阅读说明：本技术 离合器片、摩擦装置以及用于摩擦装置的摩擦环 (Clutch plate, friction device and friction ring for friction device ) 是由 A·艾克 C·梅斯特 L·约克海尔 于 2020-03-27 设计创作，主要内容包括：本发明涉及一种离合器片(10),其包括从动盘本体(20)和输出盘(24)。在从动盘本体(20)和输出盘(24)之间布置有弹簧元件(30),所述弹簧元件反作用于从动盘本体(20)和输出盘(24)之间的转动。沿轴向在从动盘本体(20)和输出盘(24)之间布置有摩擦装置(12),所述摩擦装置具有摩擦环(14)、保持元件(16)和预紧元件(18)。所述预紧元件(18)沿轴向布置在输出盘(24)和摩擦环(14)之间,以便朝向所述从动盘本体(20)将轴向力施加到所述摩擦环(14)上。保持元件(16)与输出盘(24)不可相对转动地连接并且摩擦环(14)借助于至少一个连接元件(36)与所述保持元件(16)固定地连接。由此能够避免预紧元件(18)和摩擦环(14)之间的相对运动。此外本发明还提供一种摩擦装置(12)和一种摩擦环(14)。(The invention relates to a clutch plate (10) comprising a driven plate body (20) and an output plate (24). A spring element (30) is arranged between the driven disk body (20) and the output disk (24), said spring element reacting to a rotational movement between the driven disk body (20) and the output disk (24). A friction device (12) is arranged axially between the driven disk body (20) and the output disk (24), said friction device having a friction ring (14), a holding element (16) and a prestressing element (18). The pretensioning element (18) is arranged axially between the output disk (24) and the friction ring (14) in order to exert an axial force on the friction ring (14) towards the driven disk body (20). The holding element (16) is connected to the output disk (24) in a rotationally fixed manner and the friction ring (14) is fixedly connected to the holding element (16) by means of at least one connecting element (36). Relative movement between the pretensioning element (18) and the friction ring (14) can thereby be avoided. The invention further relates to a friction device (12) and a friction ring (14).)

1. A clutch plate (10), comprising:

a driven plate body (20) as an input element of the clutch plate (10);

at least one output disc (24) of the clutch plates (10);

at least one spring element (30) arranged between the driven disk body (20) and the output disk (24), wherein the driven disk body (20) and the output disk (24) are rotatable relative to one another and the spring element (30) counteracts a rotation between the driven disk body (20) and the output disk (24); and

a friction device (12) arranged axially between the driven disk body (20) and the output disk (24), said friction device having a friction ring (14), a holding element (16) and a prestressing element (18),

wherein the pretensioning element (18) is arranged axially between the output disc (24) and the friction ring (14) in order to exert an axial force on the friction ring (14) towards the driven disc body (20),

wherein the holding element (16) is connected to the output disk (24) in a rotationally fixed manner, and the friction ring (14) is fixedly connected to the holding element (16) by means of at least one connecting element (36).

2. A clutch plate (10) according to claim 1,

wherein the retaining element (16) connects the friction ring (14) and the output disk (24) in a rotationally fixed manner, so that in the operating mode of the clutch plate (10) a relative movement in the circumferential direction between the pretensioning element (18) and the friction ring (14) is prevented as a result of the pretensioning element (18) being arranged axially between the friction ring (14) and the output disk (24).

3. A clutch plate (10) according to claim 1 or 2,

wherein the friction ring (14) is riveted to the retaining element (16).

4. A clutch plate (10) according to any preceding claim,

wherein the connecting element (36) is a conical rivet (36a), the conical rivet (36a) being conically formed in the interior of the friction ring (14), wherein the larger diameter of the conical rivet (36a) is located on an axially outer side of the friction ring (14) facing away from the retaining element (16), and wherein the smaller diameter of the conical rivet (36a) is located on an axially outer side of the friction ring (14) facing the retaining element (16).

