Why are piston rings used?

Replies

• 

  Sarathkumar Chandrasekaran

  There are mainly two purposes of pistons as follows:
  1) Act as a seal so that the oil from the sump during lubrication would not enter into combustion chamber which may result in blue gas.
  2)Another one for the lubrication purpose which help in decreasing the friction between the piston and cylinder wall.
  
  There are two piston rings as follows:
  1)Oil rings-lubrication purpose
  2)Compression rings - act as seal from combustion chamber and part below the piston.
• 

  Sarathkumar Chandrasekaran

  @#-Link-Snipped-# hope you understand .
• 

  Blv NAGABABU

  in the above fig piston rings are placed 1 inch from the crown of the piston then there is chance to develop a friction I.e., above the piston rings how it is reduce
• 

  Sarathkumar Chandrasekaran

  Blvn Lakshman

  in the above fig piston rings are placed 1 inch from the crown of the piston then there is chance to develop a friction I.e., above the piston rings how it is reduce

  Above the piston, There would be no contact between the piston wall and cylinder wall.
  Piston rings major purpose is the reduction of friction and act as a seal between the area above piston and below piston.Piston rings are the only parts to get contact with the cylinder wall.So circumferential area above or below piston rings would not have contact with cylinder walls .Hope you understand,Any doubt?Feel free to ask friend.