RU174502U1 - ELECTROMAGNET - Google Patents

Abstract

The utility model relates to electrical engineering, namely to electromagnets with permanent magnets. The technical result consists in expanding the range of applied permanent magnets, reducing the cost of refinement and reducing the complexity of design work in the development of product modifications. An electromagnet is proposed in which the casing is made in the form of a regular n-angular prism, and the lateral surface of the ring-shaped sleeve is faceted by segment flats in an amount equal to the number of casing faces. Permanent magnets are fixed by spacers between the faces of the body and the surfaces of the flats. The coil is made with an elongated central sleeve. The ring-shaped sleeve is centered on the outer surface of the sleeve, and the anchor is centered on its inner surface. The outer end of the armature is equipped with a safety cover, a spring and a guide sleeve. The electromagnet with minimal costs is modified for various working forces and for various permanent magnets within the same size, as well as when creating the overall number of products. 11 ill.

Description

The proposed utility model relates to electrical engineering, namely to electromagnets with permanent magnets, used, in particular, in circuit breakers to control the free trip mechanism.

Known electromagnets with a retracting armature, incorporating permanent magnets, see [1-8]. A feature of electromagnets with permanent magnets is an increased initial force, increased sensitivity to a control signal, and as a result, increased speed. This is explained by the constant presence in the electromagnet of the magnetic field of a permanent magnet and the use of the coil field only to strengthen it (when the magnetic fluxes of the coil and the permanent magnet coincide) or weaken (with opposite directions of magnetic fluxes) depending on the problem being solved by the electromagnet. Changing the direction of the magnetic flux of the coil is achieved by changing the direction of the control current. Due to their properties, permanent magnet electromagnets are widely used in various electrical devices (relays, switches, contactors and other automatic devices and remote control systems). Such electromagnets consist of a fixed magnetic core in the form of a cylindrical [1-4] or U-shaped case [5-7] with a cover (flange) and a cylindrical sleeve inside the case, and a moving magnetic core in the form of a cylindrical armature passing through the openings of the cover (flange) , cylindrical bushings and coils. The outer end of the cylindrical armature is used to act on the driven mechanism. Permanent ring magnets with a magnetization directed along the radius of the coil are placed between the walls of the housing and the cylindrical sleeve, see the figures for patents [1, 2, 4] and, as a rule, have their own non-standard sizes. It is sometimes proposed to replace a ring magnet with a set of separate rectangular magnets suitable for a radial clearance between the cylindrical walls of the housing and the ring-shaped sleeve [4]. A common drawback of the design of these electromagnets is the limitation in the use of permanent magnets of other geometric shapes, which limits the ability to quickly replace permanent magnets with more progressive, but having a different shape, size and material without significant structural changes. Similar problems arise when changing the supplier of permanent magnets for technical and economic reasons or when discontinuing the production of the type of magnet used. It is also difficult to modify such constructions of electromagnets to new technical parameters, which reduces the level of unification and standardization of products of the modified series. Permanent magnets can also have the shape of parallelepipeds [5, 7], which with a U-shaped case can only be placed on two sides, which limits the possibility of increasing the initial force when modifying the product to increase the initial force. In addition, structures with U-shaped magnetic circuits are characterized by slightly increased losses of the main magnetic flux generated by the coil due to scattering fields through its open side surfaces. There are also designs of electromagnets in which permanent magnets are mounted in the moving part of the magnetic circuit [8] or placed inside the core under the flat end of the armature [3]. Such designs are designed only for a specific configuration of a permanent magnet and are limited in the choice of other types of magnets.

