Single Vibration Mode Standing Wave Tubular Piezoelectric Ultrasonic Motor

The objective of this thesis is to report the single vibration mode standing wave tubular piezoelectric ultrasonic motors developed. Piezoelectric motors are driven by reverse piezoelectric effects which converts an input of ultrasonic frequency of electrical energy into an output of mechanical movement. There are many advantages of piezoelectric ultrasonic motors compared to electromagnetic motors such as simple structure, high energy density, and high torque at low speed. Three prototypes are designed and fabricated. Two motors are fabricated using PZT cylindrical tube; one with PZT teeth and the other with metal teeth. A third motor using brass tube with PZT plates attached is fabricated. After design and fabrication of three prototypes, the performances of the motors are tested using a test apparatus for speed and torque.

Single Vibration Mode Standing Wave Tubular Piezoelectric Ultrasonic Motor

The objective of this thesis is to report the single vibration mode standing wave tubular piezoelectric ultrasonic motors developed. Piezoelectric motors are driven by reverse piezoelectric effects which converts an input of ultrasonic frequency of electrical energy into an output of mechanical movement. There are many advantages of piezoelectric ultrasonic motors compared to electromagnetic motors such as simple structure, high energy density, and high torque at low speed. Three prototypes are designed and fabricated. Two motors are fabricated using PZT cylindrical tube; one with PZT teeth and the other with metal teeth. A third motor using brass tube with PZT plates attached is fabricated. After design and fabrication of three prototypes, the performances of the motors are tested using a test apparatus for speed and torque.

Meshing Drive Mechanism of Double Traveling Waves for Rotary Piezoelectric Motors

Rotary piezoelectric motors based on converse piezoelectric effect are very competitive in the fields of precision driving and positioning. Miniaturization and larger output capability are the crucial design objectives, and the efforts on structural modification, new materials application and optimization of control systems are persistent but the effectiveness is limited. In this paper, the resonance rotor excited by stator is investigated and the meshing drive mechanism of double traveling waves is proposed. Based on the theoretical analysis of bending vibration, the finite element method (FEM) is used to compare the modal shape and modal response in the peripheric, axial, and radial directions for the stator and three rotors. By analyzing the phase offset and vibrational orientation of contact particles at the interface, the principle of meshing traveling waves is discussed graphically and the concise formula obtaining the output performance is summarized, which is analogous with the principles of gear connection. Verified by the prototype experimental results, the speed of the proposed motor is the sum of the velocity of the stator’s contact particle and the resonance rotor’s contact particle, while the torque is less than twice the motor using the reference rotor.

Design of a Single and Dual Hybrid Piezoelectric Motors

In this paper, a new hybrid piezoelectric motor was developed. A range of degeneracy was found to obtain multiple choice of resonance frequency by adjusting the length of the elastic blocks neighboring to the longitudinal and torsional vibrators. A template was implemented in between the longitudinal and torsional vibrators to decrease the mutual vibration effect that effectively makes the calculated and actual driving frequency nearly close. Such configuration was instrumental to preserve the expected performance and reduce the trial-and-error design overhaul process of the elastic blocks. Moreover, a dual hybrid motor was easily formed by butting each stator of the two hybrid motors together with a rotor in the middle. Case studies of both single and dual hybrid motors are presented with both simulation and experimental results to demonstrate the structure design and the degeneracy approach. Besides the convenience of structurally combining two single hybrid motors to enhance the output, it was interesting to find out whether the proposed dual hybrid motor can significantly increase either the speed or torque by using different phase control methods. Therefore, using the dual hybrid motor provides a great advantage by providing an option for pursuing higher speed or larger torque output for certain applications.

The influence of thermodynamic history and external influences on the electrophysical properties of ferropiezoceramic materials based on a multicomponent system PZT-PMN-PZN+SiO2

This paper presents the results of a comprehensive study of the industrially produced ferro-piezoelectric ceramic material based on the PbZrO3-PbTiO3-[Formula: see text][Formula: see text]O3-[Formula: see text][Formula: see text][Formula: see text] system. Studies have confirmed that this material refers to ferro-rigid materials with high coercive fields, stable dielectric properties in a wide temperature range, practically no Curie temperature hysteresis, as well as low controllability of the dielectric constant and deformation characteristics by constant bias electric fields. The revealed correlation between dielectric, deformation characteristics and dielectric hysteresis allows us to consider this material as promising for devices operating in power modes: piezotransformers, highly loaded ultrasonic devices, piezoelectric motors, etc.

Design of Multi-DOF Spherical Piezoelectric Motor Using Electrode Configuration Based Actuating Units

Spherical piezoelectric motors (SPMs) apply piezoelectric materials as stators to generate modal responses for rotor orientation. The SPMs have the advantages of simple structure and compact size but may suffer from the difficulty of orientation manipulation. This paper presents a novel electrode configuration based SPM design for simple multi degree-of-freedom (DOF) orientation manipulation. Four piezoelectric actuating units are adopted as stators to generate 12 orientations through the integration and switch of two vibration modes of each piezoelectric actuator, including lateral mode and longitudinal mode. The dynamic characteristics associated with the design parameters at each vibration mode are experimentally obtained to evaluate the performance of the proposed SPM design.