Effect of the compressible spaces on the performance of piezoelectric pump with rhombic micro-displacement amplifying vibrator

This paper proposes a rhombic micro-displacement amplifying vibrator piezoelectric pump which introduces a mechanism called “compressible space” near inlet and outlet valves. The working principle of compressible space is presented and a simulation is conducted to verify the effect. Analysis reveals that the compressible space can reduce the transmission time of the pressure wave thus increasing the efficiency of the valves, and suppress the pressure fluctuation due to the rapid closing of the valves. The simulation shows that the pressure fluctuation in the pipe is relieved and the instantaneous pressure wave can be mostly absorbed with the presence of compressible space. Then the effect of three sizes of compressible space (area approximately 100, 150, 200 mm ² ), the number of compressible space (two and a single), the distance between the compressible space and the valve (near the valve and in the middle of the pipe) on the pump performance is experimentally investigated. Experimental results demonstrate that the effect of two compressible spaces is better than only one, and medium-sized compressible spaces have the best comprehensive effect. Meanwhile, when the compressible spaces are near the valves, the effect is better.