Mitsubishi Electric HG-AK, Instruction Manual

Page: 363 / 392

APPENDIX
App. - 16
App. 5.5 Capacity selection
As a first step, confirm the load conditions and temporarily select the servo motor capacity.
Then, determine the operation pattern, calculate required torques according to the following equations, and
check that the servo motor of the initially selected capacity may be used for operation .
(1) Initial selection of servo motor capacity
After calculating the load torque (T
L
) and load moment of inertia (J
L
), select a servo motor which will
satisfy the following two relations.
Servo motor rated torque > T
L
Servo motor J
M
> J
L
/m
m = 3 : High duty (more than 100 times/min.)
Settling time; 40 ms or less
m = 5 : Middle frequency (60 times/min. to 100 times/min.)
Settling time; 100 ms or less
m = Permissible load moment of inertia : Low duty (less than 60 times/min.)
Settling time; more than 100 ms
Find the acceleration and deceleration torques and continuous effective load torque as described in (2)
to make a final selection. For high-duty positioning, the load moment of inertia (J
L
) value should be as
small as possible.
If positioning is infrequent as in line control, the load moment of inertia (J
L
) value may be slightly larger
than in the above conditions.