FR3010470A1 - VIBRATION ABSORPTION DEVICE - Google Patents

Abstract

Vibration absorbing device (10) for a motor vehicle transmission, said device having an axis X of rotation and comprising a support (12) and an oscillator (14) oscillating on the support, said oscillator comprising a body of bearing (18a; 18b), a flyweight (16), and a damping block (20) limiting the displacement of the flyweight relative to the support, the support and the flyweight defining "support rolling track" (28a; 28b; ) and "flywheel bearing track" (46a; 46b) respectively, so that rolling of the rolling body on said runways moves the weight relative to the support, the weight having two cheeks (36a; 36b) and a fastening member (40) rigidly connecting said cheeks, the damper block being immobilized in rotation about an axis parallel to the X axis by form complementarity with the fastener.

Description

Technical Field The present invention relates to a vibration absorption device for the transmission of a motor vehicle. STATE OF THE ART In a motor vehicle transmission, for filtering the vibrations due to the acyclisms caused by the explosions in the engine cylinders, a damping device is conventionally used, associated with a clutch which selectively connects the engine to the gearbox. speeds. This clutch can be a friction clutch for a motor vehicle with a manual transmission, or be arranged in a hydrokinetic coupling device for an automatic transmission vehicle, as a locking clutch. With this damping device, generally in the form of a one-piece flywheel, a flexible flywheel, or a vibration absorption device, the effect of the engine vibrations which would otherwise be transmitted through the gearbox and cause shocks, noises or noise particularly undesirable for the occupants of the motor vehicle. The quest for obtaining ever more efficient vibration filtration has led to the integration of a pendulum oscillator with vibration absorption devices. In particular, pendulum oscillators are known in the prior art with flyweights capable of oscillating freely in an axial plane, that is to say orthogonal to the transmission axis. DE 10 2009 042 836 discloses a vibration absorption device comprising a freely movable flyweight on a support, consisting of two cheeks interconnected by three fasteners passing through the support through a window formed in said support. The fasteners hold the cheeks and avoid their deflection in an axial plane during operation of the device, which is generating parasitic vibrations. There is a need for a quieter device in operation and more efficiently filtering vibratory spectra generated by a motor. The object of the invention is therefore to at least partially meet this need. SUMMARY OF THE INVENTION The invention proposes a vibration absorption device intended for a motor vehicle transmission, said device having an axis X of rotation and comprising a support and an oscillator mounted oscillating on the support, said oscillator comprising a body of the bearing and a flyweight, the support and the flyweight defining "bearing raceway" and "flywheel raceway" respectively, so that the rolling body rolling on said raceways displaces the flyweight relative to the support, the weight comprising two cheeks and a fixing member rigidly connecting said cheeks.

According to a first aspect of the invention, the support defines a closed window passing through the support in the thickness of the support, the fixing member being arranged in the window, the fixing member and the window being shaped so as not to to hinder the oscillation movement of the oscillator relative to the support. Advantageously, the fastener contributes to the rigidity of the weight and avoids the deflection of the cheeks in an axial plane during the oscillation of the weight. Thus, the quality of the vibration filtration is improved, and together, a quiet operation of the device is ensured. According to a second aspect of the invention, the vibration absorption device comprises a damping block, limiting the displacement of the weight relative to the support, the damping block being immobilized in rotation about an axis parallel to the X axis by complementarity of form with the fastener. Advantageously, the damper block is thus simply and effectively fixed on the fastener. The wear of the damper block is also limited. The risks of loosening of the damper block of the fastener, which may result from a direct contact of the weight on the support, are thus reduced. According to a third aspect, the vibration absorption device comprises a damping block, limiting the displacement of the weight relative to the support, and immobilized in rotation about an axis parallel to the axis X by complementarity of form with the fastening member, the weight comprises at least two fastening members rigidly connecting said cheeks, the support defines a window, closed and passing through the support in the thickness of the support, and at least one fixing member is arranged in the window and at the at least one fastener is arranged outside the window.

Advantageously, the arrangement of the fasteners according to the third aspect of the invention makes it possible to fix a damping block on the oscillator to effectively damp the impacts of the weight against the support, while ensuring optimum rigidity of the weight. Silent operation of the device according to the invention is also ensured.

