GB2157790A

GB2157790A - Pulled-type friction clutch with releasable connection

Info

Publication number: GB2157790A
Application number: GB08509933A
Authority: GB
Inventors: Joachim Nittke; Alfred Schraut
Original assignee: Fichtel and Sachs AG
Current assignee: ZF Sachs AG
Priority date: 1984-04-19
Filing date: 1985-04-18
Publication date: 1985-10-30
Also published as: BR8501866A; GB8509933D0; FR2563297A1; DE3414835A1; GB2157790B

Abstract

In the release system of a friction clutch, there are provided two relatively rotatable sleeves 10,11 arranged coaxially with one another. Sleeve 11 has on its external circumference dogs 12 which, on the pushing in of the two sleeves in relation to one another run along on deflector edges 13 on simultaneous relative rotation, whereby the two sleeves, on axial movement, come into a position where each dog engages an abutment 17 and in which they can transmit the release force in the direction of pulling. On reverse axial movement and further rotation in the same direction, the dogs engage deflector edges 14 and the sleeve 11 may be released and extracted by movement in the direction of the arrow B. <IMAGE>

Description

SPECIFICATION Pulled-type friction clutch with snap connection The invention relates to a friction clutch of pulled construction type with detachable snap connection in the release system, in which the snap connection can be brought into the working position by mutual pushing in of two concentric sleeves and the disengagement operation is initiated by further pushing in.

A friction clutch of this construction type is known for example from German Publication Specification No. 3,113,463. In this known embodiment two concentric sleeves are provided and the inner sleeve has in an external groove an initially stressed wire ring which is held in the bottom of the groove by a strip spring placed thereover, by its own tension. In the pushing of the second sleeve on to the first the strip spring is pushed away in the axial direction and brought to snap in its own groove. At the same time the outer sleeve travels with an inner groove over the wire ring so that the latter can open up radially outwards by its own tension. In this opened position it is situated exactly in the middle region between outer groove and inner groove and in this way can transmit the release force contrarily of the push-in direction.For the disengagement of this snap connection the outer sleeve is moved further in the inward push-in direction and compels the wire ring, by means of an oblique edge on the groove, to enter the outer groove of the inner sleeve.

In the outer sleeve a second inner groove is provided adjoining the first inner groove and has a significantly larger groove bottom diameter so that the wire ring as a result of its own stress assumes such a large diameter that in the separating movement of the two sleeves it can be moved out of the outer groove of the inner sleeve.

The construction according to the prior art comprises a plurality of individual parts, two of which must be adapted exactly to one another in their spring characteristics. Both before assembly and after dismantlement it is necessary to bring the individual resilient components into an exact position in relation to one another.

It is the problem of the present invention to produce a snap connection which is simple to handle and manages without great preparation and without delicate individual parts.

This problem is solved in accordance with the invention by the characteristic of the main Claim. Due to the arrangement of dogs on the one, rotatable sleeve and of deflector edges and centring edges in combination with abutment pieces it is possible to produce a snap connection which manages without loose individual parts and can be assembled or dismantled as necessary from any position.

Advantageous developments of the invention are laid down in the Sub-Claims. Due to the equipment of the deflector edges with a slope having a component in the direction of rotation and a component in the push-in direction, the rotatable sleeve can be brought into or out of engagement with the other sleeve by relative axial movement between the release member and the actuating elements of the clutch. In this case the deflector edges of the abutment piece are provided with a slope which extends oppositely to the slope of the other deflector edges.

The second sleeve is preferably connected with the rotating bearing race ring of the release bearing. Thus this sleeve is especially easily rotatable in assembly and dismantlement. The dogs of the second sleeve advantageously here face radially outwards and the deflector edges and abutment pieces of the other sleeve face radially inwards.

