What is the function of piston rings installed on the piston?

[LaNoah]

The functions of piston rings installed on the piston are: 1. Sealing: To seal the combustion gases, preventing them from leaking into the crankcase from the combustion chamber, minimizing gas leakage to improve thermal efficiency. Gas leakage not only reduces engine power but also causes engine oil to deteriorate; 2. Oil regulation (oil control): To scrape off excess lubricating oil from the cylinder wall while ensuring a thin oil film remains on the wall, guaranteeing normal lubrication for the cylinder, piston, and rings; 3. Heat conduction: To transfer heat from the piston to the cylinder liner through the piston rings, serving a cooling function; 4. Support: Piston rings keep the piston in the cylinder, preventing direct contact between the piston and the cylinder wall, ensuring smooth piston movement, reducing friction resistance, and preventing piston knocking. Generally, gasoline engines use two compression rings and one oil ring, while diesel engines typically employ two compression rings and one oil ring.