Abstract: An annular stator holder within a homopolar motor housing is positioned within magnetic fields established by magnet coils positioned in surrounding relation to brushes in sliding contact with the motor rotor. Also enclosed within the stator holder is a slip ring preassembled with the brushes attached thereto on one side by soft-solder joints with the other side attached by hard-solder joints to spring devices for clamping to the stator holder by leaf springs to exert pressure on the brushes thereby maintained in sliding contact with the rotor.

Abstract: A brush assembly is formed from a single metallic foil positioned within a base portion. The foil is folded or rolled up into a plurality of closely spaced foil layers soldered to the base portion of the brush assembly. Attachment of the folded foil to the brush base portion involves use of barrier tape and/or adhesive on the folded side of the foil layers and soldering of one layer edge to the base portion which is received within a holder to position the folded foil in brushing contact along the other layer edges with a running surface under a spring bias pressure. The brush may be constructed by metal fiber braids placed on or between metal skins to form a hybrid structure. The brush assembly may be applicable to slip ring current collectors or other electric contact applications, including cleansing brush applications involving other types of brushes.