Device for damping torsional oscillations

Abstract

A device for damping torsional oscillations, including: a pendulum-type torsional oscillation damper, a supplementary torsional oscillation damper including an input element, an output element, wherein both are configured to rotate around one axis rotation, and at least one mechanical energy accumulator device disposed between the input and output elements, a torque limiter, including at least one friction coating fixed on a disk, configured to be displaced around the axis. The disk is connected to rotate with the input element of the supplementary torsional oscillation damper and the friction coating is fixed to the disk of the torque limiter by an adhesively bonded surface-to-surface joint.

Claims

1. A device for damping torsional oscillations in torque transmission, comprising: a pendulum-type torsional oscillation damper; a supplementary torsional oscillation damper, including an input element, an output element, wherein both are configured to rotate around one axis of rotation, and at least one mechanical energy accumulator device disposed between the input and output elements, wherein the pendulum-type damper is disposed downstream from the supplementary damper in a direction of the torque transmission, and the supplementary damper is disposed between a torque limiter and the pendulum type damper in the direction of the torque transmission; and the torque limiter, including at least one friction coating fixed on a disk, configured to be displaced around the axis, wherein the disk is connected to rotate with the input element of the supplementary torsional oscillation damper, wherein the at least one friction coating is fixed to the disk of the torque limiter by a surface-to-surface joint.

2. A device according to claim 1, wherein the surface-to-surface joint extends in a plane.

3. A device according to claim 1, wherein the coating is overmolded onto the disk of the limiter to form an adhesively bonded surface-to-surface joint.

4. A device according to claim 1, wherein the coating is glued onto the disk of the limiter to form an adhesively bonded surface-to-surface joint.

5. A device according to claim 1, wherein the coating is welded onto the disk of the limiter to form an adhesively bonded surface-to-surface joint.

6. A device according to claim 1, wherein axial thickness of the coating is less than 1 mm.

7. A device according to claim 1, wherein axial thickness of the assembly formed by the coating or coatings and the disk of the limiter is less than 3 mm.

8. A device according to claim 1, further comprising an output hub, configured to rotate around the axis and integral with each of the torsional oscillation dampers.

9. A device according to claim 1, wherein the supplementary damper includes an auxiliary annular skirt and two guide washers mounted on both sides of the auxiliary skirt, wherein the input element of the supplementary damper is formed by the guide washers and the output element is formed by the auxiliary skirt.

10. A device according to claim 1, wherein the pendulum-type damper includes a pendulum support configured to rotate around the axis and with at least one pendulum mass, configured to be displaced freely and to be guided by the pendulum support.

11. A device according to claim 10, wherein, when the device is viewed along the axis, the pendulum mass describes a zone of movement that is superposed at least partly on the zone of movement described by the coating.

12. A device according to claim 11, wherein, when measured along an axis parallel to the axis and passing through the pendulum mass and the coating, axial thickness of the pendulum-type damper and axial thickness of the assembly formed by the coatings and the disk of the limiter satisfy a ratio of between 3 and 8.

13. A motor vehicle transmission train comprising a device for damping torsional oscillations in torque transmission through the transmission train, the device for damping torsional oscillations comprising: a pendulum-type torsional oscillation damper; a supplementary torsional oscillation damper, including an input element, an output element, wherein both are configured to rotate around one axis of rotation, and at least one mechanical energy accumulator device disposed between the input and output elements, wherein the pendulum-type damper is disposed downstream from the supplementary damper in a direction of the torque transmission, and the supplementary damper is disposed between a torque limiter and the pendulum type damper in the direction of the torque transmission; and the torque limiter, including at least one friction coating fixed on a disk, configured to be displaced around the axis, wherein the disk is connected to rotate with the input element of the supplementary torsional oscillation damper, wherein the at least one friction coating is fixed to the disk of the torque limiter by a surface-to-surface joint.

14. The device according to claim 13, further comprising an output hub configured to rotate around the axis of rotation and integral with each of the torsional oscillation dampers, wherein the pendulum-type damper includes a pendulum support configured to rotate around the axis of rotation and with at least one pendulum mass, configured to be displaced freely and to be guided by the pendulum support, whereby the pendulum-type damper is centered on and integral with the output hub.

