SE175199C1

SE175199C1 -

Info

Publication number: SE175199C1
Authority: SE
Publication date: 1961-01-01

Description

Prioritet begard Treat den 8 december 1958 (Schweiz) Foreliggande uppfinning a-vser ett forfarande for impregnering och omgjutning .av elektriska lindningar, exempelvis i transform.atorer, stromtransformatorer ,och spanningstransformatorer anvanda lindningar .och findningskroppar (Wickelkiiiper), avensom exempelvis kondensatorlindningar med en ,gjutbar, hardbar massa. The present invention relates to a process for impregnating and recasting electrical windings, for example in transformers, current transformers and voltage transformers using windings and winding bodies (Wickelkiiiper), as well as for example capacitor windings with a , castable, hardenable mass.

En framstallning av sidana foreanal dr sedan lange land. Hos dessa utgor onagjutningsmassan lindningskroppens yttre holje samt isolering anellan de enskilda ledarna .och idelarna hos lindningen odh skyddar ,och isolerar derma mot anekanisk skada. Darvid maste lindningarna for .erhallande ay en tillracklig isolerin,g genomdrankas med .gjutmassa, varvid inga som heist luftinneslutningar fa fOrekornma innanf Or de enskilda varven och clelarna av lindningen fdr undvikande av, att .glimuriaddningar och darigenom eventuellt genomslag upptrada. Impregneringen sker vanligen vid forhojd temperatur i vakuum, varigenom den i lindnings- och isoleringsmaterialet forefintliga fuktigheten avlagsnas och faran .for tuft- eller kaseininneslutningar praktiskt taget uteslutes. Den pa sa satt impregnerade lindningskroppen erhaller clarpa ett holje medelst en massa, 'vilken for okning av holjets haltfasthet, ythardhet etc. IfOrsatts med en fyllmassa, .exempelvis kvartsmja. Fyllmassan modererar dessutoan vid stor hartsvolym den ,exoterma reaktionen oth sanker kry.mpningen och utvidgningskoefficienten hos kroppen. Da denna omgjutningsmassa har nagot andPa ,fysikaliska egenskaper, sasom exempelvis utvidgningskoefficient etc., an den for impregnering .anvanda Tna:ssan resp. den med derma impregnerade lirtdningen, foreligger risk for att mellan de bada massorna uppsta idragsprickor och halrum, vilka nedsatta den 'mekaniska och elektriska hallfastheten (glimurladdningar) hos det fardiga foremdlet. A presentation of the pages foreanal dr since long country. In these, the casting mass constitutes the outer casing of the winding body as well as insulation between the individual conductors and the parts of the winding and protects, and insulates them against anechanical damage. In this case, the windings must be sufficiently insulated to obtain sufficient insulation, whereby no hot air inclusions are allowed to form inside the individual turns and the joints of the winding to avoid glare charges and thereby any impact occurring. The impregnation usually takes place at elevated temperature in a vacuum, whereby the moisture present in the winding and insulating material is removed and the danger of tuft or casein inclusions is practically eliminated. The winding body impregnated in this way clearly receives a casing by means of a mass, which, in order to increase the strength, surface hardness, etc. of the casing, is provided with a filling mass, for example quartz. The filling mass also moderates at high resin volume the exothermic reaction and reduces the shrinkage and expansion coefficient of the body. Since this casting compound has some andPa, physical properties, such as, for example, coefficient of expansion, etc., than that used for impregnation, Tna: ssan resp. the lead impregnated with this, there is a risk that indentation cracks and cavities arise between the two masses, which reduced the mechanical and electrical half-strength (glow charges) of the finished product.

