GB2096273A

GB2096273A - Clutch disk assembly

Info

Publication number: GB2096273A
Application number: GB8210027A
Authority: GB
Original assignee: Aisin Seiki Co Ltd; Toyota Motor Corp
Current assignee: Toyota Motor Corp; Aisin Corp
Priority date: 1981-04-08
Filing date: 1982-04-05
Publication date: 1982-10-13
Also published as: JPS6324265Y2; JPS57163030U; GB2096273B

Abstract

A clutch disk assembly having a clutch plate 5 and spring retainer plate 4 disposed one on each side of a hub flange 2, and a friction plate 9 disposed between the hub flange and the spring retainer plate. The friction plate is sandwiched between an intermediate plate 8 and pressure plate 10 which are made from the same material, so that the surface-to- surface conditions between the friction plate and the plates on either side thereof will be substantially identical. Sandwiching the friction plate between identical materials facilitates control of hysteresis. <IMAGE>

Description

SPECIFICATION Clutch disk assembly The invention relates to a clutch disk assembly for use in motor vehicles, and particularly to clutch disk assemblies in which a clutch plate and a retainer plate are disposed one on each side of a hub flange, with a friction plate between the hub flange and the retainer plate.

Controlling the hysteresis of a clutch disk is an important factor for absorbing vibration, preventing resonance and suppressing vibration induced noise. In conventional clutch disk assemblies the friction plate is urged against the hub flange by a diaphragm spring and a pressure plate. Inevitably the hub flange and pressure plate are constructed of different materials and are made to different surface precisions. Since the friction plate will thus be embraced by different materials, the coefficient of friction will differ on either side of the friction plate. We have now appreciated that this is a major factor in the control of hysteresis of the clutch assembly, and places a limitation upon the accuracy of such control.

The invention provides a clutch disk assembly in which a clutch plate and a retainer plate are mounted one on each side of an annular flange of a drive hub and connected to the hub by torque transmitting means, wherein a friction plate is frictionally engaged between an intermediate plate keyed to the annular flange and a pressure plate keyed to the retainer plate to offer frictional resistance to relative angular movement between the hub and the clutch and retainer plates, and the intermediate plate and the pressure plate are constructed of the same material. The assembly of the invention makes possible a much more accurate control of hysteresis in the clutch than was previously practicable, without adding significantly to the cost or ease of assembly of the clutch.

Drawings Figure 1 is an axial section through a clutch disk assembly according to the invention, and Figure 2 is a front view of the intermediate plate of the assembly.

Referring to Figure 1, the clutch assembly, indicated generally as 1, includes a hub 2 operatively connected to a driven shaft (not shown) of a motor vehicle, and having an integral radially extending annular flange 3. A clutch plate 5, having a central opening to rotatably receive the hub 2, is located at one side of the hub flange 3, and is joined by rivets to a spring retainer plate 4, having an opening rotatably receiving the hub 2, positioned on the other side of the flange. Thus the plates 4, 5 may rotate in unison on the hub 2.

Beyond the periphery of the flange 3, the clutch plate 5 is provided with clutch facings 6 secured by rivets near the periphery of the plate 5. The flange 3, spring retainer plate 4 and plate 5 are provided with aligned windows for receiving a torsion spring 7.

A clawed, intermediate plate 8, illustrated in greater detail in Figure 2, has a central opening for receiving the hub 2 and is provided on its outer periphery with a pair of opposing claws or outturned lug portions 12 projecting outwardly from the plane of the plate 8 at an angle of 90 degrees.

