JP2017227639A - Touchdown bearing tester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touchdown bearing tester which allows for conducting tests under conditions close to actual touchdown phenomena.SOLUTION: A touchdown bearing tester includes; a rotary drive mechanism 40 for turning a rotary member 100; a coupling mechanism 50 configured to detachably couple the rotary drive mechanism 40 and the rotary member 100; and a dropping mechanism 70 configured to release the coupling between a rotation introduction shaft 21 and the rotary member 100 provided by the coupling mechanism 50 in order to drop the rotating rotary member 100 onto a touchdown bearing 120.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a test apparatus for a touchdown bearing, and more particularly, a test apparatus for a touchdown bearing that can be installed together with a magnetic bearing and can perform a rotation test of the touchdown bearing that functions as a bearing when the magnetic bearing cannot be controlled. About.

  The touch-down bearing is a rolling bearing installed together with the magnetic bearing, and normally has a configuration in which the inner ring does not contact the rotating shaft. On the other hand, when the magnetic bearing becomes uncontrollable due to some trouble, the surface facing the rotating shaft of the inner ring contacts (touches down) the rotating shaft and functions as a bearing, thereby protecting the magnetic bearing and the rotating shaft. It has a configuration.

  The touchdown bearings are required to have “rotational performance during touchdown (hereinafter referred to as rotational performance)” and “idling stop performance during contact with the rotor shaft (hereinafter referred to as idling stop function)” as unique characteristics. It is done.

  The rotation performance is performance for smoothly rotating at the time of touchdown. For example, when a touchdown bearing is used in a turbo molecular pump, if this rotational performance is high, when the rotor shaft touches down due to accidental disconnection or motor damage, the rotor shaft swings around and becomes a stator member. This prevents contact and breakage, and allows the rotor shaft to land safely.

  The idling stop function is a performance that stops the bearing at an early stage without continuing idling when the touchdown bearing contacts with the rotor shaft and idles. The touchdown bearing may come into contact with the rotor shaft due to an earthquake or vibration of peripheral equipment while the turbo molecular pump is rotating. After that, unlike when the rotor shaft touches down due to accidental disconnection or damage to the motor, the rotor shaft immediately recovers the magnetic stability and returns to the steady position, so it touches the touchdown bearing for a moment. Only then returns to the non-contact state. At this time, the touchdown bearing starts idling (usually the inner ring) in response to the rotational force from the rotor shaft, but since there is no air resistance, the touchdown bearing continues idling as it is. At this time, a large rotating noise is generated, the coated solid lubricant is worn and the film thickness is reduced, and the rotation performance cannot be fully exhibited during the original touchdown, or the temperature rises rapidly and seizure occurs. It may cause a problem that it ends up. Therefore, the touch-down bearing needs to have the capability of stopping rotation at an early stage during idling.

  In Patent Document 1, a shaft introduced from the outside of the vacuum environment is fitted to the inner diameter of the bearing disposed in the vacuum environment and the shaft is rotated to rotate the touchdown bearing, and when a predetermined rotational speed is reached. A test apparatus for a touch-down bearing that verifies the rotational performance of the touch-down bearing is disclosed by extracting the shaft from the inner diameter of the bearing while maintaining the vacuum seal, and measuring and comparing the inertia rotation time of the bearing that rotates by inertia. .

JP 2010-190397 A

  However, the test of the touchdown bearing described in Patent Document 1 is a test method under conditions deviating from the actual touchdown phenomenon. Specifically, the touchdown bearing is normally stopped, and when the magnetic bearing becomes uncontrollable, a certain heavy object falls on the stationary bearing and the touchdown bearing starts rotating. In the test of 1, the touchdown by a heavy object is not realized. Therefore, the touchdown bearing cannot be rotated and started without using an external drive source from a stationary state. In addition, during rotation start-up, since it is mechanically connected to an external drive source, the events in the meantime (especially load-conditional events) may occur in the original touch-down bearing, such as when the eccentric load is not applied to the touch-down bearing. There is no event.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a test apparatus for a touch-down bearing capable of performing a test under conditions close to an actual touch-down phenomenon.

The above object of the present invention can be achieved by the following constitution.
(1) A test apparatus for a touch-down bearing that is installed together with a magnetic bearing, and in which the inner ring does not contact the rotating shaft in a normal state and the inner ring contacts the rotating shaft and functions as a bearing when the magnetic bearing cannot be controlled. ,
A rotation drive mechanism for rotating the rotating member;
A connection mechanism for detachably connecting the rotation drive mechanism and the rotation member;
A drop mechanism that releases the connection state between the rotation drive mechanism and the rotation member by the connection mechanism and drops the rotation member in the rotation state onto the touchdown bearing;
A test apparatus for a touch-down bearing, comprising:
(2) The touch-down bearing test apparatus according to (1), wherein the touch-down bearing, the rotating member, and the connection mechanism are arranged in a vacuum chamber.
(3) The rotation drive mechanism includes a hollow rotation introduction shaft that is rotatable and extends from the outside into the vacuum chamber.
The dropping mechanism includes a piston that is integrally rotatable with the rotation introducing machine shaft and is slidable in an axial direction, is fitted to an inner peripheral surface of the rotation introducing machine shaft, and extends from the outside into the vacuum chamber. Prepared,
The test apparatus for a touch-down bearing according to (2), wherein the piston releases a connection state between the rotation drive mechanism and the rotation member.
(4) The connection mechanism includes a guide portion that is fitted with the rotating member and regulates a radial displacement of the rotating member in the rotating state,
The dropping mechanism includes an extrusion device that releases a fitting state between the guide portion and the rotating member,
The test apparatus for a touch-down bearing according to any one of (1) to (3), wherein the push-out device is disposed outside the guide portion.
(5) The touch-down bearing test apparatus according to (3) or (4), wherein the connection mechanism connects the rotation introducing machine shaft of the rotation drive mechanism and the rotation member by a magnetic force.
(6) The rotating member includes a main body portion, and an introduction shaft that extends downward from the main body portion and has the same diameter as the rotating shaft.
The test apparatus for a touchdown bearing according to any one of (1) to (5), wherein the introduction shaft is inserted into an inner ring of the touchdown bearing through a gap.

  According to the touchdown bearing test apparatus of the present invention, the rotation drive mechanism that rotates the rotation member, the connection mechanism that removably connects the rotation drive mechanism and the rotation member, the rotation drive mechanism and the rotation member by the connection mechanism, And a drop mechanism that drops the rotating member in the rotating state onto the touch-down bearing, so that the touch-down performance of the touch-down bearing is tested under conditions close to the actual touch-down phenomenon. be able to.

1 is an overall configuration diagram of a test apparatus for a touchdown bearing according to a first embodiment of the present invention. It is a principal part enlarged view of FIG. In 1st Embodiment, it is a whole block diagram of the test apparatus of the touchdown bearing which shows the state by which the connection state of the rotation drive mechanism and the rotation member was cancelled | released by the dropping mechanism. In 1st Embodiment, the dropping mechanism act | operates and it is a principal part enlarged view which shows the state from which the rotation member was isolate | separated from the rotation drive mechanism. In 1st Embodiment, it is guided by the inner ring | wheel of a touchdown bearing, and is a principal part enlarged view which shows the state which the rotating member fell on the touchdown bearing. In 1st Embodiment, after touching down, it is a principal part enlarged view which shows the state which the introduction axis | shaft of a rotating member contacts the internal peripheral surface of the inner ring | wheel of a touchdown bearing. It is a principal part enlarged view of the test apparatus of the touchdown bearing which concerns on 2nd Embodiment of this invention. In 2nd Embodiment, it is a principal part enlarged view which shows the situation of the moment when a center boss | hub and a center ring change from a contact state to a non-contact state by a dropping mechanism. In 2nd Embodiment, it is a principal part enlarged view which shows the situation of the moment when a piston advances and stops predetermined distance by the dropping mechanism, and the rotating member is falling freely. In 2nd Embodiment, it is guided to the inner ring | wheel of a touchdown bearing, and it is a principal part enlarged view which shows the state which the rotating member fell on the touchdown bearing. In 2nd Embodiment, after touching down, it is a principal part enlarged view which shows the state which the introduction axis | shaft of a rotating member contacts the internal peripheral surface of the inner ring | wheel of a touchdown bearing. It is a graph which shows the test result of the touchdown bearing implemented with the test apparatus of the touchdown bearing which concerns on 1st Embodiment of this invention.