FOrfaranden ha nu blivit känrda, vid vilka lindningskroppen fOrst impregneras under vakuum riled ett varmehardande konstharts. Den paad satt erhallna kroppen skrubbas after hardningen av impregneringsmassan pa den yttre ytan med mekaniska medel och om&lutes i ett andra separat forfarandesteg. Detta .forfarande Or tidskpdvande, emedan tvh after varandra foljande bardningsprocesser aro erforderliga, mellan vilka en rnekanisk bearbetningsprocess inkopplats, .och emedan icke med sd.kerhet en fast haftning och en blasfri och foglos ,forening erhalles mellan impregneringsmassan och onagjutningsmassan. Methods have now become known, in which the winding body is first impregnated under vacuum with a thermosetting synthetic resin. The body thus obtained is scrubbed after the hardening of the impregnating mass on the outer surface by mechanical means and resurfaced in a second separate process step. This procedure is time consuming, because two successive shaving processes are required, between which a mechanical machining process is involved, and since a solid adhesion and a blister-free and jointless one are not necessarily obtained, a connection is obtained between the impregnation mass and the unassembly mass.

Vidare liar ett forfarande bekantgjorts, vid vilket dessa hada Cirfarandesteg kombinerats och genomfores i en enda form. Forst impregneras lindningen under vakuum Tried rent gjutharts. Darpit pafylles det rned fyllmaterial farsatta gjuthartset utan upphava_nde av vakuumet I samma form. Det med fyllanaterial forsatta gjuthartset fortranger idet utanfOr lindningen befintliga renhartset ooh bildar efter hardning det yttre holjet. Olagenheter vid detta forfarande aro, .att .alla gjutningsoperationer maste uttforas under vakumm med en forhallandevis komplicerad apparatur, att den for den slutliga •gjutningen erforderliga for-men ar .upptagen under hela processens forlopp, alltsa ,aven under impregneringsprocessen, och att ,det ur formen uttrangda rena gjuthartset beroende pd hardningstiden och fOroreningarna vid uttrangning ur formen icke anera dr ,anyandbart, utan ,gar forlorat. Furthermore, a method has been disclosed in which these steps have been combined and carried out in a single form. First, the winding is impregnated under vacuum Tried pure casting resin. Darpit fills the rned filler material filled with the casting resin without causing the vacuum in the same form. The casting resin provided with filling material displaces the reindeer resin present outside the winding and, after curing, forms the outer casing. Disadvantages of this process are that all casting operations must be carried out under vacuum with a relatively complicated apparatus, that the mold required for the final casting is taken up during the whole process, that is, even during the impregnation process, and that, it The pure casting resin expelled from the mold, depending on the curing time and the impurities when expelled from the mold, do not appear there, unchangeable, but are lost.

Foreliggande uppf inning avser som ytterligare forenkling gentemot de kande ett .forfarande fOr impregnering 'oda omgjutning .av elektriska lindningar med i varme hardbara, giurbara konsthartser och kannetecknas clar- 2— — av, att lindningen impregneras, -varpa den impregnerade lindningen axkyles i sadan grad, att det vid yttre ytan haftande annu icke liardade renhartset erhaller en pastaartad eller h5gst trogflytande konsistens, att det overflodiga hartset mekaniskt avstrykes fran lindningen och att ,darpd den pa sa sill impregnerade och fran overflodigt renharts befriade lindningen omgjutes °eh .hardas i en .det slutliga yttre holjet framstallande gjutform med ett med fyllmedel forsatt harts. The present invention relates to a further simplification to the prior art of a process for impregnation or recasting of electrical windings with heat-curable, curable resins and can be characterized in that the winding is impregnated, and the impregnated winding is cooled in such to the extent that the previously unlined reindeer resin adhered to the outer surface acquires a pasty or highly viscous consistency, that the excess resin is mechanically wiped off the winding and that, when the impregnated on such herring impregnated with excess reindeer resin is hardened, the winding is cast. .the final outer casing producing mold with a resin-laden resin.

