EP4168685A1

EP4168685A1 - Cone friction clutch having an actuator and a lever for disengaging the clutch

Info

Publication number: EP4168685A1
Application number: EP20751077.7A
Authority: EP
Inventors: Manfred Gebhart; Martin BASCHNAGEL; Dirk Hartmann; Alcan INCE; Christian Grosser; Björn Bergfeld
Original assignee: Kendrion Markdorf GmbH
Current assignee: Kendrion Markdorf GmbH
Priority date: 2020-06-17
Filing date: 2020-07-17
Publication date: 2023-04-26
Also published as: WO2021254644A1; CN115885114A; US20230235796A1

Abstract

The invention relates to a friction surface clutch (10) for use in motor vehicles, in particular for switching an air compressor or the like, wherein the friction surface clutch comprises a first cone element (11) having a first friction surface (12) and a second cone element (13) having a second friction surface (14), wherein the friction surface clutch comprises an actuation apparatus (15) having an actuating element (16) for frictionally connecting and disconnecting the cone elements, wherein the cone elements are frictionally connected when the friction surface clutch is in an unactuated operating state, wherein the actuation apparatus has a pressure element (21) coupled to the actuating element and a lever device (22) which interacts with the first cone element, wherein the pressure element can be brought into engagement with the lever device when the friction surface clutch is in an actuated operating state such that the frictional connection can be released, the first cone element having a guide in which the pressure element can be guided, latched and secured against rotation, relative to the first cone element before reaching a wear limit of the friction surfaces and can be brought into engagement with the lever device in order to release the frictional connection, the pressure element being able to be unlatched from the guide, so as to leave the guide, when the wear limit of the friction surfaces is reached, such that the pressure element can no longer be brought into engagement with the lever device after leaving the guide and therefore the frictional connection can no longer be released.

Description

CONICAL FRICTION CLUTCH WITH AN ACTUATOR AND A LEVER FOR DISCONNECTING THE CLUTCH

The invention relates to a friction surface clutch and a method for actuating a friction surface clutch for use in motor vehicles, in particular for switching an air compressor or the like, the friction surface clutch comprising a first cone element with a first friction surface and a second cone element with a second friction surface, the friction surface clutch having an actuating device having an actuating element for frictionally connecting and releasing the cone elements, the cone elements being frictionally connected in an unactuated operating state of the friction surface clutch.

The above friction surface clutches are sufficiently known from the prior art and are regularly used in motor vehicles, in particular for switching an air compressor or the like on and off.

For example, DE 102007021 791 A1 discloses a friction surface clutch, in particular for use in motor vehicles, e.g. B. for switching an air compressor, known, in which at least two friction surfaces can be brought into frictional engagement, two conical pairs of friction surfaces are provided.

Such friction surface clutches, which are also referred to as cone friction surface clutches, always have a first cone element with a first friction surface and a second cone element with a second friction surface, wherein the cone elements or the friction surfaces can be positively connected and released. Compared to conventional multi-surface friction disk clutches, conical friction surface clutches have an advantage in that they have a higher one with a comparatively smaller structural volume of the clutch Can transmit torque. Furthermore, such friction surface clutches regularly comprise an actuating device with an actuating element for frictional connection and disconnection of the cone elements. The actuating element can be designed, for example, as a piston actuated by compressed air, which can press on the first conical element in such a way that it can be positively connected to the second conical element or detached from it. In addition, it can be provided that the cone elements are non-positively connected in a non-actuated operating state of the friction surface clutch. This is particularly advantageous in the event of a defect in the actuating device because the friction surface clutch can thus maintain operation despite the defect. For example, it is conceivable that the actuating device can be actuated electromagnetically. If the actuating device is no longer supplied with electrical energy due to some defect, it can no longer be actuated. Nevertheless, the cone elements remain non-positively connected so that the friction surface clutch or an air compressor switched by means of the friction surface clutch or some other auxiliary unit can maintain operation (fail-safe property).

When connecting and disconnecting the cone elements or the friction surfaces, the friction surfaces in particular are subject to progressive wear, so that the cone elements are no longer frictionally connected when the friction surfaces reach a wear limit in the non-actuated operating state of the friction surface clutch. This inevitably leads to a shutdown of an auxiliary unit, such as an air compressor, which is switched by means of the friction surface clutch. If the air compressor is now provided, for example, to supply a pneumatic brake system of a truck with compressed air, this can lead to failure of the brake system, which not least has serious consequences for a driver of the truck can. For this reason, it is desirable to provide a friction surface clutch of the type described at the outset, in which, in particular, the loosening of the cone elements when the wear limit of the friction surfaces is reached is reliably avoided.

