Lubricating oil monitoring system and vacuum pump system

Abstract

To provide a lubricating oil monitoring system capable of monitoring the condition of a vacuum pump in order to perform maintenance of the vacuum pump at an appropriate timing.SOLUTION: A lubricating oil monitoring system 30 includes a lubricating oil measurement device 31 for optically measuring lubricating oil L supplied to a bearing 18 of a vacuum pump 1, and a data processing unit 40 electrically connected to the lubricating oil measurement device 31. The lubricating oil measurement device 31 includes: an oil inspection chamber 33 to which the lubricating oil L is introduced; a light source 35 which irradiates the lubricating oil L in the oil inspection chamber 33 with inspection light including red light, green light, and blue light; a first light-receiving unit 36 that receives reflected light from the lubricating oil L irradiated with the inspection light; and a second light-receiving unit 37 that receives transmitted light from the lubricating oil irradiated with the inspection light. The data processing unit 40 is configured to determine the condition of the lubricating oil L and the bearing 18 on the basis of the combination of the color of the reflected light and the color of the transmitted light.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a lubricant monitoring system for monitoring the condition of a lubricant supplied to a bearing of a vacuum pump and the bearing, and to a vacuum pump system equipped with the lubricant monitoring system. [Background technology]

[0002] In processes for manufacturing semiconductor devices, liquid crystal panels, LEDs, solar cells, etc., process gas is introduced into a process chamber to perform various processes such as etching and CVD. The process gas introduced into the process chamber is exhausted by a vacuum pump. In general, the vacuum pump used in these manufacturing processes, which require high cleanliness, is a so-called dry vacuum pump that does not use oil in the gas flow path. A typical example of such a dry vacuum pump is a positive displacement vacuum pump that transfers gas by rotating a pair of pump rotors arranged in a pump chamber in opposite directions.

[0003] In a vacuum pump, lubricating oil is used to lubricate and cool the bearings that rotatably support the rotating shaft to which the pump rotor is fixed. The vacuum pump is provided with a lubricating oil chamber that stores the lubricating oil. When the vacuum pump is driven, the lubricating oil in the lubricating oil chamber is supplied to the bearings, lubricates and cools the bearings, and then is returned to the lubricating oil chamber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2010-150526 [Patent Document 2] JP 2011-94761 A [Patent Document 3] JP 2019-45166 A Summary of the Invention [Problem to be solved by the invention]

[0005] In order to prevent failure of the vacuum pump due to abnormality of the bearings, etc., maintenance such as changing the lubricating oil, changing the bearings, and overhauling are performed periodically. This maintenance is performed based on the accumulated operation time of the vacuum pump, regardless of the state of the vacuum pump, and may be performed even on vacuum pumps that can continue to operate. Stopping the operation of a vacuum pump that can continue to operate to perform maintenance is inefficient in terms of cost and work time. In addition, if the vacuum pump breaks down before the maintenance period, the vacuum pump may be stopped in an emergency during operation, resulting in the loss of wafers and the like that were being processed. Therefore, it is required to monitor the state of the vacuum pump in order to perform maintenance at the appropriate time.

[0006] Therefore, the present invention provides a lubricant oil monitoring system capable of monitoring the condition of a vacuum pump in order to perform maintenance of the vacuum pump at an appropriate time, and a vacuum pump system equipped with the lubricant oil monitoring system. [Means for solving the problem]

[0007] The lubricating oil supplied to the bearings of a vacuum pump is usually colorless and transparent. However, if substances resulting from abnormalities such as wear of the bearings or foreign matter originating from the process gas are mixed into the lubricating oil, its hue changes. The inventors have found that the condition of the lubricating oil and the bearings can be determined by optically measuring the lubricating oil.

