US3245015A - Coverings of coil windings of electrical apparatus - Google Patents
Coverings of coil windings of electrical apparatus Download PDFInfo
- Publication number
- US3245015A US3245015A US211495A US21149562A US3245015A US 3245015 A US3245015 A US 3245015A US 211495 A US211495 A US 211495A US 21149562 A US21149562 A US 21149562A US 3245015 A US3245015 A US 3245015A
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- US
- United States
- Prior art keywords
- coil
- cellulose
- turns
- coating
- slip coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000004804 winding Methods 0.000 title description 7
- 239000011248 coating agent Substances 0.000 claims description 28
- 238000000576 coating method Methods 0.000 claims description 28
- 239000000843 powder Substances 0.000 claims description 14
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 6
- 229920001479 Hydroxyethyl methyl cellulose Polymers 0.000 claims description 5
- 229920003086 cellulose ether Polymers 0.000 claims description 5
- 210000003298 dental enamel Anatomy 0.000 claims description 5
- 239000010445 mica Substances 0.000 claims description 5
- 229910052618 mica group Inorganic materials 0.000 claims description 5
- 239000000454 talc Substances 0.000 claims description 5
- 229910052623 talc Inorganic materials 0.000 claims description 5
- 229920000896 Ethulose Polymers 0.000 claims description 4
- 239000001859 Ethyl hydroxyethyl cellulose Substances 0.000 claims description 4
- 239000005909 Kieselgur Substances 0.000 claims description 4
- 235000019326 ethyl hydroxyethyl cellulose Nutrition 0.000 claims description 4
- 235000010944 ethyl methyl cellulose Nutrition 0.000 claims description 4
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 claims description 4
- 229920000609 methyl cellulose Polymers 0.000 claims description 4
- 239000001923 methylcellulose Substances 0.000 claims description 4
- 235000010981 methylcellulose Nutrition 0.000 claims description 4
- 229920003087 methylethyl cellulose Polymers 0.000 claims description 4
- KNXVOGGZOFOROK-UHFFFAOYSA-N trimagnesium;dioxido(oxo)silane;hydroxy-oxido-oxosilane Chemical compound [Mg+2].[Mg+2].[Mg+2].O[Si]([O-])=O.O[Si]([O-])=O.[O-][Si]([O-])=O.[O-][Si]([O-])=O KNXVOGGZOFOROK-UHFFFAOYSA-N 0.000 claims description 4
- 239000000203 mixture Substances 0.000 description 19
- 239000011230 binding agent Substances 0.000 description 9
- 239000000463 material Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 230000000855 fungicidal effect Effects 0.000 description 4
- 239000000417 fungicide Substances 0.000 description 4
- GCLGEJMYGQKIIW-UHFFFAOYSA-H sodium hexametaphosphate Chemical compound [Na]OP1(=O)OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])O1 GCLGEJMYGQKIIW-UHFFFAOYSA-H 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000007788 liquid Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 235000019982 sodium hexametaphosphate Nutrition 0.000 description 3
- 239000001577 tetrasodium phosphonato phosphate Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- ZMESHQOXZMOOQQ-UHFFFAOYSA-N 1-(naphthalen-1-ylmethyl)naphthalene Chemical compound C1=CC=C2C(CC=3C4=CC=CC=C4C=CC=3)=CC=CC2=C1 ZMESHQOXZMOOQQ-UHFFFAOYSA-N 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 229920001944 Plastisol Polymers 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 239000008199 coating composition Substances 0.000 description 2
- 239000000839 emulsion Substances 0.000 description 2
- -1 for example Substances 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 230000001788 irregular Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 2
- 239000004999 plastisol Substances 0.000 description 2
- 229940068886 polyethylene glycol 300 Drugs 0.000 description 2
- 229920000915 polyvinyl chloride Polymers 0.000 description 2
- 150000003254 radicals Chemical class 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 230000035882 stress Effects 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 description 1
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 description 1
- GAWIXWVDTYZWAW-UHFFFAOYSA-N C[CH]O Chemical group C[CH]O GAWIXWVDTYZWAW-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000004606 Fillers/Extenders Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 1
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical compound [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 235000010443 alginic acid Nutrition 0.000 description 1
- 229920000615 alginic acid Polymers 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- 235000006708 antioxidants Nutrition 0.000 description 1
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- FPAFDBFIGPHWGO-UHFFFAOYSA-N dioxosilane;oxomagnesium;hydrate Chemical compound O.[Mg]=O.[Mg]=O.[Mg]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O FPAFDBFIGPHWGO-UHFFFAOYSA-N 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 125000005395 methacrylic acid group Chemical group 0.000 description 1
- 229920003052 natural elastomer Polymers 0.000 description 1
- 229920001194 natural rubber Polymers 0.000 description 1
