FR3077609A1 - PENDULAR DAMPING DEVICE - Google Patents

Abstract

Pendulum damping device (1) intended to be integrated in a transmission chain of a motor vehicle, in particular in a clutch, comprising: - a support (2) able to move in rotation about an axis (X) - a pendulum body (3) comprising at least one oscillating weight (5) guided in oscillation relative to the support (2) and at least one connecting member (6) adapted to match at least one oscillating mass (5) to the support (2) and - a friction member (30) adapted to rub on a pendulum body (3) or a support (2), characterized in that said friction member (30) is respectively fast to rotate with the support (2) or the pendulum body (3).

Description

PENDULUM DAMPING DEVICE

Technical area

The present invention relates to a pendulum damping device, in particular for a clutch of a motor vehicle transmission system.

State of the art

A pendulum damping device is conventionally used to filter vibrations due to acyclisms in the engine of a motor vehicle. Indeed, the movements of the cylinders of an internal combustion engine generate acyclisms which vary in particular according to the number of cylinders. These acyclisms are capable of generating in turn vibrations which can pass into the gearbox and cause shocks and undesirable noise pollution. It is therefore preferable to provide a vibration filtration device.

The pendulum damping device is conventionally rigidly fixed, by means of rivets, to a flywheel, a veil, a phasing washer of a torsion damping device, in particular to a clutch, a hydrodynamic torque converter or dry or wet double clutch. Such a torsional damping device is for example known as a double damping flywheel.

Conventionally, the pendulum damping device comprises an annular support intended to be driven in rotation and one or more pendular bodies movable relative to this support. The movement of each pendulum body relative to the support is generally guided by two rolling members each cooperating on the one hand with tracks of the support, and on the other hand with tracks of the pendulum body. Each pendulum body comprises for example two pendulum masses riveted together.

A pendulum body is conventionally constituted by a pair of oscillating masses, sandwiching the support and rigidly joined together, generally by means of a spacer. The oscillating masses can be riveted to the spacer or they can have windows in which the spacer extends.

As a variant, the shape of the raceways can be such that each pendulum body is moved relative to the support at the same time:

- in translation around a fictitious axis parallel to the axis of rotation of the support and,

- Also rotating around the center of gravity of said pendulum mass, such a movement also being called "combined movement".

In operation, the pendulum bodies are moved relative to the support, combining a translational movement and a rotational movement. This movement of the pendulum bodies relative to the support makes it possible to generate a resistant filtration torque opposing the oscillating torque of the motor.

When the pendulum damping device rotates at reduced speed, typically at less than 800 revolutions / min, in particular when starting, when the vehicle is slowing down, when the engine is stopped or when changing gear ratio, the centrifugal force exerted on the pendulum bodies is reduced and the latter therefore tend to approach the axis of rotation. The contact of the pendulum bodies with the rolling tracks can thus be interrupted, which leads to undesirable noises and to shocks liable to reduce the service life of the pendulum damping device.

It is known from application FR 3 046 649 in the name of the Applicant, a pendulum damping device comprising a spring tightening the pendulum body to the support, the spring limiting the displacements of the pendulum body in the radial direction during a deceleration of the rotation of the pendulum damping device. This solution is not entirely satisfactory.

The object of the invention is therefore to provide a simple and economical solution to the problems listed above.

Summary of the invention

To this end, the invention provides a pendulum damping device intended to be integrated in a transmission chain of a motor vehicle, in particular in a clutch, comprising:

- a support able to move in rotation around an X axis,

a pendulum body comprising at least one oscillating mass guided in oscillation relative to the support and at least one connecting member adapted to match at least one oscillating mass to the support, and

- a friction member adapted to rub on a pendulum body or a support, in which the friction member is respectively integral in rotation with the support or the pendulum body.

Thus and as will be seen in more detail in the following description, the friction member is capable of rubbing on one, the other or the two oscillating masses, therefore the pendulum body, or on the support for certain relative displacements of the pendulum body and the support.

According to the invention, the friction member exerts a friction force on the pendulum body or the support which opposes the movement of this pendulum body relative to the support or vice versa which allows, due to the energy absorbed by friction, to limit the noise linked to undesirable impacts between the support and the pendulum body or between the rolling member and the pendulum body or between the rolling member and the support, likely to arise at the end of these said relative displacements.

According to the invention, the friction member can be compressed between the oscillating masses or between the supports. The friction member can exert on the pendulum body or the support an axial prestressing comprised between 2N and 15N (Newtons) preferably between 4 and 8N distributed equitably on each of the two oscillating masses or of the two supports. The overall clamping force, expressed in Newtons, depends on both the intrinsic characteristics of the friction member and the coefficient of friction between said member and the pendulum body.

