Topology selection and analysis of actuator for seat valves suitable for use in Digital Displacement pumps/motors

Digital Displacement (DD) Fluid Power is an upcoming technology setting new standards for the achievable efficiency of fluid power pumps and motors. To enable high efficiency operation fast switching electronically controlled seat valves are needed, preferably exhibiting very low flow pressure loss and switching times within a few milliseconds. These valves are mechatronic components and attention to both the electromagnetic, fluid dynamical, mechanical and control system design must be paid to ensure the needed performance. In the present work, a quick response linear electro-magnetic actuator for DD seat valves is developed, and the resulting dynamic response of the seat valve is presented. Requirements for the valve actuator is established based on the DD application, and three feasible actuator topologies are analyzed by means of transient electro-magnetic FEA simulation. From this analysis a moving coil actuator topology is selected for the DD valve. A lumped parameter model including magnetic diffusion effects of this chosen actuator is developed, which is included in the dynamic valve simulation. Result show a switching time below 2 ms and a pressure loss below 0.5 bar at 500 litres/minute for the proposed DD seat valve.