Closest to the claimed utility model in technical essence is the electromagnet described in the description of the patent for the invention [2]. The prototype is a double electromagnet with permanent magnets, but fundamentally arranged similarly to the claimed design. The prototype has an external fixed part of the magnetic circuit, consisting of a cylindrical body and lids connected to it with central holes and an annular sleeve located coaxially inside the body. The moving part of the magnetic circuit is made in the form of a cylindrical spring-loaded armature mounted on the rod, with the possibility of reciprocating movement inside the covers, ring-shaped bushings and coils. An annular permanent magnet is fixed between the inner surface of the cylindrical body and the outer surface of the annular sleeve. Through the rod, the anchor of the electromagnet is connected to the driven mechanism of the object and is driven by the supply of current to the control coils of a certain polarity and in a certain sequence. For the manufacture of the prototype, it is necessary to order a permanent magnet in special sizes, which is not always economically profitable, especially for small-scale production of products in which the magnet is used. The disadvantage of the prototype is the limited ability to use other types of permanent magnets in mass production, standard disk, plate, ring-shaped, rectangular, etc. The prototype is limited in terms of the development of other versions of the electromagnet for other efforts. For such designs, it is again necessary to order electromagnets for special sizes. Such limitations of the prototype are associated with the selected spatial layout of the design of the electromagnet.

The design of the claimed utility model is aimed at overcoming these drawbacks. The technical result achieved by the proposed utility model is:

- expanding the range of applied permanent magnets in shape, size and materials from the standard range of these products on the market, without fundamental design changes, which reduces the manufacturer’s manufacturing costs for improvements when replacing purchased products;

- to reduce the complexity of design work when creating product modifications for new parameters by increasing the level of unification and standardization of products of the modified series.

This goal is achieved by the fact that in an electromagnet with permanent magnets containing the outer stationary part of the magnetic circuit, consisting of a housing connected to it by a cover having a central hole, and an annular sleeve located inside the housing coaxially with the central hole, a movable part consisting of a cylindrical two-stage armature , with a flat inner end on the side of the step of a larger diameter and a threaded rod with a threaded sleeve on the outer end of the armature mounted to move axially inside the annular sleeve and the cover, as well as containing a coil placed coaxially inside the housing with an anchor with one end to the housing, and with the second end to the annular sleeve, permanent magnets embedded between the side surfaces of the housing and the annular sleeve, a coil spring placed outside the housing, its casing made in the form of a regular n -ugolnoy prism with an even number of faces and the side surface of the annular sleeve faceted flats segment in an amount equal koliches Wu faces the body and parallel to the opposite faces of the housing. Moreover, the surface of each flange is remote from the inner surface of the face of the casing by a distance not less than the thickness of the plate-shaped permanent magnet, and permanent magnets with magnetization in the direction of their thickness are mounted on the flats and fixed in the casing using non-magnetic spacers. In this case, the coil of the electromagnet is made with an elongated central sleeve protruding beyond its end, having a length of the protruding part of not more than the height of the annular sleeve and an outer diameter of not more than the inner diameter of the annular sleeve. The cylindrical anchor is movably placed inside the sleeve, and the ring-shaped sleeve is centered on the outer surface of the sleeve. In addition, the threaded end of the anchor is equipped with a corrugated protective cover outside, mounted on the end of the anchor with a threaded sleeve, and a guide sleeve with an outer and inner rim is mounted coaxially to the central hole. A cylindrical spring is integrated in the inner rim so that its ends are uncontrolled between the inner ends of the protective-stop cover and the guide sleeve.

The implementation of the body of the electromagnet in the form of a regular n- angular prism with an even number of faces and faceting of the side surface of the annular sleeve with segment flats in an amount equal to the number of faces of the case and parallel opposing faces of the case allows you to place n / 2 pairs of standard standard plate type magnets produced around the annular sleeve massively by many manufacturers. The separation of the surface of each flat from the inner surface of the face of the casing by a distance not less than the acceptable thickness of the lamellar permanent magnet with magnetization in the direction of their thickness permits the further use of magnets of smaller thickness, but from materials with greater coercive force. The resulting gaps between the magnet and the flat surface (or the inner face of the body) can be filled with plate gaskets if necessary. The presence of non-magnetic spacers allows reliable and unambiguous fixation of permanent magnets in the housing during assembly of the electromagnet. The implementation of the electromagnet coil with an elongated central sleeve protruding beyond its end, having a protruding part of no more than the height of the annular sleeve and an outer diameter of no more than the inner diameter of this sleeve provides easy centering of the annular sleeve along one outer seating surface of the sleeve (regardless of the seating surfaces of the movable armature) and simple modification of this sleeve for magnets of greater thickness (only one variable size - flat depth). In order to change the spring to another, with a different working force, when modifying the electromagnet, the threaded end of the armature is equipped with a removable protective-stop cover, between which the end and the end of the guide sleeve are spring-loaded. The guide sleeve is made with an outer and inner rim. The inner rim acts as a guide for the spring.

