WO2008141604A1

WO2008141604A1 - Friction clutch

Info

Publication number: WO2008141604A1
Application number: PCT/DE2008/000726
Authority: WO
Inventors: Dominik Hans
Original assignee: Luk Lamellen Und Kupplungsbau Beteiligungs Kg
Priority date: 2007-05-18
Filing date: 2008-04-28
Publication date: 2008-11-27
Also published as: DE102008021161A1; DE112008001069A5; DE112008001069B4

Abstract

The invention relates to a friction clutch in the drivetrain of a motor vehicle, with a clutch release device, comprising a slave cylinder with a slave cylinder housing, which may be rotated by means of a cap bearing and is connected to the friction clutch in a rotationally and axially fixed manner by a fixing flange on the friction clutch and encloses an annular pressure chamber with a guide sleeve in which an axially displaceable annular piston is arranged which is axially connected to a release bearing which applies force to a radially inner region of a plate spring in the axial direction, wherein a pre-loading spring is arranged between the release bearing and cap bearing.

Description

friction clutch

The present invention relates to a friction clutch according to the preamble of patent claim 1.

A generic friction clutch with a so-called cover-resistant release is known from DE 101 38 722.

An object of the present invention is to improve the friction clutch in terms of manufacturing costs and assembly costs.

This problem is solved by a friction clutch in the drive train of a vehicle with a clutch release device comprising a slave cylinder with a slave cylinder housing which is rotatably and axially fixedly connected by means of a cover bearing with a mounting flange of the friction clutch and encloses a ring-shaped pressure chamber with a guide sleeve, in which an axially displaceable Ring piston is arranged, which is axially fixedly connected to a release bearing, which acts on a radially inner portion of a plate spring in the axial direction with force, wherein between Ausrücklager and cover bearing a preload spring is arranged. In such cover-resistant Zentralausrückern the slave cylinder housing is held in the axial direction by a mounting flange and is rotatably supported by the cover bearing against the mounting flange. The applied by the Zentralausrücker axial force acts thereby between mounting flange and plate spring. The Zentralausrücker is actuated by a hydraulic system, this includes the slave cylinder, a master cylinder, a connecting both pressure medium line and possibly other hydraulic components such as vibration, vent or the like. The biasing spring serves on the one hand to apply a biasing force and transmits the drag torque between release bearing and cover bearing.

It is preferably provided that the preload spring radially surrounds the cover bearing and / or the release bearing. The preload spring is thus arranged radially outside of the two bearings, so that the release bearing and / or the cover bearing is arranged in each case radially within the preload spring. This makes it possible to minimize the distance between release bearing and cover bearing or to maximize the length of the preload spring. Preferably, it is provided that the preload spring is clamped between two spring receptacles, wherein the spring receptacles comprise a ring opening which is frictionally engaged in the circumferential direction and in the axial direction. tion frictionally and / or positively connected to the outer ring or the inner ring of the cover bearing or release bearing. The inclusion of the preload spring can thereby transmit the bearing drag. The inclusion of preload spring also does not increase the axial space. It is preferably provided that the spring receivers have pockets extending in the axial direction. The pockets are formed by an inner and outer cylindrical portion, which are closed by a bottom portion, and receive the spring ends of the biasing spring. In this way, the spring ends are "caught" so that the first spring turn always lies on the wire end and does not come to rest in the form of an over snap of the last spring turn next to the axially adjacent spring turn This can, for example, be a tab arranged on the bottom of the spring receiver, which prevents the spring from rotating.

In a preferred embodiment it is provided that the cover bearing is axially fixed with a claw ring whose outer periphery is frictionally secured to a cylindrical or conical-shaped portion of the mounting flange. The claw ring is preferably supported with its inner diameter on an outer ring or an inner ring of the cover bearing. The claw ring preferably has tabs on its outer circumference, which are furthermore preferably arranged at an offset angle relative to the plane of the ring. The tabs are so easily bent out of the plane formed by the Krallring out. The claw ring preferably has retaining lugs on its inner circumference. The retaining lugs allow a friction and / or positive connection, preferably by the retaining lugs engage in axially extending groove of the outer ring. Preferably, it is provided that the diameter of a loop enveloping the tabs in an uninstalled claw ring, ie before the mounting of the claw ring, is greater than the inner diameter of the cylindrical or pointed cone-shaped portion of the mounting flange. As a result, the straps of the claw ring exert a compressive force on the cylindrical region in the radial direction, in that the claw ring is mounted, so that the claw ring is frictionally secured in the axial direction.

