JPH0642553A - Friction clutch - Google Patents

Abstract

PURPOSE: To simplify a structure of an after-adjustment means by performing the adjustment in the axial direction corresponding to a wear condition of a friction lining by a wear compensation device and restricting the after- adjustment function by a means provided on a pressurizing plate. CONSTITUTION: A friction clutch 1 has an after-adjustment means which compensates wear in the axial direction of friction faces of a pressurizing plate 3, a pressure receive plate 6, and a friction lining 7, and the after-adjustment means consists of a wear compensation device 16 provided between a pressing belleville spring 4 and the pressurizing plate 3 and a restriction member 17 constituted as a wear sensor restricting a separation process of the pressurizing plate 3. The wear compensation device 16 has a compensation ring 26 which is loaded by a pressing plate spring 4 and consists of a thin plate having a U-shaped cross section, and an adjustment mechanism 34 is provided between the compensation ring 26 and the pressurizing plate 3 to enable automatic after- adjustment of the compensation ring 26 when the friction clutch is separated and causes lining wear and lock when the clutch is connected. The compensation ring 26 during connection stage of the friction clutch 1 maintains the specified position in the axial direction for the pressurizing plate 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction clutch, particularly for an automobile, having a pressure plate which is non-rotatably and displaceably restricted in the axial direction and which is connected to the casing. Between the pressure plate and the pressure receiving plate, for example, the flywheel, through which at least one operating member and a force accumulating member are provided. Loaded, in this case at least with post-adjustment means for compensating for wear of the friction lining of the clutch disc.

[0002]

2. Description of the Related Art An automatic rear-adjustment type clutch which performs rear-adjustment according to lining wear is disclosed, for example, in German Patent No. 2920932 and German Patent Application Publication No. 3
It is known from specification 518781.

In the case of this clutch, the post-wear adjustment is carried out via an axially adjustable support between the pressure plate and the disc spring, which support is supported on the pressure plate via a ramp. And is adjusted in the direction of the disc spring by pivoting in a circumferential direction relative to the pressure plate or by appropriately shifting the wedge body engaging between the bevels of the pressure plate or the support. It

In order to detect the lining wear state, both arrangements are provided with a number of sensor elements acting between the pressure plate and the flywheel or clutch cover,
This sensor element, when the clutch is engaged, is adjusted in response to the lining wear and limits the lifting of the pressure plate to a defined value when the clutch is disengaged.

In this case, in the new state of the clutch, the disc spring performs the same lifting stroke as the pressure plate in the area of the support when the clutch is disengaged. When lining wear occurs, the pressure plate is displaced in the direction of the flywheel. In this worn condition, the disc spring must have a greater stroke in the region of the bearing than the pressure plate by the amount of wear, whereby the support is axially adjusted in the direction of the disc spring in accordance with the play that occurs in this case. It

This type of post-conditioning does not work reliably in practice. This is because even in the case of a constant disengagement stroke, the lifting stroke of the disc spring varies considerably in the spring tongue and also in the dissociation bearing, an extremely large dissociation stroke variation occurs.

This leads to mistakes when adjusting the dissociation mechanism, for example in a mechanical dissociation mechanism, which results in a very small play or a very large preload between the dissociation member and the disc spring. This results in a completely different working point for the clutch.

When using a self-adjusting dissociation mechanism, for example a hydraulic mechanism with a signal generating and receiving cylinder, the mechanism does not work at all. The same disengagement stroke always occurs in the clutch over its service life and, in this case, as long as the lifting movement of the disc spring in the area of the support is less than or equal to the pressure plate movement Because it is not adjusted.

If, on the other hand, the disc spring makes a greater lifting movement than the pressure plate, it is adjusted in each disengagement operation independently of the lining wear and the clutch is fully adjusted in a short time. .

Another problem with the known self-adjusting clutches is that the pressure plate is excited by natural resonance vibrations and in this case is lifted axially from the disc spring, so that the adjusting device fully adjusts the clutch. Is to do.

[0011]

SUMMARY OF THE INVENTION The object of the present invention is to improve a friction clutch of the type mentioned at the outset to provide an improved post-adjustment means over the prior art, in which case the post-adjustment means. The structure is simple and the rear adjusting means requires only a small space, and furthermore, the friction clutch can be manufactured particularly easily and inexpensively.

[0012]

According to the present invention, the above-mentioned problem is solved between an operating member and a pressure plate provided for connecting and disconnecting a friction clutch, or between a force accumulating member and a pressure plate. A wear compensating device is provided in the control unit, which causes a virtually constant force load on the pressure plate by the accumulator member, in which case the wear compensating device is actuated by means of a post-adjustment corresponding to the wear. Axial adjustment is performed between the force member and the pressure plate according to the wear state of the friction lining,
In this case, the problem is solved if the wear compensation device is subsequently limited or locked by means of means provided on the pressure plate when an adjustment corresponding to the actual wear state of the friction lining is obtained. .

That is, according to the present invention, the pressurizing plate is provided with means for preventing the post-adjustment of the wear compensating device beyond the actual wear stroke. In this case, the post-wear adjustment and the post-adjustment limit are clutches. It is performed during the dissociation process.

Due to the structure and function of the friction clutch, an axially clamped disc spring is provided between the casing and the pressure plate, which disc spring is supported by the casing. Has a ring-shaped base body which is pivotable about its bearing and which forms a force-storing member, from which a radially inwardly extending tongue is formed to form the actuating member. is doing.

The limiting member of the wear compensation device is simply formed by at least one wear sensor, which wear sensor has at least one sensor component which is movable with respect to the pressure plate. The member limits the disengagement stroke of the pressure plate by abutting the stationary component axially. In this case, the axially stationary component is formed by a clutch casing or a pressure plate. The sensor component is preferably constructed and arranged in such a way that a virtually constant disengagement stroke of the pressure plate with respect to the casing is maintained over the service life of the friction clutch.

In order to ensure satisfactory lining wear, the sensor component is preferably held axially displaceable with respect to the pressure plate. For this purpose, the sensor component can be connected indirectly or directly to the pressure plate by means of an automatic rearrangement device and can be brought into contact with at least one stationary component in the axial direction to accommodate lining wear. It can move with respect to the pressure plate. This movement preferably takes place during the coupling process. The contact area for the sensor component can be provided in the clutch casing and / or the pressure plate.

