Abstract: The present invention provides a grain-oriented electrical steel sheet, for a low noise transformer, capable of reducing higher harmonics which are highly audible and lowering noise effectively, and relates to a grain-oriented electrical steel sheet for a low noise transformer, characterized by imposing a film tension of 0.5 to 6.0 MPa on the surface by coating or a method corresponding thereto, without forming a glass film on the grain-oriented electrical steel sheet or, if a glass film is formed, after removing the glass film by an arbitrary method.

Abstract: A method and apparatus are provided to increase compressive creep capabilities of high voltage coil insulation. The method preferably includes applying at least one layer of a first tape as a groundwall insulation to substantially the entire length of a high voltage coil. The first tape preferably has a first predetermined amount of resin therein. The method also includes curing the groundwall insulation for a first predetermined time period, applying at least one layer of a second tape as a protective armor overlying the groundwall insulation only to end portions of the high voltage coil after the first predetermined time period. the second tape preferably includes substantially more resin than the first tape. The method further includes curing the protective armor for a second predetermined time period.

Abstract: In a method for fabricating a surface mountable chip inductor, a spiral coil pattern is formed on a surface of a cylindrical body fabricated by mixing ferrite or ceramic powder with thermoplastic organic binder, the cylindrical body is transformed into a square-shaped body by being inserted into a square-shaped mold and being applied pressure at a certain temperature. An electric characteristic lowering problem can be prevented by forming the coil on the cylindrical body, and transforming the cylindrical body into a square-shaped body is advantageous to surface mounting.

Abstract: The present invention is directed to a method of forming an electrically insulating layer on a steel article such as a stack of electrical steel laminations or an individual, unstacked electrical steel lamination, comprising exposing the article to an oxidation atmosphere, and to a temperature (such as at least about 800° F.) for a time sufficient to form on the article an electrically insulating layer comprising hematite. The hematite layer is effective to provide the article with a surface resistivity characterized by an F-amp value of not greater than about 0.85 at a test pressure of 50 psi and a transfer surface roughness of about 10 microinches (Ra). Also featured is a steel article having the electrically insulating layer formed thereon.

Abstract: The present invention is directed to a method of forming an electrically insulating layer on a steel article such as a stack of electrical steel laminations or an individual, unstacked electrical steel lamination, comprising exposing the article to an oxidation atmosphere, and to a temperature (such as at least about 800° F.) for a time sufficient to form on the article an electrically insulating layer comprising hematite. The hematite layer is effective to provide the article with a surface resistivity characterized by an F-amp value of not greater than about 0.85 at a test pressure of 50 psi and a transfer surface roughness of about 10 micro inches (Ra). Also featured is a steel article having the electrically insulating layer formed thereon.

Abstract: A system for removing resin from the stator core of a stator of a motor involves means for removing resin (1) from an inner circumferential surface surrounding the bore of the stator core; (2) from the outer circumferential surface of the stator core; and (3) from between the windings along the end surfaces of the stator core. The circumferential surfaces have resin removed from them by moving the surfaces relative to a series of wipers. The wipers push the resin off the surfaces as they sweep the surfaces. Resin is removed from the end surfaces by blowing the resin radially inward, where it either drips off the core or is deposited on the inner circumferential surface, from which it is removed by wipers.

Abstract: A process for producing a hermetic electric compressor for a refrigerating or air-conditioning apparatus using a refrigerant having a hydrofluorocarbon base which comprises a motor unit, a compressing unit driven by the motor unit and a sealed housing enclosing the motor unit and the compressing unit and stores a refrigeration oil on the bottom of the sealed housing, wherein a solventless varnish comprising a thermosetting resin having at least two (meth)acryloyl groups in one molecule, a low-viscosity vinyl or 1-alkylvinyl monomer having an ether or ester linkage as a reactive diluent and an organic peroxide as a reaction initiator is used as an insulating varnish to insulate and fix the magnet wires of the stator of the motor unit, and the solventless varnish is cured by heating at a temperature of from 153 to 180.degree. C. for from 0.5 to 3.5 hours.

