CN112128265A

CN112128265A - Pressure fluid actuating device for a friction clutch

Info

Publication number: CN112128265A
Application number: CN202010587344.2A
Authority: CN
Inventors: S·哈恩; D·西格尔; M·格布; W·托马; M·阿贝斯卡; M·博奇
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2019-06-25
Filing date: 2020-06-24
Publication date: 2020-12-25
Also published as: DE102019209150A1

Abstract

A pressure fluid actuator assembly for a friction clutch, the pressure fluid actuator assembly comprising: a first actuating element and a second actuating element which together with the first actuating element defines an actuating pressure fluid chamber, a rotational separator bearing which is coupled or can be coupled for joint movement with the second actuating element by means of a support device of variable axial length, wherein the support device has a first device component which is axially supported or can be supported relative to the second actuating element and a second device component which is coupled for joint axial movement with the rotational separator bearing, a stop formation for defining the axial movement of the rotational separator bearing in the actuating direction, wherein the stop formation provides a reciprocal stop action between the first actuating element or/and a component which is fixed relative to the first actuating element and the second device component.

Description

Pressure fluid actuating device for a friction clutch

The present invention relates to a pressure fluid actuating device which is used, for example, in commercial vehicles for actuating a friction clutch.

Such pressure fluid actuating devices generally comprise a cylinder fixedly positioned with respect to the vehicle, and a piston defining, with the cylinder, an actuating pressure fluid chamber and displaceable in the direction of the axis of movement. The piston can act on an energy store (for example, a spring tongue of a diaphragm spring) by means of a rotary release bearing in order to carry out the clutch actuation process in this way. As the friction pads of the clutch disk, for example, wear occurs in the friction clutch, the mounting position of such a diaphragm spring acting as an accumulator in the engaged state of the friction clutch changes, since as the wear increases, the diaphragm spring may become increasingly loose when moving into the engaged state compared to a state without wear.

In order to compensate for the wear occurring in the friction clutch in such a pressure fluid actuating device, a support device having an axial length which can be varied in a manner adapted to the wear occurring in the area of the friction clutch can be provided in the support path between the rotary release bearing and the axially fixed component of the pressure fluid actuating device. The actuation path provided for the rotary release bearing must be designed such that the actuation of the friction clutch can be carried out in an emergency operation even in the event of failure of such a support device (which usually means complete axial collapse of the support device). This means that in such emergency operation, it must be possible to achieve the axial travel of the release bearing to be maintained in the event of such axial collapse of the support device.

In order to obtain information about the actuation state of such a pressure fluid actuating device, a sensor device may be provided, for example, which detects the axial positioning of the component axially displaceable by means of the rotary release bearing relative to the axially fixed component. In the event of a failure of such a sensor device or in the event of omission of the information provided by this sensor device, the pressure fluid actuating device is likewise driven in emergency operation, in order to be able to actuate the friction clutch even in this state. In such emergency operation, the rotary release bearing is maximally axially displaced for actuating the clutch, in order to ensure that the friction clutch is reliably disengaged even without recognition of the current actuation state. Since in this state the axial length of the support device is not known in principle and this support device can have a relatively large axial overall length, for example (if no or only a small wear compensation has been carried out in a previous operation), there is the risk that: if a maximum actuation path for disengaging the clutch is produced in an emergency operation in the absence of information about the actuation state, the rotary decoupling bearing is displaced axially too far onto the friction clutch and damage may occur in this case as a result of the interaction of the rotary decoupling bearing with the friction clutch.

The object of the present invention is to provide a pressure fluid actuating device for a friction clutch, which allows emergency operation with a maximum actuating travel in a reliable manner.

According to the invention, this object is achieved by a pressure fluid actuating device for a friction clutch, comprising:

-a first actuating element and a second actuating element defining an actuating pressure fluid chamber together with the first actuating element, wherein the second actuating element is movable along a movement axis in an actuating direction relative to the first actuating element from a substantially positioned position by introducing a pressure fluid into the actuating pressure fluid chamber,

a rotary release bearing coupled or couplable for joint movement with the second actuating element by means of a support device of variable axial length, wherein the support device has a first device assembly which is axially supported or supportable relative to the second actuating element and a second device assembly which is coupled for joint axial movement with the rotary release bearing, wherein the first device assembly and the second device assembly are movable relative to each other in order to vary the axial length of the support device,

-a stop formation for limiting the axial movement of the rotational separator bearing in the actuation direction, wherein the stop formation provides a mutual stop between the first actuation element or/and a component fixed relative to the first actuation element and the second device component.

By providing a stop formation which prevents excessive axial movement of the second device assembly in the actuating direction, it is ensured that: irrespective of the axial relative position of the two device components with respect to one another, in emergency operation, a reliable disengagement of the friction clutch can be achieved by a maximum axial displacement of the rotary release bearing in the actuating direction, without in this case causing excessive axial movements, in particular of the second device component or of the rotary release bearing coupled thereto for common axial movement, which could lead to damage in the region of the pressure fluid actuating device or/and in the region of the friction clutch.

In order to make the accumulator act uniformly, the following proposal is provided: the first actuating element is a cylinder, preferably an annular cylinder; and the second actuating element is a piston, preferably an annular piston.

In order to ensure a defined axial movement of the second device assembly, a guide device may be provided for axially guiding the second device assembly relative to the first actuating element.

The guide device may include a first guide element fixed relative to the first actuating element and a second guide element coupled for common axial movement with the second device assembly and axially guided on the first guide element.

In order to obtain a simple design, a stop formation can be provided in the guide device. The stop formation thus not only fulfills the function of axially guiding and, if appropriate, also rotationally fixing the second device component, but it also prevents excessive axial movement in the actuating direction.

In order to achieve a reliably functioning guide function, it is proposed: at least one guide track is provided on one of the first guide element and the second guide element, a guide means which is guided axially movably along the guide track is provided on the other of the first guide element and the second guide element in such a way as to be assigned to the at least one guide track, and an axial movement stop of the guide means assigned to the guide track is provided on the at least one guide track.

First of all, with the integration of the axial stop function into the guide device, a design that reliably absorbs the axial forces occurring can be provided in the following manner: two guide rails are provided on the one element between which the other element is accommodated in the circumferential direction, and a guide mechanism is provided on the other element in a manner assigned to each of the guide rails.

