Components of an I.C. Engine
An I.C. Engine is a heat engine where the combustion of fuel takes place inside the engine cylinder, producing power directly.
🔧 Main Parts of an I.C. Engine (With Explanation):
1. Cylinder
- Acts as the main body of the engine.
- Fuel combustion and piston movement take place here.
- Made to withstand high pressure and temperature.
- Cooled using water or air.
2. Piston
- A cylindrical part that moves up and down inside the cylinder.
- Compresses the air-fuel mixture.
- Receives force from the combustion and transmits it to the crankshaft via the connecting rod.
3. Cylinder Head
- Fixed at the top of the cylinder.
- Houses inlet and exhaust valves, spark plug/injector.
- Seals the top of the combustion chamber.
4. Piston Rings
- Fitted on the outer surface of the piston.
- Provide a seal between the piston and cylinder wall.
- Prevent leakage of combustion gases and control oil consumption.
5. Connecting Rod
- Links the piston to the crankshaft.
- Converts the reciprocating motion of the piston into rotary motion of the crankshaft.
6. Crank and Crankshaft
- Crank: Connected to the piston via the connecting rod.
- Crankshaft: Receives rotating motion and transmits it as output power.
- Also connected to the flywheel.
7. Crankcase
- Lower part of the engine housing the crankshaft.
- Acts as an oil sump for lubrication.
8. Valves
- Inlet Valve: Allows fuel-air mixture (in petrol) or air (in diesel) to enter the cylinder.
- Exhaust Valve: Expels burnt gases from the cylinder.
- Usually controlled by a cam mechanism.
9. Flywheel
- Mounted on the crankshaft.
- Stores excess energy during the power stroke.
- Releases energy during idle strokes to maintain smooth crankshaft rotation.
10. Camshaft / Cam
- Controls the timing of valve operation.
- Rotates in sync with the crankshaft and opens/closes valves at proper intervals.
11. Spark Plug / Fuel Injector
- Spark Plug (Petrol Engine): Produces spark to ignite the air-fuel mixture.
- Fuel Injector (Diesel Engine): Injects fuel into compressed air to initiate combustion.