FR3070462A1 - TORSION DAMPER - Google Patents

Abstract

Torsion damper comprising: - a primary element and a rotatably mounted X-axis secondary element on the primary element; - a pendulum damping device comprising a support and a pendulum comprising a rolling member and an oscillating oscillating weight on the support by means of the rolling member, and - a disengaging member configured to maintain a coupling of the secondary element with the support in an engaged configuration, or to decouple the secondary element from the support by rotating the support relative to the secondary element, about the axis X, in a disengaged configuration, the disengaging member being shaped to arrange the torsion damper in the disengaged configuration, respectively engaged, when the angle around the X axis between the primary and secondary elements, measured with respect to a relative angular position of the primary and secondary elements at rest is equal, respectively lower, to a disengagement travel.

Description

TORSION SHOCK ABSORBER

Technical area

The invention relates to a torsional damper, in particular intended to be integrated in a transmission chain of a motor vehicle.

State of the art

A torsional damper comprising a pendular damping device is conventionally used to filter vibrations due to acyclic movements in the engine of a motor vehicle.

Generally, the pendulum damping device comprises an annular support intended to be driven in rotation, and several pendulums, comprising oscillating masses and rolling members, the pendulums being mounted oscillating on the support around an axis parallel to the axis of rotation of the support. The displacement of an oscillating mass relative to the support is generally guided by two rolling members each cooperating with a rolling track of the support and a rolling track of the oscillating mass.

In use, the pendulums oscillate along the raceways between two opposite extreme positions defined by carried or defined stops.

When an overtorque from the engine is transmitted to the pendulum damping device, the pendulums can strike the stops, and the resulting shock can lead to a rupture of the running gear, which makes the pendulum damping device unusable.

There is therefore a need to increase the service life of pendulum damping devices and therefore of the torsional dampers which contain them.

An object of the invention is to meet this need.

Summary of the invention

To this end, the invention provides a torsional damper, in particular intended to be integrated in a transmission chain of a motor vehicle, the torsional damper comprising:

- a primary element and a secondary element rotatably mounted on the X axis on the primary element,

- a pendular damping device comprising a support and a pendulum comprising a rolling member and an oscillating mass mounted oscillating on the support by means of the rolling member, and

- a declutching member for maintaining a coupling of the secondary element with the support in a clutched configuration, and for decoupling the secondary element from the support by rotating the support relative to the secondary element, around the axis X, in a disengaged configuration, the declutching member being shaped to arrange the torsion damper in the disengaged configuration, respectively engaged, when the angle around the axis X between the primary and secondary elements, measured with respect to a relative angular position of the primary and secondary elements at rest is greater than or equal to, respectively less than, a declutching travel.

When an overtorque from a brutal retro mode (for example type 5-2 gear shift; release of the clutch pedal), is transmitted to the torsion damper, the angle around the X axis resulting between the primary and secondary elements can reach the clutch travel. The support is then detached from the secondary element, and can rotate around the X axis relative to the secondary element. The shock between the rolling member and the support is then avoided. The service life of the pendulum damping device is thus considerably increased.

A torsion damper according to the invention may also include one or more of the following optional and preferred characteristics:

the declutching member is sandwiched between the secondary element and the support; in the engaged configuration, the secondary element and the support compress the declutching member;

the declutching member is shaped so that the passage from the engaged position to the disengaged position is effected by deformation, preferably by bending, elastic of the declutching member;

the declutching member is integral in rotation about the axis X of the secondary element, and is in contact with the support and at a distance from the primary element in the engaged configuration, and is in contact with the primary element, and preferably at a distance from the support in the disengaged configuration;

the declutching member comprises an engagement means and the primary element comprises a reception means for receiving the engagement means in the disengaged configuration, the reception means being shaped so that the engagement of the engagement means in the receiving means elastically deforms the declutching member;

the declutching member is a spring washer of axis X and, preferably, the engagement means is a tongue projecting radially outward from the spring washer, and the receiving means is a lug defining a housing d 'lug for receiving the tongue;

the torsion damper comprises a transmission member, preferably rigidly fixed to the primary element and / or to the secondary element, configured to ensure an elastic coupling between the primary and secondary elements;

the transmission member has the form of an elastic blade carried by the primary element or, respectively by the secondary element cooperating with a support member carried by the secondary element or, respectively by the primary element, the member transmission has a form of helical spring disposed between the primary element and the secondary element.

