The clutch is a coupling that sits between the engine and gearbox. Its purpose is to connect and disconnect the engine’s torque to the gearbox and driving wheels.
WHY IS IT CALLED A CLUTCH?
It is called a clutch because to clutch something is to grasp something tightly—grab hold of it. An excellent way to look at it is that a clutch is a way of grabbing hold of the engine’s torque (and letting go of it as well).
WHAT’S THE PRINCIPLE?
The principle of the clutch is just like a vice. You have two sides to the vice designed to clamp down onto something, in this case, a clutch plate. When the vice is tightened, the disc is held. When the vice is loosened, the clutch plate is not maintained.