Analysis of Stiffness Effect on Valve Behavior of a Reciprocating Pump Operated by Piezoelectric Elements.

Jangmi Woo,Han Seo Ko,Dong Kee Sohn

doi:10.3390/mi11100894

Abstract

This study analyzed the characteristics of a small reciprocating pump with a cantilever valve driven by a piezo actuator. Three types of valves were fabricated to investigate the effect of the valve stiffness on the pump performance and to measure the variation in the flow rate according to the frequency. The flow rate increased with the driving frequency until a certain frequency was reached, and then it started to decrease. The rise in the pressure of the pump was found to increase as the stiffness decreased. The pump performance could be clearly distinguished according to the stiffness of the valve. The observation of the valve movements revealed that the valve opening time did not change regardless of the operating frequency, but it changed with the valve stiffness. The delay in time for the outlet valve increased significantly with an increase in the frequency. It seems that the overlap of the opening time of the inlet valve and the outlet valve plays an important role in pump performance. Therefore, it is advisable to use different designs for the inlet and outlet valves, where the shape and stiffness of the valve are adjusted.

Highlights

Hydraulic pumps are used in various applications, including for robots, precision machinery, and medical applications
Small pumps continue to be miniaturized by adopting smart materials as actuators [5]
Smart materials such as lead magnesium niobate (PMN), lead zirconate titanate (PZT), Terfenol-D, and galfenol have been employed as the driving power source of small pumps, and there have been great reductions in size and weight [6,7,8,9]

Summary

Introduction

Hydraulic pumps are used in various applications, including for robots, precision machinery, and medical applications. Smart materials such as lead magnesium niobate (PMN), lead zirconate titanate (PZT), Terfenol-D, and galfenol have been employed as the driving power source of small pumps, and there have been great reductions in size and weight [6,7,8,9]. Among these smart materials, PZT is most widely used due to its stable performance [10,11]. The effect of the stiffness of the valve was investigated in view of the valve behavior

Driving Scheme

Pump Manufacturing

Results and Discussion

Valve Behavior