Power Train
Systems Operation
6
Drive Motor
Drive Motor
(1) Shaft. (2) Cover. (3) Thermal switch (thermostat). (4) Commutator. (5) Armature assembly. (6) Field coils. (7) Frame.
(8) Brush holder.
1
3
2
4
8
7
6
5
The drive system is operated by a direct current (DC)
motor. Electric storage batteries are the source of
power for the DC motor.
The drive motor is a series wound motor and uses a
high temperature insulation. A series wound motor is
a commutator motor. The field and armature circuits
are a series, which provides a single path for the cur-
rent. Armature (5) is mounted with single row ball
bearings at each end. The ball bearings are perma-
nently lubricated with a high temperature lubricant.
The electrical connections to the motor are made at
corrosion resistant terminals on motor frame (7). On
the outside of the motor frame is cover (2) that can
be removed for easy access to the brushes and the
commutator. Field coils (6) are fastened to the inside
of the motor frame.
The four motor brushes are held in four brush hold-
ers (8). A spring holds each of the brushes against
commutator (4) as the brushes wear.
The Optional Superior (S) function equipped lift
truckÕs drive motor is protected from overheating by a
thermal switch (thermostat) (3). The thermal switch
opens at 150
L
6¡C (302
L
11¡F). It closes at 130
L
7¡C
(266
L
13¡F). When the normally closed thermal
switch is open, the amount of current through the
motor is limited to allow the motor to cool. The motor
has a fan for cooling.
The drive motor is activated when the parking brake
is released, the key and seat switch are closed, a
direction is selected and the accelerator pedal is
depressed.
The drive motor powers the power transfer group
through shaft (1).
