Study On Load-Split Characteristics And Dynamics Of Two-Stage Star Gear Trains

The paper mainly studies the load-split characteristics and nonlinear dynamics of two-stage star gear trains. Some progress and developments have been made on key issues such as load sharing analysis and design, nonlinear dynamics modeling, solution techniques to the nonlinear differential equations and dynamic behaviors analysis of the systems.The load split characteristics of two-stage star gear trains are studied and an experimental verification on dynamic load sharing is developed.The static and dynamic analysis models are presented, respectively. The load sharing coefficients of the gear train are formulated. The influences of errors, stiffness and number of star gears on the load split characteristics are analyzed. The load sharing coefficients of a two-stage star gear train are measured. The results of theory and experiment are compared.The design method of load sharing of star gear trains based on load split is proposed. Errors of basic parts are calculated based on the given load sharing coefficients by the optimization arithmetic. The static and dynamic errors of the system are designed to meet the given load sharing coefficients.The method of calculating floating displacement of the system is developed. Floating displacements of basic parts are calculated. The influences of the main designed parameters on floating displacement and the floating displacement on the load sharing coefficient are analyzed.A nonlinear dynamic analysis model including the transmission error, time-varying stiffness and backlash is constructed. A new set of coordinate is adopted in order to eliminate the rigid body movement and be convenient to solve the equation.Incremental harmonic balance method (IHBM) formulations are derived for multiple degrees of freedom nonlinear dynamic equations of two-stage star gear train with backlash. The nonlinear frequency response characteristics of the system are obtained by using IHBM. The influence of time-varying stiffness and errors on the system dynamic characteristic is analyzed. The nonlinear dynamic behavior of the system is discussed. Employing variable step size RK integration method, the nonlinear differential equations with multiple backlash are solved. The routes to chaos under the condition of changing the parameters of the system are discovered. The influence of backlash on the dynamic characteristics is investigated.