According to any of these aspects, a device according to the invention may also comprise one or more additional features of the other aspects and optional features below, according to all the possible combinations: the support is arranged partially between the cheeks , which allows the support to limit the axial movement of the weight; the support comprises a support cutout in which is disposed a rolling body; - The axial displacement of a rolling body between the cheeks is less than the thickness of the portion of the fastener contained between the cheeks; the cheeks comprise cheek recesses in which the rolling bodies are arranged, and preferably crossing the cheeks in their thickness; - The cheeks limit the axial movement of the rolling bodies; - The cheeks are shaped to define first and second bearing stops in a first direction and in a second opposite direction respectively, limiting the axial displacement of the rolling body relative to the weight; in this way, the shocks between the rolling body, flyweight and support are reduced, which reduces the operating noise of the device; - the cheeks are flat; the thickness of a cheek is less than 8 mm, preferably less than 5 mm and / or greater than 1 mm; a rolling body in the form of a roller in the form of a cylinder or barrel, and possibly having an annular extra thickness; - no rolling body is engaged in the window; - The fastener is riveted on at least one cheek, preferably on both; the device comprises a second or even a third fastener disposed outside the window; - The fastener disposed outside the window is disposed radially outside the support; - The fastener disposed outside the window is disposed radially outside the fastener disposed in the window; the contour of the portion of the fastening member on which the damping block, viewed along the axis X, is mounted has at least one axis of symmetry and / or is partly concave and / or is generally elongated and / or has a larger dimension in a orthoradial direction than in a radial direction, and / or has a plurality of protuberances; - The contact surface between the damper block and the fastener is substantially parallel to the X axis; - The fixing member defines a spacer extending between the two cheeks and whose shape, observed along the axis X, is not revolution; the thickness of the spacer, that is to say its dimension measured along the X axis, is greater than or equal to the thickness of the support; the fixing member is associated only with a single damping block; the damping block consists of an elastomeric material, preferably of rubber; - The damping block is mounted on the oscillator, preferably on a fixing member, and / or on the support and it defines at least one orthoradial stop position; - The damper block has an opening through the damper block in the thickness of the damper block, the fastener is disposed in said opening and projects axially on either side of said opening; the damping block is arranged outside the window; - The damper block is fixed on at least two fasteners; - The damper block is disposed between the two cheeks, and is preferably sandwiched between the two cheeks; the contour of the opening of the damping block observed along the X axis is closed; the damping block has a surface oriented towards the substantially flat axis X; the second fastening member, or even the third fastening member, passes through the damping block through the opening defined in the thickness of said block, and projects axially from both sides another of said opening; - The damper block partially, preferably completely, the spacer; the damping block is in contact with the support in at least one position of the weight; - The axial displacement of the damper block is limited by the cheeks and / or by a fastener; the first, second and third fasteners observed along the X axis form the vertices of a triangle, preferably isosceles or even equilateral; a single fastener is arranged in the window; the flyweight is arranged, preferably entirely, inside the virtual cylinder defined by the support during its rotation around the axis X. The invention also relates to a transmission of a motor vehicle chosen from a friction clutch. and a hydrokinetic converter, said transmission comprising a vibration absorption device according to the invention. The invention finally relates to a motor vehicle equipped with a transmission according to the invention. BRIEF DESCRIPTION OF THE FIGURES The invention will be better understood on reading the following detailed description and on examining the appended drawing, in which: FIG. 1 represents a vibration absorption device according to one embodiment; of the invention, the cheeks being shown in transparency, - Figure 2 shows an exploded view and in perspective, a detail of the device of Figure 1; - Figure 3 shows, in axial view and enlarged, the device of vibration absorption of Figure 1, the oscillator being in an orthoradial abutment position, a cheek having been removed. In the different figures, identical or similar members have been designated with the same reference. Definitions By convention, a "radial" orientation is directed orthogonally to an axis and passes through this axis. The axis defines the "axial" orientation. An "orthoradial" orientation is orthogonal to both the axis and a radial orientation. Unless otherwise indicated, the axis is the X axis of rotation of the vibration absorbing device holder.

By plane or "axial" or "radial" surface is meant a plane or a surface of which a normal vector is collinear with an axis or a radial orientation, respectively. By plane or "longitudinal" section, is meant a plane or a section containing the axis. Unless otherwise indicated, this axis is the X axis of rotation. The terms "radially inner" and "radially outer" define positions relative to the X axis: a radially inner object is closer to the X axis than a radially outer object. "Inward" and "outward" orientations correspond to orientations of a surface towards the X axis or opposite to the X axis. The normal to this surface is not necessarily radial.

