JPH0389079A - Magnetic fluid sealing device - Google Patents
Magnetic fluid sealing deviceInfo
- Publication number
- JPH0389079A JPH0389079A JP1226439A JP22643989A JPH0389079A JP H0389079 A JPH0389079 A JP H0389079A JP 1226439 A JP1226439 A JP 1226439A JP 22643989 A JP22643989 A JP 22643989A JP H0389079 A JPH0389079 A JP H0389079A
- Authority
- JP
- Japan
- Prior art keywords
- pole piece
- magnetic fluid
- fluid sealing
- ring
- gap
- 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 title claims abstract description 34
- 238000007789 sealing Methods 0.000 title claims abstract description 28
- 239000012530 fluid Substances 0.000 claims abstract description 18
- 230000002093 peripheral effect Effects 0.000 abstract description 10
- 230000000694 effects Effects 0.000 abstract description 6
- 239000000463 material Substances 0.000 description 3
- 230000004907 flux Effects 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
Landscapes
- Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
- Sealing Of Bearings (AREA)
Abstract
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は磁性流体シール装置に関する。[Detailed description of the invention] [Industrial application field] The present invention relates to a magnetic fluid seal device.
［従来の技術と発明が解決しようとする課Ｈ］従来、小
型精密モータ等に用いられる磁性流体シール装置は、第
４図に示す様に、平板環状磁石ａと、この磁石ａの内外
面に重合状に設けられる平板環状の内外ポールピースｂ
、ｃと、該ポールピースｂ、ｃとシャフトｄとの間隙部
ｅに付着される磁性流体ｒと、を備えている。[Problem H to be solved by the prior art and the invention] Conventionally, a magnetic fluid seal device used for a small precision motor, etc., has a flat annular magnet a and an inner and outer surface of the magnet a, as shown in Fig. 4. Flat annular inner and outer pole pieces b arranged in an overlapping manner
, c, and a magnetic fluid r attached to the gap e between the pole pieces b and c and the shaft d.
従って、磁性流体ｒが、モータ外部へ露出状とされ、し
かも直接的にシャツ）ｄに接触しているので、回転中に
おいて磁性流体ｒが飛散したり、磁性流体に異物が入り
込む虞れがあった。Therefore, since the magnetic fluid (r) is exposed to the outside of the motor and is in direct contact with the shirt (d), there is a risk that the magnetic fluid (r) may scatter or foreign matter may enter the magnetic fluid during rotation. Ta.
そこで、本発明゛では、回転中（高速回転中）において
も磁性流体が飛散せず、静止時においても回転時におい
ても確実にシール性能を発揮することができ、しかも、
磁性流体内へ外部から異物が混入しにくい磁性流体シー
ル装置を提供することを目的とする。Therefore, in the present invention, the magnetic fluid does not scatter even during rotation (during high-speed rotation), and sealing performance can be reliably exhibited both when stationary and when rotating.
It is an object of the present invention to provide a magnetic fluid sealing device that prevents foreign matter from entering the magnetic fluid from the outside.
上述の目的を達成するために、本発明の磁性流体シール
装置は、円筒部とシャフトとの間に介装される磁性流体
シール装置であって；上記シャフトに外嵌状として直接
又は間接的に環状磁石を固着すると共に、内径方向へ開
口する箱形のポールピース部を上記円筒部に固着して、
該ポールピース部にて該環状磁石の外面、外周面、及び
、内面を包囲状とし、かつ、該ポールピース部の磁石対
応平面部の少なくとも一方にリング状突部を設け、該ポ
ールピース部のリング状突部と環状磁石との間の隙間部
に主流体シール層を形成すると共に、該ポールピース部
の外周壁内面と環状磁石との間の隙間部に副流体シール
層を形成したものである。In order to achieve the above object, the magnetic fluid seal device of the present invention is a magnetic fluid seal device interposed between a cylindrical part and a shaft; At the same time as fixing an annular magnet, a box-shaped pole piece part opening in the inner diameter direction is fixed to the cylindrical part,
The pole piece part surrounds the outer surface, outer peripheral surface, and inner surface of the annular magnet, and a ring-shaped protrusion is provided on at least one of the magnet-compatible flat parts of the pole piece part. A main fluid sealing layer is formed in the gap between the ring-shaped protrusion and the annular magnet, and a secondary fluid sealing layer is formed in the gap between the inner surface of the outer peripheral wall of the pole piece part and the annular magnet. be.
