As a component of combustion engines, the piston converts the energy released during combustion into a mechanical action and transfers it to the crankshaft in the form of a torsional force via the piston pin and the connecting rod.
How it works
When the engine is running, the piston moves up and down in the cylinder. When the piston reaches the turning point, it slows down and then accelerates again suddenly. This produces inertia forces that act on the piston. When considered together with the forces generated by the gas pressure, this forms the piston force, which is transferred to the connecting rod and crankshaft. Connecting rods are only perfectly vertical at the upper and lower turning points. The angle of the connecting rod presses the piston against the side of the cylinder wall. The amount and direction of this force constantly change during the combustion cycle, as they depend on the piston force and the angle between the piston crown and connecting rod axis. Pistons are equipped with piston rings. They seal the combustion and working chamber in relation to the crankcase. They also remove the oil from the cylinder walls, thus controlling the oil consumption. Piston rings also discharge the heat absorbed by the piston during combustion to the cooled running surface of the cylinder liner.