JPH08320072A - Multistage magnetic fluid shaft sealing device - Google Patents
Multistage magnetic fluid shaft sealing deviceInfo
- Publication number
- JPH08320072A JPH08320072A JP7284463A JP28446395A JPH08320072A JP H08320072 A JPH08320072 A JP H08320072A JP 7284463 A JP7284463 A JP 7284463A JP 28446395 A JP28446395 A JP 28446395A JP H08320072 A JPH08320072 A JP H08320072A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic fluid
- sealing device
- communication hole
- rotary shaft
- vacuum
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、半導体製造工程や、各
種コーティング、エッチング工程などの真空プロセスで
使用する磁性流体軸シールの改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a magnetic fluid shaft seal used in a semiconductor manufacturing process and various vacuum processes such as various coating and etching processes.
【０００２】[0002]
【従来の技術】半導体製造工程などの真空プロセスにお
ける回転軸シールには、オイルシール、ウイルソンシー
ル、メカニカルシールなどが使用されてきたが、メンテ
ナンスや磨耗によるパーティクルなどの問題から、磁性
流体シールへの変更がなされてきた。従来、このような
磁性流体シールとして、回転軸に円筒状のハウジングが
軸受を介して装着されており、ハウジング内には環状の
ポールピースが永久磁石を挟んで複数設けられている。
ポールピース又は回転軸には突起が設けられ、突起に対
向した微小間隔内に磁性流体が充填されている。この磁
性流体により高圧側から低圧側に気体が抜けるのをシー
ルしている。2. Description of the Related Art Oil seals, Wilson seals, mechanical seals, etc. have been used as rotary shaft seals in vacuum processes such as semiconductor manufacturing processes. However, due to problems such as particles due to maintenance and wear, magnetic fluid seals have been adopted. Changes have been made. Conventionally, as such a magnetic fluid seal, a cylindrical housing is mounted on a rotary shaft via a bearing, and a plurality of annular pole pieces are provided in the housing with a permanent magnet interposed therebetween.
A protrusion is provided on the pole piece or the rotating shaft, and a magnetic fluid is filled in a minute interval facing the protrusion. This magnetic fluid seals the escape of gas from the high pressure side to the low pressure side.
【０００３】[0003]
【発明が解決しようとする課題】ところが、磁性流体シ
ールは摩擦がなく磨耗によるパーティクル発生は防げる
ものの、一段のシール可能圧力差が０．２〜０．５気圧
と小さいので、大気からの真空排気の初期においては、
磁性流体のシール破壊が発生し、同時に、真空に最も近
い段からは強磁性微粉末、界面活性剤、および媒体など
が真空環境に飛び散り、パーティクルの発生要因となる
問題があった。そこで、本発明は真空に最も近い段のシ
ール破壊が無く、かつ強磁性体微粉末、界面活性剤、お
よび媒体などの飛散による真空環境へのパーティクルの
発生のない多段型磁性流体軸封装置を提供することを目
的とする。However, although the magnetic fluid seal has no friction and can prevent generation of particles due to wear, since the pressure difference capable of being further sealed is as small as 0.2 to 0.5 atm, it is evacuated from the atmosphere. In the early days of
There is a problem that the magnetic fluid seal is broken, and at the same time, the ferromagnetic fine powder, the surfactant, the medium, and the like are scattered into the vacuum environment from the stage closest to the vacuum, which causes particles to be generated. Therefore, the present invention provides a multi-stage magnetic fluid shaft sealing device in which there is no seal breakage in the stage closest to vacuum and no particles are generated in the vacuum environment due to scattering of ferromagnetic fine powder, surfactant, medium, etc. The purpose is to provide.