5. A clutch plate (10) according to any preceding claim,

wherein the retaining element (16) is formed by a retaining plate, wherein the retaining plate exerts an axial force on the friction ring (14) which is at least five times smaller than the axial force exerted on the friction ring (14) by the pretensioning element (18).

6. A clutch plate (10) according to any preceding claim,

wherein the pretensioning element (18) comprises a cup spring, wherein a spring tongue (18a) of the cup spring passes through a recess of the holding element (16) in the axial direction.

7. A clutch plate (10) according to any preceding claim,

wherein a securing element (34) for rotationally fixedly connecting the output disk (24) to a driven hub (28) of the clutch plate (10) simultaneously connects the holding element (16) to the output disk (24).

8. A clutch plate (10) according to any preceding claim,

wherein the clutch plate (10) comprises two output discs (24, 26) which are connected to one another in a rotationally fixed manner and are arranged on axially opposite sides of a driven disc body (20), wherein the friction device (12) is arranged between the driven disc body (20) and a first of the two output discs (24, 26), wherein a further friction ring (32) or a further friction device (12a) is arranged between the driven disc body (20) and a second of the two output discs (24, 26).

9. A friction device (12) for a clutch plate (10) having a torsional damper, the friction device (12) comprising:

a friction ring (14);

a holding element (16); and

a pretensioning element (18),

wherein the pretensioning element (18) exerts an axial force on the friction ring (14) in the clutch plate (10) in the mounted state of the friction device (12),

wherein the holding element (16) has a fastening means (38) for fastening the holding element (16) to the element (24) of the clutch plate (10) in a rotationally fixed manner, and wherein the friction ring (14) and the holding element (16) are connected to one another in a rotationally fixed manner by means of at least one connecting element (36).

10. A friction ring (14) for a friction device (12) of a clutch plate (10), wherein the friction ring (14) has at least one axially through-opening as a fastening element in the interior of an annular surface of the friction ring (14), wherein the opening is conically configured in the axial direction.

Technical Field

The invention relates to a clutch plate with a driven plate body, an output plate and a friction device. Other aspects of the invention relate to a friction device for a clutch plate and a friction ring for a friction device.

Background

In a clutch plate with a torsional damper, a friction device is provided between a driven plate body and an output plate which are rotatable relative to each other. The friction device is composed, for example, of one or more friction rings, which are prestressed in the axial direction by means of disk springs. The axial pretensioning force can, for example, be such that, over the service life of the clutch plate, as constant a friction as possible is achieved despite the friction ring wear.

The friction ring and the pretension spring can be inserted loosely in the direction of rotation or, in the case of a rotary follower with free play in the direction of rotation, between the driven disk body and the output disk in order to enable an axial movement of the friction ring.

However, the free movement in the direction of rotation between the friction ring and the pretensioned spring can lead to greater wear on the friction device, since the parts can move relative to one another. For example, a belleville spring may be attached to the friction ring so that not all of the material of the friction ring is available for wear on the driven disc body. Therefore, wear occurs on the friction ring without thereby generating a friction effect between the driven disc body and the output disc.

DE 102011003030 a1 discloses a clutch plate with a friction device. According to the exemplary embodiment shown here, the pretensioning device and the friction ring can be connected to one another, wherein the pretensioning device has lugs on its side facing the cover plate and on its side facing the hub disk, which lugs engage in the friction ring on the one hand and engage in the cover plate on the other hand, thereby causing a rotation-preventing effect. However, the anti-rotation effect by means of the lugs engaging in the recesses may be insufficient, so that an excessive relative movement between the friction ring and the pretensioning device may still occur.

Disclosure of Invention

The object of the invention is to provide a concept which makes it possible to reduce the wear occurring on the friction ring.

This object is achieved by the subject matter of the independent claims. Further aspects and developments of the invention, which can lead to additional advantages, are described in the dependent claims, the following description and the enclosed drawings.