The invention will be explained in greater detail by reference to an example of embodiment below. Individually: Figure 1 shows the longitudinal section through a representation of principle of a complete friction clutch; Figure 2 shows the longitudinal section through the snap connection in enlarged representation; Figures 3 and 4 show the representation of the individual parts of the snap connection as development with the course of movement, and by way of detail in enlarged representation.

In Fig. 1 there is reproduced a part of a force transmission system within a motor vehicle, with a friction clutch 1 which is secured to a flywheel 2 of an internal combustion engine (not illustrated further). The friction clutch 1 has what is called a pulled-type construction in which the release elements, in the present case the diaphragm spring 5, are moved away from the flywheel 2 for disengagement. This is effected by movement of the release member 3 in the direction of the arrow B. The release member 3 is actuated for example by means of a release fork 4. The snap connection 6 here transmits the release force from the release member 3 to the diaphragm spring 5. The engagement movement is effected by movement of the release member 3 in the direction of the arrow A.In this movement the entire friction clutch 1 rotates together with the crank shaft and the gear input shaft (in the engaged condition) about the rotation axis 21.

The snap connection 6 is reproduced in enlarged representation in Fig. 2, the details of the locking device being represented in enlarged form in Figs. 3 and 4. Figs. 3 and 4 are the representation of the development of the locking parts of the snap connection 6.

The principle of the snap connection 6 already appears in Fig. 2. A first sleeve 10 is provided which is firmly connected with the diaphragm spring 5 at least in the release direction according to the arrow B. This first sleeve 10 has in its internal circumference radially inwardly directed deflector edges 1 3 and 14 and abutment pieces 1 7. The second sleeve 11, which is arranged concentrically with the first and has a smaller diameter, is provided with the corresponding counterparts of the snap connection.These are represented in the form of radially outwardly protruding dogs 1 2. Furthermore the second sleeve 11 carries on its external circumference the release bearing 7 with the bearing race ring 8 arranged fixedly in the release member 3 and with the rotating bearing race ring 9 which is secured on the second sleeve 11.

Figs. 3 and 4 show a part of the development of the regions of the two sleeves 10 and 11 which constitute with one another a snap connection. Fig. 3 shows the position according to Fig. 2 before the connection of the two sleeves 10 and 11. The connection takes place as follows:- The complete release member 3 with the release bearing 7 and the second sleeve 11 is moved in the push-in direction according to the arrow A towards the friction clutch 1 and thus also towards the first sleeve 10, which is stationary in the axial direction. The dogs 1 2 arranged on the external circumference of the second sleeve 11, which preferably have a circular contour, then travel into the circumferential interspaces between the individual abutment pieces 1 7 of the first sleeve 10.The dogs 1 2 thus move according to the indication a in the direction of the arrow A towards the first sleeve 10 as far as the position b, in which they come to abut on a deflector edge 1 3 of the sleeve 1 0. On a further movement of the second sleeve 11 in the direction of the arrow A the dogs 1 2 slide along the obliquely formed deflector edges 1 3 so that the second sleeve 11 at the same time carries out a rotating movement in the direction of the arrow C. this rotating movement is rendered possible by the arrangement of the release bearing 7 between the second sleeve 11 and the release member 3.

The position of the dogs 1 2 indicated by c is reached when the dogs come to abut on the blocking noses 1 6 between the deflector edges 1 3 and 14. Now the second sleeve 11 is moved back in the opposite direction, that is in the direction of the arrow B, whereby the dogs 1 2 come to abut on the centring edges 19 of the abutment pieces 1 7. These centring edges 1 9 have a slope extending oppositely to the slope of the deflector edges 1 3 and 14.

Thus a further rotating movement of the second sleeve 11 occurs in the direction of the arrow C. This rotating movement is limited by the fact that centring edges 18 adjoin the centring edges 1 9 of the abutment pieces 17, which edges 1 8 have an opposite slope and proceed in principle like the deflector edges 1 3 and 14. Thus the dogs 1 2 are made fast in the circumferential direction and the snap connection 6 can transmit forces in the direction of the arrow B as necessary for the transmission of the release movement to the diaphragm spring 5. This position is the working position for the entire release system.

