Патент USA US2119400код для вставки
May 31, 1938. P_ NOWAK 2,119,400 INSULATING BAND FOR ELECTRICAL MACHINES AND APPARATUS Filed May 2'7, 1956 Film o‘f polymerized acrylic acid derivative filled with a Substance of high thermal concluctivzty Inventor‘: by Paul Ncwak? His Attcucnéiyv Patented May 31, 1938 2,119,400 UNITED STATES PATENT OFFICE 2,119,400 INSULATING BAND FOR ELECTRICAL MA ‘ CHINES AND APPARATUS Paul Nowak, Berlin-Charlottenburg, Germany, assignor to General Electric Company, a cor poration of New York Application May 27, 1936, Serial No. 82,155 In Germany June 4, 1935 5 Claims. (Cl. 154—2.6) This invention relates to insulating bands for masses of high thermal conductivity which are electrical machines and apparatus and to the used according to the invention do not possess in processes ‘of making the same, themselves the mechanical strength required for One of the chief problems in the construction winding bands, chie?y due to the exceptionally 5 of electrical machines and apparatus is that of high content of ?ller such as powdered quartz, removing the heat from the windings to the ex metallic oxides alone or admixed with other crys-, . terior without allowing it to accumulate. The talline substances. It is only due to the fact that insulations hitherto used, for example, in wind these masses are worked together with bands of ing heads of machines, consist of bands of highly textile material that winding bands are obtained insulating materials which are wound around the conductors in layer thicknesses up to about which, besides their great insulating capacity 10 terior and from one another, but are very un ductivity are rolled or stuck on to the ?rm tex and thermal conductivity, passess the mechanical 3 mm. These bands ful?ll well the purpose of - strength necessary for insulating conductors and effectively insulating the windings from the ex windings. The masses of high thermal con favorable as regards the removal of heat. Since ture or web, or rolled into the latter. 15 the insulating layers consist of several super The insulating bands according to the inven imposed bands between which heat accumulation tion have a speci?c thermal resistance between occurs owing to the air layers existing between 100 and 150 thermal ohms. With a layer thick the bands, they usually have a speci?c thermal .ness for the insulation of 3 mm. this gives a resistance between 1100 and 1500 thermal ohms, thermal surface resistance of about 30-50 thermal 20 so that their thermal surface resistance for a ohms per square centimeter and, if the thermal layer thickness of 3 mm. may be estimated at resistance between the insulation and air is es approximately 500 thermal ohms per square cen timated at 300 thermal ohms as above, a total timeter. The thermal resistance outward to air intermediate resistance from the conductor to might be estimated at 800 thermal ohms at 40° the air of about 350 thermal ohms results. This C. excess temperature. Since, however, in this means an exceptionally great reduction of the case, the winding head is usually ventilated, this temperature drop in comparison with the above resistance diminishes to about 300 thermal ohms. mentioned resistance values of customary bind The heat current emanating from the conductor mgs. surface thus undergoes a thermal resistance alto As basic material for the construction of the gether of approximately 500 thermal ohms. insulating mass of high thermal conductivity it The invention is based on the problem of very considerably reducing the thermal resistance is suitable to use besides the above-mentioned polymers of the acrylic acid esters, any other without impairing the insulating qualities of the , insulating masses which can be ?lled in the winding at the same time. According to the in vention, for the insulation of electrical conduc tors and windings of electrical machines and apparatus use is made of bands which consist of a web, braiding or the like, for example, of textile threads or yarn of cotton, linen, asbestos, or ‘the like, to which is applied an insulating ma greatest possible quantity with substances of 35 high thermal conductivity such as quartz, as bestos, microasbestos, or with oxidized metallic elements such as aluminum oxide. For example, rubber, linseed oil or any mass similar to these may be used as basic material. The following 40 mass, for example, has also proved to be suitable: terial of high thermal conductivity, for example, an insulating mass which is ?lled with crystalline elements or metallic oxides. The insulating ma terial used in this case has, for example, the fol lowing composition: ' - Polymerized acrylic acid esters __________ -_ 1'70 5 Quartz powder _________________________ __ 415 Microasbestos ____________________ -c ____ __ Sulphur ________________________________ __ 10 Magnesium carbonate. ___________ __,_.._,_'___ 138' Quartz powder _____________________ _~_____' 300 . Parts by weight Beta-naphthol ___________ __~ ____ _'_ _______ __ Parts by weight Crepe rubber _________________________ ..'___ 250 410 , A mass of such composition may be rolled out to thin ?lms and then worked with the coating or intermediate layer of material. The insulating Microasbestos ____‘_ _____________________ __ 300 Diphenyl guanidine (Vulkazit D)‘; _______ __ 2 This mass is rolled on to textile bands in the un vulcanized condition and then vulcanized to‘ gether with the latter. ‘ Although it has already been proposed to in crease the,‘ thermal conductivity of insulating masses by "mixing powdered quartz or the like 2 2,119,400 _ with them, the invention makes it possible for band consisting of textile threads in contact with an insulating mass comprising polymerized acrylic acid derivative ?lled with a substantial the ?rst time to utilize in electro-technics‘ such heat-conducting masses for the manufacture oi’ insulated wires, such as are used in electrical , amount of material having approximately the machine construction for making-coil windings. thermal conductivity properties of quartz. A constructional example of an insulating layer ‘3. An insulating band for conductors and wind according to the invention is represented in the ingsin electrical machines and apparatus con drawing. The polymerized acrylic ‘acid- deriva sisting, ofiaf web ‘of textile material united with tives which are ?lled, for example, with powdered .an insulating‘ mas's- comprising a polymerized 10 quartz or material having approximatelyithej acid ester ?lled with a- substantialcamount thermal conductivity properties of quartmwhich; acrylic of powdered :quartz. ' ', ' latter expression is intended to include quart'z'jit 4. An insulating band for conductors and wind- I self, are rolled out into a ?lm I, which is ?rmly' ingsin electrical machines and apparatus pom connected on both sides with threads‘ 2‘w__hich».li_e1 - of a web of asbestos yarn united with an V15 parallel and close to one another and'which have ' sisting insulating mass comprising a- polyrnerized acrylic on one side a direction diifering by 90° irornihat _. acid ester ?lled with a. substantial amount-oi of the threads r on the other side. The threads material having approximately the thermal con-. 20 may consist of texture or interwoven ?laments '_ .ductivity properties oi.’ quarts. 01' ?brous material. 5. _An insulating band ior'conductors and wind-' -. What I claim as new and desire to secureby' ‘ 'ings in electrical machines and apparatus Icon Letters Patent 0! the United States, is:— - _ , _ sisting 01 a'_ ?lm oi"_an insulating mass 'compris_-' .. 1. An article of manufacture comprising an _~ ing a ‘polymerized acrylic acid-ester ?lled with " electrically insulating band consisting of an'inti 3 ‘,material of high thermal conductivity; comprising , ;' ' mate association of textile material and an. in-} , powdered quartz,-said him being ?rmly connected 25 sulating mass comprising polymerized acrylic-acid‘ derivative containing a substantial amount- of ‘ on‘ both sides'with textile threads._.tha_t' lie par allelfandiclose to one'another and thatv have on.» ?lling material having approximately the-thermal "one side ‘a direction diilering by ‘90°-irom-that ' conductivity properties of quartz. 2. Insulation i'or conductors and windings in 30 electrical machines and apparatus comprising 9. of the‘ threads on the other side.- " - '~ - g ' PAUL N‘owinr.v - '