JPH0643582Y2 - Magnetic fluid sealing device - Google Patents
Magnetic fluid sealing deviceInfo
- Publication number
- JPH0643582Y2 JPH0643582Y2 JP1987143011U JP14301187U JPH0643582Y2 JP H0643582 Y2 JPH0643582 Y2 JP H0643582Y2 JP 1987143011 U JP1987143011 U JP 1987143011U JP 14301187 U JP14301187 U JP 14301187U JP H0643582 Y2 JPH0643582 Y2 JP H0643582Y2
- Authority
- JP
- Japan
- Prior art keywords
- permanent magnet
- magnetic fluid
- pole piece
- inner diameter
- shaft
- 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.)
- Expired - Lifetime
Links
Landscapes
- Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
Description
【考案の詳細な説明】 本考案は、固定磁気記憶装置の回転部分の密封装置に適
用して好適な磁性流体シール装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic fluid sealing device suitable for being applied to a sealing device for a rotating portion of a fixed magnetic storage device.
固定磁気ディスク装置は、その信頼性を向上するために
種々の改良がなされている。The fixed magnetic disk device has been variously improved in order to improve its reliability.
例えば、ディスクが設定されているディスクパックの清
浄度が特に重要であり、この清浄液を保つためディスク
ドライブピンドルや、ヘッドアクチュエータの軸受のオ
イルミストやディスク外部からの塵埃等がディスク内部
に侵入するのを防止するため磁性流体シールが使われて
いる。For example, the cleanliness of the disc pack in which the disc is set is particularly important. To keep this cleaning liquid, the oil mist of the disc drive pindle, the bearing of the head actuator, and dust from the outside of the disc enter the disc. A magnetic fluid seal is used to prevent this.
例えば、この種の磁性流体シール構造は、例えば第１図
に示す如く、半径方向に磁化された環状永久磁石と永久
磁石１の外径部及び片側平面部を覆った半断面Ｌ字型の
軟磁性体ポールピースリング２と、永久磁石１の内径及
びポールピース２の内径とを貫く強磁性体シャフト４
と、シャフト４の外径とポールピース２の内及び永久磁
石１の内径との空間に磁気的に補捉される磁性流体リン
グ膜３とから構成されている（特開昭62-31776号参
照）。For example, as shown in FIG. 1, for example, a magnetic fluid seal structure of this type has a semi-section L-shaped soft magnet which covers the radially outer annular permanent magnet and the outer diameter portion and one side flat portion of the permanent magnet 1. Ferromagnetic shaft 4 that penetrates the magnetic pole piece ring 2 and the inner diameter of the permanent magnet 1 and the inner diameter of the pole piece 2.
And a magnetic fluid ring film 3 which is magnetically captured in the space between the outer diameter of the shaft 4 and the inner portion of the pole piece 2 and the inner diameter of the permanent magnet 1 (see Japanese Patent Laid-Open No. 62-31776). ).
このような構成の磁性流体シール装置は、構造が簡単で
あり、低価格という利点がある。The magnetic fluid seal device having such a structure has the advantages of simple structure and low cost.
しかし、第２図に示す如く、シールの内径面と強磁性シ
ャフト４との軸線とが互いに傾きを生ずることがあり、
このとき、結果としてシール内径線A,Bとシャフト外径
線C,D間の空隙距離が一定ではなくなり、シール部の両
端で、一方最大B,D、他方では最小A,Cとなる。However, as shown in FIG. 2, the inner diameter surface of the seal and the axis of the ferromagnetic shaft 4 may tilt with respect to each other,
At this time, as a result, the gap distance between the seal inner diameter lines A and B and the shaft outer diameter lines C and D is not constant, and at both ends of the seal portion, one is maximum B and D, and the other is minimum A and C.
従って、空隙距離の小さくなった空隙領域Ａ付近におい
ては、相対的に磁界強度が増加する。他方、空隙距離の
大きくなった空隙領域Ｂ付近においては、相対的に磁界
強度が減少する。結果として、磁性流体リング膜５は空
隙が小さい方（矢印方向）へ引き寄せようとする磁気的
力を受け、更に空隙が小さい方へ移動することになる。Therefore, the magnetic field strength relatively increases in the vicinity of the void region A where the void distance is reduced. On the other hand, in the vicinity of the void area B where the void distance is increased, the magnetic field strength is relatively reduced. As a result, the magnetic fluid ring film 5 receives a magnetic force that draws toward the smaller void (in the direction of the arrow), and moves toward the smaller void.
また、同様にシール内径線A,Bとシールの中心軸に対し
て180°の位置の内径線G,Hにおいても、磁性流体シール
膜５は空隙が小さい方Ｈ付近へ磁気的な力により移動す
る。Similarly, with respect to the seal inner diameter lines A and B and the inner diameter lines G and H at a position of 180 ° with respect to the center axis of the seal, the magnetic fluid seal film 5 is moved by magnetic force to the vicinity H where the gap is smaller. To do.
