crank shaft

grabcad

A crankshaft, related to a crank, is a mechanical component that facilitates the conversion between reciprocating and rotational motion in engines or compressors. In reciprocating engines, it transforms piston's reciprocating motion into rotational motion, while in reciprocating compressors, it does the opposite by converting rotational motion to reciprocating motion. This conversion is achieved via "crank throws" or "crankpins", offset bearing surfaces to which connecting rods attach. Crankshafts are often linked to a flywheel to diminish pulsation and sometimes a damper at the other end to reduce torsional vibrations caused by the farthest cylinders acting on the metal's torsional elasticity.