Model Engineering Glossary: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Gudgeon Pin - Piston Pin - Wrist Pin

This pin provides the articulated connection between the conrod and the piston. Note that this pin sees very high forces. Often hollow to reduce weight.

There are a number of retaining methods:

1. full floating
2. locking mechanism - C type clip
3. floating with end pads to protect cylinder walls
4. Interference fit

The picture to the left shows a piston and conrod with a drill bit taking the place of the gudgeon pin.

This particular piston and conrod is from a small 5 cylinder rotary engine which is why this conrod is different from a conventional conrod as it is the master.

In this example the gudgeon pin is held in place using a clip, the end of which can be seen clearly bent round.

This piston is from a high performance 20cc 4-stroke engine that revs to a maximum of around 11,000rpm

See also: Pistons, Pistons and Liners.

Model Engineering Glossary: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z