Driving Mechanism And Experiment Research Of Hybrid Suspension Based On Near-filed Acoustic Levitation And Pneumatic Suspension

With the rapid development of science and technology and the industrial rapidtransformation, due to the disadvantages of conventional contact transportation such as thefriction, fever, mechanical vibration of rigid structure and so on, the contact transportationcan’t meet modern industry demands. Therefore, non-contact suspension technologyemerges as the demands and arouses much attention of the domestic and foreign scholars.Pneumatic suspension is extensive applied widely in some high precision transportplatforms, because it has some merits, such as simple structure, large load capacity, andconvenience obtainment. Ultrasonic levitation technology with a new suspension style isresearched, which has some merits, for example, all materials can be levitated and it doesn’thas complex, large working device. In order to realize the non-contact linear transportation, aultrasonic traveling wave driving transportation is presented, which can only transport lightobjects due to the small load capacity of near-filed acoustic levitation (NFAL). To overcomethe matter, a new hybrid suspension style utilizing both of ultrasonic and aerostaticsuspension is put forward in the paper, which can realize the transportation of heavy loadobjects and combining the features of the large load capacity of pneumatic suspension andthe driving ability of ultrasonic traveling wave.Considering the two factors of the structure of gas-floating platform and the highquality matching performance between and disk and air, the disk piezoelectric transducer isas the research object of the paper. The size of each part of disk transducer is deduced bytheory of elastic mechanics and design theory of the longitudinal–flexural disk transducer.The disk and disk transducer are optimal designed by ANSYS and COMSOL, and thenresonance mode and acoustic pressure distribution of disk transducer is obtained, so that thehybrid suspension test prototype is manufactured with the optimal size of disk, namely,radius40mm, thickness4mm. The test system is set up, and the experimental results that theload capacity of gas-floating platform can be greatly improved adding ultrasonic levitationinto pneumatic suspension system under the condition of making sure the constant vibrationamplitude of gas-floating platform, and the load capacity of the hybrid suspension is greaterthan the total load capacities of ultrasonic and the pneumatic suspension when they work alone.For the sake of research, the easily operated method of the vibration excitation andvibration absorption is selected as the forming method of traveling waves in the paper.Firstly, the two matters of the fixed position of transducer and the matching impedance ofabsorbing transducer are analyzed using the Eular-Bernouli beam theory and the equivalentcircuit principle of transducer, respectively. Secondly, the resonant frequency of the hybridsuspension transportation system and the vibrating flat plate with performances of thegas-floating platform using ANSYS software, and then through modulating the dimensionparameters of the vibrating flat plate, make sure that the resonance frequency is equal to thatof transducer, so that high quality traveling waves can be produced by the hybrid suspensiontransportation system. Finally, the test system of hybrid suspension transportation isdesigned and tested. The experiment result shows that the hybrid suspension can realizenon-contact transportation of heavy load objects. Several physical parameters that influencethe transport speed of objects are also analyzed by experiment and theory, and theperformances of the hybrid suspension are obtained. The test result shows that for the samesurface density, the transport speed of suspended objects under hybrid suspension is largerthan that only under ultrasonic suspension.