Patent ID: 8111123

Claim:
A method of manufacturing a transformer comprising: forming a disc-wound coil comprising: providing a plurality of pre-formed cooling ducts; forming a first conductor layer comprising a plurality of disc windings arranged in an axial direction of the disc-wound coil, each of the disc windings comprising a conductor wound into a plurality of concentric turns; forming a spacer layer over the first conductor layer, the spacer layer comprising a plurality of spacers; forming a second conductor layer over the spacer layer, the second conductor layer comprising a plurality of disc windings arranged in an axial direction of the disc-wound coil, each of the disc windings comprising a conductor wound into a plurality of concentric turns, wherein the spacer layer is formed such that when the second conductor layer is formed, a plurality of axially-extending passages are formed between the first and second conductor layers; and sliding the pre-formed cooling ducts into the axially-extending passages so as to be disposed between the first and second conductor layers.