Piston Assembly

An engine's piston assembly transmits force from the expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. For the goal of compressing or ejecting the fluid in the cylinder, the function is reversed in a pump, and force is transferred from the crankshaft to the piston. Piston assembly serves as a movable stopper that forms the bottom of the combustion chamber in the cylinder. The hot combustion gases can only expand by driving the piston downward since there is a gas-tight seal between the piston and the cylinder wall.