JPS6331959B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-pressure gas circulation device, and more specifically to a device for circulating low-pressure gas within an annular closed container, in which an electric motor that rotates a fan of a blower is moved outside the closed container. This relates to the sealing of the portion where the conduction shaft penetrates the outer wall of the container if provided.

For example, in the case of a gas laser oscillation device, the area around the electrodes in the laser oscillation device is adjusted to an appropriate mixing ratio of gases such as carbon dioxide (CO ₂ ), helium (He), and nitrogen gas (N ₂ ). Stable gas laser oscillation cannot be obtained unless the gas is circulated and supplied at high speed while maintaining a constant temperature and low pressure (about 20 mmHg).

To do this, the oscillation chamber is connected in a circular manner with closed chambers such as a cooling chamber, a drive chamber for moving the gas (hereinafter referred to as the blower chamber), and a rectification chamber for adjusting the gas flow into a laminar flow to circulate the regulating gas. In addition, a vacuum pump is used to maintain low pressure, and new adjustment gas is supplied to replenish and correct the gas components and mixture ratio of the adjustment gas lost through oxidation and exhaust, and a control device is attached to control these. There is.

Conventionally, a blower equipped with an electric motor and its fan were installed in the blower room, so the gas heated around the oscillation electrode was cooled in a cooling room and then heated again by the heat generated by the electric motor and circulated.
This was not only inconvenient in terms of thermal efficiency, but also in terms of stable laser oscillation, and inconvenient in terms of the lifespan of the electric motor and troubleshooting.

The present invention has been made to solve the above-mentioned disadvantages, and preferred embodiments will be described in detail below based on the drawings.

Figure 1 shows a sealing device 1, a blower fan 3, an electric motor 5 that rotates the fan 3, and the fan 3 and the electric motor 5.
a transmission shaft 7 that connects the vacuum pump 9, an exhaust pipe 11 that connects the sealer 1 and the vacuum pump 9, and the transmission shaft 7.
shows an exhaust pipe line 17 that connects the bearing part 15 at a position that penetrates the wall 13 of the sealing device 1 and the vacuum pump 9.

FIG. 2 is an enlarged view of the vicinity of the bearing portion 15 of the first embodiment of the present invention.

In the first embodiment, a transmission shaft 7 from an electric motor 5 connected to a fan 3 of a blower is provided with, for example, mechanical seals 19 on both sides penetrating a wall 13, and protrudes from the wall 13 into the sealing device 1 to receive a bearing. An exhaust chamber 21 is provided around the space between the conduction shaft 7 and the wall body 13 in the middle of the mechanical seals 19 on both sides, and an exhaust pipe line 17 to the vacuum pump 9 is opened in the exhaust chamber 21. This is an example of

FIG. 3 shows a second embodiment of the invention.

In the second embodiment, a seal block 23 is provided on the outside of the portion where the transmission shaft 7 penetrates the wall 13, and an O-ring 25 is provided.
A rotary oil seal 27 is provided at a position corresponding to the transmission shaft 7 on the outside of the seal block 23, and the seal block 23 and the wall body 13 are properly fixed together.
A mechanical seal 19 is provided between the two, and an exhaust chamber 21 is provided in the wall 13 around the mechanical seal 19, and an exhaust pipe 11 connected to the vacuum pump 9 is opened.

An annular oil groove 29 is provided in the seal block 23 in a space between the mechanical seal 19 and the oil seal 27, where the seal block 23 corresponds to the transmission shaft 7.
are connected.

FIG. 4 shows a third embodiment of the invention.

In the device of the third embodiment, a seal block 23 is attached to the outside of the wall 13 of the sealing device 1 via an O-ring 25 by an appropriate means, and a mechanical seal 19 is provided from the wall 13 to the seal block 23. It is provided around the conduction shaft 7.

An annular oil groove 29 is provided in the seal block 23 around the mechanical seal 19 and communicates with an oil passage 33 from an oil reservoir 31 provided above.

The exhaust pipe line 17 from the vacuum pump 9 is connected to the wall 13
It opens into an exhaust chamber 21 provided annularly in the wall body 13 between the bearing portion 15 of the transmission shaft 7 passing through the shaft and the mechanical seal 19 described above.

As is clear from the three embodiments detailed above, in the apparatus according to the embodiment of the present invention, the electric motor 5 for driving the fan 3 of the blower, which is a heat source, is provided outside the sealing device 1, and its conduction shaft 7 is connected to the wall. Bearing part 1 penetrating body 13
5 is provided with two mechanical seals 19, and the vacuum pump 9 is used for suction between the two stages, or (first embodiment) a seal block 13 is provided on the outside of the wall 13, and the oil groove 29 is connected to the transmission axis. A mechanical seal 19 is installed around the 19 to prevent outside air from entering.
An exhaust chamber 21 to the vacuum pump 9 is provided around the wall 1 of the seal block 13 (second embodiment).
A mechanical seal 19 on the third side also serves as an oil groove 29, and an exhaust chamber 21 is provided outside the bearing part 15 of the wall body 13 to communicate the exhaust pipe line 17 to the vacuum pump 9 (third embodiment). It has been done.

Therefore, in both cases, two types of external air infiltration prevention means, a mechanical seal and an oil seal, are used, and exhaust is performed by a vacuum pump at the middle or innermost part, so there is no risk of causing a temperature rise in the gas inside the sealing vessel. Since there is no intrusion of outside air, there is no fear that the mixture ratio of the adjustment gas will change, maintenance and inspection of the motor is easy, and its lifespan can be extended, among other benefits.

Although the present invention will be explained using an example of a gas laser oscillation device, it is clear that the present invention can be widely used in low-pressure gas circulation devices.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the background of the implementation of the present invention, FIG. 2 is an enlarged partial view of the first embodiment of the device of the present invention, in the vicinity where the conduction axis penetrates the wall, and FIG.
The figure shows the second embodiment of the same as above, and FIG. 4 shows the third embodiment of the same. (Explanation of symbols representing main parts of drawings), 1...
Sealer, 3...Fan, 5...Electric motor, 9...Vacuum pump, 11...Exhaust pipe line, 21...Exhaust chamber,
29...Oil groove, 31...Oil sump.

Claims (1)

[Claims] 1. A device for circulating low-pressure gas in a sealed container, including a rotatable blower fan for circulating gas in the container, and an electric motor for rotating the fan connected to the outside of the container. A vacuum pump device is provided outside the container to reduce the internal gas pressure of the sealed container, and an intake pipe of the vacuum pump device is connected to the sealed container and the rotary shaft bearing portion of the blower fan. Low pressure gas circulation equipment.