CN110809678A

CN110809678A - Clutch disc with friction device

Info

Publication number: CN110809678A
Application number: CN201880044190.3A
Authority: CN
Inventors: O.马雷查尔; D.达尔
Original assignee: Valeo Embrayages SAS
Current assignee: Valeo Embrayages SAS
Priority date: 2017-06-29
Filing date: 2018-06-18
Publication date: 2020-02-18
Also published as: KR20200021949A; BR112019027326B1; BR112019027326A2; FR3068410A1; FR3068410B1; WO2019002716A1

Abstract

A clutch disc (1) comprising a peripheral torque transmitting member, a central torque transmitting member (3) and at least one torsional damping device comprising at least one elastic load washer (15) and a friction washer (14). The spring-loaded washer (15) comprises an annular contact portion (18) and at least two supporting lugs (19) extending from the annular contact portion (18), the spring-loaded washer (15) being supported by its supporting lugs (19) on the first rotary element (4) and by its annular contact on the friction washer (14). The spring-loaded washer (15) comprises at least one passage hole (20) formed in at least one of its supporting lugs (19), the friction washer (14) comprising at least one coupling tab (23) passing through said at least one passage hole (20).

Description

Clutch disc with friction device

Technical Field

The present invention relates to the field of torque transmission in motorized devices, and to clutches. And more particularly to clutch discs.

Background

For example, a motor vehicle may be provided with a clutch disposed between the engine and the transmission. The clutch generally includes a clutch mechanism and a clutch plate having a peripheral torque transmitting member and a central torque transmitting member. When the clutch is in the engaged mode, the engine is connected to the transmission through the clutch plates. The peripheral torque transmitting members are then typically clamped by a clutch mechanism so as to be driven by rotation of the engine, and the central torque transmitting member is rotationally fixed to an element of the transmission, such as a gearbox of a vehicle. When the clutch is operated toward its disengaged position, the clutch mechanism releases the clutch disc and the engine is disengaged from the transmission.

In addition to its function of coupling the engine and the transmission, the clutch disc generally performs additional functions related to filtering out the non-periodic nature of the engine and other torsional oscillations. Such filtering is typically performed by one or more torsional dampers, which are spring-damper combinations that work torsionally, allowing relative rotational movement of the peripheral torque transmitting members with respect to the central torque transmitting member during torque transmission, and damping of this non-periodic characteristic. The spring may allow relative rotation and the damping may be performed by a friction device equipped with a friction washer which is axially loaded by an elastic washer, thereby dissipating the energy accumulated in the spring by friction.

During the design of the clutch disc friction device, special attention needs to be paid to:

the washers are rotationally fixed with respect to each other and with respect to the various rotating elements of the clutch disc, so as to control the position of the friction area;

-the load applied by the elastic washer;

-a volume, in particular an axial volume.

Document FR2890713 describes a clutch disc in which the torsional damper comprises elastic axial compression washers intended to act on complementary friction surfaces, these elastic washers comprising an annular portion for the movable axial bearing, which extends radially by means of radial lugs for the fixed axial bearing. The radial lugs of two consecutive elastic washers are interposed one into the other and each require a rotation stop.

The object of the present invention is to improve the clutch disc of the prior art.

Disclosure of Invention

Accordingly, the present invention is directed to a clutch disc for connection between an engine and a transmission, the clutch disc comprising:

a peripheral torque-transmitting member and a central torque-transmitting member rotatably mounted relative to each other about an axis, an

At least one torsional damping device interposed between the peripheral torque transmitting member and the central torque transmitting member; the torsion damping device includes:

at least one spring arranged to deform when the peripheral torque transmitting member and the central torque transmitting member rotate relative to each other;

an elastomeric load washer and a friction washer coaxial with the central torque transmitting member and rotationally fixed to the first rotational element, the elastomeric load washer applying an axial load to the friction washer disposed against the second rotational element allowing relative rotation between the first and second rotational elements.

The spring load washer comprises an annular contact portion and at least two support lugs extending from the annular contact portion, the spring load washer being supported on the first rotational element by its support lugs and on the friction washer directly or indirectly by its annular contact portion. Furthermore, the spring-loaded washer includes at least one passage hole formed in at least one of its support lugs, and the friction washer includes at least one coupling piece passing through the at least one passage hole.

