TORSION DAMPER DEVICE, SEAT FOR A TORSION DAMPER DEVICE AND METHOD FOR MANUFACTURING A TORSION DAMPER.

Abstract

The invention relates to a torsion damping device (1) comprising: - a first coaxial part (5) and a second coaxial part (6), - springs (4) acting circumferentially between the first coaxial part (5) and the second coaxial part (6), - a plurality of seats (9), at least one of the seats (9) being a seat that can be mounted in a first orientation (O1) and in a second orientation (O2), this seat (9) being a worn seat mounted in the second orientation (O2) and exhibiting traces of wear (101) caused by previous use in the first orientation (O1).

Description

TORSION DAMPER DEVICE, SEAT FOR A TORSION DAMPER DEVICE AND METHOD FOR MANUFACTURING A TORSION DAMPER DESCRIPTIVE MEMORANDUM The present invention relates to a torsion damper device, a seat for a torsion damper device, and a method for manufacturing a torsion damper. The damping devices in question are of the type that includes two coaxial parts rotatably mounted against each other against springs that act circumferentially between them. A torsional damping device of this type is applied in particular to a clutch friction, particularly for a motor vehicle, particularly for trucks, or to a flywheel of such a motor vehicle, in this case commonly referred to as a dual-mass flywheel. The invention relates more particularly to the situation in which a seat acts circumferentially between at least one of the ends of at least one of the springs and each of the coaxial parts, a front part whose seat presses on the spring and a back part whose seat presses against one and / or the other of the coaxial parts. This device is described in particular in documents EP2094290, FR2627243, FR3079580, EP3026293 and EP0696694. These seats can be pivotally mounted with respect to the first and second coaxial parts around an axis parallel to the axis of rotation of the damping device. Because they are pivotally mounted, the seats, sometimes called cups, allow the springs to operate satisfactorily, even at full torque, particularly by maintaining a degree of parallelism between their ends. The seats are generally made of steel, typically cast steel, and can optionally act as a support for end pieces made of elastic or plastic material that function as full-torque stops against certain springs that press against them until their coils are contiguous. They can also be made entirely of elastic or plastic material, and are manufactured, in particular, by molding. However, these seats tend to wear and become hollow in the contact areas with the first and second coaxial parts, particularly on the upper part of their pivots, i.e., the radially outward-facing portion. This localized wear on the upper part of the pivots occurs due to friction between the seat and the first and second coaxial parts when the springs and seats are subjected to significant centrifugal forces or significant pressure applied by the torque transmitted between the first and second coaxial parts, or when returning to the neutral (or zero torque) position. In other words, with use, the seat support areas will wear down and become hollow. This can lead to premature seat wear and malfunction of the torsion-damping device. The present invention has as its particular objective to increase the service life of seats and reduce the manufacturing cost of a torsion damping device. To this end, the invention relates to a torsional damping device that includes: - a first coaxial part and a second coaxial part rotatably mounted relative to each other around an axis of rotation (X), - springs acting circumferentially between the first coaxial part and the second coaxial part so that they elastically oppose the relative rotation of the first coaxial part and the second coaxial part around the axis of rotation (X), - a plurality of seats, each seat comprising a front part that presses against a spring end, and a back part that presses on the first coaxial part and / or the second coaxial part. According to a first aspect of the invention, one of the seats is a seat that can be mounted in a first orientation and in a second orientation, this seat being a worn seat that shows signs of wear. Wear marks are understood to be the marks of wear visible to the naked eye. These traces of wear may correspond particularly to parts of the seat that have been previously hollowed out by the seat, mounted in the first orientation, pressing against the first and / or second coaxial part of a worn damping device. A worn shock absorber is defined as a shock absorber that has already been used in a first vehicle in circulation and has been sent to a recycling channel due to suspected or observed defects in its use in the first vehicle. According to one model, the worn seat is mounted in the second orientation and shows signs of wear caused by previous use in the first orientation. The seat can thus be initially mounted in two different positions and reused in one of them to extend its service life. This reduces the proportion of waste in a worn shock-absorbing device. In other words, a seat can be: - used in a first orientation in a first damper during a first life cycle, - then, having been removed from the first shock absorber, reused in a second orientation in a second shock absorber for a second life cycle. The damping device provided with the worn seat mounted in the second orientation is therefore more economical and has damping properties that are substantially equivalent to those of an equivalent damping device provided only with new seats. The torsion-damping device associated with the second life cycle of the seat may also have one or more of the following characteristics: - The back of each worn seat comprises a back face and at least one support relief protruding from the back face and arranged to press against the first coaxial part and / or the second coaxial part, the wear marks being located more than 90% or entirely on said at least one support relief. - The dorsal part of each worn seat comprises a dorsal face and at least one support relief projecting from the dorsal face and arranged to press against the first coaxial part and / or the second coaxial part, said at least one support relief comprising, viewed in a plane perpendicular to the axis of rotation (X): - a summit, - a first wall, - a second wall connected to the first wall by means of the summit and located radially outside the first wall, the traces of wear being located partially or totally on the first wall. - The wear marks located on the first wall of the worn seat were produced during previous use when the seat was used in the first orientation, i.e., when the first wall of the seat placed in the first orientation corresponded to the radially outer wall of the support relief. - The second wall is able to interact with a support portion formed in the first coaxial part and / or in the second coaxial part so that the worn seat is retained radially when subjected to centrifugal forces. - At a high speed of the torsion damper device located in the normal operating range of the torsion damper device, the seats can be centrifuged and the radially outer walls of the support reliefs are pressed on the first coaxial part and / or the second coaxial part. - Said at least one support relief extends in a direction parallel to the X axis of rotation. ζοαη ίη / 77Π7 / Ε / γΐΛΐ The top of the worn seat includes a demarcation line separating the first wall from the second wall. This makes it easier to check, during disassembly, whether the wear is concentrated only on the first wall or extends to both. If the wear is concentrated on the first wall on only one side of the demarcation line, the seat can be turned over for reuse. Conversely, if the wear extends to both sides of the demarcation line during the first use, the seat can no longer be reused in the second orientation. Thus, the line visually indicates a limit that the wear marks must not reach