FR3033380A1 - ELASTIC BLADE DAMPING DEVICE AND METHOD FOR ASSEMBLING SUCH DAMPING DEVICE - Google Patents

Abstract

The invention relates to a method for assembling a damping device for a motor vehicle transmission chain, said assembly method comprising the following steps: - providing a first element (2) and a second element capable of being rotatably mounted to each other so as to rotate relative to each other about an axis of rotation X; the first element (2) being equipped with a support element (23) and the second element carrying damping means comprising an elastic blade (14, 15); - bending the elastic blade (14, 15) so as to move its free end in the direction of bending by means of a blade positioning tool (39) and maintain the elastic blade (14, 15) in a position flexed mounting; axially bringing the first element (2) and the second element towards each other until the first and second elements are associated with one another in a relative angular position in which the elastic blade (14, 15) ) and the support element (23) are opposite; - Remove the blade positioning tool (39) to release the elastic blade (14, 15) from its bending mounting position.

Description

TECHNICAL FIELD The invention relates to the field of torsion dampers intended to equip the transmissions of a motor vehicle and aims in particular to facilitate their assembly.

BACKGROUND TECHNOLOGY Motor vehicle transmissions are generally equipped with a damping device for filtering vibrations upstream of the gearbox so as to avoid particularly undesirable shocks, noises or noise. Such damping devices are used in particular double damping flywheels (DVA), clutch friction, or locking clutches, also called "lock-up" clutches. Document FR3008152 discloses a double damping flywheel comprising a primary flywheel and a secondary flywheel movable in rotation relative to one another about an axis of rotation X. The double damping flywheel comprises means damping elastics which are formed of several resilient blades mounted on one of the flywheels and each cooperating with an associated roller rotatably mounted on the other flywheel. The resilient blades and the rollers are arranged in the intermediate space arranged axially between the flywheels. The rollers are arranged radially outside their respective elastic blade. The blades and the rollers are arranged such that, for an angular displacement between the flywheels, on either side of a relative angular position of rest, each roller moves along the associated blade and, in doing so, exerts a bending force on it. By reaction, the elastic blades exert on the rollers a restoring force which tends to bring the flywheels of primary and secondary inertia to their angular position of rest. The bending of the resilient blades thus makes it possible to damp the vibrations and irregularities of rotation between the flywheels of primary and secondary inertia while ensuring the transmission of torque. To assemble such a dual damping flywheel, the resilient blades are first mounted on one of the primary or secondary flywheels and the rollers are mounted on the other flywheels. Subsequently, the flywheels primary and secondary 3033380 2 are brought axially towards each other to be coupled axially to one another. The invention aims to improve this type of damper and their assembly process. SUMMARY An idea underlying the invention is to propose an elastic blade damping device and a method for assembling such a damping device 10 which improve the solutions of the aforementioned prior art by also improving the assembly operations. According to one embodiment, the invention provides a method of assembling a damping device for a motor vehicle transmission chain, said assembly method comprising the following steps: providing a first element and a second element adapted to be rotatably mounted to each other so as to rotate relative to each other about an axis of rotation X; the first member being provided with a bearing member and the second member carrying damping means for coupling the first and second members to provide vibration damping torque transmission between the first member and the second member; second element, the damping means comprising an elastic blade integral in rotation with the second element and having a free distal end, said elastic blade being intended to cooperate with the support element when the first element and the second element are assembled; to one another so as to allow transmission of the torque, said elastic blade being arranged such that, in operation, for relative rotation between the first member and the second member with respect to a relative rest position, the support element exerts a bending force on the resilient blade which causes a displacement of the end distal free of the elastic blade in a direction of bending and produces a reaction force of the opposite elastic blade on the support member, said reaction force being adapted to return said first and second elements to said relative position of rest; flexing the resilient blade so as to move its free end in the bending direction by means of a blade positioning tool and maintain the resilient blade in a bending mounting position by means of said blade positioning tool ; axially bringing the first element and the second element towards each other until the first and second elements are joined to one another in a relative angular position in which the elastic blade and the element of support are opposite; - remove the positioning tool from the blade to release the elastic blade from its bending mounting position. Such an assembly method is particularly advantageous in that the elastic blade is held in a bending position of assembly during the association between the two elements of the damping device which simplifies the assembly operations and the assembly. avoid soliciting the support element during assembly operations. According to other advantageous embodiments, such an assembly method may have one or more of the following characteristics: the first element and the second element are positioned angularly relative to one another before being brought closer together; axially towards each other. - The blade positioning tool comprises a rod by means of which the elastic blade is bent and held in its bending mounting position. The resilient blade and the bearing element are intended to be housed in an intermediate space arranged axially between the first element and the second element when the first element and the second element are assembled to one another. - One of the first and second elements is equipped with an access passage to the intermediate space adapted to allow the rod to access the interspace. To do this, the access passage to the intermediate space may in particular lead to the vicinity or facing a portion of the elastic blade. the resilient blade is arranged to deform in a plane perpendicular to the axis of rotation X. According to one embodiment, the access passage to the intermediate space is an orifice axially passing through one of said first and second members and the blade positioning tool shank 3033380 4 is disposed in axial orientation through said intermediate space access passage. The through hole is an oblong hole, the largest dimension of which has a radial component, and the rod of the blade positioning tool is moved within the oblong hole along its larger dimension. to flex the elastic blade. According to another embodiment, one of the first and second elements comprises a cylindrical skirt intended to cover the intermediate space arranged axially between the first element and the second element when the first element and the second element are assembled together. to the other and the access passage to the intermediate space is formed, in particular radially, in said cylindrical skirt. In this case, the shank of the positioning tool is disposed in an orientation having a radial component through said intermediate space access passage for bending the resilient blade and / or holding it in its bending mounting position. . According to an advantageous variant, the first element comprises the cylindrical skirt and the access passage to the intermediate space is a slot opening at the end of the cylindrical skirt facing the second element. In this case, the positioning tool 20 of the blade is first positioned with respect to the second element so as to bend the elastic blade and hold it in its bent mounting position and then the rod passes through said slot when axially bringing the first element and the second element towards each other. This embodiment may be particularly advantageous in that the passage of the rod inside the slot when the steering wheels are brought