Since modern clutches work to an increasing extent with a slight initial load upon the release system, even when the system is engaged, the dogs 12 cannot come out of engagement even with centring edges 1 8 and 1 9 of relatively flat formation.

As regards principle the dismantlement operation is just as simple as the assembly operation. It is initiated by a movement of the release member 3 with the second sleeve 11 in the direction of the arrow A, that is in the direction of the push-in movement. Thus the dogs 1 2 move from a position d in the direction towards the blocking noses 16, from which they are deflected on to the deflector edges 14 and thus land in the corner between the deflector edges 14 and the stop edges 20, according to the position e. Following this movement there occurs an extraction movement of the second sleeve 11 in the direction of the arrow B corresponding to the release movement of the friction clutch 1, whereby the dogs 1 2 are transferred into the position D. In this position-see especially Fig.

4-the dogs 1 2 slide on the deflector edges 1 5 of the abutment pieces 1 7 in the direction of the arrow C, and thus come out of engagement with the first sleeve 1 0. The separation is completed in this manner.It is to be taken into account here that the edges 22 of the abutment pieces 1 7 and 23 of the first sleeve 10, lying foremost in the direction of the arrow C, at connection of the deflector edges 1 4 with the stop edges 20 in each case come to lie behind the centre points of the dogs 12, in order on the other hand to render possible threading of the dogs 1 2 out of the sleeve 11 and on the other hand, in threading in, to arrive in the circumferentially next deflector edge 14, as represented in Fig. 4.

The snap connection as represented and described renders possible simple assembly and dismantlement without loose individual parts of the connection. The contours of the snap connection provided on the two sleeves can here be produced by sintering, but it is also possible to produce these contours by cold or hot deformation.

Claims

1. Friction clutch of pulled construction type with disengageable snap connection in the release system, in which the snap connection is bringable into the working position by mutual pushing in of two concentric sleeves and the release operation is initiated by further pushing in, characterised in that one of the two sleeves (10, 11) is arranged rotatably in relation to the other sleeve, at least in assembly and dismantlement, one of the two sleeves comprises at least two dogs (12) protruding in the radial direction and distributed on the circumference which in assembly by pushing in the push-in direction (A) into the other sleeve slide along on deflector edges (13) extending on the latter likewise radially in the opposite direction, with simultaneous mutual rotation, and in doing so arrive in a position (blocking nose 16) out of which the dogs come, by mutual extraction in the pushout direction (B) contrary to the push-in direction (A), to abut on centring edges (18, 19) which are arranged at an axial distance from the deflector edges and form an abutment piece (17), to reach the working position, while for the disengagement of the working position a renewed push-in movement (A) takes place with mutual rotation in the same direction (C) by sliding of the dogs (1 2) along on the prolonged deflector edges (14) and subsequent withdrawal (B) of the dogs on deflector edges (15) of the abutment pieces (17).

2. Friction clutch according to Claim 1, characterised in that the deflector edges (1 3, 14) have a slope which consists of a component of the direction of rotation (C) of the second sleeve (11) and a component of the push-in direction (A)

3. Friction clutch according to Claims 1 and 2, characterised in that the direction edges (15) and centring edges (19) of the abutment pieces (17) have a slope opposite to the slope of the deflector edges (13, 14).

4. Friction clutch according to Claims 1 to 3, characterised in that the second sleeve (12) is preferably connected with the rotating bearing race ring (9) of the release bearing (7).

5. Friction clutch according to Claims 1 to 4, characterised in that the dogs (12) of the second sleeve (11) protrude radially outwards and the deflector edges (13, 14) and abutment pieces (17) of the first sleeve (10) protrude radially inwards.

6. Friction clutch of pulled construction type with disengageable snap connection in the release system as claimed in claim 1, substantially as described herein with reference to and as illustrated by the example shown in the accompanying drawings.