What are the functions of compression rings and oil rings?
2 Answers
Compression rings serve to seal the gap between the piston and cylinder, preventing gas leakage and oil blow-by, while transferring heat from the piston to the cylinder. Oil rings function to scrape excess lubricating oil off the cylinder walls and distribute oil evenly. Below are additional details about compression rings and oil rings: 1. Compression rings: Typically, each piston in an engine is equipped with 2 to 3 compression rings. Poor sealing by compression rings can lead to difficulties in engine starting, reduced power output, increased fuel and oil consumption, among other issues. 2. Oil rings: Oil rings are divided into conventional oil rings and composite oil rings. They are a type of piston ring, usually made of alloy cast iron. The outer surface features a central groove with numerous small oil drainage holes or slots at its base.
I think the compression rings and oil rings play a crucial role in car engines, acting like guardians of the piston. Specifically, the compression rings are primarily responsible for sealing the compressed gases in the combustion chamber, preventing precious gases from leaking, which ensures the engine runs efficiently; they also help dissipate heat from the piston, preventing the engine from overheating and getting damaged. The oil ring, on the other hand, is an expert in oil management—it scrapes off excess oil from the cylinder walls, leaving a thin lubricating film to reduce friction while preventing too much oil from entering the combustion chamber and burning, which would otherwise cause blue smoke and increase fuel consumption. In the past, I neglected maintenance while driving, and after the oil rings wore out, my car lost power and became more fuel-hungry—performance only recovered after repairs. In daily use, regularly changing the oil and using qualified filters can extend the life of these rings. A reminder to everyone: don’t let the engine run under low load for too long.
