GB2116283A

GB2116283A - A clutch release assembly or a rotary clutch

Info

Publication number: GB2116283A
Application number: GB08305013A
Authority: GB
Inventors: Dr Dieter Lutz; Wolfgang Thieler
Original assignee: Sachs Systemtechnik GmbH
Current assignee: Sachs Systemtechnik GmbH
Priority date: 1982-03-06
Filing date: 1983-02-23
Publication date: 1983-09-21
Also published as: FR2522755A1; GB8305013D0

Abstract

A clutch release assembly comprises a stator (11, 12, 26) surrounding a torque transmission shaft (13) in driving connection with one (51) of the rotors of the rotary clutch assembly. An annular displacement member (14) acts on a first bearing ring (5) so as to axially displace the first bearing ring for disengagement of the rotary clutch assembly. The axial displacement member (14) is connectable to the first bearing ring (5) for common axial movement by one-way locking means (16, 18, 52) in response to applying a displacement signal to the axial displacement member. The member (14) may be displaced hydraulically by pressurisation of a chamber (25), or mechanically in alternative constructions. The locking means comprise a conical face (16) of the member (14) to urge an annular member (18) of circular cross-section into grooves formed in the outer surface (52) of the first ring (5). Alternatively, the member (18) may be of wedge-shaped cross-section engaging a plane surface (52). <IMAGE>

Description

SPECIFICATION A clutch release group for a rotary clutch assembly The present invention is directed to a clutch release group for a rotary clutch assembly, particularly for a pulled-type rotary clutch assembly.

The rotary clutch assembly comprises in short first rotor means and second rotor means for rotation about a common axis. First frictional engagement means and second frictional engagement means are provided on both rotor means, respectively. Spring means establish frictional engagement of said first and said second frictional engagement means. At least one torque transmission shaft extends along the axis and is connected for common rotation with one of the rotor means. At least one disengagement member is mounted for rotation about said torque transmission shaft with one of said rotor means and is axially displaceable in a first axial direction along said axis against the action of said spring means in view of disengagement of said frictional engagement means.

With such a rotary clutch assembly the clutch release group comprises stator means surrounding said torque transmission shaft. Further, the torque transmission shaft is surrounded by first ring means. Annular axial displacement means are provided for axially displacing said first ring means with respect to said stator means. Second ring means are mounted for common axial movement with said first ring means and are rotatably mounted with respect to said first ring means. The second ring means act upon the disengagement member in response to axial displacement of said first ring means by said axial displacement means.

Such a clutch release group is known from German 'Offenlegungsschrift' 29 1 5 989. In this known assembly the second ring means are preassembled with the disengagement member. The first ring means comprise an annular piston of an annular cylinder piston unit. The annular cylinder of this annular piston unit is supported by the stator means and fixed thereto by a releasable securing element. This releasable securing element must be manipulated both when assembling and dis-assembling the engine and the gear box, which are to be interconnected by the rotary clutch assembly.

It is a primary object of the present invention to provide a clutch release group for a rotary clutch assembly of the above-defined type which can be more easily assembled and dis-assembled, particularly when assembling and dis-assembling an engine and a gear box, which are to be interconnected by the rotary clutch assembly.

More particularly, it is a further object of the present invention to provide a clutch.release group for a rotary clutch assembly which can be assembled and dis-assembied without manipulating of securing elements by hand or by a tool.

A further object of this invention is to provide a clutch release group of the type specified above, which is of simplified and less expensive design.

A further object of this invention is to provide a highly reliable clutch release group even for long periods of operation.

In view of at least part of said object with a clutch release group as defined above connecting means are provided for connecting said first ring means and said axial displacement means for common axial movement at least in said first axial direction in response to applying a displacement signal to said axial displacement means.

When applying the principles of this invention, it is possible to pre-assemble the first and second ring means with the rotary clutch assembly and to pre-assemble the annular axial displacement means with the gear box. As the connecting means are released in absence of a displacement signal the engine with the rotary clutch assembly and the first and second ring means pre-assembled thereto, on the one hand, and the gear box with the axial displacement means pre-assembled thereto, on the other hand, can be simply pushed against one another in the final assembling stage.

In view of the connecting means being released in absence of a displacement signal to said axial displacement means the relative position of the first and second ring means, on the one hand, and the axial displacement means, on the other hand, is varied automatically when the frictional engagement means are worn and the rest position of the disengagement member in the engaged condition of the rotary clutch assembly is correspondingly dislocated in axial direction.

It is to be noted that from German 'Auslegeschrift' 27 58 365 a clutch disengagement system is known for a pressedtype rotary clutch assembly, in which for automatic compensation of wear of the frictional engagement means one-way locking means are used. However, this known one-way locking means do not allow a separation of the clutch release group into two sub-groups.

The principles of this invention are particularly applicable to pulled-type rotary clutch assemblies, because in such pulled-type rotary clutch assemblies the assembling and dis-assembling of the rotary clutch and the clutch release group is generally more complicated than with pressedtype rotary clutch assemblies.

In the accompanying drawings: Fig. 1 is a cross-sectional view along the axis of the rotary clutch assembly and the clutch release group of this invention.

Fig. 2 is a section similar to Fig. 1 with a modified embodiment.

Fig. 3 is an enlarged section of parts of Fig. 2.

Fig. 4 shows a further modified embodiment.

In principle in Figs. 1 and 2 a clutch release group 1 is illustrated which is secured on the gear box 11 concentrically with the drive-output shaft 13, and surrounds this drive-output shaft 1 3 with radial spacing. The clutch release group 1 actuates a pulled type friction clutch 2 comprising a drive disc 50, a clutch housing 8, a pressure plate 7, a diaphragm spring 6 with tongues 6a and a clutch disc 51 rotatable with a drive-output shaft 13 and axially movable with respect thereto. The clutch release unit 1 contains a release bearing 3 with a rotating bearing ring 4 and a non-rotating bearing ring 5, the rotating bearing ring 4 being either connected or made integral with a transmitting part 31 which engages with a shoulder 30 behind the radially inner ends of the spring tongues 6a and is secured thereto by a ring 29.The release bearing 3 is mounted displaceably with its nonrotating bearing ring 5 in the clutch release group 1. For this purpose a cylinder wall 26 of the clutch release group 1 has a guide sleeve 27 in which the cylindrical external circumferential face 52 of the non-rotating bearing ring 5 is mounted displaceably against a relatively slight friction force. Between the cylinder walls 12 and 26 furthermore an annular piston 14 is displaceably arranged which, as may be seen especially from Fig. 3, is guided with its external diameter in a first guide face 22 of the cylinder wall 12 and with its internal diameter in a second guide face 23 of the cylinder wall 26. The annular piston 14 with these two guide faces 22 and 23 forms a pressure chamber 25 which can be charged with the hydraulic fluid transmitting the clutch actuation force.From Fig. 3 there may also further be seen a third guide face 24 which is formed by the internal face of the guide sleeve 27 and guides the external diameter of the non-rotating bearing ring 5. It can further be seen from Fig. 3 that the annular piston 14 has a radially inwardly pointing flange 1 5, the inner face 1 6 of which is of conical formation converging towards the friction clutch 2. A locking member 17 (Fig. 3) or 18 (Fig. 1) is arranged between this conical face 1 6 and the radially outer face 52 of the non-rotating bearing ring 5. In both cases this locking member is provided as a slit ring which is provided with a circular cross-section according to Fig. 1 and with a wedge-shaped cross-section according to Figs.

2 and 3. In both cases the locking member is biased by the force of a first biasing spring 19 towards engagement with the conical face 1 6 of the annular piston 14 and the cylindrical outer face 52 of the non-rotating bearing ring 5. The spring 1 9 is supported by a washer 28 which rests on the right-hand end of the annular piston 14 and is loaded by a second biasing spring 20 supported by the cylinder wall 12. The spring 20 here has a greater spring force than the spring 1 9.

The cylinder wall 26 ends in an end face 21 which serves as an abutment face for the flange 1 5 of the annular piston 14 when the friction clutch 2 is engaged. The annular piston 14 is brought into this position by the spring 20 when the clutch is engaged and no pressure is in the pressure chamber 25. The locking members 17 and 18, respectively, are brought out of engagement with the conical face 1 6 and the cylindrical outer face 52 of the bearing ring 5 against the force of the spring 1 9, when the annular piston 14 is in this rest position, due to the face that the locking member 17 or 1 8, respectively, abuts against an abutment face 21 a of the cylinder wall 26, before the flange 1 5 of the annular piston 14 abuts against the end face 21.

According to Fig. 3 the locking member 1 7 of wedge-shaped formation projects beyond the flange 1 5 of the annular piston 14, so that on movement of the annular piston 14 in the direction of the arrow 9 towards engagement of the clutch, firstly the locking member 1 7 comes to abut on the abutment face 21 a, and later the flange 1 5 of the annular piston 14 abuts the end face 21, so that by deflection of the spring 1 9 the locking member 1 7, 1 8 comes out of engagement with the conical face 1 6 and the outer cylindrical face 52 of the bearing ring 5.

The function of the clutch release group is as follows: In the two embodiments according to Fig. 1 and Fig. 2 the cylinder 12, 26 is secured by means of the cylinder wall 12 on the gear box 11, before the engine and the gear box are assembled, and before the hydraulic connection for the pressure chamber 25 is produced. The complete release bearing 3 is pre-fitted on the engine and on the friction clutch 2 by way of the transmitter part 31 and the spring tongues 6a. For assembling the engine and the gear box it is merely necessary, for example, to flange the gear box to the engine and to introduce the non-rotating bearing ring 5 into the cylinder wall 26, namely into the bore of the guide sleeve 27.During assembling the bearing ring 5 slides along on the guide sleeve 27 and slides likewise through the bore of the locking member 17 or 18, since the annular piston 14 being in its rest position abuts on the end face 21, and thus the locking member 17, 18 is out of engagement with the conical face 16 of the annular piston 14. During the assembling operation, thus the one-way locking means are released. Thus the release bearing 3 can be introduced easily into the cylinder wail 26, since it is secured through the transmitting part 31 and the ring 29 to the ends of the spring tongues 6a.

On the first disengagement actuation of the clutch the annular piston 14 is moved in the direction of the arrow 10 away from the friction clutch 2 by a pressure rise in the pressure chamber 25. The conical face 1 6 of the flange 1 5, after the annular piston 14 has travelled a short distance to the right, engages the locking member 17 or 18, which is supported by the spring 19. By the wedge action of the conical face 1 6 the annular piston 14 now transmits the release force by way of the locking member to the non-rotatingbearing ring 5 of the release bearing 3, whereby the spring tongues 6a are likewise moved in the direction of the arrow 10 and the friction clutch 2 is disengaged. Naturally the spring is thereby compressed. In the subsequent engagement operation resulting from relaxation of pressure in the pressure chamber 25, the annular piston 14 moves in the direction of the arrow 9 towards the friction clutch 2. When the clutch engagement operation is terminated the position according to Fig. 3 is reached. In this position the locking member 1 7 begins to abut the abutment face 21 a and thus remains stationary in relation to the cylinder wall 26. The spring 20 will now next move the annular piston 14 further to the left in the direction of the arrow 9 towards the friction clutch 2 until the flange 1 5 comes into abutment with the end face 21, whereby the one-way locking means are again released.

When wear has previously occurred to the friction clutch 2 in operation the release bearing 3, the spring tongues 6a and the pressure plate 7 of the friction clutch 2 can move further to the left with respect to the gear box 11, because the bearing ring 5 is free for axial movement with respect to the annular piston 1 4 being in its rest position.

Moreover, in the engaged condition of the clutch the engine compensating the clutch and the gear box can be dis-assembled without the necessity of intervention in any of the parts transmitting the clutch actuating force from the annular piston 14 to the spring tongues 6a.

The difference in the two constructions according to Figs. 1 and 2 is to be seen merely in that the locking member 1 8 according to Fig. 1 has a circular cross-section and therefore an extension of the cylinder wall 26 must enter into the gap 1 6, 52 between the radially outer face 52 of the bearing ring 5 and the conical face 1 6 of the annular piston 14 in order to provide the abutment face 21 a at a location such that the locking member 1 8 abuts this abutment face 21 a, before the flange 1 5 abuts the end face 21.

Furthermore, the outer face 52 of the bearing ring 5 according to Fig. 1 has, in the region adjacent the locking member 1 8, grooves which are adapted to the contour of the locking member 1 8. While in this way the automatic wear readjustment is not quite stepiess as in the embodiment according to Figs. 2 and 3, higher actuating forces can be transmitted.

Fig. 4 shows a mechanically actuated clutch release group in which, in principle, the same oneway locking means are used. The rotating bearing ring 4 is connected to the tongues 6a by a transmitting flange 31, a support ring 33 and a washer 30 for deflection of the tongues 6a to the right according to arrow 10. The bearing ring 5 projecting towards the gear box 11 is of substantially cylindrical formation. This bearing ring 5 is guided axially in an annular guiding member 12' which is fixed on the gear box 11. In this guiding member 12' there is also guided an annular displacement member 37. This annular displacement member 37 is provided with two journals 38 in angular distance of 1800 which are entered offset by 900 in the illustration according to Fig. 4. These journals run in slots 39 of the guiding member 12' and are therefore secured against rotation.The annular displacement member 37 has on its internal circumference a conical face 1 6 which, together with the cylindrical external face 52 of the non-rotation bearing ring 5 and a locking member 18 arranged therebetween, constitutes one-way locking means. In this case the locking member 18 is formed as a ring and it is loaded by a spring 1 9.