[0008] Therefore, in one aspect, a lubricant monitoring system is provided, which includes a lubricant measuring device that optically measures lubricant supplied to a bearing of a vacuum pump, and a data processing unit electrically connected to the lubricant measuring device, wherein the lubricant measuring device includes an oil inspection chamber into which the lubricant is introduced, a light source that irradiates inspection light including red light, green light, and blue light onto the lubricant in the oil inspection chamber, a first light receiving unit that receives reflected light from the lubricant irradiated with the inspection light, and a second light receiving unit that receives transmitted light from the lubricant irradiated with the inspection light, and the data processing unit is configured to determine the state of the lubricant and the bearing based on the combination of the color of the reflected light and the color of the transmitted light. In one aspect, the data processing unit is configured to decompose each of the reflected light and the transmitted light into a red component, a green component, and a blue component, and to determine the condition of the lubricating oil and the bearing based on the intensities of the red component, the green component, and the blue component of the reflected light and the transmitted light, respectively. In one aspect, the conditions of the lubricant and the bearings include abnormalities of the bearings, contamination of the lubricant, and deterioration of the lubricant. In one aspect, the data processing unit is configured to determine that there is an abnormality in the bearing when the intensities of the red, green, and blue components of the reflected light are smaller than a predetermined bearing abnormality threshold, and when the intensities of the red, green, and blue components of the transmitted light are smaller than the bearing abnormality threshold. In one aspect, the data processing unit is configured to determine that the lubricant is contaminated with foreign matter when the intensities of the red, green, and blue components of the reflected light are greater than a predetermined lubricant contamination threshold and the intensities of the red, green, and blue components of the transmitted light are less than the lubricant contamination threshold. In one aspect, the data processing unit is configured to determine that the lubricant is degraded when the intensity of the red component of the reflected light is greater than a predetermined lubricant degradation threshold and the intensities of the green and blue components of the reflected light are less than the lubricant degradation threshold. In one aspect, the data processing unit is configured to calculate a color difference of the reflected light with respect to a reflected reference color based on the intensities of the red, green, and blue components of the reflected light, calculate a color difference of the transmitted light with respect to a transmitted reference color based on the intensities of the red, green, and blue components of the transmitted light, and determine the condition of the lubricating oil and the bearing based on the color difference of the reflected light and the color difference of the transmitted light. In one embodiment, the lubricant is a fluorine-based lubricant.

[0009] In one aspect, a vacuum pump system is provided comprising a vacuum pump and the lubricant monitoring system described above, the vacuum pump comprising a housing structure defining the bearing and a lubricant chamber for storing the lubricant, the lubricant measuring device being mounted to the housing structure, and the oil inspection chamber being in communication with the lubricant chamber. In one aspect, the vacuum pump system further includes a pump control unit that controls the operation of the vacuum pump, and the pump control unit is configured to output an alarm signal when the data processing unit determines that there is an abnormality in the bearing, when the lubricating oil is determined to be contaminated with foreign matter, or when the lubricating oil is determined to be deteriorated. Effect of the Invention

[0010] According to the present invention, the lubricant monitoring system is configured to determine the condition of the lubricant and the bearings based on the combination of the color of the reflected light and the color of the transmitted light, so that the condition of the lubricant and the bearings can be monitored in order to perform maintenance of the vacuum pump at the appropriate time. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram illustrating one embodiment of a vacuum pump system. [Diagram 2] FIG. 2 is a cross-sectional view of the vacuum pump shown in FIG. [Diagram 3] 2 is a cross-sectional view taken along line AA in FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view taken along line BB in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram showing one embodiment of a vacuum pump system, and Fig. 2 is a cross-sectional view of the vacuum pump 1 shown in Fig. 1. As shown in Fig. 1, the vacuum pump system includes a vacuum pump 1 that exhausts process gases used in processes for manufacturing semiconductor devices, liquid crystal panels, LEDs, solar cells, etc., and a lubricant monitoring system 30 that monitors the condition of lubricant and bearings used in the vacuum pump 1.

[0013] The vacuum pump 1 in the embodiment described below is a positive displacement vacuum pump. In particular, the vacuum pump 1 shown in Fig. 1 is a so-called dry vacuum pump that does not use oil in the gas flow path. Since vaporized oil does not flow upstream, the dry vacuum pump is suitable for use in manufacturing equipment for semiconductor devices and the like that require high cleanliness.

[0014] As shown in FIG. 2, the vacuum pump 1 includes a pump casing 2 having a pump chamber 3 therein, pump rotors 5A-5E arranged in the pump chamber 3, a rotating shaft 7 to which the pump rotors 5A-5E are fixed, and an electric motor 8 connected to the rotating shaft 7. The pump rotors 5A-5E and the rotating shaft 7 may be an integral structure. In FIG. 2, only one set of the pump rotors 5A-5E and the rotating shaft 7 are illustrated, but in this embodiment, a pair of pump rotors 5A-5E are arranged in the pump chamber 3, and the pair of pump rotors 5A-5E are fixed to the pair of rotating shafts 7, respectively. The electric motor 8 is connected to one of the pair of rotating shafts 7. In one embodiment, the pair of electric motors 8 may be connected to the pair of rotating shafts 7, respectively.

