WO2021038005A1

WO2021038005A1 - Torque transmission device

Info

Publication number: WO2021038005A1
Application number: PCT/EP2020/074015
Authority: WO
Inventors: Baptiste DELIGNIERES
Original assignee: Valeo Embrayages
Priority date: 2019-08-30
Filing date: 2020-08-27
Publication date: 2021-03-04
Also published as: JP2022545824A; FR3100297B1; FR3100297A1; CN218094058U; DE112020004101T5; JP7412539B2

Abstract

The invention relates to a torque transmission device (1) for a motor vehicle, comprising a torque input element (2, 3, 4), a torque output element (6, 7, 8), resilient members (91, 92) mounted between the torque input and output elements, and a phasing member (10, 11, 12), the resilient members being arranged in series by means of the phasing member, the torque input element, the torque output element and/or the phasing member each comprising at least one abutment means (30, 26, 27, 37) intended for limiting the compression of the resilient members, each of the abutment means of the torque input element, of the torque output element and of the phasing member being configured so that, in case of an overtorque, the torque transits through the device from the drive shaft to the driven shaft radially below the resilient members.

Description

Title of the invention: Torque transmission device

Technical area

The invention relates to the field of torque transmission devices for a motor vehicle, such as for example a double damping flywheel (DVA).

Technological background

[0002] Such a device generally comprises a torque input element, a torque output element, and elastic members mounted between the torque input and output elements and acting against the rotation. of one of said elements with respect to the other.

When the torque transmission device is of the LTD (Long T ravel Damper) type, it comprises several groups of elastic members, in which the elastic members of the same group are arranged in series by means of a phasing member so that the elastic members of each group deform in phase with each other.

It is known from patent application FR2995953 a torque transmission device comprising a LTD type shock absorber. In this type of shock absorber, the elastic members are distributed in pairs of elastic members. A first elastic member of a given pair of elastic members is arranged between the torque input element and the phasing member, then a second elastic member of this same pair of elastic members is arranged between the member. phasing and the torque output element. The torque transmission device is configured in such a way that the torque passes from the torque input element to the torque output element, passing through the first elastic member, then the phasing member. then the second elastic member.

[0005] The torque input element, the torque output element and the phasing member each have arms extending radially and supporting ends of the resilient members. Each of the elastic members is housed between two successive arms circumferentially.

To improve the filtration performance, it is planned to reduce as much as possible the section of these same arms in order to be able to increase the size of the elastic members housed between two arms.

[0007] In the event of overtorque, that is to say when the engine torque reaches between 6000 and 10,000 Nm, the torque short-circuits the elastic members, that is to say that it passes directly from the torque input element to the phasing member then from the phasing member to the torque output element while passing directly through the various arms with reduced section.

[0008] However, due to the small size of these arms, breaking points linked to this overtorque are possible.

[0009] Thus, to avoid these breaks, the arms are made with sufficiently large sections to avoid any breakage, in particular in the event of overtorque. However, the larger the size of the arms, the more the size of the springs must be reduced, which further reduces the performance of torque transmission devices, especially in terms of vibration damping.

summary

One aspect of the invention starts from the idea of solving the drawbacks of the prior art by proposing a torque transmission device preserving the reduced section areas so as to allow the insertion of elastic members of larger sizes. possible dimensions.

[0011] In particular, the invention provides for allowing the passage of the torque in the event of overtorque radially below the elastic members. Thus, in the event of overtorque, the torque no longer passes through areas of weakness of the transmission device but through areas which are not capable of supporting the elastic members. To do this, the invention provides for the production of stop means configured to allow the torque to pass radially below the elastic members in the event of overtorque.

