YASKAWA SGDS Sigma III Series - Page 322

11.1 Servomotor Capacity Selection Examples
11-5
(4) Load Moment of Inertia
• Liner motion section
• Ball screw
• Coupling
• Load moment of inertia at the motor shaft
(5) Load Moving Power
(6) Load Acceleration Power
(7) Provisionally Servomotor Selection
(a) Selecting Conditions
• T
L
≤ Motor rated torque
• Pa + Po = (1 to 2) × Motor rated output
• N
M
≤ Motor rated speed
• J
L
≤ SERVOPACK allowable load moment of inertia
The followings satisfy the conditions.
• SGMAH-02 Servomotor
• SGDS-02A01A SERVOPACK
(b) Specifications of Servomotor and SERVOPACK
• Rated output: 200 (W)
• Rated motor speed: 3000 (RPM)
• Rated torque: 0.637 (N⋅m)
• Instantaneous peak torque: 1.91 (N⋅m)
• Motor moment of inertia: 0.116 × 10
-4
(kg⋅m
2
)
• SERVOPACK allowable load moment of inertia: 3.48 × 10
-4
(kg⋅m
2
)
• Number of PG pulses: 32768 (P/R)
(8) Verification on Provisionally Selected Servomotor
• Required starting torque
J
L1
= M ( )
2
= 80 × ( )
2
= 0.507 × 10
-4
(kg  m )
P
B
2πR
0.005
2π × 1
2
J
B
= ρ  L
B
 D
B
4
= × 7.87 × 10
3
× 0.8 × (0.016)
4
= 0.405 × 10
-4
(kg  m
2
)
π
32
π
32
J
C
= M
C
 D
C
4
= × 0.3 × (0.03)
2
= 0.338 × 10
-4
(kg  m
2
)
8
1
1
8
J
L
= J
L1
 J
B
 J
C
= 1.25 × 10
-4
(kg  m
2
)
P
O
= = = 43.7 (W)
2πN
M
 T
L
60
2π × 3000 × 0.139
60
P
a
= ( N
M
)
2
= ( × 3000 )
2 -4
= 123.4 (W)
2π
60
2π
60
J
L
ta
1.25 × 10
0.1
T = + T = + 0.139
60ta 60 × 0.1
2
πN (J + J )
2
π × 3000 × (0.209 + 1.25) × 10
P
−4
MM L
L
0.597 (Nm) < Instantaneous peak torqueSatisfactory