Study On Carrier Vibration Isolation And Vibration Characteristics Of Encased Differential Planetary Train

The encased differential gear train is widely used in ships. In order to improve the ship concealment in working process and to reduce the delivery of harmful vibrations inside to the box, in this paper carrier vibration isolation and vibration characteristics of encased differential planetary train are studied.Firstly, a dynamic model of the lumped mass method of the train is established. The eccentric errors and tooth frequency errors are derived, the time-varying meshing stiffness of herringbone gear is calculated. Meshing force and damping force of the center wheel pair is calculated. The kinetic equation is derived, and the rigid body displacement of the train is eliminated. The system dynamics equations are solved based on Fourier method. Effect of carriers supporting stiffness on system natural frequency, the box body and the carrier displacement and the dynamic load is researched. Then, vibration analysis based on finite element method is researched. The influence of two planet carriers supporting stiffness on the natural frequency and vibration mode is analyzed. And the influence on the box vibration is analyzed using transient dynamic modules. The results are compared with those from the lumped mass method.Next, based on calculation results from lumped mass, further studies about effect of carriers supporting stiffness and damp on vibration isolation are done. The vibration isolation model of the system is established and appropriate isolation index is chosen. The impact of carrier supporting stiffness and damp on the isolation index is analyzed. Also coupling effects of the box bearing stiffness, differential planetary gear bearing stiffness and closed planet carrier supporting stiffness on the differential carrier supporting stiffness is analyzed. The match of two planet carriers supporting stiffness and damp is studied to ensure the box’s smooth. Finally, the multilayer vibration isolator is designed and verified by experiment. The force analysis and isolator’s stiffness and damp calculation are done. Finally, the effects of different parameters on isolator’s stiffness and damp are researched by two group experiments.