WO2016146415A1

WO2016146415A1 - Torsional damper

Info

Publication number: WO2016146415A1
Application number: PCT/EP2016/054751
Authority: WO
Inventors: Karthik Krishnasamy
Original assignee: Valeo Embrayages
Priority date: 2015-03-16
Filing date: 2016-03-07
Publication date: 2016-09-22
Also published as: FR3033857A1; FR3033857B1

Abstract

The invention relates to a torsional damper comprising: a first element and a second element that can be rotatably moved about an axis X; and a damping means (9) with plates, for transmitting torque and damping the rotational acyclisms between the first element and the second element, the damping means with plates comprising: a first and a second plate (9a, 9b) secured to the first element; and a first bearing body (11a) carried by the second element; and wherein, for a rotation in a first direction of rotation (21), bending of the first plate (9a) generates the first return force on the first bearing body (11a); and for a relative rotation in the second direction of rotation (24) opposing the first direction of rotation, bending of the second plate (9b) generates the second return force on the first bearing body.

Description

TORSION DAMPER

Technical field of the invention

The invention relates to the field of transmissions for a motor vehicle and relates, more particularly, a double damping flywheel. State of the art

In the field of automotive transmissions, it is known to provide torsion damping torque transmission devices for absorbing and damping vibrations and acyclisms generated by an internal combustion engine. The torsion dampers comprise an input member and an output member rotatable about a common axis of rotation and resilient damping means for transmitting the torque and damping rotational acyclisms between the input member. and the output element.

Such torsion dampers equip including double damping flywheels (DVA) and / or friction clutch, in the case of a manual or robotic transmission, or locking clutches, also called "lock-up" clutches, equipping hydraulic coupling devices, in the case of an automatic transmission.

The document FR3000155 illustrates a torsion damper comprising elastic damping means formed of two resilient blades mounted on the input element and each cooperating with a respective cam follower mounted on the output element.

The blades and cam followers are arranged such that, for angular displacement between the input member and the output member, on either side of a relative angular position of rest, the follower of cam moves along the blade and, in doing so, exerts a bending force on the resilient blade. By reaction, the resilient blade exerts on the cam follower a restoring force which tends to return the input and output elements to their angular rest position. The bending of the elastic blade thus makes it possible to damp the vibrations and rotational irregularities between the input member and the output member while providing torque transmission.

However, the portions of the blades subjected to the bending forces caused by the cam follower are stressed and subjected to significant stresses whatever the relative direction of rotation between the input and output elements, that is to say that a driving torque is transmitted from the primary flywheel to the secondary flywheel or a resistant torque is transmitted from the secondary flywheel to the primary flywheel.

Moreover, in view of this arrangement, the characteristic curves of transmission of the torque as a function of the deflection in the forward and backward directions can not be completely decorrelated so that certain complex curves of transmission of the torque as a function of the angular displacement can not to be realized.

SUMMARY One aspect of the invention is based on the idea of solving the disadvantages of the prior art by providing a particularly effective torsion damper.

According to one embodiment, the invention provides a torsion damper for a torque transmission device comprising:

a first element and a second element movable in rotation relative to one another about an axis of rotation X, and

a blade damping means adapted to transmit a rotational torque between the first member and the second member and damping rotation acyclisms between the first member and the second member; the blade damping means comprising:

a first elastically deformable blade and a second elastically deformable blade, the first blade and the second blade being integral in rotation with the first element, and

a first support member carried by the second element,

wherein the first support member, the first blade and the second blade are arranged such that: the first support member cooperates with the first blade by bending it to transmit a torque from the second element to the first element, and the first support member cooperates with the second blade by bending it to transmit a torque of the first element to the second element. The damper according to the invention thus makes it possible to prevent the same support member from requesting the same blade to alternately transmit a torque from the first element to the second element and from the second element to the first element. The damper according to the invention thus makes it possible to avoid the biasing of the same blade portion to transmit, alternately, a torque from the first element to the second element and from the second element to the first element.

This system reduces the fatigue of the blades of the torsion damper. In particular, the transmission of a torque in a first direction impacts a portion of the blade different from the portion of blade biased during the transmission of a torque in the opposite direction.

The torsion damper also makes it possible to transmit a torque with an acceptable stress. The system of two separate blades biased according to the direction of transmission of the torque thus makes it possible to increase the length of the blades and thus to reduce the stresses on each of the blades.

In addition, the damper also makes it possible to offer a greater variety of torque transmission curves because the portions of the blades biased for each direction of transmission of the torque are disjoint.