together makes it possible to ensure relative angular positioning of the steering wheels. According to one embodiment, the access passage to the intermediate space is formed in the first element and the rod has a ramp which is arranged to cooperate with the elastic blade so that the ramp causes the blade to bend. resilient to its flexed mounting position when the first member and the second member are moved axially toward each other. Such a ramp rod can be introduced axially through an orifice passing axially through one of said first and second elements but can also be introduced radially through a cylindrical skirt of one of the first and second elements intended to to cover the intermediate space provided axially between the first element and the second element when they are assembled to one another 5 - The elastic blade passes from a bent mounting position to a pre-stressed position in which the blade is pre-stressed by the bearing member when the blade positioning tool is removed. In other words, the resilient blade is arranged to be preloaded by the bearing member when the first member and the second member are assembled together and in their relative rest position. The elastic blade may in particular be preloaded radially towards the axis X so as to exert a reaction force directed radially outwards. According to one embodiment, the invention also provides a damping device for a motor vehicle transmission chain comprising: a first element and a second element that are rotatable relative to each other around an X axis; the first element being equipped with a bearing element and the second element carrying damping means coupling the first and the second elements so as to allow vibration-damped torque transmission between the first element and the second element; element, the damping means comprising an elastic blade integral in rotation with the second element and having a free distal end, said elastic blade cooperating with the support element so as to allow the transmission of torque, said elastic blade being arranged such that, for relative rotation between the first member and the second member with respect to a relative rest position, the backing member exerts a bending force on the resilient blade which causes displacement of the distal end free of the elastic blade in a bending direction and produces a counteracting force of the elastic blade on the support element 30, this reaction force being able to recall said first and second elements towards said relative position of rest; - The elastic blade and said support member being housed in an intermediate space provided axially between the first element and the second element; said damping device being characterized in that it comprises a passage 3033380 6 for access to the intermediate space formed in one of said first and second elements, said access passage being able to allow insertion into the inter-space of a blade positioning tool adapted to flex the resilient blade so as to move the free end of the resilient blade in the direction of bending and to maintain the resilient blade in a bending mounting position. According to other advantageous embodiments, such a damping device may have one or more of the following characteristics: the access passage opens in the vicinity of a portion of the elastic blade. - The access passage leads to a portion of the elastic blade. The access passage is formed so as to allow movement of the positioning tool, the amplitude of this movement making it possible to move the blade from a rest position to a bending installation position. - The access passage is formed to allow a translation, in particular radial, the positioning tool in a direction belonging to the plane in which the blade flexes. - When the first and second elements are in relative position of rest, the passage is located, circumferentially, between the support element and the free distal end of the blade. at least a portion of the access passage is located radially outside the elastic blade when the elastic blade is at rest. - The access passage to the intermediate space is formed by an orifice axially passing through the first or the second element. - The orifice is formed in an annular portion of radial orientation of one of the first and second elements. The orifice has an oblong shape whose longest length has a radial component. - One of the first and second elements comprises a cylindrical skirt intended to cover the intermediate space arranged axially between the first element and the second element. 30 - The access passage to the intermediate space passes through the cylindrical skirt, particularly radially. The first element comprises the cylindrical skirt and the access passage to the intermediate space is an axial slot opening at the end of the cylindrical skirt directed towards the second element. - The support element is located radially outside the elastic blade. 5 - The elastic blade is arranged to be prestressed by the support element when the first element and the second element are in their relative position of rest. Such an arrangement makes it possible to avoid operating gaps between the support element and the resilient blade, since such operating gaps would be likely to adversely affect the service life and good operation of the double damping flywheel. According to one embodiment, the damping device is a double damping flywheel. Therefore, one of said first and second elements is a primary flywheel of the double damping flywheel intended to be fixed at the end of one crankshaft and the other of said first and second elements is a secondary flywheel 15 of the dual damping flywheel which is intended to form a reaction plate for a clutch device. The access passage to the intermediate space is advantageously formed in the primary flywheel, which makes it possible not to alter the surface of the secondary flywheel intended to form a reaction plate for a clutch device. - The resilient blade has a cam surface and the support member has a cam follower arranged to cooperate with the cam surface. - The cam follower is a roller rotatably mounted on the first element, for example by means of a rolling bearing. The support element is arranged radially outside the elastic blade. Such an arrangement makes it possible to retain the elastic blade radially when it is subjected to centrifugal force. - The elastic blade is arranged to deform in a plane perpendicular to the axis of rotation. The elastic blade is arranged to deform towards the axis of rotation X during a relative rotation between the first and the second element relative to their relative position of rest. In other words, the blade has a radially movable free distal end 30333808 so that the radial distance between the axis of rotation of said free distal end varies, and more particularly decreases, as a function of the angular displacement between the first and second distal ends. and the second elements. 5 - When the damping means comprise an even number of resilient blades, two for example, the blades of each pair are symmetrical with respect to the axis of rotation X which contributes to the balance of the damping device. - When the damping device comprises a plurality of resilient blades, it comprises an access passage to the spacer space for each of the resilient blades. When the damping device comprises two elastic blades symmetrical with respect to the X axis, the two access passages to the intermediate space are diametrically opposed. According to one embodiment, the invention also provides a damping device for a motor vehicle transmission chain comprising: a first element and a second element that are rotatable relative to each other around; an X axis; the first element being equipped with a support element and the second element carrying damping means coupling the first and the second elements so as to allow vibration damping torque transmission between the first element and the second element; element, the damping means comprising an elastic blade rotatably connected to the second element, said elastic blade cooperating with the support element so as to allow the transmission of the torque and being arranged so that, for a relative rotation between the first element and the second element with respect to a relative rest position, the support element exerts a bending force on the elastic blade which produces a force of opposite reaction of the elastic blade on the support element this reaction force being able to return said first and second elements towards said relative rest position; said damping device being remarkable in that the elastic blade is prestressed by the bearing element in the relative rest position of the first and second elements.

