IAI America SSPDACR - Manual (Page 53)

8. Operating Conditions
45
8. Operating Conditions
8.1 Duty Ratio during Continuous Operation
Operate at duty ratios equal to or greater than the allowable value.
“Duty ratio” refers to a utilization ratio indicating the percentage of the time during which the actuator is operating
in one cycle.
Caution: If an overload error occurs, increase the standstill time to lower the duty or decrease
the acceleration/deceleration.
[How to Calculate Duty]
Calculate the load factor and acceleration/deceleration time ratio and find an applicable duty ratio on a graph of
calculated values.
If the load factor is less than 50%, the actuator can be operated at a duty ratio of 100% (continuous operation).
[1] Load factor LF
The maximum payload capacity at rated acceleration, and rated acceleration/deceleration, are specified in 2,
“Specifications.”
[2] Calculate the acceleration/deceleration time ratio t
od
using the calculation formula below:
Acceleration/deceleration time ratio t
od
=
Acceleration time during operation + Deceleration time during operation / Operating time (%)
Acceleration time = Operating speed [mm/s] / Acceleration during operation [mm/s 2 ] (sec.)
Acceleration (mm/s 2 ) = Acceleration (G) x 9,800 mm/s 2
Deceleration time = Operating speed [mm/s] / Deceleration during operation [mm/s 2 ] (sec.)
Deceleration (mm/s 2 ) = Deceleration (G) x 9,800 mm/s 2
[3] Find the applicable duty ratio on the graph based on each load factor LF for which the duty ratio has been
calculated, and the acceleration/deceleration time ratio t
od
.
Example) If the load factor LF is 80% and acceleration/deceleration time ratio t
od
is 80%, a reference duty is
approx. 75%.
LF = Less than 50%
LF = 60%
LF = 70%
LF = 80%
LF = 90%
LF = 100%
Reference duty (%)
Load factor (%)
Acceleration/deceleration time ratio t od (%)
Approx. 75%
100
80
60
40
20
0
0 20 40 60 80 100
[When commanded acceleration speed is lower than the
rated acceleration speed]
Load factor : LF = M × D / M r × D
r [%]
Maximum payload capacity at rated acceleration : M r [kg]
Rated acceleration/deceleration : D
r [G]
Transfer weight during operation : M [kg]
Acceleration/deceleration during operation : D [G]
[When commanded acceleration speed is higher than the
rated acceleration speed]
Load factor : LF = M × D / M
d
× D = M / M
d
[%]
Transportable weight in commanded acceleration : M
d
[kg]
Transfer weight during operation : M [kg]
Acceleration/deceleration during operation : D [G]