仿尾鳍式变截面摆动振子无阀压电叠堆泵的结构设计

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

受具有高速巡游速度的金枪鱼的启发,提出了一种微脉动、大流量、仿尾鳍变截面振子无阀压电泵。以压电叠堆为激励源,设计了仿尾鳍变截面振子,实验验证了振子的二阶弯振和金枪鱼高速巡游的摆动模式一致。利用有限元分析软件ANSYS分析了振子的模态振型,提出了模态分离更好的Y型振子。为避免压电叠堆受力不均匀而受到损坏,采用钢球和隔离块作为压电叠堆传递力和振动的媒介,实现了压电叠堆和泵腔内液体的干湿分离。设计了二级杠杆/柔铰机构,放大了振子端部柔性叶片摆动幅度。最后,研制了样机,并进行了不同驱动频率下的仿尾鳍式变截面摆动振子无阀压电叠堆泵的流量测量,结果表明,在80V正弦电压的激励下,激励频率为1 350Hz时泵的流量达到峰值(400ml/min)。本设计方案能够有效地提高泵的性能,满足工程实践中对大流量无阀压电泵的需求。

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.