GB2159241A

GB2159241A - Clutch disc with torsional vibration damper

Info

Publication number: GB2159241A
Application number: GB08512664A
Authority: GB
Inventors: Bernhard Schierling
Original assignee: Fichtel and Sachs AG
Current assignee: ZF Sachs AG
Priority date: 1984-05-25
Filing date: 1985-05-20
Publication date: 1985-11-27
Also published as: FR2564919B1; FR2564919A1; DE3419497A1; GB2159241B; GB8512664D0

Abstract

A clutch disc with torsional vibration damper, in which individual springs 7 for the under- load range are provided on both sides with spring cups 12 in each of which there is arranged a spring 13 for the idling range which is supported both on the bottom of the spring cup and in an aperture 14 of the window in the hub disc. This construction offers a space- saving accommodation of the torsion springs for the idling range and these do not have to be made longer than necessary according to their design, so that their centrifugal force loading and their consequent deflection in the radial direction can be kept very slight. It is further proposed to provide entraining elements 24 in the cover plates so that the torsion springs for the idling range which are in each case not loaded are held in the circumferential direction over the entire range of rotation angle. <IMAGE>

Description

SPECIFICATION Clutch disc with torsional vibration damper The invention relates to a clutch disc with torsional vibtration damper, especially for motor vehicle clutches, consisting inter alia of a lining carrier with friction linings, a hub, cover plates and a hub disc and of torsion springs arranged therebetween in appropriate windows, in the form of helical springs which render a relative rotation possible under torque loading, at least one torsion spring with smaller diameter and low spring rating being provided which extends at least partially within a torsion spring with larger diameter and higher spring rating and is supported on this spring through a spring cup.

Such a clutch disc is known by way of eample from German Publication specification No. 2,727,725. In this known embodiment a divided torsion spring with higher spring rating is arranged in each of corresponding windows of hub disc and cover plate, and between the two parts of this spring there are arranged spring cups which accommodate a torsion spring with smaller diameter and with lower spring rating.

The problem in this formation of springs of different spring rigidities arranged one within another is that the springs with great spring rigidity are of divided formation and therefore for example installation tolerances can take influence to a relatively great extent upon the spring characteristic curve. Moreover here again the springs with the low spring rating are unstable within certain limits due to the influences of centrifugal force.

It is the problem of the present invention, in a clutch disc with torsional vibration damper according to the opening statement to render possible a simpler attunement for the springs with the higher spring rating and to make the installation for the springs with the low spring rating as unproblematical as possible.

In accordance with the invention this problem is solved by the characteristic of the Main Claim. Due to the arrangement of at least one spring cup in an end region of a torsion spring with the larger diameter and with the greater spring rating, in combination with a torsion spring with smaller diameter and lower spring rating between the spring cup and a corresponding window edge it is possible firstly to achieve a supporting, independent of centrifugal force, of the spring with the smaler diameter, since this spring can be made short, namely according to the length necessary according to design. Moreover the attunement of the torsion springs with the greater spring rating is easier, since for example compared withthe prior art the length tolerances occur only once.

Advantageous possibilities of development are laid down in the following Sub-Claims.

Thus by way of example it is provided that a spring cup and a torsion spring with low spring rating are to be arranged in each of the two end regions of the torsion spring with the higher spring rating. In an advantageous manner here the torsion spring with the low spring rating is guided radially on the one hand in the spring cup and on the other hand in a window edge of correspondingly depressed formation. Moreover with this construction it is readily possible to arrange a further spring within the spring with the higher spring rating between the two spring cups, which further spring has a higher spring rating than the springs with the smaller diameter guided by the spring cups.

The invention will be explained in greater detail hereinafter by reference to two examples of embodiment. Individually: Figure 1 shows the partial section l-l and the partial elevation of a clutch disc; Figure 2 shows the longitudinal section ll-ll according to Fig. 1; Figure 3 shows the enlarged representation of a detail with a modification compared with Fig. 1, and Figure 4 shows a partial elevation of a clutch disc as modification of Fig. 1.

Fig. 1 shows the partial section and partial elevation of a clutch disc. The upper half is represented as section I-I according to Fig. 2 and the lower half as a pure elevation. In Fig.

2 there is reproduced the section ll-ll according to Fig. 1. The clutch disc consists of a hub 3 with hub disc 6. Cover plates 4 and 5 are arranged to both sides of the hub disc 6, the cover plate 5 being connected with the lining carriers 2 which carry the friction linings 1. Several torsion springs 7 arranged in distribution on the circumference are accommodated in approximately corresponding windows 9 of the cover plates 4 and 5 and 8 of the hub disc 6. These torsion springs 7 have a relatively large diameter and they possess a great spring rating, since they are effective in the under-load range of the clutch disc.As may be seen especially from Fig. 1, in the state of rest of the torsional vibration damper of the clutch disc the circumferential window edges 1 5 of the windows 8 in the hub disc 6 are spaced from the torsion spring 7. Into the two end regions of the torsion spring 7 there are inserted spring cups 10 of which the bowl regions 11 and bottoms 1 2 reach into the torsion spring 7. These spring cups 10 here each lie with a circular flange 1 7 upon the final turns of the torsion spring 7. In the interior of each of the spring cups 10 there is arranged a torsion spring 1 3 the diameter of which is smaller than the diameter of the torsion spring 7 and the spring rating of which is likewise smaller than the spring rating of the torsion spring 7.The spring cups 10 are brought to abut by the initial stress force of the torsion springs 1 3 in the state of rest upon the torsion spring 7, and thus this is situated at a distance from the window edges 15 of the windows 8 in the hub disc 6. The regions of the torsion springs 1 3 which protrude from the two spring cups 10 are supported peripherally in window edges 14 in the windows 8, and these window edges 14 are arranged counter-sunk in the material of the hub disc 6, for the radial guidance of the torsion springs 1 3 in the circumferential direction. As may be seen especially from Fig. 2, the torsion springs 1 3 are guided in the axial direction by the two cover plates 4 and 5.The two cover plates 4 and 5 are connected fast in rotation with one another and held spaced by connecting rivets 21 and guided in relation to the hub 3 by a friction ring 1 8. This friction ring 1 8 in combination with an oppositely arranged friction ring 1 9 ensures a friction force for the damping of torsional vibrations, in the case of mutual rotation between the friction linings 1 and the hub 3 against the force of the springs 7 and 1 3.

