Harmonic Drive FHA-Cmini Series, Manual

Page: 46 / 68

2-4 Examining operating status
Selection guidelines
2-9
1
2
3
4
5
6
7
8
9
10
11
Apx
Se
lec
tion gui
de
lin
es
Linear operation (horizontal operation)
The rotary torque when the mass W moves horizontally due to the screw of pitch P is shown below.
T: Rotary torque (N·m)
μ : Friction coefficient
W: Mass (kg)
P: Screw feed pitch (m)
Linear operation (vertical operation)
The rotary torque when the mass W moves vertically due to the screw of pitch P is shown below.
Acceleration time and deceleration time
Calculate acceleration and deceleration times for the selected actuator.
Acceleration time:
Deceleration time:
T
a
: Acceleration time (s)
T
d
: Deceleration time (s)
J
A
: Actuator inertia moment (kg·m
2
)
J
L
: Load inertia moment (kg·m
2
)
N: Actuator rotation speed (r/min)
T
M
: Maximum actuator torque (N·m)
T
F
: Actuator friction torque (N·m)
T
F
= K
T
x I
M
– T
M
K
T
: Torque constant (N·m/A)
I
M
: Max. current (A)
T
L
: Load torque (N·m): The polarity is positive (+) when the torque is applied in the rotation direction, or
negative (-) when it is applied in the opposite direction.
Example 1
Select an actuator that best suits the following operating conditions:
• Rotation speed: 100 r/min
• Load inertia moment: 0.04 kg·m
2
• Since the load mechanism is mainly inertia, the load torque is negligibly small.
1
After applying these conditions to the graph in [2-1], FHA-11C-50 is tentatively selected.
2
From the rated table in [1-4], the following values are obtained: J
A
= 0.017 kg·m
2
,
T
M
= 8.3 N·m. K
T
= 6.6 N·m/A, I
M
= 1.6A.
Mass: W
Pitch: P
Friction: μ
π ×
× × µ × =
2
P
W 8 . 9 T
π ×
× × =
2
P
W 8 . 9 T
Pitch: P
Mass: W
ta td
N
Time
Rotation speed
( )
L M
L A a
T T
N
60
2
J J t
−
×
π ×
× + =
( )
L F M
L A d
T T 2 T
N
60
2
J J t
+ × +
×
π ×
× + =