It is therefore known from the prior art to monitor wear of the friction surfaces, for example by means of a sensor, and to deactivate the actuating device shortly before a wear limit of the friction surfaces is reached, so that the non-positive connection can no longer be released. This ensures that further wear of the friction surfaces is prevented and the cone elements or the friction surfaces remain non-positively connected until the friction surface clutch is replaced. However, a friction surface clutch of this type can only be manufactured and operated in a very complex manner; in particular, additional maintenance of such a friction surface clutch is necessary in order to be able to guarantee reliable monitoring of the friction surfaces by means of a sensor. Last but not least, the manufacture and operation of such a friction surface clutch turn out to be cost-intensive.

Furthermore, from the German patent application 10 2019 101 760.2 of the same applicant, which was not yet published on the priority date of the present patent application, a friction surface clutch of the type indicated at the beginning is known, in which an actuating device has a pressure ring coupled to an actuating element and three release levers connected to a first cone element, the The pressure ring can be moved relative to the release levers in an inoperative operating state of the friction surface clutch, the pressure ring being able to be pressed onto the release lever in an actuated operating state of the friction surface clutch in such a way that a non-positive connection can be released, the pressure ring and the release lever when the Friction surface clutch can continuously be shortened by abrasion in such a way that when a wear limit of the pressure ring and the release lever is reached, the pressure ring and the release lever can no longer be contacted, so that the non-positive connection can no longer be released. It turns out to be disadvantageous here, however, that the three release levers are not necessarily shortened at the same time in such a way that the pressure ring and the release lever can no longer be contacted. It is therefore not unlikely that the thrust ring will jam with the release levers.

The present invention is therefore based on the object of proposing a friction surface clutch, a motor vehicle with a friction surface clutch and a method for actuating a friction surface clutch for use in motor vehicles, in particular for switching an air compressor or the like, which or which enables an even more reliable operation of the friction surface clutch . of the air compressor.

This object is achieved by a friction surface clutch with the features of claim 1, a motor vehicle with a friction surface clutch with the features of claim 19 and a method for actuating a friction surface clutch with the features of claim 20.

The friction surface clutch according to the invention for use in motor vehicles, in particular for switching an air compressor or the like, comprises a first cone element with a first friction surface and a second cone element with a second friction surface, the friction surface clutch having an actuating device with an actuating element for frictionally connecting and releasing the cone elements, wherein the cone elements are non-positively connected in a non-actuated operating state of the friction surface clutch, wherein the actuating device has a pressure element coupled to the actuating element and a lever device cooperating with the first cone element, wherein the pressure element can be brought into engagement with the lever device in an actuated operating state of the friction surface clutch in such a way that the frictional connection can be released, the first cone element being a guide has, in which the pressure element can be guided locked against rotation relative to the first conical element before a wear limit of the friction surfaces is reached and can be brought into engagement with the lever device to release the frictional connection, the pressure element thus exiting the guide when the wear limit of the friction surfaces is reached the guide can be disengaged so that the pressure element can no longer be brought into engagement with the lever device after leaving the guide, so that the non-positive connection can no longer be released.

Accordingly, when the friction surface clutch is actuated, the actuating element does not press directly on the first cone element, but rather the actuating device has a pressure element coupled to the actuation element and a lever device that interacts with the first cone element, the pressure element when the friction surface clutch is actuated or in an actuated operating state the friction surface clutch can be brought into engagement with the lever device in such a way that the non-positive connection can be released. In the non-actuated operating state of the friction surface clutch, the cone elements or the friction surfaces are connected in a non-positive manner. If a torque is now transmitted by means of the friction surface clutch, the cone elements execute a rotational movement. The lever device can be connected to the first conical element so that the lever device can participate in the rotational movement. Furthermore, the pressure element can, for example, via a form-fitting connection between the pressure element and the first cone element, to be rotationally synchronized with the first cone element. As a result, the pressure element can also participate in the rotational movement. The actuating element, on the other hand, can be designed or arranged in such a way that it does not take part in the rotational movement. If the friction surface clutch is now actuated, the pressure element is brought into engagement with the lever device or pressed onto the lever device. This causes a displacement or tilting of the lever device and of the first conical element interacting with it, whereby the non-positive connection is released.

When the friction surface clutch is actuated, the friction surfaces are continuously abraded in such a way that the pressure element, when a wear limit of the friction surfaces is reached, can guide the first conical element in such a way that the pressure element is locked against rotation relative to the first conical element and for Releasing the frictional connection can be brought into engagement with the lever device, leaving the guide so that the pressure element can no longer be brought into engagement with the lever device after leaving the guide. Thus, the non-positive connection can no longer be released when the wear limit is reached. It is now essential that this wear limit is reached sooner than a critical wear limit of the friction surfaces, at which the friction surfaces are abraded in such a way that the friction surfaces are no longer positively connected even in the non-actuated operating state. As a result, failure of the friction surface clutch due to wear on the friction surfaces can be reliably avoided. Thus, in particular an air compressor switched by means of the friction surface clutch, which can be provided to supply a pneumatic brake system of a motor vehicle, can maintain operation so that the motor vehicle can operate up to an exchange of the friction surface clutch can continue to travel safely. Last but not least, production and operation of the friction surface clutch according to the invention have proven to be extremely cost-effective.

