GB2338769A

GB2338769A - Clutch release device

Info

Publication number: GB2338769A
Application number: GB9907272A
Authority: GB
Inventors: Norbert Mebus; Matthias Zink; Christophe Schwartz; Piotr Olszewski; Klaus Brodtmann
Original assignee: LuK Lamellen und Kupplungsbau GmbH; INA Waelzlager Schaeffler OHG
Current assignee: LuK Lamellen und Kupplungsbau GmbH; INA Waelzlager Schaeffler OHG
Priority date: 1998-04-09
Filing date: 1999-03-31
Publication date: 1999-12-29
Anticipated expiration: 2019-03-31
Also published as: DE19914937B4; FR2777328A1; GB9907272D0; KR19990083065A; FR2777328B1; GB2338769B; DE19914937A1; BR9901252A

Abstract

The device has a release bearing 28 supported by operating element 5 axially and rotatably mounted on tubular part 7 of carrier 4 attached to a gearbox. A mechanism 10 comprising ramps 12,13, supported on support part 4 and operating element 5, and balls 20 in cage 15 causes operating element axial displacement upon rotation of the operating element through a segment shaped radial section 38 forming a pulley rotatable by a bowden cable (35, Figs 6,7), the sleeve (36) of which is connected to gearbox housing 2 by swivelable holder parts (48) to reduce cable kinking. To facilitate device fitting, the cable is divided by snap connector (49) comprising a sleeve end (236a Figs. 15a-c), a cable nipple (251) and a part (253) having apertured nipple gripping arms. A clutch wear adjuster and a gear shaft bearing mounting may be incorporated in the device (Fig. 16).

Description

- 1 OPERATING DEVICE 2338769 The invention relates to an operating device

for a clutch, more particularly for a friction clutch to be provided between an engine and a gearbox, with a release bearing for operating the clutch operating means, such as plate spring tongues, wherein the release bearing is supported by at least one support part which is to be provided on the gearbox side, and at least one axially displaceable and rotatable operating element which supports the release bearing is provided on the support part, and furthermore a ramp mechanism is provided between the support part and the operating element which is rotatable opposite same, for axially displacing said operating element.

An operating or disengagement device of this kind is described by way of example in FR A 2 658 763.

This known disengagement device has however a comparatively expensive construction and its assembly is difficult and time-consuming as a result of the large number of parts.

The object of the present invention is to provide an operating device of the kind mentioned at the beginning which has a space-saving simple construction and easy fitting. Furthermore the device should be capable of a particularly cost-effective simple production and able to be installed in a vehicle. Furthermore the device is to ensure over the entire service life of the clutch interacting therewith an optimum activation of this clutch. The operating device formed according to the invention can be used in a particularly advantageous way in conjunction with clutches such as those already P2370.P3 30 March 1999 proposed by way of example through patent applications DE 42 39 291, DE 42 39 289, DE 43 22 667 and DE 44 18 026.

According to the invention these objects and aims are achieved in that the ramps forming the ramp mechanism are supported directly by the support part and operating element and are fixed to same, and furthermore the release bearing is housed on the operating element with restricted radial displaceability. The release bearing is thus formed as a so-called self-centring release bearing so that it can be centred on the rotational axis of the clutch. By providing the corresponding ramps directly on the support part and on the fastening element it produces a particularly simple construction for the operating device which has only few component parts. In a particularly advantageous way the support part and/or the operating element can have the ramps formed directly thereon. The latter can be achieved in a particularly simple way when using shaped sheet metal parts, namely for example by imprinting.

It can be advantageous for the function of the operating device if the support part has a cylindrical attachment on which the ring-shaped operating element is housed and is axially displaceable through rotation. To this end the ring shaped operating element can form radially inside a sleeve-like axial attachment which is guided directly or indirectly on the attachment of the support part. The ramps forming the ramp mechanism can advantageously be formed by indentations or inward bulges formed radially in the area of these attachments. The ramp mechanism can advantageously be formed by at least run-up ramps provided on the support part and interacting with counter run-up ramps provided on the operating element whereby rolling bodies such as balls can be provided between these two P2370.P3 30 March 1999 1 3 - sets of ramps. By suitably selecting the run-up angle of these ramps it is possible to set the desired value for the ratio between the disengagement force required for disengaging the clutch and the force required for operating the clutch. The ramps can have over their longitudinal extension a changing run-up angle so that the aforementioned force ratio can be constant or variable over the operating path of the clutch, thus can adopt different values during operation. The ramps which rise in the axial direction of the operating device can have a pitch angle which causes no self-locking through friction inside the ramp mechanism. Advantageously this pitch angle can lie in the order of 30 to 600, preferably in the order of 450. It can be particularly advantageous for the handling and fitting of the operating device according to the invention if this operating device has a device which ensures at least up to the initial operation of a friction clutch by means of the operating device according to the invention that the operating element has a predetermined retracted position on the support part. This device can thereby be formed so that the ramp mechanism is held in a ready-to-function starting position. Advantageously a device of this kind can be active between the operating element and the support part. A device of this kind can comprise at least one spring which tensions the ramp mechanism against the disengagement direction. The operating element on the support part can thereby be forced into a retracted position. A spring of this kind can be hung by each end from the support part on one side and the operating element on the other. The spring is thereby suitably pretensioned. Furthermore the spring is formed and deformable so that the operating element is axially displaceable and rotatable relative to the support part. Advantageously a spring of this kind can be formed as a spiral spring and can have a corresponding number of P2370.P3 30 March 1999 4 windings in order to allow the required movement paths between the support part and operating element. With axial deformation of the spiral spring the spring can adopt a frusto-conical shape. By using a spring of this kind it is possible to achieve a particularly short axial construction for the operating device.

It can be advantageous if the turning angle permitted for the ramp mechanism between the support part and the operating element is restricted so that an inadmissible large axial displacement of the operating element relative to the support part is prevented by means of the ramp mechanism.

The ramp mechanism or the circumferential extension of the ramps and their pitch angle are advantageously formed so that the overall axial displacement of the release bearing or operating element which can be produced by same relative to the support part corresponds at least to the sum of the ideal disengagement path of the clutch operating means biased by the release bearing and the displacement of the release bearing which arises as a result of the wear at least on the friction linings of the clutch disc. It is thus necessary when designing the run- up ramps to take into account also at least the axial displacement of the areas of the clutch operating means, such as plate spring tongues, which are biased by the release bearing.

