TM 9-4940-421-14
REPAIR
OF
GENERATOR-WELDER
Section I. I N T R O D U C T I O N
ate electrical equipment. The 4 cycle gasoline engine is
the only source of power to operate the generator-
pose machine capable of generating direct current for
welding and 120 volts, single phase, 60 hertz, to oper-
welder.
Section II. G E N E R A T O R - W E L D E R
MAINTENANCE
generator commutator for roughness, wear, or ec-
a. Generator-Welder Armature. Refer to TM 5-764
centricity. Measure the commutator runout with a dial
for armature testing procedures.
indicator. Place the armature assembly in a lathe and
b. Shunt Field. Refer TM 5-764 for shunt field test-
turn a commutator that is 0.003 inch or more out-of-
ing procedures.
round. Make light cuts until the commutator is clean,
c. Welding Generator Series Field Group. Refer to
(6) Undercut the mica separators in the commuta-
TM 5-764 for series field group testing procedures.
tor to a depth of one-thirty-second inch below the com-
d. Welding Generator Interpole Group. Refer to TM
mutator bars, either by hand or by machine.
5-764 for interpole group testing procedures.
(7) Inspect all stator assemblies and field coils for
defective insulation broken leads, or other defects,
8-3. GENERATOR-WELDER.
Replace defective windings, leads or insulation.
a. Removal and Disassembly.
(8) Inspect generator housing and auxiliary
(1) Refer to paragraph 6-3 to remove generator-
generator for cracks or breaks. Weld minor cracks and
welder from the engine.
replace a damaged housing.
(2) Refer to paragraph 4-45 to remove welder
(9) Inspect the generator-welder base for cracks,
brushes.
breaks, and damaged mounting hardware. Weld cracks
(3) Refer to paragraph 4-46 to remove end cover
and minor breaks. Replace damaged mounting hard-
housing.
ware.
(4) Refer to paragraph 4-47 to remove auxiliary-
d. Reassembly. Reassemble in reverse order of dis-
generator brushes.
assembly.
(5) Refer to figure 6-1 and remove four capscrews
e. Installation. Install generator-welder in reverse
securing auxiliary-generator housing to generator
order of removal.
housing.
(6) Remove the armature from the generator
8-4. GENERATOR BEARING SERVICE.
housing and place in a suitable stand.
a. General. The generator end bearing is the only
(7) Remove two bolts and nuts securing brush
thing requiring lubrication. Greasing twice yearly is
holder to generator housing and remove brush holder.
sufficient for the bearing under normal use. Pressure
fittings are not recommended, because grease, under
b. Testing During or After Disassembly. Refer to
TM 5-764 and test each component of the generator-
pressure, may go through the bearing grease seal and
welder at the appropriate time during disassembly.
into the commutator.
c. Cleaning and Inspection.
b. Removal. Use a puller and remove bearing from
(1) Clean all metal parts with cleaning solvent
armature shaft.
.
and dry thoroughly (app D).
c. Cleaning and Inspection.
(2) Inspect holder assembly for breaks, cracks, or
(1) Clean the bearings in solvent and place on
other damage. Replace all parts found to be defective.
clean absorbent paper and allow to drain dry. Do not
spin the bearing dry with compressed air.
CAUTION
(2) Inspect the bearing for cracked balls or race,
Do not use emery paper or emery cloth
burned or galled spots, or excessive play due to normal
on any commutator.
(3) Clean a slightly dirty or discolored commuta-
wear. Replace a damaged or worn bearing.
tor with no. 00 sandpaper. Blow sand, dust and dirt
d. Installation
from the armature with clean, dry, compressed air.
(1) Repack the bearing with approximately one
(4) Inspect the armature shaft bearing surface for
ounce of grease, automotive and artillery, before in-
wear, galling roughness or other damage. Replace a
stallation. Pack the space to be covered by the cover
damaged bearing.
plate.
(5) Inspect the welder commutator and auxiliary
(2) Install bearing on the armature shaft.
