INTRODUCTION

DIFFERENT PARTS� Crankcase

� Cylinder & Cylinder Head

� Connecting Rod & Crankshaft Assembly

� Piston & Piston Rings

� Disc Valves

The compressor fitted on AC electric locomotives supplies compressed air for operation of air brakes, VCB, SMGR (in conventional loco), horns, wipers and other pneumatically controlled equipment.

It is a reciprocating, three cylinders, two stages, and air-cooled compressor driven by an induction motor.

The crankcase is made of high-grade cast iron and houses the crankshaft assembly and cylinders. It acts as the sump for lubricating oil and is provided with a breather (in conventional loco), drain plug and a dipstick assembly with minimum & maximum level markings. The breather maintains a partial vacuum in crankcase to facilitate better lubrication.

The cylinders and cylinder heads are made of high grade cast iron and they have close deep fins for effective cooling. The hardness of the cylinders is closely controlled to ensure high wear resistance.

Connecting rod & Crankshaft assembly is precision machined and dynamically balanced. The crankshaft is provided with single row heavy duty ball bearing at both ends.

The pistons are of automotive type and are made of low expansion aluminium alloy. They are provided with plain compression rings, stepped compression rings and slotted oil control rings. The gudgeon pins are of chrome steel, case hardened and precision ground.

Special type concentric disc valves are used for suction and discharge operations.

� Inter-Cooler

It consists of a series of copper tubes, on which fins are wound for effective cooling. It is connected between discharge of the LP cylinder heads and inlet of the HP cylinder head. It is provided with a safety valve and a drain valve.

� After-Cooler

After cooler is made of copper tubes and fins are wound on them and arranged together for better cooling. A drain valve is provided on it to drain out the condensate. A safety valve is also provided to the after-cooler in three phase locomotives.

� CouplingCompressor is directly coupled with motor by a flexible resilient coupling in conventional locomotives and by rubber tyre coupling in three phase locomotives.

� Inlet Air Filters

Compressors in conventional locomotives are fitted with oil bath air filters while in three phase locomotives they are fitted with dry type air filters. These are connected to the suction side of the LP cylinder heads.

� Fan and Fan Guard

A fan with a fan guard is provided to direct cool air on to the compressor unit in conventional loco. The fan draws air over the motor thereby cooling the motor also.

In three phase locomotives an impeller is provided on coupling assembly to provide cooling air for both the motor and compressor.

� Oil Pump (in three phase loco)An oil pump, coupled directly to the drive shaft, ensures satisfactory circulation of the lubricating oil.

TECHNICAL DATA OF COMPRESSORS FITTED ON CONVENTIONAL LOCOMOTIVES

Oil bath air filter, oil capacity 350 mlSuction filter

F x 136 spring type resilient couplingCoupling model

185 kg approx.Motor weight

14 HPMotor power

405 kg.Net weight (without motor)

1050 x 7 x 965 mmOverall dimensions

(L x W x H)

SP-150 (IOC)/ Bharat 150Lubricating oil grade

6.0 kg/ sq. cmSafety valve setting on the inter cooler

Min.600 ml, Max. 1350 mlCrankcase oil capacity

Directly coupled with motor by a resilient flange coupling

Type of drive

Anticlockwise as viewed from the non-driving end.

Direction of rotation

Disc valves Type of valves

980 rpmCompressor speed

LP – 100 x 85

HP – 60 x 85

Cylinder bore and stroke length (mm)

2No. of stages

3 (LP–2 & HP–1)No. of cylinders

1000 lpmFree air delivery

1308 lpmDisplacement

10.5 kg/sq. cmWorking pressure

Reciprocating, air cooled, “W” type and oil splash lubricated

Type

TRC 1000 MN Model

ELGIMake

TECHNICAL DATA OF COMPRESSORS FITTED ON THREE PHASE LOCOMOTIVES

20 HP/15 kW20 HP/15 kWMotor power

670 kg.500 kg.App. weight (without motor)

Oil splash2.8 to 3.4 barLubricating oil pressure

Servo Press 150 / Shell Corena P 150

Shell Corena P 100Lubricating oil grade

Min. 2500 mlMax. 3500 ml

Min. 11 litresMax. 13.75 litres

Crankcase oil capacity

Directly coupled with motor by a resilient flange coupling(Fenaflex tyre coupling)

Directly coupled with motor by a rubber tyre coupling

Type of driveDisc valvesDisc valves Type of valves980 rpm730 rpmSpeed –

LP – 127HP – 100

LP – 125 to 125.02HP – 97 to 97.02

Cylinder bore (dia.) (mm) New

3 (LP–2 & HP–1)3 (LP–2 & HP–1)No. of cylinders

10.2 kg/sq.cm10 bar Delivery pressure

1750 lpm1745 lpmFree air delivery2235 lpm2330 lpmDisplacement

Resilient mounts at three points

Resilient mounts at three points

Mounting

AC electric motor, totally enclosed

AC electric motor, totally enclosed

Drive

Reciprocating, air cooled, “W” type and oil splash lubricated

Vertical cylinder alignment, oil pump for lubrication

Type RR 20 100Type 2A320D Model

ELGIFTILMake

IMPORTANT SIZES AND LIMITS FOR ELGI RR 20 100 COMPRESSOR (In mm)

0.6 to 0.80.6 to 0.8Clearance between piston crown/top and disc valve bottom

8.

