4.7.5 Piston pin
Piston pin is a short steel tube. It passes through the upper connecting rod head and the holes in the piston (in the so-called piston bosses), thus connecting them.
The piston pin can be firmly pressed into the upper connecting rod head. In this case, the type of connection is called "fixed pin".
Piston pins of floating type are used as well. They can rotate both inside the piston bosses (visible in Figure 4.29) and inside the upper connecting rod head. In order to eliminate lateral displacement, the pin is attached on the sides with two spring-loaded retaining rings that are installed in the grooves of the piston bosses.
Note
Non-floating pins are rigidly fixed in the upper connecting rod head or in the piston bosses. When installing a floating pin, its entire surface is working, as a result of which less wear is provided and the possibility of galling is reduced.
Figure 4.29 Piston and piston pin without connecting rod.
Figure 4.30 Piston and piston pin in assembly with connecting rod.
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