【０００４】[0004]
【課題を解決するための手段】上記問題を解決するた
め、本発明は回転軸と、その周囲に微小空隙を介して半
径方向に設けられ、かつ、軸方向に複数設けられたポー
ルピースと、前記回転軸の外周又は前記ポールピースの
内周に複数個設けられたリング状の突起と、前記ポール
ピース間に挟まれて固定された永久磁石と、前記突起に
対向して前記微小空隙に充填された磁性流体とを備えた
多段型磁性流体軸封装置において、真空側から大気側に
向かって第一番目の磁性流体と第二番目の磁性流体との
間の空間を真空側に連通孔で連通させた構成にしてい
る。ポールピースに連通孔を設けるか微細な連通孔とし
てポールピースに焼結金属を用いればなおよい。また、
連通孔の内部に焼結金属又はプラスチック繊維を充填し
たものを回転軸側に用いた構成にしてもよい。In order to solve the above-mentioned problems, the present invention provides a rotating shaft, and a plurality of pole pieces provided in the radial direction with a minute gap around the rotating shaft and provided in the axial direction. A plurality of ring-shaped protrusions provided on the outer periphery of the rotating shaft or the inner periphery of the pole piece, permanent magnets sandwiched between the pole pieces and fixed, and the minute gaps facing the protrusions In the multistage magnetic fluid shaft sealing device including the magnetic fluid, the space between the first magnetic fluid and the second magnetic fluid is connected to the vacuum side from the vacuum side to the atmosphere side by the communication hole. It is configured to communicate. It is more preferable to provide a communicating hole in the pole piece or use a sintered metal for the pole piece as a fine communicating hole. Also,
A structure in which a sintered metal or a plastic fiber is filled in the communication hole may be used on the rotating shaft side.
【０００５】[0005]
【作用】上記手段により、真空側の段間空間と真空環境
とを連通孔で連通させ、最初の空間での圧力差を無くし
たので、最初の磁性流体でのシール破壊がなくなる。そ
うすると、２段目でのシール破壊が起こってもこれに伴
うパーティクルは、微細孔のフィルター効果で真空環境
への飛散を抑えることができる。With the above-mentioned means, the interstage space on the vacuum side and the vacuum environment are communicated with each other through the communication hole, and the pressure difference in the first space is eliminated, so that the first seal break in the magnetic fluid is eliminated. Then, even if the seal breaks in the second stage, the particles accompanying it can be prevented from scattering into the vacuum environment due to the filter effect of the fine holes.
【０００６】[0006]
【実施例】以下、本発明の実施例を図に基づいて説明す
る。 （第一実施例）図１は本発明の第一実施例を示す多段型
磁性流体軸封装置の部分断面図である。図において、１
は磁性材料からなる回転軸、２は円筒部、３は軸受、４
は磁性材料からなるポールピース、５は永久磁石、６は
磁性流体、７は連通孔、８は空間、９は取付け部材であ
る。回転軸１はポールピース４と対向する位置にリング
状の突起１１を設けている。磁性流体６はこの突起１１
とポールピース４間に充填している。連通孔７は真空側
のポールピース４１には真空側の端面から真空側に最も
近い突起１１間の第一の空間８１に通じるように設けら
れている。８２は真空側からみた第二の空間である。つ
ぎに動作について説明する。本発明の軸封装置を取り付
けた真空装置を大気圧から真空排気すると、第一の空間
８１も連通孔７を通して排気され、その圧力は常に真空
環境とほぼ同一の圧力となり、第一の空間８１と真空環
境との段間のシール破壊は生じない。しかし、第一の空
間８１と第二の空間８２との間には圧力差が生じ、排気
の進行とともにその圧力差は大きくなる。そして、圧力
差が耐圧を越えると真空側から二番目のシールが破壊し
リークを生じ、同時に、強磁性体微粉末、界面活性剤、
および媒体などのパーティクルが第一の空間８１内に飛
び散る。ところが、パーティクルは連通孔７のフィルタ
ー効果により真空環境内には入らない。次に装置を大気
解放すると第一の空間８１と第二の空間８２には逆の圧
力差を生じ逆方向のシール破壊が生じるため、第二の空
間８２の圧力は上昇する。次に、大気解放後に再度真空
排気を行うと、第一の空間８１側へのリークが生じる。
従って、真空排気、大気解放の繰り返しで、逆方向のシ
ール破壊が繰り返されることになる。このシール破壊時
に強磁性体微粉末、界面活性剤、および媒体などが飛散
