3-23
3-2 Servomotor Specifications
3
Specifications
The following graphs show the characteristics with a 3-m standard cable and a 200-VAC input.
Temperature Characteristics of the Servomotor and Mechanical System
OMNUC G-Series Servomotors use rare earth magnets (neodymium-iron magnets).
The temperature coefficient for these magnets is approximately
−
0.13%/
°
C. As the temperature
drops, the Servomotor's maximum momentary torque increases, and as the temperature rises, the
Servomotor's maximum momentary torque decreases.
The maximum momentary torque rises by 4% at a normal temperature of 20
°
C compared to a
temperature of
−
10
°
C. Conversely, the maximum momentary torque decreases about 8% when
the magnet warms up to 80
°
C from the normal temperature of 20
°
C.
Generally, when the temperature drops in a mechanical system, the friction torque and the load
torque increase. For that reason, overloading may occur at low temperatures. In particular, in
systems that use a Decelerator, the load torque at low temperatures may be nearly twice as much
as the load torque at normal temperatures. Check whether overloading may occur at low
temperature startup. Also check to see whether abnormal Servomotor overheating or alarms occur
at high temperatures.
An increase in load friction torque seemingly increases load inertia. Therefore, even if the Servo
Drive gains are adjusted at a normal temperature, the Servomotor may not operate properly at low
temperatures. Check to see whether there is optimal operation even at low temperatures.
0.2
1000 2000 3000 4000 5000
0
0.4
0.6
0.8
1.0
0.5
1000 2000 3000 4000 5000
0
1.0
1.5
2.0
R88M-GP10030H
R88M-GP20030H
0.90
0.32
0.32
0.16
1.75
1.82 (4700)
0.64
0.28
0.64
1.0
1000 2000 3000 4000 5000
0
2.0
3.0
4.0
R88M-GP40030H
2.0
3.60
0.64
1.3
1.3
(3600)
3.60
1.82
0.90
(N·m)
(N·m)
(N·m)
(r/min)
(r/min)
(r/min)
Continuous usage
Repetitive usage
Continuous usage
Repetitive usage
Continuous usage
Repetitive usage