Multistable proportional valve: An energy efficient approach for high temperature passive magnetic shape memory applications

Abstract:
The focus of this paper are drive technologies for multistable valves with a magnetic shape memory (MSM) element as passive unit to stabilize armature motion. In this application, the MSM element does not cause the valve motion, but the mechanical force of a bidirectional reluctance actuator deforms the MSM element mechanically. To ensure a good controllability the actuator force has to be nearly constant over stroke. This combination of a reluctance actuator and a passive MSM element leads to a very energy efficient drive technology. Conventional MSM alloys consisting of Ni, Mn, and Ga are limited in their temperature range, if they are driven by magnetic fields. In the present purely mechanical application of MSM elements, this restriction is eliminated. New alloys tuned by additional elements like Co, Fe, or Cu can increase the temperature range significantly. Using this drive technology, very energy efficient and well controllable valves are designed, which work at high operating temperatures.