Reduced manufactoring effort, lower rotor losses

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The Challenge

In the development of electromagnetic machines, minimizing ohmic losses in conductors is a key objective. For large transformers, the sheet layout is designed to enable as circular a winding as possible – that is, toroidal, representing the ideal solution to the isoperimetric problem. However, in electric motors – where torque calculation is based on the Lorentz force principle – a conductor runs orthogonally to both the field direction and the direction of motion. This setup fails to utilize geometric optimization possibilities in design that could be achieved through the use of ferromagnetic materials.

The Project

Even in rotating machines, the isoperimetric approach offers added value. By employing soft magnetic composite materials (SMC), a toroidal cross-section of the stator becomes feasible. To demonstrate this, BOMATEC has developed a technology sample: a radially wound radial flux machine, based on the isoperimetric principle.


The Solution

The ring-shaped geometry of the wound stator is made possible only through the use of soft magnetic powder composite materials (SMC). SMC allows for the magnetic flux to be directed in three dimensions without creating significant eddy current losses.

The Success

Transitioning from an orthogonal to a toroidal winding, we’ve significantly streamlined manufacturing and reduced ohmic losses in the conductor. Bolstered by BOMATEC's SNAKELINE technology, this shift also brings a marked reduction in eddy current losses in permanent magnets.


Significantly reduced manufacturing effort


Considerably lower rotor losses


Short axial length of the machine