the torsion damper comprises two receiving means, preferably symmetrical with respect to an axial plane, the axial plane preferably being a plane of symmetry of the means of engagement in the rest configuration; thus, each of the two receiving means defines a stop for the declutching member in a direction of rotation around the axis X and an opposite direction of rotation of the primary element relative to the secondary element;

the torsional damper is chosen from a double damping flywheel, a hydrodynamic torque converter and a friction disc.

The invention also relates to a motor vehicle equipped with a torsional damper according to the invention.

Brief description of the figures

Other characteristics and advantages of the invention will become apparent on reading the detailed description and on examining the appended drawing in which

FIGS. 1 and 2 represent, in schematic and partial views and along the axis X, a torsional damper according to an exemplary embodiment of the invention,

FIG. 3 represents, in radial section along the plane A-A, the torsional damper of FIGS. 1 and 2,

- Figure 4 shows, in radial section along plane B-B, the torsion damper of Figures 1 and 2, and

- Figures 5 and 6 are each an enlargement of a part of the torsion damper illustrated in Figure 3.

In the various figures, identical references are used to designate identical or analogous members.

Definitions

Unless otherwise stated,

- axially means along the axis X of rotation of the primary and secondary elements;

- radially means along a transverse axis intersecting the X axis;

- radially outward and radially inward mean along a radial direction away from the X axis, respectively towards the x axis;

- transverse means in a plane perpendicular to the X axis;

- angularly or circumferentially mean around the X axis;

- orthoradially, means perpendicular to a radial direction and in a transverse plane;

- By transverse plane, we mean a plane perpendicular to the X axis;

- By axial plane, we mean a plane containing the X axis;

- The thickness of a part refers to a dimension measured along the X axis;

- the torsion damper is at rest, in a configuration where no torque is applied between the primary element and the secondary element;

- by motor vehicle is meant not only passenger vehicles, but also industrial vehicles, which includes in particular heavy goods vehicles, public transport vehicles or agricultural vehicles; and

- "include", "understand" and "present" must be interpreted in a non-restrictive manner, unless otherwise indicated.

detailed description

As illustrated in FIGS. 1 to 4, a torsion damper 10 comprises a primary element 12, intended to be fixed to the end of a crankshaft of a combustion engine, and a secondary element 14, intended to be connected to the input shaft of a gearbox.

The primary element comprises a primary crown 16 comprising a hub 18 radially inside and of axis X, from the base of which an annular portion 20 of axis X extends extending radially towards the outside. The primary element further comprises an annular and notched starter ring 22, fixed on the radially outer face of the primary ring.

The primary element comprises a receiving means 24 formed by a lug disposed on the inner face 26 of the primary crown from which the hub projects radially. The lug can come in one piece with the primary crown or be rigidly fixed on the primary crown. The secondary element comprises a secondary crown 28, also called phasing washer, of generally annular shape of axis X and rotatably mounted around the axis X on the primary crown by means of a ball bearing 30 fixed at the same time to the hub 18 and to the phasing washer.

The secondary element further comprises at least one transmission member 32 rigidly fixed to the secondary crown by means of rivets 34. In the example illustrated, the secondary element comprises two transmission members, which are symmetrical with respect to the X axis.

The transmission member has the shape of a bent elastic blade 36 cooperating with a support member 38 carried by the primary element. The elastic blade is capable of bending and transmitting a torque between the primary element and the secondary element, the bending of the elastic blade being accompanied by a relative rotation about the axis X of the primary and secondary elements l 'one over the other. A torsion damper comprising such an elastic blade is described in application FR 3 036 448 Al.

