traction machine shed knapur

pg. 1 INDIAN RAILWAYS

HISTORICAL BACKGROUND OF INDIAN RAILWAYS

Railways made their first appearance in India in April 1953, when a section from Bombay to Kalyan

(32 miles) was opened to traffic. This was followed by Calcutta-Raniganj (120 miles) and Madras-

Arkonam line (39 miles). The management of Railways was left to private companies who used to run

this system in different territories on 99 years lease bases. There was however a clause in the lease

deed, which could enable government to purchase the line after every 25 years.

As railway system consisting of broad, meter and narrow gauges, grew in size haphazardly owing to

historical reasons, so also grew the public demand for its nationalization of the whole railway system.

On the favorable recommendations of this committee railways were gradually taken up by central

government.


This process started in 1925 took full 25 years to complete when railways were reorganized and

renamed on zonal basis up to mid. 30’s electric traction existed in India at two places namely Bombay

and Madras with total of 398 route kilometers and employing 500 V D. C. overhead supply system.

After the partition of India and with the launching of 5 years plan, it became necessary to electrify

more and more routes.

It was also in the beginning of 50’s that French National Railways published a report on the

potentialities of A.C. traction system employing 25 kv, 50HZ A.C. supply the railway board rightly

took a decision in 1957 to adopt 25 kv, 50 HZ A.C. supply for all future railways electrification. As a

result of this momentous decision, not only all the subsequent and Howrah regions was subsequently

converted to 25 kv, 50 HZ A.C. systems.

Now the electrification has become a regular program of Indian Railways and it is contemplated to

electrify trunk routes interlinking metropolitan cities of Calcutta, Delhi, Mumbai & Chennai.


INTRODUCTION

GENERAL:-

NAME: TRACTION MACHINE SHED

ADDRESS: TRACTION MACHINE SHED, KANPUR

RAILWAY STATION: KANPUR

BACKGROUND:-

1. The traction machine shed was established in year 1973 as a unit of Electric Loco Shed, Kanpur and

later on 18/01/74, it was made independent unit.

2. This shed was commissioned primarily to meet the imperative maintenance needs of electric loco motors. At present the scope of work includes following:-

a. Reclamation/rewinding of armature and stator of traction motor and other auxiliary machines of electric locos & EMU for various sheds of Indian Railways, rewinding of loco auxiliary

machines and other general power electrical machines of Northern Railways, India. b. Reclamation and repair of SL’S of Northern Railways. c. Reshafting of armatures and associated activities.

d. Stator coil manufacturing for TAO and HITACHI traction motors.


BRIEF DESCRIPTION OF ACTIVITIES OF DIFFERENT SECTIONS

1. AUXILIARY SECTION:

The unloading of machines as per instruction of PPO in the presence of testing section.

The record of auxiliary is done in the unloading register.

The decision by testing section along with the details and the work required to be done

by testing section.

The auxiliary those involve the auxiliary reported can be of two types, i.e. rewinding

and other mechanical repair.

2. TESTING:

Investigation of T.M. Armatures, Auxiliary Machines and other machines.

Testing of T.M. Armatures, Stators, Auxiliary machines and other products.

Recording of details of investigation and testing.

Issue of job cards for all machines going for under repair.

3. GENERAL-3 SECTION:

Maintaining the shed and providing several services like carpentry and preparation of

display boards etc.

4. MILL WRIGHT SECTION:

Mechanical repair ( head changing and reshafting ) of Armatures.

Shaft machining of Armatures and commutator turning.

Crane operation, welding work and wagon movement.

5. ARMATURE SECTION:

Rewinding of TAO-659. Hitachi & EMU TM armature.

Minor of TAO-659. Hitachi & EMU TM armature.


6. STATOR SECTION:

To undertake major / minor repairs of Traction Motor stators as per the job card issued by

testing section.

To dispatch the repaired stator duly tested and passed by testing section.

To undertake work of manufacturing of field coils of TM stators.

7. COIL SECTION:

To arrange and ensure manufacturing of coils for TAO- 659, EMU & Hitachi armatures.


TIG (TUNGSTON INERT GAS) WELDING MACHINE

INTRODUCTION:

Tungsten Inert Gas Welding process; commonly termed as Argon Arc Welding process; is ideally

suitable for Arc Welding of most grades of Carbon and Alloy Steel, Stainless Steel, Aluminium

and it’s Alloys, Copper, Brass, Bronze and also high temperature and hard surfacing Alloys.

PRINCIPLE:

An arc is generated b/ w two conductors of electricity, cathode and anode (considering direct current,

DC ), when they are touched to establish the flow of current and then separated by a small distance.

An arc is a sustained electric discharge through the ionized gas column called plasma b/ w the two

electrodes.

Similarly welding can be done with an arc of the alternating current (AC ), with the main difference

that the cathode and anode would change continuously and as a result, the temperature across the arc

would be more uniform compared to a DC arc.

NEED OF INERT GAS:

The Endeavour of the welder is always to obtain a joint which is as strong as the base metal and at

the same time, the joint is as homogeneous as possible. To this end, the complete exclusion of oxygen

and other gases which interfere with the weld pool to the detriment of the weld quality is very

essential. In manual metal arc welding, the use of stick electrodes does this job to some extent but

not fully. In inert gas shielded arc weldind processes, a high pressure inert gas flowing around the

electrode while welding would physically displace all the atmospheric gases around the weld metal

to fully protect it.


ELECTRODE USED IN TIG WELDING:

TIG Welding or gas tungsten arc welding ( GTAW ) is an inert gas shielded arc welding process

using non – consumable electrode. The electrode may also contain 1 to 2% thoria (thorium oxide

) mixed along with the core tungsten or tungsten with 0.15 to 0.40% Zirconia ( Zirconium oxide

). The pure tungsten electrodes are less expensive but will carry less current. The thoriated tungsten

electrodes carry high currents and are more desirable because they can strike and maintain a stable

arc with relative ease.

DESCRIPTION OF THE EQUIPMENTS:

The TIG Welding system consist of followings:

High Frequency Unit,

Welding Torch,

Gas Regulator cum Flow Meter,

Power Source A.C. or D.C.,

D.C. Suppressor,

Resistance Box and Water Circulating Unit


V.P.I. (VACUUM PRESSURE IMPREGNATION) PLANT

In TMS V.P.I. plant is a plant used for varnishing various components i.e. armature and stator

and 3 phase auxiliary machines.

Under vacuum pressure impregnation the component is varnished by infecting the suitable

varnish under pressure in an evacuated space.

Varnish is used to avoid air gaps and bubbles inside the component body and also due to varnish

armature’s and stator’s surface get unaffected by the moisture.

The armature or stator which is to be varnished is placed inside the plant where vacuum is

created by an exhausted and from varnish tank varnish enters with pressure with the help of a

compressor.

PROCEDURE:

First the component is preheated at an average temperature of 120 degree Celsius for at least

6 hours in an oven and then it is cooled to 50 to 60 degree Celsius.

Then the component is placed in V.P.I. plant and a vacuum of at least 755 mm Hg is created

which is maintained for at least 20 minutes.

Now the impregnation varnish is admitted from the bottom with motor kept in vertical position

for 30 minutes.

After this the vacuum is destroyed and the motor is kept under a pressure of 3 kg/cm sq. for

½ hour and then the component is cooled down to ambient temperature.

Different varnishes are used for different components as will as different type of armatures as

following:

Varnish is kept in an A.C. tank (such as H-71 at 25 degree cel) so that it may not freeze.

Component Varnish used

Hitachi armature HEW-290

EMU Armature FT-2005

TAO-659 Armature FT-2005

3 phase auxiliary machines H-71

Stators H-71


DYNAMIC BALANCING

Dynamic balancing is a process of balancing of machine’s rotating parts. In TMS the armatures

which are the rotating part in a motor, are balanced otherwise it may create noise as well as

armature shaft and motor may also damage.

The armature (with shaft) is rotated through spindles on lathe m/c and the imbalance is checked

by the display m/c providing data as the angle and weighty which is to be balanced. The speed

of m/c is increased gradually.

The radii of A, B, C parts (as shown in figure as Ra, Rb, Rc,) are fed on display m/c by the

operator and the lathe m,/c is started to rotate the armature. The reading is taken through the

display m/c.

The weight which is to be balanced is added or removed as per the requirement at the angle

shown on display m/c.

The armature is again rotated and checked for imbalance. If not balanced again weights are

inserted to be balanced the armature. This process is continued until the armature is completely

balanced. After the balancing of armature the display machine shows the balanced condition.

The weight range of the balancing m/c in TMS is 25 to 100 and 100 to 3000 Kgs. The data

recorded during the balancing of an armature, as an example, are as follows.

WT OF ARMATURE (KG) BALANCING SPEED

(RPM) MIN MAX

100 300 1000

300 1000 700 or 500

1000 3000 350

After balancing the weights are added are further welded so that weights may not be thrown by

centrifugal force while rotating and may fixed on armature.


AN OVERVIEW OF MACHINES AND PLANTS USED IN TMS/CNB

SL

NO

TYPE OF MACHINES PURPOSE

1 Over head crane

Capacity:-20,10,5 Tons

To shift the armature and other heavy

jobs to different places in sections.