- 239000005008 organosol coating Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000008262 pumice Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 239000011342 resin composition Substances 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000000661 sodium alginate Substances 0.000 description 1
- 235000010413 sodium alginate Nutrition 0.000 description 1
- 229940005550 sodium alginate Drugs 0.000 description 1
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 229920003051 synthetic elastomer Polymers 0.000 description 1
- 239000005061 synthetic rubber Substances 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- 235000015112 vegetable and seed oil Nutrition 0.000 description 1
- 239000008158 vegetable oil Substances 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
- H01B3/48—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances fibrous materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
- H01B3/04—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances mica
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F5/00—Coils
- H01F5/06—Insulation of windings
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/32—Windings characterised by the shape, form or construction of the insulation
- H02K3/325—Windings characterised by the shape, form or construction of the insulation for windings on salient poles, such as claw-shaped poles
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
Definitions
- the invention is capable of wide application but is especially suitable for the covering of field coils of dynamos.
- the usual covering for such coils has long been helically wound tape. After taping, the coils are curved in a press to suit the contour of the dynamo yoke.
- the present invention consists in a method of covering coil windings of electrical apparatus prior to forming or shaping the coils which comprises applying to the outside of the coil a slip coating and then applying over the slip coating an outer coating which provides a relatively strong flexible skin, the arrangement being such that during subsequent forming of the coil so covered the outer coating can move relatively to the turns of the coil.
- the slip coating preferably comprises a soft filling composition which enters the interstices between at least the outside turns of the coil so as to reduce the surface irregularities of the coil surface over which the outer coating is applied.
- the filling composition prevents partial penetration of the outer coating between the wires of the coil so that on forming of the coil the skin is not locally stressed by being forced to follow local movement among the wires nor is movement and rearrangement of the wires within the coil hindered.
- the skin is of more uniform thickness resulting in economy of outer coating material and reducing stress concentration, which could be caused by local stretching of the skin. Residual stresses in the skin are thus minimised so reducing the risk that the skin might crack or split in service after losing some of its initial elasticity through ageing or heat.
- a filling composition which is soft is meant one which comprises pulverulent material and has a low degree of cohesion owing to its being substantially unbound or underbound that is to say the amount of binder present in the finished filling composition is substantially less than that needed to fill completely the interstices between the powder particles, without voids.
- the powders should,-in general, be cheap, fine and inert.
- a wide range of powders may be used, for example, powders generally used as paint extenders.
- a coloured filling acoloured pigment in powder form may be included or constitute the pulverulent Component of the filling composition. Powders having unsuitable properties such as volatility, low melting point, or chemical reactivity with the outer coating composition or the metal of the wire of the coil or its insulation should naturally .be excluded. Electrically conductive powders would also normally not be used.
- powders in which the particles have another than spheroidal shape, such as those which are lamellar,'needle-like or irregular in shape, for example asbestine, diatomaceous earth, mica, talc and china clay.
- particles which are of less marked- 2 1y lamellar, needle-like or irregular shape could be used, for example barytes, pumice, precipitated or natural calcium carbonate, magnesium carbonate and silica.
- talc may be used as the filling composition without a binder. They may be rubbed into the interstices between the wires dry and will lodge there by their own natural cohesion. In general however a liquid vehicle is preferred. The filling composition may then be applied by dipping, brushing, spraying, wipingor in some other suitable manner.
- Binders for the filling composition may be those which when dissolved or dispersed in volatile liquids give to the composition a consistency suited to the desired method of application when present in only minor proportions.
- One group of substances suitable as binders are these used as thickeners in emulsion paints such as cellulose ethers and the sodium salt of carboxymethyl cellulose.
