WO2016177958A1

WO2016177958A1 - Vibration damper for a torque transmission device of a motor vehicle

Info

Publication number: WO2016177958A1
Application number: PCT/FR2016/051026
Authority: WO
Inventors: Jérôme BOULET; Ivan Dutier; Fabien LEBEAU
Original assignee: Valeo Embrayages
Priority date: 2015-05-07
Filing date: 2016-05-02
Publication date: 2016-11-10
Also published as: FR3035940A1; WO2016177942A1; FR3035940B1

Abstract

The invention relates to a damper, in particular a vibration damper for a motor vehicle transmission chain, the damper including: a primary mobile element (2), rotatably mobile relative to a rotation axis X; a secondary mobile element (3), rotatably mobile relative to the rotation axis X, the secondary mobile element being rotatably mobile relative to the primary mobile element relative to the axis of rotation (X); a transmission member (14, 15) including an attachment portion (18), said transmission member including a resilient blade (100) capable of bending and transmitting a rotation torque between said two elements, the bending of the resilient blade being accompanied by a relative rotation between the primary and secondary mobile elements, about a rotation axis X; and a reinforcement member (70), arranged to reinforce the support of the attachment portion of the transmission member relative to the forces which are applied to said transmission member.

Description

Torsion damper for a torque transmission device of a motor vehicle

Technical field of the invention

The invention relates to a shock absorber, in particular a torsion damper for an automobile transmission chain.

State of the art

Torsional dampers are known whose input and output elements are coupled in rotation by damping means for transmitting a torque and damping rotation acyclisms. The damping means are generally helical, bent, circumferentially disposed springs in an annular, sealed chamber which is formed between the input and output members.

The damping proposed by these dampers is not entirely satisfactory, in particular because of the high friction, and it has also been proposed to produce torsion dampers with a blade, as described in documents FR3000155 and FR3008152 which illustrate a torsion damper comprising elastic damping means formed by an elastic blade provided with a cam, and cooperating with a cam follower.

OBJECT OF THE INVENTION The object of the invention is to improve this type of damper.

For this purpose, and according to a first aspect, the invention relates to a damper, in particular an automobile torsion damper, in particular placed downstream of the engine to dampen its acyclisms, for example in the transmission chain, the damper comprising: a primary movable element, movable in rotation with respect to an axis of rotation X,

a secondary movable element, rotatable relative to the axis of rotation X, the secondary movable element being rotatable relative to the primary movable element relative to the axis of rotation X,

a transmission member comprising a fixing portion, said transmission member comprising an elastic blade capable of bending and transmitting a torque between these two elements, the bending of the elastic blade being accompanied by a relative rotation between the primary movable elements and secondary, according to the axis of rotation X,

a reinforcing member, arranged to reinforce the retention of the fastening portion of the transmission member vis-à-vis the forces to which this transmission member is subjected. Thanks to the invention, it is possible to strengthen the maintenance of the fastening portion of the transmission member when it is subjected to significant centrifugal forces or when the transmitted torque is important. This is particularly necessary when the attachment portion of the transmission member is devoid of annular body and extends over a restricted angular sector, for example less than 100 degrees.

According to other advantageous embodiments, such a torsion damper may have one or more of the following characteristics:

Preferably, the reinforcing member is arranged to reinforce the retention of the attachment portion of the transmission member with respect to the centrifugal forces to which this transmission member is subjected during the rotation of the damper.

Preferably, the attachment portion is attached to one of the primary and secondary movable elements. Preferably, the reinforcing member is arranged to counter efforts, including centrifugal forces, to which the transmission member is subjected during the rotation of the damper.

Preferably, the reinforcing member is fixed on the transmission member, in particular on its fixing portion.

Preferably, the reinforcing member is formed of a metallic material.

Preferably, the reinforcing member comprises a central opening in which extends, along the axis of rotation, a hub formed on one of the primary and secondary movable elements. This hub supports via a bearing, the other of the primary and secondary mobile elements.

Preferably, the reinforcing member extends in a plane substantially perpendicular to the axis of rotation of the damper. Preferably, the axial size of the reinforcing member is less than the axial size of the transmission member.

Preferably, the elastic blade is arranged to flex, during operation, in a plane perpendicular to the axis of rotation X.

Preferably, the attachment portion of the transmission member is mounted to rotate with one of the primary and secondary movable elements.

Preferably, the transmission member is mounted on one of the primary and secondary movable elements and the elastic blade cooperates with a support element carried by the other primary and secondary movable elements. Preferably, the support element is integral in rotation with the other of the primary and secondary mobile elements.

