摘要:
An insulating stay comprises: a central core (1) having high electrical resistance and high tensile strength; a sheath (2) of high electrical resistivity and comprising fins (3) to offer a maximum resistance path to possible surface current losses; and end fittings (4). The central core is made of resin reinforced with long, continuous fibers, and advantageously of epoxy resin reinforced with glass fibers. The sheath (2) is made of a natural or synthetic polymer, and advantageously of EPDM elastomer. The stay is manufactured by coating the central core (1) with a high viscosity glue (8) having high longitudinal resistivity, then wrapping said glue-covered core in a hollow tube (5) of raw elastomer and placing the assembly in a mold (5) where said fins (3) are formed in the sheath (2) and where the raw elastomer (5) is polymerized by vulcanization or reticulation. The stay is intended for bracing electrical installations that need to be insolated and placed at some distance from the ground.
摘要:
A method of interference-fitting either a male or female resilient member to its corresponding female or male member using a hollow mandrel cooled to preferably cryogenic temperatures which freezes a compressed resilient member to at least its glass-transition temperature. The method enables one to combine the two members before the resilient member warms to a temperature above its glass-transition temperature. The method and apparatus have found usefulness in the assembly of elastomeric high voltage electrical insulators.
摘要:
An elongated, insulative tube of high mechanical strength consists of resin bonded glass fibers wound in alternating helical and circumferential winding patterns. The glass fiber convolutions at the outer limits of these winding patterns embrace metallic inserts, securely captivating them within the open ends of the tube. Tapped central bores in these inserts threadedly receive end fittings adapting the tube to a transmission line supporting function. The tube also externally mounts a pair of spaced arcing rings and internally mounts a varistor array for protecting a transmission line against lightning strikes.
摘要:
An electrical insulator component comprises a one-piece block of moulded fins (11, 12, 13) disposed around an insulating core (10). The surface of the block of fins includes a moulding line (21, 22, 23) and said moulding line has arcuately displaced segments in that the portion 22 extends circumferentially while the portions 21 and 23 extend longitudinally but in different planes. The net result is that dirt building up along the join line does not form a continuous straight-line low resistance path for leakage currents.
摘要:
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.
摘要:
A method for fabricating a plastic electrical insulator having a fiberglass-reinforced plastic core rod and a plurality of insulator discs disposed thereon. The insulator discs are formed of a plastic molding compound which is especially suited for outdoor use. In accordance with the invention, the insulator rod is disposed in, and passes through, a mold which, when closed, is filled with the plastic molding compound for forming the insulator discs. The separation plane of the mold is situated near the outermost edge of each disc. Subsequent insulator discs are individually formed so as to partially overlap a previously molded insulator disc.
摘要:
An elongated electrical insulator has a supporting rod and barriers or screens spaced along the rod; an intermediate layer of material between the rod and the barriers or screens serves to exclude atmospheric moisture and other materials enhancing the electrical insulating characteristics of the insulator. The rod comprises a non-saponifiable resin reinforced with fiber glass of low alkali content. The barriers or screens comprise a non-saponifiable moisture-repellent polymer containing a filler. The intermediate layer comprises a moisture-repellent non-saponifiable polymer.
摘要:
An organic composite electrical insulator system includes one or more modular ethylene propylene copolymer elastomeric molded insulators or sheds bonded by a thin line bond to an epoxy or polyester resin bonded fiberglass structural member. In one embodiment, the organic composite insulator system may take the form of a suspension insulator used to support a high voltage power cable from a transmission tower. The suspension insulator includes a pair of metallic end connectors mechanically attached to opposite longitudinal ends of an elongated polyester resin bonded fiberglass core rod. The space between the end connectors along the rod is filled with a plurality of modular ethylene propylene elastomeric molded insulators or sheds having inner diameters smaller than the outside diameter of the rod in order to obtain a slip fit and thereby compressively load the interface surfaces between the sheds and the rod during the manufacture of the rod. All interface surfaces between the sheds and the rod are precoated with an adhesive prior to the assembly of the sheds on the rod. As soon as the adhesive coatings are completely dry, the sheds are stretched over the rod and slid into their final position. The rod with its assembled sheds is then subjected to a moderate temperature cure to bond the sheds to each other and to the rod.
摘要:
A suspension insulator for supporting a high voltage power cable suspended from a transmission tower includes an elongated rod for supporting a load in tension, a plurality of insulating shells serially disposed along the rod and end connectors for attaching a high tension load to the rod. At least one of the end connectors includes an elongated metal cylindrical retainer having one or more metallic members with one or more inclined surfaces disposed within the retainer and circumferentially disposed around the rod. The space between the inclined surface or surfaces and the rod is filled by an epoxy resin compound.In order to prevent excessive heating of the compound due to external flashover of the suspension insulator and the possible resultant separation of the end connector from the rod, the suspension insulator includes a generally cylindrically shaped, electrically conductive, current bypass sleeve disposed about the retainer to provide a current path physically remote from the epoxy resin compound.Compensation members are provided between adjacent serially disposed insulating elements of the suspension insulator to provide for thermally induced volumetric changes within the suspension insulator. The compensation members are fabricated from a closed cell, compressible material.The suspension insulation further includes an annularly shaped corona shield serially disposed between the current bypass sleeve and the closest insulating shell to reduce the occurrence of radio frequency interference.The suspension insulator in one arrangement includes an elongated, shedless, ceramic insulating sleeve for reducing radio frequency interference when the suspension insulator is arranged with another suspension insulator in a "V" configuration for supporting a plurality of high voltage power cables suspended from a transmission tower.
摘要:
Composite insulator having a plurality of umbrella-shaped sections on a trunk; each section is comprised of a mould filled with a hardenable material which adheres to the mould and the trunk; shaping the mould to receive the hardenable material.