When the planetary gear reduction box to determine the number of teeth of planetary gear train, to consider the following conditions:
1 transmission ratio condition
Planetary gear train design must be able to achieve a given transmission ratio, the transmission planetary gear train various types of mechanical design manual can be found from the relationship between the ratio of the number of teeth.
2. adjacency conditions
The adjacent two planetary gear addendum does not interfere with each other to ensure that there is at least among the top half of the tooth modulus voids even the heart line.
3. Concentric conditions
All actual center gear wheel pair by the center and away from the planet wheel component must be equal.
4. The assembly conditions
In the planetary gear train, several planet wheels can be loaded symmetrically with the center wheel and ensures correct engagement of teeth should have relations.