Meshing Stiffness Parametric Vibration of Coaxial Contrarotating Encased Differential Gear Train

Planetary gears are widely used in mechanical transmission systems, but the vibration and noise affect their reliability life. In this paper, torsional dynamic model of an encased differential planetary gear with coaxial contrarotating outputs considering time-varying meshing stiffness, damping, phase difference all pairs is established. By solving equations derived system, three types natural frequencies different multiplicities system obtained. The multiscale method to study parametric stability caused by results verified numerical simulation. characteristics elastic force analyzed from time domain frequency domain. variation load factor each pair input speed relationship between its peak position discussed. show that there unequal coupling phenomenon forces sets. absence external excitation, stiffness parameters not only excite main resonance response also cause superharmonic resonance, subharmonic combined resonance.