In order to determine the torque ratios, the figure shows the forces on a planetary wheel that is in a constant state of motion.
The balance of forces and moments on a planetary wheel results in:
Eq. 3-47

Eq. 3-48

Where:

In magnitude it results in:

Eq. 3-49a

Since:

The remaining torque ratios can be calculated similarly:

Eq. 3-49b

Eq. 3-49c


Thus, when losses in transferring moments are neglected, the ratio of torques on the three center shafts can be clearly determined only by geometric data of the planetary train.

For equilibrium ∑M = 0, we obtain

Eq. 3-50
Hence the torques are either split up or added. In this case the direction of the bar moment MB is opposite to the torques MS and MH acting in the same direction. When all shafts rotate in the same direction, the same is applicable to the power output of a planetary transmission.