Yaskawa SGDS Sigma III Servo Amplifier - Manual (Page 320)

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
2 πR
0.005
2 π × 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)
2 πN
M
T
L
60
2 π × 3000 × 0.139
60
P
a
=
(
N
M
) 2
=
(
× 3000
) 2 -4
= 123.4 (W)
2 π
60
2 π
60
J
L
ta
1.25 × 10
0.1
T = + T = + 0.139
60ta 60 × 0.1
2
π
N (J + J ) 2
π × 3000 × (0.209 + 1.25) × 10
P
−4
M M L
L
0.597 (N m) < Instantaneous peak torque Satisfactory