RU2623105C1 - Electrical machine - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: in an electrical machine containing a closed housing and a rotor with a shaft, a container with a desiccant, arranged as a straight tube located in an axial blind hole from the end of the shaft, is placed in the cavity of the housing. At the end of the tube, there is a dust filter. In the radial direction, the container has openings closed by an air permeable mesh, which coincide with the radial holes of the shaft of the electric machine.

EFFECT: simplification of the technology of manufacturing and installation of the container in the casing, simplification of maintenance of the container during operation.

2 cl, 1 dwg

Description

The invention relates to electrical engineering and can be used in all types of enclosed electrical machines operating in ambient conditions with high relative humidity and dust.

Known electric machine ("Design of electrical machines" - edited by IP Kopylov. M .: "Energy", 1980, p. 155), containing a closed housing with bearing shields, inside of which are placed a stator core with a winding and a rotor, mounted on bearings.

The disadvantage of an electric machine containing a closed housing with bearing shields, inside which a stator with a winding and a rotor mounted on bearings are placed, is that when heating and cooling the electric machine there is a difference in air pressure between the internal cavity of the electric machine and the atmosphere, and wet, dusty air is drawn in through the clearances in the bearing shields inside the electric machine. The ingress of dust and moisture into the bearings and on the stator winding of the electric machine leads to wear and lower reliability of the bearings and insulation of the stator winding.

Known electric machine (AS No. 1163423, published 06/23/1985), containing a closed housing, rotor, stator core with windings. To dehumidify air, a container is placed in the cavity of the machine body, for example, with silica gel impregnated with calcium chloride.

The disadvantages of this electric machine is as follows:

- during operation, the desiccant is impregnated with moisture. For example, to dry silica gel, it is necessary to purge it with dry air at a temperature of 150 ° C for 10-15 hours, such conditions in an electric machine cannot be created, therefore, with excessive moisture, a complete replacement of the contents of the container is required;

- replacement of the desiccant in the container requires complete disassembly of the electric machine, which is inconvenient during operation;

- after turning on and heating the machine, the desiccant is partially dried, and the moisture evaporated from it passes into a gaseous state, which, when cooled, again falls as a 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 contact area between the moist air inside the machine and the desiccant in the shaft cavity through the openings in the shaft.

A known electric machine (RU 2476974, published 02.27.2013) containing a closed housing, a rotor, a stator with a winding and a container with a desiccant located in the cavity of the housing, made in the form of a tube filled with a desiccant, which is connected at one end to a through hole in the stator housing. 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 housing, the frontal parts of the stator winding and the end of the core, therefore it is possible to install the container only during the manufacture or overhaul of an electric machine;

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

- the complexity of manufacturing a container in the form of an arc.

The technical result is to simplify the manufacturing technology and installation of the container in the housing, as well as simplify maintenance of the container during operation.

This is achieved by the fact that in an electric machine containing a closed housing, a rotor with a shaft, a container with a desiccant is placed in the cavity of the housing, made in the form of a straight tube located in an axial through hole from the shaft end, a dust filter is located at the end of the tube, in the radial direction the container has openings covered with a breathable mesh, matching the radial openings of the shaft of the electric machine.

The drawing shows an electric machine in section.

The electric machine contains a closed housing 1, bearing shields 2, rotor 3, shaft 4, radial holes of the shaft 5, axial through hole of the shaft 6, breathable mesh 7, tube (container) 8 filled with desiccant 9, dust filter 10, fan casing 11. Silica gel, aluminum gel, zeolite or other desiccants can be used as a desiccant.

The electric machine operates as follows.

From the end of the shaft 4 of the rotor 3 of the electric machine, an axial through hole 6 is made equal to the outer diameter of the container 8 and the radial holes 5 on the shaft 4 connecting the axial hole 6 with the cavity of the closed housing 1 of the electric machine. A container 8 is inserted into the axial hole 6 of the shaft 4. The container 8 is made in the form of a straight tube filled with a desiccant 9, on the one hand covered with a dust filter 10, and on the other hand with radial holes closed by a breathable mesh 7. Radial openings of the container 8, closed by a breathable grid 7, coincide with the radial holes 5 on the shaft 4. When you turn on and off the electric machine, heating and cooling of air 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. The aerodynamic resistance of the dust filter 10, container 8 with desiccant 9, breathable nets 7 and radial holes 5 is less than the aerodynamic resistance of the gaps in the bearing shields 2. Wet, dusty air outside the electrical machine when cooling the electric machine passes through the dust filter 10, container 8 with desiccant 9, breathable mesh 7, radial holes 5 of the shaft 4 into the cavity of the closed housing 1 of the electric machine and is dried and dust free. When the electric machine is heated, air leaves the cavity of the closed casing 1 of the electric machine through the radial holes 5 of the shaft 4, the breathable mesh 7, the container 8 with a desiccant 9 and a dust filter 10 into the atmosphere, draining the desiccant 9. To completely dehumidify a desiccant, for example silica gel, it is necessary blow with hot air at temperatures above 150 ° C for 10 hours. Such conditions in a closed housing 1 of an electric machine cannot occur, therefore, over time, the desiccant is saturated with moisture. Therefore, if the container 8 with the desiccant 9 is excessively humidified or contaminated, the container 8 is removed and replaced with a new one or only the contents of the container and the dust filter 10 are replaced. To change the container, it is not necessary to completely disassemble the electric machine, just remove the fan casing 11, remove the container 8 from the axial hole 6 shaft 4 and insert a new container 8.

Thus, in comparison with the prototype, the claimed electric machine allows you to install a container with a desiccant in the cavity of the manufactured electric machine, not only during the manufacture or overhaul of the electric machine, but also to replace the container or contents of the container during operation without dismantling the body of the electric machine.

Claims (2)

1. An electric machine comprising a closed housing, a rotor with a shaft and a container with a desiccant located in the cavity of the housing, made in the form of a tube, at the end of which there is a dust filter, characterized in that the container is made in the form of a straight tube located in an axial through hole with shaft end. 2. The electric machine according to claim 1, characterized in that in the radial direction the container has openings closed by an air-permeable mesh matching the radial openings of the shaft of the electric machine.

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