KEY to fig. 6-3:
1. Screw, fl kid, 10-32 x
14. Motor assembly bolt
2. End plate, rear end frame
15. End plate, front end frame
3. End plate gasket
16. End nut gasket
4. Locking ring
17. End nut
5. Rear end frame
18. Bearing lockscrew
6. Rear bearing
19. Lockwasher
7. Fan
20. Bearing washer
8. Armature
21. Screw, fl kid, 10-32 x I
9. Field frame housing
22. Brush cover plate
10. Front end frame
23. Brush
11. Lockwasher
24. Brush holder
12. Wire cover plate
25. Front bearing
13. Screw, rd kid, 10-32 x
26. Condensor
6-7. Vacuum Turbo-Compressor Motor Cleaning and
6-8. Vacuum Turbo-Compressor Motor Reassembly
Inspection
a. Reassembly.
Wipe off all parts of the motor except the bearings with a cloth
dampened with cleaning solvent. The bearings are life-sealed;
(1) Press fan (7, fig. 6-3) and rear bearing (6) on
to clean, wipe off their exterior surfaces with an oil-damp cloth.
shaft of armature (8). Insert armature assembly into field frame
Examine all parts for damage and wear, checking end plates,
assembly (91. Install condenser (capacitor) (26) in front end
end frames, and field frame casing for cracks and breaks.
frame (10). Position front end frame and rear end frame (5) on
Check the commutators of armature for discoloration, pits, and
field frame assembly, and secure in place with four bolts 14 and
roughness. If commutators are rough, smooth them down,
lockwashers (11)
using a fine sand-paper. Pitted or damaged commutators may
(2) Position front bearing (25), and secure to shaft
be turned down in a lathe. Keep eccentricity of the commutator
of armature (8) with bearing washer (20), lockwasher (19), and
within 0. 001 inch. Undercut the mica between commutators to
lockscrew (18).
one thirty-second of an inch. Cut mica square and remove all
burrs. Check to make certain that all conductors are firmly
(3) Insert brush holder (24) on side of front end
soldered into the commutator rises. Check the brushes and
frame (10-. Slide the brush (23) into holder. Position brush
their springs for overall damages; inspect brushes for proper
cover plate (22) and secure with two screws (21); install other
length and wearing edge. If brushes are worn to less than 11/4
brush to front end frame.
inches, or worn to half their original length, replace brushes. In-
spect the armature for damaged or missing in-sulation. Test for
(4) Tap end plate (15, fig. 6-3) into position and
grounded coils by using a test probe. Ground one probe on the
secure with four screws (11. Position end nut gasket (16) and
armature shaft and touch each commutator segment in turn. If
install end nut (171. Position wire cover plate (12) and secure
the lamp lights, the commutator touched is grounded and the
with two screws (13)
armature should be replaced. Test the capacitor with a
(5) Insert locking ring (41 in rear end frame (51.
multimeter on a low ohms scale. Place the multimeter leads
Position end plate gasket (3) and tap end plate (2) into place.
across the capacitor leads; if the capacitor is good, the meter
Secure end plate with four screws (1).
needle will rise and slowly fall. If the needle of the meter rises,
and does not fall, the capacitor should be replaced. Test for
(6) Position outlet box and secure with two screws.
shorted coils with a growler and a hacksaw blade. A shorted
Attach motor leads and secure cover (10, fig. 4-13) on box, and
armature will cause the hacksaw blade to vibrate. Inspect the
secure with four screws (9)
bearings for signs of wear and for loose inner and outer races.
b.
Installation.
Refer to paragraph 6-4.
b.
Replace bearing if races are loose or if signs of wear are
present.
Section III. LENSBOARD AND COPYBOARD DRIVE MOTORS
current only, drawing 1. 3 amperes at a speed of 1,140 rpm.
6-9. Description
The motor is self-cooled by an internal fan arrangement. Each
The copyboard drive motor (8, fig. 1-4) and the lensboard drive
motor is rated at one-fourth hp and 60-minute 50 -C.
motor (6) are identical motors used to move the copyboard and
temperature rise. The rotor is a squirrel cage type and is
lensboard by individual drivescrews. A gear pinned to the
supported by shielded ball bearings at each end.
motor shaft engages a gear keyed to the drivescrew. The
motors operate on 208 volt, 3 phase, 60 cycle, alternating
6-4