しかし、シール部とシャフト４が相対回転運動をする
と、磁性流体リング膜５は、第３図に示す如く、遠心力
により２つの膜5,5′に分離することがある。従って、
磁性流体リング膜５においては、シャフト４のＦ近傍に
おいて磁気的に遠心力に抗して磁性流体を保持できる
が、Ｄ近傍では磁気的に弱く遠心力に抗して磁性流体を
保持できなくなり、磁性流体リング膜５の一部の磁性流
体がシール装置の外部に飛散する欠点を有している。However, when the seal portion and the shaft 4 rotate relative to each other, the magnetic fluid ring membrane 5 may be separated into two membranes 5 and 5'by centrifugal force as shown in FIG. Therefore,
In the magnetic fluid ring film 5, the magnetic fluid can be magnetically retained in the vicinity of F of the shaft 4 against the centrifugal force, but in the vicinity of D, it is magnetically weak and cannot retain the magnetic fluid against the centrifugal force. It has a drawback that a part of the magnetic fluid of the magnetic fluid ring film 5 is scattered to the outside of the sealing device.
また、磁性流体リング膜５′においても、上述と同様の
メカニズムにより磁性流体の飛散することがある。Also in the magnetic fluid ring film 5 ', the magnetic fluid may be scattered by the same mechanism as described above.
このような磁性流体シール装置からの磁性流体の飛散現
象は、ディスクパックの清浄度を著しく損なうものであ
り、固定磁気ディスク装置の致命的欠陥というべきもの
である。The scattering phenomenon of the magnetic fluid from the magnetic fluid seal device significantly impairs the cleanliness of the disk pack, and is a fatal defect of the fixed magnetic disk device.
本考案は、このような磁性流体シール装置からの磁性流
体の飛散を除去するために、該磁性流体シール装置にお
いて、該環状永久磁石と半断面Ｌ字型のボールピースと
の接合内周面部の径を、接合反対外側の夫々の内周面部
の径よりも大きくなるように傾斜面とし、遠心力による
磁性流体のシール装置の外部への飛散を防止するように
した高信頼性の磁性流体シール装置を提案することを主
たる目的とする。In order to eliminate the scattering of the magnetic fluid from the magnetic fluid sealing device, the present invention provides a magnetic fluid sealing device in which the inner peripheral surface portion of the joint between the annular permanent magnet and the ball piece having an L-shaped half section is joined. A highly reliable magnetic fluid seal with a diameter that is inclined so that it is larger than the diameter of each inner peripheral surface on the opposite side of the joint to prevent the magnetic fluid from scattering to the outside of the sealing device due to centrifugal force. The main purpose is to propose a device.
本考案は、半径方向に磁化された環状永久磁石と、該外
径部及び該片側平面部を覆った半断面Ｌ字型の軟磁性体
ポールピースリングと、該永久磁石及び該ポールピース
の夫々の内径を貫く強磁性シャフトと、該シャフト外径
と該永久磁石内径及び該ポールピース内径との空隙に磁
気的に補捉される磁性流体リング膜とから構成された磁
性流体シール装置において、 該永久磁石と該ポールピースとが対向・接合し形成され
る内周面部の内径が対向してない該永久磁石及び該ポー
ルピースの内周面部の内径よりも常に大きくなるように
該永久磁石及び該ポールピースの夫々の内径部に傾斜を
持たせたことを特徴とする。The present invention relates to an annular permanent magnet magnetized in a radial direction, a soft magnetic pole piece ring having a half-section L-shape that covers the outer diameter portion and the one-sided flat portion, and the permanent magnet and the pole piece, respectively. And a magnetic fluid ring film magnetically captured in a gap between the shaft outer diameter, the permanent magnet inner diameter, and the pole piece inner diameter. The permanent magnet and the permanent magnet and the pole piece are formed such that the inner diameter of the inner circumferential surface portion formed by facing and joining the permanent magnet and the pole piece is not larger than the inner diameter of the inner circumferential surface portion of the permanent magnet and the pole piece. It is characterized in that each of the pole pieces has an inclined inner diameter.
以下本考案の一実施例について図面を参照しながら詳細
に説明する。An embodiment of the present invention will be described in detail below with reference to the drawings.
