GB2079386A

GB2079386A - Transmission clutch

Info

Publication number: GB2079386A
Application number: GB8119237A
Authority: GB
Original assignee: Fichtel and Sachs AG
Current assignee: ZF Sachs AG
Priority date: 1980-07-02
Filing date: 1981-06-22
Publication date: 1982-01-20
Also published as: DE3024969A1; FR2495715A1; GB2079386B; FR2495715B1

Abstract

A clutch consists of a flywheel (1), a pressure plate (5), a clutch disc (6) which by an internally toothed hub disc (20) is non-rotatably arranged on an externally toothed driven shaft (10), radially inwardly pointing actuating lever elements (4) on a diaphragm spring (17), and a release system comprising a rod (12) which extends in the hollow driven shaft (10) and acts on a release element (11) which has axially extending transmission arms (15) passing through the radially internal zone of the hub disc (20) and the external zone of the driven shaft (10) via openings (16) and acting on the radially internal ends of the actuating lever elements (4). <IMAGE>

Description

SPECIFICATION Transmission clutch The invention relates to a starting and engaging disengaging clutch which is intended, more especially, for motor vehicles and consists, inter alia, of a flywheel as the counter-pressure plate, a pressure plate, a clutch disc which can be clamped between the two plates by the force exerted by a spring means and which, through its internally toothed hub disc, is non-rotatably arranged on an externally toothed driven shaft; the pressure plate being directly or indirectly actuatable for engagement and disengagement through radially inwardly pointing actuating elements, which are arranged on the pressure plate side that is directed away from the flywheel, by an axially active release system.

Such a starting and engaging/disengaging clutch is known, for example, from German patent specification 1 555408. On this known clutch, the release bearing actuating the spring tongues of the diaphragm spring sits, with its non-revolving bearing ring, on a housing part which is displaceable on a sliding sleeve and in which the release fork engages.

The prior art in question relates to a so-called drawn diaphragm-spring clutch, where the diaphragm spring is supported on a larger diameter on the housing and on a smaller diameter on the pressure plate and, for disengaging the clutch, the release bearing, together with the spring tongues, has to be moved away from the flywheel. As regards the formulation and solution of the problem of the present patent application, it would also be possible without hesitation to provide in the abovementioned prior art a so-called pressed clutch or a clutch having helical springs and release levers.

It is the object of the present invention to provide, more especially for motor vehicles, a starting and engaging/disengaging clutch which allows a clutch assembly that is as simple as possible with the lowest possible constructional expenditure, for example by making use to a very considerable extent of existing series-manufactured clutch components.

At the same time, attention is to be paid to as small an axial extension of the clutch as possible.

According to the invention, this problem is solved by the features given in the characterising part of Claim 1. It is indeed already known from DAS 2 121 919 to effect an actuation of motor vehicle clutches as defined in the introductory part by means of the hollow driven shaft as well as a rod provided therein; however, in the case of this prior art, there has to be accepted an unfavourable arrangement of the spring means as well as a complicated assembly of the entire clutch. In a design as defined in the characterising part of the present patent application, there comes about, on the one hand, the possibility of continuing to use a standard clutch construction which has been well proven and, at the same time, of employing the relatively inexpensive release system via a rod in the hollow driven shaft.Moreover, the otherwise necessary sliding sleeve can be completely dispensed with and the assembly of the clutch proves to be very easy. At the same time, this system can be used for both drawn and pressed clutches.

Another advantage of this construction is to be seen in the fact that, in the engaged condition, there does not occur any relative rotation between the internal ring and the external ring of the release bearing. The entire clutch can be very compact in design in the axial direction, since both the sliding sleeve and the release fork according to the prior art are dispensed with and the gearbox housing can directly extend as far as the clutch.

The transmission arms of the release element may lie in corresponding openings in the internal toothing of the hub disc and the external toothing of the driven shaft respectively and parallel to these. There is thus no additional space requirements for these transmission arms. When the starting and engaging/ disengaging clutch is constructed as a so-called drawn clutch, the assembly is in this case particularly easy since the release element can be preassembled on the driven shaft and all that needs to be done is to axially join the engine with the complete clutch and the gearbox with the driven shaft and the release element.

It is possible to provide a construction with a particularly low expenditure relating to production, since the ring connecting the transmission arms may be simultaneously designed as the internal ring of the release bearing.

The invention will hereinafter be explained in more detail with reference to an exemplified embodiment. In the drawings: Figure 1 shows a longitudinal section through a complete clutch: Figure 2 shows the section ll-ll shown in Figure 1; Figures 3 and 4 show a section and an elevation of a release element; Figures 5 and 6 show a section and an elevation of a release element in a different constructional form.