Thus, the spring load washer and the friction washer may be rotationally fixedly mounted to the first rotational element in a radially and axially compact manner. Compactness is always an objective to be achieved in terms of the arrangement of the washers that make up the clutch disc, and the present invention allows such compactness to be achieved in a simple manner and without adversely affecting the rigidity of the individual washers.

Furthermore, the use of wide support lugs with closed apertures provided therein makes it possible to increase the rigidity of the spring-loaded gasket, compared to a spring-loaded gasket in which the perforated wide support lugs are replaced by two remote lugs having a smaller width. In other words, preferably, in order to increase the rigidity of the spring-loaded gasket with respect to the prior art spring-loaded gasket, the number of supporting lugs is divided by approximately two and their width is multiplied by twice, and closed holes are formed in these lugs.

Furthermore, the spring-loaded washer and the friction washer may be preassembled.

In addition, the diameter of the friction washer can be reduced without adversely affecting its function, so that it is possible to simply cooperate with the annular contact portion of the spring-loaded washer and to simplify its rotation blocking means in the form of one or more coupling pieces.

Thus, by means of one or more coupling tabs through one or more passage holes, the volume of the rotation blocking means of the spring-loaded washer and/or of the friction washer can be reduced.

The clutch discs may include the following additional features, either alone or in combination:

-the at least one passage hole is a closed hole. In other words, it is not a notch.

The spring-loaded washer comprises four supporting lugs distributed in two substantially perpendicular directions;

the spring-loaded washer comprises two passage holes in each support lug;

the friction washer comprises an annular friction portion and four pairs of linkage tabs extending substantially perpendicular to the plane of the annular friction portion in the direction of the first rotary element;

-the spring-loaded washer comprises a rotation-stopping tooth on at least one supporting lug, which is inserted in a rotation-stopping hole formed in the first rotary element; in other words, the spring-loaded washer may be rotationally fixedly mounted on the first rotational element via the stop tooth and the stop hole.

The rotation stop hole is a rotation stop groove.

-fitting the at least one coupling piece into the at least one passage hole such that the friction washer is prevented from rotating in both rotational directions by the spring-loaded washer; in other words, the friction washer may be rotationally fixedly mounted on the resilient load washer.

-furthermore, said at least one coupling tab is inserted into at least one end hole formed in the first rotary element; thus, the first rotational element does not form an obstacle to the axial movement of the spring-loaded washer.

-the at least one coupling piece is fitted into the at least one end hole such that the friction washer is prevented from rotating in both rotational directions by the first rotational element; in other words, the friction washer may be rotationally fixedly mounted on the first rotational element.

The clutch disc comprises a web connected to one of the central torque transmitting member and the peripheral torque transmitting member, and two guide washers connected to the other of the central torque transmitting member and the peripheral torque transmitting member and arranged on either side of the web, and a spring interposed between the web and the guide washers, the first rotary element being formed by one of the guide washers or the web.

The clutch disc comprises a web connected to one of the central torque transmitting member and the peripheral torque transmitting member, and two guide washers connected to the other of the central torque transmitting member and the peripheral torque transmitting member and arranged on either side of the web, and a spring interposed between the web and the guide washers, the first rotary element being formed by one of the guide washers;

the clutch disc comprises a web connected to the central torque transfer member, and two guide washers connected to the peripheral torque transfer members and arranged on either side of the web, and a spring interposed between the web and the guide washers, the first rotary element being formed by one of the guide washers;

-the supporting lugs (19) of the spring-loaded washer (15) have a radially outer end which is arranged against one of the guide washers between two circumferentially consecutive springs.

The second rotating element is an element connected to the web;

the second rotating element is a pre-damper box fastened to the web;

-the spring-loaded washer has a substantially frustoconical shape, the annular contact portion being on the tip side of the cone and the support lugs being on the base side of the cone.

-the support lugs extend radially towards the outside of the spring-loaded washer;

-said at least one coupling tab is arranged on the outer periphery of said friction washer;

-the at least one coupling lug extends radially towards an outer diameter of the friction washer;

-rotationally fixedly mounting the friction washer on the first rotational element and the spring load washer on the friction washer such that the spring load washer is rotationally fixedly mounted to the first rotational element only by the friction washer.

