DIESEL ENGINE

ENGINE DEVELOPMENT DIRECTORATE

RESEARCH DESIGNS AND STANDARDS ORGANISATION

(R.D.S.O.)

SAURABH CHAKRABORTY MECHANICAL ENGINEERING

FINAL YEAR

ABOUT RDSO Railways were introduced in 1853. IRCA was set up in 1903, followed by CSO. RTRC was setup in 1952. In 1957 CSO & RTRC were integrated to form

RSSO.CSO + RTRC = RDSO

FUNCTIONSTechnical advisor to Railway Board.Development of new & improved designs.Development, adoption, absorption of new

technology for IR. Development of standards for materials &

products specially needed by IR.Technical investigation, statutory clearances,

testing & providing consultancy services.

HOW DIESEL ENGINE WORKSDE relies upon compression ignition.DE’s compression ratio lies b/w 16:1 and 25:1.Temp. increases to 700C to 900C.Piston approaches TDC, fuel is injected.Ignition instantly occurs, causing a rapid increase in

cylinder temperature & pressure.Piston is driven downward with great force, pushing on

the connecting rod & turning the crankshaft. Exhaust gases will be used to drive a turbocharger.

TWO STROKEIntake begins when the piston is near BDC.Hybrid turbocharger is used, to charge the

cylinder.As the piston rises, compression takes place.Near TDC, fuel injection occur.Resulting in combustion, driving the piston

downward.Piston moves down, expelling the combustion

gases.

FOUR STROKEStarting position, intake stoke & compression

stroke

Ignition of fuel, power stroke & exhaust stroke.

VALVE TRAIN

BASIC COMPONENTS & ASSEMBLIES

OFDIESEL LOCOMOTIVE ENGINES

ENGINE BASESupports the engine blockServe as oil sump.Accommodate lube oil main header.Take lube oil pump & water pump at the free

end.Allow openings for crankcase inspection.Take fitment of crankcase explosion cover.

ENGINE BLOCKMost important & very highly stressed structure.Fitted with- 1) crank shaft 2) cam shaft 3) cylinder heads 4) pistons 5) connecting rods 6) fuel injection pumps 7) turbo support They form a complete power-pack.

CRANK SHAFTSingular costliest item in diesel engine.Medium of transforming reciprocating

motion to rotary motion.Balance weights can be either bolted up or

welded.

CAM SHAFTPerforms the vital role of opening & closing

inlet & exhaust valves.Allow timely injection of fuel inside the

cylinder.Usually 3 cams for each cylinder- 2 outer cams for exhaust & inlet valves 1 central cam for fuel injection.

CYLINDER HEADCH is held on the cylinder liners by 7 hold

down studs.Subjected to high shock stress & combustion

temperature at the lower face.Complicated casting where cooling passages

are cored for holding water.Space had been provided for passage of inlet

air & exhaust gases.Space for fuel injection nozzles, valve guides

& valve seat.

LINERSForms the wall of the combustion chamber.Guides the movement of piston.Mainly of 2 types:- Dry Liner Wet Liner

PISTONCompresses the air to required pressure &

temperatureReceives the thrust of expanding gases &

transmits the force through connecting rod.With the help of piston rings, prevents

leakage of gas from combustion chamber.

PISTON RINGSSeal the combustion chamberPrevent blow by of air & high temperature

combustion gases.Scraps down excess lube oil from walls of

cylinder liner.Prevents reaching lube oil into combustion

chamber.

TYPES OF RING COMBINATIONS5 RING COMBINATION

6 RING COMBINATION

A. Square faceB. Taper faceC. Taper faceD. Double taper faceE. Conformable

A. Square faceB. Taper faceC. Taper faceD. Double taper faceE. Double taper faceF. Conformable

CONNECTING RODConnects piston & crank shaftMedium of converting reciprocating motion

to rotary motionConnecting rod assembly consists of- 1) Connecting rod 2)Connecting rod

cap 3)Piston pin bushing 4)Bearing shell

upper 5)Bearing shell lower 6)Connecting rod

bolts & nuts

FUEL OIL SYSTEM

Consists of two integrated systems- FUEL FEED SYSTEM FUEL INJECTION SYSTEM

F.F.S. & ITS ASSOCIATE COMPONENTS

Fuel oil tankFuel primary filterFuel transfer pump or booster pumpFuel relief valveFuel secondary filterFuel regulating valve

F.I.S.When DE is started, all fuel injection pumps

start functioning.According to firing order, all F.I. pumps start

discharging fuel oil to their respective nozzles.

CHARGE AIR SYSTEMFor charge air system Turbo super charger is

used in locomotives.

TURBO SUPER CHARGER

LUBE OIL SYSTEMIt serves the following purposes: Cooling of bearing, pistons etc Protection of metal surfaces from corrosion,

rust, surface damages & wear. Keep the components clean & free from

carbon.

COOLING SYSTEMDifferent cooling systems are used:Air coolingWater coolingOil cooling