JP2001012483A - Rotating shaft device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotating shaft device capable of maintaining stable sealing performance continuously over a long period of time, simple in structure, easily manufacted at a low cost and moreover facilitating replacement and other maintenance. SOLUTION: This rotating shaft device is provided with a rotating shaft 2; a housing 5 for rotatably supporting the rotating shaft 2 at least in an axial direction through a pair of rolling bearings 4; a fluid passage 6 formed at the rotating shaft 2; and a fluid passage 7 formed between both rolling bearings 4 of the housing 5. A communicating passage 8 for communicating both fluid passages 6, 7 is provided between both rolling bearings 4 on the inner diameter side of the housing 5. Labyrinth seals 9 are provided on both axial sides of the communicating passage 8, between the rotating shaft 2 side and the housing 5 side, and restriction walls 25 of the labyrinth seals 9 are provided at spacers 22 between both rolling bearings 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum device having a suction portion on a rotary shaft side, and to other rotary shaft devices.

[0002]

2. Description of the Related Art For example, in a processing machine that rotates a workpiece such as a small-diameter disc while rotating or a cleaning machine that cleans while rotating the workpiece, a workpiece is attached to one end of a rotating shaft so that the workpiece can be easily attached and detached. A vacuuming device provided with a suction unit is used.

[0003] In this type of vacuum device, a rotary shaft having a suction portion at an upper end is rotatably supported by a housing via a pair of upper and lower rolling bearings, and a suction passage communicating with the suction portion is provided on the rotary shaft. The suction passage connected to the vacuum source side is formed between both rolling bearings of the housing, and the suction passage on the rotating shaft side and the suction passage on the housing side are formed between the upper and lower rolling bearings on the inner diameter side of the housing. In addition to providing a communication path for communication, oil seals are provided on both upper and lower sides of this communication path.
Other contact seals are provided.

[0004]

In the conventional evacuation apparatus, contact seals are provided on both upper and lower sides of the communication passage, and the contact seals prevent air from entering from the rolling bearings to the communication passage. Like that.

However, when the rotating shaft rotates at a high speed of about 8000 to 10000 times / minute, in the case of a contact type seal such as an oil seal, heat generation due to frictional heat at the contact portion is remarkable, and the seal life is extremely short. Become. Therefore, stable sealing performance cannot be maintained for a long time,
There is a problem that the contact seal needs to be replaced in a short time.

The present invention has been made in view of such conventional problems,
It is an object of the present invention to provide a rotating shaft device that can maintain stable sealing performance continuously for a long period of time, can be manufactured easily and inexpensively with a simple structure, and can easily perform replacement and other maintenance.

[0007]

SUMMARY OF THE INVENTION The present invention provides a rotating shaft, a housing rotatably supporting the rotating shaft at least in the axial direction via a pair of bearings, a fluid passage formed in the rotating shaft, A fluid passage formed between the two bearings of the housing, and a communication passage communicating between the two fluid passages between the two bearings on the inner diameter side of the housing. A labyrinth seal is provided between the rotary shaft side and the housing side between the rotary shaft and the housing on both sides in the axial direction of the communication passage.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 and FIG. 2 illustrate a first embodiment of the present invention. In FIG. 1, W is a work such as a small-diameter disk, and 1 is a vacuum evacuation device as a rotary shaft device.
It is built into washing machines.

[0010] The evacuation device 1 includes a vertical rotating shaft 2.
A suction unit 3 provided on the upper end side of the rotating shaft 2 and detachably sucking the work W by vacuum evacuation; and a housing 5 rotatably supporting the rotating shaft 2 via a pair of upper and lower rolling bearings 4. A fluid passage 6 communicating with the suction section 3 is provided on the rotating shaft 2, and a fluid passage 7 connected to a vacuum source (not shown) is provided on the housing 5, and between the rotating shaft 2 and the housing 5. A communication path 8 that connects the fluid path 6 and the fluid path 7 is provided, and labyrinth seals 9 arranged on both upper and lower sides of the communication path 8 are provided.

The suction portion 3 has a suction recess 10 formed substantially concentrically at the center on the upper surface side, and is detachably fixed by a fixing bolt 11 or the like on the upper end side of the rotating shaft 2. Rotary axis 2
Is located at the center of the upper part of the suction part.
Is formed in the axial direction, and the lower end is connected to a drive source (not shown) so that the drive source is driven to rotate at high speed.