するが、連通孔７のフィルター効果で真空環境への飛散
を抑えることが出来る。 （第二実施例）図２は本発明の第二実施例を示す多段型
磁性流体軸封装置の部分断面図である。真空側に最も近
いポールピース４３に焼結金属を用いており、永久磁石
５を介して４つの空間がもうけられている。真空側に最
も近い空間が第一の空間８１、その隣が第二の空間８２
である。４３１、４４１、４５１はポールピースに設け
た突起であり、これらの突起と回転軸１との間に磁性流
体６を充填している。動作は第一実施例と同様に行われ
る。すなわち、焼結金属を用いたポールピース４３が、
フィルター効果を奏し、強磁性体微粉末、界面活性剤、
および媒体などのパーティクルが真空環境へ飛散するこ
とを防止できる。なお、ポールピース４３に焼結金属を
用いずに第一実施例で用いた連通孔７を設けてもよい。 （第三実施例）図３は本発明の第三実施例を示す多段型
磁性流体軸封装置の部分断面図である。図において、真
空側に最も近い回転軸１に連通孔７を用いた例である。
連通孔７は真空側の回転軸１には真空側の端面から真空
側に最も近い突起１１間の第一の空間８１に通じるよう
に設けられている。連通孔７の内部の、真空側の端面か
ら真空側に最も近い第一の空間８１に至る空間部には焼
結金属又はプラスチック繊維が充填されている。動作は
第一実施例および第二実施例と同様に行われる。すなわ
ち、焼結金属又はプラスチック繊維を充填した連通孔７
が、フィルターとしての効果を奏し、真空環境に対して
強磁性体微粉末、界面活性剤、および媒体などのパーテ
ィクルの飛散を防止できるのである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a partial sectional view of a multi-stage magnetic fluid shaft sealing device showing a first embodiment of the present invention. In the figure, 1
Is a rotary shaft made of a magnetic material, 2 is a cylindrical portion, 3 is a bearing, 4
Is a pole piece made of a magnetic material, 5 is a permanent magnet, 6 is a magnetic fluid, 7 is a communication hole, 8 is a space, and 9 is a mounting member. The rotating shaft 1 is provided with a ring-shaped protrusion 11 at a position facing the pole piece 4. The magnetic fluid 6 is the protrusion 11
And the space between the pole pieces 4 is filled. The communication hole 7 is provided in the vacuum side pole piece 41 so as to communicate with the first space 81 between the protrusions 11 closest to the vacuum side from the vacuum side end surface. Reference numeral 82 is a second space viewed from the vacuum side. Next, the operation will be described. When the vacuum device equipped with the shaft sealing device of the present invention is evacuated from the atmospheric pressure, the first space 81 is also evacuated through the communication hole 7, and the pressure thereof is always almost the same as the vacuum environment. There is no seal break between the vacuum and vacuum environment. However, a pressure difference occurs between the first space 81 and the second space 82, and the pressure difference increases with the progress of exhaust. When the pressure difference exceeds the pressure resistance, the second seal from the vacuum side breaks and leaks, and at the same time, the ferromagnetic fine powder, the surfactant,
And particles such as a medium scatter in the first space 81. However, particles do not enter the vacuum environment due to the filter effect of the communication holes 7. Next, when the device is exposed to the atmosphere, a reverse pressure difference occurs between the first space 81 and the second space 82, and the seal breaks in the opposite direction, so that the pressure in the second space 82 rises. Next, when vacuum exhaustion is performed again after the atmosphere is released, a leak to the first space 81 side occurs.
