Mitsubishi MELDAS HS Series User Manual

Chapter 11 Selection
11–7
11-3-3 Continuous characteristics
A typical operation pattern is assumed, and the motor's continuous effective load torque (Trms) is
calculated from the motor shaft conversion and load torque. If numbers ① to ⑧ in the following
drawing were considered a one cycle operation pattern, the continuous effective load torque is
obtained from the root mean square of the torque during each operation, as shown in the expression
(11-3).
Motor
torque
Motor
speed
0
0
T
3
T
2
t1 t2 t3 t4
t0
T1
Time
T4
T5
T6
T7
T8
t5 t6 t7 t8
① ② ③ ④ ⑤ ⑥ ⑦ ⑧
Fig. 11-1 Continuous operation pattern
Trms =
T1
2
·t1 + T2
2
·t2 + T3
2
·t3 + T4
2
·t4 + T5
2
·t5 + T6
2
·t6 + T7
2
·t7 + T8
2
·t8
t0
.................. (11-3)
Select a motor so that the continuous effective load torque (Trms) is 80% or less of the motor rated
torque (Tra) (stall torque (Tst) in the HC, HAN Series).
Trms ≤ 0.8 • Tra (or 0.8 • Tst) ................................................. (11-4)
The amount of acceleration torque (Ta) shown in tables 11-6 and 11-7 is the torque to accelerate the
load inertia in a frictionless state. It can be calculated by the expression (11-5). (For linear
acceleration/deceleration)
Ta =
(J
L
+ J
M
)
×
N
95.5 × ta
(N•m) ................................................. (11-5)
N : Motor reach speed (r/min)
JL : Motor shaft conversion load inertia (× 10
–4
kg·cm
2
)
JM : Motor inertia (× 10
–4
kg·cm
2
)
ta : Linear acceleration/deceleration time constant (msec)

Mitsubishi MELDAS HS Series Specifications

General

Brand	Mitsubishi
Model	MELDAS HS Series
Category	Servo Drives
Language	English