Equipment Configuration - Mitsubishi Electric MELSERVO-J3 Series Instruction Manual

2. DIRECT DRIVE MOTOR

2.3.1 Equipment configuration

This section explains the system configuration with a direct drive motor. Note the following points when using a
direct drive motor.
(1) Minimum oscillation angle
If the direct drive motor rotates repeatedly by a small angle (by 70° or less), make the direct drive motor
rotate by 90° or more at least once a day in order to keep the bearing lubricated.
(2) Z-phase position
A Z-phase pulse turns on (Z-phase mark passing) when the Z-phase mark on the rotor end of the direct
drive motor passes over the connector area. Keep the Z-phase position visible even after the direct drive
motor is installed to a machine.
(3) Precautions for Z-phase mark passing
After power on, the Z-phase mark of the direct drive motor must pass the connector area once. In a system
which prevents the direct drive motor from making a full rotation, install the direct drive motor in a position
where the Z-phase mark can pass over the connector area.
(4) Vertical axis (lift)
For the system where the unbalanced torque occurs, such as a vertical axis system (lift), use the motor in
the absolute position detection system. In the absolute position detection system, the absolute position is
established when the Z-phase mark passes the connector area once.
At the system startup, make the Z-phase mark pass over the connector area, and switch the servo
amplifier's power supply from off to on.
If the direct drive motor can be rotated manually, make the Z-phase mark pass over the connector area
while only the servo amplifier's control power supply is on. After that, switch the servo amplifier's power
supply from off to on.
If the direct drive motor cannot be rotated manually, detect the magnetic poles while the torque is balanced,
then run the direct drive motor in the test mode to make its Z-phase mark pass over the connector area.
After that, switch the servo amplifier's power supply from off to on.
After the Z-phase mark passes through the connector area once, magnetic pole detection is not required.
Z-phase mark
Z-phase pulse turns
on when the Z-phase
mark passes over
the connector area.
2 - 3
Rotor (output shaft)
Encoder connector
Power supply connector