WO2019115637A1

WO2019115637A1 - Torsion damper with phasing means

Info

Publication number: WO2019115637A1
Application number: PCT/EP2018/084610
Authority: WO
Inventors: Ivan Dutier; Christophe Dhalleine
Original assignee: Valeo Embrayages
Priority date: 2017-12-13
Filing date: 2018-12-12
Publication date: 2019-06-20
Also published as: FR3074865B1; FR3074865A1

Abstract

The invention concerns a torsion damper comprising: ° a first element (1) and a second element that are able to rotate; °an elastic damping device coupling the first element (1) and the second element and comprising: a first raceway linked to the first element (1); a second raceway (8) elastically linked to the second element; °a rolling body (5) cooperating with the first and second raceways, and a toothed wheel (11) secured to the rolling body (5) in an axially offset manner and arranged to mesh with a toothed member (12) carried by one of the first element (1) and the second element (2) such that the movement of the rolling body (5) on the raceway carried by said one of the first element (1) and the second element (2) is synchronised with the rotation of the rolling body (5) about the axis of rotation of same.

Description

TORSION DAMPER WITH PHASE MEANS

TECHNICAL FIELD The invention relates to the field of torsion dampers intended to equip motor vehicle transmissions.

BACKGROUND TECHNOLOGY Motor vehicle transmissions are generally equipped with a torsion damper enabling the vibrations upstream of the gearbox to be filtered in such a way as to avoid particularly undesirable shocks, noises or noise. Such damping systems include damping dual flywheels (DVA) and / or clutch friction, in the case of a manual or robotic transmission, or locking clutches, also called "lock-up" clutches, equipping the hydraulic coupling devices, in the case of an automatic transmission.

The damping systems comprise resilient damping means rotatably coupling an input member and an output member so as to allow torque transmission and damping of rotational acyclisms.

The document FR3000155 discloses a damping system in which the elastic damping means are formed of two flexible blades. The two flexible blades are mounted on one of the input and output elements of the damping system and each cooperate with an associated cam follower. This cam follower comprises a roller rotatably mounted on the other of the input and output elements.

The document FR3032248 discloses a damping system offering a large clearance between the input element and the output element. The damping system described in document FR3032248 comprises two flexible blades mounted on one of the input and output elements, these flexible blades being similar to the flexible blades described above with reference to the document FR3000155. The other input and output element has two additional cam surfaces. The cam followers are formed by rolling bodies moving both on the cam surfaces carried by the blades and on the cam surfaces carried by the other one of the input and output elements, thereby increasing the possible angular movement between the input element and the output element.

However, slippage between the rolling bodies and the cam surfaces may occur. Since the rolling bodies are movable relative to the input member and the output member, such sliding can cause angular displacement of the rolling bodies relative to each other. This angular offset between the rolling bodies can unbalance the cooperation between the rolling bodies and the blades and thus degrade the performance of the transmission system. To avoid this, the document FR3032248 discloses a rolling body in the form of a toothed wheel, the cam surfaces being made in the form of toothed portions meshing with the toothed wheels.

The stiffness of the blade is difficult to control because of the presence of teeth on the cam surface on which the rolling body moves. In addition, the torque transmitted between the output member and the input member is limited by the presence of meshing teeth between the rolling body and the cam surface. Finally, these teeth undergo significant stresses when transmitting the torque between the input member and the output member, these stresses being able to degrade the teeth of the cam surface and / or the rolling body. Moreover, the blade described in FR3032248 is difficult to achieve.

summary

An idea underlying the invention is to provide a torsion damper having good characteristics of damping and torque transmission in a reliable and simple manner. An idea underlying the invention is to control the displacements of the rolling body with respect to the input element and / or the output element. An idea underlying the invention is to provide a torsion damper with a low risk of degradation during the transmission of torque. For this, the invention provides a torsion damper for a motor vehicle transmission chain comprising:

a first element and a second element movable in rotation relative to each other about an axis of rotation X;

an elastic damping device coupling the first member and the second member to provide vibration damping torque transmission between the first member and the second member;

said elastic damping device comprising:

a first rolling track connected by an elastic connection to the second element;

a second rolling track connected to the first element;

a rolling body cooperating with the first rolling track and with the second rolling track, said rolling body having an axis of rotation of said rolling body, said rolling body being able to move by rolling on said first and second raceways during rolling. a relative rotation between the first element and the second element;

said first and second race tracks being arranged such that, for relative rotation between the first member and the second member from an angular rest position, the first rolling body moving on the first and second raceways exerts a bending force on the elastic connection and that the elastic connection produces a reaction force on the rolling body so as to return the first element and the second element to the angular position of rest;

the resilient damping device further comprising a toothed pinion integral in rotation with the rolling body about the X axis, said toothed pinion being axially offset with the rolling body, said notched pinion being arranged to mesh with a toothed member carried by the one among the first element and the second element.

