JPS59216439A - Bearing unit of rotary electric machine - Google Patents

Abstract

PURPOSE:To readily prevent an axial current by forming an insulating layer between a bearing box and a collar by shrink-fitting a collar wound with a filmlike insulating material to the box. CONSTITUTION:An insulating layer 7a between a bearing box 1 and a collar 6 is formed by shrink-fitting a collar 6 wound with a filmlike insulating material to the box 1. The insulating layer uses, for example, a plastic film. In this manner, the layer 7a may be formed without flowing epoxy resin. The axial current can be prevented by the layer 7a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a bearing device for a rotating electrical machine, and particularly to a bearing device for a rotating electrical machine in which shaft current is prevented by an insulating plate and an insulating layer.

[Background of the invention]

FIG. 1 shows a conventional example of a bearing device for a rotating electric machine. As shown in the figure, the bearing device includes a bearing box 1, bearing covers 2a and 2b, and a bearing 4 that is provided inside the bearing box 1 and the bearing covers 2a and 2b and that slides on the rotating shaft 3. It is equipped with a bearing 4, a bearing cover 2a,
2b is an insulating plate 5, and the bearing 4 and the bearing box l are insulated by an insulating layer 7 formed between the collar 6 provided on the bearing 4 and the bearing box 1 to prevent the axial current of the bearing 4. ing. In addition, in the same figure, 8 is the bearing box 1 and the bearing cover 2a.

This is the bolt that fixes 2b.

In order to prevent electric current from flowing through the bearing 4, causing electrolytic corrosion in the bearing 4 and damaging the bearing 4, the insulating plate 5 and the insulating layer 7 are provided as described above to prevent shaft current. .

The insulating layer 7 is formed by providing an appropriate gap between the bearing box 1 and the collar 6, pouring an insulating material such as epoxy resin into the gap, and drying the insulating material.

By the way, when manufacturing by pouring epoxy resin, the epoxy resin may not penetrate into the gap sufficiently, which not only deteriorates the insulation performance between the collar 6 and the bearing box 1, but also deteriorates the insulation performance between the collar 6 and the bearing box 1. There were cases in which the adhesive force decreased and the collar 6 came off. In addition, not only are jigs and tools necessary for pouring and drying the epoxy resin, but also the resin must be removed from unnecessary parts before and after curing, which requires a large number of manufacturing steps.

[Purpose of the invention]

The present invention has been made in view of the above points, and it is an object of the present invention to provide a bearing device for a rotating electrical machine that can easily prevent shaft current.

[Summary of the invention]

That is, the present invention is characterized in that the insulating layer between the bearing box and the collar is formed by shrink-fitting the collar, which is wound with a film-like insulating material, onto the bearing box.

[Embodiments of the invention]

The insulating layer 7a, which will be described below based on the illustrated embodiment, was formed by shrink-fitting a collar 6 around which a film-like insulating material 9 was wound onto the bearing box 1. A plastic film 9 was used as the film-like insulating material 9. By doing this, the insulating layer 7a can be formed without pouring epoxy resin as in the conventional method.
The formation of the insulating layer 7a is facilitated, and a bearing device for a rotating electrical machine in which shaft current can be easily prevented can be obtained.

That is, the plastic film 9 is wrapped twice around the collar 6 (see Figure 3), and the bearing box l, which is the outside of the wrapped thing, is heated and expanded as indicated by the two-dot chain mark in the figure. (See Figure 4). In this way, since the bearing box 1 is provided with a tightening allowance, when it cools down to room temperature, the collar 6 around which the glass film 9 is wound is shrink-fitted, that is, baked, using only the force equivalent to the tightening amount. It can be fitted. If the plastic film 9 is wound around the collar 6 and shrink-fitted in this way, the bearing box 1 and the collar 6 will be connected to the plastic film 9 wound around the collar 6.
Since the bearing box 1 and the collar 6 are shrink-fitted together, there is no need for the conventional resin pouring work, making it easier to form the insulating layer 7a between the bearing box 1 and the collar 6. Prevention of current can be facilitated. Since the plastic film 9 is wrapped twice so that there is no gap between the joints, the insulation performance is maintained well and the shaft current can be sufficiently prevented. Since the collar 6 is shrink-fitted, the collar 6 does not move due to thrust force or rotational force or come off as in the conventional case, and the reliability of the bearing device can be improved. Furthermore, since the bearing box 1 and the collar 6 are integrated, the integrated structure can be mounted on the bearing 4.

Another embodiment of the invention is shown in FIG.

In this embodiment, the same plastic film 9 is wound in a single layer on the collar 6, and the same plastic film 9 is wrapped across the abutting portion of the wound end, so that no gap occurs in the wound plastic film 9. I did it like that. In this case as well, the same effects as in the above case can be achieved.

FIG. 6 shows yet another embodiment of the invention. In this example, the plastic film 9 was wound onto the collar 6 so that the winding end portion was wrapped several times. In this case as well, the same effects as in the above case can be achieved.

〔Effect of the invention〕

As mentioned above, in the present invention, the insulating layer can be formed without pouring the resin, so the insulating layer can be formed without pouring the resin, making it easier to form the insulating layer, and A bearing device for a rotating electrical machine that can easily prevent current can be obtained.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional side view of a conventional rotating electric machine bearing device, Figure 2
The figure is a longitudinal sectional side view of an embodiment of a bearing device for a rotating electrical machine of the present invention, and FIG. Fig. 4 is a side view showing a state in which a collar wrapped with a plastic film of one embodiment of a bearing device for a rotating electric machine of the present invention is shrink-fitted to a bearing box, and Fig. 5 is a side view of the bearing device for a rotating electric machine of the present invention. A side view showing a state in which a glass film is wound around the collar of another embodiment of the device, and FIG. 6 shows a state in which a plastic film is wound around the collar of still another embodiment of the bearing device for a rotating electric machine of the present invention. FIG. 1...Bearing box, 2a, 2b...Bearing cover, 4...
・Bearing, 5... Insulating plate, 6... Collar, 7a...
Insulating layer, 9...F$2 Diagram J $5

Claims (1)

[Scope of Claims] 1. A bearing box, a bearing cover, and a bearing provided in the bearing box and the bearing cover and sliding on a rotating shaft, the bearing and the bearing cover having an insulating plate. In a bearing device for a rotating electric machine, the bearing and the bearing box are each insulated by an insulating layer formed between a collar provided on the bearing and the bearing box to prevent shaft current. A bearing device for a rotating electric machine, wherein the insulating layer between the box and the collar is formed by shrink-fitting the collar, which is a film-like insulating material wound thereon, onto the bearing box. 2. The bearing device for a rotating electric machine according to claim 1, wherein the film-like insulating material is a plastic film.