RU2158035C2 - Contact system of vacuum arc chute - Google Patents

Abstract

FIELD: electrical engineering. SUBSTANCE: proposed contact system of vacuum arc chute includes mobile and immobile contacts positioned on common axis, each of them being made of contact strip with radial grooves linked via inductor to current lead and of ferromagnetic core coming in the form of disc with radial and annular grooves. Contact strip has shape of embracing ring made of current-conducting material with radial grooves inside which solid disc of contact material is made fast. Disc ferromagnetic core has continuous section of ferromagnetic material enveloped by annular groove and radial grooves located beyond periphery of annular groove located in central part. Bearing tube produced from nonmagnetic material with low conductance is fixed in annular groove. EFFECT: increased value f longitudinal magnetic flux, improved cutting-off capability of contact system, reduced cost of vacuum arc chute. 3 dwg

Description

 The invention relates to the field of electrical engineering, in particular to contact systems for vacuum interrupter chambers.

 A contact system for vacuum interrupter chambers is known, containing coaxially mutually opposite contacts, contact holders of which are made in the form of hollow cylinders with slots inclined in one direction with respect to the axis of contacts. Contact holders are equipped with inserts made of a material with high electrical resistance. (Application of Germany N 053334493, class MKI H 01 H 33/66 from 04.04.85).

 A disadvantage of the known contact system is the absence in the design of elements for suppressing eddy currents, as a result of which, due to overheating, the contact system cannot disconnect large currents.

 The closest in technical essence and the achieved result to the alleged invention is a contact system of a vacuum arcing chamber containing movable and fixed contacts located on a common axis, each of which is made of a contact plate with radial grooves connected through an inductor with a current lead, and a ferromagnetic core in the form a disk with radial grooves and an annular groove and a protrusion in the center. A recess is made in the overlay, while the ferromagnetic core is fixed on one side in the recess of the overlay, and the other ledge is connected to the current lead. In addition, the grooves in the patch and ferromagnetic core of each contact, as well as in the overlays of the opposite contacts are combined. (A.S. USSR N 1700628, class MKI H 01 H 33/66 dated 12/23/91).

 A disadvantage of the known technical solution adopted for the prototype is the high cost of manufacturing, expressed in high consumption of expensive contact material, as well as the low breaking capacity of the contact system, expressed in insufficient concentration of the axial magnetic field.

 The aim of the present invention is to reduce the cost of manufacturing a contact system by reducing the consumption rate of contact material, as well as increasing the breaking capacity of the contact system.

 This goal is ensured by the fact that in the proposed design, the contact system of the vacuum interrupter chamber contains movable and fixed contacts located on a common axis, each of which is made of a contact plate with radial grooves connected through an inductor with a current lead, and a ferromagnetic core in the form of a disk with radial grooves and ring groove. In this case, the contact patch consists of a female ring with radial grooves of electrically conductive material, inside of which a solid disk of contact material is rigidly fixed. The use of contact material in the contact system only in the contacting part allows to reduce the consumption rate of expensive contact material. In addition, in the proposed design, the disk ferromagnetic core contains in the central part a continuous portion of the ferromagnetic material, which is surrounded by an annular groove and has radial grooves located outside the periphery of the groove. In the annular groove, a support tube of non-magnetic material with low electrical conductivity is fixed. The support tube counteracts the deformation of the inductor at the moment of contact pressing, and the low electrical conductivity provides conditions for avoiding current shunting. The presence of ferromagnetic material in the central part of the ferromagnetic disk contributes to the axial concentration of the magnetic field, thereby improving the conditions for increasing the breaking capacity of the contact system.

 The invention is illustrated by drawings. Figure 1 shows a section of a vacuum interrupter chamber with movable 1 and fixed 2 contacts located on a common axis. Each contact consists of a contact pad 3 connected through an inductor 4 to a current lead 5. In the inner part of the inductor 4, a ferromagnetic core 6 is installed, which end faces the disk of the contact pad, and rests on the other end having an annular groove in which the support tube 7 is fixed into the current supply 5.

 In FIG. 2 shows a section through a contact strip consisting of a female ring 3.1 of electrically conductive material with radial grooves, inside of which a solid disk 3.2 of contact material is rigidly fixed.

 In FIG. 3 shows a disk ferromagnetic core containing in the central part a solid portion 6.1 of ferromagnetic material, which is surrounded by an annular groove 6.2 and has radial grooves 6.3 located beyond the periphery of the groove.

 The manufacturing of the contact system is carried out by soldering the parts together with brazing alloys in two stages. Initially, the contact patch is soldered with solder having a higher soldering temperature, then the remaining parts are soldered to the contact patch with solder having a lower soldering temperature.

 Contact system works as follows.

 In the on state, the movable contact 1 is closed with the stationary contact 2, an electric current flows from one current supply to another through inductors, ring plates and contact disks. The current passing through the inductors creates an axial magnetic field, which is enhanced by the presence of a ferromagnetic core. The proposed design of a ferromagnetic core in the form of a disk containing in the central part a continuous section of a ferromagnetic material more actively concentrates the axial magnetic field. In the on state, under the action of a compression spring, when sufficiently high deforming forces are created, the presence of a support tube counteracts the deformation of the inductor, and the low electrical conductivity of the tube material prevents current shunting relative to the inductor and the ring plate.

 When the contacts are opened, the arc arising on the contact disks under the influence of the axial magnetic field passes into the diffuse state and breaks when the current passes through zero.

 Compared with the known contact systems, the proposed system allows, due to the modified design of the ferromagnetic core, to increase the longitudinal magnetic field, thereby improving the conditions for increasing the breaking capacity of the contact system, and also reduces the cost of the vacuum interrupter chamber by reducing the consumption rate of the contact material.

Claims (2)

 1. The contact system of a vacuum interrupter chamber, comprising movable and fixed contacts located on a common axis, each of which is made of a contact plate connected through an inductor with a current lead and a ferromagnetic core in the form of a disk, characterized in that the contact plate consists of a female ring conductive material with radial grooves, inside of which a solid disk of contact material is rigidly fixed.  2. The contact system according to claim 1, characterized in that the disk ferromagnetic core contains in the central part a continuous portion of ferromagnetic material that is surrounded by an annular groove and has radial grooves located outside the periphery of the groove, a support tube made of non-magnetic material with a low electrical conductivity.

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