during the first use if the seat is to be reused in the second orientation. - The demarcation can be a furrow. The demarcation can also be a line marked across the crest of the seat. - The demarcation extends along an axis parallel to the X rotation axis. The summit can be a ridge that extends along an axis parallel to the X rotation axis and that separates the first wall and the second wall. - The first wall and the second wall extend in a direction parallel to the X rotation axis. The second wall is oriented radially outwards so that it is radially supported by the support portion formed in the first coaxial portion and / or the second coaxial portion. A portion oriented radially outwards does not necessarily extend strictly in the circumferential direction but may have a radial component. - The wear marks of each worn seat are located partially or completely outside the second wall. For example, more than 90% of the wear marks are located outside the second wall. - The wear marks of each worn seat are located partially or totally on the first wall. The second orientation of the worn seat in the torsion-damping device corresponds to rotating the worn seat 180 degrees relative to its previous use in the first orientation. In other words, the worn seat is reused from back to front. - The spring associated with the worn seat extends around a Y axis. - The seat has a Y' rotation axis located substantially in continuation of the Y axis of the associated spring. - The worn seat rotates between its first orientation and its second orientation on the Y' axis of the seat. - The rotation is a 180-degree rotation. - The worn seat comprises a front face arranged to press against a spring end. - The front face of the worn seat is positioned perpendicular to the Y-axis of the spring. ζοαη ίη / 77Π7 / Ε / γΐΛΐ - The worn seat is a seat that pivots on an axis parallel to the X-axis of the damping device and said at least one support relief is a pivot lug. - The worn seat comprises a first axial clamping arrangement comprising walls for axially clamping the worn seat with respect to the first coaxial part and the second coaxial part, and a second axial clamping arrangement also comprising walls for axially clamping the worn seat with respect to the first coaxial part and the second coaxial part, the first axial clamping arrangement and the second axial clamping arrangement being arranged on each side of the pivot lug, the axial clamping walls of the first axial clamping arrangement being arranged in the same planes as the axial clamping walls of the second axial clamping arrangement. Rotating the seat for its second use in the second orientation does not affect the axial clamping of the components. The worn seat was previously used with the first axial clamping device positioned radially outside the pivot lug, and the worn seat is now used in the torsion-damping device with the second axial clamping device positioned radially outside the pivot lug. - The pivot lug formed on the dorsal part of the worn seat is inserted into a first housing formed in the first coaxial part and / or into a second housing formed in the second coaxial part, the pivot lug being pressed into the first housing of the first coaxial part and / or into the second housing of the second coaxial part. - The pivot lug is shaped like a portion of a bar. - The worn seat is made of metal, for example steel. - One of the first coaxial part and the second coaxial part comprises two side washers rigidly connected to each other for joint rotation about the axis of rotation (X), and the other of the first coaxial part and the second coaxial part comprises an intermediate washer arranged about the axis of rotation (X) and axially between the two side washers, the springs of the torsion damper device being arranged in recesses in the intermediate washer and in the side washers so that they are circumferentially compressed when the side washers and the intermediate washer of the damper move away from a relative angular rest position, i.e., when they rotate relative to each other. - The first axial clamping device and the second axial clamping device each comprise a first rib and a second rib between which an edge face of the intermediate washer is inserted. - For each axial clamping arrangement, the first rib comprises an outer wall against which one of the two side washers can be axially pressed and an inner wall against which the middle washer can be axially pressed. ζοαη ίη / 77Π7 / Ε / γΐΛΐ - For each axial clamping arrangement, the second rib comprises an outer wall against which the other of the two side washers can be axially pressed and an inner wall against which the middle washer can be axially pressed. In other words, for each axial clamping arrangement, the edge faces of the two side washers are positioned axially on each side of the two ribs, and one edge face of the middle washer is positioned axially between the two ribs. - The first axial clamping device is symmetrical to the second axial clamping device with respect to the Y' axis of rotation of the worn seat used to change it from the first orientation to the second orientation. - When viewed along the Y-axis of the spring, the worn seat has a contour that has an axis of symmetry. - According to one model, the worn seat generally has a global axis of symmetry. - According to one modality, the axis of symmetry is the Y' axis of the seat or the Y axis of the associated spring. - According to one embodiment, the worn seat comprises a suitable mounting poka-yoke to prevent the worn seat from being mounted on the torsion-damping device in the first orientation. - According to one modality, the symmetry of the worn seat is only broken by the mounting pokayoke and / or the wear marks. The invention also relates to a seat (used or not) for a torsion damper device comprising, on one hand, a front portion intended to press against one end of a spring and, on the other hand, a back portion intended to press against a first coaxial portion and / or a second coaxial portion of a torsion damper device, wherein the seat can be mounted in a first orientation and in a second orientation on the torsion damper device. This seat may include one or more of the following features: - The dorsal part comprises a dorsal face and at least one support relief projecting from the dorsal face and arranged to press against the first coaxial part and / or the second coaxial part, said at least one support relief comprising, viewed in a plane perpendicular to the axis of rotation (X): - a summit, - a first wall, - a second wall connected to the first wall by means of the summit and located radially outside the first wall. ζοαη ίη / 77Π7 / Ε / γΐΛΐ - The first wall and the second wall are arranged on either side of an axis perpendicular to the dorsal face and passing through the summit. - The relief of the support extends in a direction parallel to the X rotation axis. - The summit of the seat includes a demarcation that separates the first wall from the second wall. As explained previously, it is easy to determine whether the signs of wear affect both walls or only one. - The demarcation is a furrow. - The seat is a seat that pivots on an axis parallel to the X axis of rotation of the damping device and said at least one support relief is a pivot lug. - The dorsal part is arranged in a plane P and the support relief is a bar portion having, on one surface, a substantially circular cross-section centered at C, the bar portion forming an element of a pivot connection, the axis of the bar portion passing through the center C of the bar portion extending a predetermined distance d not substantially equal to zero from plane P. - For a radius r of the substantially circular section of the bar portion, d>r / 3 and preferably d>r / 2, in particular d>2r / 3 and in particular d>r. - The seat comprises a first axial clamping arrangement comprising axial clamping walls of the seat with respect to the first coaxial