Planar Motor Driven by Cross Structured anUltrasonic Transducer

Due to the output amplitude of the planar motor driven by an X-shaped piezoelectric vibrator was fairly smaller, a planar motor resonantly driven by a cross-structure stator was proposed. It selected all the in-plane bending vibration mode of the transverse bar, the in-plane bending mode of longitudinal bar, and the out-of-plane bending mode of the stator as working modes. By coupling out-of-plane bending mode with transverse bar’s in-plane bending mode and the longitudinal bar’s in-plane bending mode, the elliptical trajectories along the yoz and xoz planes respectively were generated in the driving feet, so that the slider could be pushed to move along x, y directions. The working principle of the motor is explained. According to the requirement of working modal frequency consistency, the size of stator is optimized to be 25.5 mm × 5 mm × 5.9 mm.A FEM model for the stator was established, with which the optimal driving frequency was calculated to be 24 650 Hz, Transient analysis was also carried out which exhibited that the driving feet vibration amplitude along x, y, and z directions could reach 3.1, 6.2 and 4.3 μm when 250 V voltage was applied. It was shown that the stator hadproduced greater power and speed.