Research And Design On Double-Vibrator Piezoelectric Gas Pump

Pump is a conveying fluid or causing the fluid turbo-charged machinery, it transfers prime motor's mechanical energy or other forms of energy to the fluid, causes the fluid moving or forms the pressure. Piezoelectric pump is a new kind of fluid-flow pump using the piezoelectricity vibration direct action to the fluid. It has the simple and small structure, and its current capacity is easy to control. In the past ten years it has a rapid development. At home and abroad the present study on the piezoelectric pump focuses on delivering liquid, the technology is relatively mature, and the study of piezoelectric pump delivering gas is only at the exploratory stage, and foucuses on the one-cavity and one vibrator pump. The structure of the one cavity and one vibrator piezoelectric gas pump is simple and easy to manufacture. Multi-cavity and multi-vibrator piezoelectric gas pump using piezoelectric material's well properties of resonance, and multiple characteristics of simple structure, can minimize the size of piezoelectric pump and increase output capacity, it may be one of the best structure of piezoelectric pump.This paper proposes several different structures of double piezoelectric vibrator piezoelectric gas pump, and hopes to solve the multi-chamber piezoelectric gas pump's some basic theory and key technology through the study of double piezoelectric vibrator gas pump, to increase substantially in performance, and to manufacture actually meeting requests and having high reliability piezoelectric gas pump and the control device.1) Vibration characteristic analysis of disk piezoelectric vibratorThis paper using Analytical method deduces the peripheral fixed circular piezoelectric vibrator's vibration equation and the housing volume change equation,and central point oscillation amplitude has carried on the computation. In the effective voltage of 110V, central point oscillation amplitude ofφ35mm duplex crystal vibrator is 50.49μm , the housing volume change is 3.6x10-8m3. Uses the experimental test method, this paper carried on the static test through the laser micrometer to measure oscillation amplitude of duplex crystal vibrator's central point and from the central different distance point.The test had indicated that the vibrator's distortion surface is a paraboloid, through the curve fitting equation, the vibrator's center point oscillation amplitude is 29.7μm , the housing volume change quantity was 1.12x10-8 m3. The experiment has tested under the same peak voltage three kind of different power source profiles vibrator's central point oscillation amplitude, draw a conclusion that under the rectangular wave vibrator's central point oscillation amplitude is biggest, under the sine wave is smaller, and under the triangular wave is smallest.2) Work characteristics of the check valueCheck valve is one of the key components to determine the performance of piezoelectric pump's output, piezoelectric pump's research and development associated with check valve's development. This paper analyzes overflowing property and valve's critical working condition of different thickness of rubber umbrella valve. The experiment draw a conclusion that the 0.1mm thick umbrella valve's working ability is best, its lowest opening pressure is approximately 0.4KPa, 0.3mm thick umbrella valve's lowest opening pressure is 0.9KPa, 0.5mm thick valve's lowest opening pressure is 1.2KPa,0.1mm thick umbrella valve's opening quantity is bigger than other thickness valve.3) Research and design on Double-Vibrator piezoelectric gas pumpThis paper introduced the basic definition of the piezoelectric gas pump's output performance parameters and measurement methods, and analysis the flow measurement error sources. This paper introduced the basic definition and measurement methods of the piezoelectric gas pump output performance parameters,and analysis of the flow measurement error sources.Then the paper detailed the structure and working principle of single-vibrator single-chamber, dual-vibrator single-chamber, dual-vibrator dual-chamber series connection, double-vibrator double-chamber parallel connection and dual-vibrator dual-chamber series connection without back groove piezoelectric gas pump, and analysis the working methods driven by different working methods..4) Experimental study and rule summary on Double-Vibrator piezoelectric gas pumpRespectively, single-vibrator single-chamber, dual-vibrator single-chamber, dual-vibrator dual-chamber series connection, double-vibrator double-chamber parallel connection and dual-vibrator dual-chamber series connection without back groove piezoelectric gas pump are carried out on driven-gas test and concluded:(1) When driven by square wave the piezoelectric gas pump's output property is the best, driven by sine wave is the second, and driven by triangle wave is at the worst. However, when driven by square wave piezoelectric gas pump has the largest noise, driven by sine wave the noise is smallest, taking into account that sine wave is easier to obtain than the other two kinds of wave, so sine wave is the first choise used to drive piezoelectric gas pump.(2) The work modes of piezoelectric gas pump and liquid pump is different, in the electrical synchronous signal, dual-chamber series connection, double-vibrator double-chamber parallel connection and dual-vibrator dual-chamber series connection without back groove piezoelectric gas pump have the better output than in the electrical asynchronous signal.(3) This paper studies the effects of different thickness umbrella rubber valve on the gas pump's output properties, comes to the conclusion: using the 0.1mm thickness umbrella valve, the pump's flow output performance is the best, using 0.5mm thickness umbrella valve the pump's pressure of export pressure and self-absorption capacity is the best.(4) The initial cavity volume of the gas pump have a greater impact on pump's performance, no matter what the structure of piezoelectric gas pumps is, in the conditions of meeting the free vibration of piezoelectric vibrator, the initial cavity volume is smaller, the output of pump performance is better.(5) Test the four structures of piezoelectric gas pump with the same initial cavity volume, draw a conclusion that: double-vibrator double-chamber parallel connection piezoelectric gas pump in the electrical synchronous signal has the best flow output; dual-vibrator dual-chamber series connection piezoelectric gas pump has the best output pressure in the electrical asynchronous signal, double-vibrator double-chamber parallel connection piezoelectric gas pump in the electrical synchronous signal has the smallest output pressure. (6) Analysis that the best cavity height of the piezoelectric pump when driving water and air: for the output flow, the best cavity height driving water is about 0.3mm, and the best height for driving gas is smaller and even less than 0.1mm; for pressure of outlet and self-absorption, regardless of driving water or gas, the smaller the cavity height is, the better the pressure is. At the same time discuss the umbrella rubber valve the different working methods in driving water and air.