engine base & block
TRANSCRIPT
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
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THANK YOUTHANK YOU