15. The device according to claim 13, further comprising an engine flywheel of a torque input element connected to rotate with two drive disks which are concentric with the axis of rotation and belong to the torque limiter, wherein in the event that excessive torque is applied to the torque limiter, the at least one friction coating is able to slide relative to the drive disks, and wherein an elastic device is interposed between one of the two drive disks and a drive plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood, and other details, characteristics and advantages of the invention will become apparent by reading the description hereinafter, given by way of non-limitative example with reference to the attached drawings, wherein:

(2) FIG. 1 is a schematic and partly sectional view of an example of the device according to the invention for damping torsional oscillations.

(3) FIG. 2 represents zones of movement of a friction coating and of a pendulum mass.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(4) FIG. 1 represents a device 1 for damping torsional oscillations for a motor vehicle transmission train, equipped with: a pendulum-type torsional oscillation damper 2, a supplementary torsional oscillation damper 3, comprising an input element, an output element, wherein both are capable of rotating around one axis of rotation X, and a plurality of mechanical energy accumulator devices disposed between the input and output elements, and a torque limiter 4, comprising at least one friction coating 5 fixed on a disk 6 connected to rotate with the input element of supplementary torsional oscillation damper 3,

(5) In the example under consideration, the mechanical energy accumulator devices are curved springs 9, which act to oppose pivoting of the input element relative to the output element.

(6) In the example under consideration, supplementary damper 3 comprises an auxiliary annular skirt 10 forming the output element of supplementary damper 3 and two guide washers 11 forming the input element of this damper. These two guide washers 11 are mounted on both sides of auxiliary skirt 10 and windows 12 are made in auxiliary skirt 10, and in guide washers 11 to receive springs 9. In addition, guide washers 11 maintain these springs 9 axially such that they cannot escape.

(7) In the example under consideration, limiter 4 is positioned radially outside supplementary damper 3, and disk 6 of the limiter, which is flat, is fixed to one of the guide washers 11 by a plurality of fixation devices, for example rivets.

(8) Two coatings 5 in the form of annular disks with axis X are disposed on both sides of disk 6 of the limiter (one coating on each side) and are fixed on this disk by an adhesively bonded surface-to-surface joint.

(9) It will be noted in the example under consideration that coatings 5 in the form of disk portions may be disposed on both sides of disk 6 of the limiter, replacing the coatings in the form of annular disks.

(10) These coatings 5 may be provided with a continuously wound wire impregnated with a bonding matrix and/or with fibers added to a bonding matrix.

(11) In the example under consideration, the adhesively bonded surface-to-surface joint extends along a plane perpendicular to axis X, wherein coatings 5 and disk 6 of the limiter have facing planar surfaces that are perpendicular to axis X.

(12) This adhesively bonded surface-to-surface joint is established between the total surface of one face of the coating and disk 6 of the limiter. In the example under consideration, the adhesively bonded surface-to-surface joint may also be established only between one part of the face of coating 5 and disk 6 of the limiter.

(13) In the example under consideration, coatings 5 are overmolded onto disk 6 of the limiter to form the adhesively bonded surface-to-surface joint. It will be noted that coatings 5 may also be welded or glued.

(14) In the example under consideration, coatings 5 each have an axial thickness of less than 1 mm, preferably of less than 0.5 mm, and the axial thickness of the assembly formed by coatings 5 and disk 6 of the limiter is less than 3 mm, preferably less than 2 mm, more preferably less than 1.5 mm.

(15) Limiter 4 comprises two drive disks 15, which are concentric with axis X and integral with one another, and one drive plate 16, which is capable of rotating around axis X and of being displaced axially, and which is disposed between the two drive disks 15 and is connected to rotate with these two disks.

(16) Coatings 5 are interposed between drive plate 16 and one of the drive disks 15, in such a way that they are continuously braced on one face of drive disk 15 and on one face of drive plate 16.

(17) In the event that excessive torque is applied to limiter 4, coatings 5 are designed to be able to slide in rotation relative to drive disk 15 and to drive plate 16 on which they are braced.

(18) In the example under consideration, an elastic device, in this case a Belleville washer 18, is interposed between the other of the two drive disks 15 and drive plate 16, and so Belleville washer 18 is braced on the face of drive plate 16 opposite the face of this plate on which coating 5 is braced. This Belleville washer 18 makes it possible to maintain drive plate 16 braced against coatings 15, despite wear of these coatings 5. Belleville washer 18 is prestressed in such a way that it continuously exerts a calibrated pressing force on drive plate 16, thus permitting pinching of coatings 5 between this drive plate 16 and drive disk 15.