Further functions can be integrated into the guiding device in such a way that: a sensor unit is provided which is fixed relative to the first actuating element and detects the axial positioning of the second guide element. The guiding means thus provide sensor means which also provide the exact axial positioning of the second device component relative to the first actuating element and thus provide information representative of the actuation state of the pressure fluid actuation means.

In a further design version, the first actuating element may have an inner circumferential wall for guiding the movement of the second actuating element in the axial direction or/and together with the second actuating element defining the pressure fluid chamber, and the stop formation may comprise a movement stop on the inner circumferential wall and a counterpart movement stop on the second device assembly. The function for providing a movement stop is integrated at least partially into an assembly or component which is present in principle in a pressure fluid actuating device.

In order not to impede the movement of the second actuating element during the actuation, in particular: the movement stop comprises a stop ring accommodated in a peripheral groove of the inner peripheral wall, or/and the movement stop comprises a stop sleeve fixed on the inner peripheral wall against movement in the actuation direction and surrounding the inner peripheral wall at a radial interval.

In this embodiment, the counter-motion stop can comprise a stop section on a transmission element coupled to the rotational separator bearing for a common axial movement.

In an alternative design, the movement stop may comprise a stop ring received in a peripheral groove of the inner peripheral wall, and the mating movement stop may comprise a stop sleeve coupled for common axial movement with the second device assembly. Thus, an unimpeded axial movement of the second actuating element along the inner circumferential wall of the first actuating element can also be ensured during an actuation process to be carried out normally, irrespective of the axial relative position of the two device components with respect to one another.

In order to achieve a design which is easy to implement in terms of construction, it is proposed that: the stop sleeve is fixed on a transmission element coupled for common axial movement with the swivel release bearing or/and the stop sleeve is a sealing sleeve of the swivel release bearing which, together with a bearing outer ring of the swivel release bearing, is coupled for common axial movement with the transmission element and axially engages radially inside a bearing inner ring of the swivel release bearing.

In a further alternative design type, which can be designed very stably, for defining the maximum axial movement of the swivel bearing, the stop formation can comprise at least one, preferably a plurality of stop bolts arranged one behind the other in the circumferential direction and extending substantially axially, wherein the at least one stop bolt is arranged axially fixedly relative to the first actuating element or relative to the second device assembly, preferably relative to the first actuating element, and provides a movement stop which interacts with a counterpart movement stop on the second device assembly, or preferably the first actuating element on the second device assembly.

The counterpart movement stop can be provided by a stop eye which receives the stop bolt in an axially movable manner, and the movement stop can be provided by a stop head of the stop bolt.

In a design that is easy to implement in terms of construction, it can be provided that: the first actuating element is carried on a carrier, and at least one, preferably each, stop bolt has a bolt shank which extends through a bolt passage opening in the carrier, preferably provided with an external thread. The stop bolts, which extend through the carrier with corresponding bolt shanks, can be used with the end sections thereof, which extend through or beyond the carrier, for fastening the carrier to the carrier structure and for fastening the entire pressure fluid actuating device to the carrier structure by means of the carrier. No additional structural measures or components are then required to fix the pressure fluid actuating device in the drive train.

In order to ensure a defined positioning of the stop bolts, which also fulfills the function of securing the pressure fluid actuating device, which allows an axial relative movement between the two actuating elements, at least one, preferably each stop bolt can have a support region which is supported relative to the carrier substantially in the direction of the movement axis.

Such an axial support can be realized, for example, in a simple manner by: in at least one, preferably each stop bolt, the support region is formed integrally with the stop bolt or/and in at least one, preferably each stop bolt, the support region is provided by a support sleeve surrounding the stop bolt and supporting a stop head of the stop bolt relative to the carrier.

In a further alternative embodiment, which provides a stable mutual stop, it can be provided that: the second device assembly is arranged radially outside at least partially around an outer circumferential wall of the first actuating element designed as an annular cylinder, and the stop formation comprises a movement stop on the outside of the outer circumferential wall towards the second device assembly and a counter movement stop on the inside of the second device assembly towards the outside of the outer circumferential wall.

Here, it can be mentioned that: the movement stop comprises a stop ring, or/and the counter movement stop comprises a stop ring.

The invention also relates to a clutch system comprising a friction clutch having an accumulator which can be acted upon by the pressure fluid actuating device according to the invention for carrying out a clutch actuation process.

The present invention is described in detail below with reference to the accompanying drawings. In the drawings:

FIG. 1 shows a partial longitudinal cross-sectional view of a pressurized fluid actuation device for a friction clutch;

fig. 2 shows a partial longitudinal sectional view of the main parts of a pressure fluid actuating device with a stop formation;

fig. 3 shows a perspective view of the guide device;

figure 4 shows a cross-sectional illustration of the guide device;

fig. 5 shows another partial longitudinal section of an alternative design type of a pressure fluid actuating device with a stop formation;

fig. 6 shows a diagram corresponding to fig. 5 of an alternative design of a pressure fluid actuating device with a stop formation;

fig. 7 shows a further illustration of an alternative design of the pressure fluid actuating device with a stop formation, corresponding to fig. 5;

fig. 8 shows a perspective view of another alternative design type of a pressure fluid actuating device with a stop formation;

fig. 9 shows a perspective illustration of a modification of the design of the pressure fluid actuating device with a stop formation illustrated in fig. 8;

fig. 10 shows another perspective view of the pressure fluid actuated device of fig. 9.

Fig. 1 shows a partial longitudinal sectional view of a pressure fluid actuating device 10 for a friction clutch 12, which is also generally referred to as a disengagement device. The friction clutch 12 is illustrated by means of an accumulator 14 which is provided in the friction clutch and is designed, for example, as a diaphragm spring.

The pressure fluid actuating device 10 comprises a first actuating element 16, which provides an annular cylinder and which surrounds the axis of movement a annularly in its principally annular configuration. Here, the first actuating element 16 can be configured, for example, with a base portion 21 which also provides the outer circumferential wall 20 and a guide sleeve 23 which is connected to the base portion 21 and generally also provides the inner circumferential wall 18. A second actuating element 22, which is engaged substantially between the inner peripheral wall 18 and the outer peripheral wall 20 of the first actuating element 16, provides an annular cylinder annularly about the axis of movement a. The second actuating element 22 is fluid-tight with respect to the inner and outer

circumferential walls

18, 20 of the first actuating element 16 and is movably guided with respect thereto in the direction of the movement axis a by means of a plurality of sealing/guiding elements 24.