By "outer radial abutment position" and "inner radial abutment position" is meant any position in which an object can no longer be moved radially outwardly, inwardly respectively, in a radial direction. An outer or inner radial abutment position is not necessarily a locking position, certain radial abutment positions permitting displacement in an axial or orthoradial direction, or more generally in a direction which comprises at least one component which is not radial. By "orthoradial stop position" is meant any position in which an object can no longer be moved in orthoradial direction. An orthoradial abutment position is not necessarily a locking position, certain orthoradial abutment positions permitting displacement in an axial or radial direction, or more generally in a direction that includes at least one component that is not orthoradial. Unless otherwise indicated, a thickness is the largest dimension measured along the X axis. It may also be called "overall thickness".

A moving object that is not mechanically driven by another object, for example by a motor, is conventionally called "freely mobile".

"With one (or two)" or "comprising one (or two)" means "having at least one (or at least two, respectively)", unless otherwise indicated. An object "disposed in" a window has at least a part, or all of it contained in said window.

"Defining one" means "defining at least one", unless otherwise indicated. Detailed Description The examples illustrated by the drawing are preferred embodiments and are provided for illustrative purposes only. The invention is therefore not limited to these embodiments. FIGS. 1 to 3 show an X-axis vibration absorption device 10 according to one embodiment. The vibration absorption device comprises a support 12 on which are mounted six identical pendulum oscillators, equiangularly distributed. Only an oscillator 14 is thus described. Oscillator 14 consists of a counterweight 16 and two rolling bodies 18a and 18b.

A damping block 20 is mounted on the weight. The weight, the support and the rolling bodies may be metal alloy, preferably aluminum alloy or steel, in particular treated steel, for example 16 MnCr5. The damping block may be of elastomeric material, preferably rubber.

Support The support 12 is in the form of a disk, preferably of substantially constant thickness, preferably less than 12 mm, or even less than 8 mm, and / or greater than 2 mm, or even greater than 3 mm. The support may have a central recess 22, of axis X, in which a transmission shaft can be engaged along the axis X. Preferably, the support is defined in a substantially flat sheet. The support defines a window 24 closed, and through in the thickness of the support, the weight passing right through the support through said window. The support further comprises two support cutouts 26, passing through the support in its thickness, in which the rolling bodies are arranged.

Each support cut, whose contour, observed along the X axis, is closed, defines a bearing race 28a / 28b, on which a rolling body can move.

The support also comprises a depression 30 located at the periphery of the support which defines a radially outer bearing surface 32 on which the damping block 20 can come to support. Preferably, the window 24 and / or the depression 30 is (are) formed in the support between the support cuts 26. As illustrated in FIG. 1, the vacuum is preferably situated radially substantially outside. of the window 24. Thus, the material bridge 34 formed between the depression and the window contributes to the rigidity of the support and limits the deflection of the support in an axial plane during operation of the device. This arrangement of the depression and the window improves the absorption quality of the device. The support may further comprise bores for fixing the support on an auxiliary device, for example on a support web of a double damping flywheel. Alternatively, the support may also constitute the support web of said double damping flywheel.

Flyweight The flyweight consists of cheeks 36a and 36b extending axially on either side of the support 12 and three fasteners 40a, 40b and 40c, identical, rigidly binding the cheeks together. The cheeks have bores allowing the passage of fasteners. The fasteners are engaged in said bores and are riveted to the cheeks, preventing relative movement of one cheek relative to the other. Each fastener has a central portion, or spacer 41, located between the two cheeks, whose shape is not revolution. As illustrated in Figure 3, observed along the X axis, the spacer has a generally elongate shape, the dimension in a orthoradial direction being greater than a radial dimension. The spacer further has surfaces oriented radially inward 42a and outwardly 42b substantially flat and substantially parallel to the axis X, on which is made contact with the damper block. The spacer comprises a plurality of protuberances 43a to 43d, improving the connection between the damping block and the complementary form of fastening member.

