A flywheel is a mechanical device that stores rotational energy using the conservation of angular momentum. It is a form of kinetic energy that is proportional to the product of its moment of inertia and the square of its rotational speed. The flywheels moment of inertia is constant, which means that the stored rotational energy is directly associated with the square of its rotational speed. A flywheel is a kinetic energy analogue of an electrical inductor, and it is described in the generalized concept of an accumulator.
In a vehicle with a manual transmission, the flywheel serves a crucial purpose. It is a thick metal disc that is typically made of cast iron, steel, or aluminum. The flywheel is extremely rigid to prevent flexing or warpage during use, and it has a row of gear teeth that engage with the engine's starter motor. The flywheel is firmly bolted to a flange on the transmission side of the crankshaft inside the bell housing. On the side facing the manual transmission, the surface is smooth and flat to mate with the clutch disc.
Overall, a flywheel is an important mechanical device that stores rotational energy and plays a crucial role in manual transmissions.
