EP1957815A1

EP1957815A1 - Clutch unit

Info

Publication number: EP1957815A1
Application number: EP06818038A
Authority: EP
Inventors: Mathieu Jordan; Karl-Ludwig Kimmig; Philippe Mih
Original assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG; LuK Lamellen und Kupplungsbau GmbH
Current assignee: Schaeffler Buehl Verwaltungs GmbH; LuK Lamellen und Kupplungsbau GmbH
Priority date: 2005-11-29
Filing date: 2006-11-02
Publication date: 2008-08-20
Also published as: US20090014270A1; CN101317020A; BRPI0619374A2; KR20080071574A; WO2007062616A1; CN101317020B; DE112006002806A5; JP2009517610A; BRPI0619374A8

Abstract

The invention relates to a clutch unit which consists of at least one friction clutch comprising a pressure disk (5), which is connected to a counter-pressure disk (4) in a rotationally fixed manner, which can be drivingly connected to the output shaft of a motor but can be displaced in an axially limiting manner. The friction disk and the counter pressure disk respectively comprise a friction surface, between which the friction linings (18) of a coupling disk (19) can be tensioned. Said pressure disk is arranged in an axial manner on one side of the counter pressure disk and a lever system (11), which can be pivoted in an axial direction, is arranged on the other side of the counter pressure disk. Said lever system can be impinged upon by an actuation device (23) in order to close the clutch and can be tilted like a dual-armed lever about an annular-shaped swivel bearing (15) which is supported by the counter pressure disk or a component which is connected thereto. Said lever system is also connected to the counter pressure disk in a radially external manner via traction means (13). According to the invention, the swivel bearing is supported on an adjusting ring of an adjusting ring device in order to compensate at least the wear and tear exerted upon the friction lining of the coupling disk, which can be rotated at least in relation to the pressure disk. The clutch unit also comprises spring elements (6, 30) which are active in an axial manner on the lever system and which exert a resulting axial force onto the closure path of the clutch having a degressive force-path characteristic.

Description

Kupplungsaqqreqat

The invention relates to clutch units, comprising at least one friction clutch with a thrust washer, which is rotationally fixed relative to a counter to the output shaft of a motor counter-pressure plate, but axially limited displacement, wherein the pressure plate and the counter-pressure plate each have a friction surface, between which the friction linings of a clutch disc can be clamped, wherein the pressure plate are provided axially on one side of the counter-pressure plate and a pivotable in the axial direction lever assembly on the other side of the counter-pressure plate, the lever assembly is acted upon by an actuator for closing the clutch and the manner of a two-armed lever to one of the counter-pressure plate or one of an associated with this connected component, annular pivot bearing is tiltable, wherein the lever assembly is further radially outwardly connected via traction means with the counter-pressure plate, wide rhin the pivot bearing is supported by an adjusting ring of an adjusting device for compensating at least the wear occurring on the friction linings of the clutch disc, which is rotatable at least relative to the thrust washer.

Such coupling units have been proposed for example by DE 10 2004 018 377 A1. The above-described friction clutch is integrated into a clutch unit, which is designed as a so-called double clutch.

Basically, clutches are known with an automatic readjustment at least for the compensation of Reibbelagverschleißes. In this regard, reference is made, for example, to DE 29 16 755 A1 and DE 35 18 781 A1. In these known couplings a virtually constant application of force to the pressure plate to be effected by the pressure spring.

The present invention has for its object to make coupling units of the type mentioned in such a way that they allow a squat design at least in the axial direction. Another object underlying the present invention was to keep the actuation travel of the actuating element acting on the lever arrangement and introducing the closing force into the clutch small or substantially constant over the life of the clutch. Furthermore, an inventively trained Coupling unit to ensure optimized operation and a long service life and cost-effective production.

The aforementioned objects are achieved, inter alia, in that the lever assembly has axial spring characteristics which cause it to be urged towards a frusto-conical position corresponding to the open state of the friction clutch, the lever assembly being closed to close the friction clutch necessary pivoting at least until the beginning of the clamping of the friction linings a degressive force-displacement spring characteristic, continue to the lever assembly axially acting spring means are present, the at least one operatively braced between the counter-pressure plate or a component connected thereto and the lever assembly, plate spring-like Spring element and at least one provided between the pressure plate and the counter-pressure plate further spring element comprises, wherein the plate-spring-like spring element generates an axial force on the lever assembly, which for pivoting the Hebelano Necessary actuating force is axially oppositely directed and the further spring element via the traction means initiates an axial force on the lever assembly, which is directed axially against the force generated by the plate spring-like spring element, wherein the force exerted by the spring means on the lever assembly, resulting axial force on the closing path of the friction clutch have a degressive force-displacement curve.

