I think we have a problem with this rule. This is my understanding of the existing rule. Am I close? The rule for calculating the power distribution on a power split planetary gear system is based on the equal force rule. To calculate the power on the sun and ring of a planet set with input on the carrier we first determine the power in on the carrier. From the torque on the carrier we determine the force on the carrier based on its radius. Now we apply the equal force rule. Because of the planet gear’s independence it maintains its equilibrium between the carrier and the sun and ring. The rule is that the forces on the sun and ring from the carrier are always equal to one half each of the carrier force. The torques on the sun and ring are proportional to their radius. The power distribution between the ring and sun is rpm dependent.