The proposed utility model can be used in mass production as part of low-voltage circuit breakers for various rated currents, as a small-sized high-speed electromagnet acting on the rail of the circuit breaker free trip mechanism. Thanks to the proposed design, various plate-type permanent magnets of mass production can be used in an electromagnet. When developing designs, the model can easily be modified to the required efforts to act on the driven mechanism by selecting the number and type of permanent magnets of mass production and selecting a working spring for a given force from the normalized range operating in the industry standard.

An analysis of the prior art by the applicant, including a search by patents and scientific and technical sources of information and identification of sources containing information about analogues of the claimed utility model, allowed to establish that the applicant did not find a prototype characterized by features identical to all the essential features of the claimed utility model. The determination from the list of identified analogues of the prototype as the closest in terms of the set of essential features of the analogue made it possible to identify the set of significant distinguishing features in relation to the technical result perceived by the applicant in the claimed design set forth in the utility model formula.

Therefore, the claimed utility model meets the condition of "novelty."

The design of the claimed utility model is depicted in FIG. 1-11. In FIG. 1-4, respectively, are a general view of the electromagnet, a front view with a half section AA to the central axis, side view B and top view B. FIG. 5 is the same section AA, but shows the position of the details of the electromagnet in the initial state, which is ensured by cocking the free-trip mechanism of the circuit breaker to the standby position. In FIG. Figure 6 shows a section GG passing through the axis of symmetry of the permanent magnets perpendicular to the central axis of the electromagnet (for the position of the secant plane, see Fig. 2). FIG. 7 depicts the internal placement of disk permanent magnets on the flats of an annular sleeve with a conditionally not shown housing, cover and outer sleeves with a working spring. FIG. 8-11 repeat FIG. 7 and show the possibilities of the proposed model in terms of the use of permanent plate magnets of various shapes, sizes, and made of various materials. FIG. 8 shows the use of planar ring magnets, FIG. 9 - magnets in the form of flat square plates, FIG. 10 - in the form of a composite magnet of two rectangular, FIG. 11 - the use of a thin disk magnet of a material with greater coercive force in conjunction with a soft magnetic pad.

