A study on the small size PZT pump for cooling water circulation

In precision machinery systems for electronic devices, due to the generation of heat, cooling system is essentially needed. Miniaturized pumps have been demanded for cooling water circulation and a low power consumption. To obtain sufficient performance for practical applications, in this paper, a piezoelectric pump composed of hinge-lever using multilayer PZT actuator to generate large displacement and two sheet type check valves to control flow direction are designed. First, hinge-lever mechanism consists of a pin hinge-lever and two multilayer PZT actuators. The metal bellows is used as a flexible pump chamber. The hinge-lever mechanism produces a 560 mum displacement with free load. Second, a check valve with high response is applied and the basic characteristics are experimentally investigated with various shapes and thickness. As a result, the maximum flow rate of 1.85 l/min and maximum pumping pressure of 25 kPa are obtained with the driving frequency of 11 Hz at 100 V_p-p