It can be particularly advantageous and service life of the operating mechanism is provided in a chamber least substantially and if the ramps on the corresponding component parts form or def ine a chamber of this kind for the functioning device if the ramp which is sealed at or the shaped areas forming these ramps With this type of P2370.P3 30 March 1999 j design or arrangement of the ramp mechanism the latter can be lubricated, e.g. by means of grease. In order to form a chamber of this kind it can be advantageous if a ringshaped space is defined radially between the cylindrical or tubular attachment of the support part and the sleeve like axial attachment of the operating element enclosing same and this space is sealed at least on one of its two axial ends. A seal of this kind can be produced by means of at least one sealing ring. A sealing ring of this kind can be provided on the support part and/or on the operating element. Advantageously means are provided on the support part and/or on the operating element to axially secure the operating element on the support part. It can be advantageous if these means comprise at least one sealing ring. The sealing ring can advantageously consist of a plastics or hard rubber. The at least one sealing ring can be fixedly connected to the corresponding component part, namely the support part and/or the operating part through a snap-fit connection. A connection of this kind has the advantage that the sealing ring can be connected to the corresponding component part by clipping on same. To this end the sealing ring can have radially elastic arms or hooks which snap fit into rear cut sections on the corresponding component part which is to be connected to same.

It can be particularly advantageous if the ramp mechanism has rolling bearing elements which are positioned relative to each other in a circular arrangement through a sleeve 30 like cage. A cage of this kind can be made f rom plastics and/or metal. Advantageously the sockets of the cage for the rolling bodies are provided in a central area so that of these sockets rolling the cage forms a sleeve like attachment each side sockets. The cage can have in the area of the corresponding moulded areas which ensure that the P2370.P3 30 march 1999 - 6 bodies are secured on or in the cage. The sockets and the moulded areas can thereby be matched with each other so that the rolling bodies, such as in particular the balls, are secured on or in the cage through a snap- fit connection whereby fitting becomes significantly easier. Advantageously the cage is mounted between the operating element and the support part so that this or its sleeve like attachments serve to seal a space provided between the cylindrical attachment of the support part and the sleeve like attachment of the operating element. The cage is advantageously housed inside the operating device so that with activation the axial displacement of the cage amounts to half that of the operating element. It can be expedient if the cage encloses the cylindrical attachment of the support part directly. It can further be advantageous if the cage directly adjoins the radially inner sleeve face defined by the sleeve like axial attachment of the operating element. For sealing the chamber holding the rolling bodies of the ramp mechanism it can be particularly advantageous if the cage is provided directly between a ring-like outer sleeve face defined by the cylindrical attachment of the support part, and a ring-like inner sleeve face defined by the sleeve like axial attachment of the operating element.

It can be particularly advantageous for the production and functioning of the operating device according to the invention if the ramps formed by radial indentations in the cylindrical attachment of the support part and/or in 30 the sleeve like attachment of the operating element are covered or sealed by the cage or by the axial attachments of this cage, namely in the radial direction and during activation of the device. For the axial seal the cage can interact with at least one sealing ring which is provided as described above on the support part and/or on the P2370.P3 30 March 1999 operating element.

To this end the sealing ring can have axial attachments which engage in the radial shaped areas formed in the operating element and /or support part to produce the ramps, and are adapted to the circumferential path of these indentations.

For transferring or introducing the operating force the operating element can have a radial extension arm on which the operating means engage. Advantageously the radial extension arm can have or support radially on the outside a segment shaped area which serves to guide the cable of a Bowden cable or cable pulley. This segment or this area f orms a guide on which the cable can be wound and unwound over a certain angle.

is Advantageously the segment shaped area has a radial guide groove for the cable. The segment shaped area can be f ormed so that an at least approximately constant lever length for the cable is provided continuously over the 20 operating path. For many cases it can however also be expedient if the segment shaped area is formed in relation to the axis of rotation of the operating element so that during activation the lever length for the cable in relation to the axis of rotation is changed, e.g. becomes 25 bigger or smaller. It can be particularly advantageous if the guide area for the cable extending round the axis of rotation of the operating element has a thread-like pitch in the longitudinal direction of this axis of rotation. This means that with the presence of a cable groove this 30 has a screw-thread type path. By designing the guide area in this way it can be ensured that during rotation of the operating element the inlet or outlet contact point of the cable with the guide area, viewed in the axial direction, has practically no or only a reduced change of position P2370.P3 30 march 1999 8 relative to the support area of the sleeve of the cable pulley.

Advantageously the cable pulley can be divided into two parts which can be coupled together through a connecting device, preferably an automatic connecting device. To this it is possible to use a quick-fit coupling. A particularly simple connection of the two parts of the cable pulley can be achieved through an axial snap-fit connection. It can however be expedient also if a bayonet-type closure is used for a connection of this kind. With a split design of the cable pulley of this kind the one part can be provided or prefitted outside of the gearbox bell and the other part can be provided or prefitted inside the gearbox bell or on the operating element whereby assembly and dismantling of the gearbox and engine becomes much easier. The other part of the cable pulley which contains the sleeve is supported on a fixed component part such as the gearbox housing or clutch bell. In many cases it can also be expedient if the support part has a radial arm on which the sleeve of the cable pulley can be supported. The sleeve can thereby be guided through an opening in the clutch or gearbox bell. The radial arm of the support component can advantageously reach practically up to the opening whereby the assembly becomes significantly easier.

Dividing up the cable pulley ensures that the operating device can be fitted as an installation module on the 30 gearbox since the complete assembly of the cable pulley can also take place after assembling the engine and gearbox. The one part of the connecting device for the two parts of the cable pulley can advantageously be supported on a bearing area or support area which is 35 provided on the support part. This support area can be P237C.P3 30 March 1999 provided in the manner of a console bracket. This one part of the connecting device can be drawn against the supporting area by means of a pretensioned spring provided between the operating element and support part whereby a definite positioning is guaranteed. The other part of the cable pulley can be easily inserted with the other part of the connecting device through an opening into the clutch or gearbox bell in order to couple the two parts of the connecting device together, e.g. through a detent connection. After producing this connection the sleeve of the cable pulley used at first to apply the force required to produce the connection can be drawn back and can be supported or hung by suitable means on a fixed component part, such as e.g. the gearbox bell. This can take place for example through a bayonet-type support.

