BOGIES AND SUSPENSION - South Central Railway

CHAPTER 6 – BOGIES AND SUSPENSION
WAGON MAINTENANCE MANUAL
Page 78 of 121
Top and bottom cover plates are made of 3.15 mm thick plate of steel. It has a
rectangular shape with a semicircular portion removed from one of the edges. The
radius of the semicircular portion should invariably be more than the dia. of the axle
at the shoulder. It has a hole in the centre. The top bent edge is kept substantially long
to cover axle box top opening. For IRCA axle boxes, a separate top cover is not
required. The cover plate keeps the dust-shield in position. In addition, it also
prevents ingress of dust inside the axle box.
b) AXLE BOX TOP COVER
An opening is provided on top of the axle box for inserting the dust shield.
After inserting the dust shield, this opening is covered by axle box top cover. Top
cover should be fitted without fail otherwise dust will find its way in the axle box
through this opening. Top cover is a rectangular piece made of steel plate SI-42-S to
Specification No. IS: 226. It has two rivet holes, one at each end (6.5 mm dia. to suit
6 mm rivets).
c) DUST SHIELD
It is made of leather of either 3 ply or 2 ply. It has rectangular shape with a
circular hole in the centre. Its four outer-corners have been cut at 45 o for a length of
25 mm. It is stitched close to the outer edges and central hole. The outer leather
should be pliable and inner ply/plies should be as stiff as possible. The thickness of
the dust-shield is 9.5 + 1 mm. The manufacturing tolerance for the edge is 1.5 mm
and for the hole is + 0 mm/ -1.5 mm the outer ply is bent inwards at right angles
leaving sufficient gap from the inner ply. The thickness of the outer leather is 3 mm
for 3 ply and 5 mm for 2 ply.
Before using the dust shield it should be soaked in axle oil medium for 48
hours. It should not be allowed to come in contact with water. It should be stocked in
dry place. The dust shield should be examined, every time the axle box is repacked in
sick lines as well as at the time of POH. If found worn, torn, or if it has lost its
stiffness, it should be replaced.
d) AXLE BOX GUARD GROOVE LINER
It is a channel shape piece made of steel to Specification No. IS: 1079. The
thickness of the plate is 3.15 mm to BG and 4 mm for MG four wheeler wagon. Its
sizes are as under:-
B.G. Stock - 273 long x 60.3 + 3.4 wide x 30 mm depth
M.G. Four Wheeler Stock - 232 long x 50.8 + 8.4 wide x 22 mm depth
At bend corners, the inner radius is 6 mm for BG., 4 mm for MG four wheeler
& 3 mm for MG bogie. The Liner is tack welded vertically to the Axle Box Groove.
When the Liners are worn to such an extent that the prescribed permissible lateral and
longitudinal clearances exceed, it should be replaced. Provision of Liners prevents
wear of Axle Box Groove. The Liners can be replaced at a much lower cost
compared to repair/replacement of Axle Box.