Section IX. TRACTION MOTOR
c. It is designated as direct-current because the
78. General Data
current which operates it flows continuously in one
a. Operating Limits (Maximum).
direction.
(1)
Volts ............................................................ 00
6
(2)
Amperes......................................................650
d. It is designated series because the operating
(3)
Safe rpm ..................................................2,650
current which operates it flows continuously in windings
b. Brushes.
in series (i. e., first through one and then through the
(1)
Number of brush arms....................................4
other).
(2)
Brushes per arm..............................................2
e. One side of the motor is supported by bearings
(3)
Size of brushes (inches)..............3/4 x 1 1/2 x 2
(4)
Brush pressure (pounds) with full length
on the locomotive axle and the other side by a
brush ........................................................7 to 9
suspension nose which is cast on the motor and is
c. Normal Pole Bores at Center of Poles (inches).
supported on the truck frame crosstie.
(1)
Main poles..............................................16.375
f. Each motor is connected to its axle through a
(2)
Commutating poles................................16.375
.
single set of gears.
d. Weights (Pounds).
(1)
Motor with gear and case ......................... 210
3
80. Axle Bearing Clearances and Wear
(2)
Armature complete......................................760
e. Resistance of Windings at (Ohms at 25 .).
C
a. New axle bearings are bored 0.020 to 0.022
(1)
Armature.................................................0.0188
inch larger than the axle over the center portion and
(2)
Commutating field..................................0.0060
0.030 to 0.032 inch larger than the axle near the ends to
(3)
Series field..............................................0.0126
give a relief bore.
d. Armature Bearings.
b. The axle bearing seats in the motor are bored to
(1)
Pinion end ....................................85/MM Roller
size with an 0.016 to 0.017 inch shim between the caps
(2)
Commutator end.............................. 0/MM Ball
6
and the frame in order to give a clamping fit.
g. Axle Bearings.
(1)
Type .......................................................Sleeve
c. Wear in the axle bearings is not so serious as
(2)
Oil level (inches)-The height of oil in
wear in the armature bearings. Renew axle bearings
the axle bearings as measured fro the
m
that show wear of 1/8 to 3/16 inch maximum. The
bottom of the chamber using a flexible
amount of clearance can be measured by inserting a
gauge should be as follows:
narrow feeler gauge between the under side of the axle
Maximum.........................................2.375
.
Minimum..........................................1.125
and the bearing; the gauging can be done through the
h. Pinion Application.
windows provided for this purpose in the axle shield.
(1)
Teeth ...................................
13
15
The end wear must not be allowed to exceed a
(2)
Application temperature ( .)
C
maximum of 1/4 inch on the commutator end bearing,
Shaft temperature................ +132
+136
nor 3/32 inch on the gear case end bearing.
(3)
Advance limits
Maximum (in.)...................... 0.048
.
0.049
Minimum (in.)....................... 0.040
0.039
81. Removal and Replacing of Axle Bearings
a. In case it becomes necessary to remove the
79. Description
axle bearings while the motor is on the axle, proceed as
a. The motors are designed to give the specified
follows:
performance when operating all in parallel. This gives
(1) Run the locomotive over a pit if one is
best conditions in regard to wheel slippage at high
available, if not, locate it to the best
tractive effort.
advantage for working on underside of
b. This traction motor is of the same type as
axle.
generally used for electric traction, commonly called
(2) If the bearing being removed is on the
axle-bearing.
DIRECT-CURRENT, SERIES motor.
gear side it will be necessary to take out
the gearcase bolts and drop the lower half
of the gearcase.
(3) Take out the four axle bearing cap bolts
and remove the cap. If the cap sticks it
38
