JPH11206079A - Squirrel-cage rotor of induction motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the electric resistance of a secondary winding and enhance the efficiency of a motor, by uniformly kneading aluminum material for use in the secondary winding together with powdery or granular metal the electrical conductivity of which is higher than that of the aluminum material, and molding the mixture by die casting to form the squirrel-cage secondary winding. SOLUTION: A rotor core 1 comprises a core 1 and a squirrel-cage secondary winding 5 formed by molding aluminum material 4 in its rotor slots 3 by die casting. During die casting, powdery or granular metal the melting point of which is higher than that of aluminum material 4 and the electric conductivity of which is higher than the aluminum material, for example, copper powder 6 is kneaded together with the aluminum material 6 to form the squirrel-cage secondary winding 5. During molding the copper powder 6 in the aluminum material 4 is uniformly kneaded. In addition, the copper powder 6 is distributed to the end ring portion 7 of the squirrel-cage secondary winding 5. Therefore, the electric conductivity is enhanced. Moreover, by adjusting the quantity of the copper powder 6, the characteristics of the motor can be adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cage rotor of an induction motor having a secondary winding formed by die casting.

[0002]

2. Description of the Related Art A conventional cage rotor of an induction motor will be described with reference to FIGS. FIG. 2 is a front view of an iron core used for the cage rotor. FIG. 3 is a partial side sectional view of a cage rotor of a conventional example using the iron core of FIG. FIG. 4 is a partial side sectional view of a cage rotor in another conventional example.

In FIGS. 2 and 3, a rotor core 10
Is formed in a disk shape, and a shaft 1 is provided at the center of the disk.
1 and a plurality of rotor slots 12 for inserting a secondary winding at a circular end are laminated to form a core 13 having a cylindrical shape. ,
A so-called die-cast molding of the aluminum material 14 in the rotor slot 12 of the iron core 13 and both end surfaces of the iron core 13 is performed.
And a cage-shaped secondary winding 15.

[0004] The cage rotor 16 of the induction motor is
A rotor core 10 and a shaft 11 that passes through the center of the rotor core 10 and is attached to the rotor core 10.
It is composed of

In FIG. 4, in order to improve the efficiency of the electric motor, a rod-shaped metal having good electric conductivity, for example, a copper bar 17 is provided in each rotor slot 12 of the iron core 13.
Is inserted.

The rotor core 18 is formed by fixing the copper bar 17 in the rotor slot 12 and die-casting the gap in the rotor slot 12 and the end ring 19 with the aluminum material 14. ing.

[0007]

By inserting a rod-shaped copper bar into the rotor slot as in the cage rotor of FIG. 4, the electric conductivity of the current flowing in the rotor slot is improved, and Efficiency can be improved.

[0008] However, since the linear expansion coefficients of copper and aluminum are far apart from each other, when the difference in temperature change is large, or when an electric motor is used in a place, a crack is formed between the copper and aluminum. May occur.
Therefore, the electric conductivity of the crack is reduced, so that the efficiency of the electric motor cannot be improved to the extent that a copper bar having high cost is used.

[0009]

Therefore, according to the present invention, a powdery or granular metal having better electric conductivity than the aluminum material is added to the aluminum material used for the secondary winding together with the aluminum material. A cage-shaped rotor for an induction motor, wherein a cage-shaped secondary winding is formed by die-casting while uniformly kneading.

[0010]

[Function] To compose a basket-shaped secondary winding by die-casting while kneading a metal having a higher melting point than an aluminum material and a metal having a high electrical conductivity together with the aluminum material. Accordingly, the electric resistance of the secondary winding is reduced, and the efficiency of the motor is improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a partial sectional side view of a cage rotor according to the present invention.

In FIG. 1, a rotor core 1 is composed of an iron core 2 and a cage-shaped secondary winding 5 in which an aluminum material 4 is die-cast in a rotor slot 3 of the iron core 2 as in the prior art. It is configured.

Further, at the time of die-casting, a powdery or granular metal having a higher melting point than the aluminum material 4 and having a high electrical conductivity, for example, copper powder 6, is kneaded together with the aluminum material 4. The cage-shaped secondary winding 5 is formed. That is, by using the copper powder 6 having a melting point higher than that of the aluminum material 4, when the aluminum material 4 is melted and poured into a die cast mold, the copper powder 6 remains in a powdery or granular form. Therefore, the copper powder 6 in the aluminum material 4 can be uniformly kneaded and formed.

Further, since the copper powder 6 spreads to the end ring portion 7 of the cage secondary winding 5, the electric conductivity is improved.

Further, by adjusting the amount of the copper powder 6, the characteristics of the motor can be adjusted in accordance with the specifications of the equipment on which the motor is mounted.

[0016]

According to the present invention, the electric resistance of the secondary winding can be reduced, and the efficiency of the motor can be improved. Further, the characteristics of the electric motor can be adjusted.

[0017]

[Brief description of the drawings]

FIG. 1 is a partial sectional side view of a cage rotor according to the present invention.

FIG. 2 is a front view of an iron core used in a cage rotor.

FIG. 3 is a partial side sectional view of a conventional cage rotor using the iron core of FIG. 2;

FIG. 4 is a partial sectional side view of a cage rotor in another conventional example.

[Explanation of symbols]

 1, 10, 18 ... rotor core 2, 13 ... iron core 3, 12 ... rotor slot 4, 14 ... aluminum material 5, 15 ... squirrel cage secondary winding 6 ... copper powder 7, 19 ... end ring part 11 ... Shaft 16 ... Cage rotor 17 ... Copper bar

Claims (1)

[Claims] An aluminum motor used for a secondary winding of a squirrel-cage rotor of an induction motor in which a secondary winding is formed by die-casting. A cage rotor for an induction motor, wherein a cage-shaped secondary winding is formed by die-casting while uniformly kneading granular metal together with an aluminum material.