(First embodiment)
Hereinafter, an embodiment of a test apparatus for a touchdown bearing according to a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram of a test apparatus for a touchdown bearing according to the present embodiment. As illustrated in FIG. 1, the touchdown bearing test apparatus 10 includes a bearing holding unit 110 that holds a touchdown bearing 120, a rotating member 100 that rotates an inner ring 121 of the touchdown bearing 120, and a rotating member 100. The rotation drive mechanism 40, the connection mechanism 50 that detachably connects the rotation drive mechanism 40 and the rotation member 100, and the connection by the connection mechanism 50 is released, and the rotation member 100 in the rotating state is moved to the inner ring of the touch-down bearing 120. And a dropping mechanism 70 for dropping the head on the main body 121.

  The rotation drive mechanism 40 includes a rotation introducing machine 20 that is erected on the top plate 11 and fixed with bolts. The rotation introducing machine 20 includes a rotation introducing housing 12 having an inner peripheral surface 12 a that is concentric with the through hole 11 a of the top plate 11, and a pair of rolling bearings 13 are provided on the inner peripheral surface 12 a of the rotation introducing housing 12. A hollow rotary introduction machine shaft 21 supported by is rotatably arranged. The rotation introducing machine shaft 21 passes through the through hole 11a of the top plate 11 and is disposed from one surface side (upper side in the drawing) to the other surface side (lower side in the drawing).

  The rotation introducer 20 is a device that penetrates the rotation introducer shaft 21 into both environments while maintaining a state in which the normal pressure environment and the vacuum environment are sealed. For this reason, a vacuum-sealed seal 18 is disposed in an annular space between the inner peripheral surface 12 a of the rotation introducing housing 12 and the outer peripheral surface of the rotation introducing machine shaft 21 between the pair of rolling bearings 13. The vacuum seal 18 may be a differential exhaust seal, a magnetic seal, or a magnetic coupling.

  The lower surface side of the top plate 11 is connected to a vacuum device (not shown) (vacuum chamber or the like). Further, in the rotation introducing machine 20, the space between the top plate 11 and the flange 12b of the rotation introduction housing 12 that is bolted to the top plate 11 is sealed by an O-ring 14 that is a sealing member. Therefore, a vacuum environment (vacuum chamber V) is below the top plate 11, and a normal pressure environment (chamber) is above the top plate 11.

  A spline housing 22 is fitted on the upper end of the rotation introducing machine shaft 21 and fixed integrally therewith. A belt 27 is wound between a pulley 23 fixed to the outer peripheral surface of the spline housing 22 and a pulley 26 fixed to a drive shaft 25 of a high-frequency motor 24 that is a drive motor of the rotation drive mechanism 40. . The pulley 23, the pulley 26, and the belt 27 constitute a power transmission mechanism that transmits a rotational driving force from the high-frequency motor 24 to the rotation introducing machine shaft 21.

  The support base 28 that supports the high-frequency motor 24 is fixed on the top plate 11 with bolts 29, and the position adjustment disposed between the top plate 11 and the support base 28 with the bolts 29 loosened. The tension state of the belt 27 can be adjusted by rotating the bolt 30 and moving the support base 28 in the left-right direction. The high frequency motor 24 is rotationally controlled at an arbitrary speed by an external controller (not shown).

  FIG. 2 is an enlarged view of the vicinity of the lower portion of the rotation introducing machine shaft 21. A cylindrical magnet holder 31 is fitted on the lower end of the rotation introducing machine shaft 21 located below the top plate 11 (vacuum environment). In the magnet holder 31, a set screw 32 that penetrates the magnet holder 31 in the radial direction engages with the circumferential groove 21 a of the rotation introducing machine shaft 21, and a key 33 is disposed between the rotation introducing machine shaft 21 and the magnet holder 31. Thus, the rotation introducing machine shaft 21 and the magnet holder 31 are integrally connected.

  A cylindrical guide ring 34 is fitted on the outer peripheral surface of the magnet holder 31. The guide ring 34 is fixed to the magnet holder 31 with a screw 35 that passes through the guide ring 34 in the radial direction. The lower surface of the guide ring 34 slightly protrudes in the axial direction from the lower surface of the magnet holder 31. That is, a circular fitting recess is formed by the inner diameter of the guide ring 34 and the lower surface of the magnet holder 31, and a fitting projection (upward projection 103) of the rotating member 100 described later is fitted, whereby the rotating member Position 100.

  A ring-shaped magnet 51 is fixed to the circumferential groove 36 having a substantially rectangular cross section formed on the lower surface of the magnet holder 31 by bonding or the like. The lower surface of the magnet 51 is flush with the lower surface of the magnet holder 31. The magnet 51 is disposed in the vacuum chamber V and constitutes a connection mechanism 50 that magnetically connects the rotation introducing machine shaft 21 and the rotating member 100.

  Since the magnet 51 magnetically attracts the rotating member 100, the magnet holder 31 is preferably made of a material that does not allow magnetic flux to pass through. Austenitic stainless steel such as SUS304 and SUS316, or aluminum alloy such as A2017, A5052, A5056, A2024, and A7075. Nonmagnetic materials such as are used.

  The material of the magnet 51 is not particularly limited, but if a magnet having a large maximum energy product value such as a neodymium-based or samarium-cobalt rare-earth magnet is used in addition to a ferrite-based magnet, the size of the magnet 51 is reduced. Therefore, the present invention is suitable for the present invention in which the magnet 51 is rotated and subjected to the influence of the moment of inertia of the magnet.

The shape of the magnet 51 is preferably a ring shape considering the balance of centrifugal force. But,
Since the purpose is to attract the rotating member 100, magnets having an arc shape or the like may be arranged at equal intervals in the circumferential direction as long as a sufficient attracting force can be obtained. In order to attract the rotating member 100, the magnet 51 is magnetized in the axial direction, but is not particularly limited as long as the rotating member 100 can be attracted.

  All the central axes of the inner and outer peripheral surfaces of the rotation introducing machine shaft 21, which is a constituent member of the rotation drive mechanism 40, the spline housing 22, the pulley 23, the magnet holder 31, the guide ring 34, and the magnet 51 are the same. It is set to be positioned on the axis line CL. Therefore, when the high-frequency motor 24 is rotated, the spline housing 22 rotates together with the rotation introducing machine shaft 21 via the pulley 26, the belt 27, and the pulley 23, and further, the magnet holder 31, the guide ring 34, and the magnet 51 are connected to the high-frequency motor. It rotates in synchronization with the rotation of 24. Thereby, rotational motion can be introduced from the normal pressure environment side to the vacuum environment side.

  Returning to FIG. 1, the dropping mechanism 70 includes an actuator (linear motion motor) 71 capable of linearly driving the actuator shaft 72. The actuator 71 is fixed to an annular support member 73 disposed above the rotation introducing machine 20 via a power transmission case 38. In the actuator 71, the linear motion of the actuator shaft 72 is controlled by an external controller (not shown).

  A linear ball bearing 74 is fitted and mounted on the inner peripheral surface 73 a of the support member 73. The linear ball bearing 74 is provided with a rotary / static conversion shaft 75 that is linearly movable on the same axis as the actuator shaft 72. Accordingly, when the actuator 71 is operated, the rotary / static conversion shaft 75 moves linearly with the actuator shaft 72.

  The rotary stationary conversion shaft 75 is integrally connected to the tip (lower end) of the actuator shaft 72, and has a small diameter portion 75a fitted to the linear ball bearing 74, and a cup-shaped large formed below the small diameter portion 75a. And a diameter portion 75b. An outer ring of a pair of rolling bearings 76 to which preload is applied is fitted into the hole of the large diameter portion 75b. A rotation pin 77 is fitted into the inner ring of the pair of rolling bearings 76 and is rotatably supported.