- cellulose ethers are ethyl hydroxyethyl cellulose, methylcellulose and hydroxyethyl' methyl cellulose and methyl ethyl cellulose.
- Further substances suitable as binders are natural and synthetic rubbers, polyvinyl resins, polyacrylic and methacrylic resins and alginates, for example, sodium alginate.
- the binder and the volatile liquid vehicle must be harmless to the metal of the wire of the coil or its insulation, and, when dry, to the outer coating composition.
- the outer coating may be of any of a variety of compositions. It may, for example be (1) A plastisol or organosol (2) Arubber-resin composition (3) A composition in which a vinyl resin emulsion is v the binder.
- FIGURE 3 is an end view similar to FIGURE 2 but after forming.
- FIGURE 4 is a fragmentary cross-sectional view on line 4-4 of FIGURE 3.
- a coil winding 5 of enamel insulated copper wire is wound in fiat form as illustrated in FIGURES 1 and 2.
- a slip coating 6 is applied over its outer turns 7 to reduce the surface irregularities of the coil and provide a smooth surface over which a relatively strong, flexible outer coating 8 is applied.
- After covering the coil it is formed or shaped in a press or by rollers to the curved form shown in FIGURE 3.
- the slip coating is formed by a soft filling composition as previously defined.
- Specific examples of coverings applicable to such coils are:
- the phenyl mercurial radical is combined with dinaphthyl methane disulphonic acid.
- the sodium hexametaphosphate is a water softener and the polyethylene glycol 300 monoleate a flow promoting agent.
- a coil was dipped in this composition, allowed to dry in an oven at 150 F., and allowed to cool. It was then dipped in an organosol coating composition consisting of polyvinyl chloride dispersed in an epoxidised vegetable oil, together with minor proportions of lead stabiliser and an anti-oxidant. The coated coil was then stoved at 390 F. No splits developed in the top coating on forming, or on clamping under a pole piece within a yoke and heating in an oven for 64 hours at 302 F. 4
- Example 2 Propiofan 5D 500 Water 100 and allowed to dry for .16 hours in an oven at 150 F.
- Propiofan 5D is an approximately 50% plasticiser-free dispersion of polyvinyl propionate manufactured by the Badische Anilin & Soda Fabrik A.G.
- the coil When cold the coil was formed by compressing it within a screw press having a fixed horizontal semi-cylindrical outer component of diameter 3% inches, and a moving cylindrical inner component of diameter 2% inches. The coil was first gently squeezed by hand diametrically so as to fit within the jaws of the outer component.
- Example 3 Micronised talc powder was rubbed by hand into the interstices between the outer turns of a coil similar to that described in Example 2. The powder lodged by its natural cohesion so as to present a smooth and geometrically regular outer surface.
- the coil so prepared was dipped in the'Propiofan 5D composition as described in Example 2.
- the coating was allowed to dry for 16 hours in the oven at 150 F. When cold the coil was formed in the screw press'as described in Example 2. No splits developed in the outer coating.
- a curved electrical coil the individual turns of which are enamel insulated having over the -turns of the coil lining a slip coating consisting of the following ingredients in the parts by weight specified:
- Wate.rsoluble fungicide comprising a phenyl mercurial radical combined with dinaphthyl methane disulphonic acid group 2.6
- a curved electrical coil having over the outer turns of the coil a slip coating comprising a powder selected from the group consisting or" asbestine, diatomaceous earth, mica, talc, and china clay and a binder of cellulose ether selected from the groups consisting of ethyl hydroxyethyl cellulose, methyl cellulose, hydroxyethyl methyl cellulose and methyl ethyl cellulose, the slip coating entering the interstices between at least the outside turns of the coil so as to reduce the surface irregularities of the coil surface, and having over the slip coating an .outer relatively strong, flexible skin.
- the process of forming on the coil a protective covering which is capable of moving relative to the turns of the coil and which conforms with the shape of the coil during subsequent bending comprises applying to the outer surface of the coil a layer of slip material completely covering the outer turns of the coil, and then applying over the layer of slip material, a coating of a material providing a relatively strong flexible skin and then bending the cell from the flat form into a curved form.
