Caution
(b) Remove the tap bolts which hold
Care must always be taken to keep
the pole piece of the coil which is to
all dirt and grit away from ball
be removed, lift out the pole, and
then remove the coil.
(2) When replacing coil, the procedure should
be the reverse of that just described and
(3) Place the bearing, cartridge, and grease
the following points should be carefully
thrower in a high-temperature oil at a
noted.
temperature of 100 C. (212 F.). Use
compressor oil.
(a) It is important that the Main Coil
Spring and the wide Main Coil
(4) Remove the bearing cartridge from the
Washer be placed between the pole
hot oil, wipe off the excess oil and drop
tip and the coil with the washer
into place over the shaft.
between the coil and coil spring.
(5) Remove the grease thrower from the hot
(b) Be sure to place the Commutating
oil, wipe off the excess oil and shrink on
Coil
Spring
and
the
wide
the shaft with the chamfered side out and
Commutating Coil Washer back of
hold in place solidly against the shoulder
the commutating coil before putting
on the shaft until it has cooled.
it in place. Take care that these
(6) Pack the lower half of the grease pocket
items do not slip in between the
in the bearing cartridge full of grease as
pole and its seat when it is bolted to
specified in figure 5.
frame. Tile narrow Commutating
(7) Remove the bearing from the hot oil, wipe
Coil Washer should be placed
off the inner and outer fits, and
between the pole tip) and the coil.
immediately drop in place while the
(c) Make sure that the coil is turned
cartridge bore is still expanded. Do not
right side up and right end to, when
force this assembly-the bearing must slip
placing it ill position. Check for
into place. Hold the bearing solidly in
proper polarity according to the field
place against the grease thrower until
wiring diagram, figure 18.
tight.
(d) See that tile pole seat and back are
(8) Apply the bearing locknut and tighten the
clean and free from chips before
setscrews. Strike the bearing nut with a
putting the pole in place, and make
hammer, again tighten the setscrews and
sure that the pole is pulled "home"
peen the nut to lock the setscrews.
to its seat by the tap bolts.
(9) Fill the spaces between the balls with
(e) Measure the final pole bore at the
grease.
center of the face of the pole being
(10) Fill the grease pocket in the outer bearing
replaced and the pole diametrically
cap half full with grease. Bolt the cap with
opposite. Check with the NORMAL
its gasket in place to the bearing
POLE BORE values given on the
cartridge.
general data, paragraph 78.
(11) Some portion of the grease in the bearing
k. Assembly of Commutator End, Armature Ball
cap must make contact with the bearing
when assembled.
guide for proper bearing assembly.
(12) Check to make sure that the grease fitting
(1) Place the armature preferably in a vertical
is not damaged.
position. A hole, a little larger than the
l. Assembly of Pinion End, Armature Roller
armature diameter, cut in a low wooden
table or bench, together with some
(1) Place the armature ill a vertical position.
wooden wedges to keep the armature
A hole, a little larger than the armature
from dropping through, serves very well.
diameter, cut in a low wooden table or
(2) Clean all parts thoroughly before starting
bench, together with some wooden
to assemble.
Carefully inspect the
wedges to keep armature from dropping
bearing for cracks, pitting, or excessive
through, serves very well.
wear.
(2) Clean all parts thoroughly before starting
to assemble. Carefully inspect the
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