part and the second coaxial part, and a second axial clamping arrangement also comprising axial clamping walls of the seat with respect to the first coaxial part and the second coaxial part, the first axial clamping arrangement and the second axial clamping arrangement being arranged on each side of the pivot lug, the axial clamping walls of the first axial clamping arrangement being arranged in the same planes as the axial clamping walls of the second axial clamping arrangement. - The first axial clamping arrangement is symmetrical to the second axial clamping arrangement with respect to the Y' axis of rotation of the seat used to change it from the first orientation to the second orientation. - When viewed along the Y-axis, the seat has a contour that has an axis of symmetry. - According to one model, the seat generally has a global axis of symmetry. - The seat consists of a poka-yoke mounting system. - Of course, the seat can include any of the features already mentioned in relation to the torsion-damping device. The invention also relates to a torsion damping device comprising: - a first coaxial part and a second coaxial part rotatably mounted ζοαη ίη / 77Π7 / E / γΐΛΐ relative to each other about a rotation axis X, - springs acting circumferentially between the first coaxial part and the second coaxial part so that they elastically oppose the relative rotation of the first coaxial part and the second coaxial part around the rotation axis X, - a plurality of seats, each seat comprising, on the one hand, a front part that presses against one end of the spring and, on the other hand, a back part that presses on the first coaxial part and / or the second coaxial part, wherein at least one of the seats is a seat as described above. The device may include one or more of the following features: - It has been stated that at least one of the seats is a worn seat and shows traces of wear caused by previous use in the first orientation. - The signs of wear are located partially or totally on the first wall. - The wear marks of each worn seat are located partially or totally outside the second wall. - The wear marks of each worn seat are located partially or totally on the first wall. - The second seat orientation corresponds to a 180-degree rotation of the seat with respect to the first orientation. The invention also relates to a method for manufacturing a torsional damper comprising a first coaxial part and a second coaxial part rotatably mounted relative to each other about a rotation axis X, springs housed in recesses in the first and second coaxial parts and acting circumferentially between the first coaxial part and the second coaxial part so as to elastically oppose the relative rotation of the first coaxial part and the second coaxial part about the rotation axis X, a plurality of seats, each seat comprising a front portion pressing against an end spring and a back portion pressing on the first coaxial part and / or the second coaxial part, the manufacturing method comprising the following steps: - supply a worn seat that shows signs of wear, - mount the worn seat on a spring, - Insert the assembly comprising the worn seat and spring into a recess in the first coaxial part and into a recess in the second coaxial part. The worn seat may have one or more of the characteristics listed above. The method may include one or more of the following features: Each worn seat can be mounted in a second orientation and a first orientation. The worn seat has been mounted in the first orientation during a previous use, and the step of inserting the assembly comprising the worn seat and spring is such that the worn seat is mounted in the second orientation in the recesses of the first and second coaxial parts. The dorsal portion of each worn seat comprises a dorsal face and at least one support relief projecting from the dorsal face and suitable for pressing against the first coaxial portion and / or the second coaxial portion, said relief comprising: - a summit, - a first wall that shows signs of wear, - a second wall connected to the first wall through the summit, and the insertion step being the assembly comprising the spring and the support seats such that, when the worn seat is observed in a plane perpendicular to the axis of rotation (X), the first wall is found in the torsional damping device radially inside the second wall. Fortunately, the second wall shows no signs of wear. The worn seat comprises a first axial clamping arrangement and a second axial clamping arrangement suitable for interacting with the first and second coaxial parts of the torsion-damping device, the first axial clamping arrangement and the second axial clamping arrangement being located on each side of a pivot lug of the worn seat, the worn seat having been previously used, in the first orientation, with the first axial clamping arrangement positioned radially outside the pivot lug and the worn seat being suitable for use in the torsion-damping device, in the second orientation, with the second axial clamping arrangement positioned radially outside the pivot lug. Eventually, at least one support relief is partially or totally formed by the pivot lug. The worn seat includes a mounting poka-yoke and, during the step of inserting the assembly comprising the worn seat and spring into the first and second coaxial parts, the assembly comprising the worn seat and spring passes through a mounting template before being inserted into the recesses of the first and second coaxial parts, the mounting template including a complementary poka-yoke, the complementary poka-yoke being arranged so that the mounting template only allows passage of the worn seat in the second orientation. ζοαη ίη / 77Π7 / Ε / γΐΛΐ The poka-yoke of the worn seat is formed in one of the first axial clamping arrangement and the second axial clamping arrangement. Advantageously, prior to the supply step of a worn seat that shows signs of wear, the manufacturing method comprises the following steps: - Remove a worn shock absorber, - store the worn shock absorber seats. According to one variant, one of the first coaxial part and the second coaxial part comprises two side washers rigidly connected to each other for joint rotation around the rotation axis (X), and the other of the first coaxial part and the second coaxial part comprises an intermediate washer, the two side washers, and the intermediate washer from the worn shock absorber. In other words, this may be a method for repairing the worn shock absorber. The invention also relates to the use of a worn seat to manufacture a torsion-damping device. The worn seat and torsion damping device may comprise one or more of the features mentioned above. In particular, the worn seat has previously been used in a first orientation and the worn seat is used in a second orientation in the torsion damping device. The invention will be better understood by reading the following description and with reference to the accompanying figures. The figures are provided solely for illustrative purposes and are not intended to limit the invention. [Figure 1] illustrates a prior art torsion damping device. [Figure 2] illustrates an assembly comprising a spring and two seats of another prior art torsion damping device. [Figure 3] illustrates a front view of a worn seat from Figure 2. [Figure 4] illustrates a side view of a worn seat from Figure 2. [Figure 5] illustrates the displacement of the seat when subjected to centrifugal forces or when torque is transmitted. [Figure 6] illustrates a front view of a worn seat in a first embodiment of the invention. [Figure 7] illustrates a side view, in a plane perpendicular to the axis of rotation of the shock absorber, of the worn seat of Figure 6. [Figure 8] illustrates the principle of turning the worn seat over in Figure 6. [Figure 9] illustrates an assembly comprising a spring and two seats in a second embodiment of the invention. [Figure 10] illustrates a side view, in a plane perpendicular