Therefore, by repeatedly evacuating and releasing the atmosphere, the seal destruction in the opposite direction is repeated. When the seal is broken, the ferromagnetic fine powder, the surfactant, the medium, and the like are scattered, but the filter effect of the communication hole 7 can suppress the scattering into the vacuum environment. (Second Embodiment) FIG. 2 is a partial cross-sectional view of a multistage magnetic fluid shaft sealing device showing a second embodiment of the present invention. Sintered metal is used for the pole piece 43 closest to the vacuum side, and four spaces are provided through the permanent magnet 5. The space closest to the vacuum side is the first space 81, and the adjacent space is the second space 82.
Is. Reference numerals 431, 441, and 451 denote projections provided on the pole piece, and the magnetic fluid 6 is filled between the projections and the rotary shaft 1. The operation is the same as in the first embodiment. That is, the pole piece 43 made of sintered metal is
It exerts a filter effect, ferromagnetic fine powder, surfactant,
It is also possible to prevent particles such as the medium from scattering into the vacuum environment. The pole piece 43 may be provided with the communication hole 7 used in the first embodiment without using the sintered metal. (Third Embodiment) FIG. 3 is a partial cross-sectional view of a multistage magnetic fluid shaft sealing device showing a third embodiment of the present invention. In the figure, this is an example in which a communication hole 7 is used for the rotary shaft 1 closest to the vacuum side.
The communication hole 7 is provided in the rotary shaft 1 on the vacuum side so as to communicate with the first space 81 between the protrusions 11 closest to the vacuum side from the end surface on the vacuum side. Inside the communication hole 7, a space portion extending from the end surface on the vacuum side to the first space 81 closest to the vacuum side is filled with sintered metal or plastic fiber. The operation is the same as in the first and second embodiments. That is, the communication hole 7 filled with sintered metal or plastic fiber
However, it has an effect as a filter and can prevent scattering of particles such as the ferromagnetic fine powder, the surfactant, and the medium in a vacuum environment.
【０００７】[0007]
【発明の効果】以上述べたように、本発明によれば磁性
流体を用いた多段型軸封装置の最真空側の空間と真空環
境とを、パーティクルのフィルター効果を持つ微細な連
通孔で連通させ、真空に最も近い空間のシール破壊を無
くしたので、真空環境へのパーティクルの飛散を抑えた
多段型磁性流体軸封装置を提供できる効果がある。As described above, according to the present invention, the space on the most vacuum side of the multistage shaft sealing device using the magnetic fluid and the vacuum environment are communicated with each other through the fine communication holes having a particle filter effect. Since the destruction of the seal in the space closest to the vacuum has been eliminated, it is possible to provide a multi-stage magnetic fluid shaft sealing device in which scattering of particles into the vacuum environment is suppressed.
【図１】本発明の第一実施例を示す多段型磁性流体軸封
装置の部分断面図である。FIG. 1 is a partial cross-sectional view of a multistage magnetic fluid shaft sealing device according to a first embodiment of the present invention.
【図２】本発明の第二実施例を示す多段型磁性流体軸封
装置の部分断面図である。FIG. 2 is a partial cross-sectional view of a multistage magnetic fluid shaft sealing device according to a second embodiment of the present invention.
【図３】本発明の第三実施例を示す多段型磁性流体軸封
装置の部分断面図である。FIG. 3 is a partial cross-sectional view of a multistage magnetic fluid shaft sealing device according to a third embodiment of the present invention.
