RU2279750C2 - Method for increasing reliability of electric machine and electric machine for realization of said method - Google Patents

Abstract

FIELD: electric engineering, electro-mechanical industry, possible use for manufacturing explosion-proof electric machines.

SUBSTANCE: in the method, including pressurization of current-conductive elements outputs electric machine by means of explosion-proof cover, internal space is proposed in accordance to invention, limited by explosion-proof cover, to be subjected simultaneously to cooling, drying and dust-cleaning, while dust-cleaning is performed in places of immediate dust forming, using sticky materials as dust catchers, for example, sticky substances on basis of organic components. Also proposed is an electric machine, containing explosion-proof cover, positioned inside of which are stator, anchor, collector, coal brushes, wherein it is proposed to additionally include heat exchanger made in form of pipe, ribbed with heat-sinking plates, moisture absorber, made in form of stocking of perforated material, internal hollow of which is filled with moisture absorber, while on external surface rings are held, made of dense material, dust catcher, made in form of a layer of sticky material, applied to internal surface of explosion-proof cover, and also to surfaces of heat-sinking plates of heat exchanger and rings of moisture absorber.

EFFECT: increased operational reliability of electric machine.

2 cl, 3 dwg

Description

The invention relates to electrical engineering and can be used for the manufacture of explosion-proof electrical machines.

There is a method of increasing the reliability of an electric machine by sealing its current-carrying elements with a blown sheath, inside which a stator, a shaft with an anchor, a collector, carbon brushes are installed (see the book by V.D. Yukhimchuk. Technology and repair of DC machines, Kharkov, 2000, p.32, Fig. 1-8) - analogue.

A disadvantage of the known technical solution is that the sealing shell is made without taking into account explosiveness, which does not allow the known solution to be used in explosive atmospheres, for example, in mining mines, etc.

The closest solution to the technical nature and the effect achieved is a method of increasing the reliability of an electric machine by sealing its current-carrying elements with an explosion-proof shell, and an electric machine for its implementation, containing an explosion-proof shell, inside which a stator, rotor, collector, carbon brushes are installed (see book B .D. Yuhimchuk. Technology and repair of DC machines, Kharkov, 2000, p. 32. Fig. 1-9) - prototype.

The known solution can be used to work in explosive atmospheres, but its work will be unreliable for the following reasons:

a) heating of current-carrying elements in a closed volume leads to heating of the insulating material, its cracking and, as a result, to the loss of insulating properties;

b) after disconnecting the machine from the mains or when the load drops, the air temperature inside the machine decreases, thereby causing a drop in air pressure inside the shell. Humid air drop in air pressure inside the shell. Humid ambient air is sucked into the shell and absorbed by the insulating material, which can also lead to the loss of its insulating properties;

c) the presence of graphite brushes inside the flameproof enclosure and their abrasion during operation leads to the formation of graphite dust inside the shell, which is deposited on the electrical parts of the machine. Since graphite is a conductive material, the presence of graphite dust on the electrical parts of the machine, with poor insulation, can lead to a short to the body, and therefore to machine failure.

The objective of the invention is to increase the reliability of an electric machine.

To achieve the task in a known method of increasing the reliability of an electric machine, including sealing its current-carrying elements with a flameproof enclosure, it is proposed that the interior be insulated with a flameproof enclosure, at the same time it is cooled, dehumidified and dusted, and dust can be cleaned in places of direct dust formation using sticky materials as a dust collector , for example, adhesives based on organic components; and in an electric machine containing a flameproof enclosure with a stator, inside of which a rotor, carbon, brushes are installed, it is proposed to additionally install: 1) a heat exchanger made in the form of a pipe finned with heat-removing plates; 2) a desiccant made in the form of a stocking of perforated material, the inner cavity of which is filled, for example, with silica gel (aluminum gel or zeolite), and rings made of dense material are fixed on the outer surface; 3) a dust collector made in the form of a layer of sticky material deposited on the inner surface of the flameproof enclosure, the surface of the heat-removing plates of the heat exchanger pipe and the rings of the desiccant.

The essence of the invention is to ensure that in a closed volume of an electric machine provide safe conditions for its operation (the inner space, insulated by an explosion-proof shell, is subjected to cooling, drying and dust cleaning at the same time).

