Abstract: A dual hydraulic motor-driven vibrating pile sinking mechanism was proposed， which have two self-synchronization states of idle and pile sinking. The structure and working principle were introduced， and the dynamic model of the vibration system was established. The dimensionless coupling equation of the two vibration exciters and the criterion of synchronization and synchronization stability were deduced， and the system dynamic parameter range of the two states was determined. When the pile driver was in the idle state， the exciter worked on the far-super resonance state， the generalized dynamic symmetry angle equaled π， and the excitation forces of the two eccentric rotors were offset; when the pile driver was in the piling state， the exciter worked on the sub-resonance state， the generalized dynamic symmetry angle equaled 0， and the excitation forces of the two eccentric rotors were superimposed. Finally， it was verified by numerical simulation.

Key words: double hydraulic motor driving; vibrating pile sinking mechanism; synchronization stability criterion; far-super resonance state; sub-resonance state