At least one of the coupling tabs comprises a boss cooperating with the edge of the passage hole and forming an axial retaining element which axially retains the friction washer on the elastic load washer; thus, the spring loaded washer and the friction washer may form a preassembled subassembly.

The bosses can be obtained by means of deformation of the coupling piece, for example by shot peening;

the coupling tabs may also extend in the axial direction to promote axial retention between the bosses and the associated passage holes.

Drawings

Preferred exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

figure 1 shows a clutch disc according to the present invention in perspective view;

figure 2 shows the web of the clutch disc of figure 1;

figure 3 shows a guide washer of the clutch disc of figure 1;

FIG. 4 is an exploded view showing a spring loaded washer and a friction washer of the clutch of FIG. 1;

FIG. 5 shows the web of FIG. 2 in perspective view in association with the gasket of FIG. 4;

FIG. 6 shows the assembly of FIG. 5 in association with the guide washer of FIG. 3;

FIG. 7 shows the two gaskets of FIG. 4 in an assembled state;

FIG. 8 is a detail view of FIG. 7;

FIG. 9 is a detail view of FIG. 3;

FIG. 10 is a modified embodiment similar to FIG. 9;

FIG. 11 is a modified embodiment including an axial retaining element between the spring loaded washer and the friction washer.

Detailed Description

In the description and claims, the terms "outer" and "inner" and the orientations "axial" and "radial" will be used to indicate the elements of the torsional damper according to the definitions given in the description. The axis of rotation (X) (as shown in fig. 1) determines the "axial" orientation. The "radial" orientation is perpendicular to the axis (X). The "circumferential" orientation is perpendicular to the axis of rotation (X) and orthogonal to the radial orientation. The terms "outer" and "inner" are used to define the relative position of one component with respect to the other with reference to the axis of rotation (X), the component close to this axis being therefore called inner, on the contrary, the one positioned radially at the periphery being the outer component. Furthermore, the represented angles and angular sectors are defined relative to the rotation axis (X).

Fig. 1 shows a clutch disc 1 in a perspective view, which in the present example is intended for a motor vehicle. Such clutch discs are typically provided with friction discs (not shown) on their outer periphery.

The clutch disc 1 is used for connecting an engine and a transmission of a motor vehicle. It comprises peripheral torque transmitting members, here formed by friction discs (not shown), and a central torque transmitting member, here formed by the hub 3. The friction discs (not shown) are fixed to a rigid assembly formed by two lateral flanges, called "first guide washer 4" and "second guide washer 5", which are fastened by rivets 6.

Typically, the clutch disc 1 is mounted such that a friction disc (not shown) secured to the periphery of one of the

guide washers

4, 5 can be clamped by a clutch mechanism connected to the engine flywheel, and such that the hub 3 is rotationally connected to the input shaft of the transmission of the vehicle by means of the internal teeth 7 of the hub 3.

The clutch disc 1 is provided with a torsional damping device between its peripheral torque-transmitting members and its central torque-transmitting member, which comprises a set of springs 8 interposed between the

guide washers

4, 5 and a disc called "web 9" driven in rotation with the hub 3.

Figures 2 and 3 show the web 9 and the first guide washer 4, respectively, which are present when the clutch disc 1 is disassembled.

The web 9 of fig. 2 comprises a housing 10 for the spring 8. It has a radially inner profile 11, which radially inner profile 11 is provided with teeth for its rotational connection to the hub 3, which connection can be a direct connection through mechanical contact, or an indirect connection, for example through an additional torsional damper, known as a pre-damper. The box 16 is fastened to the web 9 and can accommodate such a possible pre-damper. The box 16 is made of plastic here and has a friction surface 12 pointing towards the first guide washer 4.

In fig. 3, the first guide washer 4 has a housing 13 for the spring 8, a fastening hole 2 for the rivet 6, and a friction washer 14 and an elastic load washer 15, the friction washer 14 and the elastic load washer 15 being overlapped so that the friction washer 14 is in contact with the friction surface 12 of the case 16 when the clutch disc 1 is assembled. The spring loaded washer 15 then applies an axial load between the friction washer 14 and the first guide washer 4, so that the friction washer 14 is urged against the friction face 12 of the box 16. The friction washer 14 and the spring loaded washer 15 the first guide washer 4 is rotationally fixed. The inner contour 17 of the first guide washer 4 surrounds the hub 3, but the hub 3 can rotate freely with respect to the two

guide washers

4, 5.