[0012] According to one embodiment, the invention provides a torque transmission device for a motor vehicle, comprising

Torque transmission device for a motor vehicle, comprising a torque input element connected to a drive shaft, a torque output element connected to a driven shaft, at least two elastic members mounted between the elements of torque input and torque output and acting against the rotation of one of said torque input and torque output elements, and a phasing member, the elastic members being arranged in series by the intermediate of the phasing member so that the elastic members deform in phase with each other, the torque input element, the torque output element and / or the phasing member each comprising at least one stop means designed to limit the compression of the elastic members, each of the stop means of the element torque input, the torque output element and the phasing member being configured in such a way that, in the event of overtorque, the torque passes through the device from the motor shaft to the shaft driven radially below the elastic members.

In one embodiment, the stop means of the phasing member comprises an upstream stop element and a downstream stop element, the upstream stop element being able to cooperate with the input element of torque and the downstream stop element being able to cooperate with the torque output element.

[0015] In one embodiment, the phasing member comprises an insert forming the stop means of said phasing member.

[0016] In one embodiment, the insert is a symmetrical part. Thus, the first stop member and the second stop member are symmetrical.

[0017] In one embodiment, the insert is formed of a central piece which extends circumferentially radially inwardly in two opposite directions so as to form an upstream stop means and a downstream stop means.

[0018] In one embodiment, the insert is made of sintered material.

[0019] In one embodiment, the density of material at the level of the stop means is greater than that present in the rest of the insert.

[0020] Indeed, the composition of the insert may be different at a location capable of transmitting torque relative to another location which does not receive torque, as is the case with the rest of the insert.

In one embodiment, a first elastic member is mounted between the torque input element and the phasing member and a second elastic member is mounted between the phasing member and the output member of torque, the insert also forms a support part of one of the ends of the first elastic member and of one of the ends of the second elastic member.

Advantageously, a reduced part of the phasing member can be easily modified without having to modify the phasing member as a whole.

[0023] In fact, the insert also forms an element which can be easily manufactured so as to take into account the different roles that it will have to occupy. The insert serves as a stop but can also serve as a means of maintaining the elastic members. Thus, the composition of the insert may differ at a first location intended to form the stop relative to another location intended to hold the associated elastic member.

In one embodiment, the phasing member is formed of two washers connected in rotation with one another, the torque output element being mounted between the two washers and forms at least one suitable protuberance to cooperate with the stop means of the phasing member.

In a preferred example, the two washers are identical.

In one embodiment, each of the washers forms from an outer radial periphery of the first radial arms, the torque output member forming a disc with second radial arms extending to an outer radial periphery of said disc, the second elastic member being mounted between a first arm and a second arm, the protuberance being formed on the outer radial periphery of the disc.

In one embodiment, the torque input element forms at least one plate with at least one window adapted to receive an elastic member, the window having an internal peripheral edge located radially between the elastic member and the axis X and a lateral bearing surface capable of supporting one end of the elastic member, the inner peripheral edge having a protuberance capable of bearing against the stop means of the phasing member.

[0028] In one embodiment, the torque input element is formed by two plates connected in rotation and arranged on either side of the phasing member.

In one embodiment, the elastic members are helical springs

In one embodiment, the phasing member is formed of two washers connected in rotation, the first stop element and the second stop element each forming a bar extending axially beyond the two washers of the control member. phasing so that at least one of two bars can come into contact with the stop means of the torque input element in the event of overtorque.

According to one embodiment of the invention, each of the washers has a circular planar surface with an outer radial periphery, from which extend first radial arms, a cavity being formed from the outer radial periphery and near the first arm, the cavity being configured to receive the bar such that an upper surface of the bar is aligned with the outer radial periphery of the corresponding washer or slightly above the outer radial periphery of the bar. corresponding washer. According to one embodiment of the invention, the elastic members are helical springs.

Brief description of the figures

The invention will be better understood, and other aims, details, characteristics and advantages thereof will emerge more clearly during the following description of several particular embodiments of the invention, given solely by way of illustration. and not limiting, with reference to the accompanying drawings.

[0032] [Fig.1] Figure 1 is an exploded perspective representation of a torque transmission device, according to one embodiment of the invention,

[0033] [fig. 2] FIG. 2 is a front view of the torque transmission device according to FIG. 1.

