JPH0572158U - Gas laser gas circulation device and its motor - Google Patents

Abstract

(57) [Abstract] (Modified) [Purpose] Relating to a gas circulation device for gas laser and its electric motor, and in particular, improvement of gas circulation device for gas laser of industrial gas laser device such as carbon dioxide laser or excimer laser and its electric motor Regarding In a gas laser gas circulation device including a blower 2 for circulating gas in a pressure vessel and an electric motor for driving the blower for circulating gas from outside the pressure vessel, the blower is driven by an output shaft inserted in the vessel. At the same time, the blower 2 and the electric motor 10 are arranged coaxially, and a magnetic fluid shaft seal is provided at the bearing of the electric motor and the output shaft end of the electric motor to prevent gas in the pressure vessel from leaking to the outside. Also,
The electric motor 10 is arranged on both sides of the blower, a joint is attached to the output shaft of the electric motor, and the blower is held by the bearings 15 and 16 of the electric motor. Alternatively, an electric motor is provided on one side of the blower, and a support shaft held by a bearing is provided on the other end side to hold the blower, and a pressure vessel is provided between the bearing on the other end side and the support shaft end of the blower. A magnetic fluid shaft seal is provided to prevent the gas inside from leaking to the outside.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas circulation device for a gas laser and an electric motor thereof, and more particularly, to an improvement of a gas circulation device for a gas laser of an industrial gas laser device such as a carbon dioxide gas laser or an excimer laser and an electric motor thereof.

[0002]

[Prior Art]

 Conventionally, in industrial high-power gas lasers such as carbon dioxide gas or excimer lasers, when CW (continuous) or high-repetition pulse oscillation operation is performed, gas circulation is performed to cool the gas and promote diffusion of discharge products. Be seen. In a conventional gas circulation device, an electric motor is installed in the atmosphere and drives a blower installed in the medium gas via a shaft sealing device that separates the laser medium gas from the atmosphere. Since the shaft sealing device is required, the bearing supporting the blower is arranged in the medium gas in the conventional gas laser.

For example, in the conventional gas laser gas circulating apparatus shown in FIG. 5, the blower 52 in the pressure vessel 51 is supported by two bearings 53 and 54. Overhanging from the bearing 53, magnetic couplings 55 and 56 are installed with a partition wall 57 interposed therebetween. The transmission of power from the electric motor 58 passes through the partition wall 57 by this magnetic coupling, is magnetically coupled, and is transmitted into the pressure vessel 51. Gas is sealed by the partition wall 57. The gap between the magnetic couplings 55, 56 and the partition wall 57 must be kept at several hundreds of microns, and the magnetic joint must be held securely, and the bearing 53 is used.

FIG. 6 shows an example of another conventional gas circulation device. In this example, the magnetic fluid seal unit 60 performs shaft sealing, and the blower 61, the magnetic fluid seal unit 60, and the electric motor 62 are independently supported by bearings. The electric motor 62 and the blower 61 are connected by universal joints 63 and 64 to absorb the misalignment between the axes.

[0005]

[Problems to be solved by the device]

 However, the conventional gas circulation device requires a bearing to support the blower in the laser medium, and a small amount of oil mist is generated from the grease that lubricates the bearing, and this oil mist reacts with the medium gas to generate impurity gas. This causes a decrease in laser output. Conventionally, an oil seal was installed next to the bearing, or the vicinity of the bearing was purged with clean gas, but countermeasures were attempted.However, problems such as the rubber used for the oil seal being corroded by the gas occurred It's not. In addition, excimer lasers that use a strongly corrosive gas such as fluorine or hydrogen chloride as the laser medium have a problem that the life of the bearing is shortened because the operating environment is different from normal.

The present invention focuses on the above-mentioned conventional problems, and relates to a gas laser gas circulation device and an electric motor thereof, and more particularly, to a gas laser gas circulation device of an industrial gas laser device such as a carbon dioxide gas laser or an excimer laser, and the same. The purpose is to provide electric motors.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, in the first aspect of the present invention, a gas laser gas circulating device for a gas laser, comprising a blower for circulating gas in a pressure vessel and an electric motor for driving the blower for circulating gas from outside the pressure vessel. In the above, the blower is driven by the output shaft inserted in the container, the blower and the electric motor are coaxially arranged, and the gas in the pressure container is prevented from leaking outside to the bearing of the electric motor and the output shaft end of the electric motor. A magnetic fluid shaft seal is provided to prevent this.

In the second invention, which is mainly based on the first invention, the electric motors are arranged on both sides of the blower, and the output shaft of the electric motor is fitted with a joint to hold the blower by the bearings of the electric motor. Further, in the third invention, an electric motor is provided on one side of the blower, and a support shaft held by a bearing is provided on the other end side to hold the blower, and the bearing on the other end side and the blower are provided. A magnetic fluid shaft seal is provided between the support shaft and the end of the support shaft to prevent gas in the pressure vessel from leaking to the outside.

