JP2003049828A - Fluid dynamic pressure bearing and spindle motor - Google Patents
Fluid dynamic pressure bearing and spindle motorInfo
- Publication number
- JP2003049828A JP2003049828A JP2001237366A JP2001237366A JP2003049828A JP 2003049828 A JP2003049828 A JP 2003049828A JP 2001237366 A JP2001237366 A JP 2001237366A JP 2001237366 A JP2001237366 A JP 2001237366A JP 2003049828 A JP2003049828 A JP 2003049828A
- Authority
- JP
- Japan
- Prior art keywords
- thrust
- dynamic pressure
- groove
- bearing
- fluid dynamic
- 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
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C17/00—Sliding-contact bearings for exclusively rotary movement
- F16C17/04—Sliding-contact bearings for exclusively rotary movement for axial load only
- F16C17/045—Sliding-contact bearings for exclusively rotary movement for axial load only with grooves in the bearing surface to generate hydrodynamic pressure, e.g. spiral groove thrust bearings
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- Motor Or Generator Frames (AREA)
- Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
- Permanent Magnet Type Synchronous Machine (AREA)
- Sliding-Contact Bearings (AREA)
- Brushless Motors (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、スラストリング部
と円柱部とを有するフランジ付シャフトと、小径円筒部
と大径円筒部と円筒状開放端部が順に形成された片袋状
段付スリーブと、前記スリーブの円筒状開放端部に圧入
固定される押えリングと、これら軸受構成部材間に形成
されたスラスト隙間を含む微小隙間に封入された潤滑油
とから構成された流体動圧軸受、及びこの流体動圧軸受
を備えたスピンドルモータに関し、特に流体動圧軸受の
スラスト動圧発生溝の構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flanged shaft having a thrust ring portion and a cylindrical portion, a single bag-shaped stepped sleeve in which a small diameter cylindrical portion, a large diameter cylindrical portion and a cylindrical open end are formed in order. A fluid dynamic bearing comprising: a pressing ring press-fitted and fixed to the cylindrical open end of the sleeve; and lubricating oil enclosed in a minute gap including a thrust gap formed between these bearing components, The present invention also relates to a spindle motor provided with this fluid dynamic pressure bearing, and particularly to the structure of a thrust dynamic pressure generating groove of the fluid dynamic pressure bearing.
【０００２】[0002]
【従来の技術】特開２００１−３２８２８号公報には、
スラストリング部と円柱部とを有するフランジ付シャフ
トと、小径円筒部と大径円筒部と円筒状開放端部が順に
形成された片袋状段付スリーブと、前記スリーブの円筒
状開放端部に圧入固定される押えリングと、これら軸受
構成部材間に形成されたスラスト隙間を含む微小隙間に
封入された潤滑油とから構成された流体動圧軸受におい
て、前記スラスト隙間を形成する静止面と回転面のいず
れか一方に設けられたスラスト動圧発生溝は、その溝深
さが前記スラスト隙間を流れる潤滑油の流速が遅い側か
ら速い側に向かって漸次深くなるように形成されている
ことを特徴とする流体動圧軸受、及びこの流体動圧軸受
を備えたスピンドルモータが開示されている。2. Description of the Related Art Japanese Patent Laid-Open No. 2001-32828 discloses
A flanged shaft having a thrust ring portion and a cylindrical portion, a single bag shaped stepped sleeve in which a small diameter cylindrical portion, a large diameter cylindrical portion and a cylindrical open end are formed in order, and a cylindrical open end of the sleeve. In a fluid dynamic bearing composed of a press ring that is press-fitted and fixed, and lubricating oil enclosed in a minute gap including a thrust gap formed between these bearing constituent members, rotation and a stationary surface that forms the thrust gap The thrust dynamic pressure generating groove provided on either one of the surfaces is formed such that the groove depth becomes gradually deeper from the slower speed side to the faster speed side of the lubricating oil flowing through the thrust gap. A characteristic fluid dynamic bearing and a spindle motor provided with the fluid dynamic bearing are disclosed.
【０００３】このような構造のスラスト動圧発生溝を採
用したスラスト動圧軸受部において、シャフトとスリー
ブとの間に保持されている圧力発生流体である潤滑油
は、両軸受構成部材の相対回転運動によりスラスト動圧
発生溝内に引き込まれる。このスラスト動圧発生溝のパ
ターンは、スパイラル、ヘリングボーン等の任意のパタ
ーンである。In the thrust dynamic pressure bearing portion which employs the thrust dynamic pressure generating groove having such a structure, the lubricating oil, which is the pressure generating fluid held between the shaft and the sleeve, is the relative rotation of both bearing constituent members. It is drawn into the thrust dynamic pressure generation groove by the motion. The pattern of the thrust dynamic pressure generating groove is an arbitrary pattern such as spiral or herringbone.