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

the first support member, the first blade and the second blade are arranged such that the first support member cooperates only with the first blade when a torque is transmitted from the second element to the first element and only with the second. blade when a torque is transmitted from the first element to the second element.

the first support member, the first blade and the second blade are arranged such that at least a portion of the torque is transmitted by the first blade regardless of the value of a torque transmitted from the second element to the first element and that at least a part of the couple is transmitted by the second blade regardless of the value of a torque transmitted from the first element to the second element.

for the entire operating range of the damper, the first support member cooperates with at least one of the first and second blades, the first support member is simultaneously in contact with the first blade and with the second blade in the angular position of rest, the blade damping means is arranged such that, for a transmission of a torque from the second element to the first element, a relative rotation in a first direction of rotation between the first and second elements from an angular rest position occurs and the blade damping means exerts a first restoring force for biasing the first and second members towards their angular rest position, and for transmitting a torque of the first member to the second element, a relative rotation in a second direction of rotation opposite the first direction of rotation between the first and second elements from the angular position of rest is and the blade damping means exerts a second biasing force to bias the first and second members toward their angular rest position; the first support member, the first blade and the second blade being arranged such that:

o for a relative rotation according to the first direction of rotation between the first and second elements from the angular position of rest, the first support member cooperates with the first blade and exerts a bending force on said first blade, bending the first blade producing on the first support member the first restoring force,

o for a relative rotation in the second direction of rotation opposite the first direction of rotation between the first and second elements from the angular position of rest, the first support member exerts a bending force on the second blade, the bending of the second blade producing on the first support member the second restoring force, each blade comprises:

a first elastically deformable section,

a second elastically deformable section, a fixing section fixed relative to the first element, and wherein the damper further comprises a second support member carried by the second element, the first support member, the second support member, the first blade; and the second blade being arranged such that:

the first support member cooperates with the first deformable section of the first blade by bending it and the second support member cooperates with the second deformable section of the second blade by bending it to transmit a torque of the second element towards the first element, and

the second support member cooperates with the second deformable section of the first blade by bending it and the first support member cooperates with the first deformable section of the second blade by bending it to transmit a torque of the first element towards the second element.

The first and second blades are arranged so that:

o for a relative rotation in the first direction of rotation between the first and second elements from the angular position of rest, the first support member exerts a bending force on the first deformable section of the first blade and the second member of support exerts a bending force on the second deformable section of the second blade, the bending of the first deformable section of the first blade and the bending of the second deformable section of the second blade jointly producing the first return force, o for a relative rotation according to the second direction of rotation between the first and second elements from the angular position from the angular position of rest, the second support member exerts a bending force on the second deformable section of the first blade and the first member d 'support exerts a bending on the first deformable section of the second blade, the bending of the second deformable section of the first me and the bending of the first deformable section of the second blade jointly forming the second restoring force,

the damper further comprises an end stop so as to limit the relative rotation between the first element and the second element. The damper further comprises:

a third and a fourth elastically deformable blades integral in rotation with the first element,

a second support member carried by the second element,

wherein the second bearing member, the third blade and the fourth blade are arranged such that:

o for a relative rotation in the first direction of rotation between the first and second elements from the angular position of rest, the second support member cooperates with the third blade and exerts a bending force on said third blade, the first force of recall being produced jointly by the bending of the first and third blades respectively on the first support member and on the second support member,

o for a relative rotation in the second direction of rotation opposite the first direction of rotation between the first and second elements from the angular position from the angular position of rest, the second support member exerts a bending force on the fourth blade, the second restoring force being produced jointly by the bending of the second and fourth blades respectively on the first support member and the second support member. each blade comprises:

a first elastically deformable section

o a second elastically deformable section

a fixing section fixed relative to the first element, and the damper further comprises a second support member carried by the second element, the first support member being arranged to cooperate with the first deformable section of the first and second blades, the second support member being arranged to cooperate with the second deformable section of the first and second blades, the first and second bearing members and the first and second blades being arranged such that:

o for a relative rotation in the first direction of rotation between the first and second elements from the angular position of rest, the first support member exerts a bending force on the first deformable section of the first blade and the second support member exerts a bending force on the second deformable section of the second blade, the bending of the first deformable section of the first blade and the bending of the second section of the second blade jointly producing the first return force,

o for a relative rotation according to the second direction of rotation between the first and second elements from the angular position of rest, the second support member exerts a bending force on the second deformable section of the first blade and the first member of support exerts bending on the first deformable section of the second blade, bending the second deformable section of the first blade and bending the first section of the second blade jointly forming the second restoring force,

the attachment section of each blade is located between the first deformable section and the second deformable section of said blade.

each blade has an axis of symmetry, a projection of the first blade in a plane perpendicular to the axis of rotation X being symmetrical to a projection of the second blade in said plane perpendicular to the axis of rotation X with respect to the X axis of rotation

alternatively, each blade has an axis of symmetry, a projection of the first blade in a plane perpendicular to the axis of rotation X being asymmetrical to a projection of the second blade in said plane perpendicular to the axis of rotation X relative to to the axis of rotation X.