[0015] The pump rotors 5A to 5E of this embodiment are Roots type pump rotors, but in one embodiment, the pump rotors 5A to 5E may be claw type pump rotors. Furthermore, the pump rotors 5A to 5E may be a combination of a Roots type pump rotor and a claw type pump rotor. The pump rotors 5A to 5E of this embodiment are multi-stage pump rotors, but in one embodiment, the pump rotors may be single stage pump rotors.

[0016] The vacuum pump 1 further includes side covers 10, 11 located outside the pump casing 2 in the axial direction of the rotating shaft 7. The side covers 10, 11 are provided on both sides of the pump casing 2 and connected to the pump casing 2. In this embodiment, the side covers 10, 11 are fixed to the end faces of the pump casing 2 by screws (not shown). In one embodiment, the side covers 10, 11 may be formed integrally with the pump casing 2.

[0017] The pump chamber 3 is formed by the inner surface of the pump casing 2 and the inner surfaces of the side covers 10 and 11. The pump casing 2 has an intake port 2a and an exhaust port 2b. The intake port 2a is connected to a chamber (not shown) filled with a gas to be transferred. In one example, the intake port 2a is connected to a process chamber of a semiconductor device manufacturing apparatus, and the vacuum pump 1 is used to exhaust a process gas from the process chamber.

[0018] The vacuum pump 1 further includes a motor housing 14 and a gear housing 16 as housing structures located outside the side covers 10, 11 in the axial direction of the rotating shaft 7. The side cover 10 is located between the pump casing 2 and the motor housing 14, and the side cover 11 is located between the pump casing 2 and the gear housing 16.

[0019] The motor housing 14 accommodates therein the motor rotor 8A and the motor stator 8B of the electric motor 8. A pair of gears 20 that mesh with each other are arranged inside the gear housing 16. Note that only one gear 20 is depicted in FIG. 2. The electric motor 8 is rotated by a motor driver (not shown), and one rotating shaft 7 to which the electric motor 8 is connected rotates the other rotating shaft 7 to which the electric motor 8 is not connected in the opposite direction via the gear 20.

[0020] In one embodiment, a pair of electric motors 8 may be provided, each coupled to a pair of rotating shafts 7. The pair of electric motors 8 are rotated in synchronous opposite directions by a motor driver (not shown), and rotate the pair of rotating shafts 7 and the pair of pump rotors 5A-5E in synchronous opposite directions. In this case, the role of gear 20 is to prevent the synchronous rotation of pump rotors 5 from becoming out of step due to an unexpected external factor.

[0021] 1 and 2, the motor housing 14 is disposed outside the side cover 10, and the gear housing 16 is disposed outside the side cover 11, but the configuration of the vacuum pump 1 is not limited to this embodiment. In one embodiment, the gear housing 16 may be disposed outside the side cover 10, and the motor housing 14 may be disposed outside the side cover 11. Furthermore, in one embodiment, both the motor housing 14 and the gear housing 16 may be disposed outside either the side cover 10 or the side cover 11.

[0022] When the pump rotors 5A-5E are rotated by the electric motor 8, gas is sucked into the pump chamber 3 of the pump casing 2 through the intake port 2a. The gas is compressed successively by the rotating pump rotors 5A-5E and transferred to the exhaust port 2b, and is discharged from the pump chamber 3 through the exhaust port 2b.

[0023] The rotating shaft 7 is rotatably supported by bearings 17 and 18. The bearing 17 is held in a bearing housing 24, and the bearing 18 is supported by the side cover 11. The bearing 17 is connected to the side cover 10 via the bearing housing 24. More specifically, the bearing housing 24 is held by the side cover 10. In one embodiment, a bearing housing that holds the bearing 18 may be disposed between the side cover 11 and the bearing 18.

