Integration of Forming Manufacturing Technology into the Component Production of Innovative Electric Motor Concepts

Abstract

Constantly increasing demands on production technology, such as sustainability and climate protection, require continuous optimization or even new development of production processes and designs, including in the field of electrical engineering. For this reason, it is also necessary to exploit the potential of various manufacturing technologies in order to achieve higher efficiency of the running machines. One way to achieve this goal is the application-optimized use of forming technology, which is less material-intensive due to its characteristics compared to, for example, cutting technology. Its use also allows better utilization of the special properties of electrical steel used in electrical machine construction or increases the so-called slot filling factor of electrical coils.Usually, motor stators consist of axially stacked, non-grain-oriented electrical steel (ngo), in whose motor slots coils of wound round wire are placed. The grain orientation of the sheets used has an influence on the amount of iron losses of the motor. With the use of round wire for the electric coils, only a slot filling factor of approx. 65 % can be achieved and thus potential for increasing the magnetic field of the coil is available. In order to achieve a higher slot filling factor, it is necessary to adapt the cross-sectional shape of the conductor material to the corresponding installation position by means of forming.In the present paper a novel approach for stator design with so-called flux barriers and thus the possibility of using radially laminated, grain-oriented plates are presented and the latest research results are shown. In addition current measurement results for the forming technical optimization of the increase of the slot filling factor of electrical coils with adapted conductor cross sections are presented and discussed.