In the preferred embodiment, it is further provided that a bearing ring of the cover bearing attached to the slave cylinder housing and / or that the release bearing is secured by a bearing ring on the annular piston. It is preferably provided that the outer ring of the cover bearing and the release bearing is frictionally connected to the bearing ring. It is preferably provided that the release bearing and the cover bearing are identical. Preferably, it is further provided that the bearing ring for the release bearing and the bearing ring for the cover bearing are identical. Due to the identical construction of the bearings and the Bearing rings, the number of required components for the clutch release device is reduced.

It is preferably provided that a thermal expansion coefficient of the bearing ring for the release bearing is equal to a thermal expansion coefficient of the slave cylinder housing. Preferably, it is further provided that a thermal expansion coefficient of the bearing ring for the cover bearing is equal to a thermal expansion coefficient of the annular piston. As a result, the game between bearing ring and slave cylinder housing or bearing ring and ring piston is independent of the operating temperature. It is preferably provided that a thrust washer is arranged between the release bearing and plate spring for adaptation to different diameters. It is preferably provided that a connecting line of the slave cylinder is laid in a loop around the slave cylinder. The loop increases the elasticity of the connecting line during rotation and in radial and axial movement of the slave cylinder relative to the transmission housing.

In the following an embodiment of the invention will be explained with reference to the accompanying drawings. Showing:

1 shows a first embodiment of a release device according to the invention a friction clutch.

FIG. 2a is a plan view of a first embodiment of a claw ring; FIG.

FIG. 2b shows a side view of the claw ring according to FIG. 2a; FIG.

Fig. 3a is a plan view of a spring receiver

Fig. 3b shows a section according to l-l in Fig. 3a

Fig. 3c is a detail view of the tongue in Fig. 3a;

4a is a plan view of the release bearing and the cover bearing;

4b shows a section according to M-II in Fig. 4a; - A -

Figure 5 is a plan view of the coupling of Figures 1 to 4 from the perspective of the transmission in the direction of the clutch ..;

6 shows a second embodiment of a disengagement device according to the invention of a friction clutch;

Fig. 7 is an enlarged detail of Fig. 6;

Fig. 8 shows a second embodiment of a claw ring.

1 shows a section through parts of a friction clutch according to the invention in the drive train of a vehicle. Shown are substantially only the components and assemblies of the clutch release device, which are relevant to the understanding of the invention. Of the coupling only a mounting flange 1 is shown. By means of several distributed over the circumference mounting holes 2 of the mounting flange 1 is connected to a flywheel of the clutch, not shown. The flywheel is rotatably connected to a crankshaft of an internal combustion engine. In addition, the flywheel means for vibration damping z. In the form of a dual-mass damper or the like. The flywheel further comprises a pressure plate and a counter-pressure plate and arranged between the pressure plate and the counter-pressure plate clutch disc. The pressure plate and the counter-pressure plate are displaceable relative to one another in the axial direction and can thereby hold the clutch disc, which in turn is non-rotatably connected to a transmission input shaft, frictionally held. The axial movement of pressure plate and counter-pressure plate relative to each other is effected via a plate spring, not shown, which is actuated in a conventional manner via a release bearing shown later. In the upper part of Fig. 1, the position of the clutch release device is shown with the clutch disengaged, in the lower region with the clutch engaged.