The spring 1 9 bears on a washer 28 fixed to the annular displacement member 37. The guiding member 12' is equipped with an abutment face 21 a which projects into the gap between the conical face 1 6 and the outer face 52 of the bearing ring 5. This abutment face 21 a serves for the unlocking of the one-way locking means in the engaged condition of the clutch, as already described with reference to the above-described hydraulically actuated clutch release groups. The spring 20 loads the annular displacement member 37 towards its rest position so that the locking member 18 is out of contact with the conical face 16 due to abutment with the abutment face 21 a.

The mechanical actuation of this clutch is performed through a release lever 34 which has a concentric opening for the passage of the driveoutput shaft 1 3 and for the passage of the guiding member 12'. This release lever 34 acts upon the two journals 38 of the annular displacement member 12', is pivotaliy mounted on a support part 35 fixed to the gear box 11 and is actuated through a pulling cable 36.

The function of this arrangement corresponds exactly to that according to Figs. 1, 2 and 3, with the difference only that here, there is a purely mechanical actuation.

At this point it should also be noted that in principle any type of connecting means can be provided between the non-rotating bearing ring and the annular displacement member 37 or the annular piston 14, respectively, provided that they are released when the friction clutch is in the engaged condition. By way of example it could be conceivable that such connecting means can be activated by the hydraulic pressure in the clutch release unit and released on relaxation of the pressure medium. Other types of connecting means responsive to axial displacement are also possible in the case of mechanical actuation.

However the one-way locking means are capable of functioning with fery little lost axial travel and are therefore especially advantageous.

The achievable advantages will be repeated briefly once more below: Due to the automatic separation of the connecting means, when the clutch is in the engaged condition, easy assembling and disassembling of gear box and engine result. For this purpose no manual actions of any kind and no special tools of any kind are necessary. When the friction clutch is in the engaged condition, there is no force transmission between the release bearing and the axial displacement means. Automatic wear compensation is achieved. Thus the axial displacement can remain limited to the absolutely necessary dimensions, whereby the space requirement in the axial direction can be kept very small. For the hydraulic actuation only a quite small quantity of hydraulic fluid in a compensation reservoir is necessary.As a whole the overall length of the clutch release group is very short, since the release bearing can be accommodated substantially concentrically within the axial displacement means and varies its position only slightly.

It is to be noted that the annular locking members 1 8 or 1 7 may be replaced by a plurality of locking members, e.g. spherical locking members.

Particularly with respect to Figs. 1 and 2 it is to be noted that the bearings rings 4 and 5 are partially surrounded by the annular piston 14 and the cylinder walls 12 and 26, so that the axial length of the clutch release group can be considerably reduced.

It is further to be noted that there exists an axial friction between the non-rotating bearing ring 5, on the one hand. and the cylinder wall 26 and the guiding sleeve 27, on the other hand. By this friction it is achieved that in the engaged condition of the clutch the tongues 6a contact the ring shoulder 30 with a small axial force, so that an undesirable noise is avoided.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principle, it will be understood that the invention may be embodied otherwise without departing from such principles. It is further to be noted that the reference numbers used in the following claims are only used for a better understanding of the claims and are by no means limitative.

Claims

1. A clutch release group for a rotary clutch assembly, particularly for a pulled-type rotary clutch assembly, said rotary clutch assembly comprising (1) first rotor means (50, 8, 7; 51) for rotation about a common axis; (2) first frictional engagement means and second frictional engagement means mounted for common rotation with said first rotor means (50, . 7) and said second rotor means (51), respectively: (3) spring means (6) establishing frictional engagement of said first and second frictional engagement means; (4) at least one torque transmission shaft (1 3) extending along said axis and connected for common rotation with one (51) of said rotor means (50,8,7:: 51), and (5) at least one disengagement member (6a) mounted for rotation about said torque transmission shaft (13) with one (50,8,7) of said rotor means (50, 8. 7: 51) and being axially displaceable in a first axial direction (10) along said axis against the action of said spring means (6) in view of disengagement of said frictional engagement means; said clutch release group comprising (a) stator means (11,12,26) surrounding said torque transmission shaft (13); (b) first ring means (5) surrounding said torque transmission shaft (13); (c) annular axial displacement means (14) for axially displacing said first ring means (5) with respect to said stator means (11, 12, 26);; (d) second ring means (3, 31,30, 29) mounted for common axial movement with said first ring means (5) and rotatably mounted with respect to said first ring means (5), said second ring means (4, 31,30, 29) acting upon said disengagement member (6a) in response to axial displacement of said first ring means (5) by said axial displacement means (14); connecting means (16, 18, 52) for connecting said first ring means (5) and said axial displacement means (14) for common axial movement at least in said first axial direction (10) in response to applying a displacement signal to said axial displacement means (14).

