This discusses how the clutch of a manual transmission vehicle works. Automatics are designed with many clutches within the transmission and therefore run differently.
What are they for?
A clutch makes it possible to stop, either in a car or in any other mechanism. The engine is left running, but it is disconnected from the object it is driving, in which case it will be cars. Without a clutch, stopping a car would require killing/shutting off the engine first. The clutch makes it possible to disconnect the engine from everything else.
Parts
Clutches are devices with 2 shafts. The first shaft is the crank shaft. The second is the drive shaft. The crank shaft is connected to the pistons and is what drives/turns the drive shaft. At the end of the crank shaft there is a flywheel. There is are many other parts and I will list them but I will explain what they do in the next section. You can also view the diagram below. The following parts are the parts that connect the drive shaft to the flywheel: clutch plate, pressure plate, diaphragm springs, studs, throw out bearings, clutch housing, release fork, and bell housing.
How do clutches work?
A clutch has to be able to disconnect from the engine and then reconnect when its needed. In order to disconnect the spinning engine from the transmission you press the clutch pedal. The pedal is connected to the release fork. The fork pushes the throw out bearings in the center of the assembly. When the bearings move towards the flywheel they push diaphragm spring in the center. This makes the outsides of the spring move as well. But the trick is that the outside moves in the opposite direction, backwards, because the studs are acting as a pivot point for the diaphragm spring. The spring on the outside is connected to the pressure plate. So when the diaphragm spring moves backwards it takes the pressure plate with it. The pressure plate is connected to the clutch plate. So when the pressure plate moves backwards the clutch plate is pulled off of the flywheel and there for disconnecting the engine from the transmission. The clutch plate is the plate that contacts the flywheel and is what will reconnect the engine to the transmission. The flywheel is usually connected to a chain which runs to the electric starter engine.
In order to reconnect, you release the clutch pedal. This pulls back the bearings. The diaphragm spring goes back to original position(remember before they were pushed backwards, so now the go forwards) and force the pressure plate against the clutch plate. The clutch plate once again makes contact with the flywheel. The friction makes the transmission turn.
Take a look at this diagram that puts everything together.
Problems
The only problem with clutches is that they will need to be replaced. A clutch is essentially like a brake, but instead of a rotor there is the flywheel. Brakes wear out just as clutches do. Depending on the power of the engine and the driver, a clutch plates life span differs. A more powerful car tends to go throw clutches quicker do to an increase in connection time. Popping the clutch as dragracers do causes more wear as well. Once wear does occur the driver will notice an increase in slip while engaging the lower gears.
