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Appendix A Calculation of total inertia (reflected to the motor shaft)
(A-1) Ventilation Fan
s
Inertia of a motor = J
s
Inertia of a fan
Total inertia J = J
(Note) If there is a pulley inbetween them, calculation will be as follows.
Motor
Rotation = N
[rpm]
1
Inertia J
[kgm2]
M
Pulley 1
Rotation = N
[rpm]
1
Inertia J
[kgm2]
1
(A-2) Truck
s
Maximum speed
s
Maximum motor rotation = N
s
Inertia of a gear box = J
s
Inertia of mechanics = J
s
Inertia of a motor
s
Inertia of the load
(*) Contact each manufacturer for each
2
J [kgm
] value.
Total inertia
W
V
Ÿ
1
J
L
2
4
W
= W
+ W
1
2
Refer to Appendix B for calculation of load inertia.
© 2002 Hitachi America, Ltd.
2
[kgm
]
M
2
= J
[kgm
] : Contact a fan manufacturer for the J
L
+ J
M
L
Pulley 2
Rotation = N
[rpm]
2
Inertia J
[kgm2]
2
= V
[m/min]
max
[rpm]
max
2
[kgm
] (*)
G
2
[kgm
] (*)
m
2
= J
[kgm
] (*)
M
2
= J
[kgm
]
L
J = J
+ J
+ J
+ J
G
m
M
L
2
max
2
[kgm
]
2
N
max
[kg] : Total weight
3
Ventilation fan
Inertia J
[kgm2]
L
Inertia
Motor
J
M
Pulley 1
J
1
Pulley 2
J
2
Fan
J
L
Total
-
Truck : W
[kg]
2
Brake
J
[kgm
B
Gear box
M
B
J
[kgm
]
2
G
Motor
Mechanics
J
[kgm
]
2
M
J
[kgm
]
2
N
[rpm]
m
max
25
value.
L
Rotation
Converted Inertia
N
1
N
1
N
J
2
2
N
J
L
2
-
J
J
J
1
M
2
Material
Ÿ W
[kg] : Possible max. weight
]
2
3
J
M
J
1
2
N
2
N
1
2
N
2
N
1
2
2
N
N
2
2
J
L
N
N
1
1
V
[m/min]
max
: Max. speed
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