Power Pack of DieselLocomotive & its componentsBy- G.N.Singh,AP(D)

POWER PACK WDM2POWER PACK WDM2Power Pack Assly WDM2

ENGINE DATAENGINE DATA CYCLE: 4 STROKE CYCLE

ASPIRATION: TURBO SUPERCHARGED

WITH CHARGE AIR COOLING

MODEL:ALCO 251 B ,( V –SHAPED, 16 CYL)

BORE: 9 INCHES (228 mm)

STROKE: 10.5 inches (267 mm)

Compression Rtio : 12.5:1 (conv),11.75:1(mod)

HORSEPOWER (GROSS): 2600 BHP

ENGINE SPEED:1000 RPM (FULL LOAD)

400 RPM (IDLE)

PISTON SPEED (MEAN): 9.89 m/sec

SWEPT VOLUME PER CYLINDER: 10.5 ltrs.

WEIGHT (DRY ENGINE): 19026 kg

POWER PACK WDM1

Cut Section of Engine

READYPOWER PACK WDM2

In Complete Power Pack WDM2

BEARING PORTION IN ENGINE BLOCK

16 CYLINDER POWER PACK COMPONENTS

ENGINE BLOCK AND ENGINE BASE ARE OF STRUCTURAL STEEL DESIGNWHEREIN PISTONS, CYL LINER, CON ROD ASSEMBLY,CRANKSHAFT ASSEMBLY AND CAMSHAFT ASSEMBLYARE ASSEMBLED TO MAKE A COMPLETE POWER PACK.ENGINE BLOCK STRUCTURE CONSISTS OF SADDLE FORGINGS ANDMICRO ALLOYED STEEL PLATES UPTO 75 MM THICKNESS.

ENGINE BLOCK ENGINE BASE

ENGINE BLOCKENGINE BLOCK

Engine Block , Fitted following important items :– Crankshaft– Cam shaft– Cylinder Head– Cylinder Liners– Piston – Con. Rods– Fuel Injection Pumps– Fuel Pump Cross head– Turbo Support– Governor etc. – Crankcase Exhauster

Provides mounting surface:-

- Turbo supercharger support

- Exhaust Manifold

- Air intake elbow

- Water elbow

- Traction Generator / Alternator

- Replaceable Liner Sleeve (fitted into lower liner bore of Cylinder Block.)

Integral part of Block:-

-Crankshaft Main Bearing Saddles

-Camshaft bearing supports

-Air intake manifold

-Cooling water, a passage on Cylinder Block

-Water from Block is conducted to Cylinder Head by Water Jumper.

Power Pack free endPower Pack free end

CRANK SHAFTCRANK SHAFT

16Cylinder Engine Crankshaft:No of Main Bearings : 9 Location of Centre Journal: 5 No. of Crankpins : 8 Lift Crankshaft at Crankpin Nos. : 2 and 7 Support Crankshaft at :Main Journals: 3 and 7

Cam ShaftCam Shaft

Camshaft performs vital role of opening and closing Inlet and Exhaust valves and timely injection of fuel in Cylinder.

3 Cams are provided for each Cylinder. 2 Outer Cams for Exhaust and Air inlet valves and central Cam for fuel injection.

Conventional CamshaftUnit Camshaft

Fabrication :-

Basic building elements of Block.

a) Saddle (Inter/Centre)

Forging mfd. from -

Steel (Specification IS : 1875.)

b) Spline

Fabricated form -

Low Carbon Steel Plates (IS:2062)-

Top Deck : 75 mm thick Plate

Side Sheet : 22mm thick Plate

Middle deck : 45 mm thick Plate

Inside Wall : 16 mm thick Plate

Saddles

Spline

Air intake manifold

1 2

3 4 Saddle Portion

Spline portion

ENG I NE

BLOCK

a) welding by process of Submerged Arc Welding (SAW) undertaken for critical joints.

b) Radiographic testing of critical welded joints

c) After fabrication, stress relieving of Engine Block

is undertaken at 640 º C (14 hours Heating 4 hours Soaking and 10 hours Cooling) in Stress Relieving Furnace.

WELDING-

Machining :

1) Marking Table- Marking of Engine Block is undertaken on maintaining required dimensions.

2) Planning Machine- Engine Block is placed on for machining inclined sides and top faces.

3) Milling Machine- Generator end’ and ‘Free end’ of Block are for maintaining required length of Block.

4) Angular Boring Machines (M/s XLO and M/s HMT) - Upper and lower Liner bores of Blocks are machined on Special purpose

Note :

*2 Bores are inclined at 22½º with vertical axis.

Concentricity of upper and lower bore ensured

due to simultaneous machining.

5) Drilling Machine.

Different size of holes drilled and tapped to UNC and UNF

– ‘Drilling / Tapping of holes on ‘Generator end’ and ‘Free end’ undertaken on Horizontal End

6) Serration Milling Machine - Serration Milling

of Saddle Faces of Engine Block along with

Main Bearing Caps

( Accuracy and furnish of serrations milled is ± 0.0002” )

Note : Each Bearing Cap is marked for location so that Bearing Cap

cannot be pooled or wrongly fitted.

After inspection Bearing Caps are assembled and MB Studs tightened to 0.040” Elongation.

Cam and Crank Boring :

7) CNC Horizontal Boring Machine.-

Boring bars used for boring Cam bore and Crank bore

Note: Weight of Block at stage is 25.2T.

8) Hydraulic Test -Cylinder Block to check for leakages from welding , Liner seat etc. (110 psi for 30 min.)

Note : Engine Blocks are found to show signs of distortion after life of 12 to 15 years of service.

