The crankshaft is the most important part of an engine. It takes the force from the connecting rod and converts it into torque which will be output by the crankshaft and drives the other accessories on the engine to work. The crankshaft is subjected to the combined action of centrifugal force of rotating mass, periodic change of gas inertial force and reciprocating inertial force, so it bears the bending and torsional load. Therefore, the crankshaft is required to be of enough strength and rigidity, and its neck surface needs to be of wear-resistance, uniform work and good balance.
