RU2629963C1 - Electrical machine - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: in an electric machine containing a stator, a rotor and a desiccant container disposed in a hermetically sealed housing having an air pressure equalizing unit inside and outside the housing, the pressure equalization unit is designed as an elastic corrugated membrane.

EFFECT: increasing the efficiency of protecting the electric machine from dust and moisture.

1 dwg

Description

The invention relates to electrical engineering and can be used to protect the insulation of electrical machines operating in conditions of high humidity and dust environment.

Known electric machine [1], containing a hermetically sealed housing with a rotor and a stator located in it and made in the form of a tube node for balancing air pressures inside and outside the machine. The tube connects the machine body with the surrounding air, it contains a container with a desiccant of absorption action, an air-permeable cap is installed on one end of it, and a dust filter is located on the other.

When the electric machine is heated, the air expands through the tube into the surrounding space, and when cooled, the outside air is sucked through the tube back into the body cavity. In this case, it is partially cleaned and drained.

The disadvantage of this electric machine is that, firstly, the desiccant and filter cannot, in principle, provide a 100% degree of purification of air from dust and moisture, so some of them nevertheless pass through the tube and accumulate in the cavity of the housing. Secondly, due to the high hydraulic resistance of the filter and the tube filled with desiccant during the cooling period of the machine, the pressure in the housing will be lower than atmospheric and humid air with dust will be sucked into the housing through shaft seals and bearing shields. All this reduces the effectiveness of protecting the electric machine from dust and moisture.

The objective of the invention is to increase the efficiency of protecting an electric machine from dust and moisture.

The technical result is achieved due to the fact that in an electric machine containing a stator, a rotor and a container with a desiccant, placed in a hermetically sealed enclosure having a unit for balancing air pressures inside and outside the box and restricting dust and moisture from entering through it in the box, a unit for balancing pressures and limiting the ingress of dust and moisture through the casing of the machine through it into the form of an elastic corrugated membrane installed between the cavity of the casing and the environment.

The essence of the invention is illustrated in the drawing.

The electric machine comprises a housing 1, bearing shields 2, a bearing 3, a stator, a rotor and a container with a desiccant (not shown), seals of the bearing shields 4 and shaft 5. A corrugated membrane 6, which performs the function of balancing the pressure inside and outside the housing cavity, is located in the protective casing 7 and separates the cavity of the machine body 8 and the environment. The membrane may also have another design, providing its free movement in the required range.

When the electric machine is running under load, the air in the cavity of the housing 1 is heated, expanded and moves the membrane 6 to the left. Since the membrane is not spring-loaded, its movement is carried out at an excess air pressure in the housing practically equal to zero.

In the disconnected state, the air inside the housing, cooling and decreasing the volume, moves the membrane to the right also at a pressure slightly different from atmospheric pressure. As a result, the absorption of humidified and dusty air from the environment through the shaft seals and bearing shields into the body cavity is eliminated. The ingress of air through the pressure equalization device is also completely eliminated due to the impermeability of the membrane.

All this ultimately increases the effectiveness of protecting the electric machine from moisture and dust contained in the air surrounding the machine.

Information sources

1. RF patent No. 2476974 publ. 02/27/2013

Claims (1)

An electric machine comprising a stator, a rotor and a desiccant container, housed in a hermetically sealed enclosure having a unit for balancing air pressures inside and outside the enclosure and restricting dust and moisture to enter through the enclosure, characterized in that the unit for balancing the pressures and restricting ingress through it dust and moisture in the machine body are made in the form of an elastic corrugated membrane installed between the body cavity and the environment.

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