An advantageous design of the invention can contain a length compensation which can compensate for example lengthening of the cable pulley, installation tolerances, wear on the clutch disc and the like so that advantageously the turning angle of the ramp mechanism can only be designed for the actual axial disengagement path of the clutch.

Advantageously the attachment of a length compensation of this kind can be directly on the operating device whereby attachment radially inside the ramp mechanism can be particularly advantageous.

An advantageous design can provide an axial freewheel which allows the compensation of an axial play between plate spring tongues and the biasing areas of the operating device when the clutch is engaged without requiring the ramps to turn relative to each other whilst during activation of the device the axial freewheel locks P2370.P3 30 March 1999 relative movement of the biasing areas against the axially movable ramp areas.

According to a further development of the invention the support part can have on the side facing the gearbox a ring-shaped axial projection which supports at least a ring-shaped sealing ring which preferably interacts with the gear input shaft. The support part can also have on the side facing the gearbox a ring-shaped axial projection which houses a bearing, such as in particular a rolling bearing for the radial mounting of the gear input shaft. Advantageously the corresponding projection can be housed in a suitably adapted recess in the gearbox housing.

Further features and advantages of the invention are apparent from the description of the following figures in which:

Figure 1 Figure 2 Figures 3,4 Figure 5 Figures 6,7 Figure 8 shows an operating and disengagement device for a clutch assembly according to the invention; shows the disengagement device according to Figure 1 on an enlarged scale; show a cage for rolling bodies for use with a disengagement device according to Figure 2; shows a variation of an embodiment of the disengagement device; each show an outside view of the operating device according to Figures 1 and 2 wherein two different operating states of this device are shown; shows a view of the operating device according to the arrow VIII of Figure 6; P2370.P3 30 March 1999 11 - Figures 9,10 Figure 11 Figure 12 Figure 13 Figure 14 Figures 15a-c show two assembly steps for attaching a cable pulley to the corresponding disengagement device; shows a detail of a further embodiment of a disengagement device; shows a further assembly design for a cable pulley; shows another embodiment of a disengagement device; shows a detail of a further embodiment of a disengagement device; show a closure for a separable cable pulley and Figure 16 shows an operating device with an adjustment device.

The disengagement device 1 shown in Figures 1 and 2 is mounted to act axially between a gearbox 2 and a friction clutch 3 of a motor vehicle (not shown in further detail).

The disengagement device 1 has an axially fixed support part 4 which can be supported axially on the gearbox housing 2 and can be connected nonrotatable to this e.g. through screw connections and/or snap fit connections or 25 axial push-fit connections. The support part 4 is in the illustrated embodiment formed as a hollow metal component part which in the assembled state encloses the gear input shaft. As can be seen in particular from Figure 2 the support part 4 is formed as a shaped sheet metal part or a 30 sheet metal structure. The support part 4 has a sleeve like area 7 whose longitudinal axis is at least approximately coaxial with the axis of the gear input shaft 6. The support part 4 has on the end section facing the gearbox 2 a ring-shaped radially extending area 8 35 which serves for axially supporting the support part 4 on P2370.P3 30 march 1999 - 12 the gearbox 2. Furthermore the fastening means such as screws provided for holding the support part 4 on the gearbox 2 can be provided between the radial area 8 and the gearbox 2. The radially aligned area 8 made of sheet metal and the sleeve like area 7 can be connected together e.g. through welding more particularly through laser beam welding 9. Through suitable design of the two parts 7 and 8 other types of connection can also be used such as e.g. shrink fit connections, connections through spot welding 10 and/or caulking and/or flanging and/or riveting. With a connection through spot welding, caulking, flanging or riveting it is expedient if the component part 7 has at least a radial step which interacts with radial areas of the component part 8 for axial security.

is on the side of the area 8 facing the gearbox 2 the support part 4 has a ring-shaped projection 8a by means of which it can be centred in a gearbox recess 2a (Figure 1) relative to the shaft 6.

It can also be advantageous if the sleeve like area 7 and the radial area 8 are formed as an integral shaped sheet metal part. The sleeve like area 7 is as shown in particular from Figure 2 enclosed by a ring-shaped 25 operating element 5 which takes up the axial forces required to disengage the friction clutch 3 and transfers same through a ramp mechanism 10 to the support part 4.

The operating element 5 is likewise formed by a ring shaped sheet metal part which defines a sleeve like attachment 11. The ramps 12,13 of the ramp mechanism 10 provided between the support part 4 and the operating element 5 are formed by run-up ramps 12 provided on the operating element 5 and interacting with the interposition of rolling bodies 14, namely balls, with counter run-up ramps 13 provided on the support part 4. The ramps 12 and P2370.P3 30 March 1999 - 13 13 are placed circumferentially and rise axially to produce an axial movement between the two component parts 4,5. With the illustrated embodiment the ramps 12, 13 are formed by indentations which are formed in the component 5 parts 4, 5 which are formed as shaped sheet metal part. The run-up ramps 12, 13 are formed in the axially extending areas 7, 11, preferably by indentations.

The ramps 12, 13 are formed with regard to their pitch so that no self-locking can occur as a result of friction inside the ramp mechanism 10. It is expedient if the pitch angle of the ramps 12, 13 lies in the order of 30 to 600, preferably in the order of 450. The pitch of the ramps can thereby be variable or constant over their circumferential extension. When using a pitch which changes over the length of the ramps the disengagement force path which is required over the disengagement path can be affected. By way of example the force path characteristic of the clutch plate springs 3a applying the contact pressure force (Figure 1) can thereby be taken into account.

The rolling bodies or balls 14 are evenly spread out in the circumferential direction and are positioned through a cage 15.

As can be seen from Figures 3 and 4 in the illustrated embodiment the cage 15 has three sockets 16 for the balls 14. The cage 15 can advantageously be formed of plastics, e.g. through injection moulding. It can also be advantageous however if the cage 15 is formed as a shaped sheet metal part. The cage 15 has in the area of the sockets 16 projections 17 which ensure that the balls 14 are held on the cage 15 secure against loss. The shaped areas or projections 17 can be formed in relation to the P2370.P3 30 March 1999 14 sockets 16 so that a detent connection is produced for the balls 14. After pressing the balls 14 into the sockets 16 these are thus secured against falling out whereby assembly is significantly easier.

