Abstract: A commutator assembly for a dynamoelectric machine with metallic brushes has a plurality of composite carbon commutator bars retained on a generally cylindrical molded core with radial extensions and retaining lips at each axial end. A hook member for each bar has a U-shaped portion clamping one end of the bar and trapped in the molded core for retention of the bar against migration due to tangential brush force and a hook portion projecting outward for armature wire connection.

Abstract: A non-micaceous commutator cone for insulating commutator bars from retaining rings of a commutator assembly in a dynamoelectric machine, comprising an annular laminated member including at least one layer of non-conductive, resin-impregnated fibrous elements sandwiched between outer layers of thin, seamless, impervious, non-thermoplastic polymeric films. The wall of this laminate has the dielectric strength, the uniform thickness, the stability, and the resiliency that are required for a commutator cone in a relatively large, high temperature machine.

Abstract: A stamped and rolled sheet metal bushing having pointed barbs on its exterior periphery and longitudinal ribs on its interior periphery is inserted into the bore of a premolded commutator assembly. An armature shaft is press fit into the bushing assembly, deforming the longitudinal ribs to couple the shaft to the bushing and embedding the pointed barbs into the molded material of the commutator to couple the bushing to the commutator.

Abstract: A dynamoelectric machine commutator structure having a plurality of conductive commutator segments secured in operating position by a commutator banding is characterized by including a flexible, thermally stable dielectric coating material between the outer edges of the commutator banding and the conductor segments in order to effectively seal the junction between those members, thereby preventing the deposit or buildup of electrically conductive contaminants at that junction so that the likelihood of electrically short circuiting the conductive segments of the commutator is effectively eliminated. According to the preferred method of the invention, a banded commutator is formed by applying such a coating to predetermined portions of the banding grooves so that the coating effectively seals the junctions between the banding and the conductive segments of the commutator, thereby preventing the accumulation of conductive contaminants at those junctions.

Abstract: An armature commutator associated with a slotted core is constructed with a temporary tang structure which is employed during winding on a tang-type winding machine. After the core is wound and the commutator bars are connected, the temporary tang structure is removed resulting in a lead loop-type wound commutator.

Abstract: Fixed members of the small-sized motor centrifugal governor switch and commutator segment metals are secured to a boss of a molding insulating resin mounted on a shaft of the rotor, thereby disposing the centrifugal governor switch on the same side as the commutator with respect to the rotor. With this construction, there is no need of installing the centrifugal governor switch in the space radially centrally of the stator magnet, hence there is no need of restricting the size of the centrifugal governor switch to be smaller than the inner diameter of the stator magnet. Accordingly the centrifugal governor switch can be made larger, thereby securing a better function.

Abstract: A metal tube with outwardly bent risers for terminals is filled with a body of plastic resin which hardens in place. Then the tube is cut through, chordwise, a plurality of times to provide a plurality of segments. An extended, base portion of the plastic resin body through which the risers extend radially outwardly continues to hold the cylindrical disposition of the metal segments, with gaps maintained therebetween. A shaft is fitted coaxially in the base portion of the plastic resin body and extends through a larger diameter central bore of the body, centrally of the commutator segments. The gaps communicate with the annular space between this bore and the shaft, for cleaning out of particulate debris by centrifugal force.

Abstract: This invention describes a method of making a commutator, for a high speed electric machine, (1) embedding a number of conductive bars in insulating plastics material to form a moulded commutator (2) the moulded commutator defining at least one annular seat (3) placing a ring of high tensile material on the seat whereby to stress the ring in tension and thereby apply a radially inward load to each bar which is greater than the centrifugal force on the bar at maximum running speed. The invention also includes a commutator made by this method.

Abstract: A discoidal armature for dynamoelectric machines has its winding conductors bonded together in a rigid structure by means of a resinous material, and its commutator bonded to the structure. The structure has a disc portion containing the coil sides and outer and inner ring portions containing the coil end-heads and other end connections. The coils have their sides and end-heads of shapes which permit them to nest closely together in an annular array of overlapping coils. They are stranded and have the strands in their side arranged to provide a tapered disc portion which is thicker at the inner ring portion than it is at the outer ring portion. The commutator consists of an annular array of segments bonded to the disc portion adjacent the outer ring portion and presents a working face on the side of the disc portion. A similar array of segments can be bonded to the other side of the disc portion to obtain a duplex commutator.

Abstract: In accordance with a preferred embodiment of this invention, a commutator for electrical machines having a polymeric spool and aluminum alloy bars uniformly spaced around its periphery is formed. This commutator is useful in low voltage applications wherein the applied or produced voltage may vary from 3 to 30 volts. A critical feature in forming this commutator is the combination of an electrolytic etch and an electrolytic oxide formation on the surface of the aluminum alloy bars. This combination of steps provides means for bonding the aluminum alloy bars to the polymeric spool and also lowers the electrical resistance of alumina. In addition, alloying elements, preferably iron, increase the conductivity of the alumina layer and directionally balance the electrical resistance across the aluminum-alumina junction.