Accordingly, a clutch plate with a friction device, for example a friction clutch for a motor vehicle, is proposed. The clutch plate according to the invention comprises a driven plate body, at least one output plate and at least one spring element arranged between the driven plate body and the output plate. The driven disk body serves as an input element for the clutch disks, for example, friction linings for a friction clutch are formed on the driven disk body, by means of which friction linings a torque can be coupled into the clutch disks. An output disk (e.g., a cover plate) can be connected in a rotationally fixed manner to an output hub of the clutch disks, so that the torque can be decoupled by means of the output disk.

It is proposed that the driven disk body and the output disk can be rotated relative to one another. The spring element is arranged such that it reacts against rotation between the driven disc body and the output disc. In particular, a plurality of spring elements, for example torsion springs, such as, for example, helical springs or compression springs, form at least partially the torsion damper of the clutch plate.

A friction device is arranged in an axial region between the driven disk body and the output disk. The friction device comprises a friction ring, a retaining element and a pretensioning element. The pretensioning element is arranged axially between the output disk and the friction ring. The pretensioning element, which is axially supported on the output disk, can thus exert an axial force on the friction ring in the direction of the driven disk body. The friction ring thus bears against the driven disk body and produces a friction action thereon. Due to friction between the friction ring and the driven disc body, wear occurs on the friction ring, and the friction ring becomes thin. However, in order to maintain a constant friction effect, the friction ring follows the driven disk body axially via the prestressing element.

In this case, it is provided that, for example, in a first axial region of the holding element, the holding element is connected to the output disk in a rotationally fixed manner. For example, the holding element can be connected directly to the output disk or to a driven hub, to which the output disk is also connected in a rotationally fixed manner.

Furthermore, it is provided that, for example, in the second axial region of the holding element, the friction ring is connected to the holding element by means of at least one connecting element. For example, the friction ring is riveted to the retaining element. In particular, a plurality of rivets arranged symmetrically in the circumferential direction can provide a rotationally fixed connection of the retaining element to the friction ring. Thus, relative movement between the friction ring and the retaining element can be advantageously reduced or prevented.

Since the holding element is connected to the output disk in a rotationally fixed manner and the friction ring is connected to the holding element by means of the connecting element in a fixedly or rotationally fixed manner, no or no significant relative rotation between the friction ring and the output disk occurs either. In particular, the plurality of connecting elements for firmly connecting the friction ring to the retaining element can further reduce the relative rotatability between the friction ring and the retaining element.

The biasing element, for example a disk spring, is arranged axially between the friction ring and the output disk, so that even during operation of the clutch disk in the rotational direction, it cannot move relative to the friction ring and the output disk, or there is relative movement in an imperceptible region in which the friction ring is not worn by the biasing element. Thus, an attachment of the pretensioning element into the friction ring due to vibrations can be avoided, and ineffective wear of the friction ring on the side facing away from the driven disk body can be reduced or avoided.

For example, the retaining element is flexible or soft in the axial direction, so that it does not or only slightly react the axial force of the pretensioning element, and the friction ring can be pressed against the driven disk body. Conversely, the holding element is rigid, for example in the direction of rotation or in the circumferential direction, so that no rotation (or only imperceptible rotation) takes place between the output disk and the holding element (for example in the second axial region of the holding element) even if the clutch plates are in operation.

The proposed play-free fixing of the friction ring on the output side makes it possible to reduce wear between the preloading element (e.g. disk spring) and the output disk (e.g. cover plate) and between the preloading element and the friction ring. One aspect of the invention relates to the attachment and implementation of a retaining plate that secures the friction ring without play (e.g., in the direction of rotation). For example, by means of the proposed connection of the holding element, the additionally required riveting process can be omitted, for example, so that a cost-effective production of the friction device clutch disk with low wear can be achieved.

