This article is about an automotive technology. There is also an article about the band Clutch.

A clutch is a subcomponent of an engine's transmission designed to allow engagement or disengagement of the engine to whatever apparatus is being driven.

There are many different clutch designs, but most are based on one or more friction discs, pressed tightly together or against a flywheel using springs. The spring pressure is released when the clutch pedal is depressed and the discs are held less tightly and allowed to rotate freely. A wet clutch is immersed in lubricating fluid to keep the surfaces clean and to cool it, for improved performance and longer life; while a dry clutch is not.

In a car it is operated by the left-most pedal using hydraulics or a cable connection from the pedal to the clutch mechanism. No pressure on the pedal means that the clutch plates are engaged (driving), while depressing the pedal will disengage the clutch plates, allowing the driver to shift gears. When the right-most pedal (the accelerator ) is pressed while the clutch pedal is being let out, the clutch plates wear out faster than normal, but this is often used for a hard launch . Some mopeds have an automatic clutch, using centrifugal forces to engage the clutch above certain rpm.

On most motorcycles, the clutch is operated by the clutch lever, located on the left handlebar. No pressure on the lever means that the clutch plates are engaged (driving), while pulling the lever back towards the rider will disengage the clutch plates, allowing the rider to shift.

A clutch may also be a device on a shaft that will "slip" when higher than normal resistance is encountered on a machine. A example of a clutch such as this may be mounted on the driving shaft of a large grass mower. The clutch will "slip" or "give" if the blades were to hit a rock, stump, or other immobile object.

See also

• fan clutch
• freewheel
• manual transmission

External link

• HowStuffWorks has a detailed explanation of the working of a clutch.