WO2016139157A1

WO2016139157A1 - Damping device having a resilient blade and method for assembling such a damping device

Info

Publication number: WO2016139157A1
Application number: PCT/EP2016/054169
Authority: WO
Inventors: Jérôme BOULET
Original assignee: Valeo Embrayages
Priority date: 2015-03-04
Filing date: 2016-02-26
Publication date: 2016-09-09
Also published as: FR3033380A1; CN208605555U; FR3033380B1

Abstract

The invention relates to a method for assembling a damping device for a drive-chain of a motor vehicle, said assembly method comprising the following steps: - providing a first element (2) and a second element able to be mounted in rotation on one another in such a way as to turn one with respect to the other around an axis of rotation X; the first element (2) being equipped with a bearing element (23) and the second element carrying damping means comprising a resilient blade (14, 15); - flexing the resilient blade (14, 15) in such a way as to move the free end thereof in the flexing direction by means of a positioning tool (39) of the blade and maintaining the resilient blade (14, 15) in a flexed mounting position; - axially bringing the first element (2) and the second element towards one another until the first and second elements associate with one another in a relative angular position in which the resilient blade (14, 15) and the bearing element (23) are opposite one another; - withdrawing the positioning tool (39) of the blade to release the resilient blade (14, 15) from the flexed mounting position thereof.

Description

ELASTIC BLADE DAMPING DEVICE AND METHOD FOR ASSEMBLING SUCH DAMPING DEVICE

Technical area

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

Technological background

Motor vehicle transmissions are generally equipped with a damping device for filtering vibrations upstream of the gearbox so as to avoid shock, noise or noise particularly undesirable. 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 double damping flywheel, the elastic blades are first mounted on one of the primary or secondary flywheels and the rollers are mounted on the other wheels. Subsequently, the flywheels of primary and secondary inertia 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 of assembling such a damping device which improve the solutions of the aforementioned prior art by also improving the operations of 'assembly.

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 on one another so as to rotate relative to each other about an axis of rotation X; the first element being provided with a support element and the second element carrying damping means for 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 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; one to the other so as to allow the transmission of the torque, said elastic blade being arranged such that, in operation, for a relative rotation between the first element and the second element relative to a relative rest position, the support element exerts a bending force on the elastic blade which causes displacement of the distal end e free of the elastic blade in a direction of bending and produces a reaction force of the opposite elastic blade on the support element, this reaction force being able to recall said first and second members to said relative rest position;

flexing the resilient blade 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 associated with one another in a relative angular position in which the elastic plate and the support element 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 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 angularly positioned relative to each other before being moved axially towards each other.

The blade positioning tool has a rod by means of which the resilient blade is bent and held in its bending mounting position.

The elastic blade and the support element are intended to be housed in an intermediate space provided 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 elastic 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 elements and the rod of the blade positioning tool is disposed in an axial orientation through said passage of access to the interspace.

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 largest dimension so to bend 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. 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 blade positioning tool is first positioned with respect to the second element so as to bend the elastic blade and maintain it in its bent mounting position and then the rod passes through said slot when the first element and the second element are brought axially towards each other. This embodiment can be particularly advantageous in that the passage of the rod inside the slot when bringing the steering wheels together ensures 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 bending of the elastic blade. towards its flexed mounting position when the first element and the second element are brought axially together the other. Such a ramp rod can be introduced axially through an orifice passing through axially 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 cover the intermediate space arranged axially between the first element and the second element when they are assembled to one another

The elastic blade moves from a bent mounting position to a preloaded position in which the blade is pre-stressed by the bearing member when the blade positioning tool is removed. In other words, the elastic blade is arranged to be prestressed by the support element when the first element and the second element are assembled to one another and in their relative position of rest. 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 movable in rotation relative to one another about an axis X;

