Maintenance 8. Arm #4
172 G10 / G20 Rev.20
8.1.2 Replacing the Joint #4 Motor: G20
A brake is mounted on the motor of Joints #3 and #4 to prevent the shaft from moving
down due to the weight of the end effector while the power to the Controller is OFF or
while the motor is in OFF status (MOTOR OFF).
Note that the brake will not work during the replacement procedure.
Move the shaft down to its lower limit before starting the replacement procedure by
following the removal steps.
Push down the shaft to its lower limit while pressing the brake release switch. Be
sure to keep enough space and prevent the
hitting any peripheral
equipment.
The brake release switch is applied to both Joints #3 and #4. When the brake
release switch is pressed, the respective brakes of the Joints #3 and #4 are released
simultaneously.
shaft falling and rotating while the brake release switch is
because the shaft may be lowered by the weight of an end effector.
top cover and the arm bottom cover.
For details, refer to Maintenance: 3. Covers.
Cut off the wire tie used for binding the motor cables to the Joint #4 motor.
connectors.
Connectors X241, X41 (Hold the claw to remove.)
Connector X64
Remove the Joint #4 motor from the reduction
gear unit
Unscrew the reduction gear unit bolts securing
the Joint #4 motor shaft and bolts securing the
Joint #4 motor.
M3×10
(Securing the motor shaft)
Remove the ring from the Joint #4 motor.
There is a brass bushing in the both
. Be careful not to lose it.