GB2145498A

GB2145498A - Damper discs

Info

Publication number: GB2145498A
Application number: GB08421253A
Authority: GB
Inventors: Yoshio Nishimura
Original assignee: Exedy Corp; Daikin Manufacturing Co Ltd
Current assignee: Exedy Corp
Priority date: 1983-08-25
Filing date: 1984-08-21
Publication date: 1985-03-27
Also published as: GB8421253D0; GB2145498B; JPS6038931U

Abstract

A damper disc comprising a splined hub 1 having a radial flange 2 around which is disposed, at a spacing 3 therefrom, a rubber ring 4. Disposed in the space 3 and extending along the flange's outer peripheral surface 5 is a ring spring 6 and a spring seat ring 7, the spring 6 and the ring 7 conforming to projections 10 and hollows 11 of the peripheral surface 5. In a first stage of torsion operation of the disc, the rubber ring 4 and the spring 6 are deformed so that the ratio of the increasing of the torque to the increasing of the torsion angle is small. In a second stage, only the ring 4 is deformed so said ratio increases. <IMAGE>

Description

SPECIFICATION Damper discs This invention relates to damper discs suitable for clutches of automobiles.

In known discs for automobiles, a hub connected to an output shaft is provided with a flange having a large diameter and a large thickness. A pair of side plates connected to a friction facing a disposed at respective sides of the flange and are connected to the flange through torsion springs. In this known disc, since the thick flange is extended to the outer peripheral portion of the disc, the disc is heavy. Furthermore, since the disc is heavy especially at the radially outer portion, the inertial mass is heavy. This results in such a disadvantage that the performance of the clutch, such as responsiveness to engaging and releasing operation, can not be sufficiently increased.

Accordingly, it is an object of the invention to provide an improved disc overcoming the above-noted disadvantages.

With this object in view the present invention provides a damper disc comprising a hub connected to an output shaft and having a radial flange of which an outer periphery is a substantially polygonal shape; an annular rubber ring disposed around the flange; an input means to which the outer periphery of the rubber ring is fixed; a spring seat fixed to the inner periphery of the rubber ring and extending substantially along the outer periphery of the flange with a space therebetween; and a soring disposed in above space and operable to be compressed by the relative twisting of the flange and the spring seat.

The invention will be described further, by way of example, with reference to the accompanying drawing in which: Figure 1 is a cross-sectional view of one half of a first preferred embodiment of the damper disc of the invention; Figure 2 is a graph illustrating the transmitted torque/torsion angle characteristic of the preferred damper disc of Fig. 1; Figure 3 is a part-sectional front elevation of part of the damper disc of Fig. 1; and Figure 4 is a cross-sectional view of an alternative embodiment of the damper disc of the invention, in the region of its hub.

Referring to Figs. 1 and 3, the first preferred embodiment of the damper disc of the invention comprises a hub 1, splined to an output shaft (only a center 0-0 thereof is illustrated), provided with a radial flange 2. A rubber ring 4 is disposed around the flange 2 with a space 3 therebetween. A belt-like ring spring 6 extending substantially along the outer peripheral surface 5 of the flange 2 is disposed in the space 3.

As shown in Fig. 2, the outer peripher of the flange 2 has a shape approximating to a regular square. Round projections 10 are formed by portions of the outer peripheral surface 5 corresponding to the corners of said regular square shape. Smoothly curved shallow hollows 11 are formed by portions corresponding to the middle portions of four sides of said square. A spring seat ring 7 extends along the outer peripheral surface 5. The width in the substantially radial direction of the space 3 is constant through the full circumference in the illustrated neutral condition (non-torsion condition). The ring spring 6 extends substantially along the outer peripheral surface 5 and the ring 7. The curvatures of the spring 6 are more tight than those of the outer peripheral surface 5 and the ring 7.In the illustrated neutral condition, the spring 6 contacts the hollows 11 of the outer peripheral surface 5 and is spaced from the projections 10 thereof. The spring 6 also contact the hollows (facing the projections 10) of the inner periphery of the ring 7 and is spaced from the projections (facing the hollows 11) thereof. The ring 7 is made from synthetic resin or metal, and is fixed to the rubber ring 4 by means of adhesion, heating of the like.

The hub 1 and the flange 2 are also made from synthetic resin or metal.

As shown in Fig. 1, the flange 2, the ring 7 and the rubber ring 4 have nearly same width (thickness). A pair of annular side plates 1 2 and 1 3 (input means) are disposed at respective sides of these members. The side plate 1 2 is provided at its inner periphery with a cylindrical flange 15, which projects oppositely to the flange 2. The inner peripheral surface of the flange 1 5 slidably contacts and is fitted to the outer peripheral surface of the hub 1. The inner periphery of other side plate 1 3 is rotatably fitted to the outer periphery of the hub 1 with or without a slight space therebetween.