The fact that the friction member is integral in rotation with the support or the pendulum body has the effect of blocking its rotation relative to the support or the pendulum body respectively.

Such a device thus makes it possible to maintain homogeneous friction whatever the movement of the pendulum body or of the support with respect to the support or to the pendulum body respectively. Such a frictional force can generate hysteresis.

Advantageously, the friction member has an axial preload and a tangential preload. In many hysteresis systems, there is play between the friction member and the element in which the latter is inserted, typically in a support or a pendulum body. This clearance comes from manufacturing tolerances and from a margin necessary for differential thermal expansion, typically when the friction member has a plastic casing while the support or pendulum body is made of steel. The tangential prestressing of the friction member within the meaning of the present invention makes it possible to fill this clearance between the friction member and the support or the pendular body. In addition, another advantage of the present invention lies in the fact that the friction member which gives the main load (axial preload) also gives the tangential preload for the filling of the game.

Advantageously, the tangential prestress is between 0.8N and 6N, preferably between 1.6N and 3.2N.

The values of the axial and / or tangential prestresses are related to the coefficients of friction of the elements of the pendulum damping device which varies according to the environment in which it is located. Those skilled in the art will therefore be able to adapt the values of the prestresses according to the environment of use.

These prestressing values are also given in the context of a friction application for a passenger vehicle. Those skilled in the art will therefore be able to adapt these values to other applications.

The device according to the invention can also include one or more of the characteristics below, considered individually or in all technically possible combinations:

The device according to the invention can operate in oil or in air;

The friction member includes:

• a first part defining a first axial end, consisting of an internal face and an external face, said external face defining a friction surface Si, • a second part defining a second axial end, consisting of an internal face and of an external face, and • an elastic element, advantageously frustoconical, extending between a first a second end, said first and second ends being in respective contact with the internal faces of said first and second parts so as to axially separate these two parts one from the other ;

- The external face of the second axial end defines a friction surface S 2 identical to the friction surface S1;

- The friction surfaces Si and S2 are parallel to each other;

- Each of the first and second parts of the friction member comprises at least one hook, the hooks being configured to establish a removable hook between them;

- The first and second parts of the friction member are identical; this makes it possible to standardize the parts to be manufactured;

- The elastic element, that is to say elastically deformable, is a frustoconical spring;

- The friction member further comprises two positioning means located on the internal parts;

- The positioning means are of frustoconical shape;

- The centers of the positioning means are circumferentially offset from one another;

- The centers of the positioning means are circumferentially offset from one another by a distance of between 5 and 50 mm;

- The value of the axial prestress is greater than 2.5N and the tangential prestress is greater than IN;

- The friction member is configured to exert braking on the pendulum or support;

- The friction member cooperates with axial internal faces of the substantially planar pendulum masses.

The invention also relates to a component for a transmission system of a motor vehicle, the component being in particular a double damping flywheel, a hydrodynamic torque converter or a friction clutch disc, comprising a pendular damping device according to the invention.

Another subject of the invention is, according to another of its aspects, a vehicle powertrain comprising:

- a vehicle propulsion thermal engine, and

- a component for a transmission system according to the invention.

Brief description of the figures

Other characteristics, objects and advantages of the present invention will appear better on reading the detailed description which follows, and with regard to the attached drawings given by way of nonlimiting example and in which:

FIG. 1 partially shows a front view and with transparency, a pendular damping device according to the present invention, the device being in a first configuration,

FIG. 2 represents a friction member according to an exemplary implementation of the invention,

FIGS. 3 represents a friction member according to another example of implementation of the invention inserted in a support,

FIGS. 4a and 4b are sectional views respectively along the section plane B-B shown in FIG. 3 and D-D shown in FIG. 4a,

- Figure 5 shows an example of a method for obtaining an elastic element compressed along two axes.

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

Definitions

For the purposes of the present invention and unless otherwise indicated, "axially" means "parallel to the axis X of rotation of the support";

"Radially" means "along a transverse axis intersecting the axis of rotation of the support";

"Angularly" or "circumferentially" means "around the axis of rotation of the support", that is to say directed orthogonally to the axis X of the support and orthogonally to the radial direction. So when two elements are said to be "circumferentially offset" with respect to each other, this means that the centers of these elements located around the axis of rotation of the support are not axially aligned. The difference between the two centers of two so-called circumferentially offset elements being the distance separating these two centers along the same circumferential plane.

"Centrifugal support" means a support force comprising a component oriented away from the X axis.