第４図は本考案の一例を示す図である。本例において
は、半径方向に磁化された環状永久磁石11と外径部及び
片面部を覆った半断面Ｌ字型の軟磁性体ポールピースリ
ング12と、永久磁石11及びポールピース12の夫々の内径
を貫く強磁性体シャフト14とシャフト14の外径と永久磁
石11の内径及びポールピース12の内径との空隙に磁気的
に補捉される磁性流体リング膜13とから構成されている
磁性流体シール装置であるが、永久磁石11とポールピー
ス12とが対向接合し形成される内周面部の内径が、対向
していない反対側の外側の永久磁石11及びポールピース
12の内周面部の内径よりも大きくなるように、永久磁石
11及びポールピース12の夫々の内周径部に傾斜面を持た
せたものである。FIG. 4 is a diagram showing an example of the present invention. In this example, a radially magnetized annular permanent magnet 11, a soft magnetic pole piece ring 12 having an L-shaped half-section covering the outer diameter portion and one surface portion, and the permanent magnet 11 and the pole piece 12, respectively. A magnetic fluid composed of a ferromagnetic shaft 14 penetrating the inner diameter, a magnetic fluid ring film 13 magnetically trapped in the gap between the outer diameter of the shaft 14 and the inner diameter of the permanent magnet 11 and the inner diameter of the pole piece 12. Although it is a sealing device, the inner diameter of the inner peripheral surface portion formed by the permanent magnet 11 and the pole piece 12 being joined to face each other is such that the outer permanent magnet 11 and the pole piece on the opposite side that are not facing each other.
Make sure that the permanent magnet is larger than the inner diameter of the inner peripheral surface of 12.
The inner peripheral diameter portion of each of 11 and the pole piece 12 is provided with an inclined surface.
したがって、第５図に示す如く、シール内径と強磁性体
シャフトとの軸線が互いに傾きを持ったとき、結果とし
てシール内径J,Kとシャフト14の外径線M,N間の空隙距離
が小さくなり、空隙領域の磁界強度が増加するから、磁
性流体13のリング膜はJ,Mの方向へ移動することにな
り、シール部の中心軸に対して180°回転した位置にお
いては、内径線S,Tとシャフト14の外径線P,Q間との空隙
距離が小さくなり、空隙領域の磁界強度が増加するか
ら、磁性流体13のリング膜はQ,Tの方向へ移動すること
になる。Therefore, as shown in FIG. 5, when the seal inner diameter and the axis of the ferromagnetic shaft are inclined with respect to each other, as a result, the gap distance between the seal inner diameter J, K and the outer diameter line M, N of the shaft 14 becomes small. Since the magnetic field strength in the void region increases, the ring film of the magnetic fluid 13 moves in the J and M directions, and at the position rotated 180 ° with respect to the central axis of the seal portion, the inner diameter line S , T and the outer diameter lines P, Q of the shaft 14 become smaller, and the magnetic field strength in the space region increases, so that the ring film of the magnetic fluid 13 moves in the Q, T directions.
この状態でシール部とシャフト14との相対回転運転をす
ると、第３図例において生じた磁性流体13のシールリン
グが２つの領域に別れるようなことはなく、第６図に示
す如く、磁性流体リング膜は１個のまま保持される。When the seal portion and the shaft 14 are rotated relative to each other in this state, the seal ring of the magnetic fluid 13 generated in the example of FIG. 3 does not separate into two regions, and as shown in FIG. One ring film is retained as it is.
この原因は、磁性流体リング膜に作用している遠心力
が、シール内径部の永久磁石11及びポールピース12の夫
々に傾斜面が形成されているので、この傾斜部をガイド
にして、永久磁石11とポールピース12とが対向・接合し
て形成される平面部の内径部へ磁性流体13を押しやるか
らと考えられる。This is because the centrifugal force acting on the magnetic fluid ring film forms an inclined surface on each of the permanent magnet 11 and the pole piece 12 in the seal inner diameter portion. It is considered that the magnetic fluid 13 is pushed to the inner diameter portion of the plane portion formed by the 11 and the pole piece 12 facing each other and being joined to each other.
従って本実施例においては、シール外部へ磁性流体シー
ルリング膜の一部が飛散するようなことは起きなかっ
た。Therefore, in this example, no part of the magnetic fluid seal ring film was scattered to the outside of the seal.
