WU Yue, YANG Zhi-Gang, LIU Yong, WANG Long, XIE Hai-Feng
(1. College of Mechanical Science and Engineering, Jilin University, Changchun, Jilin 130025, China; 2. Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, Jilin 130033, China)
The pumps driven directly by piezoelectric membrane not only have a poor performance when pumping gas, but also they may be damaged with a high temperature generated by the piezoelectric membrane when the flow of gas is blocked. Even though the pumps driven by piezoelectric stack have an excellent performance, they are quite costing. To solve the problems above, a novel piezoelectric pump was presented. The pump was driven by an annular bimorph and the displacement of the diaphragm was amplified at the resonance frequency. Firstly, the working principle of the pump was described, and a mechanic model of vibration was built to clarify displacement amplification principle. The analysis shows that the amplification factor is related to the stiffness of spring lamination and piezoelectric vibrator, viscous damping coefficient of system and driving frequency. The experimental prototypes were manufactured and the experiments indicate that the amplification factor of displacement amplifier is more than 4.2 at a 70 V sinusoidal AC driving voltage, the maximum flow rate could be up to 1 685 mL/min; when the gas flow is blocked, the pump can operate continuously as long as 2 000 h without a noted temperature rise in bimorph.
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