The presence of teeth makes it possible to limit or even prevent the sliding of the rolling body on the rolling track. Thanks to these characteristics, the position of the rolling body along the rolling track carried by the element carrying the organ dentate is mastered. Indeed, the synchronization of the rotation of the rolling body about its axis of rotation with its displacement along said raceway ensures that the sliding of the rolling body on said raceway are controlled. Thus, such a torsion damper allows a transmission of torque between the first element and the second controlled element. Such a torsion damper provides good torque transmission reliability between the first element and the second element.

Thus, the displacement of the rolling body on the rolling track carried by said one of the first element and the second element is synchronized with a rotation of the rolling body around its axis of rotation.

In addition, the rolling tracks with which the rolling body cooperates are simple to perform, these race tracks being dissociated from the synchronization system of the rotation of the rolling body and its displacement along said raceway.

In addition, such a torsion damper is reliable, the torque passing through the raceways and the rolling body does not risk degrading the notched pinion and the toothed member.

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

According to one embodiment, the cooperation between the rolling body and said one of the first element and the second element is without sliding when the notched pinion meshes with the toothed member. In other words, the meshing of the rolling body with the toothed member carried by said one of the first element and the second element prevents the sliding of the rolling body with respect to said one of the first element and the second element.

By cooperation, between the toothed body and the rolling body is meant the interpenetration of the teeth of the rolling body and the toothed member, with or without circumferential play.

It is understood by meshing the fact that a circumferential support is present between teeth of the notched pinion and teeth of the toothed member, this circumferential support tending to drive in rotation about its axis of rotation the notched pinion.

According to one embodiment, the rolling body and the notched pinion are coaxial. According to one embodiment, the notched pinion cooperates with the toothed member with a set of meshing.

Due to these characteristics, the torsion damper, and in particular the notched pinion and the toothed member, presents a low risk of degradation. Indeed, such a game limit or even completely avoids the possibility of support between the teeth of the notched pinion and the teeth of the toothed member so that the torque transmitted between the first element and the second element transits mainly, ideally integrally, by the rolling body and the rolling tracks and transits little, ideally not, by the toothed member and the notched pinion.

According to one embodiment, sliding of the rolling body on the rolling track carried by said one of the first element and the second element is slaved to the meshing clearance between the notched pinion and the toothed member, this corresponding slip and being limited play necessary for a support takes place between the teeth of the toothed member and the teeth of the notched pinion.

According to one embodiment, the clearance between the teeth of the toothed pinion and the teeth of the toothed member determines the amplitude of the permitted sliding of the rolling body on said raceway. Thus, the teeth of the toothed member and the toothed pinion limit the sliding of the rolling body on said raceway to the only slip necessary to fill the game present between said teeth.

The notched pinion can be secured in rotation to the rolling body in many ways. According to one embodiment, the notched pinion is integral with the rolling body. According to one embodiment, the notched pinion is fitted on the rolling body. According to one embodiment, the notched pinion is overmolded on the rolling body.

According to one embodiment, the notched pinion is a first notched pinion and the toothed member is a first toothed member,

and the elastic damping device further comprises a second toothed pinion integral in rotation with the rolling body, said second toothed pinion being axially offset relative to the rolling body, said second toothed pinion being arranged to mesh with a second toothed member carried by the other among the first element and the second element. Thus, the displacement of the rolling body on the rolling track carried by the other one of the first element and the second element is synchronized with the rotation of the rolling body around its axis of rotation.

According to one embodiment, the cooperation between the rolling body and said other one of the first element and the second element is non-slip when the second notched pinion meshes with the second toothed element.

According to one embodiment, the second notched pinion and the rolling body are axially offset.

According to one embodiment, the second notched pinion and the rolling body are coaxial.

According to one embodiment, the rolling body is axially interposed between the first notched pinion and the second notched pinion.

Thanks to these characteristics, the positioning of the toothed members is simple to perform. Thus, for example, each of the toothed members can be carried directly by the first element or the corresponding second element.

According to one embodiment, the second notched pinion cooperates with the second toothed member with a second set of meshing.

According to one embodiment, the sliding of the rolling body on the rolling track carried by the other one of the first element and the second element is slaved to the meshing clearance between the second notched pinion and the second toothed member, this corresponding slip and being limited to the clearance necessary for a circumferential support to take place between the teeth of the second toothed member and the teeth of the second toothed pinion.

According to one embodiment, the clearance between the teeth of the second toothed pinion and the teeth of the second toothed member determines the amplitude of the permitted sliding of the rolling body on said raceway. Thus, the teeth of the second toothed member and the second toothed pinion limit the sliding of the rolling body on said runway only slip required to fill the game present between said teeth.

