JPH09121517A - Rotor for electric equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the breakage of the tooth section of an end plate and scattering of fragments by stress concentration even when the end plate is formed of a low-strength material by arranging a high-rigidity end plate retainer composed of a nonmagnetic material between an end plate and a core retainer so that the end plate retainer can overlap the tooth section. SOLUTION: An end plate retainer 6 is shaped so that the retainer 6 can come into contact with the outer peripheral surface of a tooth section 2a with a wide area and the stresses concentrated to the root of the tooth section 2a of an end plate 2 due to a core retainer 4 can be dispersed over a wide extent. The retainer 6 is formed of a nonmagnetic material, such as the stainless steel, etc., so as to prevent the occurrence of an eddy current loss. When the retainer 6 is formed of the nonmagnetic material, the concentrated stresses do not act directly to the root of the tooth section 2a of the end plate 2, but are absorbed and dispersed by the retainer 6, even when the end plate 2 is made of a material having a low strength and high permeability. Therefore, such a risk that the section 2a is broken from its root when a rotor is rotated at a high speed is eliminated and a stator, etc., are not damaged by scattered fragments.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor for electric equipment, and more particularly to a rotor suitable for use in a rotating machine that rotates at high speed, such as an electric motor for a railway vehicle or a generator. In particular, the present invention relates to a rotor structure having end plates made of a fragile material such as a high-permeability iron core containing cobalt at both axial ends of the iron core.

[0002]

2. Description of the Related Art A conventional squirrel-cage rotor used in an induction motor is shown in FIG. 3A is a front view,
FIG. 3B is a side view. In these figures, 1 is an iron core, 2 is an end plate made of a high magnetic permeability material containing an iron-cobalt alloy, 3 is a conductor, 4 is an iron core holder, and 5 is a rotor shaft.

In the above structure, since the iron core 1 is pressed and laminated, the reaction force in the axial direction is always applied after the lamination. In order to prevent the iron core 1 from opening in the axial direction by this reaction force, both axial end portions of the iron core 1 are pressed by the iron core presser 4 via the end plates 2. However, as shown in FIG. 4, since the conductor 3 is inserted into the slot 1a of the iron core 1, the iron core retainer 4 can retain the iron core 1 only up to the roots of the teeth of the iron core 1 (portions on both sides of the slot 1). Can not.

Therefore, as shown in FIG. 5, the vicinity of the outer peripheral portion of the iron core retainer 4 is locally pressurized, and stress concentration due to the reaction force occurs at the root p of the slot 1 or the root of the tooth. Normally, end plates 2 are inserted at both axial ends of the iron core 1 in order to prevent the teeth of the iron core 1 from opening and to relieve the stress generated at the root of the teeth by the iron core retainer 4. .

[0005]

Since the end plate 2 is a part of a magnetic circuit, a high permeability material such as an iron-cobalt alloy is used, and a rolled steel plate or a rolled steel plate is used for the purpose of preventing eddy current. It uses several thin plates of core material that are spot-welded and integrated. Therefore, the rigidity of the end plate 2 is generally lower than that of a thick plate having the same thickness, and although it has an effect of preventing the tooth portion of the iron core 1 from opening, it is not sufficient to prevent stress concentration at the tooth root. there were.

That is, in the above-mentioned prior art, there is no particular problem when the rotor rotates at a low speed or when the material of the end plate 2 has sufficient strength. However, when the tensile stress due to the high speed rotation of the rotor is large or the material of the end plate 2 is brittle, the end plate 2 is broken from the root of its tooth portion due to stress concentration, and this scatters to disperse the stator coil. Damage to the insulation may result in a serious accident.

The present invention has been made to solve the above problems, and its object is to prevent breakage and scattering of teeth due to stress concentration even when the end plates are made of a magnetic material that is fragile in terms of strength. An object is to provide a rotor for electric equipment that can be prevented.

[0008]

In order to achieve the above object, the invention according to claim 1 is characterized in that an end plate made of a magnetic material having teeth is fixed to both axial ends of an iron core having teeth. In the rotor for electric equipment in which the iron core retainer is fixed to the outside thereof, between the end plate and the iron core retainer, a highly rigid end plate retainer made of a non-magnetic material is formed so as to overlap with the teeth of the end plate. It is arranged.

