JP2008192793A - Gas laser oscillator and its lubricating oil exchange method for air blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas laser device and method which materializes a mechanism for forcedly supplying or discharging a lubricating oil for an air blower at a low cost. <P>SOLUTION: A gas laser oscillator comprises: a resonator for applying a voltage to a laser gas to generate laser beams; a laser gas circuit 24 connected to the resonator; a turbo-blower 26 for circulating the laser gas in the laser gas circuit 24; a laser gas supply source 30 for supplying the laser gas to the laser gas circuit 24; and a vacuum pump 32 for discharging the laser gas from the laser gas circuit 24. When the lubricating oil of the turbo-blower 26 is exchanged, a pressure difference is generated between an oil sump 82 in the turbo-blower 26 and an oil feeding reservoir 98 or a waste oil reservoir 104 by utilizing the laser gas supply source 30 or the vacuum pump 32, and the lubricating oil is forcedly discharged from the oil sump 82 to the waste oil reservoir 104 by the pressure difference. Further, the lubricating oil is forcedly poured from the oil feeding reservoir 98 to the oil sump 82. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas laser oscillating device including a laser blower that forcibly circulates a laser gas as a laser medium, and a lubricating oil replacement method for the blower.

  High-speed axial flow carbon dioxide laser oscillation devices are widely used for laser processing because they are compact and can provide high output and have good laser light quality. Such a gas laser oscillation device includes a resonator for generating a laser beam by applying a voltage to a laser gas, and a laser gas circulation path connected to the resonator. The resonator includes a discharge tube filled with a laser gas as a laser medium, output coupling mirrors and total reflection mirrors attached to both ends of the discharge tube, and a pair of metals attached facing the outer periphery of the discharge tube. By applying a high-frequency voltage between the paired metal electrodes, a high-frequency glow discharge is generated in the discharge tube to cause laser excitation, and laser light is generated by laser excitation. The generated laser light is amplified while reciprocating between the output coupling mirror and the total reflection mirror to be in a resonance state, and a part of the laser light in the resonance state is taken out through the output coupling mirror.

  In the carbon dioxide laser oscillation device, about 20% of the electric energy injected into the laser gas through the metal electrode is converted into laser light, and the remaining electric energy is used to heat the laser gas. On the other hand, the laser oscillation gain is theoretically proportional to the-(3/2) power of the absolute temperature of the laser gas. Therefore, in order to increase the oscillation efficiency, it is necessary to forcibly cool the laser gas and lower the temperature of the laser gas. Therefore, in the high-speed axial flow type carbon dioxide laser oscillation apparatus, a turbo blower is provided in the laser gas circulation path in order to forcibly circulate the laser gas that has become high temperature by discharge and send it to the cooler for forced cooling. .

  In a turbo blower used in a carbon dioxide laser oscillation device, a turbo blade is mechanically coupled to a tip of a shaft extending from a motor chamber formed in a turbo blower housing and projecting into a gas laser circulation path with a nut. Further, a rotor is fixed to the outer periphery of the shaft accommodated in the motor chamber by shrink fitting, and the rotor and a stator fixed to the outer peripheral surface of the turbo blower motor chamber so as to surround the rotor. Constitutes a high-frequency motor that rotates a turbo blade through a shaft. The shaft is rotatably supported by a pair of rolling bearings on both sides of the high frequency motor.

  Since the turbo blade and shaft of such a turbo blower rotate at a high speed of tens of thousands of RPM by a high frequency motor, it is important to supply lubricating oil to the rolling bearing for lubrication and cooling of the rolling bearing that supports the turbo blade. As a method of supplying lubricating oil for lubrication and cooling of such rolling bearings, for example, Patent Document 1 provides an oil passage along the axial direction inside a shaft, and an oil inlet at one end thereof is placed in an oil reservoir. The oil is immersed in the oil, sucked up into the oil passage by the centrifugal force accompanying the rotation of the shaft, discharged from the oil outlet provided at the other end of the shaft, and supplied to the rolling bearing Is disclosed.

JP 7-211961 A

  The turbo blower of the gas laser oscillation apparatus having the above configuration rotates at a high speed of tens of thousands of RPMs, so it is necessary to change the lubricating oil every time a certain operation time (generally about 3000 to 6000 hours) elapses. There is. For this reason, an oil drain opening that opens to the outside is provided at the bottom of the oil reservoir provided in the motor chamber of the turbo blower. By opening an openable oil drain cock attached to the oil drain, the oil reservoir It is now possible to discharge old lubricating oil. An oil supply port extending from the outside through the turbo blower housing to the motor chamber is provided above the oil reservoir, so that new lubricating oil can be supplied from the oil supply port to the oil reservoir through the motor chamber. It should be noted that the oil filler port is sealed with a cap with a threaded portion at times other than oil exchange in order to ensure the airtightness of the motor chamber when the gas laser oscillation device is in operation.

  Conventionally, when replacing the lubricating oil in such a turbo blower, the inside of the gas laser oscillation device is opened to the atmosphere, and then the oil drain cock is opened to discharge the lubricant in the oil reservoir from the oil outlet. The inside of the gas laser oscillator is first opened to the atmosphere. When the oil drain cock is opened without opening the atmosphere, air enters the oil reservoir from the oil outlet and the lubricating oil passes through the motor chamber of the turbo blower. This is because there is a risk that high temperature lubricating oil immediately after the operation stops will be ejected from the oil discharge port. When the oil in the oil reservoir is completely discharged, the oil stop cock is closed, the cap of the oil filler is removed, and new lubricant is injected from the oil filler through the oil supply passage into the oil reservoir in the oil chamber. Finally, after the lubrication is completed, a cap is attached to the lubrication port and the lubrication port is closed.

  In the replacement method as described above, the lubricating oil is discharged from the oil reservoir and injected into the oil reservoir by gravity, but since the lubricating oil is highly viscous, it takes time to discharge and inject the lubricating oil, There is a problem of poor workability. Due to such poor workability, if the lubricating oil is not replaced or if the replacement interval is lengthened, there is a possibility that a lubrication failure may occur and the turbo blower may be broken. Further, since the turbo blower is generally disposed inside the casing of the gas laser oscillation device, the casing cover has to be removed in order to replace the lubricating oil of the turbo blower, which is troublesome.

  Lubricating oil replacement by installing an oil tank and an oil tank in the turbo blower, connecting the oil inlet and the oil tank, and connecting the oil outlet and the oil tank with pipes, and operating the solenoid valve installed in the middle of the pipe in sequence. However, as long as oiling and draining are performed by the action of gravity, the work still takes time. In addition, as long as oiling and draining are performed by the action of gravity, the oil supply tank must be provided above the oil reservoir and the oil discharge tank must be provided below the oil reservoir, and the arrangement of the oil discharge tank and the oil supply tank is also restricted.

  Accordingly, an object of the present invention is to provide a gas laser apparatus and method that solves the above-described problems of the prior art and realizes a mechanism for forcibly supplying or discharging lubricating oil for a blower such as a turbo blower at low cost. is there.

  In view of the above object, the present invention provides a resonator for generating a laser beam by applying a voltage to a laser gas, a laser gas circulation path connected to the resonator, and a laser gas in the laser gas circulation path for circulation. A blower, a laser gas supply source for supplying laser gas to the laser gas circulation path, and a vacuum pump for discharging laser gas from the laser gas circulation path. A gas laser oscillation device configured to lubricate the bearing by supplying lubricating oil in an oil reservoir provided in the blower to a bearing that rotatably supports the oil reservoir, and from the outside of the blower to the oil reservoir An oil supply passage for supplying lubricating oil, an oil discharge passage for discharging the lubricating oil from the oil reservoir to the outside of the blower, and A first on-off valve for opening and closing the oil passage, a second on-off valve for opening and closing the oil passage, and differential pressure generating means for forcibly creating a pressure difference between the oil reservoir and the outside A gas laser oscillation device comprising:

  In the gas laser oscillation device of the present invention, a pressure difference is forcibly generated between the oil reservoir and the oil supply tank or the oil discharge tank by the differential pressure generating means, thereby forcibly injecting or discharging lubricating oil to the oil reservoir. Making it possible. For example, by increasing the pressure in the oil reservoir from the outside, the lubricating oil can be forced out of the oil reservoir and discharged to the outside, and by reducing the pressure in the oil reservoir from the outside, Lubricating oil can be sucked and forcibly injected into the oil reservoir.

  In one embodiment, the differential pressure generating means includes the laser gas supply source, and the laser gas circulation from the laser gas supply source when the first on-off valve is closed and the second on-off valve is opened. By supplying laser gas to the path, and making the pressure of the laser gas in the oil reservoir of the blower communicating with the laser gas circulation path higher than the atmospheric pressure or the pressure in the oil discharge tank connected to the oil discharge passage, The lubricating oil in the oil reservoir is forcibly discharged to the outside of the blower through the oil drain passage.

  The differential pressure generating means includes the vacuum pump, an oil reservoir suction path for communicating the vacuum pump and the oil reservoir, and a third on-off valve for opening and closing the oil reservoir suction path, When the first on-off valve is opened and the second on-off valve is closed, the third on-off valve is opened and the oil reservoir is connected to the atmospheric pressure or the oil supply passage by the vacuum pump. By making the pressure lower than the pressure in the oil tank, the lubricating oil may be forcibly injected into the oil reservoir from the outside of the blower through the oil supply passage.

  In another embodiment, the differential pressure generating means opens and closes the oil drain tank suction path for communicating the vacuum pump, the oil drain tank connected to the oil drain passage and the vacuum pump, and the oil tank suction path. And when the first on-off valve is closed and the second on-off valve is open, the fourth on-off valve is opened and the vacuum pump is used to discharge the oil tank. By making the internal pressure lower than the pressure in the oil reservoir, the lubricating oil in the oil reservoir is forcibly discharged to the oil drain tank through the oil drain passage.

  The differential pressure generating means is configured to open and close the oil supply tank pressurization path, the oil supply tank pressurization path that communicates the laser gas supply source, the oil supply tank connected to the oil supply path, and the laser gas supply source. The fifth on-off valve, and when the first on-off valve is opened and the second on-off valve is closed, the fifth on-off valve is opened and the oil tank is supplied from the laser gas supply source. By supplying a laser gas to the oil tank and making the pressure in the oil tank higher than the pressure in the oil reservoir, the lubricating oil in the oil tank is forcibly injected into the oil reservoir through the oil passage. It may be.

In another aspect, the present invention provides a resonator for generating a laser beam by applying a voltage to a laser gas, a laser gas circulation path connected to the resonator, and a laser gas in the laser gas circulation path for circulation. And a vacuum pump for discharging laser gas from the laser gas circulation path, the blower having a turbo blade attached to the tip. In the gas laser oscillation apparatus configured to lubricate the bearing by supplying lubricating oil in an oil reservoir provided in the blower to a bearing that rotatably supports the lubricating oil in the oil reservoir of the blower A lubricating oil replacement method for a blower to be replaced, wherein the lubricating oil is supplied from the outside of the blower to the oil reservoir. When the first on-off valve for opening and closing the passage is closed and the second on-off valve for opening and closing the oil discharge passage for discharging the lubricating oil from the oil reservoir to the outside of the blower is opened The laser gas is supplied from the laser gas supply source to the laser gas circulation path in the previous period and the pressure of the laser gas in the oil reservoir of the blower communicating with the laser gas circulation path is made higher than the atmospheric pressure, whereby the oil is passed through the oil drain passage. Forcefully drain the lubricating oil in the reservoir to the outside of the blower,
When the first on-off valve is closed and the second on-off valve is opened, the pressure inside the oil reservoir is connected to the atmospheric pressure or the oil supply passage using the vacuum pump. A method for replacing the lubricating oil for a blower in which the lubricating oil is forcibly injected into the oil reservoir from the outside of the blower through the oil supply passage by making it lower.

  According to the present invention, since the lubricating oil is injected or discharged from the oil reservoir by forcibly generating a differential pressure between the oil reservoir and the outside, the time required for the injection or discharging operation of the lubricating oil can be shortened. it can. Further, if a differential pressure is forcedly generated between the oil reservoir and the outside by using a vacuum pump or a laser gas supply source generally provided in the gas laser oscillation device, forced injection and discharge of lubricating oil to the oil reservoir is performed. Can be realized at low cost, and the lubrication oil injection and discharge operations can be easily automated.

Hereinafter, an embodiment of a robot system of the present invention will be described with reference to the drawings.
Initially, with reference to FIG. 5, the whole structure of the gas laser oscillation apparatus 10 of this invention is demonstrated. FIG. 5 shows a carbon dioxide laser oscillation device that uses carbon dioxide gas as a laser medium as the gas laser oscillation device 10. The gas laser oscillating device 10 includes a resonator 12, which includes a discharge tube 14 filled with a laser gas as a laser medium, output coupling mirrors 16 attached to both ends of the discharge tube 14, and total reflection. The mirror 18 and a pair of metal electrodes 20 mounted on the outer periphery of the discharge tube 14 so as to face each other. In the resonator 12, a high frequency voltage is applied between the pair of metal electrodes 20 by a high frequency power source to generate a high frequency glow discharge in the discharge tube 14 to cause laser excitation, and laser light is generated by laser excitation. The generated laser light is amplified while reciprocating between the output coupling mirror 16 and the total reflection mirror 18 to be in a resonance state, and a part of the laser light in the resonance state is taken out through the output coupling mirror 16.

  The gas laser oscillator 10 shown in FIG. 5 further includes a laser gas circulation path 24 connected to the resonator 12 and a turbo blower 26 driven by an inverter 28 as a blower for circulating the laser gas in the laser gas circulation path 24. A laser gas supply source 30 connected to the laser gas circulation path 24 on the downstream side of the turbo blower 26 for supplying the laser gas to the laser gas circulation path 24, and an upstream side of the turbo blower 26 for discharging the laser gas from the laser gas circulation path 24. A vacuum pump 32 connected to the laser gas circuit 24, a first cooler 34 disposed between the vacuum pump 32 and the turbo blower 26 in the laser gas circuit 24, and a turbo blower 26 and a laser gas supply source in the laser gas circuit 24 30 with a second cooler 36 disposed between Obtain.

  Specifically, the laser gas supply source 30 and the laser gas circulation path 24 are connected by an air supply pipe 38 as shown in FIG. 1, and the laser gas supply source 30 is located in the middle of the air supply pipe 38. A decompressor 40 for reducing the pressure of the laser gas supplied from the air to a desired pressure, an air supply on-off valve 42 for opening and closing the air supply pipe 38, and an air supply for adjusting the laser gas supply amount The air supply flow rate adjustment valve 44 connected in series downstream of the gas on / off valve 42 (the side far from the laser gas supply source 30), and the air supply in parallel with the air supply on / off valve 42 and the air supply flow rate adjustment valve 44 A filling on / off valve 46 connected to the pipe 38 is provided. As the air supply on / off valve 42, the air supply flow rate adjustment valve 44, and the charging on / off valve 46, electromagnetic valves that can be controlled by a control device such as a sequencer or a programmable controller are used.

  Further, as shown in FIG. 1, the vacuum pump 32 and the laser gas circulation path 24 are connected by an exhaust pipe 48, and an exhaust for adjusting the laser gas discharge flow rate is provided in the middle of the exhaust pipe 48. A flow rate adjusting valve 50, an exhaust bypass valve 52 connected to the exhaust pipe 48 in parallel with the exhaust flow rate adjusting valve 50, and a downstream side of the exhaust flow rate adjusting valve 50 for opening and closing the exhaust pipe 48 ( An exhaust on-off valve 54 disposed on the side close to the vacuum pump 32 is provided. As the exhaust flow control valve 50, the exhaust bypass valve 52, and the exhaust on / off valve 54, electromagnetic valves that can be controlled by a control device are used.

  When starting such a gas laser oscillation device 10, first, the vacuum pump 32 exhausts from the resonator 12 and the laser gas circulation path 24 of the gas laser oscillation device 10, and then a predetermined flow rate of laser gas is supplied from the laser gas supply source 30 to the laser gas circulation path 24. And the resonator 12 is filled. When the gas laser is filled in the laser gas circulation path 24 and the resonator 12 when the gas laser oscillation device 10 is started up, the filling on-off valve 46 can be opened to fill the laser gas at a large flow rate. When exhausting from the laser gas circulation path 24 and the resonator 12 when the gas laser oscillator 10 is started, the exhaust bypass valve 52 can be opened to exhaust at a large flow rate. When the pressure of the laser gas in the laser gas circulation path 24 of the gas laser oscillation device 10 and the resonator 12 reaches a predetermined value, the exhaust gas is then exhausted and filled by the vacuum pump 32 with the exhaust bypass valve 52 closed. The laser gas supply from the laser gas supply source 30 with the on-off valve 46 closed is simultaneously performed, and the laser gas pressure 24 is maintained at a predetermined value while the laser gas circulation path 24 and the resonator 12 in the gas laser oscillator 10 are maintained. A part of the laser gas is continuously replaced with fresh laser gas little by little. This prevents a decrease in laser output due to contamination of the laser gas in the gas laser oscillator 10.

  During operation of the gas laser oscillator 10, the laser gas is forcibly circulated by the turbo blower 26 and circulates in the resonator 12 and the laser gas circulation path 24 at a speed of about 200 m / second or more. A part of the laser gas flowing in the resonator 12 is discharged to the outside by the vacuum pump 32, and then guided to the first cooler 34 along the laser gas circulation path 24, and is given to the laser gas mainly by discharge. Heating energy is removed and cooled. The laser gas cooled by the first cooler 34 is compressed by the turbo blower 26 and sent to the second cooler 36 along the laser gas circulation path 24. The compressed laser gas is cooled by removing the heat of compression by the second cooler 36, then mixed with a predetermined amount of fresh laser gas supplied from the laser gas supply source 30, and returned to the resonator 12 again. .

  Since the resonator 12, the laser gas supply source 30, the vacuum pump 32, the first cooler 34, and the second cooler 36 described above are the same as the well-known ones used in the conventional gas laser oscillation device, Detailed description of the configuration is omitted.

Next, a first embodiment of a turbo blower lubricating oil replacement system used in the gas laser oscillation device 10 of FIG. 5 will be described with reference to FIG.
In the turbo blower 26, the laser gas is sucked from the first cooler 34 in the direction of the arrow 56, divided into two directions as indicated by the arrow 58, and discharged in the centrifugal direction. The first cooler 36 is connected to the second cooler 36.

  The turbo blower 26 includes a shaft 64 that extends from the motor chamber 62 formed in the housing 60 so as to protrude into the gas laser circulation path 24 in the vertical direction, and a turbo blade 66 is a nut (not shown) at one end of the shaft 64. It is combined with. A rotor 68 is fixed to the outer periphery of the shaft 64 accommodated in the motor chamber 62 by shrink fitting. The rotor 68 and the outer peripheral surface of the motor chamber 62 of the turbo blower 26 are surrounded by the outer periphery of the rotor 68. The fixed stator 70 constitutes a high-frequency motor that rotates the turbo blade 66 via the shaft 64. In addition, a pair of rolling bearings 72 are provided on both sides of the high frequency motor in order to rotatably support the shaft 64. Note that a labyrinth seal (not shown) is provided at a portion where the shaft 64 protrudes from the housing 60 to the laser gas circulation path 24, so that the lubricating oil in the motor chamber 62 enters the laser gas circulation path 24. On the other hand, a slight amount of laser gas is allowed to flow from the laser gas circulation path 24 into the motor chamber 62 through the labyrinth seal, and the laser gas circulation path 24 and the motor chamber 62 are in communication with each other.

  Inside the shaft 64, there is provided a lubricating oil passage 76 extending from the lubricating oil inlet 74 provided at the lower end along the axial direction of the shaft 64, and on the outer peripheral surface of the shaft 64 above the upper rolling bearing 72. The opening is connected to the lubricating oil outlet 78. Specifically, the lubricant outlet 78 is formed by a small diameter hole extending through the lubricant passage 76 perpendicular to the axis of the shaft 64.

  An oil reservoir 82 communicating with the motor chamber 62 via a communication passage 80 is further formed in the housing 60 of the turbo blower 26. The oil reservoir 82 is lubricated for lubricating and cooling the rolling bearing 72. Oil is stored. The lower end of the shaft 64 (the end where the lubricating oil inlet 74 is formed) is immersed in the lubricating oil in the oil reservoir 82. Further, a lubricating oil return passage 84 is provided along the longitudinal direction of the stator 70 in a portion of the housing 60 outside the stator 70 of the turbo blower 26.

  The lubricating oil in the oil reservoir 82 is pressed against the inner wall surface of the lubricating oil passage 76 by the centrifugal force accompanying the rotation of the shaft 64, and at this time, a component force in a direction to push up the lubricating oil along the inner wall surface is generated. Acts on lubricating oil. As a result, the lubricating oil is sucked up along the lubricating oil passage 76 and discharged from the lubricating oil outlet 78 into the motor chamber 62 in the form of a mist. Part of the released lubricating oil lubricates and cools the rolling bearing 72. The remaining lubricating oil is guided below the motor chamber 62 through the lubricating oil return passage 84 and then collected again in the oil reservoir 82 through the communication passage 80. In this way, the lubricating oil always circulates while the shaft 64 rotates, lubricating and cooling the rolling bearing 72. In the turbo blower 26, a mechanism for lubricating and cooling the rolling bearing 72 through the lubricating oil passage 76 provided in the shaft 64 is a well-known mechanism as disclosed in, for example, Patent Document 1. Detailed description is omitted.

  A motor chamber exhaust port 86 extending from the motor chamber 62 to the outer peripheral surface of the housing 60 is provided in the housing 60 of the turbo blower 26, and a motor chamber exhaust pipe 88 extending from the vacuum pump 32 is provided in the motor chamber exhaust port 86. It is connected. Further, an electromagnetic valve capable of controlling the operation by a control device such as a sequencer or a programmable controller is provided as a motor chamber exhaust opening / closing valve 90 for opening / closing the motor chamber exhaust piping 88 in the middle of the motor chamber exhaust piping 88. Is provided. The motor chamber exhaust pipe 88, the motor chamber exhaust port 86, the motor chamber 62, and the communication passage 80 that allows the motor chamber 62 and the oil reservoir 82 to communicate with each other are an oil reservoir that allows the vacuum pump 32 and the oil reservoir 82 to communicate with each other. The suction passage is configured, and the motor chamber exhaust on-off valve 90 functions as an on-off valve for opening and closing the oil pool suction passage.

  An oil supply port 92 for supplying lubricating oil to the oil reservoir 82 from the outside of the turbo blower 26 is provided at the upper portion of the oil reservoir 82, while the lubrication in the oil reservoir 82 is provided on the bottom surface of the oil reservoir 82. An oil discharge port 94 for discharging oil to the outside of the turbo blower 26 is provided. The bottom surface of the oil reservoir 82 is inclined downwardly toward the oil outlet 94 as shown in FIG. 1 so that all the lubricating oil in the oil reservoir 82 is discharged from the oil outlet 94. It is preferable that

  One end of a lubricating oil injection pipe 96 is connected to the oil supply port 92, and the other end of the lubricating oil injection pipe 96 is connected to an oil supply tank 98 containing new lubricating oil. The oil supply port 92 and the lubricating oil injection pipe 96 constitute an oil supply passage. Further, in the middle of the lubricating oil injection pipe 96, an electromagnetic valve whose operation can be controlled by a control device is provided as an oil supply opening / closing valve 100 for opening and closing the lubricating oil injection pipe 96. For example, as shown in FIG. 1, the oil tank 98 can be a hard plastic bottle containing a quantity of lubricating oil required for one lubricating oil change. The upper 2/3 of the bottle is preferably filled with nitrogen in order to prevent oxidation and moisture absorption of the lubricating oil. The operator may connect such a bottle to the lubricating oil injection pipe 96 and seal it before replacing the lubricating oil. The lubricating oil injection pipe 96 is attached to the bottle so that the end thereof is arranged near the bottom of the bottle. Nitrogen enclosed in the bottle partially leaks into the atmosphere when the bottle is mounted, and the bottle is at atmospheric pressure.

  On the other hand, one end of a lubricating oil discharge pipe 102 is connected to the oil discharge port 94, and the other end of the lubricating oil discharge pipe 102 is connected to a drain oil tank 104 for collecting the discharged lubricating oil. ing. The oil discharge port 94 and the lubricating oil discharge pipe 102 constitute an oil discharge passage. In addition, an electromagnetic valve whose operation can be controlled by a control device is provided in the middle of the lubricating oil discharge pipe 102 as a drain oil on-off valve 106 for opening and closing the lubricating oil discharge pipe 102. For example, the oil drain 104 can be an empty hard plastic bottle as shown in FIG. A small hole is formed in the stopper of the bottle used as the oil draining tank 104 so that the inside of the bottle is always equal to the atmospheric pressure.

  The oil supply tank 98 and the oil discharge tank 104 may be supplied once every time the lubricating oil is changed, or may be supplied once every several times. As the oil supply tank 98 and the oil discharge tank 104, appropriate ones such as a metal container and a polyethylene flexible bag can be used in addition to the plastic bottle. Further, in FIG. 1, the piping system around the turbo blower 26 is shown in a simplified manner. These piping systems include a pressure sensor (not shown) for measuring the pressure of the laser gas in the piping as necessary. ) May be provided as appropriate.

Lubricating oil replacement using the turbo blower lubricating oil changing system shown in FIG. 1 is performed in the following procedure.
During operation of the gas laser oscillating device 10, the supply gas on / off valve 42 is opened and the charging on / off valve 46 is closed, and the gas flow is adjusted from the laser gas supply source 30 to the desired flow rate by the supply air flow control valve 44. While the laser gas is supplied to the passage 24, the exhaust bypass valve 52 is closed and the exhaust on-off valve 54 is opened, and the vacuum pump 32 controls the laser gas circulation passage 24 while adjusting the flow rate to a desired flow rate. Laser gas is discharged. Thereby, a part of the laser gas in the laser gas circulation path 24 and the resonator 12 of the gas laser oscillator 10 is continuously replaced with fresh laser gas little by little. During operation of the gas laser oscillator 10, the motor chamber exhaust opening / closing valve 90 is also opened so that the pressure in the motor chamber 62 is slightly lower than the pressure in the laser gas circulation path 24. Is preferred. Thereby, it is possible to prevent the mist-like lubricating oil in the motor chamber 62 from entering the laser gas circulation path 24. During operation of the gas laser oscillator 10, the oil supply on / off valve 100 and the oil discharge on / off valve 106 are kept closed.

  When replacing the lubricating oil, first, the exhaust on-off valve 106 and the motor chamber exhaust on-off valve 90 are closed, and the vacuum pump 32, the laser gas circulation path 24, and the motor chamber 62 are disconnected. Next, the decompressor 40 is adjusted to supply laser gas from the laser gas supply source 30 to the laser gas circulation path 24 until a predetermined pressure is reached. At this time, the filling on-off valve 46 may be opened. The pressure is preferably about 0.02 MPa (gauge pressure). Along with this, the pressure in the motor chamber 62 communicating with the laser gas circulation path 24 increases to the same level, and the pressure in the oil reservoir 82 communicating with the motor chamber 62 through the communication path 80 also increases to the same level.

  Next, the oil discharge on / off valve 106 is opened while the oil supply on / off valve 100 is closed. Since the pressure in the oil reservoir 82 is higher than the pressure in the oil discharge tank 104, that is, the atmospheric pressure, the lubricating oil in the oil reservoir 82 is pushed out by the pressure of the laser gas in the oil reservoir, and the oil outlet 94 and the lubricating oil discharge pipe 102 are forcibly discharged into the oil discharge tank 104. When the lubricating oil in the oil reservoir 82 is completely discharged, the laser gas in the oil reservoir 82 is released into the atmosphere through the oil discharge port 94, the lubricating oil discharge pipe 102 and the oil discharge tank 104, and the pressure in the oil reservoir 82. Decreases to atmospheric pressure.

  Next, after closing the oil discharge on / off valve 106 and sealing the motor chamber 62 and the oil reservoir 82, the vacuum pump 32 is started, and the exhaust on / off valve 54 and the motor chamber exhaust on / off valve 90 are opened to open the vacuum pump 32. The motor chamber 62 and the laser gas circulation path 24 are brought into communication with each other. As a result, the laser gas in the motor chamber 62 and the laser gas circulation path 24 is discharged, and the pressure in these portions and the oil reservoir 82 communicating with these portions becomes lower than the atmospheric pressure. Since the pressure in the motor chamber 62 and the oil reservoir is lower than the pressure in the oil tank, when the oil supply opening / closing valve 100 is opened in this state, the lubricating oil in the oil tank 98 is injected into the lubricating oil due to the differential pressure. The oil is forcedly injected into the motor chamber 62 and the oil reservoir 82 through the pipe 96 and the oil supply port 92. When the above-described bottle (the one in which the upper 2/3 of the bottle is filled with nitrogen) is used as the oil tank 98, if the pressure in the motor chamber 62 and the oil reservoir 82 is 1/3 of the atmospheric pressure. Since the nitrogen at the top of the bottle expands three times, almost the entire amount of lubricating oil in the bottle can be injected into the motor chamber 62 and the oil reservoir 82. When the injection of the lubricating oil is completed, the oil supply opening / closing valve 100 is closed and the lubricating oil replacement operation is completed.

FIG. 2 shows a second embodiment of a lubricating oil changing system for turbo blowers used in the gas laser oscillator 10 of FIG. In FIG. 2, the same reference numerals are assigned to the portions corresponding to those in FIG.
In the second embodiment shown in FIG. 2, in order to generate a differential pressure in the oil reservoir 82 and the oil supply tank 98, the decompressor 40 and the supply air for the supply pipe 38 extending from the laser gas supply source 30 are used. 1 is different from the first embodiment shown in FIG. 1 in that an oil tank pressurizing pipe 108 branched from the on-off valve 42 is connected to the oil tank 98. The oil tank pressurization pipe constitutes an oil tank pressurization path. In the middle of the oil tank pressurization pipe 108, an oil tank pressurization on / off valve 110 for opening and closing the oil tank pressurization pipe 108 and an oil tank addition for adjusting the flow rate of the laser gas flowing through the oil tank pressurization pipe 108 are provided. An oil supply tank pressurizing flow rate adjusting valve 112 disposed on the downstream side of the pressure on-off valve 110 (the side close to the oil supply tank 98) is provided. The oil reservoir 82 is provided with an oil amount sensor 114 for detecting the level of the lubricating oil in the oil reservoir 82. Furthermore, an oil amount sensor (not shown) may be provided at the bottom of the oil tank 98. Other configurations are the same as those of the first embodiment, and a description thereof is omitted here.

  When replacing the lubricating oil in the turbo blower 26, first, the lubricating oil is discharged from the oil reservoir 82 to the oil discharge tank 104 with the oil supply opening / closing valve 100 and the oil tank pressurization opening / closing valve 110 closed. The procedure for discharging the lubricating oil from the oil reservoir 82 to the oil discharge tank 104 is the same as in the first embodiment. When the discharge of the lubricating oil from the oil reservoir 82 is completed, the oil opening / closing valve 106 is closed and the motor chamber 62 and the oil reservoir 82 are sealed, then the oil supply opening / closing valve 100 is opened, and the oil tank pressurization opening / closing is delayed a little. Open valve 110. As a result, the laser gas decompressed to a predetermined pressure by the decompressor 40 from the laser gas supply source 30 is supplied to the oil tank 98, and the pressure in the oil tank 98 rises, and this pressure causes lubrication from within the oil tank 98. Oil is forcibly injected into the motor chamber 62 and the oil reservoir 82 through the lubricating oil injection pipe 96 and the oil supply port 92. The injection speed of the lubricating oil from the oil tank 98 can be adjusted by changing the opening of the oil tank pressurization flow rate adjustment valve 112. When the oil amount sensor 114 detects that the lubricating oil has been injected into the oil reservoir 82 to a predetermined liquid level, the oil tank pressurizing on-off valve 110 is closed, and the injection of the lubricating oil is completed. The oil amount sensor 114 is also useful for detecting that the lubricating oil has decreased for some reason during normal operation. When the oil amount sensor is provided at the bottom of the oil tank 98, the oil tank pressurizing on-off valve 110 can be automatically closed when the oil amount sensor no longer detects the lubricating oil. In this case, it is also useful to automatically confirm that the replacement lubricant is prepared prior to the replacement of the lubricant.

FIG. 3 shows a third embodiment of a lubricating oil replacement system for turbo blowers used in the gas laser oscillator 10 of FIG. 3, parts corresponding to those in FIG. 1 are denoted by the same reference numerals.
In the third embodiment shown in FIG. 3, a drainage tank suction pipe 116 is connected between the vacuum pump 32 and the drainage tank 104 in order to generate a differential pressure between the oil reservoir 82 and the drainage tank 104. This is different from the first embodiment shown in FIG. The oil tank suction pipe 116 constitutes an oil tank suction path. An oil tank suction opening / closing valve 118 for opening and closing the oil tank suction pipe 116 is provided in the middle of the oil tank suction pipe 116. Other configurations are the same as those of the first embodiment, and a description thereof is omitted here.

  When the lubricating oil of the turbo blower 26 is replaced, first, the exhaust on-off valve 54 and the motor chamber exhaust on-off valve 90 are closed to cut off the vacuum pump 32 from the laser gas circulation path 24 and the motor chamber 62. Next, the decompressor 40 is adjusted, and the laser gas is supplied from the laser gas supply source 30 to the laser gas circulation path 24 until the pressure is close to atmospheric pressure. At this time, the filling on-off valve 46 may be opened. Next, the vacuum pump 32 is started, and the oil tank suction open / close valve 118 is opened while the exhaust open / close valve 54 and the motor chamber exhaust open / close valve 90 are closed. Since the connecting portion between the drainage tank suction pipe 116 and the drainage tank 104 and the connecting portion between the lubricating oil discharge pipe 102 and the drainage tank 104 are sealed, the inside of the drainage tank 104 becomes lower than the atmospheric pressure. Next, when the drain oil on-off valve 106 is opened after a while, the lubricating oil in the oil reservoir 82 is lubricated by the oil outlet 94 and the lubrication due to the pressure difference between the pressure in the oil reservoir 82 and the pressure in the oil drain tank 104. The oil is forcedly discharged to the oil discharge tank 104 through the oil discharge pipe 102. After a sufficient time for discharging the lubricating oil has elapsed, the oil on / off valve 106 and the oil tank suction on / off valve 118 are closed to complete the lubricating oil discharge operation. The oil drain tank 104 is removed from the lubricating oil discharge pipe after the lubricating oil discharging operation is completed, and the discharged lubricating oil is discarded. When the lubricating oil discharging operation is completed, the lubricating oil is subsequently injected into the oil reservoir 82. Since the procedure for injecting the lubricating oil into the oil reservoir 82 is the same as that in the first embodiment, the description thereof is omitted here.

  As described above, in the gas laser oscillation device 10 of the present invention, the lubricating oil in the oil reservoir 82 is pressurized or the negative pressure in the oil reservoir 82 is utilized by using the gas laser supply source 30 and the vacuum pump 32 that are generally provided in the gas laser oscillation device 10. Thus, a differential pressure is generated between the oil reservoir 82 and the oil supply tank 98 or the oil discharge tank 104, and the lubricating oil in the oil reservoir 82 is forcibly discharged by this differential pressure, and the oil reservoir 82 is lubricated. Force oil. Therefore, the lubricating oil can be discharged and injected into the oil reservoir 82 in a short time without newly adding an expensive device. Moreover, since supply and discharge | emission of lubricating oil are not performed using gravity, the restrictions on arrangement | positioning of the oil supply tank 98 and the oil drain tank 104 and arrangement | positioning of various piping also decrease. For example, the oil tank 98 can be disposed at a position lower than the turbo blower 26, and the oil discharge tank 104 can be disposed at a position higher than the turbo blower 26.

  Further, since the replacement of the lubricating oil is performed by opening and closing each on-off valve, when the lubricating oil is replaced, the injection cap is not opened as in the prior art, and moisture and airborne particles in the atmosphere are removed from the motor chamber 62. In addition, the possibility of entering the oil reservoir 82 is greatly reduced as compared with the prior art. In addition, the lubrication oil replacement operation can be easily automated. In the first to third embodiments, the operation of each on-off valve is controlled by the control device, and the lubricating oil is automatically replaced, thereby preventing an erroneous operation by the operator.

  The gas laser oscillation apparatus 10 according to the present invention has been described based on the illustrated embodiment. However, the present invention is not limited to the illustrated embodiment. For example, as shown in FIG. 4, in the second embodiment, an oil drain tank suction pipe 116 may be provided between the vacuum pump 32 and the oil tank 104 as in the third embodiment. is there.

