The total achievement of connecting rods is to integrate multiple connecting rods together, in order to better exert their stability, connect the piston and crankshaft, and transmit the force acting on the piston to the crankshaft, transforming the reciprocating motion of the piston into the rotational motion of the crankshaft.
The connecting rod assembly consists of a connecting rod body, a connecting rod big end cap, a connecting rod small end bushing, a connecting rod big end bearing shell, and connecting rod bolts (or screws). The connecting rod group bears the gas force transmitted by the piston pin, as well as the swinging and reciprocating inertial forces of the piston group. The magnitude and direction of these forces vary periodically.
Therefore, the connecting rod is subjected to alternating loads such as compression and tension. The connecting rod must have sufficient fatigue strength and structural stiffness. Insufficient fatigue strength often leads to the fracture of connecting rod bodies or connecting rod bolts, resulting in major accidents of complete machine damage.