The housing 5 is fixed to a predetermined support frame 12 so as to protrude upward from the support frame 12.
In the housing 5, a fluid passage 7 penetrating in the radial direction is formed substantially at the center between the upper and lower rolling bearings 4. The rolling bearing 4 is, for example, a ball bearing or the like, in which a number of balls 15 are interposed between the outer ring 13 and the inner ring 14, and a predetermined distance is provided between the housing 5 and the rotating shaft 2 in the vertical direction. Has been interposed.

The inner ring 14 of each rolling bearing 4 is removably fitted to the small diameter portion 16 of the rotating shaft 2, and the inner ring 14 is provided at the upper and lower ends of the large diameter portion 17 of the rotating shaft 2 and at the small diameter portion 16 side. It is fixed via an inner ring pressing body 19 between the screwed fixing nut 18. The outer ring 13 of each rolling bearing 4 is fitted on the inner diameter side of the housing 5, the outer ring spacers 21 and 22 interposed between the upper and lower outer rings 13, and the outer ring retainers fixed to the upper and lower ends of the housing 5. It is fixed by the body 20.

The inner diameter side of the housing 5 has substantially the same diameter in the vertical direction over the upper and lower rolling bearings 4, and the outer ring 13, the outer ring spacers 21, 22 and the outer ring of each rolling bearing 4 are provided on the inner diameter side. The holding body 20 is detachably fitted. The outer ring retainer 20 has a flange portion detachably fixed to upper and lower end surfaces of the housing 5 with bolts or the like. It should be noted that there is a minute gap between the outer diameter surface of the inner ring pressing body 19 and the inner diameter surface of the outer ring pressing body 20, and both are relatively rotatable in a non-contact state.

The outer ring spacers 21 and 22 include upper and lower rolling bearings 4.
There is one or more, for example three, between them, and a communication passage 8 is formed in the outer ring spacer 21 at the center thereof. The communication passage 8 has a circumferential groove 23 on the inner diameter side of the outer ring spacer 21 and the circumferential groove 23.
And a radial through-hole 24 communicating with the fluid passage 7 side. In addition, the communication passage 8 is provided with upper and lower rolling bearings 4.
It is located approximately in the middle between them.

A labyrinth seal 9 is provided on the inner diameter side of each of the upper and lower outer ring spacers 22. The labyrinth seal 9 is for sealing between the rotating shaft 2 side and the housing 5 side between the upper and lower rolling bearings 4 and on both upper and lower sides of the communication passage 8, and as shown in FIG. The diaphragm wall 25 is integrally formed on the inner diameter side of the use spacer 22 and the sealing surface 29 on the outer diameter side of the large diameter portion 17 of the rotating shaft 2.

A plurality of aperture walls 25 are provided at predetermined intervals (for example, substantially equal intervals) in the vertical direction of the outer ring spacer 22. 25 and concave portions 26 are formed alternately in the vertical direction.

Each of the throttle walls 25 has a trapezoidal cross section in which the axial dimension on the inner diameter side is reduced, and is formed in an annular shape continuously in the circumferential direction. The angle of inclination of the outer side surface 28 opposite to the diametrical direction is set so that the air from each rolling bearing 4 side is difficult to enter.
The outer surface 28 is smaller than 27. Therefore,
The cross-sectional shape on the inner diameter side of the outer ring spacer 22 is generally saw-tooth-shaped by a plurality of throttle walls 25 so that the outer surface 28 of the spacer 22 blocks entry of the atmosphere.

The gap between the inner diameter on the inner end side of each throttle wall 25 and the outer diameter of the sealing surface 29 on the rotating shaft 2 side is, for example, 0.02 to 0.02 in diameter.
The gap is as small as about 0.05 mm. Note that the sealing surface 29 is a smooth surface.

A seal member 30 such as an O-ring is provided on the outer diameter side of the upper and lower outer ring spacers 22, and the seal member 30 allows the inner diameter side of the housing 5 and the outer diameter side of the outer ring spacers 21 and 22 to be provided. Is sealed between.

In the evacuation apparatus 1 having the above-described structure, the work W
When attaching to the suction part 3 on the rotating shaft 2, the fluid passage
7 is connected to a vacuum source by a control valve, etc.
Since the inside becomes negative pressure by the evacuation of the vacuum source, the work W placed thereon can be sucked and fixed by the suction unit 3. When removing the work W, the evacuation may be released by a control valve or the like.

Therefore, the work W is attached to the suction portion 3 on the rotating shaft 2.
When the work W is rotated at a high speed around the rotation shaft 2 to perform predetermined processing, washing, or the like, the work W can be easily and reliably attached to and detached from the suction unit 3.

The rotating shaft 2 is rotatably supported by a housing 5 via upper and lower rolling bearings 4. During the suction of the workpiece W, the rotating shaft 2 is connected via a communication passage 8 between the housing 5 and the rotating shaft 2. The fluid passage 7 on the housing 5 side communicates with the fluid passage 6 on the rotating shaft 2 side to evacuate.

In this case, since the labyrinth seals 9 are provided on both upper and lower sides of the communication passage 8, the labyrinth seal 9 can seal between the housing 5 side and the rotary shaft 2 side.
Atmospheric air can be prevented from entering the communication passage 8 from each rolling bearing 4 side.

Further, since the non-contact type labyrinth seal 9 is employed, there is no problem such as heat generation and abrasion of the seal portion due to frictional heat as compared with the case where a conventional contact type seal is used. For this reason, the durability is remarkably improved, stable sealing performance can be continuously maintained for a long period of time, and the number of maintenance such as inspection and replacement of the seal can be minimized.

Further, the labyrinth seal 9 is provided with a throttle wall on the outer ring spacer 22 disposed between the outer rings 13 of the upper and lower rolling bearings 4.
25 and the outer ring spacer 22 with the labyrinth seal 9
Since the exclusive use for the labyrinth seal 9 is not required, the structure can be simplified, and when performing maintenance such as inspection and replacement of the labyrinth seal 9, the outer ring spacer 21 is required. , 22 can be easily attached and detached. Since the outer ring spacers 21 and 22 are divided into those for the communication passage 8 and those for the labyrinth seal 9, each processing is easy.

The labyrinth seal 9 has a plurality of throttle walls 25 in the axial direction of the rotary shaft 2, and a gap between the inner diameter of the throttle wall 25 and the outer diameter of the seal surface 29 on the rotary shaft 2 side is defined as a minute gap. At the same time, the inclination angle of the outer side surface 28 is set to an angle close to a right angle with respect to the axial direction as compared with the inner side surface 27 of each of the diaphragm walls 25, and the cross-sectional shape including the plurality of diaphragm walls 25 is formed into a sawtooth shape. As a result, entry of air from the labyrinth seal 9 can be prevented as much as possible, and sufficient sealing performance can be secured.

FIG. 3 illustrates a second embodiment of the present invention,
The outer surface 28 of the diaphragm wall 25 is substantially parallel to the diameter direction of the rotating shaft 2, that is, substantially perpendicular to the axial direction of the rotating shaft 2.
In this case, due to the outer surface 28 of the throttle wall 25, there is an advantage that the flow resistance when the air enters is further increased, and the sealing performance of the labyrinth seal 9 is improved.

FIG. 4 illustrates a third embodiment of the present invention,
The outer surface 28 of the aperture wall 25 is inclined in the same direction as the inner surface 27. In this case, the inner diameter side of each of the throttle walls 25 is inclined outward in the axial direction of the rotary shaft 2.

Therefore, as shown by arrows in FIG. 4, even if there is air entering along the inner surface 27 of the outer throttle wall 25,
When passing through the inner diaphragm wall 25, the inner outer surface 28
And a part of the inner surface 27 circulates in the recess 26 between the inner surface 27 and the outer surface 27. Therefore, in this case, the air cannot enter the communication passage 8 unless the air passes through the throttle walls 25 inclined outward, so that the sealing performance of the labyrinth seal 9 is further improved.