A slave cylinder 3 comprises a slave cylinder housing 4 and an integral with this guide sleeve 5 and an annular piston 6. The slave cylinder housing 4 and the guide sleeve 5 include a pressure chamber 7, in which the annular piston 6 is arranged axially displaceable. The annular piston 6 is provided at the pressure chamber 7 side facing with a seal 8, which seals the pressure chamber 7 to the environment. The slave cylinder 3 is connected to a slave cylinder mounting 9 to prevent rotation with a transmission, not shown in Fig. 1. The slave cylinder attachment 9 is not used here for the transmission of axial or radial forces of the slave cylinder 3 on the transmission housing. Instead of being directly connected to the transmission, the slave cylinder attachment 9 can also z. B. attached to a clutch bell or the like. The slave cylinder attachment 9 essentially serves to prevent rotation of the slave cylinder 3, and the slave cylinder 3 is a so-called cover-resistant release mechanism, which is secured in the axial direction to the attachment flange, as described in more detail below.

The slave cylinder housing 4 is fixedly and rotatably connected to the mounting flange 1 in the axial direction by means of a cover bearing 10. A thrust washer 11 which presses axially with a pressure ring 12 on an inner peripheral region of a diaphragm spring, not shown here, is rotatably connected via a release bearing 13 with the annular piston 6. The release bearing 13 comprises an outer ring 14 and an inner ring 15. The inner ring 15 comprises an axially extending inner ring disc 16 which is received in a stepped bore 17 of the pressure plate 11. In this way, a positive connection in the actuating direction of the coupling between the inner ring disk 16 and the pressure plate 11 is produced. Alternatively, the pressure plate 11 may be fixedly connected to the inner ring disk 16, z. B. by a frictional engagement such as a press fit or the like. The outer ring 14 of the release bearing 13 has a radially extending outer annular disc 18 whose inner diameter is smaller than the smallest inner diameter of the inner ring 15. The outer ring disc 18 is frictionally and positively connected at its inner diameter 19 in a shoulder 29 of a bearing ring 20. The bearing ring 20 is in turn positively and frictionally received in a shoulder 21 of the annular piston 6.

The cover bearing 10 is identical to the release bearing 13 and includes an inner ring 22 and an outer ring 23. The outer ring 23 includes an outer annular disc 25 which is received with an inner diameter 26 to form-fit pressure in a shoulder 27 of a bearing ring 24.

The inner ring 22 of the cover bearing 10 comprises an inner ring disc 30, which rests against a radially extending disc flange 31 of the mounting flange 1. The inner ring disc 30 projects beyond the remaining parts of the cover bearing 10 in the radial direction, thus has a larger outer diameter than, for example, the outer ring 23 of the cover bearing 10. The inner ring disc 30 is pressed by a Krallringes 32 on the disc flange 31 and thus fixed axially relative to the mounting flange 1 , 2 shows a plan view of the claw ring 32 with FIG. 2 a, with FIG. 2 b a side view of the claw ring 32. The claw ring 32 has an outer diameter DA in undeformed and unobstructed state The claw ring 32 comprises an annular disk 35, on the outer circumference of which are arranged radially at an angle α to the disk plane 36 inclined tabs 35 are arranged. Characterized in that the outer diameter DA in the uninstalled state of the Krallringes 32 is greater than the inner diameter Dl of the cylindrical portion 33, the Krallring 32 is frictionally fixed in a- xialer direction of the mounting flange 1 and centered in the radial direction. In installation position, the annular disc 34 of the Krallringes 32 abuts against the inner ring disc 30 of the cover bearing 10. The setting angle α of the tabs 35 is selected so that when a load on the ring 32 in the axial direction, a self-reinforcing effect occurs such that the radial pressure force of the tabs 35 is increased in the radial direction and thus the friction force in the axial direction is greater.

