– A-54 –
Panasonic Corporation Electromechanical Control Business Division
industrial.panasonic.com/ac/e/
©
Panasonic Corporation 2018
AQCTB02E 201806-E
– A-55 –
Panasonic Corporation Electromechanical Control Business Division
industrial.panasonic.com/ac/e/
©
Panasonic Corporation 2018
AQCTB02E 201806-E
Motor selection
• Shape
• Shape
• Shape
• Shape
• Shape
• Shape
• Shape
• Shape
• Shape
• Shape
How to calculate moment of inertia
GD
2
= WD
2
+ 4WS
2
(kgf·cm
2
)
W
: Weight
(kgf)
D
: Diameter
(cm)
S
: Turning radius
(cm)
J (Inertia calculation)
GD
2
(Flywheel effect calculation)
J = W (kg·cm
2
)
W
: Mass
(kg)
D
: Outer diameter
(cm)
L
: Length
(cm)
GD
2
= W (kgf·cm
2
)
W
: Weight
(kgf)
D
: Outer diameter
(cm)
L
: Length
(cm)
J = W (a
2
+ b
2
) (kg·cm
2
)
W
: Mass
(kg)
a.b
: Length of side
(cm)
GD
2
= W (a
2
+ b
2
) (kgf·cm
2
)
W
: Weight
(kgf)
a.b
: Length of side
(cm)
J = WD
2
(kg·cm
2
)
W
: Mass
(kg)
D
: Diameter
(cm)
GD
2
= WD
2
(kgf·cm
2
)
W
: Weight
(kgf)
D
: Diameter
(cm)
J = W (D
2
+ d
2
) (kg·cm
2
)
W
: Mass
(kg)
D
: Outer diameter
(cm)
d
: Inner diameter
(cm)
GD
2
= W (D
2
+ d
2
) (kgf·cm
2
)
W
: Weight
(kgf)
D
: Outer diameter
(cm)
d
: Inner diameter
(cm)
J = WD
2
(kg·cm
2
)
W
: Mass
(kg)
D
: Outer diameter
(cm)
GD
2
= WD
2
(kgf·cm
2
)
W
: Weight
(kgf)
D
: Outer diameter
(cm)
J (Inertia calculation)
GD
2
(Flywheel effect calculation)
J (Inertia calculation)
GD
2
(Flywheel effect calculation)
J (Inertia calculation)
GD
2
(Flywheel effect calculation)
J (Inertia calculation)
GD
2
(Flywheel effect calculation)
• Disk
• Hollow circular cylinder
• Sphere
• Cube
• Slender round bar
D
D
d
D
c
b
a
L/2
L/2
D
J (Inertia calculation)
GD
2
(Flywheel effect calculation)
Equivalent all inertia on axis “a”
J = J1 +
(
)
2
J2 (kg·cm
2
)
n
1
: Speed of axis “a”
(r/min)
n
2
: Speed of axis “b”
(r/min)
J1
: J of axis “a”
(kg·cm
2
)
J2
: J of axis “b”
(kg·cm
2
)
Equivalent all flywheel effect on axis “a”
GD
2
= GD
21
+
(
)
2
GD
22
(kgf·cm
2
)
n
1
: Speed of axis “a”
(r/min)
n
2
: Speed of axis “b”
(r/min)
GD
21
: GD
2
of axis “a”
(kgf·cm
2
)
GD
22
: GD
2
of axis “b”
(kgf·cm
2
)
J = JA + (kg·cm
2
)
W
: Mass
(kg)
P
:
Lead of feed screw
(cm)
JA
: Inertia of feed screw
(kg·cm
2
)
GD
2
= GD
2A
+ (kgf·cm
2
)
W
: Weight
(kgf)
P
:
Lead of feed screw
(cm)
GD
2A
: Flywheel effect of feed screw
(kgf·cm
2
)
J = (kg·cm
2
)
W
: Mass on the conveyor
(kg)
D
: Drum diameter
(cm)
*
Inertia of drum not included
GD
2
= WD
2
(kgf·cm
2
)
W
: Weight
on the conveyor
(kgf)
D
: Drum diameter
(cm)
*
Flywheel effect of drum not included
J = WD
2
+ WS
2
(kg·cm
2
)
W
: Mass
(kg)
D
: Diameter
(cm)
S
: Turning radius
(cm)
J = WL
2
(kg·cm
2
)
W
: Mass
(kg)
L
: Length
(cm)
1
3
1
8
1
8
1
10
1
12
3D
2
+ 4L
2
48
3D
2
+ 4L
2
12
1
3
2
5
1
2
1
2
1
8
WD
2
4
W·P
2
4π
2
n
2
n
1
n
2
n
1
W·P
2
π
2
1
2
4
3
GD
2
= WL
2
(kgf·cm
2
)
W
: Weight
(kgf)
L
: Length
(cm)
J (Inertia calculation)
GD
2
(Flywheel effect calculation)
J (Inertia calculation)
GD
2
(Flywheel effect calculation)
J(Inertia calculation)
GD
2
(Flywheel effect calculation)
J (Inertia calculation)
GD
2
(Flywheel effect calculation)
• Straight bar
• Discrete shaft
• Horizontal linear motion
• Ball screw
• Reducer
L
D
S
D
W
W
P
J1 (GD
2 1
)
J2 (GD
2 2
)
a
b
n
1
n
2
Inertia
