The design and experiment of a novel ultrasonic motor based on the combination of bending modes

• A novel ultrasonic motor using two orthogonal bending modes is proposed.
• The structure of the proposed motor is simple; it is easy to be fabricated.
• The ultrasonic motor has the potential for application in small system.
• The movement trajectories of particles on the foot are overlapped circles.

This paper presents a new-type linear ultrasonic motor which takes advantage of the combination of two orthogonal bending vibration modes. The proposed ultrasonic motor consists of eight pieces of PZT ceramic plates and a metal beam that includes two cone-shaped horns and a cylindrical driving foot. The finite element analyses were finished to verify the working principle of the proposed motor. The mode shapes of the motor were obtained by modal analysis; the elliptical trajectories of nodes on the driving foot were obtained by time-domain analysis. Based on the analyses, a prototype of the proposed motor was fabricated and measured. The mechanical output characteristics were obtained by experiments. The maximal velocity of the proposed motor is 735 mm/s and the maximal thrust is 1.1 N.