each blade is asymmetrical, a projection of the first blade in a plane perpendicular to the axis of rotation X being symmetrical to a projection of the second blade in said plane perpendicular to the axis of rotation X with respect to the axis of rotation X

the first and second blades are fixed independently of one another on the first element.

the first blade and the second blade are stacked axially.

the first blade is fixed on the first element bearing axially against said first element, the torsion damper further comprising a spacer, the second blade being fixed on the first element bearing axially against the spacer, the spacer being axially interposed between the second blade and the first element, a portion of the first blade and a portion of the second blade being axially superimposed,

each blade is fixed on the first element by two rivets,

each first and second blade has a cam surface and the first bearing member comprises a cam follower arranged to cooperate with the cam surface of the first blade to transmit a torque of the second member to the first member and the surface of the first member; cam of the second blade for transmitting a torque from the first member to the second member.

- The cam follower is a roller mounted to rotate on the second element by means of a rolling bearing.

the first support member is arranged radially outside the first and second resilient blades. 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.

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 appended figures.

In these figures:

Figure 1 is a schematic perspective view of a double damping flywheel in the mounted state;

FIG. 2 is a schematic perspective view of the double damping flywheel of FIG. 1 in which the secondary flywheel is partially shown so as to display the means for fixing the blades;

Figure 3 is a schematic representation of the blades and cam followers in a rest position of the double damping flywheel.

FIG. 4 is a front view of a double damping flywheel of FIG. 1 represented in an angular displacement position of the steering wheels according to a direct direction relative to their rest position and in which the secondary flywheel is not shown to view the blades;

FIG. 5 is a front view of a double damping flywheel of FIG. 1 represented in a position of maximum angular displacement of the flywheels in a direct direction with respect to their rest position in which the secondary flywheel is not shown in order to to visualize the blades;

Figure 6 is a front view of the double damping flywheel of Figure 1 shown in a position of maximum angular displacement in a retro direction and wherein the secondary flywheel is not shown to view the blades;

Figure 7 is a front view of a double damping flywheel according to another embodiment shown in a rest position and wherein the secondary flywheel is not shown to view the blades; FIG. 8 is a front view of the double damping flywheel of FIG. 7 represented in a position of maximum angular displacement in the direct direction between the primary flywheel and the secondary flywheel and in which the secondary flywheel is not shown in order to visualize the blades;

FIG. 9 is a front view of the double damping flywheel of FIG. 7 represented in a position of maximum angular displacement in the retro direction having a maximum relative rotation in the second direction of rotation between the primary flywheel and the secondary flywheel and in which the secondary flywheel is not shown to view the blades.

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 torsion damper. By convention, the "radial" orientation is directed orthogonally to the X axis of rotation of the torsion damping elements determining the "axial" orientation and, from the inside to the outside, away from said axis. The "circumferential" orientation is directed orthogonally to the X axis of rotation of the torsion damper and orthogonal to the radial direction. Thus, an element described as circumferentially developing is an element whose component develops in a circumferential direction. The terms "external" and "internal" are used to define the relative position of one element relative to another, with reference to the axis of rotation X of the damper, an element close to the axis is thus described as internal as opposed to an external element located radially at the periphery. The description below is for illustrative purposes in the context of a double damping flywheel. However, the invention applies to any torsion damper intended to be disposed in the transmission chain of a motor vehicle, between the internal combustion engine and the gearbox. Such a torsion damper can be integrated in many torque transmission devices such as a double damping flywheel, a coupling clutch of a hydraulic coupling device or a clutch friction. For the purposes of the present description and of the claims, the term "first element" may designate a torque input element of a shock absorber, such as a primary flywheel of a double damping flywheel and the term "second element". A torque output element, such as a secondary flywheel of a double damping flywheel, or vice versa.

Figure 1 shows a schematic perspective view of a double damping flywheel 1 in the assembled state. A double damping flywheel 1 comprises a primary flywheel 2, intended to be fixed at the end of a crankshaft of an internal combustion engine, not shown, and a secondary flywheel 3 which is centered and guided on the primary flywheel 2 by means of a ball bearing. The secondary flywheel 3 is intended to form the reaction plate for a clutch, not shown, ensuring the transmission of torque to the input shaft of a gearbox. The flywheels of primary inertia 2 and secondary 3 are movably mounted about an axis of rotation X and are further movable in rotation relative to each other about said axis X.