FIG. 5 illustrates a fourth embodiment of the present invention. In this embodiment, there is one spacer 21 for the outer ring between the upper and lower rolling bearings 4, and a circumferential groove 23 is provided substantially at the center in the axial direction on the inner diameter side of the spacer 21 for the outer ring. Squeezing wall 25
Are formed respectively. On the other hand, on the outer diameter side of the large-diameter portion 17 of the rotary shaft 2, a circumferential groove 31 and a throttle wall 32 are formed opposite to the circumferential groove 23 and the throttle wall 25 of the outer ring spacer 21. The two peripheral grooves 23 and 31 form a communication passage 8, and the labyrinth seals 9 are formed by the throttle walls 25 and 32 on both sides thereof.

As described above, the diaphragm wall 2 of the labyrinth seal 9
5, 32 may be provided on the inner diameter side of the outer ring spacer 21 and the outer diameter side of the rotating shaft 2. The number of outer ring spacers 21 is not limited to one, but may be two or more, each of which may be divided into the communication passage 8 and the labyrinth seal 9.

FIG. 6 illustrates a fifth embodiment of the present invention. In this embodiment, an inner ring spacer 33 corresponding to the interval between the inner rings 14 of the upper and lower rolling bearings 4 is fitted on the outer diameter side of the large diameter portion 17 of the rotating shaft 2. On the outer diameter side,
The circumferential grooves corresponding to the circumferential groove 23 of the outer ring spacer 21 and the throttle wall 25, respectively.
31 and a diaphragm wall 32 are provided.

Between the outer ring spacer 21 and the inner ring spacer 33, there is provided a communication passage 8 formed by circumferential grooves 23, 31 and a labyrinth seal 9 formed by throttle walls 25, 32. The space between the inner diameter side of the inner ring spacer 33 and the outer diameter side of the rotary shaft 2 is sealed by a sealing material 34 such as an O-ring.

As described above, the inner ring spacer is provided on the outer diameter side of the rotating shaft 2.
The communication passage 8 and the labyrinth seal 9 may be provided between the inner ring spacer 33 and the outer ring spacer 21 by fitting the inner ring 33.

In this embodiment, the large diameter portion 17 of the rotary shaft 2 is fitted with the inner ring spacer 33. However, the large diameter portion 17 may be omitted depending on the fixing structure of the upper and lower rolling bearings 4. Axis of rotation
It is also possible to fit the inner ring spacer 33 directly on the outer diameter side of 2, and to regulate the distance between the inner rings 14 of the upper and lower rolling bearings 4 with the inner ring spacer 33.

The outer ring spacer 21 is omitted, and the housing
A step is provided on the inner diameter side of the rolling bearing 4 to regulate the outer ring 13 side of the rolling bearing 4, the inner diameter side of the housing 5 is made a smooth sealing surface, the throttle wall 32 of the inner ring spacer 33 and the sealing surface on the housing 5 side. Thus, the labyrinth seal 9 may be formed.

FIG. 7 illustrates a sixth embodiment of the present invention,
Between the upper and lower rolling bearings 4, a vacuum passage 36 on the rotating shaft 2 side is provided.
And a communication passage 39 communicating the vacuum passage 36 on the rotary shaft 2 side and the vacuum passage 37 on the housing 5 side so that the liquid in the pool 38 can be recovered. is there.

The rotary shaft 2 is provided with an upper large-diameter portion 41 and a lower small-diameter portion 42 between the upper and lower rolling bearings 4 with a step portion 40 interposed therebetween. A through hole 36a on the lower end side is provided in the radial direction. An outer ring spacer 21 corresponding to the upper large diameter portion 41 and the lower small diameter portion 42 is provided on the inner diameter side of the housing 5 with the step portion 40 interposed therebetween, and the pool portion 38 is integrated with the outer ring spacer 21. Is formed.

The outer ring spacer 21 has an outer peripheral wall 43 corresponding to the through hole 36a at a predetermined distance from the outer diameter side of the upper large diameter portion 41.
An inner peripheral wall portion 44 located near the outer side of the lower small diameter portion 42 near the lower side of the step portion 40, and a bottom wall portion 45 between the outer peripheral wall portion 43 and the inner peripheral wall portion 44 are integrally provided. The outer wall 43, the inner wall 44, and the bottom wall 45 form a pool 38.

The lower part of the outer ring spacer 21 has a housing
5 is formed below the bottom wall 45 of the reservoir 38, and a through hole 47 that vertically communicates the peripheral groove 46 with the reservoir 38 is formed in the bottom wall 45. Is formed.