An actuating pressure fluid chamber 26, which is closed off in a fluid-tight manner by means of different sealing/guide elements 24, is formed between the first actuating element 16 and the second actuating element 22. Via an interface, not shown, a pressure fluid (for example compressed air) can be introduced into the actuating pressure fluid chamber 26 in order to establish a force action acting on the second actuating element 22 or moving it in the actuating direction B relative to the first actuating element 16 by establishing a fluid pressure in the actuating pressure fluid chamber 26. When the second actuating element 22 is moved in the direction of movement B, the second actuating element 22 acts on a radially inner region (for example, a spring tongue of the radially inwardly engaging energy store 14) by means of, for example, a rotary release bearing 28 which is held on the second actuating element, in order to displace or pivot this region in order to carry out a disengagement process in the direction of movement B and in this way reduce or eliminate the action of the energy store 14 on the pressure plate of the friction clutch 12.

A transmission element 30, which is of annular design and is guided movably in the direction of the movement axis a on the second actuating element radially on the inside, is arranged between the rotational release bearing 28 and the second actuating element 22. The transmission element 30 supports or carries the rotational separator bearing 28 in the axial direction and is preloaded in the direction axially away from the second actuating element 22 by means of a preload spring 32 which is supported on the one hand on the transmission element 30 and on the other hand on the second actuating element 22.

By means of a support device, generally designated 34, which acts by means of a pressure fluid, an at least axially fixed coupling can be established between the second actuating element 22 and the transmission element 30 which carries the rotary throwout bearing 28 or is coupled with the rotary throwout bearing for a common axial movement. The support device 34 comprises a support cylinder 36 which can in principle be displaced in the direction of the axis of movement a and which is acted upon by a first preloading device 38 in a release direction F substantially opposite to the actuating direction B. The first preloading device 38 may, for example, comprise a preloading spring 40, which may, for example, be designed as a helical compression spring, arranged about the axis of movement a. The preload spring 40 is supported on the one hand on the transmission element 30 and on the other hand on the support cylinder 36 and thus presses the support cylinder in the release direction F against the second actuating element 22.

The outer circumferential wall 20 of the first actuating element 16 provides, with its axial end region, a release-direction movement stop 42, against which the support cylinder 36 can come into abutment with a radially outwardly engaging stop section 44 when moving in the release direction F, so that the support cylinder 36 cannot move further in the release direction F if the stop setting is reached. However, the second actuating element 22 can be moved in the release direction F beyond the stop position of the support cylinder 36 into a basic position in which it abuts, for example, axially against the first actuating element 16. The second actuating element 22 is preloaded into the basic position by a preload spring 32 which substantially provides a second preloading device 46. In the basic position of the second actuating element 22, the support cylinder 36 which remains in the stop position is not axially supported on the second actuating element 22, so that, when moving in the actuating direction B from the basic position, the second actuating element 22 first passes through a small inoperative stroke in which it does not axially carry along the support cylinder 36. Only when the second actuating element 22 reaches or comes into contact with the support cylinder 36 which is initially held in the stop position, with further movement in the actuating direction B, does the second actuating element 22 bring the support cylinder 36 with it with further movement in the actuating direction B.

The support device 34 also includes a support piston 48. As also the support cylinder 36, this support piston also has a basically annular design and engages in its annular design into the annular design of the support cylinder 36. The support cylinder 36 and the support piston 48 together define a support pressure fluid chamber 50 annularly about the axis of motion a, which can be connected and disconnected to a support pressure fluid balance volume 54 by a support pressure fluid valve (generally designated 52). An annular sealing element 56 is carried on the support piston 48 and ensures a fluid-tight closure of the support pressure fluid chamber 50. The support piston 48 is itself designed as part of the transmission element 30 or is fixed thereto and is therefore coupled to the transmission element for joint movement in the direction of the movement axis a.

The support pressure fluid valve 52 comprises a spool 60 preloaded by a preload spring 58 in a direction towards the open position of the support pressure fluid valve 52. This spool is accommodated displaceably in the direction of the axis of movement a in a valve chamber 62 and has an application section 64 which, in the position of the spool illustrated in fig. 1 and corresponding to the open position of the support pressure fluid valve 52, will project axially by the support cylinder 36 to the second actuating element 22.

With the second actuating element 22 positioned in the basic position and the support cylinder 36 positioned in the stop position, the spool 60 can be axially supported on the second actuating element 20, so that a connection is established between the support pressure fluid chamber 52 and the support pressure fluid equalizing volume 54 by means of an opening which is open with respect to the valve chamber 62 and a circumferential depression on the spool 60. On both axial sides of the circumferential depression, the valve slide 60 is guided in a sealing manner relative to the valve chamber 62 by means of sealing elements, for example O-rings.

If the second actuating element 22 is moved from its position essentially in the actuating direction B close to the support cylinder 36 which is initially held in the stop position, the second actuating element 22 pushes the spool 60 into the valve chamber 62 against the preloading action of the preloading spring 58, so that the circumferential depression on the spool 60 is displaced relative to the openings which are open relative to the valve chamber 62 and these openings are covered or closed by the closing section of the spool 60. In this closed position of the supporting pressure fluid valve 52, the connection between the supporting pressure fluid chamber 50 and the supporting pressure fluid equalizing volume 54 is interrupted, so that the supporting pressure fluid chamber 50 is closed and in this state the pressure fluid present therein is sealed off in a fluid-tight manner. Such a pressure fluid is preferably a liquid (e.g. oil or the like), so that due to the incompressibility of the supporting pressure fluid there is an axially fixed coupling between the supporting cylinder 36 and thus also the second actuating element 22 (on the one hand) and the supporting piston 48 and thus the transmission element 30 or the rotational release bearing 28 (on the other hand).

The support pressure fluid balance volume 54 provided at the support piston 36 is formed in a balance housing 66. This balancing housing may be fixed thereon in such a way as to surround the support cylinder 36 radially outside and thus provide an annular structure supporting the pressure fluid balancing volume 54. This supporting pressure fluid balance volume is closed by an axially movable sealing element 68 which is preloaded by a preload spring 70 (e.g. a wave spring or the like).

During clutch actuation operation, pressurized fluid is introduced into the actuation pressurized fluid chamber 26 to exert an actuation force on the accumulator 14. As a result of the fluid pressure built up in the actuating pressure fluid chamber 26, a force acting in the actuating direction B on the second actuating element 22 is generated, which force triggers a movement of the second actuating element 22 in the actuating direction B. In this case, the second actuating element 22 first moves without the support cylinder 36 until the valve slide 60 is pushed into the valve chamber 62 in the state illustrated in fig. 2 and thus closes the support pressure fluid chamber 50. In this state, the second actuating element 22 bears axially against the support cylinder 36 and thus carries it with it from its stop position in the actuating direction B. Since the support pressure fluid chamber 50 is closed and the support pressure fluid is incompressible, in this state there is also an axially fixed coupling between the second actuating element 22 and the rotary release bearing 28, so that the second actuating element is also displaced axially and acts radially inwardly on the accumulator 14 to disengage the friction clutch 12.

In order to engage the friction clutch 12 again, the pressure in the actuating pressure fluid chamber 26 is reduced or released, so that the rotary release bearing 28 and thus the transmission element 30 and the second actuating element 22 are moved in a release direction F opposite the actuating direction B, in particular under the force of the accumulator 14. This movement can continue, for example, until the second actuating element 22 again abuts against the first actuating element 16. Before this, during this movement, the support cylinder 36 has been fixed in its stop position by the release direction movement stop 42. In this state, a connection is again established between the support pressure fluid chamber 50 and the support pressure fluid balance volume 54.

If wear occurs in the friction clutch 12, this generally has the following consequences: when the engagement process is carried out, i.e. when the second actuating element 22 is moved in the release direction F, the energy store 14 is moved or relaxed further in the axial direction in its radially inner region than in the case of a state in which there is no or little wear in the friction clutch. This means that, in the transition to the engaged state of the energy store 14, the supporting cylinder 36 is axially fixed by the release direction movement stop 42 and, by continuing the movement of the second actuating element 22 to its basic position, the supporting pressure fluid valve 52 reaches its open position, the energy store 14 can push the supporting piston 48 further into the supporting cylinder 36 by means of the transmission element 30. With the support pressure fluid valve 52 in its open position, support pressure fluid can be pressed from the support pressure fluid chamber 50 into the support pressure fluid equalizing volume 54 by this support pressure fluid valve. This supporting pressure fluid balance volume contains the supporting pressure fluid with the sealing element 68 displaced and the preload spring 70 compressed.

With the second actuating element 22 in its basic position, in particular also pressed against the first actuating element 16 by the preloading action of the preloading spring 32, the energy store 14 can thus be brought into a further relaxed position, corresponding to the wear occurring in the friction clutch 12, against the preloading action of the preloading spring 32. In the next disengagement operation to be carried out, first of all the second actuating element 22 is moved again with a small lost motion until the second actuating element comes into contact again with the support cylinder 36 or until the support pressure fluid valve 52 is again in its closed position, and then, with a further insertion of the support piston 48 into the support cylinder 36 and therefore a smaller volume of the support pressure fluid chamber 50, an axially fixed coupling is once again established between the second actuating element 22 and the transmission element 30 by means of the support device 34. In this way, the method can continuously and variably compensate for wear occurring in the friction clutch during the respective actuation.

In the pressure fluid actuating device 10 shown in fig. 1, the jointly axially displaceable support cylinder 36, which carries out the actuation process in the actuation direction B by means of the second actuating element 22, together with a component or assembly carried there for joint movement therewith, constitutes a first device assembly 72 of the support device 34 in the support path between the second actuating element 22 and the rotational release bearing 28. The transmission element 30, together with the support piston 48 arranged thereon, substantially forms a second device arrangement 74, which can be axially moved together with the rotary release bearing 28 during the actuation process and also during the compensation process. The axial structural length of the support device 34 can be varied (in particular reduced when compensating for wear) by an axial relative movement of the two

device components

72, 74 relative to one another in a manner adapted to the wear occurring in the friction clutch 12.

It is also possible to implement the support device 34 in other ways, which has an axial length that is variable depending on the wear generated in the friction clutch 12 and subsequently compensated for, and which in the example shown works with pressure fluid. It is therefore also possible for the support device 34 to be formed with two annular ramp elements which are rotatable relative to one another about the axis of movement and which bear against one another by means of respective axially oriented ramp surfaces. The relative rotation of the two ramp elements results in a change in the axial structural length of the support device comprising two such ramp elements due to the ramp faces derived from one another. One of these ramp elements can be axially supported on the second actuating element 22 and can be rotated relative to this second actuating element about the axis of movement a, while the other ramp element, which is in principle held fixedly in terms of rotation, can transmit the actuating force to the rotational decoupling bearing 28. In the event of wear in the friction clutch 12, the rotatable ramp element can be released for rotation, so that by changing the axial overall length of the support device configured in this way, in particular by reducing the axial overall length, the wear occurring in the friction clutch 12 and occurring in the very pronounced loosening movement of the energy store 14 can be compensated for. In this embodiment, the two ramp elements each form the first device component or the second device component or provide a substantial part thereof.

The stop formations for: in the event of a failure of the sensor device which detects the axial relative position of the two actuating

elements

16, 22 and thus a loss of information about the actuation state of the pressure fluid actuating device 10, it is possible to continue operation in an emergency actuation mode which in principle permits actuation of the friction clutch 12 for disengagement or engagement thereof, but nevertheless ensures that excessive axial displacements of the system region, in particular of the rotary release bearing 28 or the kinematic coupling therewith, do not occur, which would lead to damage to the pressure fluid actuating device 10 or to the components of the friction clutch 12. It should be noted here that only the system regions which are essential in the context of the invention, in particular the two actuating

elements

16, 22 and the transmission element 30 of the second device arrangement 74, are shown in fig. 2. The further system regions which act between the second actuating element 22 and the transmission element 30, i.e. the further parts of the first device arrangement 72 and the second device arrangement 74 of the support device 34, are not shown, again in order to show that in the context of the present invention different structural embodiments can be selected in order to provide a support device 34 which is variable in axial length in a manner adapted to the wear occurring in the friction clutch 12.

Fig. 1 to 4 show a guide device 76 provided in a manner assigned to the second device assembly 74, which guide the second device assembly in the axial direction and counteract a rotational movement about the movement axis a.

The guide device 76 comprises a first guide element 78 which is fixed, for example by screwing, riveting or the like, to a plate part 80 which is firmly connected to the first actuating element 16. The guide device 76 also comprises a second guide element 82, which is firmly connected to the second device assembly 74, in particular to the transmission element 30 thereof.