The secondary element comprises an annular part 40 rigidly connected to the phasing washer by means of the rivets. In the example illustrated, the rivets sandwich and compress a stack formed by the phasing washer, the transmission member and the annular part.

The annular part has an annular groove 42 whose section in an axial plane is in the shape of a "U". The annular groove thus defines a radially inner axial wall 44 from which extend radially outward the lower 46 and upper 48 radial walls. The lower radial wall, respectively upper, is arranged opposite a face of the primary crown , respectively secondary. The lower radial face is in contact with a radial face of the elastic blade.

The torsion damper further comprises a pendular damping device 50 comprising a support 52 of axis X, coaxial with the primary and secondary elements, of generally annular shape. The pendulum damping device further comprises a plurality of pendulums 54, which are preferably, as illustrated, distributed regularly around the axis X.

Each pendulum comprises an oscillating mass 56 consisting of two weights rigidly connected to each other and extending on each side of the support, and at least one rolling member 58, interposed between the oscillating mass and the support so as to roll on at least one support rolling track and on two tracks of oscillating mass when the oscillating mass oscillates relative to the support. The support track is defined by the edge of a recess formed in the thickness of the support and the pendulum mass track is defined by the edges of recesses formed in the thickness of the weights of the oscillating mass. In the example illustrated, each pendulum comprises an oscillating mass and two rolling members.

The pendulum damping device is housed between the primary and secondary crowns. In particular, the support is partially engaged in the annular groove of the annular part.

Furthermore, the torsion damper comprises a declutching member 60 disposed between the primary element and the secondary element.

In the example illustrated, the declutching member is a spring washer 62 of axis X, of generally annular and coaxial shape with the support and the primary and secondary elements.

The declutching member is arranged in the torsion damper so as to encircle the hub while being arranged at a distance from the hub. In particular, the declutching member is housed between the support and the annular part.

In the engaged configuration, illustrated in particular in FIGS. 4 to 5, the declutching member is in abutment on the secondary element, by means of a contact with the annular part, and in abutment on the support.

In the engaged configuration, the declutching member is compressed by the secondary element and by the support, so as to couple, that is to say, to link integrally in rotation about the axis X, the support and the secondary element.

The declutching member has a bearing face 64 for pressing on the secondary element and a bearing face 66 for pressing on the support, arranged at a distance radially from one another and, preferably, like this is shown in Figures 3 to 5, axially spaced from one another.

The declutching member comprises an engagement means 68. In the example illustrated, the engagement means is formed by a tongue projecting radially outwards, and arranged in the engaged configuration at a distance from the element. primary.

The declutching member is shaped to cooperate, via the engagement means 68, with the receiving means 24 in the disengaged configuration, as described below.

The engagement means and the receiving means are, in the rest position, angularly spaced apart from one another by an angle Db or "declutching clearance". In other words, the primary element must rotate at least the angle Db before the engagement means engages in the reception means. Preferably, the declutching movement is between Dr -2 ° and Dr -10 °, preferably between Dr -2 ° and Dr 5 °.

The Qb angle is related to the back deflection of the DVA (here Dr).

Qb = Ωγ -5 ° OR Qb = Ωγ -x% of Ωγ.

In the example illustrated, the primary element comprises receiving means in the form of four lugs formed by two pairs of lugs, the lugs of each pair being symmetrical with respect to an axial plane.

Each lug has an inclined lug wall 69 located at a distance from the inner face of the primary crown. The inclined lug wall defines with the primary crown a lug housing 72 for receiving the tongue.

The inclined lug wall is preferably inclined, so that the space between the inclined lug wall and the primary crown decreases as the engagement means 68, i.e. - say the tongue, in the lug housing 72.

In the engaged configuration, the support and the disengaging member are integral in rotation about the X axis. When applying a torque on the primary element, the secondary element is movable in rotation around the axis X relative to the primary element. Beyond an angle around the axis X between the primary and secondary elements, measured relative to the relative angular position of said elements at rest, greater than or equal to the declutching movement, the tongue is engaged in the housing lug.

