Männänrenkaat

Männänrenkaat, also known as piston rings, are crucial components in internal combustion engines. They are typically made of cast iron or steel and are designed to fit into grooves on the outer diameter of a piston. The primary functions of piston rings are to seal the combustion chamber, control the consumption of lubricating oil, and transfer heat from the piston to the cylinder wall.

There are usually at least two rings per piston. The uppermost ring is called the compression ring, and its main purpose is to create a seal between the piston and the cylinder wall, preventing combustion gases from escaping into the crankcase. This ensures that the maximum pressure is exerted on the piston during the power stroke, maximizing engine efficiency.

Below the compression ring is the oil control ring. This ring has a more complex design, often with a spring-loaded expander, and its function is to scrape excess lubricating oil from the cylinder walls. This oil is then returned to the crankcase, preventing it from entering the combustion chamber where it would burn and cause smoke and carbon deposits.

Proper functioning of piston rings is essential for engine performance, fuel economy, and emissions control. Wear or damage to piston rings can lead to a loss of compression, increased oil consumption, and potential engine damage. Therefore, they are considered wear items and are replaced during engine overhauls.