#$%^&*AU2020101860A420200924.pdf#####ABSTRACT The present application provides a variable-chamber valveless piezoelectric pump, including a pump body, wherein a piezoelectric vibrator is mounted in a pump chamber of the pump body, and a longitudinal section of the pump chamber is semicircular； the pump chamber is divided into a first chamber, a second chamber and a third chamber from front to rear, wherein an inner diameter of the third chamber is larger than that of the first chamber, an inner diameter of the second chamber gradually increases from front to rear, and the first chamber and the third chamber are in transitional connection through the second chamber； and a caudal fin made of flexible material is connected to a rear end of the piezoelectric vibrator and is a trapezoid with a width gradually increasing from front to rear. The application can effectively reduce the phenomenon of liquid backflow.15 71 12 13 81 8 Fig.1 2 15 12 4 21 22 23 7 7113 11 14 Fig.2 1/2
