Direct Drive Motor - LG WM0742H Series Training Manual

TRAINING MANUAL
WM0742HGA

DIRECT DRIVE MOTOR

The motor is a direct-drive, brushless, DC
motor. It is attached to the drum via a
splined shaft, eliminating belts, pulleys,
transmissions, and the inherent problems
associated with them. The rotor is attached
to the shaft by one large bolt.
The DC motor can be driven from stopped
to maximum speed in infinite steps in either
direction. There are 36 poles on the
stator; 12 permanent magnets spaced
around the rotor. There are no brushes to
wear out. Unlike a more traditional
brushless motor, the rotor surrounds the
stator rather than being attached to it.
A Hall Effect Sensor determines the speed
and direction of the motor.
It also can read that the load is off balance
when the drum speed fluctuates.
The Hall Effect sensor is easily removed
and replaced. You'll have to remove the
rotor and stator to access the sensor.
When replacing the rotor, the drum may
move forward enough to make replacing
the bolt difficult. Carry a longer bolt in
your toolbox to use to install the rotor,
then remove and replace it with the factory
bolt after the shaft has been pulled back
and the rotor is pushed in place.
Before going to this trouble, check the
connector on the main board. It is the
white connector (circled in red.) Pull the
connector off and verify the board is
receiving a signal from the hall sensor.
(See pages 48 ~ 52 for more information.)
Page 31
WM0742HGA
TRAINING MANUAL