"Motor vehicle" means not only passenger vehicles, but also industrial vehicles, which includes heavy goods vehicles, public transport vehicles or agricultural vehicles.

By "pendulum body" is meant a mass which is mounted so as to oscillate on the support in response to acyclisms of the vehicle engine. A pendulum body is conventionally constituted by a pair of oscillating masses ", extending so as to sandwich the support and rigidly joined together. A pendulum body can also be constituted by a single oscillating mass.

"Braking" means the action of friction opposing a movement without completely blocking it.

Two pieces are said to be "paired" when they are permanently immobilized relative to one another. This immobilization can result from a fixing of the first part on the second part directly or by means of one or more intermediate parts.

The rest position of the device is that in which the oscillating masses are subjected to a centrifugal force, but not to torsional oscillations originating from the acyclisms of the heat engine.

The oscillating masses are said to be "supported by centrifugal force" when the speed of rotation of the support is sufficient to keep the oscillating masses pressed radially outward against the rolling members, and by their means against the support.

Unless otherwise indicated, the verbs "to include", "to present" or "to understand" must be interpreted broadly, that is to say without limitation.

Detailed description of the invention

A pendulum damping device 1 according to the invention is partially shown in FIG. 1. The device 1 is in particular able to equip a motor vehicle transmission system, being for example integrated into a component not shown of such a transmission system , this component being for example a double damping flywheel, a hydrodynamic torque converter, a flywheel integral with the crankshaft, a dry or wet double clutch, a simple wet clutch, a hybrid powertrain component, or a friction friction disc. clutch.

This component can be part of a powertrain of a motor vehicle, the latter comprising a heat engine having a predetermined number of cylinders, for example three, four or six cylinders.

In known manner, such a component may comprise a torsion damper having at least one input element, at least one output element, and elastic return members with circumferential action which are interposed between said input and output elements . Within the meaning of the present application, the terms “entry” and “exit” are defined with respect to the direction of transmission of the torque from the heat engine of the vehicle to the wheels of the latter.

The pendulum damping device 1 comprises a pendulum body 3 mounted on a support 2. The pendulum body 3 comprises two oscillating masses 5 paired by means of at least one connecting member commonly called “spacer” 6. Each of the oscillating masses 5 comprises a body which extends radially and circumferentially, and is of generally arcuate shape. The oscillating masses 5 are located on either side of a support 2 and are axially opposite.

The pendulum damping device 1 also comprises a friction member 30.

Support 2 can be:

- an input element of the torsion damper,

- an output element or an intermediate phasing element disposed between two sets of shock absorber springs, or

an element linked in rotation to one of the aforementioned elements and distinct from the latter, then being for example a support specific to the device 1.

The support 2 is in particular a guide washer or a phasing washer.

The support 2 can also be other, such as a flange.

In the example considered, the support 2 generally has the form of a ring constituted by a cut metal sheet, generally made of steel, of a thickness typically less than 10 mm, preferably less than 9 mm, preferably less than 8 mm. .

Additional members, such as damping buffers and / or stops and / or guides for damping and / or limiting and / or guiding the oscillation movement of the oscillating masses, for example made of polymer, can be fixed to the support 2

A plurality of windows 19 passes through the support 2 according to its thickness. The windows 19 define empty spaces inside the support 2. The windows 19 can be arranged in pairs. The pairs of windows 19 are regularly distributed over the entire circumference of the support 2. The support 2 comprises as many pairs of windows 19 as there are oscillating masses 5.

The device 1 also comprises at least one rolling member 11, for example a roller. Each pendulum body 3 is conventionally mounted oscillating on the support 2 by means of two rolling members 11 which each pass through a window 19 of the support and guide the movement of the oscillating masses 5 relative to the support 2. Each rolling member 11 cooperates on the one hand with a rolling track 12 secured to the support 2 and on the other hand with a rolling track 13 secured to the pendulum body 3 when the pendulum body 3 is supported by centrifugal force. The edges of the windows 19, in particular the radially external parts of said edges, define the support raceways 12. The radially external concave edge of the spacer 6, turned towards the outside of the support 2, can form the raceway spacer 13. Alternatively, the radially internal concave edge of a window made in one of the oscillating masses 5 can form the spacer race track 13. The rolling members 11 can be freely mounted in the windows 19 of the support 2 The rolling surface of the rolling member 11 can be a cylinder of constant radius.

In FIG. 1, one of the oscillating masses is shown in transparency to reveal the raceways 12, 13 and the race members 11.

