JPH06165451A - Squirrel cage induction motor - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a squirrel-cage induction motor, and an object thereof is to increase the maximum number of revolutions of the end ring and to minimize the decrease in efficiency. It is to provide a squirrel cage induction motor. [Structure] A material having strength against stress due to centrifugal force, such as aluminum, is used for the end ring 7, and a material having low electric resistance, such as copper, is used for the conductor rod 8 surrounded by the silicon steel plate 9. To do.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squirrel cage induction motor.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional example of a squirrel cage induction motor. The motor is surrounded on the outside by a housing 1 and an end bracket 2, and a rotor 5 is supported by a bearing 3. Further, the rotor is composed of a silicon steel plate 9 which is a magnetic material, a conductor rod 8 surrounded by the silicon steel plate 9 and an end ring 7 on the silicon steel plate 9, which is a conventional squirrel cage induction motor. The conductor rod 8 and the end ring 7 are mainly integrally formed by die casting, and the conductor rod 8 and the end ring 7 are made of the same material.

[0003]

Conventionally, the conductor rod and the end ring are made of the same material having low electric resistance in order to improve the motor characteristics, and the end ring part not surrounded by the silicon steel plate is There was a problem that the allowable stress was low and the rotation speed could not be increased. An object of the present invention is to solve the above problems and to provide a squirrel cage induction motor capable of increasing the maximum rotation speed.

[0004]

The above object is achieved by using a material for the end ring which has a high allowable stress against centrifugal force.

[0005]

By taking the above-mentioned means, the strength of the end ring is improved, so that the maximum rotation speed of the squirrel cage induction motor can be set high.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a longitudinal sectional view of the rotor, and FIG. 2 is a top view of the rotor. In the present embodiment, the periphery is surrounded by a silicon steel plate, copper having a low electric resistance is used for the conductor rod 8 which is strong in strength, and the end ring 7 which is weak in strength and is not enclosed in the periphery is shown in FIG. As shown in, by using aluminum, which has a higher specific strength than copper, the allowable stress against the centrifugal force during motor rotation was increased, and it was possible to increase the maximum rotation speed.

Since the end ring 8 has less dimensional restrictions than the conductor rod 7, a sufficient cross-sectional area can be secured, and even if aluminum, which has a higher electric resistance than copper, is used, the reduction in efficiency is minimized. Can be suppressed to

As described above, according to this embodiment, since the strength of the end ring 7 can be improved, the rotation of the end ring 7 can be performed at a higher speed than the conventional one, and the reduction in efficiency can be minimized. A motor can be provided.

[0009]

According to the present invention, since the strength of the end ring can be improved, it is possible to provide a squirrel cage induction motor capable of increasing the maximum rotation speed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a rotor of a squirrel cage induction motor of the present invention.

2 is a top view of the rotor of FIG. 1. FIG.

FIG. 3 is a vertical sectional view of a conventional squirrel-cage induction motor.

FIG. 4 is a table showing specific strengths of copper and aluminum.

[Explanation of symbols]

1 is a housing, 2 is an end bracket, 4 is a stator, 5 is a rotor, 7 is an end ring, 8 is a conductor rod, and 9 is a silicon steel plate.

Claims (1)

[Claims] 1. In a squirrel cage induction motor in which a conductor rod and an end ring, which are secondary conductors of a rotor, are made of copper and rotate at a high speed, a material having a low electric resistance is used for the conductor rod of the rotor. A squirrel cage induction motor characterized by using a material having higher allowable stress against centrifugal force than the material of the conductor rod for the end ring.