Vocational Training Project Report

VOCATIONAL TRAINING PROJECT REPORT

INDIAN RAILWAYS DIESE LOCOMOTIVE WORKS(DLW),VARANASI Submitted by: HARSHIT KUMAR

Vocational training project report

ACKNOWLEDGEMENT

First of all, I am grateful to Mr. S. P. Singh, Principal TTC, DLW , and Varanasi for providing me this opportunity by giving me permission to undergo practical training at this esteemed organization.

I would sincerely like to thank the employees and officers of DLW, VARANASI for their help and support during the vocational training. Despite their busy schedules, they took time out for us and explained to us the various aspects of the working of the plant, from the production shops.

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ACKNOWLEDGEMENT

First of all, I am grateful to Mr. S. P. Singh, Principal TTC, DLW , and Varanasi for providing me this opportunity by giving me permission to undergo practical training at this esteemed organization.

I would sincerely like to thank the employees and officers of DLW, VARANASI for their help and support during the vocational training. Despite their busy schedules, they took time out for us and explained to us the various aspects of the working of the plant, from the production shops.

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PREFACE

The objective of the practical training is to learn something about industries practically and to be familiar with the working style of a technical person to adjust simply according to the industrial environment. It is rightly rightly said practical life is is far away from from theoretical theoretical one. one. We learn in class room can give the practical exposure or real life experience no doubt they help in improving the personality personalit y o f the student, but the practical exposure in the field will help the student in long run o f life and will be able to implement the theoretical knowledge. I am student of final year, mechanical engg. and this report is written on the basis of practical knowledge acquired by me during the period of practical training taken at Diesel Locomotive Works, Varanasi .

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CONTENTS

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S PROFILE . .................................................................................................................... 0-13 DLW’ S

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HEAVY MACHINE HEAVY MACHINE SHOP SHOP . ................................................................................................... 14-20

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ROTOR SHOP . ...................................................................................................................... 21-32

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LOCO ASSEMBLY LOCO ASSEMBLY SHOP SHOP . .................................................................................................... 33-42

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PAINT SHOP PAINT SHOP . ........................................................................................................................ 43-56

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INNOVATIONS IN GLOBAL LOCOMO TIVES.…………………………………………………………..5 7 7

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VALUE ADDITION ………………………………………………………………………………………………5 ………………………………………………………………………………………………5 8

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A BEREIF OVERVIEW ABOUT DLW Diesel Locomotive Works (DLW), an ISO 9001, ISO 14001 & OHS 18001 Certified Organization, is a production unit under the ministry of railways. This was setup in collaboration with American Locomotive Company (ALCO), USA in 1961 and the first locomotive was rolled out in 1964 and dedicated to the nation. DLW is one of the few integrated loco builders in the world. It manufactures locomotives which are variants based on the original ALCO designs dating to 1960s and the GM EMD designs of the 1990s. This unit produces diesel-electric locomotives and DG sets for Indian railways and other customers in India and abroad.

Installed Production Capacity - 150 Locomotives/ year Total Staff

- 5936 (as on 01.06.09)

Total Production

- 5577locos, 53 DG Sets (up to June 2009)

Silent Features 

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A flagship production unit of Indian Railways offering complete range of products in its area of operation with annual turnover of over 2124 Crore. State of the art Design and Manufacturing facility to manufacture 200 locomotives per annum with wide range of related products viz. DG Sets, Loco components and subassemblies. Supply of spares required to maintain Diesel Locomotives and DG sets. Unbeatable trail-blazing track record in providing cost-effective, eco-friendly and reliable solutions to ever increasing transportation needs for over four decades. A large base of delighted customers among many countries viz. Myanmar, Sri Lanka, Malaysia, Vietnam, Bangladesh, Tanzania, Angola, to name a few, bearing testimony to product leadership in its category. Fully geared to meet specific transportation needs by putting Price - Value - Technology equation perfectly right.

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PRODUCTS Its manufacturing facilities are flexible in nature. These can be utilized for the manufacture of different design of locomotives of various gauges suiting customer requirements and other products. Specifications and details of current products:

::ALCO:: 1). BROAD GAUGE MAIN LINE FREIGHT LOCOMOTIVE: WDG 3A Diesel Electric main line, heavy duty goods service locomotive, with 16 cylinder ALCO engine and AC/DC traction with micro processor controls. Wheel Arrangement

Co-Co

Track Gauge

1676 mm

Weight

123 t

Length over Buffers

19132 mm

Wheel Diameter

1092 mm

Gear Ratio

18 : 74

Min radius of Curvature

117 m

Maximum Speed

105 Kmph

Diesel Engine

Type : 251 B,16 Cyl.V

HP

3100

Brake

IRAB-1

Loco

Air, Dynamic

Train

Air

Fuel Tank Capacity

6000 litres

2). BROAD GAUGE MAIN LINE MIXED SERVICE LOCOMOTIVE: WDM 3D Diesel Electric Locomotive with micro processor control suitable for main line mixedService train operation. Wheel Arrangement

Co-Co

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Track Gauge

1676 mm

Weight

117 t

Max. Axle Load

19.5 t

Length over Buffer 18650 mm Wheel Diameter

1092 mm

Gear Ratio

18 : 65

Maximum Speed

120 Kmph

Diesel Engine

Type : 251 B-16 Cyl. ‘V’ type (uprated)