The function of the torsional vibration damper is as follows:- Starting from Fig. 1, on torque loading of the friction linings 1 in relation to the hub 3, regarded as held fast, a torque is transmitted through the cover plates 4 and 5 and through their windows 9 to the spring arrangements.

The windows 9 are here formed, in accordance with the lower half of Fig. 1, so that in the circumferential direction they grasp around the flanges 1 7 of the two spring cups 10. Thus in the case of torque loading in the clockwise direction the spring cup 10 arranged on the left is loaded through the windows 9 and transmits the loading through the torsion springs 7 to the spring cup 10 arranged on the right, and this conducts the force into the torsion spring 1 3 arranged on the right. After the intended spring distance between the right spring cup 10 and the corresponding window edge 1 5 of the window 8 is taken up the spring cup comes to abut on the window edge 1 5 and from this moment onwards only the torsion spring 7 is loaded.This change of loading is the transition from idling operation to operation under load. In the case of torque loading in the converse direction of rotation logically the loading of the torsion spring 1 3 aranged on the left first takes place until the spring cup 10 arranged on the left abuts on the window edge 15.

Since now the spring travel of the torsion springs 7 in general is made greater than the spring travel of the torsion springs 1 3 and these, provided that they are not inserted with relatively great initial stress, can become free at maximum torque loading in the circumferential direction, in the preent case pegs 24 are arranged in the two cover plates 4 and 5 and reach so far inwards that they can entrain the torsion spring 1 3 not loaded in each case practically together with the pertinent spring cup 10 in the circumferential direction.

In Fig. 1 the further torsion spring 1 6 arranged between the bottoms 1 2 of the two spring cups 10 and within the torsion spring 7 provides the possibility of influencing the spring rating in the under-load range to a greater extent. Thus with the aid of such additional springs with the existing dimensions the attunement in the under-load range can easily be adapted to a greater extent.

Fig. 3 shows in principle the unilateral arrangement of a spring cup 10 with a torsion spring 1 3 between this spring cup 10 and the set-back window edge 14 of the window edge 1 5 of the window 8 in a hub disc 6. The arrangement corresponds in principle to that of Figs. 1 and 2, merely with the difference that only in the case of torque loading in one direction can a low spring rating be achieved by means of the torsion spring 1 3.

Fig. 4 shows the detail of a view of a clutch disc with a torsional vibration damper, in which a different type of guidance of the unloaded torsion springs 1 3 in the circumferential direction is realised. In this case the clear internal width of the two cover plates 4 and 5 is made less than the diameter of the torsion springs 1 3-in contrast to the embodiments according to Figs. 1 and 2-but apertures 22 are provided in the cover plates 4 and 5 for the torsion springs 13, each having an edge 23, so that in principle a contour of the windows 8 and 9 is achieved corresponding to the contour of the window 8 according to Fig. 1. Here again it is ensured that the unloaded torsion spring 1 3 is entrained in the circumferential direction parallel to the corresponding spring cup 10 and thus cannot become loose within its circumferential clamping.

Claims

1. Clutch disc with torsional vibration damper, especially for motor vehicle clutches, consisting inter alia of a lining carrier with friction linings, a hub, cover plates and a hub disc and torsion springs arranged therebetween in appropriate windows, in the form of helical springs which render a relatie rotation possible under torque loading, at least one torsion spring with smaller diameter and low spring rating being provided which extends at least partially within a torsion spring with larger diameter and higher spring rating and is supported on this spring through a spring cup, characterised in that at least one torsion spring (7) with larger diameter is provided at the one end region with a spring cup (10) which reaches with its bowl region (11) and bottom (12) into the torsion spring (7) and constitutes a support for a torsion spring (13) of smaller diameter, this torsion spring (13) protruding, when the clutch disc is in the unloaded condition, in the circumferential di rection out of the spring cup (10) and being supported outside on a corresponding component (14, 23, 24).

2. Clutch disc according to Claim 1, characterised in that in the transition from the low spring rating to the higher spring rating the spring cup (10) comes to abut on a corresponding window edge (15).

3. Clutch disc according to Claims 1 and 2, characterised in that the torsion spring (7) with the higher spring rating has a spring cup (10) and a torsion spring (13) with low spring rating at each of the two end regions.

4. Clutch disc according to Claims 1 to 3, characterised in that for the radial guidance of the torsion springs (13) with the low spring rating the corresponding window edge (14) is made circumferentially depressed.

5. Clutch disc according to Claims 1 to 4, characterised in that in the cover plates (4, 5) at the circumferential interval of the window edges (14) of the windows (8) of the hub disc (6) there are provided entraining elements (23, 24) which in the case of torque loading hold the torsion springs (1 3) with low spring rating which are unloaded in each case in circumferential clamping.

6. Clutch disc according to Claims 1 to 5, characterised in that a further torsion spring (16) is arranged in each case between the mutually facing bottoms (12) of two adjacent spring cups (10) and thus also within the spring turns of the torsion springs (7) with the higher spring rating.

7. Clutch disc with torsional vibration damper as claimed in claim 1, substantially as described herein with reference to and as illustrated by any one of the examples shown in the accompanying drawings.