JPH06178489A - Spindle motor - Google Patents
Spindle motorInfo
- Publication number
- JPH06178489A JPH06178489A JP4350425A JP35042592A JPH06178489A JP H06178489 A JPH06178489 A JP H06178489A JP 4350425 A JP4350425 A JP 4350425A JP 35042592 A JP35042592 A JP 35042592A JP H06178489 A JPH06178489 A JP H06178489A
- Authority
- JP
- Japan
- Prior art keywords
- groove
- axial
- annular
- dynamic pressure
- pressure bearing
- 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.)
- Granted
Links
- 230000002093 peripheral effect Effects 0.000 claims abstract description 52
- 239000000314 lubricant Substances 0.000 claims abstract description 37
- 238000006073 displacement reaction Methods 0.000 abstract description 10
- 230000000694 effects Effects 0.000 description 3
- 239000005871 repellent Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000011109 contamination Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000002940 repellent Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
Landscapes
- Sliding-Contact Bearings (AREA)
- Motor Or Generator Frames (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、軸体に対しスリーブ体
が、潤滑剤を介して自在に相対回転し得るように外嵌さ
れたスピンドルモータに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor in which a sleeve body is externally fitted to a shaft body so as to freely rotate relative to the shaft body through a lubricant.
【０００２】[0002]
【従来の技術及び解決しようとする課題】パーソナルコ
ンピュータ等の機器の一層の小形化、高容量化により、
それらに組み込まれる記録媒体（例えばハードディス
ク）駆動用のスピンドルモータについても、一層の小形
化、高精度化が要請されている。そしてそれに伴い、ス
ピンドルモータの軸受についても一層の小形化、高精度
化が要求されている。2. Description of the Related Art Due to further miniaturization and higher capacity of devices such as personal computers,
Further miniaturization and higher precision are also required for spindle motors for driving recording media (for example, hard disks) incorporated therein. Along with this, further miniaturization and higher precision are required for the bearings of the spindle motor.
【０００３】従来、スピンドルモータに用いる軸受とし
ては、玉軸受が多く採用されている。ところが、スピン
ドルモータの小形化、特に小外径化が進行すると、それ
に見合う小外径の玉軸受を用いたのでは、モータ組立時
に内外輪の変形が生じ易いこと等により、十分な回転精
度を実現することが実際上困難なものとなりがちであ
る。また騒音や振動の問題も起こり易い。Conventionally, ball bearings have been widely used as bearings used in spindle motors. However, as miniaturization of spindle motors, especially smaller outer diameters progresses, ball bearings with smaller outer diameters that match the smaller spindle motors may be used, which may cause deformation of the inner and outer rings during motor assembly. It tends to be practically difficult to achieve. Also, noise and vibration problems are likely to occur.
【０００４】記録媒体駆動用のスピンドルモータの場
合、小外径化に伴い高速回転が要求されるので、これら
の問題が一層助長される。さらに、外径の大小にかかわ
らず、玉軸受の精度には限界があり、要求仕様を満足し
ない場合が考えられる。In the case of a spindle motor for driving a recording medium, high speed rotation is required as the outer diameter becomes smaller, so these problems are further aggravated. Furthermore, regardless of the size of the outer diameter, there is a limit to the accuracy of the ball bearing, and it may be possible that the required specifications are not satisfied.
【０００５】そのため、主として小形のスピンドルモー
タとして、ロータハブ部の基部の内周側に回転スリーブ
部を有し、その回転スリーブ部が固定支柱部に外嵌され
て回転自在に支持されることにより動圧ラジアル軸受が
構成されているスピンドルモータが提案されている。Therefore, as a small-sized spindle motor, a rotary sleeve portion is provided on the inner peripheral side of the base portion of the rotor hub portion, and the rotary sleeve portion is externally fitted to the fixed column portion and rotatably supported to move. A spindle motor having a pressure radial bearing has been proposed.
【０００６】ところが、回転駆動される記録媒体面上に
磁気ヘッド等をミクロン或はサブミクロンオーダで浮上
させて読み／書きを行うためのスピンドルモータの場合
などにおいては、ロータの軸線方向の変位も十分に小さ
く抑えられなければならず、また、軸受の潤滑剤が飛散
して記録媒体面等を汚損するおそれが効果的に防がれな
ければならない。However, in the case of a spindle motor for reading / writing by flying a magnetic head or the like on the surface of a recording medium that is rotationally driven in the order of microns or submicrons, the axial displacement of the rotor also occurs. It must be kept sufficiently small, and the lubricant of the bearing must be effectively prevented from scattering and contaminating the surface of the recording medium.
【０００７】本発明は、従来技術に存した上記のような
問題点に鑑み行われたものであって、その目的とすると
ころは、軸体とスリーブ体の相対回転中における径方向
変位及び軸線方向変位を、動圧軸受部によりそれぞれ十
分に小さく抑えることができると共に、潤滑剤が漏出し
てモータ外部の空間を汚染することが、モータの小形化
を損なわずに効果的に防止され得るスピンドルモータを
提供することにある。The present invention has been made in view of the above-mentioned problems existing in the prior art, and its object is to provide a radial displacement and an axial line during relative rotation of the shaft body and the sleeve body. The directional displacement can be sufficiently suppressed by the dynamic pressure bearing portions, and the leakage of the lubricant and the contamination of the space outside the motor can be effectively prevented without impairing the downsizing of the motor. To provide a motor.