HP

3300 HP (standard UIC condition)

Transmission

Electric AC / DC

Brake

IRAB-1 system

Loco

Air, Dynamic, Hand

Train

Air

Fuel Tank Capacity

5000 litres

::EMD:: 1). WDG4 - 4000 HP GOODS LOCOMOTIVE Broad Gauge freight traffic Co-Co diesel electric locomotive with 16 Cylinder 4000 HP engine, AC-AC transmission, microprocessor controlled propulsion and braking with high traction high speed cast steel trucks. First turned out in 1999 with transfer of technology from General Motor (USA), this locomotive has exceptional fuel efficiency and very low maintenance requirements. The heart of loco Traction Control Converter uses the GTO devices (obsolete technology). Now the IGBT devices, has been introduced from Oct 2006. It is the latest technology and will be cost effective and gives higher reliability. The locomotive power has been upgraded to 4500 BCV and the first Loco (Loco No 12114) was manufactured in May 07. Diesel engine: 

16 Cylinder 710 G3B, 2 stroke, turbocharged after cooled

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Fuel Efficient Engine

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Injection System Direct Unit Injector

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Governor: Woodward

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Compression Ratio- 16:1

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Lube Oil Sump Capacity: 950 Lts

Transmission: 

Electrical AC-AC

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6 Traction motor ( 3 in parallel per bogie)

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Suspension - Axle hung / taper roller bearing

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Gear Ratio - 90:17

2). WDP4 – 4000 HP PASSENGER LOCOMOTIVE State-of-Art, Microprocessor controlled AC-AC; Passenger Locomotive Powered with 16-710G3B 4000HP Turbo charged two strokes Engine. Fabricated rigid design under frame, two stage suspension, and High Traction High Speed 3 axle (HTSC) light weight cast truck frame attribute to high adhesionperformance. First turned out in 2003, this locomotive has exceptional fuel efficiency and very low maintenance requirements. It is specifically designed for heavy haul passenger traffic requirements for Indian Railways The WDP4 fleet is being upgraded by provision of hotel load feature along with power up gradation to 4500 HP. Diesel Engine 

16 Cylinder 710 G3B, 2 stroke, turbocharged after cooled

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Fuel Efficient Engine

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Injection System: Direct Unit Injector

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Governor: Woodward

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Compression Ratio- 16:1

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Lube Oil Sump Capacity: 1073 Lts.

Transmission 

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Electrical AC-AC 4 Traction motor ( 3 in parallel per bogie) Suspension: Axle hung / taper roller bearing Gear Ratio: 77:17

::DG SETS:: DLW manufactures DG sets using DLW built engines. These DG sets are suitable for standby as well as base load applications and are seismically qualified.

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Alternators used are the state-of-the-art brushless type with static AVR. Control system is PLC based, with fault diagnostic feature. The alarms and shut downs can be customized as per requirement. Engine

ALCO- 251

Power Rating

800 KW, 1500 KW, 1750 KW, 2000 KW, 2200 KW, 2400 KW.

Speed of engine

1000 rpm

Cooling arrangement

Radiator/ Heat exchanger

Control system

PLC based

Starting system

Air motor/ DC motor

Some other products that are manufactured according to demands of customer and are exported are: WDM 2

WDM 3A

WDP 1

WDG

2600 HP BG mixed traffic 3100 hp AC/DC BG Mixed Traffic 2300 hp BG Intercity Passenger (140 km/h) 3300 hp AC/ DC BG Freight

3C

YDM4

1350 hp MG Mixed Traffic

*Note: Nomenclature (Naming) of DLW Locomotives: D → Diesel Type W→ Wide (width of gauge) G→ Goods P→ Passenger M→ Multipurpose x→ Any numbers in the name represent the horsepower (hp=x×1000) A→ 100 hp B→ 200 hp C→ 300 hp ; and so on... Hence WDG-3A stands for Wide Diesel Goods- 3100 hp e ngine & WDP-4 represents Wide Diesel Passenger- 4000hp

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Organization DLW’S Vision: “ To be a World class manufacturer of Diesel Electric locomotive.”

Their Mission: “We shall achieve our vision through Continuous Improvement in the areas of Product Quality, Research and Development, Supplier Partnership, Human Resource Development and Team Work with emphasis on Core Competence Leading to Customer Satisfaction And Business Excellence.”

Quality Policy: “We are committed to Excellence in all Activities and Total Customer Satisfaction through Continuous Improvement in Quality of Products and services. ”

Manufacturing Process 

Block Division 

Flame Cutting of Components Steel plates are ultrasonically tested before being precision cut by numerically controlled flame cutting machines, Plasma Cutting Machine. Components are straightened and machined prior to fitting & tacking on fixture designed especially for engine block fabrication to ensure close tolerance on engine block.

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Fabrication of Engine Block Components after flame cutting and various machining operations are fit and tack welded before taking on rollovers. Heavy Argon-CO2 welding is done on these rollovers. High quality of welding is done by qualified welders. Weld joints are subjected to various tests like ultrasonic, X-rays, Visual etc. Down-hand welding is ensured using specially designed positioners. Fabrication of engine block is completed by submerged arc welding using semi-automatic welding machines. Special fixtures are used for making down-hand welding possible in inaccessible areas. Critical welds are subjected to radiographic

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examination. After complete welding weldment is stress relieved and marking is done for subsequent machining.

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Engine Division: 

COMPONENT MACHINING

Over 2000 components are manufactured in-house at DLW. These include ALCO turbo superchargers, lubricating oil pumps, cam shafts, cylinder heads, chrome plated cylinder liners, connecting rods and various gears. Our well-equipped Machine Shops have dedicated lines for operations like turning, milling, gear hobbling, drilling, grinding and planning etc. In addition, DLW is equipped with a variety of special purpose machines and a large number of state-of-theart CNC machines to ensure quality and precision. Associated manufacturing processes like heat treatment and induction hardening are also carried out in-house. A completely new Chrome Plating Shop for Cylinder Liners has been set up with modern infrastructure like fume extraction system and Programmable Logic Controlled material movement system.

