JPH0281364A - Magnetic disk device - Google Patents
Magnetic disk deviceInfo
- Publication number
- JPH0281364A JPH0281364A JP23233288A JP23233288A JPH0281364A JP H0281364 A JPH0281364 A JP H0281364A JP 23233288 A JP23233288 A JP 23233288A JP 23233288 A JP23233288 A JP 23233288A JP H0281364 A JPH0281364 A JP H0281364A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic fluid
- magnetic
- inner diameter
- ring
- spindle motor
- 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
- 239000011553 magnetic fluid Substances 0.000 claims abstract description 46
- 238000007789 sealing Methods 0.000 abstract 2
- 238000010276 construction Methods 0.000 abstract 1
- 239000006185 dispersion Substances 0.000 abstract 1
- 230000002265 prevention Effects 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 4
- 230000006378 damage Effects 0.000 description 3
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Landscapes
- Rotational Drive Of Disk (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、磁気ディスク装置のスピンドルモータハブ内
部の防塵に係り、特に、温度、圧力変化による磁性流体
の流出防止に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to dust prevention inside a spindle motor hub of a magnetic disk device, and particularly to prevention of outflow of magnetic fluid due to changes in temperature and pressure.
従来の磁気ディスク装置は、温度、圧力変化により、磁
性流体の流出が生じていた、この磁性流体流出に対して
、圧力等の変化の影響を避ける流出防止構造と流出後の
飛散を防止する構造があるが、後者の方法では、特開昭
62−73480号で飛散防止キャップを別に設けるこ
とにより、流出に対する飛散を防止していた。In conventional magnetic disk drives, magnetic fluid leaks due to changes in temperature and pressure.In order to prevent this magnetic fluid from flowing out, we have developed a structure that prevents the magnetic fluid from being affected by changes in pressure, etc., and a structure that prevents it from scattering after it flows out. However, in the latter method, JP-A No. 62-73480 discloses that a scattering prevention cap is provided separately to prevent scattering due to outflow.
上記従来技術は、磁性流体の飛散以前の流出について考
慮されておらず、流出液が遠心力によって飛散する場合
の防護のみであった。この為、遠心力以外の力、圧力等
が働いた場合、流出液が防護壁に収まらず、スピンドル
モータ内部、外部へ飛散、付着し、磁気ディスク等の損
傷が生じた。The above-mentioned conventional technology does not take into consideration the outflow of the magnetic fluid before it is scattered, and only protects against the case where the outflow liquid is scattered due to centrifugal force. For this reason, when a force or pressure other than centrifugal force is applied, the outflow liquid is not contained within the protective wall, but scatters and adheres to the inside and outside of the spindle motor, causing damage to the magnetic disk, etc.
つまり、飛散以前の流出において、徐々に圧力変化が加
わり、にじみ出る場合と、急激な圧力変化が加わり、破
壊する場合とがあって、後者の場合には、防護壁前の流
出防止構造が必要となるのである。In other words, in the outflow before scattering, there are cases where a gradual pressure change is applied and oozes out, and there are cases where a sudden pressure change is applied and the outflow breaks down, and in the latter case, a spill prevention structure in front of the protective wall is required. It will become.
本発明の目的は、急激な圧力変化等に際しても磁性流体
の流出及び飛散を防止することにある。An object of the present invention is to prevent the magnetic fluid from flowing out and scattering even in the event of sudden pressure changes.
上記目的を達成するために、本発明は磁性流体に急激な
圧力変化が加わらない様にする事、若しくは、磁性流体
シール本体と磁性流体とスピンドルモータシャフトから
成る磁気回路内で流出しない様にすれば良いことに鑑み
、後者において、磁性流体シール本体の環状ヨークの少
なくとも一枚の内径を、他の環状ヨーク内径とスピンド
ルモータシャフト外径とすきまより小さくなる様にした
ものである。In order to achieve the above object, the present invention prevents sudden pressure changes from being applied to the magnetic fluid or prevents it from flowing out within the magnetic circuit consisting of the magnetic fluid seal body, the magnetic fluid, and the spindle motor shaft. In view of this, in the latter case, the inner diameter of at least one of the annular yokes of the magnetic fluid seal body is made smaller than the gap between the inner diameter of the other annular yokes and the outer diameter of the spindle motor shaft.
磁性流体シール本体の環状ヨークと環状マグネットと磁
性流体とモータシャツI・からなる磁気回路は、環状マ
グネットのN極から出た磁束が環状ヨーク、磁性流体、
シャフトを介してS極へ流れ込む動作をする。この際、
磁性流体の環状ヨーク及び、シャフトとの結合の強さは
、環状ヨークの内径とシャフト外径のすきまが小さい程
強くなり、磁性流体が磁気回路外へ流出しにくくなる。The magnetic circuit consists of the annular yoke of the magnetic fluid seal body, the annular magnet, the magnetic fluid, and the motor shirt I. The magnetic flux emitted from the N pole of the annular magnet flows through the annular yoke, the magnetic fluid, and the magnetic circuit.
