According to the general industry standard of operation, there are two types of piston pin installation.
Firstly, full floating connection. When the engine works, the piston pin, connecting rod and piston pin seat have relative movement, so that the piston pin can swing freely in the connecting rod bushing and piston pin seat, so that the wear is uniform. In order to prevent the full floating piston pin axial movement scratching the cylinder wall, the piston pin is equipped with retaining rings at both ends for axial positioning.
Since the piston is aluminum piston and the piston pin is made of steel, aluminum has a higher thermal expansion than steel. In order to ensure high temperature work piston pin and piston pin seat hole for the transition fit, assembly , first the aluminum piston heated to a certain degree, and then the piston pin into the installation, this installation is more widely used.
Secondly, semi-floating coupling. Semi-floating coupling is in the engine work, the piston pin and piston pin seat hole for clearance fit, while the piston pin and connecting rod small head for interference fit, the piston pin can only float in the pin seat hole, pin seat hole without snap ring, the two ends of the small head does not have to be fitted with connecting rod bushings, the piston pin parts of uneven wear.
