Valveless piezoelectric pumps have the advantages of simple fabrication, lower cost, and high cleanliness. Valveless piezoelectric pump compared with valved piezoelectric pump, the backflow phenomenon is more serious, which greatly limits the application in reality. In this paper, a valveless piezoelectric pump with an inner triangle structure is proposed to increase to the resistance of reverse flow by the inner concave triangle structure to achieve the purpose of reducing backflow. The factors influencing the efficiency of forward flow were analyzed by theoretical modeling. Then, the flow resistance of this valveless piezoelectric pump is numerically calculated by finite element analysis. Finally, the output performance of the pump was experimentally investigated. The experimental results show that when the number of concave triangles in the flow channel are two, the inclination angle (B) are 45°, and the height are 3 mm, the performance of this valveless piezoelectric pump is optimal, and the flow rate and pressure reach 190.86 ml/min and 673 Pa respectively. This study provides some valuable insights to improve its performance and practice. This piezoelectric micropump could generate large flow rates and output pressures with great advantages in the fields of mechanical lubrication and biomedicine.

无阀压电泵具有制作简单、成本低、清洁度高等优点。无阀压电泵与有阀压电泵相比，倒流现象更为严重，极大地限制了在实际中的应用。本文提出了一种内三角形结构的无阀压电泵，通过内凹三角形结构增加对逆流的阻力，达到减少逆流的目的。通过理论建模分析了影响正向流动效率的因素。然后，通过有限元分析数值计算了这种无阀压电泵的流动阻力。最后，对泵的输出性能进行了实验研究。实验结果表明，当流道内凹三角形数量为两个、倾角（B）为45°、高度为3 mm时，该无阀压电泵的性能最优，流量和压力分别达到 190.86 ml/min 和 673 Pa。这项研究提供了一些有价值的见解，以提高其性能和实践。这种压电微型泵可以产生大的流量和输出压力，在机械润滑和生物医学领域具有很大的优势。