Connecting Rod Design and Function

Connecting Rod Design and Function

This section examines the connecting rod. The connecting rod connects the piston to the crankshaft. It is fastened to the piston at its little end by a piston pin also known as a gudgeon pin. In some engines the pin is a press fit in the small end of the connecting rod. In others it is clenched to the connecting rod with a clamping bout. Another method lets the pin float in about the piston and connecting rod and it is held with circlips. These are bearing in the small end of the connecting rod.

The big end of the connecting rod has a detachable cap and carries two halves of the big end bearing. The big end is attached to the crankshaft at the crankpin channel.

Connecting rods must be very strong and rigid and is light as possible. They are subject to the stretching and pressing and bending so they are highly stress.

They are cast or forged to form an edge near the small end and an eye near the big end. This shape provides greatest strength to resist the stresses than a solid rod of the same mass. To maintain engine balance all the connecting rods in an engine are in a matched seat.


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