Magnetic Flux Control through Magnetic Shape Memory Alloys in Reluctance Actuators

Abstract:
High-performance mechatronics which can be used in clean rooms – e.g. magnetically levitated systems – requires innovative actuator concepts. Actuators should have high power density, low energy consumption during stationary operation, very low wear and abrasion, and contactless force generation. Magnetic shape memory alloys (MSM) actuators offer a high strain of up to 6 % as well as multi-stable positioning and therefore have low power dissipation under static load. The strain of an MSM stick determines its permeability, which can be used as a sensory effect. Present MSM actuator concepts, however, do not offer contactless force generation. This paper shows the concept, key experiments and simulations of an MSM stick as variable magnetic reluctance in a permanent magnetic reluctance actuator. The adjustable reluctance of the MSM stick is used to control the magnetic flux and thus the force on a ferromagnetic armature. This approach promises compact, low-power and wear-free actuator designs, which can be combined with classic reluctance actuators.