In the embodiment illustrated in FIG. 2, the two fasteners 40b and 40c are located outside the window 24 in the radially outer depression, the third fastener 40a being located inside the window 24. In a variant not shown, two fasteners may be disposed within the window. Preferably then, only a fastener is located in the radially outer depression. As illustrated in Figures 1 to 3, and preferably, at least one fastener is located radially inwardly relative to another. Preferably, the fastener located outside the window is disposed radially outside the fastener disposed in the window. More preferably, the three fasteners are arranged to form the three vertices of a triangle, preferably isosceles, even equilateral, when observed along the axis X. As illustrated more particularly in FIG. fastening 40a disposed in the window can not come into contact with the window 24 of the support. Preferably, the shortest distance between the edge 42 of the window 24 and the fastener 40a disposed in the window is greater than 0.5 mm, or even greater than 1 mm. Preferably, the thickness of the spacer Ee is greater than the thickness of the support Es, preferably greater than 1.1 × Es, preferably greater than 1.2 × Es. The cheeks each comprise two cheek recesses 44a and 44b into which the rolling bodies 18a and 18b respectively penetrate. A cheek recess 44a or 44b can thus define a feeder roll track 46a or 46b, respectively. The cheeks are substantially annular, flat and each extend in a substantially axial plane. In an embodiment not shown, the cheeks may have a curved surface. In an embodiment not shown, the cheeks have cheek recesses not passing through the weight in the thickness, and superimposed on the lateral faces of the rolling bodies, so as to protect the rolling bodies housed between the two cheeks. . Preferably, a feeder is shaped so as not to come into contact with an adjacent feeder. Preferably, in a position of maximum approximation between two adjacent flyweights, the spacing between said adjacent flyweights is greater than the thickness of the support Es. Preferably, the weight is disposed, preferably entirely, within the virtual cylinder defined by the support during its rotation about the axis X.

Bearing Body In the oscillating movement of the flyweight, the rolling bodies can slide and / or preferably roll along the feeder bearing tracks and the bearing raceway.

Preferably, as illustrated in FIG. 3, a rolling body has a shape of revolution, and preferentially the shape of a barrel or a cylinder, and may comprise a central annular extra thickness 48 intended to roll on the track of support bearing. The central annular thickening is preferably shaped to not be able to penetrate the cheek recesses in which the ends of the rolling body penetrate. It can thus abut with the lateral faces of the opposite cheeks, and thus limit the axial displacement of the rolling body. Preferably, the difference between the distance separating the two cheeks and the thickness of the annular extra thickness is less than 5 mm, or even less than 3 mm, or even less than 1 mm.

Damper Block As shown in Figures 1 to 3, the damper block 20 is disposed between the two cheeks, and can be sandwiched between them. The damper block has an opening through the damper block according to its thickness. Preferably, as illustrated in Figure 1, it has two openings 50a and 50b through. A fastener is disposed in each of these openings and passes through the damper block from one side. Preferably, each fastener is mounted in force in the damper block, to form a rigid assembly. Preferably, for this purpose, each opening 50a and 50b has a shape substantially complementary to the shape of the spacer 41. In this way, no rotation of the damper block is possible relative to the fastener. The damping block has a generally elongated shape, and has a radially inwardly oriented peripheral surface 52 which is substantially complementary to the surface 32 of the depression 30 on which it bears, as shown in FIG. 3. Preferably, the radially inwardly oriented peripheral surface 52 is substantially planar. Preferably, the length of this surface is greater than the distance between the two fasteners located outside the window, preferably greater than 3 cm. Thus, the damping block can define a contact zone with the outwardly facing surface of the depression 30 whose area is optimal, thus effectively damping shocks in a substantially radial direction between the weight and the support. The operating silence of the device is therefore improved.

Furthermore, this optimal area of contact area reduces the wear of the damper block; indeed, for a given friction force, the frictional stress, defined by said friction force divided by the surface on which the contact is made, is reduced. The damping block also has rounded lateral surfaces 54, shaped to be substantially complementary to the lateral surfaces 55 of the depression. Thus, when the oscillator enters the orthoradial stop position, the damping block can effectively dissipate the energy of the shock between the oscillator and the support. The two rounded sides of the damper block working mainly in compression in the area of contact with the support, frictional wear is limited.

Operation Preferably, after mounting the vibration absorbing device on a transmission of a vehicle, the X axis is substantially orthogonal to the direction of Earth's gravity. In the absence of rotation of the support 12, as shown in Figure 3, if the oscillator 14 is located in the upper part of the device, the damper block rests on the support. Thus, during the transient phases, for example during the stopping of the motor, the oscillator can pass from an outer radial abutment position to an inner radial abutment position, in which the damping block 20 rests on the support, the transition between the two said stop positions being performed silently. If the weight 16 is in the lower part of the device, it does not rest directly on the support but on the rolling bodies 18a and 18b. During a rotation of the support around the X axis, the weight and the rolling bodies undergo the effect of the centrifugal acceleration. The device is configured so that the damping block is detached from the radially outer bearing surface located in the peripheral depression. The rolling bodies then come into contact with the bearing tracks of support and flyweight. The rolling bodies then work mainly in bending.