[0024] The vacuum pump 1 includes a housing structure forming a lubricant chamber for storing lubricant L for lubricating and cooling the bearing 17 and / or the bearing 18. In this embodiment, the housing structure is the gear housing 16, which forms a lubricant chamber 26 for storing lubricant L for lubricating and cooling the bearing 18. In one embodiment, the housing structure is the motor housing 14, which may form a lubricant chamber for storing lubricant L for lubricating and cooling the bearing 17.

[0025] An oil plate 28 is attached to one end surface of the gear 20 in the gear housing 16. The oil plate 28 is connected to each of the pair of rotating shafts 7 and rotates together with the rotating shafts 7. In one embodiment, the oil plate 28 may be connected to one of the pair of rotating shafts 7. The lubricating oil L is scooped up by the rotation of the oil plate 28 and supplied to the bearing 18. The lubricating oil L supplied to the bearing 18 is returned to the lubricating oil chamber 26 after lubricating and cooling the bearing 18. The lubricating oil L in this embodiment is colorless and transparent, and an example of the lubricating oil is a fluorine-based lubricating oil. However, the lubricating oil L is not limited to this embodiment, and may be a lubricating oil having another color.

[0026] The color of the lubricating oil L supplied to the bearings 18 of the vacuum pump 1 changes due to the inclusion of substances resulting from abnormalities such as wear of the bearings 18 and foreign matter originating from the process gas. When wear powder resulting from wear of the bearings 18 or fine debris resulting from damage to the bearings 18 gets mixed into the lubricating oil L, the lubricating oil L turns black.

[0027] Furthermore, if foreign matter originating from the process gas gets mixed into the lubricating oil L, the lubricating oil L may become cloudy. The foreign matter originating from the process gas is a by-product of the process gas (e.g., SiO2, NH4Cl, etc.). In one example, if hard particles such as SiO2 get mixed into the lubricating oil L as a by-product of the process gas, it may accelerate wear of the bearing 18. In another example, if corrosive particles such as NH4Cl get mixed into the lubricating oil L as a by-product of the process gas, it may corrode the bearing 18. Furthermore, if the lubricating oil L is altered and deteriorated due to the influence of the process gas, the lubricating oil L may turn red. Therefore, the lubricating oil monitoring system 30 is configured to monitor the state of the lubricating oil L and the bearing 18 by optically measuring the lubricating oil L.

[0028] 1, the lubricant monitoring system 30 includes a lubricant measuring device 31 that optically measures the lubricant L supplied to the bearings 18 of the vacuum pump 1, and a data processing unit 40 electrically connected to the lubricant measuring device 31. The lubricant measuring device 31 is attached to the outer surface of the gear housing 16. The lubricant measuring device 31 is attached to a position facing the vicinity of the oil level of the lubricant L in the gear housing 16. In one embodiment, the lubricant measuring device 31 may be attached to an end surface of the gear housing 16.

[0029] Fig. 3 is a cross-sectional view taken along line AA in Fig. 1, and Fig. 4 is a cross-sectional view taken along line BB in Fig. 3. As shown in Fig. 3, a through hole 16a is formed in the side wall of the gear housing 16 to which the lubricant oil metering device 31 is attached. The through hole 16a is formed near the bottom of the gear housing 16, and the lower end of the through hole 16a is located lower than the oil level of the lubricant oil L in the lubricant oil chamber 26. Therefore, the lubricant oil L in the lubricant oil chamber 26 flows out to the outside of the gear housing 16 through the through hole 16a. The lubricant oil metering device 31 is attached so as to face the through hole 16a of the gear housing 16.

[0030] The lubricant measuring device 31 includes a main body case 32 and an oil inspection chamber 33 into which the lubricant L in the lubricant chamber 26 is introduced. The oil inspection chamber 33 is formed by the inner surface of the main body case 32. The oil inspection chamber 33 opens at the contact surface of the main body case 32 with the gear housing 16, and communicates with the lubricant chamber 26 through the through hole 16a. The lubricant L in the lubricant chamber 26 is introduced into the oil inspection chamber 33 through the through hole 16a.

[0031] 4, four through holes 32a into which fasteners (e.g., screws) for fixing the lubricant oil measuring device 31 to the gear housing 16 are inserted are formed near the corners of the main body case 32. However, the number and positions of the through holes 32a are not particularly limited as long as the lubricant oil measuring device 31 can be fixed to the gear housing 16.

