermediate helical spring. In a plane comprising the axis (Y) and passing through the rim, the rim has a generally triangular section, one of the sides of the generally triangular section forming the inclined wall and another of the sides of the generally triangular section forming part of the outer or inner contour of the centering device.The spring arrangement comprises a second seat comprising an internal bearing surface on which a second end of the inner coil spring can bear and an external bearing surface on which a second end of the outer coil spring can bear, the second seat further comprising a centering device projecting relative to the internal bearing surface and relative to the external bearing surface of the second seat, the centering device of the second seat having on the one hand an external contour outside of which the second end of the outer coil spring is arranged and on the other hand an internal contour inside of which the second end of the inner coil spring is arranged, the centering device of the second seat further having an intermediate bearing face on which a second end of the intermediate coil spring can bear.The second end of the intermediate coil spring has a chamfer and the centering device of the second seat has a centering edge cooperating with the chamfer of the intermediate coil spring to center the intermediate coil spring. For a distance L1 separating the outer coil spring from the inner coil spring, and for a coil diameter of the intermediate coil spring, the coil diameter and the centering device of the second seat are arranged so that 0.75 < D / L1 < 0.97, preferably 0.75 <D / L1<0,9, notamment 0,8<D / L1<0,90. Pour une distance L2 séparant le contour interne et le contour externe du centreur du deuxième siège, la distance L2 est agencée de sorte que 0,75< D / L1 < 0,97, de préférence 0,75<D / L1<0,9, notamment 0,8<D / L1<0,90. .

[0009] The invention also relates to a torsion damper for a motor vehicle torque transmission device comprising a spring arrangement as described above, a first element extending around an axis of rotation (X) and intended to be driven in rotation by a torque input element, a second element extending around the axis of rotation (X) and intended to drive in rotation a torque output element, the spring arrangement being arranged between the first element and the second element so as to transmit a torque between the first element and the second element and dampen the torque oscillations between the first element and the second element. According to one embodiment, the shock absorber comprises a plurality of spring assemblies distributed regularly around the axis of rotation (X).

[0010] The invention also relates to a torque transmission device for a motor vehicle comprising:a torque input element capable of receiving the torque generated by the vehicle engine; a torque output element capable of transmitting a torque to a transmission member of the vehicle; a first element extending about an axis of rotation (X) and rotatably coupled to the torque input element, a second element extending about the axis of rotation (X) and rotatably coupled to the torque output element, a spring arrangement as mentioned above, the spring arrangement being arranged between the first element and the second element so as to transmit a torque between the first element and the second element and dampen torque oscillations between the first element and the second element.According to one embodiment, the torque transmission device is a clutch disc, the torque input element comprising a friction disc, the torque output element comprising a central hub capable of driving a gearbox input shaft, one of the first element and the second element comprising a central disc and the other of the first element and the second element comprising two lateral washers arranged on either side of the central disc. According to one embodiment, the torque transmission device comprises a plurality of spring assemblies distributed around the axis (X) and each spring arrangement is arranged in a recess of the central disc and in two windows formed respectively in each lateral washer.

[0011] The invention also relates to a clutch for a motor vehicle comprising a torque transmission device as described above and a clutch mechanism capable of authorizing, interrupting or limiting the transmission of the torque transmitted to the friction disc. Preferred examples of embodiment of the invention will now be described with reference to the accompanying drawings in which: figure 1 represents a sectional view of a clutch disc provided with a spring arrangement according to the invention; the figure 2 is a perspective view of the clutch disc of the figure 1 ; there figure 3 is a view along a section perpendicular to the X axis of the clutch disc of the figure 1 ; there figure 4 is a sectional view showing the arrangement of springs according to a first embodiment; the Figure 5 is an enlarged view showing the seat centering device of the figure 4 ; there figure 6 is a perspective view of the headquarters of the figure 4 ; there figure 7 is a perspective view of a variant of the seat of the figure 6 ; there figure 8 is a perspective view of the intermediate coil spring of the first embodiment. figure 9 is a sectional view showing the arrangement of springs according to a second embodiment; figure 10 is an enlarged view showing the seat centering device of the figure 9 ; there figure 11 is a perspective view of the headquarters of the figure 9 ; there figure 12 is a perspective view of the intermediate coil spring of the second embodiment.

