JPS56161621A - Oil-immersed transformer - Google Patents

Abstract

PURPOSE:To eliminate the danger of fire due to the breakage of the outside cases of the transformer even when a serious internal short-circuit trouble happened to the transformer by a method wherein flanges are installed at the coupling sections of the upper and the lower outside cases and a high density energy welding is performed. CONSTITUTION:The flanges 3c and 3d of the same narrow width are installed on the upper outside case 1 and the lower outside case 2. The flanges 3c and 3d are closely adhered and a sealing weld section 6 is formed on this closely adhered sections by performing a high density energy welding. In the oil-immersed transformer constituted as above, the moment which will work on the sealed weld section 6 can be reduced remarkably even when the force of pulling apart the flange section to each other is generated due to the increased inner pressure. Through these procedures, the internal force generated from the welding section 6 is small and cracks are hard to be developed even when such a serious internal short-circuit trouble as to generate cracks on the sealed weld section of the upper and the lower outside cases of the transformer occurs. Accordingly, the spouting of insulating oil can be prevented and the danger of occurrence of fire can be eliminates as well.