15
Kinetic energy
Allowable kinetic energy is shown in Table 1.
Since the rotary actuator reaches the rotation end in the middle of acceleration, terminal acceleration
"ω" can be found with the calculation shown below
：
ω = 2θ / t
θ:
：
Rotating angle (rad)
t:
：
Rotation time (s)
Kinetic energy E can be found with the formula below
：
E = 1 / 2
・
I
・
ω
2
Therefore, rotation time "t" of the rotary actuator is as shown below.
t
＝
E
I
2
2
E
：
Kinetic energy (J)
I
：
Moment of inertia (kg / m
2
)
θ:
：
Rotating angle (rad)
180
o
= 3.14 rad
During uniform acceleration, angular speed ω after t seconds and
displacement angle θ can be found as shown below.
ω
＝
x t
(1)
θ
＝ ∫
t d t
＝
1 / 2
t
２
+
C
(2)
C is integration constant.
When t = 0, rotation angle θ = 0, so the integration constant is C = 0.
θ = 1 / 2
t
2
= 1 / 2 ω t
Therefore,
ω = 2 θ / t
Table 1 Unit (J)
Model
Allowable kinetic energy
CRB
10
0.00015
CRB
15
0.001
CRB
20
0.003
CRB
30
0.02
CRB
40
0.04