to the axis of rotation of the ζοαη ίη / ζζηζ / E / γίΛΐ shock absorber, of a worn seat from Figure 9. [Figure 11] illustrates a front view of the worn seat in Figure 10. [Figure 12] illustrates a first template for assembling an assembly comprising a spring and two new seats. [Figure 13] illustrates the step of inserting the assembly comprising the spring and seats. [Figure 14] illustrates a second template for assembling an assembly comprising a spring and two worn seats, for manufacturing a torsion damping device according to the second modality. [Figure 15], [Figure 16] and [Figure 17] illustrate variant modalities. In the description and claims, the terms exterior and interior, as well as axial and radial orientations, shall be used to designate elements of the torsional damping device according to the definitions given in the description. The X-axis of rotation of the damping device determines the axial orientation. Therefore, an axial rotation is a rotation about the X-axis, and the axial fixation of an element limits, or even prevents, the translation of that element parallel to this X-axis. The radial orientation is orthogonal to the X-axis. The circumferential orientation is orthogonal to the X-axis of rotation and orthogonal to the radial direction. In the radial direction, the terms exterior and interior 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 this axis is thus described as interior relative to an exterior component located radially on the periphery. Figure 1 shows an example of a known torsional damping device 1 described in patent application FR3079580. The damping device 1 is associated in this case with a friction disc 2 and a central hub 3 to form a clutch disc 1 suitable for placement between a vehicle's engine and its gearbox. The friction disc 2 includes a circular friction lining. The friction lining is designed to be selectively pressed by a clutch mechanism against a flywheel attached to the vehicle's engine to transmit torque between the engine and the friction disc. The central hub 3 is designed to be coupled so that it is forced to rotate, via its internal splines, with the input shaft of the vehicle's gearbox. In this way, torque can be transmitted between the friction disc 2 and the central hub 3, or vice versa, via the torsional damping device 1. The torsional damping device 1 allows relative rotational movement about the X-axis between the central hub 3 and the friction disc 2 to dampen torsional oscillations during torque transmission. In this example, the torsional damping device includes five springs 4 arranged circumferentially around the central hub 3. The torsional damping device compresses the springs 4 between a first coaxial part 5 and a second coaxial part 6 to provide damping. In this example, the second coaxial part 6 consists of a pair of side washers 60, also referred to as guide washers 60, which are rigidly connected to each other for joint rotation. The first coaxial part 5 comprises an intermediate washer 50, hereinafter referred to as the flange 50, positioned axially between the two guide washers 60.In this example, the friction disc 2 is fixed to the flange 50, for example by rivets, and the two guide washers 60 are both fixed by rivets to the central hub 3, on both sides of the flange 50. The guide washers 60 and the flange 50 thus constitute an axial stack of three discs with possible relative rotation between the flange 50 and the guide washers 60, which also corresponds, in the absence of a pre-damper, to the possible rotation between the friction disc 2 and the central hub 3. For each spring 4, the flange 50 comprises an opening 7 and the guide washers 60 each comprise an opening 8. The corresponding spring 4 is mounted in the openings 7, 8 such that its ends each interact with an edge of the opening 7 and an edge of each opening 8. The ends of the spring 4 interact with the openings 7, 8 by means of two seats 9, each positioned at one end of the spring 4. Therefore, each of the seats 9 presses against an edge of the opening 7 and against an edge of each of the openings 8. Pivot lugs 10 are provided to allow the seats 9 to pivot with respect to the flange 50 and with respect to the guide washers 60. At the level of each spring 4, when relative axial rotation occurs between the flange 50 and the two guide washers 60, one of the seats 9 is compressed solely by the flange 50 and moves away from the edges of the openings 8 in the guide washers 60, while the other seat 9, at the opposite end of spring 4, presses only against the guide washers 60 as the edge of the opening 7 in flange 50 moves away. Spring 4 is thus compressed during the relative movements between flange 50 and guide washers 60 to perform the torsional damping function. The interaction between the ends of spring 4 and flange 50 and guide washers 60 is optimized and made more reliable by the seats 9, which hold spring 4 in place and provide an interface that prevents the ends of spring 4 from becoming excessively damaged by contact with flange 50 and guide washers 60. The seats 9 also provide satisfactory guidance of spring 4 because the pivot lugs 10 allow compression of spring 4 without spurious forces. The ends of spring 4 remain substantially parallel to each other during compression, due to the pivot lugs 10. Figures 2 to 5 show another known prior art seat 9 that also has a pivot lug 10. The pivot lug 10 of the seat is in the form of a crossbar that extends substantially along the diameter of the seat 9. The seat shown is worn. It has wear marks 101. The pivot lug 10 presses together on three pivot notches, namely, the pivot notch 53 of the flange 50 in the center and, axially on either side of it, the two pivot notches 63 of the guide washers 60. The housing created by the three pivot notches 53, 63 thus receives the pivot leg 10, allowing it to pivot about an axis that extends axially, i.e., parallel to the rotation axis X. Pivot notch 53 is provided on the corresponding edge of opening 7 and each pivot notch 63 is provided on a corresponding edge of opening 8. These seats 9 also include axial clamping arrangements, described below, which include clamping walls that maintain relative positions, in the axial direction, between seat 9 and flange 50 and between seat 9 and guide washers 60. Each seat comprises a first clamping device 120 and a second clamping device 130, each of which comprises a first rib 121, 131 and a second rib 122, 132 between which a flange edge face 50 is inserted. For each axial clamping arrangement, the first rib 121, 131 comprises an outer wall 126, 136 against which one of the two side washers 60 can be axially pressed and an inner wall 123, 133 against which the flange 50 can be axially pressed. Likewise, for each axial clamping device 120, 130, the second rib 122, 132 comprises an outer wall 128, 138 against which the other of the two side washers 60 can be axially pressed and an inner wall 125, 135 against which the flange 50 can be axially pressed. In other words, for each axial clamping arrangement, the edge faces of the two side washers 60 are positioned axially on each side of the two ribs 121, 122, 131, 132 and one edge face of the flange 50 is positioned axially between the two ribs. When viewed in a plane perpendicular to the axis of rotation (X), the pivot lug 10 comprises: - an S summit, - an interior wall; - an outer wall joined to the first wall by means of the summit S and located radially outside the inner wall. When mounted and the shock absorber is worn, this seat therefore exhibits signs of wear 101 located partially or totally on the outer wall due to centrifugal forces and the forces of approach of the seat by one of the coaxial parts, as explained above. In particular, the outer wall is able to interact with a support portion formed in the first coaxial part or the second coaxial part in such a way that the worn seat zoan Ln / zznz / E / YiAi is retained radially when subjected to centrifugal forces (Figure 5). Due to centrifugal forces E and torque transmission forces, wear marks 101 appear on the outer wall of the pivot lug in the areas of the lug that press against the flange 50 and the side washers 60. In other words, when worn, the seats of Figures 2 to 5 exhibit wear marks 101 concentrated on the outer wall of the pivot lug 10. It is not possible to rotate this prior art seat so that the second and first walls of the pivot lug are reversed, as this seat has radially inward recesses on its outer contour through which portions of the side washers can pass. If this type of seat were mounted from back to front, an undesirable interference would therefore occur between the side washers 60 of the damping device and the seat 9, on the radially inward portion of the seat 9. Figures 6 to 9 show a seat of a first embodiment of a torsional damping device. The first embodiment of a torsional damping device has coaxial parts 5, 6 and springs 4 of the same type as those illustrated in Figure 1. Elements identical to or performing the same function as the elements described above have the same reference sign. According to this first embodiment, the torsion-damping device comprises a seat 9 that can be mounted in a first orientation OI and in a second orientation O2, this seat 9 being a worn seat mounted in the second orientation O2 and bearing traces of wear 101 caused by previous use in the first orientation OI. Wear marks are understood to be the marks of wear visible to the naked eye. Seat 9 can initially be used in two different positions and reused in one of the two positions to extend its service life. The seat illustrated in Figures 6 and 7 is suitable for such reuse. This seat 9 comprises a front part 9F that presses against a spring end 4, and a back part 9D that presses on the first coaxial part 5 and / or the second coaxial part 6. The front portion 9F comprises a front face arranged to press against a spring end 4. The front face of the worn seat 9 is arranged perpendicular to the Y-axis of the spring. The dorsal part 9D of each worn seat 9 comprises a dorsal face 92 and at least one pivot lug 10 protruding from the dorsal face 92 and arranged to press against the first coaxial part 5 and / or the second coaxial part 6. In figures 6 and 7, the wear marks are located on the first wall 12, which in this case is on the top, i.e. radially on the outside, when the seat is mounted on the shock absorber, since figures 6 and 7 illustrate a worn seat in its first orientation. After a disassembly step of a worn damping device in which this seat is positioned in this first orientation, the seat is reused in a torsional damper according to the first embodiment of the invention so that the wear marks 101 are located partially or completely on the radially inner wall 12 (first wall 12). The second wall 11, which will be under the most stress during the second use of the seat, is thus in very good condition. The wear marks 101, which are then located on the first wall 12 of the pivot lug, have no impact on the effectiveness of the torsional damping device. The switch from the previous first use of the seat in its first orientation OI to its reuse (or second use) in its second orientation O2 is shown schematically in Figure 8.The second orientation 02 of the worn seat 9 in the torsion damper 1 corresponds to a 180-degree rotation of the worn seat with respect to its first orientation OI in the worn damper. The spring associated with the worn seat extends around a Y-axis, and the worn seat rotates between its first and second orientations around a Y'-axis of the seat substantially aligned with the Y-axis of the spring with which it interacts. In other words, the worn seat 9 is reused from back to front. With reference to the right side of Figure 8, which illustrates the worn seat in a plane perpendicular to the rotation axis X in its second orientation 02, it can be seen that the pivot lug 10 comprises: - an S summit, - a first wall 12, - a second wall 11 joined to the first wall by means of the summit S and located radially outside the first wall 12. The signs of wear are located in this case entirely on the first wall 12. The second wall 11 is able to interact with a support part 51 formed in the first coaxial part 5 and / or a complementary second support part formed in the second coaxial part 6 such that the worn seat 9 is retained radially when subjected to centrifugal forces. When seat 9 is mounted within the torsion-damping device, the pivot lug 10 extends in a direction parallel to the rotation axis X. The summit S of seat 9 is an axially extending ridge that separates the first wall and the second wall. The first wall 12 and the second wall 11 also extend in a direction parallel to the rotation axis X. Within the scope of the invention, it shall be understood that the second wall 11 is situated, with respect to the rotation axis X of the torsion damper and in the second orientation 02, radially outside the first wall 12. When the seat 9 is mounted on the torsion damper device, in particular according to the first embodiment, its second wall 11 is oriented radially outwards so that it is radially retained by the support portion formed in the first coaxial part 5 and / or the complementary second support portion formed in the second coaxial part 6. In this case, as can be seen on the right side of Figure 8, the wear marks 101 of each worn seat 9 are located completely outside the second wall 11 when it is positioned for reuse in its second orientation. The wear marks 101 of the worn seat in figure 8 are in this case located entirely on the first wall 12. The X-axis is shown in Figure 8 to distinguish between the two orientations OI and O2. Of course, the distance separating it from seat 9 has been shortened. The worn seat 9 comprises a first axial clamping arrangement 120 comprising walls for axially clamping the worn seat with respect to the first coaxial part 5 and the second coaxial part 6, and a second axial clamping arrangement 130 comprising walls for axially clamping the worn seat with respect to the first coaxial part 5 and the second coaxial part 6. The first axial clamping device 120 and the second axial clamping device 130 are arranged on both sides of the pivot lug 10. The axial clamping walls of the first axial clamping arrangement 120 are arranged in the same planes as the axial clamping walls of the second axial clamping arrangement 130. The worn seat 9 was previously used with the second axial clamping arrangement 130 placed radially within the pivot lug and the worn seat 9 is used in the torsion damping device with the first axial clamping arrangement 120 placed radially within the pivot lug 10. The first clamping arrangement 120 and the second clamping arrangement 130 each comprise a first rib 121, 131 and a second rib 122, 132 between which an edge face of the flange 50 is inserted. For each axial clamping arrangement 120, 130, the first rib 121, 131 comprises an outer wall 126, 136 against which one of the two side washers 60 can be axially pressed and a first inner wall 123, 133 against which the flange 50 can be axially pressed. For each axial clamping arrangement, the second rib 122, 132 comprises a second outer wall 128, 138 against which the other of the two side washers 60 can be axially pressed and a first inner wall 133, 135 against which the flange 50 can be axially pressed.In other words, for each axial clamping arrangement 120, 130, the edge faces of the two side washers 60 are axially positioned on both sides of the two ribs 121,122,131,132 and an edge face of the flange 50 is axially positioned between these two ribs. The first axial clamping arrangement 120 is symmetrical to the second axial clamping arrangement 130 with respect to the rotation axis Y of the worn seat used to change it from the first orientation OI to the second orientation O2. The axial clamping is therefore identical in the first orientation OI and in the second orientation O2 of the seat 