In an alternative embodiment, the friction device can be arranged in a mirror image in the clutch plate, so that the prestressing element is arranged axially between the driven disk body and the friction ring is pressed against the output disk. The holding plate can be connected to the driven disk body in a rotationally fixed manner.

As mentioned above, the friction ring may be riveted with the retaining element. For example, the connecting element is a conical rivet inside the friction ring. It is provided here that the conical rivet of larger diameter is arranged on the axially outer side of the friction ring facing away from the retaining element, shown toward the driven disk body. The conical rivet of smaller diameter is in turn arranged on the axially outer side of the friction ring, which is shown towards the retaining element. When the side of the friction ring facing the driven disc body is worn away due to friction between the friction ring and the driven disc body, the rivet is also worn away therewith. Due to the conical shape of the rivet, a secure connection between the holding element and the friction ring can advantageously be maintained in spite of wear.

The holding element is formed by a holding plate, for example. The retaining plate can be soft or flexible in the axial direction, so that it exerts only a small axial force on the friction ring when mounted, for example under pretensioning. For example, the axial force exerted by the retaining plate is at least 3 times (or 5 times, or 10 times) less than the axial force exerted by the pretensioning element on the friction ring. Due to the low axial stiffness of the holding element, a clamping-free axial mobility of the friction ring can be advantageously achieved and/or the friction force can be defined by dimensioning the prestressing element. For example, the tangential stiffness of the retaining element may be at least 10 times (or 15 times, or 20 times) higher than the axial stiffness of the retaining element. A high tangential stiffness may result in a high resistance to rotation between the friction ring and the output disc.

According to one embodiment, the holding element has a recess. The recesses may be distributed in the circumferential direction. The pretensioning element may comprise a disk spring with spring tongues directed radially outward. At least some of the spring tongues can each pass axially through a recess of the retaining element. This makes it possible to arrange the pretensioning element and the holding element in a common axial region. For example, the holding element surrounds the pretensioning element. By passing the spring tongue through the recess of the holding element, a connection can also be established between the pretensioning element and the holding element, so that a friction device can be provided as a unit held together, for example, in order to be able to mount it in a clutch plate in a simple manner.

For example, the output disc is connected to the driven hub by means of a first connecting element (e.g. a rivet). The holding element can be connected to the output disk in a rotationally fixed manner by means of a second connecting element (for example a rivet). In an advantageous development, however, it is provided that a common connecting element connects both the holding element and the output disk to the driven hub. For example, a common rivet can connect the output disk, the holding element and the driven hub to one another in a rotationally fixed manner.

According to one refinement, the clutch plate comprises two output discs. The two output disks are connected to one another in a rotationally fixed manner and are each arranged on axially opposite sides of the driven disk body. The proposed friction device is arranged between the driven disc body and the first of the two output discs. A friction ring may be provided between the second output disc and the driven disc body. For example, the friction ring may be loosely arranged or connected with the second output disc. Alternatively, it can be provided that a further friction device according to the proposed friction device is arranged between the second output disk and the driven disk body. This advantageously increases the amount of wear of the friction device and/or allows higher friction forces to be achieved.

Another aspect of the invention relates to a friction device for a clutch plate having a torsional vibration damper. The friction device comprises a friction ring, a retaining element and a pretensioning element. The pretensioning element exerts an axial force on the friction ring in the mounted state of the friction device in the clutch plate. The holding element has a fastening means (for example an opening for a rivet) for fastening the holding element to the elements of the clutch plate in a rotationally fixed manner. The holding element can be connected in a rotationally fixed manner, for example, to the output disk of the clutch disk, to the driven disk body or to the driven hub. The friction ring and the holding element are connected to one another in a rotationally fixed manner by means of at least one connecting element (for example a rivet or a screw).

Another aspect of the invention relates to a friction ring for a friction device for a clutch plate. The friction ring has a radially inner opening for attaching the friction ring to the hub. The friction ring also has at least one through-going axial opening as a fixing element for receiving a rivet inside the annular surface of the friction ring. The opening is tapered in the axial direction. The friction ring can advantageously be connected to the holding element of the friction device by means of a conical rivet, so that the connection to the holding element is maintained even in the event of partial wear of the rivet.

