Traction Rolling Stock - Indian Railways Institute of Electrical ...

The flexible coupling, connecting the motor and the compressor consists of 2 hubs. Each hub is
provided with a number of grooves to hold a spring which transmits the rotation from the motor to
compressor. Care is necessary in the assembly of couplings, particularly in checking for both
parallel and angular alignment and in setting the correct gap (0.8 mm). The coupling grooves must
be completely packed with grease before the spring is inserted and a further liberal application of
grease after its insertion is essential. After the assembly of the outer shell the maximum possible
quantity of grease must be forced in through the greasing nipple. This type of coupling does not
require any attention during running except for the periodical replenishing of grease.
Replacement item
i) If any ring of gold spring is broken in the middle, the grid spring should be replaced.
ii)
If a tooth or a number of teeth of coupling hubs are broken it should be replaced.
6.2.1 Bibby coupling assembly procedure (Ref. fig.6.2.1)
1) Check parallelism by using straight edge over the tops of the hubs at each quarter
points at 90° apart. Make final check after foundation bolts are tightened down.
2) Check the gap between hub faces to ensure that it is within 0.8 mm to 1 mm.
Check angular alignment using feelers in the gap at each quarter points at
93° apart.
3) After thoroughly packing the grooves with grease press the spring into its position.
Then apply grease liberally on it. Draw the covers into position and tighten the
bolts. Inject maximum amount of grease through grease nipple.