According to one embodiment, the rolling body is a first rolling body and the elastic connection connecting the first raceway and the second element is a first elastic connection, the notched pinion being a first notched pinion and the toothed member being a first toothed member, the elastic damping device further comprising A third rolling track connected to the first element,

A fourth rolling track connected by a second elastic connection to the second element,

A second rolling body cooperating with the third and fourth rolling track and able to move on said third and fourth raceways during a relative rotation between the first element and the second element,

Said third and fourth raceways being arranged such that, for a relative rotation between the first and the second element from the angular position of rest, the second rolling body moving on the third and fourth raceways exerts a force bending on the second elastic connection and that the second elastic connection produces a reaction force on the second rolling body so as to return the first element and the second element to the angular position of rest,

The elastic device further comprising a third toothed pinion rotationally integral with the second rolling body, said third pinion being axially offset relative to the second rolling body, said third pinion being arranged to mesh with a third toothed member carried by said one of the first element and the second element.

Thus, the displacement of the second rolling body on the rolling track carried by said one of the first element and the second element is synchronized with a rotation of the second rolling body around its axis of rotation.

According to one embodiment, the cooperation between the second rolling body and the corresponding raceway connected to said one of the first element and second element is non-slip when the third toothed pin meshes with the third toothed member.

According to one embodiment, the resilient damping device comprises a flexible blade mounted on the second element, said flexible blade having a face carrying the first rolling track, a flexible portion of the flexible blade forming the elastic connection connecting the first track. rolling on the second element. According to one embodiment, the toothed member is carried by the second element, this toothed member being fixed on the flexible blade.

According to one embodiment, the face bearing the first raceway is a radially outer face of the flexible blade.

According to one embodiment, the rolling body has a contact surface with the rolling tracks.

The term "smooth running surface" means a substantially smooth surface, having no edge on its surface cooperating with the raceway, for example not crenellated, the rolling body having for example a cylindrical or elliptical cylinder shape.

According to one embodiment, the toothed member is formed in a sheet.

According to one embodiment, the toothed member is carried by the second element, this toothed element being fixed on the flexible blade mounted on the second element. In other words, the toothed member is carried by the second element via the flexible blade.

According to one embodiment, the second toothed member is fixed on the flexible blade.

According to one embodiment, the first raceway and / or the second raceway is circular or non-circular.

Brief description of the figures

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly in the course of the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes. with reference to the accompanying drawings.

- Figure 1 is a front view of a torsion damper according to a first embodiment of the invention wherein the secondary flywheel is not shown;

- Figure 2 is a sectional view of the torsion damper of Figure 1; - Figure 3 is a front view of the torsion damper of Figure 1 illustrating by transparency the cooperation between the notched pinion and the notched portion carried by the primary flywheel;

- Figure 4 is a detailed view illustrating the cooperation between the notched pinion and the notched portion carried by the primary flywheel;

FIG. 5 is a schematic perspective view of a rolling body according to the second embodiment;

- Figure 6 is a front view of a torsion damper according to the second embodiment wherein the secondary flywheel is only partially illustrated;

FIG. 7 is a sectional view of the torsion damper of FIG. 6.

- Figure 8 and Figure 9 show a variant of the second embodiment.

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 damper determining the "axial" orientation and, from the inside towards the outside away from said axis, the "circumferential" orientation is directed orthogonally to the axis of the torsion damper and orthogonal to the radial direction. The terms "external" and "internal" are used to define the relative position of one element relative to another, with reference to the X axis of rotation of the torsion damper, an element close to the axis is thus described as internal as opposed to an external element located radially at the periphery.

The remainder of the description is made with reference to the figures in the context of a torsion damper of the double damping flywheel type. This description is not limiting and the invention is applicable by analogy to any other type of torsion damper. A double damping flywheel as illustrated in Figures 1 to 4 comprises a primary flywheel 1, hereinafter primary flywheel 1, and a secondary flywheel 2 (shown in Figure 2), hereinafter flying secondary 2, which are arranged in the transmission chain of a motor vehicle, respectively engine side and gearbox side. The primary flywheel 1 constitutes an input element of the double damping flywheel and is intended to be fixed at the end of a driving shaft, such as the crankshaft of an engine. The secondary flywheel 2 constitutes an output element of the double damping flywheel and forms a reaction plate of a coupling clutch to a driven shaft, such as the input shaft of a gearbox. The primary flywheel 1 and the secondary flywheel 2 comprise an inner and outer hub respectively. The primary flywheel 1 and the secondary flywheel 2 are rotatably mounted around a common axis of rotation X via a bearing interposed radially between the inner hub and the outer hub. The primary flywheel 1 comprises a plate developing radially from the inner hub. A peripheral portion of the plate carries a skirt 3 protruding axially towards the secondary flywheel 2.