The retaining plate on the friction device advantageously provides a pulling force on the friction ring which acts away from the friction surface of the friction ring. The pretensioning element likewise advantageously provides a pretensioning force which acts towards the friction surface of the friction ring. Advantageously, the tensile force acts on the friction element in the radial direction in addition to the preload force. The connecting element between the holding plate and the friction ring on the friction device is advantageously arranged radially outside the pretensioning element. Experiments have shown that the described friction device surprisingly has a longer service life than originally expected. This effect is explained in detail in the following description of the figures.

Further improvements of the friction device and the friction ring relate to features such as from the improvements already described in connection with the clutch plates. Therefore, repetitive description is omitted and corresponding features relating to the friction device and the friction ring should also be considered disclosed.

Drawings

Some embodiments of the apparatus are described in detail below, by way of example only, with reference to the accompanying drawings. Structurally or functionally identical elements are denoted by the same reference numerals in the figures. The individual features shown only in the individual figures can likewise be combined with the devices shown in the other figures. The figures show:

FIGS. 1a-1c are one embodiment of a clutch plate having a friction device;

FIGS. 2a-2c are an embodiment of a clutch plate having a friction device with a curved retaining plate;

3a-3b are one embodiment of a clutch plate having a friction device coupled to a cover plate of the clutch plate at a radial configuration of a retainer plate;

FIG. 3c is an example of different axial positions of the retaining element;

4a-4c are one embodiment of a clutch plate having a friction device with a retainer plate having an axially decreasing stiffness;

5a-5b are one embodiment of a clutch plate having a friction device with a tapered rivet;

6a-6b are perspective views of an embodiment of a clutch plate with a friction device, the friction disc having a cover plate and no cover plate, respectively;

FIG. 7 is another embodiment of a clutch plate with a friction device having a retainer plate with an axially decreasing stiffness; and

FIG. 8 is an embodiment of a clutch plate having two friction devices.

Detailed Description

Fig. 1a shows an exemplary embodiment of a clutch plate 10 with a friction device 12. The friction device 12 comprises a friction ring 14, a holding plate 16 and a pretensioning element 18. The clutch plate 10 has a driven plate body 20 as an input member of the clutch plate 10. The friction linings 22 of the clutch disks 10 are attached to the radially outer region of the driven disk body 20. The clutch plate 10 also has a first output disc 24 and a second output disc 26. The output disks 24, 26 formed by the two cover plates are connected in a rotationally fixed manner to one another and to the driven hub 28 of the clutch plate 10. The driven hub 28 has radially inner teeth, for example for coupling the clutch plate 10 to a transmission shaft.

Disposed in the windows of the driven disk body 20 and the output disks 24, 26 are spring elements 30 which provide torsional vibration damping of the clutch plates 10. The driven disk body 20 is rotatable relative to the output disks 24, 26, with the spring elements 30 reacting relative rotation between the driven disk body and the output disks. The friction means 12 between the driven disc body 20 and the first output disc 24 may for example provide a damping action against the vibrations of the spring element 30. A further friction ring 32 is arranged between the driven disk body 20 and the second output disk 26, by means of which friction effect can be increased.

The output disks 24, 26, the holding element 18 and the driven hub 28 are connected to one another in a rotationally fixed manner by a rivet connection 34. The friction ring 14 is in turn connected in a rotationally fixed manner to the holding element 16, in this case riveted, so that the prestressing element 18, which is arranged axially between the friction ring 14 and the output disk 24, cannot move relative to the friction ring 14 and the first output disk 24. This prevents the pretensioning element 18 from being integrated into the friction ring 14. The pretensioning element 18 continuously presses the friction ring 14 against the driven disc body 20 until wear occurs.