Preferably, the support element is arranged radially outside the elastic blade. Thus the support member radially maintains the elastic blade when subjected to centrifugal force.

Preferably, the resilient blade has a cam surface.

If desired, the cam surface is concave along the entire length, this concavity being on the side of the axis of rotation.

Preferably, the support member has a cam follower cooperating with the cam surface of the blade.

Preferably, the elastic blade of the transmission member is bent around the axis of rotation X, from the attachment portion to a free distal end.

Advantageously, the cam surface is located on a surface of the blade located radially outside the blade.

Preferably, the cam follower is disposed radially outwardly of the resilient blade.

Preferably, the cam follower comprises a roller rotatably mounted on the primary movable element. Preferably, the cam follower is held in abutment against its respective cam surface and is arranged to roll against said cam surface during relative rotation between the primary and secondary members. Advantageously, the cam surface is arranged such that, for an angular displacement between the primary element and the secondary element with respect to an angular position of rest, the cam follower exerts a bending force on the elastic blade producing a reaction force able to return said primary and secondary elements to said angular position of rest.

The attachment portion of the blade is closer to the axis of rotation than the blade.

Preferably, the elastic blade has a bend connecting to the fixing portion.

Preferably, the bend has an angle of about 180 ° so that the remainder of the blade surrounds the attachment portion which is closer to the X axis.

According to one embodiment, the fastening portion and the elastic blade of the transmission member are formed in one piece. Preferably, the attachment portion of the transmission member is attached to one of the primary and secondary movable elements with fasteners such as rivets. The reinforcing member allows these fixing elements to better withstand the forces transmitted by the transmission member to the primary or secondary mobile element which carries it.

The fasteners extend axially and the end of the fasteners located on the upstream side extends axially beyond the reinforcing member.

Preferably, the angular sector covered by the reinforcing member is greater than the angular sector covered by the attachment portion of the transmission member. Preferably, the damper comprises a plurality of transmission members. These transmission members are advantageously distant from each other. Preferably, a plurality of transmission members are arranged on the same plane perpendicular to the axis of rotation X.

Preferably, each transmission member comprises an elastic blade cooperating with a support element which is specific to it.

Preferably, the transmission members located on the same plane are symmetrical with respect to the axis of rotation X.

Preferably, the reinforcing member is fixed on the transmission member by virtue of the fastening elements of the transmission member on the primary or secondary movable element which carries it. The reinforcing member thus makes it possible to limit the shear stresses in these fastening elements.

Preferably, the transmission member is arranged axially between one of the primary and secondary movable elements which carries it and the reinforcing member. Thus the forces from the transmission member can be resumed on both ends of the fastener, to prevent the torsion of this fastener. If desired, a portion of the reinforcing member may be attached to one of the primary and secondary movable members on which the transmission member is carried, by means of additional fastening elements, such as rivets.

For example, the reinforcing member may be attached directly to one of the primary and secondary movable elements on which the transmission member is carried. The additional fastening elements, remote from the transmission member, make it possible to reinforce the retention of the transmission member and to better transmit the torque between the transmission member and the primary or secondary movable member which carries the member of transmission.

The reinforcing member comprises a bearing surface on which the fixing element rests.

The reinforcing member is arranged to stiffen the fastening elements, so as to avoid torsion of the fastening elements when the transmission member is subjected to a centrifugal force or when it transmits a large torque.

The fastening elements are arranged on a circle whose center is located substantially on the axis of rotation X.

Preferably, the fastening element comprises a body parallel to the axis of rotation X. Preferably, the fastening portion of the transmission member is fixed to one of the primary and secondary movable elements by a plurality of fasteners such as rivets, and the reinforcing member is arranged to reinforce at least one of these fasteners against forces. Preferably, the reinforcing member comprises an outer peripheral edge extending circumferentially around the axis of rotation X.

Preferably, the outer peripheral edge of the reinforcing member extends radially outwardly of the fastening elements. The peripheral border external of the reinforcing member is advantageously free. The reinforcing member carries no mass of inertia, for example pendulum.

Preferably, at least a portion of the outer peripheral edge of the reinforcing member extends in a plane perpendicular to the axis of rotation.

Preferably, when the fastening elements are rivets, the reinforcing member extends entirely on one side of a plane passing through the rivet heads. Preferably, the rim of the reinforcing member is devoid of axial extension.

Preferably, the flange of the reinforcing member is devoid of cylindrical axial extension, particularly with respect to the axis of rotation X.

Preferably, the reinforcing member is stamped so as to have sectors axially offset with respect to one another.

Preferably, the reinforcing member has an annular shape.

Preferably, the reinforcing member is formed in a sheet.