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-damped torque transmission between the first element and the 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 cooperating with the support element so as to allow transmission of the torque, said elastic blade being arranged such that so that, for a relative rotation between the first member and the second member relative to a relative rest position, the support member exerts a bending force on the resilient blade which causes a displacement of the distal end free of the elastic blade in a direction of flexion and produces a reaction force opposite the elastic blade on the support element, this reaction force being able to return said first and second elements towards said relative position of rest;

the elastic blade and said support element being housed in an intermediate space arranged axially between the first element and the second element;

said damping device being characterized in that it comprises an access passage to the intermediate space formed in one of said first and second elements, said access passage being able to allow the introduction into space interlayer of a blade positioning tool adapted to bend the resilient blade so as to move the free end of the resilient blade in the direction of bending and to maintain the elastic blade in a bent 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 opens out facing a portion of the elastic blade.

The access passage is formed to allow movement of the positioning tool, the magnitude of this movement to move the blade from a rest position to a bending position of mounting.

- 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. The access passage to the intermediate space passes through the cylindrical skirt, in particular 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 facing the second element.

The support element is located radially outside the elastic blade.

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 elastic blade because such operating gaps would be likely to adversely affect the service life and the 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 a crankshaft and the other of said first and second elements is a secondary flywheel of the double 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 such that the radial distance separating the axis of rotation from said free distal end varies, and more particularly decreases, as a function of the angular displacement between the first and the second distal end. second elements.

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.

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-damped torque transmission between the first element and the second element; , the damping means comprising an elastic blade integral in rotation with the second element, said resilient blade cooperating with the support element so as to allow transmission of the torque and being arranged in such a way that, for a relative rotation between the first element and the second element relative to a relative position of rest, 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 a 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 prestressing by the support 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 mounted in rotation through 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 element, for example a bore formed on the first element.

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 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 element partially covers the rollers and comprises a second reinforcing element, formed for example by a bore adjusted 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 a motor vehicle comprising a damping device mentioned above.

Brief description of the figures

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly in the course of the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes. 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 of rods of a blade positioning tool.

- Figure 3 is a partial view of the double damping flywheel of Figure 2 in which the rods of the blade positioning tool, able to bend the elastic blades are introduced through the oblong holes 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.

- Figure 5 is a partial view of the double damping flywheel according to the second embodiment, wherein the secondary flywheel is not shown to allow visualization of slots formed in a cylindrical skirt of the primary flywheel and able to allow the passage stems of the blade positioning tool when assembling the double damping flywheel.

- Figure 6 is a front view of the double 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. - Figure 8 is a detailed view of one of the rods of Figure 7 and its contact with one of the elastic blades during assembly of the double damping flywheel.

- Figure 9 is a rear view of the double damping flywheel of Figures 7 and 8 and the blade positioning tool.

Detailed description of embodiments

In the description and the claims, the terms "external" 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 damper. 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. Furthermore, the terms "rear" AR and "front" 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 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 fixing the steering wheel Primary 2 on 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, during the assembly of 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 steering wheel. primary 2.

In Figure 1, it is observed that the secondary flywheel 3 comprises a flat annular surface 10, facing rearwardly, intended to form a bearing surface 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 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 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 embodiment shown, each resilient blade 14, 15 is attached independently 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 and 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, 15 has two regions. radially offset from each other and separated by a radial gap.

Although the invention is described above in connection with elastic blades 14, 15 having an inner strand 16 and an outer strand 17 connected by a bent portion 18, it is obvious that it is in no way limited 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 can be carried by the same annular body fixed on the secondary flywheel and / or have different shapes, as illustrated for example in the 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 elastic blade 14, 15 has a cam surface January 1 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 rollers 23 mounted movable in rotation on the primary flywheel 2. The cam followers 22 are held in abutment against their respective cam surface January 1 and are arranged to roll against said cam surface during a relative rotation between the primary flywheels 2 and secondary 3. Furthermore, the cam followers 22 are arranged radially outside their respective cam surface January 1 so as to maintain the radial blades 14, 15 radially when subjected to centrifugal force.

Each cam surface January 1 is arranged such that, for a 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, 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). Moreover, the torsional vibrations 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 arranged axially between the primary and secondary 2 flywheels 3.