Comparative analysis with the prototype shows that the proposed method of increasing the reliability of an electric machine is characterized in that the internal space isolated by the flameproof enclosure is subjected to cooling, drying and dust cleaning at the same time, and the dust is cleaned in places of direct dust formation using sticky materials, such as adhesives, as a dust collector based on organic components, and the electric machine is additionally equipped with: 1) a heat exchanger made in the form of t Uba finned heat-plates; 2) a desiccant made in the form of a stocking of perforated material, the inner cavity of which is filled with a desiccant, and rings made of dense material are fixed on the outer surface; 3) a dust collector made in the form of a layer of sticky material deposited on the inner surface of the flameproof enclosure, the surface of the heat-removing plates of the heat exchanger pipe and the rings of the desiccant, therefore, the claimed solution meets the criterion of "novelty."

Conducted patent research allows us to conclude that the proposed solution meets the inventive step, because there are no solutions with similar features in the patent literature.

The proposed electric machine is shown in the drawing.

Figure 1 shows a General view of an electric machine.

Figure 2 is a section aa of figure 1.

Figure 3 is a General view of the desiccant.

It consists of a flameproof enclosure with a stator 1. Inside the enclosure 1 are installed: a rotor 2, a collector 3, carbon brushes 4, a brush holder 5, a heat exchanger 6, made in the form of a pipe 7 with finned heat-removing plates 8; desiccant 9, made in the form of a stocking 10 of perforated material, the inner surface of which is filled with a desiccant (for example, silica gel or zeolite), and rings 11 made of dense material are fixed on the outer surface. The electric machine is also equipped with a dust trap 12, made in the form of a layer of sticky material deposited on the inner surface of the flameproof enclosure with the stator 1, the surface of the heat-removing plates 8 of the pipe 7 of the heat exchanger 6 and the rings 11 of the desiccant 9. The desiccant 9 with adhesive rings 11 is installed from the side of the collector 3 directly in the zone of formation of graphite dust and is fixed to the housing of the flameproof shell 1.

The electric machine operates as follows:

When you turn on the machine, its winding is heated, while heating the inner space, isolated by an explosion-proof shell with a stator 1, to temperatures of 150-180 ° C.

At the same time as the electric machine is turned on, the coolant supply valve (not shown) is opened in the pipe 7 of the heat exchanger 6, the liquid (for example, water) is heated (thereby cooling the internal space insulated by the flameproof enclosure 1) and discharged into the technical water supply system (in the drawing not shown).

The interior, insulated by flameproof enclosure 1, is cooled to the required temperatures.

After disconnecting from the mains or when the load drops, the air temperature inside the machine decreases. In this case, moist ambient air is sucked into the flameproof enclosure 1. Due to the small size of the free volume of the electric machine, moisture is absorbed from the air by the desiccant 9, which reduces the absorption of moisture by the insulation of the electric machine. When the collector 3 rotates, the brushes 4 are abraded, as a result of which coal dust is released. Coal dust under the action of centrifugal forces (circular rotation of the rotor 2) is directed mainly towards the desiccant 9, the outer surface of which is equipped with a dust collector 12, the sticky layer of rings 11. The bulk of the graphite dust adheres to the sticky rings 11. Only a small mass of particles of graphite dust spreads in a closed space, heading to the inner walls of the flameproof shell 1, the heat exchanger 6, which are also equipped with a dust collector 12, made in the form of a layer of sticky material deposited on Cored oil surface flameproof enclosure 1 and the surface of the heat-removing heat exchanger plates 8 6. Adhesion of dust particles on the graphite layer of the adhesive material of the dust collector 12 clears the inner space of a flameproof enclosure which reduces the deposition of dust particles on the conductive elements.

Accumulated dust is periodically removed during the process of regulation along with a layer of sticky material from the surfaces of the flameproof enclosure 1 and heat transfer plates of the heat exchanger 6. After that, a new layer of sticky material is applied to these surfaces. Desiccant 9 together with rings 11 is replaced with a new one. Then the electric machine is assembled and set up. The machine is ready to go. After turning on the machine, the cycle repeats.

Claims (2)

1. A method of increasing the reliability of an electric machine, including sealing its current-carrying elements with a flameproof enclosure, characterized in that the internal space insulated by the flameproof enclosure is subjected to cooling, drying and dust cleaning at the same time, and the dust is cleaned in places of direct dust formation using sticky materials as a dust collector, for example, adhesives based on organic components. 2. An electric machine containing a flameproof enclosure with a stator, inside of which a rotor, collector, carbon brushes are installed, characterized in that it is additionally equipped with a heat exchanger made in the form of a pipe finned with heat-removing plates, a desiccant made in the form of a stocking of perforated material, internal the cavity of which is filled with a desiccant, and on the outer surface are fixed rings made of dense material, and a dust collector made in the form of a layer of sticky material Ala deposited on the inner surface of the flameproof enclosure, the surface of the heat sink plates of the heat exchanger pipe and the desiccant rings.

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