[0032] The lubricant measuring device 31 includes a light source 35 that irradiates an inspection light onto the lubricant L in the oil inspection chamber 33, a first light receiving unit 36 ​​that receives reflected light from the lubricant L irradiated with the inspection light, and a second light receiving unit 37 that receives transmitted light from the lubricant L irradiated with the inspection light. The light source 35 and the first light receiving unit 36 ​​are attached to one side wall 32b of the main body case 32. The second light receiving unit 37 is attached to the other side wall 32c of the main body case 32. The oil inspection chamber 33 is located between the light source 35 and the second light receiving unit 37, and is also located between the first light receiving unit 36 ​​and the second light receiving unit 37. The inspection light irradiated from the light source 35 includes red light, green light, and blue light.

[0033] The main body case 32 has a first light transmitting portion 38 adjacent to the light source 35 and the first light receiving portion 36, and a second light transmitting portion 39 adjacent to the second light receiving portion 37. The first light transmitting portion 38 is located within one side wall 32b of the main body case 32, and extends from the light source 35 and the first light receiving portion 36 to the oil inspection chamber 33. The second light transmitting portion 39 is located within the other side wall 32c of the main body case 32, and extends from the second light receiving portion 37 to the oil inspection chamber 33.

[0034] The first light transmitting portion 38 and the second light transmitting portion 39 are made of a transparent material that transmits the inspection light irradiated from the light source 35, the reflected light from the lubricating oil L, and the transmitted light from the lubricating oil L. However, the configuration of the first light transmitting portion 38 and the second light transmitting portion 39 is not particularly limited as long as they can transmit the inspection light irradiated from the light source 35, the reflected light from the lubricating oil L, and the transmitted light from the lubricating oil L. For example, in one embodiment, the entire main body case 32 may be made of a transparent material that transmits the transmitted light.

[0035] The first light transmitting section 38 and the second light transmitting section 39 are disposed at a position lower than the oil level of the lubricating oil L in the oil inspection chamber 33. The first light transmitting section 38 is positioned on the optical path of the inspection light irradiated from the light source 35 and the reflected light from the lubricating oil L. The second light transmitting section 39 is positioned on the optical path of the transmitted light from the lubricating oil L.

[0036] The inspection light emitted from the light source 35 is guided to the lubricant L in the oil inspection chamber 33 through the first light transmitting section 38. The inspection light irradiated to the lubricant L is reflected from the surface of the lubricant L, passes through the lubricant L, and is guided to the second light transmitting section 39. The straight line connecting the first light transmitting section 38 and the second light transmitting section 39 is located on the optical path of the light passing through the lubricant L. The reflected light from the lubricant L irradiated with the inspection light is received by the first light receiving section 36 through the first light transmitting section 38. The transmitted light from the lubricant L irradiated with the inspection light is received by the second light receiving section 37 through the second light transmitting section 39.

[0037] The light source 35, the first light receiving unit 36, and the second light receiving unit 37 are electrically connected to the data processing unit 40. When the data processing unit 40 issues a command to the light source 35, the light source 35 irradiates light onto the lubricant L in the oil inspection chamber 33. The measurement data of the reflected light from the lubricant L received by the first light receiving unit 36 ​​and the measurement data of the transmitted light from the lubricant L received by the second light receiving unit 37 are sent to the data processing unit 40. An RGB color sensor can be used for the first light receiving unit 36 ​​and the second light receiving unit 37. The measurement data of the reflected light from the lubricant L received by the first light receiving unit 36 ​​includes color data of the reflected light, and the measurement data of the transmitted light from the lubricant L received by the second light receiving unit 37 includes color data of the transmitted light.

[0038] The data processing unit 40 is configured to determine the state of the lubricant L and the bearing 18 based on a combination of the color of the reflected light from the lubricant L received by the first light receiving unit 36 ​​and the color of the transmitted light from the lubricant L received by the second light receiving unit 37. More specifically, the data processing unit 40 separates the reflected light from the measurement data of the reflected light sent from the first light receiving unit 36 ​​into red, green, and blue components, and separates the transmitted light from the measurement data of the transmitted light sent from the second light receiving unit 37 into red, green, and blue components. Furthermore, the data processing unit 40 determines the state of the lubricant L and the bearing 18 based on the intensities of the red, green, and blue components of the reflected light and the transmitted light, respectively. Specific examples of the state of the lubricant L and the bearing 18 include an abnormality in the bearing 18, contamination of the lubricant L, and deterioration of the lubricant L.

