A compact linear-rotary impact motor based on a single piezoelectric tube stator with two independent electrodes

A compact linear-rotary impact motor based on a single piezoelectric tube actuator is proposed. The motor can realize independent linear and rotary motions. With two independent electrodes, the piezoelectric actuator has an outer diameter of 6 mm, a thickness of 0.5 mm, and a length of 25 mm. The actuator produces a maximum axial displacement of 2.17 µm with a driving voltage of 720 V_p-p (peak-to-peak driving voltage), and it produces a maximum torsional angle of 599.98 µrad with a driving voltage of 720 V_p-p. The prototype motor can achieve the independent linear velocities of 6263.45 µm/s and -6331.58 µm/s in the positive and negative directions of motions under the saw-shaped driving voltage of 560 V_p-p at 8 kHz. The motor can realize the independent rotary velocities of 1.22 × 10⁶µrad/s and -1.21 × 10⁶µrad/s in the two motions under the saw-shaped driving voltage of 560 V_p-p at 9 kHz. The maximum output force of the motor is 0.45 N, and the maximum output torque is 0.80 mN m for linear and rotary motions, respectively.