Med Fordel sker impregneringen pa. sd satt, att lindningen avgasas oeh avfuktas vid forminskat tryck vid eventuellt forhojd temperatur och darpa omgjutes i ett vhl derma temperatur flytande renharts. Dessutom kan efter impregneringen i vakuum intrangningen ax renhartset i lindningen ytterligare forbattras genom anvandning av tryck, exempelvis gen-om en under overtryck staende inert gas. Genom anvandning av ett ,sadant tryck kan mangden av den lindningen tillfOrda impregneringsmass an yt terligare 116 j as. With Advantage, the impregnation takes place on. so that the winding is degassed and dehumidified at reduced pressure at any elevated temperature and the drop is cast in a reindeer resin liquid at a temperature of this temperature. In addition, after the impregnation in a vacuum, the intrusion of the pure resin into the winding can be further improved by applying pressure, for example by means of an inert gas under overpressure. By using such a pressure, the amount of impregnating mass applied to that winding can be further 116.

Omgjutningen med renharts kan antingen ske i en speciell bleckform, genom neddoppfling 1 en panna eller genom anvandning av det s. k. centrifugalgjutningsforfarandet. Intrangniugen av renhartset i lindningen kan forstarkas genom anvandning av tryck, -exempelvis genom en under overtryck stiende inert gas. Aviagsnandet av det axkylda och darvid flytande eller pastaartade renhartset kan ske for hand med en spatel, genom aystrykning med en putslinjal eller genom avblasning med tryckluft. The casting with reindeer resin can either take place in a special tin form, by immersion in a pan or by using the so-called centrifugal casting process. The intrusion of the reindeer resin into the winding can be enhanced by the use of pressure, for example by an inert gas under overpressure. The removal of the ax-cooled and thereby liquid or pasty reindeer resin can be done by hand with a spatula, by ironing with a plaster ruler or by blowing with compressed air.

Den pastaartade eller hogst trogflytande konsistensen maste vara sadan, att -vid uttagning av lindningen ur formen och efter avstrykning icke den faran forefinnes, att ur de yttre skikten eller delarn.a av lindningen hartset flyter -ut °eh -att pa 'sa. .satt bildas halrum, som icke ater sluta sig. I allmanhet kan egenskapen has ett renharts resp. en renhartshardarblandning av vid avkylning antaga en sadan pastaartad eller hogst trogflytande kensistens hanforas dartill, att hardaren eller den hardningen farorsakande komponenten utkristalliserar, men gar emellertid yid darpa fOljande uppvarmning ater i laming i hartset. I utkristalliserat tillstand bortfaller hardarens hardamle verkan pa hartset ,och massan kan i detta tillstand lagras, utan att avert efter langre tid en hardning erhalles. The pasty or highly viscous consistency must be such that, when the winding is removed from the mold and after wiping, there is no danger of the resin flowing out of the outer layers or parts of the winding, .sat halls are formed, which do not close again. In general, the property can have a reindeer resin resp. a pure resin hardener mixture of, on cooling, assuming such a pasty or highly viscous consistency is carried out to the point that the hardener or the hardening-causing component crystallizes out, but nevertheless undergoes subsequent heating in paralysis in the resin. In the crystallized state, the hardening effect of the hardener on the resin disappears, and the mass can be stored in this state, without a cure being obtained after a long time.

I stallet for renhartset kan man for impregneringen ax lindningen avert anvanda nagot med fyllmedel utdrygat -harts, Icor det fall detta forhaller sig som renharts. Instead of the reindeer resin, for the impregnation of the winding avert can be used something with filler-extended resin, in case this behaves like reindeer resin.

Den efter avstrykningen av det overflodiga hartset foljande omgjutningen med ett med fyllmedel f5rsatt harts maste ske pa .sa sat, att en saker haftning anellan den impregnerade lindningen oeh den yttre omgjutningen utan halrum eller sprickor erhalles. The casting following the removal of the excess resin with a resin provided with filler must take place in such a way that a certain adhesion is obtained between the impregnated winding and the outer casting without cavities or cracks.