Abstract: A method for coating a core of a small sized motor having a jig or the like by applying a liquid primer forming a primer coat film followed by applying a powder coating using either a friction charging type electrostatic powder gun or an inner charging type electrostatic powder gun. This method prevents rust from forming on the shaft hole and its peripheral portions covered by the jig, and it prevents the deterioration of the insulation coat film on the winding wires upon contact with burrs.

Abstract: A method of forming flexible disks containing annular loop packets for the purpose of transmitting traction forces between fastening elements is disclosed. The loop packets and the fastening elements are combined into a ring and subsequently embedded in rubber-elastic material. In a preparatory operation, the loop packets are injection-coated either individually or in groups by a coating of elastomer material, which defines and stabilizes their outer contour. The elastomer material is only partially vulcanized before the ring is completely embedded in the rubber-elastic material. Injection coating renders the loop packets or groups of loop packets into components which are true to shape and size with defined wall thicknesses. Consequently, the characteristics and the life of the flexible disks are standardized for mass production and material consumption is reduced.

Abstract: An electrical component comprising an electrical component having an exterior protective layer on at least a portion of a surface. The layer is a cured copolymer of a reaction between at least one oligomer having a terminal ethylenically unsaturated group and at least one monomer having a terminal ethylenically unsaturated group. Alternatively, the layer is a cured copolymer of a reaction between at least two oligomers having a terminal ethylenically unsaturated group. The copolymerization reaction is preferably in the presence of a free radical initiator curing agent and a transition metal catalyst.

Abstract: An apparatus and a method provide for the extruding of thermoplastic insulation onto complex shapes, such as generator stator bars. The method of the present invention comprises the steps of feeding the complex shape through a central bore of an extrusion die to deposit a thermoplastic coating along the entire length of the shape as the extrusion die traverses the length of the complex shape.

Abstract: A method for manufacturing a laminate comprising at least two sheets of magnetic material is disclosed. The laminate may be used to form a stacked transformer core. The method increases the productivity of the core-stacking process, decreases the core loss destruction factor, decreases total core loss, decreases acoustic noise generated by the electrical device employing the laminate, and does all of this in a manner which is commercially practical. The method comprises applying an adhesive, preferably a hot melt adhesive, in a pattern of thin beads onto one side of a first lamina or sheet of magnetic material, the pattern comprising a plurality of lines, the lines being substantially parallel to each other and substantially perpendicular to a direction of grain orientation or rolling direction of the lamina. A second lamina is then stacked onto the one side of the first lamina, and then a compressive force is applied to specified areas of the laminate.

Abstract: High voltage generator stator bar for electrical generators internally graded with a fast drying, electrically conductive, carbon-filled thermoplastic paint composition exhibit improved electrical dissipation factor tip-up values.

Abstract: There is disclosed a method and apparatus for coating an electromagnetic coil, particularly stator coils for an electric motor, with an insulating catalyzed resin material. The catalyzed resin material is a two component material comprising an epoxy resin and a catalyst. The catalyzed resin material is a free flowing liquid at a first temperature and begins to cure rapidly at a second elevated temperature. The stator coils are first heated by supplying current to the stator coils to raise the temperature of the stator coils to the first temperature. The free flowing liquid catalyzed resin material is dispensed through nozzles onto the stator coils as the stator coils and the nozzles move relative to each other. After the liquid catalyzed resin material has been dispensed in a predetermined amount, at predetermined locations, for predetermined times, the catalyzed resin material is allowed to penetrate the stator coils.

Abstract: A system for processing components which are to be transferred to second system. Portions of the system are selectively controlled so that when demand from the second system is stopped, processing of the components is allowed to be completed as needed. The system includes a preparation station which is stopped once demand is stopped, a processing station which continues to process components until such process can be safely stopped without producing unusable finished products, and a waiting station which is stopped once demand is stopped. The capacity of the waiting station is adjustable in order to accommodate components which must be passed out of the processing station so that other components may be passed through the processing station to complete all uninterruptable processes.