2. A clutch release group as set forth in claim 1, said first ring means (5) being axially guided by said stator means (11, 12, 26).

3. A clutch release group as set forth in claim 1, wherein said displacement means comprise an annular displacement member (14) concentric with said first ring means (5) and being axially movable in said first axial direction (10) in response to said displacement signal and said connecting means (16, 18, 52) comprise one-way locking means between said annular displacement member (14) and said first ring means (5), said one-way locking means (16, 18, 52) being lockable in response to axial movement of said annular displacement member (14) in said first direction (10).

4. A clutch release group as set forth in claim 3, wherein said one-way locking means (16, 18, 52) are biased towards an unlocked condition when said rotary clutch assembly is in an engaged condition.

5. A clutch release group as set forth in claim 3.

wherein said annular displacement member (14) is biased towards a rest position corresponding to the engaged condition of said rotary clutch assembly.

6. A clutch release group as set forth in claim 3, wherein said one-way locking means (1 6, 18, 52) comprise an axially converging gap (16, 52) radially between said annular displacement member (14) and said first ring means (5) and at least one locking member (18) within said converging gap (16, 52).

7. A clutch release group as set forth in claim 6, wherein said locking member (18) is a slit annular locking member.

8. A clutch release group as set forth in claim 6, wherein said locking member (18) has a circular profile when regarded in a sectional plane containing said axis.

9. A clutch release group as set forth in claim 6, wherein said locking member (17) has a wedgeshaped profile when regarded in a sectional plane containing said axis.

10. A clutch release group as set forth in claim 6, wherein said locking member (18) is biased by first biasing spring means (19) towards a locking position with respect to said annular displacement member(14) and said annular displacement member (14) is biased by second biasing spring means (20) towards a rest position corresponding to the engaged condition of said rotary clutch assembly, said locking member (18) abutting a first abutment face (Z 1 a) fixed with respect to said stator means (11, 12, 26) when said annular displacement member (14) is moved towards said rest position, said locking member (18) being removed from said locking position with respect to said annular displacement member (14) against the action of said first biasing spring means (19) when abutting said first abutment face (21a).

11. A clutch release group as set forth in claim 10, wherein said rest position of said annular displacement member (14) is defined by a second abutment face (21) fixed with respect to said stator means (11, 12, 26).

12. A clutch release group as set forth in claim 10, wherein said annular displacement member is an annular piston (14) of an annular fluid-operated cylinder-piston unit (12,26,14), an annular cylinder (12, 26) of said annular cylinder piston unit being fixed with respect to said stator means (11, 12, 26), said annular cylinder (12, 26) comprising a radially outer wall (12) and a radially inner wall (26), said annular piston (14) being guided between said radially outer wall (12) and said radially inner wall (26).

13. A clutch release group as set forth in claim 12, said radially inner wall (26) having substantially axially directed end face means (21, 21 a) at one of its axial ends, said annular piston (14) comprising a radially inwardly directed flange (15) adjacent said end face means (21, 21 a), said radially inwardly directed flange (15) defining said annular gap (16, 52) together with said first ring means (5), said axially directed end face means (21, 21 a) comprising at least one of said first abutment face (21 a) and a second abutment face (21) defining the rest position of said annular piston (14).

14. A clutch release group as set forth in claim 12, said first ring means (5) being guided by the radial inner wall of said annular cylinder (12,26).

1 5. A clutch release group as set forth in claim 14, said radially inner wall (26) being provided with a low friction guiding sleeve (27) for said first ring means (5).

1 6. A clutch release group as set forth in claim 14, wherein said first ring means (5) comprise a radially outer bearing ring (5) axially guided by said radially inner wall (26) and having an extension defining said annular gap (1 6, 52) together with said radially inner circumferential face (16) of said flange (1 5).

1 7. A clutch release group as set forth in claim 3, wherein said annular displacement member (37) is axially movable by mechanical transmission means (34, 36).

18. A clutch release group for a rotary clutch assembly substantially as herein described with reference to the accompanying drawings.