Between the outer ring 14 of the release bearing 13 and the outer ring 23 of the cover bearing 10, a biasing spring 37 is arranged. For this purpose, on the outer ring 14 of the release bearing 13, a release bearing side spring receptacle 38 and on the outer ring 23 of the cover bearing 10, a cover bearing side spring retainer 39 is arranged. Fig. 3 shows with Fig. 3a is a plan view of the spring receptacle 38 and 39, in Fig. 3b shows a section according to ll in Fig. 3a and in Fig. 3c is a detail view of the tongue 49. The spring retainers 38, 39 are identical and As shown in Fig. 3 comprise a cup-shaped receiving ring 40 in the cross-section, comprising an outer cylindrical portion 41 and an inner cylindrical portion 42 which are interconnected by a disc-shaped bottom portion 43. The outer cylindrical portion 41 forms with the inner cylindrical portion 42 and the disc-shaped bottom portion 43 a pocket 28 for receiving a spring end of the biasing spring 37. The inner cylindrical portion 42 merges into an annular opening 44 which at a shoulder 45 at the transition of the outer diameter of Outer ring 14 and 23 is defined by a first outer ring diameter D1 to a second outer ring diameter D2. The inner cylindrical portion 42 has an axial length LI, the outer cylindrical portion 41 has an axial length LA. The lengths LI and LA are dimensioned so that they are significantly larger, for example, twice as large as the diameter of the individual turns of the biasing spring 37. As a result, when the pretensioning spring 37 is compressed, a plurality of spring coils come into the area between the inner and outer cylindrical areas 41, 42, so that they are guided in the radial direction and radial slippage of the pretensioning spring 37 is avoided.

The receiving ring 40 comprises in the region of the annular opening 44 four areas 46 with a large inner diameter and four areas 47 with a small inner diameter. The areas 46 with large inner diameter have an inner diameter DFG, the areas 47 with a small inner diameter have the inner diameter DFI. The areas 47 with a small inner diameter together with the outer diameter D1 of the outer ring 14 and 23, a frictional connection z. B. in the form of a press or transition fit, the areas 46 with large inner diameter form, for example, a clearance with the outer ring 14, 23. The terminals of the receiving ring on the outer ring ensures the transmission of Lageschleppmoments during operation and acts as captive during assembly. The division into the regions 46 with a large inner diameter and the regions 47 with a small inner diameter is effected by introducing recesses 48 into the inner cylindrical region 42 in the region of the annular opening 44. The inner cylindrical region 42 is bent inward when the recesses 48 are punched out, so that the smaller diameter DFI results here compared to the diameter DFG. In the bottom portion 43 of the receiving ring 40, a tongue 49 is stamped into the receiving area for the biasing spring 37, which acts as a rotation of Vorlastfeder 37 against the receiving ring 40 by one end of the spring coils abuts the tongue 49. The receiving geometry for the preload spring is thus placed radially outside the respective bearing, whereby the axial distance of the bearings can be minimized.

The spring receivers 38, 39 are arranged radially outside of the release bearing 13 or top bearing 10. This allows a comparatively large axial length of the biasing spring 37 and a corresponding reduction of the distance between the cover bearing 10 and release bearing 13 at a predetermined axial length of the biasing spring 37th

4a shows a plan view and FIG. 4b shows a section according to M-II in FIG. 4a of the release bearing or the cover bearing 10. Both bearings each comprise cages 50 for specifying a distance between the individual balls 51 of the bearings Circumferential direction and sealing washers 52 for sealing the bearings to the outside. The sealing inward takes place through the bearing rings 20 and 24, respectively, by forming a labyrinth seal with the inner ring 15 or 22.

Fig. 5 shows a plan view of the coupling according to FIGS. 1 to 4 from the perspective of the transmission in the direction of the coupling. A connecting line 53 connects the slave cylinder 3 and the pressure chamber 7 of the slave cylinder 3 with an otherwise not shown hydraulic system. The connecting line 53 is guided with a loop 54 around the slave cylinder 3 in an arc, so that here a very large elasticity of the connecting line 53 with respect to a rotation of the slave cylinder 3 and with respect to radial movements of the Slave cylinder 3 results. In order to compensate for the eccentric movement of the releaser relative to the stationary transmission housing, the line must have a high elasticity. This is accomplished by placing the wire in loop 54 around the slave cylinder housing. The thermal expansion coefficient of the material of the bearing rings 24 and 20 chosen so that this is similar or equal to the thermal expansion coefficient of the annular piston 6 and the slave cylinder housing 4.