The cage 15 has starting from the sockets 16 axially on both sides a sleeve like area 18, 19.

As can be seen from Figure 2 the ring-shaped or tubular cage 15 is housed directly on the sleeve like area 7 of the support part 4. Radially outside, the tubular cage 15 is enclosed directly by the sleeve like attachment 11 of the operating element 5. The cage 15 thus fillsout a ring shaped space which is provided between the sleeve like area 7 and the sleeve like attachment 11.

The cage is is likewise displaced during axial displacement of the operating element 5 relative to the support part 4, namely by about half the axial path covered by the operating element 5. During rotation of the operating element 5 the cage 15 also turns. The length of the sleeve like areas 18, 19 or of the cage 15 is designed so that the shaped areas 20, 21 formed radially in the component parts 4, 5 to produce the run-up ramps 12, 13, viewed in the radial direction, are constantly covered whereby the penetration of dirt or the escape of grease possibly contained in the area of the ramp mechanism 10 is avoided.

The axial openings provided in the area of the shaped areas 20, 21 in the embodiment shown in Figures 1 and 2 are closed by sealing rings 22, 23 as apparent in particular from Figure 2. The sealing ring 22 is fitted axially onto the sleeve like area 7 and is held on same at least axially e.g. by snap-fit connection. The sealing P2370.P3 30 March 1999 - is ring 22 has a ring-shaped area 24 whose radially outer sleeve face interacts with the tubular cage 15, namely to form a seal for the ramp mechanism 10. Axial attachments extend from the ring-shaped area 24 and reach axially into the shaped areas 20.

The sealing ring 23 engages round the tubular cage 15 and is fixedly connected axially to the operating element s.

The sealing ring 23 can as can be seen from Figure 5 have likewise a ring-shaped area 26 with axial attachments 27 which engage in the shaped areas 21 of the operating element 5. The sealing ring 23 forms together with the cage 15 a seal for the ramp mechanism 10. The sealing rings 22, 23 can be matched in relation to the cage 15 so that they each form together with this cage 15 a gap seal so that with axial displacement of the operating element 5 relative to the support part 4 there is no or practically no friction. The sealing ring 23 is provided axially fixed on the operating element 5. To this end axial snap fitting connections can be used for example, like also for the sealing ring 22. Advantageously the sealing rings 22, 23 can be made from plastics.

The operating element 5 of Figure 2 supports a release bearing 28 wherein the bearing 28 has opposite the operating element 5 a restricted radial displaceability, namely against a force locking engagement in the form of a relative tensioning 29 of the non-circumferential bearing ring 30. In the case of the illustrated embodiment the radially outer bearing ring 30 is not circumferential and the radially inner bearing ring 31 serves as apparent from Figure 1 for biasing the clutch operating means in the form of plate spring tongues 32. In the illustrated embodiment the bearing ring 31 which can rotate with the clutch 3 has radially aligned biasing areas 33 which P2370.P3 March 1999 - 16 interact with the operating areas 34 which in the illustrated embodiment are formed by tongue tips of the plate spring tongues 32.

As can be seen in particular from Figures 2, 6, 7 and 8 with the illustrated embodiment the disengagement device 1 or the operating element 5 can be operated through a Bowden or cable pulley 35. To this end the sleeve 36 (Figure 7) of the cable pulley 35 is supported on a fixed component part - in the illustrated embodiment on the gearbox housing or on the clutch bell 2 - and the cable 37 contained in the sleeve 36 is in active connection with the operating element 5 to transfer the operating force. To this end the operating element 5 has a radial area 5a which has radially outside a segment-shaped section 38 which has a hanging area or fastening area 39 (Figure 7, 8) for the one end of the cable 37.

As can be seen in particular from Figures 2, 6, 7 and 8 the segment shaped section 38 forms or supports radially outside a guide area 40 with a groove 41 for the cable 37.

The segment shaped section 38 with the guide area 40 can be made from sheet metal and can be formed in one piece with the sleeve like attachment 11 or however can be fixedly connected as a single shaped sheet metal part to the sleeve like attachment 11 e.g. through welding, riveting, caulking etc. With the design according to Figure 2 the section 38 is formed by a plastics part which is connected to the attachment 11. This connection can be produced through riveting or welding of the parts 11, 38. The section 38 can also be injection moulded on the part 11 in a particularly advantageous way.

P2370.P3 30 March 1999 17 is With the embodiment according to Figure 5 the segment shaped section 38 is formed as a composite structural element, namely through a metal reinforcement disc 42 which is encased by injection moulded plastics at least to form the guide areas 40. As can be seen in particular from Figure 5 the radial areas of the reinforcement disc 42 can also be provided with a plastics layer, and also a ring-shaped plastics area 43 is injection moulded in the radially inner areas of thereinforcement disc 42 to serve to hold and support the release bearing 28. In the illustrated embodiment the connection between the sleeve like attachment 11 and the component part forming the segment shaped section 38 is likewise produced through injection-moulded plastics fastening means. To this end the sleeve like attachment 11 has at one end area a ringshaped radial area 44 with recesses in which axial attachments 45 engage.

As can be seen f rom Figures 6 and 7 the guide area 40 having the groove 41 is thread like, seen in the axial direction of the disengagement device 1. The pitch is selected so that during rotation of the operating element 5 relative to the support part 4 and the axial displacement of the operating element 5 which is thereby produced the run- in point or run-in area 46 of the cable into the guide area 40 or groove 41 - viewed in the axial direction of the disengagement device 1 - practically does not change or however this axial displacement is restricted at least to an amount which does not produce any events which could affect the running of the cable.

A design of the disengagement device according to Figures 1 to 8 is particularly advantageous since an axially compacted construction is guaranteed through the arrangement of the release bearing 28 inside the axial P2370.P3 30 March 1999 18 extension of the sleeve like attachment 11. By using shaped sheet metal parts which have a comparatively thin material thickness a radially compacted method of construction is also possible.

Advantageously at least some individual component parts of the disengagement device 1 can be formed at least in part also as plastics parts or sintered parts.

As can be seen from Figure 7 in this embodiment the sleeve 36 of the cable pulley 35 is supported through the gearbox housing 2. According to a variation of the embodiment however the support part 4 can also have a radial extension arm on which the sleeve 36 of the cable pulley 35 can be supported so that through the cable 37 the operating element 5 can be turned relative to the support part 4 and can thereby be axially displaced.

