Specialized Concentrated Focused
「
22
」
Servo Motor
divided by rotating inertia value of the motor (with symbol
“J
M
”). The parameter for inertia ratio of WISE
driver is Pr004, whose default value is 250, namely, 2.5 times of the value of rotating inertia value of the
motor.
According to general standards, for motor with 0.75kW less capacity, inertia ratio is 20 times or less,
while for ones with 1.0kW less capacity, it is 10 times or less.
If more quick response is required, the inertia ratio should be smaller; on the contrary, if acceleration
time can be several seconds, a larger inertia ratio can be enabled. Please note that unit of motor inertia
listed on the product catalog is
“
×
10
-4
kg
·
m
2
”.
Shape
Formula for J
Shape
Formula for J
Disc
D
2
2
1
[
]
8
J
WD kg m
W:Mass [kg]
D:Outer diamater [m]
Hollow cylinder
d
D
2
2
2
1
(
)[
]
8
J
W D
d
kg m
W:Mass [kg]
D:Outer diameter [m]
d:Inner diameter [m]
Prism
a
c
b
2
2
2
1
(
)[
]
12
J
W a
b
kg m
W:Mass [kg]
a,b,c:Lengths of three
sides of the prism
[m]
Homogeneous
cylinder rod
D
L/2
L/2
2
2
2
1
(3
4
)[
]
48
J
W
D
L
kg m
W:Mass [kg]
D:Outer diameter [m]
L:Length [m]
Straight rod
L
2
2
1
[
]
3
J
WL kg m
W:Mass [kg]
L:Length of rod [m]
Cylinder rod
away from the
rotating
center
D
S
2
2
2
1
[
]
8
J
WD
WS kg m
W:Mass [kg]
D:Outer diamter [m]
L:Length [m]
Rotary axis away
from the cube
center
2
2
2
2
(
)[
]
12
a
b
J W
R
kg m
W:Mass[kg]
a,b:Length/width of
cube [m]
R:Length [m]
Reducer
J
1
J
2
n
1
n
2
a
b
Convert to inertia ratio of a
axis
2
2
2
1
2
1
(
)
[
]
n
J
J
J kg m
n
n
1
:rotational speed of a axis
[r/min]
n
2
:rotational speed of b axis
[r/min]