The intermediate plate 8 is positioned on the hub 2 and is keyed to the flange 3 on the side thereof facing the plate 4, by fitting the claws 12 into corresponding holes 1 3 provided in the flange, so that the intermediate plate will not rotate with respect to the hub 2. A friction plate 9 is mounted on the hub 2 and placed in abutting surface contact with the intermediate plate 8. A pressure plate 10 is provided with a central opening for receiving the hub 2. A portion of the pressure plate 10 at the inner circumference thereof is bent outwardly from the plane of the plate to form a leg or out-turned lug portion 14. The pressure plate 10 is rotatably mounted on the hub 2 with the side of the plate opposite the leg 14 being placed in abutting surface contact with the friction plate 9.The spring retainer plate 4 is provided with a notch at a portion thereof corresponding to the leg 14 of the pressure plate 10, the notch loosely receiving the leg 1 4 so that the pressure plate 10 is keyed to the plate 4 to secure it against rotation with respect to the plate 4 but allow sliding of the plate 10 in the axial direction. A diaphragm spring 11 is interposed between the pressure plate 10 and the spring retainer plate 4 with its outer periphery engaging a step portion on the inner side of the spring retainer plate 4, and its inner periphery engaging the L-shaped portion of the pressure plate 10 where the pressure plate is provided with the leg 14. The spring 11 provides a biasing force against the pressure plate 1 0.

It will be understood that the intermediate plate 8, friction plate 9, pressure plate 10 and diaphragm spring 11 are sandwiched between the flange 3 and spring retainer plate 4 in the mentioned order. In other words, the friction plate 9 is sandwiched between the clawed intermediate plate 8 and the pressure plate 10.

In accordance with a feature of the present invention, the intermediate plate 8 and pressure plate 10 are constructed of identical material and are finished to the same surface precision. The surface-to-surface conditions, such as the coefficient of friction, between the friction plate 9 and the intermediate plate 8 and pressure plate 10 in pressured contact with the friction plate on either side thereof, will therefore be almost identical.

In operation, the clutch disk assembly 1 is mounted on a driven shaft for the transmission of a motor vehicle in the conventional manner. If the clutch is engaged during acceleration or driving, the plates 4, 5 move relative to the hub 2 and flange 3. When the driver eases off the accelerator pedal, on the other hand, the vehicles coasts under the drag of the engine, reversing the relative movement of the plates 4, 5 and the hub flange 3, as is well known in the art. Owing to such rotational motion, the friction plate 9 slides against the pressure plate 1 0, and may slide against the intermediate plate 8.However, since the intermediate plate 8 and pressure plate 10 consist of identical material in accordance with the feature of this invention, it is possible to foresee, and hence to sense with great accuracy, the sliding conditions that prevail on either side of the friction plate 9 owing to the aforementioned relative rotational movement. This in turn facilitates greatly control of the amount of hysteresis developed by the clutch disk assembly 1 when the vehicle in which the clutch assembly is installed is accelerated and decelerated.

In the above arrangement a modification is possible in which the claw 12 of the intermediate plate 8 can be engaged with the window provided in the flange 3 for receiving the torsion spring 7.

This makes it possible to dispense with the hole 13, so that the flange 3 need not be subjected to additional machining. To receive the claw a notch may be formed on the window that receives the torsion spring 7.

Owing to the particular structure of the inventive clutch disk assembly and the fact that the friction plate 9 is sandwiched between identical materials, control of hysteresis is facilitated during rotation relative to the friction plate, thereby providing a greater reduction in vibration and vibration-induced noises through a simple and easily assembled construction.

Claims

1. A clutch disk assembly in which a clutch plate and a retainer plate are mounted one on each side of an annular flange of a drive hub and connected to the hub by torque transmitting means, wherein a friction plate is frictionaliy engaged between an intermediate plate keyed to the annular flange and a pressure plate keyed to the retainer plate to offer frictional resistance to relative angular movement between the hub and the clutch and retainer plates, and the intermediate plate and the pressure plate are constructed of the same material.

2. A clutch disk assembly according to claim 1, wherein the coefficient of friction between the intermediate plate and the friction plate is approximately equal to that between the pressure plate and the friction plate.

3. A clutch disk assembly according to claim 1 or claim 2, wherein the pressure plate is keyed to the retainer plate by at least one out-turned lug portion of the pressure plate engaging an aperture in the retainer plate.

4. A clutch disk assembly according to any preceding claim, wherein the intermediate plate is keyed to the hub by at least one out-turned lug portion of the pressure plate engaging an aperture or recess in the hub.

5. A clutch disk assembly according to any preceding claim, wherein the frictional engagement is maintained between the friction plate and the intermediate and pressure plates by a diaphragm spring interposed between the retainer plate and the pressure plate.

6. A clutch disk assembly substantially as described herein with reference to the drawings.