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5
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Planetary gearboxes RG
Duty cycle
The correct investigation of actual duty cycle is the basic rule in planetary gearbox selection.
An operative and basic duty cycle can be pictured as follows: :


Torque
Nm
T
2 max
T
2 mid


T
ime
T
2 mid



Speed
rpm
n
2 max

n
2 mid
Time
t
1
t
2
t
3
t
4
t
tot
= Cycle
where:
n
2 max
[ rpm ] - Max. speed
n
2 mid
[ rpm] - Average speed
t
1
[ s ]
- Acceleration time
t
2
[ s ]
- Operation time
t
3
[ s ]
- Deceleration time
t
4
[ s ]
- Pause time
T
2 max
[ Nm ] - Max. acceleration torque
T
2 mid
[ Nm ] - Operation torque
T
2 dec
[ Nm ] - Deceleration torque




Operation
The operative duty cycle fixed, there are two operation ways:
-
Continuous (S1)
-
if
S
p
>
60%
- or S
t
> 20
minutes
otherwise
-
Intermittent (S5)
-
if
S
p
<
60%
-
and
S
t
< 20
minutes

where:
S
p
- per cent operation time
S
t
- operation time
min
- minutes
[min]
60
t
t
t
t
S
[%]
100
t
t
t
t
t
S
4
3
2
1
t
tot
4
3
2
1
p
Duty cycle - Operation
[min]
60
t
t
t
t
S
[%]
100
t
t
t
t
t
S
4
3
2
1
t
tot
4
3
2
1
p