9. The worn seat 9 has a contour with an axis of symmetry. The rotation axis Y' of the seat is therefore an axis of symmetry. Unlike the known seat in Figures 3 and 4, this seat can therefore be mounted in both orientations O1 and O2. According to a second embodiment shown in Figures 9 to 11, the torsion damping device comprises a worn seat 9 provided with a mounting poka-yoke 98 suitable to prevent the worn seat 9 from being mounted on the torsion damping device in the first OI orientation. Figures 9 to 11 illustrate a worn seat in its first orientation OI. As can be seen in Figure 11, the symmetry of the worn seat is only broken by the mounting poka-yoke 98 and the wear marks 101. The poka-yoke 98 of the worn seat is formed in this case in the first axial clamping arrangement 120, in its ribs 121, 131. In this case, the poka-yoke takes the form of cavities 98. According to one variant, not polished, the wear marks are not concentrated on a pivot lug but on another type of support relief. The invention also relates to a method for manufacturing a torsional damper comprising a first coaxial part and a second coaxial part rotatably mounted relative to each other about a rotation axis X, springs housed in recesses in the first and second coaxial parts and acting circumferentially between the first coaxial part and the second coaxial part so as to elastically oppose the relative rotation of the first coaxial part and the second coaxial part about the rotation axis X, a plurality of seats, each seat comprising a front portion pressing against an end spring and a back portion pressing on the first coaxial part and / or the second coaxial part, the manufacturing method comprising the following steps: - feed a worn seat 9 that shows signs of wear and originates from a worn damping device, - mount the worn seat 9 on a spring 4 of the torsion damper device, ζοαη ίη / ζζηζ / E / γίΛΐ - arrange the assembly comprising the worn seat 9 and the spring 4 in the recesses of the first and second coaxial parts. Preferably, each worn seat 9 is capable of being mounted in a first orientation 01 and a second orientation 02, the worn seat being mounted in the first orientation on the worn damping device, and the step of arranging the assembly comprising the worn seat and the spring being such that the worn seat is mounted in the second orientation in the recesses in the first and second coaxial parts. The dorsal portion 9D of each worn seat comprises a dorsal face and at least one pivot lug 10 projecting from the dorsal face 92 and arranged to press against the first coaxial portion 5 and / or the second coaxial portion 6, the assembly comprising the worn seat and the spring 4 being positioned such that said at least one pivot lug 10 comprises, viewed in a plane perpendicular to the X-axis: - an S summit, - a second wall 11 arranged radially off the summit S, - a first wall 12, arranged radially inside the summit S and joined to the second wall through the summit S, the wear marks 101 being essentially, or even completely, located on the first wall 12 of said at least one pivot lug 10. The worn seat 9 comprises a first axial clamping arrangement 120 and a second axial clamping arrangement 130 suitable for interacting with the first and second coaxial parts 5 and 6 of the torsion-damping device 1, the first axial clamping arrangement 120 and the second axial clamping arrangement 130 being situated on either side of the pivot lug 10 of the worn seat 9, the worn seat 9 having been previously used, in the first orientation OI, with the first axial clamping arrangement 130 positioned radially within the pivot lug 10 and the worn seat 9 being suitable for use in the torsion-damping device, in the second orientation O2, with the first axial clamping arrangement 120 positioned radially within the pivot lug 10. In the embodiment of figures 9 to 14, the worn seat 9 includes a mounting poka-yoke 98 and the assembly comprising the worn seat and spring passes through a mounting template before being inserted into the recesses of the first and second coaxial parts 5 and 6, the mounting template including a complementary poka-yoke that interacts with the mounting poka-yoke 98. Two mounting templates can be used. The seat orientations in Figures 12 and 14 are shown in parentheses. A first assembly template 201 can be used with new seats 9 equipped with a poka-yoke 98. ζοαη ίη / ζζηζ / Ε / γίΛΐ The complementary poka-yoke 198 of the first mounting template 201 is arranged so that the first mounting template 201 only allows the passage of the new seat 9 in the first OI orientation. After they have been removed from a worn damping device, a second mounting template 202 can be used to remount the worn seats onto a torsion damping device. The complementary poka-yoke 298 of the second mounting template 202 is arranged so that the second mounting template 202 only allows the worn seat 9 to pass through in the second orientation 02. In this case, the complementary poka-yoke 298 of the second mounting template 202 is located radially inside the opening through which the spring passes, while the complementary poka-yoke 198 of the first mounting template 201 is located radially outside the opening through which the spring passes. Therefore, the seat cannot be remounted in the used OI position. In this case, the poka-yoke is formed by two cavities 98 formed in the seat 9, more specifically in the axial clamping ribs 121 and 122. The complementary poka-yoke 198, 298 of the first and second mounting templates is a protrusion 198, 298. The cavity 98 slides around the protrusion 198, 298 during the assembly of the assembly comprising the seats 9 and the spring 4 on the first and second coaxial parts. According to one variant, the cavity is formed on the mounting template and the protrusion is formed on the seat. The manufacturing method can be implemented in two different contexts. In a first context, the shock absorbers are manufactured with worn seats 9. In this case, the worn seats 9 come from different worn shock absorbers that have been disassembled and whose worn seats have been preserved and stored for reuse. In a second implementation context, the worn shock absorbers are repaired and their worn seats 9 are reinstalled from back to front. The side washers 60 and the intermediate washer 50 of such shock absorbers may, for example, remain unchanged. It will be understood that during the second life cycle of the worn seat, new traces of wear will appear, not shown on the right side of figure 8, on the second wall 11 (second orientation of the seat). Another variant of the seat is shown in Figures 15 and 16. The summit S comprises a demarcation groove 160 that separates the first wall 12 from the second wall 11. The seats pivot around an axis parallel to the X rotation axis of the damping device and the support reliefs 10 are pivot lugs. 700(1 ίη / 77Ω7 / Β / YΙΛΙ As can be seen in Figure 17, it is advantageous that the seats can pivot and that the seat pivot is offset. The dorsal face 92 of the dorsal part 9D is disposed in a plane P, and the support relief is a bar portion having, on one surface, a substantially circular cross-section centered at C. The bar portion forms an element of a pivot connection, the axis of the bar portion passing through the center C of the bar portion and extending a predetermined distance d, not substantially equal to zero, from the plane P. Preferably, for a radius r of the substantially circular cross-section of the bar portion, d > r / 3 and preferably d > r / 2, in particular d > 2r / 3 and in particular d > r. According to other variants of the modality, the friction disc can be mounted on a side washer and the central drive hub of the gearbox input shaft can be coupled to the flange. In the case of a double-mass flywheel, the second coaxial part may consist of a primary flywheel optionally provided with a cover, and the first coaxial part may consist of a flange coupled to the secondary flywheel.

