Patent ID: 7647692
Filing Date: 2010-01-19
Classification: H01F,Y10T

Abstract:
1. A method of manufacturing an electrical transformer coil comprising: providing a mandrel; providing a plurality of pre-formed plastic cooling ducts; providing conductive material; winding the conductive material around the mandrel to form a plurality of layers; during the winding, positioning the pre-formed plastic cooling ducts so as to be disposed between the layers; encapsulating the layers with the pre-formed plastic cooling ducts disposed in-between in a resin; placing plugs in opposing open ends of each of the pre-formed plastic cooling ducts before the layers and the pre-formed plastic cooling ducts are encapsulated in the resin; removing the plugs after the layers and the pre-formed plastic cooling ducts are encapsulated in the resin; and allowing the resin to cure while the cooling ducts remain disposed between the layers, thereby permanently incorporating the cooling ducts into the electrical transformer coil.