JP2016219717A - Gas laser oscillation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas laser oscillation device capable of clearly separating occurrence of presence or absence of misalignment of a rotary section caused by breakage of the bearing of a blower, or the like, capable of detecting misalignment without taking time after occurrence thereof, while furthermore capable of emergency stop of the rotary section when a determination is made that misalignment has occurred.SOLUTION: A gas laser oscillation device includes a blower for supplying laser gas, the rotary section of the blower includes a shaft provided with an impeller at the tip, a drive section for rotating the shaft, and a co-rotating ring placed between the impeller and an upper bearing. A non-rotating section includes a housing, a scroll covering the impeller, and a fixed part spacer placed at a position facing the co-rotating ring while having a predetermined gap thereto. A temperature detector in contact with the fixed part spacer is provided.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a laser oscillation device using a laser medium gas.

  The gas laser oscillation device has a circulation circuit that compresses and circulates a mixed gas such as carbon dioxide (hereinafter referred to as laser gas), and in the circulation circuit in which the laser gas is sealed, an electrode, a total reflection mirror, and a partial reflection mirror are provided. Is provided. The laser gas is excited by the discharge generated from the electrode, and the excited laser gas is resonated between the total reflection mirror and the partial reflection mirror, and is taken out as a laser output.

  As one element in the configuration of the laser gas circulation circuit, there is a turbo-type air blower that rotates a turbo blade at high speed to compress and circulate laser gas.

  In this type of turbo-type blower, a turbo impeller is rotatably disposed above a housing, a mechanism for compressing and discharging laser gas is provided, and a motor for rotating the turbo impeller at a high speed is disposed below. Has been. And the rotary body which consists of this motor, a rotor, a turbo blade | wing, a rotating shaft, etc. is supported by the bearing.

  In the blower, the shaft of the rotating part is displaced due to deterioration of the bearing due to long-term use at high speed rotation, and the impeller of the rotating part comes into contact with the scroll of the non-rotating part, leading to breakage. Circulating the inside, there is a possibility that the entire gas laser oscillator is damaged.

  That is, the rotating shaft of the blower causes an axis shift for some reason, the impeller of the rotating part and the scroll of the non-rotating part come into contact with each other, and the fragments circulate in the circulation circuit, so that the entire gas laser oscillation device Therefore, in order to restore the gas laser oscillation device, it is necessary to replace the laser gas circulation circuit components in addition to the replacement of the blower device, which requires much cost and time. Therefore, it has been a problem to forcibly stop the blower before the damage is expanded.

  Since bearings that cause such shaft misalignment generate heat due to poor lubrication, foreign matter intrusion, etc., as a first conventional technique, an attempt was made to prevent damage to the blower by detecting heat early and issuing an alarm. There are some (see, for example, Patent Document 1).

  As a second prior art, there is one that attempts to detect an axis deviation by simultaneously detecting vibrations of a rotating part. In order to reduce the load on the turbo impeller and reduce the shaft misalignment when the preset vibration threshold is exceeded, control is provided to reduce the gas pressure in the circulation circuit sealed with laser gas to prevent damage to the blower. (For example, refer to Patent Document 2).

JP 2011-113993 A JP 2011-187526 A

  However, in the gas laser oscillating device according to the first prior art, although it is possible to detect the gradually changing deterioration of the bearing, it is not possible to clearly determine the occurrence of the axis deviation that should be stopped urgently. If the judgment is made too severe, the stop is repeated unnecessarily, and if a loose reference is provided, there is a possibility that the moment of occurrence of the axis deviation may be missed.

  In addition, in the second prior art, since the occurrence of the shaft misalignment is detected through an indirect decrease called vibration, the occurrence of the shaft misalignment cannot always be detected without an interval, and there is a possibility that the emergency stop cannot be handled.

  Furthermore, the conventional method of issuing an alarm by temperature detection or vibration detection takes time until the rotating shaft stops, and is not sufficient to fulfill the original purpose of preventing damage expansion.

  Therefore, the present invention solves the above-mentioned problems, clearly separates the presence or absence of the occurrence of shaft misalignment of the rotating part caused by the blower bearing breakage, etc., and detects it immediately after the shaft misalignment occurs. Further, it is an object of the present invention to provide a gas laser oscillation device capable of urgently stopping the rotating portion when it is determined that the axis deviation has occurred.

  In order to solve the above problems, a gas laser oscillation device according to the present invention forms a discharge path for exciting a laser medium, a blower for blowing laser gas, and a laser gas circulation path between the discharge means and the blower. The air blower includes a rotating part that is rotated by shaft driving means, a non-rotating part that does not rotate, and an upper bearing and a lower bearing provided between them, and the rotating part is a tip. A housing in which the impeller portion is provided, a drive portion for rotating the shaft, and a co-rotating ring disposed between the impeller and the upper bearing, wherein the non-rotating portion houses the rotating portion. A scroll that covers the impeller, a fixed spacer that is disposed at a position facing the co-rotating ring with a predetermined gap from the co-rotating ring, and a temperature detector that contacts the fixed spacer. For example it was, is intended.

  Further, on the extension of the shaft, a shaft pressing brake portion that is movable in the axial direction is further provided, and when the bearing is determined to be abnormal, the rotating portion of the blower is stopped by the shaft pressing brake portion. It is.

  With the above configuration, the gas laser oscillation device according to the present invention includes a temperature detection unit that is in contact with the fixed portion spacer, provides a predetermined temperature threshold value, and the temperature detected by the temperature detection unit is the upper bearing temperature detection unit. If the temperature is higher than the detected temperature, it is determined that the bearing is abnormal. In other words, when a shaft misalignment occurs, the frictional heat of the member that contacts the rotating part is directly measured first, so the presence or absence of the shaft misalignment is clearly separated, and after the shaft misalignment occurs Can be detected without putting

  Furthermore, a shaft pressing brake portion that is movable in the axial direction is further provided on the extension of the shaft, and when the bearing is determined to be abnormal, the rotating portion of the blowing means is stopped by the shaft pressing brake portion.

Configuration diagram of a gas laser oscillation apparatus according to an embodiment of the present invention Cross-sectional view of a blower according to an embodiment of the present invention Partial detail drawing of the air blower which concerns on embodiment of this invention Detailed view of shaft pressing brake part according to an embodiment of the present invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same components are denoted by the same reference numerals, and the description thereof may be omitted.

(Embodiment 1)
<Main configuration and operation of gas laser oscillator>
FIG. 1 is a configuration diagram of a gas laser oscillation apparatus according to an embodiment of the present invention. The gas laser oscillation device 100 includes a discharge tube 101, electrodes 102 and 103, a power source 104, a total reflection mirror 106, a partial reflection mirror 107, a laser gas channel 110, heat exchangers 111 and 112, and a blower device 200.

  The discharge tube 101 is made of a dielectric material such as glass, the electrodes 102 and 103 are provided around the discharge tube, and the power source 104 is connected to the electrodes. A discharge space 105 is formed in the discharge tube 101 sandwiched between the electrodes 102 and 103. The total reflection mirror 106 and the partial reflection mirror 107 are fixedly disposed at both ends of the discharge space 105 to form an optical resonator. The laser beam 108 is output from the partial reflection mirror 107.

  A laser gas flow 109 circulates in the gas laser oscillator 100. The laser gas flow path 110 is connected to the discharge tube 101 by a laser gas introduction part 115. The heat exchangers 111 and 112 have a function of lowering the temperature of the laser gas whose temperature has been increased by the discharge in the discharge space 105 and the operation of the blower 200. The blower 200 circulates the laser gas and obtains a gas flow of about 100 m / sec in the discharge space 105.

  The above is the configuration of the gas laser oscillation apparatus according to the embodiment of the present invention. The operation of the gas laser oscillation apparatus of the present invention configured as described above will be described.

  The laser gas sent out from the blower 200 passes through the laser gas flow path 110 and is introduced into the discharge tube 101 from the laser gas introduction unit 115. In this state, discharge is generated in the discharge space 105 from the electrodes 102 and 103 connected to the power source 104.

  The laser gas in the discharge space 105 is excited by obtaining this discharge energy, and the excited laser gas is brought into a resonance state by an optical resonator formed by the total reflection mirror 106 and the partial reflection mirror 107, and the laser is emitted from the partial reflection mirror 107. The beam 108 is used for applications such as laser processing.

<Details of configuration and operation of blower>
Next, the configuration and operation of the blower 200 according to the embodiment of the present invention will be described with reference to FIG.

  FIG. 2 is a structural cross-sectional view of the blower according to the embodiment of the present invention. The blower device 200 includes a motor rotor 201, a rotating shaft 202, an impeller 203, a motor stator 204, a housing 205, a scroll 206, an upper bearing 207, a lower bearing 208, a co-rotating ring 209, a nut 210, and a fixed portion spacer 211. .

  The structure of the blower device 200 is divided into a rotating part and a non-rotating part, and the rotating part is composed of the motor rotor 201, the rotating shaft 202, the impeller 203, the upper bearing 207, and the lower bearing 208. The non-rotating portion includes a housing 205 that houses the rotating portion, a scroll 206 that covers the impeller, and a co-rotating ring 209.

  The motor rotor 201 is coupled to the rotating shaft 202, and an impeller 203 is provided at the tip of the rotating shaft 202. A motor stator 204 is disposed coaxially with the motor rotor 201, and the motor stator 204 is fixed to the housing 205. When AC power is supplied to the motor stator 204 from the outside, the motor rotor 201 rotates and rotates the impeller 203 via the rotating shaft 202.

  A scroll 206 is disposed around the impeller 203, and a laser gas flow 109 is generated by the rotation of the impeller 203. The rotating shaft 202 is held in a rotatable state by an upper bearing 207 and a lower bearing 208 that are arranged at two locations on the upper and lower sides. The upper bearing 207 and the lower bearing 208 are coupled to the rotating shaft 202.

  Furthermore, the characteristic part of the air blower 200 which concerns on embodiment of this invention is demonstrated, using FIG. 3 of a fragmentary detailed view.

  A co-rotating ring 209 is attached to the impeller 203 of the blower device 200. If the positional relationship between the impeller 203 and the co-rotating ring 209 is shifted during rotation, the balance of the rotating part is lost, which causes a swing. The co-rotating ring 209 is press-fitted and centered on the impeller 203 and fixed.

  The inner ring of the upper bearing 207 is fixed to the rotating shaft 202 by press fitting, and the impeller 203 and the co-rotating ring 209 are pressed against the inner ring of the upper bearing 207 by tightening the nut 210 attached to the upper part of the rotating shaft 202. It is fixed to the rotary shaft 202 in the form.

  The fixed part spacer 211 includes temperature detecting means 215 and is fixed to the housing 205 so as to face the co-rotating ring 209. Further, a gap is provided between the fixed portion spacer 211 and the co-rotating ring 209, and the gap is sufficiently smaller than the gap between the impeller 203 and the scroll 206.

  For this reason, contact is not usually made, but if a shaft misalignment occurs due to a bearing abnormality, the rotating shaft 202 swings during rotation, and when the co-rotating ring 209 and the fixed portion spacer 211 are first tilted around the point 212, To touch.

  At this time, since the gap between the fixed portion spacer 211 and the co-rotating ring 209 is sufficiently smaller than the gap between the impeller 203 and the scroll 206, it is possible to prevent the scroll 206 and the impeller 203 from contacting each other.

  Further, when the rotating shaft 202 swings during rotation and tilts around the point 212, when the co-rotating ring 209 and the fixed portion spacer 211 come into contact, frictional heat is generated in the fixed portion spacer. This frictional heat is detected by temperature detecting means 215 provided on the fixed portion spacer 211.

  When the signal from the temperature detection means 215 is input to the control means 113, the value for the temperature preset in the control means 113 is compared with the input value, and when the input value is determined to be greater than or equal to the preset value, While stopping the external electric power sent to the power supply 104 and the motor stator 204, the alarm means 114 is operated and an abnormality is reported to an operator.

  Further, the blower 200 is provided with a shaft pressing brake device 213 as shown in FIG. A brake holder 214 is attached to the scroll 206, and the shaft pressing brake device 213 is held by the brake holder 214 immediately above the rotation shaft 202 in the axial direction.

  Further, the shaft pressing brake device 213 is movable in the direction of the rotating shaft 202 and compares the value for the temperature set in advance by the control means 113 with the input value, and the input value is greater than or equal to the preset value. When the determination is made, the shaft pressing brake device 213 moves in the direction of the rotating shaft 202, is brought into contact with the rotating shaft 202, and the rotating shaft 202 is forcibly stopped by generating a frictional force between the shaft pressing brake device 213 and the rotating shaft 202. Let

  Further, when the shaft pressing brake device 213 moves in the direction of the rotating shaft 202 and comes into contact with the rotating shaft 202, the rotating shaft 202 is further pressed downward, so that the gap between the scroll 206 and the impeller 203 is further expanded. Contact between 206 and the impeller 203 can be avoided.

  Further, since the portion where the shaft pressing brake device 213 is attached is a part of the flow path of the laser gas flow 109, the shaft pressing brake device 213 has a shape with little influence on the laser gas flow 109.

  As described above, according to the gas laser oscillation device of the present embodiment, the presence or absence of the occurrence of axial misalignment of the rotating part caused by the breakage of the bearing of the blower is clearly separated, and after the occurrence of the axial misalignment Can be detected without any delay, and when it is determined that an axis deviation has occurred, the rotating part can be stopped urgently.

  In other words, the gas laser oscillation device according to the present invention can detect the occurrence of the axial displacement and stop the air blowing device urgently as soon as the rotation shaft of the air blowing device is displaced. In addition, the rotating shaft can be forcibly stopped, so the blower stop time can be further shortened, and the impeller of the rotating part and the scroll of the non-rotating part can be prevented from being damaged by contact, and further, the damage can be prevented from expanding. Therefore, the cost and time required for restoration of the gas laser oscillation device can be greatly reduced.

  The gas laser oscillation device according to the present invention clearly separates the presence or absence of the occurrence of axial misalignment of the rotating part caused by the damage of the bearing of the blower, and can detect without any gap after the occurrence of the axial misalignment, When it is determined that an axis deviation has occurred, the rotating part can be stopped urgently, which is useful in a laser oscillation device using a laser medium gas.

DESCRIPTION OF SYMBOLS 100 Gas laser oscillation device 101 Discharge tube 102 Electrode 103 Electrode 104 Power supply 105 Discharge space 106 Total reflection mirror 107 Partial reflection mirror 108 Laser beam 109 Laser gas flow 110 Laser gas flow path 111 Heat exchanger 112 Heat exchanger 113 Control means 114 Alarm means 115 Laser gas Introducing portion 200 Blower device 201 Motor rotor 202 Rotating shaft 203 Impeller 204 Motor stator 205 Housing 206 Scroll 207 Upper bearing 208 Lower bearing 209 Co-rotating ring 210 Nut 211 Fixing portion spacer 212 Center point when the rotating shaft is tilted 213 Shaft pressing brake device 214 Brake holder 215 Temperature detection means

Claims (7)

A discharge means for exciting the laser medium, a blower for blowing laser gas, and a laser gas path for forming a circulation path of the laser gas between the discharge means and the blower,
The blower device is composed of a rotating part that rotates by shaft driving means, a non-rotating part that does not rotate, and an upper bearing and a lower bearing provided therebetween,
The rotating part includes a shaft provided with an impeller part at a tip thereof, a driving part for rotating the shaft, and a co-rotating ring arranged between the impeller and the upper bearing,
The non-rotating part is a housing that houses the rotating part, a scroll that covers the impeller, a fixed part spacer that is disposed at a position facing the co-rotating ring with a predetermined gap from the co-rotating ring, A gas laser oscillation apparatus comprising a temperature detection unit in contact with the fixed unit spacer.   The gas laser oscillator according to claim 1, wherein the material of the fixed portion spacer is lower in hardness than the shaft.   3. The gas laser oscillation device according to claim 1, wherein a gap between the fixed portion spacer and the co-rotating ring is smaller than a gap between the impeller and the scroll.   A predetermined temperature threshold value is provided, and when the temperature detected by the temperature detection unit is higher than the temperature detected by the upper bearing temperature detection unit, it is determined that the bearing is abnormal. The gas laser oscillation device described.   The shaft pressing brake part movable in the axial direction is further provided on the extension of the shaft, and the rotating part of the blower is stopped by the shaft pressing brake part when it is determined that the bearing is abnormal. The gas laser oscillation device according to any one of the above.   The gas laser oscillation device according to claim 5, wherein the shaft pressing brake portion is installed on the scroll so as to extend the shaft and not block the laser gas flow path.   The gas laser oscillation device according to claim 5 or 6, wherein the pressing brake portion is movable in the axial direction of the shaft, and contacts the shaft to stop the rotating portion of the blower when it is determined that the bearing is abnormal.

Images