The primary flywheel 2 comprises a radially inner hub supporting the rolling bearing ball which cooperates with an inner hub of the secondary flywheel 3. Ports for the passage of fastening screws are provided on the primary flywheel 2 and the secondary flywheel 3 in order to allow the attachment of the primary flywheel 2 to the crankshaft of the engine. The secondary flywheel 3 also has holes for passage for fixing a damping means on the secondary flywheel 3 using fastening means 4 such as rivets. The primary flywheel 2 carries, on its outer periphery, a ring gear 5 for driving in rotation of the primary flywheel 2 with a starter. The secondary flywheel 3 has a flat annular surface 6, turned away from the primary flywheel 2, forming a bearing surface for a friction lining of a clutch disc (not shown). The secondary flywheel 3 comprises, close to its outer edge, pads 7 and orifices 8 for mounting a clutch cover. The primary flywheels 2 and secondary 3 are coupled in rotation by a damping means which transmits torque and dampen rotation acyclisms between the primary flywheel 2 and secondary 3 to reduce vibrations from the engine. The damping means is capable of transmitting a driving torque from the primary flywheel to the secondary flywheel and a resistant torque from the secondary flywheel to the primary flywheel. The transmission of a driving torque from the primary flywheel to the secondary flywheel causes relative rotation of the primary flywheel relative to the secondary flywheel from the angular position of rest in a direct direction of rotation, while the transmission of a resistant torque causes a relative rotation of the primary flywheel relative to the secondary flywheel from the angular position of rest in a direction of retro rotation. In FIGS. 3 to 9, below, the arrows 24, 124 represent the relative rotation in the direct direction of the primary flywheel with respect to the secondary flywheel from the angular position of rest while the arrows 21, 121 represent the relative rotation according to the retro direction of the primary flywheel relative to the secondary flywheel from the angular position of rest. The damping means is an elastic means which exerts between the primary flywheel and the secondary flywheel a return force which tends to bring the flywheels of primary and secondary inertia to their angular position of rest. The damping means 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 the torque.

FIG. 2 represents a schematic perspective view of the double damping flywheel 1 of FIG. 1 in which the secondary flywheel 3 is partially shown so as to display the attachment of elastic blades 9 of a damping means on the secondary flywheel 3.

In the embodiment shown in FIGS. 2 to 9, this damping means comprises two resilient blades 9 mounted integral in rotation with the secondary flywheel 3. Each blade 9 is fixed on the secondary flywheel by means of rivets 4.

A fixing section of each blade is arranged to remain rigid and does not cooperate with the cam follower 1 1 which will be described later.

The blades 9 are axially superimposed. A first blade 9a is fixed directly in contact against the secondary flywheel 3. A second blade 9b is fixed on the secondary flywheel 3 via a spacer 10. This spacer 10 is interposed axially between the secondary flywheel 3 and the second blade 9b. The spacer 10 has an axial thickness substantially equal to the thickness of the first blade 9a. The thickness of the spacer 10 avoids excessive friction between the first blade 9a and the second blade 9b during bending of the blades 9. The fastening rivets 4 of the first blade 9a are symmetrical to the fastening rivets 4 of the the second blade 9b with respect to the axis of rotation X of the torsion damper 1.

Figure 3 shows schematically the blades 9 cooperating with cam follower 1 1.

The blades 9 and the cam followers 1 1 of FIG. 3 are represented in a rest position of the double damping flywheel 1. The rest position of the double damping flywheel 1 corresponds to an equilibrium position taken by the flywheels when no torque is transmitted between the primary and secondary flywheels. The first blade 9a has a general shape of crescent moon or horseshoe. The first blade 9a comprises, from a first end 12 to a second end 13, a first arcuate portion 14, a fixing portion 15 and a second arcuate portion 16. The first blade 9a may, as desired, be made of in one piece or be composed of a plurality of lamellae arranged axially against each other. The attachment portion 15 has two through-passages 17 intended to cooperate with the rivets 4 to ensure the attachment of the first blade 9a on the secondary flywheel 3.

The radius of curvature of the first arcuate portion 14 and the length of this first arcuate portion 14 are determined according to the desired stiffness characteristic of the first blade 9a. The first arcuate portion 14 extends substantially circumferentially from the attachment portion 15 to the first end 12. The first arcuate portion 14 has an increasing radial dimension from the first end 12 to the attachment portion 15.

The first blade 9a is symmetrical about an axis 22 perpendicular to the axis of rotation X and passing through the axis of rotation X. In the illustrated embodiment, this axis of symmetry 22 passes in the center of the fixing portion of the first blade 9a, between the first arcuate portion 14 and the second arcuate portion 16. Thus, the second arcuate portion 16 has a shape similar to that of the first arcuate portion 14.

The first arcuate portion 14 has on a radially outer face a cam surface 18. This cam surface 18 cooperates with a first cam follower 11a. The cam surface 18 develops from the first end 12 to a rest zone 19 of the radially outer face of the first arcuate portion 14. The resting zone 19 corresponds to the zone of the first arcuate portion 14 against which the first cam follower 1 1a is supported when the double damping flywheel 1 is in the rest position.