By contacting the wear sensor with a suitable axially stationary component, the wear compensator is offloaded during the disengagement stroke, so that if lining wear is present, the wear compensator then adjusts the sensor. The adjustment is possible until limited by the cooperation of the component and the adjustment member of the wear compensation device.

Advantageously, a number of wear sensors are provided which are distributed over the circumference of the pressure plate, the wear sensors impacting the pressure plate against the axis of rotation of the friction clutch in the disengaged state of the friction clutch. Guarantees a free positioning.

Advantageously, the sensor component has an abutment area which cooperates with the opposite abutment area of the rear adjustment member or compensation component of the wear compensation device when the friction clutch is disengaged. The sensor component, which ensures a constant lifting stroke of the pressure plate, can be connected to the pressure plate, preferably via an automatic adjustment device.

Such a post-adjustment device is produced, for example, by a frictional connection between the pressure plate and the sensor component, the frictional connection being overcome if a predetermined force is exceeded during the connection process. , Whereby the sensor component is readjusted relative to the pressure plate in accordance with the actual wear that has occurred.

However, the rear-adjustment device can also be obtained by means similar to a freewheel, which allows rear-adjustment of the sensor component with respect to the pressure plate during the coupling process, whereas the sensor component when the clutch is disengaged. The member is locked with respect to the pressure plate by the rear adjustment device.

A particularly simple and functional construction of the post-adjustment means for compensating for lining wear inside the friction clutch is that the compensating device has a bearing component, especially for accumulators such as disc springs. And between this support component and the pressure plate an adjusting mechanism is provided which causes automatic post-wear adjustment of the support component when the friction clutch is disengaged and which is self-locking when the clutch is engaged. Guaranteed by being provided.

This means that the compensator is released when the support component is unloaded and the compensator remains adjusted, ie locked, when the support component is loaded.

For this purpose, advantageously, the support component is axially displaceable in a direction away from the pressure plate and axially lockable in a direction relative to the pressure plate. in this case,
The compensator acts like a freewheel when the friction clutch is disengaged and self-locks when the friction clutch is engaged.

A particularly advantageous design of the compensator is ensured by the use of a ring-shaped component for forming the compensating component. In this case, the ring-shaped component is supported by the pressure plate via the lamp. The lamps cooperate with counter lamps, in which case the lamps are preferably clamped to one another via at least one spring element.

In this case, the lamp and the counter lamp can be constituted by individual constituent members which can be arranged between the pressure plate and the ring-shaped constituent member, for example, a wedge-shaped constituent member.
However, it is also possible to directly form at least one of the lamps into a ring-shaped component or pressure plate.

In a simple structure of the friction clutch, the ring-shaped component is constructed as a hollow thin plate-shaped member with a U-shaped cross section, in which case a circumferential ramp forming a ramp is formed in the free space of the component. It is obtained by accommodating the components distributed over. In this case, this wedge-shaped component is preferably non-rotatable with the ring-shaped component.

An advantageous design of the compensator is obtained in that the wedge-shaped component is guided axially displaceably with respect to the ring-shaped component. The counter lamp can likewise be constituted by a wedge-shaped component, which is axially engaged in the free space surrounded by the compensating component, which is at least partly ring-shaped, and which is attached to the pressure plate and the compensating component. It can rotate with respect to it. In this case, it is further advantageous if the compensation component is held non-rotatably with respect to the pressure plate.

The counter lamp is spring-loaded in the direction of the lamp in order to ensure an automatic rearrangement of the compensator.
Such a spring load is provided by a spring, for example a coil spring, clamped between the components forming the ramp and the counter lamp, in which case the spring is likewise accommodated in the ring-shaped free space of the compensation component. However, it can also be designed as a compression spring.

The components forming the counter lamp are at least partially housed between the components forming the lamp in the axial direction and the ring-shaped compensating component. For the satisfactory holding and guidance of the springs for tensioning the lamp and the counter lamp, at least the end areas of the spring are guided by the components forming the lamp and the counter lamp.

Suitable components for this purpose have at least an add-on or projection extending within the end region of the preloaded spring. In this case, the springs are respectively wedge-shaped components, which are non-rotatably and axially movably connected to the ring-shaped support component, and circumferentially adjacent wedges, which are rotatable with respect to the support component. Between the strip-shaped component.

The components forming the lamp and / or the counter lamp are simply made of plastic, for example by an injection process. Suitable plastics are preferably heat-insulated or heat-resistant plastics, for example thermoplastic or thermoset plastics. In this case, the material forming the lamp component and / or the counter lamp component preferably has a high friction value which corresponds to the friction value of the friction lining material.

The compensator is designed to self-lock when axially clamped by appropriate selection of the ramp and / or on-ramp ride-on angle and the coefficient of friction between the ramp and the on-ramp. it can. For this purpose, the lamps and / or the counter lamps are axially 5 ° to 20 °.
To have an elevation angle of 8 degrees, preferably 8 to 12 degrees,
Designed. Thus, by properly designing the compensator, the compensator is self-locking during the friction clutch engagement phase, thereby eliminating the need for additional means to prevent undesired return adjustment of the compensator.

The force-storing members for tensioning the ramps and the counter lamps are tightened so that they are always adjusted after lining wear has occurred or existed, that is to say that they are adjusted after wear even when the clutch is rotating. It is fixed. The spring loading of the lamps and the counter lamps in this case advantageously does not impair or practically impair the functioning of other springs, in particular the actuating and adjusting springs and the leaf springs connecting the pressure plate to the casing or cover. Done.

However, for many use cases, the post-adjustment means are preferably speed-related. Thus, for example, centrifugal forces acting on the individual components of the afterconditioning means can be used to operate and / or shut off the afterconditioning means in certain operating conditions of the internal combustion engine. In particular, the rear-adjustment means can be locked by means associated with centrifugal force at a given rotational speed or above a certain rotational speed range.

For many use cases, it is advantageous for the post-adjustment means to work only at least approximately at idling speeds or below the idling speed, so that the post-wear adjustment results in low internal combustion engine speeds. The post-adjustment means can be designed so that only in the case of
The means for effecting the interruption or unblocking of the post-wear adjustment can advantageously be formed by a component which is part of the compensator and which forms, for example, the lamp and / or the counter lamp.

