Pilot study 3D Printing electric motors

The central research objective in this project is the examination and the testing how additive manufacturing processes are useable for the production of encoderless controlled permanentmagnetic synchronous DC motors (PMSM). As basematerial a soft-magnetic-composite is used first. But other materials can also be part of the research.

The additive manufacturing processes provide three central advantages in comparison to conventional processes which are of importance for the application fields of PMSM and the industrial production of controlled drives.

• The needed leakage paths can be designed in a complex geometry so that on one hand the mechanical boundary conditions can be optimized and on the other hand the magnetic conductivity can be minimised. For this lattice structures can be includes in the parts. Because of this the new design of the rotor is not limited by 2D cross sections. Instead it can be designed and produced in 3D.
• The impact of the punching tool and the associated uncertainties of the magnetic properties are completely eliminated. The new manufacturing technology is expected to give a significantly better prognosis and reproducibility of the magnetic properties. This aspects are not only of great importance for encoderless controlled drives but also for highly exploited Electric drives in general.
• It is also conceivable for future projects, that permanent magnet material also engage in the printing process, which will not be further examined in the context of this feasibility study . This eliminates the usual limitations of the magnet dimensions and shapes. The decreases of the cost by saving material and the absence of finishing processes are also economically interesting aspects for such a project. Moreover the execution of a slanted rotor is connected to this process with no extra effort possible.

A part of the feasibility study the practical testing on the basis of test specimens and the printing of a first demonstrator engine are in the foreground.

Here, the DMRC contribute its experience in additive manufacturing in the project and to draw on the existing technical equipment for the production of the test specimens and the demonstrator.

The IAL as the lead research facility for the sensorless ATEM project has access on the partial results and experience in the field of machine design of sensorless PMSM.

At the end of this project initial statements on the importance of additive manufacturing for electrical engineering are to be derived.