In the illustrated embodiments the operating element 5 is operated through the cable pulley 35. Howeverother operating means can also be used such as e.g. servo motors which are driven hydraulically, pneumatically or electrically and bias or turn the operating element 5 through corresponding connecting means. Servo motors of this kind can be housed where applicable directly adjoining the disengagement device 1 whereby it can also be advisable to provide a servo motor of this kind on the support part 4.

As can be seen from Figures 2 and 5 a return spring 47 is provided between the relevant support part 4 and the associated operating element 5 and is pretensioned so that when the disengagement device 1 is not f itted the spring forces the operating element 5 into its position which is 35 retracted relative to the support part 4. The spring 47 P2370.P3 30 March 1999 19 - is formed as a spiral spring which is hung at one end on the operating element 5 and at the other end on the support part 4. The spiral form of the spring 47 requires a very small axial structural space. The windings 47a of the return spring 47 are formed so that both a satisfactory axial displacement and a rotation of the operating element 5 relative to the support part 4 is possible.

After fitting the disengagement device 1 and the cable pulley 35 an energy accumulator acts on the operating element 5 in the disengagement direction and when the disengagement device 1 is not activated, whereby this energy accumulator produces an axial force which greater than the axial force exerted by the return spring 47 on the operating element 5 whereby the biasing areas 33 provided on the circumferential bearing ring 31 are pressed with a defined force against the operating areas or tongue tips 34 of the clutch activating means or plate spring tongues 32. It is thereby ensured that the release bearing always adjoins the tongue tips 34 with a predetermined prestrain. This prestrain can be in the order of 10 N to 70 N for passenger vehicles. The energy accumulator applying this axial force can advantageously act on the cable 37 and by way of example can be provided in the extension area of the cable pulley 35 or in the area of the clutch pedal cable 37.

or the actuator acting on the With the support of the sleeve 36 on a fixed component part, namely the gearbox or clutch housing 2 shown in the Figures 7 and 8 the end area 36a of the sleeve is held practically rigid and is axially supported. Thus as can be seen f rom Figures 6, 7 a kink can be produced within the cable 37. In order to avoid such a kink or at least P2370.P3 30 march 1999 to reduce same the holder parts 48 holding the end area 36a can be formed so that they ensure a joint-type, more particularly ball or calotte like support on the corresponding fixed component part 2 whereby an angular swivelling of the end area of the sleeve 36 can be ensured and thus the sleeve 36 and the cable 37 can be aligned accordingly in order to avoid at least too much bending of the cable.

AS can be seen from Figures 6, 7 and 8 the cable pulley 35 can advantageously be divided into two parts 35a, 35b which can be coupled together preferably through an automatic or independent connecting device 49. This automatic connecting device can form a quick- fit coupling which can be formed as an axial snap-fit connection. The one part 35a of the cable pulley 35 is formed by a cable section 35a which is fixed or hung by its one end area 50 on the guide area 40 and in the nonfitted state of the disengagement device 1 is supported by its other end area 51 on an extension arm or a moulded area 52 of the support part 4, as shown in Figures 6 and 8. The circumferential force required for this can be applied by the return spring 47 (Figure 2, 5). Through this type of design for the disengagement device it is ensured that at least with 25 the other part 35b of the cable pulley 35 not fitted the end area 51 of the cable section 35a has a defined position whereby a particularly simple coupling of the two parts 35a, 35b of the cable pulley 35 is ensured through the connecting device 49. To dismantle the automatic 30 connecting device 49 a recess an be provided in the gearbox housing 2 through which a tool such as e.g. a screw driver can be passed in order to unlock or release the connecting device 49. The cable pulley 35 is thus divided into a part 35b which is mounted from the outside 35 of the gearbox bell 2 and into a part 35a which is P2370.P3 March 1999 prefitted inside the gearbox bell 2. Dividing up and arranging the cable pulley 35 in this way guarantees easier fitting of the disengagement device 1 as an installation module for prefitting of the gearbox and subsequent f itting of the complete cable pulley. With a design according to Figures 8 to 10 the part 35b of the cable pulley 35 can be inserted with the quick-fit coupling connector 53 through an opening 54 of the gearbox housing or clutch bell 2 and can be connected through comparatively minimum amount of force in the longitudinal direction of the sleeve 36 with the end area 51 which forms the counter member of the connecting device 49, e.g. through snap fit connection or detent engagement. The force required to produce the connection 49 is applied by the sleeve 36 or the end member 55 holding the end area of the sleeve 36. To this end the sleeve 36 or theend member 55 acts on the quick-fit coupling connector 53 (see corresponding position according to chain-dotted lines in Figure 8). After the detent engagement of the connecting device 49 the sleeve 36 or the end member 55 connected thereto is drawn back and supported on the housing 2. To this end as can be seen from Figures 9 and 10 the housing 2 has an assembly opening 56 which allows the enlarged area 57 of the end member 55 to only pass through in a quite specific angular position. After withdrawing the end member 55 the enlarged area 57 can be turned accordingly so that it can be supported on the support area 58 provided on the housing 2. This position is shown in Figure 10. The f inal support of the sleeve on the housing 2 is thus through a bayonet-type support or connection.

With the design according to Figure 5 the support part 4 has on the side of the radial area 8 remote from the operating element 5 an axial ring-shaped attachment 59 of P2370.P3 30 March 1999 1\ 22 - enlarged diameter which holds a radial shaft sealing ring 60 centred. This ring 60 interacts with the gear input shaft. The axial attachment 59 can be pushed into a suitably adapted ring-shaped recess in the gearbox.

Radially outside of the axial attachment 59 is a further seal e.g. in the form of a ring 61 which when screwing on the disengagement device 1 forms a static seal opposite the gearbox housing. With the embodiment according to Figure 5 the axial attachment 59 is formed in one piece with the sleeve like area 7. Where applicable the axial attachment 59 can also be formed longer and can hold a bearing, such as in particular a rolling bearing 62 for the gear input shaft. A design of this kind is shown in Figure 11 (in addition to Figure 2) whereby with this design the axial attachment 59 is formed as a separate sheet metal part 63 which is connected to the sleeve like area 7 eg through welding and/or press connection.

