How is the up and down motion of a motorcycle piston converted into rotational motion through the connecting rod and crankshaft?
Publish Time: 2024-08-08
Connection between piston and connecting rod
Piston pin: The piston pin connects the piston and the small end of the connecting rod, and plays the role of transmitting force. When the piston reciprocates up and down in the cylinder, this force will be transmitted to the connecting rod through the piston pin.
Connecting rod: The connecting rod is a long rod-shaped component, whose large end is connected to the crankshaft and the small end is connected to the piston through the piston pin. The main function of the connecting rod is to convert the linear motion of the piston into the rotational motion of the crankshaft.
Conversion of piston motion into crankshaft rotation
Motion transmission: When the fuel burns in the cylinder to produce high-temperature and high-pressure gases, these gases will push the piston downward. This linear motion of the piston is transmitted to the connecting rod through the piston pin, which in turn causes the connecting rod to start moving.
Connecting rod rotation: Since the large end of the connecting rod is connected to the crankshaft, when the connecting rod starts to move under the push of the piston, it will rotate around the center of the crankshaft. This rotational motion is carried out along the axis of the crankshaft.
Crankshaft rotation: The crankshaft is a component with multiple cranks, each of which is connected to a connecting rod. When the connecting rod rotates around the center of the crankshaft, it drives the crankshaft to rotate as well. This rotational motion is the main source of power output from the engine.
Specific steps of the working process
In a four-stroke motorcycle engine, the movement of the piston and the rotation of the crankshaft are completed through the following steps:
Intake stroke: The piston moves downward, the intake valve opens, and the mixture enters the cylinder.
Compression stroke: The piston moves upward, the intake and exhaust valves close, and the mixture is compressed.
Power stroke: The mixture is ignited by the spark plug, generating high-temperature and high-pressure gas that pushes the piston downward. In this process, the linear motion of the piston is converted into the rotational motion of the crankshaft through the connecting rod.
Exhaust stroke: The piston moves upward again, the exhaust valve opens, and the exhaust gas is discharged from the cylinder.
Through this process, the up and down motion of the motorcycle piston is successfully converted into the rotational motion of the crankshaft, thereby driving the motorcycle forward. This process is one of the core links in the operation of the engine and the key to the normal driving of the motorcycle.
