Mitsubishi Electronics MDS-D-SPJ3 Engraver User Manual


 
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7 Selection
MITSUBISHI CNC
(e) Confirmation in the torque characteristics
Confirm whether the maximum torque "Ta1" and maximum torque occurrence speed "Nm" required for
this acceleration/deceleration pattern calculated in the item "(b)" to "(d)" are in the short time operation
range of the torque characteristics.
Motor torque characteristics
If they are not in the short time operation range, return to the item "(b)" to "(d)" and make the linear
acceleration/deceleration time constant "ta" large.
If the acceleration specification cannot be changed (the linear acceleration/deceleration time constant
cannot be increased), reconsider the selection, such as increasing the motor capacity.
1. In selecting the maximum torque "Ta1" required for this acceleration/deceleration pattern, the
measure of it is 80% of the motor maximum torque "T
MAX
"
2. In high-speed rotation range, confirm that the maximum torque "Ta1" and maximum torque
occurrence speed "Nm" required for this acceleration/deceleration is in the short time operation
range.
3. The drive system efficiency is normally approx. 0.95 in the ball screw mechanism and approx. 0.8
in the gear mechanism
4. For the torque characteristics in the motor high-speed rotation range, the AC input voltage is 200V.
If the input voltage is low or if the power wire connecting the servomotor and drive unit is long (20m
length), the short time operation range is limited. In this case, an allowance must be provided for
the selection of the high-speed rotation range.
0 2000 4000
0
20
40
100
80
60
Rotation speed [r/min]
Continuous operation range
Short time operation range
Required maximum torque: Ta1
Required maximum torque occurrence speed: Nm
Motor maximum torque
High-speed rotation range
torque characteristic
Torque [N m]
POINT