The first cam follower 11a is carried by the primary flywheel 2. The first cam follower 11a here is a roller 20 rotatably mounted on the primary flywheel 2. The first cam follower 11a is held in position. bearing against the cam surface 18. The roller 20 is arranged to roll against the cam surface 18 during a relative movement between the primary flywheels 2 and secondary 3 in the forward direction 24. The first cam follower 1 1 a is disposed radially outside the first arcuate portion 14 so as to radially maintain the first arcuate portion 14 when subjected to centrifugal force. The cam surface 18 is arranged such that, for a relative rotation between the primary flywheel 2 and the secondary flywheel 3 in the forward direction 24 from the rest position as shown in Figure 3, the first cam follower 1 1 a moves on the cam surface 18 exerting a bending force on the first arcuate portion 14. By reaction, the first arcuate portion 14 exerts on the first cam follower 1 1 has a restoring force having a circumferential component which tends to return the primary flywheels 2 and secondary 3 to the rest position. Thus, the first arcuate portion 14 is able to transmit a driving torque from the primary flywheel 2 to the secondary flywheel 3. In addition, 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 bending of the first arcuate portion 14.

The second arcuate portion 16 has a cam surface 23. During a relative rotation between the primary flywheel 2 and the secondary flywheel 3 from the angular position of rest in the retro direction 21, the cam surface 23 cooperates with a second follower cam 1 1 b. The second cam follower 11a is symmetrical to the first cam follower 11a relative to the axis of rotation X. The cooperation between the cam surface 23 and the second cam follower 11b during a rotation relative between the primary flywheel 2 and the secondary flywheel 3 in the retro direction 21 is similar to the cooperation between the cam surface 18 of the first arcuate portion 14 and the first cam follower January 1 at a relative rotation between the primary flywheel 2 and secondary flywheel 3 in the forward direction 24.

On the other hand, the first blade 9a and the second blade 9b illustrated in FIG. 3 have a similar shape. However, the first blade 9a and the second blade 9b are fixed on the secondary flywheel 3 in opposite orientations. More particularly, there is a symmetry of the blades relative to each other when they are projected in a plane orthogonal to the X axis.

On the one hand, the projection of the first blade 9a in a plane perpendicular to the axis of rotation X is symmetrical with respect to the axis of rotation X at the projection of the second blade 9b in this same plane perpendicular to the axis of rotation X. This allows to balance the damper. On the other hand, in the embodiment illustrated in FIGS. 2 to 6, the first blade 9a and the second blade 9b are also symmetrical in projection in a plane perpendicular to the axis of rotation X, with respect to a parallel plane. to the axis of rotation X and passing through the positions taken by the cam followers in the angular position of rest. This allows symmetrical damping in live and in retro.

Due to the opposite orientation between the first blade 9a and the second blade 9b, a first arcuate portion 25 of the second blade 9b cooperates with the first cam follower 11a during a relative rotation between the primary flywheel 2 and the secondary flywheel 3 in the retro direction 21 and a second arcuate portion 26 of the second blade 9b cooperates with the second cam follower 1 1b during a relative rotation between the primary flywheel 2 and the secondary flywheel 3 in the forward direction 24. The cooperation between the arcuate portions 25 and 26 of the second blade 9b and the first and second cam followers 11a and 11b is similar to the cooperation between the arcuate portions 14 and 16 of the first blade 9a and the first and second cam followers 1 1 a and 1 1 b. Thus, a relative rotation between the primary flywheel 2 and the secondary flywheel 3 in the forward direction 24 from the rest position causes the first cam follower 11a to cooperate with the cam surface 18 of the first arcuate portion 14 of the first blade 9a and simultaneously the cooperation of the second cam follower 11b with a cam surface 27 of the second arcuate portion 26 of the second blade 9b. Likewise, a relative rotation between the primary flywheel 2 and the secondary flywheel 3 in the retro direction 21 from the rest position causes the second cam follower 1 1b to cooperate with the cam surface 23 of the second arcuate portion 16 of the first blade 9a and, simultaneously, the cooperation of the first cam follower 11a with a cam surface 28 of the first arcuate portion 25 of the second blade 9b. As described above, the cooperation between the cam followers 1 1 and the blades 9 exerts a force capable of returning the primary flywheels 2 and secondary 3 to the rest position. Moreover, by symmetry of the blades 9 in projection relative to the plane described above, the cam surfaces of the blades are of identical circumferential length in the embodiments illustrated in Figures 2 to 6. In a preferred embodiment illustrated in FIG. 3, in the rest position of the double damping flywheel 1, the first cam follower 11a is in simultaneous contact with the first arcuate portion 14 and 25 respectively of the first blade 9a and of the second blade 9b. Similarly, in this rest position, the second cam follower 11b is in simultaneous contact with the second arcuate portion 16 and 26 respectively of the first blade 9a and the second blade 9b.