The primary flywheel 1 and the secondary flywheel 2 are coupled in rotation by a damping means. This damping means comprises two flexible and resilient blades 4 each cooperating with a respective rolling body 5.

In the embodiment illustrated in Figures 1 to 3, the blades 4 are manufactured independently, each blade 4 having a mounting portion 6 and a flexible portion 7 which are specific thereto. The two blades 4 as illustrated in Figures 1 to 3 are symmetrical with respect to the axis of rotation X. This symmetry of the blades 4 allows to advantageously achieve the two blades 4 identically. Thus, the characteristics described below for one of the blades 4 apply by analogy to the other blade 4. Similarly, the description given below for a rolling body 5 and its arrangement in the double damping flywheel s applies by analogy to both rolling bodies 5.

Each blade 4 is mounted on and secured in rotation with the secondary flywheel

2. The blades 4 are mounted on the secondary flywheel by any suitable means, for example by riveting the mounting portion 6 on the secondary flywheel 2. radially outer face of the flexible portion 7 of each blade 4 comprises a raceway forming a cam surface 8, hereinafter referred to as the first cam surface 8, cooperating with a respective rolling body 5. Each blade 4 is elastically deformable. The blades 4 are for example made of a spring material such as spring steel, for example by a thin cutting process on a sheet of 12 mm thick.

As illustrated in Figures 2 and 3, a radially inner face of the skirt 3 also forms two raceways or cam surfaces 9, hereinafter called second cam surfaces 9, each cooperating with a respective rolling body 5.

Each rolling body 5 comprises a circular cylindrical roller radially interposed between one of the first cam surfaces 8 and one of the second respective cam surfaces 9. The roller face cooperating with the first and second cam surfaces 8, 9 as well as said first and second cam surfaces 8, 9 are preferably substantially smooth, that is, smooth and boneless surfaces. The rolling bodies 5 are rotatably mounted around the axis of rotation X both with respect to the primary flywheel 1 and the secondary flywheel 2. As illustrated in FIG. 3, the rolling bodies 5 are held radially in abutment against the first and second cam surfaces 8, 9 with which they cooperate. For example, the blades 4 each resiliently cooperate with a respective rolling body 5 to keep said rolling body 5 radially in abutment against the corresponding second cam surface 9. In other words, the blades 4 are arranged so that the flexible portion 7 of each blade elastically presses the first cam surface radially against the corresponding rolling body 5, this support of the first cam surface 8 against the rolling body 5 supporting said rolling body 5 against the corresponding second cam surface 9. The rolling bodies 5 can be made of many materials, for example steel.

As illustrated in FIG. 1, the double damping flywheel further comprises two axial retaining plates 10. These axial retaining plates 10 are fixed on one face of the skirt 3 axially facing the secondary flywheel 2. Each plate Axial retainer 10 develops circumferentially in an angular sector corresponding to the angular sector of a respective second cam surface 9. In addition, these axial retaining plates 10 protrude radially inwardly beyond said second cam surface 9. Thus, the rolling body 5 bears against said second cam surface 9 is axially interposed between the plate of the primary flywheel 1 and the corresponding axial retaining plate 10 of axially holding said rolling body 5 on the primary flywheel 1.

The torsion damper illustrated in FIG. 1 is in a rest position in which no torque passes between the primary flywheel 1 and the secondary flywheel 2. A transmission of torque between the primary flywheel 1 and the secondary flywheel 2 is accompanied by relative movement between the primary flywheel 1 and the secondary flywheel 2. During this relative travel, each rolling body 5 moves along one part of the first cam surface 8 and, on the other hand, the second cam surface 9 with which it cooperates. Thus, during a torque transmission, the angular displacement between the primary flywheel 1 and the secondary flywheel 2 corresponds to a travel of the rolling bodies 5 at the same time on the first cam surfaces 8 and on the second cam surfaces 9. The displacement of the rolling bodies 5 along the first cam surfaces 8 from the rest position causes the flexible portions 7 of the blades 4 to bend. The bending of the flexible portions 7 of the blade 4 generates a reaction force tending to bring the rolling bodies back. 5, and therefore the primary flywheel 1 and the secondary flywheel 2, in the rest position. In other words, the blades 4 develop an elastic return torque tending to return the primary flywheel 1 and the secondary flywheel 2 to a relative angular position of rest.

The damping means is thus capable of transmitting a driving torque from the primary flywheel 1 to the secondary flywheel 2 (forward direction) and a resistant torque of the secondary flywheel 2 to the primary flywheel 1 (retro direction). The documents FR3008152 and FR3032248 describe the general operation of the cooperation between the rolling body 5 and the flexible blade 4 of such a torsion damper with flexible and resilient blades.

