JPH06105499A - Bearing bracket for rotary electric machine - Google Patents

Abstract

PURPOSE:To largely and freely vary the natural frequency of a nearing bracket by fixing so as to bury a damping steel plate in a part of a lost foam pattern of the bracket, and integrally casing the plate. CONSTITUTION:Mold coating for improving sand strip is applied to the surface of a lost foam pattern 6 of a bearing bracket. The pattern 6 is installed in a casing flask, and sand is charged by vibrating the flask. Then, molten metal is transferred to the pattern 6 via a runner provided in the sand. The pattern 6 is melted with the transferred metal of a high temperature, lost, and the metal is cured after the pattern 6. In this case, a damping steep plate 5 is not melted with the metal, cast and buried in the metal. Thus, noise, vibration generated in a rotary electric machine can be reduced by the plate 5 of the bracket.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a bearing bracket for a rotating electric machine, which is formed by pouring a metal for melt casting by a disappearance model casting method.

[0002]

2. Description of the Related Art FIG. 3 shows a general structure of a rotary electric machine. In FIG. 3, the bearing brackets 1 are installed on the left and right sides of the stator frame 2, and have a role of holding the bearing 3 and a role of preventing foreign matter from entering the rotating electric machine.

The conventional bearing bracket 1 is integrally formed of a metal for melt casting, and electromagnetic vibration generated in the rotating electric machine is transmitted from the iron core 4 to the stator frame 2 and easily transmitted to the bearing bracket 1. When the resonance point of this frequency and the natural frequency of the bearing bracket 1 overlap, a large vibration is generated in the rotating electric machine body. In addition, mechanical noise generated by the bearing 3 is also easily transmitted by the bearing bracket 1 and appears as noise of the entire rotary electric machine.

A conventional countermeasure against vibration is to reinforce the ribs on the bearing bracket 1 or to increase the wall thickness of the bearing bracket 1 so that the bearing bracket 1 itself has a natural frequency as little as possible. It should be offset from the electromagnetic vibration generated from. Furthermore, as a measure against noise,
This can be dealt with by increasing the wall thickness of the bearing bracket, and this does not appear as a significant effect.

[0005]

In the conventional bearing bracket 1 as described above, the bearing bracket 1 has the same structure even if the ribs are reinforced or the wall thickness is increased because the metal is integrally formed of the same material for melt casting. It is difficult to significantly change the natural frequency, and the weight also increases.

Further, in order to reinforce the ribs or change the wall thickness of the bearing bracket 1, a new casting die is used or the die is changed, and the bearing bracket 1 is cast every time a problem of vibration or noise occurs. A mold is required, which causes problems in terms of casting mold management, standardization, and mold manufacturing cost.

According to the present invention, the damping steel plate material is cast on a part of the bearing bracket by the disappearance model casting method, so that the noise leaking to the outside by transmitting the bearing bracket is transmitted to the outside through the damping steel plate material. The purpose is to prevent leakage and to change the natural frequency of the bearing bracket significantly and freely by changing the shape and thickness of the damping steel plate material.

[0008]

According to the present invention, a bearing bracket is formed by casting molten metal into a vanishing model, and a damping steel plate material is embedded in a part of the vanishing model of the bearing bracket. It is characterized in that a part of the vibration-damping steel plate material is integrally cast into the bearing bracket by being fixed.

[0009]

According to the above-mentioned means, the damping steel plate member 5 which is a separate body can be cast integrally using the vanishing model, and the noise which tries to leak outside by transmitting the bearing bracket 1 is damped. Material 5
It becomes difficult to leak to the outside through the. Moreover, since the vibration damping steel plate material 5 can change the natural frequency of the bearing bracket 1, it is easy to shift the resonance point with the electromagnetic vibration.

[0010]

Embodiments of the present invention will be described below with reference to FIGS.
Will be described with reference to. First, FIG. 4 is a view showing a disappearing model 6 of the bearing bracket. The damping rope plate member 5 is fixed to the inner peripheral portion of the vanishing model 6 so that a part 5a thereof is embedded. The damping rope plate member 5 is press-formed into a concave shape and a convex shape as shown in FIG. This shape is formed in various combinations depending on the frequency of resonance.