Preferably, the transmission member is arranged axially between one of the primary and secondary movable elements on which it is mounted and the reinforcing member.

Preferably, the transmission member is clamped axially, in particular riveted, between one of the primary and secondary movable elements on which it is mounted and the reinforcing member. Preferably, the reinforcing member comprises an opening, or indentation, in which is introduced at least one of the fastening elements of the transmission member.

The reinforcing member then makes it possible to limit the shear stresses in these fastening elements.

Preferably, the fixing element comprises a head which clamps the reinforcing member against the transmission member. Preferably, the bearing surface of the reinforcing member, formed by this opening, or indentation, retains the fixing element radially, especially with respect to the forces.

Preferably, the opening is a hole axially through the reinforcing member.

Preferably, the damper comprises a first and a second transmission members. Preferably, the first and second transmission members are distant from each other.

Preferably, the first and second transmission members each comprise a blade.

Preferably, the first and second transmission members are arranged on the same plane perpendicular to the axis of rotation.

Preferably, the reinforcing member comprises a first portion mounted on the attachment portion of the first transmission member and a second portion, integral rotation of the primary or secondary mobile element on which is mounted the transmission member at a distance from the first transmission member. Thus, this second part of the reinforcing member reinforces the maintenance of the first transmission member.

The second part of the comfort member comprises a part fixed on the second transmission member.

The second part of the reinforcing member comprises a portion fixed on the primary or secondary movable element on which is mounted the transmission member.

The second part of the reinforcing member comprises a portion directly attached to the primary or secondary movable element on which is mounted the transmission member.

Preferably, the first part of the reinforcing member is pressed against the fixing portion of the first transmission member. Preferably, this first part is located between two steps of the reinforcing member.

Preferably, the attachment portion of the transmission member is arranged circumferentially between these two steps.

Preferably, the reinforcing member is fixed both to the attachment portion of the first transmission member and to an attachment portion of the second transmission member.

Thus, at least a part of the forces originating from the first transmission member is compensated, even balanced or neutralized, thanks to the reinforcement, by the efforts from the second transmission member. This also makes it possible to reduce the stresses at the level of the fastening elements.

Also, when the first and second transmission members are arranged symmetrically with respect to the axis of rotation, for example diametrically opposite, the forces, including centrifugal forces, received by the reinforcing member are balanced.

The reinforcing member is advantageously arranged to balance and neutralize the stresses applied to the fastener or elements.

Preferably, this second part of the reinforcing member is pressed against the fixing portion of the second transmission member.

Preferably, the reinforcing member has a thickness of between 0.5 mm and 10 mm, for example between 0.7 mm and 5 mm, in particular between 1 mm and 3 mm.

Preferably, the damper comprises friction members arranged to exert a friction resisting torque between the primary and secondary movable elements, at an angular displacement between said primary and secondary moving elements.

Preferably, the reinforcing member comprises at least one driving element arranged to rotate one of these friction members.

Preferably, the friction members comprise a first friction washer arranged to be rotated by the reinforcing member, integral in rotation with one of the primary and secondary movable elements, and a second friction washer arranged to be driven. in rotation by the other of the primary and secondary mobile elements, and a spring washer of the type "Belleville" arranged to exert a pushing force of the first friction washer against the second friction washer.

Preferably, the drive element is arranged to rotate the first friction washer.

Preferably, the driving element is an insert attached to the reinforcing member. Preferably, the driving element is a rivet riveted to the reinforcing member at a distance from the fastening elements of the transmission member.

Preferably, the driving member of the reinforcing member is engaged with a complementary driving element arranged on the first friction ring.

Preferably, the reinforcing member comprises at least one drive sector of this first friction washer, and at least one attachment sector on the transmission member.

Preferably, the reinforcing member comprises two diametrically opposed attachment sectors.

Preferably, the reinforcing member comprises two drive sectors of this first diametrically opposed friction washer.

Preferably, the reinforcing member comprises reinforcing steps. These steps stiffen and reinforce the reinforcing member vis-à-vis the efforts, including centrifugal, which is subject to this transmission member. Preferably, the reinforcing member is substantially plane between the steps.

Preferably, the driving elements are elements projecting axially towards the first friction washer.

Preferably, the projecting elements of the reinforcing member cooperate with openings or indentations formed on the first friction ring, to drive it in rotation. Preferably, the reinforcing member is fixed at a time:

on one of the primary and secondary movable elements which carries the transmission member, at a distance from the transmission member, and

on at least one of the transmission members, preferably on each transmission member.

