Harmonic Drive CHA - Page 67

671018854 12/2015 V01
Actuator selection
Intermittent duty
Speed [rpm]
Continuous
duty
Torque [Nm]
FHA-25C-50L
Illustration 67.1
Tentatively select a required actuator based upon load conditions.
FHA-25C-50 meets the tentative selection requirements from
catalogue value (see rating table)
Calculation of the
duty factor
n
2
= 40 rpm< n
max
= 90 rpm
J
L
= 1.3 kgm
2
< 3J
out
= 2.58 kgm
2
ED =
0.1 + 0.1 + 0.1
· 100%
1.3
ED = 23 %
Calculate required acceleration torque (T
1
)
T
rms
= 35 Nm
n
av
= 6 rpm
T
1
= 5 +
2π
·
(1.3 + 0.86) · 40
= 93 Nm
60 0.1
Confirm: Is the required acceleration torque less than
the maximum output torque of the actuator?
Check according to the performance characteristics
T
rms
and n
av
are inside the continuous duty zone
T
1
= 95 Nm < T
max
= 151 Nm
Yes
Confirm final selection
Calculate effective torque (T
rms
)
T
1
= 95 Nm
T
2
= T
L
= 5 Nm
T
3
= T
L
- (T
1
- T
L
) = - 85 Nm
95
2
· 0.1 + 5
2
· 0.1 + (-85)
2
· 0.1
T
rms
= 1.3 = 35 Nm
Calculation of the average speed
n
av
= 6 rpm
No
ED = 1 min.
min
-1
= rpm
^
n
av
=
40
2
.
0,1 + 40
.
0,1 + 40
.
0,1
2
1,3