PISTON RINGS
A piston ring is a split ring that fits into a groove on the outer diameter of a piston in a reciprocating engine such as an internal combustion engine or steam engine.
The three main functions of piston rings in reciprocating engines are :
- Sealing the combustion chamber so that there is minimal loss of gases to the crankcase.
- Improving heat transfer from the piston to the cylinder wall.
- Regulating engine oil consumption by scraping oil from the cylinder walls back to the sump.[1]
The gap in the piston ring compresses to a few thousandths of an inch when inside the cylinder bore. Piston rings are a major factor in identifying if an engine is two stroke or four stroke. Three piston rings suggest that it is a four-stroke engine while two piston rings suggest that it is a two-stroke engine. Most piston rings are made of a very hard and somewhat brittle cast iron.
