RU213232U1 - ELECTROMAGNETIC CONTACTOR - Google Patents

Abstract

The utility model relates to motor control devices with a single rest position. The technical result is to provide a reliable clamp between the contacting parts. The electromagnetic contactor is equipped with moving and fixed contacts. The electromagnetic drive contains two short-circuited turns and a set of plates containing through holes for connecting these plates into a single structure by means of rigid fasteners, forming recesses for placing short-circuited turns in them. The electromagnetic drive contains plates coated with a dielectric layer. 3 ill.

Description

The utility model relates to motor control devices with a single rest position. The utility model can be used in the field of electrical engineering, in motor control devices, including starters and contactors.

The closest in technical essence is the device of an electromagnetic contactor (RU 2231159, publ.: 20.06.2004 Bull. No. 17), intended for use with a star-delta starting switch, configured to start a three-phase electric motor in order to provide subsequent running the engine at its full speed. The time relay located in the housing is made together with the housing. The electromagnetic contactor device is configured to turn on and off the main power source due to electronic switching operations carried out by the main circuit electromagnet and the vertically movable main circuit element. The electromagnetic contactor device is also configured to selectively perform star connection or delta connection according to the switching operation of the star-delta electromagnet and the vertically movable member. The disadvantage of this technical solution is not sufficiently reliable clamp between the contact parts.

The task to be solved by the claimed utility model is to provide a reliable clamp between the contacting parts.

This problem is solved due to the fact that the electromagnetic contactor, equipped with movable and fixed contacts, the electromagnetic drive contains at least two short-circuited turns and a set of plates containing through holes for connecting these plates into a single structure by means of rigid fasteners, forming at least four recesses for placement of short-circuited turns in them.

The technical result provided by the above set of features is to provide a reliable clamp between the contacting parts.

The utility model can be used in the field of electrical engineering in motor control devices, including contactors and starters.

The term "electromagnetic drive" means that the force necessary to close the main contacts is provided by an electromagnet.

The term "short-circuited coil" means an element of the electromagnetic drive of the switching device, which creates a magnetic flux lagging behind the main flux. This keeps the moving part of the magnet of the electromagnetic drive in the closed state when the AC voltage passes through zero.

The term "coil" means a set of turns of enameled wire on a frame. The coil of the electromagnetic drive according to this utility model means a coil that is part of an electromagnet, the operation of which leads to the closure of the main contacts.

The term "plate" means a body bounded by two parallel planes, the distance between which, called the thickness of the plate, is small compared to its other dimensions.

The term "set" means a collection of parts.

The term "electromagnetic drive" means that the force necessary to close the main contacts is provided by an electromagnet. An electromagnetic drive is a set of parts directly or indirectly involved in moving the main moving contacts, among other parts. The electromagnetic drive contains movable and fixed parts of the magnetic circuit (including their components), coils (one or more) (including coil components), a traverse for moving contacts, parts for supplying voltage to the electromagnetic drive, fastening elements, etc.

The utility model is illustrated by drawings, which show:

figure 1 - drawing of the plate,

figure 2 - a set of plates,

figure 3 - a set of plates placed short-circuited coils.

The electromagnetic drive contains a set of plates. The plates are coated on both sides with a dielectric, contain through holes 1, as well as recesses 2 for placing short-circuited turns 3 in them. For example, varnish, enamel or any other dielectrics known to science can be used as a dielectric. The coating of each plate of the magnetic circuit on both sides with a dielectric changes the direction of the magnetic flux, the magnetic flux moves in a direction along each insulated plate. Making the plates insulated creates many directional flows, compensating for the eddy losses that occur for alternating current. Eddy currents are electric currents that arise as a result of electromagnetic induction in a conductive medium (usually in a metal) when the magnetic flux penetrating it changes. Eddy currents generate their own magnetic fluxes, which, according to Lenz's rule, oppose the magnetic flux of the coil and weaken it. In addition, they cause heating of the magnetic circuit, which is a waste of energy and leads to a weakening of the magnetic flux.

Coating the plates on both sides with a dielectric is also necessary due to the fact that the plates on both sides are in contact with adjacent plates of the magnetic circuit. Due to the content of the dielectric on the plates on both sides, the necessary trajectory of the magnetic flux is provided, the reduction of magnetic field losses associated with eddy currents, the increase in the magnetic flux passing through the magnetic circuit improves the magnetization of the magnetic circuit, thus providing a reliable clamp between the contacting parts (moving and stationary part of the magnetic circuit).

Through through holes 1, a set of plates are pulled together into a single structure by means of rigid fasteners. Thus, the magnetic flux passing through the magnetic circuit increases, since the total magnetic field with this design consists of a plurality of magnetic fields of each of the plates. The tightening of the plates together eliminates the gaps between the plates. The gaps between the plates weaken the magnetic field due to magnetic flux losses. The rigid connection of the plates to each other in a single structure, excluding gaps, an increase in the magnetic flux passing through the magnetic circuit, improves the magnetization of the magnetic circuit, thus providing a reliable clamp between the contacting parts (moving and fixed part of the magnetic circuit).

The use of rigid fasteners to connect the plates into a single structure, in contrast to gluing, is most effective in eliminating gaps. The gaps between the plates weaken the magnetic field due to magnetic flux losses. The rigid connection of the plates reduces losses, increases the magnetic flux passing through the magnetic circuit, improves the magnetization of the magnetic circuit, thus providing a reliable clamp between the contacting parts (moving and stationary parts of the magnetic circuit).