Therefore, the reservoir 38, the through hole 47, and the peripheral groove 46 form a communication passage 39 for communicating the vacuum evacuation passage 36 on the rotating shaft 2 side with the vacuum evacuation passage 37 on the housing 5 side. Also, during vacuum evacuation, the reservoir portion is formed through the through hole 47 and the peripheral groove 46.
The liquid in 38 can be recovered to the vacuum passage 37 side.

A seal member 48 such as an O-ring is provided at the lower end of the outer ring spacer 21. In addition, upper large diameter part 41 and lower small diameter part
Sealing surfaces 41a and 42 for labyrinth seal 9
a is formed. The evacuation passage 36 corresponds to the fluid passage 6 in FIG. 1, the evacuation passage 37 corresponds to the fluid passage 7 in FIG. 1, and the other structures are substantially the same as those in FIG.

In this type of evacuation apparatus 1, the work
When a liquid such as a cooling liquid or cleaning liquid is supplied to the W side,
When W is adsorbed to the suction section 3 by vacuum evacuation, the liquid in the suction recess 10 passes through the vacuum evacuation passage 36 and the upper and lower rolling bearings.
In some cases, the liquid may enter between the rotary shaft 2 and the housing 5 between them, or the liquid accumulated in the suction recess 10 may enter through the evacuation passage 36 by natural flow.

However, in this embodiment, the evacuation passage
Since the reservoir 38 is provided corresponding to the lower end of 36, even if liquid may enter from the evacuation passage 36, the liquid can be captured and stored in the reservoir 38, The liquid does not flow to the lower rolling bearing 4 side. Therefore, the problem that a lubricant such as grease of the lower rolling bearing 4 flows due to the liquid entering from the evacuation passage 36 can be solved, and the lubricating property of the lower rolling bearing 4 can be maintained.

The liquid accumulated in the accumulation part 38 can be easily collected outside from the evacuation passage 37 of the housing 5 through the through hole 47 and the peripheral groove 46 by evacuation. Because of this
There is no problem that the liquid accumulated in the reservoir 38 overflows from the reservoir 38.

In particular, in the outer peripheral wall portion 43, the through hole 36 of the evacuation passage 36 is formed.
Since a surrounds a, even if the liquid scatters from the through-hole 36a due to the centrifugal force at the time of rotation of the rotating shaft 2, the splash of the liquid can be received by the outer peripheral wall 43 and guided to the pool 38. Further, since the inner peripheral wall portion 44 is provided below the step portion 40 at the lower end of the upper large diameter portion 41, the liquid dripped from the upper large diameter portion 41 side can be reliably received by the pool portion 38.

In this embodiment, the pool 38 is provided in the middle outer ring spacer 21 and the labyrinth seal 9 is provided in the upper and lower outer ring spacers 22.
The outer ring 21 and 22 may be integrally formed, or the intermediate outer ring spacer 21 may be used.
The upper and lower outer ring spacers 22 may be integrated.

The reservoir 38 may be formed integrally with the inner diameter side of the housing 5 without being provided in the outer ring spacer 21. Therefore, it is sufficient that the pool portion 38 is fixed at least on the inner diameter side of the housing 5, and it does not matter whether or not the pool portion 38 is provided integrally with the housing 5.

When the reservoir 38 is provided integrally with the housing 5, the through hole 47 of the bottom wall 45 of the reservoir 38 constitutes a part of the evacuation passage 7 on the housing 5 side.
The space above the 38 constitutes the communication path 39.
Also, the housing 38 communicates with the bottom side of the reservoir 38.
5, a vacuum passage 37 may be formed in the radial direction.

FIG. 8 employs a staggered labyrinth seal 9, which can be implemented in this case as well. FIG. 8A shows the throttle wall 25 of the outer ring spacer 22 in the recess 35 of the inner ring spacer 33, and the throttle wall 32 of the inner ring spacer 33 as the outer ring spacer.
22 correspond to the concave portions 26 respectively. And each diaphragm wall 25,3
The axial thickness of No. 2 is almost the same.