[0039] When a substance resulting from an abnormality in the bearing 18 gets mixed into the lubricating oil L, the lubricating oil L turns black. As a result, the intensities of the red, green, and blue components of the reflected light from the lubricating oil L and the red, green, and blue components of the transmitted light from the lubricating oil L become smaller than those of a normal (new) lubricating oil. Therefore, the data processing unit 40 determines that there is an abnormality in the bearing 18 when the intensities of the red, green, and blue components of the reflected light are smaller than a predetermined bearing abnormality threshold value and the intensities of the red, green, and blue components of the transmitted light are smaller than the predetermined bearing abnormality threshold value. The intensities of the red, green, and blue components are expressed by a numerical value of 0 to 255, for example.

[0040] When foreign matter originating from the process gas is mixed into the lubricant L, the lubricant L becomes cloudy. As a result, the intensities of the red, green, and blue components of the reflected light from the lubricant L become greater than those of a normal (new) lubricant, while the intensities of the red, green, and blue components of the transmitted light from the lubricant L become smaller than those of a normal (new) lubricant. Thus, the data processing unit 40 determines that the lubricant L is contaminated with foreign matter when the intensities of the red, green, and blue components of the reflected light are greater than a predetermined lubricant contamination threshold value and the intensities of the red, green, and blue components of the transmitted light are less than the predetermined lubricant contamination threshold value.

[0041] The lubricant contamination threshold is determined in advance based on the type of process gas exhausted by the vacuum pump 1. The type of foreign matter mixed into the lubricant L varies depending on the type of process gas exhausted by the vacuum pump 1. For example, in the case of a process gas containing silicon, particles of SiO2, which are a by-product of the process gas, may be mixed into the lubricant L. The SiO2 particles mixed into the lubricant L may promote wear of the bearing 18, and there is a high risk of causing an abnormality in the bearing 18. Therefore, when a process gas containing silicon is exhausted by the vacuum pump 1, the lubricant contamination threshold may be determined to be a relatively small value.

[0042] When the lubricant L deteriorates (or corrodes) due to the influence of the process gas, the lubricant L may turn red. In such a case, the intensity of the red component of the reflected light is greater than that of a normal (new) lubricant, and the intensities of the green and blue components of the reflected light are smaller than that of a normal (new) lubricant L. Therefore, the data processing unit 40 determines that the lubricant L has deteriorated when the intensity of the red component of the reflected light is greater than a predetermined lubricant deterioration threshold value and the intensities of the green and blue components of the reflected light are smaller than the lubricant deterioration threshold value.

[0043] The data processing unit 40 is composed of at least one computer. The data processing unit 40 includes a storage device 40a in which a program is stored, and a calculation device 40b that executes calculations according to instructions included in the program. The storage device 40a includes a main storage device such as a random access memory (RAM), and an auxiliary storage device such as a hard disk drive (HDD) or a solid state drive (SSD). Examples of the calculation device 40b include a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). However, the specific configuration of the data processing unit 40 is not limited to these examples.

[0044] According to this embodiment, the lubricant monitoring system 30 is configured to determine the state of the lubricant L and the bearings 18 based on a combination of the color of the reflected light and the color of the transmitted light. Therefore, the states of the lubricant L and the bearings 18 can be monitored in order to perform maintenance of the vacuum pump 1 at an appropriate time.

[0045] In one embodiment, the data processing unit 40 calculates the color difference of the reflected light with respect to the reflected reference color based on the intensities of the red, green, and blue components of the reflected light, calculates the color difference of the transmitted light with respect to the transmitted reference color based on the intensities of the red, green, and blue components of the transmitted light, and judges the state of the lubricant L and the bearing 18 based on the color difference of the reflected light and the color difference of the transmitted light. The reflected reference color may be a specific color (e.g., white), or may be the color of the reflected light when the test light is irradiated on a normal (new) lubricant. The transmitted reference color may be a specific color (e.g., white), or may be the color of the transmitted light when the test light is irradiated on a normal (new) lubricant.

