The elastic deformations of bearings of the coaxial members and a sun-planet-ring path were respectively considered on the carrier's and planet's bearing center

and then an equivalent model of an epicyclic gear system was established. The load sharing behavior of an epicyclic gear system was simulated by the motions of the carrier rigid body

and a model to calculate load sharing in an epicyclic gear system was presented. And then the quantitative relations among load sharing

the equivalent stiffness of bearing and errors were obtained by the proposed approach

and the influences of all kinds of factors on load sharing were analyzed. The results show that when the difference between the equivalent stiffness of carrier bearing and the equivalent stiffness of planet bearing is more than two orders of magnitude

load sharing is only related to the equivalent stiffness of planet bearing and tangential position error of the planet

so the load can be evenly distributed by reducing tangential position error of planet and the equivalent stiffness of planet bearing. Cyclical excitations will be caused by the eccentricity errors of planet or sun

and the dynamic load coefficient can be increased

so the dynamic loads will be evenly distributed by reducing the eccentricity errors of the planet and sun.