How Does a Clutch Work?

How does a clutch work? These simple drawings explain it well. When it is necessary to disconnect the engine from the wheels, the clutch intervenes, as in gear changes; if the engine were connected, the gearbox would experience violent jolts from the engine and would have a short lifespan.

The clutch transmits motion through friction until it is disengaged via the pedal. The engine transmits motion to a disc facing another disc connected to the secondary shaft.

When the two discs engage, motion is transmitted; when they separate, it is not. The video shows very explanatory drawings illustrating how motion is transmitted from the engine to the secondary shaft via the clutch. It also clearly illustrates the function of the pressure plate and the clutch linkages.

It then shows a picture of the diaphragm spring that tends to compress all the components it contains. The components rotating with the engine force the disc to rotate at the same speed.

This is how the clutch is "engaged". Behind the clutch disc components, there is a bearing called a release bearing, which has no influence until the pedal is pressed. When this happens, it exerts pressure on the diaphragm spring, which will tend to flatten, releasing the disc from its grip, thus disconnecting the wheels from the engine.

This is a type of clutch known as "single dry disc", but it is not the only type, although it is the most common.