In this paper,a static model of encased differential herringbone train system with intermediate floating components is proposed based on the theory of the concentrated parameter. In this model,the curves of the eccentric and installation errors versus the load sharing factors are obtained by calculating the load sharing factors,and then the impacts of the errors on the load sharing behaviors of the train system are analyzed. The results show that ( 1) at the same initial phase angle,the eccentric errors of the planet /star gears have no influence on the load sharing factors; ( 2) unlike the planet gears of the differential stage,the load sharing factors of the star gears,which are caused by the installation errors,do not change with time in the encased stage; and ( 3) the load sharing factors of the differential stage are greater and more sensitive to the errors than those of the encased stage.