Understanding a marine diesel engine

2-stroke Cross-Sectional View

4 – stroke cross-sectional view

Function of Parts

Parts in alphabetical order.

No.	Parts	Definition/Function
1	Connecting Rod	·         Changes the reciprocating motion of piston into rotary motion at crankshaft ·         Transmits the power produced at piston to crankshaft
2	Cylinder Block	·         Holds engine component (pistons, cylinders, camshaft and oil pump) ·         Hold crankshaft that converts rotating motion to reciprocating motion
3	Cylinder Head (4-stroke)	·         Carries inlet and exhaust valve. ·         An injector is also mounted on cylinder head
4	Cylinder Liner	·         Forms a sliding surface for the piston rings while retaining the lubricant within ·         Receives combustion heat through the piston and piston rings and transmits the heat to the coolant. ·         Prevents the compressed gas and combustion gas from escaping
5	Crank Pin	·         Transfer  power and motion to the crank shaft which come from piston through connecting rod
6	Crank Shaft	·         Receives oscillating motion from connecting rod and gives a rotary motion to the main shaft. ·         Drives the camshaft which actuate the valves of the engine
7	Cam Shaft	·         Takes driving force from crankshaft through gear chain ·         Operates the inlet and exhaust valve with the help of cam followers,push rod and rocker arms
8	Crosshead	·         A beam that connects the piston rod to the connecting rod
9	Crosshead Guide	·         Allowing the crosshead to only move in the same direction as the piston travel
10	Fuel Injector	·         Delivers fuel in fine spray under pressure
11	Fuel Pump	·         Deliver metered amount of fuel into cylinder through fuel delivery pipe & fuel injector
12	Inlet Valve & Exhaust Valve (4-stroke)	·         Inlet valve allow the fresh charge of air-fuel mixture to enter the cylinder bore ·         Exhaust valve permits the burnt gases to escape from the cylinder bore at proper timing
13	Gudgeon Pin (4-Stroke)	·         Connects the piston with small end of connecting rod.
14	Governor	·         Controls the speed of engine at a different load by regulating fuel supply in diesel engine.
15	Piston Rings	·         Prevents the compressed charge of fuel-air mixture from leaking to the other side of the piston. ·         Oil rings used for removing lubricating oil from the cylinder after lubrication. ·         Prevents the excess oil to mix with charge.
16	Piston Skirt	·         Carries gudgeon pin and rub against liner.
17	Push rod & Rocker arm (4-stroke)	·         Push rods sit on the cam so when engine is running ·         Push rods go up and down in a timed sequence and with the rocker arms, open and close the inlet and exhaust valves.
18	Piston	·         Compresses air in between cylinder head and piston crown.
19	Scavenge Ports (2-stroke)	·         Pushes exhausted gas-charge out of the cylinder ·         Draw in a fresh draught of air ready for the next cycle.
20	Stuffing Box	·         A type of seal that prevents fluids from leaking inside of machine parts.
21	Turbocharger	·         A device that uses the energy of exhaust gases coming out from an engine to compress the air going into the engine.