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するため
に、本発明のスピンドルモータは、略円筒面形状外周部
と、径方向外方に張り出し、軸線方向の両環状面が前記
略円筒面形状外周部に対し垂直状をなす環状突部とを有
してなる軸体と、略円筒面形状外周部に外嵌された略円
筒面形状内周部と、環状突部に嵌合し、軸線方向の両環
状面が前記環状突部の両環状面と平行状をなす径方向内
方開口の環状凹部とを有するスリーブ体とを備えてな
り、軸体に対しスリーブ体が、潤滑剤を介して自在に相
対回転し得るように外嵌されたスピンドルモータであっ
て、略円筒面形状外周部に有するラジアル受部と略円筒
面形状内周部に有するラジアル滑部とによりラジアル動
圧軸受部が構成され、環状突部の両環状面にそれぞれ有
するアキシャル受部と環状凹部の両環状面にそれぞれ有
するアキシャル滑部とにより、それぞれアキシャル動圧
軸受部が構成され、軸体とスリーブ体との間隙のうちモ
ータ外部とアキシャル動圧軸受部またはラジアル動圧軸
受部との間の部分において、軸体の全周に亙って設けら
れた周方向の第１凹溝とスリーブ体の全周に亙って設け
られた周方向の第２凹溝とが、任意の横断面で、両凹溝
の両端縁の位置がそれぞれ食い違った状態で向かい合っ
たものとしている。In order to achieve the above object, the spindle motor of the present invention has a substantially cylindrical surface-shaped outer peripheral portion and a radially outward projecting portion, and both annular surfaces in the axial direction have the substantially cylindrical surface. A shaft body having an annular protrusion that is perpendicular to the outer peripheral portion, a substantially cylindrical inner peripheral portion that is externally fitted to the outer peripheral portion of the substantially cylindrical surface, and the annular protruding portion, A sleeve body having both annular surfaces in the axial direction and an annular recess having a radially inward opening that is parallel to both annular surfaces of the annular projection, and the sleeve body with respect to the shaft body is provided with a lubricant. A spindle motor externally fitted so as to be able to freely rotate relative to each other, the radial dynamic pressure bearing having a radial receiving portion provided in an outer peripheral portion of a substantially cylindrical surface shape and a radial sliding portion provided in an inner peripheral portion of the substantially cylindrical surface shape. And the axial receiving portions that are respectively formed on both annular surfaces of the annular protrusion. An axial dynamic pressure bearing portion is configured by the axial sliding portions that are respectively provided on both annular surfaces of the annular concave portion, and the outside of the motor and the axial dynamic pressure bearing portion or the radial dynamic pressure bearing portion in the gap between the shaft body and the sleeve body. In the portion between, the first groove in the circumferential direction provided over the entire circumference of the shaft body and the second groove in the circumferential direction provided over the entire circumference of the sleeve body are arbitrary. In the cross section, it is assumed that the positions of both edges of the biconcave groove are opposite to each other.
【０００９】[0009]
【作用】軸体の略円筒面形状外周部に有するラジアル受
部とスリーブ体の略円筒面形状内周部に有するラジアル
滑部とにより構成されるラジアル動圧軸受部によって、
軸体とスリーブ体の相対回転中における径方向変位が規
制され、軸体における環状突部の両環状面に有するアキ
シャル受部とスリーブ体における環状凹部の両環状面に
有するアキシャル滑部とによりそれぞれ構成される両ア
キシャル動圧軸受部によって、軸体とスリーブ体の相対
回転中における軸線方向変位が規制される。With the radial dynamic pressure bearing portion constituted by the radial receiving portion provided on the outer peripheral portion of the substantially cylindrical surface of the shaft body and the radial sliding portion provided on the inner peripheral portion of the substantially cylindrical surface shape of the sleeve body,
The radial displacement of the shaft body and the sleeve body during relative rotation is restricted, and the axial receiving portions on both annular surfaces of the annular projection of the shaft body and the axial sliding portions on both annular surfaces of the annular recess of the sleeve body respectively respectively. The axial displacement of the shaft body and the sleeve body in the axial direction during relative rotation is restricted by the constituted both axial dynamic pressure bearing portions.
【００１０】アキシャル動圧軸受部またはラジアル動圧
軸受部における潤滑剤は、軸体とスリーブ体との間隙を
毛管現象等によりモータ外部側へ流動しようとする。軸
体とスリーブ体との間隙のうちモータ外部とアキシャル
動圧軸受部またはラジアル動圧軸受部との間の部分に、
周方向の第１凹溝と周方向の第２凹溝がそれぞれ全周に
亙って設けられており、両凹溝は、任意の横断面で、両
凹溝の両端縁の位置がそれぞれ食い違った状態で向かい
合っている。The lubricant in the axial dynamic pressure bearing portion or the radial dynamic pressure bearing portion tends to flow to the outside of the motor through the gap between the shaft body and the sleeve body due to a capillary phenomenon or the like. In the gap between the shaft body and the sleeve body between the outside of the motor and the axial dynamic pressure bearing portion or the radial dynamic pressure bearing portion,
A circumferential first groove and a circumferential second groove are respectively provided over the entire circumference. The both grooves have arbitrary cross sections, and the positions of both end edges of the both grooves are different from each other. Are facing each other.
