YASKAWA SGM7E - Selecting the Servomotor Capacity

2.1 Selecting the Servomotor Capacity
2-2
2.1 Selecting the Servomotor Capacity
Contact your Yaskawa representative for information on the Servomotor capacity selection soft-
ware.
Refer to the following selection examples to select Servomotor capacities with manual calculations.
1. Mechanical Specifications
2. Motor Speed of Direct Drive Servomotor
3. Operation Pattern
4. Load Moment of Inertia
5. Load Acceleration/Deceleration Torque
6. Provisional Selection of Direct Drive Servomotor
 Selection Conditions
• Load acceleration/deceleration torque < Instantaneous maximum torque of Direct Drive
Servomotor
• Load moment of inertia < Allowable load moment of inertia ratio (J
R
) × Moment of inertia of
Direct Drive Servomotor (J
M
)
Turntable
Servomotor
D
T
Item Code Value Item Code Value
Tur ntable Mass
W
12 kg
Acceleration/
Deceleration
Time
t
p
= t
psa
= t
psd
0.1 s
Tur ntable
Diameter
D
T
300 mm
Operating
Frequency
t
f
2 s
Rotational Angle
per Cycle
θ 270 deg Load Torque
T
L
0 Nm
Positioning Time
t
0
0.35 s Settling time
t
s
0.1 s
N
O
= × = × = 300 (min
-1
)
360 (t
0
- t
p
- t
s
)
θ
360 (0.35 - 0.1 - 0.1)
270 6060
300
0.1
0.1 0.1
t
s
2.0
0.35
Motor speed (min
-1
)
Time (s)
One cycle (t
f
)
t
0
t
s
t
psd
t
psa
8
1
8
1
J
L
= × D
T
2
× W = × (300 × 10
-3
)
2
× 12 = 0.135 (kg  m
2
)
T
a
= J
L
× 2 π × = 0.135 × 2 π × = 42.4 (N  m)
N
O
/60
t
p
300/60
0.1