The first guide element 78, which is of substantially fork-shaped design, has two

limbs

84, 86 with a circumferential spacing from one another, which on their sides facing one another have inwardly (i.e. respectively toward the other limb) open, groove-like guide tracks 88, 89. These guide rails extend longitudinally in the direction of the movement axis a and have

notches

90, 91 which open upwards or radially outwards at their end regions close to the plate member 80. At the other axial end, as illustrated in fig. 4, the guide tracks 88, 89 are each defined by an

axial movement stop

92, 93.

On the second guide element 82, a guide 94 or 96 is provided which is designed in a projecting manner in such a way that it is assigned to the

respective branch

84, 86 or to the

respective guide track

88, 89 formed therein. When the guide device 76 is assembled, the two guide means 94, 96 are moved through the

recesses

90, 91 into the guide tracks 88, 89, so that the second guide element 82 is guided axially in a defined manner relative to the first guide element 78 when the guide means 94, 96 are accommodated in the assigned

guide track

88, 89, and is also held against movement in the circumferential direction relative to the first guide element. Thus, the second device assembly 74, which is fixedly connected with the second guide member 82, is also held against rotational movement relative to the first actuating member 16.

At the same time, the axial movement stops 92, 93 (which are arranged at the axial ends of the

branches

84, 86 and define the guide tracks 88, 89 in the actuating direction B) form, in cooperation with the guide means 94, 96, a stop formation 98 which defines the axial movement of the second device assembly 74 relative to the first actuating element 16.

The stop formation 98 is designed in such a way that: also for the state of maximum axial length of the support device 34, the stop formation allows such an axial displacement of the second device assembly 74 and thus also of the rotary release bearing 28, so that a complete disengagement of the friction clutch 12 can take place. In the case of a situation in which the movement in the actuating direction B is at its maximum and the friction clutch 12 is therefore disengaged in a situation in which the support device 34 has its maximum axial structural length, i.e. in a situation in which wear compensation has not yet taken place in principle, the guide means 94, 96 have their minimum spacing relative to the axial movement stops 92, 93. As the wear increases and the axial length of the support device 34 decreases, the spacing between the guide mechanisms 94, 96 relative to the axial movement stops 92, 93 decreases when the friction clutch 12 is disengaged.

A magnetic element 100 is carried on the second guide element 82. A sensor unit 102 assigned to the magnetic element 100, covering the first guide element 78, is provided, which detects the position of the magnetic element 100 and thus provides information about the axial positioning of the second guide element 82 and thus also of the second device assembly 74. In this way, the instantaneous actuation state of the pressure fluid actuator 10 can be seen and the pressure fluid actuator can be controlled or regulated accordingly, in order to be able to carry out the disengagement process or the engagement process of the friction clutch 12 in a defined manner. The sensor unit 102 constitutes, in the case of interaction with the magnetic element 100, a sensor device generally designated 104. It should be noted that such a sensor device 104 detecting, for example, the axial positioning of the second guide element 82 may also be designed in another way or operate with another detection mechanism (for example, optical detection).

If a defect occurs in the region of the sensor device 104 and the sensor device can no longer provide information representing the axial positioning of the second device arrangement 74 and thus of the rotary release bearing 28, it is also necessary to create a possibility of being able to actuate the friction clutch 12 in an emergency operation. In such an emergency operation, in order to disengage the friction clutch 12, a maximum fluid pressure or a maximum fluid quantity is introduced into the actuating pressure fluid chamber 26, in order in this way to bring about a maximum axial displacement of the second actuating element 22 and thus of the rotary release bearing 28. Since the degree of wear compensation before in this state and the degree of change in the axial structural length of the support device 34 corresponding thereto are not known in principle, or it is not known whether a defect in the support device 34 would lead to an axial collapse thereof, in such a case of maximum displacement of the second actuating element 22, for disengaging the friction clutch 16, such an axial path must pass through the actuating direction B, so that, irrespective of the axial structural length of the support device 34 which is instantaneously present, the rotary release bearing 28 is axially displaced or brought into such an axial positioning so far that the friction clutch 12 is completely disengaged there. Since the stop formation 98 is designed in principle to permit an axial displacement of the second device arrangement 74 to such an extent that the friction clutch 12 can be disengaged even in the case of the greatest axial structural length of the support device 34, but in principle no axial displacement of the second device arrangement 74 in a significantly excessive manner is permitted or impossible, it is likewise ensured by the action of the stop formation 98 in emergency operation (i.e. in the case of the greatest pressure-exerting effect of the pressure fluid actuating device 10) that the second device arrangement 74 and thus the rotation release bearing 28 can be axially displaced to such an extent that the friction clutch 12 is completely disengaged, but nevertheless an axial movement beyond this is substantially impossible. This means that: by means of the stop formation 98, it is ensured that, even under maximum pressure loads, the second actuating element 22 and, in addition, the second device arrangement 74 are only displaced into an axial position which substantially likewise corresponds to or only slightly exceeds the reachable axial position of the second device arrangement 74 or of the rotational release bearing 28 in normal actuating operation and at the maximum axial structural length of the support device 74. The following risks are thereby eliminated: the rotational release bearing 28 is axially displaced so far that it interacts with the components of the friction clutch 12 and is damaged there or the components of the pressure fluid actuating device 10 are released from one another.

Before describing an alternative design type of such stop forming member 98 in the following, it should be noted that: as is illustrated in fig. 1, the guide device 76 and also the sensor device 104 arranged thereon are also arranged in the pressure fluid actuating device 10 in a further embodiment of the stop formation 98, in order to provide, even without the function of an axial movement stop integrated in the guide device 76, on the one hand a rotationally fixed connection of the second device arrangement 74 and, on the other hand, information representing the axial positioning thereof.

As is also illustrated, for example, in fig. 2, the stop formation 98 can provide, for example, a direct interaction between the peripheral wall 20 of the first actuating element 16 and the transmission element 30 and thus a substantially cylindrical section 153 of the second device assembly 74 which surrounds the peripheral wall 20 radially outside. On the outer side 154 of the outer circumferential wall 20, which is oriented radially outward and thus faces the cylindrical section 153, a stop ring 162, which projects radially outward and provides a movement stop 156, is provided in the outer circumferential groove. On an inner side 158 of the cylindrical section 153, which is radially opposite the outer side 154 of the outer circumferential wall 20 and radially inward, a stop ring 164 is provided in the inner circumferential groove, which provides a mating movement stop 160.

