| Gas diaphragm pump as a fluid pump, recently it has been more widely used inthe field of biological medicine, fine chemicals, aerospace, micro-electromechanicalsystems.The gas diaphragm pump has two major classes in the market,one is driven bymotor cam mechanism,and the other by the piezoelectric diaphragm of the piezoelec-tric vibrator.However, the electromagnetic diaphragm pump will have a complexstructure, the high cost, noise and other issues in the actual application process,andthe piezoelectric diaphragm has the low volume change rate,and the piezoelectric vi-brator is overheating, easily broken and easy to depolarization.This paper is funded by the National Natural Science Foundation“piezoelectricgas diaphragm design theory and key technology researchâ€ï¼Œthe project number is50735002，it first propose magnetic spring is used to construct the resonance pump,and study the relevant theoretical and technical issues.The paper presents magnetic spring is used for resonant pump,which can in-crease the pump rate of volume change, make the system architecture to simplify, re-duce noise, increase system reliability and stability. The most important thing is ad-justing axial gap of the magnetic spring to change the stiffness of the mechanical sys-tem, and thus very convenient to adjust the resonant frequency of the mechanical sys-tems.The piezoelectric vibrator is the core component of the resonant piezoelectric airpump with magnetic spring, and provide incentives for the whole resonance system.Inthe paper, we use the epoxy to bond circular piezoelectric ceramic and ring substrate,Piezoelectric vibrator as a part of the magnetic spring resonant pump excitating body，by simulation, exciting body modal analysis and harmonic response analysis to de- termine the final structure parameters of the piezoelectric vibrator.The magnetic charge theory is used to derivate the axial force of the magneticspring,and by dividing the cell, using the discrete summation methods and the use ofmatlab programming to calculate the axial force and axial spacing of the magneticspring.And then use the curve fitting method to find the relationship, the derivative ofthe relation, obtained the relationship between the axial stiffness and axial spacing ofthe magnetic spring. And design experiments to measure axial force of the magneticspring,use the same method of derivation of the fitting curve to obtain the relationshipbetween axial stiffness and axial force.The paper describes in detail the working principle of resonant pump with themagnetic spring, makes qualitative analysis of the resonance body how to work, andget the key role of the magnetic spring on the whole exciting body;designs its keycomponents, establishs a dynamic model of its exciting body part, gets a key factor toaffect the displacement of exciting body part; calculates the stiffness of the key com-ponents; uses precision impedance analyzer and laser micrometer to measure the re-sonant frequency of the exciting body and the displacement of the excitation, and getrelationship between the resonance frequency of exciting body part and The axial gapof the magnetic spring, which is compared with the displacement of the center pointof the piezoelectric vibrator, and at last get the excitation displacement of magnifica-tion.A detailed description of the basic structure and working process of the pumpbody of the magnetic spring resonant pump are made. The pump diaphragm is opti-mized by shell theory, and ultimately determine the film’s structure parameters;Thepaper analysis the impact on pump performance of the volume rate of change of thecavity, the fluid flow and lagging of valve; dsign experimental setup to test the outputperformance of the pump;by experimental test diameter of the valve of the valveblock, the cantilever width, the pretension of the cavity height and seat height is opti-mized, and ultimately determine the resonant pump body structure parameters.However, due to processing errors axial stiffness of magnetic spring in resonantpump spring and the calculated value is not consistent actually, Magnetic spring magnet in the axial direction is not completely concentric, This will produce a addi-tional radial force on the basis of originally only an axial force, radial force and axialforce would be suspended magnet is connected to the piezoelectric vibrator generatedtorque, which Lead to the piezoelectric vibrator to reverse in the vertical direction. Asthe axial gap decreases, the radial force is growing more and more serious, and tworing magnet eccentric more serious. So axial stiffness of magnetic spring should besmaller than the theoretical value, the radial stiffness will increase.the key to success resonance pump with magnetic spring lies in the control ofthe magnetic spring axial stiffness, increase the incentive of the piezoelectric vibrator,and to improve the utilization efficiency of the piezoelectric vibrator excitation. Con-trol of the magnetic spring axial stiffness can learn from the research results achievedby the magnetic levitation trains and magnetic bearings; The key to increase the in-centive of the piezoelectric vibrator is to seek piezoelectric ceramics with high qualityperformance parameters to make the piezoelectric vibrator; to improve use efficiencyof incentive of piezoelectric vibrator must be achieved through the improvement ofthe structural design of resonant pump. |
