A Novel Concept for Boosting the Suction Line of Piston Pumps by Piezo-Actuated Pipe Walls

Abstract

Axial and radial piston pumps are the work horse of the fluid power industry in the medium to high power range. During the maturation of the technology in the last five decades, both the pressure levels and the maximum rotational speeds have been increased significantly to meet the market demands for an increased power to weight or size ratio. The maximum speed of operation is often limited by cavitation occuring in the suction duct of pumps. A well known but expensive solution to the problem is the use of booster pumps to raise the suction pressure at the piston pump inlet. The rationale behind this solution is very simple: The pressure oscillations inevitably caused by the nonuniform operation of the piston pump will occur around an increased mean pressure level, thereby raising also the pressure minima and avoiding cavitation. The present paper looks into the dynamics of the suction process in more detail. A simulation model of an axial piston pump with a detailed model of the wave propagation in the suction line is analysed for the potential of mitigating the pressure oscillations locally at the pump inlet by actuating the pipe wall for instance with piezo ring actuators. In a first simulation study, the power electronics of the actuation system is idealized and a mathematical optimization of the actuation signals for a certain operating point of the pump is set up. A theoretical proof of concept can be achieved in this simulation. A second, and more detailed simulation includes the computation of power budgets for the power electronics operating the piezo actuation. An experimental proof of concept is left to future work at this point.