In an embodiment not shown, the assembly of the blades 4 and the rolling bodies 5 is reversed so that the element carrying the blades 4 is the primary flywheel 1. In another embodiment not illustrated, the blades 4 are joined by a common mounting portion 6, for example in the form of an annular mounting portion 6 from which the flexible portions 7 of each of the blades 4 develop. elsewhere, the blades 4 can be made using a plurality of lamellae superimposed axially for example by clinching.

Ideally, the cooperation between the rolling body 5 and the first and second cam surfaces 8, 9 is non-slip. In particular, it is preferable to ensure the transmission of torque by rolling the rolling body rather than sliding to limit the wear of the device and make it more stable. In addition, since the rolling bodies 5 are not rotatably connected to either the primary flywheel 1 or the secondary flywheel 2, it is important to ensure that the transmission of torque between the primary flywheel 1 and the secondary flywheel 2 is correctly balanced when the double damping flywheel comprises a plurality of rolling bodies 5 each cooperating with a respective blade 4, as illustrated in FIGS. 1 to 3. In other words, it is necessary to ensure that each rolling body 5 causes the same deformation of the blade 4 with which it cooperates to ensure that all the blades 4 generate the same reaction force.

Indeed, the reaction force generated by the flexible portion 7 of each blade 4 depends directly on the flexion of said flexible portion 7. However, this flexion of the flexible portion 7 is directly related to the bearing position of the corresponding rolling body 5 on the first cam surface 8 of said flexible portion 7. Therefore, if one of the rolling bodies 5 cooperates slidably with one of the corresponding first and / or second cam surface 8, 9 while the other or the other rolling bodies 5 cooperate with the corresponding first and / or second cam surfaces 9 without slipping, an angular offset occurs between the different rolling bodies 5 of the double damping flywheel. Because of this angular offset between the rolling bodies 5, said rolling bodies 5 are not in contact at the same locations of the first cam surfaces 8 with which they cooperate. Thus, the reaction forces generated by the different blades 4 are not symmetrical and the transmission of torque between the primary flywheel 1 and the secondary flywheel 2 is not balanced. Such imbalance in the torque transmission between the primary flywheel 1 and the secondary flywheel 2 is detrimental to the proper functioning of the torsion damper. Therefore, it is important to limit, if not prevent, slippage of the rolling bodies 5 on the first and / or second cam surfaces 8, 9 to ensure that the rolling bodies 5 maintain a stable relative angular position and therefore cooperate. in a uniform manner with the flexible blades 4 and generate a substantially uniform and balanced bending of the flexible portions 7 of the different blades 4.

For this, the torsion damper illustrated in FIGS. 1 to 4 comprises, for each rolling body 5, a device for synchronizing said rolling body 5. This synchronization device comprises a notched pinion 11 and a toothed member 12 cooperating together to synchronize the rotation. of the corresponding rolling body 5 and the displacement of said rolling body 5 on the second cam surface 9 with which it cooperates.

The toothed pinion 11 is rotatably connected to the rolling body 5. Typically, the rolling body 5 forms a first smooth-walled circular cylindrical section and is fixed coaxially to a second circular cylindrical section with a notched wall.

The notched pinion 11 and the rolling body 5 can be made in many ways. According to one embodiment, the rolling body 5 and the notched pinion 11 are made in one piece in the same material. In another embodiment, the rolling body 5 and the notched pinion 11 are made in two separate pieces joined by any suitable fastening means, such as for example by gluing, pegging, welding, sintering or other fitting.

In addition, the notched pinion 11 can be made of many materials. According to one embodiment, the toothed pinion 11 is made of plastic. Such a toothed pinion 11 of plastic material limits the noise that may result from the contacts with the toothed member 12. In one embodiment, the toothed pinion 11 is for example overmolded on the rolling body 5. In another embodiment, the rolling body 5 comprises a housing and the notched pinion 11 comprises a pin fitted into said housing of the rolling body 5.

The notched pinion 11 is coaxial with the rolling body 5. In the embodiment illustrated in FIGS. 1 to 4, the notched pinion 11 and the rolling body 5 have a circular shape, the notched pinion 11 having a diameter smaller than the diameter. of the rolling body 5. The notched pinion 11 is axially offset with the rolling body 5. The toothed pinion 11 is axially interposed between the primary flywheel 1 and the rolling body 5.

The toothed member 12 is fixedly mounted on the primary flywheel 1, on the primary flywheel plate 1 in the embodiment illustrated in FIGS. 1 to 4.