[0034] [Fig.3] Figure 3 is a perspective representation of an insert of the torque transmission device according to Figure 1, and

Description of the embodiments

Unless otherwise indicated, "axially" means "parallel to an axis of rotation X of the device"; “Radially” means “along a transverse axis intersecting the axis of rotation of the device”; “Angularly” or “circumferentially” means “around the axis of rotation of the device”.

[0036] Figure 1 illustrates an overview in perspective of a torque transmission device 1 according to one embodiment of the invention. More precisely, such a torque transmission device 1 forms a double damping flywheel or DVA. Such a torque transmission device 1 comprises a torque input element 2 adapted to be connected to a crankshaft (not shown). This torque input element 2 forms a primary flywheel comprising two plates 3 and 4 connected in rotation with one another by means of connection means (not shown) such as rivets. A first plate 3 close to the engine side is connected to a starter ring 5. A second plate 4 is placed opposite the first plate 3.

[0037] The torque transmission device 1 also comprises a torque output element 6 formed by a disc 7 (or web) and a secondary flywheel 8 connected in rotation with one another. This torque output element is able to be connected to a gearbox input shaft (not shown).

Elastic members such as 91, 92 are positioned between the torque input element 2 and the torque output element 6. These elastic members 91, 92 are here all identical but could be different from each other in another example. They form here coil springs.

The transmission device 1 also comprises a phasing member 10 comprising two washers 11 and 12. In this non-limiting example, these two washers 11 and 12 are identical and are connected in rotation with respect to each other by connection means such as rivets 13 for example. The phasing member 10 is mounted floating. In particular, it is arranged so as to be inserted between two elastic members 91, 92 while being capable of moving in rotation relative to the torque input element 2 and relative to the torque output element 6.

Each of the elastic members 91, 92 is intended to be in contact with the phasing member 10. In particular, each of the washers 11 and 12 comprises at least one arm 14 forming an elongation of material extending radially in the opposite direction to the axis of rotation X. In the example in FIG. 1, each of the washers 11 and 12 comprises three arms such as 14 angularly evenly distributed. The washers 11 and 12 are arranged so that their respective arms are superimposed on each other.

The elastic members 91, 92 are organized in pairs of upstream and downstream elastic members. In particular, an upstream elastic member 91 and a downstream elastic member 92 are arranged on either side of each of the arms 14 of the phasing member 10. By upstream elastic member is meant elastic member capable of being placed in contact with the phasing member. torque input element. By downstream elastic member is meant elastic member capable of being placed in contact with the torque output element.

Each of the upstream elastic members 91 has a first end 15 and a second end 17. The first end 15 is intended to be in contact with the arm 14 of the phasing washer 10. The second end 17 is intended to be in contact torque input element 2.

Each of the downstream elastic members 92 has a third end 16 and a fourth end 18. The third end 16 is intended to be in contact with the arm 14 of each of the washer 11 and 12 of the phasing member 10. The fourth end 18 is intended to be in contact with the torque output element 6, in particular here via the disc 7.

The phasing member 10 comprises an insert 19 disposed on at least one arm 14 of one of the washers 11, 12. According to this embodiment, the insert 19 is formed in one piece but could be formed from several pieces or be integral with the arm 14. The insert 19 is, in this embodiment, disposed axially between two washers 11 and 12. More precisely, the insert 19 is positioned fixed in rotation between two arms 14. The insert 19 forms a central part 23 delimiting an upstream lateral bearing surface 20 and a downstream lateral bearing surface 21 adapted to receive respectively the first end 15 of the upstream elastic member 91 and the third end 16 of the downstream elastic member 92. Each of these lateral bearing surfaces 20 and 21 has a guide stud such as 22 around which the end of the corresponding elastic member is inserted. These lateral bearing surfaces 20 and 21 each extend in a plane which is inclined relative to a plane intersecting perpendicularly the axis of rotation X and perpendicularly the plane in which the arm 14 extends. These bearing surfaces sides 20 and 21 extend while covering cross sections formed by the two washers 11 and 12.