The lug is shaped so that when the angle around the axis X between the primary and secondary elements reaches the declutching travel, the lug exerts on the tongue an axial force directed in the same direction as the force qu 'exercises the support on the spring washer.

As illustrated in FIG. 5, the tongue has a flat end portion 74 parallel to a transverse plane. When the tongue 68 is engaged in the lug housing 72, the end portion of the tongue bears against the inclined wall 69 of the lug. By increasing the angle around the axis X between the primary and secondary elements, the tongue follows the inclination of the inclined lug wall by approaching the inner face 26 of the primary crown. The axial displacement of the tongue is accompanied by an elastic bending of the spring washer, as indicated by the arrow F in FIG. 5, which results in a reduction of the pressure of the spring washer on the support, or even in a loss of contact between the support and the spring washer. The torsion damper is then placed in the disengaged configuration. The pendulum damping device is thus decoupled from the secondary element, and can rotate around the X axis relative to the secondary element, reducing, or even preventing the impact of the rolling members against the support.

In the disengaged configuration, where the clutch clearance is reached, the elastic blades are elastically deformed and recall the primary element to return the torsional damper to the rest position. The angle around the X axis between the primary and secondary elements is then reduced and becomes less than the declutching travel. The declutching member being rigidly connected to the secondary element, the tongue is then released from the lug housing and the declutching member returns to its initial position by elastic return. The support and the secondary element are then coupled again.

As is now clearly apparent, the invention provides a solution for limiting the risk of rupture of the oscillating pendulum masses.

This increases the service life of the torsion damper.

Of course, the invention is not limited to the particular embodiment described above.

Claims (10)

1. Torsional damper (10), in particular intended to be integrated in a transmission chain of a motor vehicle, the torsional damper comprising: a primary element (12) and a secondary element (14) rotatably mounted on the X axis on the primary element, - a pendulum damping device (50) comprising a support (52) and a pendulum (54) comprising a rolling member (58) and an oscillating mass (56) mounted oscillating on the support by means of the rolling member , and a declutching member (60) configured to maintain a coupling of the secondary element with the support in a clutched configuration, or to decouple the secondary element from the support by rotating the support relative to the secondary element, around the X axis, in a disengaged configuration, the declutching member being shaped to arrange the torsion damper in the disengaged configuration, respectively engaged, when the angle around the X axis between the primary and secondary elements , measured with respect to a relative angular position of the primary and secondary elements at rest is greater than or equal to, respectively less than, a clutch clearance. 2. Torsional damper according to claim 1, in which the declutching member is sandwiched between the secondary element and the support. 3. Torsional damper according to any one of claims 1 and 2, wherein in the engaged configuration, the secondary element and the support compress the declutching member. 4. Torsional damper according to any one of the preceding claims, in which the disengaging member is shaped so that the transition from the engaged position to the disengaged position is effected by deformation, preferably by bending, elastic of the member clutch release. 5. Torsional damper according to any one of the preceding claims, in which the declutching member is integral in rotation about the axis X of the secondary element, and is in contact with the support and at a distance from the element. primary in the engaged configuration, and is in contact with the primary element in the disengaged configuration. 6. Torsion damper according to any one of the preceding claims, in which the disengaging member comprises an engagement means (68) and the primary element comprises a reception means (72) for receiving the engagement means. in the disengaged configuration, the receiving means being shaped so that the engagement of the engagement means in the receiving means elastically deforms the declutching member. 7. Torsional damper according to any one of the preceding claims, in which the disengaging member is a spring washer of axis X and, preferably, the engagement means is a tongue projecting radially outwards from the spring washer, and the receiving means is a lug defining a lug housing for receiving the tongue. 8. Torsional damper according to any one of the preceding claims, further comprising a transmission member, configured to provide elastic coupling between the primary and secondary elements. 9. Torsional damper according to any one of the preceding claims, chosen from a double damping flywheel, a hydrodynamic torque converter and a friction disc. 10. Motor vehicle equipped with a torsion damper according to the preceding claim.