Siemens Aktiengesellschaft

Transformatoren Union Aktiengesellschaft

Transormatoren Union Aktiengesellschaft

Wolfgang Bendel

Friedrich Alber

Gerhard Altmann

Wolfgang Rogler

Helmut Markert

Rudolf Dedelmahr

Rudolf Link

Hermann Eyrich

Klaus Seeliger

Klaus Kretzschmar

Richard Pfeiffer

The invention relates to a heat-hardened molded material produced from a resin mixture of a polyfunctional epoxide, a polyfunctional isocyanate and a reaction accelerator, which optionally contains additives and/or fillers. The objective is to make a resin mixture which permits the manufacture of a highly heat-resistant molded material, and which has at the same time a high-temperature cycle resistance and good mechanical properties. For this purpose, the polyfunctional epoxide of the resin includes a polyoxyalkylene glycol polyglycidyl ether.

Heat-hardenable reaction resin mixtures for impregnating and embedding

The invention relates to a method for impregnating and embedding electrical windings, especially coils of transformers, by means of an impregnating or casting resin based upon polyepoxide-polyisocyanate mixtures in the presence of a reaction accelerator latent at the processing conditions, which employs conditions that prevent the formation of gas and shrinkage voids in the cast in winding. To this end, the resin including, if applicable, additives, is dried at reduced pressure and while stirring at temperatures of up to 110.degree. C. and the winding is cast-in with the dried resin at reduced pressure and at temperature of up to 110.degree. C.; then the reduced pressure is removed and the winding is exposed to overpressure. Subsequently, generating by an elevated temperature in the electrical winding by Joule heat in the conductor, the cross-linking reaction of the resin is started and is controlled as a function of the reaction heat, until the winding is removed from the mold and post-hardened.

Method for impregnating and embedding electrical windings

Method of manufacturing a transformer winding embedded in casting resin by winding coils respectively by themselves and independently of one another for disposition thereof in tandem in axial direction of the winding includes placing the wound coils in a substantially annular casting mold having an inner and an outer jacket, with respective impregnated corrugated mats of insulating material as spacers disposed between the inner jacket and the coils as well as between the coils and the outer jacket, the inner and the outer jackets being fixed between mold end walls at respective ends of the casting mold; and disposing the casting mold containing the wound coils in an evacuated chamber and pouring casting resin into the casting mold through an axially parallel slot formed in the outer jacket thereof. Additionally included are spreading the inner jacket in radial direction so as to permanently deform the inner spacer to a dimension at which the radial extent of the inner spacer is reduced, the inner jacket being formed with axially parallel edges at ends thereof overlapping in circumferential direction and slidable on one another during the deformation so as to spread the inner jacket in radial direction; fixing the coils of the winding on the inner spacer against movement in axial direction; and surrounding respective edges at the ends of the inner and the outer jackets with an elastic layer at the inner face of the respective mold end walls.

Method of manufacturing transformer windings embedded in casting resin

Coupling transformer

Multiphase transformer for power distribution in a supply network includes a single block of cast resin having high voltage and low voltage conductor windings embedded therein, and an iron core with a plurality of legs and an upper and lower yoke formed of closely-stacked transformer laminations centrally embedded in the block, the block having axially-extending ribs integral therewith defining troughs between the ribs and defining spaces between the ribs and the core, legs and yokes, watertight caps disposed between the ribs closing off the troughs and holding the core, legs and yokes, and mechanically compacted dry quartz sand filled in the space.

Multiphase transformer for power transmission in a supply system

Growing community of inventors

Leonberg, Germany

Wolfgang Bendel