A piston ring is a split ring, usually made of metal, which is attached to the outer diameter of a piston in an internal steam engine or combustion engine. These piston rings are mainly manufactured and categorized on the basis of usability and function. The primary and most significant usage of these rings is to seal the chamber, which can be either a combustion chamber of a 2 stroke or a 4 stroke steam engine. Marine engines tend to possess three or even more types of rings fitted on the outer boundary of the piston. You can buy these rings from a reliable pistons dealer or you also have the option to buy them online.
The piston ring is considered to be an important piston part. The numbers and functionality of piston rings differ depending on the capacity and type of the engine. For instance, in 2 stroke large engines, compression type piston rings are opted for use in order to completely seal the combustion chamber.
Functions of piston rings
The following are some of the main functions of piston rings in an engine.
These rings help seal the combustion chamber so that there is hardly any loss of gases to the crank case.
- Piston rings improve heat transfer from the piston to the cylinder wall.
- It also helps to maintain the necessary amount of oil between the cylinder wall and the piston.
- It regulates engine oil consumption by scraping oil from the cylinder walls back to the sump.
- There are many types of piston rings available in the market such as wiper ring, oil ring, compression ring, and so on. However, we are going to learn more about one type of piston rings, and that is, the compression rings.
The compression rings are the closest rings to the combustion gases and are known to be exposed to the greatest quantity of chemical corrosion as well as the highest operating temperature. A compression ring tends to transfer about 70 per cent of the combustion chamber heat from the piston to the cylinder wall.
A taper faced compression ring is a type of piston ring that possesses approximately a 1 degree taper angle on the running surface. This taper tends to provide a mild wiping action in order to prevent extra or excess oil from reaching the combustion chamber.
A barrel faced compression ring is a type of piston ring that contains a curved running surface so as to provide consistent lubrication of the cylinder wall and piston ring. Moreover, this also tends to offer a wedge effect which optimizes the oil distribution throughout the full stroke of the piston. Apart from this, the curved running surface helps in reducing the possibility of an oil film breakdown because of excess pressure on the edge of the ring.
As mentioned earlier, if you are interested in buying piston rings, make sure that you buy it from a reliable pistons dealer because only then you would be getting high quality products.