Due to the post-adjustment function of the compensator, it is particularly advantageous if the clutch is disengaged in the range of the diameter of the pressure plate load by the disc spring, the disc spring travel being determined by a limiting member or a wear sensor for lifting the pressure plate. Designed to be larger than the process. This allows the compensating device to be unloaded after the abutment of the axially stationary component to the limiting member and thus to be released for the subsequent adjustment.

According to an advantageous configuration, the compensating device comprises two lamp devices which are in contact with each other, one of the lamp devices being non-rotatable with respect to the pressure plate and the other of the lamp devices. It is non-rotatable with respect to the compensating component loaded by the energy storage member, in which case the compensating component is pivotable with respect to the pressure plate.

The invention further relates to a friction clutch, in particular for motor vehicles, which has a pressure plate which is connected to the casing in a non-rotatable, axially restricted and displaceable manner, in this case between the casing and the pressure plate. A crimping disc spring is axially clamped on the one side, which on the one hand is swivelable about a ring-shaped swivel bearing supported by the casing and on the other hand a pressure plate and a pressure plate and a pressure plate. ,
For example, a post-adjustment means is provided for compensating wear of the friction lining of the clutch disk under load in the direction of a tightenable clutch disk with the flywheel, which post-adjustment means is provided by a compression spring. This produces a virtually constant force load on the pressure plate, in which case a wear compensator is provided between the crimp disc spring and the pressure plate, the wear compensator being axially displaceable At least one compensating component,
Furthermore, the axial dissociation stroke of the pressure plate is such that at least one component is axially stationary with respect to the pressure plate, such as a casing and / or
Axial movement of the compensating component with respect to the pressure plate, which is restricted by the restriction member acting with the pressure plate and is maintained at least substantially constant, and the restriction member is at least disengaged from the friction clutch. Is restricted.

Furthermore, for the function of the friction clutch, in particular for reducing the dissociation force profile or the required maximum dissociation force, it is particularly advantageous if a clampable clutch disc is provided between the pressure plate and the pressure plate. A so-called lining elastic body (known from DE-A 36 31 863) is arranged between the friction linings.

The use of such a clutch disc assists the operation, especially the disengagement stroke of the friction clutch. This is due to the fact that the lining elastic body clamped in the friction clutch engaged state exerts a reaction force on the pressure plate against the force exerted on the pressure plate by the pressure disc spring or the operation disc spring. is doing.

In the case of the dissociation process, during axial displacement of the pressure plate, the pressure plate is first pushed back by the lining elastic body which is elastically elastically clamped, in which case at the same time the crimping which is present in the dissociation range and falls relatively steeply Due to the characteristic curve division of the disc spring, the force exerted by the crimp disc spring on the pressure plate is reduced. As the force exerted from the crimp disc spring to the pressure plate decreases, the return force exerted from the lining elastic body to the pressure plate also decreases.

The force actually required to disengage the friction clutch is obtained by the difference between the restoring force of the lining elastic body and the crimping force of the crimp disc spring, and in this case, if necessary, between the pressure plate and the casing. The axial force of the leaf spring clamped at is taken into account. After the lining elastic body has relaxed, i.e. when the pressure plate is lifted from the friction lining or the clutch disc is released by the pressure plate, the required disengagement force is mainly defined by the crimp spring.

The force / stroke characteristic of the lining elastic body, the force / stroke characteristic of the crimp disc spring, and the force / stroke characteristic of the leaf spring are as follows:
The pressure plates are adapted to one another so that when the clutch disc is released, the force required to operate the crimp disc spring occupies a low level. That is to say, by adjusting or adapting the characteristics of the lining elastic body to the force profile formed or combined by the crimping disc spring and optionally a leaf spring, the crimping disc spring until the clutch disc is released by the pressure plate. The operating force for the crimp disc spring is virtually unnecessary in the extreme case.

Thus, when adapting the individual spring forces, the axial forces exerted by the leaf springs acting between the pressure plate and the casing must be taken into account. Furthermore, when designing the clutch, it is necessary to consider that the sliding or adjusting force of the wear sensor is provided by at least one crimping force accumulating element, for example a disc spring, and thus of a correspondingly strong construction. is there.

Further advantageously, the adjustment force of the wear sensor is designed such that this adjustment force is certainly greater than the combined axial force produced by the clamping of the wedge bodies forming the ramp and the counter ramp. The axial force is absorbed by the wear sensor.

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The friction clutch 1 shown in FIGS. 1 and 2 comprises a casing 2 and an axially restricted and displaceable pressure plate 3 which is non-rotatably connected to the casing. There is.

A crimping disc spring 4 is clamped in the axial direction between the pressure plate 3 and the cover 2, and the crimping disc spring swivels around a ring-shaped swivel bearing 5 supported by the casing 2. A pressure-bearing plate 6, which is possible and is immovably connected to the casing 2, is loaded, for example in the direction of a flywheel, with a pressure plate 3, whereby the friction lining of the clutch disc 8 between the friction faces of the pressure plate 3 and the pressure plate 6 is applied. 7 is fixed.

The pressure plate 3 is non-rotatably connected to the casing 2 via a pivot member that extends in the circumferential direction or the tangential direction as the leaf spring 9. In the exemplary embodiment shown, the clutch disc 8 has a so-called lining spring segment 10, which guarantees a gradual torque formation when the friction clutch is engaged, in this case both in the mutual direction. It allows a gradual increase in the axial force acting on the friction lining 7 over a limited axial displacement of the friction lining 7.

However, it is also possible to use a clutch disc in which the friction lining is essentially immobile in the axial direction on at least one supporting disc.

In the illustrated embodiment, the crimp disc spring 4 has a ring-shaped base body 4a for exerting a crimping force, from which an operating tongue piece 4b extending inward in the radial direction extends. In this case, the crimping disc spring 4 can load the pressure plate 3 in the range where the crimping disc spring is located further outside in the radial direction, and can be swung about the swivel bearing 5 in the range where it is located further inside in the radial direction. As it is, it is built in.

The swivel support 5 includes two swivel support members 11,
12, the swivel support member is formed by a wire rod, and a crimp disc spring is axially held or clamped between the swivel support members. A holding member as a rivet member 15 is fixed to the cover in order to prevent the operation / crimping disc spring from rotating and to hold the wire rods 11 and 12 in a centered manner with respect to the casing 2. Respectively extend by means of axially extending shafts 15a via notches provided between adjacent disc spring tongues 4b.

The friction clutch 1 has a post-adjustment means for compensating the axial wear of the friction plates of the pressure plate 3, the pressure-receiving plate 6 and the friction lining 7, and the post-adjustment means are the crimp disc spring 4 and the pressure plate. 3 and a limiting member 17 configured as a wear sensor for limiting the dissociation stroke of the pressure plate 3.

Limiting member 17 acting as a wear sensor
Each have a bush 18 which is non-rotatably received in a hole 20 of the pressure plate 3. The bush 18 forms a slit 21 through which two leaf spring elements 22 extend in the axial direction.

The leaf spring elements 22 are supported on one another, in this case at least one leaf spring element 2.
2 is curved, but it is advantageous if both leaf spring elements 22 are curved in opposite directions. The leaf spring element 22 is received in the bush with a defined preload and is thus movable in the axial direction of the friction clutch 1 relative to the bush 18 against a predetermined frictional resistance.

The axial length of the leaf spring element 22 is such that, in the illustrated embodiment, the leaf spring element is axially stationary relative to the axially stationary clutch component (in the illustrated embodiment, in the outer edge region 23 of the casing 2). In contrast, it is chosen to have a defined play 24 corresponding to a given dissociation stroke of the pressure plate 3.

In the engaged state of the friction clutch, the leaf spring element 22 contacts the pressure receiving plate 6 at the end 22a opposite to the casing 2, so that when the friction lining 7 is worn, the pressure plate 3 corresponds to the lining wear. It can be displaced axially with respect to the leaf spring element 22, ie against the frictional connection between the bush 18 and the leaf spring element 22, which is preferably made of plastic or friction material.

In the illustrated embodiment, the hole 20 through which the bush 18 is axially and circumferentially fixed by press fitting is
Provided in the pressure plate projection 25, the pressure plate projection extends outward in the radial direction and one leaf spring 9 is pivotally attached to the pressure plate projection by a rivet connecting member 9a.

The movement of the bush 18 in the direction of the pressure receiving plate 6 is
The bush has a brim 18a at the end facing the casing, which prevents it from being supported by the pressure plate 3 through the brim.

The reciprocal movement of the bush 18 from the hole 20 in the direction of the casing or the clutch cover 2 causes the leaf spring 9 to partially cover the bush 18 in the radial direction, as shown in phantom in FIG. If necessary, it is prevented by additionally immovably axially fixing it in the bore 20. Furthermore, the rotation of the bush is prevented by the bush having a molding, in particular a step, which receives the leaf spring region 19 covering the bush.

The wear compensator 16 is a compensating ring 2 which is loaded by a crimping leaf spring 4 and consists of a thin plate of U-shaped cross section.
6 has a compensating component (illustrated in plan view in FIG. 5). The compensating component is the bottom 2 facing the crimp leaf spring 4.
On the side of 7 there is at least one ring-shaped axial projection or projections 28, which are preferably evenly distributed over the circumference and stamped into the sheet material. Formed by the deformed portion.

The segmented projections 28 provide radial passages between the disc spring base body 4a and the compensating ring 26 in the area between the circumferentially adjacent projections 28, which allow air flow for cooling. Will be formed.

As is apparent from FIG. 2, the compensating ring 26 is centered with respect to the pressure plate 3. For this purpose, the pressure plate 3 has at least one step 29 which aligns the axially radially extending inner wall 30 of the compensation ring 26 with respect to the pressure plate 3.
The step portion 29 is formed by a closed surface that extends in the circumferential direction, or is formed by segment-shaped surfaces that are spaced from each other in the circumferential direction.

Furthermore, the compensation ring 26 has an axially extending radially outer wall 31 which, together with the inner wall 30 and the bottom 27, forms a ring-shaped free space 26a.

On the outside in the radial direction, the compensation ring 26 is a radial overhang or projection 32 which forms a stopper.
Which has a counter-acting stop 33 which is an axially movable component of the wear sensor 17 as the leaf spring element 22.

The opposed stopper 33 is the leaf spring element 22.
Is formed by an integrally formed projection, which extends radially inward and covers the overhang 32. As a result, the axial movement of the compensation ring 26 in the direction away from the pressure plate 3, i.e. in the direction of the casing, is restricted by the counterstop 33.

An adjusting mechanism 34 is provided between the compensating ring 26 and the pressure plate 3, and this adjusting mechanism is used when the friction clutch is disengaged or when lining wear occurs.
When the friction clutch is engaged, allowing automatic rearrangement of the compensation ring 26, it acts in a self-locking or locking manner, whereby the compensating ring 26 acts on the pressure plate 3 during the engagement phase of the friction clutch 1. Maintain a defined axial position relative to it. This defined position can be changed only during the dissociation process and depending on the lining wear that occurs.

The rear adjustment device 34 has a large number of, preferably circumferentially evenly distributed pairs of wedge bodies 35, 36, which wedge bodies have a ring-shaped free space of the compensation ring 26. It is accommodated in 36a.

The wedge member 36 supported on the ring-shaped surface 37 of the pressure plate 3 is connected to the compensating ring 26 so as not to be rotatable but movable in the axial direction. For this purpose, the compensating ring 26 has in the region of the axially extending walls 30, 31 moldings 38, 39 as indentation deformations, which in the region of the free space 26a are suitable for the wedge body 36. To form a protrusion that engages in a recess or groove 40, 41 adapted to the.

The grooves 40, 41 or the molded portions 38, 39 extend in the axial direction of the friction clutch. The wedge body 35 is housed approximately axially between the bottom 27 of the compensation ring 26 and the wedge body 36. The wedge bodies 35, 36 have ride-on ramps 42, 43 that extend in the circumferential direction and that rise in the axial direction, through which the wedge bodies 35, 36 assigned in pairs are supported.

The wedge body 35, on the other hand, is supported on the bottom of the compensation ring 26 and is movable in this direction in the circumferential direction. The riding ramps are clamped together. For this purpose, the force accumulating member 44 as a coil spring
Is housed in a free space 26a, the coil spring being supported at one end by a compensation ring 26 on a non-rotatable wedge 36 and at the other end by a circumferentially movable wedge 35.

To retain the coil spring 44, the wedges 35, 36 are provided with protrusions 4 at the end facing the appropriate coil spring.
5, 46, which engages in the spring winding and thus holds the spring end. Further coil spring 44
Are guided via the bottom 27 of the compensation ring 26 and the wall areas 30, 31.

In the illustrated embodiment, the compensation ring 26 is prevented from rotating with respect to the pressure plate 3. For this reason, as is apparent from FIG. 4, the pressure plate 3 is provided with an axial projection 47 as a pin, and this projection is provided with the projecting portion 32.
Extends in the axial direction through a notch 48 provided in the range. Due to this rotation prevention, the contact area of the overhanging portion 32 is always positioned and maintained below the facing stopper 33 of the leaf spring element 22 during the friction clutch operation.

In the illustrated embodiment, the wedges 35, 36 are made of a heat resistant plastic, for example a thermoplastic or thermosetting plastic which is additionally reinforced with fibers. This allows the wedge body 3 to act as a rear adjustment member.
5,36 are manufactured as injection molded parts in a simple form.

However, it is advantageous if at least one wedge of the pair of wedges is made of a friction material, for example a lining material. However, the wedge body or the rear adjusting member 35, 36 can also be manufactured as a thin plate forming member as well as a sintering member.

The rise angle and extension of the ride ramps 42, 43 ensure a post-adjustment of the wear that occurs on the friction surfaces of the pressure plate 3 and the pressure plate 6 and on the friction lining 7 throughout the service life of the friction clutch. Is designed to.

The wedge angle 49 or the rising angle 49 of the riding ramps 42 and 43 with respect to the plane perpendicular to the rotation axis of the friction clutch means that the friction generated when the riding ramps 42 and 43 are fastened to each other is between the riding ramps. Have been chosen to prevent the skidding of. Ramp-up lamps 42, 43
The rising angle 49 is 5 degrees to 20 depending on the material pair in the range
The degree is preferably 10 degrees. The wedge body 35 that is movable in the circumferential direction is arranged so that the wedge tip points in the rotational direction 50.

Riding ramps 42, 43 and ascending angle 49
The tightening action of the coil spring 44 of the
It is designed so that the combined axial force acting on 6 is smaller than the required sliding force of the sensor component 22 of the limiting member 17.

When the crimp disc spring is designed, the pressure plate 3
Must be taken into account so that the crimping force provided by the crimping disc spring is increased only by the required sliding force of the sensor component 22 and by the clamping force of the leaf spring clamped between the cover 2 and the pressure plate 3. I won't.

Furthermore, the individual components are the contact wear between the crimp disc spring 4 and the compensation ring 26 as well as the sensor component 2.
It must be designed in such a way that the contact wear between the pressure plate 2 and the pressure plate 6 or between the sensor component 22 and the casing 2 is kept slightly in proportion to the wear on the lining 7.

In order to prevent the curved or corrugated leaf spring element 22 from consuming the clamping force due to the very high temperatures that occur in the pressure plate 3 during the coupling process, the bushing 18 is preferably of low thermal conductivity. Made from materials with high friction values. The wedge bodies 35, 36 can also be made of the same material.

In order to satisfactorily cool the friction clutch, in particular the pressure plate 3, it is possible to provide radially extending circumferentially distributed grooves in the pressure plate 3 (one groove 51 in FIG. 2). Is shown by a chain line). This radial groove 51
Viewed in the circumferential direction, each is provided between two adjacent pairs of wedges and extends between the compensation ring 26 and the pressure plate 3.

In the area of the coil spring 44, the compensation ring 26
Has an axial cutout starting from the bottom 27,
This forms a radial passage between the disc spring 4 and the compensation ring 26.

In order to enhance the wear resistance of the various contact points, a wear resistant layer in a suitable range, for example a hard chrome layer,
It is also possible to provide a molybdenum layer or to provide special wear-resistant components in the contact area. Thus, for example, the wear sensor can be provided with a plastic shoe in the area of contact with the pressure plate 6 and the casing 2.

The leaf spring 9 for transmitting the torque to the pressure plate 3 displaces the pressure plate 3 in the direction of the casing 2 between the pressure plate 3 and the casing 2 in a friction clutch disengaged state.
It is preloaded. This ensures that the compensating ring 26 remains in contact with the crimp disc spring 4 virtually throughout the disengagement phase or until the limiting member 17 is acted on.

In the region of the tongue tip 4c, the disengagement stroke of the friction clutch is advantageously chosen such that in the clutch disengaged state the outer edge of the crimp disc spring 4 is lifted from the compensation ring 26 by a small amount. In other words, this means that when the friction clutch is disengaged, the disc spring stroke is larger than the diameter range of the pressure plate load by the pressure disc spring 4 and larger than the lifting stroke 24 of the pressure plate 3 defined by the stroke limiting member 22. ing.

The relative positions of the individual components shown in FIG. 2 correspond to the new state of the friction clutch. Especially when the friction lining 7 is worn in the axial direction, the position of the pressure plate 3 is displaced in the direction of the pressure plate 6 so that the pressure force exerted by the pressure disc spring in the conical ratio and thus in the friction clutch connection is advantageously increased. Changes in an increasing direction. Due to this change, the axial position of the pressure plate 3 with respect to the sensor component member 22 axially supported by the pressure receiving plate changes.

On the basis of the disc spring force acting on the compensating ring 26, the compensating ring 26 follows the axial displacement of the pressure plate caused by the lining wear, whereby the stopper 32 of the compensating ring 26 causes the sensor component 22 to move. From the range used as the counter-stop as the projection 33, it is lifted in the axial direction by a value approximately corresponding to the lining wear.

The compensating ring 26 maintains its axial position with respect to the pressure plate during the coupling process. This is because the compensating ring is loaded in the direction of the pressure plate 3 by the crimp disc spring 4 and the wear compensating device has a self-locking action during the coupling process.
That is, it acts as a blocking member in the axial direction.

When the friction clutch is disengaged, the pressure plate 3 is loaded by the leaf spring 9 in the direction of the casing 2 and is displaced until the sensor component 22 contacts the casing 2 or the casing stopper area 23. The axial position of the compensation ring 26 with respect to the pressure plate 3 is maintained until this disengagement stroke, which corresponds to the lifting stroke of the pressure plate 3.

When the dissociation process is continued, the pressure plate 3 stops, whereas the compensating ring 26 follows the dissociating movement of the disc spring in the axial direction within the load diameter range, that is, the compensating ring 2
The stopper 32 of No. 6 follows the counter stopper 33 of the sensor component member 22 again. The axial movement of the compensation ring 26 is caused by the wedge body 35, which is loaded by the coil spring 44. Wedge body 35
Moves circumferentially with respect to the wedge body 36 until the compensation ring 26 is clamped against the counter-stop 33 of the sensor component 22.