According to one embodiment, the cam follower is a roller rotatably mounted on the first element, for example by means of a rolling bearing integral in rotation with the first element. Preferably, the rollers are rotatably mounted by means of rolling members, such as balls, rollers or needles. Preferably, the rollers are each carried by a cylindrical rod extending parallel to the axis of rotation. Preferably, the cylindrical rod has a radial extension at a first end which is fitted into a first reinforcing member, for example a bore formed on the first member. Preferably, the cylindrical rod is fixed to the first element by means of a fastening element, such as a screw, mounted in an orifice passing through the first element parallel to the axis of rotation. Preferably, the fastening element of the cylindrical rod is a screw 15 cooperating with a thread formed inside the cylindrical rod. Preferably, the bore and the orifice are coaxial and the bore has a diameter greater than the diameter of the orifice. If necessary, the orifice opens into the spacer space of the damper by the bore.

If desired, an intermediate cylinder may be fitted around the cylindrical rod to form the raceway of the running gear. Preferably, a cap attached to the first member partially overlaps the rollers and includes a second reinforcing member, formed for example by a bore fitted around a second end of the cylindrical rod. Preferably, the first and second reinforcing elements are located axially on either side of the rolling members. According to one embodiment, the invention also provides an automobile vehicle comprising a damping device mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and other objects, details, features and advantages thereof will become more clearly apparent from the following description of several particular embodiments of the invention given only for illustrative and non-limiting, with reference to the accompanying drawings. - Figure 1 is a partial sectional view of a double damping flywheel with elastic blades. FIG. 2 is a partial view of a double damping flywheel according to a first embodiment, in which the secondary flywheel is not shown in order to allow a visualization of the oblong orifices formed in the primary flywheel and allowing the introduction stems of a blade positioning tool. FIG. 3 is a partial view of the double damping flywheel of FIG. 2 in which the rods of the blade positioning tool, able to bend the elastic blades, are introduced through the oblong orifices formed in the primary flywheel. - Figure 4 is a partial view of a double damping flywheel according to a second embodiment, illustrating the secondary flywheel, the resilient blades and a blade positioning tool. FIG. 5 is a partial view of the double damping flywheel according to the second embodiment, in which the secondary flywheel is not shown in order to allow visualization of slots formed in a cylindrical skirt of the primary flywheel and able to allow the rods passage of the blade positioning tool when assembling the double damping flywheel. Figure 6 is a front view of the dual damping flywheel of Figures 4 and 5 and the blade positioning tool. - Figure 7 illustrates a primary flywheel of a double damping flywheel according to a third embodiment and a blade positioning tool equipped with rods passing through holes of the primary flywheel. FIG. 8 is a detailed view of one of the rods of FIG. 7 and of its contact with one of the elastic blades during the assembly of the double damping flywheel. FIG. 9 is a rear view of the double damping flywheel of FIGS. 7 and 8 and of the blade positioning tool. DETAILED DESCRIPTION OF EMBODIMENTS In the description and the claims, the terms "external" 5 and "internal" as well as the "axial" and "radial" orientations will be used to designate, according to the definitions given in the description, elements of the shock absorber. By convention, the "radial" orientation is directed orthogonally to the axis X of rotation of the damper determining the "axial" orientation and, from the inside towards the outside away from said axis, the orientation "circumferential" is directed orthogonally to the axis of the damper and orthogonal to the radial direction. The terms "external" and "internal" are used to define the relative position of one element relative to another, with reference to the axis X of rotation of the damper, an element close to the axis is thus qualified. internally as opposed to an outer member located radially peripherally. On the other hand, the terms "rearward" AR and "forward" AV are used to define the relative position of one element relative to another in the axial direction, an element intended to be placed close to the engine being designated by before and an element intended to be placed close to the gearbox being designated by the rear. In relation with FIG. 1, a double damping flywheel 1 20 is seen comprising a primary flywheel 2 intended to be fixed at the end of a crankshaft of an internal combustion engine, not shown, and a steering wheel. secondary inertia 3 which is centered and guided on the primary flywheel 2 by means of a bearing 4, such as a rolling bearing ball. The secondary flywheel 3 is intended to form the reaction plate of a clutch, not shown, connected to the input shaft of a gearbox. The primary flywheel 2 comprises a radially inner hub 5 supporting the bearing 4, an annular portion 6 extending radially from the hub 5 and a cylindrical skirt 7 extending axially rearwardly from the outer periphery of the annular portion. 6. The primary flywheel 2 is provided with orifices 8 allowing the passage of fixing screws, intended for fastening the primary flywheel 2 to the crankshaft of the engine. The primary flywheel 2 carries, on its outer periphery, a ring gear 9 for driving in rotation of the primary flywheel 2, using a starter.