According to a second aspect of the present invention, in the above rotor for electric equipment, the end plate retainer connects a plurality of tooth parts that overlap with the tooth parts of the end plate, and And a connecting portion that overlaps with the iron core retainer.

In the present invention, the stress caused by pressing the iron core at the root of the tooth portion of the end plate is absorbed and dispersed by the end plate pressing and applied to the end plate, and is not directly applied to the root of the tooth portion. Therefore, the teeth of the end plate are not broken from the root when the rotor rotates at high speed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional technique are designated by the same reference numerals, and detailed description thereof will be omitted. Below, different parts will be mainly described. 1 shows an embodiment in which the present invention is applied to a squirrel-cage rotor of an induction motor.
1A is a front view, and FIG. 1B is a side view.

In these drawings, reference numeral 6 designates an end plate retainer, and this end plate retainer 6 is formed of a thick plate having a high rigidity made of a non-magnetic material such as stainless steel. The front shape of the end plate retainer 6 is completely the same as that of the end plate 2, or, as shown in FIG. 2, has a tooth portion 6a having a height slightly lower than the tooth portion 2a of the end plate 2. In addition, in FIG. 1B and FIG. 2, 6b is a connecting portion that connects a plurality of tooth portions 6a to each other, and this connecting portion 6b overlaps with the iron core retainer 4, and the tooth portion 6a is a tooth of the end plate 2. It is superposed on the part 2a.

The shape of the end plate retainer 6 is the core retainer 4
Therefore, it is desirable that the shape is such that the stress concentrated on the roots of the tooth portions 2a of the end plate 2 is dispersed in a wide range so as to come into contact with the outer peripheral surface of the tooth portions 2a over a wide area. Here, the end plate holder 6 needs to be formed of a non-magnetic material so as not to cause an eddy current loss, and the material is not limited to metal and may be hard plastic or the like.

The end plate retainer 6 is attached to the outside of the end plate 2 at both axial end portions of the iron core 1, and the iron core retainer 4 is fixed to the outside thereof.

With this structure, even when a brittle high-permeability material is used for the end plate 2, the stress concentration at the point p shown in FIG. 1 (b) is absorbed and dispersed by the end plate retainer 6, It is not directly applied to the root of the tooth portion 2a of the end plate 2. Therefore, even when the rotor rotates at high speed, there is no risk of the tooth portion 2a being broken from its root, and there is no risk of damage to the stator or the like due to scattering of chips.

According to the present invention, not only the squirrel-cage rotor of an induction motor, but also a rotor having an iron core having teeth and an end plate and having a structure in which these are fixed from the outside by an iron core retainer It can also be applied to machine rotors.

[0017]

As described above, according to the present invention, the end plate holder arranged between the iron core holder and the end plate can prevent breakage of the tooth portion of the end plate before the tooth portion is broken. It is possible to realize a highly reliable rotor by preventing various accidents due to the scattering of. Further, the structure of the end plate holder itself is extremely simple, and the manufacturing cost and the assembly cost are low, which is economical.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention (FIG.
It is (a)) and a side view (FIG.1 (b)).

FIG. 2 is a perspective view showing in detail an A portion in FIG.

FIG. 3 is a front view (FIG. 3A) and a side view (FIG. 3B) showing a conventional technique.

FIG. 4 is a perspective view showing in detail a B portion in FIG.

FIG. 5 is an explanatory diagram of a problem of the related art.

[Explanation of symbols]

 1 iron core 1a slot 2 end plate 2a tooth portion 3 conductor 4 iron core retainer 5 rotor shaft 6 end plate retainer 6a tooth portion 6b connecting portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Shibano 1-1, Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Electric Co., Ltd.

Claims (2)

[Claims] 1. A rotor for an electric device, wherein end plates of a magnetic material having teeth are fixed to axially opposite ends of an iron core having teeth, and iron core retainers are fixed to the outer sides of the end plates. A rotor for electric equipment, characterized in that a highly rigid end plate retainer made of a non-magnetic material is arranged between the plate and the iron core retainer so as to overlap with a tooth portion of the end plate. 2. The rotor for an electric device according to claim 1, wherein the end plate retainer connects a plurality of tooth portions overlapping with the tooth portions of the end plate, and these tooth portions are connected to each other, and the iron core retainer is retained. A rotor for an electric device, comprising a connecting portion that overlaps.