The lever arrangement may be advantageously formed by a plurality of radially oriented in an annular array levers. In order to impart the necessary axial spring properties to such a lever arrangement, the individual levers can be coupled to one another, with connecting sections formed integrally with the levers being able to be provided for coupling. These connecting sections can form an annular energy store together with the levers. However, the provided between the adjacent levers connecting portions may also have a loop-shaped course in the radial direction. By appropriate configuration of existing between the individual levers connecting portions thus the desired spring characteristic for the lever assembly can be realized. In addition to or as an alternative to the connecting sections, it is possible to use a ring-like spring element, for example a plate spring-like element, which is connected at least axially to the individual levers and is elastically deformed as a result of this pivoting. To form the adjusting device, it may be expedient if the adjusting ring is supported axially via a ramp system provided in an annular arrangement. The support can be done directly or indirectly on the counter-pressure plate. The ramp system advantageously has a plurality of ramps extending in the circumferential direction and rising in the axial direction. The pitch angle of the ramps is preferably designed such that a self-locking within the ramp system is present. If necessary, the ramps can be provided along their extent with a certain roughness or with low profilings (for example sawtooth-shaped). The roughness or the profilings are designed such that a displacement of the ramps in the adjustment direction is possible, but slipping thereof is prevented. The adjustment function of the ramp system can be ensured in a simple manner by means of at least one energy storage, which braces the ramp system in the adjustment direction.

Advantageously, the plate-spring-like spring element which acts on the lever arrangement may be provided between the latter and the counter-pressure disk.

The further spring elements provided between the pressure disk and the counter-pressure disk can be formed in a simple manner by axially prestressed leaf springs. Such leaf springs are firmly connected with at least one end with the counter-pressure disk and with another end or area with the pressure disk. Such spring elements ensure on the one hand the torque transmission between thrust washer and counter-pressure plate and on the other hand, the axial displacement of the pressure plate during the clutch operation. It is particularly advantageous if the spring elements are installed in such a braced manner that they urge or urge the pressure disk axially in the opening direction of the coupling.

For the function of the clutch unit or the friction clutch, it may be particularly advantageous if there is a lining suspension between the back to back arranged friction linings of the clutch disc. Such a pad suspension causes an additional axial support force in the direction of the pivot bearing is exerted on the lever assembly, as soon as the friction linings are moved axially towards each other by the pressure plate, whereby the lining suspension is braced. The effect of the pad suspension is transmitted via the traction means on the lever assembly. - A -

For the function of the adjusting device, it is particularly advantageous if, at least approximately when the thrust washer is adjacent to the friction lining adjacent thereto and the friction lining wear is absent, the axial forces acting in the closing direction on the lever arrangement are in equilibrium with the total spring force acting counter to this closing direction on the lever arrangement. This total spring force is at least by at least one braced between the lever assembly and the counter-pressure plate or a component connected thereto, plate spring-like component and by effective between pressure plate and counter-pressure plate tensioned leaf springs and optionally by a result of the support of the pressure plate on the adjacent friction lining by means of the lining suspension formed axial support force. The axial effect of the plate-spring-like component on the lever arrangement is directed against the axial action of the tensioned leaf springs and possibly the axial force generated by the lining suspension on the lever arrangement.

In an advantageous manner, the clutch unit may be constructed such that the wear compensation takes place by means of the adjusting device, at least substantially during an opening phase of the clutch unit or the friction clutch. The interpretation of the adjusting device and their vote on the other components of the clutch assembly and the friction clutch is preferably such that the wear adjustment is at least approximately at fully relaxed pad suspension during an opening phase of the clutch assembly and the friction clutch.

Further structural and functional advantageous design features are explained in more detail in connection with the following description of the figures.

Showing:

FIG. 1 shows a half section through a friction clutch configured according to the invention,

FIG. 2 shows a detail of the adjusting device which is used in the friction clutch according to FIG. 1, Figures 3 to 7 are diagrams with different characteristics, from which the interaction of the individual spring and adjusting elements of a friction clutch according to the invention can be seen and

8 shows a double clutch unit with the friction clutch according to FIG. 1.

The half-cut and schematically illustrated coupling unit 1 in Figure 1 comprises at least one friction clutch 2. The friction clutch 2 has in the illustrated embodiment, a housing 3, which is fixed or rigidly connected to a reaction plate 4. In the illustrated embodiment, the housing 3 simultaneously forms the housing of a further friction clutch whose other components, such. B. lever system, thrust washer, etc., are arranged axially between the housing 3 and the counter-pressure plate 4, as can be seen from Figure 8.

The friction clutch 2 further has a thrust washer 5, which is arranged on the side facing away from the housing 3 of the counter-pressure plate 4. The pressure plate 5 is by means of spring elements 6, here in the form of leaf springs, with the reaction plate 4 against rotation, but limited axially displaceable, connected. For this purpose, the ends of the leaf springs 6 are firmly connected on the one hand with the pressure plate 5 and on the other hand with the counter-pressure plate 4, z. B. by riveting.

The thrust washer 5 carries traction means 7, which extend axially through clearances 8 of the counter-pressure plate 4 and at its end of the thrust washer 5 end 9 carry a pivot bearing 10 on which a lever member 11 is supported tiltable or pivotable. In the illustrated embodiment, the pivot bearing 10 is formed integrally with the traction means 7 and formed by radially inwardly directed portions 12 of the traction means 7.