The toothed member 12 is arranged radially on the outside of the notched pinion

1 1. This toothed member 12 has a shape of an arc of a circle. A radially outer face of the toothed member 12 is joined to the radially inner face of the peripheral skirt 3 of the primary flywheel 1. In other words, the toothed member 12 extends radially inwardly the radially inner face of the skirt. .

The toothed member 12 develops in an angular sector around the axis of rotation X corresponding to the angular sector of the corresponding second cam surface 9. In addition, the toothed member 12 is mounted on the primary flywheel 1 axially offset with the second cam surface 9. More particularly, the toothed member 12 is axially interposed between the second cam surface 9 and the primary flywheel plate 1 Thus, the second cam surface 9 is in radial relation with the rolling body 5 and the toothed element 12 is in radial relation with the notched pinion 11.

A radially inner face of the toothed member 12 comprises a row of teeth. The notched pinion 11 and the toothed member 12 are arranged in such a way that the notched pinion 11 moves along the toothed member 12 during a relative deflection between the primary flywheel 1 and the secondary flywheel 2, otherwise said when the rolling body 5 moves on the second cam surface 9.

When the rolling body 5 moves on the second cam surface 9 without sliding, the rolling body 5 rotates about its axis of rotation. The notched pinion 1 1 being rotationally integral with the rolling body 5, the notched pinion 11 then moves along the toothed member 12 by rotating about the axis of rotation of the rolling body 5. During its displacement, the teeth of the toothed pinion 1 1 cooperate with the teeth of the toothed member 12. However, this cooperation can be done without transmission of torque between the notched pinion 11 and the toothed member 12, that is to say without support circumferential between the teeth of the toothed pinion 11 and the teeth of the toothed member 12, because the toothed pinion January 1 is rotated by the rotation of the rolling body 5 moving without sliding along the second cam surface 9 Thus, the couple transiting between the primary steering wheel 1 and the steering wheel secondary 2 is transmitted mainly by the rolling body 5 and the first and second cam surfaces 8, 9, and in a limited or no way by the toothed pinion 11 and the toothed member 12.

The sliding between the rolling body and the second cam surface 9 is limited by a circumferential contact between the teeth of the toothed pinion 11 and the teeth of the toothed member 12. The teeth of the notched pinion 11 then mesh the teeth of the toothed tooth. toothed member 12 so as to impose the rotation of the toothed pinion 11 around the axis of rotation of the rolling body 5. The notched pinion 1 1 and the rolling body 5 being integral in rotation, the engagement of the teeth of the notched pinion 11 with the teeth of the toothed member 12 impose the rotation of the rolling body 5 and therefore interrupts the sliding phenomenon between the rolling body 5 and the second cam surface 9. In other words, the notched pinion 11 meshes the toothed member 12 so as to to prevent sliding of the rolling body 5 on the second cam surface 9.

Thus, the engagement of the toothed pinion 11 on the toothed member 12 ensures that the displacement of the rolling body 5 on the second cam surface 9 is synchronized with the rotation of the rolling body 5 about its axis of rotation. .

If so desired, a clearance can be present between the teeth of the toothed pinion 11 and the teeth of the toothed member 12. As explained above, when the rolling body 5 moves along the second cam surface 9 without sliding, the rolling body 5 and the toothed pinion 11 are rotated by the non-slip cooperation between the rolling body 5 and the second cam surface 9. Due to the clearance between the teeth of the toothed pinion 11 and the teeth the toothed member 12 and the rotational drive of the toothed pinion 11 by the rolling body 5, the teeth of the toothed pinion 11 do not undergo circumferential force by meshing with the teeth of the toothed member 12. In other words , this game ensures that the rotation of the notched pinion January 1 is imposed by the rotation of the rolling body 5 when the rolling body 5 cooperates with the second cam surface 9 without sliding. This makes it possible to transmit most or all of the torque between the rolling body and the cam surface and not between the pinion and the toothed member.

Thus, the teeth of the notched pinion 11 mesh the teeth of the toothed member 12 to impose a rotation on the notched pinion 11 only after a sliding between the rolling body 5 and the second cam surface 9. This sliding is then automatically interrupted when the teeth of the toothed pinion 11 bear circumferentially against the teeth of the toothed member 12. In effect, since the teeth 1 1 toothed gear meshes with the teeth of the toothed member 12, this meshing requires a rotation of the notched piston 1 1 and thus a rotation of the rolling body 5 moving on the second cam surface 9. Such a sliding between the body 5 and the second cam surface 9 is therefore present only on a restricted portion of the second cam surface 9, said restricted portion corresponding to the clearance between the tooth of the notched pinion 11 and the teeth of the toothed member 12.