It flows into the south pole through the shaft. On this occasion,
The strength of the coupling of the magnetic fluid with the annular yoke and the shaft becomes stronger as the gap between the inner diameter of the annular yoke and the outer diameter of the shaft is smaller, and the magnetic fluid becomes less likely to flow out of the magnetic circuit.
ここで、環状ヨークのうち、スピンドルモータハブ外部
、あるいは、内部に近いもののうち少なくとも1枚に磁
性流体を注入せず、環状ヨークの内径を小さくし、磁性
流体の流出防護壁的役割を持たせる0例えば、最悪の磁
性流体の破裂の時もモータハブ外部へ流出前に、環状ヨ
ークとシャフト間すきまで捕え、新しい磁気回路を構成
する。Here, magnetic fluid is not injected into at least one of the annular yokes outside or close to the inside of the spindle motor hub, and the inner diameter of the annular yoke is made small to serve as a protective wall for the outflow of magnetic fluid. 0 For example, even in the worst case of magnetic fluid rupture, the gap between the annular yoke and the shaft is captured before it flows out of the motor hub, and a new magnetic circuit is constructed.
この時、環状ヨークとシャフト間のすき間が破壊前より
小さくなり、磁性流体のシャフト等との結合が大きくな
る為、初期耐圧よりアップすることになる。At this time, the gap between the annular yoke and the shaft becomes smaller than before the destruction, and the coupling of the magnetic fluid with the shaft, etc. increases, resulting in an increase in the withstand pressure from the initial state.
以下、本発明の一実施例を第1図及び第2図により説明
する。An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.
第1図は、磁気ディスク装置のスピンドルモータの内部
構造図であり、4個の環状ヨーク11間に3個の環状マ
グネット12を挟んであり、環状ヨーク11上下の2個
の内径が、中央の1個の内径より小さいものから成る、
磁性流体シール本体7がスピンドルモータハブ1の上下
に配されである。第2図に示すように、上下の磁性流体
シール本体7の径は、上側のシャフト9の径が下側より
小さい為、」;側シール本体内径も下側より小さい。FIG. 1 is an internal structural diagram of a spindle motor of a magnetic disk device, in which three annular magnets 12 are sandwiched between four annular yokes 11, and the two inner diameters of the upper and lower annular yokes 11 are centered. Consisting of one piece smaller than the inner diameter,
Magnetic fluid seal bodies 7 are arranged above and below the spindle motor hub 1. As shown in FIG. 2, since the diameter of the upper shaft 9 is smaller than that of the lower side, the inner diameter of the upper and lower magnetic fluid seal bodies 7 is also smaller than that of the lower side.
磁性流体シール本体7はスピンドルモータハブ1に対し
、非磁性体8を介して接着されており。The magnetic fluid seal body 7 is bonded to the spindle motor hub 1 via a non-magnetic material 8.
内径ではシャフト9の外径と磁性流体13を介して磁気
回路を構成している。The inner diameter forms a magnetic circuit via the outer diameter of the shaft 9 and the magnetic fluid 13.
これによって、防塵シールとしての役割を持たせること
が出来る。This allows it to function as a dustproof seal.
ここで、環状ヨーク11と環状マグネット12と磁性流
体13とスピンドルモータシャフト9から成る磁気回路
の初期状態について説明すると、初期状態においては、
4個の環状ヨークのうち中央の2個の環状ヨークllb
に磁性流体を注入して、磁気回路を構成させ防塵機能を
果している。Here, to explain the initial state of the magnetic circuit consisting of the annular yoke 11, annular magnet 12, magnetic fluid 13, and spindle motor shaft 9, in the initial state,
The two central annular yokes of the four annular yokes llb
A magnetic fluid is injected into the core to form a magnetic circuit, which provides a dustproof function.
この状態から、温度変化や圧力変化によって、磁性流体
が初期状態の磁気回路から流出した場合、上下の内径の
小さい環状ヨークllaが流出防護壁となり、スピンド
ルモータハブ外部、内部への流出を防ぐ。In this state, if the magnetic fluid flows out of the magnetic circuit in the initial state due to a temperature change or pressure change, the upper and lower annular yokes lla with small inner diameters act as outflow protection walls to prevent outflow to the outside and inside of the spindle motor hub.