The permanent magnet electromagnet (see Fig. 1 - Fig. 4) contains an external fixed part of the magnetic circuit, consisting of a housing 1 made in the form of a regular n- angular prism with an even number of faces (for the given specific design n = 4) connected to cover 2, having a Central hole 3, and an annular sleeve 4, located inside the housing coaxially with the Central hole 3. The movable part of the magnetic circuit consists of a cylindrical two-stage anchor 5, with a flat inner end 6 from the side of the greater of diameter and a threaded rod 7 with a threaded bushing 8 on the outer end of the anchor. An anchor 5 is mounted axially movable inside an annular cover 2, a sleeve 4 and a coil 9. The axial movement of the armature 5 is bounded down by the flat end 6 against the bottom 10 of the housing 1 (see Fig. 5), and upward by the shoulder 11 cover 2 (see Fig. 2). The coil 9 is placed inside the housing 1 coaxially with the anchor 5 with one end to the bottom 10 of the housing 1, the second end to the ring-shaped sleeve 4. The coil 9 is made with an elongated central sleeve 12 protruding beyond its end, having a length of the protruding part no more than the height of the ring-shaped sleeve 4 and the outer diameter not more than the inner diameter of the annular sleeve. The height of the annular sleeve 4 itself is selected not less than the linear size of the permanent magnets planned for use. The inner diameter of the sleeve 12 is selected not less than the outer diameter of the armature 5 and provides a running landing of the armature along a single landing surface - the inner surface of the sleeve. The manufacture of the sleeve 12 from antifriction plastic (caprolon, fluoroplastic) also reduces the wear of the rubbing surfaces of the armature 5. The outer surface of the sleeve 12 is also the only one for centering the annular sleeve 4, which contributes to the manufacturability of the assembly of the electromagnet, eliminates the dependence on other diametrical assembly surfaces. The elongated sleeve 12 of the coil 9 provides accurate centering of the magnetic system of the electromagnet, the constancy of the non-magnetic gap, the elimination of unilateral forces of magnetic traction between the armature and the core parts, which ultimately contributes to the stable operation of the electromagnet. The ring-shaped sleeve 4 is externally faceted by segment flats 13 (see Fig. 6). Their number corresponds to the number of faces of the body. Each flat 13 is made so that it is removed from the inner surface 14 of the opposite face of the housing 1 by a distance of not less than the thickness t of the used ferrite permanent magnets 15 with acceptable technical characteristics. Magnets 15 are mounted on the flats 13 of the annular sleeve 4 and are symmetrical with respect to the plane of symmetry of the electromagnet using spacers 16 and 17 made of non-magnetic materials. In FIG. 7 shows a general view of the mounted permanent magnets 15 having a disk shape with a locking element 17. FIG. 7 the housing 1 with the cover 2 is conventionally not shown. Also not shown are parts mounted on the outside of the housing above the electromagnet cover. The upward movement of the armature 5 is provided by a working spring 18 (see FIG. 2 and FIG. 5), which is installed between the inner ends of the guide sleeve 19 and the protective-stop sleeve 20. The guide sleeve 19 is mounted on the cover 2 coaxially with the central hole 3. The safety-stop the sleeve 20 is mounted on the threaded end 7 of the armature 5 with the threaded sleeve 8 and protects the spring from the penetration of foreign objects inside. The threaded sleeve 8 is pressed into the protective thrust sleeve 20, which is provided with a corrugation 21 on the outside for ease of assembly. The direction for the spring 18 when it is compressed creates an inner rim 22 of the sleeve 19, and the outer rim 23 protects the movable sleeve 20 from accidental lateral mechanical influences. The working spring 18 transfers its force to the trip mechanism of the circuit breaker (the mechanism is not shown in the drawings) through the sleeve 20 and the threaded sleeve 8. The permanent magnets 15 used in this design of the electromagnet can be of another shape, for example, flat ring 24, (see Fig. . 8), flat square 25, (see Fig. 9), in the form of a set of two rectangular 26 (see Fig. 10). Suitable shaped magnets from other materials with improved magnetic properties may also be used. The smaller thickness of the more powerful disk magnets 27 is supplemented to a thickness t by shims 28 of soft magnetic material (see Fig. 11).

