YASKAWA SGM7J-A5A, Technical Supplement

Page: 595 / 622

Appendices
Capacity Selection for Servo Motors
577
Appendices
Capacity Selection Example for Direct Drive Servo Motors
1.
Mechanical Specifications
2.
Motor Speed of Direct Drive Servo Motor
3.
Operation Pattern
4.
Load Moment of Inertia
5.
Load Acceleration/Deceleration Torque
6.
Provisional Selection of Direct Drive Servo Motor

Selection Conditions
•
Load acceleration/deceleration torque < Instantaneous maximum torque of Direct Drive Servo Motor
•
Load moment of inertia < Allowable load moment of inertia ratio (J
R
)

Moment of inertia of Direct
Drive Servo Motor (J
M
)
The following Servo Motor meets the selection conditions.
• SGMCV-17CEA11

Specifications of the Provisionally Selected Servo Motor
Item Value
Rated Torque 17 (N

m)
Instantaneous Maximum Torque 51 (N  m)
Turntable
Servo Motor
DT
Item Code Value Item Code Value
Turntable Mass
W
12 kg
Acceleration/
Deceleration
Time
t
p
= t
psa
= t
psd
0.1 s
Turntable
Diameter
D
T
300 mm
Operating
Frequency
t
f
2 s
Rotational Angle
per Cycle

270 deg Load Torque
T
L
0 N  m
Positioning Time
t
0
0.35 s Settling Time
t
s
0.1 s
NO =
×
=
×
= 300 (min -1 )
360 ( t0 - tp - ts )
θ
360 (0.35 - 0.1 - 0.1)
270 60 60
300
0.1
0.1 0.1
ts
2.0
0.35
Motor speed (min -1 )
Time (s)
One cycle ( tf )
t0
ts
tpsd
tpsa
8
1
8
1
JL =
×
DT
2
×
W =
×
(300
×
10
-3
)
2
×
12 = 0.135 ( kg m
2
)
Ta = JL
×
2
π ×
= 0.135
×
2
π ×
= 42.4 (N m)
NO /60
tp
300/60
0.1