RU2694071C2 - Electric machine - Google Patents

Abstract

FIELD: machine building.SUBSTANCE: invention relates to electric machine engineering and can be used in closed electric machines operated in environment with high humidity and dustiness. In an electrical machine containing a closed housing, a rotor and a desiccant with a dust filter and radial holes arranged in the axial hole from the shaft end face, the axial hole is made through or composite from two ends of the shaft on a part of its length. At that, the size of radial shaft holes is smaller than the size of the desiccant particles.EFFECT: reduction of aerodynamic resistance on the path of air movement through the dust filter, desiccant, radial holes, simplification of operation and maintenance when replacing desiccant.3 cl, 2 dwg

Description

The invention relates to electrical engineering and can be used in all types of closed electric machines, operated in ambient conditions with high humidity and dust.

Known electrical machine (and.with. SU 561254 A1, and.with. SU 1163423 A), containing a closed case, a rotor, a stator core with windings. For the dehumidification of the air in the cavity of the machine body absorber absorber is placed.

The disadvantages of this electric machine are as follows:

- during operation, the desiccant is impregnated with moisture. For example, drying of silica gel requires purging with dry air at a temperature of 150 ° C for 10-15 hours, such conditions cannot be created in an electric machine, therefore, if excessively wetted, a full replacement of the contents of the container is required;

- replacement of silica gel in the container requires a complete disassembly of the electric machine, which is not convenient during operation;

- after switching on and heating the machine, the desiccant is partially dried and the moisture evaporated from it goes into a gaseous state, which when cooled again drops out in the form of condensate to the insulation of the windings, reducing their reliability;

- the process of moisture absorption by the desiccant is slowed down due to the limited area of contact between the humid air inside the machine and the desiccant in the cavity of the shaft through the holes in the shaft.

Known electrical machine (RU 2476974, published 02.27.2013) containing a closed housing, a rotor, a stator with a winding and a container with a desiccant made in the form of a tube filled with desiccant, which is connected to a through hole in the stator housing at the end. The container is located in the cavity between the housing, the frontal parts of the stator winding and the end of the core.

The disadvantage of this electric machine is:

- the container is installed in a hard-to-reach place, namely in the cavity between the case, the frontal parts of the stator winding and the core butt, therefore it is possible to install the container only during the manufacture or overhaul of the electric machine;

- it is impossible to replace the container during the operation of the electric machine;

- the complexity of the manufacture of the container in the form of an arc.

A known electric machine (RU 2623105, published 06/22/2017) containing a closed housing, a rotor with a shaft, in the cavity of which a container with a desiccant is placed, made in the form of a straight tube located in an axial non-through hole at the end of the shaft, a dust filter is located at the end of the tube In the radial direction, the container has openings closed by an air-permeable mesh that coincides with the radial openings of the shaft of the electric machine.

The disadvantages of this machine are:

- the axial hole is located only on one side of the shaft, so the aerodynamic resistance in the path of air flow through the dust filter, the desiccant is not low enough;

- in case of replacement of the desiccant, it is not convenient to get it from the closed axial bore on the shaft;

- the container is inconvenient in operation, as it is necessary to combine the radial holes in the container closed with an air-permeable mesh and the radial holes of the shaft, fix it so that it does not rotate.

The technical result is to reduce the aerodynamic drag by half in the path of air movement in the path of the dust filter, desiccant, radial holes, since the holes are made on both sides of the shaft, or the through hole. Simplifies operation and maintenance when replacing a desiccant:

- it becomes convenient to remove the spent desiccant from the through-hole;

- when filling the cavity of the shaft there is no need to combine the radial holes in the container closed with a breathable mesh and the radial holes of the shaft, fix it so that it does not rotate.

This is achieved by the fact that in an electric machine that contains a closed case, a rotor and a desiccant with a dust filter and radial holes placed in an axial hole at the shaft end, the axial hole is made through or partly at two ends of the shaft for a part of its length, and the size of the radial holes of the shaft smaller particle size of desiccant.

The drawing shows an electric machine in section with two non-through holes (Fig. 1), an electric machine in section with a through hole (Fig. 2).

The electric machine contains a closed housing 1, bearing shields 2, rotor 3, shaft 4, radial holes of shaft 5, axial blind hole of shaft 6 filled with desiccant 7, fan casing 8, dust filter 9. Silica gel, alumogel, zeolite can be used as desiccant or other desiccants.

The electric machine works as follows.

From the ends of the shaft 4 of the rotor 3 of the electric machine, an axial blind hole 6 (FIG. 1), or a through hole 6 (FIG. 2) and radial holes 5 on the shaft 4, connecting the axial hole 6 with the cavity of the closed housing 1 of the electric machine, are performed. A desiccant 7 is placed in the axial hole 6 of the shaft 4. At the ends of the shaft 4, the axial openings 6 are closed by a dust filter 9. The size of the radial holes of the shaft 5 is smaller than the size of the desiccant particles, so the desiccant particles cannot penetrate through the radial openings of the shaft 5. the air is heated and cooled in the cavity of the closed housing 1 of the electric machine. When this occurs, the pressure difference between the cavity of the closed housing 1 of the electric machine and the atmosphere. Aerodynamic resistance of dust filter 9, axial bore 6 with desiccant 7, radial bores 5 less than aerodynamic resistance of gaps in bearing shields 2. Damp dusty air outside the electric machine when the electric machine cools through dust filter 9, axial bore 6 with desiccant 7, radial holes 5 of the shaft 4 into the cavity of the closed housing 1 of the electric machine and at the same time it is dried and dust free. When the electric machine is heated, air escapes from the cavity of the closed body 1 of the electric machine through the radial holes 5 of the shaft 4, the axial hole of the shaft 6 with a desiccant 7 and the dust filter 9 into the atmosphere drying the desiccant 7. For complete desiccation of the desiccant, for example, silica gel, it must be blown hot air at temperatures above 150 ° C for 10 hours. Such conditions in a closed housing 1 electric machine can not occur, therefore, over time, the desiccant becomes saturated with moisture. Therefore, if the axial bore of the shaft 6 with the desiccant 7 is excessively wetted or contaminated, the desiccant 7 and the dust filter 9 are removed and replaced with a new one. Clearing the axial through hole 6 (figure 2) and removing the desiccant 7 is possible by applying compressed air from one of the ends of the shaft 4, or by any rod having a radial size smaller than the diameter of the through hole 6.

Thus, compared with the prototype, the inventive electric machine more effectively dries and dedust the air that enters the cavity of the closed case of the machine, since the aerodynamic drag in the air path is two times less. The operation of the electric machine is simplified, as it becomes easier to replace the desiccant.

Claims (3)

1. An electric machine comprising a closed case, a rotor and a desiccant with a dust filter and radial holes placed in an axial bore at the shaft end, characterized in that axial bores containing a desiccant are made on both sides of the shaft. 2. Electrical machine under item 1, characterized in that the axial hole is made through. 3. Electrical machine under item 1, characterized in that the size of the radial holes of the shaft is smaller than the particle size of the desiccant.

Images