2030Connecting rod small end needle roller bearing internal diameter

7.

Normal 0.03 to 0.07Max. 0.5

Normal 0.03 to 0.11Max. 0.2

Piston ring side play in groove 6.

Normal 0.08 to 0.25Max. 0.5

Normal 0.10 to 0.35Max. 0.45

Piston ring butt clearance 5.

Normal 0.15 to 0.16Max. 0.25

Normal 0.18 to 0.27Max. 0.3

Diametrical clearance between cylinder and piston

4.

2030Gudgeon pin size (dia.)3.

99.85 ± 0.005126.822Piston (dia.)2.

100127Cylinder bore (dia.) 1.

HP LP DescriptionSr.

IMPORTANT SIZES AND LIMITS FOR ELGI TRC 1000 MN COMPRESSOR (In mm)

1.4 to 1.61.4 to 1.6Clearance between piston crown/top and disc valve bottom

8.

1820Connecting rod small end needle roller bearing internal diameter

7.

Normal 0.06 to 0.09Max. 0.12

Normal 0.04 to 0.08Max. 0.12

Piston ring side play in groove 6.

Normal 0.08 to 0.25Max. 0.40

Normal 0.08 to 0.25Max. 0.40

Piston ring butt clearance 5.

Normal 0.06 to 0.09Max. 0.20

Normal 0.15 to 0.16Max. 0.25

Diametrical clearance between cylinder and piston

4.

1820Gudgeon pin size (dia.)3.

59.9299.85 ± 0.005Piston (dia.)2.

60100Cylinder bore (dia.) 1.

HP LP DescriptionSr.

CLEARANCES AND LIMITS FOR FTIL 2A320D COMPRESSOR

0.10 – 0.150.03

0.10 – 0.15-

Crankshaft end float Ovality of big and little end bearings

11.

1.50.9 – 1.4Clearance between piston at top dead center and suction valve stop

10.

M6 fitInterference 0.033 Clearance 0.017

Crankcase bore to front end bearing (170 mm nominal dia.)

9.

M5 fitM5 fit

Interference0.013 – 0.0280.013 – 0.028

Roller bearing bore to crankshaftFront end (80 mm nominal dia.)Drive end (80 mm nominal dia.)

8.

0.090.020 – 0.063Crankshaft journal to big end bearing (58 mm nominal dia.)

7.

0.050.002 – 0.014Gudgeon pin to piston bore(30 mm nominal dia.)

6.

0.050.003 – 0.015Gudgeon pin to little end bush(30 mm nominal dia.)

5.

0.350.35

0.38 – 0.630.29 – 0.54

Piston ring butt clearanceLPHP

4.

0.150.05 – 0.10Side clearance of ring in grooveHP & LP

3.

0.2900.220

0.1 – 0.1320.07 – 0.099

Piston to cylinderLP (125 mm nominal dia.)HP (97 mm nominal dia.)

2.

0.07-Ovality of cylinder HP & LP 1.

Limits for wear (mm)

Clearance when new (mm)

DescriptionSr

TRIP SHED TO ENSURE USE OF ONLY APPROVED LUBRICANTS FOR ELECTRIC LOCO COMPRESSORS

For compressor 2A320D (FTIL/ SWIL/ D&M) Shell Corena P 100

For ELGI compressor RR20 100 SP 150 (IOC)/ Shell Corena P 150

For ELGI Compressor TRC 1000 MN SP 150 (IOC)/ Bharat 150

+ 0.01

- 0.00+ 0.01

- 0.00

+ 0.000

- 0.005

+ 0.000

- 0.005

+ 0.05

- 0.00

+ 0.01

- 0.00

+ 0.000

- 0.0254

+ 0.000

- 0.005

+ 0.000

- 0.005

Do’s

Don’ts

(For Official Use Only)

PAMPHLET on

AIR COMPRESSORS OF AC ELECTRIC LOCOMOTIVES

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Maharajpur, GWALIOR - 474 005

It is clarified that this pamphlet does not supersede any existing provisions laid down by RDSO, Railway Board or OEMs. The pamphlet is for guidance only and it is not a statutory document.

If you have any suggestion or comment, please write to:Director (Electrical), CAMTECH, Maharajpur,Gwalior (M.P.) – 474 005

Ph.0751-2470740, Fax 0751-2470841Email : direlcamtech@gmail.com

Disclaimer:

SAFETY TIPS

� Don’t neglect the routine attention .

� Use proper tools for maintenance.

� Keep away hands and other body parts from fan and other rotatingparts of compressor.

� Keep air compressor room/ floor neat and clean.

� Maintain distance from air outlets.

� Cut off the electric supply before doing any repair work on compressor.

� Don’t attempt to operate the air compressor with known unsafe condition.

� Don’t use inflammable material for cleaning of compressor.

� Don’t keep any tool or loose items, cotton jute etc. on the compressor.

� Don’t run the compressor without fan guard.