RU2457599C2 - Electric machine - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: electric machine contains a stator (1), a rotor (2), an external blower (3), the stator core (1) assembled of electrotechnical steel sheets designed as having concentric projections (9) within the outer diameter zone with ventilation holes (10) therein. During the stator assembly each sequential sheet (group of sheets) of the stator core is tangentially shifted relative to the preceding sheet (group of sheets) by a distance of the pitch of ventilation holes (10) in the core sheets concentric projections (9). Envisaged in the structural element (6) for the stator support on the external blower (3) side are air-directing enclosures (14), ventilation holes (16) and windows (15) for cooling air passage.

EFFECT: electric machine cooling improvement.

2 cl, 3 dwg

Description

The invention relates to the field of electrical engineering.

Known electric machine, designed to work in an environment with a high dust content, the active elements of which - the windings and magnetic cores of the stator and rotor - are cooled by a constant volume of air, the circulation of which inside the electric machine is provided by an internal fan. The internal air, in turn, is cooled in the air cooler by the external air, which is purged through the air cooler by an external fan. The air cooler consists of alternating chambers, one of which (for example, odd) passes hot internal air, the other (even) is cold outside air (see, for example, A.E. Alekseev "Design of electrical machines", SEI, 1958 ., p. 63, fig. 2-42).

A closed electric blower machine, adopted for the prototype, is also known with a more efficient tubular air cooler, in which the external air is blown through the cooler tubes by the external fan, and the internal hot air moves across the cooler tubes (see the mentioned monograph, p. 65, Fig. 2-46) .

A common drawback of these electric machines with air coolers is the relatively low cooling efficiency, greater consumption of materials and labor costs for manufacturing.

The main task that the invention solves is a significant increase in the cooling efficiency of an electric machine while reducing both the consumption of materials and labor costs for its manufacture.

The technical result is achieved by the fact that in an electric machine containing a rotor, a stator, the magnetic core of which is assembled from sheets made of sheet steel with grooves in the area of the inner diameter for the stator winding, an external fan, structural elements that support the stator and the entire electric machine as well as air guide casings, sheets of the magnetically conductive stator core in the area of the outer diameter are made with four concentric protrusions, which are provided in ventilation holes with a pitch along the circumference of the arrangement, a multiple of the pitch along the grooves for the stator winding, each subsequent sheet of the stator core or each subsequent group of sheets of the stator core during assembly of the core is tangentially shifted relative to the previous sheet or relative to the previous group of sheets by the size of the step along the ventilation holes in the concentric protrusions sheets, and in the structural element supporting the stator and the entire electric machine, air is provided on the side of the external fan honapravlyayuschie cubicle, air vents and windows for the cooling air passage connecting the air outlet area of the external fan with ventilation holes in the end face of the stator core.

In the electric machine, on the side of the working end of the shaft, air guide baffles, ventilation holes and windows for the exit of cooling air are made, which coincide in the structural elements that support the stator and the entire electric machine on the side of the external fan.

The proposed design is illustrated by drawings, where are schematically shown in:

figure 1 is a longitudinal section of an electric machine;

figure 2 is a cross section A-A in figure 1 of the stator core (the rotor is conventionally not shown);

figure 3 is a view of E in figure 2 (scan) - the location of the concentric protrusions of the stator sheets on the outer surface of the stator core.

The closed electric blown machine contains a stator 1, a rotor 2, an external fan 3 at the free end of the rotor shaft 2, a fan casing 4, bearing shields 5, structural elements 6 and 7, which support the stator 1 and the entire electric machine. The sheets of the stator core 1 are made of thin-sheet electrotechnical steel in the inner diameter zone with grooves for stator winding, with an outer diameter of 8 and concentric protrusions 9, in which ventilation holes are provided 10. The value of the outer diameter 8 from the point of view of the most economical use of electrical steel is determined by the width of the workpiece sheet (roll) of electrical steel. The number of concentric protrusions 9 of the stator core sheet 1 is four.

In the process of assembling the stator core 1, each subsequent sheet (or each subsequent group of sheets) is tangentially shifted (shifted), for example, always in one direction relative to the previous sheet (or previous group of sheets) by one ventilation hole. Moreover, on the outer surface of the stator core 1, spiral projections 11 with axial ventilation ducts 12 are formed on concentric protrusions on the core sheets, and spiral ventilation ducts 13 are formed between the protrusions 11. As a result, a very large cooled surface of the stator core 1 is formed. If necessary, when stator core is assembled 1, a different order of the tangential displacement of subsequent sheets (groups of sheets) relative to the previous ones can be specified.

The cooling air of the environment (its movement is shown by arrows) from the external fan 3 through the channels formed in the supporting structural element 6 of the stator 1 and the electrical machine as a whole by baffles 14, windows 15 and ventilation openings 16, enters the axial ventilation ducts 12 and spiral ventilation ducts 13 and in the space between the stator core 1 and the casing 17, blowing around the entire outer surface of the stator core 1, passes, for example, into the upper part of the electric machine and is released into the environment s under the hood 18 in a limited sector of the space.

All losses in the core and stator winding 1 and partly in the core and rotor winding 2 losses are absorbed by this air. Only losses in the rotor 2, partly into the stator core 1, and partially into the environment through end structural elements, in particular through bearing shields 5.

The use of external air to remove the main losses directly from the surface of the stator core 1 puts the cooling efficiency of the proposed closed blown electric machine at the level of cooling efficiency of normal blown electric machines, and the greatly increased cooled surface significantly increases this efficiency, i.e. cooling of the proposed closed blown electric machine is more efficient than cooling a normal blown electric machine, and even more so of a prototype. At the same time, material consumption has been significantly reduced. no air coolers are needed and labor costs for the manufacture of an electric machine are significantly reduced.

The cooling of this closed blow-off electric machine can, if necessary, be further intensified by performing in the structural element 7 supporting the stator 1 and the electric machine, air guide baffles, ventilation openings and windows for cooling air outlet similar to baffles 14, windows 15 and ventilation holes 16 in feature 6.

Claims (2)

1. An electric machine containing a rotor, a stator, the magnetic core of which is assembled from sheets made of sheet steel with grooves in the area of the inner diameter for the stator winding, an external fan, structural elements that support the stator and the entire electric machine, as well as air guards characterized in that the sheets of the magnetically conductive core of the stator in the area of the outer diameter are made with four concentric protrusions, in which ventilation holes are provided with a step along the circumference of the arrangement, a multiple of the step along the grooves for the stator winding, each subsequent sheet of the stator core or each subsequent group of sheets of the stator core during assembly of the core is tangentially shifted relative to the previous sheet or relative to the previous group of sheets by the size of the step along the ventilation holes in the concentric protrusions of the sheets , and in the structural element that supports the stator and the entire electric machine on the side of the external fan, air guide burners are provided Odds, vents and windows for the passage of cooling air connecting the air outlet from the external fan with ventilation holes in the end face of the stator core. 2. The electric machine according to claim 1, characterized in that in the structural elements that support the stator and the entire electric machine on the side of the working end of the shaft, air guides, ventilation holes and windows for the exit of cooling air are made, which coincide in the structural elements that provide support the stator and the entire electric machine on the side of the external fan.

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