Abstract: The present invention is directed to a method of imparting moisture resistance to epoxies. Moisture resistant epoxy compositions are formed from epoxies and alkenylsuccinic anhydride (ASA) such as tripropenylsuccinic anhydride (TSA). The epoxy compositions, following cure, show surprisingly improved moisture resistance and retention of properties when exposed to warm, humid environments.

Abstract: An epoxy powder is electrostatically charged and spray-coated onto the series loop connections 16, 18 of a dynamoelectric machine. With the series loop connections grounded, the electrostatically charged particles adhere to the connections and wrap about the front, back and sides of the connections to provide a substantially uniform thickness or build-up of the electrically insulating epoxy powder. With the series loop connections preheated, the epoxy will begin to melt and flow, further ensuring a uniform build-up and thickness about the connections. The spray-coating is then heat-cured, thereby affording electrically insulated series loop connections at the opposite ends of the dynamoelectric machine.

Abstract: An armature stator comprises an iron core and a coil directly mounted on the iron core. The coil is composed of wound electric wire which has a coating comprising an inorganic material, such as ceramic. A bonding material of the inorganic material is formed over the coil and iron core for filling any gaps and adhering the coil and iron core together into a unitary structure. To improve the reliability of the coil, after the electric wire is wound to form the coil, a filling material comprised of the inorganic material is formed over the coil by vacuum impregnation, and then sintered so as to repair defects in the coating disposed on the electric wire. After the bonding material is formed over the coil, which is directly mounted on the iron core, it is cured under high temperature. The armature stator thus constructed can be used with high reliability in high temperature and high vacuum applications.

Abstract: The apparatus, system and method utilize sequential sprays of wet, low-temperature steam, and dry, high-temperature steam to clean the exterior of laminated objects as well as to effect volatilization of liquid contaminates trapped between lamina thereof. Water is injected into the conduit through which the low-temperature steam is delivered, so as to produce a desirable concentration of droplets therein. A conveyor moves the laminated objects along a horizontal path through zones in which they are sprayed by the low temperature and high temperature steam, and then through a zone in which they are electrostatically coated with powder.

Abstract: A method and apparatus for coating insulating materials onto the outer surface of an armature of an electric motor whereby insulating material is inhibited from being coated on a commutator and a driving shaft associated with the armature by covering the commutator and a portion of the driving shaft with a cap and directing an air flow through a gap formed between the cap and the commutator and the driving shaft such that air is discharged near a boundary between a commutator base and the armature, thus preventing insulating material from entering the gap and coating the commutator or the portion of the driving shaft.

Abstract: The method utilizies steam to clean the exterior of laminated objects, preliminary to electrostatic powder coating, as well as to effect volatilization of liquid contaminates trapped between lamina thereof. Off-gassing that would otherwise occur when the objects are heated to effect fusion of the powder deposit is thereby avoided.

Abstract: A method for coating an armature of a rotary electric apparatus conducts the coating process step by step in first and second processes for coating the external circumference of an armature with a coating material. The second coating process is conducted after the first coating material already coated by the first coating process is gelled to a hardened state.

Abstract: The invention comprises applying to a substrate a precursor of an organo-metallic compound, the precursor preferably consists of one or more pairs of ligand substituted Group III and V elements. The precursor is decomposed and deposits onto a receiving layer held at the decomposing temperature of the vaporized material.

Abstract: An electrically insulating coating is formed on a metallic surface by applying a film of an aqueous fluoride-free composition which contains a water-dilutable synthetic resin, a dispersed waxlike substance, an inorganic or organic pigment, a borate, an alkali metal hydroxide, ammonia or an organic amine for adjusting the pH to between 7 and 9, and drying the moist film at a temperature between 120 and 350.degree. C.

Abstract: A process for applying an electrically insulative layer on a metal surface which comprising suspending an electrically insulative powder in a highly volatile solvent by ultrasonic vibration to give a suspension, applying said suspension on the surface of said metal surface, and then evaporating said solvent, leaving an electrically insulative layer consisting of said insulative powder.

