Design and testing of a universal motor using a soft magnetic composite stator

Design and test results are reported for a vacuum cleaner universal motor with the stator core manufactured from compacted iron powder. The isotropic magnetic properties allow freedom to create better-shaped windings and savings in copper. The core is separated into poles and half-yokes, split on the axial centreline, allowing bobbin winding of the field and easy assembly. The motor uses the existing production rotor, brushes and bearings. Tests show the new motor to be near identical electrically, but slightly better than the existing machine when placed in the vacuum cleaner.