JPS6373852A - Rotor - Google Patents

Abstract

PURPOSE:To make the molten metal flow of die casting uniform and reduce a die casting cavity at an end ring section, by providing the shaft-directional end section of an end ring, with a cylindrical ring thinner in the diameter direction than the end ring. CONSTITUTION:Via the shaft-directional penetrating hole 2 of a core 1, an end ring 3 formed by die casting is provided with cylindrical rings 4a, 4b. An end ring 3a side is provided with a die casting gate, and by taking gas out of the tip section of the cylindrical ring 4b, gas to stand at an end ring 3b is concentrated at the cylindrical ring 4b, and the die casting cavity of the end ring 3b can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to the structure of a rotor of an electric motor, and particularly to a rotor structure suitable for reducing the occurrence of die-cast cavities in an end ring portion during die-casting work.

[Conventional technology]

As a method for preventing the occurrence of die casting cavities, for example, Japanese Patent Application Laid-Open No. 56-1
As described in No. 07766, a configuration has been proposed in which a small hole passing through the iron core is provided in the core, and the small hole is connected to an end ring on the opposite side of the sprue to allow die-casting gas to escape.

[Problem that the invention seeks to solve]

However, with the conventional structure, sufficient consideration has not been given to the clogging of the gas escape passage by the die-cast metal when the gas escape passage is changed due to variations in the stacked thickness of the iron core, mold friction, etc.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to equalize the t&[E deviation of die casting and to reduce die casting cavities in the end ring portion, which cause variations and deterioration of motor characteristics.

[Means for solving problems]

Generally, in a rotor having end rings at both ends, a die-cast sprue 1o is provided on one end ring side, and gas is vented from the other end ring side, as shown in FIG. (In the figure, the → mark indicates the d of the die-casting hot water, and the -R mark indicates the degassing.) However, due to the occurrence of hot water flakes and clogging of the degassing hole of the die-casting mold, a sufficiently large degassing hole was not provided. In addition, die casting cavities occur in the end ring due to gas entrainment due to uneven die casting melt dripping. These die-cast holes cause variations in secondary resistance, resulting in variations and deterioration in the characteristics of the electric machine. Furthermore, end rings 3h and 5b, 3a and 5a
In a rotor with a structure in which a step is provided in the end ring part to absorb the unbalanced load by making the rotor unbalanced, the unevenness of hot water washing increases and the occurrence of die-casting cavities increases. The variation in the balance amount also increases.

In the present invention, a cylindrical ring thinner than the radial thickness of the end ring is provided at the axial end of the end ring, and gas is vented from the end of the ring.

[Effect]

This configuration equalizes the distance of the die-casting vortex flow, suppresses the occurrence of die-casting cavities, and directs the generation of die-casting cavities to the cylindrical ring side, thereby eliminating die-casting cavities in the end ring that have a large effect on characteristics. can be reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, a cylindrical ring 4a is inserted into an end ring 3 formed by die-casting through an axial through hole 2 of an iron core 1.
, 4b are provided. By providing a die-casting sprue on the end ring 3a side and venting gas from the tip of the cylindrical ring 4b, the gas that should stay in the end ring 3b concentrates in the cylindrical ring 4b, causing die-casting holes in the end ring 3b. can be reduced, the rotor secondary resistance is stabilized,
This has the effect of suppressing variations and deterioration in motor characteristics.

Although the embodiment of FIG. 1 has cylindrical rings on both sides, it may also be provided on one side.

Figure 2 shows a rotor used for unbalanced loads such as rotary compressors, with a step 5 provided on the end ring portion 4,
The rotor is equipped with an unbalance to absorb the load unbalance, and the balance of the rotating system is corrected. In this rotor,
By providing the cylindrical ring 4, the cylindrical ring 4a
The distance from the tip of the cylindrical ring 4b to the tip of the cylindrical ring 4b becomes equal, and the die-casting vortex flow becomes uniform. Also, die-casting cavities at the end ring portion and the step portion are also reduced, so that the rotation of one rotor is reduced. The balance will be accurate.

FIGS. 3 and 4 show examples in which cylindrical rings 4a and 4b are provided at the outer circumferential portion and the intermediate portion of the end ring, respectively, and the effects are the same as those described above.

Furthermore, FIG. 5 shows an example in which cooling fins 6 are provided on the cylindrical rings 4a, 4b provided in the middle part of the end rings in FIG.
This improves the strength of the cooling fins 6. Of course, combinations of the respective shapes are also possible.

〔Effect of the invention〕

According to the present invention, it is possible to make the die-casting vortex flow uniform, and by moving the gas venting part away from the end-link part, it is possible to reduce die-casting cavities in the end-ring part. It has the effect of suppressing variations and deterioration in characteristics, reducing unbalance due to the die-casting of the end ring, and cooling by increasing the heat dissipation area of the two rotors.

[Brief explanation of the drawing]

FIG. 1 is a two-sided view for explaining the configuration of one embodiment of the present invention, and FIGS. 2, 3, 4, and 5 are two-sided views for explaining other different embodiments. The plan view and FIG. 6 are diagrams for explaining a conventional die-casting method. DESCRIPTION OF SYMBOLS 1... Rotor core, 2... Core through hole, 3... End ring, 4... Cylindrical ring, 5... Balance weight end ring step, 6... Cooling fin, 7...
・Outer cylinder of die-casting mold, 9... End ring mold on the opposite sprue side, 8... End ring mold on the sprue side, 10...
Die-cast sprue part Fig. 1, Fig. 4, Fig. 5, Fig. 6 Z

Claims (1)

[Claims] 1. In a rotor having an end ring formed by die-casting through which the iron cores having an axial through hole are laminated, and which are formed by die-casting at both axial ends of the iron core through the through hole, further A rotor characterized by having a cylindrical ring that is thinner in the radial direction than the end ring.