JPH11178295A - Rotating electric machine rotor - Google Patents

Abstract

(57) [Summary] (Corrected) [Problem] A rotating electric machine that is a large rolling machine and frequently rotates forward and backward has a problem in that reliability is low in mechanical strength. An end ring (3) is provided with a recess (dent) in a portion near a rotor bar (2) at a side end of a rotor core (1) side or at a position in contact with the rotor bar (2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor for a rotating electric machine, and more particularly to a rotor for a rotating electric machine having suitable mechanical performance for use in an induction motor for rolling.

[0002]

2. Description of the Related Art A conventional rotating electric machine rotor is disclosed in
As described in Japanese Patent No. 6060, in an end ring connected to the end of the rotor bar, in order to prevent eddy current from being generated in the end ring due to leakage magnetic flux generated at the end of the stator coil, the end ring is Several grooves are provided on the outer peripheral surface or the outer end surface.

In such a structure, as shown in FIGS. 3 to 5, broken lines generated in the rotor bar 2 and the end ring 3 due to heating of the connecting operation (brazing or welding) between the rotor bar 2 and the end ring 3. The deformation and residual stress indicated by, the deformation and centrifugal stress indicated by a two-dot chain line due to the centrifugal force of the rotating rotor bar 2 and the end ring 3, etc. At the boundary between the end ring 3 having a large sectional rigidity and the rotor bar 2 having a much smaller sectional rigidity due to a shock due to an excessive repetitive torque such as a large biting torque and an abnormal load torque, etc.
Due to the structure in which the sectional rigidity changes suddenly, there is a defect that the rotor bar 2 is cracked 4 or, in the worst case, cut off.

[0004]

SUMMARY OF THE INVENTION The above prior art is a large-sized rolling machine and a rotating electric machine that frequently rotates forward and backward.
There is a problem in that the reliability is low in terms of mechanical strength.

An object of the present invention is to solve the above problems and to provide a highly reliable rotor for a rotating electric machine.

[0006]

In order to achieve the above-mentioned object, in order to achieve the above-mentioned object, a concave portion is formed near a rotor bar at a side end of the end ring on a rotor core side or at a position in contact with the rotor bar.
Is provided. That is, the rotor bar 2 and the end ring 3 are deformed or heated by the connection bar (brazing or welding) between the rotor bar 2 and the end ring 3 due to the deformation and residual stress, and the centrifugal force during rotation. Rotor bar 2 and end ring 3 against the stress generated by the deformation and centrifugal stress of the reversing mill, large biting torque and excessive repetition torque in the reversible mill, and shock caused by abnormal load torque. By providing a recess in the end ring 3 at or near the contact point, the change in the cross-sectional rigidity of the rotor bar 2 and the end ring 3 is reduced as much as possible, so that stress relaxation is measured and cracks or It is designed to prevent cutting.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
This will be described with reference to FIG. The rotor bar 2 inserted into a plurality of slots provided on the outer periphery of the rotor core 1 is connected at both ends to an end ring 3 by brazing or welding. At the end face of the end ring 3 on the rotor core 1 side, the end ring 3 is in contact with the rotor bar 2 or a concave portion is provided in the vicinity thereof.

According to the present invention, the centrifugal stress generated in the end ring 1 and the rotor bar 2 due to the rotation of the rotor, the large biting torque due to the reversible rotation for driving the rolling mill, and other abnormal load torques are excessive. The stress caused by the shock of the repetitive torque can be gradually changed (decreased) by providing the recess,
By alleviating the stress at the boundary between the connecting portions of the rotor bar 2 and the end ring 3, cracks or cuts 4 generated in the rotor bar 2 can be prevented, and a rotor of a rotating electric machine with improved reliability can be provided. There is an effect that can be.

[0009]

According to the present invention, the stress concentration on the rotor bar is alleviated by gradually changing the cross-sectional rigidity at the boundary between the rotor bar and the end ring connecting portion, and the crack or cut of the rotor bar is reduced. Loss can be prevented.

[0010] In connection work (brazing or welding) between the rotor bar and the end ring, the preheating work is short.
The temperature is also made uniform, and there is an effect that it is possible to prevent a heating deformation in a connection operation (brazing or welding), reduce a residual stress, and provide a rotor of a rotating electric machine with improved reliability.

[Brief description of the drawings]

1A and 1B are a cross-sectional view and a partial cross-sectional view showing a connection state of a rotor bar and an end ring in a rotor of a rotary electric machine according to an embodiment of the present invention.

FIGS. 2A and 2B are a partial sectional view and a partial side sectional view showing another embodiment of the present invention.

FIG. 3 is a partial cross-sectional view illustrating the operation of a rotor bar and an end ring.

FIG. 4 is a partial side view showing the operation of FIG. 3;

5 (a) and 5 (b) are cross-sectional views of a main part of a conventional rotor.

[Explanation of symbols]

1 ... rotor core, 2 ... rotor bar, 3 ... end ring,
4: Crack or cut.

Claims (2)

[Claims] 1. A rotating electric machine, wherein rotor bars are directly inserted into axial slots provided on an outer peripheral portion of a laminated rotor core, both ends of which protrude from the rotor core, and are connected by end rings. A rotor for a rotating electric machine, wherein a dent portion is provided at a side end of the end ring on the rotor core side of the end ring. 2. The rotor for a rotary electric machine according to claim 1, wherein the dent portion is provided in contact with the rotor bar or in the vicinity of the rotor bar.