According to an advantageous embodiment, the radii of curvature and the stiffness of the arcuate portions are such that, in the rest position, each cam follower 11 is located at the end of the cam surfaces of the two arcuate portions with which it cooperates. Thus, during relative rotation between the primary flywheel 2 and the secondary flywheel 3, each cam follower January 1 cooperates with only one arcuate portion of the blades 9, the other arcuate portion not being solicited. Typically, each cam follower 1 1 bends only one of the first and second blades during a relative rotation between the primary flywheel and the secondary flywheel 3. In other words over the entire operating range of double damping flywheel, that is to say, whatever the torque transmitted between the primary flywheel 2 and the secondary flywheel 3, each cam follower 1 1 cooperates with one or other of the blades 9a, 9b. Such a configuration of the damping means reduces the stress of the blades in use. More particularly, this configuration of the damping means prevents a same portion of the blade 9 is constrained both during a transmission of torque between the primary flywheel 2 and the secondary flywheel 3 in the retro direction 21 that in the direct direction 24. The portion of the blade 9 biased during a transmission of torque between the primary flywheel 2 and the secondary flywheel 3 in the retro direction 21 is "independent" of the portion of the blade 9 requested during a transmission of torque between the primary flywheel 2 and the secondary flywheel 3 in the forward direction 24. This independence of the portions of the blade 9 biased according to the direction of transmission of torque between the primary flywheel 2 and the secondary flywheel 3 also makes it possible to achieve independent cam surfaces. That is, the cam surfaces being carried by distinct arcuate portions, they may have distinct stiffness and radius of curvature characteristics so that the cooperation between the cam surface of a cam is portion of the blade 9 and the corresponding cam follower is not related to the cooperation between the cam surface of the other portion of the blade 9 and the corresponding cam follower. In addition, the axial superposition of the blades 9 makes it possible to lengthen the circumferential length of the blades 9 and thus to obtain a better damping of vibrations and acyclisms with a large angular displacement.

The damping flywheel 1 can also be equipped with a friction assembly arranged to exert a friction-resistant torque during the relative rotation between the primary and secondary flywheels 3. The friction assembly is thus able to dissipate by friction the energy accumulated in the blades 9.

Figure 4 is a front view of a double damping flywheel in Figure 1 having a relative rotation between the primary flywheel and the secondary flywheel and wherein the secondary flywheel is not shown to view the blades.

During a relative rotation between the primary flywheel 2 and the secondary flywheel in the forward direction 24, the first cam follower 11a moves from the angular position of rest along the cam surface 18 of the first portion. arcuate 14 of the first blade 9a. The second blade 9b is shown in dashed lines in areas where the first blade 9a and the second blade 9b are axially superimposed. The radius of curvature of the first arcuate portion 25 of the second blade 9b is such that the first cam follower 11a does not cooperate with said first arcuate portion 25 of the second blade 9b.

Similarly, the second cam follower 1 1 b cooperates with the second arcuate portion 26 of the second blade 9b only. Thus, the restoring force reminding the primary flywheel 2 and the secondary flywheel 3 to their rest position results from the bending of the first arcuate portion 14 of the first blade 9a and the bending of the second arcuate portion 26 of the second blade 9b which are the only portions urged during a relative rotation between the primary flywheel 2 and the secondary flywheel 3 in the forward direction 24.

In order to reduce the parasitic friction likely to affect the damping function, the roller 20 is advantageously rotatably mounted on the primary flywheel 2 by means of rolling members (not shown), such as only balls, rollers or needles. The roller 20 is for example carried by a cylindrical rod 29 extending parallel to the axis of rotation X and one end of which is fixed inside a bore (not shown) formed in the primary flywheel 2. Moreover, , the cylindrical rod 29 is received inside a through orifice formed in a sleeve 30. The roller 20 is rotatably mounted around the sleeve 30. To do this, the rolling members cooperate, on the one hand, with a rolling track formed on the outer periphery of the sleeve 30 and, on the other hand, with a rolling track formed on the inner periphery of the roller 20. FIGS. 5 and 6 are front views of a double damping flywheel of FIG. 1 having a maximum relative rotation between the primary flywheel 2 and the secondary flywheel 3 respectively in the forward direction 24 and in the retro direction 21. In these FIGS. 5 and 6, the secondary flywheel is not shown in order to visualize the blades 9. The double damping flywheel 1 advantageously has a stop capable of limiting the relative movement between the primary flywheel 2 and the secondary flywheel. two projections 31 fixed on the secondary flywheel which each cooperate with a respective abutment surface 32 when they come into abutment, said abutment surfaces 32 being fixed on the primary flywheel 2. The abutment surfaces 32 are for example formed around each cam follower 1 1 as illustrated in FIGS. 5 and 6.

Figure 7 is a front view of a double damping flywheel according to another embodiment in which the secondary flywheel is not shown to view the blades. With reference to FIGS. 7 to 9, the elements of the double damping flywheel having a shape and / or function similar to the corresponding elements illustrated with reference to FIGS. 1 to 6 bear the same references increased by 100.