The pendulum bodies 3 are preferably distributed equiangularly around the axis X. Preferably, their number is greater than or equal to two and / or less than eight. The device can in particular comprise two, three, four, five, six or seven oscillating masses 3.

The oscillating masses 5, the connecting members 6 and the rolling members 11 are for example made of steel. Each rolling member 11 and associated connecting member 6 are arranged in the same window 19 formed in the support 2.

The device 1 further comprises a friction member 30 disposed axially between the first and second oscillating masses 5. The friction member 30 can be housed in an opening 34 formed in the support 2 and able to rub on the first and second masses oscillating 5. The opening 34 is here dedicated to the friction member 30, that is to say that it receives no other element. The opening 34 is separate from the windows 19.

The friction member 30 is respectively integral in rotation with the support 2. The opening 34 and the shape of the friction member 30 are for example configured so that the friction member 30 is integral in rotation with the support 2. In other words, the opening 34 is configured so that the friction member 30 does not follow the movements (translation and rotation) of the pendulum body 3. In the case of the device according to the present invention, if the support 2 is not in rotation, the friction member 30 therefore cannot be either. For example, when the pendulum body 3 is rotated, the friction member 30 rubs on the latter to dampen the rotation.

The friction member 30 makes it possible in particular to constrain the movement of the pendulum body 3 or of the support 2 in the circumferential and rotational direction.

Advantageously, the opening 34 has a shape consisting of at least two points located at different distances from a point called the center. Typically, the opening 34 has any geometric shape other than a circle. Advantageously, the opening 34 and the friction member 30 have partially complementary shapes, even more advantageously, completely complementary. In the example of FIG. 1, the opening 34 and the friction member 30 have completely complementary shapes.

Advantageously, the radial dimension of the opening 34 is just greater than the radial dimension of the friction member 30. This radial clearance is in particular between 1% and 10% of the radial dimension of the friction member in the opening 34.

In the embodiment illustrated in FIG. 1 and in accordance with the invention, the friction member 30 is independent of the support 2 and of the pendulum body 3. It is not rigidly fixed either on the support 2 or on the pendulum body 3.

Advantageously, the absence of rigid attachment of the friction member 30 allows in particular a simpler and faster assembly of the device 1.

In a variant not shown, the pendulum damping device 1 comprises a pendulum body 3 comprising an oscillating mass 5 mounted between two supports 2. The friction member 30 is then housed in an opening of the oscillating mass and is able to rub on the two supports 2 located axially on either side of the oscillating mass 5.

FIG. 2 represents a friction member 30 such as can be used in the device 1 according to the present invention.

The friction member 30 has a first part 32 and a second part 33 which can form a housing. As illustrated in FIG. 1, the first part 32 defines the end of the friction member 30 disposed opposite the first pendulum mass 5 of the pendulum body 3 while the second part 33 defines the end of the member friction 30 disposed opposite the second pendulum mass 5 of this pendulum body 3.

The first part 32 defines a first axial end and consists of an internal face 32i and an external face 32e. The external face 32e defining a friction surface SI. The second part 33 defines a second axial end and consists of an internal face 33i and an external face 33e. The external face 33e defining a friction surface S2. Advantageously, the friction surface S2 is identical to the friction surface S1. The internal faces 32i and 33i being in contact with the elastic element 31.

In the embodiment illustrated in Figure 2, each of the first and second parts 32 and 33 includes a hook. The grip can be represented by a hook 35 on the one hand and an ear 36 on the other hand so that the hook 35 of the first part 32 and the ear 36 of the second part 33, and vice versa form a removable hook.

Advantageously, the friction member 30 further comprises an elastic element 31 housed inside this friction member 30. The elastic element 31 thus does not define the periphery of the friction member 30. Advantageously, the elastic element 31 is a frustoconical spring.

Advantageously, the friction member 30 also comprises two positioning means 37 located respectively on said internal faces 32i and 33i.

FIG. 3 represents the friction member 30 according to another example of implementation of the invention inserted in a support 2. In the example considered, the friction member 30 is not clamped between the two oscillating masses 5 of the pendulum body 3. In the absence of such tightening, these are the hooks of the member of the friction member 30, which can be represented by a hook 35 on the one hand and an ear 36 on the other part, which hold the first part 32 and the second part 33 together. An embodiment of the removable hanging system is presented in more detail in FIGS. 4a and 4b.

Advantageously, the hook (s) serve to hold the first and second parts 31 and 32 of the friction member in place on the production line.

