Structure design of piezoelectric resonant air pump with magnetic spring

On the basis of principles of vibrating piezoelectric vibrators to syntonize the connected diaphragms,a piezoelectric resonant air pump with a magnetic spring was proposed to improve the driving ability of the piezoelectric pump for gas moving.First,the working principle of the piezoelectric resonant air pump with magnetic spring was analysed,a dynamic model of the pump resonance was established and the main factors effecting the membrane amplitude were obtained.Then,a prototype was designed and the resonance frequency of the system and the displacement magnification of the piezoelectric vibrator were measured by an impedance analyzer and a photovoltaic displacement sensor,respectively.Finally,a testing facility to measure the volume and output pressure of the resonance pump was developed and the effects of the axial distance of magnetic spring on the output volume and pressure were analyzed.Experimental results indicate that the amplification factor is 4.5 when the sinusoidal AC driving voltage,resonant frequency and the magnetic force of the axial spacing of the magnetic spring are 200 V,133 Hz and 9 mm,respectively.Moreover,the maximum flow rate is 524 ml/min and the maximum pressure is 9.2 kPa.Results demonstrate that the gas transportation capacity has been improved by using the proposed piezoelectric resonant air pump.