High-voltage polymeric insulator with sheath of elastic and rigid segments and method of making same

Abstract

An insulator comprising a rod made of continuous glass fiber impregnated with epoxy resin, metal end fittings, and a polymeric sheath. The rod is tightly embedded in the sheath and the ends of the rod are pressed into the fittings. The sheath consists of alternately mounted segments of two types: spacing sleeves made of elastic material and externally profiled sleeves made of stiff material. The spacing sleeve has beads at the ends. In order to transfer axial forces, the spacing sleeves are partly covered by the profiled sleeves, said covered portion including the beaded ends. The method by which this insulator is made consists in that, first, the spacing sleeves, made of silicone rubber, are cast directly onto the rod by the pressure-injection method; second, the rod is covered by a layer of adhesive agent from the silicone group and, third, in the interspaces formed between the spacing sleeves, the profiled sleeves are cast in a split mold by means of the injection method. The split mold covers the fragments of the spacing sleeves, some of which are used as the packing of the split mold. According to the thickness of the rod and the required mechanical strength of the insulator, the length of the rigid segments is selected so that in the connecting layer the permissible internal stresses, due to variable temperature and load conditions during operation, are not exceeded. The material for the rigid segments is a cast epoxy composition.

Dependencies are inferred from the claim text.