[0012] In the description and the claims, the terms "external" and "internal" as well as the orientations "axial" and "radial" will be used to designate, according to the definitions given in the description, main elements of the torque transmission device. The X axis of rotation determines the "axial" orientation. An axial rotation is therefore a rotation around the X axis. The "radial" orientation is directed orthogonally to the X axis. The circumferential orientation is directed orthogonally to the X axis of rotation and orthogonally to the radial direction. The terms "external" and "internal" are used to define the relative position of one component with respect to another, with reference to the X axis of rotation, a component close to said axis is thus qualified as internal as opposed to an external component located radially on the periphery. Furthermore, the angles and angular sectors expressed are defined in relation to a rotation around the X axis.

[0013] However, with regard to the characteristics related to the arrangement of springs, and in particular to the seats and springs, the reference axis is the Y axis which corresponds to the axis of the intermediate coil spring.

[0014] The spring arrangement according to the invention can be integrated into any torsion damper arranged on a vehicle transmission chain or powertrain and intended to transmit engine torque.

[0015] THE figures 1 à 3 illustrate an exemplary embodiment in which the spring arrangement according to the invention is integrated into a clutch disc 1 intended to be placed between the engine of a vehicle and its gearbox.

[0016] The clutch disc 100 comprises a circular friction disc 2 provided with linings and a central hub 3B provided with internal splines. The friction disc 2 is intended to be driven in rotation by friction between a pressure plate of a clutch mechanism and a flywheel driven by the engine of the vehicle. The central hub 3B is intended to be coupled in rotation, thanks to its internal splines, to the input shaft of the gearbox of the vehicle. A torque is thus transmitted between the friction disc 2 and the central hub 3B or vice versa.

[0017] The clutch disc 100 is provided with a torsion damper 1 allowing a relative rotational movement around the X axis between the central hub 3B and the friction disc 2 to allow the damping of torsional oscillations during the transmission of the torque.

[0018] The torsion damper 1 comprises, in the present example, five spring arrangements 4 arranged circumferentially around the central hub 3B.

[0019] The torsion damper is adapted to compress the springs of the spring arrangements 4 between a first rotating element 5 and a second rotating element 6 to ensure damping of acyclisms.

[0020] There figure 1 is a sectional view of the clutch disc. In the present example, the second rotating element 6 consists of a pair of side washers, hereinafter referred to as guide washers 6, which are integral in rotation with each other. The first rotating element 5 here consists of a central disc 5, hereinafter referred to as the disc 5, arranged between the two guide washers 6. In the present example, the friction disc 2 is integral in rotation with the disc 5, for example by means of a rivet fixing. The two guide washers 6 are both fixed by rivets to an external hub 3A, on either side of the disc 5.

[0021] Angular movement is possible between the central hub 3B and the external hub 3A. A pre-damper PA is used here to dampen vibrations at low torque, particularly at idle. This pre-damper comprises an input member coupled to the guide washers 6 and an output member coupled to the central hub 3B.

[0022] As seen on the figure 1 , the guide washers 6 and the disc 5 thus constitute an axial stack of three discs with a possible relative rotation between the disc 5 and the guide washers 6 and another possible rotation between the guide washers 6 (coupled to the external hub 3A) and the central hub 3B.

[0023] For each spring arrangement 4, the web 5 has a recess 7 and the guide washers 6 each have a window 8. The corresponding spring arrangement 4 is mounted in the windows and recess 8, 7 so that its ends each cooperate with an edge of the recess 7 and an edge of each window 8. The ends of the spring arrangement 4 cooperate with the windows 7, 8 by means of two seats 9 and 11. Each of the seats 9 and 11 therefore bears against an edge of the recess 7 and against an edge of each of the windows 8.