ポールピース部と環状磁石とで形成された空隙部では、
リング状突部と環状磁石との間に形成される隙間部に磁
束が集中するので、磁性流体は該隙間部に主として保持
され主流体シール層を形成し、該主流体シール層で保持
しきれない磁性流体は、ポールピース部の外周壁内面と
環状磁石との間に形成される隙間部に保持され副流体シ
ール層を形成する。また、磁性流体は、箱形のポールピ
ース部内に充填されるので、磁外流体は外部には露出状
とならない。In the gap formed by the pole piece and the annular magnet,
Since the magnetic flux is concentrated in the gap formed between the ring-shaped protrusion and the annular magnet, the magnetic fluid is mainly retained in the gap and forms a main fluid sealing layer, and the magnetic fluid is not completely retained by the main fluid sealing layer. The remaining magnetic fluid is held in the gap formed between the inner surface of the outer circumferential wall of the pole piece portion and the annular magnet, and forms a sub-fluid seal layer. Further, since the magnetic fluid is filled in the box-shaped pole piece portion, the extramagnetic fluid is not exposed to the outside.
以下、実施例について図面を参照して説明する。 Examples will be described below with reference to the drawings.
第２図は本発明に係る磁性流体シール装置１を使用した
スピンドルモータを示し、このモータは、図示省略の磁
気ディスクを取付けるハブ（円筒部２）がシャフト３の
廻りに回転するものであって、該シャフト３はフランジ
型ブラケント４に立設され、該シャフト３に一対の軸受
５．５を介して円筒部２が回転自在に枢支されている。FIG. 2 shows a spindle motor using the magnetic fluid seal device 1 according to the present invention, in which a hub (cylindrical portion 2) to which a magnetic disk (not shown) is attached rotates around a shaft 3. The shaft 3 is erected on a flange type bracket 4, and the cylindrical portion 2 is rotatably supported on the shaft 3 via a pair of bearings 5.5.
また、シャフト３にはステータ６が外嵌固定され、円筒
部２内周面には、ヨーク７を介してロータマグネット８
が固着されている。Further, a stator 6 is externally fitted and fixed to the shaft 3, and a rotor magnet 8 is attached to the inner peripheral surface of the cylindrical portion 2 via a yoke 7.
is fixed.
しかして、磁性流体シール装置１は、第１図に示す様に
、円筒部２とシャフト３との間に介装され、環状磁石９
と、該磁石９の外面９ａ、外周面９ｂ及び内面９ｃを包
囲状とする箱形のポールピース部１０と、該環状磁石９
とポールピース部１０の間の空隙部に充填される磁性流
体１３と、を備えている。As shown in FIG.
, a box-shaped pole piece portion 10 surrounding the outer surface 9a, outer peripheral surface 9b, and inner surface 9c of the magnet 9; and the annular magnet 9.
and a magnetic fluid 13 filled in the gap between the pole piece part 10 and the pole piece part 10.
環状磁石９はシャフト３に外嵌固着されるへ一ス材１４
に固定されている。つまり、ベース材１４外周中央部に
周溝１５を形成し、該周溝１５に環状磁石９の内周縁部
を嵌合させている。また、磁石９外周而９ｂにはリング
状の保護林１６が付着されている。The annular magnet 9 has a heel member 14 that is externally fitted and fixed to the shaft 3.
is fixed. That is, a circumferential groove 15 is formed in the center of the outer circumference of the base material 14, and the inner circumferential edge of the annular magnet 9 is fitted into the circumferential groove 15. Further, a ring-shaped protected forest 16 is attached to the outer periphery 9b of the magnet 9.
次に、ポールピース部１０とは、横断商略り字状の磁性
材からなる一対のリング体１７．１８からなり、該リン
グ体１７．１８が開側の如く組み合わされて内径方向へ
開口する箱形とされている。Next, the pole piece part 10 is composed of a pair of ring bodies 17 and 18 made of magnetic material in the shape of a transversal abbreviation, and the ring bodies 17 and 18 are combined so as to open in the inner diameter direction. It is said to be box-shaped.
そして、ポールピース部ＩＯの磁石対応平面部１９゜２
０には、リング状突部２１・・・が設けられ、該突部２
１と環状磁石９との間に隙間部２２が形成される。And the magnet corresponding flat part 19°2 of the pole piece part IO
0 is provided with a ring-shaped protrusion 21..., and the protrusion 2
A gap 22 is formed between the annular magnet 1 and the annular magnet 9.
また、ポールピース部ｌＯと環状磁石９とで形成された
空隙部では、リング状突部２１と環状磁石９との間の隙
間部２２に磁束が集中するので、磁性流体１３は該隙間
部２２に保持され、主流体シール層２９を形成する。In addition, in the gap formed by the pole piece lO and the annular magnet 9, the magnetic flux concentrates in the gap 22 between the ring-shaped protrusion 21 and the annular magnet 9, so the magnetic fluid 13 flows into the gap 22. The main fluid sealing layer 29 is formed.
