Formulas given in this chapter are only for reference and description of the adopted algorithms. Basic kinematic scheme of the planetary transmission is shown in figure 2.1.
Figure 2.1: Kinematic scheme of the planetary transmission
Numbered components in figure 2.1 are:
)
)
)
There are several transmission ratios for different mounting and variants which is shown in table 2.1 where
| Input | Fixed input | Output | Transmission ratio |
| Sun | Carrier | Ring |  |
| Ring | Carrier | Sun |  |
| Carrier | Sun | Ring |  |
| Ring | Sun | Carrier |  |
| Sun | Ring | Carrier |  |
| Carrier | Ring | Sun |  |
The most common variant is Sun - Ring - Carrier. Other connections are also used. Number of teeth is tested with the following equation
where 
must be whole number.