En sadan fran halrum och darmed fran fara for glimurladdningar fni impregnering, liksom aven haftning av omgjutningsmassan pa lindningen, kan ytterligare forbattras, om anslutning till den e-ventuellt under forminskat tryck utforda oingjutningen det kade trycket avbrytes och ersattes genom overtryck, vilket verkar pa omgjutningsmassans yta. Such a separation from the cavity and thus from the danger of glow charges due to impregnation, as well as the adhesion of the casting compound to the winding, can be further improved if connection to the e-valve under reduced pressure challenges the casting, the increased pressure is interrupted and replaced by overpressure, which acts on the casting mass. surface.

Da hard-ham a impregnerings- och oingjutningsmassor vid deras hardning visa en viss reaktionskrympning 0.r det lampligt att pa sa satt avpassa de Ifor detta andamal avsedda hartserna ,och igjutmassorna, att omgjutningsmassan hardas .forst sedan impregneringsmassan hardnat. Fifr att astadkomma en tvangsstyrd efterflytning av den genom den kemiska reaktionen forminskade volymen av det i lindningen inneslutna impregneringshartset, saint en absolut tat omslutning av lindnangskroppen med .omgjutningsmassan, forlanges anvandningen av Overtrycket tills omgjutningsmassan hardnat. Som medium kan anvandas saval torr tryckluft som aven kvave eller en annan inert gas. Since the impregnating and casting compositions harden during their curing show a certain reaction shrinkage, it is appropriate to adjust the resins intended for this purpose in this way, and the casting compositions, so that the casting compound hardens only after the impregnating mass has hardened. In order to achieve a forced flow of the volume of the impregnating resin enclosed in the winding by the chemical reaction, as an absolute tight enclosure of the winding body with the casting mass, the use of the overpressure is required until the casting mass hardens. As a medium, as well as dry compressed air as well as nitrogen or another inert gas can be used.

Exempel som askadliggora forfarandet enligt uppfinningen aterfirmas i slutet av beskrivningen. Examples which ash the process according to the invention are given at the end of the description.

F8rdelarna hos det uppfinningsenliga fOrfarandet hanfora sig 1 forsta hand ,dartill, att praktiskt taget inga eller endast ,obetydliga forluster av rent gjutharts uppkomma, emedan det efter aykylningen av den impregnerade liadningskroppen ,avstrukna gjuthartset pa grand av dess raga temperatur ater kan anvandas, di praktiskt taget annu ingen hardning agt rum. Det i den slutliga gjutformen inforda, med fyllmedel forsedda hartset uttranger till .151jd av sin h5gre temperatur ,och storre tathet det ,annrt vid yttre ytan av lindningen haftande tunna skiktet av renharts ,och bringas pa sa satt i fast kontakt med lindningens yttre yta. Det sistnamnda fir av vikt for astadkommande av ,en verkligt mekaniskt robust lindning, t. ex. hos spolkroppar, mattransformatorer eller andra transformatorer. Man undviker Masa den vid det inledningsvis beskrivna tvastegsforfarandet bestaende risken, att mellan den inre impregneringskroppen °eh den yttre omgjutningskroppen upptrada spanningar, vilka kunna leda bill hal- andra ,sidan ar forfarandet betydligt enklame -an -del averts& inledningsvis beskrivna f Orfarandet, vid vilket impregneringen och omgjutningen genomfores under vakuum i gamma form. Den ytterst omstandliga apparaturen fOr ingjutning, uttrangning, tomning och avluftning av de olika gjutmassorna blir overflodig eller forenklas atminstone hogst betydligt. Vidare undvikes -den -vid detta fbrfarande uppkomna stora f5rlusten av icke pa nytt vandbar men hartsmassa. The advantages of the process according to the invention are first and foremost, to the effect that practically no or only insignificant losses of pure casting resin occur, since after the cooling of the impregnated charge body, the casting resin stripped off due to its low temperature can practically be used. taken annu no hardening agt rum. The resin introduced into the final mold, provided with filler, protrudes to its high temperature, and has a greater density than the thin layer of reindeer resin adhering to the outer surface of the winding, and is thus brought into firm contact with the outer surface of the winding. The latter is important for achieving a truly mechanically robust winding, e.g. in coil bodies, mat transformers or other transformers. Masa avoids the risk inherent in the two-step process initially described, that stresses occur between the inner impregnation body and the outer casting body, which can lead to the other side, since the procedure is considerably simpler -and-partly averted & initially described in the procedure, in which the impregnation and recasting is carried out under vacuum in gamma form. The extremely cumbersome apparatus for grouting, extruding, emptying and venting the various casting masses becomes superfluous or at least is greatly reduced. Furthermore, the great loss of non-renewable but resinous mass arising from this process is avoided.

