the future

What will bring the future for the clutch?

At this moment there are realy promoting electric cars around the world. But do electric cars need a clutch? NO!

They are directly driven from the engine, the current determines the power deliverd to the wheels.

The elektric cars are yet not very popular, but within 10 or 15 years they will!

presentation: a car clutch for dummies

A car clutch for dummies

View more presentations from Thijs Leroy.

diaphragma spring

The diaphragma spring is works like a regular spring. You press on it and it wil shorten.

they are fabricated of cold rolled springs steel to 50CrV4
life: >1 000 000 operations

more info is difficult to find about a clutch of 1987. Even people is business don't know the spring rate...

Why a diaphragma spring?
A normal spring like we know will be pressed more easy after a period of time. A diaphrama spring does the opposite, it will be harder to be pressed.

clutch assembly volvo 240

In "vraagbaak Volvo 240" I found a drawing of the cluth whith some interesting properties.

pressure group, bearing

The bearing used to push the parts together is a thrust bearing. The part which make conctact with spinning parts will turn together with these parts. The other parts are connected to the lever. But it isn't a rigid connection. it has the possibility to turn around an axis. This is important otherwise you will wring the primary shaft if you use your clutch pedal. This should cause serious damage to your primary shaft.

consequence: gearbox are so engineerd that the bearings will brake before the primary shaft. If you wring the shaft to much you will create some slack in the bearings... your gears in the gearbox will be destroyed!

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.