【００１１】そのため、アキシャル動圧軸受部またはラ
ジアル動圧軸受部の側から流動してきた潤滑剤の流動
は、最初に軸体とスリーブ体との間隙が広がる位置にお
いて、すなわち一方の凹溝における最初の端縁と他方の
凹溝における最初の端縁との間で、その潤滑剤の表面張
力により阻止され、これが１段目のシールとして作用す
る。この１段目のシールが損なわれて前記一方の凹溝内
に潤滑剤が充満するに至った場合、前記他方の凹溝にお
ける最初の端縁と前記他方の凹溝における他の端縁との
間で、その潤滑剤の表面張力により阻止され、これが２
段目のシールとして作用する。Therefore, the flow of the lubricant flowing from the side of the axial dynamic pressure bearing portion or the radial dynamic pressure bearing portion is first at a position where the gap between the shaft body and the sleeve body widens, that is, at the first in one of the concave grooves. Between the edge of the groove and the first edge of the other groove is blocked by the surface tension of the lubricant, which acts as a first stage seal. When the seal in the first step is damaged and the one groove is filled with the lubricant, the first edge of the other groove and the other edge of the other groove are separated from each other. In between, the surface tension of the lubricant prevents it from
Acts as a stage seal.
【００１２】[0012]
【実施例】本発明の実施例を、図面を参照しつつ説明す
る。図１乃至図６は、本発明の１実施例としての軸固定
形のスピンドルモータについてのものであって、図１は
その半断面図である。Embodiments of the present invention will be described with reference to the drawings. 1 to 6 relate to a fixed shaft type spindle motor as one embodiment of the present invention, and FIG. 1 is a half sectional view thereof.
【００１３】第１ブッシュ１０の中央部に設けられた嵌
合孔１２に、円柱状の固定支柱１４の下端部が嵌合固定
された状態で、その固定支柱１４が第１ブッシュ１０に
対し垂設されている。第１ブッシュ１０における嵌合孔
１２の外周部には、上方に突起した環状突部１６が設け
られており、その環状突部１６の外周部に、ステータコ
イル１８が捲回されたステータコア１９が固定されてい
る。With the lower end of the columnar fixed column 14 fitted and fixed in the fitting hole 12 provided in the central portion of the first bush 10, the fixed column 14 is suspended from the first bush 10. It is set up. An annular protrusion 16 protruding upward is provided on an outer peripheral portion of the fitting hole 12 in the first bush 10, and a stator core 19 having a stator coil 18 wound around the outer peripheral portion of the annular protrusion 16 is provided. It is fixed.
【００１４】固定支柱１４の上部には、環状板状のスラ
スト板２６が外嵌固定されている。更に、固定支柱１４
の上端部には、略円筒状の第２ブッシュ３０が外嵌固定
されている。第２ブッシュ３０の下面はスラスト板２６
の上面のやや上方に位置する。スラスト板２６の上下面
は、固定支柱１４の円筒面形状の外周面１４ｃに対し垂
直状をなす。この実施例では、これらの固定支柱１４、
スラスト板２６及び第２ブッシュ３０が、軸体を構成し
ている。An annular plate-shaped thrust plate 26 is externally fitted and fixed to the upper portion of the fixed column 14. Furthermore, the fixed support 14
A substantially cylindrical second bush 30 is externally fitted and fixed to the upper end of the. The lower surface of the second bush 30 is the thrust plate 26.
Located slightly above the upper surface of. The upper and lower surfaces of the thrust plate 26 are perpendicular to the cylindrical outer peripheral surface 14c of the fixed column 14. In this embodiment, these fixed columns 14,
The thrust plate 26 and the second bush 30 form a shaft body.
【００１５】図２は、スリーブ部材及びロータハブの断
面図である。スリーブ部材３８は、内周面３８ａ１が略
円筒面形状をなす小径のスリーブ部３８ａと、そのスリ
ーブ部３８ａの上端部において径方向外方及び上方に張
り出した環状部３８ｂと、環状部３８ｂの外周部から上
方に延びた上方突部３８ｃからなる。スリーブ部３８ａ
は固定支柱１４に外嵌され、上方突部３８ｃには、スリ
ーブ部３８ａの上端面との間にスラスト板２６を挟んだ
状態で、第２ブッシュ３０との間に僅かな径方向空隙を
隔てて環状の第３ブッシュ４０が内嵌固定されている。
従って、スリーブ部材３８と第３ブッシュ４０とにより
径方向内方開口の環状凹部４３が形成され、その環状凹
部４３内にスラスト板２６の外周側が嵌合している。こ
の実施例では、これらのスリーブ部材３８と第３ブッシ
ュ４０により構成されるスリーブ体が、液状の潤滑剤
（図１では記載を省略している。）を介して前記軸体に
対し自在に回転し得るものとなっている。FIG. 2 is a sectional view of the sleeve member and the rotor hub. The sleeve member 38 includes a small-diameter sleeve portion 38a having an inner peripheral surface 38a1 having a substantially cylindrical surface shape, an annular portion 38b projecting radially outward and upward at an upper end portion of the sleeve portion 38a, and an outer periphery of the annular portion 38b. The upper projection 38c extends upward from the section. Sleeve part 38a
Is externally fitted to the fixed column 14, and a slight radial gap is formed between the upper protrusion 38c and the second bush 30 with the thrust plate 26 sandwiched between the upper protrusion 38c and the upper end surface of the sleeve 38a. The annular third bush 40 is internally fitted and fixed.