During emergency operation and when the second device assembly 74 is correspondingly axially displaced, a maximum pressure is exerted, the stop ring 162 comes into contact with the stop ring 164 and thus prevents further axial movement of the second device assembly 74 and therefore of the rotational release bearing 28. Since this abutting interaction can be provided substantially in the entire circumferential direction, a stable axial support is achieved which prevents the second device assembly 74 from tilting.

In the design illustrated in fig. 5, the stop formation 98 comprises a stop ring 110 inserted into an outer circumferential groove 108 on the guide sleeve which is assigned to the first actuating element 16 and which provides the inner circumferential wall 18 in the region of the axial end 106 of the guide sleeve 23. The stop sleeve 112, which surrounds the guide sleeve 23 at radial intervals, is axially supported with its base 114 on the stop ring 110 in the actuating direction B, so that the stop sleeve 112 cannot move in the actuating direction B beyond the axial positioning shown in fig. 5. The stop sleeve 112 provides a motion stop 116 in connection with the stop ring 110. The stop section 118 formed on the transmission element 30 of the second device arrangement 74 provides a counter-movement stop 120, which is in principle axially opposite the stop sleeve 112 or is positioned in the same radial region as the stop sleeve.

During normal actuation, even in the event of disengagement of the friction clutch 12, i.e. in the event of maximum displacement of the second device assembly 74 in the actuation direction B, the stop section 118 does not reach the stop sleeve 112 or the movement stop 116, i.e. has a certain axial spacing therefrom or is in substantially load-free contact therewith. If an emergency operation is required, the stop section 118 can be brought into contact with the stop sleeve 112, which then prevents the further axial displacement of the transmission element 30 and thus also of the rotational release bearing 28 by bearing against the stop ring 110. In this way, too, the axial movement of the second device arrangement 74 can be approximately ended in a state corresponding to a normal actuation process in which no wear compensation is carried out, or the movement is allowed to slightly exceed this, without however generating an excessive movement of the rotary release bearing 28 in the direction of the friction clutch 12.

Fig. 6 and 7 show further alternative designs of such stop formations. Fig. 6 shows that the stop ring 110 is again carried on the guide sleeve 23 or the inner circumferential wall 18 provided by the guide sleeve. The stop sleeve 112 is now fixed to the transmission element 30 of the second device assembly 74. The radially inwardly engaging base 114 of the stop sleeve 112 can come into axial abutment with the stop ring 110 when an emergency operation is carried out and thus prevent an excessive axial displacement of the second device assembly 74 in the actuating direction B. The stop ring 110 thus generally provides a movement stop 116 of the second device assembly 74, while the stop sleeve 112 provides a counterpart movement stop 120, in particular with its base 114.

As illustrated in fig. 7, the function of the stop sleeve 112, which can be seen in fig. 6, can be assumed by a sealing sleeve 146 which is arranged on the rotational release bearing 28. The sealing sleeve 146 together with the bearing outer ring 148 of the rotational release bearing is fixed to the transmission element 30 of the second device assembly 74 or is clamped firmly between these two components. The sealing sleeve 146 extends radially inward from its clamping point between the bearing outer ring 148 and the transmission element 30 and engages approximately completely in the axial direction with a substantially cylindrical section 150 on a bearing inner ring 152 of the rotary release bearing 28. A gap seal is thus formed between the bearing inner ring 152 and the cylindrical section 150, which gap seal prevents dirt from penetrating into the region of the rotary throwout bearing 28 and envelops the rotary throwout bearing and thus also defines a lubricant receiving space which is substantially enveloped outwards.

The base 114 of the stop sleeve 112 illustrated in fig. 6 can also be designed as an integral component of the sealing sleeve 146 shown in fig. 7 and configured somewhat larger or of its cylindrical section 150, so that the mating movement stop 120 of this design is then provided on or by the sealing sleeve 146 and the stop sleeve provided as a separate component can therefore be dispensed with.

Fig. 6 and 7 also show that different measures can be provided in order to obtain a closed configuration which prevents the ingress of dirt. As fig. 6 shows, therefore, a corrugated closing element 122, which is connectable on the one hand to the stop sleeve 112 or the sealing sleeve 146 in fig. 7 and on the other hand to the guide sleeve 23 (for example, is constructed from a plastic or rubber material) and which does not in principle impede the axial movement of the stop sleeve 112 relative to the guide sleeve 23. According to the embodiment illustrated in fig. 7, a closure element 124 of annular design, for example of felt material or the like, can be provided, for example on the region of the sealing sleeve 146 corresponding to the base 114 of the stop sleeve 112, which closure element is displaced along the outer surface of the guide sleeve 23 when the second device component 74 is moved axially.

With reference to the design illustrated in fig. 5 to 7, it should be noted that: the radial spacing of the stop sleeve 112 or the sealing sleeve 146 from the outer circumference of the guide sleeve 23 creates an axial gap 126 into which the radially inner section 128 of the second actuating element 22 guided on the guide sleeve 23 can enter when a wear compensation process is carried out and in this case the axial overall length of the support device 34 is reduced. Thus, the stop sleeve 112 or the sealing sleeve 146 does not hinder the gradual relative displacement between the second device assembly 74 and the second actuating element 22, which is also caused by wear during the operational service life.

Fig. 8 shows a further embodiment of the stop formation 98. It is seen that in the example shown, this stop formation 98 has two

stop bolts

130, 132 which extend in the direction of the movement axis a. These stop bolts are positioned on both sides of the guide device 76 or the sensor device 104 and are fixed to the plate part 80, for example by welding or/and screwing or/and pressing. Two

stop bolts

130, 132 extend in the direction of the movement axis a through stop tabs or stop

eyelets

134, 136 assigned to these stop bolts and arranged on the outer circumference of the transmission element 30 or openings arranged therein. At its end facing away from the plate part 80, the

stop bolts

130, 132 have stop heads 138, 140 which provide respective movement stops 137, 139, with which stop

holes

134, 136, which provide respective mating movement stops 142, 144, come into abutment when an axial displacement of the second device assembly 74 is carried out in an emergency operation, and in this case a continued axial movement of the second device assembly 74 is interrupted.