The lifting stroke of the pressure plate 3 is ensured by a leaf spring 9 in the embodiment shown, which leaf spring is
Is installed between the casing 2 and the pressure plate 3 so as to have an axial preload that compresses the casing 2 in the direction of the casing 2.

When the crimp disc spring 4 is further swung in the disengagement direction, the crimp disc spring is lifted from the compensation ring 26 in the radially outer region. This is because, as already mentioned, the compensation ring 26 is restrained axially with respect to the pressure plate 3 by the sensor component 22. At least a slight lifting of such a crimp disc spring 4 with respect to the compensation ring 26 during the disengagement process is particularly advantageous for the function of the rear adjustment means.

The post-adjustment means 17; 34 according to the present invention ensures that the post-adjustment of the compensating ring 26 by the wedge bodies 35, 36 is always performed in accordance with the lining wear amount. This means that the compensating ring 26 has wedges 35, 3
Due to the axial tightening between the rear adjustment member as 6 and the sensor component 22, this causes the compensation component as the compensation ring 26 to be post-adjusted by a value greater than the appropriate lining wear. Being prevented from being done.

Furthermore, the design of the rear adjustment means according to the invention allows the rear adjustment means to be operated in the case of an excessive stroke in the area of the disengaging member such as the disc spring tongue 4b or in the case of an axial vibration of the pressure plate. It is guaranteed that no adjustment is made. This is because the wear sensor is axially supported by the wear compensator 34, which has a self-locking action even when it comes into hard contact with the casing 2, that is, via the counterstopper with respect to the pressure plate 3.

That is, in the disengaged state of the friction clutch, an axial force acts on the sensor component member 22 in the direction of the pressure receiving plate 6,
This force is greater than the frictional connection between the sensor component 22 and the pressure plate 3, in which case the sensor component does not move axially with respect to the pressure plate 3.

By means of the post-adjustment means according to the invention, the crimp disc spring operates over virtually the same characteristic curve range over the entire service life of the friction clutch and the clamping position is kept substantially constant with the friction clutch engaged. Therefore, a pressing force that is substantially invariable is applied to the pressure plate 3. In this way, the lining 7 is preferably arranged so that the spring segment 1
In combination with the clutch discs which are spring-elastically supported to one another through zero, a crimp disc spring with a characteristic curve which gradually decreases over the disengagement stroke can be used.

This results in a relatively low level of disengagement force to be actually exerted and, over the service life of the friction clutch, as long as the lining elastic properties do not change significantly over the service life of the friction clutch. Maintained constantly above.

When disengaging such a friction clutch,
The crimp disc spring 4 is swiveled about a swivel bearing 5, in which case the spring segment 10 is relaxed over a certain subrange of the axial disengagement stroke of the pressure plate 3 and thus the axial force exerted by the spring segment. Assists the disengagement process of the friction clutch. In other words, this means that at the coupling position of the friction clutch, a maximum dissociation force, which is slightly smaller than the dissociation force theoretically generated from the assembled position of the crimp disc spring 4 and the leaf spring 9, is applied.

If the elastic or slack range of the spring segment is exceeded, the friction lining 7 is released, so that the crimp disc spring 4 is still active due to the progressively decreasing characteristic curve range. The dissociation force that must be exerted is significantly reduced compared to the dissociation force corresponding to the integration point or integration position according to FIG. When the dissociation process is continued, the dissociation force decreases at least until the maximum point or the minimum point of the characteristic curve of the crimp spring 4 is reached.

The post-adjustment means shown in FIGS. 1 and 2 advantageously has the individual windings of the coil spring 44 for post-adjustment supported on the outer wall 31 of the compensating ring 26 when the friction clutch rotates. It is designed in such a way that the adjusting force exerted in the circumferential direction by the coil spring 44 is reduced or eliminated altogether on the basis of the frictional resistance between the spring winding and the compensation ring 26. That is, when the friction clutch rotates, the coil spring 44 virtually behaves rigidly based on the frictional force that suppresses the spring action.

Further, the wedge body 35 for the rearward adjustment is likewise based on the centrifugal force acting on the wedge body, and the wall 3 of the compensating ring 26 is also formed.
1 is supported in the radial direction and is prevented from rotating by the frictional force generated between the wedge body 35 and the compensation ring 26.

As a result, the wear compensating device 34 is not rotated by the coil spring 44 at least in the upper rotational speed range of the idling rotational speed of the inner-twist engine. In other words, the friction clutch 1 is designed so that the lining wear compensation is carried out only when the friction clutch is operated at idling speed or at least approximately at idling speed.

The compensating ring 26 is locked by the wear compensating device 3
By a suitable design of 4, it is also possible to carry out the adjustment after lining wear only when the inner-twisting engine is stopped, i.e. when the friction clutch does not rotate or at very low speeds. .

The constituent members 35 and 3 which constitute the rear adjustment lamp.
The material pairs between 6 as well as the material of the component cooperating with this component are advantageously an attachment which prevents post-conditioning between the ramp and the component cooperating with it over the operating life of the friction clutch. It is chosen so that it does not cause To avoid such adhesion, at least one of said components can be provided with a coating layer at least in the area of the lamp or the support surface.

In order to prevent an adhesive bond between the on-ramp and the on-ramp, an axial force for separating or peeling off the ramp is applied to the rear adjusting member when the friction clutch is disengaged or when adjusting after wear. At least one means for exerting can be provided.

In the new state of the friction clutch, that is, in the state before the friction clutch is fixed to the pressure receiving plate 6 by inserting the clutch disc, the wedge body 3 is provided.
Since 5 occupies a position further retracted with respect to the wedge body 36 compared to the position shown in FIG. 3, the compensation ring 26 has the most retracted position in the direction of the pressure plate 3 and thus the pressure plate 3. The unit of the compensation ring 26 requires very little axial structural space.

In order to hold the wedge body 35 in the retracted position before assembling the friction clutch, the wedge body 35 has an engagement range as a notch 52 for a turning or restraining member. Such restraint members are provided during the manufacture or assembly of the friction clutch and are removed after the friction clutch has been mounted on the flywheel 6, so that the rear adjustment device 34 becomes functional.

In the illustrated embodiment, a longitudinal slit 53 extending in the circumferential direction is provided in the compensation ring 26, and the engaging range of the restraining member or the turning tool is engaged in the notch 52 through the slit. It is guided through in order to fit together.
In this case, the longitudinal slits provided in the circumferential direction have at least an extension whose rotation amount corresponds to the maximum post-wear adjustment angle of the wedge body 35 in the circumferential direction.

The wedge body 35, which is held in the retracted position in the circumferential direction in the new state of the friction clutch, is retained in this position by the sensor component 22 which secures the compensation ring 26 in the retracted position. The coupling portion having a self-adjusting action between the sensor component 22 and the pressure plate 3 is a coil in which the sliding force required to move the sensor component 22 with respect to the pressure plate 3 loads the wedge body 35. Spring 4
Must be configured to be greater than the resultant force exerted on the compensation ring 26 caused by 4.

In the embodiment shown in FIGS. 1 and 2, the lamp 43 is used.
Can be formed directly by the compensation ring 26, for example by stamping a bevel, in which case the compensation ring 26 must be rotatable with respect to the pressure plate 3 by means of a coil spring 44. In such an embodiment, the wedge body 36
Is non-rotatably formed on the pressure plate 3 or is directly formed integrally with the pressure plate.

Furthermore, in such an embodiment, the overhang 32 is ensured in order to ensure that the axial limiting action between the sensor component 22 and the compensation ring 26 is maintained over the service life of the friction clutch. The stop configured as should be circumferentially extended corresponding to the required rear adjustment pivot angle of the compensation ring 26.

In the last-mentioned embodiment, the compensating ring 26 for post-adjustment is of a simple form even after the friction clutch is assembled, in particular the overhanging part 3 as a stopper extending in the circumferential direction.
It is possible to rotate from the outside in the radial direction via 2, and this projecting portion can be approached via a penetrating portion provided on the outer peripheral surface of the clutch casing 2. This radial penetration can in particular accommodate the torque transmission projection 25 of the pressure plate 3 as well as the leaf spring 9.

A further advantage of the post-adjustment means according to the invention is that the principle of the post-adjustment means can also be used in the case of so-called tension friction clutches. In this friction clutch, a disc spring is pivotally supported on the cover in the radially outer edge region and loads the pressure plate in the radially inner edge region. Such a clutch is shown in FIG.

Between the disc spring 104 and the pressure plate 103,
A wear compensating device 134 is provided that is constructed similarly to that described in connection with FIGS. 1 and 2. The post-adjustment compensating ring 126 cooperates with the sensor component 122 via the taut wear sensor 117. The post-adjustment of the sensor component 122 with respect to the pressure plate 103 is performed by bringing the stopper range 122a into contact with the casing 102 or the cover. The sensor component 122 likewise has a stopper 13 which limits the axial travel of the pressure plate 3 during the dissociation process.
Have three.

In order to enable the satisfactory functioning of the rear adjustment means according to FIG. 6, the compensation ring 126 can be moved at least slightly axially with respect to the sensor component 122. This means that a suitable abutment 133 with play between the sensor component 122 and the compensation ring 126.
a is provided or by the compensation ring 126 having a radial extent 126a which is spring-elastically deformable in the axial direction, ie elastically flexible.

According to a variant embodiment not shown, instead of cooperating the sensor component 122 with the cover 102, it advantageously cooperates with the disc spring 104 at least axially when at least the friction clutch is engaged. You can also let it. In this case, the sensor component 122 and the disc spring 10
Advantageously, the abutment with 4 takes place at a radial height of at least approximately the support diameter of the casing 2 or the disc spring support diameter. For tension-type friction clutches, it is advantageous if the bearing diameter of the wear sensor in the disc spring is larger than the bearing diameter of the disc spring in the pressure plate.

In the embodiment shown in FIG. 7, the wear sensor 21 is used.
7 is directly contained in the base of the pressure plate 203. The sensor component member 222 covers the cover area 22 forming an opposed stopper.
3 has a stopper area 222a cooperating with it. The cover area 223 is integrally provided with the fixing member 202a,
The disc spring 204 is pivotally supported by the cover 202 via the fixing member.

In the illustrated embodiment, the fixing or holding member 2
02a is integrally formed by a tongue piece formed of a cover material, through which the disc spring 20 is axially arranged.
4 is extended. A wear compensator 234 is provided radially outside the wear sensor 217 provided in the radial range of the disc spring base body 204a.

In the embodiment according to FIG. 7, the sensor component 2
Instead of cooperating axially with the casing 202 or the cover area 223, 22 is preferably at least axially the disc spring 20 when at least the friction clutch is engaged.
4 can be supported. For this reason, the disc spring 204 has a notch in the axial direction, and the sensor component is inserted through this notch, so that the stopper range 222a is the disc spring instead of the opposed stopper range 223 in the friction clutch connected state. Axially supported by 204.

When the friction clutch is disengaged, the stopper area 222a is lifted from the disc spring 204. This is because the stopper area 222a is provided on a diameter smaller than the support diameter of the spring plate in the pressure plate 203. This is because the stopper range 222a is closer to the swing diameter of the disc spring than the support diameter between the pressure plate 203 and the disc spring 204.

The present invention is not limited to the illustrated embodiment, but can be implemented in various modes.

[Brief description of drawings]

FIG. 1 is a diagram showing a friction clutch of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a partial cross-sectional view taken along the line IV-IV in FIG.

5 shows a compensating ring used in the friction clutch according to FIGS. 1 and 2. FIG.

FIG. 6 is a diagram showing a first variation embodiment of the friction clutch according to the present invention.

FIG. 7 is a diagram showing a second variation embodiment of the friction clutch according to the present invention.