Therefore, the sleeve member 38 and the third bush 40 form an annular recess 43 having an inward opening in the radial direction, and the outer peripheral side of the thrust plate 26 is fitted in the annular recess 43. In this embodiment, the sleeve body constituted by the sleeve member 38 and the third bush 40 is freely rotated with respect to the shaft body through a liquid lubricant (not shown in FIG. 1). It is possible.
【００１６】図３及び図４は、第２ブッシュ３０と第３
ブッシュ４０とに亙る要部拡大断面図である。第２ブッ
シュ３０の外周部には、径方向外方へ開口する断面半円
形状の周方向の第１凹溝４１が、全周に亙って設けら
れ、第３ブッシュ４０の内周部には、径方向内方へ開口
する断面半円形状の周方向の第２凹溝４２が、全周に亙
って設けられている。任意の横断面において、第１凹溝
４１の下端縁の軸線方向位置は、第２凹溝４２のほぼ中
央部であり、第２凹溝４２の上端縁の軸線方向位置は、
第１凹溝４１のほぼ中央部であって、両凹溝４１・４２
の両端縁の位置がそれぞれ食い違った状態で向かい合っ
ている。3 and 4 show the second bush 30 and the third bush 30.
FIG. 7 is an enlarged cross-sectional view of a main part of the bush 40. On the outer peripheral portion of the second bush 30, a first concave groove 41 having a semicircular cross-section that opens radially outward is provided over the entire circumference, and on the inner peripheral portion of the third bush 40. Is provided with a second circumferential groove 42 having a semicircular cross section and opening inward in the radial direction over the entire circumference. In an arbitrary cross section, the axial position of the lower end edge of the first concave groove 41 is substantially the center of the second concave groove 42, and the axial position of the upper end edge of the second concave groove 42 is
At the substantially central portion of the first recessed groove 41, both recessed grooves 41, 42
The two edges of the two are facing each other in different positions.
【００１７】スリーブ部３８ａの内周面３８ａ１（ラジ
アル滑部）と、固定支柱１４の外周面１４ｃのうち内周
面３８ａ１に相対する部分（ラジアル受部）とによりラ
ジアル動圧軸受部Ｒ１が構成されている。スリーブ部３
８ａの内周面３８ａ１のうち上端部と下端部の全周に亙
って、スリーブ部材３８の順方向回転（図における上か
ら見て反時計回り）によりスリーブ部３８ａと固定支柱
１４の外周面１４ｃとの間に介在する潤滑剤に高圧を発
生させるヘリングボーン溝４６が設けられている。な
お、このようなヘリングボーン溝は、固定支柱１４の外
周面１４ｃに設けてもよい。またヘリングボーン溝以外
の溝を採用することも可能である。A radial dynamic pressure bearing portion R1 is constituted by an inner peripheral surface 38a1 (radial sliding portion) of the sleeve portion 38a and a portion (radial receiving portion) of the outer peripheral surface 14c of the fixed strut 14 facing the inner peripheral surface 38a1. Has been done. Sleeve part 3
Outer peripheral surfaces of the sleeve portion 38a and the fixed support column 14 by the forward rotation (counterclockwise when viewed from above in the figure) of the sleeve member 38 over the entire circumference of the upper end portion and the lower end portion of the inner peripheral surface 38a1 of 8a. A herringbone groove 46 for generating a high pressure is provided in the lubricant interposed with 14c. In addition, such a herringbone groove may be provided on the outer peripheral surface 14 c of the fixed column 14. It is also possible to adopt a groove other than the herringbone groove.
【００１８】スリーブ部３８ａの下部外周面は、環状突
部１６の内周面と若干の径方向間隙を隔てて相対してお
り、スリーブ部３８ａの上部は、拡径され、その外周面
は、ステータコア１９の内周面と若干の径方向間隙を隔
てて相対している。そして、スリーブ部３８ａと、それ
に相対する第１ブッシュ１０及びステータコア１９とに
より、ラビリンスシール状の効果が得られ、ラジアル動
圧軸受部Ｒ１からの潤滑剤がモータ外部へ飛散すること
が防止される。The lower outer peripheral surface of the sleeve portion 38a is opposed to the inner peripheral surface of the annular projection 16 with a slight radial gap, and the upper portion of the sleeve portion 38a is expanded in diameter and its outer peripheral surface is It faces the inner peripheral surface of the stator core 19 with a slight radial gap. The sleeve portion 38a and the first bush 10 and the stator core 19 facing the sleeve portion 38a provide a labyrinth seal-like effect and prevent the lubricant from the radial dynamic pressure bearing portion R1 from scattering to the outside of the motor. .
【００１９】図５はスラスト板２６の正面図、図６は、
その平面図である。スラスト板２６の上下環状面（アキ
シャル受部）と環状凹部４３の上下環状面（アキシャル
滑部）とにより、それぞれアキシャル動圧軸受部Ａ１・
Ａ２が構成されている。スラスト板２６の上下環状面と
環状凹部４３の上下環状面はそれぞれ平行状に相対し、
それらの間は、それぞれ例えば１２μｍ程度の僅かな軸
線方向ギャップを隔てている。スラスト板２６の上下環
状面のうち外周側における全周に亙って、スリーブ部材
３８及び第３ブッシュ４０の順方向回転により環状凹部
４３の上下環状面との間に介在する潤滑剤に高圧を発生
させるヘリングボーン状溝４８・５０が設けられてい
る。なお、このようなヘリングボーン状溝は、環状凹部
４３の上下環状面に設けてもよい。またスパイラル溝以
外の溝を採用することも可能である。FIG. 5 is a front view of the thrust plate 26, and FIG. 6 is
It is the top view. By the upper and lower annular surfaces (axial receiving portions) of the thrust plate 26 and the upper and lower annular surfaces (axial sliding portions) of the annular recess 43, respectively, the axial dynamic pressure bearing portion A1.
A2 is configured. The upper and lower annular surfaces of the thrust plate 26 and the upper and lower annular surfaces of the annular recess 43 respectively face each other in parallel,
Each of them is separated by a slight axial gap of, for example, about 12 μm. The forward rotation of the sleeve member 38 and the third bush 40 applies a high pressure to the lubricant present between the upper and lower annular surfaces of the annular recess 43 over the entire circumference of the upper and lower annular surfaces of the thrust plate 26. The herringbone-shaped grooves 48 and 50 to be generated are provided. The herringbone-shaped groove may be provided on the upper and lower annular surfaces of the annular recess 43. It is also possible to adopt a groove other than the spiral groove.
【００２０】環状部３８ｂの上面部には、上方開口の環
状溝部５２（この実施例では、断面略Ｖ字形状としてい
る。）が設けられている。この環状溝部５２の内表面
は、用いられる潤滑剤との接触角が鈍角となるように、
所謂撥油処理が施されている。An annular groove portion 52 (having a substantially V-shaped cross section in this embodiment) having an upper opening is provided on the upper surface of the annular portion 38b. The inner surface of the annular groove 52 has an obtuse contact angle with the lubricant used,
So-called oil repellent treatment is applied.
【００２１】ロータハブ５６は、全体として筒状をな
し、周壁部５６ａの上端部内方に基部５６ｂが位置し、
周壁部５６ｂの下端外方に外方張出部５６ｃが位置す
る。このロータハブ５６は、基部５６ｂにおいてスリー
ブ部材３８の上方突部３８ｃ及び環状部３８ｂに外嵌固
定されることにより、スリーブ部材３８と同軸状をなし
ている。勿論、ロータハブ５６とスリーブ部材３８が一
体に形成されたものであっても差し支えない。周壁部５
６ａの内周部には、円筒状のロータマグネット５８を内
嵌保持した円筒状のロータヨーク６０が内嵌固定され、
ステータコア１９と径方向間隙を隔てて相対している。
基部５６ｂには、周壁部５６ａに外嵌されたハードディ
スク等の記録媒体を外方張出部５６ｃとの間に挟圧保持
するためのクランパ（図示を略す。）を螺子止するため
の螺子孔６２が形成されている。The rotor hub 56 has a tubular shape as a whole, and the base portion 56b is located inside the upper end portion of the peripheral wall portion 56a.
The outward projecting portion 56c is located outside the lower end of the peripheral wall portion 56b. The rotor hub 56 is coaxial with the sleeve member 38 by being externally fitted and fixed to the upper protrusion 38c and the annular portion 38b of the sleeve member 38 at the base portion 56b. Of course, the rotor hub 56 and the sleeve member 38 may be integrally formed. Peripheral wall part 5
A cylindrical rotor yoke 60 in which a cylindrical rotor magnet 58 is fitted and held is internally fixed to the inner peripheral portion of 6a,
It is opposed to the stator core 19 with a radial gap.
A screw hole for screwing a clamper (not shown) for pinching and holding a recording medium such as a hard disk externally fitted on the peripheral wall portion 56a between the base portion 56b and the outward projecting portion 56c. 62 is formed.
【００２２】スリーブ部３８ａの上部が拡径され、強度
が高められているので、例えば図２に示されるような状
態で、チャック６３によりその拡径部分を比較的強く保
持することができる。このように保持した状態で、ロー
タハブ５６における周壁部５６ｂの外周面、外方張出部
５６ｃの上面及びスリーブ部３８ａの内周面の加工、並
びにスリーブ部３８ａの内周面にヘリングボーン溝４６
等の溝を設ける加工（サイジング）を、チャック６３に
よる保持位置を変更することなく連続的に行い得る。Since the diameter of the upper portion of the sleeve portion 38a is expanded and the strength thereof is increased, the expanded diameter portion can be held relatively strongly by the chuck 63 in the state shown in FIG. 2, for example. In this state of holding, the outer peripheral surface of the peripheral wall portion 56b of the rotor hub 56, the upper surface of the outwardly projecting portion 56c and the inner peripheral surface of the sleeve portion 38a are machined, and the herringbone groove 46 is formed on the inner peripheral surface of the sleeve portion 38a.
Processing (sizing) of providing grooves such as can be continuously performed without changing the holding position by the chuck 63.
【００２３】ロータハブ５６の下端内周部には、第４ブ
ッシュ６４が内嵌固定されており、第１ブッシュ１０の
外周部に外嵌固定された第５ブッシュ６６と、径方向空
隙を隔てて相対している。A fourth bush 64 is fitted and fixed to the inner peripheral portion of the lower end of the rotor hub 56, and is separated from a fifth bush 66 which is fitted and fixed to the outer peripheral portion of the first bush 10 by a radial gap. It is opposite.
【００２４】ラジアル動圧軸受部Ｒ１によって、スリー
ブ部材３８の回転中における固定支柱１４に対する径方
向変位を十分に小さく抑えることができ、アキシャル動
圧軸受部Ａ１・Ａ２によって、スリーブ部材３８の回転
中における固定支柱１４に対する軸線方向変位を十分に
小さく抑えることができる。The radial dynamic pressure bearing portion R1 can sufficiently reduce the radial displacement of the sleeve member 38 with respect to the fixed column 14 during rotation, and the axial dynamic pressure bearing portions A1 and A2 enable the sleeve member 38 to rotate. The axial displacement with respect to the fixed column 14 can be suppressed sufficiently small.
【００２５】アキシャル動圧軸受部Ａ１における潤滑剤
６８は、第２ブッシュ３０と第３ブッシュ４０との間
隙、すなわち軸体とスリーブ体との間隙を、毛管現象等
により上方、すなわちモータ外部側へ流動しようとす
る。アキシャル動圧軸受部Ａ１の側から流動してきた潤
滑剤６８の流動は、図３に示されるように、最初に第２
ブッシュ３０と第３ブッシュ４０との間隙が広がる位置
において、すなわち第２凹溝４２における下端縁と第１
凹溝４１における下端縁との間で、その潤滑剤６８の表
面張力により阻止され、これが１段目のシールとして作
用する。この１段目のシールが損なわれて第２凹溝４２
内に潤滑剤６８が充満するに至った場合、第１凹溝４１
における下端縁と第２凹溝４２における上端縁との間
で、その潤滑剤６８の表面張力により阻止され、これが
２段目のシールとして作用する。The lubricant 68 in the axial dynamic pressure bearing portion A1 causes the gap between the second bush 30 and the third bush 40, that is, the gap between the shaft body and the sleeve body to move upward due to a capillary phenomenon or the like, that is, toward the outside of the motor. Trying to flow. The flow of the lubricant 68 that has flowed from the side of the axial dynamic pressure bearing portion A1 is, as shown in FIG.
At the position where the gap between the bush 30 and the third bush 40 widens, that is, the lower edge of the second groove 42 and the first
Between the lower edge of the groove 41 and the lower edge, the surface tension of the lubricant 68 prevents the lubricant from acting as a first-stage seal. The seal of the first stage is damaged and the second groove 42
When the inside of the lubricant 68 is filled, the first groove 41
The surface tension of the lubricant 68 prevents the gap between the lower end edge of the second concave groove 42 and the upper end edge of the second concave groove 42, which acts as a second-stage seal.
【００２６】上下間隔を隔てて２段にシールを設けるよ
りも小さい所要長さでもって２段のシールとして機能さ
せることができるので、モータを小形化しつつモータ外
部空間への潤滑剤６８の飛散を効果的に防止することが
できる。また第１凹溝と第２凹溝により、比較的大きな
潤滑剤貯留容量が得られるので、温度変化による潤滑剤
６８の体積膨張等に対する対応力も比較的大きい。この
実施例では、第１凹溝４１及び第２凹溝４２の断面形状
を半円形状（湾曲状）としているので、断面方形状の場
合に比し、凹溝形成加工が容易であり、シール効果も優
れる。Since it is possible to function as a two-stage seal with a required length smaller than that in which two-stage seals are provided with a vertical gap therebetween, it is possible to reduce the size of the motor and prevent the lubricant 68 from scattering into the space outside the motor. It can be effectively prevented. Further, since the first groove and the second groove can obtain a relatively large lubricant storage capacity, the ability to cope with volume expansion of the lubricant 68 due to temperature change is relatively large. In this embodiment, since the cross-sectional shapes of the first concave groove 41 and the second concave groove 42 are semicircular (curved), the concave groove forming process is easier and the sealing is easier than in the case of the rectangular sectional shape. The effect is also excellent.
【００２７】また、環状部３８ｂの上面部に、内表面に
撥油処理が施された環状溝部５２が設けられているの
で、環状部３８ｂ及び上方突部３８ｃと第３ブッシュ４
０との間から滲出しようとする潤滑剤６８は、環状溝部
５２内に、接触角が鈍角の状態で効果的に保持され、モ
ータ外部への滲出が防止される。Further, since the annular groove portion 52 whose inner surface is oil-repellent is provided on the upper surface of the annular portion 38b, the annular portion 38b, the upper protrusion 38c and the third bush 4 are provided.
The lubricant 68, which tends to ooze out from between 0 and 0, is effectively held in the annular groove portion 52 with the contact angle being an obtuse angle, and oozing out to the outside of the motor is prevented.
【００２８】図７は、別の実施例についての要部拡大断
面図である。この実施例では、第２ブッシュ３０ｍの外
周部に、径方向外方へ開口する断面方形状の周方向の第
１凹溝４１ｍが、全周に亙って設けられ、第３ブッシュ
４０ｍの内周部には、径方向内方へ開口する断面方形状
の周方向の第２凹溝４２ｍが、全周に亙って設けられて
いる。任意の横断面において、第１凹溝４１ｍの下端縁
の軸線方向位置は、第２凹溝４２ｍの下端縁のやや上方
であり、第１凹溝４１ｍの上端縁の軸線方向位置は、第
２凹溝４２ｍの上端縁のやや下方であって、両凹溝４１
ｍ・４２ｍの両端縁の位置がそれぞれ食い違った状態で
向かい合っている。また第３ブッシュ４０ｍの内周部の
うち第２凹溝４２ｍの下方には、順方向回転により潤滑
剤６８ｍが下方へ流れるように、スパイラル溝等の溝部
７０が設けられている。FIG. 7 is an enlarged cross-sectional view of the essential parts of another embodiment. In this embodiment, a first recessed groove 41m having a rectangular cross-section that opens radially outward is provided on the outer peripheral portion of the second bush 30m over the entire circumference, and the first recessed groove 41m is provided inside the third bush 40m. In the peripheral portion, a second concave groove 42m having a rectangular cross section and opening inward in the radial direction is provided over the entire circumference. In an arbitrary cross section, the axial position of the lower edge of the first groove 41m is slightly above the lower edge of the second groove 42m, and the axial position of the upper edge of the first groove 41m is the second axial position. Slightly below the upper edge of the concave groove 42m,
The positions of both edges of m and 42m are facing each other with their positions being different from each other. Further, a groove portion 70 such as a spiral groove is provided below the second concave groove 42m in the inner peripheral portion of the third bush 40m so that the lubricant 68m flows downward by forward rotation.
【００２９】第２ブッシュ３０と第３ブッシュ４０との
間隙を、上方へ流動する潤滑剤６８ｍは、実線で示され
るように、第２凹溝４２ｍにおける下端縁と第１凹溝４
１ｍにおける下端縁との間で、その潤滑剤６８ｍの表面
張力により阻止され、これが１段目のシールとして作用
する。この１段目のシールが損なわれて第２凹溝４２ｍ
内に潤滑剤６８ｍが充満するに至った場合、２点鎖線で
示されるように、第１凹溝４１ｍにおける下端縁と第２
凹溝４２ｍにおける上端縁との間で、その潤滑剤６８ｍ
の表面張力により阻止され、これが２段目のシールとし
て作用する。また、モータの順方向回転時には、溝部７
０により潤滑剤６８ｍが下方へ流れようとするので、潤
滑剤６８ｍの上方漏出、すなわちモータ外部への漏出が
より効果的に防止される。The lubricant 68m that flows upward in the gap between the second bush 30 and the third bush 40 has a lower end edge of the second groove 42m and the first groove 4 as shown by the solid line.
It is blocked by the surface tension of the lubricant 68m between itself and the lower edge at 1m, and this acts as a first-stage seal. This first-stage seal is damaged and the second groove 42m
When the inside of the lubricant is filled with the lubricant 68m, as shown by a chain double-dashed line, the lower edge of the first groove 41m and the second groove 41m
Between the upper edge of the groove 42m and the lubricant 68m
It is blocked by the surface tension of the, and this acts as a second-stage seal. Further, when the motor rotates in the forward direction, the groove 7
Since the lubricant 68m tends to flow downward due to 0, the lubricant 68m is more effectively prevented from leaking upward, that is, leaking to the outside of the motor.
【００３０】なお、以上の各実施例についての記述にお
ける上下位置関係は、単に図に基づいた説明の便宜のた
めのものであって、実際の使用状態等を限定するもので
はない。The vertical positional relationship in the above description of each embodiment is merely for convenience of description based on the drawings, and does not limit the actual use state or the like.
【００３１】[0031]
【発明の効果】本発明のスピンドルモータでは、ラジア
ル動圧軸受部及び両アキシャル動圧軸受部によって、軸
体とスリーブ体の相対回転中における径方向変位及び軸
線方向変位をそれぞれ十分に小さく抑えることが可能で
ある。而も、両凹溝の両端縁の位置がそれぞれ食い違っ
た状態で第１凹溝と第２凹溝が向かい合っていることに
より、２段にシールを設けるよりも小さい所要長さでも
って２段のシールとして機能させることができるので、
モータを小形化しつつモータ外部空間への潤滑剤の飛散
を効果的に防止し、動圧軸受部の潤滑が損なわれてその
寿命が短くなることを防止する効果もある。また第１凹
溝と第２凹溝により、比較的大きな潤滑剤貯留容量が得
られるので、温度変化による潤滑剤の体積膨張等に対す
る対応力も比較的大きい。In the spindle motor of the present invention, the radial dynamic pressure bearing portion and the both axial dynamic pressure bearing portions can sufficiently suppress radial displacement and axial displacement during relative rotation of the shaft body and the sleeve body. Is possible. In addition, since the first groove and the second groove are opposed to each other in a state in which the positions of both edges of the both grooves are different from each other, the two steps have a required length smaller than that of the seal provided in two steps. Since it can function as a seal,
It also has an effect of effectively preventing the lubricant from scattering to the outer space of the motor while reducing the size of the motor, and preventing the lubrication of the dynamic pressure bearing portion from being impaired and shortening its life. Further, since the first groove and the second groove provide a relatively large lubricant storage capacity, the ability to cope with the volume expansion of the lubricant due to temperature changes is relatively large.
【図１】スピンドルモータの半断面図である。FIG. 1 is a half sectional view of a spindle motor.
【図２】スリーブ部材及びロータハブの断面図である。FIG. 2 is a sectional view of a sleeve member and a rotor hub.
【図３】第２ブッシュと第３ブッシュとに亙る要部拡大
断面図である。FIG. 3 is an enlarged cross-sectional view of a main part of a second bush and a third bush.
【図４】第２ブッシュと第３ブッシュとに亙る要部拡大
断面図である。FIG. 4 is an enlarged cross-sectional view of a main part of a second bush and a third bush.
【図５】スラスト板の正面図である。FIG. 5 is a front view of a thrust plate.
【図６】スラスト板の平面図である。FIG. 6 is a plan view of a thrust plate.
【図７】別のスピンドルモータについての要部拡大断面
図である。FIG. 7 is an enlarged cross-sectional view of a main part of another spindle motor.