Med f5rdel sker evakueringen och impregneringen vid hogre temperaturer, i allmanhet — vid cirka 100 till 120° C, avstrykningen av overflodig impregn.eringsmassa vid rumstem- peratur eller atminstone vid en temperatur, vilken tillater en enkel bearbetning f or hand uta.n fara fOr forstOring. Det for impregnering anvanda konsthartset maste vid forhojd im- pregneringstemperatur vara fillräckligt tunnflytande, for att imed sakerhet intranga i alla linclningskroppens mellanrum, m.edan det vid avkylnin,g till avstrykningstemperatur erhaller segflytande, foretradesvis ,degig konsistens. Givetvis aro principiellt sett joke e.nd.ast de i exemplen angivna gjuthartsema utan aven andra hardbara anassor lampade, GM dessa uppvisa den ovan 'anforda erforderliga konsistensforandringen mom .det erforderliga temperaturomradet. Nedan .askadliggora tva exempel :forfarandet .enligt uppfinningen Exempel 1. Spollindningen till en spanningstransformator inbaddades i en bleckforin. I denna hleekform ,holls spollindningen pa sa salt, att den pa alla sidor inkl. undersid.an befann sig pa ett avstand av cirka 1 cm frail bleckformens yagg. Advantageously, the evacuation and impregnation takes place at higher temperatures, in general - at about 100 to 120 ° C, the wiping off of excess impregnation mass at room temperature or at least at a temperature which allows a simple processing by hand without danger of forstOring. The synthetic resin used for impregnation must be sufficiently thin at elevated impregnation temperature, in order to penetrate with certainty into all the spaces of the lining body, while at cooling to g of wiping temperature it acquires a viscous, preferably, doughy consistency. Of course, in principle, jok.an.ast the casting resins given in the examples without also other hardenable anasses lamped, GM these exhibit the above 'required required consistency change with the required temperature range. Below are two examples: the method according to the invention Example 1. The coil winding of a voltage transformer was embedded in a tin liner. In this hleek form, the coil winding is kept so salty that it on all sides incl. the underside was at a distance of about 1 cm from the yoke of the tin mold.

Lindning och bleckform uppvarindes forst till cirka 120° C och avfuktades och avgasades darpa i en till cirka 120° C uppvarmd vakuumkittel. Winding and tin form were first heated to about 120 ° C and dehumidified and degassed in a vacuum kettle heated to about 120 ° C.

Samtidigt lordningstalldes ett ,gjutharts (renharts) genom blandning av 100 viktdelar av ett genom kondensation av 4,4'-dihydroxidifenyl-dimetylmetan med epiklorhydrin i narvaro av alkali framstallt ,epoxiharts med en epoxidhalt av cirka 4,6 epoxidekvivalenter per kg, med 65 viktdelar av ett Brut ay 35 viktdelar ftalsyraanhydrid oeh 65 viktdelar tetrahydraftalsyraanhydrid fraanstallt harts. Fore blandningen med hardaren 'forvirmdes epoxihartset till en temperatur av 100° C och avgasades vid donna temperatur .cirka 1 timine under ornroring i ett vakuum av ,cirka 0,5 mm Hg, och ,darpa tillsattes hardaren. At the same time, a casting resin (pure resin) was mixed by mixing 100 parts by weight of one by condensation of 4,4'-dihydroxydiphenyl-dimethylmethane with epichlorohydrin in the presence of alkali prepared, epoxy resin having an epoxide content of about 4.6 epoxide equivalents per kg, with 65 parts by weight of a Brut ay 35 parts by weight of phthalic anhydride and 65 parts by weight of tetrahydraphthalic anhydride prepared resin. Before mixing with the hardener, the epoxy resin was pre-heated to a temperature of 100 ° C and degassed at this temperature for about 1 hour while stirring in a vacuum of about 0.5 mm Hg, and then the hardener was added.

