Into what two categories do piston rings fall?

Piston rings play a crucial role in the functioning of an engine by serving two fundamental purposes, which is why they are categorized into compression rings and oil control rings.

Compression rings are designed to seal the combustion chamber, preventing gases produced during combustion from escaping into the crankcase. This sealing allows for maximum energy extraction from the fuel, resulting in efficient engine performance and better fuel economy.

On the other hand, oil rings are responsible for controlling the amount of engine oil that reaches the combustion chamber. They scrape excess oil off the cylinder walls to minimize oil consumption and prevent oil from burning along with the air-fuel mixture, which could lead to increased emissions and potential engine damage.

This division into compression and oil rings forms the basis for understanding how piston rings contribute to the overall operation of an engine, making this categorization invaluable for those involved in engine design, maintenance, and repair.