It should be noted that more than the two illustrated

stop bolts

130, 132 may be provided, or they may also function at other circumferential locations between the first actuating element 16 or the plate member 80 fixed thereto and the second device assembly 74. The positioning that can be seen in fig. 8 is therefore advantageous in that the plate part 80 is designed to project radially outwards in this circumferential region in order to fix the first guide element 78 of the guide device 76 thereto.

Fig. 9 and 10 show a modification of the pressure fluid actuator shown in fig. 8 with respect to the design of the stop formation 98. In this design version as well, the stop formation 98 comprises a plurality of stop bolts, wherein in the illustrated design example, in addition to the

stop bolts

130, 132, equivalent stop bolts 130 'and 132' are provided in terms of construction and mode of operation. The design and mode of action of this stop formation 98 is therefore explained below primarily with reference to the

stop bolts

130, 132. Thus, the stop bolts 130 ', 132' are each identically constructed and function. It can be seen here that a total of four

stop bolts

130, 132, 130 ', 132' are arranged approximately uniformly distributed in the circumferential direction, wherein the two stop bolts 130 ', 132' are arranged on both sides of a mounting region 166 in which, for example, the first guide element 78, which can be seen in fig. 8, is fastened to the plate part 80. In the axial direction, the mounting region 168 is opposite the plate part, in which the second guide element 82, which is likewise visible in fig. 8, can be fastened to the second device arrangement 74, in particular to the transmission element 30 thereof.

Corresponding stop tabs or stop

eyelets

134, 136 are provided on the second device component 74 (for example on its transmission element 30) in a manner assigned to the

respective stop bolts

130, 132, 130 ', 132'.

Openings

170, 172 are provided in each case, through which the stop bolts 130, 132 (and likewise the stop bolts 130 ', 132') pass, so that the respective stop heads 138, 140 can engage the

stop sleeves

134, 136 from behind on their side facing away from the plate part 80.

Bolt through

openings

174, 176 are formed in the plate part 80, through which bolt through openings the

stop bolts

130, 132 with the

respective bolt shanks

178, 180 are passed. The

stop bolts

130, 132 thus project with the

respective end regions

182, 184 out of the plate part 80 in the direction of the movement axis a. The

stop bolts

130, 132 are formed with an external thread at least in these

end regions

182, 184 projecting out of the plate part 80 and can be screwed into assigned internal thread openings of the carrier structure for fastening the entire pressure fluid actuating device 10 on the carrier structure in the drive train. Thus, the

stop bolts

130, 132 not only provide movement stops 137, 139 with their respective stop heads 138, 140, but they also serve to fix the pressure fluid actuator 10 in the drive train by means of the plate part 80 acting as a carrier 81.

In order to be able to fulfill these two functions,

respective support regions

186, 188 are provided on the

stop bolts

130, 132. These support regions can be provided, for example, as integral components of the

stop bolts

130, 132 designed as stepped bolts and hold the carrier 81 (i.e. the plate part 80) securely on the carrier structure with the pressure fluid actuating device 10 fixed on the carrier structure. Alternatively, the

support regions

186, 188 may be provided by support sleeves surrounding the

stop bolts

130, 132, which are held between the respective stop heads 138, 140 and the plate member 80 and thus ensure a defined spacing of the stop heads 138, 140 and the plate member 80 and hold the plate member 80 against the load-bearing structure.

Finally, it should be pointed out that it is of course also possible to provide different stop formations as described above in the same pressure fluid actuating device.

List of reference numerals

10 pressure fluid actuating device

12 friction clutch

14 accumulator

16 first actuating element

18 inner peripheral wall

20 outer peripheral wall

21 base part

22 second actuating element

23 guide sleeve

24 sealing/guiding element

26 actuating a pressure fluid chamber

28 rotating release bearing

30 transfer element

32 preloaded spring

34 support device

36 support cylinder

38 first preloading means

40 preloaded spring

42 release direction movement stop

44 stop section

46 second preloading device

48 support piston

50 support pressure fluid chamber

52 support pressure fluid valve

54 support pressure fluid balance volume

56 sealing element

58 preload spring

60 valve core

62 valve chamber

64 application zone

66 balance shell

68 sealing element

70 preloaded spring

72 first device Assembly

74 second device assembly

76 guide device

78 first guide element

80 plate member

81 Carrier

82 second guide element

84 branch

86 branch

88 guide rail

89 guide rail

90 recess

91 notch

92 axial movement stop

93 axial movement stop

94 guide mechanism

96 guide mechanism

98 stop forming member

100 magnetic element

102 sensor unit

104 sensor device

106 axial end portion

108 peripheral groove

110 stop ring

112 stop sleeve

114 base part

116 motion stop

118 stop section

120 paired motion stops

122 closure element

124 closure element

126 gap

128 radially inner section

130 stop bolt

132 stop bolt

134 stop eyelet

136 stop eyelet

137 movement stop

138 stop head

139 motion stop

140 stop head

142 mating motion stops

144 mating motion stops

146 sealing sleeve

148 bearing outer ring

150 cylindrical section

152 bearing inner ring

153 cylindrical section

154 outer side

156 motion stop

158 inner side

160 mating motion stops

162 stop ring

164 stop ring

166 mounting area

168 mounting area

170 opening

172 opening

174 bolt through opening

176 bolt through opening

178 shank of bolt

180 bolt bar

182 end region

184 end region

186 support area

188 support region

Axis of motion A

B direction of actuation

F direction of release

Claims

1. A pressure fluid actuated device for a friction clutch, the pressure fluid actuated device comprising:

-a first actuating element (16) and a second actuating element (22) defining an actuating pressure fluid chamber (26) together with the first actuating element (16), wherein the second actuating element (26) is movable along a movement axis (A) in an actuating direction (B) with respect to the first actuating element from a substantially positioned position by introducing a pressure fluid into the actuating pressure fluid chamber (26),

-a rotational separator bearing (28) coupled or couplable for joint movement with the second actuating element (22) by means of a support device (34) of variable axial length, wherein the support device (34) has a first device assembly (72) axially supported or supportable relative to the second actuating element (22) and a second device assembly (74) coupled for joint axial movement with the rotational separator bearing (28), wherein the first device assembly (72) and the second device assembly (74) are movable relative to each other in order to vary the axial length of the support device (34),

-a stop formation (98) for limiting the axial movement of the rotational separator bearing (28) in the actuation direction (B), wherein the stop formation (98) provides a reciprocal stop action between the first actuation element (16) or/and an assembly fixed relative to the first actuation element (16) and the second device assembly (74).