Preferably, the steps of the reinforcing member extend axially so that the reinforcing member can be plated, at least partially, against the primary or secondary mobile element which carries the transmission member. Preferably, the axially offset sectors of the reinforcing member comprise at least one attachment sector on the transmission member and at least one additional attachment sector on the primary or secondary movable element which carries the transmission member. Preferably, the reinforcing member comprises two additional diametrically opposed attachment sectors.

Preferably, the additional fastening sector comprises a driving element of the first friction ring. The driving element is a boss formed on the reinforcing member, for example by stamping.

The drive member is engaged with a complementary drive member projecting axially from the first friction washer.

The complementary drive element is a stud.

Two complementary drive elements are arranged circumferentially on either side of a drive element so that the first friction washer is able to be driven in both directions of rotation.

A gap is arranged circumferentially between the complementary driving elements and the driving elements to obtain a slide hysteresis device.

If desired, the support element is a roller movable in rotation with respect to the primary or secondary movable element which carries it, in order to be able to accomplish a curvilinear path on at least one angular sector, the curvilinear displacement of this roller relative to the first element being accompanied by a displacement of this roller on the elastic blade, in particular by rolling, by bending it. Preferably, the reinforcing member comprises an axial retaining element arranged to retain axially the primary or secondary movable element carrying the transmission member relative to the bearing.

Preferably, the axial retaining element is arranged to retain axially the primary or secondary movable element which carries the organ of transmission to prevent it from moving axially away from the other primary and secondary moving elements.

Preferably, the axial retaining element is arranged to bear against the bearing when one of the primary and secondary movable element deviates axially from the other of the primary and secondary movable elements.

Preferably, the reinforcing member comprises a radially inner rim on which is formed the axial retaining element.

Preferably, the axial retaining element is mounted bearing against the bearing.

Preferably, the axial retaining element is mounted bearing against the bearing with a preload.

Preferably, a clearance can be left between the axial retaining element and the bearing. Preferably, the bearing comprises an outer ring, an inner ring and rolling bodies extending between said inner and outer rings, the axial retaining member being arranged to bear against the outer ring of the bearing.

The invention also relates to a double damping flywheel, the primary flywheel being formed by one of the primary and secondary movable elements and the secondary flywheel being formed by the other primary and secondary movable elements. If desired, the fastening elements of the transmission member are arranged radially outside the fastening screws of the primary flywheel on the crankshaft. Where appropriate, the reinforcing member comprises passages through which pass these fixing screws.

The passages are radially inside the drive elements of the first friction ring.

The invention also relates to a device comprising:

a primary movable element, movable in rotation with respect to an axis of rotation X,

a transmission member comprising a fixing portion, said transmission member comprising an elastic blade capable of bending and transmitting a torque between these two elements, the bending of the elastic blade being accompanied by a relative rotation between the primary and secondary, along the axis of rotation X,

and the attachment portion of the transmission member is attached to one of the primary and secondary movable members with only two fastener elements such as rivets.

When the transmission member is attached to one of the primary and secondary movable members with only two fastener elements such as rivets spaced appropriately, the damper may in some cases be devoid of a reinforcing member. The invention also relates to a device comprising:

and the attachment portion of the transmitting member is attached to one of the primary and secondary movable members with fastener elements such as rivets, and at least one of the primary and secondary movable members has holes therein. aeration.

The invention will be better understood, and other objects, details, features and advantages thereof will appear more clearly in the following description of several particular embodiments of the invention, given solely for illustrative purposes and not limiting, with reference to the accompanying drawings.

On these drawings:

Figure 1 is a front view, schematic and partial, of a damper according to a first embodiment of the invention.

FIG. 2 is a schematic and partial perspective view of certain elements of the damper of FIG. 1.

FIG. 3 is a sectional view along III-III, schematic and partial, of certain elements of the damper of FIG. 1.

FIG. 4 is a schematic and partial perspective view of certain elements of the damper of FIG. 1. FIG. 5 is a sectional view along VV, schematic and partial, of the damper of FIG. 1.

Figure 6 is a schematic and partial perspective view of some elements of the damper, according to a second embodiment.

FIG. 7 is a sectional view along VII-VII of certain elements of the damper of FIG. 6

Figure 8 is a schematic and partial perspective view of some elements of the damper, according to a third embodiment.

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 X, the "Circumferential" orientation is directed orthogonally to the X axis of rotation of the damper and substantially perpendicular to the radial direction. The term "circumferentially" is used here to describe a curved path, circular or otherwise, around the axis of rotation, and does not necessarily refer to a closed curve here. 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.

The term "front" characterizes, in the transmission chain, an element facing the engine and the term "rear" characterizes an element turned in the opposite direction to the engine.