With the embodiment shown in Figure 12 of an axial support of the sleeve 136 of the cable pulley 135 an axially displaceable support sleeve 165 is provided on the end member 155 enclosing the end area of the sleeve 136 and is mounted on the end member 155 in a retracted position 165a. The end member 155 can thereby be pushed correspondingly far through the recess 154 provided in the bell 102, namely in order to be able to produce in a similar way to the connection described in Figure 8 the connection 49 between the two cable pulley parts. After this connection has been made the sleeve 136 or the end member 155 is drawn back at least into the solid line position and the sleeve 165 is pushed from the position 165a into the position 165b. During this displacement the ring 165 slides over radially resilient detent noses 166 provided on the end member 155. These noses 166 form support areas for the ring 165. The sleeve 136 or the end P2370.P3 30 March 1999 -1 member 155 is supported axially on the housing 102 through these noses 166 with the interposition of the ring 165.

The disengagement member 201 shown in Figure 13 differs from that already described in that the support part 204 and the operating element 205 are formed more solid. The component parts 204, 205 can be made for example of a fibrereinforced plastics. At least one of the parts 204 205 can however also be made as a sintered part or as a flow-pressed part or as a forged part.

The self centring release bearing 228 is supported through the inner ring 230 of the bearing by the operating element 205. To this end the inner bearing ring 230 has a radially aligned ring-shaped area 230a which is connected to the operating element 205 through a friction tension unit 229. With the illustrated embodiment according to Figure 13 the bearing 228 is supported by the areas 230a on the end side or on the end area of the sleeve 211 of the operating element 205.

With the embodiment shown in Figure 2 for producing the friction tensioning 29 through which the bearing 28 is held on the operating element 5 a shaped sheet metal part 70 is provided which engages round the ring-shaped attachment 43 of the support part 5 by an axial ringshaped area 71. Snap-fit connections 72 are provided between the ring- shaped area 71 and the axial attachment 43 whereby an automatic hold is guaranteed during assembly of the corresponding parts. The radial area 73 of the outer bearing ring 30 is tensioned between a plate spring 74 supported on the shaped sheet metal part 70 and the ringshaped area 75 which stretches radially inwards from the axial ring-shaped area 71. The area 75 is supported axially on the attachment 43. With the embodiment shown P2370.P3 30 March 1999 1 24 in Figure 13 the hold of the bearing 228 is likewise produced through a part 270 which is arranged and formed similar to the part 70 according to Figure 2. With the design according to Figure 13 the part 270 is pushed or clipped axially onto the end of the sleeve like area 211 facing the friction clutch.

With the design according to Figure 14 the radially extending area 308 of the operating element 305 has a ring-shaped axial attachment 343 or several axially extending tongues 343, radially inside which a plate spring like component part 374 is clipped in which biases and thus clamps with friction a radial section 373 of the inner bearing ring 331 against a radial section of the radial area 308.

Figures 15a - c show a connecting device 249 which is similar to the connecting device 49 (Figure 8). Figure 15a shows the state prior to fitting, Figure 15b shows the connecting device 249 in the fitted state and Figure 15c shows the state during separation of the connecting device 249.

The connecting device 249 connects the two cable sections 235a, 23sb inside the gearbox bell 2 together as in Figure 8 whereby the connecting device 249 can be connected and separated without auxiliary means.

The construction of the connecting device 249 is designed so that the end area 236a of the sleeve 236 is formed as a socket, or a corresponding end member 236a is attached on the sleeve 236 which can be firmly connected similar for example to that 36a in Figure 8 - with the gearbox bell.

At the end of the cable section 235b is fitted a conically or semi-circular formed nipple 251 with an angular P2370.P3 30 March 1999 25 circumferential profile 251a. An axially aligned stepped bore 236b is provided in the end member 236a into which the nipple 251a can be sunk. An axially active energy accumulator 260 - here formed as a coil compression spring - is inserted axially tensioned axially between the contact bearing face 236c of the stepped bore 236b and the contact bearing face 251b of the nipple 251.

The other component part 253 forming the connecting device is set on a moulded area 252 of the support part (not shown) of the disengagement device. The component part 253 can thereby have an axially recessed attachment 252a which is pushed into the shaped area 252 or is connected to the shaped area in another way or is only placed against same. The cable section 235 is connected by a nipple 235b with the component part 253 and is tensioned with the component part 253 in the cable pulley direction by means of a return spring (not shown) of the disengagement device. The component part 253 is formed from a suitably shaped sheet metal or injection moulded plastics part so that a number, preferably three extension arms 253a are provided which point in the cable pulley direction and are arranged at angles of about 1200 relative to each other about the centre point of the cable pulley and which have window-shaped recesses 253b on their outer areas. The ends 253c of the extension arms are angled radially outwards - relative to the centre point of the cable pulley - and. form together a run-up profile for the nipple 251 and the end member 236a which has for this purpose a complementary run-up incline 236c.

The method of functioning of the connecting device 249 is such that the end part 236a not yet fixed on the gearbox bell is pushed into the gearbox bell with the assistance 35 of the sleeve 236 which has sufficient rigidity to prevent P2370.P3 30 March 1999 -1 26 bending. Thus first the nipple 251 meets the run-up prof ile of the ends 253c of the extension arms and is tensioned axially against the end piece 236a by means of the coil compression spring 260. With further movement in 5 the direction of the component part 253 first the nipple 251 and then the moulded inclines 236c widen out the extension arms 253a until the nipple 251 is pressed by the spring force of the coil compression spring 260 into the inner area of the component part 253 until stopping with the nipple 235b. The sleeve 236 is then drawn back and the nipple 251 engages by its outer profile 251a in the recesses 253b. The radially inwardly acting rigidity of the extension arms 253a hold the nipple in its position. The end piece is removed from the gearbox bell and fixed on the gearbox housing. The adjustment of the cable pulley takes place on the clutch pedal or by shortening the sleeve 236.

An opening of the connection, which is required for example in the event of repair, is carried out by loosening the end piece from the housing wall and inserting it into the gearbox bell by means of the sleeve 236. An axial pressure of the run-up inclines 236c on the run-up profile of the ends 253c of the extension arm causes a radial expansion of the extension arms 253a and a release of the nipple 251 from the recesses 253b. BY pulling on the cable section 235b the nipple is drawn against the action of the coil compression spring 260 into the stepped bore 236b and the end piece 236a can be removed completely from the gearbox bell without resistance.