In this second embodiment, the damping means has an asymmetry. In the embodiment shown, in order to obtain an asymmetric damping means, each blade 109a is asymmetrical. Which means the first arcuate portion 114 of the first blade 109a and the second arcuate portion 116 of the first blade 109a are not symmetrical. Here we note that the second arcuate portion 1 16 on which the second support member rests is shorter than the first arcuate portion 1 14 on which the first support member rests. The first blade 109a and the second blade 109b in projection in a plane perpendicular to the axis of rotation X remain however symmetrical with respect to the axis of rotation X.

A second variant, not shown, provides on the contrary that the first arcuate portion and the second arcuate portion 116 of the first blade 109a are symmetrical but that the first blade 109a and the second blade 109b project in a plane perpendicular to the axis. rotation X are not symmetrical with respect to the axis of rotation X.

In each of these variants, the asymmetry of the damping means causes a difference in circumferential length of the cam surfaces of the blades 109 between the direct direction 124 and the retro direction 121. Thus, in the rest position as illustrated in FIG. 7, the cam surface 118 of the first arcuate portion 14 of the first blade 109a has a circumferential length greater than the circumferential length of the cam surface 123 of the second arcuate portion 1 16 of said first blade 109a. Likewise, the cam surface 127 of the second arcuate portion 126 of the second blade 109b has a circumferential length greater than the circumferential length of the cam surface 128 of the first arcuate portion 125 of the second blade 109b.

The asymmetry of the damping means thus makes it possible to obtain stiffness characteristics and / or maximum deflection angles that are different depending on whether a driving torque is transmitted (direct direction) or whether a resisting torque is transmitted ( Retro direction). Figures 8 and 9 show a front view of a double damping flywheel 101 of Figure 7 in a position of maximum relative rotation respectively in retro and forward direction. In these figures 8 and 9, the secondary flywheel 103 is not shown in order to view the blades 109.

As illustrated in FIGS. 8 and 9, the double damping flywheel according to the second embodiment, the angular displacement between the primary flywheel 102 and the secondary flywheel 103 is superior in the forward direction 124 with respect to the retro direction 121. The other characteristics of the blades and cam followers, however, remain the same as those of the first embodiment. For example, each blade 109 is fixed by means of two rivets 104 or else, in the rest position, the cam followers 11 1 are simultaneously in contact with the corresponding cam surfaces of the two blades 109.

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.

In particular, in an alternative embodiment not shown, the structure is reversed and the blades are fixed on the primary flywheel 2 while the rollers are carried by the secondary flywheel 3.

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. Torsion damper for a torque transmission device comprising:

a first element (3, 103) and a second element (2, 102) rotatable relative to one another about an axis of rotation X, and

a blade damping means (9, 109) adapted to transmit a rotational torque between the first member and the second member and damping rotation acyclisms between the first member (3, 103) and the second member (2, 102); the blade damping means comprising:

a first elastically deformable blade (9a, 109a) and a second elastically deformable blade (9b, 109b), the first blade (9a, 109a) and the second blade (9b, 109b) being integral in rotation with the first element (3, 103), and

o a first support member (1 1 a, 1 1 1 a) carried by the second element

(2, 102),

wherein the first bearing member (11a, 11a), the first blade (9a, 109a) and the second blade (9b, 109b) are arranged such that:

the first support member (11a, 11a) cooperates with the first blade (9a, 109a) by flexing it to transmit a torque from the second member to the first member, and

the first support member (11a, 11a) cooperates with the second blade (9b, 109b) by bending it to transmit a torque from the first member to the second member.

A torsion damper according to claim 1, wherein the first support member (11a, 11a), the first blade (9a, 109a) and the second blade (9b, 109b) are arranged such that so that the first support member (11a, 11a) cooperates only with the first blade (9a, 109a) when a torque is transmitted from the second member to the first member and only with the second blade (9b , 109b) when a torque is transmitted from the first element to the second element.

A torsion damper according to claim 1 or 2, wherein the first support member (11a, 11a), the first blade (9a, 109a) and the second blade (9b, 109b) are arranged so that at least a portion of the torque is transmitted by the first blade regardless of the value of a torque transmitted from the second element to the first element and that at least a portion of the torque is transmitted by the second blade regardless of the value of a torque transmitted from the first element to the second element.

4. torsion damper according to any one of claims 1 to 3, wherein for the entire range of operation of the damper, the first support member (1 1 a, 1 1 1 a), cooperates with least one of the first and second blades.

