Study On The Intermediate Fixed Inertial Drive Type Resonant Piezoelectric Pumps

Piezoelectric pump, which serves as a fluid transporting device with precise output, possesses the merits of simplified and minor structures. Consequently, researches on piezoelectric pump have attached great attention in recent years. Based on the National Natural Science foundation project "Basic theory and key technique research of the inertial piezoelectric fluid actuator", this dissertation proposes an inertial resonant piezoelectric pump fixed in the mediate with the combination of resonant technology. The rectangular piezoelectric vibrator, which works as the driving element in the novel piezoelectric pump, generates the inertial impact force through electromechanical energy conversion.Specific research contents are as follows:1. The rectangular piezoelectric vibrator in this study, which is regarded as the driving element, is fixed in the mediate. And it can transfer electricity into mechanical energy through converse piezoelectric effect. The former forth vibration modes and the deflection characteristics of the vibrator are obtained by conducting COMSOL software. Furtherly, mathematical model of the tip deflection, tip impact force are built and simulated by MATLAB software to acquire their factors. In addition, experimental tests are conducted to explore the influences of driving voltage and frequency.2. Subsequently, the excitation unit is designed and the mechanism is analyzed. Formulations of the amplitude of piezoelectric vibrator, diaphragm and output flow of the pump are derived by building dynamic model of excitation unit. Besides, rigidity of diaphragm and piezoelectric vibrator are also computed through the mathematical model. Tests on exploring the resonant frequency by precise Impedance Analyzer and the amplified effects of excitation unit on displacement of vibrator by laser sensor are performed.3. Working mechanism of the proposed resonant piezoelectric pump with umbrella shaped valve is analyzed, deflection of the diaphragm is calculated and optimized as well. After building the testing platform, parameters of valve diameter and cavity height are optimized through experiments on output performances. In addition, influences of volume change rate of the cavity, dimension of piezoelectric vibrator, residual bubbles in the cavity and input voltage on output performances are studied based on experimental comparisons.4. Working mechanism of valveless pump with asymmetrical taper pipe is analyzed, and structure parameters are determined prior to experiments. Conclusion can be derived that the pump equipped with umbrella shaped valve is better than valveless pump in terms of output flow.