JP2019027940A - Vibration measuring device of bearing for vacuum - Google Patents

Abstract

To provide a vibration measuring device of a bearing for a vacuum that can detect a vibration of a bearing for vacuum which operates in a vacuum environment, by an acceleration sensor set under a normal pressure.SOLUTION: The present invention includes a vibrator 32, which can be displaced in the direction of vibration of a bearing 1 for vacuum set in a vacuum chamber VR; a vibration unit 30, which can penetrate the top plate 11 of the vacuum chamber VR; rings 39, 40, and 43 between the top plate 11 and the vibration unit 30 for sealing the vacuum chamber VR; and a vibration acceleration pick-up 48 in the vacuum chamber VR, which detects the vibration of the vibrator 32.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibration measurement device for a vacuum bearing, and more particularly to a vibration measurement device for a vacuum bearing that detects vibration of a vacuum bearing operating in a vacuum environment.

  As part of equipment for manufacturing an FPD (flat panel display), there are vacuum processing apparatuses such as a sputtering apparatus, a plasma CVD apparatus, and an ion implantation apparatus. These vacuum processing apparatuses include a transfer device and a transfer robot that transfer a workpiece such as a substrate in a vacuum state. Rolling bearings are used for the rotation support portions of the transfer device and the transfer robot. As described above, the abnormality diagnosis of the bearing operating in the vacuum environment is to directly measure the output value (for example, dynamic friction torque, vibration acceleration, etc.) of the bearing because the bearing is arranged in the vacuum environment. difficult. Patent Document 1 discloses a vacuum processing apparatus that can measure the dynamic friction torque of a ball bearing disposed in a vacuum processing apparatus via a drive shaft that is rotated and introduced from outside the vacuum environment.

JP 2000-236314 A

However, in the vacuum processing apparatus described in Patent Document 1, since the measurement value includes at least the dynamic friction torque of the bearing that supports the drive shaft of the rotation introducing machine, the test bearing is accurately diagnosed for abnormality. It was difficult.
An acceleration sensor that measures vibration acceleration is configured by stacking piezoelectric elements, and an adhesive is used as a binder that mediates the stacking of piezoelectric elements. For this reason, when an acceleration sensor is arranged in the vicinity of the test bearing (in a vacuum environment) to measure the vibration acceleration of the test bearing, the adhesion constituting the acceleration sensor (hereinafter also referred to as “vibration acceleration pickup”) in the vacuum environment. Since the properties of the agent change and the acceleration sensing characteristics change, vibration testing of the vacuum bearing has been difficult.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a vacuum bearing vibration measuring apparatus capable of accurately detecting vibration of a vacuum bearing operating in a vacuum environment. It is in.

The above object of the present invention can be achieved by the following constitution.
(1) A vibrator unit including a vibrator displaceable in a vibration direction of a vacuum bearing provided in the vacuum chamber, and penetrating a partition wall constituting the vacuum chamber;
A sealing member provided between the partition wall and the vibrator unit and sealing the vacuum chamber;
An acceleration sensor disposed outside the vacuum chamber and connected to the vibrator unit to detect vibration of the vibrator;
A vibration measurement device for a vacuum bearing, comprising:
(2) The vibrator unit includes a cylindrical portion that is fitted to the columnar vibrator, a disk that is coaxial with the cylindrical portion and has a larger diameter than the cylindrical portion, and is disposed outside the vacuum chamber. A vibrator holder that is displaceable in a vibration direction of the vacuum bearing together with the vibrator by being fastened to the vibrator.
The vibration measurement device for a vacuum bearing according to (1), wherein a front end surface of the cylindrical portion faces the vacuum chamber.
(3) The axial center of the vibrator and the acceleration sensor are coaxially arranged on a straight line passing through the center of the vacuum bearing, and the vacuum sensor according to (1) or (2) Bearing vibration measuring device.
(4) The vibration measurement device for a vacuum bearing according to any one of (1) to (3), wherein the vibrator is formed of a member having heat insulation performance.
(5) The vibrator unit is provided outside the vacuum chamber, and further includes a heat dissipating unit that dissipates heat from the vacuum bearing, according to any one of (1) to (4), Vibration measurement device for vacuum bearings.
(6) In any one of (1) to (5), the sealing member is an O-ring that supports the vibrator so as to be displaceable in an oscillating direction of the vacuum bearing by an elastic force. The vibration measuring apparatus of the vacuum bearing as described.
(7) A vibrator housing is provided between the through hole of the partition wall and the vibrator unit.
The vibration measuring device for a vacuum bearing according to (6), wherein the O-ring is disposed in an O-ring groove formed on an inner peripheral surface of the vibrator housing or an outer peripheral face of the vibrator unit. .
(8) The vibration measurement device for a vacuum bearing according to any one of (1) to (7), wherein the acceleration sensor is fixed to one end outside the vacuum chamber of the vibrator unit by a magnetic force. .

