Design and modelling of fast switching efficient seat valves for digital displacement pumps

Digital Displacement Fluid Power Pumps/Motors are promising candidates for revolutionizing the efficiency of fluid power systems, which traditionally has suffered from poor efficiencies, especially at part load. The key to obtain efficient part load operation with digital displacement technology lies in the development of very fast switching seat valves with a corresponding low pressure loss. The present article is on design and modelling of such an efficient seat valve, which is a mechatronic approach where considerations of different technology fields must be taken into account. Models include valve orifice flow, valve movement and valve actuation. A design method for selecting the optimum valve diameter and stroke length for a given displacement volume is presented. Furthermore, a prototype valve is manufactured and experimental results show good correspondence with modelled results.