The presence of this game does not interfere with the synchronization of the rotation of the rolling body 5 with its displacement along the second cam surface 9. In addition, such a game ensures that the torque transiting between the primary flywheel 1 and the steering wheel secondary 2 passes essentially through the rolling body 5 and the first and second cam surfaces 8, 9, without passing through the notched pinion 11 and the toothed member 12. Indeed, the notched pinion 11 and the toothed member 12 engage only to synchronize the rotation of the rolling body with its displacement along the second cam surface 9. As a result, the risk of shear at the toothed pinion 11 is limited since the torque transiting between the primary flywheel 1 and the secondary flywheel 2 exerts little or no stress on said notched pinion 11.

FIGS. 5 to 8 illustrate a second embodiment in which the rotation of the rolling body 5 is synchronized on the one hand with its displacement along the second cam surface 9 and, on the other hand, with its displacement along the first cam surface 8. In this second embodiment, the same elements or exercising the same function as those described above with respect to the first embodiment bear the same reference.

In this second embodiment, the notched pinion 11 is a first toothed pinion 11 and the toothed member is a first toothed member 12. The synchronization between the rotation of the rolling body 5 and its displacement along the second cam surface 9 is carried out as described above with respect to the first embodiment, the first toothed pinion 11 integral in rotation with the rolling body 5 cooperating, with or without play, with the first toothed member 12 mounted on the primary flywheel 1. The synchronization of the rotation of the rolling body 5 with its displacement along the first cam surface 8 is analogous to the synchronization between the rotation of the rolling body 5 with its displacement along the second cam surface 9. Indeed, this second embodiment comprises a second synchronization device similar to the first synchronization device. This second synchronization device comprises a second toothed pinion 13 and a second toothed element 14 cooperating together to synchronize the displacement of the rolling body 5 on the first cam surface 8.

The second notched pinion 13 is integral in rotation with the rolling body 5.

In a similar manner to the first notched pinion 10, the second notched pinion 13 can be secured to the rolling body 5 in many ways, for example by being integral, in two separate parts joined by any suitable fastening means such as gluing, welding, fitting, overmolding, sintering etc. The second notched pinion 13 is coaxial with the rolling body 5. Likewise, the second notched pinion is preferably made of plastic in order to limit the contact noise between the second notched pinion 13 and the second toothed member 14. In the embodiment illustrated in FIG. Figures 5 to 8, the second notched pinion 13 and the rolling body 5 have a circular shape, the second notched pinion 13 having a diameter smaller than the diameter of the rolling body 5.

The second toothed gear 13 is axially offset with the rolling body 5. The second toothed gear 13 is axially interposed between the secondary flywheel 2 and the rolling body 5. In other words, the rolling body 5 is coaxially interposed between the first notched pinion 10 and the second notched pinion 13.

The second toothed member 14 is fixedly mounted on the secondary flywheel 2.

This second toothed member 14 has a circular shape. In the embodiment illustrated in FIGS. 5 to 8, this second toothed element 14 is fixed on a radially intermediate portion of a face of the plate of the secondary flywheel 2 facing the primary flywheel 1. A radially outer face the second toothed member 14 has a row of teeth.

The second toothed member 14 is arranged in an angular sector around the axis of rotation X corresponding to the angular sector around said axis of rotation X in which the first cam surface 8 develops. The second toothed element 14 is axially offset with respect to the first cam surface 8. More particularly, the second toothed element 14 is axially interposed between the first cam surface 8 and the secondary flywheel plate 2 so that the first surface of cam 8 is vis-à-vis the radial rolling body 5 and the second toothed member 14 is vis-à-vis the radial second toothed pinion 13.

The second toothed pinion 13 and the second toothed element 14 are arranged in such a way that the second toothed pinion 13 moves along the second toothed element 14 when the rolling body 5 moves on the first cam surface 8.

In a similar way to the cooperation between the first toothed pinion 11 and the first toothed member 12 described above with reference to FIGS. 1 to 4, the second toothed pinion 13 is rotated and displaced along the second toothed member 14 by the rolling body 5 when the rolling body 5 moves on the first cam surface 8 without sliding. The second toothed pinion 13 then cooperates with the second toothed element 14 with a limited torque transmission, preferably without torque transmission, between the second toothed pinion 13 and the second toothed element 14.

Conversely, when the rolling body 5 moves on the first cam surface 8 with sliding, the second toothed pinion 13 moves along the second toothed member 14 and meshes with the second toothed member 14 to force the rotation of said second notched pinion 13, and thus the rolling body 5. Thus, the second toothed pinion 13 and the second toothed member 14 prevent the rolling body 5 from continuing to cooperate with the first cam surface 8 with sliding. As a result, the displacement of the rolling body 5 on the first cam surface 8 is synchronized with the rotation of the rolling body 5 about its axis of rotation.

