Piezoelectric traveling wave rotary ultrasonic motors are motors that generate torque by using the friction force between a piezoelectric composite ring (or disk-shaped stator) and a metallic ring (or disk-shaped rotor) when a traveling wave is excited in the stator. The motor speed is proportional to the amplitude of the traveling wave and, in order to obtain large amplitudes, the stator is ex...

BACKGROUND Ultrasonic motors (USM) are based on the concept of driving the rotor by a mechanical vibration excited on the stator via piezoelectric effect. USM exhibit merits such as simple structure, quick response, quiet operation, self-locking when power off, nonelectromagnetic radiation and higher position accuracy. PRINCIPAL FINDINGS A cylindrical type traveling wave ultrasonic motor usin...

This thesis describes development of a new actuator technology for integrated machines of the future: piezoelectric ultrasonic micromotors. Ultrasonic motors o er the advantages of low speed, high torque operation without the need for gears. They can be made compact and lightweight and provide a holding torque in the absence of applied power due to the traveling wave frictional coupling mechani...

In this paper, we present a new method based on Optimal Safety Factors (OSF) in the context of the Reliability-Based Design Optimization (RBDO) analysis of ultrasonic motors with traveling wave taking into account the contact between the different components (stator and rotor). We will underline also the different methods of the RBDO analysis and we highlight the advantage of our approach based...

Having natures of low speed, high torque and quick response characteristics, ultrasonic motors (USM) are applied in robot, precision machine and optical instruments. A lightweight actuator is essential to decrease the total weight and increase the operability. Although USMs, in general, are superior to conventional electromagnetic motor in torque/weight ratio, lighter motor is demanded. In this...

Ultrasonic motor’s model adapting to control application is the foundation of the motor’s high performance control. Ultrasonic motor’s frequency-speed control model gives a signification to improve speed control performance. This paper shows the design of stepping response experiments, and also explains the model identification of USM by the way of characteristic point method. Considering its t...