Abstract: A method of making a laminated structure for use in an electrical apparatus. A female mold is produced having an upwardly facing cavity of a shape corresponding to the laminated structure. A layer of a ferrous metal is sprayed onto the bottom surface of the mold and subsequently an electrically insulated layer is applied to the layer of metal. Alternate layers of the ferrous metal and the insulating layer are deposited in the cavity of the mold to provide a laminated structure in which the metal and insulating layers are integrally bonded together. Through use of the method of the invention, a ferrous metal with the most desirable electrical characteristics can be employed.

Abstract: A method of consolidating a magnetic core which contains amorphous metal, including the step of thermal spraying an electrically non-conductive material on the edges of the laminations which make up the magnetic core.

Abstract: The invention relates to heat-hardenable reaction resin mixtures which contain polyfunctional epoxides, polyfunctional isocyanates and a reaction accelerator as well as, optionally containing customary additives and/or fillers. The invention has the object of achieving reaction resin mixtures which are stable in storage, consist of individual components that are easy to mix, exhibit a prolonged prehardening period and permit at the same time the manufacture of materials which combine the good mechanical properties and the high temperature-cycle resistance of polyurethane structures with the good thermal properties of oxazolidinone and isocyanurate structures. According to the invention, the reaction resin mixtures contain as polyfunctional isocyanates, isocyanate prepolymerisates in the form of reaction products of diphenyl methanediisocyanate and a diol, or of an isocyanate mixture of diphenyl-methanediisocyanate and a polymethylenepolyphenylisocyanate (with a functionality greater than 2) and a diol.

Abstract: A hardenable liquid adhesive material is dispensed onto opposite end turn portions of coils in winding means of a loose wound core with a greater amount of the liquid adhesive material flowing therefrom generally along one of the opposite side turn portions of the coils into the slots of a generally loose lamination stack of the loose wound core in which the one opposite side turn portion of the coils are received in response to the rotation of the loose wound core in one direction and with a greater amount of the liquid adhesive material flowing generally along the other of the opposite side turn portions of the coils into the slots of the loose lamination stack in which the other opposite side turn portions of the coils are received in response to the rotation of the loose wound core in another direction opposite the one direction thereby to generally equalize the liquid adhesive material fill of the slots.

Abstract: A highly fluid, solventless heat curable resin is formulated from an admixture comprising a polyglycidyl aromatic amine, a polycarboxylic acid anhydride curing agent, and a curing accelerator. The heat curable formulation exhibits low viscosity and is useful as an encapsulant and insulation for electrical members exposed to high electrical stress. Magnetic coils encapsulated with the cured formulation resist corona discharge at electrical stresses in excess of 2100 volts per mil.

Abstract: A method for insulating slots of a rotor in an electrical rotating machine comprises steps of removing punching oil from a rotor core assembly by heating only the interior of the slots to a high temperature while axially compressing the rotor core assembly, applying a liquid electric insulating paint to the inner wall surfaces of the slots by introducing the paint only into the slots and then discharging the paint from the slots while pressurizing the rotor core assembly, applying a negative pressure to the lower ends of the slots to remove the paint collected at the lower ends of the slots, and heating at least the interior of the slots to bake the paint on the inner wall surfaces of the slots.

Abstract: A solid insulator for an electric equipment coil is proposed which comprises a base film of a polyester, and a protective film of a resin selected from the group consisting of polypropylene, polyester, fluoropolymer, and aramid resin, which is formed on at least one major surface of said base film. There is also proposed an electric equipment coil comprising a winding which is resistive to hydrolysis and chemicals, an insulating film surrounding said winding, and a water-soluble insulating varnish filled and cured under heating between turns of said winding, wherein said insulating film comprises above said solid insulator.

Abstract: An improved insulating sheath for an electrical conductor, which is impregnated with a hardenable impregnating resin and afterwards hardened, has alternating layers of porous support and thermostable plastic foil support tapes of inorganic sheet type insulating material. The two tape multiple layered sheath gives increased dielectric strength and heat resistance without impairing resin impregnation capacity.

