CN111326941B

CN111326941B - Air-tight device

Info

Publication number: CN111326941B
Application number: CN201911065217.XA
Authority: CN
Inventors: 冈田康弘; 万雅史; 田中研太; 河村让一
Original assignee: Sumitomo Heavy Industries Ltd
Current assignee: Sumitomo Heavy Industries Ltd
Priority date: 2018-12-14
Filing date: 2019-11-04
Publication date: 2023-02-24
Anticipated expiration: 2039-11-04
Also published as: KR20200073984A; JP7120902B2; JP2020096140A; TW202027384A; TWI723619B; CN111326941A

Abstract

The invention provides a gas-tight device which can keep the gas container such as a chamber airtight without using a sealing mechanism. The motor is mounted to the gas container, and includes a motor container and a rotating shaft, which are disposed outside the gas container filled with the gas and form an airtight space together with the gas container. The motor container includes a partition portion that partitions a space inside the gas container and a space inside the motor container. The rotating shaft extends from the inside of the motor container to the inside of the gas container through the 1 st hole provided in the partition portion. The partition portion is provided with a 2 nd hole for allowing gas to flow between a space in the motor container and a space in the gas container, in addition to the 1 st hole.

Description

Air-tight device

The present application claims priority from japanese patent application No. 2018-234718, filed on 12, 14, 2018. The entire contents of this Japanese application are incorporated by reference into this specification.

Technical Field

The present invention relates to an airtight device.

Background

A gas laser device such as a discharge excitation carbon dioxide laser includes a chamber for accommodating a discharge electrode, an optical resonator, a laser gas, and the like. A blower is disposed in the chamber to circulate the laser gas. A motor for driving the blower is disposed outside the chamber, and a rotating shaft of the motor is inserted into the chamber from outside the chamber. In order to maintain airtightness in the chamber, a sealing mechanism is provided in a hole through which the rotating shaft passes (for example, patent document 1).

In the laser gas apparatus described in patent document 1, a motor case (motor container) is filled with an inert gas, and the pressure in the motor case is set to be higher than the pressure in the chamber. As the seal mechanism, for example, a lip seal made of PTFE or the like excellent in abrasion resistance is used. Even if the sealing mechanism has poor sealing, the laser gas does not leak from the chamber to the outside because the pressure in the motor housing is set to be higher than that in the chamber.

Patent document 1: japanese patent laid-open publication No. 9-283821

If a failure occurs in the sealing mechanism, the gas in the motor case flows into the chamber, and the composition of the laser gas in the chamber changes.

Disclosure of Invention

The invention aims to provide a gas-tight device which can keep the gas container such as a chamber airtight without using a sealing mechanism.

According to an aspect of the present invention, there is provided a gas sealing device having:

a gas container filled with a gas; and

a motor including a motor container disposed outside the gas container and forming an airtight space together with the gas container, and a rotating shaft,

the motor container includes a partition portion that partitions a space inside the gas container and a space inside the motor container,

the rotating shaft extends from the inside of the motor container to the inside of the gas container through a 1 st hole provided in the partition portion, and the partition portion is provided with a 2 nd hole for allowing gas to flow between a space in the motor container and a space in the gas container, in addition to the 1 st hole.

According to another aspect of the present invention, there is provided a gas sealing device having:

a gas container filled with a gas;

a motor including a motor container and a rotating shaft, the motor container being disposed outside the gas container and forming an airtight space together with the gas container; and

a bearing that supports the rotary shaft to be rotatable with respect to the motor case,

the motor container is provided with a partition part and a gas path,

the partition portion partitions a space inside the motor container and a space inside the gas container and is provided with a 1 st hole through which the rotation shaft passes,

the gas path allows gas to flow between a space in the motor case and a space in the gas case without passing through the bearing.

Since the gas container and the motor container form an airtight space, the airtightness of the space in the gas container can be ensured without hermetically sealing the 1 st hole through which the rotary shaft passes.