- said layer of slip material comprises a soft filling composition which includes a pulverulent material and has a low degree of cohesion and which enters the interstices between at least the outside turns of the coil so as to reduce the surface irregularities of the coil surface.
- said layer of slip material consists of a powder selected from the group consisting of asbestine, diatomaceous earth, mica, talc and chinaclay and a binder of cellulose ether selected from the group consisting of ethyl hydroxyethyl-cellulose, methyl cellulose,hydroxyethyl methyl cellulose and methyl ethyl cellulose.
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Insulation, Fastening Of Motor, Generator Windings (AREA)
- Paints Or Removers (AREA)
- Insulating Of Coils (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Description
E. B. TANNER April 5, 1966 COVERINGS OF COIL WINDINGS OF ELECTRICAL APPARATUS Filed July 23, 1962 United States Patent 3,245,015 COVERINGS 0F COIL WINDIN GS OF ELECTRICAL APPARATUS Edward Butler Tanner, Hampton-in-Arden, England, assignor to Pinchin Johnson & Associates Limited, Ladywood, England, a British company, and Joseph Lucas (Industries) Limited, Birmingham, England, a British company Filed July 23, 1962, Ser. No. 211,495 Claims priority, application Great Britain, July 29, 1961, 27 ,622/ 61 7 Claims. (Cl. 336229) This invention relates to the application of protective coverings to coil windings for electrical apparatus in which the coils after being wound and the protective coating applied have to be formed or shaped.
The invention is capable of wide application but is especially suitable for the covering of field coils of dynamos. The usual covering for such coils has long been helically wound tape. After taping, the coils are curved in a press to suit the contour of the dynamo yoke.
The present invention consists in a method of covering coil windings of electrical apparatus prior to forming or shaping the coils which comprises applying to the outside of the coil a slip coating and then applying over the slip coating an outer coating which provides a relatively strong flexible skin, the arrangement being such that during subsequent forming of the coil so covered the outer coating can move relatively to the turns of the coil.
The slip coating preferably comprises a soft filling composition which enters the interstices between at least the outside turns of the coil so as to reduce the surface irregularities of the coil surface over which the outer coating is applied.
The filling composition prevents partial penetration of the outer coating between the wires of the coil so that on forming of the coil the skin is not locally stressed by being forced to follow local movement among the wires nor is movement and rearrangement of the wires within the coil hindered. The skin is of more uniform thickness resulting in economy of outer coating material and reducing stress concentration, which could be caused by local stretching of the skin. Residual stresses in the skin are thus minimised so reducing the risk that the skin might crack or split in service after losing some of its initial elasticity through ageing or heat.
By a filling composition which is soft is meant one which comprises pulverulent material and has a low degree of cohesion owing to its being substantially unbound or underbound that is to say the amount of binder present in the finished filling composition is substantially less than that needed to fill completely the interstices between the powder particles, without voids.
For the filling composition the powders should,-in general, be cheap, fine and inert. A wide range of powders may be used, for example, powders generally used as paint extenders. For a coloured filling acoloured pigment in powder form may be included or constitute the pulverulent Component of the filling composition. Powders having unsuitable properties such as volatility, low melting point, or chemical reactivity with the outer coating composition or the metal of the wire of the coil or its insulation should naturally .be excluded. Electrically conductive powders would also normally not be used.
In general we prefer powders in which the particles have another than spheroidal shape, such as those which are lamellar,'needle-like or irregular in shape, for example asbestine, diatomaceous earth, mica, talc and china clay. However other particles which are of less marked- 2 1y lamellar, needle-like or irregular shape could be used, for example barytes, pumice, precipitated or natural calcium carbonate, magnesium carbonate and silica.
Some of these powders, talc for example, may be used as the filling composition without a binder. They may be rubbed into the interstices between the wires dry and will lodge there by their own natural cohesion. In general however a liquid vehicle is preferred. The filling composition may then be applied by dipping, brushing, spraying, wipingor in some other suitable manner.
Binders for the filling composition may be those which when dissolved or dispersed in volatile liquids give to the composition a consistency suited to the desired method of application when present in only minor proportions. One group of substances suitable as binders are these used as thickeners in emulsion paints such as cellulose ethers and the sodium salt of carboxymethyl cellulose. Examples of cellulose ethers are ethyl hydroxyethyl cellulose, methylcellulose and hydroxyethyl' methyl cellulose and methyl ethyl cellulose. Examples of further substances suitable as binders are natural and synthetic rubbers, polyvinyl resins, polyacrylic and methacrylic resins and alginates, for example, sodium alginate.
