First of all, a complete set of requirements for the electric motors to be designed was produced. The simulation cases to be performed for the verification of the compliance of the requirements at the design stage were defined, together with the acceptance procedure.
As a first step a pre-sizing and optimization approach of the ADDIMOT motor was performed in order to determine the required main dimensions of the magnetic motor, its winding configuration, material consumption weight, etc. This sizing and optimization approach was applied to a number of different motor configurations in order to select the most promising ones: radial PMSM (internal and external rotor), with and without Halbach configuration magnets, single and double rotor, single, double and triple stage axial configurations.
As a conclusion of this first step, the conducted study has not only served to select the most adequate machine topology (external rotor PMSM configuration) in consensus with the TM, but also provide a basis for sizing similar devices in the future as well.
After this pre-sizing, starting from the basic geometry of the electric motor, a complete TO methodology was established: load conditions set up on nominal geometry, TO frozen areas, FEM problem solving for mass reduction and load conditions set up on optimized geometry.
With this procedure, optimized designs that comply with the weight requirement for the electric motor (less than 3kg) was produced.
In parallel with the design and optimization of the electric motor, several steps towards the manufacturing of SLM processed parts were taken. First of all, a thorough study about the most suitable materials for the application was done. Finally, the different powder alloys were completely characterized in terms of mechanical properties and magnetic properties.
Hard Magnets:
NdFeB alloy has been manufactured and fully characterized in Ceit.
Soft magnets:
From the different materials with the required properties, only three materials have been selected for extensive testing:
Supermalloy: This material was not available commercially and therefore Ceit atomised the required powder.
Permendur: This material was not available commercially and therefore Ceit atomised the required powder.
Fe6.5Si: This alloy has been purchased to Sandvik Osprey.
After the characterization of the different powder alloys, many iterations of sample manufacturing were produced for Fe6.5Si and Permendur with the objective of having good density characteristics, absence of cracks and low porosity.
The first choice for soft magnetic material was Fe6.5Si with the rationale of being a good compromise between expected properties and cost. However, after intensive work it was not possible to achieve a set of process parameters to manufacture samples without the presence of cracks. Fe6-5Si material had to be discarded and the work began from scratch with Permendur.
Permendur parts achieved a very good compromise between magnetic and mechanical properties, after intensive work fine tuning the SLM process parameters and the heat treatments needed after SLM process.
Once the manufacturing process was correct, a critical design of the ADDIMOT electric motor was produced and three prototypes were manufactured and tested.
The test shown very good motor performance with a weight reduction of 30% enabled by Additive Manufacturing. Moreover, a safety and reliability analysis was conducted and a thorough cost analysis comparing the traditional manufacturing routes and the new one proposed in ADDIMOT project, being the conclusion that the ADDIMOT approach is feasible for future active inceptor electric motor design and manufacturing.
Finally, several dissemination and exploitation activities have been done, including participation in conferences and exhibitions, and possibilities for exploitation of ADDIMOT results both in the aeronautic and industrial sectors.
