压电双晶片和单晶片驱动下泵的输出性能研究

Research on Output Performance of Pump Driven by Bimorph and Unimorph

为从理论上获得压电泵在薄片型压电双晶片和单晶片（统称压电振子）驱动时的输出一流量关系，需要获得二者振动时产生的容积变化量。假设压电振子在周边固定约束条件下，应用弹性薄板的小挠度弯曲变形理论，推导了压电双晶片和单晶片振动时的容积变化方程，并根据方程对铜基板直径为35mm，压电陶瓷直径为29mm，基板和压电陶瓷厚度同时为0．2mm和0．3mm2种规格的压电单晶片和双晶片进行了振动容积计算。计算结果显示，相同基板和陶瓷厚度的双晶片振动产生的容积变化量是单晶片的2．3倍。将上诉压电振子应用到单腔压电泵上进行输送气体流量测试，获得的实际输出流量比在1．5～2倍之间，理论计算结果与试验测试结果比较接近。理论推导结果为比较双晶片和单晶片驱动下压电泵的输出能力提供了可靠依据。

The two changes in volume of the chamber need to be deduced in order to get the output flow-rate relations of piezoe- lectric pump driven by bimorph and unimorph （generally referred to as the piezoelectric vibrator）. The volume change equation of bimorph and unimorph were derived under the fixed boundary condition based on the small deflection bending theory for the elas- tic thin plates. The volume change two types of bimorph and unimorph with 35 mm diameter copper subetrate and 29 mm diameter piezoelectric ceramics whose thickness are both 0.2 mrn and 0.3 mm were calculated. The calculation results show that the vol- ume change of bimorph with the same thickness of substrate and ceramic production is 2.3 times of unimorph. The test output re- suits ratio was between 1.5 ~ 2 times when the piezoelectric vibrators were applied to drive single-chamber piezoelectric pump for conveying gas . The theoretical calculation data was close to the test results . The theoretical results provides a reliable basis for comparing the output ability of piezoelectric pump driven by bimorph and unimorph.