FIG. 8B is a drawing wall of the outer ring spacer 22.
25 is in the recess 35 of the inner ring spacer 33, and the diaphragm wall 32 of the inner ring spacer 33.
Correspond to the concave portions 26 of the outer ring spacer 22 respectively. And
The axial thickness of each of the throttle walls 25 and 32 is such that the throttle wall 25 of the outer ring spacer 22 is thinner and the throttle wall 32 of the inner ring spacer 33 is thicker. The thickness of each of the diaphragm walls 25 and 32 may be reversed.

As described above, the labyrinth seal 9 may be of a staggered type in which the throttle walls 25 of the outer ring spacer 22 and the throttle walls 32 of the inner ring spacer 33 are alternately provided in the axial direction. .
In this case, the throttle wall 25 of the outer ring spacer 22 and the inner ring spacer 33
Since the flow path between them becomes a zigzag maze by the restriction wall 32, the sealing performance of each labyrinth seal 9 is further improved.

The outer diameter of the throttle wall 32 of the inner ring spacer 33 is
The diameter of the outer ring spacer 22 is slightly smaller than the inner diameter of the throttle wall 25. Thus, the inner ring spacer 33 can be inserted into the outer ring spacer 22 in the axial direction, and assembly, disassembly, and the like can be easily performed.

In this embodiment, the outer ring spacer 22 is provided on the inner diameter side of the housing 5 and the inner ring spacer 33 is provided on the outer diameter side of the rotary shaft 2, and the diaphragm walls 25, 32 are formed on these. However, one of the outer ring spacer 22 and the inner ring spacer 33 is omitted, and the throttle wall 25 or the throttle wall 32 on the omitted side is integrated with the inner diameter side of the housing 5 or the outer diameter side of the rotating shaft 2. May be formed.

Although the embodiment of the present invention has been described in detail, the present invention is not limited to this embodiment.
Various changes can be made without departing from the spirit of the present invention. For example, in FIGS. 5 and 6, the inner and outer side surfaces of each of the throttle walls 25 and 32 are substantially perpendicular to the axial direction of the rotary shaft 2, respectively. However, the sectional shapes shown in FIGS. good.

Each of the diaphragm walls 25 and 32 has an L-shaped cross section in which the tip side is bent outward in the axial direction, a T-shaped cross section in which the tip side projects on both sides in the axial direction, or a cross section as long as machining is possible. It is also possible to have a special cross-sectional shape such as an S-shape.

Further, in the embodiment, the evacuation apparatus 1 used for a processing machine, a washing machine and the like is illustrated, but the application is not limited to the processing machine and the washing machine and the like.
At the tip, middle, and other appropriate locations in the axial direction of the
It goes without saying that any device with 3 can be used for all of them.

Further, the evacuation apparatus 1 of the embodiment has a rotating shaft
Although the vertical type in which 2 are arranged in the vertical direction is illustrated, the present invention is not limited to the vertical type. For example, the rotating shaft 2 may be arranged in a horizontal direction or in an oblique direction. Therefore, the present invention can be applied to a horizontal type, an obliquely inclined type, and other various types.

Further, in the embodiment, the evacuation device 1 is exemplified, but a compressed gas may be sent through the fluid passages 6, 7 and the communication passage 8, or a liquid or the like may be sent. good. Therefore, the present invention can be applied to devices other than the evacuation device 1. When a pressurized fluid such as a compressed gas is sent through the fluid passages 6 and 7 and the communication passage 8, it is effective to reverse the direction of the throttle wall 25 of the labyrinth seal 9.

Rolling bearings 4 include those other than ball bearings.
For example, a roller bearing or the like may be used. Also rolling bearing
4 is sufficient if there are at least two in the axial direction of the rotating shaft 2.
The rotating shaft 2 may be supported via more than two rolling bearings 4. Further, a sliding bearing may be used instead of the rolling bearing 4.

[0062]

According to the present invention, a labyrinth seal for sealing between the rotating shaft side and the housing side is provided between both bearings and on both axial sides of the communication passage. As compared with the case of using a, there is an advantage that stable sealing performance can be continuously maintained for a long period of time, the structure can be manufactured simply and inexpensively, and replacement and other maintenance can be facilitated. Further, since the throttle wall of the labyrinth seal is provided at the spacer between the two bearings, a member dedicated to the labyrinth seal is not required, and the structure can be simplified.