During assembly of the coupling according to the invention, only the cover bearing 10 is placed in the mounting flange 1 and then the ring 32 is pushed over the cover bearing 10. In this case, the inner diameter of the ring 32 comes to rest on the radially protruding part of the inner ring disc 30. The tabs 35 on the outer diameter of the ring 32 are set up in the installation angle α and are larger in outer diameter in the uninstalled state than the inner diameter of the cylindrical portion 33 of the mounting flange 1, which forms the mounting flange for the ring 32. This results in a radial bias of the tabs 35. The installation angle α is chosen so that adjusts itself to a self-reinforcing effect when loaded against the mounting direction.

Fig. 6 shows a second embodiment of a release device according to the invention a friction clutch. In this case, the arrangement of outer ring 14 and inner ring 15 and inner ring 22 and outer ring 23 is reversed compared to the embodiment of FIG. While in the embodiment of FIG. 1, the inner rings 15 and 22 are arranged axially outwardly and accordingly the outer rings 15 and 23 are arranged axially inward, in the embodiment of FIG. 6, the inner rings 15 and 22 are arranged axially inside and corresponding to the outer rings 15 and 23 arranged axially outside. Accordingly, the storage of spring receptacles 38 and 39 is changed, these are now fixed to the respective inner rings 15 and 22 respectively. For this purpose, these radially inside each have axially outwardly projecting cup-shaped folds 55 and 56, respectively, the hollow cylindrical axial projections 57 and 58 of the inner rings 15 and 22 engage behind. The claw ring 32 is supported here on the outer ring 23 of the cover bearing 10.

Fig. 7 shows the arrangement of the claw ring 32 and the spring retainer 39 on the cover bearing 10 of FIG. 6 in an enlarged section.

Fig. 8 shows a three-dimensional view of the claw ring 32 for use in the embodiment of Figures 6 and 7. The claw ring 32 has at its inner diameter retaining lugs 59, each in an axial groove, not shown, of the outer ring 23rd intervention. The retaining lugs 59 establish a form-locking connection in the circumferential direction between the claw ring 32 and the outer ring 23. In the axial direction, the connection can be play-related or preferably frictionally engaged. When mounting the cover bearing 10, the claw ring 32 does not have to be retrofitted as a separate part, but can be plugged onto the outer ring 23 and mounted together with the cover bearing 10.

During the marriage of the clutch and the release button, the diaphragm spring tongues of the clutch must be preloaded in order to be able to place the release mechanism on the clutch without force. For this, the thrust washer is loosely placed on the diaphragm spring tongues. On the mounting device clutching a gripping tool is mounted, that the pressure washer engages the inner diameter and the clutch disengages. The release system is then placed on the coupling so that the bolts thread into the hole on the mounting flange. Then the clutch and release system can be riveted.

LIST OF REFERENCE NUMBERS

Mounting flange Mounting hole Slave cylinder Slave cylinder housing Guide sleeve Ring piston Pressure chamber Seal Slave cylinder mounting Cover bearing Thrust washer Thrust ring Release bearing Outer ring Inner ring Inner ring washer Stepped bore Outer ring washer Inner diameter Bearing ring Inner ring Outer ring Bearing ring Outer ring disc Inner diameter Heel Pocket Heel Inner ring disc Disc flange Claw ring Cylindrical area Ring disc Tabs Ring plane Preload spring Relay bearing side spring retainer Cover bearing side spring retainer Retaining ring Outer cylindrical Inner cylindrical area Bottom area Ring opening Heel Large inner diameter area Small inner diameter area Recess Tongue Cage Balls Gaskets Connecting cable Loop Bend Bend Tab Tab Tab Tab Tab

Claims

claims

1. friction clutch in the drive train of a vehicle with a clutch release device comprising a slave cylinder (3) with a slave cylinder housing (4) by means of a cover bearing (10) rotatably and axially fixed to a mounting flange (1) of the friction clutch is connected and with a guide sleeve (5 ) enclosing an annular pressure chamber (7) in which an axially displaceable annular piston (6) is arranged, which is axially fixedly connected to a release bearing (13) which acts on a radially inner portion of a plate spring in the axial direction with force, characterized a preload spring (37) is arranged between release bearing (13) and cover bearing (10).

