Appendix 2-1-3 Continuous Characteristics - Mitsubishi Electric MELDAS MDS-R Series Technical Specification And Instruction Manual

Appendix 2-1-3 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 (2-2).
Motor
0
speed
Motor
0
torque
T1
Trms =
Select a motor so that the continuous effective load torque Trms is 80% or less of the stall torque Tst.
Trms ≤ 0.8 . Tst
The amount of acceleration torque (Ta) shown in tables 2-1 and 2-2 is the torque to accelerate the load
inertia in a frictionless state. It can be calculated by the expression (2-4). (For linear acceleration/
deceleration)
(J + J
L
Ta =
95.5 × ta
For an unbalance axis, select a motor so that the motor shaft conversion load torque (friction torque +
unbalance torque) is 60% or less of the stall.
≤ 0.6 . Tst
T
L
Appendix 2. Selection
<1> <2> <3>
T
1
T
2
T
3
t t t
1 2 3
Fig. 1 Continuous operation pattern
2 2 2
·t1 + T2 ·t2 + T3 ·t3 + T4
) × N
M (N . m)
N : Motor reach speed
J : Motor shaft conversion load inertia
L
J : Motor inertia
M
ta : Linear acceleration/deceleration time constant
<4> <5> <6> <7>
T
4
T
6
T
5
t t t
4 5 6
t
0
2 2 2
·t4 + T5 ·t5 + T6 ·t6 + T7
t0
.................................................. (2-3)
..................................................
.................................................. (2-5)
A2 - 3
<8>
T
7
Time
T
8
t t
7 8
2 2
·t7 + T8 ·t8
....................
(r/min)
(kg . cm
2
)
(kg . cm 2
)
(ms)
(2-2)
(2-4)