Further, a plurality of spacers are provided in the axial direction between the two bearings, and a spacer for the communication passage and a spacer for the labyrinth seal are separately provided, and the throttle wall constituting the labyrinth seal is provided on the latter spacer. Since a plurality of spacers are formed in the axial direction, processing of each spacer is easy, and each spacer can be individually replaced as needed.

Further, a plurality of throttle walls are provided in the spacer for the outer ring on the inner diameter side of the housing in the axial direction, and the outer diameter side of the rotary shaft is a smooth sealing surface, and a labyrinth seal is constituted by the throttle wall and the sealing surface. The structure of the labyrinth seal can be simplified. Since each throttle wall of the labyrinth seal is formed in a saw-tooth shape, the sealing performance of the labyrinth seal is improved.

A rotary shaft having a suction portion is arranged, a vacuum passage connected to the suction portion is provided on the rotary shaft, and a vacuum passage connected to a vacuum source is provided on the housing. Since a reservoir for storing the liquid and a communication passage connecting the two vacuum passages so as to collect the liquid in the reservoir are provided between the bearings, there is a liquid that enters through the vacuum passage on the rotating shaft side. However, the lubrication of the bearing is not impaired by the liquid. In addition, since the pool is provided in the outer ring spacer between the two bearings, the structure can be simplified.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an evacuation apparatus showing a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part showing the first embodiment of the present invention.

FIG. 3 is a sectional view of a main part showing a second embodiment of the present invention.

FIG. 4 is a sectional view of a main part showing a third embodiment of the present invention.

FIG. 5 is a sectional view of a main part showing a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a main part showing a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a main part showing a sixth embodiment of the present invention.

FIGS. 8A and 8B are cross-sectional views of main parts showing a staggered labyrinth seal of the present invention.

[Explanation of symbols]

 2 Rotary shaft 3 Suction unit 4 Rolling bearing 5 Housing 6,7 Fluid passage 8 Communication passage 9 Labyrinth seal 21,22 Spacer for outer ring 25,32 Throttle wall 29 Seal surface 33 Spacer for inner ring 36,37 Vacuum passage 38 Reservoir Part 39 Connecting passage

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Chikamori 2-34, Minamiuematsucho, Yao-shi, Osaka Mitsuhiro Machinery Co., Ltd. Harada Manufacturing F-term (reference) 3C016 DA08 3J016 AA02 BB17 CA07 3J042 AA03 BA01 CA10

Claims (6)

[Claims] A rotating shaft, a housing rotatably supporting the rotating shaft in at least an axial direction via a pair of bearings, a fluid passage formed in the rotating shaft, and a portion between the bearings of the housing. Each having a formed fluid passage,
In a rotary shaft device provided with a communication passage communicating the two fluid passages between the two bearings on the inner diameter side of the housing, the rotation shaft side is provided between the two bearings and on both axial sides of the communication passage. A rotating shaft device comprising a labyrinth seal between the rotating shaft device and the housing. 2. The rotary shaft device according to claim 1, wherein a throttle wall of the labyrinth seal is provided at a spacer between the two bearings. 3. A plurality of spacers are provided in the axial direction between the two bearings, and the spacers for the communication passage and the spacers for the labyrinth seal are separated from each other. The rotary shaft device according to claim 1, wherein a plurality of throttle walls forming the labyrinth seal are formed in an axial direction. 4. A plurality of throttle walls are provided in an axial direction on an outer ring spacer on an inner diameter side of the housing, and an outer diameter side of the rotary shaft is a smooth sealing surface, and the rotation wall is formed by the throttle wall and the sealing surface. The rotating shaft device according to any one of claims 1 to 3, wherein the labyrinth seal is configured. 5. The rotary shaft, wherein the rotary shaft having a suction portion is arranged, a vacuum passage communicating with the suction portion is provided on the rotary shaft, and a vacuum draw passage connected to a vacuum source is provided on the housing. A reservoir for storing the liquid from the vacuum pumping passage on the side, and a communication passage connecting the vacuum pumping passages so as to be able to collect the liquid in the reservoir, are provided between the bearings. The rotary shaft device according to any one of claims 1 to 4. 6. The rotary shaft device according to claim 1, wherein the reservoir is provided in an outer ring spacer between the two bearings.