(19) In the example under consideration, the assembly formed by coatings 5 and disk 6 of the limiter on which they are overmolded is designed to be able to slide in rotation relative to drive disks 15 and to drive plate 16 in the event that excessive torque is applied to limiter 4.

(20) The two drive disks 15 therefore bracket coatings 5 and disk 6 of the limiter and, with increasing distance from axis of rotation X, these two drive disks 15 approach one another, to the point of coming into contact. In the region of this contact zone, it is possible to make the two drive disks 15 integral with one another by means of a plurality of rivets 20.

(21) The two drive disks 15 are therefore made integral radially outside coatings 5 and, in the same radial region, these two disks are connected to rotate with a torque-input element of device 1. In the example under consideration, the torque-input element is an engine flywheel 21 formed in several distinct parts.

(22) In the example under consideration, engine flywheel 21 is designed to be fixed on a driving shaft, such as a crankshaft of an internal combustion engine.

(23) In the example under consideration, the torque is transmitted from engine flywheel 21 to limiter 4 then to supplementary damper 3, the auxiliary skirt 10 of which forming the output element is integral with a force-fitted output hub 23 of the device.

(24) This output hub 23, which is able to rotate around axis X, is capable of transmitting a torque, for example to a driven shaft, not represented here.

(25) In the example under consideration, supplementary damper 3 is centered on output hub 23 via auxiliary skirt 10.

(26) Furthermore, pendulum-type damper 2 may be equipped with a pendulum support 25 capable of rotating around axis of rotation X and with a plurality of pendulum masses 26. Via pendulum support 25, this pendulum-type damper 2 is centered on and integral with output hub 23.

(27) Pendulum support 25, which does not extend radially beyond coatings 5, is integral with and centered on output hub 23 by force-fit. Pendulum support 25 is formed in one piece and is rigid. Pendulum support 25 does not have any part having noteworthy elasticity.

(28) Pendulum masses 26, mounted peripherally on pendulum support 25, are capable of being displaced freely relative to this support while being guided thereby.

(29) Pendulum masses 26 are caused to execute a pendulum-type movement during operation, and they have two parts 27 mounted axially on both sides of pendulum support 25 and connected to one another by two crosspieces, each passing through an opening of pendulum support 25. A roller 29 cooperates with two rolling tracks, each made in an opening 30 of one part 27 of pendulum mass 26, and with a third rolling track formed by the rim of an opening 31 of pendulum support 25 different from the openings of the pendulum support dedicated to the crosspieces.

(30) In reacting to torsional oscillations or acyclical rotational irregularities, each pendulum mass 26 is able to be displaced in such a way that its center of gravity oscillates in the manner of a pendulum.

(31) In the example under consideration, axial thickness 36 of pendulum-type damper 2 in the region of pendulum masses 26 ranges between 9 and 15 mm.

(32) In the example under consideration, pendulum-type damper 2 is offset axially from supplementary damper 3 and from limiter 4. Furthermore, this pendulum-type damper 2 is outside the path taken by the torque. In fact, the torque would always be transmitted by device 1 if pendulum-type damper 2 were not present.

(33) In the example under consideration, supplementary damper 3 is disposed, in the sense of torque transmission, between limiter 4 and the pendulum-type damper 2.

(34) In the example under consideration, pendulum masses 26 and coatings 5 are offset axially, and they overlap at least partly when device 1 is viewed along axis X.

(35) This overlap can be seen in FIG. 2, which represents zones of movement of coatings 5 and of pendulum masses 26 respectively.

(36) The zones of movement of pendulum masses 26 or of coatings 5 are all of the positions occupied by these pendulum masses and these coatings.

(37) The pendulum masses 26 all describe the same movement zone 32, which movement zone is superposed axially and partly on movement zone 33 described by coatings 5. In certain configurations of device 1, at least one axis exists that is parallel to axis X and passes through both a coating 5 and a pendulum mass 26.

(38) In the example under consideration, and with reference to FIG. 1, when measured along an axis parallel to axis X and passing through both a pendulum mass 26 and a coating 5, axial thickness 36 of pendulum-type damper 2 on the one hand and axial thickness 35 of the assembly formed by coatings 5 and disk 6 of the limiter on the other hand satisfy a ratio of between 3 and 8, preferably of between 5 and 7.5.

(39) The invention is not limited to the examples that have just been described.