In selecting the most suitable Planetary Gearbox for your application, the TAB output torque is the most important variable. Use the equation compendium below to calculate this variable. Reduction ratio i is used to reduce the relatively high motor speed nM
to a lower output speed nAB.
With: i = nM / nABYour desired nominal output torque TN is therefore calculated as follows:
TN = TM · i · h / sf
- Reduction ratio i (for reduction ratio, see Ratios & P/N tab above)
- Gear efficiency h is found in data for specific MDrivePlus/rotary motor - gearbox combinations (see product datasheets).
When calculating the actual output torque TAB, the calculated nominal output torque TN and the operating factor CB should also be taken into account. CB is merely a factor which addresses the different working conditions of a Planetary Gearbox and which is the result of your subjective appraisal. It is therefore only meant as a guide value. We include the following factors in the rough estimation of the operating factor CB—direction of rotation, load (shocks) and daily operating time. Please refer to the table below to calculate the approximate operating factor CB.
| Determining
the Operating Factor CB |
| Direction
of Rotation |
Load
(shocks) |
Daily
operating time |
| |
|
3
hours |
8
hours |
24
hours |
| Constant |
Low 1 |
CB = 1.0 |
CB = 1.1 |
CB = 1.3 |
| |
Medium 2 |
CB = 1.2 |
CB = 1.3 |
CB = 1.5 |
| Alternating |
Low 3 |
CB = 1.3 |
CB = 1.4 |
CB = 1.6 |
| |
Medium 4 |
CB = 1.6 |
CB = 1.7 |
CB = 1.9 |
1
Low shock – Motor turns in one direction only and has ramp up at start.
2 Medium shock – Motor turns in one direction and has no ramp up at start.
3 Low shock – Motor turns in both directions and has ramp up at start.
4 Medium shock – Motor turns in both directions and has no ramp up at start.
The maximum output torque TAB is then calculated as follows:
TAB = TN · CB
