以两级行星齿轮传动系统为研究对象，基于集总参数法，引入时变啮合刚度、齿侧间隙、综合啮合误差等非线性因素，考虑了级间相对浮动，建立了系统“平移-扭转”耦合强非线性动力学方程组(EOM)。通过对系统微分方程组进行数值积分求解，分别分析了有无级间相对浮动时多误差耦合以及相对浮动间隙的大小对系统均载特性的影响。结果表明：多误差的耦合作用会使系统均载性能变差，且构件误差对所在一级的均载特性影响程度更大；级间相对浮动能够有效改善系统的均载性能，减弱构件误差的级间耦合作用，且随着相对浮动间隙的增大系统第一级均载性能得到改善。

The translation-torsion coupling dynamics equations of motion(EOM) were established for a two-stage planetary gear transmission system, using the lumped parameter method.The nonlinear factors such as time-varying mesh stiffness, backlash, comprehensive meshing error and relative floating between stages were considered.The EOM were solved by the numerical integration method, and the effects of the multi-error coupling and the relative floating clearance on the load sharing characteristic of the system were analyzed.The results show that the coupling effect of comprehensive meshing errors will deteriorate the system’s load sharing performance.The load sharing characteristic of the stage becomes worse when the comprehensive meshing errors are introduced by the components of this stage.The relative floating between stages can effectively improve the load sharing performance of the system and reduce the inter-stage coupling effect of component errors.Meanwhile, the first-stage load sharing performance of the system is improved with the additional consideration of the relative floating clearance in the EOM.