[0046] Color difference ΔE1 of reflected light against the reflected reference color RGB is expressed by the following equation (1).

number

[0047] Color difference ΔE2 of transmitted light compared to the transmitted reference color RGB is expressed by the following equation (2).

number

[0048] In one example, the reflected reference colors R1a, G1a, and B1a are the intensities of the red, green, and blue components of the reflected light when a test light is irradiated onto a normal (new) lubricant, and the transmitted reference colors R2a, G2a, and B2a are the intensities of the red, green, and blue components of the transmitted light when a test light is irradiated onto a normal (new) lubricant.

[0049] The data processing unit 40 detects the color difference ΔE1 of the reflected light. RGB and color difference of transmitted light ΔE2 RGB The state of the lubricating oil L and the bearing 18 is determined based on the color difference ΔE1 of the reflected light. RGB The more the hue of the reflected light deviates from the hue of the reflected reference color, the greater the color difference ΔE2 of the transmitted light. RGB The more the hue of the transmitted light is different from the hue of the transmitted reference color, the larger the color difference ΔE1 of the reflected light. RGB is greater than a predetermined reflection color difference threshold value, and the color difference of the transmitted light ΔE2 RGB is greater than a predetermined transmitted color difference threshold, it is determined that there is an abnormality in the bearing 18 or the lubricant L. The reflected color difference threshold, the transmitted color difference threshold, and the conditions for determining the state of the lubricant L and the bearing 18 are determined in advance based on the reflected reference color and transmitted reference color, etc.

[0050] As shown in Fig. 1, the vacuum pump system further includes a pump control unit 50 that controls the operation of the vacuum pump 1, and a display device 55 that displays an alarm regarding the state of the lubricant L and the bearings 18. The data processing unit 40 and the display device 55 are electrically connected to the pump control unit 50. The results of the determination of the state of the lubricant L and the bearings 18 by the data processing unit 40 are sent to the pump control unit 50. The pump control unit 50 is configured to output an alarm signal when the data processing unit 40 determines that there is an abnormality in the bearings 18, that the lubricant L is contaminated with foreign matter, or that the lubricant L is deteriorated.

[0051] The display device 55 is composed of a liquid crystal display or the like. The alarm signal output from the pump control unit 50 is sent to the display device 55. The display device 55 displays an alarm regarding the state of the lubricating oil L and the bearings 18 based on the alarm signal output from the pump control unit 50. This enables the operator to perform maintenance of the vacuum pump 1 at an appropriate time based on the alarm displayed on the display device 55.

[0052] In one embodiment, the pump control unit 50 may output a bearing abnormality alarm signal indicating that there is an abnormality in the bearing 18 when the data processing unit 40 determines that there is an abnormality in the bearing 18. Similarly, the pump control unit 50 may output a lubricant contamination alarm signal indicating that the lubricant L is contaminated with foreign matter when the data processing unit 40 determines that the lubricant L is contaminated with foreign matter, and may output a lubricant deterioration alarm signal indicating that the lubricant L is deteriorated when the data processing unit 40 determines that the lubricant L is deteriorated.

[0053] In this case, based on the bearing abnormality alarm signal, the display device 55 displays an alarm indicating that there is an abnormality in the bearing 18. Similarly, based on the lubricant contamination alarm signal, the display device 55 displays an alarm indicating that the lubricant L is contaminated with foreign matter, and based on the lubricant deterioration alarm signal, displays an alarm indicating that the lubricant L is deteriorating.

[0054] In one embodiment, the alarm indicating that there is an abnormality in the bearing 18 displayed by the display device 55 may include a message urging the replacement of the bearing 18, and the alarm indicating that the lubricating oil L is contaminated with foreign matter and the alarm indicating that the lubricating oil L has deteriorated may include a message urging the replacement of the lubricating oil L. This allows the operator to carry out appropriate maintenance in accordance with the state of the vacuum pump 1 based on the message displayed on the display device 55.

[0055] The pump control unit 50 is composed of at least one computer. The pump control unit 50 includes a storage device 50a in which a program is stored, and a calculation device 50b that executes calculations according to instructions included in the program. The storage device 50a includes a main storage device such as a random access memory (RAM), and an auxiliary storage device such as a hard disk drive (HDD) or a solid state drive (SSD). Examples of the calculation device 50b include a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). However, the specific configuration of the pump control unit 50 is not limited to these examples.