In a variant not shown, the friction member 30 can be housed in an opening of the support 2 or of the pendulum body 3 and axially tightened by two oscillating masses 5 of the pendulum body 3 or by two supports 2, respectively. Advantageously, when the friction member 30 is tightened axially by two oscillating masses 5 of the pendulum body 3 or by two supports 2, the ends 37 and 38 of the hooks are spaced apart axially and are therefore no longer in contact.

As shown in Figures 3 and 4a, the elastic element 31 extends between a first and a second end, said first and second ends being in respective contact with the internal faces (32i and 331) of said first and second axial ends (32 and 33).

Advantageously, the friction member 30 has an axial preload and a tangential preload. The axial prestress is obtained by tightening the elastic element 31 by bringing the first and second parts 32 and 33 together.

Advantageously, the tangential prestressing is obtained by shearing the first part 32 and the second part 33. If we consider that the first part 32 and the second part 33 together form a rectangular parallelepiped, the shearing is a variation of the angle, which is no longer straight. This corresponds to forces acting parallel to the face, typically with respect to the first and second friction surfaces S1 and S2.

As shown in FIGS. 3 and 4a, the shearing has the effect of shifting circumferentially and by a distance d of between 5 and 50 mm, the centers of the positioning means 37 relative to one another. Before shearing the centers of the positioning means 37 located around the axis of rotation of the support 2 being axially aligned.

FIG. 5 represents an example of a shearing method making it possible to circumferentially offset the centers of the positioning means 37 relative to one another. During a first step, the first and second parts 32 and 33 are placed on an elastic element 31 which is not compressed, such as a straight or frustoconical spring. During a second step, vertical compression, that is to say in a plane perpendicular to the surfaces Si and S2 is carried out by bringing the first and second parts 32 and 33 together, this so as to obtain the axial prestress. Finally, horizontal shearing, that is to say in a plane parallel with respect to the surfaces S1 and S2, is carried out via the displacement of the two parts 32 and 33, causing an inclination of the elastic element 31 by opposing a force. It is therefore clear from these steps that the friction member 30 comprises an elastic element 31 compressed along two axes.

Advantageously, the horizontal shearing is achieved by the displacement in a plane parallel to the surfaces Si and S2 of one or both of the first and second parts 32 and 33. When a single part 32 or 33 is moved in a plane parallel to surfaces SI and S2, the second part 32 or 33 is stationary.

Of course, the invention is not limited to the embodiments described and shown, provided for illustrative purposes only. The different embodiments could also be combined.

Claims (10)

1. Pendulum damping device (1) intended to be integrated in a transmission chain of a motor vehicle, in particular in a clutch, comprising: - a support (2) able to move in rotation about an axis (X), - a pendulum body (3) comprising at least one oscillating mass (5) guided in oscillation relative to the support (2) and at least one connecting member (6) adapted to match at least one oscillating mass (5) to the support ( 2) and - a friction member (30) adapted to rub on a pendulum body (3) or a support (2), characterized in that said friction member (30) is respectively integral in rotation with the support (2) or with the pendulum body (3). 2. Device according to claim 1, characterized in that said friction member (30) has an axial preload and a tangential preload. 3. Device according to claim 1 or 2, characterized in that the friction member (30) comprises: a first part (32) defining a first axial end, consisting of an internal face (32i) and an external face (32e), said external part (32e) defining a friction surface Si, a second part (33) defining a second axial end, consisting of an internal face (33i) and an external face (33e), and - an elastic element (31), advantageously frustoconical, extending between a first and a second end, said first and second ends being in respective contact with the internal faces (32i and 33i) of said first and second parts (32 and 33) so to axially separate these two parts from one another. 4. Device according to claim 3, characterized in that said external face (33e) of the second axial end defines a friction surface S2 identical to the friction surface Si. 5. Device according to claim 3 or 4, characterized in that each of said first and second parts (32 and 33) comprises at least one hook, said hooks being configured to establish a removable hook between them. 6. Device according to any one of claims 3 to 5, characterized in that said friction member (30) further comprises two positioning means (37) located on said internal faces (32i and 33i), the centers of said means positioning being offset circumferentially relative to each other. 7. Device according to claim 6, characterized in that said centers of the positioning means (37) are offset circumferentially with respect to one another by a distance of between 5 and 50 mm. 8. Device according to any one of the preceding claims, characterized in that the value of the axial prestress is greater than 2.5N and the tangential prestress is greater than IN. 9. Component for a transmission system of a motor vehicle, the component being in particular a double damping flywheel, a hydrodynamic torque converter or a friction clutch disc, comprising a pendular damping device according to any one of claims preceding. 10. Vehicle powertrain comprising: - a vehicle propulsion thermal engine, and - a component for a transmission system according to the preceding claim.