以上述べたごとく本考案によれば、半径方向に磁化され
た環状永久磁石と、該外径部及び該片側平面部を覆った
半断面Ｌ字型の軟磁性体ポールピースリングと、該永久
磁石及び該ポールピースの夫々の内径を貫きかつ永久磁
石及びポールピースの軸芯に対し軸芯が傾斜する強磁性
シャフトと、該シャフト外径と該永久磁石内径及び該ポ
ールピース内径との空隙に磁気的に補捉される磁性流体
リング膜とから構成された磁性流体シール装置におい
て、該永久磁石と該ポールピースとが対向・接合し形成
される内周面部の内径が対向してない該永久磁石及び該
ポールピースの外側内周面部の内径よりも常に大きくな
るように該永久磁石及び該ポールピースの夫々の内径部
に傾斜を持たせたので、 軸芯が傾斜したままシャフトが回転した際、磁束密度の
不均衡が生じても磁性流体自体は中央の径大部に移動す
ることになるため、磁性流体が回転時の遠心力により、
シール外部へ飛散することのない利点を持った高信頼性
の磁性流体シール装置の提供が可能となる。As described above, according to the present invention, an annular permanent magnet magnetized in the radial direction, a soft magnetic pole piece ring having a half-section L-shape that covers the outer diameter portion and the one side flat portion, and the permanent magnet. And a ferromagnetic shaft that penetrates the inner diameter of each of the pole pieces and has an axis inclined with respect to the axis of the permanent magnet and the pole piece, and a magnetic field in the gap between the outer diameter of the shaft and the inner diameter of the permanent magnet and the inner diameter of the pole piece. In a magnetic fluid seal device composed of a magnetic fluid ring film that is trapped in a static manner, the inner diameter of an inner peripheral surface portion formed by facing and joining the permanent magnet and the pole piece is not opposed. And since the inner diameters of the permanent magnet and the pole piece are inclined so that they are always larger than the inner diameter of the outer inner peripheral surface of the pole piece, when the shaft rotates while the shaft core is inclined, Magnetic flux tight Even if a degree of imbalance occurs, the magnetic fluid itself will move to the large diameter part in the center, so due to the centrifugal force when the magnetic fluid rotates,
It is possible to provide a highly reliable magnetic fluid seal device having the advantage of not scattering outside the seal.
第１図、第２図及び第３図は従来の例を示す断面図、第
４図、第５図及び第６図は夫々本考案の一実施例を示す
断面図である。 11……永久磁石、12……ポールピース、13……磁性流
体、14……回転軸。1, 2, and 3 are sectional views showing a conventional example, and FIGS. 4, 5, and 6 are sectional views showing an embodiment of the present invention. 11 …… Permanent magnet, 12 …… Pole piece, 13 …… Magnetic fluid, 14 …… Rotary shaft.
Claims (1)
外径部及び該片側平面部を覆った半断面Ｌ字型の軟磁性
体ポールピースリングと、該永久磁石及び該ポールピー
スの夫々の内径を貫きかつ永久磁石及びポールピースの
軸芯に対し軸芯が傾斜する強磁性シャフトと、該シャフ
ト外径と該永久磁石内径及び該ポールピース内径との空
隙に磁気的に補捉される磁性流体リング膜とから構成さ
れた磁性流体シール装置において、 該永久磁石と該ポールピースとが対向・接合し形成され
る内周面部の内径が対向してない該永久磁石及び該ポー
ルピースの外側内周面部の内径よりも常に大きくなるよ
うに該永久磁石及び該ポールピースの夫々の内径部に傾
斜を持たせたことを特徴とする磁性流体シール装置。1. A ring-shaped permanent magnet magnetized in the radial direction, a soft magnetic pole piece ring having a half-section L-shape that covers the outer diameter portion and the flat surface on one side, and the permanent magnet and the pole piece. A ferromagnetic shaft that penetrates the respective inner diameters and has an axis inclined with respect to the axis of the permanent magnet and the pole piece, and is magnetically captured in a gap between the outer diameter of the shaft and the inner diameter of the permanent magnet and the inner diameter of the pole piece. In a magnetic fluid seal device including a magnetic fluid ring film, the inner diameter of an inner peripheral surface formed by facing and joining the permanent magnet and the pole piece does not face each other. A magnetic fluid seal device characterized in that the inner diameters of the permanent magnet and the pole piece are inclined so as to be always larger than the inner diameter of the outer inner peripheral surface portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1987143011U JPH0643582Y2 (en) | 1987-09-21 | 1987-09-21 | Magnetic fluid sealing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1987143011U JPH0643582Y2 (en) | 1987-09-21 | 1987-09-21 | Magnetic fluid sealing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0194668U JPH0194668U (en) | 1989-06-22 |
| JPH0643582Y2 true JPH0643582Y2 (en) | 1994-11-14 |
Family
ID=31409448
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1987143011U Expired - Lifetime JPH0643582Y2 (en) | 1987-09-21 | 1987-09-21 | Magnetic fluid sealing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0643582Y2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2535736Y2 (en) * | 1989-12-28 | 1997-05-14 | 日本電産株式会社 | Magnetic fluid sealing device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6165967A (en) * | 1984-09-06 | 1986-04-04 | Nippon Seiko Kk | Magnetic fluid seal structure |
| JPS62155327A (en) * | 1985-12-26 | 1987-07-10 | Matsushita Electric Ind Co Ltd | Bearing device for rotating shaft |
-
1987
- 1987-09-21 JP JP1987143011U patent/JPH0643582Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0194668U (en) | 1989-06-22 |
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