Case Study: Stator Superior and Inferior

Process: Conventional powder metallurgy

Material: Soft-magnetic composite

Density: 7.4 g/cm³

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End Use and Function

This soft-magnetic composite superior and inferior stator is used in a mono-phase induction ceiling fan motor. The component was specifically designed for the PM process to take advantage of the 3-D magnetic flux.

Fabrication

The parts are made using an iron powder coated with an insulating inorganic material that has high resistivity, and the parts have excellent magnetic permeability. A high compacting pressure of 800 MPa (60 tsi) was required to achieve the 7.4 g/cm³ minimum density. During engineering, the proper tooling material was identified, resulting in reduced tool wear and increased tool life. The parts are cured rather than sintered, and a special fixture was required to check the strength of the cured component.

Results

The use of an axial flux motor resulted in a change from 152 mm (6 in.) to 80 millimeter (3.1 in) in the outer diameter, less copper wiring, a 76% reduction in the mass of the motor, and 35% less energy consumption with less noise in service.