The rolling bearing 4 comprises an outer ring, an inner ring and rolling bodies extending between said inner and outer rings. The hub 5 of the primary flywheel 2 comprises a shoulder 5a, serving to support the inner ring of the rolling bearing and retaining it rearwardly. Similarly, the secondary flywheel 3 has on its inner periphery a shoulder 3a serving to support the outer ring of the rolling bearing 4 and retaining said outer ring forward. A circlip 28 is mounted in a groove in the hub 5 of the primary flywheel 2, at the rear of the inner ring and thus retains the inner ring forward. Thus, when assembling the double damping flywheel 1, the circlip 28 is mounted in the groove of the hub 5 when the secondary flywheel 3 has been fitted onto the primary flywheel 2 and thus makes it possible to axially couple the secondary flywheel 3 to the 2. In FIG. 1, it can be observed that the secondary flywheel 3 comprises a plane annular surface 10, turned towards the rear, intended to form a bearing surface 15 for a friction lining of a clutch element. , not shown. The secondary flywheel 3 comprises, close to its outer edge, pads, not shown, and / or orifices for mounting a cover of the clutch device. In relation with FIG. 2, damping means 20 are observed coupling the primary flywheel 2 and the secondary flywheel 3 (not shown) so as to allow transmission of the vibration damping torque between the primary and secondary flywheels 2. 3. The elastic damping means comprise two resilient blades 14, 15 bent around the axis of rotation X. The two resilient blades 14, 15 are symmetrical to each other with respect to the axis of rotation X. In the illustrated embodiment, each resilient blade 14, 15 is independently attached to the secondary flywheel. To do this, each elastic blade 14, 15 comprises a fastening portion 13 which is fixed on the secondary flywheel 3 by means of a plurality of rivets. Furthermore, each elastic blade 14, 15 has an internal strand 16, an outer strand 17 and a bent portion 18 connecting the inner strand and the outer strand. The bent portion has an angle of about 180 ° so that a portion of the inner strand is located radially between a portion of the outer strand and the X axis. In other words, each elastic blade 14, 3033380 13 comprises two regions radially offset from each other and separated by a radial space. Although the invention is described above in connection with resilient blades 14, 15 having an inner strand 16 and an outer strand 17 connected by a bent portion 18, it is quite obvious that it is by no means limited thereto. and that it will be possible in particular to use elastic blades 14, 15 which have different shapes or whose attachment is provided in a different manner. Thus, in other embodiments, the resilient blades may be carried by the same annular body fixed to the secondary flywheel and / or have different shapes, as illustrated for example in document FR3008152. Similarly, it will also be possible to provide elastic damping means having only one elastic blade or on the contrary more than two elastic blades. Each resilient blade 14, 15 has a cam surface 11 which is arranged to cooperate with a support member formed by a cam follower 22 carried by the primary flywheel 2. The cam followers 22 are here movable mounted rollers 23. in rotation on the primary flywheel 2. The cam followers 22 are held in abutment against their respective cam surface 11 and are arranged to roll against said cam surface during relative rotation between the primary and secondary flywheels 2. On the other hand, the cam followers 22 are arranged radially outside their respective cam surface 11 so as to radially hold the spring blades 14, 15 when subjected to centrifugal force. Each cam surface 11 is arranged such that, for relative rotation between the primary flywheel 2 and the secondary flywheel 3 in one direction or the other, from a relative angular position of rest, the cam follower 22 is moves on the cam surface and exerts a bending force on the elastic blade 14, 15 which moves the free end of the resilient blades towards the axis X. By reaction, the elastic blade 14, 15 exerts on the cam follower 22 a return force having a circumferential component which tends to bring the primary flywheels 2 and secondary 3 to their relative angular position of rest. Thus, the resilient blades 14, 15 are capable of transmitting a driving torque from the primary flywheel 2 to the secondary flywheel 3 (forward direction) and a resistant torque of the secondary flywheel 3 to the primary flywheel 2 (retro direction). Furthermore, the vibrations of torsion and the irregularities of torque which are produced by the engine and transmitted by the crankshaft to the primary flywheel 2 are damped by the bending of the elastic blades 14, 15. The elastic blades 14, 15 and the rollers 23 are housed in an intermediate space provided axially between the primary flywheels 2 and secondary 3. As shown in FIG. 1, the rollers 23 are advantageously rotatably mounted on the primary flywheel 2 by means of rolling elements 24, such as balls, rollers or needles, so as to reduce parasitic friction that may affect the damping function. The rollers 23 are each carried by a cylindrical rod 25 extending parallel to the axis of rotation X. The cylindrical rod 25 has a radial extension at a first end which is fitted into a first reinforcing element formed by a bore 41 formed on the primary flywheel 2. The cylindrical rod 25 is fixed to the primary flywheel by means of a screw 42 mounted in an orifice 43 passing through the primary flywheel 2 in a manner parallel to the axis of rotation X, this screw cooperating with a formed thread. inside the cylindrical rod. The bore 41 and the orifice 43 are coaxial and the bore 43 has a diameter greater than the diameter of the orifice. The orifice 43 opens into the interspace of the double damping flywheel through the bore 41. An intermediate cylinder 45 can be fitted around the cylindrical rod 20 to form the rolling track of the rolling members 24. A cap 46, fixed on the primary flywheel partially covers the rollers 23. This cap 46 comprises a second reinforcing element formed by a bore 47 fitted around a second end of the cylindrical rod 25. The cylindrical rod 25 can thus rely on the first and second 25 reinforcing elements under the action of radial forces exerted by the blade 14. These reinforcing elements are located axially on either side of the raceway. Advantageously, in the relative position of rest between the primary flywheels 2 and secondary 3, each elastic blade 14, 15 is pre-stressed radially towards the axis X by the roller 23 with which it cooperates and thus exerts a force of reaction directed radially outwardly on the roller 23 associated. Such pre-stressing of the resilient blades ensures permanent contact between the rollers 23 and the resilient blades 14, 15 which makes it possible to avoid play which may induce shocks 23 and the blades 14 to operate in operation. 15 and, therefore, reduce the life of the rolling members 24. In an alternative embodiment not shown, the structure is reversed and the resilient blades 14, 15 are fixed on the primary flywheel 2 while the rollers 5 23 are mounted in rotation on the secondary flywheel 3. In relation with FIGS. 2 and 3, it can be seen that the annular portion 6 of the radial orientation of the primary flywheel is equipped with two oblong orifices 27 allowing the insertion of the rods 26, illustrated in FIG. 3, a blade positioning tool 39. The two oblong orifices 27 are diametrically opposed and open respectively in the vicinity of a portion of the one and the other of the two blades. elastic 14, 15. The largest dimension of the oblong orifices 27 extending substantially in a radial direction. A method of assembling the double damping flywheel of Figures 1 to 3 will now be described.