しかして、充填される磁性流体１３は、隙間部２２・・
・の許容容量より多く充填され、隙間部２２で保持しき
れない磁性流体１３を発生させておく。Therefore, the magnetic fluid 13 to be filled is filled in the gap 22...
The magnetic fluid 13 is filled in an amount larger than the allowable capacity of the magnetic fluid 13 and cannot be held in the gap 22.
従って、余った磁性流体１３が第１図と第２図に示す様
に、ポールピース部１０の外周壁内面２３と環状６４３
石９との間の隙間部３０に副流体ソール層２４を形成す
る。つまり、この副流体シール層２４にて、該内面２３
と環状磁石９の外周面９ｂ（具体的には、保護林１６の
外周面）との間をシールする。また、回転中においても
磁性流体１３は外周壁内面２３近傍に溜まるので、外部
へ漏れることがない。Therefore, as shown in FIG. 1 and FIG.
A sub-fluid sole layer 24 is formed in the gap 30 between the stone 9 and the stone 9. In other words, in this sub-fluid seal layer 24, the inner surface 23
and the outer peripheral surface 9b of the annular magnet 9 (specifically, the outer peripheral surface of the protected forest 16). Further, even during rotation, the magnetic fluid 13 remains near the inner surface 23 of the outer circumferential wall, so that it does not leak to the outside.
次に、第３図は他の実施例を示し、この場合、環状磁石
９は直接的にシャフト３に固定され、また、ポールピー
ス部ｌＯは一つ部材から構成されている。Next, FIG. 3 shows another embodiment, in which the annular magnet 9 is directly fixed to the shaft 3, and the pole piece portion IO is composed of one member.
即ち、この場合のポールピース部ｌＯは、リング状の内
外壁２５．２６と、内外壁２５．２６の外周縁を連結す
る外周壁２７と、からなり、内外壁２５．２６の磁石対
応平面部１９．２０にリング状突部２１・・・が形成さ
れている。That is, the pole piece portion lO in this case is composed of ring-shaped inner and outer walls 25.26 and an outer circumferential wall 27 that connects the outer peripheral edges of the inner and outer walls 25.26, and the magnet-compatible flat portion of the inner and outer walls 25.26. A ring-shaped protrusion 21... is formed at 19.20.
しかして、この場合も一ヒ述の場合と同様、余った磁性
流体が回倒の如く外周壁内面２３近傍に溜まり、副流体
シール層２４を形成し、高性能のシール機能を発揮する
。In this case as well, as in the case described above, the excess magnetic fluid accumulates near the inner surface 23 of the outer circumferential wall, forming a sub-fluid sealing layer 24 and exhibiting a high-performance sealing function.
なお、本発明は上述の実施例に限定されず、本発明の要
旨を逸脱しない範囲で設計変更自由であり、例えば、保
護材１６を省略し、それに代えて環状磁石９を所定寸法
に延長してもよく、また、保護林１６の材質としては、
非磁性体であってもよい。Note that the present invention is not limited to the above-described embodiments, and the design may be changed without departing from the gist of the present invention. For example, the protective material 16 may be omitted and the annular magnet 9 may be extended to a predetermined dimension instead. Also, the materials of the protected forest 16 are:
It may be a non-magnetic material.
さらに、リング状突部２１としては、ポールピース部１
０の磁石対応平面部１９．２０のうちどちらか一方のみ
に形成するも、その数を増減させるも自由である。Furthermore, as the ring-shaped protrusion 21, the pole piece portion 1
It is free to form it on only one of the magnet corresponding flat parts 19 and 20 of 0, or to increase or decrease the number thereof.
（発明の効果〕
本発明は上述の如く構成されているので、次に記載する
効果を奏する。(Effects of the Invention) Since the present invention is configured as described above, it produces the following effects.
磁性流体１３は箱形のポールピース部１０内部に充填さ
れるので、該磁性流体１３は外部に露出状とならず、磁
性流体１３内へ外部から異物がｌ昆人してシール性能を
低下させることがなく、また、回転中においても、磁性
流体１３はモーフ外部へ飛散することがないので、ディ
スク室等の汚染を有効に防止出来る。さらに、主流体シ
ール層２９及び副流体シール層２４にてシールされるの
で、より高性能のシール効果を発揮することができるの
で、この磁性流体シール装置によれば、モータ静止時、
及びモータ回転時のどちらの場合にも優れたシール効果
を発揮する。Since the magnetic fluid 13 is filled inside the box-shaped pole piece portion 10, the magnetic fluid 13 is not exposed to the outside, and foreign matter enters the magnetic fluid 13 from the outside and deteriorates the sealing performance. Moreover, since the magnetic fluid 13 does not scatter to the outside of the morph even during rotation, contamination of the disk chamber etc. can be effectively prevented. Furthermore, since the main fluid sealing layer 29 and the subfluid sealing layer 24 provide sealing, a higher sealing effect can be achieved. According to this magnetic fluid sealing device, when the motor is stationary,
Excellent sealing effect is exhibited both when the motor is rotating and when the motor is rotating.
