
B--65245EN/02
1. MAINTENANCE OF SERVO MOTOR
MAINTENANCE OF
SERVO MOTOR
171
Make the following checks about once a year.
(1) Observation of torque command (TCMD) waveform and velocity
command (VCMD) waveform
Using an oscilloscope, display a normal voltage waveform. Compare
the normal waveform with that observed at a periodic check.
The waveform varies with the load, feedrate, and other conditions.
Compare t he waveforms observed under identical conditions (rapid
traverse at reference position return, low--speed feed, for example).
For details of the observation, see Appendix E, ”Servo C heck Board.”
(2) Waveform diagnosis
Check the observed waveform for the following points:
1. Check whether the peak current at rapid traverse
acceleration/deceleration exceeds the rating of the amplifier.
If the peak current exceeds the normal value, the load conditions
of the machine m ay have been changed, or the motor may be
defective.
Rating of the amplifier
Observed waveform
A change in the load conditions of the m echanical system may be
caused by the following:
D The internal friction of the machine has changed over time.
D The machine efficiency has been degraded, requiring more
power.
Increased friction
Degraded efficiency
The amplifier ratings are as follows:
ϒ0.5/3000, ϒ 1/3000, ϒ 2/3000, ∼ 1/3000, ∼2/2000, ∼ 2/3000 12Apeak
ϒ3/3000, ϒ 6/2000, ∼ M2/3000, ∼ M2.5/3000, ∼ C3/2000,
∼C6/2000, ∼ C12/2000
20Apeak
∼ 3/3000, ∼6/2000, ∼ 12/2000, ∼ 22/1500, ∼ C22/1500 40Apeak
∼ 6/3000, ∼12/3000, ∼ 22/2000, ∼ 30/1200,
∼ M6/3000, ∼ M9/3000, ∼ L6/3000, ∼L9/3000
80Apeak
1.3
PERIODIC CHECK OF
SERVO MOTOR