Advantageously, a pressure ring can be provided as the pressure element and the lever device can comprise at least two, preferably three, release levers, wherein the pressure element can comprise a base body and a number of pressure segments corresponding to a number of release levers, which are in the form of a segment of a circle, in an axial direction from the base body protruding projections can be formed, wherein the pressure element can be brought into engagement with the release levers via the pressure segments. In this case, the pressure ring can be evenly brought into engagement with the lever device or pressed against the lever device. The release levers can preferably be arranged at regular intervals around an axis of rotation of the first conical element and be connected to the first conical element with a radial inside of the release lever in a form-fitting manner. The pressure ring can then be axially displaceable to an axis of rotation of the first conical element and, via the pressure segments, press radially outwardly as far as possible onto an axial side of the release lever, so that the release lever can perform a tilting movement. The axial side can be tilted radially inward against a direction of movement of the pressure ring in such a way that the first conical element can be displaced against the direction of movement of the pressure ring, whereby the non-positive connection between the conical elements can be released. The pressure element or the base body can expediently form the pressure segments.

In a preferred embodiment of the friction surface clutch, the first conical element can have a number corresponding to the number of pressure segments on the guide at least co-forming passages have, in which the pressure segments can at least partially intervene in the non-actuated operating state before the wear limit of the friction surfaces is reached, so that the pressure segments can be held in the passages so that they cannot rotate in relation to the first conical element, the passages of the pressure segments in the actuated operating state in such a way can be penetrated so that the pressure segments can be brought into engagement with the release levers arranged behind the passages, viewed in the axial direction.

In a structurally advantageous embodiment of the invention, the first conical element can be moved away from the pressure element in the axial direction in the event of continued wear of the friction surfaces, so that the pressure segments can no longer intervene in the passages in the non-actuated operating state when the wear limit of the friction surfaces is reached , whereby the pressure segments can be disengaged from the guide leaving the guide.

According to a further development, after leaving the guide, the pressure segments can be rotated by an angle of rotation relative to the first conical element, so that the pressure segments can no longer be pressed onto the inner surface in the actuated operating state, at least partially resting on an inner surface of the first conical element, in alignment with the passages . In particular, due to rotational accelerations, which can act on the pressure element when the friction surface clutch is actuated, the pressure segments can then rotate so far in relation to the passages that the pressure segments are no longer aligned with the passages, i.e. not when the friction surface clutch is actuated engage more in the passages or can reach through them, but rather at least partially on an inner surface of the first Press the cone element or come to rest against it. Because the pressure segments no longer press on the lever device, but on the inner surface, the non-positive connection can no longer be released. Rather, the non-positive connection between the cone elements and thus a torque transmitted between the cone elements is reinforced when the friction surface clutch is actuated again when the wear limit is reached, since the cone elements are pressed against one another during this actuation. The angle of rotation can be related to an axis of rotation of the first conical element as the axis of rotation.

Advantageously, the first conical element can have a stop limiting the angle of rotation and / or at least one receiving pocket into which at least one of the pressure segments can be latched after it has left the guide completely. The stop can prevent the pressure segments from locking into passages adjacent to these passages after they have left the passages, as a result of which the non-positive connection could possibly be released again. The receiving pocket guarantees that at least one of the pressure segments can be held in the receiving pocket in such a way that it cannot rotate after it has snapped into place in the receiving pocket. As a result, it is then no longer possible to loosen the non-positive connection. A receiving pocket is advantageously assigned to each printing segment. The receiving pocket can form the stop. For example, the receiving pocket can be designed in the form of a recess.

The actuating element can preferably be actuated pneumatically, hydraulically or electromagnetically. The actuating element can particularly preferably be actuated pneumatically. In the non-actuated operating state of the friction surface clutch, the actuating element then just not acted upon by a pressure. The compressed air required to actuate the friction surface clutch can also be generated directly by the air compressor, it being conceivable that the air compressor fills a reservoir with compressed air, which can be provided to supply a pneumatic brake system of a motor vehicle.

According to an expedient construction of the invention, the actuating element can be designed as a piston. The piston can then be mounted in a receiving space of a housing of the friction surface clutch in a stationary manner relative to the housing and displaceably parallel to an axis of rotation of the conical elements. In addition, the pressure element can rotate relative to the piston.

In an advantageous variant of the invention, the actuating element can be designed to be spring-returnable. Accordingly, the actuating device can have a spring which holds the actuating element in the non-actuated operating state of the friction surface clutch in an initial position or allows it to return from an end position to the initial position when changing from the actuated operating state to the non-actuated operating state.

In a special development of the invention, the actuating device can have a spring device, preferably a disc spring, particularly preferably two disc springs stacked alternately on top of one another, by means of which the cone elements can be frictionally compressible in the non-actuated operating state of the friction surface clutch. The spring device can be connected to the first conical element so that it can participate in a rotational movement of the first conical element. When you press the Friction surface clutch, the lever device interacting with the first cone element can press the first cone element against the spring device, wherein the non-positive connection can be released. It can also be provided that the lever device presses against the spring device. A lever element can optionally be arranged between the lever device and the spring device. The friction surfaces can then advantageously be designed in such a way that their wear limit is reached comparatively more quickly than a wear limit of the spring device. In this way, undesired loosening of the conical elements in the non-actuated operating state due to wear of the spring device can be avoided.

Advantageously, the first conical element can be positively connected to a hub of the friction surface clutch by means of a toothing, wherein the hub can be arranged on a shaft of the friction surface clutch. In this way, a rotational movement of the first conical element can be transmitted to the shaft. The shaft can then serve as an output shaft, by means of which a torque can be transmitted to the air compressor.

In this context, it can also be advantageous if the first conical element is axially displaceable along an axis of rotation of the first conical element. Thus, the non-positive connection and detachment of the conical elements can take place in a simple manner by means of an axial displacement of the first conical element.

In a particularly preferred embodiment of the invention, an outside of a jacket of the first conical element can form the first friction surface and an inside of a jacket of the second conical element can form the second friction surface. Furthermore, the second conical element can be mounted on a shaft of the friction surface clutch by means of a roller bearing of the friction surface clutch. Balls, cylindrical rollers or needle rollers, which can be arranged in a bushing of the roller bearing, can be provided as the rolling elements of the roller bearing. As a result of a conical connection of the conical elements, the roller bearing can be relieved of load in a radial direction, whereby the susceptibility of the roller bearing to standstill markings (false brinelling) can be reduced.

In an advantageous variant of the invention, the second conical element can be connected to a drive wheel of the friction surface clutch. A torque can thus be transmitted directly to the second cone element, for example from an internal combustion engine of the motor vehicle.

In particular, a gear wheel can be provided as the drive wheel. A number of teeth or a diameter of the gear can be adapted to a desired transmission ratio.

The second conical element can also be screwed to the drive wheel. In this case, the drive wheel can then be detached from the second conical element in a simple manner and thus exchanged.

The friction surfaces can advantageously be made of steel. This can significantly reduce wear on the friction surfaces.

Furthermore, an inclination of the friction surfaces with respect to an axis of rotation of the conical elements can be in the range from 5 ° to 10 °. As a result, a high surface pressure of the friction surfaces with respect to one another can be achieved by means of a low application of axial force, so that a large torque can be transmitted. According to a structurally advantageous embodiment of the invention, the cone elements can be integrated into a housing of the friction surface clutch. This can prevent dirt or dust from penetrating the friction surface clutch. The housing can also form a receiving space for the actuating element.

The motor vehicle according to the invention has an air compressor or the like and a friction surface clutch for switching the air compressor. With regard to the advantageous effects of the motor vehicle according to the invention, reference is made to the description of the advantages of the friction surface clutch according to the invention.

Further advantageous embodiments of the motor vehicle emerge from the description of features in the dependent claims which refer back to device claim 1.

In the method according to the invention for actuating a friction surface clutch for use in motor vehicles, in particular for switching an air compressor or the like, a first cone element of the friction surface clutch with a first friction surface with / from a second cone element of the friction surface clutch with a second friction surface is made by means of an actuating element of an actuating device of the friction surface clutch non-positively connected / released, the cone elements being non-positively connected in a non-actuated operating state of the friction surface clutch, a pressure element of the actuating device coupled to the actuating element being brought into engagement with a lever device of the actuating device that interacts with the first cone element in an actuated operating state of the friction surface coupling the frictional connection is released, the pressure element before reaching a wear limit of the Friction surfaces in a guide of the first conical element are guided locked against rotation in relation to the first conical element and are brought into engagement with the lever device to release the frictional connection, the pressure element being disengaged from the guide when the wear limit of the friction surfaces is reached, leaving the guide such that the pressure element can no longer be brought into engagement with the lever device after leaving the guide, so that the non-positive connection can no longer be released. Regarding the advantageous effects of the method according to the invention, reference is made to the description of the advantages of the friction surface clutch according to the invention.

Further advantageous embodiments of the method emerge from the description of features in the dependent claims which refer back to device claim 1.

