A High-Power Linear Ultrasonic Motor Using Bending Vibration Transducer

To overcome the modal degeneration problem that commonly exists in the design of ultrasonic motors (USMs) using composite vibration modes, a high-power linear USM using a bending vibration transducer is proposed in this paper. In this new design, two orthogonal bending vibration modes with the same order are superimposed in the motor and generate elliptical motions at the two driving feet. Square cross-section structure is adopted by the motor to ensure that the two bending modes have the same resonance frequency. After the introduction of the working principle, the motor is analyzed by using finite-element method. A prototype motor is fabricated and measured. Typical output of the prototype is a no-load speed of 1527 mm/s and a maximum thrust force of 50 N at a voltage of 200 V_rms. This study verifies the feasibility of the proposed design and provides a way to improve the output power of USMs.