Abstract: An insulated electrical member adapted for high voltage use is made by (1) covering a conducting member having a porous layer disposed thereon with a non-linear stress grading composition comprising cycloaliphatic epoxy resin, non-linear silicon carbide and an effective amount of curing agent, (2) curing the non-linear stress grading composition at up to about 130.degree. C., (3) impregnating the porous layer with a reactive insulating resin composition containing polar components, such that the resin composition contacts the non-linear stress grading composition, and (4) heating the covered, impregnated electrical member to cure the insulating resin composition, where the non-linear stress grading composition after insulating resin cure is characterized as remaining adherent to the member.

Abstract: This invention relates to the stitch-bonded high temperature fabric insulation of the coils of rotating electric machinery, particularly large rotating machinery such as generators and medium to large motors, and is concerned not only with such insulation during manufacture of the machinery but also with the rewinding of such machinery for repair or refurbishment.

Abstract: A flexible mica tape having a low gel time is prepared from a composition of an epoxy resin, an organotin salt, and catechol or pyrogallol. A mica sheet is immersed in the composition and the solvent is evaporated to form a tack-free A-staged resin. A conductor is wound with the tape and is impregnated with an impregnating resin using vacuum-pressure impregnation.

Abstract: A sprayable, solventless bracing composition is made from the admixture of 100 parts of bisphenol A epoxy resin, up to about 8 parts of a coloring pigment, about 0.5 to about 4 parts of a thixotropic agent, about 100 to about 200 parts of butadiene/acrylonitrile polymer, and about 20 to about 40 parts of an amine terminated curing agent.

Abstract: An insulation system for winding of electric rotating machines having thermal resistance of class H or more and excellent adhesiveness between a conductor and an insulating layer and resistance to thermal stress can be produced by wrapping a plurality of layers of an insulating tape or sheet having thermal resistance of class H or more around a winding conductor, impregnating the thus treated winding conductor with a solventless varnish consisting essentially of 1 equivalent of an epoxy compound containing at least two vicinal epoxy groups, more than one equivalent of an organic polyisocyanate, and then heating the inpregnated winding conductor at a temperature above 60.degree. C. for a time sufficient to form and cure a resin containing as recurring units at least two isocyanurate rings directly bonded to one another through the residue of the polyisocyanate and two oxazolidone rings directly bonded to each other through the residue of the polyepoxide in the presence of 0.

Abstract: A rotating electric machine with a cylindrical rotor and a cylindrical stator enclosing the rotor is provided with coatings on the outer surface of the rotor and the inner surface of the stator for the enhancement of radiative heat exchange between these components.

Abstract: In a novel method of forming a stator, armature, coil, etc., the steps of bonding a structure of magnet wire by applying a coating of reactive spooling oil to the length of magnet wire, followed by forming the magnet wire into a coil about an armature, making an open coil, or inserting the latter into a slot section of the core of a stator, and heating the magnet wire until the coating is converted to a hard adhesive thereby permanently forming the bonded structure of magnet wire.

Abstract: Electric windings comprising an electric conductor and a plurality of cured insulating layers wrapping around the conductor, said cured insulating layers being obtained by bonding two or more insulating materials with a binder solution containing a mixture of a condensation polymerization type silicone resin containing hydroxyl groups in the molecule and an addition polymerization type silicone resin to form a composite insulating material, wrapping the composite insulating material around the conductor, impregnating the wrapped composite insulating material with an impregnating varnish of an epoxy-isocyanate resin and curing the impregnated composite insulating material, have excellent water resistance in addition to excellent thermal resistance, and mechanical properties.

Abstract: A grain-oriented silicon steel sheet having substantially no glass film can be obtained by subjecting a cold rolled silicon steel sheet having a final gauge to a decarburization annealing to form subscale on the steel sheet surface, applying an annealing separator consisting of hydrated silicate mineral fine powder, a strontium- or barium-containing compound, calcium oxide or calcium hydroxide and the remainder being Al.sub.2 O.sub.3, and finally annealing the above treated steel sheet. The steel sheet has excellent punchability when the steel sheet is coated with a phosphate system or chromate-organic resin mixture system insulating coating.

Abstract: A resinous composition, suitable as a high voltage insulation for electrical members, is made from an admixture containing: 100 parts of an epoxy resin, about 25 to 200 parts of an acid anhydride reactive with the epoxy resin, about 0.01 to 2.0 parts of chromium or zirconium acetylacetonate, acting as a latent accelerator and about 0.3 to 30 parts of a selected organic carboxylic acid, acting as a co-accelerator.

Abstract: A method for remanufacturing turbine vane clusters of gas turbine engines is disclosed. Concepts and techniques for salvaging undamaged vanes from a damaged vane cluster are developed. In accordance with the method taught, protective coatings on the vane clusters are removed and residual stresses in the vanes are relieved before salvageable vanes are separated from their original vane cluster.

Abstract: Resins, made by admixing polyacrylic resin and epoxy resin in a weight ratio of polyacrylic:epoxy of 10:0.1 to 100 are cured in a diffusion gas atmosphere. An insulated conductor is coated with the polyacrylic-epoxy resin and cured without heat in a contacting gas atmosphere, such as nitrogen, carbon dioxide, argon, helium, methane, or hydrogen.

Abstract: A photosensitive, solventless, low viscosity, oil free coating composition is made by admixing: (A) about 40 wt.% to about 90 wt.% of an alkyd component, consisting essentially of a polyhydric alcohol and a dibasic aromatic and aliphatic acid mixture with (B) about 10 wt.% to about 60 wt.% of an acrylate monomer and (C) an effective amount of a photoinitiator; the composition characterized by having a viscosity of up to about 2,000 cps. at 25.degree. C., and being capable of forming an ultraviolet radiation cured, hard, pin hole free film, having a thickness of under about 5 mils.

Abstract: Silicon steel sheets which have a silicate protective coating are further protected by being first coated with an aqueous solution containing (1) phosphate ions, (2) silica grains, (3) iron and/or manganese ions, and (4) negative ions which convert to volatile products at temperatures below 400.degree. C, and then heated to temperatures of between about 400.degree. and 1100.degree. C for periods of between about 1/2 minute to 10 minutes in order to form a further protective phosphate layer.

Abstract: A highly flexible mica winding tape is made by: (A) mixing epoxide resin with solvent, (B) adding from 0.01 to 5.0 parts per 100 parts epoxide resin of an organo-tin compound, and mixing to form a homogeneous admixture, (C) applying the admixture to a flexible sheet material comprising mica, so that the organo-tin compound contacts the mica, causing the organo-tin compound to act as a latent catalyst, and (D) removing solvent, to form a flexible sheet with substantially unreacted epoxide resin containing an amount of substantially unreacted organo-tin catalyst effective to advance the epoxide in the sheet material from the substantially unreacted state to a cured thermoset state upon heating over a resin-catalyst temperature of 120.degree. C.

Abstract: Coated electrical steel sheets having excellent punchability, weldability and insulation resistance are produced by applying an electrical steel sheet with a treating dispersion obtained by compounding the particle separating resin emulsion and the compatible resin to an aqueous solution containing chromic acid in the particularly defined amount and baking the thus applied steel sheets. To the treating dispersion may be added saccharides or polyhydric alcohols as a reducing agent or boric acid or phosphoric acid.

Abstract: The apparatus, system and method utilize sequential sprays of wet, low-temperature steam, and dry, high-temperature steam to clean the exterior of laminated objects as well as to effect volatilization of liquid contaminates trapped between lamina thereof. Water is injected into the conduit through which the low-temperature steam is delivered, so as to produce a desirable concentration of droplets therein. A conveyor moves the laminated objects along a horizontal path through zones in which they are sprayed by the low temperature and high temperature steam, and then through a zone in which they are electrostatically coated with powder.