The inventive idea is not limited to cone clutches, but can of course also be transferred in particular to multi-disk clutches or friction-disk clutches.

Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings.

Show it:

1 shows a perspective partial sectional view of a friction surface clutch in an unactuated operating state;

2 shows a partial sectional view of a pressure element disengaged from a guide; 3 shows a perspective partial view of a pressure element locked in a guide, viewed against an axial direction; 4 shows a perspective partial view of the pressure element disengaged from the guide, viewed against the axial direction;

5 shows a perspective partial view of the pressure element disengaged from the guide and rotated relative to a first conical element, viewed against the axial direction;

Fig. 6 is a partial perspective view of the first cone member viewed in the axial direction;

7 is a partial perspective view of the pressure element disengaged from the guide, viewed in the axial direction; 8 shows a perspective partial view of the pressure element disengaged from the guide and rotated relative to the first conical element, viewed in the axial direction;

9 is a partial perspective view of the pressure element engaged in a receiving pocket, viewed in the axial direction;

10 is a partial perspective view of the pressure element engaged in the receiving pocket, viewed in the axial direction; 11 is a perspective partial sectional view of a friction surface clutch in an inoperative operating state of FIG Friction surface clutch before a wear limit of friction surfaces is reached;

FIG. 12 is a perspective partial sectional view of the friction surface clutch in an actuated operating state of FIG

Friction surface clutch before a wear limit of friction surfaces is reached;

13 shows a perspective partial sectional view of the friction surface clutch with a pressure element disengaged from a guide;

14 shows a perspective partial sectional view of the friction surface clutch with the pressure element disengaged from the guide and rotated relative to a first conical element;

15 is a perspective view of the pressure element.

1 shows a friction surface clutch 10 in an unactuated operating state of the friction surface clutch 10, the friction surface clutch 10 having a first cone element 11 with a first friction surface 12 and a second cone element 13 with a second

Friction surface 14 includes. In the inoperative operating state of the

Friction surface clutch 10, the cone elements 11 and 13 or the friction surfaces 12 and 14 are connected in a non-positive manner. Furthermore, the friction surface clutch 10 has an actuating device 15 with an actuating element 16, which is formed here by a pneumatically actuatable piston, by means of which the

Loosen conical elements 11 and 13 or allow them to be positively connected. The actuating element 16 is in a receiving space 17 of a housing 18 of the friction surface clutch 10 via roller bearings 19 and 20 of the actuating device 15 axially to a not shown here

The axis of rotation of the first conical element 11 is mounted displaceably. The Actuating element 16 is axially displaceable from an initial position to an end position. In addition, the actuating device 15 has a spring, not shown here, which the actuating element 16 when the friction surface clutch 10 is transferred from the actuated operating state to the non-actuated operating state or in the event that the actuating element 16 is no longer acted upon by a pressure from which Spends end position in the start position. The first conical element 11 is positively connected by means of a toothing, not shown here, to a hub of the friction surface clutch 10, also not shown here, the hub being arranged on a shaft of the friction surface clutch 10, also not shown here. The first conical element 11 is axially displaceable along the axis of rotation. The shaft in turn is mounted in the housing 18 of the friction surface clutch 10 by means of a roller bearing (not shown here). The second conical element 13 is mounted on the shaft via a roller bearing (not shown here) of the friction surface clutch 10, rotationally symmetrical to the axis of rotation, and is connected by means of screws (not shown) to a drive wheel (not shown) designed as a gearwheel. A disk, not shown here, positively connected to the shaft, secures the second conical element 13 against axial displacement. If the drive wheel is now driven by a drive device not shown here, for example an internal combustion engine, a torque applied by the drive device to the drive wheel or the second conical element 13 is transmitted to the first conical element 11 in the non-actuated operating state.

The actuating device 15 further has a pressure element 21 coupled to the actuating element 16 and a flebel device 22 which interacts with the first conical element 11, the pressure element 21 being in this way with the friction surface clutch 10 when the friction surface clutch 10 is actuated or in an actuated operating state of the friction surface clutch 10 Lever device 22 can be brought into engagement so that the non-positive connection can be released. In the non-actuated operating state of the friction surface clutch 10, the cone elements 11 and 13 or the friction surfaces 12 and 14 are non-positively connected. If a torque is now transmitted by means of the friction surface clutch 10, the cone elements 11 and 13 execute a rotational movement. The lever device 22 is connected to the first conical element 11 so that the lever device 22 takes part in the rotational movement of the conical elements 11 and 13. Furthermore, the pressure element 21 is rotationally synchronized with the first conical element 11 via a form-fitting connection between the pressure element 21 and the first conical element 11. As a result, the pressure element 21 also participates in the rotational movement of the conical elements 11 and 13. The actuating element 16, on the other hand, is designed or arranged in such a way that it does not take part in the rotational movement of the conical elements 11 and 13. If the friction surface clutch 10 is now actuated, the pressure element 21 is brought into engagement with the lever device 22 or pressed onto the lever device 22. This causes a displacement or tilting of the lever device 22 and of the first conical element 11 interacting with it, whereby the force-fit connection is released.