[0024] Pivoting means are provided to allow pivoting of the seats 9 and 11 relative to the web 5 and relative to the guide washers 6. This pivoting is permitted about an axially extending axis. In the present example, the pivoting means consist of a pivot 10 which each seat 9 and 11 comprises, as well as a first pivoting notch made on the web 5, as well as a pair of second pivoting notches provided on each of the guide washers 6. The first pivoting notch is provided on the corresponding edge of the recess 7, and the pair of second pivoting notches is provided on the corresponding edge of each window 8. The pivot 10 of the seats 9 and 11 here consists of a projecting surface of the seat, in the form of a transverse bar extending substantially along a diameter of the seat.The pivot 10 jointly bears on the three pivot notches (the first pivot notch in the center and, on either side of the latter, the pair of second pivot notches). The housing created by the three pivot notches thus receives the pivot 10, allowing it to pivot about an axis extending axially, that is to say parallel to the X axis.

[0025] At each spring arrangement 4, when a relative axial rotational movement takes place between the web 5 and the two guide washers 6, one of the seats 9 is compressed only by the web 5 and moves away from the edges of the windows 8 of the guide washers 6, while the other seat 11, on the opposite end of the spring arrangement 4, comes to bear only on the guide washers 6 while the edge of the window 7 of the web 5 moves away. The spring arrangement 4 is in this way compressed during the relative movements between the web 5 and the guide washers 6 to provide the torsion damping function.

[0026] The cooperation of the spring arrangements 4 with the web 5 and the guide washers 6 is optimized and made more reliable thanks to the seats 9 and 11 which allow the spring arrangement 4 to be held in place and an interface preventing the ends of the springs 4 from being damaged in contact with the web 5 and the guide washers 6.

[0027] Seats 9 and 11 also allow optimal guidance of the springs thanks to pivot 10 ensuring compression of the springs without parasitic effort. In fact, the ends of the springs remain substantially parallel to each other during compression, thanks to pivot 10.

[0028] The seats 9 and 11 are further guided axially relative to the web 5 and the guide washers 6, participating in the stopping in axial translation of the web 5 and the guide washers 6. Each seat 9, 11 comprises for this purpose guide arrangements comprising surfaces which maintain the relative positions, along the axial direction, between the seat 9, 11 and the web 5 and between the seat 9, 11 and the guide washers 6.

[0029] On the figure 4 a first embodiment of a spring arrangement 4 is shown. This spring arrangement 4 comprises: an inner coil spring 43, an intermediate coil spring 42, inside which the inner coil spring 43 is housed, an outer coil spring 41, inside which the intermediate coil spring 42 and the inner coil spring 43 are housed, a first seat 9 comprising an inner bearing surface 93 on which a first end 43-1 of the inner coil spring 43 can bear and an outer bearing surface 91 on which a first end 41-1 of the outer coil spring 41 can bear. a second seat 11 comprising an inner bearing surface 93 on which a second end 43-2 of the inner coil spring 43 can bear and an outer bearing surface 91 on which a second end 41-2 of the outer coil spring 41 can bear.

[0030] As can be seen on the figure 4 , the intermediate coil spring extends along an axis Y around which its turns are wound. The inner coil spring 43, the intermediate coil spring 42 and the outer coil spring 41 are substantially coaxial.

[0031] Each seat 9 further comprises a centering device 95 projecting relative to its internal bearing surface 93 and relative to its external bearing surface 91.

[0032] The centering device 95 of the first seat 9 has on the one hand an external contour 96 outside of which the first end 41-1 of the external helical spring 41 is arranged and on the other hand an internal contour 97 inside of which the first end 43-1 of the internal helical spring 43 is arranged.

[0033] The centering device 95 of the first seat 9 further has an intermediate bearing face 98 on which a first end 42-1 of the intermediate helical spring 42 can rest.

[0034] The first end 42-1 of the intermediate coil spring 42 has a chamfer 42C and the centering device 95 of the first seat 9 has a centering rim 99 arranged to cooperate with the chamfer 42C of the intermediate coil spring 42 to center the intermediate coil spring 42.

[0035] In order to reduce the stiffness of the spring arrangement in a given space requirement, for a distance L1 separating the outer helical spring 41 from the inner helical spring 43, and for a coil diameter D of the intermediate helical spring 42, the coil diameter D and the centering device 95 are arranged so that 0.75 < D / L1 < 0.97. Advantageously, this ratio D / L1 can be measured in any plane including the Y axis of the intermediate helical spring and passing through the centering device.