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Engine Assembly & Testing Pre-inspected engine block, crankshaft, camshafts, cylinder liners, pistons, connecting rods, cylinder heads, exhaust manifold, turbo-supercharger and all related piping is used in assembly of engine. Electrical machines like traction alternator, auxiliary generator and exciter are thereafter coupled on the engine. The complete power pack with electrics are tested on Computerized Engine Test Beds to verify horsepower output. Vital parameters of engine are checked to assure the quality of product.

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Only after the engine parameters are found perfect the power packs are cleared for application on locomotives. 

Vehicle Division: 

Component Fabrication Precision cutting and forming of sheet metal is utilised for manufacture of superstructures including drivers cab, engine hoods, and compartments for housing electrical equipment. All activities connected with pipes like pickling, bending, cutting, forming and threading of pipes of various sizes are undertaken in another well-equipped work area. All electrical equipment is assembled in the fabricated control compartments and driver?s control stands is done in another work area.

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Under frame Fabrication Under-frames are fabricated with due care to ensure designed weld strength. Requisite camber to the underframe is provided during fabrication itself. Critical Welds areas are tested radio-graphically. Welder training and their technical competence are periodically reviewed. EMD under-frame is fabricated using heavy fixtures, positioners to ensure down hand welding. Fixtures are used to ensure proper fitting of components and quality welding in subsequent stages.

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BOGIE MANUFACTURING Special purpose machines are utilised for machining cast and fabricated bogie frames. Axle and wheel disc machining is undertaken on sophisticated CNC machines. Inner diameter of wheel discs are matched with the outer diameter of axles and assembled on wheel press. The complete truck (bogie), including bogie frames, wheels and axles, brake rigging and traction motors are assembled which is ready for application to locomotive.

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LOCOMOTIVE ASSEMBLY

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Tested engines are received from Engine Division. Similarly under-frames are received from Loco frame Shop and Assembled trucks from Truck Machine Shop. Superstructures and contractor compartments are received from respective manufacturing and assembly shops of Vehicle Division. Important alignments like crank shaft deflection; compressor alignment and Eddy Current clutch/radiator fan alignment are done during assembly stage. Electrical control equipments are fitted and control cable harnessing is undertaken. The complete locomotive is thus assembled before being sent onwards for final testing and painting. all locomotive systems are rigorous tested as per laid down test procedures before the locomotive is taken up for final painting and dispatch.

Recent Milestones and Future Plans 

Milestones achieved: 1. Transfer of Technology Agreement DLW entered in an agreement with General Motors of USA (now EMD) for technology of transfer to manufacture high horse-power 4000HP AC-AC GT46MAC and GT46PAC locomotives in India. 

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Only country outside North-America to have this leading edge technology.

2. Locomotive design projects

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WDG4 locomotive with IGBT base TCC (Siemens & EMD) turned out.

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Indigenous AC-AC control for WDG4 (with distributed power controls).

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Indigenous AC-AC control for WDP4 (with hotel load capability).

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WDP4 locomotive with IGBT base TCC & Hotel load capability.

Future Plans: 1. Assimilation of GM technology to manufacture their latest 710 series of diesel electric locomotives.

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2. To emerge as a globally competitive locomotive manufacturer. 3. To develop as an export hub for ALCO/ GM locos for Asian market. 4. To follow an export led growth strategy through continuous improvement. 5. Cost effectiveness and technology/ product up-gradation as a key to retain global competitiveness by putting price-value-technology equation right.

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HMS

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HEAVY M/C SHOP This shop carries out the machining of Cylinder Block (M.G. & B.G.) main bas e, saddler Main bearing caps, Splines, Turbo Super Charger, Lube Oil, Fuel Oil & Water header) com bearing housing.

OPERATIONS PERFORMED IN THE SHOP: 

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Tapping - A tap enters the workpiece axially and cuts internal threads into an existing hole. The existing hole is typically drilled by the required tap drill size that will accommodate the desired tap. The tap is selected based on the major diameter and pitch of the threaded hole. Threads may be cut to a specified depth inside the hole (bottom tap) or the complete depth of a through hole (through tap).

Drilling - A drill bit enters the workpiece axially and cuts a blind hole or a through hole with a diameter equal to that of the tool. A drill bit is a multi-point tool and typically has a pointed end. A twist drill is the most commonly used, but other types of drill bits, such as a center drill, spot drill, or tap drill can be used to start a hole that will be completed by another operation.

Boring - A boring tool enters the workpiece axially and cuts along an internal surface to form different features, such as steps, tapers, chamfers, and contours. The boring tool is a single-point cutting tool, which can be set to cut the desired diameter by using an adjustable boring head. Boring is commonly performed after drilling a hole in order to enlarge the diameter or obtain more precise dimensions.

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Milling – It is the process of machining flat, curved or irregular surfaces by feeding the workpiece against a rotating cutter containing a number of cutting edges. Milling is versatile for a basic machining process, but because the milling set up has so many degrees of freedom, milling is usually less accurate than turning or grinding unless especially rigid fixturing is implemented.

Honing: Honing is an abrasive machining process that produces a precision surface on a metal workpiece by scrubbing an abrasive stone against it along a controlled path. Honing is primarily used to improve the geometric form of a surface, but may also improve the surface texture. Typical applications are the finishing of cylinders for internal combustion engines, air bearing spindles and gears. Types of hone are many and various but all consist of one or more abrasive stones that are held under pressure against the surface they are working on.

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Grinding: Grinding is a finishing process used to improve surface finish, abrade hard materials, and tighten the tolerance on flat and cylindrical surfaces by removing a small amount of material. In grinding, an abrasive material rubs against the metal part and removes tiny pieces of material. The abrasive material is typically on the surface of a wheel or belt and abrades material in a way similar to sanding. On a microscopic scale, the chip formation in grinding is the same as that found in other machining processes. The abrasive action of grinding generates excessive heat so that flooding of the cutting area with fluid is necessary.