The traction means 7 may be formed by individual, distributed over the circumference, hook-like components. Advantageously, however, this traction means 7 may also be formed by a preferably made of sheet metal component having an annular portion 13, from which emanate a plurality of axial legs 14 which are fixedly connected to the pressure plate 5. Radially within the pivot bearing 10, the lever member 11 is supported on an annular support 15. The annular support 15 is supported by an annular member 16, which is part of an adjusting device 17, by means of which at least the wear occurring on the friction linings 18 of a clutch disc 19 can be compensated for at least partially automatically.

The friction linings 18 are clamped between the thrust washer 5 and the counter-pressure disc 4 when closing the clutch 2. As already indicated, the counter-pressure disk 4 can be part of a clutch unit which has two clutches. Such coupling units can be used, for example, in conjunction with so-called powershift transmissions.

Between the axially arranged back to back friction linings 18, a so-called pad suspension 20 is preferably provided, which ensures a progressive structure of the transferable from the friction clutch 2 torque when closing the friction clutch. Such padding suspensions have become known, for example, from DE 198 577 12 A, DE 199 802 04 T1 or DE 29 515 73 A1.

The axially compressible between the pivot bearing 10 and the annular support 15 lever element 11 is variable in its conicity and preferably has a self-suspension or elasticity, which causes a Konizitätsveränderung of the lever member 11 in the sense of opening the friction clutch 2. To close the friction clutch 2, the radially inner tips 21 of the lever member 11 forming lever 22 are acted upon. For this purpose, a closing force is provided at least substantially in the friction clutch 2 initiating actuator 23, which is displaced to close the friction clutch 2 in the direction of the arrow 24. The actuating element 23 advantageously comprises a roller bearing and forms part of an actuating system which may be designed as a pneumatic, hydraulic, electrical or mechanical actuating system or else has a combination of the mentioned actuating possibilities, that is, for example, is designed as an electrohydraulic actuating system.

The lever member 11 is advantageously formed by a plurality of provided in annular arrangement levers 25, which are connected to each other in the circumferential direction in an advantageous manner. The existing between the individual levers 25 compounds may be integrally formed with these levers or by an additional Fe- derelement, z. B. annular plate spring which is connected to the levers 25. The existing between the individual levers 25 compounds are suitably designed such that the lever member 11 has an axial elasticity, which ensures the possibility of a Konizitätsveränderung of the lever member 11. Such lever elements have been proposed for example by DE 103 40 665 A1, DE 199 05 373 A1, EP 0 992 700 B1 and EP 1 452 760 A1.

The spring elements 6, which ensure the torque transmission between the thrust washer 5 and the counter-pressure plate 4 and the housing 3, have a defined axial bias, which ensures that the pressure plate 5 is acted upon in the opening direction of the friction clutch 2. This means in the illustrated embodiment that the pressure plate 5 is urged away axially by the biased leaf springs 6 in the direction of the arrow 24 of the counter-pressure plate 4, which in turn the friction linings of the clutch disc 18 can be released. The bias of the leaf springs 6 further ensures that the pivot bearing 10 is always urged axially in the direction of the radially outer regions of the lever member 11.

As shown schematically in FIG. 2, the annular component 16 designed as an adjusting ring has ramps 26 extending in the circumferential direction and rising in the axial direction, which are supported on counter ramps 27 carried by the housing 3. The counter ramps 27 can advantageously be formed directly by integrally formed in the region of the housing bottom 28 ramps. In the circumferential direction of the adjusting ring 16 is acted upon by springs 29 which are clamped between the housing 3 and this adjusting ring 16.

Further details regarding the operation of an adjusting device 17, the design possibilities for the ramps 26 and the counter ramp 27 and the design and arrangement of the springs 29, from DE 42 39 291 A1, DE 42 39 289 A1, DE 43 22 677 A1 and DE 44 31 641 A1 are taken.

The lever member 11 is additionally acted upon axially opposite to the direction of arrow 24 by a spring element 30, which is operatively braced here between the housing 3 and the lever member 11. The spring member 30 thus exerts an axial force on the lever member 11, which by means of the spring elements 6 the traction means 7 is directed opposite to the axial force exerted on the lever element 11. In the illustrated embodiment, the spring element 30 is formed by a tellerfederarti- ges component, which has at least one serving as an energy storage annular body. In the illustrated embodiment, the spring element 30 is supported via radially outer regions on the housing 3 and radially further inwardly located regions on the lever element 11.

