BOGIES AND SUSPENSION - South Central Railway

CHAPTER 6 – BOGIES AND SUSPENSION
WAGON MAINTENANCE MANUAL
Page 22 of 121
The centre pivot bottom fits in internal opening provided in the bolster
opposite to its internal vertical surface of the bottom recess. The bottom
surface of the flange rests on the bolster and is tack welded all round at its
outer most periphery. The centre pivot top rests on the hemispherical surface
of the centre pivot bottom.
IV. CENTRE PIVOT RETAINER
Its top surface is circular and lateral surface is hemispherical with flat
surface in the bottom. Both top and bottom surfaces have circular recesses in
the centre. The depth of the top recess is 15 mm and dia. 175 mm. The depth
of the bottom recess is 12 mm and dia. 110 mm. The top surface is 240 mm
in dia. It has been chamfered at 45 0 for a depth of 2 mm. The dia. of the
bottom surface is 130 mm. The total height of the retainer is 42 mm. There is
a centre hole of 60 mm dia, 15 mm long. The hemispherical surface has a
radius of 168.5 mm. The top surface, the top recess surface, bottom flat
surface are rough machined. The hemispherical surface, the central hole
surface and the inner surface of the bottom recess are finish machined. The
chamfered surface is rough machined.
The centre pivot retainer rests on the top surface of the boss of the
bogie centre pivot bottom. Thus a small clearance is left between the inner
hemispherical surface of the bogie centre pivot top and the retainer. The
washer is made to rest on the top recess of the centre pivot retainer.
V. CENTRE PIVOT WASHER
The washer assembly has 2 different parts glued together. The
thickness of each pivot is 10 mm with 170-mm external dia. and 60 mm
internal dia. The top is made of steel and the bottom part is made of either
Buna synthetic rubber or India rubber. The latter is glued to the former and
both together are stocked as washer.
The bottom rubber portion of the washer rests on the top recess of the
retainer. The head of the centre bolt rests on its top steel surface.
VI. CENTRE PIVOT BOLT
It is made of steel size 227 mm long x 56 mm dia. The length of the
threaded portion from bottom is 79 mm. The circular head is of 80 mm dia.,
25 mm thick. The circular head has been machined to two flat edges opposite
to each other kept at a distance of 70 +0/ -1.2 mm. An undercut of 8 mm
width x 3 mm depth has been provided at a distance of 79 mm from bottom.
The thread is of M-56 size. A hexagonal castle nut to suit M-56 thread of 74
mm height is used on this bolt. The material of the castle nut is same as that
of the bolt130 mm external dia. 58 mm internal dia. and 10 mm thick washer
is used before the nut.