The proposed permanent magnet electromagnet operates as follows. When cocking the free-release mechanism of the circuit breaker (not shown in the drawings) to the “ready for shutdown” position, the armature 5, under the influence of the switch, which is applied to the end of the threaded nut 8, moves its flat end 6 towards the bottom 10, reducing the air the gap δ (see Fig. 2). In this case, the magnetic fields of the magnets 15 come into force, the lines of force of which are closed in the circuit "magnet 15 pole N - core 1 - air gap δ - armature body 5 - side surface of the ring-shaped sleeve 4 - pole S of magnet 15". At a certain value of the air gap δ, the total force of the field of permanent magnets becomes greater than the force of the working spring and the anchor with its flat end 6 is attracted to the bottom 10 of the core 1 (see Fig. 5). In this position, the electromagnet is ready to perform its main function, to activate the free trip mechanism of the circuit breaker. Upon receipt of a short-term control current in the coil 9 of the corresponding magnitude and polarity, which creates a magnetic flux in the coil that is opposite in direction to the total flux of permanent magnets 15, an instantaneous attenuation of the magnetic flux from the permanent magnets occurs. The armature 5 under the action of the working spring 18 on one side and under the influence of magnetic forces of the increasing magnetic field already in the circuit "magnet 15 pole N - core 1 - cover 2 - the body of the armature 5 - side surface of the ring-shaped sleeve 4 - pole S of magnet 15" moves sharply upward and the end face of the sleeve 8 acts on the mechanism of free tripping, which automatically opens the contacts of the switch. The proposed design of the electromagnet, thanks to the housing 1 in the form of a regular n- angular prism and faceted flats in an amount equal to the n ring-shaped sleeve 4, allows, in contrast to the prototype, to use permanent magnets of various shapes of a wider nomenclature from the standard range of mass-produced sizes and their combinations, namely:

- disk 15, FIG. 7, including composite of several within the thickness t ;

- ring 24, FIG. 8, including composite of several within the thickness t ;

- plate square 25, FIG. 9, including composite of several within the thickness t ;

- rectangular 26, FIG. 10, in the form of a set across the width of the flat;

- other acceptable forms that fit into the space between the face 14 of the housing 1 and the flat 13 of the sleeve 4 and satisfying the given efforts.

At the same time, advanced opportunities are provided in the selection of magnets from various materials from a number of:

- inexpensive ferrite (ceramic ferritobarium and ferritostrontium) general applications for operating temperatures not lower than -20 ° C;

- expensive cobalt samarium with increased coercive force and intended for operation at elevated temperatures up to + 350 ° C;

- Neodymium based on neodymium-iron-boron alloys with a working temperature range from -60 to + 150-220 ° C.

- “iron-cobalt” based on the “iron-chromium-cobalt” alloy, as they are more resistant to mechanical stress, demagnetization and high temperatures than ceramic and neodymium;

- promising nanostructured, magnetically hard based on FeCrCo alloys with improved characteristics.

Advanced opportunities appear due to the fact that magnets from various materials, including new ones, for their competitive promotion on the market, are made, first of all, in standard forms (discs, flat rings, rectangular plates, rods), as used in domestic and other mass production devices. The design of the proposed model is precisely oriented to these standard forms of permanent magnets.

Thus, the first goal of the claimed model is achieved: expanding the range of applied permanent magnets in shape, size and materials without fundamental structural changes, which reduces the manufacturer’s production costs for finalizing the electromagnet when replacing permanent magnets for technical and economic reasons.

For the development of modifications (designs) of an electromagnet within the same size, the following are provided:

1) a removable protective and resistant cover 20 with a threaded sleeve 8 mounted therein, which make it easy to replace one standard working spring 18 with another standard one to increase or decrease the working force of the electromagnet;

2) ring-shaped sleeve 4 faceted by flats 13, with the possibility of modifying it to a size t , i.e. for magnets of various acceptable thicknesses, both in the direction of increasing and decreasing the size (soft magnetic strips 28 can be used to reduce, see Fig. 11);

3) coil 9, operating in a short-term, almost pulse mode, having sufficient overload capacity for control current and not requiring, within the same size, changing its winding data.

For the development of modifications (designs) of an electromagnet of other dimensions for large working efforts, the following are provided:

a) the execution of the housing 1 with an increased number of faces (for example, with 6 or 8 faces) and, accordingly, the execution of an annular sleeve 4 with an increased number of flats 13;

b) the basic solution of pairing the annular sleeve 4 and the armature 8 by means of an elongated sleeve 12 of the coil 8, which ensures the consistency and repeatability in all versions of the electromagnet of the exact centering of the magnetic system of the electromagnet with a stable non-magnetic gap, with the elimination of unilateral forces of magnetic tension between the armature 5 and the core parts, with reducing the wear of the rubbing surfaces of the armature 5 and the sleeve 12 due to the choice of material of the sleeve with low values of the coefficient of friction for metal.