[0036] Advantageously, the coil diameter D and the centering device 95 are arranged so that 0.75 <D / L1<0,9. Ainsi, ce ratio représente un bon compromis pour, premièrement : éviter les phénomènes de frottement entre d'une part le ressort intermédiaire 42 et le ressort externe 41, et d'autre part entre le ressort intermédiaire 42 et le ressort interne 43, et deuxièmement faire baisser la raideur de l'agencement de ressort 4 dans un encombrement donné. De façon préférée, le diamètre de spire D et le centreur 95 sont agencés de sorte que 0,8<D / L1<0,90, par exemple D / L1=0,85.

[0037] Similarly, for a distance L2 separating the internal contour 97 and the external contour 96 of the centering device 95, the distance L2 is such that 0.8 <D / L2<1, et notamment 0,9<D / L2<1.

[0038] THE figures 6 et 7 present two variant embodiments of the centering device 95. In these two variants, the rim 99 projects relative to the intermediate support face 98 of the intermediate helical spring 42.

[0039] In the first variant of the figure 6 , the centering device 95 extends circumferentially all around the Y axis of the intermediate helical spring 42. The centering device 95 therefore has the shape of a tube projecting relative to a front face of the seat comprising the internal bearing surface 93 and the external bearing surface 91. The rim 99, in particular its inclined wall 94, are arranged at the end of the tube opposite the internal 93 and external 91 bearing surfaces.

[0040] In the second variant of the figure 7 , the centering device 95 comprises four pads P spaced from each other, each pad P having an internal edge facing the Y axis of the intermediate helical spring 42 and forming the internal contour 97 of the centering device 95, and each pad P having an external edge facing the side opposite the Y axis of the intermediate helical spring 42 and forming the external contour 96 of the centering device 95.

[0041] In this variant, the internal contour 97 and the external contour 96 of the centering device 95 are therefore discontinuous.

[0042] In another variant not shown, some pads may form part of the inner contour without forming part of the outer contour and other pads may form part of the outer contour without forming part of the inner contour.

[0043] In these two variants, the centering rim 99 comprises an inclined wall 94 pressed against the chamfer 42C of the intermediate helical spring 42. The inclined wall 94 of the centering device 95 connects the intermediate bearing face 98 of the centering device 95 to the external contour 96 of the centering device 95. Indeed, in these two variants, the inclined wall 94 of the centering device cooperates with a chamfer 42C formed on a radially external edge of the first end 42-1 of the intermediate helical spring 42. The intermediate spring 42 and its chamfer 42C are visible on the figure 8 .

[0044] THE figures 9 à 12 illustrate a second embodiment in which the position of the centering rim 99 of the seat 9 differs from that of the first embodiment.

[0045] In this embodiment, the centering rim 99 also comprises an inclined wall 94 pressed against the chamfer 42C of the intermediate helical spring 42. The inclined wall 94 of the centering device 95 connects the intermediate bearing face 98 of the centering device 95 to the internal contour 97 of the centering device 95. In fact, the inclined wall 94 of the centering device 95 cooperates with a chamfer 42C formed on a radially internal edge of the first end 42-1 of the intermediate helical spring 42. The intermediate spring The intermediate spring 42 and its chamfer 42C are visible on the figure 12 In this embodiment the centering device extends continuously around the Y axis.

[0046] With this embodiment, we also have 0.75 < D / L1 < 0.97, preferably 0.75 <D / L1<0,9, notamment 0,8<D / L1<0,90.

[0047] According to a variant not shown, the centering device of this embodiment can be formed by a plurality of pads spaced from each other, like the variant of the previous embodiment.

[0048] In these two embodiments, we note in particular on the figures 5 And 10 that the shape of the rims 99 makes it possible to maintain ratios D / L1 and D / L2 within the ranges of values ​​mentioned above. In a plane comprising the Y axis and passing through the rim 99, the rim 99 has in both embodiments a section of generally triangular shape, one of the sides of which forms the inclined wall 94.