As can be seen from Figure 1, the lever 22 are pivoted about the annular support 15 in the manner of a two-armed lever during pivoting of the lever member 11. This pivoting is effected by introducing a force by means of the actuating element 23 on the lever tips 21st

The pivoting of the lever element 11 in the region of the annular support 15 is ensured by the fact that the force generated by the leaf springs 6 and the closing forces introduced in the region of the lever tips 21, resulting on the lever member 11 resulting axial force is greater than that of the spring element 30 on the Lever element 11 exerted axial force. In the case of the above-mentioned balance of forces, the axial force generated by the springs 29 via the ramp system 26, 27 must also be taken into account, which is exerted on the lever element 11 via the annular component 16. This axial force is to be added to the force exerted by the spring element 30 axial force. In the following, however, reference is made only to the axial force exerted by the spring element 30 on the lever element 11, wherein this information is to be considered such that in this axial force and the axial force generated by the springs 29 is included.

In the mounted, ready new condition of the friction clutch 2 acts on the lever tips 21 in the direction of arrow 24, a base force that determines the frustoconical starting position of the lever member 11 at new friction clutch 2. The operational starting position of the individual coupling components is given when, after assembly of the friction clutch 2, this has been actuated at least once, so that the individual components can assume their initial position due to the then adjusting force relationships between the various spring elements.

The base load acting on the lever tips 21 can be ensured, for example, by means of a stop for the release bearing or actuating element 23 provided on the transmission side. This stop urges the actuator 23 in the assembly of the engine and transmission in an axial position, which the desired base load and / or conicity ensures the lever member 11. Advantageously, such a stop can also be axially adjustable, so that any existing axial tolerances can be compensated.

The individual axial forces acting on the lever element 11 are matched with respect to one another such that an adjustment of the adjusting device 17 is impossible, provided that no wear occurs, at least on the friction linings 18. The relationship between the individual spring and actuating forces will be described in more detail below.

From Figure 1 is also removed that, as soon as during a closing phase of the clutch 2, the friction linings 18 between the thrust washer 5 and the counter-pressure plate 4 to be clamped, which then additionally acts on the lever member 11 by the pad spring 20 generated axial force.

Due to the aforementioned force relationships or force measurements is, if no wear is present, ensures that upon pivoting of the lever member 11 this remains in contact with the annular support 15 and is pivoted about this annular support 15 in the manner of a two-armed lever. As a result, the thrust washer 5 is acted upon and displaced by the traction means 7 in the closing direction, wherein at the same time the spring elements 6 formed here by leaf springs are clamped. During this pivoting of the lever element 11 can, if the plate spring-like spring element 30 is not supported at the radial height of the annular support 15 on the lever member 11, also a certain elastic deformation (suspension) of the plate spring-like spring element 30 occur. In the illustrated embodiment of Figure 1, a certain relaxation of the plate-spring-like spring element 30 would take place because the support diameter of the spring element 30 on the lever member 11 is greater than the diameter of the annular support 15th

As already mentioned, in the absence of wear acting on the lever member 11 in the direction of arrow 24, resulting spring force during the entire closing and opening travel of the friction clutch 2 is always greater than the force exerted by the plate spring-like spring member 30 to the lever member 11 axial force. As a result, an unintentional rotation and thus adjustment in the area of the adjusting device 17 is prevented.

By the interaction of the adjusting device 17 with at least the plate-spring-like spring element 30, the leaf spring elements 6 and in the region of the lever tips 21 einwir- kenden closing force, a wear compensation device is formed, which causes at least on the friction linings 18, at least a partial compensation of this wear by axial tracking of the annular support 15 when wear occurs. The balance of power between the various acting on the lever member 11 spring elements and the spring properties of the lever element 5 itself are preferably coordinated so that the required to close the friction clutch 2 in the region of the lever tips 21 actuating travel in the direction of the arrow 24 remains practically constant, at opened and closed friction clutch 2, the axial position of the lever tips 6 each remain practically constant. This ensures that also the actuating element 23 operates over the entire life of the friction clutch practically via the same axial actuating travel. This operation of the wear compensation device is achieved by appropriate design or assessment of the force acting on the lever member 11 spring elements and the spring characteristics of the lever member 5, wherein the leverage ratios are to be considered, which are present between the individual annular Abstütz-, Federbeaufschlagungs- and actuation zones of the lever element eleventh ,

In connection with the characteristic curves entered in the diagrams according to FIGS. 3 to 7, the mode of operation of the friction clutch 2 described above will now be explained in greater detail.

The ratios shown in Figure 3 correspond to the new state of the mounted friction clutch 2 after a single operation, ie without any wear has occurred.

The dot-dash line 100 corresponds to the force exerted on the lever tips 21 axial force, which is necessary to cause a Konizitätsveränderung of the resilient lever member 11. The characteristic 100 is based on a deformation of the lever member 11 between two annular supports whose radial distance corresponds to the radial distance between the formed by the annular member 16 annular support 15 and the annular Beaufschlagungsbereich 31 at the lever tips 21 for the actuator 23. The occupied by the lever member 11 operating point when new and after the first operation of the friction clutch 2 corresponds to the point 101. Through this operating point 101, the angular installation position of the lever member 11 is determined at operable new friction clutch 2. From Figure 3 it can be seen that the lever member 11 has a spring characteristic, at least over the portion 102nd the total Einrückweges the thrust washer 5, from which the friction linings 18 begin to be clamped between the friction surfaces of the thrust washer to be moved 5 and counter-pressure plate 4, a sloping or degressive force-displacement curve 10Oa. It is particularly expedient, as can be seen from FIG. 3, if this degressive force-displacement curve extends beyond the partial region 102 in the closing direction. The force profile section 104 of the characteristic curve 100 via the engagement path 103 can be adapted to the respective application by appropriate design of the resilient lever element 11.

