JPS5840757Y2 - Dust prevention equipment for rotating electrical machines - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a dustproof device for an explosion-proof structure of a pressure-resistant and explosion-proof rotating electric machine.

An example of this type of rotating electrical machine is shown in FIG. 1, and its explosion-proof structure is shown in FIG. 2.

In these figures, 1 is a shaft, 2 is a fan boss that also serves as an external fan and an internal fan, 3 is a partition plate, 4 is a white metal cast into the inner diameter of the partition plate 3, 5 is an external fan, and 6 is an internal fan. , 7 are anti-rotation nuts which fix the boss 2 to the rotating shaft 1.

Next, the operation of the above-mentioned components will be explained.

As the shaft 1 rotates, the boss 2 and nut 7 also rotate together.

Therefore, both fans 5 and 6 also rotate, with external fan 5 sucking in outside air and internal fan 6 circulating inside air.

Meanwhile, the partition plate 3 and the white metal 4 remain stationary.

The explosion-proof structure of the conventional rotating electric machine is as described above, so when it rotates, the external fan 5 sucks in the outside air with a lot of dust. The drawback was that the open explosion-proof surface could become clogged with dust, which could lead to a burnout accident.

This idea aims to eliminate the above-mentioned drawbacks by locating the explosion-proof surface closer to the shaft than the outside diameter of the external fan button and internal fan, and making the stationary part and rotating part that constitute the explosion-proof surface By reducing the volume of the gap between the fans and by providing a pressure relief hole at a position opposite to the gap between the stationary part and the rotating part of both fans, dust and dirt can be removed from the explosion-proof surface and the fan boss. To provide a dust prevention device for a rotating electrical machine that prevents the dust from clogging the gap between the rotating part and the rotating part.

An embodiment of this invention will be described below with reference to the drawings.

In Figure 3, 1 is a shaft, 2 is a boss that also serves as an external fan and an internal fan, 3 is a partition plate, and 4 is a white metal cast into the inner diameter part of the partition plate 3, and this inner diameter surface constitutes the explosion-proof surface a. do.

5 is an external fan, 6 is an internal fan, and these fans 5
, 6 are fixed to the boss 2 with bolts 8.

The boss 2 has a small outer diameter, and the explosion-proof surface a is positioned on both fans 5.
, 6 closer to the shaft 1 than the outer diameter of the boss 2, the gap volume between the explosion-proof surface a and the outer diameter face of the boss 2 is made smaller than that of the conventional one. The gap between them is the same as before, but the diameter from the center of shaft 1 to the explosion-proof surface button a and the outer diameter surface is smaller than before, so the circumferential length of the gap is shortened, and the total volume of the gap is The smaller size makes it difficult for dust to enter.

In addition, a pressure relief hole 9 is formed in the side plate of the external fan 5 and the internal fan 6 at a position facing the gap between the explosion-proof surface a and the outer diameter face of the boss. The gap and the pressure relief hole 9 of the fan 6 communicate in a straight line, so that if dust or the like enters the gap, it can be effectively discharged.

As explained above, according to this invention, the gap volume between the explosion-proof surface, which is provided on a stationary part such as a partition plate and is located on the shaft side of the fan diameter, and a rotating part such as a fan boss is reduced. Since a pressure relief hole is provided at a position opposite to the gap between the stationary part and the rotating part of the fan, it is possible to prevent dust and dirt from entering the explosion-proof surface part and clogging it, thereby reducing the risk of burning out the rotating electric machine. It can be eliminated.

[Brief explanation of drawings]

Figure 1 is a half-cut side view showing an example of a conventional rotating electric machine;
The figure is a side sectional view showing one side of the shaft of an explosion-proof structure of a conventional rotating electric machine, and FIG. 3 is a side sectional view of one side of the shaft of the explosion-proof structure showing an embodiment of the invention. 1...shaft, 2...boss, 3...partition plate, 4...
White metal, 5... External fan, 6... Internal fan, 9... Pressure release hole, a... Explosion-proof surface, b...
・Boss outer diameter surface. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] An explosion-proof surface is formed on the inner circumferential surface of the partition plate attached to the stationary part, and the outer circumferential surface of the fan boss attached to the rotating shaft is opposed to the explosion-proof surface through a small gap, so that an external surface is formed on the outside of the fan boss. In a pressure-resistant explosion-proof rotating electric machine in which a fan is installed and an internal fan is installed inside the fan boss, the explosion-proof surface is located between the external fan and the internal fan closer to the rotating shaft than the outer periphery of both the fans, and A dustproof device for a rotating electrical machine, characterized in that pressure relief holes are provided at positions facing the minute gaps of the fan.