During rotation of the support, the weight 16 is rotated about the axis X of rotation. Under the effect of rotational speed variations of the support, the flyweight can oscillate relative to the support in an axial plane. The rolling bodies then guide the movements of the weight relative to the support, by moving in an axial plane, by sliding and / or preferably by rolling, along the support bearing tracks 28a and 28b, and bearing tracks. weight bearing 46a and 46b. The radial movement of the weight relative to the rolling bodies and the support advantageously avoids a blockage of the weight in its oscillation movement. The fastener disposed in the window then moves between two extreme positions in the window, and never comes into contact with the edge 42 of the window 24. In particular, the spacer 41 of the fastener 40a and the window 24 are shaped so that the spacer is moved away from the edge 42 of the window in all the positions of the feeder, for example in the position of radial outer abutment or orthoradial abutment of the weight. Furthermore, this fastener ensures the maintenance of high rigidity, thus avoiding the bending, with respect to an axial plane, of the cheeks under the effect of the centrifugal acceleration. The oscillation movement of the flyweight is limited by the contact of the side surfaces 55 of the depression with the side surfaces 54 of the damping block in the oscillation orthoradial stop positions of the oscillator, as shown in FIG. the damper block strikes the side walls, the elastic properties of the material constituting the damping block promote silent damping of the weight against the support. The invention is not limited to the embodiment described and shown. In particular, in one embodiment, the support comprises several windows in which fasteners are arranged, so as to further stiffen the connection between the cheeks of the weight. All possible combinations and characteristics relating to the different aspects of the invention are envisaged.

Claims (1)

REVENDICATIONS1. Vibration absorbing device (10) for a motor vehicle transmission, said device having an axis X of rotation and comprising a support (12) and an oscillator (14) oscillating on the support, said oscillator comprising a body of bearing (18a; 18b), a flyweight (16), and a damping block (20) limiting the displacement of the flyweight relative to the support, the support and the flyweight defining "support rolling track" (28a; 28b; ) and "flywheel bearing track" (46a; 46b) respectively, so that rolling of the rolling body on said runways moves the weight relative to the support, the weight having two cheeks (36a; 36b) and a fastening member (40) rigidly connecting said cheeks, the damper block being immobilized in rotation about an axis parallel to the X axis by form complementarity with the fastener. Device according to the preceding claim, the contour of the portion of the fastener on which is mounted the damping block, observed along the X axis having at least one axis of symmetry. Device according to the preceding claim, said contour being partly concave. Device according to any one of the preceding claims, the contour of the portion of the fastening member on which is mounted the damping block, observed along the axis X, being of generally elongate shape. Device according to any one of the preceding claims, the contour of the portion of the fastening member on which is mounted the damping block, observed along the X axis, having a larger dimension in a orthoradial direction than in a radial direction . Device according to any one of the preceding claims, the contour of the part of the fastening member on which the damping block, viewed along the X axis, is mounted having a plurality of protuberances (43a, 43b, 43c, 43d). . Apparatus according to any one of the preceding claims, wherein the contact area between the damping block and the fastening member is substantially parallel to the X axis. 152. 3. 4. 5. 5. 6. 6. 308. Device according to any one of the preceding claims, the damper block having an opening (50a; 50b) passing through the damper block in the thickness of said damper block, the fixing member being disposed in said opening and projecting axially from both sides of said opening. 9. Device according to any preceding claim, the damper block being in contact with the support in at least one position of the feeder. 10. Device according to any one of the preceding claims, the axial displacement of the damper block being limited by said cheeks and / or by a fastener. 11. Device according to any one of the preceding claims, the fixing member defining a spacer (41) extending between the two cheeks, the thickness of the spacer being greater than or equal to the thickness of the support. 12. Device according to any one of the preceding claims, the feeder being disposed, preferably entirely, inside the virtual cylinder defined by the support during its rotation about the X axis. 13. Transmission of a vehicle automobile selected from a friction clutch and a hydrokinetic converter, said transmission comprising a vibration absorbing device according to one of the preceding claims. 14. Motor vehicle equipped with a device according to the preceding claim. 20