In a similar manner to the first embodiment described above with reference to FIGS. 1 to 4, a clearance can therefore be present between the teeth of the second notched pinion 13 and the teeth of the second toothed member 14. Such a game makes it possible to limit the transmission of torque by the second notched pinion 13 and the second toothed member 14 during transmission of torque between the primary flywheel 1 and the secondary flywheel 2. FIGS. 8 and 9 show a preferred variant of this second embodiment in which the second toothed element 14 is fixed on the flexible blade 4. The second toothed element can in particular be riveted on the blade 4.

Thus it is not necessary to take into account the radial displacement of the blade to manage the interpenetration of the teeth of the pinion gear 13 and the second toothed member 14.

This toothed member 14 is formed in a sheet and has the advantage of being compact radially.

In a non-illustrated embodiment, the double damping flywheel comprises the second synchronization device only, without having the first synchronization device. Thus, in this non-illustrated embodiment, the rotation of the rolling body 5 about its axis of rotation is synchronized with its displacement along the first cam surface 8 only, without being synchronized with its displacement along the second surface. of cam 9.

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, although the invention is described above in connection with an elastic damping device comprising two sliding bodies each cooperating with two raceways, the invention is not limited to such an embodiment and the resiliently damping device is also likely to comprise a greater number of rolling bodies, each of the rolling bodies being mounted in rotation on the phasing element.

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.

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

Claims

A torsion damper for a motor vehicle drive chain comprising:

a first element (1) and a second element (2) rotatable relative to each other about an axis of rotation X;

an elastic damping device coupling the first element (1) and the second element (2) so as to allow vibration damping torque transmission between the first element (1) and the second element (2);

said elastic damping device comprising:

a first raceway (8) connected by an elastic connection to the second element (2);

a second raceway (9) connected to the first element (1);

a rolling body (5) cooperating with the first rolling track (8) and with the second rolling track (9), said rolling body (5) having an axis of rotation of said rolling body (5), said rolling body being suitable moving rolling on said first and second raceways (8, 9) during relative rotation between the first member (1) and the second member (2);

said first and second raceways (8, 9) being arranged such that for relative rotation between the first element (1) and the second element (2) from an angular position of rest, the first body (5) traveling on the first and second rolling tracks exerts a bending force on the elastic connection and that the elastic connection produces a reaction force on the rolling body (5) so as to recall the first element (1) and the second element (2) to the angular position of rest;

the resilient damping device further comprising a notched pinion (11, 13) integral in rotation with the rolling body (5) about the X axis, said notched pinion (1 1, 13) being axially offset with the rolling body ( 5), said notched pinion (11, 13) being arranged to mesh with a toothed member (12, 14) carried by one of the first member (1) and the second member (2).

2. torsion damper according to claim 1, wherein the notched pinion (11, 13) cooperates with the toothed member (12, 14) with a set of meshing.

3. torsion damper according to one of the preceding claims, wherein the notched pinion is overmolded on the rolling body.

4. torsion damper according to one of the preceding claims, wherein the notched pinion is a first toothed pinion (1 1) and the toothed member is a first toothed member (12),

and wherein the resilient damping device further comprises a second notched pinion (13) rotationally integral with the rolling body (5), said second pinion (13) being axially offset relative to the rolling body (5), said second pinion pinion gear (13) being arranged to mesh with a second toothed member (14) carried by the other of the first element (1) and the second element (2).

5. torsion damper according to the preceding claim, wherein the rolling body (5) is axially interposed between the first toothed pinion (1 1) and the second notched pinion (13).

6. torsion damper according to one of claims 4 to 5, wherein the second toothed pinion (13) cooperates with the second toothed member (14) with a second set of meshing.

Torsion damper according to one of the preceding claims, wherein the rolling body is a first rolling body and the elastic connection connecting the first rolling track (8) and the second element (2) is a first elastic connection, the toothed pinion being a first notched pinion and the toothed member being a first toothed member, the elastic damping device further comprising

A third rolling track connected to the first element (1),

A fourth rolling track connected by a second elastic connection to the second element (2),

A second rolling body cooperating with the third and fourth rolling track and able to move on said third and fourth rolling tracks during a relative rotation between the first element (1) and the second element (2),

8. torsion damper according to one of the preceding claims, wherein the elastic damping device comprises a flexible blade (4) mounted on the second member (2), said flexible blade (4) having a face carrying the first track rolling member (8), a flexible portion of the flexible blade (4) forming the elastic connection connecting the first raceway (8) to the second element (2).

9. torsion damper according to the preceding claim, wherein the toothed member is carried by the second member (2), the toothed member being fixed on the flexible blade (4).

Torsion damper according to one of the preceding claims, wherein the rolling body has a contact surface with the rolling tracks.