第１図は本発明の一実施例を示す拡大断面図、第２図は
本発明に係る（ｉ性流体シール装置を使用したモーフの
断面図、第３図は他の実施例の拡大断面図である。第４
図は従来例の拡大断面図である。
２・・・円筒部、３・・・シャフト、９・・・環状磁石
、９ａ・・・外面、９ｂ・・・外周面、９ｃ・・・内面
、ＩＯ・・・ポールピース部、１３・・・磁性流体、１
９．２０・・・磁石対応平面部、２１・・・リング状突
部、２２．３０・・・隙間部、２４・・・副流体シール
層、２９・・・主流体シール層。
第１
図
第２図
第３図
第４図FIG. 1 is an enlarged cross-sectional view showing one embodiment of the present invention, FIG. 2 is a cross-sectional view of a morph using an i-fluid seal device according to the present invention, and FIG. 3 is an enlarged cross-sectional view of another embodiment. 4th
The figure is an enlarged sectional view of a conventional example. 2... Cylindrical part, 3... Shaft, 9... Annular magnet, 9a... Outer surface, 9b... Outer peripheral surface, 9c... Inner surface, IO... Pole piece part, 13...・Magnetic fluid, 1
9.20... Magnet compatible flat part, 21... Ring-shaped protrusion, 22.30... Gap part, 24... Secondary fluid seal layer, 29... Main fluid seal layer. Figure 1 Figure 2 Figure 3 Figure 4
Claims (1)
シール装置であって、 上記シャフト３に外嵌状として直接又は間接的に環状磁
石９を固着すると共に、内径方向へ開口する箱形のポー
ルピース部１０を上記円筒部２に固着して、該ポールピ
ース部１０にて該環状磁石９の外面９ａ、外周面９ｂ、
及び、内面９ｃを包囲状とし、かつ、該ポールピース部
１０の磁石対応平面部１９、２０の少なくとも一方にリ
ング状突部２１・・・を設け、該ポールピース部１０の
リング状突部２１と環状磁石９との間の隙間部２２に主
流体シール層２９を形成すると共に、該ポールピース部
１０の外周壁内面２３と環状磁石９との間の隙間部３０
に副流体シール層２４を形成したことを特徴とする磁性
流体シール装置。[Claims] 1. A magnetic fluid sealing device interposed between the cylindrical portion 2 and the shaft 3, which fixes an annular magnet 9 directly or indirectly to the shaft 3 in an externally fitted manner, and , a box-shaped pole piece part 10 that opens in the inner radial direction is fixed to the cylindrical part 2, and the outer surface 9a, the outer circumferential surface 9b,
And, the inner surface 9c is made into an encircling shape, and a ring-shaped protrusion 21 is provided on at least one of the magnet-compatible flat parts 19 and 20 of the pole piece part 10, and the ring-shaped protrusion 21 of the pole piece part 10 A main fluid sealing layer 29 is formed in the gap 22 between the annular magnet 9 and the gap 30 between the outer circumferential wall inner surface 23 of the pole piece part 10 and the annular magnet 9.
A magnetic fluid sealing device characterized in that a subfluid sealing layer 24 is formed in the magnetic fluid sealing device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1226439A JPH0389079A (en) | 1989-08-31 | 1989-08-31 | Magnetic fluid sealing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1226439A JPH0389079A (en) | 1989-08-31 | 1989-08-31 | Magnetic fluid sealing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0389079A true JPH0389079A (en) | 1991-04-15 |
Family
ID=16845130
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1226439A Pending JPH0389079A (en) | 1989-08-31 | 1989-08-31 | Magnetic fluid sealing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0389079A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5659445A (en) * | 1993-12-14 | 1997-08-19 | Hitachi, Ltd. | Recording disk apparatus and rotational supporting structure therefor having improved lubrication arrangement |
| US5973878A (en) * | 1993-12-14 | 1999-10-26 | Hitachi, Ltd. | Recording disk apparatus and rotational supporting structure therefor, having a magnetic lubricant seal which is inclined |
-
1989
- 1989-08-31 JP JP1226439A patent/JPH0389079A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5659445A (en) * | 1993-12-14 | 1997-08-19 | Hitachi, Ltd. | Recording disk apparatus and rotational supporting structure therefor having improved lubrication arrangement |
| US5973878A (en) * | 1993-12-14 | 1999-10-26 | Hitachi, Ltd. | Recording disk apparatus and rotational supporting structure therefor, having a magnetic lubricant seal which is inclined |
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