一种新型共振式气体压电泵

A novel resonantly-driven piezoelectric gas pump

针对膜片式压电泵气体驱动能力不足,被输送气体流动受阻时压电振子易发热受损,以及叠堆式共振压电泵造价高昂等问题,提出了一种以圆环状压电双晶片为动力源,通过位移放大机构驱动的新型共振式气体压电泵.对新型共振式气体压电泵的工作原理及其位移放大原理进行了分析,建立了该泵的振动力学模型.分析结果表明,该泵位移放大效果与压电双晶片提供的驱动位移有关,系统放大倍数与弹簧片和压电振子的刚度、系统的黏性阻尼因子及激励频率有关.设计并制作了新型共振式气体压电泵的试验样机,使用阻抗分析及激光测量方法测试了其位移放大效果,并验证了气体输出性能.试验表明,在70 V的正弦交流电压驱动下,该泵通过共振方式可将输出端位移放大至压电振子位移的4.2倍以上,气体输出流量可达1 685 mL/min.在气体流动受阻的情况下,该泵连续工作2 000 h无明显温升.

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 piezoelec- tric 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 piezoelec- tric pump was presented. The pump was driven by an annular bimorph and the displacement of the dia- phragm was amplified at the resonance frequency. Firstly, the working principle of the pump was de- scribed, 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 pie- zoelectric vibrator, viscous damping coefficient of system and driving frequency. The experimental pro- totypes 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.