The binder and the volatile liquid vehicle must be harmless to the metal of the wire of the coil or its insulation, and, when dry, to the outer coating composition.
The outer coating may be of any of a variety of compositions. It may, for example be (1) A plastisol or organosol (2) Arubber-resin composition (3) A composition in which a vinyl resin emulsion is v the binder.
' tion of a coil winding for electrical apparatus covered according to the invention, before forming.
FIGURE 3 is an end view similar to FIGURE 2 but after forming.
FIGURE 4 is a fragmentary cross-sectional view on line 4-4 of FIGURE 3.
A coil winding 5 of enamel insulated copper wire is wound in fiat form as illustrated in FIGURES 1 and 2. After winding the coil, a slip coating 6 is applied over its outer turns 7 to reduce the surface irregularities of the coil and provide a smooth surface over which a relatively strong, flexible outer coating 8 is applied. After covering the coil it is formed or shaped in a press or by rollers to the curved form shown in FIGURE 3. l
The slip coating is formed by a soft filling composition as previously defined. Specific examples of coverings applicable to such coils are:
Sodium hexametaphosphate (Albright & Wilson: Calgon) 1.4 Polyethylene glycol 300 Monoleate (Union Carbide: Nonex 26) 14.8 A water-soluble fungicide (Ward Blenki-nsop:
In the water-soluble fungicide (RD113) the phenyl mercurial radical is combined with dinaphthyl methane disulphonic acid.
The sodium hexametaphosphate is a water softener and the polyethylene glycol 300 monoleate a flow promoting agent.
A coil was dipped in this composition, allowed to dry in an oven at 150 F., and allowed to cool. It was then dipped in an organosol coating composition consisting of polyvinyl chloride dispersed in an epoxidised vegetable oil, together with minor proportions of lead stabiliser and an anti-oxidant. The coated coil was then stoved at 390 F. No splits developed in the top coating on forming, or on clamping under a pole piece within a yoke and heating in an oven for 64 hours at 302 F. 4
Example 2 Propiofan 5D 500 Water 100 and allowed to dry for .16 hours in an oven at 150 F.
Propiofan 5D is an approximately 50% plasticiser-free dispersion of polyvinyl propionate manufactured by the Badische Anilin & Soda Fabrik A.G.
When cold the coil was formed by compressing it within a screw press having a fixed horizontal semi-cylindrical outer component of diameter 3% inches, and a moving cylindrical inner component of diameter 2% inches. The coil was first gently squeezed by hand diametrically so as to fit within the jaws of the outer component.
No splits developed in the outer coating when the coil was screwed down tightly within the press as described.
A similar coil without the preliminary application of the soft filling composition was dipped in the Propiofan 5D composition and allowed to dry for 16 hours in an oven at 150 F. When this coil, atterallowing to cool, was similarly formed in the screw press several splits developed in the coating.
Example 3 Micronised talc powder was rubbed by hand into the interstices between the outer turns of a coil similar to that described in Example 2. The powder lodged by its natural cohesion so as to present a smooth and geometrically regular outer surface.
The coil so prepared was dipped in the'Propiofan 5D composition as described in Example 2. The coating was allowed to dry for 16 hours in the oven at 150 F. When cold the coil was formed in the screw press'as described in Example 2. No splits developed in the outer coating.
I claim:
1. A curved electrical coil,the individual turns of which are enamel insulated having over the -turns of the coil lining a slip coating consisting of the following ingredients in the parts by weight specified:
Wate.rsoluble fungicide comprising a phenyl mercurial radical combined with dinaphthyl methane disulphonic acid group 2.6
and which enters the interstices between at least the outside turns of the coil so as to reduce the external surface irregularities of the coil and having over the slip coating an outer relatively strong flexible skin.
