Gm Global Technolgoy Operations, Inc.

Sam B Parker

Robert W Ward

David Allen Score

William E Boys

A method of manufacturing an armature for a DC motor comprising the steps of: (a) retaining a plurality of armature conductors pre-positioned in a pre-mold position; (b) placing the armature conductors in a mold; (c) adding to the mold a predetermined quantity of soft-magnetic particles, each soft-magnetic particle coated with a non-magnetic material, wherein said particles surround at least a portion of each of the conductors; (d) applying pressure to the mold to affect a compaction molding of the coated soft magnetic particles into a composite structure, wherein the particles and the non-magnetic material form a composite structure armature core substantially encapsulating the conductors within the armature core.

Composite armature assembly

A rotor for an alternating current generator of the Lundell type. The rotor shaft carries two segments which have interleaved pole teeth. The rotor has a core member and a field coil disposed about the core member. The segments and/or core member are formed of compressed powder iron particles having a particle size in a range of about 10 to 250 microns. In the manufacture of the core and/or segments the iron powder particles are coated with a thermoplastic material and this thermoplastic coated iron particle material is compacted in the molding dies of a press. After compaction to the desired shape, the part is sintered at a temperature of about 2050.degree. F. to burn-off the thermoplastic material that coated the iron particles.

Alternating current generator rotor

A method of manufacturing an electromagnetic device having regions of ferromagnetic material and permanent magnet material is disclosed. The electromagnetic assemblies of this invention utilize thermoplastic encapsulated iron powders and epoxy resin encapsulated permanent magnet powder. A motor frame and permanent magnet assembly is formed in a first example, while a permanent rotor assembly is formed in a second. The motor frame and permanent magnet assembly has a ferromagnetic frame defined by a region of encapsulated iron powder and an annular array of permanent magnets defined by a region of encapsulated permanent magnet material. The permanent magnet rotor assembly has a ferromagnetic core defined by a region of encapsulated iron powder and a permanent magnet shell defined by a region of encapsulated permanent magnet material. In the processing of both the motor frame and permanent magnet assembly and the rotor assembly, annular inner and outer punch elements coaxial with a central core rod are supported within a heated die casing for independent extension and retraction along the central axis. The inner and outer punch elements are retracted to form cavities which are filled with the encapsulated permanent magnet and ferrous powders, respectively, for the motor frame and permanent magnet assembly, while the reverse exists for the manufacture of the permanent magnet rotor assembly. Coaxial pressing mechanisms individually and concurrently compress the powders to fuse and compact them to a predetermined axial length.

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Anderson, IN, United States of America

Sam B Parker