The electromagnetic drive contains a set of plates that form at least four recesses 2 for placing two short-circuited turns 3 in them. they have two short-circuited turns 3 (Fig. 3) (one short-circuited turn is placed in two recesses). The presence of four recesses for short-circuited coils allows short-circuited coils placed in the grooves of the magnetic circuit of the electromagnetic drive to create a magnetic flux at the moment the alternating current passes through zero. Four narrow recesses are needed to provide a niche for pressing the two short-circuited turns in the plate set and increasing the lagging magnetic flux, providing electrical contact between the two short-circuited turns and plates. The recesses are made narrow equal to the thickness of the short-circuited coil, two short-circuited coils in these recesses are well pressed against the plates. Four recesses formed by a set of plates allow two short-circuited turns to perform the function: to increase the magnetic flux at the moment the alternating current passes through zero, to increase the lagging magnetic flux. Thus, a set of plates forming at least four recesses for placing at least two short-circuited turns in them, and at least two short-circuited turns increase the magnetic flux and provide reliable pressure between the contacting parts (between the movable part of the magnetic circuit and the fixed part of the magnet). The presence of at least four recesses allows you to place in them and provide electrical contact with at least two short-circuited turns, and this is essential to improve the pressing of the moving part to the fixed part of the magnetic circuit at the moment of zero crossing.

Short-circuited turns cause a change in magnetic flux, creating a magnetic flux lagging behind the main flux, thereby holding the armature when the alternating current passes through zero.

The formula for the magnetic flux created by one turn

Ф=B⋅S⋅cosα, where

Ф - magnetic flux, Wb;

B - magnetic induction, T α

The formula for the magnetic flux created by N turns

Ф=N⋅B⋅S⋅cosα, where N is the number of turns.

Other things being equal, the formula for the magnetic flux created by two short-circuited turns

Ф=2⋅B⋅S⋅cosα, that is, the magnetic flux created by two short-circuited turns will be 2 times more than one.

Based on the foregoing, an increase in the lagging magnetic flux, which ensures reliable pressing of the movable part of the magnetic circuit to the stationary part of the magnetic circuit of the electromagnetic drive at the moment of zero crossing, is ensured due to the presence of at least two short-circuited turns located in four recesses of the plates, it also increases the magnetization of the magnetic circuit at the moment of transition through zero.

The device works as follows.

When power is applied to the magnet coil of the electromagnetic drive, the movable part of the electromagnetic drive starts to move. Under the action of the electromagnetic drive, six movable contact parts associated with the movable part of the electromagnetic drive come into motion. Six movable contact parts move to close with six fixed contact parts. In the closed position of the contact parts, the current flows from the source to the consumer through the current-carrying parts of the motor control device. The presence of two short-circuited turns provide sufficient lagging magnetic flux at the time of the zero crossing of the AC, increase the lagging magnetic flux and increase the power of the drive at the time of the zero crossing. Short-circuited turns are made of metals, due to their properties to be well magnetized. Two short-circuited turns are placed in the recesses of the magnetic circuit in two places of contact between the movable and fixed parts of the magnetic circuit, this is most effective, since the magnetic flux is created in the place where it is necessary to magnetize the movable part and draw it to the fixed part of the magnetic circuit. Thus, at the moment the alternating current passes through zero, the magnetic flux increases in the right place and the power of the electromagnetic drive increases. To achieve an increase in the power of the magnet, the electromagnetic drive contains ten and/or more plates coated with a dielectric layer, containing through holes, and also contains ten and/or more plates coated with a dielectric layer, containing recesses for placing short-circuited turns in them. The total magnetic flux consists of the magnetic fluxes of each of the plates, so the use of ten plates in the composition of the electromagnetic drive increases the power of the magnetic drive by increasing the magnetic flux.

The electromagnetic drive of the claimed utility model has the ability to control the switching of contact parts. Switching of contact parts is carried out under the action of an electromagnetic drive. The movable part of the magnetic circuit of the electromagnetic drive is magnetized and attracted to the magnetized fixed part of the magnetic circuit, the clamping is carried out the more reliably, the stronger the parts of the magnetic circuit of the electromagnetic drive are magnetized. The electromagnetic drive controls the moving contacts, rigid connection by means of fasteners and a traverse of the moving contacts and the moving part of the electromagnetic drive allows you to control the moving contact parts. The moving contact parts are pressed against the fixed parts the stronger and more reliably, the stronger and more reliably the movable part of the magnetic circuit of the electromagnetic drive is pressed against the stationary part of the electromagnetic drive. The movable contact parts are pressed against the fixed contact parts, thus providing a reliable clamping between the contact parts (contact parts).

When voltage is applied to the coil of an electromagnetic drive, the current, passing through the turns of the coil, creates electromagnetic fields, the movable and stationary parts of the magnetic circuit are magnetized, while the movable part of the magnetic circuit is magnetized (attracted, while moving) to the stationary part of the magnetic circuit of the electromagnetic drive. The stationary part of the electromagnetic drive remains stationary during the operation of the contactor. Empirically, in the process of testing samples (depending on the size), one or more short-circuited turns can be added to the described two short-circuited turns, in which case the number of grooves provided for accommodating short-circuited turns in them will increase to achieve optimal operation of the magnetic circuit of the electromagnetic drive. Four is the minimum number of notches formed for two short-circuited turns.

Claims (2)

1. An electromagnetic contactor equipped with movable and fixed contacts, characterized in that the electromagnetic drive contains two short-circuited turns and a set of plates containing through holes for connecting these plates into a single structure by means of rigid fasteners, forming recesses for placing short-circuited turns in them, with This electromagnetic drive contains plates coated with a dielectric layer. 2. Electromagnetic contactor according to claim 1, characterized in that the set of plates forms four narrow recesses equal to the thickness of the short-circuited coil.

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