Dot salunda erhallna gjuthartset g5ts snabbt i en under ett vakuum av cirka 0,2 mm Hg befintlig bleckform pA sh satt, att harts ets vatskeyta befann :sig cirka 2 cm over lindningen. Vakuumet 'hade ,dessforinnaii genom inledning av torr luft (ledd genom blakiselgel) instants pa ,ett varcle am cirka 1,5 mm Hg. The casting resin thus obtained was quickly poured into a tin form under a vacuum of about 0.2 mm Hg so that the water surface of the resin was about 2 cm above the winding. The vacuum, therefore, by the introduction of dry air (led by black silica gel) instantaneously, had a temperature of about 1.5 mm Hg.

Efter gjutningen bolls formen 30 minuter yid delta vakuum. Darpa 'upphavdes vakuumet i impregneringskitteln och ,ersattes i .och fOr astadkommande av tryckf5rtatning under 10 minuter med torr luft vid 2 ato. After casting, the mold is balled for 30 minutes in a vacuum. The vacuum was then maintained in the impregnation kettle and replaced with pressure air for 10 minutes with dry air at 2 atm.

Bleckformen med lindningen uttogs ur impregneringskitteln och lamnades stkende f Or avsvalning till rumstemperatur. Efter :avsvalning uppvarmdes bleckformens yta till cirka 50° C och narmare .bestamt :sa lange, att lindningen kunde 'utdragas ur formen. Daipa aystroks med en spatel det utaripa. lindningen haftande hartset. The tin form with the winding was removed from the impregnation kettle and left to cool to room temperature. After cooling, the surface of the tin mold was heated to about 50 ° C and closer to certain length so that the winding could be pulled out of the mold. Daipa aystroks with a spatula it utaripa. the winding adhesive resin.

Den ph sh satt avstrukna lindningskroppeIi. infordes i en till 50° C fOrvarnid ,gjutform med onskad form och evakuerades i en till 130° C upphettade ldttel yid -ett vakuum ay 1 mm Hg. I den under vakuum befintliga formen gjots Iclarpa genast ett med kvartsmja utdrygat .gjutharts. Detta bestod ay 100 vikt- delar epoxiharts och 30 viktdelar ay ovan anforda hardare, .utdrygat med 200 viktdelar kvartsmji51. Derma blandning avtuftades dessforinnan mid en temperatur ay cirka 130° C under vakuum. Epoxihartset framstalld:es ph samma satt som det ,for impregnering anvancla hartset, men hade en epoxidhalt ay 2,3 till 2,6 epoxidekvivalenter per kg. The ph sh sat stripped winding bodyIi. was introduced into a pre-molded to 50 ° C, mold of the desired shape and evacuated in a well heated to 130 ° C with a vacuum of 1 mm Hg. In the vacuum-formed form, Iclarpa was immediately cast a quartz-smeared casting resin. This consisted of 100 parts by weight of epoxy resin and 30 parts by weight of the above hardener, extended by 200 parts by weight of quartz. This mixture was previously tufted at a temperature of about 130 ° C under vacuum. The epoxy resin is prepared in the same manner as the resin used for impregnation, but had an epoxide content of 2.3 to 2.6 epoxide equivalents per kg.

