Motion Mechanism Analysis of a Two-Degree-of-Freedom Spherical Motor

The working principle of a two-degree-of-freedom piezoelectric spherical motor using only one piezoelectric element was analyzed. The resonance frequencies of the motor's plate type piezoelectric vibrator were calculated by finite element method. The computer simulation was executed to analyze the motion trajectory of the four contact points between the stator and the sphere. Simulation results verified that the four contact points can form timing reasonable elliptical trajectories which re designed to drive the sphere to form two rotation degrees of freedom. The conclusion indicated the formation of two-dimensional movement mechanism of the spherical motor.