Automobile Clutch
In the figure below, you can see that the flywheel is connected to the engine, and the clutch plate is connected to the transmission.


Exploded view of car clutch

When your foot is off the pedal, the springs push the pressure plate against the clutch disc, which in turn presses against the flywheel. This locks the engine to the transmission input shaft, causing them to spin at the same speed.


Photo courtesy Carolina Mustang
Pressure plate

The amount of force the clutch can hold depends on the friction between the clutch plate and the flywheel, and how much force the spring puts on the pressure plate. The friction force in the clutch works just like the blocks in the friction section of Brakes , except that the spring presses on the clutch plate instead of weight pressing the block into the ground.


How a clutch engages and releases

When the clutch pedal is pressed, a cable or hydraulic piston pushes on the release fork, which presses the throw-out bearing against the middle of the diaphragm spring. As the middle of the diaphragm spring is pushed in, a series of pins near the outside of the spring causes the spring to pull the pressure plate away from the clutch disc (see below). This releases the clutch from the spinning engine.



Clutch plate

Note the springs in the clutch plate. These springs help to isolate the transmission from the shock of the clutch engaging.




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Introduction to How Clutches Work
Why Do We Need Clutches?
Automobile Clutch
What Can Go Wrong