Study On Non-contact Linear Ultrasonic Piezoelectric Actuator

This Research Comes from National Natural Science Foundations of China (10604032 and 50735002) and Aviation Science Fund (2007ZE52053).Different from the driven ways of traditional contact-type ultrasonic piezoelectric actuator, the linear actuator based on near-field acoustic levitation is a new driving type which has a kind of solid - liquid - solid driving way. It would have great potential for applications in aerospace field, material science, high-purity material production lines, as well as the micro-mechanical assembly operations. To the high value of current non-contact linear transmission in the modern hi-tech production line, this dissertation carried out research on non-contact linear ultrasonic piezoelectric actuator design and analysis. The main works are as follows:1. Studied on the formation of traveling wave in sheet, study on the feasibility of the traveling wave formation by Excitation - Absorber in depth, and study on positioning method for the excitation and absorber points of actuators theoretically.2. PZT8 materials were selected as the core piezoelectric elements of Langevin oscillator, by analyzing the amplitude amplification of different type horns, and the ladder-type horn was chosen as a shaped device of Langevin oscillator.3. Based on the finite element method, a pair of Langevin oscillator was designed, and a prototype was manufactured. Using Langevin oscillator appended the radiation installation disk, a levitation experiment was carried out on the near-field acoustic ability, and the experimental results were compared with the squeezing air membrane suspension theory.4. Based on the theory of viscous fluid and to discuss the driving principle of non-contact ultrasonic actuator, a theoretical analysis on the driving force was conducted.5. By using finite element software, the whole structure of the actuator was simulated, and then the best match impedance of the actuator was calculated according to the equivalent circuit method. Actuator prototype was processed out and the relevant tests were executed for obtaining the output characteristics.