JPS622932Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shaft sealing device for a totally enclosed external fan-shaped rotating electric machine.

For example, FIG. 1 shows a completely enclosed external fan jacket cooling type rotating electrical machine among conventional totally enclosed external fan type rotating electrical machines. is fixed to the housing 4, and the stator core 3 is fixed to the housing 4 with a gap therebetween. A pair of covers 5 and 6 each having a central opening are fixed to both ends of the housing 4.
Shaft sealing devices 7 and 8 are fixed to the center openings of these covers 5 and 6, respectively. As described above, the rotating shaft 1 is rotatably supported, and the rotor core 2 and stator core 3 are kept in a sealed state.
A load is connected to the right end side of the rotating shaft 1 in the figure, and an external fan, that is, a cooling fan 14 is fixed to the end of the rotating shaft 1 on the opposite connection side or the opposite load side via a member 13. ing. This fan 1
A cylindrical fan cover 1 to cover 4
6 is fixed to a plurality of cooling fins 15 formed on the outer peripheral surface of the housing 4. A wire mesh 17 is fixed to the central opening of the fan cover 16, and when the rotating shaft 1 rotates, air flows from outside through the wire mesh 17 toward the cooling fins 15 as the cooling fan 14 rotates as shown by the arrow. I am guided. The shaft sealing device 8 on the opposite load side has a structure similar to that of the bearing device 7 on the load side, and includes a bearing box 9 fixed to the cover 6 via its protrusion 9a, and an inner oil sealing device fixed to the bearing box 9. It consists of a guard 10 and an outer oil guard 11 (in this specification, the side of the rotor core 2 and stator core 3 that are kept in a sealed state is called the inner side, and the opposite side is called the outer side). A slide bearing 12 is fixed to the bearing box 9 and supports the rotating shaft 1 in a sealed state with the above-described configuration.

When the rotating electric machine of the totally enclosed external fan jacket cooling type configured as described above is driven, the cooling fan 14 rotates as described above, air flows as shown by the arrow, and the inside of the rotating electric machine passes through the cooling fins 15. The heat generated in the cooling fan 14 is dissipated into the atmosphere, and due to the blowing action of the cooling fan 14, the inside of the cooling fan 14, that is, the space indicated by a, is placed in a high pressure state. Therefore, this high pressure is applied to the interior C of the bearing box 9 through the gap b formed between the outer oil guard 11 and the rotating shaft 1. Slide bearing 12
Since the bearing box 9 is supplied with lubricating oil as is well known, an oil mist is generated inside the bearing box 9. Due to the above-mentioned high pressure, this further causes the inner oil guard 10 to
It penetrates into the rotating electrical machine through the gap d between the rotor core 2 and the rotary shaft 1, that is, into the rotor core 2 and stator core 3 side.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a shaft sealing device for a completely enclosed external fan-shaped rotating electrical machine that can prevent oil leakage into the rotating electrical machine. According to the present invention, this purpose is to form a gap between the rotating shaft and the outer oil guard and the inner oil guard on both sides of the fully enclosed external fan-shaped rotating electrical machine equipped with a bearing box containing a bearing. In the shaft sealing device, the air passage has a flow resistance smaller than that of an air passage communicating from the gap between the outer oil guard on the outer fan side and the rotating shaft to the inside of the bearing box. This is achieved by a shaft sealing device for a completely enclosed external fan-shaped rotating electrical machine, characterized in that a hole is formed in the radial direction of the outer oil guard, and the hole is connected to a communication member that communicates with the atmosphere outside the machine. Ru.

Hereinafter, details of the present invention will be explained based on illustrated embodiments.

FIG. 2 is an enlarged cross-sectional side view of the main parts of a completely enclosed fan jacket cooling type shaft sealing device according to an embodiment of the present invention, and parts corresponding to those in FIG. 1 are designated by the same reference numerals. shall be.

That is, this embodiment is constructed in exactly the same way as the conventional example shown in FIG. 1 except for the parts shown in FIG. In FIG. 2, the shaft sealing device 30 on the opposite load side includes a bearing box 9 (partially shown), an inner oil guard (not shown in FIG. 2) fixed to the bearing box 9, and an outer oil guard fixed thereto (not shown in FIG. 2). It consists of an oil guard 22. Inner oil guard and outer oil guard 22
There are several irregularities 23 on the inner circumferential surface that fits into the rotating shaft 1.
is formed. Although these irregularities are also formed in the conventional inner oil guard 10 and outer oil guard 11, they are omitted in FIG. 1 for the sake of clarity.

An annular groove 24 is further formed on the inner circumferential surface of the outer oil guard 22, and a through hole 25 that communicates with the annular groove 24 and opens on the outer circumferential surface of the outer oil guard 22 is formed. A pipe 20 is fixed to this through hole 25. This fixation is achieved, for example, by using the through hole 25 as a screw hole and screwing a threaded portion formed at the lower end of the pipe 2 into the through hole 25 . The pipe 20 extends upward, and its upper end is connected to the fan cover 1.
It is tightly fitted into an opening 16a formed in 6. In this way, the groove 24 of the outer oil guard 22 is communicated with the atmosphere outside the rotating electric machine.

