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Rated output
torque Mn2 [Nm]
Torque output transmissible under uniform loading and referred
to the input speed n1 and the corresponding output
speed n2.
The output torque can be calculated with the following formula:
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Torque demand
Mr2 [Nm]
Torque calculated based on application requirements. It must
be = Mn2 of the chosen BOX unit. |
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Input power
Pn1 [kW]
This is the power value of the motor applied to the input
shaft and corresponding to a certain input speed n1
a service factor fs=1.
and a duty service S1 It is even possibile to calculate the
motorsize necessary by using the formula:
Since the value calculated in this way could not really correspond
to an input power actually available in the IEC standardised
motors, it will be necessary to choose, among the input powers
available, the one which is immediately higher, checking this
in the motive catalogue of the motors. |
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Gear ratio i
It is the relationship of the input speed n1 and
the output speed n2
In the BOX units with pre-stage reduction (BOX+PC), the total
ratio is given by the PC pre-stage reduction ratio multiplied
by the BOX unit ratio. In the combined BOX units (BOX+BOX),
the total ratio is the result of the product of the ratio of
the two single boxes composing the combined unit. |
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Input speed n1
[rpm]
It is the speed the BOX unit is driven at. |
|
Output speed
n2 [rpm]
It is the rotation speed of the output shaft. |
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Service factor
fs
It is a numeric value describing the BOX unit service duty.
With unavoidable approximation, it takes into consideration:
- the daily working hours h/d
- the load classification a, b, c (see
graph. Nr.2), and then the moment of inertia of the driven
masses.
- The number of starts per hour s/h
- . The presence of brake motors, for which it is necessary
to multiply for 1.12 the service factor value deducted by
from graph. Nr.2
- . The significance of the application in terms of safety,
for example lifting of parts
In graph. Nr.2 the service factor fsr
required by a certain application can be attained, after having
selected the proper "daily working hours" (h/d) column, by
intersecting the number of starts per hour (s/h) and one of
the a, b or c curves. The curves a, b and c are linked with
the load classification described in graph. Nr.2
| load
classification |
application |
| easy
starting, smooth operation, small masses be accelerated |
belt conveyors for light
material; centrifugal pumps; rotary gear pumps; screw
feeders for light materials; lifts; bottling machines;
auxiliary controls of tool machines; fans; power generators;
fillers; small mixers |
| starting
with moderate loads,
uneven operating conditions, medium size masses to
be accelerated |
belt conveyors with varied
load with transfer of bridge trucks for light duty;
levelling machines; shakers and mixed for liquid with
variable density and viscosity; machines for the food
industry (kneading troughs, mincing machines, slicing
machines, etc); sifting machines for sand gravel; textile
industry machines; cranes, hoists, goodstifts; fertilizer
scrapers; concrete mixers; folding machines; winches;
crane mechanisms |
| uneven
operation
heavy loads,
larger masses to be accelerated |
conveyors with violent jerks;
compressors ad alternate pumps with 1 or more cylinders;
machinery for bricks, tiles and clay; kneaders; milling
machines; lifting winches with buckets; rotting furnaces;
heavy fans or mining purposes; mixers for heavy materials;
machine-tools; planing kinds; alternating saws; shears;
tumbling barrels; vibrators; shredders; turntables |
If, after the selection of the right Mr2
and n2, in the following performance
tables, you don't find a BOX unit whose service factor fs
is equalof the requested one fsr,
you can choose a BOX unit in which Mn2
> Mr2.
In fact, in order to satisfy n2 è
you can choose another BOX unit whose output torque is Mc2,
output torque, where
Note: This rule is valid only if the new BOX unit that has been
selected in this way has a service factor fs
<1 in the performance tables.
From another point of view, the value of fs
fs in the performance tables refers to a case in which the effective
torque requested by the application Mr2
matches perfectly with the one appearing on the catalogue Mn2
Whenever the torque indicated in the performance table is higher
than the requested one, the offered service factor of the performance
table can be increased according to the formula:
The value calculated in this way must be ≥fsr
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| PERFORMANCE CHARTS
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| 
P1 0,06 kw - P1 0,09 kw - P1
0,13 kw
P1 0,18 kw - P1 0,25 kw - P1
0,37 kw
P1 0,55 kw - P1 0,75 kw - P1
1,1 kw
P1 1,5 kw - P1 2,2 kw - P1
3 kw
P1 4 kw - P1 5,5 kw - P1
7,5 kw
P1 9,2 kw - P1 11 kw - P1 15 kw |
Remark:
This table is in PDF format. To view and print it, you need
Acrobat Reader:
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