The central part 23 extends circumferentially radially outwardly in two opposite directions so as to form a first extension 24 and a second extension 25. The first extension 24 and the second extension 25 extend radially beyond. above the arms 14. The first extension 24 serves to hold the first end 15 of the upstream elastic member 91 and the second extension 25 serves to hold the third end 16 of the downstream elastic member 92. In this example, the first extension 24 and the second extension 25 extend beyond the outer radial periphery of each of the washers 11 and 12.

The central part 23 also extends circumferentially radially inwardly in two opposite directions so as to form an upstream stop means 26 and a downstream stop means 27. The upstream stop means 26 and the stop means downstream 27 also extend so as to cover other cross sections of the two washers 11 and 12. The upstream stop means 26 is designed so as to be able to come into contact with the torque input element 2 in case of overtorque. Thus, more precisely the upstream stop means 26 extends axially at least beyond the cross section of the washer which is intended to be as close as possible to the torque input element. In this example, as the torque input element is formed by a first plate 3 and a second plate 4, it suffices for the upstream stop means 26 to extend beyond the cross section of the first plate 3 or of the corresponding second plate 4.

In the preferred example, the insert 19 is a symmetrical piece which means that the upstream stop means 26 and the downstream stop means 27 extend in the same way with respect to a central axis of symmetry Y FIG. 3. By cross section is meant a section made along a plane intersecting a part along a plane perpendicular to the plane in which the part extends.

In the example of the invention, the upstream stop means 26 and the downstream stop means 27 extend axially while covering the two washers 11 and 12. In this example, the two washers 11 and 12 have a localized recess

36 to receive the upstream stop means 26. The recess 36 is made radially inwardly so that the upstream stop means 26 is flush with the outer periphery 38 of the washers. Thus, the implantation diameter of the elastic members is not impacted and can be optimized so as to reduce the size of such a device.

Each of the plates 3 and 4 form windows 28 each housing an upstream elastic member 91 and a downstream elastic member 92. In this example, each of the plates forms three windows such as 28 regularly angularly distributed.

Each of the windows 28 forms a radially inner edge 29 delimiting a fourth stop means 30 against which the upstream stop means 26 is adapted to come into contact. This fourth stop means 30 forms a shoulder. Each of the windows 28 also delimits an upstream side bearing surface 31 and a downstream side bearing surface 32. The upstream side surface 31 serves as a support for the upstream elastic member 91.

The shoulder 30 and the upstream stop means 26 of the phasing member 10 are separated by a distance d (not shown) measured circumferentially between the shoulder 30 and the upstream stop means 26 which is between a distance d1 (not shown) corresponding to a state of rest of the upstream elastic member 91 and a distance d2 (not shown) corresponding to a state of overtorque or maximum admissible torque before the device stops. According to the invention, in such a state of overtorque or a state of maximum admissible torque, the resilient member mounted 91 has turns which are not contiguous.

The web 7 has a structure similar to that of the washers 11 and 12. Indeed, the web has three radial extensions 33 angularly evenly distributed, each having an upstream side bearing surface 34 and a downstream side bearing surface 35. The downstream side bearing surface 35 serves as a support for the downstream elastic member 92.

The web 7 forms a flat disc with an outer radial periphery 36 extending in a first circle of center X and from which extends the three radial extensions 33. At least one protuberance such as 37 is formed at starting from the outer radial periphery 36, in particular near the place where one of the radial extensions 33 is formed. According to the example illustrated, three protuberances such as 37 are formed, each near a corresponding radial extension 33.