2. A curved electrical coil, the individual turns of which are enamel insulated having over the outer turns of the coil a slip coating comprising a powder selected from the group consisting or" asbestine, diatomaceous earth, mica, talc, and china clay and a binder of cellulose ether selected from the groups consisting of ethyl hydroxyethyl cellulose, methyl cellulose, hydroxyethyl methyl cellulose and methyl ethyl cellulose, the slip coating entering the interstices between at least the outside turns of the coil so as to reduce the surface irregularities of the coil surface, and having over the slip coating an .outer relatively strong, flexible skin.
3. A curved electrical coil according to claim 2 wherein the outer coating is a plastisol.
4. In the art of forming electrical windings wherein an enamel insulated wire is Wound into a fiat coil formed of a plurality of turns arranged in contiguous relation, the process of forming on the coil a protective covering which is capable of moving relative to the turns of the coil and which conforms with the shape of the coil during subsequent bending, which process comprises applying to the outer surface of the coil a layer of slip material completely covering the outer turns of the coil, and then applying over the layer of slip material, a coating of a material providing a relatively strong flexible skin and then bending the cell from the flat form into a curved form.
5. The method according to claim 4 in which said layer of slip material comprises a soft filling composition which includes a pulverulent material and has a low degree of cohesion and which enters the interstices between at least the outside turns of the coil so as to reduce the surface irregularities of the coil surface.
6. A method of covering coil windings of electrical apparatus according to claim 4 wherein the slip coating consists of:
Parts by weight Mica powder, 200 mesh 437 Hydroxyethyl methyl cellulose 13.9 Water 850 Sodium hexametaphosphate 1.4 Polyethylene glycolrnonoleate 14.8 A water-soluble fungicide 2.6
7. The method according to claim 4 in which said layer of slip material consists of a powder selected from the group consisting of asbestine, diatomaceous earth, mica, talc and chinaclay and a binder of cellulose ether selected from the group consisting of ethyl hydroxyethyl-cellulose, methyl cellulose,hydroxyethyl methyl cellulose and methyl ethyl cellulose.
References Cited by the Examiner UNITED STATES PATENTS 2,210,704 8/1940 Brown etal.
2,411,284 11/1946 Miller 117218 2,526,483 10/1950 Ingmanson 174-120 X 2,718,544 9/1955 Shepp 174113 2,795,640 6/ 1957 Crandall 174-120 3,013,109 12/1961 German -et al. 174.1l3 3,134,845 5/1964 George 1744121 X OTHER REFERENCES The Condensed Chemical Dictionary, fifth edition, Reinhold Publishing Corp, N.Y .,-1956, QD 505, pp. 806 and 997.
ROBERT K. SCHAEFER, Primary Examiner.
w. A. WIRTZ, JOHN F. BURNS, Examiners.
I. C. HOLMAN, D. A. KETTLESTRINGS, H. HUBER- FELD, Assistant Examiners.
Claims (1)
- 2. A CURVED ELECTRICAL COIL, THE INDIVIDUAL TURNS OF WHICH ARE ENAMEL INSULATED HAVING OVER THE OUTER TURNS OF THE COIL A SLIP COATING COMPRISING A POWDER SELECTED FROM THE GROUP CONSISTING OF ASBESTINE, DIATOMACEOUS EARTH, MICA, TALC, AND CHINA CLAY AND A BINDER OF CELLULOSE ETHER SELECTED FROM THE GROUPS CONSISTING OF ETHYL HYDROXYETHYL CELLULOSE, METHYL CELLULOSE, HYDROXYETHYL METHYL CELLULOSE AND METHYL ETHYL CELLULOSE, THE SLIP COATING ENTERING THE INTERSTICES BETWEEN AT LEAST THE OUTSIDE TURNS OF THE COIL SO AS TO REDUCE THE SURFACE IRREGULARITIES OF THE COIL SURFACE, AND HAVING OVER THE SLIP COATING AN OUTER RELATIVELY STRONG, FLEXIBLE SKIN.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB27622/61A GB1034441A (en) | 1961-07-29 | 1961-07-29 | Improvements in or relating to coverings of coil windings of electrical apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3245015A true US3245015A (en) | 1966-04-05 |
Family
ID=10262598