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TYPES OF MACHINE PROVIDED IN THE SHOP 

RADIAL ARM DRILL PRESS The radial arm drill press is the hole-producing work horse of the machine shop. The press is commonly refered to as a radial drill press. The radial arm drill press allows the operator to position the spindle directly over the workpiece rather than move the workpiece to the tool. The design of the radial drill press gives it a great deal of versatility, especially on parts too large to position easily. Radial drills offer power feed on the spindle, as well as an automatic mechanism to raise or lower the radial arm. The wheel head, which is located on the radial arm, can also be traversed along the arm, giving the machine added ease of use as well as versatility. Radial arm drill presses can be equipped with a trunion table or tilting table. This gives the operator the ability to drill intersecting or angular holes in one setup.

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Angular Boring Machine Angular boring "V" boring is done of special purpose machine. This special purpose machine has two high precision angular boring bars. The cutting inserts are arranged on boring bars to achieve evenly distributed cutting load during boring operation. This contributes to accuracy while machining. Boring bars are mounted on high precision bearings which provide control on size during angular boring. The machine is capable of boring and drilling to different sizes.

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Portal Milling Machine Engine block machining is done on Portal Milling Machine which is a 5 axis CNC machine with SIEMENs 840-D state of art system control with dedicated tool management system. This machine performs milling, drilling, tapping and boring operations in single setting. The machine accuracy of 10 micron enables adhering to the tolerance required on engine block.

Other machines besides these are: –

Tracer Planner machine.

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Hill Acme koing structural milling machine.

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Double Housing planned machine (32´, 24’, & 16’ ).

TOOLS Used:1. O.K. Tool (Rough & Finis h) 2. C.C. Milling cutter (4´, 9´, & 10´) 3. Boring Tipped Tool (Rough & Finish) 4. Serration Cutter. 5. Honing Stone (For hand honing). 6. Drill, Reamer, Tap (Various Seizer).

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CUTTING TOOL MATERIALS USED

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HIGH CARBON STEELS High Carbon (H.C.) steels (1.16 – 1.30% Carbon) are of little practical use in modern manufacturing processes. At room temperature, the hardness of H.C. Steel compares favorably with Cast Cobalt Alloy and High Speed Ste el, in the region of 55 – 60 H.R.C During the metal cutting process however tool temperature increases dramatically. The hardness value of H.C. Steel falls rapidly with increasing temperature; consequently only very slow cutting speeds can be employed when using H.C. Steel to prevent rapid dulling of the tool.

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HIGH SPEED STEELS High Speed Steels (H.S.S.) were developed in the early 20 th century F.W. Taylor and R. White discovered that alloying elements such as Tungsten, Chromium and Vanadium with H.C. steel and subjecting the resulting alloy to a special heat-treatment resulted in a Tool Steel that retained hardness at temperatures up to 600 o C – a property known as hot hardness. Use of this Alloyed Steel for tools allowed much higher cutting speeds than those for H.C. Steels – hence the name High Speed Steel. Drill bits are generally of this material.

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CAST COBALT ALLOY (STELLITE) Developed independently to H.S.S., Cast Cobalt Alloys do not use Steel; typically they are composed of 38 to 53% Cobalt, 30 to 33% Chromium and 10 to 20% Tungsten. Cast Cobalt Alloys or Stellite tools have good hardness (58 to 64 H.R. C.) but are not as tough as H.S.S. They are suitable for rapid stock removal at elevated temperatures and cutting speeds but are sensitive to impact and shock.

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CARBIDES All the tool materials described so far are still limited in their hot hardness, wear resistance and strength. In 1930s Germany a tool material was developed that combined good hot hardness and thermal conductivity and low thermal expansion. Known as Carbides they are produced by a powder metallurgy process, cementing the Carbide particles with a matrix of other metallic powders. The resulting solid is then sintered (pressed together at high temperatures and pressures). At this stage various shapes of tool can be produced prior to final grinding. Tungsten Carbide (W.C.) uses Cobalt particles as the matrix. The proportion of W.C. to Cobalt affects the property of the finished tool; more Cobalt gives less hardness and wear resistance but greater toughness – more (W.C.) reduces toughness but increases wear resistance.

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Titanium Carbide (TiC) has greater hardness but less toughness than W.C. It is suitable for machining hard materials and higher cutting speeds when a N ickel-Molybdenum Alloy is used as a matrix. 

CERAMICS Ceramic tools are made by cold pressing very pure powders of Aluminum Oxide and Titanium Oxide into the required shape and then sintering, in a manner similar to Carbide tools. Ceramic tools are chemically inert, have excellent hot hardness and wear resistance but are very brittle.

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ROTOR SHOP

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ROTOR SHOP

This shop deals with the manufacturing of Turbocharger. Turbocharger is known as the Heart of Diesel Loco motive. Basically in this Section manufacturing, assembly & sub assembly of Turbocharger is done. But the outer casing of Turbocharger is manufactured in Heavy Machine Shop. Turbocharger is use for the providing fresh air to the engine. Due to this the efficiency & power generated by engine is increased. For t he running of Turbocharger we are not using any extra energy source like generator, motor etc. For starting of Turbocharger generally we use exhaust gasses.