The proposed measures for the development of designs of an electromagnet with permanent magnets within the same size and designs of new dimensions can reduce the complexity of design work and their duration, increase the level of unification and standardization of modified products.

Thus, the implementation of an electromagnet with permanent magnets in the claimed form with new structural elements, namely, a body in the form of a regular n- angular prism with an even number of faces, with a ring-shaped sleeve faceted by segment flanges in an amount equal to the number of faces of the body, with a coil with a protruding behind its end face with an elongated central sleeve, with spacer elements, with a protective stop cover and a guide sleeve, and the placement of these structural elements in the described relationship and relative position SRI with the other parts of the electromagnet, have led to the proposed model, the declared technical result.

The described design of the utility model and a description of its operation indicate the compliance of the claimed utility model with the following set of conditions:

- a device embodying the claimed model, when implemented, is intended for use in circuit breakers and relates to electrical engineering, namely, to electromagnets with permanent magnets;

- for the claimed design in the form as described in the stated utility model formula, the possibility of its implementation using the means described in the application is confirmed;

- a device embodying the claimed utility model, when implemented, is capable of ensuring the achievement of the technical result perceived by the applicant.

Prototypes of the inventive electromagnet were manufactured and tested with positive results in the composition of circuit breakers for high currents.

Therefore, the claimed utility model meets the condition of "industrial applicability".

Sources taken into account:

1. Description of the patent for the invention RU 2233496 H01F 7/16 publ. 07/27/2004.

2. Description of the patent for the invention RU 2242816 H01F 7/16 publ. 12/20/2004.

3. Description of the patent for the invention RU 2306626 H01F 7/12 publ. 02/10/2011.

4. Description of the patent for utility model RU 121642 H01F 7/16 publ. 10/27/2012.

5. Description of the patent US 4509026 (A) H01F 7/16 04/02/1985.

6. Description of the patent US 4644311 (A) H01F 7/13 02/17/1987.

7. Description of the patent US 4730175 (A) H01F 7/08 03/08/1988.

8. Description of the patent US 5949315 (A) H01H 51/22 09/07/1999.

Claims (1)

A permanent magnet electromagnet comprising an outer fixed part of a magnetic circuit consisting of a housing connected to it by a cover having a central hole and an annular sleeve located inside the housing coaxially with the central hole, a movable part consisting of a cylindrical two-stage armature with a flat inner end on the side of the step a larger diameter and a threaded rod with a threaded sleeve on the outer end of the armature mounted axially mounted inside the ring the core sleeve and the cover, as well as containing a coil placed coaxially inside the body with an anchor one end to the body, and the second end to the ring-shaped sleeve, permanent magnets embedded between the side surfaces of the body and the ring-shaped sleeve, a cylindrical spring located outside the case, characterized in that its body is made in the form of a regular n-coal prism with an even number of faces, the side surface of the annular sleeve is faceted by segment flats in an amount equal to the number of faces of the body, and parallel to opposite sides of the body, and the surface of each flat is remote from the inner surface of the face of the body by a distance not less than the thickness of the plate-shaped permanent magnet, and permanent magnets with magnetization in the direction of their thickness are mounted on the flanges and fixed in the body using non-magnetic spacers, while the magnet coil made with an elongated central sleeve protruding beyond its end, having a protruding part no more than the height of the annular sleeve and the outer diameter p is not more than the inner diameter of the ring-shaped sleeve, the cylindrical armature is movably inside the sleeve, and the ring-shaped sleeve is centered on the outer surface of the sleeve, in addition, the threaded end of the armature is equipped with a corrugated outside protective thrust cover fixed to the end of the armature with the threaded sleeve, and on the cover A guide sleeve with an outer and inner rim is installed coaxially with the central hole, inside which a coil spring is integrated so that its ends are involuntarily between the inner and the ends of protective hard cover and the guide sleeve.

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