When the rotating shaft 1 rotates, the space a behind the cooling fan 14 becomes high pressure as in the case of FIG.
High pressure is applied to the outer gap e between the outer oil guard 22 and the rotating shaft 1, and air flows through it.
Since the groove 24 communicates with the atmosphere, air flows through the groove 2.
4. Guided out of the machine through the pipe 20. In other words, since the groove 24 is always at a pressure approximately equal to atmospheric pressure, the outer oil guard 22 and the rotating shaft 1
The high pressure in the space a behind the cooling fan 14 is not applied to the inner gap f between the cooling fan 14 and the cooling fan 14. Therefore,
High pressure is not applied to the inside of the bearing box 9, and the atomized oil smoke generated inside the bearing box 9 does not enter the inside of the rotating electric machine as in the conventional case. This will prevent so-called oil leaks.

Note that the axial length of the outer oil guard 22 of this embodiment is longer than that of the conventional outer oil guard 11 because of the groove 24 formed therein. Bearing box 9
When fixing with screws, there will be no problem if the notch 26 is formed except for the part where the pipe 20 is connected, as shown by the dotted line in FIG.

Further, although only the pipe 20 extending upward is shown in FIG. 2, a pipe extending downward symmetrically may be connected to the outer oil guard 22 in the same manner as described above. Since fan-shaped rotating electric machines are often used in places with a lot of dust, a dust filter may be attached to the upper end opening of the pipe 20 extending upward.

FIG. 3 is a cross-sectional front view of the main parts of a shaft sealing device according to another embodiment of the present invention. In this embodiment, a pair of pipes 34 and 36 are fixed to the outer oil guard 32 on the left and right sides. The outer oil guard 32 is formed with an annular groove 46 and through holes 48, 50 communicating with the annular groove 46, as in the case of FIG.
Pipes 34 and 36 are fixed to 50, respectively.

Bent pipes 38, 40 are connected to the tips of the pipes 34, 36 extending left and right.
Small pipes 42 and 44 are fixed to each of them. As a result, the opening of the communicating pipe made up of the pipes 34, 36, the bent pipes 38, 40, and the small pipes 42, 44 to the atmosphere is directed downward, which is particularly convenient when used in a dusty place. As mentioned above, dust filters may also be attached to the small pipes 42, 44.

In addition, in the outer oil guard 32, the connecting portions 32c and 32d of the pipes 34 and 36 are made thick.
Parts 32a, 3 attached to the bearing box with bolts
2b is formed thinly.

Although each embodiment of the present invention has been described above, the present invention is of course not limited to these embodiments, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiments, one or two pipes are connected to the outer oil guard, but a larger number of pipes may be connected.

Further, in the above embodiment, the annular grooves 24, 46 are formed on the inner peripheral surface of the outer oil guard, but these may be omitted and only the through holes 25, 48, 50 are formed. In this case, the through hole extends from the outer circumferential surface of the outer oil guard to the inner circumferential surface, and the through hole opens in the gap between the inner circumferential surface and the rotating shaft 1, but the diameter of the through hole It is clear that substantially the same effect as the above embodiment can be obtained if is made sufficiently large. That is, air resistance is much smaller in the passage toward the pipe than in the passage toward the interior of the rotating electric machine.

In addition, although the above embodiments have been described with reference to a completely enclosed external fan jacket cooling type rotating electrical machine, the rotating electrical machine is not limited to this, and may also be applied to other types of rotating electrical machines, such as a completely enclosed external fan pipe cooling type and a completely enclosed external fan core cooling type. The present invention is applicable.

Furthermore, although the above embodiments have been explained with respect to sliding bearings, the present invention is of course not limited to this, and can be applied to other bearings, such as rolling bearings.
In the examples, we did not particularly explain the lubricating oil supply method to the bearings, but as long as the shaft seal device has the above-mentioned configuration, such as forced lubrication method, self-lubrication method, oil bath lubrication method, etc. Applicable.

The shaft sealing device for a totally enclosed external fan-shaped rotating electrical machine of the present invention has an extremely simple and compact structure, and can reliably prevent oil leakage from the shaft sealing device into the rotating electrical machine.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a cross-section of the upper half of a conventional fully enclosed fan-cooled rotating electrical machine, and FIG. 2 is a main part of a completely enclosed external fan-cooled rotating electrical machine according to an embodiment of the present invention. FIG. 3 is an enlarged sectional side view of FIG. 3, and FIG. 3 is a sectional front view of a main part of a totally enclosed external fan envelope-cooled rotating electric machine according to another embodiment of the present invention. In addition, in the figure, 1... rotating shaft, 9... bearing box, 14... cooling fan, 20, 34, 36...
...Pipe, 22, 32...Outer oil guard, 2
4,46...groove.

Claims (1)

[Scope of utility model registration request] A gap is formed between the rotary shaft and the outer oil guard and the inner oil guard are fixed on both sides.
In a shaft sealing device for a fully enclosed external fan-shaped rotating electric machine equipped with a bearing box containing a bearing, an air passage communicating from a gap between the external oil guard on the external fan side and the rotating shaft to the inside of the bearing box. A through hole having a flow path resistance smaller than the flow path resistance is formed in the radial direction of the outer oil guard, and is connected to a communication member that communicates with the atmosphere outside the machine. Shaft sealing device for totally enclosed external fan type rotating electric machine.