In the fourth invention, a magnetic fluid shaft seal for preventing gas in the pressure vessel from leaking to the outside is provided in the electric motor between the bearing of the electric motor and the output shaft end of the electric motor. The blower is driven by an electric motor arranged on the bearing side and an electric motor in which the bearing is hermetically sealed.

Further, in the fifth method, which is mainly based on the fourth invention, the pressure detecting means for detecting the breakage of the magnetic fluid shaft seal is provided in the electric motor sealed in the housing.

[0011]

[Action]

 According to the above configuration, the electric motor is attached to the pressure vessel that seals the laser medium with the flange, and the gas seal and the fixing are performed at the same time. An electric motor is installed in at least one pressure vessel of the blower to drive the blower, and the shafts at both ends of the blower and the output shafts of the electric motors on both sides of the pressure vessel, or one shaft of the blower and the output shaft of the electric motor. Assemble the other shaft of the blower and the support shaft with a fixed shaft joint. This eliminates the need to dispose the bearing in the medium gas, and a small amount of oil mist is not generated from the grease that lubricates the bearing, so that the laser output does not decrease. Also, since the electric motor is sealed and the pressure detector is installed, even if the magnetic fluid seal is broken, it can be easily detected. Furthermore, since the magnetic fluid seal gap is maintained by using the bearing that holds the rotor of the electric motor, it is not necessary to install a separate bearing that holds the magnetic fluid seal, and the overall length of the gas laser gas circulation device can be shortened. ..

[0012]

【Example】

 Embodiments of a gas laser gas circulating apparatus for a gas laser and an electric motor thereof according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall configuration diagram showing a first embodiment of a gas circulating apparatus for a gas laser and an electric motor thereof according to the present invention. In FIG. 1, a blower 2 that circulates a gas is housed in a pressure vessel 1 that encloses a laser medium. Further, an electric machine 10 described later is attached to the pressure vessel 1 by a flange 13a of a front case 13 of the electric motor. The blower 2 arranged in the pressure vessel 1 is driven by the output shaft 12a of the electric motor 10 inserted into the pressure vessel 1 from outside the pressure vessel 1. An O-ring groove 13b is provided in the flange 13a, and an O-ring 4 is attached to seal the gas in the pressure vessel 1. The shaft 2a from the blower 2 is fixed to the output shaft 12a of the electric motor 10 by the joints 5 and 6. In the case of this embodiment, this joint is composed of fixed joints 5 and 6. FIG. 2 is a front sectional view of the electric motor 10. The rotor 11 of the electric motor 10 is fixed to the shaft 12, and the shaft 12 is supported by bearings 15 and 16 fixed to the electric motor front case 13 and the body case 14. The shaft at one end of the shaft 12 is supported by a bearing 15 and serves as an output shaft 12a. A magnetic fluid seal 20 is arranged between the shaft end 12b of the output shaft 12a and the bearing 15. An O-ring 21 is arranged between the electric motor front case 13 of the electric motor 10 and the main body case 14 to form a sealed structure. A pressure sensor 22 is arranged in the main body case 14 to detect the pressure in the electric motor 10. Further, although not shown, the outer circumference of the main body case 14 of the electric motor may be covered with a water cooling jacket, or the main body case 14 may be provided with a water cooling hole.

Next, the operation of the above embodiment will be described. The electric motor 10 is attached to the pressure vessel 1 for sealing the laser medium, and the gas in the pressure vessel 1 is sealed by the magnetic fluid seal 20 and the blower 2 is supported. At this time, the flange 13a is attached to the hole formed in the pressure vessel 1 with a spigot structure, and the spigot is machined with sufficient concentricity. Further, since the bearing hole 15a of the electric motor front case 13 and the hole 20a of the magnetic fluid seal 20 are integrally machined, the machining accuracy is ensured, and the shaft 12 and the magnetic fluid seal 20 have a small size of several tens of microns. The gap can be maintained, and the magnetic fluid is held by the magnetic force, so that the seal is reliably performed. Through the magnetic fluid seal 20, the shafts 2a and 2b at both ends of the blower 2 are driven from both sides by the output shaft 12a of the electric motor 10 through the fixed shaft couplings 5 and 6. As a result, the bearing 15 is not provided in the medium gas, and a small amount of oil mist is not generated from the grease that lubricates the bearing 15. Further, the magnetic fluid seal 20 will not function, and gas will flow from the magnetic fluid seal 20 to the electric motor 10 side, or from the electric motor 10 side to the pressure vessel 1, and the electric motor 10 will be sealed even if it leaks. The gas is sealed. Further, the leaked gas pressure has a volume of the body case 14 of the electric motor 10 much smaller than the volume of the pressure vessel 1, so that the pressure of the body case 14 becomes substantially equal to the pressure in the pressure vessel 1. Therefore, the leaked gas pressure can be easily detected by detecting it with the pressure sensor 22 provided in the main body case 14 of the electric motor 10. Normally, the pressure in the main body case 14 of the electric motor 10 is atmospheric pressure, the pressure in the pressure vessel 1 is 100 Torr or less for the carbon dioxide laser, and 2 to 6 kg / cm 2 for the excimer laser or the TEA carbon dioxide laser. Since there is a difference from the case 14, it can be easily detected.