2. Friction clutch according to claim 1, characterized in that the preload spring (37) radially surrounds the cover bearing (10) and / or the release bearing (13).

3. Friction clutch according to claim 1 or 2, characterized in that the preload spring (37) is clamped between two spring receivers (38, 39), wherein the spring receivers (38, 39) comprise an annular opening (44) which is frictionally engaged in the circumferential direction and in axial direction frictionally and / or positively connected to an outer ring (14, 23) of the cover bearing (10) and release bearing (13) is connected.

4. Friction clutch according to claim 1 or 2, characterized in that the preload spring (37) is clamped between two spring receivers (38, 39), wherein the spring receivers (38, 39) comprise an annular opening (44), the frictionally engaged in the circumferential direction and in the axial direction frictionally and / or positively connected to an inner ring (15, 22) of the cover bearing (10) and release bearing (13) is connected.

5. Friction clutch according to claim 3 or 4, characterized in that the spring receivers (38, 39) in the axial direction extending pockets (28).

6. friction clutch according to one of claims 3 to 5, characterized in that at least one of the spring receivers (38, 39) comprises means (49) for fixing the biasing spring (37) against rotation.

7. Friction clutch according to one of the preceding claims, characterized in that the cover bearing (10) with a claw ring (32) whose outer periphery frictionally secured to a cylindrical portion (33) of the mounting flange is axially fixed.

8. Friction clutch according to one of the preceding claims, characterized in that the claw ring (32) with its inner diameter on an outer ring (23) of the cover bearing (10) is supported.

9. friction clutch according to one of the preceding claims, characterized in that the claw ring (32) with its inner diameter on an inner ring (22) of the cover bearing (10) is supported.

10. Friction clutch according to one of claims 7 to 9, characterized in that the claw ring (32) on its outer periphery lugs (35).

11. Friction clutch according to one of claims 6 to 7, characterized in that the claw ring (32) on its inner circumference retaining lugs (59).

12. Friction clutch according to claim 11, characterized in that the retaining lugs (59) engage in an axially extending groove of the outer ring (23).

13. Friction clutch according to one of claims 10 to 12, characterized in that the tabs are arranged in a setting angle (α) relative to a ring plane (36).

14. Friction clutch according to one of claims 10 to 13, characterized in that the diameter of the tabs (35) enveloping circle at an uninstalled Krallring (32) is greater than the inner diameter of the cylindrical portion (33) of the mounting flange (1).

15. Friction clutch according to one of the preceding claims, characterized in that a bearing ring (24) of the cover bearing (10) is fastened to the slave cylinder housing (4).

16. Friction clutch according to one of the preceding claims, characterized in that the release bearing (13) by means of a bearing ring (20) on the annular piston (6) is attached.

17. Friction clutch according to claim 15 or 16, characterized in that the outer ring (14, 23) of the cover bearing (10) and the release bearing (13) frictionally connected to the bearing ring (20, 24).

18. Friction clutch according to one of the preceding claims, characterized in that the release bearing (13) and the cover bearing (10) are identical.

19. Friction clutch according to one of the preceding claims, characterized in that the bearing ring (20) for the release bearing (13) and the bearing ring (24) for the cover bearing (10) are identical.

20. Friction clutch according to one of the preceding claims, characterized in that a connecting line (53) in a loop (54) is laid around the slave cylinder (3).

21. Friction clutch according to one of the preceding claims, characterized in that a thermal expansion coefficient of the bearing ring (20) for the release bearing (13) is equal to a coefficient of thermal expansion of the slave cylinder housing (4).

22. Friction clutch according to one of the preceding claims, characterized in that a coefficient of thermal expansion of the bearing ring (24) for the cover bearing (10) is equal to a thermal expansion coefficient of the annular piston (6).

23. A friction clutch according to any one of the preceding claims, characterized in that between the release bearing (13) and plate spring, a thrust washer (11) is arranged.