2 Lathe:

(1) Turning lathe

(2) Grinding lathe

(a) Commutator turning

(b) Shaft turning

(c) Other job’s turning

Shaft grinding

3 Shaper machine Shaping the shafts at a specific angle.

4 Milling m/c To cut the groove in teeth in gears.

5 Boring & Drilling machines Bore and drill making in shafts of

Armatures and other jobs.

6 Hydraulic press

Capacity: (1) 300 tons

(2) 300 tons

(3) 70 tons and 60 tons

For de shafting and re shafting in

general section

For pressing the stator coils to shape

them in stator section

For shaping coils with the help of dies in

manufacturing of armature coils in

coil section

7 Brazing To connect the terminals in stator coils

in stator section.

8 Edge winding m/c For the forming of coils in stator

section using suitable fixtures.


LATHE

Lathe is the oldest tool invented ,starting with the Egyptian tree lathes. In the Egyptian tree lathe, one

end of the rope wound round the work piece is attached to a flexible branch of a tree while the other

end is pulled by the operator, thus giving the rotary motion to the work piece.

The principal form of surface produced in a lathe is the cylindrical surface. This is achieved by rotating

the work piece while the single point cutting tool removes the material by traversing in a direction

parallel to the axis of rotation and termed as “ Turning “.The popularity of the lathe due to the fact that

a large variety of surfaces can be produced.

Different types of lathes are used in manufacturing shops. Some of them are:

Centre lathe

Tool room lathe

Special purpose lathes

Copying lathe

Gap bed lathe

Capstan and turret lathes

Automatic lathes.

The centre lathe is the most common lathe which derives its name from the way a work piece is

clamped by centers in a lathe, through this is not the only way in which the job is mounted. This is

sometimes also called as engine lathe in view of the fact that early lathes were driven by steam engines.

The tool room lathe is generally meant for applications of tool making, where the accuracy desired is

much higher than that is normally required for general production work.

Special purpose lathes are developed from the centre lathe to cater to special forms of application

which cannot be handled by the conventional centre lathe.


Capstan and turret lathes and automatic lathes cater to high rate production and thus are used for special

application purposes.

MILLING

After lathes, Milling machines are the most widely used for manufacturing applications. In

milling the work piece is fed into a rotating milling cutter, which is a multi point tool, unlike a

lathe, which uses single point cutting tool. The tool used in milling is called the ‘Milling

Cutter’.

In the milling process, each of the cutting edges removes material for only a part of the rotation

of the milling cutter. As a result, the cutting edge has time to cool before it again removes

material. Thus the milling operation is much cooler compared to the turning operation. This

allows for much larger material rates.

In TMS, Milling m/c is mainly used for cutting key grooves on shafts and cutting the groove

on gear teeth.

SHAPER

The shaper is a m/c which uses only reciprocating action.

The shaper is a relatively slow m/c tool with very slow metal removal capability.

The shaper uses a single point cutting tool similar to a clapper box which in turn is mounted to

a reciprocating ram. The ram while undertaking the cutting stroke (forward stroke) pushes the

cutting tool through the work piece to remove the material. When the ram returns (Return or

Idle stroke) cutting takes place.

The single point cutting tool is clamped in the tool head. The tool head has the ability to swivel

the cutting tool in any angle while clamping the tool with any overhang, depending upon the

requirement. The swiveling ability is important for the tool to machine surfaces that are not in

a horizontal plane.

The shaper is generally used for machining flat surfaces in horizontal, vertical and angular

directions. It can also be used for machining convex and concave curved surfaces. The actual

surface generated is by means of the linear motions of the cutting tool.


PLANER

The Planer is very similar to the shaper in terms of the surfaces that can be generated.

A planer is generally used for machining large work pieces which cannot be held in a shaper.

In a shaper, the cutting tool reciprocates during the cutting motion, while in case of planer the

work table reciprocates.

The feeding motion in a planer is given to the cutting tool, which remains stationary during the

cutting motion.

The tool head can be moved along the cross rail for the feeding action while the depth of the

cut can be controlled by moving the tool downwards.

It is possible to mount more than one tool head on the cross rail as well as on the columns on

the both sides, so that multiple can be completed simultaneously. This helps min total

machining time since planning is a relatively slow operation like shaping.

DRILLING

Machining round holes in metal stock is one of the most common operations in the manufactur ing

industry. It is estimated that of all the machining operations carried out, there are about 20% hole

making operations. Drilling in the operation used for hole making in solid materials. The cutting tool

used for making holes in solid material is called the “Twist Drill “. It basically consists of two parts;

the body consisting of the cutting edges and the shank which is used for holding purpose. This has two

cutting edges and two opposite spiral flutes cut into its surface. These flutes serve to provide clearance

to the chips produced at the cutting edges. They also allow the cutting fluid to reach the cutting edges.


