Abstract: Dynamoelectric machines are disclosed that are characterized by lengthened ground potential leakage current paths, desirable mechanical conformations, mechanical integrity when subjected to expected centrifugal forces, and ease of manufacture. One process involves establishing an extended or elongated path for commutator leakage currents with a path extending structure, establishing a cantilevered insulation skirt about the in-board or armature coil end of a commutator, and securely fastening such skirt to the commutator. The material utilized in making the skirt is one: that has electrical properties that permit it to withstand leakage currents without tracking; that for practical purposes is non-burnable, so as to resist flashovers or sparking; and that has the ability to withstand elevated temperatures that are encountered within dynamoelectric machine.

Abstract: Dynamoelectric machines characterized by lengthened ground potential leakage current paths, desirable mechanical conformations, mechanical integrity when subjected to expected centrifugal forces, and ease of manufacture. One process involves establishing an extended path for commutator leakage currents with a path extending structure, establishing a cantilevered insulation skirt about the in-board or armature coil end of a commutator, and securely fastening such skirt to the commutator. The material utilized in making the skirt is one: that has electrical properties that permit it to withstand leakage currents without tracking; that for practical purposes is non-burnable, so as to resist flashovers or sparking; and that has the ability to withstand elevated temperatures that are encountered within dynamoelectric machine. The skirt is provided with openings therein and sandwiched between two glass based bands that adhere to another through the openings and thus lock the skirt in place on the commutator body.

Abstract: An insulated coil assembly for use in electrical apparatus includes a coil of conductive wire formed in a predetermined configuration around selected portions of which is disposed an insulating layer comprised of a cured resin impregnated, close woven, heat-cleaned glass fiber tape.

Abstract: A rotor structure for dynamoelectric machines includes a central shaft, defining a rotation axis, which supports main rotor windings. A winding support is disposed about and secured to the shaft and an encapsulated equalizer winding assembly is supported by said winding support. An expansion member is positioned between at least a portion of said encapsulated equalizer winding assembly and said winding support and an insulating resin covers at least exposed, proximate portions of said winding support, said expansion member and said encapsulated equalizer winding assembly.

Abstract: A knitted glass fiber tube is everted, or turned inside out to convert the usual outward flare which develops at the cut end thereof into a purse mouth which tends to urge the cut end inward against the peripheral surface of a conductor bar passing therethrough. The intimate contact between the cut end of the everted knitted glass fiber tube and the conductor bar resists deposition of conductive contaminants which may otherwise reduce the insulation provided by the everted knitted glass fiber tube.

Abstract: A band of fabric over the interface between the slot armor and the copper bar of a pole face winding is both resistant to migration of conductive contaminants under the edge of the slot armor and hospitable to the application and retention of an insulating paint layer over such interface. The band of fabric is preferably of woven glass fiber with a tenacious pressure sensitive adhesive on one side and with the other side bare. The adhesive is compatible with the material of the slot armor, sticks readily to the copper bar and to the bare surface of the woven glass fiber fabric band. The bare side of the fabric provides a good mechanical bond to the insulating paint layer and thereby encourages the establishment and retention of an unbroken paint layer over the interface. The combination provides a long electrical leakage current path between the copper bar and the iron of the pole.

Abstract: A dynamoelectric machine pole and coil assembly having a magnetic pole member around which a preformed coil of insulated magnet wire is mounted. The assembly is characterized by including a plurality of preformed, extended corner sheets of insulating material that are positioned to extend around and beyond each of the corners of the magnetic pole member into overlapping relationship with adjacent extended corner sheets. The extended corner sheets are bonded to the pole member and to one another at their overlapped ends. Projecting tip portions on the magnetic pole member have their upper surfaces completely shielded from the energizing coil by lip parts of the extended corner insulating sheets. A felt piece impregnated with thermosetting resin is used to make a readily conformable corner section of the lip part.

Abstract: A dynamoelectric machine pole and coil assembly having a magnetic pole member around which a preformed coil of insulated magnet wire is mounted. The assembly is characterized by including a plurality of preformed, extended corner sheets of insulating material that are positioned to extend around and beyond each of the corners of the magnetic pole member into overlapping relationship with adjacent extended corner sheets. The extended corner sheets are bonded to the pole member and to one another at their overlapped ends. Projecting tip portions on the magnetic pole member have their upper surfaces completely shielded from the energizing coil by lip parts of the extended corner insulating sheets. A felt piece impregnated with thermosetting resin is used to make a readily conformable corner section of the lip part. The cured piece is free of voids, so reinforces the insulation of the ground barrier of the assembly at the critical corner areas.