Mitsubishi Electric Melservo-J5 MR-J5 Series - Page 167

6 OPTIONS AND PERIPHERAL EQUIPMENT
6.2 Regenerative option
165
6
*1 Load torque converted into equivalent value on servo motor shaft TL can be calculated with the following formula. T
L
= {(F
C
+ ( × W
L
×
g)) × S} / (2000 ×  × )
*2 Load moment of inertia converted into equivalent value on servo motor shaft JL can be calculated with the following formula. J
L
= J
L1
+
J
L2
+ J
L3
J
L1
is the load moment of inertia of the moving part, J
L2
is the load moment of inertia of the ball screw, and J
L3
is the load
moment of inertia of the coupling. J
L1
and J
L2
can be calculated with the following formulas. J
L1
= W
L
× (S / (20 × ))
2
J
L2
= {( ×
0.0078 × (L
B
/ 10)) / 32} × (D
B
/ 10)
4
From the calculation results in (1) to (8), find the absolute value (Es) of the sum total of negative energies.
■Losses of servo motor and servo amplifier in regenerative mode
The following table lists the efficiencies and other data of the servo motor and servo amplifier in the regenerative mode.
Inverse efficiency (
m
): Efficiency including some efficiencies of the servo motor and servo amplifier when rated (regenerative)
torque is generated at rated speed. Efficiency varies with the speed and generated torque. Because the characteristics of the
electrolytic capacitor change with time, allow inverse efficiency of approximately 10 % higher than those shown above.
Capacitor charging (Ec): Energy charged into the electrolytic capacitor in the servo amplifier
Regenerative
power
Torque T applied to servo motor [N•m]
*1*2
Energy E [J]
(1)
(2) T
2
= T
L
E
2
= 0.1047 • N • T
2
• t
1
(3)
(4), (8) T
4
, T
8
= 0 E
4
, E
8
= 0 (No regeneration)
(5)
(6) T
6
= T
L
E
6
= 0.1047 • N • T
6
• t
3
(7)
Servo amplifier Inverse efficiency [%] Capacitor charging [J]
MR-J5W2-22G_ 85 17
MR-J5W2-44G_ 90 21
MR-J5W2-77G_ 90 44
MR-J5W2-1010G_ 90 44
MR-J5W3-222G_ 85 21
MR-J5W3-444G_ 90 31
(J
L
/ + J
M
) • N
9.55 • 10
4
t
psa1
1
•
T
1
=
+ T
L
2
0.1047
E
1
=
• N • T
1
• t
psa1
-(J
L
•  + J
M
) • N
9.55 • 10
4
t
psd1
1
•
T
3
=
+ T
L
2
0.1047
E
3
= • N • T
3
• t
psd1
(J
L
/ + J
M
) • N
9.55 • 10
4
t
psa2
1
•
T
5
=
+ T
L
2
0.1047
E
5
=
• N • T
5
• t
psa2
-(J
L
•  + J
M
) • N
9.55 • 10
4
t
psd2
1
•
T
7
=
+ T
L
2
0.1047
E
7
= • N • T
7
• t
psd2