Components of Turbocharger:-For assembly of Turbojet following parts are manufactured in Rotor Shop---1. Impeller 2. Inducer 3. Nose piece 4. Stud Rotor 5. Nut 6. Washer 7. Thrust Washer 8. Key 9. Oil Slinger 10. Turbine Disc 11. Turbo Shaft 12. Lock plate

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Assembly of Turbocharger:-The assembly of turbocharger is done by dividing whole turbocharger in three parts. These are as follows---1. Rotor 2. Compressor 3. Casing

1. Rotor:-- Rotor is the inlet part of turbocharger which is comprises with following parts. Turbo Disc, Rotor stud, Turbo shaft, thrust collar, Nose disc, Washer & Nut. Rotor is rotating at speed of 1 8000 rpm & working at high temperature due to that the rotor is made of steel. 2. Compressor: -- Compressor is the combination of impeller & inducer. Impeller is made up of Al alloy. Impeller & inducer is use for sucking of fresh air from environment. 3. Casing: -- Casing is made of M.S. & also a special type of coating is done. Due to that coating it can easily resist the heat. For the proper working & life of Turbocharger balancing of impeller, inducer & turbine disc is done by help o f Dynamics Balancing Machine.

DESCRIPTION The turbocharger assembly, Figure 1, is primarily used to increase engine horsepower and provide better fuel economy through the utilization of exhaust gases. As shown in cross-section, Figure 3 and Figure 4, the turbocharger has a single stage turbine with a connecting gear train. The connecting gear train is necessary for engine starting, light load operation, and rapid acceleration. Under these conditions there is insufficient exhaust heat energy to drive the turbine fast enough to supply the necessary air for combustion, and the engine is actually driving the turbocharger through the gear train assisted by exhaust gas energy. When the engine approaches full load, the heat energy in the exhaust, which reaches temperatures approaching 538 C (1000 F) is sufficient to drive the turbocharger without any help from the engine. At this point, an overrunning clutch in the drive train disengages and the turbocharger drive is mechanically disconnected from the engine gear train.

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Figure 1. Typical Turbocharger Assembly

On turbochargers for 8-cyl. engine, the turbine shaft is driven by the engine gear train through a series of gears in the turbocharger. A turbocharger drive gear, which is a part of the spring drive gear assembly, meshes with the turbocharger idler gear, driving the carrier drive gear. The carrier shaft drives the sun gear on the turbine shaft through three planet gears when the turbocharger is being driven by the engine. The sun gear meshes with the planet gears which, in turn, mesh with a ring gear in the overrunning clutch assembly. The ring gear is fixed, when the engine is driving the turbine, because the direction of torque at the ring gear locks the overrunning clutch. When the turbine is being driven entirely by exhaust gas energy, the direction of torque is reversed and the clutch overruns, allowing the ring gear to rotate. The overrunning clutch consists of 12 rollers in tapered slots. The slots are formed by the combination of a stationary clutch support and the pockets in the cam plate. The cam plate, ring gear support, and the ring gear are doweled and bolted together, and rotate as a unit. When the engine is driving the turbine, the rollers are wedged in the small side of the cam plate pockets, as a result of the direction of torque, locking the cam plate to the stationary clutch support. This locking action prevents the ring gear from turning. Because the planet gear shafts are driven as a part of the carrier shaft, the planet gears rotate in the locked ring gear to drive the sun gear on the turbine shaft. When the exhaust energy becomes great enough to drive the turbine without help from the engine, the torque at the sun gear, planet gears, and ring gear reverses direction. This causes the rollers to move to the wide end of the cam plate pocket, unlocking the clutch, permitting it to overrun, and allowing the ring gear to rotate. From this point on, with increased load and speed, the turbocharger overruns the engine drive and the planet gears slowly turn the ring gear.

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On turbochargers for 12, 16 and 20-cyl. engine, the turbine shaft is driven by the engine gear train through a series of gears in the turbocharger. A turbocharger drive gear, which is a part of the clutch drive gear assembly, meshes with the turbocharger idler gear, driving the carrier drive gear. The carrier shaft drives the sun gear on the turbine shaft through three planet gears when the turbocharger is being driven by the engine. The sun gear meshes with the planet gears which, in turn, mesh with a fixed ring gear in the carrier shaft support assembly. When the turbine is being driven entirely by exhaust energy, the direction of torque transmitted back through the gears in the turbocharger unlocks the overrunning clutch. The overrunning clutch consists of 16 rollers in tapered slots. The slots are formed by the combination of a clutch drive support and the pockets in a cam plate. The cam plate, a clutch support, and a cam plate retainer are doweled and bolted together, and rotate as a unit. The unit in turn bolts to the turbocharger drive gear. The clutch drive support is bolted to the No. 2 idler gear. When the engine is driving the turbine, the rollers are wedged in the small side of the cam plate pockets, as a result of the direction of torque, locking the cam plate to the clutch drive support (turbocharger drive gear to the No. 2 idler gear). Because the planet gear shafts are driven as a part of the carrier shaft, the planet gears rotate in the fixed ring gear to drive the sun gear on the turbine shaft. When the exhaust energy becomes great enough to drive the turbine without help from the engine, the torque back through the turbocharger gears reverses direction. This causes the rollers to move to the wide end of the cam plate pocket, unlocking the clutch, permitting it to overrun. From this point on, with increased load and speed, the turbocharger overruns the engine drive.

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FIGURE 3

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FIGURE 4

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MANUFACTURING: Different parts of turbocharger are machined through Lathe machine in this shop. Machining is a term used to describe a variety of material removal processes in which a cutting tool removes unwanted material from a work piece to produce the desired shape. The work piece is typically cut from a larger piece of stock, which is available in a variety of standard shapes, such as flat sheets, solid bars, hollow tubes, and shaped beams. Machining can also be performed on an existing part, such as a casting or forging. A typical lathe machine is shown below:

LATHE MACHINE

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Bed - The bed of the turning machine is simply a large base that sits on the ground or a table and supports the other components of the machine.