In a first step, the rollers 23 are mounted on the primary flywheel 2 while the elastic blades 14, 15 are mounted on the secondary flywheel 3. Thereafter, the primary flywheel 2 and the secondary flywheel 3 are presented one opposite each other in a corresponding relative angular position, at approximately 15 °, to their relative position of rest.

A blade positioning tool is then approached from the front face of the primary flywheel 2 and positioned so that the rods extend substantially parallel to the X axis and pass through the oblong orifices 27 passing axially through the annular portion 6. The length of the rods 26 and the axial spacing between the primary flywheel 2 and the secondary flywheel 3 25 are, at this stage, such that the free end of each of the rods 26 is positioned radially to the outside a portion of one of the elastic blades 14, 15, here outside the outer strand. The rods 26 are then moved within the oblong orifices 27, towards the X axis, ie radially inwards, which causes the elastic blades 14, 15 to bend radially towards the X axis. X axis. The rods 26 are held in position so as to hold the elastic blades 14, 15 in a bending position of mounting.

The primary flywheels 2 and secondary 3 are then brought closer together axially from each other until the secondary flywheel 3 is fitted onto the primary flywheel 2 via the rolling bearing 4. The blade positioning tool can then be removed by extracting the rods 26 from the oblong holes 27 so as to release the elastic blades 14, 15 from their bent mounting position (Figure 3). Such a mounting method thus makes it possible to bring the primary and secondary wheels 2 axially closer in a simple manner, without the need to exert a major axial assembly force likely to damage the cam follower and / or the blade. . In addition, an angular positioning defect 10 between the flywheels during the axial approach is allowed, the primary flywheel 2 and secondary 3 being returned to their relative position of rest as soon as the positioning tool is removed. We observe that the oblong orifices are here formed through the primary flywheel, which makes it possible not to damage the flat annular surface 15 of the secondary flywheel which is intended to form a reaction plate for a clutch device. It may, however, be envisaged to arrange the oblong holes through the secondary flywheel 2, which would make it possible to cooperate the blade positioning tool with the elastic blades 14, 15 before the flywheels 2, 3 are placed one. next to each other.