Possible relative rotation between the web 9 and the first guide washer 4 tends to compress the spring 8 inserted in the housing 10, 13, also causing relative rotation of the friction washer 14 with respect to the box 16, thus causing the friction washer 14 to rub on the friction face 12 under a load determined by the elastic load washer 15.

Fig. 4 shows in perspective view the spring-loaded washer 15 crossed by the friction washer 14.

The spring-loaded washer 15 has an annular contact portion 18 and, in this example, four support lugs 19 extending from the annular contact portion 18. The annular contact portion 18 has a substantially disc shape intended to exert pressure on the friction washer 14. Four supporting lugs 19 are regularly distributed in two substantially perpendicular directions over the outer contour of the annular contact portion 18. The elastic load washer 15 is made of a material chosen for its elastic properties, for example steel, and has a shape, for example, substantially frustoconical, so as to be able to perform its axial spring function. In the present example, the annular contact portion 18 is on the tip side of the cone and the support lugs 19 are on the base side of the cone, which means that the support lugs 19 extend radially towards the outside of the spring-loaded washer 15.

In the present example, the spring load washer 15 bears by its support lugs 19 on the first rotary element of the clutch disc formed by the first guide washer 4 and by its annular contact portion 18 on the friction washer 14. The friction washer 14 itself is then supported on a second rotating element formed by a box 16 fastened to the web 9.

In the present example, each supporting lug 19 of the elastic load washer 15 comprises a pair of passage holes 20 and a rotation-stopping tooth 22, the rotation-stopping tooth 22 being intended to cooperate with the first guide washer 4 to rotationally fix the elastic load washer 15 to the first guide washer 4.

The friction washer 14 shown in fig. 4 comprises an annular friction portion 21, which annular friction portion 21 has a substantially disc-like shape and is intended to come into contact with the friction face 12 of the box 16. During the relative rotation of the web 9 with respect to the

guide washers

4, 5, friction occurs between the annular friction portion 21 of the friction washer 14 and the friction face 12 of the box 16. The friction washer 14 is here metallic, which means an advantageous metal-plastic friction.

The friction washer 14 further comprises four pairs of coupling tabs 23, each coupling tab 23 extending substantially perpendicularly with respect to the plane of the annular friction portion 21.

Fig. 5 shows the web 9, the friction washer 14 and the spring-loaded washer 15 present in the friction disc 1 in the mounted state of the friction disc 1. Fig. 5 does not show the first guide washer 4 in order to reveal the cooperation between the friction washer 14, the elastic load washer 15 and the web 9.

Thus, the spring-loaded washer 15 bears against the first guide washer 14 by means of its support lugs 19, so that the friction washer 14 is pressed against the box 16. As shown in fig. 5, the coupling piece 23 of the friction washer 14 passes through the passage hole 20 of the elastic load washer 15.

The friction washer 14 coupled to the elastic load washer 15 is shown in a perspective view in fig. 7, with the coupling piece 23 passing through the passage hole 20.

Fig. 8 is a detailed view of the assembly of fig. 7 and shows one of the support lugs 19 of the spring-loaded washer 15 through which the coupling piece 23 passes, as seen from below.

The coupling piece 23 also passes through an end hole 24 formed in the first guide washer 4. Fig. 6 is identical to fig. 5, except for the fact that this time the first guide washer 4 has been shown, and fig. 6 shows the coupling piece 23 inserted into the end aperture 24.

According to a number of variants, the friction washer 14, the elastic load washer 15 and the first guide washer 4 are rotationally fixed.

According to a first variant, and with reference to fig. 9, the elastic load washer 15 is mounted rotationally fixed to the first guide washer 4 by means of each rotation-stopping tooth 22 inserted into a rotation-stopping slot 25 formed in the first guide washer 4. Fig. 3 shows four rotation stop teeth 22 inserted into four rotation stop slots 25. Each supporting lug 19 of the spring-loaded washer 15 is arranged against the first guide washer 4, with its stop tooth arranged circumferentially between two successive springs.