FIG. 3 is an overall configuration diagram showing a second embodiment of the gas circulating apparatus for gas laser of the present invention. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In FIG. 3, the electric motor 10 is arranged in the pressure vessel 1a on one side of the blower 2, and the one shaft 2a of the blower 2 and the output shaft 12a of the electric motor are assembled to drive the blower 2. The other shaft 2b of the blower is attached to the support shaft 25 at the joint portion 26. The support shaft 25 is supported by a cover 27 inserted into the spigot portion 1a of the pressure vessel 1 via a bearing 28, and the joint 25a of the support shaft 25 of the joint portion 26 and the joint 2c of the blower 2 are pivotally inserted. Has been fixed. Further, the joint 12c of the output shaft 12a of the electric motor is pivotally inserted and fixed to the joint 2d of the blower 2. The magnetic fluid seal 20 is disposed between the bearing 28 and one shaft 2b of the blower 2, the outer diameter of the magnetic fluid seal 20 is inserted into the hole 27a of the cover 27, and the inner diameter is the outer diameter of the support shaft 25. 25a and a predetermined clearance. As a result, the bearing is not provided in the medium gas, and a small amount of oil mist is not generated from the grease that lubricates the bearing, so that the laser output is not reduced.

FIG. 4 is an overall configuration diagram showing a third embodiment of the gas circulating apparatus for gas laser of the present invention. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In FIG. 4, a part of the pressure of the blower 2 is used to provide another pressure circulation path 35, and a filter 36 is disposed in the middle of the pressure circulation path 35 so that dust such as dust generated in the gas, For example, the dust that floats in the gas due to the sputtering of the electrode due to discharge or the like is removed, and the cleaned gas is introduced into the vicinity of the magnetic fluid seal 20 to prevent dust from being mixed with the magnetic fluid and degrading the magnetic fluid. It is configured to prevent. This extends the life of the magnetic fluid.

[0016]

[Effect of the device]

 As described above, according to the present invention, since the bearing in the laser medium gas can be eliminated, there is no oil mist or reaction product with the medium gas, and it is possible to prevent the laser output from decreasing. Furthermore, with an excimer laser that uses a strongly corrosive gas, since the bearing is operated in the atmosphere, the life of the bearing can be extended and the life can be predicted. In addition, even if the magnetic fluid seal is broken, the laser medium does not leak to the outside, so it is safe to use toxic gas, and the excellent effect of easy detection can be obtained.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment of a gas circulating apparatus for a gas laser and an electric motor thereof according to the present invention.

FIG. 2 is a front sectional view of a gas circulating electric motor for a gas laser according to the present invention.

FIG. 3 is an overall configuration diagram showing a second embodiment of the gas laser gas circulating apparatus and the electric motor thereof according to the present invention.

FIG. 4 is an overall configuration diagram showing a third embodiment of the gas circulating apparatus for gas laser of the present invention.

FIG. 5 is an overall configuration diagram showing a first embodiment of a conventional gas laser gas circulating apparatus and an electric motor thereof.

FIG. 6 is an overall configuration diagram showing a second embodiment of a conventional gas laser gas circulating apparatus and its electric motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure vessel 2 Blowers 5, 6, 12c, 26a Joint 10 Electric motor 12 Shaft 12a Output shaft 15, 16 Bearing 20 Magnetic fluid seal 22 Pressure sensor 25 Support shaft 28, 29 Bearing

Claims (5)

[Scope of utility model registration request] 1. A blower for circulating gas in a pressure vessel,
In a gas laser gas circulation device comprising an electric motor for driving a blower that circulates gas from outside the pressure vessel, the blower is driven by an output shaft inserted in the vessel, and the blower and the electric motor are coaxially arranged, and the electric motor And a magnetic fluid shaft seal for preventing the gas in the pressure vessel from leaking to the outside of the bearing and the output shaft end of the electric motor. 2. An electric motor is provided on both sides of the blower, and
2. The gas circulating apparatus for a gas laser according to claim 1, wherein a joint is attached to the output shaft of the electric motor, and the blower is held by the bearing of the electric motor. 3. An electric motor is provided on one side of the blower, and a support shaft held by a bearing is provided on the other end side to hold the blower, and the bearing on the other end side and the support shaft end of the blower are provided. The gas circulation device for a gas laser according to claim 1, further comprising a magnetic fluid shaft seal for preventing the gas in the pressure vessel from leaking to the outside. 4. A magnetic fluid shaft seal for preventing gas in the pressure vessel from leaking to the outside is provided inside the electric motor between the bearing of the electric motor and the output shaft end of the electric motor, and is arranged on the bearing side of the electric motor. An electric motor for gas circulation for a gas laser, characterized in that the blower is driven by an electric motor in which an armature and bearings are sealed in a housing. 5. A pressure detecting means for detecting breakage of a magnetic fluid shaft seal is arranged in an electric motor sealed with a housing.
A gas circulation electric motor for the gas laser described.