Fig. 1b shows a separate view of the friction means 12. The holding element 16 and the friction ring 14 are firmly connected to one another by a connecting element 36, here in the form of a rivet. The holding element 16 has a fixing means 38, here in the form of a recess, radially inside the friction ring, by means of which the holding element 16 can be connected to the output disk 24 using the rivet connection 34. The pretensioning element 18 is formed by a disk spring. The connecting region 16a of the holding element 16 is guided radially around the spring tongue 18a of the cup spring. The pretensioning element 18 is arranged at least partially axially between the friction ring 14 and the connection region of the holding element 16 and the fastening means 38. The friction device 12 can thus be provided as a unit and the pretensioning element 18 can be fixed between the friction ring 14 and the retaining element 16.

Fig. 1c shows the friction device 12 with the output disc 24 in a view looking into the friction ring 14. The fixing means 38, here in the form of a recess or hole, of the holding element 16 overlaps with the recess of the output disc 24, so that the output disc 24 and the holding element 16 can be riveted together with the driven hub 28. The connection of the friction ring 14 is effected by a riveting process via a holding element 16, for example a holding plate. The fixing plate and the friction ring are fixed to or riveted with the main rivet of the clutch plate, for example. The retaining element 16 shown in fig. 1a-1c may be a pure stamping (e.g., without a bending process). The profile is chosen such that the pretensioning element 18 (e.g. a disk spring) is pre-centered by the arms (simplifying assembly).

Fig. 2a-2c show an embodiment of a clutch plate 10 with a friction device 12 with a curved holding plate 16. In contrast to the exemplary embodiment shown in fig. 1a to 1c, the connecting element 36, which is in the form of a rivet 36 connecting the holding plate 16 to the friction ring 14, is arranged radially outside the prestressing element 18. Like the holding element 16, the friction ring 14 shown in fig. 2a to 2c has a radial structure 16b of the holding element 16, on which the rivets 36 are arranged. This increases the radial stiffness or the tangential stiffness of the holding element 16. At the same time, the radial structure 16b has a curvature in the axial direction in order to reduce the axial stiffness of the holding element 16. The curved edge of the curved portion extends here substantially in the circumferential direction. Thus, the holding element may be a stamped part and a bent part. During assembly, the pretensioning element 18 (e.g. a disc spring) and the friction ring can be pre-centered by the arms, which in turn can simplify assembly.

Fig. 3a and 3b show an exemplary embodiment of a clutch plate 10 with a friction device 12, which is connected to a cover plate 24 of the clutch plate 10 on a radial structure 16b of the holding plate 16. In the embodiment shown in fig. 3a, the output disc 24 is connected to the driven hub 28 by means of rivets 34 through fastening elements 24a (e.g. recesses or holes, see fig. 3 b). In contrast, the holding plate 16 is connected to the output disk 24 in the form of rivets using the fixing mechanism 38. The rivet 38 is disposed on the radial structure 16b of the retainer plate 16. In contrast, the friction ring 14 is connected to the holding element 16 in the radial region of the pretensioning element 18 by means of rivets 36.

The double rivet provided by the fastening means 38 acts, for example, positively with respect to the deformation of the friction device, in particular in the tangential direction of the torque acting. For example, a double rivet may improve tangential stiffness compared to a simple rivet. The double rivet, in contrast to a simple rivet, for example, results in the friction device not being deformed tangentially during installation, i.e. in the torque-free state. For example, in the exemplary embodiment shown, the mounting position is prestressed in order to distribute stresses, for example, to the service life of the friction ring due to the retaining element in the event of wear, see also fig. 3 c. In the installed position, a pretensioning force is generated, for example, as a result of an axial deformation of the retaining element, axial stresses no longer being present after half wear, but axial stresses are present again when the wear is complete (for example, as in the starting position).