In a non-illustrated embodiment in which the elastic blades 14, 15 are fixed on the primary flywheel 2 and the rollers 23 rotatably mounted on the secondary flywheel 3, it is particularly advantageous to arrange the oblong holes through the primary flywheel 2. This allows, on the one hand, to preserve the friction surface of the secondary flywheel 3, and on the other hand, to allow positioning of the positioning tool before the flywheels 2, 3 are positioned in position. vis-a-vis. The double damping flywheel shown in FIGS. 4 to 6 has a structure identical to that of FIGS. 1 to 3 which is described above and differs only in the structure of the access passages to the intermediate space between the flywheels 30 allowing the passage of the rods of the positioning tool. In this embodiment, the access passages to the intermediate space between the flywheels are constituted by slots 29, shown in FIG. 5, passing radially through the cylindrical skirt 7, these slots extending here in a direction axial along the cylindrical skirt to lead to the axial end of the cylindrical skirt 7 vis-à-vis the secondary flywheel 3. A method of assembling such a dual damping flywheel will be described below.

As in the previous embodiment, the rollers 23 are mounted on the primary flywheel 2 while the elastic blades 14, 15 are mounted on the secondary flywheel 3 (not shown in Figure 5). Subsequently, as shown in Figures 4 and 6, a blade positioning tool 33 is brought closer to the rear face of the secondary flywheel 3. The blade positioning tool 33 10 here comprises a bar 32 which extends according to a radial direction and two wings 31 extending axially, perpendicular to the bar 32, at both ends of the bar 32. In position, the two wings 31 extend diametrically on either side of the secondary flywheel 3 and bear rods 30 extending radially. The rods 30 are each mounted movably in a radial direction on the associated flange 31 and are thus able to exert a bending force on the resilient blades 14, 15 so as to cause the resilient blades 14, 15 to flex radially towards the yoke. X axis and maintain them in a bending position of mounting. According to one embodiment, the rods 30 have a thread and each pass through a corresponding threaded bore in the flange 31 associated. The rods 30 are thus able to move radially inwards in order to ensure the bending of the resilient blades 14, 15 while ensuring retention in the bent mounting position of said resilient blades 14, 15 without the need for additional locking means. in position of the stems. Subsequently, the primary flywheel 2 and the secondary flywheel 3 are presented opposite one another in a relative angular position in which the rods 30 are located opposite the slots 29 formed in the skirt. This relative angular position corresponds substantially to the relative position of rest of the primary flywheels 2 and secondary 3. Thereafter, the primary flywheels 2 and secondary 3 are brought axially close to one another until that the secondary flywheel 3 is fitted on the secondary flywheel 3 via the rolling bearing 4. In relation to FIG. 5, it is observed that, after the axial contact of the primary flywheels 2 and secondary 3, the rods 30 of the tool The positioning tool of the blades 33 is engaged through the slots 30 in the cylindrical skirt 7 of the primary flywheel 2. The blade positioning tool 33 can be removed at this stage by moving the rods beforehand. 30 radially outwardly so as to release the resilient blades 14, 15 from their bent mounting position.

This embodiment is particularly advantageous in that the slots 29 formed in the primary flywheel 2 provide a guide rods 30 during the axial approximation of the primary flywheel 2 and secondary 3 and further provide a keying function ensuring correct relative positioning between the primary 2 and secondary 3 flywheels during assembly.

In another alternative embodiment not illustrated, the elastic blades 14, 15 are fixed on the primary flywheel 2 while the rollers 23 are rotatably mounted on the secondary flywheel 3. In this case, the access passages to the spacing between the flywheels 2, 3 are not necessarily slots opening at the axial end of the cylindrical skirt vis-à-vis and may be formed of orifices formed in the cylindrical skirt 7. In this case, the positioning tool is first placed on the primary flywheel 2 before the primary flywheel 2 and secondary 3 are mounted on one another. The double damping flywheel shown in FIGS. 7 to 9 differs from the damping double flywheels described above only by the structure of the passages 20 for access to the intermediate space between the flywheels. In this embodiment, the access passages to the intermediate space between the flywheels 2, 3 consist of orifices 34 passing through the annular portion 6 of radial orientation of the primary flywheel 1 and having dimensions complementary to that of the rods. 35 of the blade positioning tool 37.

In this case, as shown in detail in FIG. 8, the end of each rod 35 has a ramp 38 adapted to cooperate with a portion of the respective elastic blade 14, 15 and oriented so that when the flywheels primary 2 and secondary 3 are brought closer to each other, the orientation of the ramp 38 leads to a bending of the elastic blade 14, 15 towards the axis X.