In addition, the actuating device 15 has a spring device 23, which is formed here by two alternately stacked disc springs 24 and 25, by means of which the cone elements 11 and 13 can be positively compressed in the non-actuated operating state. In the non-actuated operating state, the pressure element 21 rotatable relative to the actuation element 16 is not contacted by the actuation element 16. When the friction surface clutch 10 is actuated, the actuating element 16 is displaced axially to the axis of rotation, in an axial direction A, in the direction of the pressure element 21. In the course of an axial displacement of the Actuating element 16, actuating element 16 contacts pressure element 21 in such a way that a radially inwardly extending section 26 of an axial side 27 of pressure element 21 rests precisely in a recess 28 of actuating element 16. The pressure element 21 mechanically coupled to the actuation element 16 is then moved in the course of a further axial displacement of the actuation element 16 until the actuation element 16 has reached the end position. In the end position, the pressure element 21 presses on the lever device 22 which is connected to the first conical element 11 and which is in engagement with the spring device 23. This leads to a tilting of the lever device 22, as a result of which the first conical element 11 is displaced axially to the axis of rotation, counter to the axial direction A, in the direction of the actuating element 16. As a result, the non-positive connection between the conical elements 11 and 13 is released, so that a torque applied to the second conical element 13 can no longer be transmitted to the first conical element 11.

A pressure ring is provided as the pressure element 21 and the lever device 22 comprises three release levers 29, only one of which can be seen in FIG. 1. The release levers 29 are arranged at regular intervals around the axis of rotation of the first conical element 11. The pressure element 21 comprises a base body, not shown here, and three pressure segments, also not shown here, which are designed as circular segment-shaped projections protruding from the base body in the axial direction A, also not shown here, the pressure element 21 via the pressure segments with the release levers 29 in Are brought into engagement.

When the friction surface clutch 10 is actuated, the friction surfaces 12 and 14 are continuously abraded in such a way that the pressure element 21 at a Reaching a wear limit of the friction surfaces 12 and 14 such a guide 30 of the first conical element 11, in which the pressure element 21 can be guided in a non-rotatable manner with respect to the first conical element 11 before the wear limit of the friction surfaces 12 and 14 is reached and for releasing the non-positive connection with the lever device 22 can be brought into engagement, leaving the guide 30 so that the pressure element 21 can no longer be brought into engagement with the lever device 22 after leaving the guide 30. Thus, the non-positive connection can no longer be released when the wear limit is reached. This is shown in FIG. In particular, it can be seen here that the pressure element 21 has disengaged from the guide 30. As a result, the pressure element 21 can rotate relative to the first conical element 11 due to rotational accelerations.

3 to 10 shows an advantageous embodiment of a first cone element 31 and a pressure element 32. The friction surface clutch 10 shown in FIG. 1 can include the first cone element 31 and / or the pressure element 32.

A pressure ring is provided as the pressure element 32, the pressure element 32 comprising a base body 33 and three pressure segments 34, of which only one is shown here, the pressure segments 34 being designed as circular segment-shaped projections protruding in the axial direction A from the base body 33, wherein the pressure element 32 can be brought into engagement via the pressure segments 34 with release levers, not shown here. The pressure element 32 forms the pressure segments 34.

Furthermore, the first conical element 31 has three passages 36 at least co-forming a guide 35 of the first conical element 31, into which the pressure segments 34 in the non-actuated operating state before reaching the wear limit of friction surfaces not shown here engage at least partially so that the pressure segments 34 can be held in the passages 36 so that they cannot rotate in relation to the first conical element 31, the passages 36 being able to be penetrated by the pressure segments 34 in the actuated operating state in such a way that the pressure segments 34 with the, in the axial direction A considered, behind the passages 36 arranged release levers, not shown here, can be brought into engagement. From Fig. 3 it can be seen how a pressure segment

34 at least partially engages in a passage 36 or in the guide

35 is engaged.

With continuous wear of the friction surfaces, the first conical element 31 is moved away from the pressure element 32 in the axial direction A, so that the pressure segments 34 no longer engage in the passages 36 in the non-actuated operating state when the wear limit of the friction surfaces is reached, whereby the pressure segments 34, leaving the guide 35, disengage from the guide 35, which is shown in FIGS. 4 and 7.

