UA12723U - Rotor of an electric machine with axial ventilation - Google Patents

Abstract

The proposed rotor of an electric machine with axial ventilation contains a magnetic core, a rotor winding, and axial ventilation channels. The ventilation channels are arranged between the slots of the rotor winding. The number of the channels may differ from the number of the slots.

Description

Description of the invention

The useful model refers to electrical engineering, in particular, to asynchronous electric motors. 2 A well-known rotor with axial ventilation of an asynchronous electric motor, in which the winding of short-circuited rods is located in grooves with expansion in the middle part. The free space between the surfaces of the rods and the inner surfaces of the grooves performs the function of axial channels |11).

However, the disadvantage of this design is additional loading of the most used part of the magnetic circuit. Expanding and deepening the groove to accommodate not only the rods, but also the axial 70 channels, will lead to an additional increase in the induction in the rotor tooth and yoke, which will worsen the energy characteristics of the engine. The inductive resistance of the widened and deepened groove will increase, accordingly - the power factor will decrease.

Filling part of the groove on the side of the yoke with air will create a large resistance to the magnetic flux and will make it possible to squeeze out the current intensively at start-up and maximum load, that is, the multiplicity of starting and maximum 72 moments will be low.

The rod is inside the axial channel, therefore, in the start-up mode, when the rods are heated strongly, the air inside the grooves will also heat up, and due to its low thermal conductivity, heat transfer from the rod to the metal-intensive parts of the electric motor will be difficult.

The proposed useful model is designed to solve the problem of creating such a design of the rotor with axial ventilation of the electric machine, in which, thanks to the new solution, the removal of heat from the rotor will improve. When implementing the proposed useful model, a technical result can be obtained - an improvement in the energy characteristics of the engine and, accordingly, an increase in the power factor, an improvement in the temperature state of the rotor, and a simplification of the design of the electric machine.

For this purpose, in the well-known rotor with axial ventilation of an electric machine, which contains a shaft, magnet wire, winding and axial ventilation ducts, it is proposed to make axial ventilation ducts in the magnetic duct of the rotor in the form of holes in the border zone of the rotor with the shaft and to place between the axes of the grooves in which the winding is placed, while the number of axial ventilation channels may or may not coincide with the number of grooves.

Thus, what is new in the technical solution that is claimed is that the axial ventilation channels are made in the magnetic field of the rotor in the form of holes in the zone bordering the rotor shaft and are located between the axes of the grooves in which the winding is located, while the number of axial ventilation channels may or may not coincide with the number of grooves. -

The proposed distinguishing features allow to improve the energy characteristics of the engine and, accordingly, to increase the power factor, improve the temperature state of the rotor, and simplify the overall design of the electric machine. --

The listed features, different from the prototype, are necessary and sufficient in all cases that are covered by the scope of legal protection of the used utility model.

In addition, the holes in the sheets of the magnetic circuit can have a round shape or the shape of segments with an increased arc-shaped side in the direction of the grooves. With 50 The phenomenon of uneven distribution of magnetic flux in the yoke is used to reduce magnetic losses in steel: for this purpose, holes are located on the rotor sheet in sectors with weakened magnetic flux. z» The proposed useful model is explained by drawings: - Fig. 1 shows a longitudinal section of the rotor of an electric machine; - Fig. 2 shows a cross-section of the rotor of an electric machine; - Figure 3 shows the paths of the magnetic flux in the rotor yoke with the new location of the ventilation holes; ka - in Fig. 4 shows the shape of the ventilation holes, which is recommended.

The rotor contains a shaft 1, a magnetic core 2, in the grooves of which the rotor winding is located. For an asynchronous 7 electric motor with a short-circuited rotor, the winding is made of rods 4 of conductive materials, such as aluminum, copper or brass.

The rods 4 at the exit from the magnetic conductor 2 are connected to the short-circuited ring 5. In the boundary zone c» of the magnetic conductor 2 with the shaft 1, holes b are made in the sheets of the magnetic conductor, which carry the function of axial ventilation channels. The holes would be located on equal-sized areas 8 between the axes of 7 grooves 3. The number of axial ventilation channels depends on the required intensity of rotor cooling and the degree of saturation of its yoke with magnetic flux. c To increase the cross-sectional area of the holes b, they can be made round or in the form of segments directed by the wide arcuate side 9 to the side of the grooves C with rods 4.

When the rotor rotates, the refrigerant that fills the internal cavity of the electric machine and passes through the axial ventilation channels formed by the ventilation holes 6 in the sheets of the magnetic circuit 2, removes 60% of the heat, thereby improving the temperature of the rotor.

In order to equalize the magnetic flux in the teeth between the ventilation channels, the authors suggest maintaining the following ratio of hole sizes 6: а/ю-142 ХП, where а is the width of the opening along the upper base, mm; bo b - the width of the opening along the lower base, mm;

yo - height of the ventilation channel, mm;

Or - boring diameter, mm.

Among the advantages of the proposed design of the rotor, the following can be attributed: - an increase in the perimeter of the ventilation holes on the side of the winding leads to an increase in the cooling area; - the alignment of the magnetic flux in the teeth between the ventilation holes leads to a reduction in eddy current losses, hysteresis, pulsation losses in this zone; - the depth of penetration of the magnetic flux into the shaft will increase by approximately 2595, due to the use of the reserves of the shaft to close the weakened magnetic flux along it; 70 - cooling of the magnet wire and the shaft occurs directly by the flow of refrigerant passing through the ventilation channels.

In general, the proposed design of the rotor with axial ventilation of the electric machine is simple and technological, because it allows you to obtain ventilation axial channels in the magnetoconductor of the rotor during stamping of its sheets.

Sources of information: 1. Author's certificate of the USSR Mo714577, НО2КЗ/24, 1978Г.

Claims (2)

The formula of the invention , , . what, , , and 1. A rotor with axial ventilation of an electric machine, which contains a shaft, a magnet wire, a winding and axial ventilation channels, which is characterized by the fact that the axial ventilation channels are made in the magnet wire of the rotor in the form of holes in the border zone of the rotor with the shaft and are located between the axes of the grooves in which the winding is placed, while the number of axial ventilation channels may or may not coincide with the number of grooves. 2. A rotor with axial ventilation of an electric machine, according to claim 1, which differs in that the holes in the magnetic circuit sheets can have a round shape or the shape of segments with an enlarged arcuate side in the direction of the grooves. (ze) s u s e - and? - ime) -and ime) syu" 60 b5