Title: Method of making electrical coils having improved strength and oil permeability

• Summary
• Claims
• Description
• View all

Abstract: A porous, electrical insulating adhesive substrate is made, by uniformly coating a flexible, porous sheet material with adhesive resin particles having an average particle size of between about 37 to 420 microns, the adhesive coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution, and then heating the coated sheet material between about 85.degree. to 250.degree.C, forming a discontinuous 0.25 to 7 mil dry coating of discrete adhesive particles having substantially rounded cross sections bonded to the sheet material, said adhesive coating covering from about 5 to 50 percent of the sheet material area in a non-patterned random distribution; the coated sheet may then be inserted as oil permeable layer insulation between high voltage windings and low voltage windings and between layers of high and low voltage windings in a wound coil assembly, after which the assembly can be heated at a temperature and for a time effective to securely bond the winding layers together, to provide a porous, oil permeable, bonded transformer coil assembly.


Do you think this is a good invention? Vote now: