JPH022697A - Laser oscillator - Google Patents

Abstract

PURPOSE:To improve strength, wear resistance and heat resistance of a rolling element or the like of a bearing, preventing a bearing from being damaged in a short time by a method wherein a blower for a gas circulator consists of a turbo blower which rotates in laser gas and the bearing of the blower is made of ceramic. CONSTITUTION:In a laser oscillator consisting of a discharge tube which laser- excites with gas discharge, an optical resonator which generates laser oscillation, a blower and a gas circulator which forcedly cools laser gas with a cooler, said blower is composed of a turbo blower which rotates in laser gas, and a bearing of the blower is made of ceramic. For example, rolling elements 24, 25 between an inner wheel and an outer wheel of antifriction bearings 19, 20 are made of ceramic with alumina contained as a main component. This increases strength of the rolling element by 3 to 4 times, preventing damage of bearings caused by fatigue due to repetitive load application on raceway surfaces of inner and outer wheels and on the raceway surface of the rolling element, and damage caused by deterioration of fatigue limitation due to wear caused by friction and friction heat.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a high-power laser such as a CO□ laser for processing,
Specifically, the present invention relates to a CO laser oscillation device that is smaller and lighter and has improved oscillation characteristics, reliability, and maintainability.

[Conventional technology]

FIG. 3 shows the configuration of a conventional CO laser oscillation device. In the figure, an output coupling mirror 2 and a total reflection mirror 3 are installed at both ends of a discharge tube 1. Further, two metal electrodes 4 and 5 are attached to the outside of the discharge tube 1, and a high frequency voltage is applied between them by a high frequency power source 6, and a high frequency glow discharge is generated inside the discharge tube 1 to generate a laser beam. Excitation takes place. The optical axis of the laser beam inside the discharge tube 1 is indicated by 13, and the optical axis of the laser beam taken out from the output coupling mirror 2 is indicated by 14.

When the laser oscillation device is started, the entire interior of the device is first evacuated by the vacuum pump 12. Then, the valve 11 is opened and a predetermined flow rate of laser gas is guided from the cylinder 10, and the gas pressure inside the device reaches the specified value.After that, the vacuum pump 12 continues to exhaust and supply gas is introduced, and the gas pressure is maintained at the specified value. However, part of the laser gas is continuously replaced with fresh gas, thereby preventing gas contamination.

Furthermore, in FIG. 4, the laser gas is circulated within the apparatus by a blower 9. Its purpose is to cool the laser gas.

In CO, laser, about 20% of the injected electrical energy is converted into laser light, and the rest is consumed for gas heating. However, according to theory, the laser oscillation gain is -(3/2) of the absolute temperature T.
), so forced cooling of the laser gas is necessary to increase the oscillation efficiency. Laser gas is approximately 100m
The liquid passes through the discharge tube at a flow rate of /sec, flows in the direction shown by the arrow, and is guided to the cooler 8. Here, heating energy mainly due to discharge is removed. Since compression heat is generated in the blower 9, the gas passes through the cooler 7 before being led to the discharge tube 1 again. Since these coolers 7 and 8 are well known, detailed explanation will be omitted.

FIG. 4 shows the structure of a conventional turbo blower. turbo wing 1
6 is rotated at a high speed of about 100,000 RPM by a motor consisting of a rotor 17 attached to a shaft 26 and a stator 18. Therefore, compared to a low-speed Roots blower, the volume is smaller in inverse proportion to the rotation speed.

Furthermore, rolling bearings 19 and 20 are used to support the shaft 26 due to low bearing loss and cost.

The rolling elements of the rolling bearings 19 and 20 are made of 1 inch high carbon chromium bearing (JIS standard number 5UJ2-4). For bearing lubrication, oil-jet or oil-air lubrication is used to periodically supply oil to the bearings due to high-speed rotation. In FIG. 5, an oil supply unit 1-21 uses air to atomize oil to the rolling shafts 19 and 20, and supplies the atomized oil to the rolling bearings through passages 22 or 23.

[Problem to be solved by the invention]

The conventional laser oscillation device shown in FIGS. 3 and 4 has the following problems.

Since the rolling elements of rolling bearings are made of steel, the rolling elements may fatigue due to repeated loads applied to the raceway of the inner and outer rings and the raceway surface of the rolling element, wear due to friction on the raceway surface, and fatigue limit decrease due to frictional heat. Bearing damage occurred during this period.

The present invention has been made in view of these points, and an object of the present invention is to provide a gas laser device in which the bearing of the blower is made of ceramic.

[Means to solve the problem]

In order to solve the above problems, the present invention consists of a discharge tube that excites the laser by gas discharge, an optical resonator that performs laser oscillation, a gas circulation device that forcibly cools the laser gas by using a blower and a cooler, etc. A laser oscillation device is provided, wherein the blower is comprised of a turbo blower rotating in laser gas, and the blower has a bearing made of ceramic.