If a gas passage through which gas can flow without passing through the bearing is provided between the space in the motor container and the space in the gas container, the flow rate of gas passing through the bearing decreases, and the flow velocity also decreases. Therefore, deterioration of the bearing due to gas flowing through the bearing can be suppressed.

Drawings

Fig. 1 is a schematic sectional view of an airtight device according to an embodiment.

Fig. 2 is a perspective view of the motor of the airtight device according to the embodiment as viewed from the partition portion side.

Fig. 3 is a schematic cross-sectional view of the airtight device in the case of exhausting the gas from the gas container according to the embodiment.

Fig. 4 is a schematic cross-sectional view of the airtight device when gas is introduced into the gas container according to the example.

Fig. 5 is a schematic sectional view of an airtight device according to another embodiment.

Fig. 6 is a cross-sectional view perpendicular to an optical axis of a gas laser apparatus according to still another embodiment.

In the figure: 10-motor, 11-rotation shaft, 12-motor container, 12A-housing portion, 12B-partition portion, 13-front bearing, 14-rear bearing, 15-rotor, 16-stator, 21-1 st hole, 22-2 nd hole, 23-3 rd hole, 24-4 th hole, 25-bearing support portion, 26-bolt hole, 50-gas container, 51-opening portion of gas container, 52-optical chamber, 53-blower chamber, 54-upper and lower partition plates, 54A, 54B-opening provided in upper and lower partition plates, 55-discharge electrode, 56-discharge region, 57-optical resonator, 58-partition plate, 61-introduction port, 62-introduction valve, 63-gas supply source, 65-exhaust port, 66-exhaust valve, 67-vacuum pump, 71-1 st gas flow path, 72-2 nd gas flow path, 73-blower, 74-impeller, 75-heat exchanger.

Detailed Description

An airtight device according to an embodiment will be described with reference to fig. 1 to 4.

Fig. 1 is a schematic sectional view of an airtight device according to the present embodiment. In fig. 1, a component actually constituted by combining a plurality of individual components is shown as one component, and the individual components are not shown separately. In the case where a plurality of members are fastened and fixed by bolts or the like, a fixing tool such as a bolt is not illustrated in fig. 1. Also, known members such as O-rings used for ensuring airtightness are not shown in fig. 1.

The gas sealing device according to the present embodiment includes a gas container 50 and a motor 10 attached to the gas container 50. The motor 10 includes a rotating shaft 11 and a motor container 12 installed outside the gas container 50. The motor case 12 includes a housing portion 12A for housing the rotor 15 and the stator 16, and a partition portion 12B for closing an opening of the housing portion 12A.

The gas container 50 is provided with an opening 51, and the motor 10 is attached to the gas container 50 by a bolt or the like so that the partition portion 12B thereof closes the opening 51. The partition portion 12B serves as a flange for mounting the motor 10 to the gas container 50. The motor container 12 forms an airtight space together with the gas container 50. The partition portion 12B partitions the space inside the motor container 12 and the space inside the gas container 50.

In the motor case 12, the rotary shaft 11 is rotatably supported by the partition portion 12B via a front bearing 13 and is rotatably supported by the housing portion 12A via a rear bearing 14. For example, rolling bearings are used as the front bearing 13 and the rear bearing 14. A rotor 15 is fixed to the rotating shaft 11, and a stator 16 is fixed to the housing portion 12A.

The rotary shaft 11 extends from the inside of the motor container 12 to the inside of the gas container 50 through the 1 st hole 21 provided in the partition portion 12B. In the partition portion 12B, in addition to the 1 st hole 21, a 2 nd hole 22 is provided. The 2 nd hole 22 allows gas to flow between the space in the motor container 12 and the space in the gas container 50.

The space in the motor case 12 is partitioned into a space in which the rotor 15, the stator 16, and the like are arranged and a space on the distal end side of the rotary shaft 11 by the rear bearing 14. The 3 rd hole 23 communicates two spaces partitioned by the rear bearing 14 with each other. For example, the 3 rd hole 23 is provided in the wall of the housing portion 12A or a fixing member (not shown) that fixes the outer ring of the rear bearing 14.

The gas container 50 is provided with an inlet port 61 and an outlet port 65. The introduction port 61 is connected to a gas supply source 63 via an introduction valve 62, and the exhaust port 65 is connected to a vacuum pump 67 via an exhaust valve 66. When the exhaust valve 66 is opened and the vacuum pump 67 is operated, the space in the gas container 50 is exhausted. When the introduction valve 62 is opened, the gas is introduced into the gas container 50 from the introduction port 61.

Fig. 2 is a perspective view of the motor 10 for the airtight device according to the present embodiment. The motor case 12 is constituted by a housing portion 12A and a partition portion 12B. The partition portion 12B is provided with a 1 st hole 21 and a 2 nd hole 22. The rotation shaft 11 protrudes from the inside of the motor case 12 through the 1 st hole 21. A slight gap is secured between the side surface of the 1 st hole 21 and the side surface of the rotary shaft 11. The 2 nd hole 22 opens on the surface outside the partition portion 12B. A plurality of bolt holes 26 are provided near the outer peripheral edge of the partition portion 12B. The motor 10 is fixed to the gas container 50 (fig. 1) by passing bolts through the bolt holes 26.

Fig. 3 is a schematic cross-sectional view of the airtight device in the case of exhausting gas from the inside of the gas container 50 according to the embodiment. In fig. 3, the flow of gas is indicated by arrows. When the introduction valve 62 is closed, the exhaust valve 66 is opened, and the vacuum pump 67 is operated, the gas container 50 is exhausted through the exhaust port 65. At this time, the space in the motor case 12 in which the rotor 15 and the stator 16 are accommodated is also exhausted through the 1 st hole 21 and the 2 nd hole 22. At this time, the gas in the space on the distal end side of the rear bearing 14 moves to the space in which the rotor 15 and the stator 16 are accommodated through the 3 rd hole 23.

Fig. 4 is a schematic cross-sectional view of the airtight device when gas is introduced into the gas container 50 according to the embodiment. In fig. 4, the flow of gas is indicated by arrows. When the exhaust valve 66 is closed and the introduction valve 62 is opened, the gas is introduced from the gas supply source 63 into the gas container 50 through the introduction port 61. The gas introduced into the gas container 50 is also introduced into the space in the motor container 12, in which the rotor 15 and the stator 16 are accommodated, through the 1 st hole 21 and the 2 nd hole 22. Then, the gas is introduced into the space on the tip side of the rear bearing 14 through the 3 rd hole 23.

Next, the excellent effects of the present embodiment will be described.

In the present embodiment, the space inside the container is hermetically isolated from the outside (e.g., the atmosphere) by the two containers, the gas container 50 and the motor container 12. Even if gas flows between the space in the gas container 50 and the space in the motor container 12 through the 1 st hole 21 and the 2 nd hole 22, the space in the gas container 50 can be kept in a state of being hermetically isolated from the outside. As described above, in the present embodiment, the space in the gas container 50 and the space in the motor container 12 are set to the same gas atmosphere, and allow gas to flow therebetween. Therefore, the space inside the gas container 50 can be isolated from the outside without hermetically sealing the 1 st hole 21 through which the rotating shaft 11 passes.

When the gas container 50 is exhausted (fig. 3) and when the gas container 50 is introduced (fig. 4), the gas passing through the 1 st hole 21 passes through the gap of the front bearing 13. If the flow rate of the gas passing through the 1 st hole 21 is high, grease of the front bearing 13 is scattered, and the inside of the gas container 50 is contaminated by the grease. Further, the life of the front bearing 13 is shortened by the splash of the grease.

In the present embodiment, since the gas flow path including the 2 nd hole 22 is provided in parallel with the gas flow path including the gap of the front bearing 13 and the 1 st hole 21, the flow of the gas flowing between the space in the gas container 50 and the space in the motor container 12 is dispersed in the 1 st hole 21 and the 2 nd hole 22. Since the flowing gas flow is dispersed, the amount of gas passing through the 1 st hole 21 decreases, and the flow rate also decreases. Therefore, the grease of the front bearing 13 can be prevented from splashing. As a result, contamination in the gas container 50 and deterioration of the front bearing 13 can be suppressed.

When the gas moves between the two spaces partitioned by the rear bearing 14, the gas passes through a gas flow path formed by the gap of the rear bearing 14. In the present embodiment, since the 3 rd hole 23 is provided in parallel to the gas flow path formed by the gap of the rear bearing 14, the amount of gas passing through the gap of the rear bearing 14 is reduced. Therefore, the splash of grease of the rear bearing 14 and the deterioration of the rear bearing 14 can be suppressed. The volume of the space on the distal end side of the rear bearing 14 is sufficiently smaller than the volume of the space in which the rotor 15 and the stator 16 are accommodated. Therefore, when the exhaust gas and the gas are introduced, the amount of gas moving between the two spaces partitioned by the rear bearing 14 is small. Therefore, if the flow rate of the gas moving between the two spaces is so low that the grease does not splash, the 3 rd hole 23 may not be provided.

In order to suppress the scattering of grease from the front bearing 13, the flow path resistance of the 2 nd hole 22 is preferably set to be smaller than the flow path resistance of the gas flow path constituted by the gap of the front bearing 13 and the 1 st hole 21.

Next, with reference to fig. 5, an airtight device according to another embodiment will be described. Hereinafter, the description of the configuration common to the airtight devices according to the embodiments shown in fig. 1 to 4 will be omitted.

Fig. 5 is a schematic sectional view of the airtight device according to the present embodiment. In the present embodiment, the No. 2 hole 22 (fig. 1) is not provided in the partition portion 12B of the motor case 12. The front bearing 13 is supported by the bearing support portion 25 of the housing portion 12A rather than the partition portion 12B. The bearing support portion 25 protrudes from the inner surface of the housing portion 12A toward the rotary shaft 11, and supports the front bearing 13 at the front end thereof.

The bearing support portion 25 is provided with a 4 th hole 24 for allowing gas to flow between a space on the partition portion 12B side of the bearing support portion 25 and a space in which the rotor 15 and the stator 16 are accommodated. By providing the 1 st hole 21 and the 4 th hole 24 in series, a gas passage (flow path indicated by an arrow in fig. 5) is formed, through which gas can flow between the space in the motor case 12 and the space in the gas case 50 without passing through the gap of the front bearing 13.

Next, the excellent effects of the present embodiment will be described.

When the gas container 50 is exhausted and the gas is introduced into the gas container 50, the gas flows between the space in the gas container 50 and the space in the motor container 12 through the 1 st hole 21. In the motor case 12, the gas flows through the gas passage formed by the gap of the front bearing 13 and the 4 th hole 24. In the present embodiment, the gas flow path formed by the 4 th hole 24 is provided in parallel with the gas flow path formed by the gap of the front bearing 13. Therefore, the flow of the gas flowing between the two spaces partitioned by the front bearing 13 is dispersed to the gas flow path formed by the gap of the front bearing 13 and the 4 th hole 24. This reduces the amount of gas passing through the gap of the front bearing 13, and can slow the flow rate of the gas. As a result, the grease of the front bearing 13 can be prevented from splashing.

In the present embodiment, since the gas flow path formed by the 1 st hole 21 and the gas flow path formed by the 4 th hole 24 are connected in series, the flow resistance of the gas flow path connecting the space in the gas container 50 and the space in the motor container 12 is larger than that in the embodiment shown in fig. 1. Therefore, when the pressure in the gas tank 50 is equal to the pressure in the motor tank 12, the independence between the space in the gas tank 50 and the space in the motor tank 12 can be improved.

Next, a gas laser apparatus according to still another embodiment will be described with reference to fig. 6. The gas sealing device according to the above-described embodiment is used in the gas laser device according to the present embodiment.

Fig. 6 is a cross-sectional view of the gas laser apparatus according to the present embodiment, the cross-sectional view being perpendicular to the optical axis. The gas container 50 is filled with laser gas. The internal space of the gas container 50 is partitioned by the upper and lower partition plates 54 into an upper optical chamber 52 and a lower blower chamber 53. A pair of discharge electrodes 55 are disposed in the optical chamber 52. A discharge region 56 is defined between the pair of discharge electrodes 55. In the cross section shown in fig. 6, an optical resonator 57 is disposed at a position overlapping the discharge region 56.

A partition 58 is disposed in the optical chamber 52. The separator 58 partitions a 1 st gas flow path 71 from the opening 54A provided in the upper and lower separators 54 to the discharge region 56, and a 2 nd gas flow path 72 from the discharge region 56 to the other opening 54B provided in the upper and lower separators 54. The laser gas flows through the discharge region 56 in a direction orthogonal to the optical axis. The discharge direction is orthogonal to both the flow direction of the laser gas and the optical axis direction. The blower chamber 53, the 1 st gas channel 71, the discharge region 56, and the 2 nd gas channel 72 constitute a circulation channel through which the laser gas circulates.

A blower 73 is disposed in the blower chamber 53. The blower 73 is composed of a motor 10 attached to the wall surface of the gas container 50 and an impeller 74 provided at the tip of the rotating shaft 11 of the motor 10. The gas-tight space is formed by the gas container 50 and the motor container 12 of the motor 10. The blower 73 generates a flow of the laser gas to circulate the laser gas through a circulation path formed in the gas container 50.

A heat exchanger 75 is accommodated in the circulation path in the blower chamber 53. The laser gas heated in the discharge region 56 is cooled by the heat exchanger 75, and the cooled laser gas is supplied to the discharge region 56 again.

An inlet port 61 is provided on a wall surface of the optical chamber 52, and an exhaust port 65 is provided on a wall surface of the blower chamber 53. The laser gas in the gas container 50 is discharged from the gas discharge port 65, and the laser gas is introduced into the gas container 50 from the introduction port 61.

Next, the excellent effects of the present embodiment will be described.

When the laser gas deteriorates and needs to be replaced, the inside of the gas container 50 is first evacuated, and then the laser gas is introduced into the gas container 50. In the present embodiment, the gas container 50 and the motor 10 use the gas sealing device according to the embodiment shown in fig. 1 or 5. Therefore, when the gas container 50 is evacuated, the grease of the front bearing 13 (fig. 1 and 5) can be prevented from scattering. As a result, contamination in the gas container 50 and deterioration in the cleanliness of the laser gas can be suppressed, and stable laser oscillation can be performed. Moreover, deterioration of the front bearing 13 can be suppressed.

Further, since airtightness is ensured by the gas container 50 and the motor container 12 (fig. 1 and 5) of the motor 10, it is possible to suppress entry of an undesirable gas component into the gas container 50.

The above embodiments are merely examples, and it is needless to say that the structures shown in different embodiments may be partially replaced or combined. The same operational effects of the same structure in the plurality of embodiments are not mentioned one by one in each embodiment. Furthermore, the present invention is not limited to the above-described embodiments. For example, it will be apparent to those skilled in the art that various changes, modifications, combinations, and the like can be made.

Claims

1. An airtight device, characterized in that,

comprises a motor having a motor container disposed outside a gas container filled with a gas and forming an airtight space together with the gas container, and a rotating shaft,

the rotating shaft extends from the inside of the motor container to the inside of the gas container through a 1 st hole provided in the partition portion,

the partition portion includes, in addition to the 1 st hole, a 2 nd hole for allowing gas to flow between a space in the motor container and a space in the gas container, and the 1 st hole and the 2 nd hole constitute a gas flow path connected in parallel.

2. The hermetic device according to claim 1,

the motor further includes a bearing supporting the rotation shaft to the partition portion at a portion where the rotation shaft passes through the 1 st hole to enable the rotation shaft to rotate with respect to the partition portion.