１ ：回転軸 ６ ：磁性流体 １１：突起 ７ ：連通孔 ２ ：円筒部 ８ ：空間 ３ ：軸受 ８１：第一の空
間 ４、４１〜４５：ポールピース ８２：第二の空
間 ４３１、４４１、４５１：突起 ９ ：取付け部
材 ５ ：永久磁石1: Rotating shaft 6: Magnetic fluid 11: Protrusion 7: Communication hole 2: Cylindrical part 8: Space 3: Bearing 81: First space 4, 41-45: Pole piece 82: Second space 431, 441, 451 : Protrusion 9: Mounting member 5: Permanent magnet
Claims (4)
半径方向に設けられ、かつ、軸方向に複数設けられたポ
ールピースと、前記回転軸の外周又は前記ポールピース
の内周に複数個設けられたリング状の突起と、前記ポー
ルピース間に挟まれて固定された永久磁石と、前記突起
に対向して前記微小空隙に充填された磁性流体とを備え
た多段型磁性流体軸封装置において、 真空側から大気側に向かって第一番目の磁性流体と第二
番目の磁性流体との間の空間を前記真空側に連通孔で連
通させたことを特徴とする多段型磁性流体軸封装置。1. A rotary shaft, a plurality of pole pieces provided in the radial direction through a minute gap around the rotary shaft, and a plurality of pole pieces provided in the axial direction, and a plurality of pole pieces on the outer circumference of the rotary shaft or the inner circumference of the pole piece. A multi-stage magnetic fluid shaft seal including individually provided ring-shaped protrusions, a permanent magnet sandwiched between the pole pieces and fixed, and a magnetic fluid filled in the minute voids facing the protrusions. In the apparatus, a multi-stage magnetic fluid shaft characterized in that the space between the first magnetic fluid and the second magnetic fluid from the vacuum side to the atmosphere side is communicated with the vacuum side by a communication hole. Sealing device.
ことを特徴とする請求項１記載の多段型磁性流体軸封装
置。2. The multistage magnetic fluid shaft sealing device according to claim 1, wherein the communication hole is provided in the pole piece.
属を用いた微細孔からなることを特徴とする請求項１記
載の多段型磁性流体軸封装置。3. The multi-stage magnetic fluid shaft sealing device according to claim 1, wherein the communication hole is a fine hole using sintered metal for the pole piece.
記連通孔の内部の少なくとも一か所に焼結金属又はプラ
スチック繊維を充填したことを特徴とする請求項２記載
の多段型磁性流体軸封装置。4. The multi-stage magnetic fluid according to claim 2, wherein the communication hole is provided in the rotary shaft, and at least one of the communication hole is filled with a sintered metal or a plastic fiber. Shaft sealing device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7284463A JPH08320072A (en) | 1995-03-20 | 1995-10-04 | Multistage magnetic fluid shaft sealing device |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7-87520 | 1995-03-20 | ||
| JP8752095 | 1995-03-20 | ||
| JP7284463A JPH08320072A (en) | 1995-03-20 | 1995-10-04 | Multistage magnetic fluid shaft sealing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08320072A true JPH08320072A (en) | 1996-12-03 |
Family
ID=26428781
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7284463A Pending JPH08320072A (en) | 1995-03-20 | 1995-10-04 | Multistage magnetic fluid shaft sealing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08320072A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107740866A (en) * | 2017-11-03 | 2018-02-27 | 广西科技大学 | A kind of staged device for sealing magnetic fluid |
| CN107939979A (en) * | 2017-12-14 | 2018-04-20 | 广西科技大学 | A kind of radially type labyrinth type device for sealing magnetic fluid |
| CN113074254A (en) * | 2021-04-15 | 2021-07-06 | 西华大学 | High-speed magnetic fluid sealing device for high-temperature working condition |
-
1995
- 1995-10-04 JP JP7284463A patent/JPH08320072A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107740866A (en) * | 2017-11-03 | 2018-02-27 | 广西科技大学 | A kind of staged device for sealing magnetic fluid |
| CN107740866B (en) * | 2017-11-03 | 2023-05-02 | 广西科技大学 | Stepped magnetic fluid sealing device |
| CN107939979A (en) * | 2017-12-14 | 2018-04-20 | 广西科技大学 | A kind of radially type labyrinth type device for sealing magnetic fluid |
| CN107939979B (en) * | 2017-12-14 | 2023-05-02 | 广西科技大学 | Radial divergent labyrinth type magnetic fluid sealing device |
| CN113074254A (en) * | 2021-04-15 | 2021-07-06 | 西华大学 | High-speed magnetic fluid sealing device for high-temperature working condition |
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