  On the other hand, a spline unit 78 in which a female spline (not shown) is formed in the axial direction is fixed to the through hole 22a formed at the center of the spline housing 22. A spline shaft 79 is spline fitted to the female spline of the spline unit 78. The upper end of the spline shaft 79 and the rotary pin 77 are integrally connected via a rotary joint 80. The spline unit 78 may be a ball spline.

  As a result, when the spline housing 22 is rotationally driven by the high-frequency motor 24, the spline shaft 79 rotates via the spline unit 78, and the rotation pin 77 connected to the spline shaft 79 by the rotary joint 80 rotates. Since the rotation pin 77 is rotatably supported by a pair of rolling bearings 76 and the rotary / static conversion shaft 75 is connected to the actuator shaft 72, the rotary / static conversion shaft 75 does not rotate.

  The spline shaft 79 can be rotated by being driven by the high frequency motor 24, and can be linearly moved with respect to the spline unit 78 by being driven by the actuator 71. That is, the spline shaft 79 is configured to freely move linearly while rotating.

  A piston 81 is slidably fitted in the axial direction on the inner peripheral surface 21 b of the hollow rotation introducing machine shaft 21. The male screw 81a formed at the upper end of the piston 81 is screwed into the lower end of the spline shaft 79, and the piston 81 and the spline shaft 79 are integrally connected in the axial direction.

  In the piston 81, three O-ring grooves 81b in which the O-ring 82 is mounted are formed in the upper part and the lower part of the piston 81, respectively. The inner peripheral surface 21b of the rotation introducing machine shaft 21 is finished with a good surface roughness, and the piston 81 with the O-ring 82 mounted on each O-ring groove 81b is fitted to the rotation introducing machine shaft 21. A space between the piston 81 and the piston 81 is vacuum-sealed.

  Basically, at least one O-ring 82 may be provided between the rotation introducing machine shaft 21 and the piston 81. The O-ring 82 below the piston 81 is vacuum-sealed, and the two upper O-rings 82 function as backups. That is, the vacuum environment and the normal pressure environment are sealed by the O-ring 82 below the piston 81, and the tip 81c of the piston 81 exists in the vacuum environment. The diameter of the tip 81c of the piston 81 is smaller than the inner diameter of a slide bearing 83 described later, and can enter the slide bearing 83 when the actuator 71 is operated.

  The lower part of the inner peripheral surface 21b of the rotation introducing machine shaft 21 is slightly enlarged in diameter, and a hollow slide bearing 83 is fixed by adhesion. The plain bearing 83 may be a linear motion bearing. A cylindrical portion 84 a of a pressing member 84 having a substantially inverted T-shaped axial section is fitted to the slide bearing 83 coaxially. The pressing portion 84b having a larger diameter than the columnar portion 84a is accommodated in the enlarged diameter portion 21c formed at the lower end portion of the rotation introducing machine shaft 21. The lower surface of the pressing portion 84b is the same surface as the lower surface of the magnet holder 31, that is, the lower surface of the magnet 51, or is slightly recessed.

  In the state shown in FIG. 2, the lower surface of the pressing portion 84 b is in contact with the upper surface of the rotating member 100 that is attracted and held by the magnetic force of the magnet 51. For this reason, when the rotating member 100 is not present, the pressing member 84 may fall out of the sliding bearing 83 and fall, but the pressing member 84 is made of a ferromagnetic material, so that the leakage magnetic flux from the magnet 51 Will not be caught and fall. As the ferromagnetic material of the pressing member 84, mild steel tempered steel such as S45C, high strength non-tempered steel such as SUJ2 hardened steel and TBH steel, high speed steel such as SKD5 and SKH4, and the like are suitable.

  The center lines of the actuator shaft 72, rotary stationary conversion shaft 75, rotary pin 77, rotary joint 80, spline shaft 79, piston 81, and pressing member 84, which are constituent members of the dropping mechanism 70, are located on the same axis CL. It is set to be. The axis CL of the dropping mechanism 70 and the axis CL of the rotation drive mechanism 40 are the same axis.

  As a result, when the actuator 71 is operated, the linear motion of the actuator shaft 72 is transmitted to the pressing member 84 via the rotary stationary conversion shaft 75, the rotary pin 77, the rotary joint 80, the spline shaft 79, and the piston 81. It moves and presses the rotating member 100 held by the magnetic force of the magnet 51 downward.

  A bearing holder 110 for installing the test touchdown bearing 120 directly below the rotation introducing machine shaft 21 includes a cylindrical case 111 fixed to the lower surface of the top plate 11 and a lower surface attached to the lower surface of the cylindrical case 111. The board part 112 and the bearing holding stand 113 fixed to the center part of the lower board part 112 are provided. The bearing holding base 113 is open on the upper surface and has an inner peripheral surface 113a having the same inner diameter as the outer diameter of the outer ring 122; Have The inner diameter of the inward projection 113 b is slightly larger than the inner diameter of the outer ring 122. Thereby, the touch-down bearing 120 has the outer ring 122 fitted and held on the inner peripheral surface 113a of the bearing holding table 113 and the upper surface of the inward projection 113b, and the inner ring 121 does not come into contact with the bearing holding table 113. The bearing holder 113 is rotatably supported.

  The test touch-down bearing 120 is formed by fitting the outer ring 122 to the inner peripheral surface 113 a and then screwing a substantially crank-shaped pressing plate 114 that contacts the upper surface of the outer ring 122 to the bearing holding table 113. 113 is fixed. As a result, the test touchdown bearing 120 is set on the bearing holder 113 in a state where the center of the inner ring 121 and the axis CL of the rotation drive mechanism 40 and the dropping mechanism 70 coincide with each other, and enters the vacuum chamber V. Be placed.

  The rotating member 100 includes a substantially frustoconical main body 101 that extends downward, and an introduction shaft 102 that extends downward from the main body 101 and has the same diameter as the rotation shaft. The outer diameter of the introduction shaft 102 is smaller than the inner diameter of the inner ring 121 of the test touchdown bearing 120, and when the test touchdown bearing 120 is fixed to the bearing holder 113, the introduction shaft 102 has the inner ring 121. It inserts through a predetermined gap, without contacting.

  A disc-shaped upper convex portion 103 is integrally formed on the upper surface of the main body 101, and a disc-shaped lower convex portion 104 is integrally formed on the lower surface of the main body 101. The outer diameter of the upper protrusion 103 is the same as the inner diameter of the guide ring 34. That is, the upper convex portion 103 becomes a fitting convex portion that fits into a fitting concave portion formed by the guide ring 34 and the magnet holder 31. By fitting the upper convex portion 103 (fitting convex portion) of the rotating member 100 and the fitting concave portion, the rotating member 100 has the center line of the rotation driving mechanism 40 and the axis CL of the dropping mechanism 70. Installed in accordance.

  The outer diameter of the lower convex portion 104 is smaller than the inner diameter of the outer ring 122 of the test touchdown bearing 120, and more specifically, is set in consideration of the gap between the introduction shaft 102 and the inner diameter of the inner ring 121. . That is, when the rotating member 100 is touched down, the rotating member 100 does not come into contact with the outer ring 122 of the touchdown bearing 120 even if the introduction shaft 102 moves in the radial direction within the inner diameter of the inner ring 121 by the gap. ing.

  The rotating member 100 is a ferromagnetic material, for example, general mild steel, ferritic stainless steel such as SUS430, martensitic stainless steel such as SUS420J2, precipitation hardening stainless steel such as SUS630, or the like, or SK material, SKD material, SKH material, etc. Use tool steel.

<Test procedure for touchdown bearings>
Next, a test procedure of the touchdown bearing by the touchdown bearing test apparatus of the present embodiment will be described.

  The test bearing is used for performance evaluation as a touchdown bearing, and is appropriately selected depending on the purpose of the test. For example, when verifying the difference in the touchdown performance depending on the bearing material, a bearing having a different material such as SUS440C or SUJ2 is selected. Alternatively, when verifying performance due to differences in bearing configuration, use bearings with or without cages, or when verifying performance due to differences in bearing types, such as deep groove ball bearings or angular contact ball bearings. Is selected. Furthermore, when verifying the performance due to the difference in lubricant, bearings filled and coated with different lubricants are selected. In addition, when verifying the performance due to the difference in the lubrication part, apply lubrication only to the rolling element bearing bearing, the rolling element and bearing inner ring bearing, or the bearing inner ring end face only. Various combinations are conceivable, such as selecting a suitable bearing.