After leaving the guide 35, the pressure segments 34 rotate, as can be seen from FIGS. 5 and 8, relative to the first conical element 31 by an angle of rotation not shown here, so that the pressure segments 34 are no longer aligned with the passages 36 in the actuated operating state can be pressed at least partially against an inner surface 37 of the first conical element 31 on the inner surface 37. In particular, due to rotational accelerations which act on the pressure element 32 when a friction surface clutch, not shown here, which can include the first conical element 31 and the pressure element 32, is activated, the pressure segments 34 then rotate relative to the passages 36 to such an extent that the Pressure segments 34 no longer have the passages

36 align, the pressure segments 34 when the The friction surface clutch therefore no longer engages in the passages 36 or is able to pass through them, but rather press at least partially on the inner surface 37 of the first conical element 31 or come into contact with it. Because the pressure segments 34 no longer press on the release lever but on the inner surface 37, the non-positive connection can no longer be released.

Furthermore, as can be seen in particular from FIGS. 6, 9 and 10, the first conical element 31 has stops 38 limiting the angle of rotation and receiving pockets 39 in which the pressure segments 34 engage after they have completely left the guide 35.

Furthermore, FIGS. 6 to 10 show that the first conical element 31 has a toothing 40, by means of which the first conical element 31 can be positively connected to a hub of the friction surface clutch, not shown here, the hub on a shaft of the friction surface clutch, also not shown here can be arranged.

11 to 14 shows a friction surface clutch 41 together. In particular, FIGS. 11 to 14 show a first conical element 42, a second conical element 43, release lever 44, a guide 45 and a pressure element 46 with a pressure segment 47.

11 and 12 show the friction surface clutch 41 in an unactuated or actuated operating state of the friction surface clutch 41 before a wear limit of friction surfaces, not shown here, is reached. In FIG. 11 the pressure segment 47 is locked into the guide 45.

13 and 14 show the friction surface clutch 41 after the wear limit of the friction surfaces has been reached. The pressure segment 47 is disengaged from the guide 45 and is relative to the first conical element 42 twisted. In FIG. 14, the pressure segment 43 is locked into a receiving pocket 48.

Ultimately, FIG. 15 shows the pressure element 46, designed as a pressure ring, which has a base body 49 and three pressure segments 47.

List of reference symbols

10 friction surface clutch

11 first conical element 12 first friction surface

13 second cone element

14 second friction surface

15 actuating device

16 actuating element 17 receiving space

18 housing

19 rolling bearings

20 roller bearing 21 pressure element 22 lever device

23 Spring device

24 disc spring

25 disc spring

26 Section 27 Axial Side

28 recess

29 Release Lever

30 leadership

31 first cone element 32 pressure element

33 base body

34 pressure segment

35 Leadership

36 passage 37 inner surface

38 stop 39 storage pocket

40 toothing

41 friction surface clutch

42 first cone element 43 second cone element

44 Release Lever

45 leadership

46 pressure element

47 pressure segment 48 receiving pocket

49 base body A axial direction

Claims

1. Friction surface clutch (10, 41) for use in motor vehicles, in particular for switching an air compressor or the like, the friction surface clutch having a first cone element (11, 31, 42) with a first friction surface (12) and a second cone element (13, 43) with a second friction surface (14), the friction surface clutch having an actuating device (15) with an actuating element (16) for frictionally connecting and releasing the cone elements, the cone elements being frictionally connected in an unactuated operating state of the friction surface clutch, characterized in that the The actuating device has a pressure element (21, 32, 46) coupled to the actuating element and a lever device (22) which interacts with the first conical element, the pressure element being able to be brought into engagement with the lever device in an actuated operating state of the friction surface clutch in such a way that the frictional connection can be released is, wob ei the first conical element has a guide (30, 35, 45) in which the pressure element can be guided locked against rotation relative to the first conical element before a wear limit of the friction surfaces is reached and can be brought into engagement with the lever device to release the frictional connection, the When the wear limit of the friction surfaces is reached, the pressure element can be disengaged from the guide leaving the guide in such a way that the pressure element can no longer be brought into engagement with the lever device after leaving the guide, so that the frictional connection can no longer be released. Friction surface clutch according to Claim 1, characterized in that a pressure ring is provided as the pressure element (21, 32, 46) and that the lever device (22) comprises at least two, preferably three, release levers (29, 44), the pressure element having a base body (33 , 49) and a number of pressure segments (34, 47) corresponding to a number of release levers, which are designed as circular segment-shaped projections protruding from the base body in an axial direction (A), the pressure element engaging the release levers via the pressure segments can be brought.