Here, the case of manufacturing the vanishing model 6 will be described with reference to FIG. In this case, the shape recess of the bearing bracket 1 is formed in one lower die 7 which is formed by dividing the outer die into two along the axis. The damping rope plate member 5 is arranged in the lower mold 7, and the upper mold 8 is fitted to the lower mold 7. The disappearance model 6 of the bearing bracket is molded by injecting foam beads into the gap 9 formed by the upper mold 8 and the lower mold 7 and curing the foam beads.

Next, the case of casting a bearing bracket using the disappearing model 6 will be described. First, a coating mold is applied to the surface of the disappearing model 6 to improve the separation of sand. The disappearing model 6 is set in a casting flask, and the flask is vibrated to carry out sand filling. Then, the molten metal is poured into the vanishing model 6 through a runner provided in the sand. The injected high-temperature molten metal melts and disappears the disappearing model 6, and the molten metal hardens after the disappearing model. In this case, the damping rope plate material is not melted by the molten metal but is cast and embedded in the molten metal.

According to this embodiment having the above structure, the disappearance model 6
Since the damping bracket plate member 5 which is a separate body is integrally cast using the above, the bearing bracket 1 is cast.
Since the shape plate thickness of the damping rope plate member 5 can be freely set, the damping rope plate member can be selected in accordance with the electromagnetic frequency and the noise value, so that effective countermeasures can be taken. Further, since the mold of the bearing bracket 1 is not changed, it is not necessary to manage the mold, manufacture the mold, and change the mold. (Other embodiments)

In the above-described embodiment, the damping rope plate member 5 is fixed to the disappearance model 6 when the disappearance model 6 is formed by the molds 7 and 8. However, the invention is not limited to this, but after the disappearance model is formed. The damping rope plate member 5 may be freely attached. In this case, it becomes possible to use the damping rope plate material only in the most effective portion.

[0015]

According to the present invention, the damping rope plate material is integrally cast by fixing so that a part of the separate damping rope plate material is embedded in a part of the disappearing model of the bearing bracket. Thus, the noise and vibration generated inside the rotating electric machine are reduced by the vibration damping steel plate material of the bearing bracket. Furthermore, the electromagnetic vibration and the natural vibration of the bearing bracket are shifted by forming the shape of the vibration damping steel plate material into a concave or convex shape by pressing or changing the natural thickness of the bearing bracket by changing the plate thickness. Therefore, the vibration of the entire rotating electric machine can be reduced.

The noise generated from the bearing is also shielded by the vibration-damping rope plate material of the bearing bracket, so that it is difficult to leak to the outside and the noise can be reduced. According to the bearing bracket of the present invention, measures against vibration and noise can be taken without adding reinforcing ribs and changing the wall thickness, so that the bearing bracket can be made lightweight and standardized, and a low-noise, low-vibration rotating electric machine is provided. it can.

[Brief description of drawings]

FIG. 1 is a view of a bearing bracket of the present invention seen from the inside,

FIG. 2 is an arrow direction view of the bearing bracket of the present invention taken along the line AA.

FIG. 3 is an overall view of a conventional rotating electric machine,

FIG. 4 is a vanishing model diagram for the bearing bracket of the present invention,

FIG. 5 is a BB cross-sectional view of a bearing bracket disappearance model.

[Fig. 6] Diagram of damping rope plate material,

FIG. 7 is a cross-sectional view of a mold for creating a disappearance model.

[Explanation of symbols]

 1 …… Bearing bracket 2 …… Rotating electric machine frame 5,5a …… Damping rope plate 6 …… Disappearance model

Claims (1)

[Claims] 1. A bearing bracket for a rotary electric machine, which is formed by pouring a molten casting metal into a vanishing model portion, wherein a damping steel plate material is previously fixed to the vanishing model portion, and the molten casting metal is placed in the vanishing model portion. A bearing bracket for a rotary electric machine, wherein the damping steel plate material is embedded in a cast product as a part of a bearing bracket by casting.