Figure 16 shows an operating device 30 which is comparable with the operating devices 1 of the preceding f igures but which has in addition a length compensation 360.

P2370.P3 30 March 1999 27 The length compensation 360 is compensated in the illustrated embodiment by an axial freewheel which in the engaged state of the clutch compensates a distance d which can result from the wear on the clutch disc and the like, in that the sleeve like component part 305a is displaceable axially relative to the axially displaceable operating element 305 against the axial action of the energy accumulator 363 and is brought to bear against the spring tongues 332 of the plate spring which is not shown in further detail.

The axially active energy accumulator 363 provided in this embodiment as a spiral spring is supported on one side on the radially aligned connecting ring 305c of the operating element 305 with the ramps 312 and on the other side on the radially aligned attachment 305b which engages on its outer circumference round the spiral spring and holds the release bearing 328. Furthermore radially expanded tongues 305d are provided on the outer circumference of the radially aligned attachment 305b and form with the ramps 311 an axial stop with the sleeve like component part 308 of the support part 304 connected to the gearbox.

In order to form the axial freewheel clamping rollers 361 are housed radially between the sleeve like component part 305a and the cone 368 which tapers towards the clutch and which is fixedly connected to the operating element 305.

The clamping rollers control the axial displacement between these parts in dependence on their axial position.

When the clutch is engaged the sensor element 362 which guides the clamping rollers 361 axially and circumferentially strikes against a component part fixed on the gearbox, such as here the component part 308 by means of a radially enlarged attachment 362a wherein a P2370.P3 30 March 1999 28 - further axially active energy accumulator 364 - here in the form of a plate spring - is tensioned between the radially enlarged attachment and the disengagement ring 305c and during a reverse movement of the operating element 305 during a disengagement process of the clutch positions the clamping bodies 361 axially in an area in which no blocking action arises between the cone 368 and the sleeve like component part 305a.

During a disengagement process of the clutch with an axial displacement of the operating element 305b relative to the sleeve like component part 308 which results from the rotary movement along the ramps 311, 122, the energy accumulator 364 which has previously been pressed into a block, moves the sensor element 362 against the direction of movement of the operating element 305 and thereby tensions the clamping rollers 361 which are axially guided in the sensor element between the cone 368 and the sleeve like component part 305b so that a relative movement of the two parts against each other is blocked and the rotary movement of the operating element 304 is transformed through the rams 311, 312 entirely into an axial movement of the release bearing 328 which is transferred free of play by means of the biasing areas 333 of the bearing ring 331 to the plate spring tongues 332.

The pretensioning device 363 of the length compensation 360 is thereby matched to the pretensioning device (not shown in further detail here) of the cable pulley so that in each case the energy accumulator 363 axially active between the sleeve like component part 305a and the operating element 305 is more strongly dimensioned that the energy accumulator which is provided for the length compensation of the cable pulley. This ensures that a distance d which arises through wear is initially P23X.P3 30 March 1999 compensated and thus the ramps 311, 312 are f irst pushed into the axially shortest position and then the length compensation of the cable pulley becomes active.

It is evident that the length compensation 360 according to the invention can be integrated in all the embodiments of the operating device and the component parts of the length compensation can finished like the remaining component operating device.

be manufactured, treated and parts of the The patent claims filed with the application are proposed wordings without prejudice for obtaining wider patent protection. The applicant retains the right to claim further features disclosed up until now only in the description and/or drawings.

References used in the sub-claims refer to further designs of the subject of the main claim through the features of each relevant sub-claim; they are not to be regarded as dispensing with obtaining an independent subject protection for the features of the sub- claims referred to.

The subjects of these sub-claims however also form 25 independent inventions which have a design independent of the subjects of the preceding claims.

The invention is also not restricted to the embodiments of the description. Rather numerous amendments and modifications are possible within the scope of the invention, particularly those variations, elements and combinations and/or materials which are inventive for example through combination or modification of individual features or elements or process steps contained in the drawings and described in connection with the general P2370.P3 30 March 1999 description and embodiments and claims and which through combinable features lead to a new subject or to new process steps or sequence of process steps insofar as these refer to manufacturing, test and work processes.

P2370.P3 30 March 1999

Claims

1. Operating device for a clutch, more particularly for 5 a friction clutch to be provided between an engine and a gearbox, with a release bearing for operating the clutch operating means, wherein the release bearing is supported by a support part which is to be provided on the gearbox side, and at least one operating element which supports the release bearing and which is rotatable and axially movable relative to the support part is provided on said support part, wherein furthermore a ramp mechanism is provided between the support part and the operating element for axially displacing said operating element, wherein the ramps making up the ramp mechanism are supported directly by the support part and the operating element and are fixed to same and the release bearing is housed on the operating element with the possibility of restricted radial displacement.

2. operating device according to claim 1 characterised in that the support part and/or the operating element has ramps formed directly thereon.

3. operating device according to one of claims 1 and /or 2 characterised in that the support part has a cylindrical attachment on which the ringshaped operating element is housed.

4. operating device according to claim 3 characterised in that the ringshaped operating element has radially inside a sleeve-like axial attachment which is guided on the attachment of the support part.

P2370.P3 30 March 1999 32 -

5. Operating device according to one of claims 1 to 4 characterised in that the ramp mechanism is formed at least by run-up ramps provided on the support part and interacting with counter run-up ramps provided on the operating element and rolling bodies are provided between the run-up ramps and the counter run-up ramps.

6. operating device according to one of claims 1 to 5 characterised in that the ramp mechanism has ramps rising 10 in the axial direction of the operating device.

7. operating device according to one of claims 1 to 6 characterised in that the ramps of the ramp mechanism have a pitch angle which causes no self-locking through 15 friction inside the ramp mechanism

8. Operating device according to one of claims 1 to 7 characterised in that the ramps have a pitch angle between 300 and 600, preferably in the order of 450.

9. operating device according to one of claims 1 to 8 characterised in that the ramp mechanism is tensioned through at least one spring against the disengagement or resetting direction.

10. Operating device according to claim 9 characterised in that the spring has windings which are placed round the attachment of the support part.

11. Operating device according to claim 9 or 10 characterised in that the spring axially tensions the ramp mechanism at least when the operating device is not mounted in the vehicle.