Figure 1 shows a longitudinal section through a complete clutch. It is constructed in the usual way, that is to say the flywheel 1 is directly bolted to the crank shaft 2 of the internal-combustion engine not shown. The flywheel 1 simultaneously serves as the counter-pressure plate, and the housing 3 is secured thereto. A clutch disc 6 is arranged, with its friction linings, between the flywheel 1 and the pressure plate 5, there being provided a spring means in the form of a diaphragm spring 17 which biases the pressure plate 5 in the direction oftheflywheel 1 and thus clamps the clutch disc 6 for the transmission of the torque. In the present case, there is shown a so-called pressed diaphragm-spring clutch, that is to say that the diaphragm spring 17 is disengaged by the spring tongues 4 being moved in the direction of the flywheel 1.The clutch disc 6, with its hub disc 20, is axially displaceable through an internal toothing 18 but is non-rotatably mounted on an external toothing 19 of the driven shaft 10. The driven shaft 10, for its part, is mounted in the gearbox housing 7 through a bearing 8, a seal 9 being provided for sealing the clutch chamber. All the parts move around the common axis of rotation 21. The actuation of the clutch is affected through a rod 12 which is mounted in the hollow driven shaft 10. This rod 12 acts on a release element 11 in the space between the end of the driven shaft 10 at the clutch end and the flywheel 1.This release element 11, which is shown by itself in Figures 5 and 6, extends with, for example, three transmission arms 15, which are uniformly distributed on the circumference, parallel to the axis of rotation 21 through openings 16 in the zone of the toothings 18 and 19 as far as radially inside the spring tongues 4 of the diaphragm spring 17. There, these transmission arms 15 carry a release bearing 13 which, for its part, acts on the spring tongues 4. Furthermore, each of these transmission arms 15 is equipped with a collar 14 for securing the release bearing 13 axially. As can be seen particularly clearly in Figure 2, the transmission arms 15 extend in openings 16 which are provided between the hub disc 20 and the driven shaft 10, namely by providing recesses in some teeth of the internal toothing 18 and the external toothing 19 respectively.

The assembly of a clutch which is developed in this way is very easy. The release element 11 is placed on the drive shaft 10 which projects from the gearbox housing 7 and is provided with the rod 12, so that it comes to lie, with its transmission arms 15, in the openings 16 in the external toothing 19. At this point in time, the release bearing 13 has already been secured on the release element 11. Now the gearbox and the engine can be joined in that the clutch, with the clutch disc 6 and the internal toothing 18 of the hub disc 20,is pushed onto the driven shaft 10 with the release element 11. Ail that is necessary during this process is that care should be taken that the internal toothing 18 of the hub disc 20 agrees with the external toothing 19 of the driven shaft 10 and the openings 16 for the transmission arms 15.

Particularly if a so-called drawn clutch is involved, the clutch assembly advantageously is effected in such a way that the release element with the release bearing is already placed into the internal toothing of the hub disc during the fitting-together of the clutch and that the driven shaft then only needs to be introduced into the release element during the assembly of the engine and the gearbox. On a so-called drawn clutch, the diaphragm spring 17 is supported, in the zone of its external diameter, on the housing 3 and, in the zone of its smaller diameter, on the pressure plate 5, contrary to the illustration of Figure 1. The disengaging movement is then effected by a pulling force transmission to the rod 12, forcing this latter to be fixedly connected to the release element 11. Forthis purpose, a thread is provided between the two parts. Furthermore provided is a collar 23, on which the release bearing 13 is supported. For the exact reception of the release bearing 13, the transmission arms 15, of which there may be, for example three, may be provided with a closed rotating ring 22 in the reception zone of the release bearing 13. This ring does not hinderthe assembly if its internal diameter is largerthanthe external diameter of the external toothing 19 of the driven shaft 10. A more far-reaching simplification of the construction and a reduction of the individual components come about if this ring 22 is itself designed as an internal ring for the release bearing and is provided with a track for the rolling elements.

Claims

1. Astarting and engaging/disengaging clutch which is intended, more especially, for motor vehicles and consists, inter alia, of a flywheel as the counter-pressure plate, a pressure plate, a clutch disc which can be clamped between the latter two by the force exerted by a spring means and which, through its internally toothed hub disc, is nonrotatably arranged on an externally toothed driven shaft; the pressure plate being directly or indirectly actuatable for engagement and disengagement through radially inwardly pointing actuating elements, which are arranged on the pressure plate side that is directed away from the flywheel, by an axially active release system, characterised in that the release system comprises a rod (12) which extends in the hollow driven shaft (10) and which ends in the space between the driven shaft (10) end at the clutch end and the flywheel (1) and, there, acts on a release element (11 ) which has axially extending transmission arms (15) which point away from the flywheel (1) and which extend in the radially internal zone of the hub disc (20) and in the external zone of the driven shaft (10) and pass through these in corresponding openings (16) and act on the radially internal ends ofthe actuating elements (4).

2. A starting and engaging/disengaging clutch as claimed in Claim 1, characterised in that the transmission arms (15) extend in the zone between the internal toothing (18) and the external toothing (19), openings (16) being provided in the toothings for passing-through the guidance by way of recesses corresponding to the respective circumferential extension of the transmission arms.

3. A starting and engaging/disengaging clutch as claimed in Claims 1 and 2, characterised in that the transmission arms (15) extend in the zone of the toothings (18, 19) parallel to the axis of rotation (21) of the clutch and have a larger mean diameter in the zone that is radially inside the actuating elements (4) than in the zone of the toothings.

4. A starting and engaging/disengaging clutch as claimed in Claims 1 to 3, characterised in that in the zone that is radially inside the actuating elements (4), the transmission arms (15) form a closed ring (22) for the reception of a release bearing (13).

5. A starting and engaging/disengaging clutch as claimed in Claim 4, characterised in that the ring (22) is directly provided with a track for the rolling elements of the release bearing.

6. A starting and engaging/disengaging clutch as claimed in Claims 4 and 5, characterised in that the inside diameter of the ring (22) is at least slightly larger than the outside diameter of the external toothing (19) of the driven shaft (10).

7. Astarting and engaging/disengaging clutch as claimed in Claims 1 to 6, characterised in that as the spring means and the actuating elements there is provided a diaphragm spring (17) having spring tongues (4).

8. A starting and engaging'disengaging clutch substantially as described herein with reference to the accompanying drawings.