What is the function of a crankshaft?

The crankshaft takes the piston from an up and down motion and changes it to a rotating motion. The crankshaft is near the bottom of the engine.

The crankshaft works to change piston motion with the help of connecting rods on the pistons. The crankshaft has journals, a crankshaft snout, counterweights and a crankshaft flange. The journals allow the crankshaft to fit into the main bearings of the engine block. The counterweights prevent vibration and balance the crankshaft. The snout is the front end and the flange connects to the flywheel, which helps in rotating the crankshaft by working with the starter motor.