Omron R88M-K Series User Manual page 212

3-3 Servomotor Specifications
Temperature Characteristics of the Motor and Mechanical System
 OMNUC G5-Series AC Servomotors use rare earth magnets (neodymium-iron magnets). The
temperature coefficient for these magnets is approx. -0.13%/
As the temperature drops, the motor's momentary maximum torque increases, and as the
temperature rises, the motor's momentary maximum torque decreases.
 The momentary maximum torque rises by 4% at a normal temperature of 20
temperature of −10
the magnet warms up to 80
 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 during starting at low temperature.
Also check to see whether abnormal motor overheating or alarms occur at high temperatures.
3
 An increase in load friction torque seemingly increases load inertia.
Therefore, even if the drive gains are adjusted at a normal temperature, the motor may not operate
properly at low temperatures. Check to see whether optimal operation can be obtained even at
low temperatures.
3-95
°
C. Conversely, the momentary maximum torque decreases about 8% when
°
C from the normal temperature.
OMNUC G5-SERIES AC SERVOMOTOR AND SERVO DRIVE USER'S MANUAL
°
C.
°
C compared to a