Headstock assembly - The headstock assembly is the front section of the machine that is attached to the bed. This assembly contains the motor and drive system which powers the spindle. The spindle supports and rotates the workpiece, which is secured in a workpiece holder or fixture, such as a chuck or collet.

Tailstock assembly - The tailstock assembly is the rear s ection of the machine that is attached to the bed. The purpose of this assembly is to support the other end of the workpiece and allow it to rotate, as it's driven by the spindle. For some turning operations, the workpiece is not supported by the tailstock so that material can be removed from the end.

Carriage - The carriage is a platform that slides alongside the workpiece, allowing the cutting tool to cut away material as it moves. The carriage rests on tracks that lay on the bed, called "ways", and is advanced by a lead screw powered by a motor or hand wheel.

Cross slide - The cross slide is attached to the top of the carriage and allows the tool to move towards or away from the workpiece, changing the depth of cut. As with the carriage, the cross slide is powered by a motor or hand wheel.

Compound - The compound is attached on top of the cross slide and supports the cutting tool. The cutting tool is secured in a tool post which is fixed to the compound. The compound can rotate to alter the angle of the cutting tool relative to the workpiece.

Turret - Some machines include a turret, which can hold multiple cutting tools and rotates the required tool into position to cut the workpiece. The turret also moves

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along the workpiece, feeding the cutting tool into the material. While most cutting tools are stationary in the turret, live tooling can also be used. Live tooling refers to powered tools, such as mills, drills, reamers, and taps, which rotate and cut the workpiece.

COMMON OPERATIONS PERFORMED IN THIS SHOP 1.) EXTERNAL OPERATIONS 

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Turning - A single-point turning tool moves axially, along the side of the workpiece, removing material to form different features, including steps, tapers, chamfers, and contours. These features are typically machined at a small radial depth of cut and multiple passes are made until the end diameter is reached.

Facing - A single-point turning tool moves radially, along the end of the workpiece, removing a thin layer of material to provide a smooth flat surface. The depth of the face, typically very small, may be machined in a single pass or may be reached by machining at a smaller axial depth of cut and making multiple passes. Grooving - A single-point turning tool moves radially, into the side of the workpiece, cutting a groove equal in width to the cutting tool. Multiple cuts can be made to form grooves larger than the tool width and special form tools can be used to create grooves of varying geometries.

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Cut-off (parting) - Similar to grooving, a singlepoint cut-off tool moves radially, into the side of the workpiece, and continues until the center or inner diameter of the workpiece is reached, thus parting or cutting off a section of the workpiece.

2.) INTERNAL OPERATIONS 



Drilling - A drill enters the workpiece axially through the end and cuts a hole with a diameter equal to that of the tool.

Boring - A boring tool enters the workpiece axially and cuts along an internal surface to form different features, such as steps, tapers, chamfers, and contours. The boring tool is a single-point cutting tool, which can be set to cut the desired diameter by using an adjustable boring head. Boring is commonly performed after drilling a hole in order to enlarge the diameter or obtain more precise dimensions.

MULTI SPINDLE VERTICAL TURRET LATHE Turret lathes are mostly horizont al axis single spindle type. The multiple spindle vertical turret lathes are characterized by : • Suitably used for large lot or mass production of jobs of generally;

Δ chucking type Δ relatively large size Δ requiring limited number of machining operations •

Machine axis – vertical for

Δ lesser floor space occupied Δ easy loading and unloading of blanks and finished jobs Δ relieving the sp indle s of ben ding lo ads d ue to jo b weig ht

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•

Number of spindle – four to eight

Fig. 5 visualize the basic configuration of multiple spindle vertical turret Lathes which are comprised m a i n l y of a large disc type spindle carrier and a tool holding vertical ram as shown. .

dle automat

Fig. 5

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LOCO ASSEMBLY SHOP

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PROCESS OF LOCO ASSEMBLY SHOP FRAME MARKING

COLOUR MATCHING

FRAME BEARING OF LOADING PAD POSITION

ENGINE SETTING ON FRAME PROVIDED LEVELLING PEACES OF HIGH CARBON STEEL BETWEEN ENGINE LOADING PAD AND ENGINE MOUNTING PAD ON FRAME

BOLTING OF ENGINE MOUNTING PAD WITH UNDER FRAME AT TORQUE OF 500 POUND.

COUPLING OF ENGINE SHAFT AFTER HEATING AT 110°F (SOAKING PERIOD 4 HRS.).

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SETTING OF HUB BEARING ON ENGINE CRACK SHAFT END.

COMPRESSOR BASE SETTING.

FITMENT OF COUPLING ON COMPRESOR SHAFT AT 110 °F.

COMPRESSOR SETTING.

ENGINE TO COMPRESSOR ALIGNMENT AND DRILL DWELLING.

COMPRESSOR CENTER LINE LOWER THAN CENTER LINE OF ENGINE SHAFT (15 THAU TO 2 THAU TOLARANCE ALLOWED)

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ANGULARITY NOT MORE THAN 6 THAU.

RADIATORS COMPARTMENT SETTING.

ECC SETTING

ECC TO COMPRESSOR ALIGNMENT

CHECK RUNOUT BY DIAL GAUGE (6 THOU MAXIMUM)

RADIATOR FAN SETTING.

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GAP BETWEEN BLADE AND RADIATOR COMPARTMENT MAINTAINED AT MIN. ¼ INCH AT ANY PLACE AND TOTAL GAP OF BOTH ENDS AT 180 ° NOT MORE THAN 1.18 INCH.