Friction surface clutch according to claim 2, characterized in that the first conical element (11, 31, 42) has a number of passages (36) which at least co-form the guide (30, 35, 45) corresponding to the number of pressure segments (34, 47), in which the pressure segments in the non-actuated operating state at least partially engage before the wear limit of the friction surfaces (12, 14) is reached, so that the pressure segments can be held in the passages in such a way that they cannot rotate relative to the first conical element, the passages of the pressure segments in the actuated operating state in such a way it can be reached through that the pressure segments can be brought into engagement with the release levers (29, 44) arranged behind the passages, viewed in the axial direction (A). Friction surface clutch according to Claim 3, characterized in that the first conical element (11, 31, 42) can be moved away from the pressure element (21, 32, 46) in the axial direction (A) with continued wear of the friction surfaces (12, 14) so that the pressure segments (34, 47) no longer engage in the passages (36) in the non-actuated operating state when the wear limit of the friction surfaces is reached, whereby the pressure segments can be disengaged from the guide when leaving the guide (30, 35, 45).

Friction surface clutch according to claim 4, characterized in that the pressure segments (34, 47) after leaving the guide (30, 35, 45) can be rotated relative to the first conical element (11, 31, 42) by an angle of rotation, so that the pressure segments are no longer in alignment with the passages (36) in the actuated operating state and can be pressed at least partially against an inner surface (37) of the first conical element on the inner surface.

Friction surface clutch according to claim 5, characterized in that the first conical element (11, 31, 42) has a stop (38) limiting the angle of rotation and / or at least one receiving pocket (39, 48) into which at least one of the Pressure segments (34, 47) can be locked after they have completely left the guide (30, 35, 45).

7. Friction surface clutch according to one of the preceding claims, characterized in that the actuating element (16) can be actuated pneumatically, hydraulically or electromagnetically.

8. friction surface clutch according to one of the preceding claims, characterized in that the actuating element (16) is designed as a piston.

9. friction surface clutch according to one of the preceding claims, characterized in that the actuating element (16) is designed to be spring-returnable.

10. Friction surface clutch according to one of the preceding claims, characterized in that the actuating device (15) has a spring device (23), preferably a disc spring, particularly preferably two disc springs (24, 25) stacked in alternating directions, by means of which the conical elements (11, 13 , 31, 42, 43) in the unactuated Operating state of the friction surface clutch (10, 41) are non-positively compressible.

11. Friction surface clutch according to one of the preceding claims, characterized in that the first conical element (11, 31, 42) is positively connected to a hub of the friction surface clutch (10, 41) by means of a toothing (40), the hub on a shaft of the Friction surface clutch is arranged.

12. Friction surface clutch according to one of the preceding claims, characterized in that the first conical element (11, 31, 42) is axially displaceable along an axis of rotation of the first conical element.

13. Friction surface clutch according to one of the preceding claims, characterized in that an outside of a jacket of the first conical element (11, 31, 42) has the first friction surface (12) and an inside of a jacket of the second conical element (13, 43) is the second friction surface ( 14) trains.

14. Friction surface clutch according to one of the preceding claims, characterized in that that the second cone element (13, 43) by means of a roller bearing of the friction surface clutch (10, 41) on a shaft of the

Friction surface clutch is stored.

15. Friction surface clutch according to one of the preceding claims, characterized in that the second conical element (13, 43) is connected to a drive wheel of the friction surface clutch (10, 41).

16. Friction surface clutch according to one of the preceding claims, characterized in that the friction surfaces (12, 14) are made of steel.

17. Friction surface clutch according to one of the preceding claims, characterized in that an inclination of the friction surfaces (12, 14) to an axis of rotation of the cone elements (11, 13, 31, 42, 43) is in the range of 5 ° to 10 °.

18. Friction surface clutch according to one of the preceding claims, characterized in that the cone elements (11, 13, 31, 42, 43) are integrated into a housing (18) of the friction surface clutch (10, 41). 19. Motor vehicle with an air compressor or the like and a friction surface clutch (10, 41) according to one of the preceding claims for switching the air compressor.

20. A method for actuating a friction surface clutch (10, 41) for use in motor vehicles, in particular for switching an air compressor or the like, wherein a first cone element (11, 31, 42) of the

Friction surface clutch with a first friction surface (12) with / from a second cone element (13, 43) of the friction surface clutch with a second friction surface (14) is positively connected / released, the cone elements being frictionally connected in a non-actuated operating state of the friction surface clutch, characterized in that, that a pressure element (21, 32, 46) of the actuating device coupled to the actuating element is actuated in one

Operating state of the friction surface clutch is brought into engagement with a lever device (22) of the actuating device that interacts with the first conical element, that the force-fit connection is released, the pressure element in a

Guide (30, 35, 45) of the first conical element is guided locked against rotation relative to the first conical element and is brought into engagement with the lever device to release the frictional connection, the pressure element leaving the guide out of the guide when the wear limit of the friction surfaces is reached is disengaged that the pressure element after a Leaving the guide can no longer be brought into engagement with the lever device, so that the non-positive connection can no longer be released.