RU2710687C1 - Pin-type linear insulator - Google Patents

Abstract

FIELD: electric power engineering.

SUBSTANCE: invention relates to electric power industry, namely to pin-type linear insulators intended for insulation and fixation of wires on overhead transmission lines. Insulator consists of internal insulation part 1 and external insulation part 2, which are gaplessly connected to each other. Part 1 made of electric insulating glass, electro-technical porcelain or from structural plastic has head 5 with grooves 6 for wire fixation and threaded hole 7 for pin 3. Head 5 can be made in the form of chute 8 with a freely rotating split bushing 9 inserted into it, which allows excluding the output of wire 4 from chute 8 at mechanical actions and damage of the inner insulation part 1 by wire 4 during rolling. Outer insulation part 2 made of bell-shaped or cone-shaped polymer hydrophobic material defines electric strength of insulator for breakdown and mechanical strength of insulator at action of bending mechanical loads from wire 4. Material for the outer insulation part 2 is an organosilicon or silicone composition which provides the required length of the path of electric current leakage on the insulator surface between wire 4 and pin 3.

EFFECT: providing the insulator with high characteristics in terms of operational reliability, mechanical strength and breakdown voltage, as well as providing moisture-discharge specific stresses twice as high as those of insulators made from hydrophilic glass or porcelain.

1 cl, 1 dwg

Description

The invention relates to the field of electric power, in particular to linear pin insulators used for insulation and fastening of wires on overhead power lines and in switchgears of high voltage substations.

Known pin linear insulator, consisting of an insulating body with a blind hole for attaching the insulator to a pin containing at least one rib and taking place for lateral mounting of the wire, while the insulating body is made of silicone rubber, and the upper level of the blind hole is higher places of lateral fastening of the wire, and there is no thread in the blind hole of the insulating body, the insulating body is made of heat-shrink tracking resistant material, and the ribs are made spiral E [1].

In this technical solution, the insulator (its insulating body) is entirely made of organosilicon rubber, which has high hydrophobicity (non-wettability), that is, on the surface of such insulators during wetting a continuous water film is not created and, therefore, conditions will not be created for the development of a discharge over the surface insulator; however, such materials are not characterized by sufficient mechanical strength and their use as a power element for insulators is problematic from the point of view of ensuring operational reliability.

The closest technical solution in relation to the proposed is a pin linear insulator containing at least two concentrically mounted and interconnected internal and external insulating parts [2].

The main disadvantage of insulators of this design is the low moisture discharge voltages on the surface of the glass or porcelain, from which their insulating elements are made, in case of pollution in operating conditions, which significantly reduces the reliability of overhead power transmission lines. All other things being equal, namely, equal to the leakage length of electric current, the intensity of contamination and humidification, the protection of a part of the insulator from contamination and moisture, the moisture discharge voltage of the insulator depends on the conductivity of the pollution layer, i.e., on the wettability of the material of which the insulator is made. Porcelain and glass are well-wettable (hydrophilic) materials, on the surface of which, when wet, a continuous water film is created that promotes the development of an electric discharge over the surface of the insulator.

The applicant set himself the task of developing a new pin linear insulator, characterized by high moisture discharge voltages on its surface during contamination and at the same time ensuring sufficient mechanical strength under operating conditions. The indicated positive technical result was achieved due to a new set of essential design features listed in the claims of the invention below: “a pin insulator containing at least two concentrically mounted and interconnected internal and external insulating parts; the inner insulating part forming the power unit for fixing the insulator on the pole of the support and the wire on the insulator is made of insulating glass or of electrical porcelain or of structural plastic with a head having annular and upper diametrically located grooves intended for fastening the wire and a threaded hole for a pin, while the external insulating part, made bell-shaped or conical in shape from a polymer hydrophobic material, is rigidly fixed to the inside its insulating parts; the head of the internal insulating part is made in the form of a gutter designed to locate wires in it and to ensure the possibility of rolling them when installing an overhead power line; in the groove of the head of the inner insulating part there is a freely rotating split sleeve designed to prevent the wire from exiting the groove during mechanical stress and to prevent damage to the inner insulating part by the wire during rolling; the external insulating part is made of an organosilicon composition or of a silicone composition; the external insulating part is molded directly onto the internal insulating part installed in the mold, pre-coated with a binder in the contact zone of both parts, by feeding the silicone mixture into the said mold and curing it at a temperature of 100 - 140 ° С for 4- 20 minutes; the outer insulating part is rigidly fixed to the inner insulating part by means of a special adhesive layer. "

The invention is illustrated by drawings, where figure 1 shows a General view of a pin linear insulator made according to the present invention according to the first and dependent claims.

The inventive pin linear insulator, contains two concentrically installed insulating parts 1, 2, which are seamlessly interconnected by a binder. The internal insulating part 1 is a power unit and is intended for mounting the insulator on the pin 3 of the support of the overhead power line and wire 4 on the insulator. It is made of insulating glass, electrotechnical porcelain or structural plastic with a head 5 having annular and upper diametrically located grooves 6 for fastening the wire, and a threaded hole 7 for the pin 3 for attaching the insulator to the support of the overhead power line. The head 5 of the inner insulating part 1 can be made in the form of a groove 8, the shape of which is convenient for placing wires in it when rolling and installing them on an overhead power line. In addition, a freely rotating split sleeve 9 can be inserted in such a groove 8, which will allow to exclude the exit of the wire 4 from the groove 8 under external mechanical influences and damage to the inner insulating part 1 by the wire 4 during rolling.

The internal insulating part 1 determines the dielectric strength of the insulator for breakdown, namely, the breakdown voltage of the insulator along the shortest path between the wire 4, fixed in the grooves 6 of the head 5 and the grounded pin 3, and the mechanical strength of the insulator when exposed to bending mechanical loads from the wire 4.

The external insulating part 2, is made bell-shaped or conical in shape from a polymer hydrophobic material, and it is rigidly fixed to the inner insulating part 1 or is performed along with it. As a material for the external insulating part 2, an organosilicon or silicone composition is taken. The external insulating part 2 provides the necessary length of the leakage path of electric current along the surface of the insulator between the wire 4 and the pin 3.

The manufacture of the insulator according to the present invention is carried out in two stages as follows:

The first stage is the manufacture of the inner insulating part 1 and then the second stage is the molding on the part 1 of the outer insulating part (skirt) 2. The manufacture of the inner insulating part 1 is made by pressing of insulating glass from a melt with subsequent heat treatment - annealing. If the inner insulating part 1 is made of electrotechnical porcelain, the manufacturing process involves successive operations of forming the porcelain mass, drying, glazing, firing and further machining. The manufacture of the inner insulating part 1 of structural plastics is carried out by injection molding on injection molding machines. The formation of the outer insulating part 2 is carried out by installing the inner insulating part 1, previously coated with a binder in the contact zone of both parts 1, 2, in the mold, feeding the mold with silicone-silicone mixture and its subsequent vulcanization at a temperature of 100 ÷ 140 ° С for 4 ÷ 20 minutes. It is also possible to pre-fabricate the external insulating part 2 or several external insulating parts 2 at once by feeding the silicone mixture into the mold under pressure and curing it at a temperature of 100 ÷ 140 ° C for 4 ÷ 20 minutes. Then the finished external insulating part 2 is rigidly fixed to the internal insulating part 1 using special adhesives.

The inventive pin linear insulator is characterized by high mechanical strength and high breakdown voltage, since its power unit is made of the corresponding materials having the specified parameters (insulating glass, electrical porcelain, structural plastics), and also provides moisture-specific (per unit length of the electrical leakage path) current) voltage is twice as large as hydrophilic glass or porcelain due to the manufacture of an external insulating part (skirt) of gy hydrophobicity silicone rubber; the insulator passed electrical and mechanical tests with positive results, is characterized by high operational reliability, is serially manufactured and delivered to electric power facilities.

Sources of information taken into account when submitting this application:

[1]. Description of the invention to the patent of the Russian Federation No. 2291506 "Pin insulator". Startsev V.V., Н01В 17/20, announced on March 10, 2006, published on January 10, 2007. Bulletin No. 1.

[2]. Description of the invention to the patent of the Russian Federation No. 2248057 "Pin linear insulator", Arzhevitin A. N et al., Н01В 17/32, filed October 1, 2003, published March 10, 2005, Bulletin No. 7.

Claims (1)

A linear pin insulator comprising at least two concentrically mounted and interconnected internal and external insulating parts, characterized in that the internal insulating part forming a power unit for attaching the insulator to the support pole and wires on the insulator is made of insulating glass, or electrical porcelain, or of structural plastic with a head having annular and upper diametrically located grooves intended for fastening the wire, and a threaded hole a hole for the pin, while the external insulating part made of a bell-shaped or conical shape of a polymer hydrophobic material is rigidly fixed to the inner insulating part by means of an adhesive layer or by molding directly on the internal insulating part installed in the mold, previously coated with a binder in the contact zone both parts by feeding into the mold under pressure a silicone mixture and its vulcanization.

Images