FIGS. 1 to 5 show a damper 1 forming a double damping flywheel. In this embodiment, the transmission member is mounted on the secondary flywheel. An inverted structure with the transmission member mounted on the primary flywheel would also be possible.

The double damping flywheel 1 comprises a primary element 2, forming here a primary flywheel intended to be fixed at the end of a crankshaft of an internal combustion engine, not shown, and a secondary element 3 forming here a steering wheel. secondary inertia which is centered and guided on the primary flywheel 2 by means of a bearing 4, such as a rolling bearing ball. Indeed, the transmission members 14 15 are carried here by the secondary flywheel, but in an embodiment not shown, the transmission members could be carried by the primary flywheel.

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 towards the rear.

The primary flywheel 2 is provided with orifices 8a allowing the passage of fastening screws 8, for fastening the primary flywheel 2 to the crankshaft of the engine (not shown). 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 4a, an inner ring 4b and rolling bodies 4c extending between said inner and outer rings.

The secondary flywheel 3 comprises a flat annular surface 10, turned towards the rear, intended to form a bearing surface for a friction lining of a clutch element, not shown. The secondary steering wheel 3 comprises, close to its outer edge, pads 24 for mounting a cover of the clutch device.

With reference to FIG. 2, it can be seen that the damper comprises a first 14 and a second transmission member mounted integral in rotation with the secondary flywheel 3.

The two transmission members 14, 15 are symmetrical to each other with respect to the axis of rotation X.

Each transmission member 14, 15 comprises an elastic blade 100 capable of bending and transmitting a torque between these two elements 2 and 3, the bending of the elastic blade 100 being accompanied by a relative rotation between the primary and secondary wheels 2 and 3, according to the axis of rotation X.

Each elastic blade 100 is arranged to flex, during operation, in a plane perpendicular to the axis of rotation (X).

Each transmission member 14 and 15 comprises a fastening portion 13 integral in rotation with the secondary flywheel 3.

Each fixing portion 13 is fixed to the secondary flywheel 3 by means of three rivets 77.

Each elastic blade 100 is bent around the axis of rotation X, from the attachment portion 13 to a free distal end 102. Furthermore, each elastic blade 100 has a bend 18 connected to the fixing portion 13. The bend 18 has an angle of about 180 ° so that the remainder of the blade 100 surrounds the attachment portion 13 which is closer to the X axis. In relation with FIG. 4, the elastic blade 100 of each transmission member 14 and 15 cooperates with a bearing element 110 carried by the primary flywheel 2.

The bearing element 110 is integral in rotation with the primary flywheel 2. The support element 110 is arranged radially outside the elastic blade 100. Thus, the support element 110 radially maintains the elastic blade 100 when subjected to centrifugal force.

In FIG. 2, it can be seen that each elastic blade 100 has a cam surface 101. Here the cam surface is concave along its entire length, this concavity being on the side of the axis of rotation X.

The support member comprises a cam follower 110 cooperating with the cam surface 101 of the blade 100.

The cam surface 101 is arranged such that, for an angular displacement between the primary flywheel 2 and the secondary flywheel 3 relative to an angular position of rest, the cam follower 110 exerts a bending force on the elastic blade 100 producing a reaction force able to return said primary and secondary flywheels 3 to said angular position of rest.

The cam surface 101 is located on a surface 103 of the blade 100 located radially outside the blade 100. Also, the cam follower 110 is disposed radially outside the elastic blade 100.

This cam follower 110 comprises a roller 23 mounted to rotate on the primary flywheel 2 by means of rolling members (not shown), such as balls, rollers or needles, so as to reduce parasitic friction. likely to affect the depreciation function. The rollers 23 are each carried by a cylindrical rod 25 extending parallel to the axis of rotation X and an end of which is fixed inside an orifice formed in the primary flywheel 2.

Thus, the resilient blades 100 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 that are produced by the engine and transmitted by the crankshaft to the primary flywheel 2 are damped by the flexion of the elastic blades 100. The operation of this type of damping is detailed in the application. FR3000155.

The elastic blades 100 and the rollers 23 are housed in a space provided axially between the primary and secondary 2 flywheels 3.

Each cam follower 110 is held in abutment against its respective cam surface 101 and is arranged to roll against said cam surface 101 during a relative rotation between the primary and secondary 2 flywheels 3.

According to one embodiment, the fastening portion 13 and the elastic blade 100 of the transmission member are formed in one piece.

The transmission members 14, 15 are arranged symmetrically with respect to the axis of rotation. The fixing portion 13 and the elastic blade 100 are formed in one piece, from the same piece.

The double damping flywheel therefore has

a primary flywheel 2, rotatable relative to an axis of rotation X, a secondary flywheel 3, rotatable relative to the axis of rotation X, the secondary flywheel being rotatable relative to the primary flywheel relative to the axis of rotation (X), two transmission members 14 and 15 each comprising a fastening portion 13 and each transmission member comprising an elastic blade 100 capable of flexing and transmitting a torque between these two flywheels, the bending of the elastic blade being accompanied by a rotation relative between the primary and secondary flywheels, according to the axis of rotation X, a reinforcing member 70, arranged to reinforce the retention of the fastening portion 13 of each transmission member vis-à-vis the efforts to which this organ is subjected of transmission. The reinforcing member 70 is thus arranged to counter the centrifugal forces to which each transmission member 14 and 15 is subjected during the rotation of the damper 1.

As can be seen in FIG. 2, the reinforcing member 70 is fixed on each transmission member 14 and 15.

The reinforcing member 70 is preferably formed of a metallic material.

The reinforcing member 70 extends in a plane substantially perpendicular to the axis of rotation X of the damper 1.

In FIGS. 2 and 3, it can be seen that the axial size of the reinforcing member 70 is smaller than the axial size of each transmission member 14 and 15.

The attachment portion 13 of each transmission member 14 and 15 is fixed to the secondary flywheel 3 with fastening elements 77 such as rivets. The reinforcing member 70 is fixed to the secondary flywheel 3 by virtue of the fastening elements 77 of each transmission member 14 and 15. The reinforcing member 70 is thus arranged to reinforce these fixing elements 77 against the forces. The reinforcing member 70 is fixed to each transmission member 14 and 15 by virtue of the rivets 77. The reinforcing member thus makes it possible to limit the shear stresses in these rivets 77. The reinforcing member 70 is thus arranged to neutralize the stresses, in particular centrifugal, applied to the rivets 77. By stiffening the rivets 77, the reinforcing member makes it possible to prevent the rivets 77 from being twisted or torn off when the transmission member transmits a large torque or when it is subject to significant centrifugal force.

The fixing elements 77 are arranged on a circle whose center is located substantially on the axis of rotation X.

The reinforcing member 70 has a bearing surface 71 on which the fixing element 77 rests.

Preferably, each fastener element 77 comprises a body 78 parallel to the axis of rotation X.

The reinforcing member 70 has an outer peripheral edge 72 extending circumferentially around the axis of rotation X. The outer peripheral edge 72 of the reinforcing member 70 extends radially outside the rivets 77 and the outer peripheral edge 72 of the reinforcing member 70 is free. The reinforcing member 70 does not in fact carry any pendulum mass. At least a portion of the outer peripheral edge 72 of the reinforcing member 70 extends in a plane P perpendicular to the axis of rotation X.

As seen in Figure 3, the reinforcing member 70 extends entirely on one side of a plane passing through the heads 79 of rivets 77. The reinforcing member 70 is devoid of axial extension.

In Figure 2 we see that the reinforcing member 70 is stamped so as to have sectors S1, S2, S3, S4 axially offset with respect to each other.

The reinforcing member 70 has steps 73 of reinforcement. These steps stiffen and strengthen the reinforcing member 70 vis-à-vis the forces generated by the transmission members.

The reinforcing member 70 is substantially plane between the steps 73. The reinforcing member generally has an annular shape.

The reinforcing member 70 is formed in a sheet. The reinforcing member has a thickness of between 0.5 mm and 10 mm, for example between 0.7 mm and 5 mm, in particular between 1 mm and 3 mm.

As seen in Figure 3, the transmission member 14 is arranged axially between the reinforcing member 70 and the secondary flywheel 3. More specifically, the transmission member 14 is riveted axially between the reinforcing member 70 and the secondary steering wheel 3.

The reinforcing member 70 comprises an axial retaining element 88 arranged to axially retain the secondary flywheel 3 carrying the transmission member 14, relative to the bearing 4. The axial retaining element 88 is arranged to support against the bearing 4 when the secondary flywheel 3 deviates axially from the primary flywheel 2. The reinforcing member comprises a radially inner flange 88 on which is formed the axial retaining element 88. Here, the axial retaining element 88 is supported against the bearing 4. If desired the axial retaining element 88 can be mounted bearing against the bearing 4 with a preload.

The bearing 4 comprises an outer ring 4a, an inner ring 4b and rolling bodies 4c extending between said inner and outer rings 4b 4a, the axial retaining element 88 being arranged to bear against the outer ring 4a of the bearing 4.

The reinforcement member comprises a plurality of apertures 74, some of which receive fastening rivets 77 of each transmission member 14 and 15. Each rivet 77 comprises a head 79 which clamps the reinforcing member 70 against the transmission member 14 or 15.

The bearing surface 71 of the reinforcing member 70, formed by this opening 74, radially retains the rivet 77 vis-à-vis efforts.

The opening 74 is an orifice 74 passing axially through the reinforcing member 70.

It can be seen in FIG. 2 that the first 14 and second 15 transmission members are distant from one another.

The reinforcement member comprises a first portion 75 mounted on the attachment portion 13 of the first transmission member 14 and a second portion 76 fixed on the attachment portion of the second transmission member 15. Thus, at least a portion of the forces received by the reinforcing member at the first transmission member may be neutralized by the forces received by the reinforcing member at the second transmission member. Here, as the first and second transmission members are arranged symmetrically with respect to the axis of rotation, the centrifugal forces received by the reinforcing member are balanced.

The first portion 75 of the reinforcing member 70 is pressed against the fastening portion 13 of the first transmission member 14. This first portion 75 is located between two steps 73 of the reinforcing member 70. The transmission member 14 , in particular its fixing portion 13, is arranged circumferentially between these two steps 73.

Similarly, the second portion 76 of the reinforcing member 70 is pressed against the fixing portion of the second transmission member 15.

As seen in Figures 4 and 5, the damper 1 further comprises friction members 30 arranged to exert a resistant torque between the primary flywheel 2 and the secondary flywheel 3 during the relative movement. The friction members comprise a spring washer, of "Belleville type" 32, a first friction washer 34 adapted to be rotated relative to the primary flywheel 2 during a relative deflection between the primary flywheels 2 and secondary 3 and a second friction washer 33, integral in rotation with the primary flywheel 2 and. The spring washer 32 is axially wedged in the opposite direction to the motor by a circlip. The spring washer 32 exerts an axial force on the second friction washer 33 which clamps the first friction washer 34 between said second friction washer 33 and the primary flywheel 2. The second friction washer 33 has on its inner periphery cooperating legs with grooves provided on the outer peripheral edge of the hub 5 of the primary flywheel 2, so as to secure in rotation the second washer of friction 33 with the primary flywheel 2. The first friction washer 34 has, meanwhile, on its outer peripheral edge notches 35 adapted to cooperate, with a given circumferential clearance, with drive elements 38 formed on the body reinforcement 70, so as to allow a relative movement of the first friction washer 34 relative to the primary flywheel 2, during a relative movement between the primary flywheel 2 and secondary 3.

Preferably, the driving elements 38 of the reinforcing member 70 are engaged with the indentations 35 arranged on the first friction ring 34. Thus, these driving elements 38 rotate the first friction ring 34.

The driving elements 38 are elements projecting axially towards the first friction ring 34. The driving elements 38 are here rivets 38 riveted to the reinforcing member 70 at a distance from the fastening elements 77 of the body 70. These drive rivets 38 do not ensure the attachment of the reinforcing member 70 and are arranged on drive sectors S2 and S4 of the reinforcing member. Thus, the reinforcing member comprises two attachment sectors S1 and S3 on the transmission member and two drive sectors S2 and S4 of the friction ring. These two attachment sectors SI and S3 are diametrically opposed. The two drive sectors S1 and S3 are also diametrically opposed. FIG. 4 also shows that the primary flywheel 2 intended to be fixed to the crankshaft comprises ventilation holes 99, here preferably arranged in a circular manner around the axis of rotation X.

FIGS. 6 and 7 describe a second embodiment of the invention in which the reinforcing member 270 is attached both to the secondary flywheel 3 and to each transmission member 14 and 15. The reinforcing member 270 is attached directly to the secondary flywheel 3 with additional fastening elements 298 such as rivets 298. The reinforcing member 270 is also attached directly to each transmission member with fastening elements 277 such as rivets 277.

Preferably, the reinforcing member here extends circumferentially 360 degrees. Nevertheless, it would also be possible to implement two reinforcing members each extending 180 degrees each independently fixed on their own transmission member and on the secondary flywheel with additional fasteners.

To do this, the steps 273 of the reinforcing member 270 extend axially so that the reinforcing member 270 can be plated, at least partially, against the secondary flywheel 3.

The sectors S2, S4 and S1, S3 axially offset from the reinforcing member 270 comprise two attachment sectors S1 and S3 on the transmission members 14 and 15 and two additional attachment sectors S2 and S4 on the secondary flywheel. 3. The two fixing sectors SI and S3 on the transmission members 14 and 15 are diametrically opposed. The two additional attachment sectors S2 and S4 on the secondary flywheel 3 are also diametrically opposed.

Additional attachment sectors S2 and S4 on the secondary flywheel

each comprise a drive element 238 of one of the friction members 234 (Figure 7).

The driving element is here a boss 238 formed on the reinforcing member 270, for example by stamping. As can be seen in the sectional view of FIG. 7 which represents the reinforcement member and the first friction washer 234, the drive element 238 is engaged with a complementary drive element 235 projecting axially from the first friction washer 234, towards the reinforcing member 270.

The complementary drive element 235 is a stud arranged circumferentially between the drive element 238 and a step 273 of the reinforcing member.

Two complementary drive elements 235 are arranged circumferentially on either side of a driving element 238 so that the friction washer 234 is driven in both directions of rotation.

A space E is arranged circumferentially between the complementary drive elements 235 and the drive elements 238 to obtain a slide hysteresis device. FIG. 8 shows a third embodiment in which the two fastening elements 377 of each transmission member 314 and 315 are arranged radially outside the fastening screws 8 of the primary flywheel on the crankshaft. . The reinforcement member 370 thus comprises passages 340 through which these fastening screws 8 pass.

The passages 340 are radially inside the drive elements 338 of the friction member. These training elements 338 are obtained here by stamping the reinforcing member 370, so as to project axially.

Again, the radially inner flange 388 of the reinforcing member forms an axial retaining member 388 bearing against the bearing 304 to prevent the secondary flywheel from moving away from the primary flywheel.

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

A shock absorber, in particular an automobile torsion damper, the shock absorber comprising:

a primary movable element (2) rotatable relative to an axis of rotation X,

a secondary movable element (3) rotatable relative to the axis of rotation X, the secondary movable element being rotatable relative to the primary movable element relative to the axis of rotation (X),

a transmission member (14, 15) comprising a fixing portion (13), said transmission member comprising an elastic blade (100) capable of flexing and transmitting a torque between these two elements, the flexion of the elastic blade ( 100) being accompanied by a relative rotation between the primary and secondary moving elements, along the axis of rotation X, a reinforcing member (70), arranged to reinforce the retention of the fastening portion of the transmission member to the efforts to which this organ of transmission is subjected.

2. Damper according to the preceding claim characterized in that the reinforcing member is fixed on the transmission member.

3. Shock absorber according to one of the preceding claim characterized in that the reinforcing member extends in a plane substantially perpendicular to the axis of rotation of the damper.

4. Damper according to one of the preceding claims characterized in that the transmission member is mounted on one of the primary and secondary movable elements and the elastic blade cooperates with a support element carried by the other movable elements primary and secondary.

5. Damper according to the preceding claim characterized in that the elastic blade has a cam surface and the support member comprises a cam follower cooperating with the cam surface.

6. Damper according to one of the preceding claims characterized in that the fastening portion of the transmission member is fixed to one (3) of the primary and secondary movable elements with fastening elements (77) such that rivets.

7. Shock absorber according to the preceding claim characterized in that the reinforcing member is fixed to the transmission member by means of these fastening elements (77).

8. Damper according to one of claims 6 and 7 characterized in that the fixing portion (18) is fixed to one of the primary and secondary movable elements by a plurality of fastening elements (77) such as rivets and the reinforcing member (70) is arranged to reinforce at least one of the fasteners against the forces.

9. Damper according to one of the preceding claims characterized in that the reinforcing member (70) comprises steps (73) of reinforcement.

10. Shock absorber according to one of the preceding claims characterized in that the transmission member (14, 15) is arranged axially between one (3) of the primary and secondary movable elements which carries it and the reinforcement member ( 70).

11. Damper according to one of claims 6 to 10 characterized in that the reinforcing member (70) comprises an opening, or indentation (74) into which is introduced at least one of the fastening elements (77). of the transmission member (14, 15).

12. Damper according to one of the preceding claims characterized in that the damper (1) comprises a first (14) and a second (15) transmission members remote from each other.

13. Shock absorber according to the preceding claim characterized in that the reinforcing member comprises a first portion (75) mounted on the fastening portion (13) of the first transmission member (14) and a second portion (76) mounted solidarity. in rotation of the primary or secondary mobile element on which is mounted the transmission member at a distance from the first transmission member (14).

14. Damper according to one of the preceding claims characterized in that the damper comprises friction members (30) arranged to exert a friction resisting torque between the primary and secondary movable elements, at an angular displacement between said elements. primary and secondary movable members and the reinforcing member comprises at least one drive element (38) arranged to rotate one (34) of these friction members.

15. Shock absorber according to one of the preceding claims characterized in that the reinforcing member (270) is fixed at a time:

on the transmission member.