The method of assembling such a damping flywheel is as follows. In a first step, the rollers 23 are mounted on the primary flywheel 2 while the elastic blades 14, 15 are mounted on the secondary flywheel 3. As shown in FIGS. 7 and 8, rods 35 whose end is equipped with a ramp 38 are inserted inside the orifices 34 passing axially through the primary flywheel 2. As shown in FIG. 9, the rods 35 may in particular be carried by a bar 36 so as to allow simultaneous introduction of the two rods. 35 The rods 35 are positioned so that the surfaces of the ramps 38 are directed towards the X axis. The inclination of the ramps 38 is such that their surface approximates the X axis in s away from the end of the rod 38. Thereafter, the primary flywheel 2 and the secondary flywheel 3 are presented opposite each other in a relative angular position corresponding substantially to their relative position of rest. The primary and secondary flywheels are then moved axially towards one another until the secondary flywheel 3 is fitted onto the primary flywheel 2 via the rolling bearing 4. As shown in FIG. 8, during this connection, the resilient blades 14, 15 come into contact with the ramps 38 of the rods 35, causing the resilient blades 14, 15 to bend inwards. This avoids axially biasing the rollers 23 during assembly operations. Subsequently, the blade positioning tool 37 is removed by extracting the rods 35 from their respective aperture 34 to release the resilient blades 14, 15 from their bent mounting position. Note that, according to another embodiment, not shown, it is also possible to use such rods provided with ramps in combination with orifices formed in the cylindrical skirt of the primary flywheel. In this case, the ramps are formed at the end of the rods.

Although the invention has been described in connection with several particular embodiments, it is quite obvious that it is in no way limited thereto and that it comprises all the technical equivalents of the means described and their combinations if These are within the scope of the invention. The use of the verb "include", "understand" or "include" and its conjugate forms does not exclude the presence of other elements or steps other than those set forth in a claim. The use of the indefinite article "a" or "an" for an element or a step does not exclude, unless otherwise stated, the presence of a plurality of such elements or steps.

In the claims, any reference sign in parentheses can not be interpreted as a limitation of the claim.

Claims (19)