1 shows a first embodiment of a lubricating oil replacement system for a turbo blower used in a gas laser oscillator of the present invention. 2 shows a second embodiment of a lubricating oil replacement system for turbo blowers used in the gas laser oscillation device of the present invention. 7 shows a third embodiment of a lubricating oil changing system for turbo blowers used in the gas laser oscillation device of the present invention. 4 shows a fourth embodiment of a lubricating oil replacement system for turbo blowers used in the gas laser oscillation device of the present invention. 1 shows an overall configuration of a gas laser oscillation device of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Gas laser oscillator 24 Laser gas circulation path 26 Turbo blower 30 Laser gas supply source 32 Vacuum pump 64 Shaft 66 Turbo blade 72 Rolling bearing 82 Oil reservoir 86 Motor chamber exhaust hole 88 Motor chamber exhaust piping 90 Motor chamber exhaust on-off valve 92 Oil supply port 94 Oil discharge port 96 Lubricating oil injection pipe 100 Oil supply opening / closing valve 102 Lubricating oil discharge pipe 106 Oil discharge opening / closing valve 108 Oil supply tank pressurization pipe 110 Oil supply tank pressurization opening / closing valve 116 Oil discharge tank suction pipe 118 Oil discharge tank suction On-off valve

Claims (6)

A resonator for generating a laser beam by applying a voltage to the laser gas, a laser gas circulation path connected to the resonator, a blower for circulating the laser gas in the laser gas circulation path, and the laser gas circulation path A laser gas supply source for supplying a laser gas; and a vacuum pump for discharging the laser gas from the laser gas circulation path, wherein the blower is mounted on a bearing that rotatably supports a shaft having a rotor blade attached to a tip. A gas laser oscillation device configured to lubricate the bearing by supplying lubricating oil in an oil reservoir provided inside a blower,
An oil supply passage for supplying lubricating oil to the oil reservoir from the outside of the blower;
An oil discharge passage for discharging lubricating oil from the oil reservoir to the outside of the blower;
A first on-off valve for opening and closing the oil supply passage;
A second on-off valve for opening and closing the oil drain passage;
Differential pressure generating means for forcibly creating a pressure difference between the oil reservoir and the outside;
A gas laser oscillation apparatus comprising:   The differential pressure generating means includes the laser gas supply source, and supplies the laser gas from the laser gas supply source to the laser gas circulation path when the first on-off valve is closed and the second on-off valve is opened. The oil pressure through the oil discharge passage is increased by setting the pressure of the laser gas in the oil reservoir of the blower communicating with the laser gas circulation path to be higher than the atmospheric pressure or the pressure in the oil discharge tank connected to the oil discharge passage. The gas laser oscillation apparatus according to claim 1, wherein the lubricating oil in the reservoir is forcibly discharged to the outside of the blower.   The differential pressure generating means includes the vacuum pump, an oil reservoir suction passage for communicating the vacuum pump and the oil reservoir, and a third on-off valve for opening and closing the oil reservoir suction passage, When the first on-off valve is opened and the second on-off valve is closed, the third on-off valve is opened, and the oil supply is connected to the oil reservoir at atmospheric pressure or the oil supply passage by the vacuum pump. 3. The gas laser oscillation device according to claim 1, wherein the lubricating oil is forcibly injected into the oil reservoir from the outside of the blower through the oil supply passage by lowering the pressure in the tank. 4.   The differential pressure generating means includes a drainage tank suction passage for communicating the vacuum pump, a drainage tank connected to the drainage passage and the vacuum pump, and a fourth opening / closing for opening and closing the drainage tank suction path. And when the first on-off valve is closed and the second on-off valve is opened, the fourth on-off valve is opened and the pressure in the oil discharge tank is adjusted by the vacuum pump. The gas laser oscillation device according to claim 1, wherein the oil in the oil reservoir is forcibly discharged to the oil discharge tank through the oil discharge passage by making the pressure lower than the pressure in the reservoir.   The differential pressure generating means includes a laser gas supply source, an oil tank connected to the oil supply passage, and a fuel tank pressurizing path for communicating the laser gas supply source, and a first oil tank for opening and closing the oil tank pressurizing path. And when the first on-off valve is opened and the second on-off valve is closed, the fifth on-off valve is opened and the laser gas is supplied from the laser gas supply source to the fuel tank. The lubricating oil in the oil tank is forcibly injected into the oil reservoir through the oil passage by making the pressure in the oil tank higher than the pressure in the oil reservoir. The gas laser oscillation apparatus as described in any one of Claim 2 and Claim 4. A resonator for generating a laser beam by applying a voltage to the laser gas, a laser gas circulation path connected to the resonator, a blower for circulating the laser gas in the laser gas circulation path, and the laser gas circulation path A laser gas supply source for supplying a laser gas, and a vacuum pump for discharging the laser gas from the laser gas circulation path, wherein the blower is mounted on a bearing that rotatably supports a shaft having a turbo blade attached to a tip. In the gas laser oscillation device configured to supply the lubricating oil in the oil reservoir provided in the blower to lubricate the bearing, the lubricating oil replacement method for the blower replaces the lubricating oil in the oil reservoir of the blower. There,
An oil discharge passage for closing a first on-off valve for opening and closing an oil supply passage for supplying lubricating oil to the oil reservoir from the outside of the blower and discharging the lubricant from the oil reservoir to the outside of the blower When the second on-off valve for opening and closing is opened, a laser gas is supplied from the laser gas supply source to the laser gas circulation path in the previous period and communicates with the laser gas circulation path. By making the pressure higher than atmospheric pressure, the lubricating oil in the oil reservoir is forcibly discharged to the outside of the blower through the oil discharge passage,
When the first on-off valve is closed and the second on-off valve is opened, the pressure inside the oil reservoir is connected to the atmospheric pressure or the oil supply passage using the vacuum pump. Lubricating oil replacement method for a blower characterized in that the lubricating oil is forcibly injected into the oil reservoir from the outside of the blower through the oil supply passage by lowering.

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