Design, Fabrication and Performance of a Compact Motor with Spray-formed Soft-magnetic Composite Stator Core

This paper presents design, fabrication, and performance of a compact motor with a soft-magnetic composite stator core. The stator core is produced in a near-net manner through the process of spray-forming. Spray-forming is an additive deposition process that enables production of soft-magnetic composite material with an optimal blend of magnetic, structural, and thermal properties. The motor is a single sided axial flux permanent magnet motor, featuring three-dimensional flux flow through the stator core, whose outer diameter, rated torque, rated speed, and motor constant are chosen to match those of a reference radial flux motor developed for use in robot actuators. The motor design is optimized to leverage the three-dimensional magnetic flux flow capability, minimize overall motor length, and motor volume, facilitate ease of fabrication, minimize motor thermal resistance, and withstand the internal axial loading typical of a single-sided axial flux design. The optimized motor design, stator fabrication method, motor assembly steps and motor performance test results are presented. The resulting motor is shown to have a 36% lower volume than the reference radial flux motor.