Testbench for actuators based on magnetic-shape-memory ferromagnets.

Profil Titel	Testbench for actuators based on magnetic-shape-memory ferromagnets.
Referenz	10 ES 28G2 3JE1
Herkunftsland	Spain
Kooperationsart	Angebot
Eintrag/Änderung	2010-11-30 / 2010-11-30
Status	Dieses Profil ist abgelaufen! Falls Sie denoch Interesse haben, kontaktieren Sie uns. (2011-07-12)

Kurzfassung

A Spanish public research organisation has developed a testbench with which linear actuators of very short motion range, and in particular those built with magnetic-shape-memory ferromagnets, can be characterized. The bench allows to simultaneously evaluate both the operating conditions and the components of the actuator in different configurations, thus approaching real working situations. Partners interested in a patent license are being sought.

Details

Magnetic Shape Memory materials (MSMM) and alloys (MSMA), which change their size as much as a 10% in volume under the application of a magnetic field due to a microscopic phase transition called martensitic transformation (MT), are of great technological interest, since they allow exerting a force or generating motion when they are deformed. Since MSM materials are capable of converting magnetic into mechanical energy, they can be used to develop intelligent actuators where a mechanical action is produced by applying a magnetic field. Examples of these are linear motors or proportioning valves.

Actuators are designed with the aid of testbenches, where the working conditions of a real mechanical system using actuators can be simulated. General purpose testbenches can only evaluate their characteristics in a fixed configuration of the working conditions and a particular combination of its components (ferromagnetic nucleus, specific type of payload, etc.). But the performance of a MSMM-based actuator is determined by four independent parameters (magnetic field necessary to produce the MT, the reaction of the MSMM under mechanical deformation—in particular under “acoustic assistance”, the reduction of the magnetic field needed to cause the MT by a periodic change in shape—and the effect of control systems), so that this kind of testbench is insufficient.

To surmount these difficulties a modular testbench has been developed that can simultaneously evaluate both working conditions and components. Specifically, it allows changing the configuration and situation of the components, narrowing the gap between laboratory and real operating conditions and making it possible to characterize high performance MSMM-based actuators.

The three modules of this testbench, aligned and joint on a machined base, contain a sample of the MSM material, the different payloads applied on the material, the sensors to measure the different characteristics, and a wave generator to evaluate the effect of acoustic assistance. Among the characteristics of the MSMM that can be obtained with it are the elongation (deformation), the current and voltage required for that elongation, the maximum and blocking forces, the reaction time, and the minimum magnetic field that must be applied to produce the MT. The influence of size, shape, material or geometry of the ferromagnetic core on the wave generating system or on the configuration of exerted forces can be determined.

Innovative Aspects:
- The modular design of the testbench makes it possible to add, substitute and modify the different components of the actuator, thus enabling the separate evaluation of the MSMM and the components, as well as their interdependency.

- It is possible to try different configurations of the magnetic materials: different MSM materials, presence or absence of a ferromagnetic core.

- Actuating frequencies up to the kHz-regime are supported.

- The mobile base adds to the versatility and flexibility of the actuator, since it allows modifying its structure and simulating any possible configuration.