assembly to be removed and will permit
cause sparking. Undercutting can be done to the best
handling of the armature with ropes,
advantage by the use of one of the small power-driven
without damage to the disks.
saws which are built for this purpose.
d. After the commutator has been turned or stoned
(5) Remove the bolts that hold the front
and undercut, the burrs which are always formed on the
bearing cartridge in the housing.
edges of the bar during the process, will be carefully
(6) Insert the two armature removal studs in
removed with a three-cornered cutting tool, the ends of
two of the tapped holes in the cartridge.
the commutator bars rounded, the slots cleaned out, and
These studs are not furnished with the
the commutator finally polished with fine sandpaper and
generator, but can be made similar to the
then blown off with compressed air. Lift the brushes
long studs shown on the tool drawing,
when smoothing a commutator in the machine and do
not replace until all grit has been removed. Never use
commutator
from
striking
the
emery cloth or emery paper on a commutator.
brushholders.
(7) The armature can now be removed from
71. Dismantling and Assembling Generator
the generator by passing a heavy rope
a. Dismantling Generator from Engine. In case it is
around the armature and moving the
necessary to make internal repairs to an armature,
armature slowly toward the coupling end
bearing, or field coils, the following procedure will be
of the generator. A piece of pipe will be
followed in taking the generator apart.
needed over the shaft extension at the
commutator end to permit sliding the
(1) Remove electrical connections between
armature through the frame far enough
the generator and other apparatus.
that it can be handled entirely from the
(2) Remove all the bolts holding the coupling
other end. Care must be taken that the
disk to the flywheel.
armature does not rub the poles during
(3) Remove all the bolts holding the
this operation, and that the commutator
generator frame to the engine bell
does not rub the brushholder box.
housing.
(4) Remove the bolts holding the generator
supporting feet to the locomotive
(1) Remove the armature from the generator
mountings.
as described in preceding paragraph and
(5) Slide the generator away from the engine
block in a horizontal position.
and insert fiber wedges between the
(2) Remove the bolts which hold the outside
armature and poles to prevent the
bearing cap to the cartridge and remove
armature from rubbing the poles.
the cap.
(6) The complete generator may now be lifted
(3) Straighten the lockwasher and remove the
from its mountings and removed from the
bearing locknut using the special spanner
locomotive.
wrench shown on figure 10.
b. Removal of Armature.
(4) Pull the bearing and inner grease thrower,
(1) When necessary to remove the armature
using the special puller tool shown on
from the generator, first dismantle the
generator from the engine as described in
cartridge; place the single plate over the
the preceding paragraph.
studs against the end of the shaft and
(2) Lift the brushes far enough out of the
tighten the nuts evenly on the outside of
brush box that they will not slide back on
the plate until the bearing assembly is
the commutator.
pulled from the shaft.
(3) Protect the commutator by wrapping it
(5) Remove the bearing from its push fit in
with heavy fishpaper.
the cartridge; if necessary, tap lightly
(4) Remove the bolts holding the coupling
around the cartridge with a rawhide
disk to the generator coupling flange.
mallet.
This allows the coupling disk and fan
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