The dotted line 105 represents the applied by the pad spring segments 20 axial spreading force, which acts between the friction linings 18. This axial spreading force counteracts the axial closing force introduced by means of the lever element 11 onto the pressure disk 5. This force applied by the lining suspension 20 is transmitted to the lever element 11 via the traction means 7. The applied by the lining suspension 20 axial force counteracts the introduced on the lever tips 21 closing force because the lever 22 and the lever member 11, as already mentioned, are mounted with respect to the annular support 15 in the manner of a two-armed lever or is. The ratio between the force to be applied to the annular loading area 31 for compressing the pad spring 20 and the axial force exerted by the pad spring 20 in the region of the pivot bearing 10 corresponds at least substantially to the ratio of the radial distance between the annular support 15 and the pivot bearing 10 on the one hand and to the radial distance between the annular support 15 and the annular loading region 31 on the other. With respect to the axially on both sides of the lever member 5 on this exerted axial forces, however, the axial force generated by the pad spring 20 and introduced by the actuator 23 on the lever tips 21 axial force in the same axial direction, here in the direction of arrow 24th

The effect of the pad spring 20 is present as soon as the friction pads 18 between the friction surfaces of the pressure plate 5 and the reaction plate 4 begin to be clamped. The latter is the case after the portion 102 of the Einrückweges 103 has been covered by the pressure plate 5 in the closing direction. The portion 102 corresponds to the Lüftweg, which is required to ensure a certain axial clearance for the friction linings 18. Such a game is necessary to avoid the transmission of a large drag torque on the clutch disc 19 when disengaged friction clutch 2. Such a drag torque would impair at least the switchability of the transmission. The line 106, which is extended beyond the control point 107 also dashed, represents the resulting force curve, which is generated by the superposition or addition of at least the force curves of the leaf springs 6 and the plate spring-like spring element 30. The at least of the leaf springs 6 and the spring element 30th generated forces act in opposite axial directions on the lever member 11 a. From Figure 1 it can be seen that the plate-spring-like spring element 30 exerts a force on the lever member 11, which is directed axially against the introduced in the region of the lever tips 21 closing force and introduced by the leaf springs 6 in the pivot bearing 10 in the lever member 11 axial force. As already mentioned, a relatively small axial force is exerted on the lever element 11 by the springs 29 via the ramps 26, 27, which is effective parallel to the force exerted by the spring element 30 force.

It can be seen from FIG. 3 that the resulting force curve according to the line 106 has a characteristic curve profile decreasing with increasing tension or deformation of at least the spring elements 6 and 30. It can be seen that, due to the selected courses of the lines 100 and 106, these intersect in the region of the control point 107 and thereafter the force ratio between the two lines 100 and 106 reverses. This has the consequence that after exceeding the control point 107, the at least by the spring elements 6 and 30 on the lever member 11 exerted, resulting axial support force is greater than the force applied to deform the lever member 11 in the region of the lever tips 21 closing force.

As already mentioned, after the partial region 102 has been exceeded, that is, when passing through the point 107, the lining suspension 20 also becomes effective. As a result, when the partial region 102 is exceeded in the direction of engagement, the actuating force required for pivoting the lever element 11 increases until the end of the engagement path 103. This increase is represented by the line segment 109 extending over the second subregion 108 of the engagement path 103.

From Figure 3 it is further seen that in the absence of wear or in the new state of the friction clutch via Teileinrückweg 102, the force curve according to the line 104 is greater than the over the same portion 102 occurring force curve according to the line 106. This ensures that the Lever element 11 always exerts an axial force on the annular support 15 and the annular member 16, whereby a rotation of this component is prevented. In the area of control point 107, if no wear is that is, at least an axial balance between the aforementioned forces present, whereby even then an undesirable adjustment within the friction clutch 2 is avoided. Exceeding the control point 107 is due to the added effect of the pad spring 20 and the associated increase in the actuation force to close the friction clutch, the force acting on the annular support 15 axial force increases and thus increases the safety with respect to an undesired adjustment of the adjuster 17.

With reference to FIGS. 4 to 6, the basic development of the resulting force curve according to the course of lines 106, 109 of FIG. 3 will now be briefly explained.

FIG. 4 shows a possible spring characteristic 120 of a plate-spring-like spring element corresponding to the spring element 30. The characteristic 120 has in the illustrated embodiment, a course that can be generated by appropriate coordination of the radial width and the thickness of the spring body of a plate spring-like component. The illustrated characteristic curve 120 has virtually a plateau or a horizontally extending region 121. Via the region 121, which extends at least substantially parallel to the abscissa, the spring element 30 generates an at least substantially constant axial force; the illustrated region 121 is practically linear. However, this area 121 could also have a different course, such. B. a slightly curved course.