As represented 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 the parasitic friction that may occur. to assign the depreciation 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 arranged 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 parallel to the axis of rotation X, this screw cooperating with a thread formed at the 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 intermediate space of the double damping flywheel through the bore 41. An intermediate cylinder 45 can be fitted around the cylindrical rod 25 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 rest on the first and second reinforcing elements under the action of the 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 reaction force directed radially outwardly on the roller 23 associated. Such pre-stressing of the resilient blades ensures a permanent contact between the rollers 23 and the resilient blades 14, 15 which makes it possible to avoid play that may induce in operation shocks between the rollers 23 and the blades 14, 15 and therefore reduce the life of the running gear 24.

In an alternative embodiment not shown, the structure is reversed and the elastic blades 14, 15 are fixed on the primary flywheel 2 while the rollers 23 are rotatably mounted on the secondary flywheel 3.

With reference to FIGS. 2 and 3, it can be seen that the radially oriented annular portion 6 of the primary flywheel is equipped with two oblong orifices 27 allowing the insertion of the rods 26, illustrated in FIG. 3, with a positioning tool. The two oblong orifices 27 are diametrically opposed and open respectively in the vicinity of a portion of one and the other of the two elastic blades 14, 15. The largest dimension of the oblong orifices 27 extends substantially according to a radial orientation.

A method of assembling the double damping flywheel of Figures 1 to 3 will now be described.

At first, the rollers 23 are mounted on the primary flywheel 2 while the elastic blades 14, 15 are mounted on the secondary flywheel 3. Subsequently, the primary flywheel 2 and the secondary flywheel 3 are presented one in facing each other in a relative angular position corresponding, at about 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 of the primary flywheel 2. The length of the rods 26 and the axial spacing between the primary flywheel 2 and the secondary flywheel 3 are, at this stage, such that the free end of each of the rods 26 is positioned radially outside the a portion of one of the elastic blades 14, 15, here outside the outer strand.

The rods 26 are then moved inside the oblong holes 27, towards the axis X, that is to say radially inwards, which causes the elastic blades 14, 15 to bend radially towards the axis. X. The rods 26 are maintained in position so as to maintain the resilient blades 14, 15 in a bending mounting position.

The primary flywheels 2 and secondary 3 are then moved axially close to each other until the secondary flywheel 3 is fitted on the primary flywheel 2 via the rolling bearing 4. The blade positioning tool can then be removed by extracting the rods 26 of the oblong holes 27 so as to release the resilient 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 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 holes are here formed through the primary flywheel, which makes it possible not to damage the flat annular surface 10 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 makes it possible, 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. to face.

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 wheels 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 an axial direction on the 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 here comprises a bar 32 which extends in 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 carry rods. 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 elastic blades 14, 15 to bend radially towards the X axis and maintain them in a flexed mounting position. 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 maintaining a bent mounting position of said resilient blades 14, 15 without the need for additional locking means. position of the stems.

Subsequently, the primary flywheel 2 and the secondary flywheel 3 are presented facing each other in a relative angular position in which the rods 30 are located opposite the slots 29 formed in the cylindrical skirt. 7 of the primary flywheel 2. This relative angular position substantially corresponds to the relative rest position of the primary flywheels 2 and secondary 3.

Subsequently, the primary flywheels 2 and secondary 3 are moved axially from one another until the secondary flywheel 3 is pressed on the secondary flywheel 3 via the rolling bearing 4. In connection with FIG. 5, it can be seen that after the primary flywheels 2 and secondary 3 are brought axially together, the stems 30 of the blade positioning tool 33 are engaged through the slots 29 formed in the cylindrical skirt 7 of the primary flywheel 2. The blade positioning tool 33 can at this point be removed, by moving the rods 30 radially outwardly so as to release the elastic blades 14, 15 of their flexed 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 flywheels primary 2 and secondary 3 during their 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 in the cylindrical skirt 7. In this case, the Positioning tool is first set up on the primary flywheel 2 before the primary 2 and secondary 3 flywheels are mounted on top of each other.

The double damping flywheel represented in FIGS. 7 to 9 differs from the double damping flywheels described above only by the structure of the access passages 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 Figure 8, the end of each rod 35, has a ramp 38 adapted to cooperate with a portion of the elastic blade 14, 15 respective and oriented such that when the primary flywheels 2 and secondary 3 are brought towards each other, the orientation of the ramp 38 leads to a bending of the elastic blade 14, 15 to 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 insertion of the two rods 35 into each other. The rods 35 are positioned such that the surfaces of the ramps 38 are directed towards the X axis. The inclination of the ramps 38 is such that their surface approaches the X axis away from the end of the stem 38.

Subsequently, the primary flywheel 2 and the secondary flywheel 3 are presented opposite each other in a relative angular position substantially corresponding to their relative rest position.

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 elastic blades 14, 15 come into contact with the ramps 38 of the rods 35, which causes the elastic 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 orifice 34 so as 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 obvious that it is not limited thereto and that it comprises all the technical equivalents of the means described and their combinations if they are within the scope of the invention. The use of the verb "to include", "to understand" or "to include" and its conjugated forms does not exclude the presence of other elements or steps other than those set out 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

1. A method of assembling a damping device for a motor vehicle chain, said assembly method comprising the following steps:

- providing a first element (2) and a second element (3) adapted to be rotatably mounted 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 direction of bending by means of a tool for positioning the blade (33, 37, 39) and maintain the elastic 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.

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 equipped with a passage ( 27, 29, 34) to access 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 interspace is an orifice (27, 34) axially extending through one of said first and second members (2, 3) and wherein the shank (26, 35) of the blade positioning tool (33, 37, 39) is disposed in an axial orientation through said passageway to the interspace.

4. 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 positioning tool of the blade is moved to the interior of the oblong aperture along its largest dimension to flex the resilient 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. The assembly method according to claim 5, wherein the first element (2) comprises the cylindrical skirt (7) and in which the passage access to the intermediate space is a slot (29) opening at the end of the cylindrical skirt (7) directed towards the second element (3) and in which the tool is first positioned. positioning the blade (32) relative to the second member (3) to flex the resilient blade (14, 15) and hold it in its bent mounting position and then the rod (30) passes through said slot (29). ) when axially bringing the first element (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 and wherein the rod (35) has a ramp (38) which is arranged to cooperate with the resilient blade (14, 15) so that the ramp (38) causes flexing of the resilient blade to its bent mounting position when the first member (2) and the second member (3) are brought together axially towards each other.

8. Assembly method 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 d support (23) when the blade positioning tool (33, 37, 39) is removed.

9. Damping device for a motor vehicle transmission chain comprising:

a first element (2) and a second element (3) rotatable relative to one another 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 a torque transmission with damping of the 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) co-operating with the support element (23) so as to allow the transmission of the torque, said elastic blade being arranged such that, for a relative rotation between the first element (2) and the second element (3) with respect to 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 it a force contrary 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 member (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 elastic blade (14, 15) so as to move the free end of the blade elastic in the direction of flexion and to maintain the elastic blade in a bending mounting position.

The damping device according to claim 9, wherein when the first and second members are in relative rest position, the passage is located in an angular sector extending from the free distal end to the support member. .

1 1. Damping device according to claim 9 or 10, wherein the access passage to the intermediate space is formed by an orifice (27, 34) axially passing through the first or the second element

12. A damping device according to claim 1 1, 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 formed axially between the first element and the second element and wherein the passage (29) for access to the interspace through the cylindrical skirt (7).

14. damping device according to claim 13, wherein the first element (2) comprises the cylindrical skirt (7) and wherein the access passage 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).

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. 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 of 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:

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 a torque transmission with damping of the 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 support element (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 element support (23) exerts a bending force on the resilient blade (14, 15) which produces a counteracting force of the elastic blade on the bearing 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.

19. A damping device according to claim 18, wherein the cam follower is a roller (23) rotatably mounted on the first member (3).