HEAT TREATMENT

Heat treatment of metals may be defined as an operation or a combination of operations involving the

heating and cooling of metals or alloys in the solid state to produce certain desired properties. Only by

heat treatment it is possible to alter the structure and consequently the mechanical properties of metals

required for normal operation of modern machinery and tools. As well, many shaping, forming and

joining processes involve heating and cooling the metal and thus “accidental” heat treatment may

result. All heat treatment processes may be considered to consist of three main parts:

The heating of the metal to the pre-determined temperature.

The soaking of the metal at that temperature until the structure becomes uniform throughout

the section.

The cooling of the metal at some pre-determined rate to cause the formation of desirable

structures within the metal for the desired properties.

METHODS OF HEAT TREATMENT:

Following are same methods of heat treatment:-

(1) Annealing

(2) Normalizing

(3) Hardening

(4) Tempering

(5) Case hardening


BRIEF DESCRIPTION OF WORKS HELD IN GENRAL SECTION

In general section repairing and maintenance of machines are being done. Following are some works

which are done in this section with their procedure.

ARMATURE MECHANICAL REPAIR:

Armature is received from armature section with job card.

Racers are removed from the CE (commutator end) & PE (pinion end) if intact by

heating it with gas welding plant.

Gullet ring is cut and removed by gas welding.

HEAD CHANGING:

Armature is baked at 180 degree Celsius for 16 hours.

The shaft is pressed out with the help of 300 ton press by applying pressure 150 to 250 ton.

Head is removed from armature with the help of crane. If requires , hammering is done and

head is removed.

The shaft is cooled down to the atmosphere temperature.

The shaft is pressed in head applying 75 ton pressure on the 300 ton press (in case of TAO-

659 armature).

The head is checked for ovality and grooves are cut on lathe machine.

Armature is baked in oven for 16 hours at 180 degree Celsius.

The shaft with head is pressed in armature applying 75 to 150 ton pressure on 300 ton press.

The armature is cooled down to atmospheric temperature.

The additional sleeve is preheated with oxyacetylene flame and is shrunk fitted in the shaft.

Commtator risers are turned on the lathe machine.

The armature with job card is returned to armature section.


RESHAFTING:

Armature is baked at 180 degree Celsius for 16 hours.

The shaft is pressed out by 150 to 250 ton pressure on hydraulic press.

The new machined shaft is pressed in by applying 75 to 150 ton pressure on 300 ton press.

The armature is cooled down to atmospheric temperature.

The additional sleeve is pre-heated with oxyacetylene flame and is shrunk fitted in the shaft.

The riser is turned for coil stripping.

Armature is returned to armature section for rewinding with job card.

HEAD CHANGING + RESHAFTING:

Procedure is the same as in head changing only difference is that new shaft and new head are used in

this case.

MACHINING WORK:

Drilling and taping on both end of the shaft is done as per drawing on radial drilling

machine.

Final machining and grinding of the shaft is done on the kirloskar lathe/HMT lathe as per

the drawing.

Key groove is cut on milling machine.

Key is fitted in key groove.

Shaft is ready for use.

Turning of riser of commutators of all rewound armatures is done.

Stator coil machining.


WAGON MOVEMENT:

Wagon which comes from different railways following actions are taken for unloading and loading.

To pull wagon in TM shed with the help of fork lifter/man power.

To open and closed the root of departmental wagons for unloading and loading.

To seal and tag the wagon for its dispatch.

To push out the wagon out of TMS with the help of fork lifter.

CRANE OPERATION:

To provide crane drivers to operate the EOT cranes.


MEANING OF SOME TERMS:

WINDING OF COIL:

As the coils are in the form of strips which is bended in the u- shapes through edges on Edge Winding

m\ c.

CRUSHING:

As due of winding of coil, it swells out on bends. To remove this and maintain an overall same

thickness of coil crushing is done with the help of hydraulic press m / c.

MILLING & BUFFING:

In this process, cleaning, removing of dirt, dust and equalizing and scraping the surface of coil are

held.

PICKLING:

Pickling is held in a steel tank in which there is a mixture of H2SO4, Sodium di Cromate and water in

the ratio of 20: 20: 60. In this mixture coil is dipped so as to remove ashes of annealing, dirt, CuS,

Oxide layer etc. to get bright and clean copper surface.

POTTING:

It is the process of applying a mixture of HEW- 823 A&B on the surface of coil to seal it up so that it

may fix and may not move.

POURING:

Pouring is a process of filling the gap b/w shoe and coil.

H. F. TEST:

High Voltage (H.V.) test is for checking the coil not to be earthed or shorted.

traction machine shed knapur

Engineering

committee railways

management of railways

traction system

auxiliary section

s electric traction

loco auxiliary machines

french national railways

railway system