Mitsubishi HG-RR ユーザーズマニュアル

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APPENDIX 
App. -  24 
 
(6)  Load moment of inertia (converted into equivalent value on servo motor shaft) 
Moving part 
 
J
L1
 = W • 
2
S  10
-3
2
 = 1.52 • 10
-4
 [kg•m
2
 
Ball screw 
 
J
L2
 = 
32
B
 • D
B
4
 • 
n
1
2
 = 0.24 • 10
-4
 [kg•m
2
 
ρ = 7.8 • 10
3
 [kg/m
3
] (iron) 
 
Gear (servo motor shaft) 
 
J
L3
 = 
32
G
 • D
G1
4
 = 0.03 • 10
-4
 [kg•m
2
 
Gear (load shaft) 
 
J
L4
 = 
32
G
 • D
G2
4
 • 
n
1
2
 = 0.08 • 10
-4
 [kg•m
2
 
Full load moment of inertia (converted into equivalent value on servo motor shaft) 
 
J
L
 = J
L1
 + J
L2
 + J
L3
 + J
L4
 = 1.9 • 10
-4
 [kg•m
2
 
(7)  Temporary selection of servo motor 
Selection conditions 
 
(a)  Load torque < servo motor rated torque 
 
(b)  Full load moment of inertia < J
R
 • moment of inertia of the servo motor 
J
R
: Recommended load to motor inertia ratio 
According to above conditions, HG-KR23 (rated torque: 0.64 N•m, maximum torque: 2.2 N•m, 
moment of inertia: 0.221 • 10
-4
 kg•m
2
) is selected temporarily.