LONG HOOD PRIMARY SETTING

SHORT HOOD SETTING

AFTER ABOVE OPERATIONS

FTMB SETTING

RTMB SETTING

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COMPRESSOR PIPING

LUBE OIL COOLER, LUBE OIL FILTER SETTING AND PIPING

LONG HOOD FINAL SETTING

RADIATOR SETTING

ENGING COOLING PIPING AND CYCLONIC FILTER ASSEMBLY

CAB FININSHING WORK

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LOWERING ON BOGIES (WHEEL UP)

DISPATCH TO LOCO TESTING SHOP FOR FINAL TESTING.

•

PARALLEL TO THIS ABOVE WORK, FOLLOWING WORK HAS ALSO DONE –

CAB HOOD SETTING

–

BRAKE RAKE SETTING

–

CAB HOOD PIPING

–

CAB SETTING

–

CONTROL PANEL SETTING

–

AIR BRAKE PANEL PIPING

–

AIR BRAKE TESTING

–

LEAKAGE TEST BY SOAP SOLUTION

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PAINT SHOP

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PAINT SHOP Paint is defined as a pigmented liquid, which when applied on to a surface as a thin layer, forms a dry adherent film after a time.

Paint Components: The three main components of an (organic) paint coating are: 1. Pigment - Provides opacity, colour (also can provide corrosion resistance, water barrier properties, viscosity control, etc.); primer coatings are s ometimes named after a pigment, for example zinc-rich primer. 2. Binder (resin) - Binds the ingredients (holds everything together), forms the film; also known as the non-volatile vehicle; paint coatings are often named after the resin, for example epoxy, vinyl, polyurethane, acrylic, etc. 3. Volatile vehicle (solvent or dispersant) - Dissolves or disperses the binder, allows the coating to spread out. A distinction can be made between a non-convertible coating (cures by evaporation of the solvent without a chemical change to the resin) and a convertible coating (cures by a chemical change in the resin, polymerization).

Paint System: The sum of all coats of paint on a work is called paint system . A Paint System generally comprises of: –

Primer

–

Putty

–

Under coat

–

Top coat

Basically the type of Vehicle or Binder characterizes the Paint System. •

PRIMER - A primer is a preparatory coating put on materials before painting, i.e. first layer on the bare steel surface. Metal hydroxides/oxides do not provide a solid surface for the paint to adhere to, and paint will come off in large flakes. Using a primer will provide extra

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insurance against such a scenario. An additional reason for using a primer on metal could be the poor condition of the surface. Purpose:

•

•

•

•

Provide corrosion protection.

•

To wet the surface of the substrate.

•

Provide adhesion between substrate & putty/surfacer/undercoat.

•

Contains mainly Zinc Phosphate or Red Lead in suitable vehicle.

PUTTY - A dough like material applied on primer. It is typically a linseed oil based product, done to level up the surface imperfections like dents, undulations etc up to 10mm deep. It should have good compatibility with primer & undercoats. It is applied by knife of about 30 cm width. UNDERCOAT/ SURFACERS – It is an intermediate coating applied over primed/putty applied surface. The material shall have good compatibility with putty, Zinc phosphate primer & finishing coats. Purpose of applying it are as follows: •

To improve adhesion & impact strength between primer & top coats.

•

To protect the primer and enable it to retain its inhibiting effect on the metal.

•

Gives a smooth, uniform & non-absorbent base for top coat.

TOP COAT - The final coating is described as the top or finish coat enamel. Normally one or two coats are required for DFT. Purpose : •

Principally weather resistant.

•

Protects the metal against environment.

•

Destructive UV light.

•

Ingress of air & moisture.

•

Attack from chemicals and corrosive fumes.

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Paint System in IR –

Water base

–

Oil base

–

Acrylic base

–

Alkyd base

–

PU base

–

Epoxy base

ALKYD PAINT - A single pack system based on oleo resin & synthetic resin (phthalic anhydride). MERITS 1.

Good resistance to weathering

2.

Stability to sun light

3.

Good resistance to water & alkali.

DEMERITS 1.

Low durability

2.

Poor gloss retention

3.

Frequent repainting

4.

Not suitable for immersion service

EPOXY PAINT - Epoxy is a two pack system containing epoxide synthetic resin & amine as hardener. MERITS -

1.

It is non-toxic.

2.

Good flexibility.

3.

Epoxy resins are abundantly available in our country.

4.

Excellent adhesion property.

5.

Good resistance to water, moisture & organic solvents.

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6.

Excellent color & gloss retention.

7.

Easy application.

8.

Excellent chemical, abrasion & corrosion resistance.

DEMERITS 1.

High initial cost.

2.

Low pot life.

3.

High consumption of costly thinner.

4.

Not suitable for water immersion service.

EPOXY-PU PAINT - Polyurethane is also a two pack system consisting of aliphatic hexamethale isocyanate and polyol. MERITS 1. Better durability. 2. Better abrasion resistance. 3. Better gloss retention. 4. Better UV resistance. 5. Excellent resistance to water and many chemicals. DEMERITS 1. Poor adhesion to steel surfaces. 2. Very toxic. 3. Poor pot life. 4. High surface finish is required.

APPLICATION OF PAINT Application of paint is done mainly by•

BRUSHING

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•

SPRAYING

•

DIPPING

RIGHT TOOLS FOR PAINT APPLICATION The most appropriate and effective ways are: AIR SPRAY GUN •

•

•

Paint must be non sticky when thinned to spraying viscosity so that it will easily break into droplets It must be stable when thinned to a viscosity low enough for spraying. Must contain a solvent which is volatile enough to evaporate before the paint reaches the surface.

AIRLESS SPRAY •

•

•

The paint is atomized by high pressure pumping rather than being broken up by large volume of air mixed with it. The paint must have the following propertiesThe paint can be sprayed at higher solids & higher viscosity, a thicker film being applied for each pass of the spray gun. The solvent blend need not evaporate so quickly because there is less solvent in the paint at application viscosity.

