New manufacturing methods for electric motors using different soft magnetic material combinations

This paper presents the manufacturing experience of an outer rotor permanent magnet synchronous machine with four different stators. The advantageous features of powder technology and molding techniques are tested when constructing and manufacturing the stators for a 28-pole 30-slot machine. The selected machine configuration is taking advantages of the concept of the modular windings and at the same time facing the challenges of undemanding winding production, which is suitable for injection and rotation molded magnetic cores. The geometric tolerances of the modular winding segments and the requirements for the electric insulation system have the main influence on the selection of alternatives methods for manufacturing powdered magnetic cores. The tight connection between the material engineering, research on the production techniques and the modeling of energy conversion processes have positively influenced the machine design towards improved electromagnetic and thermal characteristics of the product. The main outcomes of the manufacturing methods and electromagnetic design are discussed when combining the modular windings together with compression and molded soft magnetic composite powders.