SU1552297A1 - Squirrel-cage rotor of induction motor - Google Patents

Abstract

The invention relates to electrical engineering. The purpose of the invention is to increase reliability and simplify the design. The rotor contains laminated core 1, winding rods 3, counter wedges 5. Elastic rings 6 press rods 3 against the groove walls and are placed with a gap in the annular grooves of spacers 8. Elastic rings 6 prevent radial movement of the rods 3 during start-up and during operation. Rings 6 and gaskets 8 can be made of magnetized materials, which reduces their heating. The angle between the extensions of the lateral sides of the upper part of the rods can be at least 45 °, whereby the rings 6 will compensate for the tangential thermal expansions of the rods 3. 2 Cp. f-ly, 3 ill.

Description

figure 1

The invention relates to the field of electrical engineering, in particular to asynchronous motors, whose short-circuited windings are assembled from separate rods and short-circuiting rings.

The purpose of the invention is to increase reliability and simplify the design.

Figure 1 shows the rotor, a longitudinal section; figure 2 - node I in figure 1; on fig.Z - section A-Anafig.2

The core 1 of the rotor stocked from stamped sheets of electrical steel is placed on shaft 2. The rotor winding rods 3 in grooves A are fixed from the bottom of the grooves by counter wedges 5, and after the rotor has been manufactured, the counter wedges 5 rest on both the elastic rings 6 and the bottom of the grooves A. Elastic rings 6 are placed in annular grooves 7 spacers 8 with guaranteed clearances both in diameters and in the axial direction. When the rods 3 are fastened in the grooves A, the elastic rings 6 with opposite wedges 5 are deformed — their diameter is reduced from the initial one in the free state to the diameter along the bottom of the grooves 4 of the rotor core 1. Thus, the rods 3 from the side of the elastic rings 6 created a force action directed from the bottom of the grooves And

During the first start-up of the engine with the drive mechanism, the rotor winding rods 3 rigidly fixed in the grooves A (the counter wedges 5 lie on the bottom of the grooves A) do not move due to the electrodynamic and centrifugal forces in the grooves due to the absence of radial clearances, Rod 3 the start-up process, however, overheats, which leads to their plastic deformation, the magnitude of which for

1 of the rotor must be defined so that the forces on the rods 3, created by elastic rings 6 in the direction from the bottom of the grooves A, are not less than the values of electrodynamic forces acting in the process of direct engine starts on the rods 3 in the direction to the bottom of the grooves A. In this case, during all subsequent starts of the engine, the electrodynamic forces will not be able to move the rods 3 in the direction of the bottom of the grooves A. Thus, the vibration of the rods 3 in the grooves A

when the engine starts, and thus, the efficiency of the rotor winding is high.

When the rods are heated 3 R in subsequent engine starts, their increase

The radial dimensions are compensated by the additional deformation of the elastic rings 6. If the overheating of the rods 3 does not further exceed the initial values accepted as permissible, additional plastic deformations in the rods x 3 will not occur. When the rotor is cooled, after each successive switching on of the engine, the rods 3 of the rotor windings will still be pressed against the side walls of the slots A with elastic rings 6 due to the preservation of the residual deformation of these rings.

If necessary, to reduce losses and heating spacer 8 and elastic rings 6 can be made of non-magnetic, and gasket 8 of non-metallic materials. In the case of the use of the rotor of the proposed design in asynchronous motors for

Q especially heavy starts (with significant overheating of the rods during the start) the angle between the lateral sides at the tops of the rods in the cross section can be made equal to AB or more than 0

five

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The specific rotor is determined in these cases in the cases of elastic rings 6 by the basal geometry of the rods and the magnitude of their overheating per start, taken as permissible. After the rotor is cooled, the rods 3 in the grooves A do not receive radial freedom — the elastic rings 6 will be pressed against the side walls of the grooves A. In this case, the initial deformation of the elastic rings 6 will decrease by the amount of radial movement in the grooves A of the rods 3 after they acquire plastic deformation during start-up. engine The magnitude of this particular residual deformation of the rings 6 and the number of rings 6 on the core

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The tangential thermal expansion of the rods is also compensated.

The effect of the proposed rotor design is determined primarily by its simplicity, less laboriousness and increased reliability of the rotor winding rods, since in this case there is no need for a large number of punches for cutting elements of additional packages of the rotor core and the complex packages themselves are replaced. spacers, simplified production organization, decreases the likelihood

in these cases, elastic rings 6 are

The tangential thermal expansion of the rods is also compensated.

The effect of the proposed rotor design is determined primarily by its simplicity, less laboriousness and increasing the reliability of the rotor winding rods, since in this case there is no need for a large number of punches for cutting elements of additional rotor core packages and the complex packages themselves are replaced by simple spacers. production organization decreases the likelihood

errors in the assembly of the core, provided greater certainty in the work of elastic rings, the impact of which on the rods is realized without friction from pressing the core.

Claims (3)

1. A short-circuited rotor of an asynchronous motor, containing a core made of electrical steel sheets with grooves in which winding rods are mounted, fixed by wedges, and elastic elements placed along its length, characterized by T A J f Fig .2 that, in order to increase reliability and simplify the design, the elastic elements are made in the form of rings, spacers with annular grooves are installed between the core sheets, and the rings are located in annular grooves with a gap. 2. Rotor pop. 1, differing from the fact that remote gaskets and elastic rings made of non-magnetic materials. 3. A rotor according to claims 1 and 2, characterized in that the angle between the 5 DNs and the extensions of the lateral sides of the upper part of the rods in the transverse settlement is not less than 45 °.  Aa Fi.Z