[Description of Reference Signs] 1 friction clutch 2 casing 3 pressure plate 4 accumulator 4a base 4b tongue 5 swivel bearing 6 pressure plate 7 friction lining 8 clutch disc 16 wear compensator 17 limiter 26 compensator ring 26a free space 35, 36 Components 42 Lamp 43 Opposite Lamp

Claims (29)

[Claims] 1. A friction clutch, in particular for a motor vehicle, having a pressure plate which is connected to a casing so as to be non-rotatable and axially restricted so that it can be displaced. At least one friction clutch is provided between the casing and the pressure plate. An operating member and a force accumulating member are provided, and the pressure plate is loaded through the operating member and the force accumulating member in the direction of the clutch disc that can be tightened between the pressure plate and the pressure receiving plate, for example, the flywheel, In this case, at least post-adjustment means for compensating the wear of the friction lining of the clutch disc is provided, and this post-adjustment means has a wear compensation device provided between the operating member or the accumulating member and the pressure plate. The wear compensating device makes an axial adjustment between the operating member or the accumulating member and the pressure plate in accordance with the wear state of the friction lining. A friction clutch, in particular for motor vehicles, characterized in that, if an adjustment corresponding to the actual wear condition of the inning is obtained, the wear compensation device is subsequently limited in its adjusting function by means provided on the pressure plate. 2. A disc spring tensioned in the axial direction is provided between the casing and the pressure plate, and the disc spring is rotatable about a ring-shaped bearing portion supported by the casing, and 2. A friction clutch according to claim 1, comprising a ring-shaped base body forming a force-storing member, from which a tongue extending inward in the radial direction departs. 3. A limiting member for a wear compensation device is formed by at least one wear sensor, which wear sensor has a sensor component which is movable with respect to a pressure plate. 3. The friction clutch according to claim 1, wherein the frictional clutch limits the disengagement stroke of the pressure plate by abutting on the stationary component member in the axial direction. 4. At least a sensor component which is axially displaceable and axially displaceable, such as a pressure plate, is connected via an automatic rearrangement device and which is axially stationary. 4. Friction clutch according to claim 3, which is rearwardly adjustable by abutting on one component, e.g. the casing and / or the pressure plate. 5. The movable sensor component has an abutment area which cooperates with the opposite abutment area of the compensating component of the compensating device when the friction clutch is disengaged. The friction clutch according to claim 3 or 4. 6. The friction clutch according to claim 3, wherein the movable sensor component is supported by the pressure plate via a rear adjustment device. 7. The compensator has a bearing component for the energy storage member, and between the bearing component and the pressure plate an automatic wear of the bearing component when the friction clutch is disengaged. An adjusting mechanism is provided which causes a rear adjustment and which is self-locking when the clutch is engaged.
The friction clutch according to any one of 1 to 6. 8. The friction clutch according to claim 7, wherein the support member is axially movable in a direction away from the pressure plate and is axially lockable in a direction relative to the pressure plate. 9. Compensation device according to claim 1, wherein the compensating device acts like a freewheel when the friction clutch is disengaged and is self-locking when the friction clutch is engaged. Friction clutch. 10. The friction clutch according to claim 1, wherein the compensating device has a compensating component formed by a ring-shaped component. 11. The friction clutch according to claim 10, wherein the ring-shaped component member is supported by the pressure plate via a ramp. 12. The lamp cooperates with an opposing lamp,
The friction clutch according to claim 11. 13. The friction clutch according to claim 12, wherein the ramp and the counter ramp are clamped to each other via a spring. 14. The ring-shaped component is constructed as a hollow sheet-shaped component having a U-shaped cross section, in which case:
14. Friction clutch according to any one of claims 10 to 13, wherein wedge-shaped components distributed circumferentially forming a ramp are housed in the free space of the components. 15. The friction clutch according to claim 14, wherein the wedge-shaped component member is prevented from rotating with respect to the ring-shaped component member. 16. The friction clutch according to claim 14, wherein the wedge-shaped component member is axially movable with respect to the ring-shaped component member. 17. The counter lamp is constituted by a wedge-shaped component which engages in a free space surrounded at least in part by a ring-shaped compensation component and which comprises a pressure plate and Friction clutch according to any one of claims 12 to 16, which is rotatable with respect to the compensating component. 18. The friction clutch according to claim 5, wherein the compensating component is prevented from rotating with respect to the pressure plate. 19. A friction clutch according to claim 11, wherein the opposed ramp is spring-loaded in the direction of the ramp. 20. The friction clutch according to claim 19, wherein the spring loading is provided by a spring, for example a coil spring, clamped between the components forming the ramp and the counter ramp. 21. The counter lamp forming component is at least partially housed between the axial lamp forming component and the compensating component.
The friction clutch according to any one of items 0 to 0. 22. Friction according to any one of claims 11 to 21, characterized in that at least the end region of the spring which clamps the ramp and the counter lamp is guided by the components forming the ramp and the counter lamp. clutch. 23. The friction clutch according to claim 11, wherein the components forming the ramp and / or the counter lamp are made of a heat-insulating and heat-resistant material. 24. The component according to claim 11, wherein the components forming the lamp and / or the counter lamp are made of a heat-resistant material, for example a thermoplastic or thermosetting plastic. Friction clutch. 25. The friction clutch according to claim 11, wherein the material forming the ramp component and / or the counter ramp component has a high friction value. 26. When the clutch is disengaged, the disc spring stroke is designed to be larger than the pressure plate lifting stroke defined by the limiting member in the diameter range of the pressure plate load by the disc spring. The friction clutch according to any one of items 1 to 7. 27. The friction clutch of claim 26, wherein the compensator is offloaded on each disengagement stroke. 28. The compensating device comprises two ramp devices in contact with each other, one ramp device being non-rotatable with respect to the pressure plate and the other ramp device being loaded by the energy storage element. 25. A friction clutch according to any one of claims 1 to 24, wherein the friction clutch is non-rotatable with respect to the compensating component, in which case the compensating component is rotatable with respect to the pressure plate. 29. A friction clutch, particularly for an automobile, having a pressure plate that is non-rotatably and displaceably restricted in the axial direction and is coupled to a casing, wherein a pressure disc spring is provided between the casing and the pressure plate. Is clamped axially, the crimping disc spring being pivotable on the one hand about a ring-shaped swivel bearing supported by the casing and on the other hand a pressure plate and a pressure plate, for example a flywheel. Between the crimp disc spring and the pressure plate in a type in which a post-adjustment means for compensating the wear of the friction lining of the clutch disc is provided in the direction of the tightenable clutch disc in this case. A wear compensation device is provided between the wear compensation device and the wear compensation device, the wear compensation device having at least one compensation component axially displaceable and loaded by a pressure spring. And the axial dissociation stroke of the pressure plate is limited and maintained at least approximately constant by a restriction member acting between the pressure plate and at least one axially stationary component, the restriction member being at least A friction clutch, characterized in that when the friction clutch is disengaged, it limits the axial movement of the compensation component relative to the pressure plate.