Fig. 3c shows exemplary different axial positions of the holding element 16. For example, the friction ring 14 is in a stress-neutral first axial position in the initial state, i.e. in the delivery state. For installation in the clutch plate, the friction ring 14 can press the holding element 16 against the output disk 24, so that a pretension is generated on the holding element 16. If, after the friction ring 14 has been completely worn, the tensioning element, which is not shown here, pushes the holding element 16 away from the output disk 24, a stress is again produced in the holding element in the direction opposite to the tensioning force. The stress-neutral position of the retaining element 16 between the installation position and the wear-end position can reduce the force exerted by the retaining element 16 on the friction ring 14 in its entirety.

Fig. 4a-4c show an embodiment of a clutch plate 10 with a friction device 12, the holding plate 16 of which has a reduced axial stiffness. Fig. 4b shows the friction device 12 with the output disc 24, and fig. 4c shows a detail view of the friction device 12 shown in fig. 4a, in the embodiment shown the radial structure 16b of the holding element 16 being bent into a tab 16c, see also fig. 4 c. The bent tab 16c can, for example, achieve a further reduction in the axial stiffness of the holding element 16 while increasing the tangential stiffness.

Fig. 5a and 5b show an exemplary embodiment of a clutch plate 10 with a friction device 12 having a conical rivet 36a in a side sectional view. Fig. 5b shows the area marked in fig. 5a in an enlarged manner, in the exemplary embodiment shown, the holding plate 16 effecting the connection of the friction ring 14 by means of a conical rivet 36 a. The rivet 36a is conically shaped in the axial region of the friction ring 14, wherein the rivet 36a has a larger radius towards the driven disk body 20. The receptacle of the friction ring 14 for the rivet 36a is also conical. Such a conical receptacle can be produced, for example, by punching or embossing, so that no additional drilling is required. The rivet 36a is countersunk on the cone side by the selected geometry. As the friction ring wears, the rivet connection also wears away, but the rivet head (Schlie β kopf) remains on account of the conical shape and therefore does not lose its connection to the retaining element 16.

Fig. 6a to 6b show the clutch plate 10 in perspective view with and without the friction means of the cover plate 24. In fig. 6b, the friction ring 14 and the pretensioning element 18 (e.g. a disk spring) can be clearly seen. Furthermore, rivets 34 are shown, which connect the output disk 24 to a hub ring 40 of the driven hub 28 in a rotationally fixed manner. For example, the clutch plates shown in fig. 6a and 6b may be provided with the proposed friction means 12.

Fig. 7 shows a further embodiment of a clutch plate with a friction device, the holding plate of which has a reduced axial stiffness. As shown in the embodiment of fig. 4a to 4c, the retaining plate 16 according to the embodiment of fig. 7 has bent tabs 16 c. The holding plate 16 is in this case only circularly curved in the radially outer region, but is otherwise flat, for example, in the first and second axially outer regions. The illustrated design of the bent tab 16c results, for example, in a particularly low axial force exerted by the retaining element 16. For example, the illustrated form of the holding element 16 can be used to stress-neutrally effect the installation of the friction device 12 without the pretensioning force shown in fig. 3c being required, for example.

Fig. 8 shows an exemplary embodiment of a clutch plate with two friction devices 12, 12 a. In other words, the clutch plate shown in fig. 8 is provided with a double friction device. As shown in the previous figures, a first friction device 12 is arranged between the driven disc body 20 and the output disc 24. In contrast, a further friction device 12a, which comprises a friction ring, a holding element and a prestressing element, is arranged between the driven disk body 20 and the second output disk 26 instead of the friction ring 32. In general, all previously shown embodiments of the friction device may also be mounted on both sides, for example to provide an increased amount of wear of the friction device.

Guided friction devices are shown in this disclosure. The friction ring can be prevented from rotating by the proposed concept. The holding plate for the friction ring is, for example, designed in the axial direction in order to be able to compensate for wear of the friction ring. In contrast to other friction devices comprising a friction ring with play, for example in the event of vibrations/friction torques, the attachment of a disk spring generating a preload force to the cover plate and/or the friction ring can also be avoided. Force/travel losses can thus be avoided, whereby the entire wear width of the friction ring can be used. The service life of the friction device can thus be extended.

