Design and simulation of high pressure piezohydraulic pump with active valves

Pumps incorporated with active valves provide active control on both the inlet and outlet valves. Here piezoelectric actuation is used as the actuation system since piezoelectric actuators can produce controlled actuation. Also piezoelectric actuators can produce high displacement with large force and has advantages such as high resolution, fast response, high stability, high reliability, compactness etc. In this work active valves are designed for a high pressure piezo-hydraulic pump. Flexural amplifiers for piezoelectric actuators are designed for the valve diaphragm actuation as well as for the pumping diaphragm actuation. There are three slotted diaphragms designed and operated by three separate flexurally amplified piezoelectric actuators. The flexural amplifiers and the diaphragms are analysed using ANSYS analysis software. Suitable mathematical model is developed using MATLAB software for synchronizing the sequence of actuation with respect to timing. Here Bouc-Wen model is made use for modelling the hysteresis effect. MATLAB Simulink is used to develop the model and simulations are performed to determine the displacement produced by the piezoelectric actuators when applied with a voltage. Also simulations are carried out for the determination of pumped volume, flow rate and stroke length of a particular cylinder.