[0049] In the first embodiment of the figure 5 , another of the sides of the generally triangular section forms part of the external contour 96 of the centering device 95.

[0050] In the second embodiment of the figure 10 , another of the sides of the generally triangular section forms part of the internal contour 97 of the centering device 95.

[0051] As previously indicated, the spring arrangement here comprises two seats 9 and 11 arranged at each end of the springs 41, 42 and 43. Here the two seats 9 and 11 are identical.

[0052] Thus, the centering device 95 of the second seat 11 has on the one hand an external contour 96 outside of which the second end 41-2 of the outer helical spring 41 is arranged and on the other hand an internal contour 97 inside of which the second end 43-2 of the inner helical spring 43 is arranged. The centering device 95 of the second seat 11 also has an intermediate bearing face 98 on which a second end 42-2 of the intermediate helical spring 42 can bear. The second end 42-2 of the intermediate helical spring 42 has a chamfer 42D and the centering device 95 of the second seat 11 also has a centering rim 99 cooperating with the chamfer 42D of the intermediate helical spring 42 to center the intermediate helical spring 42.

[0053] Similarly, for a distance L1 separating the outer helical spring 41 from the inner helical spring 43 and for a coil diameter D of the intermediate helical spring 42, the coil diameter D and the centering device 95 of the second seat 11 are arranged so that 0.75 < D / L1 < 0.97. 0.7 < D / L1 < 0.97, preferably 0.75 <D / L1<0,9, notamment 0,8<D / L1<0,90.

[0054] The centering edges 99 are arranged to cooperate with the chamfer 42C of the intermediate coil spring but as can be seen in the figure 10 , the intermediate coil spring can be mounted around the inclined wall with a mounting clearance so that the intermediate coil spring is not radially prestressed by the centering device.

[0055] Similarly, in the case of the first embodiment, the intermediate coil spring may be mounted inside the inclined wall with mounting clearance.

[0056] According to another embodiment not shown, the friction disc is fixed on one of the guide washers and the disc is coupled, via a pre-damper or not, to the central hub.

[0057] Other torque transmission devices may be implemented. For example, the spring arrangement may be provided in any type of torque transmission devices such as, for example, other types of clutch discs, torque limiters, double damped flywheels, or any other device comprising a torsion damper.

Claims

1. Arrangement of springs (4) for a motor vehicle torque transmission device, comprising: - an inner helical spring (43), - an intermediate helical spring (42), inside which the inner helical spring (43) is housed, - an outer helical spring (41), inside which the intermediate helical spring (42) and the inner helical spring (43) are housed, - a first seat (9) comprising an internal bearing surface (93) on which a first end (43-1) of the inner helical spring (43) can bear and an external bearing surface (91) on which a first end (41-1) of the outer helical spring (41) can bear, the first seat (9) also having a centring device (95) projecting with respect to the internal bearing surface (93) and with respect to the external bearing surface (91); the centring device (95) of the first seat (9) having on the one hand an external contour (96) on the outside of which the first end (41-1) of the outer helical spring (41) is arranged and on the other hand an internal contour (97) on the inside of which the first end (43-1) of the inner helical spring (43) is arranged, the centring device (95) of the first seat (9) also having an intermediate bearing face (98) on which a first end (42-1) of the intermediate helical spring (42) can bear, the first end (42-1) of the intermediate helical spring (42) having a chamfer (42C) and the centring device (95) of the first seat (9) having a centring lip (99) arranged to cooperate with the chamfer (42C) of the intermediate helical spring (42) so as to centre the intermediate helical spring (42), said arrangement of springs being characterized in that, for a distance L1 separating the outer helical spring (41) from the inner helical spring (43), and for a turn diameter D of the intermediate helical spring (42), the turn diameter (D) and the centring device (95) are arranged such that 0.75<D / L1<0.97, and in that, for a distance (L2) separating the internal contour (97) and the external contour (96) of the centring device (95) of the first seat (9), the distance (L2) is such that 0.8<D / L2<1.