In this first embodiment, the friction washer 14 is rotationally fixedly mounted to the spring-loaded washer 15 by means of a coupling piece 23, the coupling piece 23 fitting in a width-fitting manner into the passage hole 20 of the spring-loaded washer 15. For example, the passage hole 20 has a substantially rectangular profile to provide a flat contact with the edge of the coupling piece 23, the coupling piece 23 being mounted in a fitting or even slightly clamping manner in the through hole 20 so as to ensure that one washer can be driven in rotation by the other washer in both directions of rotation. Furthermore, the end hole 24 has a larger width than the coupling piece 23, so that the coupling piece 23 can freely pass through the end hole 24 without touching the edge. The width extends in the circumferential direction. Therefore, the end hole 24 does not interfere with the coupling piece 23; the end holes 24 do not contribute to the rotational fixation of the two

washers

14, 15. The end hole 24 only allows the coupling piece 23 to pass through, so that the coupling piece 23 does not axially abut against the first guide washer 4 when the spring-loaded washer 15 is compressed against the first guide washer 4.

According to this first variant, the coupling tabs 23 of the friction washers 14 can advantageously be axially shortened, since they are only rotationally coupled to the elastic load washer 15.

According to a second variant, the friction washer 14 is mounted rotationally fixed on the first guide washer 4 by means of a coupling piece 23, the coupling piece 23 fitting in a width-adapted manner into an end hole 24 of the first guide washer 4. For example, the end holes 24 have a substantially rectangular profile to provide a flat contact with the edges of the coupling tabs 23, the coupling tabs 23 being mounted in these end holes 24 in a fitting or even slightly clamping manner so as to ensure the rotational coupling of the friction washers 23 and the first guide washers 4 in both directions of rotation. According to this second variant, this time, the passage hole 20 has a greater width than the coupling piece 23, so that the coupling piece 23 can pass freely through the passage hole 20 without touching the edges. Therefore, the passage hole 20 does not interfere with the coupling piece 23, but merely helps to allow the coupling piece 23 to pass through the support lug 19.

According to a third variant with respect to fig. 10, the supporting lugs 19 of the elastic load washer 15 do not comprise rotation-stopping teeth 22. The width dimensions of the passage hole 20 and the end hole 24 are determined to be suitable for the coupling piece 23. The coupling piece 23 is thus mounted in the passage hole 20 and in the end hole 24 in a fitting or even slightly clamping manner, so that the coupling piece 23 directly ensures the coupling of the friction washer 14 and of the spring-loaded washer 15 with the first guide washer 4 in both rotational directions.

Fig. 11 depicts a variant embodiment of the coupling piece 23. They comprise a boss 42 cooperating with the edge of the passage hole 20, so as to form an axial retention element which axially retains the friction washer 14 on the elastic load washer 15. Thus, the spring loaded washer and the friction washer may form a preassembled subassembly. The bosses may be obtained by a method of deforming the coupling piece, for example by shot peening. The coupling tabs extend in the axial direction to promote axial retention between the boss 42 and the associated passage hole 20.

Other modified embodiments may be implemented without departing from the scope of the invention. For example, the annular contact portion 18 may be on the base side of the cone formed by the spring-loaded washer 15, while its support lugs 19 are on the tip side of the cone, which means that the support lugs 19 extend radially towards the inside of the spring-loaded washer 15. In this case, the friction washer 14 may be adapted to such a spring-loaded washer 15 by having a radially inwardly extending coupling piece 23 and by cooperating with the support lug 19 by passing through the passage hole 20.

Furthermore, the pair formed by the friction washer 14 and the elastic load washer 15 may be located axially elsewhere in the clutch disc, which means that the first and second rotary elements of the clutch disc may be elements other than the first guide washer 4 (e.g. the second guide washer 5 or other elements) and the box 16 (e.g. the web 9 or other elements), respectively; all that is required is to allow relative rotation between the first and second rotational elements by means of the torsional damper.

Instead of a single friction washer 14 and a single spring-loaded washer 15, a plurality of washer pairs 14, 15 may also be provided in a stacked manner.

Furthermore, for a clutch disc comprising a plurality of torsional dampers, the invention may be applied to any torsional damper.