Reclamation of Engine Block is undertaken at DMW/Patiala.

Maximum possible misalignment permitted in Main Bearing Bore is :

(a) Horizontal Misalignment : Between 2 adjacent Bores : 0.002” Between 2 Non adjacent Bores : 0.004”

(b)Vertical Misalignment :

Between 3 adjacent Bores : 0.0015” Between 2 Non adjacent Bores : 0.003”

Note : * Above alignment of MB bores is checked with the help of Mandrel and Feeler Gauge.

* Optical Collimator is also used at DLW for checking above alignment.

LINER BORE – WITH SLEEVE

LinerLiner

Improved Design LinerImproved Design Liner

HONEY CHROME LINER

•Surface hardened with chrome layer.

•Layer thickness 6-8 thou.

•Surface hardened to 1000 VHN.

•Surface finish to 50-100 RMS

OPEN GRAIN LINER•Surface hardened with chrome layer.•Layer thickness 7.5-9.5 thou.•Surface hardened to 1000 VHN.•Surface hardened with chrome layer.•Low manufacturing cost.•Plating surface finish to 40-80RMS.•Advantages: Longer life, Lower LOC

LINER SLEEVELINER SLEEVE

Overhauling of Engine Block:-

1) Drain Engine and strip Block of all attaching parts, preparatory to its removal from Engine Base.

2) Remove two Nos. Block to Base dowels located at each end on right side of Engine.

3) Working through openings in Base, remove Cap screws and Lock washer between Block and Base.

4) Apply Lifting hooks to Eye Bolt at power take-off end and Lifting plate bolted to free end and lift Block from

Base.

Inspection of Block :

5) Clean and inspect Engine Block (by Magna flux process) for cracks , signs, leaks and other damages.

Removal of Cylinder Liner Sleeve: -

6) When inside diameter of sleeve exceeds maximum specified limit , Sleeve shall be replaced.

(Liner sleeve tool is required for removal of Liner Sleeve)

7) Hydrostatic Testing - 2.5kg/cm2 at normal temps.

1. 1. CHECKING MAIN BEARING BORES – OUT OF ROUNDNESS

MB Bore diameter :- Checked at planes A, B and C and D, E and F (½” from edge).

1. Diameter (New) : 9.0355 - 9.0370” Diameter (Worn) : 9.0350-9.0395”

Out-of-Roundness : 0.0035”

A

Bc

2. Taper : Check vertical taper between planes A and D and Taper at 45º from vertical between Planes B and F and C and E .

Vertical Plane : 0.001” 45º from Vertical : 0.003”

3. Horizontal Misalignment : Two adjacent Bores : 0.002” Two Non-adjacent Bores : 0.004”

4. Vertical Misalignment : Three Adjacent Bores : 0.0015”

Two non-adjacent Bores : 0.003”

*No compensation allowed for out-of-roundness ,taper

or difference in diameter.

5. Bore Camshaft Hauling Diameter (New) : 4.7500 – 4.7515” Condemning Diameter : 4.7525”

Checking Vertical and Horizontal Misalignment of Main Bearing Bores

LINER SLEEVE TOOL

–

OF CAMSHAFT BORE AND CYLINDER

LINER SEAT

Description : Engine Base is a welded steel structure ,Fabricated from

Steel (Specification IS:2062 with 0.2% Carbon).

– Lubricating Oil Pump (LOP)

– Water Pump (WP)

– 4 nos.Engine Mounting Pads

- Traction Generator Magnet Frame bottom Foundation bolt fitted on Main Base.

– Acts as a Lubricating oil reservoir (Sump)

ENGINE BASE

* Screens fitted across the Base at each Cylinder location. to prevent foreign matter.

– Accommodates Lube Oil Main Header

– Baffle Plates provided for strengthening structure and arresting splash of Lube Oil.

-Lub oil carried in Base below the Base Screen ,Sump capacity enhanced from 910 Liters to 1050/1270 Liters -Lub oil drain plug, -Bayonet Gauge (with high/low level markings) -Filler Pipe are located in the Base.

- Removable Door ,Openings on each side of Base gives access –

- Con. Rod bearings,

Crankshaft and Main Bearings

inspecting oil lines, piston skirts and Cylinder Liners..

–

CRANKCASE INSPECTION DOOR

Explosion doors mounted on right and left side of Base

at the Power take-off end.

CRANKCASE EXPLOSION DOOR

CRANKCASE EXPLOSION DOOR

CYLINDER HEADCYLINDER HEAD

251 Plus Cyl.hd251Cyl.hd

Piston & Connecting RodPiston & Connecting Rod

Steel cap PistonSteel cap PistonAluminum alloy Piston

Connecting Rod Assembly

Improved Piston Ring DesignImproved Piston Ring Design

Square, taper, taper, oil conformable and oil scraper configuration

Barrel taper, taper, oil scraper and oil conformable configuration.

Fuel efficient piston rings Advantages•Reduced piston / ring and liner wear •Reduced lube oil consumption. •Reduced fuel oil consumption.

1. Plasma filled top ring

2. 2nd Taper ring

3. 3rd Taper ring

4. 4&5 Oil conformable ring

CONVENTIONAL FE RING

A sealing compound is applied before fitting the block to Base

make the crank case air tight so that crank case vacuum

can be maintained.

2.while assembling ,block and base should be perfectly aligned within the limit(Gen end:0.000.Side ways:0.002 max.)

3. Apply and tighten several cap screws and lock washer between base& block.

Assembly of Engine Base &BlockAssembly of Engine Base &Block

–

THANK YOUTHANK YOU