１４ 固定支柱 １４ｃ 外周面 ２６ スラスト板 ３０ 第２ブッシュ ３８ａ スリーブ部 ３８ａ１ 内周面 ４０ 第３ブッシュ ４１ 第１凹溝 ４２ 第２凹溝４２ ６８ 潤滑剤 Ａ１ アキシャル動圧軸受部 Ａ２ アキシャル動圧軸受部 Ｒ１ ラジアル動圧軸受部 14 fixed column 14c outer peripheral surface 26 thrust plate 30 second bush 38a sleeve portion 38a1 inner peripheral surface 40 third bush 41 first concave groove 42 second concave groove 42 68 lubricant A1 axial dynamic pressure bearing portion A2 axial dynamic pressure bearing portion R1 radial dynamic pressure bearing
Claims (1)
出し、軸線方向の両環状面が前記略円筒面形状外周部に
対し垂直状をなす環状突部とを有してなる軸体と、 略円筒面形状外周部に外嵌された略円筒面形状内周部
と、環状突部に嵌合し、軸線方向の両環状面が前記環状
突部の両環状面と平行状をなす径方向内方開口の環状凹
部とを有するスリーブ体とを備えてなり、 軸体に対しスリーブ体が、潤滑剤を介して自在に相対回
転し得るように外嵌されたスピンドルモータであって、 略円筒面形状外周部に有するラジアル受部と略円筒面形
状内周部に有するラジアル滑部とによりラジアル動圧軸
受部が構成され、 環状突部の両環状面にそれぞれ有するアキシャル受部と
環状凹部の両環状面にそれぞれ有するアキシャル滑部と
により、それぞれアキシャル動圧軸受部が構成され、 軸体とスリーブ体との間隙のうちモータ外部とアキシャ
ル動圧軸受部またはラジアル動圧軸受部との間の部分に
おいて、軸体の全周に亙って設けられた周方向の第１凹
溝とスリーブ体の全周に亙って設けられた周方向の第２
凹溝とが、任意の横断面で、両凹溝の両端縁の位置がそ
れぞれ食い違った状態で向かい合っていることを特徴と
するスピンドルモータ。1. A shaft having a substantially cylindrical surface-shaped outer peripheral portion and an annular projection projecting outward in the radial direction and having both axial annular surfaces perpendicular to the substantially cylindrical surface-shaped outer peripheral portion. The body, the inner peripheral portion of the substantially cylindrical surface externally fitted to the outer peripheral portion of the substantially cylindrical surface, and the annular projection are fitted to each other so that both annular surfaces in the axial direction are parallel to both annular surfaces of the annular projection. And a sleeve body having an annular recess with a radially inward opening formed therein, wherein the sleeve body is externally fitted to the shaft body so as to be freely rotatable relative to each other via a lubricant. The radial dynamic pressure bearing portion is constituted by the radial receiving portion provided on the outer peripheral portion of the substantially cylindrical surface shape and the radial sliding portion provided on the inner peripheral portion of the substantially cylindrical surface shape, and the axial receiving portions provided on both annular surfaces of the annular protrusion, respectively. With the axial slides that are provided on both annular surfaces of the annular recess, respectively The axial dynamic pressure bearing part is configured, and is provided over the entire circumference of the shaft body in the part between the outside of the motor and the axial dynamic pressure bearing part or the radial dynamic pressure bearing part in the gap between the shaft body and the sleeve body. The first groove in the circumferential direction and the second groove in the circumferential direction provided over the entire circumference of the sleeve body.
A spindle motor characterized in that the groove and the groove are opposed to each other in an arbitrary cross section, with the positions of both edges of the groove being different from each other.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35042592A JP3145820B2 (en) | 1992-12-02 | 1992-12-02 | Spindle motor |
| US08/122,194 US5457588A (en) | 1992-09-22 | 1993-09-15 | Low profile hydrodynamic motor having minimum leakage properties |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP35042592A JP3145820B2 (en) | 1992-12-02 | 1992-12-02 | Spindle motor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06178489A true JPH06178489A (en) | 1994-06-24 |
| JP3145820B2 JP3145820B2 (en) | 2001-03-12 |
Family
ID=18410410
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP35042592A Expired - Fee Related JP3145820B2 (en) | 1992-09-22 | 1992-12-02 | Spindle motor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3145820B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20010010896A (en) * | 1999-07-23 | 2001-02-15 | 이형도 | Motor |
| US6219199B1 (en) | 1997-09-12 | 2001-04-17 | Matsushita Electric Industrial Co., Ltd. | Spindle device having a dynamic-pressure-fluid bearing |
-
1992
- 1992-12-02 JP JP35042592A patent/JP3145820B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6219199B1 (en) | 1997-09-12 | 2001-04-17 | Matsushita Electric Industrial Co., Ltd. | Spindle device having a dynamic-pressure-fluid bearing |
| US6301074B2 (en) | 1997-09-12 | 2001-10-09 | Matsushita Electric Industrial Co. Ltd. | Spindle device having a dynamic-pressure-fluid bearing |
| US6404586B2 (en) | 1997-09-12 | 2002-06-11 | Matsushita Electric Industrial Co., Ltd. | Spindle device having a dynamic-pressure-fluid bearing |
| KR20010010896A (en) * | 1999-07-23 | 2001-02-15 | 이형도 | Motor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3145820B2 (en) | 2001-03-12 |
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