A Novel 2-Dof Ultrasonic Motor Design, Simulation, and Experimental Investigation

This paper proposes a bonded type longitudinal bending hybrid 2-DoF ultrasonic motor with a simple structure, compact volume, and lightweight to satisfy the demands for precision driving and control in narrow space. The motor has a pyramid-shaped piezoelectric mover and a friction base with concave spherical surface as a stator, and the preloading force is provided by a pressure spring placed inside the piezoelectric mover. The bending vibration and longitudinal vibration of the mover are used as the working modes. The ultrasonic motor has the characteristics of small volume, lightweight, high output force, and quickly moves. Experimental results indicated that 1) Under the excitation voltage of 550 Vpp, the maximum angular velocity in x and y directions can reach 414 deg/s; 2) Under the excitation voltage of 525 Vpp, the maximum output forces of the motor in x and y directions were 5.25 N and 5.34 N, respectively.