P2370.P3 March 1999

12. Operating device according to one of claims 1 to 11 characterised in that the turning angle allowed for the ramp mechanism between the support part and operating element is restricted.

13. operating device according to claim 12 characterised in that the turning angle is measured so that the overall axial displacement of the release bearing which can be produced through the ramp mechanism corresponds at least to the sum of the ideal disengagement path of the clutch operating means which can be operated by the disengagement device, and the displacement of the release bearing which takes place as a result of the wear at least on the friction linings of the clutch disc.

is

14. Operating device according to one of claims 1 to 13 characterised in that a device is provided which guarantees the operating element a predetermined retracted position on the support part at least up to the initial operation of a clutch by means of the operating device.

15. Operating device according to claim 14 characterised in that the ramp mechanism is held in a ready- to- function position through the device.

16. Operating device according to one of claims 14, 15 characterised in that the device acts between the operating element and the support part.

17. Operating device according to one of claims 1 to 16 characterised in that the ramp mechanism is housed in a chamber which is sealed at least substantially.

18. Operating device according to claim 17 characterised in that the ramp mechanism is lubricated.

P2370.P3 30 March 1999 34

19. operating device according to one of claims 1 to 18 characterised in that a ring-shaped space is defined radially between the cylindrical attachment of the support part and the sleeve like axial attachment of the operating element enclosing same and this space is sealed at least on one of its two axial ends.

20. operating device according to claim 19 characterised in that the seal is provided by means of at least one sealing ring.

is

21. Operating device according to one of claims 19, 20 characterised in that a sealing ring is provided for the ring-shaped space on the support part and/or on the operating element.

22. Operating device according to one of claims 1 to 21 characterised in that means are provided on the support part and/or on the operating element and axially secure the operating element on the support part.

23. Operating device according to one of claims 19 to 22 characterised in that the operating element is axially secured on the support part by at least one sealing ring.

24. Operating device according to one of claims 1 to 23 characterised in that the ramp mechanism has rolling bearing elements which are positioned by a sleeve like cage relative to each other in a circular arrangement.

25. Operating device according to claim 24 characterised in that the cage is made from plastics and/or metal.

P2370.P3 30 March 1999 1 - 35

26. Operating device according to claim 24 or 25 characterised in that the cage has sockets for the rolling bodies and a sleeve like attachment each side of these sockets.

27. Operating device according to one of claims 24 to 26 characterised in that the cage or the sleeve like attachments serve to seal a ring-shaped space which is provided between the cylindrical attachment of the support part and the sleeve like axial attachment of the operating element.

28. Operating device according to one of claims 24 to 27 characterised in that during operation of the operating device the axial displacement of the cage amounts to half that of the operating element.

29. Operating device according to one of claims 24 to 28 characterised in that the cage directly encloses the cylindrical attachment of the support part.

30. Operating device according to one of claims 24 to 29 characterised in that the cage directly adjoins the radially inner ring-like sleeve face which is defined by the sleeve-like axial attachment of the operating element.

31. Operating device according to one of claims 24 to 30 characterised in that the cage is provided directly between a ring-like outer sleeve face defined by the cylindrical attachment of the support part, and a ringlike outer sleeve face defined by the sleeve like axial attachment of the operating element.

32. Operating device according to one of claims 24 to 29 characterised in that the ramps formed by radial P2370.P3 30 March 1999 1 36 indentations in the cylindrical attachment of the support part and/or in the sleeve like attachment of the operating element are sealed by the cage or by the axial attachments of the cage.

33. Operating device according to one of claims 19 to 32 characterised in that the sealing ring and the cage interact as a seal.

34. Operating device according to one of characterised in that the radial moulded the operating element and/or support part are closed axially by axial attachments ring provided on a sealing ring and 15 circumferential path of the indentations.

claims 19 to 31 areas formed in to produce ramps of the sealing adapted to the

35. Operating device according to one of claims 19 to 32 characterised in that at least one sealing ring is fixedly coupled to the support part and/or to the operating element through an axially active snap-fit connection.

36. Operating device according to one of claims 1 to 33 characterised in that the operating element has a radial extension arm with a segmentshaped area on which the cable of a cable pulley is attached and guided over a certain angle.

37. Operating device according to claim 36 characterised in that the segment shaped area forms a guide groove for the cable which extends round the longitudinal axis of the operating device and has a thread-like pitch along this longitudinal axis.

P2370.P3 30 March 1999 37 -

38. Operating device according to one of claims 1 to 37 characterised in that the operating element is operable through a cable pulley.

39. Operating device according to claim 38 characterised in that the cable pulley is divided into two parts which can be coupled together through a connecting device, preferably an automatic device.

40. Operating device according to claim 39 characterised in that the connecting device is a quick-fit coupling.

41. Operating device according to claim 39 or 40 characterised in that the connecting device is formed by an axial snap-fit connection.

42. Operating device according to one of claims 39 or 40 characterised in that the connecting device is formed by a bayonet-type closure.

43. Operating device according to one of claims 39 to 42 characterised in that a part of the cable pulley is supported by the operating element and attached to same at one end.

44. Operating device according to one of claims 39 to 43 characterised in that the other part of the cable pulley is supported through the cable pulley sleeve on a fixed component part such as a gearbox housing or clutch bell.

45. Operating device according to at least one of the preceding claims characterised in that the support part has on the side facing the gearbox a ringshaped axial projection which supports at least one sealing ring.

P2370.P3 30 March 1999 38 -

46. operating device according to at least one of the preceding claims characterised in that the support part has on the side facing the gearbox a ring-shaped axial projection inside which a bearing such as in particular a 5 rolling bearing is set for the gearbox input shaft.

47. Operating device according to one of claims 45, 46 characterised in that the projection can be housed in a suitable recess in the gearbox housing.

48. Operating device according to one of claims 1 to 47 characterised in that the turning angle is independent of the wear on the clutch.

49. Operating device according to one of claims 1 to 48 characterised in that in the operating device an axial compensation is provided to compensate wear, installation tolerances and/or lengthening of the means operating the operating device.

50. Operating device according to claim 49 characterised in that the axial compensation is an axial freewheel.

51. Operating device according to one of claims 48 to 50 characterised in that the compensation is provided radially inside the ramp mechanism.

52. Operating device substantially as herein described with reference to the accompanying drawings.

P2370.P3 30 March 1999