4 shows the point 122. Since the friction linings 18 are subject to wear over the life of the friction clutch 2 (for example in the order of a total of 2 to 3 mm), the state of stress changes of the spring element 30. In the case of maximum wear, in the exemplary embodiment illustrated, the spring element 30 should have, for example, a bracing state which corresponds to the point 123. It can thus be seen from FIG. 4 that, viewed over the service life of the friction clutch 2, the axial force exerted by the spring element 30 on the lever element 11 remains at least substantially constant.

FIG. 5 shows the spring characteristic 140, which is generated by the leaf spring elements 6 in the illustrated embodiment. The leaf spring elements 6 are here designed such that they produce a practically linear characteristic. The leaf spring elements 6 are installed in such a way that they have an axial force when the friction clutch 2 is mounted ready for use exert the pressure disk 5, which corresponds to the point 141. With increasing displacement of the pressure plate 5, as a result of pad wear, the leaf springs 6 are additionally braced so that they exert an increasing axial force on the thrust washer 5 and thus also on the lever member 11 over the life of the friction clutch 2. When there is maximum wear, the leaf springs 6 have an operating point which corresponds to point 142.

FIG. 6 shows the resulting line of force curve 150 which is produced by superposition, that is to say addition of the linear course 121 of the characteristic curve 120 and the spring characteristic curve 140. It should be noted that with respect to the lever member 11, the axial forces generated by the energy storage elements 6 and 30 are axially opposite. It can be seen that this resulting force curve 150 over the life of the friction clutch 2 has a sloping course. The characteristic points corresponding to the new state and the worn state of the friction clutch 2 are indicated by 151 and 152.

The operating points 122, 123, 141, 142 and 151, 152 contained in FIGS. 4 to 6 correspond in each case to those operating points of the various spring elements 6 and 30 which are present when the coupling 2 is ready for operation and ready for operation.

It should be mentioned that for generating the leaf springs 6 associated, shown in Figure 5 spring characteristic 140, it is expedient if the mounting portions between the leaf springs 6 and the reaction plate 4 - viewed in the axial direction - are further away from the reaction plate 4, As the attachment areas between the spring elements 6 and the pressure plate 5. From Figure 1, this is not apparent. However, it is also possible to arrange the attachment areas of the leaf springs 6 on the components 4, 5 in the axial direction differently, wherein the leaf springs 6 to be generated progressivity exerted by these axial force by appropriate shaping of the spring elements 6 and possibly a compression of these spring elements in whose longitudinal direction can take place. If necessary, additional spring elements can also be used within the friction clutch 2, which ensure, in cooperation with the other spring elements, a course similar to the course of force 150 according to FIG.

Characteristic regions 153, 154 which show the effect of the pad suspension acting after a defined engagement path (eg 102 according to FIG 20 take into account. In the diagram shown in FIG. 6, the characteristic areas 153, 154 run downwards because the axial force generated by the pad spring 20, which acts axially on the lever element 20, is opposite to the axial force exerted by the spring element 30 on the lever element 11.

The principle will now be explained with reference to FIG. 7, which effects an adjustment in the readjusting device 17 or in the wear compensation device comprising it. It should first of all be noted that the distances used or changes in these travel ranges for explaining the mode of operation of a readjustment cycle as well as the force changes taking place are shown excessively in order to facilitate the understanding. In fact, these changes and adjustments take place in relatively small steps, with the operating or Nachstellpunkte due to existing in the overall system friction clutch hysteresis and disturbance forces, z. B. due to vibrations, subject to certain variations, so are available within a certain bandwidth.

The diagram according to FIG. 7 is based on the assumption that a certain amount of wear on the friction linings 18 has taken place when the friction clutch 2 is closed. This increases the pivot angle of the lever member 11 by an amount that is dependent on this wear. This is evident from the fact that, in FIG. 7, the engagement path 103a of the pressure disk 5 is greater than the engagement path 103 according to FIG. 3, ideally in the event of wear occurring at least on the friction linings 18. Assuming that the spring properties of the pad spring 20 have remained the same, the portion 108a, over which this pad spring 17 is effective, with the portion 108 of Figure 3 is the same size. Due to the wear, however, is the portion 102a, the opening of the friction clutch between the path 110 (from the effect of the pad spring 20 on the pressure plate 4 is no longer present) and the path 111, the installation position of the lever member 11 with the friction clutch open the second corresponds, has been enlarged. As can be seen in connection with FIGS. 3 and 7, this increase in the opening travel 102a causes that for pivoting the lever element 11 in the area of the lever tips