Furthermore, a laser oscillation device is provided in which two turbo blades are arranged so that thrust forces are applied in opposite directions.

[Effect]

In turbo blowers, the strength of the rolling elements is improved by using ceramics for the rolling elements of rolling bearings, etc.
Improves wear resistance and heat resistance to prevent bearing damage in a short period of time.

Furthermore, since the turbo blades are arranged so that thrust forces are applied in opposite directions, the forces in the thrust direction are balanced, increasing safety, and the thrust load applied to the bearings is also reduced, extending the life of the bearings.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a configuration diagram of an embodiment of the laser oscillation device of the present invention. The same components as in FIG. 4 are given the same reference numerals, and detailed explanation thereof will be omitted.

Although the turbo blades 16 are shown as centrifugal blades, they may be diagonal flow blades or axial flow blades.

The rolling elements 24 and 25 between the inner and outer rings of the rolling bearings 19 and 20 are made of ceramic.

For example, the strength of a ceramic rolling element mainly composed of alumina (ALz Ox) is 330 kg/cd, and the hardness is Vickers 1500. In contrast, conventional high carbon chromium steel has a hardness of 100 kg/cii and Vickers 360. Therefore, by increasing the strength of the rolling elements by 3 to 4 times, fatigue due to repeated loads applied to the raceway surfaces of the inner and outer rings and the raceway surfaces of the rolling elements, wear due to friction on the raceway surfaces, and fatigue limits due to frictional heat are reduced. Bearing damage caused by this can be prevented.

In the above explanation, the rolling elements of the rolling bearing are made of ceramic, but similar effects can be obtained by using a ceramic sliding bearing.

The turbo blower shown in Fig. 1 is applied to a laser oscillation device with an output of approximately IKW, but larger turbo blades may be used to achieve even higher output, but from a cost standpoint, using the same blade is preferable. is desirable. FIG. 2 shows the structure of a turbo blower with a laser output of about 2 KW. In FIG. 0, reference numeral 31 is a turbo blower, and the bearings are the same as those in FIG. 1, so they are omitted. Note that the arrow in the figure indicates the direction in which the laser gas flows.

Two turbo blades 16 and 32 are attached above and below the shaft. With this configuration, two turbo blades can be rotated with one set of bearing and drive motor, which is advantageous in terms of cost. 1
7 is a rotor, and 18 is a stator. Here, by attaching the turbo blades to the same shaft, load fluctuations in the thrust direction are canceled out, resulting in a very small thrust load, improved stability, and a very long life.

FIG. 4 is a configuration diagram of a conventional turbo blower.

〔Effect of the invention〕

As explained above, in the present invention, since ceramic is used for the rolling elements of the rolling bearing, the strength, wear resistance, and heat resistance of the rolling elements of the bearing can be improved, and damage to the bearing can be prevented in a short period of time.

Furthermore, since the turbo blades are arranged so that thrust forces are applied in opposite directions, the forces in the thrust direction are balanced, increasing stability, and the thrust load applied to the bearings is also reduced, extending the life of the bearings.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram of a turbo blower with a laser output of about IKW according to the present invention, Fig. 2 is a structural diagram of a turbo blower with a laser output of about 2 KW, and Fig. 3 is a structural diagram of a conventional CO□ laser oscillation device. ...−・−・・−Discharge tube 2−・−−−−1−−−−−−−・Output coupling mirror 3・
- Total reflection mirror 4.5 - - - - - Electrode 6 - - High frequency power supply 7.8 - - - - - - - - Cooler 9 - - −
−−−−−−・−・・・Blower o−−−−−−−−
−−−−−−Gas cylinder 2・・・−・・・・−−−−−
・Vacuum pump 3・・・・−・・−Intra-cavity laser beam optical axis 4−・・−・・−−−−−・−Outer cavity laser beam optical axis 6−・−−1−−−− −・・−Turbo blade 7・・−・−・−・−−−−One rotor 8−・−m−～−・−・−Stator

Claims (5)

[Claims] (1) In a laser oscillation device consisting of a discharge tube that excites the laser by gas discharge, an optical resonator that performs laser oscillation, a gas circulation device that forcibly cools the laser gas using a blower and a cooler, the blower is in the laser gas. 1. A laser oscillation device comprising a turbo blower that rotates at a speed of 100.degree. C., the blower having a bearing made of ceramic. (2) The laser oscillation device according to claim 1, wherein the bearing is a rolling bearing, and the rolling elements of the rolling bearing are ceramic. (3) The laser oscillation device according to claim 1, wherein the bearing is a ceramic sliding bearing. (4) The laser oscillation device according to claim 1, wherein the turbo blower is composed of one turbo blade. (5) The laser oscillation device according to claim 1, wherein the turbo blower has two turbo blades provided on the same shaft so that thrust loads are applied in opposite directions.