What to inspect in a locomotive?

Cab AC ducts were in should be checked for shabby condition.

Make sure Inspection staff     has the fitment drawings of Cab AC ducts.

If not, Same to be collected from design office.

Problem may be reported  regarding gap between mounting brackets of transformer in three phase locos  and should be looked into.

Another problem should be noted during the inspection:-

See in above picture, you find Long nut  here and               Small nut there .

Size of the nut ( check if trade item) should be same . Some nuts can be 3 mm shorter than others in the same bracket.

If it is reported that the battery box was tag welded then  same has to be run welded in the shed.

Vertical portion

It is to be seen that not only the battery boxes are mounted on  run welded brackets only, the vertical portion on the bracket should not be left unwelded at  any place.

Battery boxes ( which are 100 % trade items ) should be   tag welded at places inside the box?

  

TM shop should be  visited  in order to find out condition of brush insulators and tightness of brush holder pockets.   

Complaint of   shed that CCPT 16 A fuse was being used in place of 10 A, need examination.

About loco bearings and centre pivot

If failure of Racers occurs in WAG9 locos, procedure to mount axle should be inspected in the shop.:

G9 Racer is induction heated before fitting over the axle journal. ( two racers on each side ).

Axle box     and          Racer        Bearing in above and below snap.

Due to failure of induction heaters, gas heated racers may get the profile damaged and this may result in failure. B 

The radial clearance measurement procedure ( different for SKF and FAG racers ) should be followed with the help of NO-GO gauges.

Centre Pivot:

Castings need to be rejected during machining if there are  large number of blow holes.

Blow holes in Centre Pivot of WAP4 ( Raj ) locos loo like this:

Force fit Racer of WAP5 locos should be  examined while fitment.

Traction Motor of Locomotive

 
How to do Backlash measurement of pinion-gear ? 

IN TM shop was   following problems can be analysed:-.

When three teeth match, filler gauge is used to make one side gap NIL, then clearance between other side gives the backlash.

Pinion Draw measurement to be inspected.

a)    Color matching ( more than 90% ensured) sould be done for proper interference between two surfaces.

b)   Pinion inserted.

c)    Pinion drawn out , induction heated and again inserted.

d)   Pinion draw= ©-(b)

Lateral and longitudinal bogie clearances can be measured as in above picture .

Shown in above: Modified stator clamps to hold bracing ring which protects overhang portion from vibrations .

Greasing nipple and bearing cover groove matching is necessary for proper greasing in HITACHI motors.  

The bearing cover groove , if not in matching location, results in blockage of path. This cover is supposed to be shrink fit but is press fitted in the shop.