Mitsubishi Electric MR-J4-100B(-RJ), Instruction Manual

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15. USING A DIRECT DRIVE MOTOR
15 - 1
15. USING A DIRECT DRIVE MOTOR
CAUTION
When using the direct drive motor, read the "Direct Drive Motor Instruction
Manual".
POINT
Refer to section 1.4 for the software version of a servo amplifier that is
compatible with the direct drive servo system.
15.1 Functions and configuration
15.1.1 Summary
The fields of semiconductor/LCD manufacturing systems, mounters, and others have strong demands for
high accuracy and efficiency. Therefore, the number of systems using a direct drive motor for a drive axis
has been increasing. The direct drive servo system includes the following features.
(1) Performance
(a) The direct drive servo system ensures the high-rigidity and the high-torque. A high-resolution
encoder enables the high-accuracy control.
(b) The high-resolution encoder contributes to the high-indexer accuracy.
(c) Since reducer is no longer required, no backlash occurs. In addition, the settling time is reduced, and
the high-frequency operation is enabled.
(d) Since reducer is no longer required, the motor does not deteriorate with time by reducer.
(2) Mechanism
(a) The motor's low profile design contributes to compact moving part of the machine and a low center
of gravity for enhanced equipment stability.
(b) The motor has an inner rotor with hollow shaft which enables cables and pipes to be passed
through.
(c) Lubrication and the maintenance due to abrasion are not required.
The following shows the differences between the direct drive motor and the rotary servo motor.
Category Item
Differences
Remark
Direct drive motor Rotary servo motor
External I/O signal FLS (Upper stroke limit),
RLS (Lower stroke limit) Required
(for magnetic pole
detection) Not required Automatically turns on in the
parameter setting.
Motor pole
adjustment Magnetic pole detection Required Not required
(default setting) Automatically executed at the first
servo-on after the power is turned
on.
For the absolute position detection
system, [Pr. PL01] can disable the
magnetic pole detection. (Refer to
(3) (a) of section 15.3.2.)
Absolute position
detection system Absolute position encoder
battery Required Required
Absolute position storage
unit (MR-BTAS01) Required Not required