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US211495A Expired - Lifetime US3245015A (en) | 1961-07-29 | 1962-07-23 | Coverings of coil windings of electrical apparatus |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US3245015A (en) |
| DE (1) | DE1295083B (en) |
| ES (1) | ES279534A1 (en) |
| GB (1) | GB1034441A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4008368A (en) * | 1968-05-11 | 1977-02-15 | Kabel-Und Metallwerke Gutehoffnungshutte Aktiengesellschaft | Electrical conductor having inhibited polymer compositions |
| US5604693A (en) * | 1995-08-16 | 1997-02-18 | Micron Technology, Inc. | On-chip program voltage generator for antifuse repair |
| EP1376830A3 (en) * | 2002-06-21 | 2006-07-05 | Harmonic Drive Systems Inc. | Method for manufacturing a coil winding assembly of a concentrated winding motor |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0687637B2 (en) * | 1985-02-05 | 1994-11-02 | 三菱電機株式会社 | Field coil |
| DE4344044A1 (en) * | 1993-12-23 | 1995-06-29 | Abb Research Ltd | Electrical insulation material and method for producing an electrically insulated conductor |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2210704A (en) * | 1939-05-06 | 1940-08-06 | Westinghouse Electric & Mfg Co | Insulating material |
| US2411284A (en) * | 1943-06-29 | 1946-11-19 | American Anode Inc | Nondeteriorating rubber insulated wire |
| US2526483A (en) * | 1949-04-26 | 1950-10-17 | Whitney Blake Co | Method of minimizing adhesion between rubber insulation layers of electric conductors and the resultant article |
| US2718544A (en) * | 1950-09-09 | 1955-09-20 | Gen Electric | Jacketed multiple conductor cable |
| US2795640A (en) * | 1956-02-01 | 1957-06-11 | Gen Electric | Electrical cable subject to irradiation |
| US3013109A (en) * | 1961-03-16 | 1961-12-12 | Anaconda Wire & Cable Co | Electric cable |
| US3134845A (en) * | 1961-02-13 | 1964-05-26 | Gen Cable Corp | Telephone drop wire |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB670548A (en) * | 1948-10-28 | 1952-04-23 | Westinghouse Electric Int Co | Improvements in or relating to a method of insulating electrical coils |
-
1961
- 1961-07-29 GB GB27622/61A patent/GB1034441A/en not_active Expired
-
1962
- 1962-07-23 US US211495A patent/US3245015A/en not_active Expired - Lifetime
- 1962-07-26 ES ES0279534A patent/ES279534A1/en not_active Expired
- 1962-07-27 DE DEP29915A patent/DE1295083B/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2210704A (en) * | 1939-05-06 | 1940-08-06 | Westinghouse Electric & Mfg Co | Insulating material |
| US2411284A (en) * | 1943-06-29 | 1946-11-19 | American Anode Inc | Nondeteriorating rubber insulated wire |
| US2526483A (en) * | 1949-04-26 | 1950-10-17 | Whitney Blake Co | Method of minimizing adhesion between rubber insulation layers of electric conductors and the resultant article |
| US2718544A (en) * | 1950-09-09 | 1955-09-20 | Gen Electric | Jacketed multiple conductor cable |
| US2795640A (en) * | 1956-02-01 | 1957-06-11 | Gen Electric | Electrical cable subject to irradiation |
| US3134845A (en) * | 1961-02-13 | 1964-05-26 | Gen Cable Corp | Telephone drop wire |
| US3013109A (en) * | 1961-03-16 | 1961-12-12 | Anaconda Wire & Cable Co | Electric cable |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4008368A (en) * | 1968-05-11 | 1977-02-15 | Kabel-Und Metallwerke Gutehoffnungshutte Aktiengesellschaft | Electrical conductor having inhibited polymer compositions |
| US5604693A (en) * | 1995-08-16 | 1997-02-18 | Micron Technology, Inc. | On-chip program voltage generator for antifuse repair |
| EP1376830A3 (en) * | 2002-06-21 | 2006-07-05 | Harmonic Drive Systems Inc. | Method for manufacturing a coil winding assembly of a concentrated winding motor |
Also Published As
| Publication number | Publication date |
|---|---|
| ES279534A1 (en) | 1963-01-16 |
| DE1295083B (en) | 1969-05-14 |
| GB1034441A (en) | 1966-06-29 |
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