  First, as shown in FIGS. 1 and 2, with the introduction shaft 102 of the rotating member 100 inserted into the inner ring 121 of the test touchdown bearing 120, the upper convex portion 103 of the rotating member 100 is moved to the guide ring 34. And is attracted and held by the magnetic force of the magnet 51. Further, the outer ring 122 of the test touchdown bearing 120 is fitted to the inner peripheral surface 113 a of the bearing holding table 113, the pressing plate 114 is brought into contact with the upper surface of the outer ring 122, and screwed to the bearing holding table 113. The test touch-down bearing 120 is fixed to the bearing holder 113. Then, it is confirmed that there is a gap between the introduction shaft 102 of the rotating member 100 and the inner ring 121 of the touch-down bearing 120, and the preparatory work for the test is performed.

  The rotating member 100 is configured such that the upper convex portion 103 is fitted to the inner diameter of the guide ring 34, whereby the central axis of the rotating member 100 and the central axis of the rotation introducing machine shaft 21 (the axis CL of the rotation drive mechanism 40 and the dropping mechanism 70). It is attached in a state where and match.

  Here, when the high frequency motor 24 is rotated, the rotation of the drive shaft 25 is transmitted to the spline housing 22 via the pulley 26, the belt 27, and the pulley 23, and the rotation introducing machine shaft 21 that is integrally fixed to the spline housing 22 is rotated. Rotate. Furthermore, the magnet holder 31 fixed to the rotation introducing machine shaft 21, the guide ring 34, the magnet 51, and the rotating member 100 attracted and held by the magnet 51 rotate in synchronization with the rotation of the high frequency motor 24.

  When the rotating member 100 rotates, generally there is a slight eccentric load (unbalance) around the axis of the rotating member 100, so that centrifugal force in a direction perpendicular to the axis is generated. Since the protrusion 103 is fitted to the guide ring 34 and is attracted to the magnet holder 31 by the magnetic force of the magnet 51, the rotating member 100 does not separate from the magnet holder 31.

  Simultaneously with the rotation of the rotation introducing machine shaft 21, a spline unit 78 fixed to the spline housing 22, a spline shaft 79 that is spline-fitted to the spline unit 78, a piston 81 connected to the spline shaft 79, a rotary joint 80, and a rotation The pin 77 rotates in synchronization with the rotation of the high frequency motor 24. Since the rotation pin 77 is rotatably supported by a pair of rolling bearings 76, the rotary / static conversion shaft 75 and the actuator shaft 72 do not rotate.

  Next, when the rotation speed of the rotary member 100 in the vacuum chamber V reaches a predetermined speed, as shown in FIG. 3, the actuator 71 is operated to linearly move the actuator shaft 72 downward in the figure. The rotary stationary conversion shaft 75 supported by the linear ball bearing 74 moves downward. Accordingly, the rotary pin 77, the rotary joint 80, the spline shaft 79, the piston 81, and the pressing member 84 linearly move downward while rotating.

  Although the rotation pin 77 is rotating, it is rotatably supported by the pair of rolling bearings 76, so that the linear movement of the rotation pin 77 is not hindered by the rotation, and the rotation motion and the linear motion are simultaneously performed. Done. The piston 81 rotates at the same rotational speed as the rotation introducing machine shaft 21, that is, without relative rotation. Therefore, the O-ring 82 seals a vacuum between the rotation introducing machine shaft 21 and the piston 81 that moves linearly. Vacuum grease, vacuum oil, or the like is applied to the O-ring 82 to improve lubrication performance and sealing performance when the O-ring slides.

  Referring also to FIG. 4, when the pressing member 84 is pressed by the piston 81, the pressing member 84 that is slidably supported by the slide bearing 83 moves downward and is in the same plane as the lower surface of the magnet holder 31. The pressing portion 84b protrudes from the lower surface of the magnet holder 31 and presses the rotating member 100 downward.

  Since the thrust of the actuator 71 is set larger than the magnetic force of the magnet 51 that attracts the rotating member 100, the rotating rotating member 100 is separated from the magnet 51. Eventually, as the distance between the magnet 51 and the rotating member 100 increases, the attracting force of the magnet 51 gradually decreases, and when the upper convex portion 103 of the rotating member 100 and the guide ring 34 are not fitted, the rotating member 100 is removed. Is not in mechanical contact with any member and is released into the air.

  At this time, the force acting on the rotating member 100 (the center of gravity of the rotating member 100) becomes the inertial force of the rotating member 100 that linearly moves downward by the actuator 71, the centrifugal force of the rotating rotating member 100, and gravity (more details). In addition, an attractive force acts from the magnet 51). Therefore, the rotating member 100 advances in the direction of the resultant force of three forces of inertia, centrifugal force, and gravity.

  The actuator 71 stops operating when the piston 81 overcomes the attractive force of the magnet 51 and presses the pressing member 84 to a position where the rotating member 100 can fall by its own weight. At this time, since the pressing member 84 is captured by the leakage magnetic flux of the magnet 51, the pressing member 84 is stopped and held on the spot without dropping together with the rotating member 100.

  The rotating member 100 falls in the resultant direction of the three forces described above. However, before the rotating member 100 touches down, when the introducing shaft 102 contacts the inner ring 121 of the touchdown bearing 120, the rotating member 100 is moved to the introducing shaft 102. Is guided and dropped by the inner ring 121 of the test touchdown bearing 120 for insertion, and the lower convex portion 104 of the rotating member 100 comes into contact with the inner ring 121 of the touchdown bearing 120 and touches down.

  In the following description, it is assumed that the introduction shaft 102 of the rotating member 100 touches down the inner ring 121 of the touchdown bearing 120.

  As shown in FIG. 5, the rotating member 100 that falls is in contact with the inner ring 121 of the touch-down bearing 120 for the introduction shaft 102 or momentarily, and the lower convex portion 104 of the rotating member 100 is the touch-down bearing. Touching down the end face of the inner ring 121 of 120, it touches. The rotating member 100 continues to rotate even when dropped, and the rotation speed thereof is the same as the rotation speed of the rotation introducing machine shaft 21 immediately before being detached from the magnet holder 31.

  Referring also to FIG. 6, the rotating member 100 touched down on the inner ring 121 of the touch-down bearing 120 first slides between the lower surface of the lower convex portion 104 and the upper end surface of the inner ring 121 to move the inner ring 121. Start rotating. Thereafter, the introduction shaft 102 moves in the radial direction within the inner diameter of the inner ring 121 and rotates the inner ring 121 while repeatedly sliding and rolling between the outer diameter of the introduction shaft 102 and the inner diameter of the inner ring 121. Speed accelerates.

  While the rotational speed of the inner ring 121 of the touchdown bearing 120 gradually increases and the rotational speed of the rotating member 100 gradually decreases, when both of them become the same rotational speed, the two rotate as a unit, and the rotational speed of the both becomes the same. When a difference occurs, the inner ring 121 continues inertial rotation while repeating a complicated rotation state, such as rotating with a relative angular velocity.

  When the rotational energy held by the rotating member 100 immediately before the touchdown is consumed due to the above-described sliding or rolling, the touchdown bearing 120 stops with the rotating member 100 placed on the inner ring 121.

  Then, the inertial rotation time until the touchdown bearing 120 stops is measured and compared, or the rotation state during inertial rotation, for example, the occurrence condition of ball clogging, the presence or absence of lubricant depletion, the noise during inertial rotation Check for occurrence and bearing damage. Alternatively, the touchdown bearing 120 that has been touched down a predetermined number of times is disassembled and observed. Thereby, various touchdown performances of the touchdown bearing 120 are verified.

  After the rotation of the touchdown bearing 120 is stopped, the high frequency motor 24 is stopped, the actuator 71 stopped in the forward state is returned to the original operation start position, and the rotating member 100 is again returned to the magnet holder by the magnetic force of the magnet 51. If it adsorbs to 31, the 2nd touchdown performance test of the same bearing can be started. Moreover, the touchdown performance test of the new touchdown bearing 120 can be performed by repeating the above-described procedure.

  As described above, according to the touchdown bearing test apparatus 10 of the present embodiment, the rotation drive mechanism 40 that rotates the rotation member 100 and the connection mechanism that removably connects the rotation drive mechanism 40 and the rotation member 100. 50 and a dropping mechanism 70 that releases the connection state between the rotation introducing machine shaft 21 and the rotation member 100 by the connection mechanism 50 and drops the rotation member 100 in the rotation state onto the touch-down bearing 120. The touchdown performance of the touchdown bearing 120 can be tested under conditions close to the touchdown phenomenon.

  Moreover, since the touchdown bearing 120, the rotation member 100, and the connection mechanism 50 are arrange | positioned in the vacuum chamber V, the touchdown performance of the touchdown bearing 120 in a vacuum environment can be tested.

The rotation driving mechanism 40 includes a hollow rotation introducing machine shaft 21 that is rotatable and extends from the outside into the vacuum chamber V, and the dropping mechanism 70 can rotate integrally with the rotation introducing machine shaft 21 and is axially oriented. The piston 81 includes a piston 81 that is slidably fitted into the inner peripheral surface 21b of the rotation introducing machine shaft 21 and extends from the outside into the vacuum chamber V. The piston 81 includes the rotation drive mechanism 40, the rotation member 100, and the like. Therefore, the touchdown bearing 120 in the vacuum chamber V can be operated from the outside in the atmospheric environment to test the touchdown performance.

Moreover, since the connection mechanism 50 connects the rotation introducing machine shaft 21 and the rotating member 100 of the rotation drive mechanism 40 by the magnetic force of the magnet 51, the rotation introducing machine shaft 21 and the rotating member 100 can be easily connected and released. .

  The rotating member 100 includes a main body 101 and an introduction shaft 102 that extends downward from the main body 101 and has the same diameter as the rotation shaft. The introduction shaft 102 forms a gap in the inner ring 121 of the touchdown bearing 120. Therefore, the rotating member 100 can be rotated to a predetermined rotational speed without affecting the touch-down bearing 120. Further, the rotating member 100 that rotates can be guided and dropped by the inner ring 121, and the touchdown test can be stably performed.

(Second Embodiment)
Next, a touch-down bearing test apparatus according to a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, the configuration of the connection mechanism and the dropping mechanism is different from that of the first embodiment. For this reason, description is abbreviate | omitted or simplified about the same or equivalent part as 1st Embodiment.

  The dropping mechanism 70 of the present embodiment includes an actuator shaft 72, a rotary stationary conversion shaft 75, a rotary pin 77, a rotary joint 80, a spline shaft 79, and a piston 81, which are substantially similar in configuration to the first embodiment. On the other hand, as shown in FIG. 7, the dropping mechanism 70 of the present embodiment mainly includes a pressing member 140, an upper magnet 170, and an ejector pin (hereinafter referred to as an E pin) 180 constituting the extrusion device of the present invention. Prepare.

  The pressing member 140 pushed out by the tip 81c of the piston 81 has a top shape in which a flange portion 141 is attached coaxially with the shaft portion 143 at an axially intermediate portion. The shaft portion 143 of the pressing member 140 is separated from the tip 81c of the piston 81 and in a lower position than the tip 81c of the piston 81 when the rotating member 100 and the rotation introducing machine shaft 21 are magnetically connected (set state). Is located.

  The upper plain bearing 150 is fitted to the inner diameter of the tip of the rotary introducer shaft 21, and the upper magnet housing 160 is fitted coaxially to the outer diameter of the tip of the rotary introducer shaft 21. The upper magnet housing 160 is formed in a substantially sleeve shape, a flange portion 161 is formed on one end surface in the axial direction (lower side in the figure), and the upper magnet 170 is embedded in the lower end surface of the flange portion 161. The upper magnet 170 has a ring shape with a circular cylinder, and is disposed coaxially with the upper magnet housing 160. The upper magnet 170 does not have to be a single ring, and a plurality of cylindrical magnets may be arranged at coaxially equidistant positions with respect to the upper magnet housing 160. The lower end surface of the upper magnet 170 is embedded in the upper magnet housing 160 by means such as adhesion or interference fit so as to be installed in the same plane as the lower end surface of the upper magnet housing 160. Although the upper magnet 170 is magnetized in the axial direction, an attracting force that does not fall in the vertical direction can be obtained by magnetically attracting a back plate 185 joined to a pressing member 140 containing an E pin 180 described later. If so, the magnetization direction is not limited.

  The flange portion 141 of the pressing member 140 is provided with three or more (for example, six) stepped holes 142 penetrating between the end surfaces of the flange portion 141 in the vertical direction. The plurality of stepped holes 142 are disposed at equal positions with respect to the shaft portion 143, and the centers of the pitch circles of the plurality of stepped holes 142 are disposed coaxially with the shaft portion 143. An ejector pin (hereinafter referred to as an E pin) 180 is configured in a stepped shape in which a pin portion 181 on the small diameter side and a root enlarged portion 182 on the large diameter side are arranged coaxially. The E pin 180 is manufactured by diverting a commercially available ejector pin that is built in a resin injection mold and is used when a molded part is discharged from the mold hole. On the small diameter side of the stepped hole 142 of the flange portion 141, the E pin 180 is fitted with a clearance accuracy with the outer diameter of the pin portion 181, and at the same time, the root enlarged portion 182 has a large diameter of the stepped hole of the flange portion 141. Stored with clearance on the side. Therefore, the pin portions 181 of each E pin 180 are also arranged at equal positions with respect to the shaft portion 143, and the center of the pitch circle of the pin portion 181 is disposed coaxially with the shaft portion 143.

  An elastic member 186 such as an O-ring is inserted around the base side of the pin portion 181, and the E pin 180 is arranged so that the pin portion 181 protrudes from the small diameter side mouth of the stepped hole 142 of the flange portion 141. The flanged portion 141 is loaded into the stepped hole 142. Thereafter, the substantially flat ring-shaped back plate 185 is inserted into the shaft portion 143 of the pressing member 140 from the end surface side of the root enlarged portion 182 of the E pin 180 and fastened to the end surface of the flange portion 141 of the pressing member 140. In this state, the end surface of the root enlarged diameter portion 182 is pressed against the back plate 185 by the function of the elastic member 186 and is in close contact with the back plate 185.

  The elastic member 186 only needs to have the above function, and may be a compression spring, for example. By using a polishing tool for injection molded E pins, the E pins 180 can have the same overall length (distance from the end surface of the pin portion 181 to the end surface of the root enlarged portion 182) of the plurality of E pins 180. is there. When all the E pins 180 having the same overall length are used and loaded into the pressing member 140 and the back plate 185 is fastened, a plurality of (three or more) pin portions 181 protrude from the flange portion 141 of the pressing member 140. The end surfaces of any pin portions 181 are located in the same plane perpendicular to the axis of the pressing member 140 itself.

  The material of the pressing member 140 may be general mild steel, austenitic stainless steel, etc., martensitic stainless steel, precipitation hardening stainless steel, etc., but the two shaft portions are the upper slide bearing 150 and the lower SK material, SKD material, SKH material, or the like may be used because the sliding with the side slide bearing 155 prevents wear.

  Further, the back plate 185 needs to be a ferromagnetic material, and for example, general mild steel, ferritic stainless steel such as SUS430, martensitic stainless steel such as SUS420J2, precipitation hardening stainless steel such as SUS630, or the like is used. The back plate 185 is manufactured with good flatness of the end faces and parallelism between the both end faces.

  The back plate side of the shaft portion 143 of the pressing member 140 is fitted to the inner diameter of the upper slide bearing 150 with a high clearance accuracy. Since the inner diameter of the upper plain bearing 150 is arranged coaxially with the rotation introducing machine shaft 21, the shaft portion 143 of the pressing member 140 is also coaxial with the rotation introducing machine shaft 21. The outer diameter of the back plate 185 and the equal diameter of the upper magnet 170 are set so that the end surface of the back plate 185 is in contact with part or all of the end surface of the upper magnet 170. The end surface of the back plate 185 is It is attracted to the end face of the upper magnet 170. Since the pressing member 140 to which the back plate 185 and the E pin 180 are attached is fastened with a screw, the pressing member 140 with the E pin 180 is attracted to the upper magnet 170. Since the magnetic force of the upper magnet 170 is set so that the pressing member 140 with the E pin 180 can be held without being dropped, the pressing member 140 with the E pin 180 moves downward from the upper slide bearing 150 in the figure. There is no slipping down.

  The outer peripheral surface of the flange portion 161 of the upper magnet housing 160 is formed coaxially with the inner peripheral surface of the upper magnet housing 160. Since the inner peripheral surface of the upper magnet housing 160 is fitted to the outer peripheral surface of the tip of the rotation introducing machine shaft 21, the outer diameter of the flange portion 161 of the upper magnet housing 160 is coaxial with the rotation introducing machine shaft 21. The inner peripheral surface 165a of the lower magnet housing 165 is fitted to the outer peripheral surface of the flange portion 161 with high accuracy. The lower magnet housing 165 has a plurality of inner peripheral surfaces 165a to 165d having different inner diameters depending on a plurality of steps. Inner circumferential surfaces 165a to 165d of the lower magnet housing 165 are coaxially formed. A lower slide bearing 155 is fitted on the inner peripheral surface 165c of the lower magnet housing 165 by bonding or press-fitting. A cylindrical portion 156 is formed on one side of the end portion of the lower slide bearing 155 and functions as positioning when the lower slide bearing 155 is fitted to the inner peripheral surface 165c of the lower magnet housing 165.

  The material of the upper slide bearing 150 and the lower slide bearing 155 is not particularly limited, but may be made of general mild steel, stainless steel such as SUS304, brass, resin such as PEEK or PTFE. Brass may be disliked in the vacuum high-temperature environment process because the contained Zn may evaporate and cause contamination, but in this embodiment, the temperature does not increase significantly with respect to room temperature. There is no concern about that.

Since the inner diameters of the upper and lower sliding bearings 150 and 155 are coaxial with the outer diameters of the upper and lower sliding bearings 150 and 155, the inner diameter of the upper sliding bearing 150 and the inner diameter of the lower sliding bearing 155 are rotational. It is arranged coaxially with the introduction machine shaft 21.
Further, if the outer diameter of the back plate side portion of the shaft portion 143 of the pressing member 140 is the upper shaft outer diameter, and the outer diameter of the non-back plate side portion is the lower shaft outer diameter, the upper shaft outer diameter is The inner diameter of the upper sliding bearing 150 and the outer diameter of the lower shaft portion are coaxially fitted to the inner diameter of the lower sliding bearing 155, respectively, with a good clearance accuracy. For this reason, it is possible to move the shaft part 143 up and down by using both the inner diameter of the upper slide bearing 150 and the inner diameter of the lower slide bearing 155 as guides. 21 and the same axis are maintained. The top dead center when the pressing member 140 moves linearly is a position where the end surface of the back plate 185 is attracted to the end surface of the upper magnet 170, while the bottom dead center is the anti-back plate of the flange portion 141 of the pressing member 140. The side end surface is a position in contact with the end surface of the cylindrical portion 156 of the lower slide bearing 155.

  The outer peripheral surface of the flange portion 161 of the upper magnet housing 160 and the inner peripheral surface 165a of the lower magnet housing 165 are fitted and fastened coaxially with each other. In addition, the end surface of the flange portion 161 of the upper magnet housing 160 and the upper axial end surface of the lower magnet housing 165 that come into contact with the end surface are both flat and have direct contact with the respective axes at the same time. The angle is also well formed. A magnet embedding groove 166 is provided coaxially with the axis of the lower magnet housing 165 itself on the lower end surface of the lower magnet housing 165 (hereinafter referred to as a magnet groove end surface 165e). In addition, a lower magnet 175 for attracting the rotary member 100 is embedded in the magnet embedding groove 166 so as to be the same end surface as the magnet groove end surface 165e. The lower magnet 175 has a ring shape like a circular cylinder, and is embedded in the magnet embedding groove 166 by adhesion or press fitting. Further, since the magnet groove end surface 165e of the lower magnet housing 165 and the upper axial end surface of the lower magnet housing 165 are formed with high parallelism, the magnet groove end surface 165e of the lower magnet housing 165 rotates. A good perpendicularity with respect to the introduction machine shaft 21 is maintained.

  The magnet groove end surface 165e of the lower magnet housing 165 is provided with a through hole 167 penetrating the axial upper end surface continuous with the lower end of the inner peripheral surface 165b of the lower magnet housing 165. The through holes 167 are provided with the same pitch circle diameter as the pitch circle diameter of the E pins 180 and the same number as the E pins 180, and the inner diameter of the through holes 167 is the same as that of the pin portion 181 of the E pin 180. It is set slightly larger than the outer diameter. For this reason, the pressing member 140 can be directly moved while the E pin 180 is inserted into the through hole 167. When the back plate 185 of the pressing member 140 is attracted to the upper magnet 170, that is, when the position of the pressing member 140 is at the top dead center, the end surface of the E pin 180 slightly extends from the mouth of the through hole 167. It is set to be in the position. Further, when the pressing member 140 starts to move linearly and the back plate 185 is separated from the adsorption of the upper magnet 170, the end of the E pin 180 starts to protrude from the mouth of the through hole 167 immediately from the mouth of the through hole 167. The falling distance of the E pin 180 is set.

  The inner peripheral surface 165 d of the lower magnet housing 165 is provided inside the pitch circle of the through hole 167. The downward end surface that is continuous with the inner peripheral surface 165d of the lower magnet housing 165 has a squareness accurately secured to the axis of the lower magnet housing 165 itself, while the inner peripheral surface 165d is accurately aligned with the shaft. Coaxiality is ensured. A center ring 187 having a ring shape with a rectangular cross section is fitted to the inner peripheral surface 165d of the lower magnet housing 165 by adhesion or press fitting or the like. The center ring 187 is fitted with a center boss 105 of the rotating member 100 described later, and restricts the displacement of the rotating member 100 in a rotating state in the radial direction. The center ring 187 has an outer diameter and an inner diameter that are formed with good concentricity, both end faces are formed with a high degree of parallelism, and the inner diameter and outer diameter are formed with a right angle with respect to the end face. Therefore, the inner diameter of the center ring 187 and the rotation introducing machine shaft 21 are coaxial.

Since the upper magnet housing 160 and the lower magnet housing 165 embed the upper magnet 170 and the lower magnet 175, respectively, austenitic stainless steel such as SUS304, which is a nonmagnetic material, is used. The center ring 187 prevents wear on the inner diameter of the center ring 187, and the E pin 180 prevents tool tip end surfaces of the pin portion 181 from wearing, such as tool steel such as SK material and SKD material, and SKH material. High-speed tool steel such as is used.
Further, the upper magnet 170 and the lower magnet 175 may be made of any material as long as they can attract the respective attracted objects (the pressing member 140 and the rotating member 100) and secure a magnetic force that prevents them from dropping. On the other hand, if a rare earth magnet such as a samarium cobalt magnet or a neodymium magnet is used for the upper magnet 170 and the lower magnet 175 in addition to a ferrite magnet, they have a large maximum energy product. Can be set small. This makes it possible to set the upper magnet housing 160, the lower magnet housing 165, and the like to be small, which is suitable for the present test apparatus that rotates them at a high speed.

  In the present embodiment, the connection mechanism that detachably connects the rotation drive mechanism 40 and the rotation member 100 mainly includes the lower magnet 175 and the center ring 187 that constitutes the guide portion of the present invention.

  Similar to the first embodiment, the rotating member 100 includes a main body 101, an introduction shaft 102, and a downward convex portion 104. The outer diameter dimension of the lower convex portion 104 is set to be larger than the outer diameter dimension of the inner ring 121 of the touchdown bearing 120 to be tested and smaller than the inner diameter dimension of the outer ring 122 facing the end surface of the lower convex portion 104. Has been. Flat cylindrical portions having a diameter corresponding to the lengths of the upper and lower trapezoids are connected to both end faces of the main body 101.

  A flat cylindrical center boss 105 is provided on the upper bottom stepped end surface 101a of the main body 101 coaxially with the axis of the rotating member 100 itself. The outer diameter of the center boss 105 is fitted with the inner diameter of the center ring 187 with high accuracy. The upper bottom side stepped end surface 101a of the main body 101 is formed with a right angle on the axis of the rotating member 100 itself. The height from the upper bottom stepped end surface 101a of the center boss 105 is such that when the center boss 105 is inserted into the center ring 187, the upper bottom stepped end surface 101a first contacts the end surface of the lower magnet 175. The end face of the center boss 105 does not bottom out in the center ring 187.

  Since the outer diameter dimension of the upper bottom side step portion of the rotating member 100 is set to be larger than the inner diameter dimension of the lower magnet 175, when the center boss 105 is fitted to the center ring 187, the lower magnet 175 Part or all of the end surface comes into contact with the upper bottom stepped end surface 101 a of the main body 101, and the rotating member 100 is attracted to the lower magnet 175. Since the magnetic force of the lower magnet 175 is set so that the rotating member 100 can hold its own weight after adsorbing the rotating member 100, the rotating member 100 does not fall off the center ring 187 due to its own weight.

  The upper bottom stepped end surface 101a is shaped with a right angle with respect to the axis of the rotating member 100 itself, and the center boss 105 of the rotating member 100 and the introduction shaft 102 of the rotating member 100 are coaxial. Therefore, when the outer diameter of the center boss 105 is fitted to the inner diameter of the center ring 187 and the upper bottom stepped end surface 101a is attracted to the lower magnet 175, the introduction shaft 102 of the rotation member 100 and the rotation introduction machine shaft 21 are coaxial. Will be set. By rotating the rotation introducing machine shaft 21 in this state, the rotating member 100 can be rotated while maintaining the same axis as the rotation introducing machine shaft 21.

  Also in the present embodiment, the rotating member 100 is made of a ferromagnetic material, for example, general mild steel, ferritic stainless steel such as SUS430, martensitic stainless steel such as SUS420J2, precipitation hardening stainless steel such as SUS630, or SK material. Tool steel such as SKD material or SKH material is used. Since the rotating member 100 is frequently attached to and detached from the center ring 187 when the touchdown test is repeatedly performed, it is preferable in terms of wear resistance to use tool steel or the like as the material.

  The touchdown bearing 120 through which the introduction shaft 102 of the rotating member 100 passes is arranged coaxially with the rotating member 100, and the inner diameter of the bearing 120 and the outer diameter of the introduction shaft 102 of the rotating member 100 form a clearance. . For this reason, when the rotation introducing machine shaft 21 is rotated, the mechanically integrated rotating member 100 rotates, but the touchdown bearing 120 always maintains the same size clearance as the introducing shaft 102 of the rotating member 100. It is stationary. The end surface of the inner ring 121 of the touch-down bearing 120 is opposed to the end surface of the lower convex portion 104 of the rotating member 100, and both end surfaces are arranged with a right angle with the axis of the rotating member 100 itself. Assuming that the magnetic coupling with the lower magnet 175 is released and the robot directly falls in the posture, the outer diameter of the introduction shaft 102 of the rotating member 100 and the inner diameter of the inner ring 121 pass while maintaining the original clearance. Thus, the both end faces come into contact with the entire circumference at the same time.

  In the assembly of the rotating member 100 and the rotation introducing machine shaft 21 of the present embodiment, after the introducing shaft 102 of the rotating member 100 is passed through the bearing 120 and the rotating member 100 is disposed at a predetermined position of the bearing 120, the center boss 105 is moved. The center ring 187 cannot be fitted. For this reason, the rotating member 100 is attracted to the lower magnet 175 while the center boss 105 is fitted to the center ring 187 to ensure mechanical integration between the rotation introducing machine shaft 21 and the rotating member 100, and then the bearing 120 is rotated. The members 100 are assembled from the leading end of the introduction shaft 102 and arranged in a predetermined position.

  In the test apparatus of this embodiment in which the introduction shaft 102 is arranged at a predetermined position of the bearing 120 and the rotating member 100 and the rotation introduction machine shaft 21 are assembled, the rotation introduction machine shaft 21 rotates, and when the rotation speed reaches a predetermined rotation speed, the actuator 71 is operated to move the piston 81 straight (forward) downward as shown in FIG. When the piston 81 moves forward and the tip 81c of the piston 81 contacts the upper end surface of the pressing member 140, and when the piston 81 further moves forward, the pressing member 140 is pushed by the tip 81c of the piston 81 and moves forward integrally with the piston 81. Start. When the pressing member 140 moves forward, the end face of the back plate 185 is separated from the end face of the upper magnet 170, and the mutual magnetic attractive force is attenuated. However, since the magnetic attractive force still remains, the pressing member 140 falls freely. The forward movement is continued while being integrated with the tip 81c of the piston 81.

  As the pressing member 140 moves forward, the E pin 180 also moves forward. Initially, the tip end surface of the E pin 180 moves downward in the through hole 167 and then begins to protrude from the through hole 167. Then, the tip end surface of the E pin 180 that has moved forward contacts the upper bottom stepped end surface 101a of the main body 101 of the rotating member 100 and pushes the rotating member 100 downward as it is. Since the center boss 105 is engaged with the center ring 187 of the rotating member 100, the rotating member 100 advances straight downward while the outer diameter of the center boss 105 and the inner diameter of the center ring 187 slide. If the straight line continues, the outer diameter of the center boss 105 and the inner diameter of the center ring 187 were in contact with each other straight portion, but reached one of the R chamfered portions and reached the R chamfered portion. Then, the contact is terminated and the mechanical guide is lost. The outer diameter of the center boss 105 and the inner diameter of the center ring 187 are not lost at the same time for the entire circumference, but microscopically, part of them is in contact and the rest already has either R chamfer. The contact / non-contact state of being in a non-contact state already exists as a pre-stage where no contact is made over the entire circumference.

  At that time, since the rotating member 100 is rotating, it receives a centrifugal force. For this reason, the rotating member 100 rotates in the plane of the drawing with a part of the region in the above contact state as a fulcrum, and the tip of the introducing shaft 102 of the rotating member 100 is moved out of the axis of rotation so as to swing the neck. The power of jumping out works. That is, the rotating member 100 starts to tilt with respect to the rotation axis.

  However, in the present embodiment, since the E pins 180 are located at three or more positions outside the outer diameter of the center boss 105, the tip end surface of the E pin 180 serves as a stopper and the rotating member 100 is inclined as described above. I can't. Therefore, the rotating member 100 is pushed out from the axis of rotation without departing from the axis. FIG. 8 shows a situation at that moment when the center boss 105 and the center ring 187 change from the contact state to the non-contact state.

  FIG. 9 shows the moment when the piston 81 moves forward a predetermined distance and stops. The tip 81c of the piston 81 and the end surface of the shaft portion 143 of the pressing member 140 are in contact with each other, but there is still a distance between the end surface of the flange portion 141 of the pressing member 140 and the end surface of the lower slide bearing 155. Therefore, the pressing member 140 and the lower sliding bearing 155 do not collide before the piston 81 presses the pressing member 140. Since the piston 81 is stopped, the pressing member 140 has an initial speed downward and starts to fall freely, but the back plate 185 leaves an attractive force with the upper magnet 170, so that it becomes a brake, When the end surface of the shaft portion 143 of the pressing member 140 is slightly separated from the tip 81c of the piston 81, the pressing member 140 stops.

  Since the tip of the E pin 180 is located in the middle of the through hole 167 of the lower magnet housing 165 before starting the forward movement, the protruding distance of the tip of the E pin 180 is larger than the distance that the pressing member 140 has advanced. Is slightly smaller. Until the piston 81 moves forward and stops, the tip end surface of the E pin 180 has a thrust to push the rotating member 100. When the center boss 105 of the rotating member 100 moves away from the center ring 187, the rotating member 100 starts a free fall with an initial speed. Until then, the tip of the E pin 180 disposed at the equidistant position is started. The rotating member 100 moves forward while maintaining the same axis as the axis of rotation while being in contact with both. Since the state is maintained even after the free fall starts, as shown in FIG. 10, the introduction shaft 102 of the rotating member 100 does not contact the inner ring 121 of the touch-down bearing 120, and the inner ring end surface and the lower convexity of the rotating member 100. It falls freely until it touches the end surface of the part 104 and touches down.

  Next, as shown in FIG. 11, the rotating member 100 touched down rotates around its own axis, and the end surface of the inner ring 121 of the bearing 120 and the end surface of the lower convex portion 104 of the rotating member 100 slide. The inner ring 121 starts to rotate. Since both end faces have a relative speed, the rotating member 100 moves on the end face of the inner ring 121 until the bearing inner diameter and the outer diameter of the introduction shaft 102 of the rotating member 100 come into contact with each other. After that, the rotating member 100 and the inner ring 121 are integrated and start to rotate around the shaft of the bearing 120, and after continuing to rotate for a while, the inner ring 121 on which the rotating member 100 is placed is stopped by the friction of the bearing, One touchdown of the touchdown bearing test is completed.

  As described above, according to the test apparatus for a touchdown bearing of the second embodiment, the connection mechanism 50 is fitted to the center boss 105 of the rotating member 100 so that the rotating member 100 in the rotating state is displaced in the radial direction. The drop mechanism 70 includes an E pin 180 for releasing the fitting state between the center ring 187 and the center boss 105 of the rotating member 100, and has a pitch circle diameter larger than the inner diameter of the center ring 187. Since the pin 180 is disposed, the touchdown on the end surface of the inner ring 121 of the touchdown bearing 120 can be performed more stably without the rotating member 100 tilting during the fall.

  In order to confirm the usefulness of the test apparatus of the touchdown bearing of the present invention, a performance test of the touchdown bearing with or without a lubricant was performed using the test apparatus of the touchdown bearing of the present invention. The specifications of the test apparatus and the test bearing were as follows.

-Weight of test device rotating member: Fixed shaft rotating member introduction shaft outer diameter: 5 mm
Falling distance of rotating member: 13mm
Rotational speed: 10000 min-1
Environment: Normal pressure

-Test bearing material: SUS440C bearing type: angular contact ball bearing, without cage (total ball specification)
Inner ring inner diameter: 6mm
Lubricating coating: Configuration 1: No lubricating coating, number of test bearings (2)
Configuration 2: MoS2-based solid lubricating coating, number of test bearings (7)
Film part: Rolling body

  In addition, since this test was performed for the usefulness determination of the test apparatus of a touchdown bearing, each test was implemented in the normal pressure environment. The success or failure of the touchdown was determined to be successful if both the ball clogging and other abnormalities did not occur during inertial rotation and the inertial rotation time was 2 minutes or longer. And the usefulness of the test apparatus was determined by whether or not a difference was detected in the performance of the two types of touchdown bearings.

  FIG. 12 shows the test results, while the two touchdown bearings for test 1 in the configuration 1 without the lubricating coating failed to pass the judgment criteria, whereas the rolling element was provided with the MoS2-based solid lubricating coating. The seven touchdown bearings of Configuration 2 were capable of 11 to 21 touchdowns.

  From the above results, it was proved that the touchdown performance of the touchdown bearing can be verified by the test apparatus for the touchdown bearing of the present invention.

Note that the present invention is not limited to the above-described embodiments and examples, and modifications, improvements, and the like can be made as appropriate.
For example, the configuration of the rotation drive mechanism is not limited to the present embodiment as long as the drive force of the rotation drive motor can be transmitted to the rotation drive machine shaft of the rotation drive machine.
Specifically, the rotation introduction machine is integrated with the rotation drive mechanism, or coaxially built in or directly connected to the rotation drive mechanism, and can rotate independently without requiring a rotation drive mechanism outside. Also good.

Moreover, the structure of a connection mechanism is not limited to the magnet of this embodiment.
For example, the connection mechanism uses the elastic force of an elastic member (such as a liquid medium such as rubber, resin, elastomer, spring, oil, etc.) to grip the fitting convex portion of the rotating member on the inner diameter or outer diameter. May be. Alternatively, the connection mechanism may use an electromagnet. In this case, by changing the amount of power supplied to the electromagnet, it is possible to perform a touchdown test in which the suction force is adjusted according to the weight of the rotating member and the weight of the rotating member is arbitrarily changed.

Furthermore, the fitting recess that fits with the fitting protrusion of the rotating member is not limited to the combination of the guide ring and magnet holder of the first embodiment or the center ring of the second embodiment.
Further, the pair of bearings of the rotation introducing machine may be disposed on the normal pressure side by a sealing mechanism (differential exhaust seal, magnetic seal, magnetic coupling, etc.). In that case, since the bearing is not disposed in a vacuum environment, the bearing lubricant does not contaminate the vacuum environment.

  In addition, the rotating member of the present invention has a main body part for securing the weight of the fallen object and an introduction shaft that serves as a drop guide for the inner diameter of the touchdown bearing, and may be of a top-shaped shape. It is not necessary to have the substantially trapezoidal shape described above. If the main body has a substantially trapezoidal shape, the center of gravity of the rotating member becomes closer to the touch-down bearing, so that the touch-down test can be repeated more stably.

DESCRIPTION OF SYMBOLS 10 Test apparatus of touchdown bearing 20 Rotation introduction machine 21 Rotation introduction machine shaft 21b Inner peripheral surface 40 Rotation drive mechanism 50 Connection mechanism 51 Magnet 70 Dropping mechanism 81 Piston 100 Rotating member 101 Main body part 102 Introduction shaft 105 Center boss 120 Touchdown bearing 121 Inner ring 140 Press member 175 Lower magnet (magnet)
180 Ejector pin (extrusion device)
187 Center ring (guide part)
V Vacuum chamber

Claims (6)

A test apparatus for a touch-down bearing that is installed together with a magnetic bearing, and in which the inner ring does not normally contact the rotating shaft, and when the magnetic bearing cannot be controlled, the inner ring contacts the rotating shaft and functions as a bearing,
A rotation drive mechanism for rotating the rotating member;
A connection mechanism for detachably connecting the rotation drive mechanism and the rotation member;
A drop mechanism that releases the connection state between the rotation drive mechanism and the rotation member by the connection mechanism and drops the rotation member in the rotation state onto the touchdown bearing;
A test apparatus for a touch-down bearing, comprising:   The test apparatus for a touch-down bearing according to claim 1, wherein the touch-down bearing, the rotating member, and the connection mechanism are disposed in a vacuum chamber. The rotation drive mechanism includes a hollow rotation introduction machine shaft that is rotatable and extends from the outside into the vacuum chamber,
The dropping mechanism includes a piston that is integrally rotatable with the rotation introducing machine shaft and is slidable in an axial direction, is fitted to an inner peripheral surface of the rotation introducing machine shaft, and extends from the outside into the vacuum chamber. Prepared,
The touchdown bearing test apparatus according to claim 2, wherein the piston releases a connection state between the rotation driving mechanism and the rotation member. The connection mechanism includes a guide portion that is fitted with the rotating member and regulates a radial displacement of the rotating member in the rotating state,
The dropping mechanism includes an extrusion device that releases a fitting state between the guide portion and the rotating member,
The test apparatus for a touch-down bearing according to claim 1, wherein the push-out device is disposed outside the guide portion.   The touch-down bearing test apparatus according to claim 3, wherein the connection mechanism connects a rotation introducing machine shaft of the rotation driving mechanism and the rotation member by a magnetic force. The rotating member includes a main body portion, and an introduction shaft that extends downward from the main body portion and has the same diameter as the rotation shaft,
The touchdown bearing test apparatus according to claim 1, wherein the introduction shaft is inserted into an inner ring of the touchdown bearing via a gap.

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