2. Arrangement of springs (4) according to the preceding claim, wherein the turn diameter (D) and the centring device (95) are arranged such that 0.75<D / L1<0.9.

3. Arrangement of springs (4) according to either of the preceding claims, wherein the turn diameter (D) and the centring device (95) are arranged such that 0.8<D / L1<0.90, for example D / L1=0.85.

4. Arrangement of springs (4) according to one of the preceding claims, wherein the intermediate helical spring (42) extends along an axis (Y) and the centring device (95) extends circumferentially all around the axis (Y).

5. Arrangement of springs (4) according to one of Claims 1 to 4, wherein the centring device (95) comprises a plurality of lugs (P) spaced apart from one another, at least some of the lugs (P) having an internal edge turned towards the axis (Y) of the intermediate helical spring and forming the internal contour (97) of the centring device (95), and at least some of the lugs (P) having an external edge turned away from the axis (Y) of the intermediate helical spring and forming the external contour (96) of the centring device (95).

6. Arrangement of springs according to one of Claims 1 to 5, wherein the centring lip (99) has an inclined wall (94) pressed against the chamfer (42C) of the intermediate helical spring (42), the inclined wall (94) of the lip (99) being arranged on an end of the centring device (95) that is axially opposite the internal and external bearing surfaces of the first seat.

7. Arrangement of springs according to one of Claims 1 to 6, wherein the inclined wall (94) of the centring device (95) connects the intermediate bearing face (98) of the centring device (95) to the external contour (96) of the centring device (95).

8. Arrangement of springs according to one of Claims 1 to 6, wherein the inclined wall (94) of the centring device (95) connects the intermediate bearing face (98) of the centring device (95) to the internal contour (97) of the centring device (95).

9. Arrangement of springs according to one of Claims 1 to 8, wherein, in a plane comprising the axis Y and passing through the lip, the lip (99) has a section of triangular overall shape, one of the sides of the section of triangular overall shape forming the inclined wall (94) and another of the sides of the section of triangular overall shape forming a part of the external (96) or internal (97) contour of the centring device (95).

10. Arrangement of springs according to one of Claims 1 to 9, comprising a second seat (11) comprising an internal bearing surface (93) on which a second end (43-2) of the inner helical spring (43) can bear and an external bearing surface (91) on which a second end (41-2) of the outer helical spring (41) can bear, the second seat (11) also having a centring device (95) projecting with respect to the internal bearing surface (93) and with respect to the external bearing surface (91) of the second seat (11), the centring device (95) of the second seat (11) having on the one hand an external contour (96) on the outside of which the second end (41-2) of the outer helical spring (41) is arranged and on the other hand an internal contour (97) on the inside of which the second end (43-2) of the inner helical spring (43) is arranged, the centring device (95) of the second seat (11) also having an intermediate bearing face (98) on which a second end (42-2) of the intermediate helical spring (42) can bear.

11. Torque transmission device (100) for a motor vehicle, comprising: - a torque input element (2) able to receive the torque generated by the engine of the vehicle; - a torque output element (3) able to transmit torque to a transmission member of the vehicle; - a first element (5) extending around an axis of rotation (X) and rotationally coupled to the torque input element (2), - a second element (6) extending around the axis of rotation (X) and rotationally coupled to the torque output element (3), - an arrangement of springs (4) according to one of the preceding claims, the arrangement of springs (4) being arranged between the first element (5) and the second element (6) so as to transmit torque between the first element (5) and the second element (6) and damp the torque oscillations between the first element (5) and the second element (6).

12. Torque transmission device (100) for a motor vehicle according to the preceding claim, wherein the torque transmission device (100) is a clutch disc (100), the torque input element comprising a friction disc (2), the torque output element (3) comprising a central hub (3B) able to drive a gearbox input shaft, one out of the first element (5) and the second element (6) comprising a central disc (5) and the other out of the first element (5) and the second element (6) comprising two lateral washers (6) arranged on either side of the central disc (5).

13. Clutch for a motor vehicle, comprising a torque transmission device (100) according to either of Claims 11 and 12 and a clutch mechanism that is able to authorize, interrupt or limit the transmission of the torque transmitted to the friction disc (2).