The side plate 1 2 is provided at its radially outer portion with a bent cylindrical portion 1 7. The outer peripheral surface of the rubber ring 4 is fully fixed to the inner peripheral surface of the culindrical portion 1 7 by heating or adhesion. An outer peripheral portion 1 9 of the side plate 1 2 extends radially outwardly from the end of the cylindrical portion 1 7. Radially inner portions of cushioning plates 21 are fixed to the outer peripheral portion 1 9 by rivets. The cushioning plates 21 are also fixed to the outer peripheral portion of the side plate 1 3. The cushioning plates 21 are disposed annularly.Facings 22 are fixed to respective surfaces of the cushioning plates 21.

Operation of the first preferred damper disc is as follows. When the facing 22 is presed to a flywheel (not shown) by a pressure plate (not shown), a torque of an engine is transmitted from the flywheel through the facing 22 and the plates 21 to the side plate 1 2. The torque is then transmitted from the side plate 1 2 through the rubber ring 4, the spring seat ring 7, the spring 6, flange 2 and the hub 1 to the output shaft. In this operation, the side plate 1 2 twists with respect to the hub while at the same time elastically deforming the rubber ring 4 and the spring ô, so that the torque vibration is absorbed by the elastical deformation of the rubber ring 4 and the spring 6. The displacement or length of the elastical deformation increases according to the transmitted torque.Thus, as shown in Fig. 2, the twisting or torsion angle D of the side plate 1 2 with respect to the hub 1 increases according to the transmitted torque.

In torsion operation, the flange 1 5 slides on the hub 1. Furthermore, sliding takes place on surfaces of annular wave spring 25 and a washer 26 disposed between the side plates 1 2 and 13 and the flange 2. Therefore, the friction force of the sliding causes a hysteresis torque H in a damping characteristic as illustrated in Fig. 2. This hysteresis torque also absorbs the torque vibration.

The sizes and shapes of the flange 2 and the ring 7 may be set so that the spring 6 may be prevented from further compression during the torsion operation. In this case, both the rubber ring 4 and the spring 6 are deformed in a first stage of the torsion operation, so that the ratio of the increasing of the torque T to the increasing of the torsion angle D is small. In the second stage after the first stage, only the rubber ring 4 is deformed, so that the ratio of the increasing of the torque T to the increasing of the torsion angle D increases. As described above, the transmitted torque-torsion angle characteristic can change in two stages or stops. Therefore, the torque vibration can be absorbed both in the small torque range and the high torque range.In order to change the characteristic in two or more stages, double or triple rubber rings, which have small and large diameters and different elastical charactenstics respectively, may be employed.

According to the invention, as stated herein before, the diameter of the flange 2 is small, and the light rubber ring 4 is disposed in a position which a radially outer portion of a conventional metal flange occupies. Therefore, the preferred disc of the invention can be light. More especially, the weight of the radially outer portion of the disc can be reduced.

Therefore, the inertial force of the disc can be reduced, and thus, the power transmitting performance, such as a responsiveness, of the clutch can be improved.

The shapes of the flange 2, spring 6 and ring 7 may be another polygon having three, five or more corners.

Instead of the washer 26 in Fig. 1, as illustrated in Fig. 4, the disc may be provided with a bush 32 having a radial flange 31 and a cylindrical portion 30. The flange 31 is disposed between a side plate 12 and a flange 2. The cylindrical portion 30 is fitted between a outer peripheral surface of a hub 1 and the inner periphery of the side plate 1 3.

Claims

1. A damper disc comprising a hub connected to an output shaft and having a radial flange of which an outer periphery is a substantially polygonal shape, an annular rubber ring disposed around the flange; an input means to which the outer periphery of the rubber ring is fixed; a spring seat fixed to the inner periphery of the rubber ring and extending substantially along the outer periphery of the flange with a space therebetween; and a spring disposed in above space and operable to be compressed by the relative twisting of the flange and the spring seat.

2. A damper disc as claimed in claim 1 wherein the outer periphery of the flange is provided at portions corresponding to the corners of said polygonal shape with round projections and is provided at portions between the adjacent projections with curved hollows, said spring seat is provided at the inner periphery with hollows and projections extending substantially along said projections and hollows respectively, and said spring in the neutral position contacts the hollows of the flange and the spring seat and are spaced from the projections of the flange and the spring seat.

3. A damper disc as claimed in claim 1 wherein said input means consists of annular side plates disposed at both sides of said flange, spring, spring seat and rubber ring, said side plates being fitted at the inner peripheries to the outer periphery of the hub and being fixed at the outer peripheries together, and one of the side plates is provided with a cylindrical outer peripheral portion of which an inner peripheral surface is fixed to the outer peripheral surface of the rubber rine

4. A damper disc as claimed in claimed ! wherein a friction member is disposed between the radially inner portions of the side plate and the flange.

5. A damper disc as claimed in claim 1 wherein a friction facing is connected to the outer periphery of the side plate.

6. A damper disc substantially as hereinbefore described with reference to and as illustrated in Figs. 1 and 3, or in Fig. 4 of the accompanying drawing.