What is the function of the crank-connecting rod mechanism?
2 Answers
The crank-connecting rod mechanism converts the reciprocating motion of the piston into the rotational motion of the crankshaft, while transforming the force acting on the piston into the torque output by the crankshaft to drive the rotation of the car's wheels. The crank-connecting rod mechanism consists of three main parts: the engine block group (including stationary components such as the cylinder block, crankcase, oil pan, cylinder liner, cylinder head, and cylinder gasket), the piston-connecting rod group (including moving components such as the piston, piston rings, piston pin, and connecting rod), and the crankshaft-flywheel group (including mechanisms such as the crankshaft, flywheel, torsional vibration damper, and balance shaft). There are three types of crank-connecting rod mechanisms: double crank, double rocker, and crank-rocker. A component that can perform circular motion is called a crank, while one that can only swing within an angle less than 360° is called a rocker. A double crank mechanism involves one crank driving another crank to rotate, while a double rocker mechanism involves one rocker driving another rocker to swing. In a crank-rocker mechanism, when the crank is the driving component, it performs circular motion to drive the rocker to swing; when the rocker is the driving component, it swings to drive the crank to perform circular motion.
As an automotive repair technician, I've seen many engine core components, and the role of the crankshaft connecting rod mechanism is absolutely crucial. Simply put, it's like the heart's blood vessels connecting the engine, converting the piston's reciprocating linear motion in the combustion chamber into the rotational power of the crankshaft, ultimately driving the wheels forward. Imagine when you press the accelerator, the pistons move up and down to squeeze energy from gasoline—this mechanism rotates, and the car moves. It not only ensures smooth power transmission but also reduces engine vibration. In the cars I've repaired, if the connecting rod is deformed or the crankshaft is worn, it can lead to engine knocking, soaring fuel consumption, or even stalling. So regular inspection of this component is critical, especially for older vehicles, as it can prevent a lot of trouble.