In tests, a surprising effect was found in the friction device according to the invention, which effect significantly exceeded the service life compared to the expected technical improvement. These surprising effects are exemplarily explained by using the friction device 12 according to fig. 2a-2c, but can be found in all friction devices described herein.

The first effect occurs when the friction means 12 exert an axial force on the connecting element 36, in particular the rivet 36, which acts away from the friction surface.

In particular, such an axial force is exerted on the connecting element by the retaining plate 16, which pulls the connecting element towards said retaining plate. The retaining plate applies an axial force to the friction ring that is directed away from the friction surface of the friction ring with the driven disk body. This axial force Z is shown, for example, in fig. 2a and is referred to below as the tensile force Z.

In addition, an axial pretensioning force V is exerted by the pretensioning element 18. The pretensioning element 18 presses the friction ring towards the friction surface with the driven disc body 20.

In the new state, the friction ring 14 has high rigidity, so that the friction ring 14 is worn evenly over its entire contact surface with the driven disk body 20. Correspondingly, the connecting element 36 is also worn. But the stiffness of the friction ring 14 decreases with increasing wear. The tensile force Z causes the wear in the region of the connecting element 36 to be lower than in the radial region of the prestressing element. Thus, the connecting element 36 wears more slowly than expected, thereby providing a longer useful life for the friction device 12. Furthermore, a greater amount of wear is used in the radially inner region of the friction ring.

Starting from a disk-shaped friction ring with a constant thickness, it is clear at the end of the service life that the thickness of the friction ring in the region of the connecting element 36 is smaller on the radial inside than on the radial outside.

Another effect is also produced by the wear of the friction ring 14. The function of the friction means 12 is defined by the possibility of providing sufficient force acting on the friction ring. When the force provided by the pretensioning element is reduced too much, the friction means will lose its effect.

The effective axial force acting on the friction ring is derived from the individual components, the prestressing element, the retaining element and the friction ring on the friction device.

F_{General assembly}＝F_{Pretensioning element}–F_{Holding element}

The sign of the holding element is selected to be negative, since it preferably has an axial pretensioning force opposite to the pretensioning element. The friction ring does not exert any force on the friction device itself, but rather supports the forces acting on it from the pretensioning element and the holding element. The retaining element therefore reduces the force of the pretensioning element.

The actual pretensioning element, for example a disk spring, has a spring force that depends on the compression path. Such pretensioning elements therefore operate in a specific functional window, wherein the spring force generally decreases at the end of the service life. In the case of a cup spring, the spring force is first increased and then decreased from the new state of the friction device.

As the wear increases, the thickness of the friction ring decreases so that it becomes softer and softer. This results in the friction ring absorbing a part of the force of the holding element. The force is considered as a whole to yield the following formula:

F_{general assembly}＝F_{Pretensioning element}–F_{Holding element}+F_{Friction ring}

For "-F_{Holding element}+F_{Friction ring}"shows that the force component of the holding plate acting on the pretensioning element decreases with increasing service life. Thus, as the service life increases, the total force provided in the friction device 12 decreases more slowly than expected. The service life of the friction device is thereby increased, since the necessary axial force is provided for a significantly longer time than originally intended, unexpectedly.

List of reference numerals:

10 clutch plate

12 Friction device

12a further friction device

14 Friction ring

16 holding element

16a connection region

16b radial structure

16c bent tab

18 pretensioning element

20 driven disc body

22 Friction lining

24 first output tray

24a fixing mechanism

26 output tray

28 driven hub

30 spring element

32 friction ring

34 rivet

36 connecting element

36a conical rivet

38 fixing mechanism

40 hub ring

Z tension

V-pretightening force