Torsion damper according to one of Claims 1 to 5

4, wherein the blade damping means is arranged such that, for transmission of a torque from the second member to the first member, a relative rotation in a first direction of rotation (21, 121) between the first and second members (2, 102, 3, 103) from an angular position of rest occurs and the blade damping means exerts a first restoring force to recall the first and second members (2, 102, 3, 103) to their angular position of rest, and that for a transmission of a torque from the first element to the second element, a relative rotation in a second direction of rotation (24, 124) opposite the first direction of rotation between the first and second elements (2, 102, 3, 103) from the angular position of rest is made and the blade damping means exerts a second restoring force to return the first and second members (2, 102, 3, 103) to their position angular rest;

the first support member (11a, 11a), the first blade (9a, 109a) and the second blade (9b, 109b) being arranged such that:

for a relative rotation in the first direction of rotation (21, 121) between the first and second elements (2, 102, 3, 103) from the angular position of rest, the first support member (1 1 a, 1 1 1 a) cooperates with the first blade (9a, 109a) and exerts a bending force on said first blade (9a, 109a), flexing the first blade (9a, 109a) producing on the first bearing member ( 1 1 a, 1 1 1 a) the first restoring force, for a relative rotation in the second direction of rotation (24, 124) opposite the first direction of rotation (21, 121) between the first and second elements (2, 102, 3, 103) from the angular position of rest, the first bearing member (11a, 111a) exerts a bending force on the second blade (9b, 109b), the bending of the second blade (9b, 109b) producing on the first bearing member (11a, 111a) the second restoring force.

The torsion damper according to claim 5, wherein the first support member (11a, 111a) is simultaneously in contact with the first blade (9a, 109a) and with the second blade (9b, 109b) in the angular position. rest.

A torsion damper according to any one of claims 1 to 6, wherein each blade (9, 9a, 9b, 109, 109a, 109b) comprises:

a first elastically deformable section (14, 114, 25, 125),

a second elastically deformable section (16, 116, 26, 126), an attachment section (15) fixed with respect to the first element (3, 103), and wherein the damper further comprises a second support member ( 11b, 111b) carried by the second element (2, 102),

the first support member (11a, 111a), the second support member (11b,

111b), the first blade (9a, 109a) and the second blade (9b, 109b) being arranged such that:

the first support member (11a, 111a) cooperates with the first deformable section (14, 114) of the first blade (9a, 109a) by bending it and the second support member (11b, 111b) cooperates with the second deformable section (26, 126) of the second blade (9b, 109b) flexing it to transmit torque from the second member to the first member, and the second member (11b, 111b) cooperating with the second section deformable (16, 116) of the first blade (9a, 109a) by bending it and the first bearing member (11a, 111a) cooperates with the first deformable section (26, 126) of the second blade (9b, 109b) ) by flexing it to transmit a torque from the first element to the second element.

A torsion damper according to claim 7, wherein the securing section (15) of each blade (9, 109) is located between the first deformable section (14, 14, 25, 125) and the second deformable section ( 16, 1, 16, 26, 126) of said blade (9, 109).

A torsion damper according to claim 7 or 8, wherein each blade has an axis of symmetry, a projection of the first blade in a plane perpendicular to the axis of rotation X being symmetrical to a projection of the second blade in said plane perpendicular to the axis of rotation X with respect to the axis of rotation X.

Torsion damper according to one of claims 7 to 9, wherein each blade is asymmetrical, a projection of the first blade in a plane perpendicular to the axis of rotation X being symmetrical to a projection of the second blade in said plane perpendicular to the axis of rotation X with respect to the axis of rotation X.

1 1. A torsion damper according to one of claims 1 to 10, wherein the first and second blades (9a, 109a, 9b, 109b) are attached independently of one another to the first member (3, 103). ).

12. torsion damper according to one of claims 1 to 1 1, wherein the first blade and the second blade are (9a, 109a, 9b, 109b) stacked axially.

13. torsion damper according to one of claims 1 to 12, wherein the first blade (9a, 109a) is fixed on the first member (3, 103) in axial abutment against said first element (3, 103), torsion damper further comprising a spacer (10), the second blade (9b, 109b) being fixed on the first element (3, 103) in axial abutment against the spacer (10), the spacer (10) being axially interposed between the second blade (9b, 109b) and the first element (3, 103), a portion of the first blade (9a, 109a) and a portion of the second blade (9b, 109b) being axially superimposed.

A torsion damper according to any one of claims 1 to 13, further comprising an end stop (31, 32) so as to limit the relative rotation between the first member (3, 103) and the second member (2, 102,).

15. torsion damper according to one of claims 1 to 14, wherein each blade (9, 109) is fixed on the first element by two rivets (4, 104).

Torsion damper according to one of Claims 1 to

15, wherein each first and second blades has a cam surface and the first support member has a cam follower arranged to cooperate with the cam surface of the first blade (9a, 109a) to transmit a torque of the second member. to the first member and the cam surface of the second blade (9b, 109b) for transmitting a torque from the first member to the second member.