GENERAL REQUIREMENT OF A GOOD PAINTING ATMOSPHERIC CONDITION 

Atmosphere should be free from dirt.



Pressure of spray shop should be slightly higher than atmospheric pressure.



Temperature of the surface should be above the dew point of the air.



Weather should be dry & fairly warm.

SURFACE CONDITION 

The surface should be free from oil, grease, dirt, visible mill scale, rust, paint and any other deposits.

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



The surface should be slightly roughened to form a suitable anchor pattern for coatings. The surfaces to be painted must be carefully cleaned

PAINT CONDITION 

Careful staring of the paint before use.



Paint to be correctly thinned.



Paint to be applied quickly but evenly.





Thorough stirring of the paint before application, taking special care to incorporate any pigment which has settled at the bottom of the can. Paint & the article to be sprayed are at least room temperature.

SPRAY GUN CONDITION 

The gun should always be pointed at right angle to the object.



The gun should be stroked at approx. 6 to 10 inches from the surface being sprayed.



The operator should release the trigger of the gun at the end of each stroke.



The spray gun should not be moved rapidly.

FAILURE OF PAINT The main reasons of paint failure after application on surface are the applicator and improper treatment of surface. While there have been cases of paint also, but they are but rare. Application Defects can be attributed to: 





Dilution - This usually occurs when the dilution of the paint is not done as per manufacturer’s recommendation. There can be a case of over dilution and under dilution, as well as dilution with the incorrect diluents. Contamination - Foreign contaminants added without the manufacturers consent which results in various film defects. Peeling/Blistering - Most commonly due to improper surface treatment before application and inherent moisture/dampness being present in the substrate.

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







Chalking - Chalking is the progressive powdering of the paint film on the painted surface. The primary reason for the problem is polymer degradation of the paint matrix caused by attack by UV radiation in sunshine. Cracking - Cracking of paint film is due to the unequal expansion or contraction of paint coats. It usually happens when the coats of the paint are not allowed to cure/dry completely before the next coat is applied. Erosion - Erosion is very quick chalking. It occurs due to external agents like air, water etc. Blistering - Blistering is due to improper surface exposure of paint to strong sunshine

LOCO PAINT PROCESS Loco Cleaning by Compressed Air

Erasing by Thinner.

Then cleaning by Compressed Air.

Again cutting by 150 No. PSA Gold Paper

Then cleaning by Compressed Air

Tacking by TAC Cloth

Then out side Masking & inside Masking, Truck Masking Page 50


Mixing of Primer

Filtered by Malmal.

Then spray on Loco by Spray Machine

Deposited on surface 25-35 μ

Interior area H.R.(Heat Resistant) gray painting

Drying of Primer painted Loco at Ambient Temperature

Cutting of Primer by 150 PSA Gold paper

Cleaning by Compressed Air

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Mixing of Under Coat

Filtered by Malmal

Spray on Loco by Spray Machine

Deposited on surface 25-35 μ

Drying Under Coat at ambient temperature

Cutting of under coat by 240 PSA Gold cutting paper

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Mixing of Paint according to different colors scheme of different types of Loco

Spray on Loco surface by spray machine.

Drying of Painting

Demasking.

Touch up work

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BEFORE PRIMER

AFTER PRIMER

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AFTER UNDERCOAT

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AFTER COMPLETE PAINTING COLOR COADING FOR PIPE (LOCO) 1. Water Pipe

:

C Green Finishing

2. Air Pipe

:

White Finishing

3. Drainage Pipe

:

Black Finishing

4. Vacuum Pipe Finishing

:

French Blue

5. Conduit Pipe

:

Light Orange Finishing

6. Fuel Oil Pipe

:

Light Brown Finishing

7. Lube Oil Pipe

:

Dark Brown Finishing

8. Fire

:

Signal Red Finishing

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INNOVATIONS IN GLOBAL LOCOMOTIVES Why diesel-electric locos? Diesel is a non renewable source of energy and can’t be replenished once finished. So why not go for electric locomotives, which pick up electrical power from an overhead wire or a third rail laid beside the track? When I asked this question from my project guide, he simply answered that the cost of electric transmission lines is huge and also The first cost of an electric locomotive is far greater than a diesel locomotive. Hence even at those places where transmission lines have been la id, diesel-electric locos are still used!

Recent trends Recent innovations in technology have been driven by a desire to find safer, faster, and more reliable means of getting from place to place. For passenger transportation, speed and convenience are primary goals. For freight transportation, speed, reliability, and efficiency, or carrying more cargo for less money and arriving on time, have been the motivating factors. The diesel-electric locomotives cannot go on indefinitely and there is need to look for smarter methods in locomotive transport sector. Most modern transportation systems rely on petroleum for energy, but this source of energy is finite and creates serious environmental effects when used in the internal-combustion engine. Research into alternative fuel sources, such as electrical storage, natural gas, methanol, ethanol, fuel cells, and solar energy, will continue in order to ensure a reliable supply of energy for the transportation systems of the world. Several new forms of propulsion are also being investigated. Several technologies that are shaping society in a variety of ways will likely characterize the future of locomotive transportation. Intelligent transportation systems apply the latest advances in computers and electronics to better control vehicle operations. Computerized road maps used with the Global Positioning System (GPS) help drivers to navigate. Research is also being conducted into improving the materials used for constructing the locomotives. Composite material, which is a hybrid consisting of many different component materials, can provide lightweight, extremely strong, and highly durable material for loco construction. With the lighter weight, locos can become more fuel efficient. Explained on the following page is the working of a magnetically levitated locomotive that very surely is the technology of the future!

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Vocational Training Project Report

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