Harmonic Drive FHA Mini Series, Руководство пользователя

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Chapter 2 Guidelines for sizing
FHA-mini
30
• Horizontal linear motion
The following formula calculates the torque for horizontal linear motion of mass [W] fed by the screw of
pitch [P].
T: torque (N•m)

: coefficient of friction
W: mass (kg)
P: screw pitch (m)
• Vertical linear motion
The following formula calculates the torque for vertical linear motion of mass [W] fed by the screw of
pitch [P].
2-4-4 Acceleration time and deceleration time
Calculate acceleration and deceleration times for the selected actuator.
Acceleration:
Deceleration:
T
a
: acceleration time (sec)
T
d
: deceleration time (sec)
J
A
: actuator inertia (kg•m
2
)
J
L
: load inertia (kg•m
2
)
N: actuator speed (rpm)
T
M
: maximum torque of actuator (N•m)
T
F
: actuator friction torque at max. speed (N•m)
T
F
= K
T
x I
M
- T
M
where, K
T
: torque constant (N•m/A)
I
M
: maximum current (A)
T
L
: load torque (N•m)
note that the polarity of the load torque is plus (+) for counter direction of revolution, and minus
(-) for same direction.
• Example 1:
The load conditons are:
Rotary speed: 100rpm
Moment of inertia: 0.04 kg•m
2
Load torque is negligibly small.
(1)
Refering the figure in section 2-1, FHA-11C-50 actuator is selected for the load.
(2)
Refering the specification table in section 1-4, J
A
=0.017 kg•m
2
, T
M
=8.3 N•m, K
T
=6.6 N•m/A,
and I
M
=1.6A are obtained for the FHA-11C-50.
(3)
T
F
= 6.6x1.6-8.3 = 2.3 N•m is obtained with the formula above.
(4)
Acceleration and deceleration times are:
t
a
= (0.017+0.04)x2x
π
/60x100/8.3 = 0.072 s
t
d
= (0.017+0.04)x2x
π
/60x100/(8.3+2x2.3) = 0.046 s
(5)
If the calculated acceleration/deceleration times are too long, correct the situation by:
Reducing load moment of inertia
Selecting an actuator with a larger frame size
Mass: W
Pitch: P
Friction:

Pitch: P
Mass: W
ta td
N
Time
Speed