The protuberance 37 and the downstream stop means 27 of the phasing member 10 are separated from each other by a distance D measured circumferentially between the protuberance

37 and the downstream stop 27 between a distance D1 corresponding to a state of rest of the downstream elastic member 92 and a distance D2 corresponding to a state of overtorque of the device. This distance D2 is obtained so that the turns of the downstream elastic member 92 are not contiguous.

In operation, the engine torque passes from the plate 3 and the plate 4, to each of the upstream elastic members 91, then passes through each of the radial arms 14 of each of the washers 11 and 12, then passes through each of the downstream elastic members 92, then through the web 7.

In the event of overtorque, the engine torque passes directly through the stops 30,26,27,37 bypassing the passages through the various arms of the device. Since the various stops 30,26,27,37 are located radially inside the elastic members 91, 92, the arms are not stressed and the overtorque does not risk damaging them.

Claims

[Claim 1] A torque transmission device (1) for a motor vehicle, comprising a torque input element (2,3,4) connected to a drive shaft, a torque output element (6,7,8 ) connected to a driven shaft, at least two elastic members (9 _I , 9 ₂ ) mounted between the torque input and torque output elements and acting against the rotation of one of said elements of torque input and torque output, and a phasing member (10, 11, 12), the elastic members being arranged in series via the phasing member so that the elastic members are deformed into phase with each other, the torque input element, the torque output element and / or the phasing member each comprising at least one stop means (30,26,27,37) adapted to limit the compression of the elastic members, each of the stop means of the torque input element, of the torque output element and of the phasing member being configured to such that, in the event of overtorque, the torque passes through the device from the motor shaft to the shaft driven radially below the elastic members.

[Claim 2] Device according to claim 1, wherein the stop means of the phasing member comprises an upstream stop member (26) and a downstream stop member (27), the upstream stop member (26) being able to cooperate with the torque input element and the downstream stop element (27) being able to cooperate with the torque output element.

[Claim 3] Device according to claim 1 or claim 2, wherein the phasing member comprises an insert (19) forming the stop means (26,27) of said phasing member.

[Claim 4] Device according to claim 3, wherein the insert is a symmetrical piece.

[Claim 5] Device according to claim 3 or 4, in which the insert is formed by a central piece (23) which extends circumferentially radially inwardly in two opposite directions so as to form an upstream stop means (26) and a downstream stop means (27).

[Claim 6] Device according to one of claims 3 to 5, in which the insert is made of sintered material.

[Claim 7] Device according to claim 6, wherein the density of material at the stopper means is greater than that present in the rest of the insert.

[Claim 8] Device according to one of claims 3 to 7, wherein a first elastic member (9i) is mounted between the torque input member and the phasing member and a second elastic member (9 ₂ ) is mounted between the phasing member and the torque output member, the insert also forms a support part of one of the ends of the first elastic member and of one of the ends of the second elastic member.

[Claim 9] Device according to one of claims 1 to 8, wherein the phasing member is formed of two washers (11, 12) connected in rotation with one another, the torque output member being mounted between the two washers and forms at least one protuberance (37) able to cooperate with the stop means of the phasing member.

[Claim 10] A device according to claim 9, wherein each of the washers forms from an outer radial periphery of the first radial arms (14), the torque output member forming a disc with second radial arms (33) extending to an outer radial periphery (36) of said disc, the second resilient member being mounted between a first arm and a second arm, the protrusion being formed on the outer radial periphery of the disc.

[Claim 11] Device according to one of claims 1 to 10 wherein the torque input element forms at least one plate (4,5) with at least one window (28) adapted to receive an elastic member, the window having an internal peripheral edge (29) located radially between the elastic member and the X axis and a lateral bearing surface (31) capable of supporting one end of the elastic member, the internal peripheral edge having a protuberance (30) able to come to bear against the stop means of the phasing member.

[Claim 12] Device according to one of claims 1 to 11, wherein the torque input element is formed by two plates (4,5) connected in rotation and arranged on either side of the member. phasing.

[Claim 13] Device according to one of claims 1 to 12 in which the elastic members are coil springs.