REVENDICATIONS1. A method of assembling a damping device for a motor vehicle transmission chain, said assembly method comprising the following steps: - providing a first element (2) and a second element (3) capable of being mounted in rotating on one another so as to rotate relative to each other about an axis of rotation X; the first element (2) being provided with a support element (23) and the second element (3) carrying damping means for coupling the first and the second elements so as to allow damping torque transmission vibrations between the first element and the second element, the damping means comprising an elastic blade (14, 15) integral in rotation with the second element (3) and having a free distal end, said elastic blade (14, 15) being intended to cooperate with the support element when the first element and the second element are assembled to each other so as to allow the transmission of the torque, said elastic blade being arranged so that, in operation, for a relative rotation between the first element (2) and the second element (3) relative to a relative rest position, the support element (23) exerts a bending force on the elastic blade (14, 15) which causes a displacement of the free distal end of the resilient blade in a bending direction and produces a counteracting force of the resilient blade (14, 15) on the bearing member (23), this force reaction being able to recall said first and second elements (2, 3) to said relative position of rest; - bending the elastic blade (14, 15) so as to move its free end in the bending direction by means of a blade positioning tool (33, 37, 39) and hold the spring blade (14, 15 ) in a flexed mounting position by means of said blade positioning tool (33, 37, 39); axially bringing the first element (2) and the second element (3) towards each other until the first and second elements (2, 3) are associated with one another in a relative angular position in which the elastic blade (14, 15) and the support element (23) are opposite; - remove the blade positioning tool (33, 37, 39) to release the elastic blade (14, 15) from its bending mounting position. 3033380 22 2. Assembly method according to claim 1, wherein the blade positioning tool (33, 37, 39) comprises a rod (26, 30, 35) by means of which the elastic blade (14, 15). is bent and held in its bending mounting position and in which the elastic blade (14, 15) and the bearing element (23) are intended to be housed in an intermediate space arranged axially between the first element (2) and the second element (3) when the first element (2) and the second element (3) are assembled to one another, one of the first and second elements (2, 3) being provided with a passage (27, 29, 34) for access to the intermediate space adapted to allow the rod (26, 30, 35) to access the interspace. 3. Assembly method according to claim 2, wherein the elastic blade (14, 15) is arranged to deform in a plane perpendicular to the axis of rotation X, in which the access passage to the space insert is an orifice (27, 34) extending axially through one of said first and second members (2, 3) and wherein the blade position tool shank (26, 35) (33, 37, 39) is disposed in an axial orientation through said intermediate space access passage. 4. An assembly method according to claim 3, wherein the orifice is an oblong orifice (27), the largest dimension of which has a radial component and in which the rod of the blade positioning tool is moved. the inside of the oblong aperture along its largest dimension to flex the elastic blade (14, 15). 5. Assembly method according to claim 2, wherein one of the first and second elements (2, 3) comprises a cylindrical skirt (7) intended to cover the intermediate space arranged axially between the first element (2) and the second element (3) when the first element (2) and the second element (3) are joined to each other, in which the access passage to the intermediate space (29) is formed in said skirt cylindrical (7) and wherein the shank (30) of the blade positioning tool (32) is disposed through said intermediate space access passage (29) with an orientation having a radial component for bending the elastic blade (14, 15) and / or maintain it in its flexed mounting position. 6. An assembly method according to claim 5, wherein the first element (2) comprises the cylindrical skirt (7) and wherein the passageway 3033380 23 to access the interspace is a slot (29) opening at the level the end of the cylindrical skirt (7) directed towards the second element (3) and in which the blade positioning tool (32) is first positioned relative to the second element (3) so as to flexing the resilient blade (14, 15) and maintaining it in its bent mounting position, and then the rod (30) passes through said slot (29) when axially moving the first member (2) and the second element (3) towards each other. The method of assembly according to claim 3 or 5, wherein the access passage to the intermediate space (34) is formed in the first element 10 and wherein the rod (35) has a ramp (38) which is arranged to cooperate with the elastic blade (14, 15) so that the ramp (38) causes the resilient blade to bend towards its bending mounting position when the first member (2) and the second member (3) are moved axially towards each other. 8. A method of assembly according to any one of claims 1 to 7, wherein the elastic blade (14, 15) passes from a bent mounting position to a prestressed position in which the blade is prestressed by the element. (23) when the blade positioning tool (33, 37, 39) is removed. 9. A damping device for a motor vehicle transmission chain comprising: a first element (2) and a second element (3) rotatable relative to each other about an axis X; the first element (2) being equipped with a support element (23) and the second element (3) carrying damping means coupling the first and the second elements so as to allow damping torque transmission; vibrations between the first element and the second element, the damping means comprising an elastic blade (14, 15) integral in rotation with the second element (3) and having a free distal end, said elastic blade (14, 15) cooperating with the support element (23) so as to allow torque transmission, said resilient blade being arranged such that, for relative rotation between the first member (2) and the second member (3) relative to at a relative position of rest, the support element (23) exerts a bending force on the elastic blade (14, 15) which causes a displacement of the free distal end of the elastic blade in a bending direction and produces a force 3033380 24 of opposite reaction of the elastic blade on the support element, this reaction force being able to return said first and second elements to said relative position of rest; the elastic blade (14, 15) and said support element (23) being housed in an intermediate space provided axially between the first element and the second element; said damping device being characterized in that it comprises a passage (27, 29, 34) for access to the intermediate space formed in one of said first and second elements, said passage (27, 29, 34) being able to allow the introduction into the intermediate space of a blade positioning tool (33, 37, 39) adapted to bend the resilient blade (14, 15) so as to move the free end of the elastic blade according to the direction of bending and to maintain the elastic blade in a bending position of mounting. The damping device according to claim 9, wherein when the first and second members are in the relative rest position, the passage is located in an angular sector extending from the free distal end to the element. support. The damping device according to claim 9 or 10, wherein the access passage to the spacer space is formed by an orifice (27,34) axially extending through the first or second element. 12. A damping device according to claim 11, wherein the orifice (27) has an oblong shape whose longest length has a radial component. 13. damping device according to claim 9 or 10, wherein one of the first and second elements (2, 3) comprises a cylindrical skirt (7) intended to cover the intermediate space arranged axially between the first element and the second element and wherein the passage (29) for access to the intermediate space passes through the cylindrical skirt (7). 14. A damping device according to claim 13, wherein the first element (2) comprises the cylindrical skirt (7) and wherein the passage 30 for access to the intermediate space is a slot (29) opening at the level of the end of the cylindrical skirt (7) directed towards the second element (3). 3033380 25 15. damping device according to any one of claims 9 to 14, wherein the bearing element (23) is located radially outside the elastic blade (14, 15). 16. Damping device according to any one of claims 9 to 15, wherein the elastic blade (14, 15) is arranged to be prestressed by the support element (23) when the first element (2) and the second element (3) are in their relative position of rest. 17. A damping device according to any one of claims 9 to 16, wherein one of said first and second elements is a primary flywheel (2) of a double damping flywheel intended to be fixed at the end. a crankshaft and the other of said first and second elements is a secondary flywheel (3) of the double damping flywheel which is intended to form a reaction plate for a clutch device. 18. Damping device for a motor vehicle transmission chain comprising: a first element (2) and a second element (3) movable in rotation with respect to each other about an axis X; the first element (2) being equipped with a support element (23) and the second element (3) bearing damping means coupling the first and second elements so as to allow damping torque transmission; vibrations between the first element and the second element, the damping means comprising an elastic blade (14, 15) integral in rotation with the second element (3), said elastic blade (14, 15) cooperating with the element of support (23) so as to allow transmission of the torque and being arranged such that, for a relative rotation between the first element (2) and the second element (3) with respect to a relative rest position, the bearing element (23) exerts a bending force on the elastic blade (14, 15) which produces a force of opposite reaction of the elastic blade on the support element, this reaction force being able to recall said first and second elements towards said relative position of rest; said damping device being characterized in that the elastic blade is prestressed by the bearing element in the relative rest position of the first and second elements. 3033380 26 19. A damping device according to claim 18, wherein the cam follower is a roller (23) rotatably mounted on the first member (3).