Structure design of caudal-fin-type piezoelectric-stack pump with variable cross-section oscillating vibrator

Based on a variable cross-section oscillating vibrator,a caudal-fin-type piezoelectric-stack pump with a high flow rate was proposed.Firstly,the caudal-fin-type variable cross-section oscillating vibrator,whose second order bending modal agrees with tuna's high cruise swing mode was designed by using the piezoelectric-stack as an excitation source.Then,FEM software ANSYS was used to analyze the modal shape of the vibrator and a better Y vibrator was presented.To prevent the uneven distribution of loading applied to the piezoelectric-stack and to avoid the damage of piezoelectric-stack,a steel ball and an isolation block were used as the media of forces and vibration to separate the piezoelectric-stack from the water in a chamber.Furthermore,the mechanism of two-stage level/flexure-hinge was designed to amplify the tip amplitude of the vibrator.Finally,a prototype was designed and fabricated,and the experiments on measuring the flow rate varying with frequencies were performed.The experiment shows that the flow rate of the pump reaches 400 ml/min driven by AC voltage of 80 V under the frequency of 1 350 Hz.It concludes that the design can enhance the performance of the pump effectively,and meets the demand of the high flow rate valve-less pump in engineering practices.