Claims

1. A clutch disc (1) for connection between an engine and a transmission, comprising:

peripheral and central torque-transmitting members (3), said peripheral and central torque-transmitting members (3) being mounted so as to be rotatable relative to each other about an axis (X); and

at least one torsional damping device interposed between the peripheral torque transmitting members and the central torque transmitting member, the torsional damping device comprising:

at least one spring (8) arranged to deform when the peripheral torque transmitting member and the central torque transmitting member (3) rotate relative to each other;

an elastic load washer (15) and a friction washer (14) coaxial with the central torque transmitting member (3) and rotationally fixed to the first rotary element (4), the elastic load washer (15) applying an axial load to the friction washer (14) disposed against the second rotary element (16), allowing relative rotation between the first rotary element (4) and the second rotary element (16),

characterized in that the spring-loaded washer (15) comprises an annular contact portion (18) and at least two supporting lugs (19) extending from the annular contact portion (18), the spring-loaded washer (15) bearing on the first rotary element (4) by its supporting lugs (19) and on the friction washer (14) directly or indirectly by its annular contact; and wherein the spring-loaded washer (15) comprises at least one passage hole (20) formed in at least one of its supporting lugs (19), the friction washer (14) comprising at least one coupling tab (23) passing through said at least one passage hole (20).

2. A clutch disc according to claim 1, characterized in that the spring load washer (15) comprises two passage holes (20) in each support lug (19).

3. A clutch disc according to any one of claims 1-2, characterized in that the friction washer (14) comprises an annular friction portion (21) and four pairs of tie tabs (23) extending substantially perpendicular to the plane of the annular friction portion (21) in the direction of the first rotary element (4).

4. A clutch disc according to any one of claims 1 to 3, characterized in that the elastic load washer (15) comprises rotation stop teeth (20) on at least one support lug (19), the rotation stop teeth (22) being inserted in rotation stop holes (25) formed in the first rotary element (4).

5. A clutch disc according to any one of claims 1-4, characterized in that the at least one coupling piece (23) is fitted into the at least one passage hole (20) such that the friction washer (14) is prevented from rotating in both directions of rotation by the spring-loaded washer (15).

6. A clutch disc according to any one of claims 1 to 5, characterized in that the at least one coupling piece (23) is furthermore inserted in at least one end hole (24) formed in the first rotary element (4).

7. A clutch disc according to claim 6, characterized in that the at least one coupling piece (23) is fitted into the at least one end hole (24) such that the friction washer (14) is prevented from rotating in both directions of rotation by the first rotational element (4).

8. A clutch disc according to any one of claims 1 to 7, characterized in that it comprises a web (9) connected to one of the central torque transmitting member (3) and the peripheral torque transmitting member, and two guide washers (4, 5) connected to the other of the central torque transmitting member (3) and the peripheral torque transmitting member and arranged on either side of the web (9), and a spring (8) interposed between the web (9) and the guide washers (4, 5), the first rotary element (4) being formed by one of the guide washers (4) or by the web (9).

9. A clutch disc according to claim 8, characterized in that the web (9) is connected to the central torque transmitting member (3), two guide washers (4, 5) are connected to the peripheral torque transmitting member, the first rotational element (4) being formed by one of the guide washers (4).

10. A clutch disc according to claim 9, characterized in that the supporting lug (19) of the spring-loaded washer (15) has a radially outer end which is arranged against one of the guide washers (4) between two consecutive springs (8) in the circumferential direction.

11. A clutch disc according to any one of claims 8 to 10, characterized in that the second rotary element (16) is an element connected to the web (9).

12. A clutch disc according to any one of the preceding claims, characterised in that the support lugs (19) extend radially towards the outside of the spring-loaded washer (15).

13. A clutch disc according to any one of claims 1 to 12, characterized in that the at least one coupling piece (23) is arranged on the outer periphery of the friction washer (14).

14. A clutch disc according to any one of claims 1 to 13, not dependent on claim 5, characterized in that a friction washer is rotationally fixedly mounted on the first rotational element and the spring load washer (15) is rotationally fixedly mounted on the friction washer, such that the spring load washer (15) is rotationally fixedly mounted to the first rotational element (4) only by means of the friction washer (14).

15. A clutch disc according to any one of claims 1 to 14, characterised in that at least one of the coupling tabs comprises a boss (42) which cooperates with an edge of the at least one passage hole (20) and forms an axial retaining element which axially retains the friction washer on the elastic load washer.