Den med hartset &tam formen lamnades staende en kvarts timme vid ett undertryck ay 3 mm Hg, varefter formen uttogs ,ur makuurnkitteln och hardades 20 timmar i en ugn -vid 130° C. Darpa uttogs den fardiga, omgjutna Iindningskroppen ur formen och fick lhngsamt svalna. The resin & tame mold was left standing for a quarter of an hour at a negative pressure of 3 mm Hg, after which the mold was removed from the makur oven and cured for 20 hours in an oven at 130 ° C. Darpa removed the finished, molded inlet body from the mold and allowed to cool slowly. .

Den ph sa satt ,erhallna lindningen underkastades de vanliga elektriska provningarna, sasom matningar ay :skiktisolerin.g, isolering mot jord, 'stotpakanning och glimurtaddningsbenagenhet vid radiofrekvens, varvid synnerligen goda resultat erhollos. The pH thus obtained, the obtained winding, was subjected to the usual electrical tests, such as power supplies ay: layer insulation, insulation against earth, bump packing and glare tampering with radio frequency, whereby extremely good results were obtained.

Exempel 2. Impregnering .och .onigjutning am en spollindning utfordes pa samma salt soin i exempel 1, men i .motsats till detta .exempel upphorde behandlingen med vakuum genast efter gjutningen av impregneringsformen och ins.attes fortatning med ton- Tuft vid 2 ato. Likasa upphorde vakuumbehandlingen genast sedan oragjutningsformen Ifyllts. och .om.gjutningsmassan -fortatades genom torr tryckluft vid 2 ato. ,ena .sidan utnyttjades .darigenam brukstiden (»potlif e») for impregneringshartset battre och A andra Isidan forhindrades genom tryckfortatningen under hardningen uppkomsten ay hatrum, 'sprickor osv. i gjutkroppen. Example 2. Impregnation and non-casting in a coil winding are challenged on the same salt soin in Example 1, but in contrast to this example, the treatment with vacuum ceased immediately after the casting of the impregnation mold and insertion was continued with ton- Tuft at 2 atm. Likewise, the vacuum treatment ceased immediately after the mold was filled. and the casting mass was continued through dry compressed air at 2 atm. , on the one hand, the pot life was used ("potlif e") for the impregnating resin better and on the other hand the ice side was prevented by the pressure increase during the hardening the formation of hatred spaces, cracks, etc. in the casting body.

Claims

P at ent ansprik:

1. Procedure for impregnation, and re-casting of electric windings with marine curable, castable synthetic resins, characterized in that the winding is impregnated, the winding impregnated on such a salt is cooled to such an extent that all the annu joke hardened at the outer surface the reindeer resin .recoveres a pasty oiler highly viscous and has consisted in that the excess resin is mechanically wiped off the winding oda to drip. the pH was thus impregnated, and freed from excess reindeer resin, the winding is recast and hardened in a mold producing the final outer shell with a resin provided with filler.

2. A method according to claim 1, characterized in that in connection with the impregnation the winding is reduced to a reduced pressure and, if necessary, the temperature is reduced to 4 to 175,197 and de-fused, and the resin is mixed with a reindeer resin flowing at that temperature.

3. A method according to patent claim 1, characterized in that the impregnation takes place in a different form.

4. A method according to claim 1, Unsubscribed from the fact that the impregnation takes place by immersion under reduced pressure in a hollow container containing the reindeer resin.

5. A method according to claim 1, characterized in that the impregnation takes place by using the centrifugal casting method.

6. A method according to claim 1, claimed in claim that the introduction of the impregnating resin into the winding is enhanced by the application of pressure.

7. A method according to patent claim 1, characterized in that it is placed under pressure with the casing provided until hardening of the resin provided with filler is obtained, before the curing is completed at normal pressure.

8. A method according to claim 1, characterized in that the coiled winding was pressurized and that the pressure was maintained throughout the firing process.

9. A method according to claim 1, Unsubscribed, in that the impregnation is carried out at a temperature above 100 ° C and the removal of the pure resin is carried out at a temperature of below 50 ° G. Request publications: