JP3312305B2 - Laser gas transfer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser gas circulating circuit in which a laser oscillation tube is interposed. The present invention relates to a laser gas transfer device having a blower for gas circulation, that is, a turbo blower.

[0002]

2. Description of the Related Art Carbon dioxide laser oscillators for processing machines are
The laser oscillation gas is circulated in the oscillation tube without sealing. The laser gas circulation path includes a laser oscillation tube, a cooler,
Rotor blades of a turbo blower are connected in series. The turbo blower includes a motor, a blower rotating shaft, a bearing for supporting the blower rotating shaft, and the like, in addition to the rotating blades. Conventionally, ball bearings have been used as bearings for turbo blowers, and lubricating oil has been used for lubricating the ball bearings.

[0003]

In a ball bearing using lubricating oil, lubricating oil is atomized and mist enters the circulation path, and enters a laser oscillation tube inserted in series in the circulation path. The mist adheres to the resonance mirror, seizes the lubricating oil component at the reflection part of the oscillation laser by the oscillation laser, and the mist causes a complicated chemical change to become an impurity in the excited gas. Intrusion, causing the performance degradation of the oscillator. Further, the metal powder due to the friction of the bearing member also enters the circulation path, and accelerates the performance degradation of the oscillator, similarly to the lubricating oil.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention is directed to a laser gas transfer device of a gas laser oscillation device, which has an object described in (O01) below. (O01) Prevent impurities such as lubricating oil mist and metal powder from entering the laser oscillation gas circulating in the laser gas circulation path.

[0005]

Next, the present invention devised to solve the above-mentioned problems will be described. The elements of the present invention are used to facilitate correspondence with the elements of the embodiments described later. The reference numerals of the elements of the embodiment are enclosed in parentheses. The reason why the present invention is described in correspondence with the reference numerals of the following embodiments is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

In order to solve the above problems, a laser gas transfer device (U) of the present invention is disposed in a laser gas circulation path (8) for circulating a laser oscillation gas through a laser oscillation tube (1). A gas circulation blower (9) and a blower rotating shaft (14) integrally connected to the gas circulation blower (9);
A bearing (27, 29) for rotatably supporting the blower rotating shaft (14); a motor (M) for rotating the blower rotating shaft (14); and a blower rotating shaft (1).
4), a laser gas transfer device (U) including a bearing (27, 29) and a casing that covers the outside of the motor (M), wherein the following requirements (Y01) to (Y03) are provided. (Y01) The bearings (27, 29) are composed of a radial gas bearing (27) and a thrust gas bearing (29). (Y02) An apparatus for supplying a laser oscillation gas having a pressure higher than a pressure of the laser oscillation gas in the laser gas circulation path (8) to the radial gas bearing (27) and the thrust gas bearing (29), A gas transfer supported on the blower rotation shaft (14) and transferred to the rear radial gas bearing (27) and thrust gas bearing (29) at the rear while increasing the pressure of the laser oscillation gas in the laser gas circulation path (8). A gas supply device for bearings having means (31). (Y03) The centrifugal blower, wherein the gas transfer means (31) includes a disk (31a) fixed to the blower rotation shaft and a number of blades (31b) fixed to the disk.

Further, the laser gas transfer device (U) according to the first embodiment of the present invention includes the bearing gas supply device (U) according to the present invention.
1) is characterized by having the following requirements (Y04) to (Y05). (Y04) A laser gas connection path (2) connecting the laser gas circulation path (8) and the gas bearings (27, 29).
2), (Y05) Gas transfer means for bearing (31) arranged in the laser gas connection path (22).

A laser gas transfer device (U) according to a second embodiment of the present invention has the following requirements (Y06) to (Y07) in the laser gas transfer device (U) according to the first embodiment. Features. (Y06) the laser gas connection path (22) is formed in an annular shape around a blower rotation shaft (14) between the gas circulation blower (9) and the gas bearings (27, 29); Y07) The bearing gas transfer means (31) is a centrifugal blower (31) fixed to the blower rotation shaft (14).
It was constituted by.

[0009]

Next, the operation of the present invention having the above-mentioned features will be described. The laser gas transfer device (U) according to the present invention having the above-mentioned features is provided inside the casing with the blower rotating shaft (1
4) is rotationally driven by the motor (M). The gas bearings (27, 29) include a disk (31a) fixed to a blower rotation shaft and a number of blades (31) fixed to the disk.
The gas for laser oscillation having a pressure higher than the pressure of the gas for laser oscillation is supplied by the gas supply device for bearing (U1) having the centrifugal blower (31) consisting of b), so that the gas bearings (27, 29) The blower rotation shaft (14) is rotatably supported. Thus, the blower rotation shaft (14)
Is a gas bearing using gas for laser oscillation (27, 2).
Since it is supported by 9), impurities that degrade the laser oscillation performance do not enter the laser gas circulation path (8).

Further, in the laser gas transfer device (U) according to the first embodiment of the present invention having the above-mentioned features, the laser oscillation gas in the laser gas circulation path (8) is provided with a laser gas connection path (22) and a laser gas connection path (22). The gas is supplied to the gas bearings (27, 29) by bearing gas transfer means (31) arranged in the laser gas connection path (22). In this case, there is no need to newly install a gas supply source for supplying the gas bearings (27, 29).

Further, in the laser gas transfer device (U) according to the second embodiment of the present invention having the above-mentioned features, the laser gas circulation path (8) is provided with a laser oscillation gas, and the laser gas circulation blower (9). ) And the gas bearings (27, 29), a laser gas connection path (22) formed annularly around a blower rotation axis (14), and the blower rotation axis (14) of the laser gas connection path (22). ) Fixed to the centrifugal blower (3
According to 1), the gas is supplied to the gas bearings (27, 29). In this case, there is no need to secure a space for newly providing the laser gas connection path (22) or a new member for configuring the laser gas connection path (22).

[0012]

(Embodiment 1) Next, Embodiment 1 of the laser gas transfer device of the present invention will be described. FIG. 1 is an explanatory diagram of a laser oscillation device in which a first embodiment of a laser gas transfer device is incorporated. The laser oscillation device of this embodiment is a carbon dioxide laser oscillation device. Reference numeral 1 denotes a laser oscillation tube having resonance mirrors -2 and 3 at both ends. A negative and positive electrode 4 is provided inside the laser oscillation tube 1, and a power supply V is provided between the negative and positive electrodes 4. It is interposed. In the laser oscillation tube 1, a carbon dioxide gas and a mixed gas for oscillation excitation added with a nitrogen gas and a helium gas (that is, a gas for laser oscillation) are continuously flown.
Therefore, the laser oscillation tube 1 is provided with an inlet 5 for introducing the laser oscillation gas and an outlet 6 for discharging the gas.
These inlets 5 and outlets 6 are interposed in one closed laser gas circulation path 8.

The laser gas circulation path 8 is provided with a laser gas circulation blower 9 of the laser gas transfer device U. In addition, the laser gas circulation path 8 has a portion between the outlet 6 and the suction side of the laser gas circulation blower 9,
Cooling units 10 and 11 each using a heat exchanger are provided between the laser and the discharge side of the laser gas circulation blower 9.
Reference numeral 12 denotes a heater or gas regenerator in which a catalyst or the like for returning carbon monoxide and carbon to carbon dioxide formed by changing carbon dioxide in the laser oscillation tube 1 is enclosed. 8 is provided in a conduit 8a which draws in a part of the return gas in the tube 8 and returns it to the laser oscillation tube 1. Further, the pressure regulating valve 13 arranged in the laser gas circulation path 8 is used to introduce the laser gas circulation path 8 at a constant pressure of the excitation gas from a gas cylinder (not shown).

FIG. 2 is a detailed explanatory view of the laser gas transfer device U shown in FIG. The laser gas transfer device U
It has a blower rotating shaft 14 integrally connected to the laser gas circulation blower 9 and a casing 16 for accommodating the blower rotating shaft 14. Inside the casing 16, a radial bearing space 17 and a thrust bearing space 1 are provided.
8 and a drive motor interior space 19 are formed. Further, inside the casing 16, a vortex chamber 32 of the laser gas circulation path 8 in which the laser gas circulation blower 9 is disposed.
An annular communication hole 20 for communicating the inside with each of the spaces 17, 18, 19 is provided around the blower rotation shaft.

The communication hole 20 is provided with a plurality of annular boosting spaces 21 in multiple stages. The bearing space 1
7. Space 18 for thrust bearing, space 1 for driving motor interior
9, and the communication hole 20 are formed in a coaxial cylindrical shape,
The blower rotation shaft 14 is arranged coaxially at the center of the blowers. The periphery of the blower rotation shaft 14 and the communication hole 20
The laser gas connection passage 22 is formed by an annular gap formed between the inner surface of the blower 9 and the gap between the rear surface of the blower 9 for laser gas circulation and the casing 16. The front end (left end in FIG. 2) of the blower rotation shaft 14 extends into the laser gas circulation path 8 and is connected to the laser gas circulation blower 9.

The drive motor interior space 19 is provided in the middle of the bearing space 17. A stator coil 25 is fixed and fitted in the drive motor interior space 19, and a rotor 26 made of a permanent magnet is coaxially disposed inside the stator coil 25. TA2
6 is mounted on the blower rotation shaft 14. A motor M is composed of the stator coil 25 and the rotor 26. An annular radial gas bearing 27 is provided between the cylindrical inner peripheral surface of the casing 16 forming the bearing space 17 and the blower rotary shaft 14. As the radial gas bearing 27, various conventionally known radial gas bearings can be employed.

A flange 28 is coaxially fixed to the other end of the blower rotary shaft 14 in the thrust bearing space 18, and is provided between the front and rear end surfaces of the flange 28 in the axial direction and the front and rear end surfaces of the thrust bearing space 18. Is provided with a thrust gas bearing 29. As the thrust gas bearing 29, various conventionally known thrust gas bearings can be employed.

In each of the multi-stage pressurizing spaces 21 of the annular communication hole 20 for communicating the inside of the laser gas circulation path 8 with each of the spaces 17, 18, 19, a centrifugal force as a gas transfer means for bearing is provided. A blower 31 is provided. The centrifugal blower 31 raises the pressure of the laser gas in the laser gas circulation path 8 while raising the rear gas bearings 27 and 29.
It is a device to supply to. Each centrifugal blower 31 is composed of a disk 31a fixed to the blower rotating shaft 14 and a number of radially extending blades 31b fixed to the front surface (left side in FIG. 2) of the disk 31a. Each centrifugal blower 31
When it rotates, the gas on the front side of the disk 31a is transferred to the radially outer peripheral portion by centrifugal force. The gas transferred to the radially outer portion goes around the rear surface of the disk 31a and moves rearward. The laser gas connection path 22 and the plurality of centrifugal blowers 31 constitute a bearing gas supply device U1.

Around the laser gas circulation blower 9, a vortex chamber 32 (see FIG. 1) forming a part of the laser gas circulation path 8 is provided. A laser gas circulation path 8 extending tangentially from the vortex chamber 32 is connected to the outlet 6,
A laser gas circulation path 8 extending from the laser oscillation tube 1 is connected to the suction side (see FIG. 2) of the laser gas circulation blower 9 in the axial direction.

(Operation of the First Embodiment) Next, the operation of the first embodiment having the above-described configuration will be described. When the pressure regulating valve 13 is opened, a laser oscillation gas composed of carbon dioxide gas, nitrogen gas, and helium gas is introduced into the laser gas circulation path 8 and an electric current is supplied to the stator coil 25, the rotor 26 is sealed. The rotation of the blower rotation shaft 14 and the blower 9 for circulating the laser gas is carried out by the rotation of the rotor 26 and the rotor 26 in the space 19 for the interior of the drive motor inside the rotor 16 to increase the pressure of the laser gas. The pressure of the laser oscillation gas whose pressure has been increased is about 150 mb (millibar) near the outlet of the vortex chamber 32, and the laser gas starts to circulate in the laser gas circulation path 8. When a voltage is supplied to the negative and positive electrodes 4 of the laser oscillation tube 1, the gas in the laser oscillation tube 1 is excited,
The circulating gas whose temperature rises due to oscillation of the processing laser light is cooled by heat exchange by the cooling units 10 and 11.

Spaces 17 and 18 in which the gas bearings 27 and 29 are disposed communicate with the laser gas circulation path 8 through a gap between the casing 16 and the blower rotating shaft 14, that is, a laser gas connection path 22. I have. Since the load capacity of the gas bearing is proportional to the ambient pressure, the pressure around the radial bearing 27 is reduced by the vortex chamber 32 of the laser gas circulation path 8.
If the pressure in the vicinity of the outlet is about 150 mb, the load capacity is reduced to about 1/7 of that in the case where the apparatus is used under atmospheric pressure, so that it does not function as a bearing. However, in this embodiment, the gas around the laser gas circulation blower 9, that is, the laser gas in the laser gas circulation path 8 enters the pressure-raising space 21 via the laser gas connection path 22, and The air is transferred rearward by centrifugal blowers (bearing gas transfer means) 31 arranged in multiple stages in the space 21. By this transfer, 150 mm is set in the vortex chamber 32 of the laser gas circulation path 8.
The pressure of the laser gas, which was about mb, rises to about atmospheric pressure in the bearing spaces 17 and 18 in which the radial gas bearing 27 and the thrust gas bearing 29 are arranged. For this reason, the gas bearings 27 and 28 have a load capacity enough to support the blower rotating shaft 14 so as to be rotatable in both the radial direction and the thrust direction.

[0022]

[0023]

[0024]

(Modifications) Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, but falls within the scope of the present invention described in the appended claims. Various small design changes can be made. For example, the present invention can be applied to a gas laser oscillator other than the carbon dioxide laser oscillator.

[0026]

According to the laser gas transfer device of the present invention having the above-described structure, since the lubricating oil mist is not mixed into the gas supplied to the laser oscillator, the gas is not contaminated and the laser is not contaminated. The mirror of the oscillator is not contaminated, which has the effect of extending the life of the laser oscillator. Furthermore, since the gas for laser oscillation compressed in the direction of the bearing is supplied from the gas supply device for the bearing, the gas heated by the bearing action can be prevented from entering the blower side, and the fixed disk is fixed. By means of the centrifugal blower comprising a large number of blades fixed to the disk, the pressure of the laser oscillation gas at a low pressure can be sufficiently increased to the pressure required for the gas bearing.

[Brief description of the drawings]

FIG. 1 is an explanatory view of Embodiment 1 of a laser gas transfer device of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

[Explanation of symbols]

U: laser gas transfer device, U1: bearing gas supply device, M
... Motor, 1 ... Laser oscillation tube, 8 ... Laser gas circulation path,
9 ... Blower for laser gas circulation, 14 ... Blower rotating shaft, 2
DESCRIPTION OF REFERENCE NUMERALS 1: boosting space, 22: laser gas connection path, 25: stator coil, 26: rotor, 27, 28: gas bearing, 3
1 ... gas transfer means for bearing (centrifugal blower), 36 ... gas transfer means for bearing (vacuum pump),

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01S 3/00-3/30 F16C 32/06

Claims (1)

(57) [Claims] 1. A gas circulation blower disposed in a laser gas circulation path for circulating a laser oscillation gas through a laser oscillation tube, a blower rotating shaft integrally connected to the gas circulation blower, and In a laser gas transfer device including a bearing that rotatably supports a blower rotation shaft, a motor that rotationally drives the blower rotation shaft, and a casing that covers the outside of the blower rotation shaft, the bearing, and the motor, the following requirements ( (Y01) to (Y03), a laser gas transfer device, (Y01) the bearing is constituted by a radial gas bearing and a thrust gas bearing. (Y02) A device for supplying a laser oscillation gas having a pressure higher than a pressure of the laser oscillation gas in the laser gas circulation path to the radial gas bearing and the thrust gas bearing, wherein the gas is supported by the blower rotating shaft and A gas supply device for bearings, comprising gas transfer means for transferring pressure to the radial gas bearing and the thrust gas bearing at the rear while increasing the pressure of the laser oscillation gas in the laser gas circulation path. (Y03) The gas transfer means is a centrifugal blower comprising a disk fixed to the blower rotation shaft and a number of blades fixed to the disk.