2. Pressure fluid actuating device according to claim 1, wherein said first actuating element (16) is a cylinder, preferably an annular cylinder; and the second actuating element (22) is a piston, preferably an annular piston.

3. Pressure fluid actuating device according to claim 1 or 2, characterized in that a guiding device (76) is provided for axially guiding the second device assembly (74) with respect to the first actuating element (16).

4. Pressure fluid actuating device according to claim 3, characterized in that the guide means (76) comprise a first guide element (78) which is fixed with respect to the first actuating element (16) and a second guide element (82) which is coupled with the second device assembly (74) for common axial movement and is axially guided on the first guide element (78).

5. A pressure fluid actuating device according to claim 3, characterized in that the stop formation (98) is provided in the guide device (76).

6. Pressure fluid actuating device according to claim 4, characterized in that at least one guide track (88, 89) is provided on one of the first guide element (78) and the second guide element (82), that a guide means (94, 96) which is guided axially movably along the guide track (88, 89) is provided on the other of the first guide element (78) and the second guide element (82) in a manner assigned to the at least one guide track (88, 89), and that an axial movement stop (92, 93) for the guide means (94, 96) assigned to the guide track (88, 89) is provided on the at least one guide track (88, 89).

7. Pressure fluid actuating device according to claim 6, characterized in that two guide tracks (88, 89) are provided on the one element accommodating the other element therebetween in the circumferential direction, and that a guide means (94, 96) is provided on the other element in an assigned manner to each of the guide tracks (88, 89).

8. Pressure fluid actuating device according to claim 4 or claim 7, characterized in that a sensor unit (102) is provided which is fixed with respect to the first actuating element (16) and detects the axial positioning of the second guide element (82).

9. Pressure fluid actuating device according to claim 2, characterized in that the first actuating element (16) has an inner circumferential wall (18) for guiding the movement of the second actuating element (22) in the axial direction or/and which together with the second actuating element (22) defines the pressure fluid chamber (26), and the stop formation (98) comprises a movement stop (116) on the inner circumferential wall (18) and a counterpart movement stop (120) on the second device assembly (74).

10. A pressure fluid actuating device according to claim 9, characterized in that the movement stop (116) comprises a stop ring (110) accommodated in a peripheral groove (108) of the inner peripheral wall (18), or/and that the movement stop (116) comprises a stop sleeve (112) fixed on the inner peripheral wall (18) against movement in the actuating direction (B) and surrounding the inner peripheral wall (18) at a radial interval.

11. Pressure fluid actuating device according to claim 10, characterized in that the counter motion stop (120) comprises a stop section (118) on a transmission element (30) coupled for common axial movement with the rotational split bearing (28).

12. Pressure fluid actuating device according to claim 9, characterized in that said movement stop (116) comprises a stop ring (110) housed in a peripheral groove (108) of said inner peripheral wall (18), and said counter movement stop (120) comprises a stop sleeve (112; 146) coupled to said second device assembly (74) for a common axial movement.

13. Pressure fluid actuating device according to claim 12, characterized in that the stop sleeve (112; 146) is fixed on a transmission element (30) coupled for common axial movement with the swivel release bearing (28) or/and the stop sleeve (146) is a sealing sleeve (146) of the swivel release bearing (28) which, together with a bearing outer ring (148) of the swivel release bearing (28), is coupled for common axial movement with the transmission element (30) and axially engages radially inside a bearing inner ring (152) of the swivel release bearing (28).

14. Pressure fluid actuating device according to one of claims 1, 2, 4, 5, 7, 9, 10 to 13, characterized in that the stop formation (98) comprises at least one, preferably a plurality of stop bolts (130, 132, 130 ', 132') arranged one after the other in the circumferential direction and extending substantially axially, wherein the at least one stop bolt (130, 132, 130 ', 132') is arranged axially fixedly with respect to the first actuating element (16) or with respect to the second device assembly (74), preferably with respect to the first actuating element (16), and provides a movement stop (137, 139) which interacts with a mating movement stop (142 ) on the second device assembly (74), or preferably with the first actuating element (16) on the second device assembly (74).

15. A pressure fluid actuating device according to claim 14, wherein the counter motion stop (142, 144) is provided by a stop eye (134, 136) axially movably receiving the stop bolt (130, 132, 130 ', 132'), and the motion stop (137, 139) is provided by a stop head (138, 140) of the stop bolt (130, 132, 130 ', 132').

16. Pressure fluid actuating device according to claim 15, characterized in that the first actuating element (16) is carried on a carrier (81) and at least one, preferably each stop bolt (130, 132, 130 ', 132') has a bolt shank (178, 180), preferably provided with an external thread, which extends through a bolt through opening (174, 176) in the carrier (81).

17. Pressure fluid actuating device according to claim 16, characterized in that at least one, preferably each stop bolt (130, 132, 130 ', 132') has a support area (186, 188) which is supported relative to the carrier (81) substantially in the direction of the movement axis (a).

18. Pressure fluid actuating device according to claim 17, characterized in that in at least one, preferably in each stop bolt (130, 132, 130 ', 132'), the support region (186, 188) is formed integrally with the stop bolt (130, 132, 130 ', 132'), or/and in at least one, preferably in each stop bolt (130, 132, 130 ', 132'), the support region (186, 188) is provided by a support sleeve surrounding the stop bolt (130, 132, 130 ', 132') and supporting a stop head (138, 140) of the stop bolt (130, 132, 130 ', 132') relative to the carrier (81).

19. Pressure fluid actuating device according to claim 2, characterized in that the second device assembly (74) is arranged to surround the outer circumferential wall (20) of the first actuating element (16) at least partially radially outside, and the stop formation (98) comprises a movement stop (156) on an outer side (154) of the outer circumferential wall (20) towards the second device assembly (74) and a counterpart movement stop (160) on an inner side (158) of the second device assembly (74) towards the outer side (154) of the outer circumferential wall (20).

20. Pressure fluid actuating device according to claim 19, wherein the movement stop (156) comprises a stop ring (162) or/and the counter movement stop (160) comprises a stop ring (164).

21. Clutch system comprising a friction clutch (12) having an accumulator (14) which can be acted upon by a pressure fluid actuating device (10) according to one of the preceding claims for carrying out a clutch actuating process.