The role of the piston pin
The piston pin is used to connect the piston and the connecting rod, and transfer the force of the piston to the connecting rod, and vice versa.
The piston pin bears a great periodic impact load under high temperature conditions. Because the piston pin swings at a small angle in the pin hole, it is difficult to form a lubricating oil film and the lubrication conditions are poor. For this reason, the piston pin must have sufficient rigidity, strength and wear resistance. The quality should be as small as possible, and the pin and the pin hole should have an appropriate clearance and good surface quality. In general, the stiffness of the piston pin is particularly important. If the piston pin is bent or deformed, the piston pin seat may be damaged.
In short, the working condition of the piston pin is that the bearing pressure ratio is large, the oil film cannot be formed, and the deformation is not coordinated. Therefore, its design requires sufficiently high mechanical strength and wear resistance, as well as high fatigue strength.
There are three ways to fix the piston pin:
The first type uses a floating pin, which can rotate on the piston pin seat and the small end of the connecting rod.
The second is that the piston pin is fixed on the piston pin seat and can be rotated at the small end of the connecting rod.
In the third type, the piston pin is fixed at the small end of the connecting rod and can rotate in the piston pin seat.