21 to be introduced holding force during the opening of the friction clutch 2 by a certain distance 112a is smaller than the over this distance 112a then existing resultant force (or the force curve), which forces the lever member 11 axially in the direction of the annular support 15. The surface resulting from the intersection of the characteristic curves 106, 100 and 109 is hatched in FIG. Due to the forces occurring during wear, at least on the friction linings 18, the lever element 11 is initially pivoted about the annular support 15 in the manner of a two-armed lever when opening the friction clutch 2. In this case, the pivot bearing 10 and the components connected thereto are displaced axially in the direction of the arrow 24, whereas the lever tips 21 are moved axially against the direction of the arrow 24. This pivoting takes place until the point 113 marked 113 in FIG. 7 is reached. Upon continuation of the pivotal movement of the lever member 11 in the opening direction now pivots the lever member 11 in the manner of a one-armed lever to the annular pivot bearing 10. This pivoting is due to the fact that in the direction of arrow 24 on the lever member 11 in the region of the lever tips 21 introduced axial Operating force when overspreading the point 113 is smaller than the resulting axial support force for the lever member 11, which is opposite to the arrow 24. This support force is applied substantially by the annular spring element 30. The pivoting of the lever member 11 about the annular pivot bearing 10 stops at least approximately until the point 114 exceeds the resulting, acting on the lever member 11 in the direction of arrow 24, axial force is greater again than the resulting force curve according to the line 106th , which acts against the arrow direction 24 axially on the lever member 11.

During the aforementioned operating phase in which the lever member 11 is pivoted about the annular pivot bearing 10 in the manner of a one-armed lever, the adjusting ring 16 is relieved, so that it can follow the pivotal movement of the lever member 11. This results in at least a certain adjustment of the wear occurring on the friction linings 18. The size of this adjustment is dependent on the lever element 11 existing lever ratios. Among other things, these lever ratios are predetermined by the diameters of the pivot bearing 10, the annular support 15 and the annular loading area 31.

The aforementioned leverage ratios as well as acting on the lever member 11, the pivoting and displacement of the same determinative, forces and the spring properties of the lever member 11 are preferably coordinated so that over the life of the friction clutch 2 and in the open state thereof, the lever tips 21 a practically constant have axial position. This implies that, although the lever tips 21 maintain a practically constant axial position with respect to the clutch housing 3 or with respect to the axially stationary components, the outer area (in the area of the annular pivot bearing 10) of the lever element 11 is displaced axially got to. This is necessary to ensure that despite the wear occurring on the friction linings 18 and the associated axial displacement of the pressure disk 5, the actuating travel necessary for closing the friction clutch 2 in the region of the lever tips 21 remains at least approximately constant. Due to the kinematics or Verschwenkverhältnisse for the lever member 11 existing in a construction according to Figure 1, the axial adjustment path in the region of the annular support 15 is smaller than the axial amount of wear on the friction linings 18, in accordance with the existing lever ratios. In the embodiment shown in Figure 1, the axial adjustment in the region of the annular support 15 is approximately 0.7 to 0.8 times the axial wear amount, at least on the friction linings 18. These leverage ratios are mainly determined by the radial distance between the annular support 15 and the annular loading area 31 on the one hand and the radial distance between the annular pivot bearing 10 and the annular loading area 31 on the other.

The requirement that the lever tips 21 should maintain an at least constant axial position over the life of the friction clutch, requires that the lever element 11 changes its state of tension at least when the friction clutch 2 is open. This is done by appropriate adjustment of the annular support 15. This change also causes a change in the state of tension of the spring elements 6 and 30, at least when the friction clutch is open. The latter is due to the fact that the spring elements 6 and 30 are supported either indirectly or indirectly on the lever element 11 axially, which, as already mentioned, in turn assumes a, over the life of the friction clutch changing, strained position.

The aforementioned changes in the state of tension, at least the spring elements 6 and 30 and the lever member 11, have the consequence that the lever element 11 and the spring elements 6 are additionally braced over the life of the friction clutch 2 by a certain amount, whereas the spring element 30 a reduction of his in the new state of the friction clutch existing tension state undergoes. The latter means that (as can be seen in connection with the various diagrams according to FIGS. 3 to 7), the resulting supporting force for the lever element 11, which is generated at least by the spring elements 6 and 30, decreases with increasing wear on the friction linings 18. This is also shown in FIG. 3 by the dashed extension of the line 106. Also the force curve required in the area of the lever tips 21 pivoting of the lever member 11 decreases by the mentioned additional tension of the lever member 11 at least over the path 102 from.

The spring characteristics of the individual elements, in particular of the components 11, 6 and 30, are designed such that despite the aforementioned displacements or changes in the operating point or the working areas of these resilient components, the prescribed adjustment principle due to the existing balance of power over the life of the friction clutch preserved.

By appropriate design of at least the spring elements 6 and 30, a resulting force curve can be generated, which has a substantially constant force at least over the axial adjustment path of the pressure plate 5. Such a course of force will be substantially parallel to the abscissa in FIG. In such a design, the then taking place axial displacement of the lever member 11 may take place such that the lever member 11, at least in the engaged state of the clutch 2 and possibly also in the disengaged state of the clutch 2, each having a constant taper.