Claims

1. A seat (9) for a torsion damping device comprising, on one side, a front part (9F) intended to press against one end of a spring (4) and, on the other side, a back part (9D) intended to press against a first coaxial part (5) and / or a second coaxial part (6) of a torsion damping device, characterized in that the seat (9) can be mounted in a first orientation (01) and in a second orientation (02) on the torsion damping device.

2. The seat (9) according to claim 1, further characterized in that the dorsal part (9D) comprises a dorsal face (92) and at least one support relief (10) projecting from the dorsal face (92) and arranged to press against the first coaxial part (5) and / or the second coaxial part (6), said at least one support relief (10), viewed in a plane perpendicular to the axis of rotation (X): - a summit (S), - a first wall (12), - a second wall (11) joined to the first wall by means of the summit (S) and located radially outside the first wall (12); the first wall (12) and the second wall (11) being arranged on either side of an axis perpendicular to the dorsal face and passing through the summit (S).

3. The seat according to the preceding claim, further characterized in that the relief of the support (10) extends in a direction parallel to the rotation axis X.

4. The seat according to claim 2 or 3, further characterized in that the summit (S) comprises a demarcation (160) that separates the first wall (12) from the second wall (11).

5. The seat according to the preceding claim, further characterized in that the demarcation (160) is a groove.

6. The seat according to any one of claims 2 to 5, further characterized in that the seat (9) is a seat pivoting about an axis parallel to the rotation axis X of the damping device and said at least one support relief (10) is a pivot lug.

7. The seat according to the preceding claim, further characterized in that the dorsal part (9D) is arranged in a plane P and the support relief is a bar portion having, on one surface, a substantially circular cross-section centered at (C), the bar portion forming an element of a pivot connection, the axis of the bar portion passing through the center (C) of the bar portion extending a predetermined distance (d) not substantially equal to zero from plane P.

