clutch plate, material

One important thing of the clutch plate is the used material of friction material.
There is a total contactarea of about 440 cm².

the material has to be resistant to the large amount of power.
One of the materials used is a kind of organic material:
Metal-fibres woven into "organic" (CF aramid with other materials)
advantages: long life, operating temperature, hard use possible
used for cars up to 400HP

In the friction material there are some grooves. Whats the fuction of them?
They will drain heat caused by friction, but also by a large pressure.
There will be always microscopic moves between f.e. the clutch plate and the flywheel. The friction will lead to very small particles of organic material. These have to been removed, because they act lik sandpaper for the same organic material.
They will also drain little drops of oil if there is a small leak. !!oil in the clutch will destroy the flywheel, clutch plate and pressure groep!!

more info: www.uucmotorwerks.com/clutch

clutch plate, springs

In the sketch below you see a spring. In the clutch of a volvo 24O there are four of them.

This is just for a smooth ride and is not necessary for the function of the clutch.
The driving part (friction plates and steel plate) of the clutch plate pushes to te springs, the springs will be pressed and they push to the driven part (connection whith the primary shaft).
So if there is suddenly a large power-increase the springs will intercept so the car will accelarte smoothly and not in shocks.

This is why race cars don't have springs in the clutch. It causes a very litte decrease in power a a little delay in power trasmitting.

clutch plate - rivets

The sketch in the previous post shows a couple of rivets. But why do they use rivets?

Especially these who connect the friction material with the other parts of the clutch. Because this is the place where power transmit from one part to another.

If the clutch is in function, so all parts are connected by a large force, the frition plates are pushed between the flywheel and the pressure group. But a part of the clutch plate is pushed between the two friction plates. So there is a friction force between the different parts of the clutch plate. Rivets are necessary to keep the clutch plate together if there is no connection.

Another aspect is that it is useless to disconnect the friction plates from the clutcht plate. If the friction plates are destroyed, the whole clutch is probably at the end of his life.
Its also a very easy connection, no turning tools are required

clutch plate - sketch

connection primary shaft - clutch plate

The connection between these two parts needs a radical fixation, but a axial freedom, but still be able to translate the power from one part to the other.

A good solution is a splined shaft.

It will be a 21x24 splined shaft

the properties: z= 34 (the last unvisible column)

more info: tabellenboek voor metaaltechniek (E31 - p 212)