GB2162284A

GB2162284A - A torsion damping device

Info

Publication number: GB2162284A
Application number: GB8419284A
Authority: GB
Inventors: I C Maycock
Original assignee: Automotive Products PLC
Current assignee: Automotive Products PLC
Priority date: 1984-07-27
Filing date: 1984-07-27
Publication date: 1986-01-29
Also published as: GB8419284D0

Abstract

A torsion damping device such as a driven plate for a clutch comprises a driven disc for connection to a splined input shaft (11A) of a gearbox, and a pair of driving discs (17A, 18A) drivingly connected to the driven disc by a number of circumferentially spaced springs (31A). The driven disc is not connected to a splined boss as is usual but has splines 19A formed directly in it for engagement with the input shaft (11A). <IMAGE>

Description

SPECIFICATION A torsion damping device This invention relates to torsion damping devices of a type commonly used in the driven plates of friction clutches and are of the kind in which at least one driving plate is adapted for connection in use to an engine and at least one driven disc is provided for driving a splined transmission shaft, resilient means being provided to oppose relative movement of the driving plate with respect to the driven disc.

Known torsion damping devices of the kind described above incorporate a hub at the inner periphery of the driven disc to connect the driven disc to the splined transmission shaft. This has the disadvantage that the hub must provide two concentric locations one with the driving plate and the other with the transmission shaft, if the damping device is to rotate concentrically about the axis of the transmission shaft.

The hub therefore must be an accurately formed component and as such is expensive to manufacture and assemble.

According to the invention there is provided a torsion damping device of the kind referred to wherein the driven disc is of substantially the same thickness at its inner and outer peripheral regions and has teeth arounds its inner peripheral edge for engagement with the splined transmission shaft.

The invention will now be described with reference to the accompanying drawings in which: Figure 1 is a front elevation of a clutch driven plate incorporating a torsion damping device according to the invention; Figure 2 is a section on the line 2-2 of Fig.

1; Figure 3 is a section similar to that of Fig. 2 showing a clutch driven plate incorporating another torsion damping device according to the invention; and Figure 4 is an enlarged view of part of the inner periphery of the clutch driven plate of Fig. 4 showing a modification.

Referring to Figs. 1 and 2 of the drawings there is shown a rigid driving plate 1 3 adapted for connection to an engine by means of an annular friction facing carrier 1 4 rivetted to the driving plate 13, the outer peripheral portion of which comprises a series of resilient metal cushion members 1 5 supporting friction facings 16.

Two annular driven discs in the form of sheet metal side plates 1 7 and 1 8 each have teeth 1 9 around their inner peripheral edges for engagement with a splined transmission shaft 11. The side plates 17, 18 are each provided with a circular series of substantially rectangular windows 21 near their outer peripheries, corresponding to the larger windows 22 formed in the driving plate 1 3.

The side plate 1 7 and 1 8 are held against the ends of a spacer sleeve 1 2 by a series of circumferentially spaced tongues 25 which are bent over at right angles to the plane of the side plate 1 7. The driving plate 1 3 is formed with slots 26 of greater circumferential width than the tongues 25 which pass through the slots 26. The ends of the tongues 25 are reduced in width and enter notches 27 in the side plate 18, the side plate 1 8 being held firmly against shoulders 28 on the tongues 25 by staking the ends of the tongues 25.

Coiled compression springs 31 are mounted in the windows 21, 22 to provide resilient resistance to the limited relative rotational movement of the driving plate 1 3 and the friction carrier 1 4 with respect to the side plates 17,18 The windows 21 have a radial width less than the diameter of the springs 31, so that the side plates 1 7 and 1 8 retain the spring 31 in the windows 21.

Frictional damping of the annular friction facing carrier 1 4 and the driving plate 1 3 is provided by mounting a first ring 32 of friction material between the other side of the driving plate 1 3 and a second ring 33 of friction material between the other side of the driving plate 1 3 and a pressure plate 34 held against rotation relative to the side plate 1 8 by a tongue 35 on the pressure plate 34 engaged with a hole 36 in the side plate 18, a Belleville washer 37 being mounted between the pressure plate 34 and the side plate 1 8 to apply axial pressure to the pressure plate 34.

A second embodiment of the invention is shown in Fig. 3, many of the features of which are similar to those previously described with reference to Figs. 1 and 2.

Two annular driving plates are in the form of sheet metal side plates 1 7A and 1 8A the outer peripheries of which are joined together by a number of spacers 40A. An annular friction facing carrier 1 4A is attached to one side plate 1 7A for connection to the output from an engine (not shown). An annular driven disc 13A positioned between the side plates 17A,18A has a plurality of teeth 1 9A around its inner peripheral edge for engagement with the splined transmission shaft 11 A.

Springs 31A in windows in the side plates 1 7A and 1 8A and in the driven disc 1 3A act as resilient means to oppose relative angular movement of the side plates with respect to the driven disc in a similar manner to springs 31 shown in Figs. 1 and 2.

In a modification shown in Fig. 4 the teeth 1 9B of the driven disc 1 3B are deformed along the axis of the transmission shaft to increase the effective area of contact between the driven disc 13B and the transmission shaft 11 B. A similar modification may be made to the teeth 1 9 of the side plates 1 7 and 18 shown in Figs. 1 and 2.

Claims

1. A torsion damping device comprising at least one driving plate adapted for connection in use to an engine and at least one driven disc for driving a splined transmission shaft, resilient means being provided to oppose relative movement of the driving plate with respect to the driven disc, wherein the driven disc is of substantially the same thickness at its inner and outer peripheral regions and has teeth around its inner peripheral edge for engagement with the splined transmission shaft.

2. A torsion damping device as claimed in Claim 1, in which the inner periphery of the or each drive disc is deformed to produce an enlarged contact area between the or each driven disc and the splined transmission shaft.

3. A torsion damping device substantially as described herein with reference to Figs. 1 and 2, or Fig. 3, or Fig. 3 modified as described with reference to Fig. 4 of the accompanying drawings.