Piston

Introduction:  It is a disc or cylindrical part that slides to and fro in a hollow cylinder.

Definition:       

“In an internal-combustion engine it is forced to move by the expanding gases in the cylinder head and is attached by a pivoted connecting rod to a crankshaft or flywheel, thus converting reciprocating motion into rotation.”

Piston:

     

 

 

 

 

 

 

 

 

 

 

Fig: Piston

 

• Pistons harness the energy of the power stroke and transfer the force toward the crankshaft.

 

Piston terminology:

• Head or crown
• Ring grooves
• Ring lands
• Oil return holes
• Skirt
• Pin hole
• Pin boss
• Pin offset                       

 

A piston of an internal combustion engine serves three functions:

1. It forms a movable wall of the combustion chamber.
2. It transmits turning force to the crankshaft via the connecting rod.
3. It functions like a crosshead and transmits side thrust, which is due to the angularity of the connecting rods, to the cylinder walls.