Abstract: For the production of a cast resin coil consisting of a plurality of axially superimposed flat coils, it is proposed that the corresponding flat coils be first of all produced by winding a first inner partial winding and a second outer partial winding with the interposition of individual spacer members by which sector-shaped intervening spaces are formed. The individual flat coils are then placed together axially and oriented so that their intervening spaces coincide, thus forming axial cooling channels. Moldings are inserted into each of said channels. This is followed by the encapsulation of the assembled flat coils. After the curing of the casting resin, the moldings are removed from the cooling channels. A cast resin coil produced in this manner has an impregnable layer of material, preferably in the region of the cooling channels by which the wall thickness of the cooling channels is predetermined in relation to the corresponding strip conductors.

Abstract: A clamping frame for a transformer core has a clamping frame part and a tensioner. The surfaces of the tensioner and of the clamping frame part abutting the transformer core lie in a common plane. The tensioner features an engagement part, which engages in a recess of the clamping frame part.