防護壁的環状ヨークの存在は、磁性流体の破裂的流出の
様な最悪の条件下にても、ヨーク内径とシャフト外径の
すきまにて流出磁性流体を捕える動作が意図されており
、以後、捕えた磁性流体と共に、磁気回路を構成する為
のものである。The presence of the annular yoke as a protective wall is intended to trap the outflowing magnetic fluid through the gap between the inner diameter of the yoke and the outer diameter of the shaft, even under the worst conditions such as an explosive outflow of magnetic fluid. It is used to construct a magnetic circuit together with the captured magnetic fluid.
本実施例によれば、従来の磁気回路による防塵動作の他
に、磁性流体シール本体7の最上、最下の径の小さい環
状ヨークllaによって、温度変化や圧力変化等による
磁性流体13の流出防止の動作も可能であり、流出から
派生した磁気ヘッド、磁気ディスクの破損防止にも効果
がある。According to this embodiment, in addition to the dust-proof operation by the conventional magnetic circuit, the annular yoke lla with a small diameter at the top and bottom of the magnetic fluid seal body 7 prevents the magnetic fluid 13 from flowing out due to temperature changes, pressure changes, etc. operation is also possible, and is also effective in preventing damage to magnetic heads and magnetic disks resulting from leakage.
本発明によれば、温度変化、圧力変化による磁性流体の
流出の防止に効果がある。According to the present invention, it is effective to prevent the magnetic fluid from flowing out due to temperature changes and pressure changes.
具体的に言えば、磁性流体シール本体を構成する環状ヨ
ークと環状マグネットと共に磁気回路を構成する磁性流
体、スピンドルモータシャフトにおいて、スピンドルモ
ータ内部、外部に近い環状ヨークの少なくとも1個の内
径を小さくしたことによる初期磁気回路からの磁性流体
のスピンドルモータハブ外部、内部流出防護と、磁性流
体破裂の様な最悪流出で捕えた磁性流体との別磁気回路
端成を行え、この磁気回路は、初期の磁気回路の耐圧よ
りもアップできるという効果もある。Specifically, in the magnetic fluid that constitutes the magnetic circuit together with the annular yoke and annular magnet that constitute the magnetic fluid seal body, and the spindle motor shaft, the inner diameter of at least one of the annular yokes near the inside and outside of the spindle motor is reduced. In order to prevent the magnetic fluid from leaking to the outside and inside of the spindle motor hub from the initial magnetic circuit, and to separate the magnetic fluid caught in the worst case of leakage such as a magnetic fluid rupture, this magnetic circuit is It also has the effect of increasing the withstand voltage of the magnetic circuit.
第1図は、本発明の一実施例を示す構造断面図、第2図
は本発明の詳細を示す磁性流体シール本体断面図である
。
7・・・磁性流体シール本体、 8・・・非磁性体、9
・・・スピンドルモータシャフト、
11a・・・環状ヨーク、llb・・環状ヨーク、12
・・環状マグネッ1へ、13・・・磁性流体。FIG. 1 is a structural sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view of the magnetic fluid seal main body showing details of the present invention. 7... Magnetic fluid seal body, 8... Non-magnetic material, 9
... Spindle motor shaft, 11a... Annular yoke, llb... Annular yoke, 12
...To the annular magnet 1, 13...Magnetic fluid.
Claims (1)
トと環状マグネット、磁性流体等から成るスピンドルモ
ータの防塵機構を有する磁気ディスク装置において、環
状ヨークと環状マグネットの磁気回路のうち、少なくと
も1枚の環状ヨークの内径を小さくすることを特徴とす
る磁気ディスク装置。(1) In a magnetic disk drive having a dustproof mechanism for a spindle motor consisting of a spindle motor hub, a spindle motor shaft, an annular magnet, a magnetic fluid, etc., the inner diameter of at least one annular yoke among the annular yoke and the magnetic circuit of the annular magnet A magnetic disk device characterized by making it smaller.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP23233288A JPH0281364A (en) | 1988-09-19 | 1988-09-19 | Magnetic disk device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP23233288A JPH0281364A (en) | 1988-09-19 | 1988-09-19 | Magnetic disk device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0281364A true JPH0281364A (en) | 1990-03-22 |
Family
ID=16937539
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP23233288A Pending JPH0281364A (en) | 1988-09-19 | 1988-09-19 | Magnetic disk device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0281364A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03203067A (en) * | 1989-12-28 | 1991-09-04 | Nippon Densan Corp | Spindle motor |
US6185067B1 (en) * | 1998-06-17 | 2001-02-06 | Western Digital Corporation | Disk drive with reduced thermal expansion induced disk slip |
-
1988
- 1988-09-19 JP JP23233288A patent/JPH0281364A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03203067A (en) * | 1989-12-28 | 1991-09-04 | Nippon Densan Corp | Spindle motor |
US6185067B1 (en) * | 1998-06-17 | 2001-02-06 | Western Digital Corporation | Disk drive with reduced thermal expansion induced disk slip |
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