A flywheel is a special mechanical device design to efficiently store kinetic energy by the working stroke. The engine flywheel serves to accumulate energy during the working stroke, rotate the crankshaft during auxiliary strokes, reduce the unevenness of the shaft rotation, smooth out the moment the parts of the crank mechanism pass through the dead points, facilitate starting the engine and car moving from its place.
By the engine starting the ignition of the working mixture occurs in the cylinders and the flywheel ensures the rotation of the crankshaft from the end of the stroke in one cylinder to its beginning in the next in accordance with the order of operation of the engine cylinders.
A flywheel is casting from gray cast iron. The main bulk of the metal is on the rim to increase the moment of inertia. A gear rim is install or put on the flywheel rim to rotate the crankshaft when starting the engine with a starter. The crown is bolted. The surface of the flywheel is contact with the clutch disc is ground and polish.
There are marks on the rim or end of the flywheel that allow you to set the piston of the first cylinder to top dead center. The crankshaft assembly with the flywheel and clutch is subject to dynamic and static balancing. So that unbalanced inertia forces do not cause engine vibration and accelerate wear of the main bearings.
Typically, a flywheel is attach to the crankshaft flange with bolts that are heat treat or ground. The castellate nuts screw onto these bolts are thoroughly split. The mold from the mounting holes on the flywheel and in the flange is circumferentially offset by several degrees, which ensures the exact connection of the flywheel and the crankshaft if for some reason they were disassembled. In diesel engines, the flywheel is fastened with bolts that are screw directly into the crankshaft. In this case, the flywheel is precisely fix relative to the necks of the crankshaft with two pins.