  According to the vibration measuring apparatus for a vacuum bearing of the present invention, the vibrator unit that is displaceable in the vibration direction of the vacuum bearing provided in the vacuum chamber, the vibrator unit that penetrates the partition wall of the vacuum chamber, the partition wall, and the vibration Since it is provided with a sealing member that is provided between the slave unit and seals the vacuum chamber, and an acceleration sensor that is disposed outside the vacuum chamber and detects vibration of the vibrator, it operates in a vacuum environment. The vibration of the bearing can be measured by an acceleration sensor arranged at normal pressure. Thereby, the vibration of the vacuum bearing can be accurately measured.

It is a side view of the vibration measuring apparatus of the vacuum bearing which concerns on this invention. It is a principal part enlarged view of the vibration measuring apparatus of the vacuum bearing shown in FIG. It is a graph which shows the test result of the total rotation speed, vibration, and temperature of the vacuum bearing in an endurance test. It is a principal part enlarged view of the graph shown in FIG.

  Hereinafter, an embodiment of a vibration measuring apparatus for a vacuum bearing according to the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the vibration measurement device 10 for a vacuum bearing uses a vibration acceleration pickup 48, which is an acceleration sensor provided outside the vacuum environment, to vibrate the vibration of the vacuum bearing 1 disposed in the vacuum environment. It can be measured. The vacuum bearing 1 includes an outer ring 2, an inner ring 3, a plurality of rolling elements 4 disposed between the raceways 2 a and 3 a of the outer ring 2 and the inner ring 3, a cage 5 that holds the rolling elements 4, and A pair of shield plates 6 are provided.

  The vacuum chamber is composed of a top plate 11, side walls 12 and 13, and a bottom plate 16 constituting a partition, and is isolated from the surroundings (outside) to form a vacuum chamber VR that can maintain the inside in a vacuum environment. . On the bottom plate 16 of the vacuum chamber, a pair of gate-shaped housings 17 facing each other are erected. The bottom plate 16 is connected to an exhaust port 16a that is connected to a vacuum pump (not shown) to make the vacuum chamber VR a vacuum environment in a vacuum-tight manner.

  A bearing housing 18 having a collar portion 18 a is fitted in each portal housing 17, and the collar portion 18 a is integrally fixed to a side surface of the portal housing 17 with a screw 19.

  The bearings for vacuum 18 are respectively fitted in the bearing holes 18b formed on the same axis of the pair of bearing housings 18, and both ends of the rotary shaft 20 disposed horizontally are rotatably supported. The inner ring 3 of each vacuum bearing 1 is fixed in the axial direction by a nut 22 whose one end abuts on a stepped portion 20 a formed at the end of the rotary shaft 20 and whose other end is screwed through a thrust washer 21. ing.

  The outer ring 2 of each vacuum bearing 1 is fitted into the bearing hole 18 b of the bearing housing 18, and one end of the rotating shaft 20 opposite to the stepped portion 20 a abuts against the pressing ring 23. The pressing ring 23 is urged toward the stepped portion 20 a by the elastic force of the coil spring 24. As a result, a constant pressure preload is applied to each vacuum bearing 1. A heater 25 for heating the vacuum bearing 1 to raise the temperature is provided on the outer periphery of the flange portion 18a of the bearing housing 18.

  A rotating introduction shaft 26 that is driven to rotate by a motor (not shown) disposed outside the vacuum chamber VR, that is, in a normal pressure (hereinafter also referred to as “in the atmosphere”) environment, is coupled to the rotating shaft 20. Connected through. The rotation introducing shaft 26 is disposed in the vacuum chamber VR, and a magnetic seal, a magnetic coupling, a differential exhaust seal, an O-ring, or the like is provided between the motor driving shaft and the rotation introducing shaft 26 (both shown in FIG. The vacuum of the vacuum chamber VR is maintained.

  The materials of the gate-type housing 17, the bearing housing 18, and the rotary shaft 20 are not particularly limited, and are generally mild steel, austenitic stainless steel such as SUS304, martensitic stainless steel such as SUS420J2 and SUS440C, and ferritic stainless steel such as SUS430. Precipitation hardening type stainless steel such as steel and SUS630 can be used.

  Moreover, the material of the coil spring 24 can use a general piano wire, an oil tempered wire, etc. When heating with the heater 25 and performing a high temperature test, it is stainless steel, such as SUS304 and SUS631, and also 350 degreeC or more. When the above test is performed, it is desirable to use an alloy material having excellent heat resistance such as Inconel 600 and Inconel X-750.

  The material of the coupling 27 is not particularly limited, and general aluminum alloys such as A5052, A5056, duralumin such as A2017, A2024, A7075, stainless steel such as SUS316L, SUS304, SUS303, etc. are used alone or in combination. Used for.

  Further, when the test is performed by raising the temperature of the vacuum bearing 1, it is conceivable that the rotary shaft 20 is thermally expanded. Therefore, the coupling 27 is an allowable axial displacement that can sufficiently absorb the thermal expansion length. It is good to choose what has. Although not shown, a shaft, a cup covering the shaft, and a ball coupling of the type in which both are mechanically coupled with a ball are preferable because the allowable axial displacement is large.

  In the figure, the load applied to the vacuum bearing 1 is only the preload load by the coil spring 24. However, if necessary, a bearing box (not shown) is disposed between the pair of vacuum bearings 1 and the bearing. A radial load can also be applied by suspending a load on the box. In that case, the load is supported by the two vacuum bearings 1.

  On an extension line of the vertical line V passing through the center of the vacuum bearing 1, a vibrator unit 30 penetrating the top plate 11 of the vacuum chamber VR in the vertical direction is disposed coaxially with the vertical line V. The vibrator unit 30 mainly includes a substantially columnar vibrator 32, a vibrator holder 33, and a fin block 34.

  The vibrator 32 transmits the vibration of the vacuum bearing 1 to the vibration acceleration pickup 48, and the tip end portion 32a formed in a hemispherical shape is formed on the upper surface 17a of the gate-shaped housing 17 formed horizontally with good flatness. It is in contact. That is, the vibrator 32 is in contact with the upper surface 17a of the portal housing 17 at the axial center position.

  The vibrator holder 33 is fitted with the vibrator 32 and has a cylindrical portion 33a whose front end face faces the vacuum chamber VR, and is coaxial with the cylindrical portion 33a and has a larger diameter than the cylindrical portion 33a. It has the disk part 33b arrange | positioned on the outer side (outside). The vibrator 32 and the vibrator holder 33 are integrally fastened by a bolt provided at a portion of the disk portion 33b that closes one end of the cylindrical portion 33a.

  A vibrator housing 35 is attached to the penetrating portion of the top plate 11 through which the vibrator unit 30 passes. The vibrator housing 35 includes a housing cylindrical portion 35a and a collar portion 35b provided at one end portion in the axial direction of the housing cylindrical portion 35a.

  The housing cylindrical portion 35a is inserted into the through hole 11a of the top plate 11 from the vacuum chamber VR side, and the collar portion 35b is in contact with the lower surface 11b of the top plate 11 and the upper surface 11c side (vacuum chamber VR) of the top plate 11. And a substantially ring plate-like back plate 37 disposed on the outer side of the plate and a bolt 38. That is, the top plate 11 is sandwiched from above and below by the flange portion 35b of the housing cylindrical portion 35a and the back plate 37.

  A through hole having an inner diameter larger than the outer diameter of the cylindrical portion 33a of the vibrator holder 33 is formed in the back plate 37 so as not to interfere with the vibrator holder 33 to be inserted. The housing cylindrical portion 35a is inserted into the through hole 11a of the top plate 11 and the collar portion 35b is in contact with the lower surface 11b of the top plate 11, and the upper end surface of the housing cylindrical portion 35a is the upper surface of the top plate 11. It is designed not to protrude from 11c.

  When the top plate 11 is made of glass, a flat ring 50 made of an elastic member such as nitrile rubber or silicon rubber is inserted between the back plate 37 and the top plate 11 to prevent breakage of the glass. Is good.

  A gap between the collar portion 35b and the lower surface 11b of the top plate 11 is sealed by an O-ring 39 attached to an O-ring groove 35c formed on the upper surface of the collar portion 35b. By fastening the upper end surface of the housing cylindrical portion 35a and the back plate 37, the O-ring 39 is compressed, thereby expressing a predetermined hermetic sealing performance between the through hole 11a of the top plate 11 and the vibrator housing 35. doing. The arrangement position of the O-ring 39 is not limited to the above-described position, and the O-ring 39 may be arranged at any position as long as the space between the through hole 11a of the top plate 11 and the vibrator housing 35 can be hermetically sealed. Can do.

  In the fitting hole 35d formed in the housing cylindrical portion 35a of the transducer housing 35, the cylindrical portion 33a of the transducer holder 33 inserted from above (outside the vacuum chamber VR) in the drawing is axially (vertical direction). ) Is slidable and fits with high clearance accuracy. The space between the fitting hole 35d of the housing cylindrical portion 35a and the cylindrical portion 33a of the vibrator holder 33 is sealed by an O-ring (sealing member) 40 attached to an O-ring groove 35e on the inner peripheral surface of the fitting hole 35d. It has been stopped. That is, the tip of the vibrator unit 30 is disposed in the vacuum chamber VR, and the disk unit 33b side of the vibrator unit 30 is disposed in normal pressure outside the vacuum chamber VR. The O-ring groove 35e may be provided on the outer peripheral surface of the vibrator holder 33, contrary to the above.

  In the O-ring 40 that seals between the vibrator holder 33 and the housing cylindrical portion 35a by elastic force, the vibration direction (vertical axis direction) of the vibrator holder 33 and the slidable direction of the O-ring 40 are the same direction. Therefore, attenuation of vibration acceleration by the O-ring 40 can be minimized.

  A substantially cylindrical fin block 34 is fastened to the upper surface of the disk portion 33 b of the vibrator holder 33 by screws 41. A space between the upper surface of the disk portion 33b and the lower surface of the fin block 34 is sealed by an O-ring 43 attached to an O-ring groove 42 provided in the disk portion 33b. The O-ring 43 hermetically seals the inner peripheral surface of the cylindrical portion 33 a of the vibrator holder 33 and the outer peripheral face of the vibrator 32.

  The fin block 34 has a large number of slits carved from the outer diameter toward the center, and acts as a heat sink for heat dissipation. Note that the upper surface of the disk portion 33b is formed with a right angle with respect to its own axis of the vibrator holder 33 and with a good flatness. In addition, since the upper and lower surfaces of the fin block 34 are shaped with high parallelism, the normal line of the fin block end surface is parallel to the vertical line V passing through the center of the vacuum bearing 1. Accordingly, the fin block 34 is coaxially fastened to the upper surface of the disk portion 33 b of the vibrator holder 33.

  The material of the vibrator 32 includes general mild steel, austenitic stainless steel such as SUS304, martensitic stainless steel such as SUS420J2 / SUS440C, ferritic stainless steel such as SUS430, precipitation hardening stainless steel such as SUS630, and the like. It can be used, and wear resistance performance is improved by using tool steel such as SK material, SKD material, SKH material and the like. In addition, heat insulation performance is improved by using machinable ceramics such as engineered ceramics such as silicon nitride, alumina and zirconia, fluorine phlogopite, and fluorine phlogopite zirconia whose thermal conductivity is about 40 w / m · K or less. Then, it becomes possible to cope with a test at a higher temperature.

  The material of the vibrator holder 33 and the vibrator housing 35 is not only general soft steel, but also austenitic stainless steel such as SUS304, martensitic stainless steel such as SUS420J2 / SUS440C, ferritic stainless steel such as SUS430, SUS630. The precipitation hardening type stainless steel etc. are used.

  The top plate 11 is made of austenitic stainless steel such as SUS304, SUS316, SUS316L, general aluminum alloys such as A5052, A5056, duralumin such as A2017, A2024, A7075, etc. You may enable it to look inside the room VR. As the material of the glass, tempered glass, quartz glass, etc. can be used in addition to general soda glass, and heat-resistant glass added with boron oxide is suitable for a bearing test at a high temperature.

  The material of the fin block 34 is not only general mild steel, but also austenitic stainless steel such as SUS304, martensitic stainless steel such as SUS420J2 / SUS440C, ferritic stainless steel such as SUS430, and precipitation hardening stainless steel such as SUS630. A general aluminum alloy such as A5052, A5056, duralumin such as A2017, A2024, A7075, or the like is used. When an aluminum alloy is used, the heat dissipation performance as a heat sink is improved because the thermal conductivity is large.

  A magnet plate 44 is fastened coaxially with the fin block 34 by screws 45 on the upper surface of the fin block 34. On the magnet plate 44, a magnet holder 46 in which a magnet (not shown) is embedded is attracted and held by the magnetic force of the magnet. A screw shaft (not shown) protruding below the pickup adapter 47 is screwed and fixed to a female screw (not shown) formed on the upper surface side of the magnet holder 46. A female screw (not shown) of the vibration acceleration pickup 48 is screwed and fixed to a screw shaft (not shown) protruding above the pickup adapter 47. That is, the pickup adapter 47 has two screw shafts protruding upward and downward. Furthermore, the magnet holder 46, the pickup adapter 47, and the vibration acceleration pickup 48 are unitized with their centers being coaxial.

  The upper and lower surfaces of the fin block 34, the magnet plate 44, the magnet holder 46, and the pickup adapter 47 are formed with good parallelism and flatness. Therefore, by attracting and holding the magnet holder 46 so as to be coaxial with the magnet plate 44, the centers of the magnet plate 44, the magnet holder 46, the pickup adapter 47, and the vibration acceleration pickup 48 are the center of the vacuum bearing 1. It is located on an extension of the vertical line V that passes through.

  The material of the magnet plate 44 is a ferromagnetic material such as martensitic stainless steel such as SUS420J2 and SUS440C, ferritic stainless steel such as SUS430, and precipitation hardening stainless steel such as SUS630, in addition to general mild steel.

  The magnet embedded in the magnet holder 46 has a sufficient magnetic force so that it does not fall off even if the vibration acceleration pickup 48 is arranged so as to be directly below the vertical direction after the pickup adapter 47, the vibration acceleration pickup 48, etc. are fastened. Have. The material of the magnet holder 46 is not particularly limited, and in addition to general mild steel, austenitic stainless steel such as SUS304, martensitic stainless steel such as SUS420J2 / SUS440C, ferritic stainless steel such as SUS430, precipitation hardening such as SUS630. In addition to type stainless steel, general aluminum alloys such as A5052 and A5056, duralumin such as A2017, A2024, and A7075 can be used.

  Next, a procedure for measuring the vibration of the vacuum bearing 1 by the vacuum bearing vibration measuring apparatus 10 of the embodiment will be described.

  First, the two vacuum bearings 1 are set on the rotary shaft 20 in the vacuum chamber VR, the test apparatus is assembled by a predetermined procedure, and the rotary shaft 20 is arranged horizontally by the portal housing 17. The rotating shaft 20 is connected to the rotation introducing shaft 26 by a coupling 27. Further, the exhaust port 16a provided on the bottom plate 16 of the vacuum chamber is connected to a vacuum pump (not shown) in a vacuum-tight manner.

  Further, the vibrator unit 30 is formed by loading and fastening the vibrator 32 to the vibrator holder 33, fastening the fin block 34 to the vibrator holder 33, and fastening the magnet plate 44 to the fin block 34. As described above, the vibrator unit 30 is vacuum-sealed between the vibrator 32 and the vibrator holder 33.

  Until the two vibrator units 30 are inserted into the fitting holes 35 d of the vibrator housing 35 from the normal pressure space side (above), the tip 32 a of the vibrator 32 is brought into contact with the upper surface 17 a of the portal housing 17. Go straight. The O-ring 40 disposed in the vibrator housing 35 seals the space between the vibrator unit 30 and the vibrator housing 35 to complete the vacuum sealing in the vacuum chamber VR.

  Further, when the magnet holder 46 is attracted to the magnet plate 44 almost coaxially, the vibrator 32 and the vibration acceleration pickup 48 are arranged substantially coaxially. Furthermore, since the fitting hole 35d of the vibrator housing 35 is on the vertical line V passing through the center of the vacuum bearing 1, the vibration acceleration pickup 48 is disposed on the vertical line V.

  Then, after operating the vacuum pump to exhaust the internal air from the exhaust port 16a of the vacuum chamber VR to make the vacuum chamber VR a vacuum environment of a predetermined pressure, the rotation introducing shaft 26 is moved by a motor (not shown). The rotation shaft 20 is rotated through the rotation shaft 20, and the rotation test in the vacuum environment of the vacuum bearing 1 mounted on the rotation shaft 20 is performed.

  Since the vibrator unit 30 is vacuum-sealed by the O-ring 40 attached to the cylindrical portion 33a of the vibrator holder 33 during the rotation test of the vacuum bearing 1 disposed in the vacuum environment, The vacuum chamber VR is drawn by a suction force corresponding to the cross-sectional area of the holder 33. That is, the tip 32 a of the vibrator 32 is in contact with the upper surface 17 a of the portal housing 17 with a constant and stable load due to the suction force over the entire test period of the vacuum bearing 1. Thereby, stable vibration measurement becomes possible.

  The vibration acceleration pickup 48 is united by being coaxially fastened with the magnet holder 46 via the pickup adapter 47. Then, by causing the magnet holder 46 to be attracted coaxially to the magnet plate 44, the vibration acceleration pickup 48 is coaxial with the axis center of the vibrator 32 and is disposed on the vertical line V passing through the center of the vacuum bearing 1. . Thereby, the vibration acceleration in the vertical direction of the vacuum bearing 1 is transmitted to the vibration acceleration pickup 48 and measured with a minimum time lag.

  Further, the test of the vacuum bearing 1 at a high temperature can be performed by energizing the heater 25 disposed in the collar portion 18 a of the bearing housing 18 and heating the vacuum bearing 1 through the bearing housing 18. For the temperature of the vacuum bearing 1, a temperature sensor such as a thermocouple (not shown) is placed in contact with the vacuum bearing 1 (for example, the outer ring 2), and energization to the heater 25 is controlled while measuring the temperature of the vacuum bearing 1. Thus, it can be set to an arbitrary temperature. Thus, since the vibration measuring apparatus 10 is used for a test under a high temperature environment, it is desirable that the O-rings 39, 40, and 43 use high-temperature O-rings.

  In general, the sensor body of the vibration acceleration pickup 48 is configured by stacking piezoelectric elements, and a correct output can be obtained only within a specified temperature range. That is, in the test of the vacuum bearing 1 at a high temperature, the heat of the vacuum bearing 1 (bearing housing 18) may affect the measurement value of the vibration acceleration pickup 48. For this reason, the heat conducted from the bearing housing 18 to the vibration acceleration pickup 48 is limited by forming the vibrator 32 with a material having a thermal conductivity of about 40 w / m · K or less such as ceramics to have a heat insulating function. It is good. Furthermore, if heat is radiated by the heat radiating function of the fin block 34, the influence of heat on the vibration acceleration pickup 48 can be minimized. It is preferable to improve the heat radiation efficiency by supplying an air flow to the fin block 34 by a fan or a cooler (not shown).

Therefore, according to the vibration measuring apparatus 10 for a vacuum bearing having the above configuration, even when the vacuum bearing 1 is held at a high temperature in a vacuum environment, the heat insulating function of the vibrator 32 and the heat dissipation function of the fin block 34 are used. The vibration of the vacuum bearing 1 is continuously and accurately measured with the vibration acceleration pickup 48 placed at room temperature and normal pressure while minimizing the influence of heat on the vibration acceleration pickup 48. can do.
Furthermore, since the vibration direction (vertical axis direction) of the vibrator 32 and the slidable direction of the O-ring 40 are the same direction, attenuation of vibration acceleration by the O-ring 40 is minimized, and measurement with high accuracy is possible. Is possible. In addition, the vibrator 32 is drawn into the vacuum chamber VR by a suction force corresponding to the cross-sectional area of the vibrator holder 33, and the vibrator 32 is always pressed against the upper surface 17 a of the portal housing 17 with the same load value. Therefore, stable transmission of vibration is ensured at all times without separation between the portal housing 17 and the vibrator 32, and accurate measurement is possible.

As described above, according to the vacuum bearing vibration measuring apparatus 10 of the present embodiment, the vacuum chamber VR is provided with the vibrator 32 that can be displaced in the vibration direction of the vacuum bearing 1 provided in the vacuum chamber VR. A vibrator unit 30 penetrating the top plate 11, O-rings 39, 40, 43 provided between the top plate 11 and the vibrator unit 30 to seal the inside of the vacuum chamber VR, and outside the vacuum chamber VR. And a vibration acceleration pickup 48 that detects the vibration of the vibrator 32. Therefore, the vibration of the vacuum bearing 1 that operates in a vacuum environment is accurately detected by the vibration acceleration pickup 48 that is disposed in normal pressure. Can be measured.
In particular, the vibration acceleration pickup 48 formed by laminating piezoelectric elements is disposed in a normal pressure / normal temperature environment, so that a correct output can be obtained. Further, the adhesive can maintain the binder function without changing the properties of the adhesive that mediates the lamination of the piezoelectric elements, and there is no possibility that the vibration sensing characteristics of the vibration acceleration pickup 48 will change.

  The vibrator unit 30 is fitted to a columnar vibrator 32 and is formed coaxially with the cylindrical part 33a and larger in diameter than the cylindrical part 33a and disposed outside the vacuum chamber VR. And a vibrator holder 33 that is displaceable in the vibration direction of the vacuum bearing 1 together with the vibrator 32 by being fastened to the vibrator 32. Since the distal end surface of the cylindrical portion 33a faces the vacuum chamber VR, the vibrator 32 abuts against the upper surface 17a of the gate-type housing 17 with a constant and stable load by a suction force corresponding to the cross-sectional area of the vibrator holder 33, and is stable. Vibration measurement.

  Further, since the axial center of the vibrator 32 and the vibration acceleration pickup 48 are arranged coaxially on a straight line passing through the center of the vacuum bearing 1, that is, on the vertical line V, the vibration value of the vacuum bearing 1 is not lost. It can be captured with a vibration acceleration pickup.

  Further, since the vibrator 32 is formed of a member having heat insulation performance, heat transmitted from the vacuum bearing 1 to the vibration acceleration pickup 48 can be cut off, and the vacuum bearing 1 is in a high temperature environment. However, the influence of heat on the vibration acceleration pickup 48 can be eliminated and measurement can be performed with high accuracy.

  In addition, the vibrator unit 30 is provided outside the vacuum chamber VR and further includes a fin block 34 that radiates heat from the vacuum bearing 1, so that the heat transmitted from the vacuum bearing 1 can be radiated. Even when the vacuum bearing 1 is in a high temperature environment, the influence of heat on the vibration acceleration pickup 48 can be eliminated and measurement can be performed with high accuracy.

  Further, since the sealing member is an O-ring 40 that supports the vibrator 32 so as to be displaceable in the vibration direction of the vacuum bearing 1 by an elastic force, vibration attenuation by the O-ring 40 can be suppressed to a minimum. The vibration of the vacuum bearing 1 can be measured with high accuracy.

  A vibrator housing 35 is provided between the through hole 11 a of the top plate 11 and the vibrator unit 30, and the O-ring 40 is formed in an O-ring groove 35 e formed on the inner peripheral surface of the vibrator housing 35. Since it is arranged, the space between the top plate 11 and the vibrator unit 30 can be hermetically sealed by the O-ring 40.

  Further, since the vibration acceleration pickup 48 is fixed to one end outside the vacuum chamber VR of the vibrator unit 30 by a magnetic force, the vibration acceleration pickup 48 can be easily attached and detached.

  In order to confirm the effect of the present invention, until the bearing life is reached while measuring the vibration value of the vacuum bearing 1 in a vacuum environment using the vacuum bearing vibration measuring apparatus 10 shown in FIG. 1 according to the present invention. The durability test was conducted.

Test conditions:
Test bearing: Bearing type: Deep groove ball bearing (No .: 6200), press cage
Material: Made of SUS440C
Inner diameter: 10mm
Lubricant coating: Applying oil for vacuum
Film part: Rolling surface
Number: 2 Axis posture: Horizontal Rotational speed: 10000 min ⁻¹
Environment: Vacuum environment of about 1 Pa Bearing temperature: 300 ° C

The test results are shown in FIGS. As shown in FIGS. 3 and 4, the vibration value of the two vacuum bearings 1 significantly increased when it exceeded approximately 8 million revolutions. Furthermore, when the test was continued, when the vibration acceleration pickup 48 detected abnormal vibration when the rotation reached approximately 11.05 million rotations, it was determined that the bearing life was reached, and the test was terminated. In the confirmation work after the end of the test, any of the vacuum bearings 1 is found to have a large twisting feeling and has reached the lubrication life.
From the above test results, it was confirmed that the vibration measurement of the vacuum bearing 1 according to the present invention enables vibration measurement of the vacuum bearing 1 in a vacuum environment and under high temperature conditions.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

DESCRIPTION OF SYMBOLS 1 Vacuum bearing 10 Vibration measuring apparatus 11 of a vacuum bearing 11 Top plate (partition wall)
16 Bottom plate (partition)
25 Heater 30 Vibrator unit 32 Vibrator 33 Vibrator holder 33a Cylindrical part 33b Disk part 34 Fin block (heat dissipation part)
40 O-ring (sealing member)
48 Vibration Acceleration Pickup (Acceleration Sensor)
V Vertical line (vibration direction of vacuum bearing)
VR vacuum chamber

Claims (8)

A vibrator unit including a vibrator displaceable in a vibration direction of a vacuum bearing provided in the vacuum chamber, and penetrating a partition wall constituting the vacuum chamber;
A sealing member provided between the partition wall and the vibrator unit and sealing the vacuum chamber;
An acceleration sensor disposed outside the vacuum chamber and connected to the vibrator unit to detect vibration of the vibrator;
A vibration measurement device for a vacuum bearing, comprising: The vibrator unit includes a cylindrical part that is fitted to the columnar vibrator, a disk part that is coaxial with the cylindrical part and has a larger diameter than the cylindrical part, and is disposed outside the vacuum chamber; And a vibrator holder that is displaceable in the vibration direction of the vacuum bearing together with the vibrator by being fastened to the vibrator,
The vibration measuring device for a vacuum bearing according to claim 1, wherein a front end surface of the cylindrical portion faces the vacuum chamber.   The vibration measurement device for a vacuum bearing according to claim 1 or 2, wherein the axial center of the vibrator and the acceleration sensor are coaxially arranged on a straight line passing through the center of the vacuum bearing. .   The vibration measurement device for a vacuum bearing according to any one of claims 1 to 3, wherein the vibrator is formed of a member having heat insulation performance.   5. The vacuum bearing according to claim 1, wherein the vibrator unit further includes a heat radiating portion that is disposed outside the vacuum chamber and radiates heat from the vacuum bearing. Vibration measurement device.   The vacuum seal according to claim 1, wherein the sealing member is an O-ring that supports the vibrator so as to be displaceable in an oscillating direction of the vacuum bearing by an elastic force. Bearing vibration measuring device. A vibrator housing is provided between the through hole of the partition wall and the vibrator unit,
The vibration measurement device for a vacuum bearing according to claim 6, wherein the O-ring is disposed in an O-ring groove formed on an inner peripheral surface of the vibrator housing or an outer peripheral face of the vibrator unit. .   The vibration measurement device for a vacuum bearing according to any one of claims 1 to 7, wherein the acceleration sensor is fixed to one end of the vibrator unit outside the vacuum chamber by a magnetic force.

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