[0056] The above-described embodiments have been described for the purpose of enabling a person having ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments are naturally possible for a person skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope according to the technical idea defined by the claims. [Explanation of symbols]

[0057] 1. Vacuum pump 2 Pump casing 2a Air intake 2b Exhaust port 3. Pump Room 5A~5E Pump rotor 7 Rotation Axis 8 Electric motor 8A motor rotor 8B Motor stator 10,11 Side cover 14 Motor housing 16 Gear housing 16a through hole 17,18 Bearings 20 Gear 24 Bearing housing 26 Lubricant room 28 Oil plate 30 Lubricant Monitoring System 31 Lubricating oil measuring device 32 Main unit case 32a through hole 33 Oil Inspection Room 35 Light source 36 1st light receiving section 37 2nd light receiving section 38 1st light transmission section 39 Second light transmitting part 40 Data Processing Section 40a storage device 40b Arithmetic unit 50 Pump control section 50a storage device 50b Arithmetic unit 55 Display device L Lubricating oil

Claims

1. a lubricant measuring device for optically measuring the lubricant supplied to a bearing of a vacuum pump; A data processing unit electrically connected to the lubricant measuring device, The lubricant measuring device is an oil inspection chamber into which the lubricating oil is introduced; a light source that irradiates the lubricating oil in the oil inspection chamber with inspection light including red light, green light, and blue light; a first light receiving unit that receives reflected light from the lubricant oil irradiated with the inspection light; a second light receiving unit that receives light transmitted through the lubricant oil irradiated with the inspection light; The lubricant monitoring system, wherein the data processing unit is configured to determine a condition of the lubricant and the bearing based on a combination of the color of the reflected light and the color of the transmitted light.

2. 2. The lubricant monitoring system of claim 1, wherein the data processing unit is configured to decompose each of the reflected light and the transmitted light into a red component, a green component, and a blue component, and determine a condition of the lubricant and the bearing based on the intensities of the red component, the green component, and the blue component of the reflected light and the transmitted light, respectively.

3. The lubricant monitoring system of claim 2 , wherein the condition of the lubricant and the bearings includes anomalies in the bearings, contamination of the lubricant, and deterioration of the lubricant.

4. 4. The lubricant oil monitoring system of claim 3, wherein the data processing unit is configured to determine that there is an abnormality in the bearing when the intensities of the red, green, and blue components of the reflected light are smaller than a predetermined bearing abnormality threshold value and when the intensities of the red, green, and blue components of the transmitted light are smaller than the bearing abnormality threshold value.

5. The lubricant monitoring system of claim 3, wherein the data processing unit is configured to determine that the lubricant is contaminated with foreign matter when the intensities of the red, green, and blue components of the reflected light are greater than a predetermined lubricant contamination threshold and the intensities of the red, green, and blue components of the transmitted light are less than the lubricant contamination threshold.

6. The lubricant monitoring system of claim 3, wherein the data processing unit is configured to determine that the lubricant has deteriorated when the intensity of the red component of the reflected light is greater than a predetermined lubricant deterioration threshold and the intensity of the green and blue components of the reflected light is less than the lubricant deterioration threshold.

7. The data processing unit includes: calculating a color difference of the reflected light relative to a reflected reference color based on the intensities of the red, green, and blue components of the reflected light; calculating a color difference of the transmitted light relative to a transmitted reference color based on the intensities of the red, green, and blue components of the transmitted light; The lubricant monitoring system of claim 1 configured to determine a condition of the lubricant and the bearing based on the color difference of the reflected light and the color difference of the transmitted light.

8. The lubricant monitoring system of claim 1 , wherein the lubricant is a fluorine-based lubricant.

9. A vacuum pump; A lubricant monitoring system according to any one of claims 1 to 8, The vacuum pump is The bearing; a housing structure that defines a lubricating oil chamber that stores the lubricating oil; the lubricant metering device is mounted to the housing structure; The oil inspection chamber is in communication with the lubrication oil chamber.

10. A pump control unit for controlling the operation of the vacuum pump is further provided.

10. The vacuum pump system according to claim 9, wherein the pump control unit is configured to output an alarm signal when the data processing unit determines that there is an abnormality in the bearing, when the data processing unit determines that the lubricating oil is contaminated with foreign matter, or when the data processing unit determines that the lubricating oil has deteriorated.

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