f. Remove the bearing, gear collar, and gear
from the countershaft with finger pressure applied
g. Remove the gear collar from the gear and
place this collar on the new gear.
h. Slide the assembly (gear collar and new gear)
onto the countershaft.
i. Inspect the bearing. Note that on one side
of the bearing the inner race is flush with the out-
side race. The inner race is recessed on the other
side of the bearing. Insert the bearing onto the
countershaft with the recessed inner race side
toward the outside of the gearbox (the side upon
which the bearing cover plate is mounted). Since
the inner race rotates with the countershaft, as-
sembly in this manner will insure against the inner
race rubbing on the bearing plate when the plate
j. Replace the bearing cover plate.
k. Center the gear (and the gear collar) on the
countershaft so that the gear is at the hole in the
motor shaft that receives the worm.
l. Place the new worm into the motor shaft hole
and tighten it with the Allen setscrew wrench and
the spanner wrench. The worm now should be
in mesh with the gear.
m. Move the gear (and the gear collar) along
the countershaft in either direction until it is
stopped by the worm. Now move the gear in the
105. Replacing Worm and Gear
other direction along the countershaft until it is
Synchronous Motor KBA-2
stopped by the worm. The distance of lateral
movement of the gear along the shaft allowed by
Normally, the gear should be replaced when the
the worm will be approximately one-sixteenth of
worm is replaced. Although the gear may not
an inch. Moving the gear one-half of this dis-
display excessive wear, it becomes, in time, charged
tance from either extreme will center the gear on
with abrasive particles which may cause undue
n. Tighten the gear-collar set screw.
113 before starting replacement. The motor may
o. The new worm must be mounted with partic-
be left mounted on the facsimile set during re-
ular orientation to the motor shaft where worm
and gear run smoothest. Turn the power on and
a. Remove the spanner wrench and the top
start the motor.
cover plate (four screws) from the gearbox. Re-
move the No. 6 Allen setscrew wrench (mounted
Note. There is danger of high-voltage shock when work-
ing near the motor with the power on. Use extreme cau-
on clip on gearbox).
tion when making adjustments described in the rest of
b. Insert the No. 6 Allen setscrew wrench in
the taper screw of the worm, and grip the slot with
p. With the motor running at synchronous
speed, place two fingers of the left hand on the
c. Loosen the taper screw, remove the Allen
wrench and the spanner wrench, and pull the
top of the motor gearbox, one finger above each
worm gear up out of the motor shaft.
countershaft bearing. The trembling sensation
d. Remove the bearing cover plate (four screws).
that will be felt must be minimized to insure
smooth worm and gear operation. (To ascertain