8. The seat according to the preceding claim, further characterized in that, for a radius (r) of the substantially circular cross-section of the bar portion, d>r / 3 and preferably d> r / 2, in particular d>2r / 3 and in particular d>r.

9. The seat according to any one of claims 2 to 8, further characterized in that it comprises a first axial clamping arrangement (120) comprising walls (123, 125, 126, 128) for axially clamping the seat with respect to the first coaxial part (5) and the second coaxial part (6), and a second axial clamping arrangement (130) also comprising walls (133, 135, 136, 138) for axially clamping the seat with respect to the first coaxial part (5) and the second coaxial part (6), the first axial clamping part (120) and the second axial clamping arrangement (130) being arranged on each side of the pivot lug (10), the axial clamping walls of the first axial clamping arrangement being arranged in the same planes as the axial clamping walls of the second axial clamping arrangement.

10. The seat according to any one of claims 1 to 9, further characterized in that the seat comprises a mounting poka-yoke (98).

11. The seat according to any one of claims 1 to 10, further characterized in that the second orientation of the seat corresponds to a rotation of the seat of 180 degrees with respect to the first orientation.

12. A torsion damping device (1) comprising: - a first coaxial part (5) and a second coaxial part (6) rotatably mounted relative to each other about a rotation axis (X), - springs (4) acting circumferentially between the first coaxial part (5) and the second coaxial part (6) so as to elastically oppose the relative rotation of the first coaxial part (5) and the second coaxial part (6) about the rotation axis (X), - a plurality of seats (9), each seat (9) comprising on one side a front portion (9F) pressing against one end of a spring (4), and on the other side a back portion (9D) pressing on the first coaxial part (5) and / or the second coaxial part (6), characterized in that at least one of the seats (9) is a seat according to one of the preceding claims.

13. The damping device according to the preceding claim, further characterized in that said at least one of the seats is a worn seat that shows traces of wear (101) caused by previous use in the first orientation (OI).

14. The damping device according to claims 2 and 13, further characterized in that the wear marks are located partially or totally on the first wall (12).

15. The damping device according to claim 13 or 14, further characterized in that the wear marks (101) of each worn seat (9) are located partially or totally outside the second wall (11).

16. The damping device according to one of claims 13 to 15, further characterized in that the wear marks (101) of each worn seat (9) are located partially or totally on the first wall (12).

17. A method for manufacturing a torsional damper (1) comprising a first coaxial part (5) and a second coaxial part (6) rotatably mounted relative to each other about a rotation axis (X), springs (4) housed in recesses in the first and second coaxial parts (5, 6) and acting circumferentially between the first coaxial part (5) and the second coaxial part (6) to elastically oppose the relative rotation of the first coaxial part (5) and the second coaxial part (6) about the rotation axis (X), a plurality of seats (9), each seat comprising, on one side, a front portion (9F) pressing against one end of a spring (4) and, on the other side, a back portion (9D) pressing against the first coaxial part (5) and / or the second coaxial part (6), the manufacturing method comprising the following steps: - supplying a worn seat (9) exhibiting traces of wear, - mounting the worn seat (9) on a spring (4),- Insert the assembly comprising the worn seat (9) and the spring (4) into a recess in the first coaxial part (5) and into a recess in the second coaxial part (6).

18. The method of manufacturing a torsional damper according to claim 17, further characterized in that each worn seat (9) is capable of being mounted in a first orientation (01) and in a second orientation (02), the worn seat (9) having been mounted in the first orientation (01) during a previous use, the step of inserting the assembly comprising the worn seat (9) and the spring (4) being such that the worn seat (9) is mounted in the second orientation (02) in the recesses in the first and second coaxial parts (5, 6).

19. The method of manufacturing a torsion damper according to claim 17 or 18, further characterized in that the worn seat includes a mounting poka-yoke (98) and, during the insertion step of the assembly formed by the worn seat (9) and the spring (4) in the first and second coaxial parts (5, 6), the assembly comprising the worn seat (9) and the spring (4) passes through a mounting template (202) before being inserted into the recesses in the first and second coaxial parts (5, 6), the mounting template (202) including a complementary poka-yoke (298), the complementary poka-yoke (298) being arranged so that the mounting template only allows the passage of the worn seat (9) in the second orientation (02).

20. The method of manufacturing a torsion damper according to any one of claims 17 to 19, further characterized in that the dorsal part (9D) of each worn seat (9) comprises a dorsal face (92) and at least one support relief (10) projecting from the dorsal face (92) and suitable for pressing against the first coaxial part (5) and / or the second coaxial part (6), the support relief (10) comprising: - a summit (S), - a first wall (12) bearing wear marks (101), - a second wall (11) connected to the first wall (12) via the summit (S), the step being to insert the assembly comprising the spring (4) and the support seats (9) such that the first wall (12) is located in the torsion damper device (1) radially within the second wall (11). 5 21. The method of manufacturing a torsion damper according to any one of claims 17 to 20, further characterized in that, prior to the step of supplying a worn seat (9) with traces of wear, the manufacturing method comprises the following steps: - disassembling a worn damper, - storing the worn damper seats.

22. The method of manufacturing a torsional damper according to the preceding claim, further characterized in that one of the first coaxial part (5) and the second coaxial part (6) comprises two side washers (60) rigidly connected to each other for joint rotation about the axis of rotation (X), and the other of the first coaxial part (5) and the second coaxial part (6) comprises an intermediate washer (50), the two side washers (60), and the intermediate washer (50) derived from the worn damper.

23. The use of a worn seat (9) for the manufacture of a torsional damper device.

Images