Connecting rod is one of the main transmission mechanisms of automobile engines. It connects the piston and crankshaft, transmitting the pressure of the expanding gas acting on the top of the piston to the crankshaft, and reversibly converting the reciprocating linear motion of the piston into the rotational motion of the crankshaft to output power.

The function of the connecting rod is to transmit the force borne by the piston to the crankshaft, and convert the reciprocating motion of the piston into the rotational motion of the crankshaft.

The connecting rod is composed of connecting rod body, connecting rod cap, connecting rod bolt, and connecting rod bearing shell. The connecting rod body and connecting rod cap are divided into connecting rod small head, connecting rod body, and connecting rod large head.

The connecting rod small head is used to install the piston pin to connect the piston. The shaft is usually made into a "I" or "H" - shaped cross-section in order to reduce mass while meeting strength and stiffness requirements.

The connecting rod big end is connected to the connecting rod journal of the crankshaft. Generally, it is made into a separate type, and the half cut with the shaft is called the connecting rod cap, which is connected as a whole by connecting rod bolts.

The connecting rod bearing is installed in the connecting rod big end hole seat, and is integrated with the connecting rod journal on the crankshaft, making it one of the most important mating pairs in the engine. The commonly used wear-resistant alloys include white alloy, copper lead alloy, and aluminum based alloy.

Connecting rod is an important component in engines such as automobiles and ships. It connects the piston and crankshaft, and its function is to convert the reciprocating motion of the piston into the rotational motion of the crankshaft, and transmit the force acting on the piston to the crankshaft to output power. In operation, the connecting rod not only bears the pressure generated by the combustion chamber gas, but also longitudinal and transverse inertial forces. Therefore, the connecting rod operates under a complex stress state. It is subjected to both alternating tensile and compressive stresses, as well as bending stresses.