FIG. 8 shows a dual-clutch unit 201 which has two friction clutches 202 and 203, which are arranged on both sides of a plate 204 designed as a counterpressure disk. In the illustrated embodiment, the friction clutch 202 is constructed with respect to the functional arrangement of the individual components, as described in connection with the preceding figures.

LIST OF REFERENCES

A clutch unit

friction clutch

casing

Reaction plate

thrust washer

spring elements

traction means

Free space away from the end

pivot bearing

lever member

Areas annular area axial legs annular support annular component

readjustment

friction linings

clutch disc

Pad suspension radially inner tips

lever

actuator

arrow

lever

ramps

counter-ramps

caseback

feathers

spring element

impingement

100 characteristic 101 operating point

102 subarea

102a opening path

103 Einrückweg

104 force profile section

105 characteristic

106 characteristic

107 control point

108 Second subarea

109 line section

110 way

111 way

112

112a route

113 operating point

114 operating point

120 spring characteristic

121 Horizontal area

122 operating point

123 operating point

140 spring characteristic

141 operating point

142 operating point

150 line of force

151 characteristic point

152 characteristic point

153 characteristic area

154 characteristic range

201 double clutch unit

202 friction clutch

203 friction clutch

204 counter pressure disc

Claims

claims

1. Clutch assembly consisting of at least one friction clutch with a pressure plate, which is rotatable relative to a drive shaft of a motor connectable counter-pressure plate, but axially limited displacement, wherein the pressure plate and the counter-pressure plate each have a friction surface, between which the friction linings of a clutch disc can be clamped are, wherein the pressure plate are provided axially on one side of the reaction plate and an axially pivotable lever assembly on the other side of the counter-pressure plate, the lever assembly is acted upon by an actuator for closing the clutch and the manner of a two-armed lever to one of the counter-pressure plate or one of a supported associated with this component annular pivot bearing is tiltable, wherein the lever assembly is further connected radially on the outside by means of traction means with the counter-pressure plate, further the Schwenklageru ng is supported by an adjusting ring of an adjusting device for compensating at least the wear occurring on the friction linings of the clutch disc, which is rotatable at least with respect to the counter-pressure plate, characterized in that the lever arrangement has axial spring characteristics, which cause it to be urged in the direction of a frusto-conical position , which corresponds to the open state of the friction clutch, wherein the lever assembly on the need for closing the friction clutch pivoting at least until the beginning of clamping the friction linings a degressive force-displacement spring characteristic, continue to the lever assembly axially acting spring means are present, at least one operatively connected between the counter-pressure plate or a component connected to this and the lever assembly braced, plate-spring-like spring element and at least one between the pressure plate and the counter-pressure washer vorg Esehenes further spring element comprise, wherein the plate-spring-like spring element generates an axial force on the lever assembly, which is axially directed counter to the pivoting of the lever assembly actuating force axially, and the further spring element via the traction means introduces an axial force on the lever assembly, which axially from the pellerfe- force generated by such a spring element is opposite, wherein the force exerted by the spring means on the lever assembly resulting axial force on the closing path of the friction clutch has a degressive force-displacement curve.

2. Clutch assembly according to claim 1, characterized in that the adjusting ring is axially supported via a ramp system provided in an annular arrangement.

3. Clutch assembly according to claim 2, characterized in that the ramp system is braced over at least one energy storage in the sense of an axial wear adjustment.

4. Clutch assembly according to one of claims 1 to 3, characterized in that the plate spring-like spring element is provided axially between the lever arrangement and the counter-pressure plate.

5. Clutch assembly according to one of claims 1 to 4, characterized in that the measures provided for between the pressure plate and the counter-pressure plate further spring elements are formed by axially biased leaf springs.

6. Clutch assembly according to one of claims 1 to 5, characterized in that a lining suspension is provided between the friction linings of the clutch disc.

7. Clutch assembly according to one of claims 1 to 6, characterized in that at least approximately when the thrust washer on the adjacent friction lining of the clutch disc and in the absence of Reibbelagverschleiß the axially acting in the closing direction of the lever assembly forces are in equilibrium with the on the lever assembly axially against this closing direction axially acting total spring force.

8. Clutch assembly according to claim 7, characterized in that the total spring force at least by at least one braced between the lever assembly and the counter-pressure plate or a component connected to this plate spring-like component and by between pressure plate and counter-pressure disc effectively tensioned leaf springs and possibly by one, as a result the support of the thrust washer on the adjacent friction lining, formed by the lining suspension axial support force is formed.

9. Clutch assembly according to claim 8, characterized in that the axial action of the plate-spring-like component is directed counter to the lever arrangement of the axial action of the tensioned leaf springs and possibly the axial force generated by the lining suspension on the lever assembly.

10. clutch unit according to one of claims 1 to 9, characterized in that the wear compensation by means of the adjusting device takes place during an opening phase of the clutch.

11. Clutch assembly according to one of claims 1 to 10, characterized in that the wear compensation by means of the adjusting device is at least approximately at fully relaxed pad suspension during an opening phase of the clutch unit.