【０００４】潤滑油は、そのパターンに従う流線によっ
てスラスト動圧発生溝内を流れるが、スラスト動圧発生
溝の溝深さは流線にそって入口から奥に行くに従って浅
くなるため、全体としてスラスト隙間における動圧は高
くなる。要するに、上述の構造のスラスト動圧発生溝を
採用した流体動圧軸受は、溝深さが流線に沿って変化し
ない流体動圧軸受に比べて、より高いスラスト動圧を効
率良く発生させることができる。このスラスト動圧軸受
部のスラスト動圧の圧力パターンは、図５に示す如くで
ある。Lubricating oil flows in the thrust dynamic pressure generating grooves by the streamlines according to the pattern, but the groove depth of the thrust dynamic pressure generating grooves becomes shallower from the inlet to the back along the streamlines, so that as a whole. The dynamic pressure in the thrust gap becomes high. In short, the fluid dynamic bearing that employs the thrust dynamic pressure generating groove with the above-mentioned structure can generate a higher thrust dynamic pressure more efficiently than a fluid dynamic bearing whose groove depth does not change along the streamline. You can The pressure pattern of the thrust dynamic pressure of the thrust dynamic pressure bearing portion is as shown in FIG.
【０００５】ところが、図５に示す如く、上述の構造の
スラスト動圧軸受部では潤滑油をスラスト動圧発生溝に
急激に引き込むために、その潤滑油の入口付近が負圧と
なってしまい、その場所に泡が発生する。するとスラス
ト隙間を高速で流れる潤滑油が途切れるという事態が発
生し、スラスト動圧が不安定となってＮＲＲＯ等の振れ
を大きくするという好ましくない事態が生じる。そし
て、最悪の場合には、シャフトがスリーブにかじりつい
て、回転が停止してしまうこともある。However, as shown in FIG. 5, in the thrust dynamic pressure bearing portion having the above-mentioned structure, the lubricating oil is drastically drawn into the thrust dynamic pressure generating groove, so that a negative pressure is generated near the inlet of the lubricating oil. Bubbles are generated at that place. Then, a situation occurs in which the lubricating oil that flows through the thrust gap at high speed is interrupted, and the thrust dynamic pressure becomes unstable, which causes an undesirable situation in which the NRRO or the like is greatly shaken. In the worst case, the shaft may bite the sleeve and the rotation may stop.
【０００６】また、溝深さを一定に保って形成されたス
ラスト動圧発生溝であっても、そのフランジ径方向の圧
力は負圧になる。即ち、スラスト動圧発生溝の溝深さを
５μm〜２０μmの範囲で変化させて、最大圧力とフラン
ジ径方向圧力をシュミレーションしてみると、図７に示
す如く、最大圧力は１００ｋＰａ〜１４０ｋＰａの範囲
で変化し、フランジ径方向圧力は−３０ｋＰａ〜−４０
ｋＰａの範囲で変化している。いずれの溝深さにおいて
も、フランジ径方向圧力は負の圧力である。Further, even in the thrust dynamic pressure generating groove formed by keeping the groove depth constant, the pressure in the radial direction of the flange becomes a negative pressure. That is, when the maximum depth and the pressure in the radial direction of the flange are simulated by changing the groove depth of the thrust dynamic pressure generating groove in the range of 5 μm to 20 μm, the maximum pressure is in the range of 100 kPa to 140 kPa, as shown in FIG. The pressure in the radial direction of the flange changes from -30 kPa to -40
It changes within the range of kPa. The flange radial pressure is a negative pressure at any groove depth.
【０００７】図１のスピンドルモータの流体動圧軸受を
構成するフランジ付シャフト１のスラストリング３の上
下面に、その溝深さが前記スラスト隙間を流れる潤滑油
の流速が遅い側から速い側に向かって漸次深くなるよう
なスパイラルパターンのスラスト動圧発生溝を設けた場
合、上記負圧はスラストリング３の外周面と段付スリー
ブ４の大径円筒部の内周面との間の微小隙間に発生す
る。また、ヘリングボーンパターンのスラスト動圧発生
溝を設けた場合、上記負圧はスラストリング３の外周面
と段付スリーブ４の大径円筒部の内周面との間の微小隙
間と、スラストリング３の上下面のシャフト側付近に発
生する。The upper and lower surfaces of the thrust ring 3 of the flanged shaft 1 constituting the fluid dynamic pressure bearing of the spindle motor shown in FIG. 1 have groove depths from the slow side to the fast side of the flow velocity of the lubricating oil flowing through the thrust gap. When a thrust dynamic pressure generating groove having a spiral pattern that gradually becomes deeper toward the outside is provided, the negative pressure causes a small gap between the outer peripheral surface of the thrust ring 3 and the inner peripheral surface of the large diameter cylindrical portion of the stepped sleeve 4. Occurs in. In addition, when the thrust dynamic pressure generating groove having a herringbone pattern is provided, the negative pressure causes a minute gap between the outer peripheral surface of the thrust ring 3 and the inner peripheral surface of the large-diameter cylindrical portion of the stepped sleeve 4, and the thrust ring. It occurs near the shaft side of the upper and lower surfaces of No. 3.
【０００８】また、図１のスピンドルモータの流体動圧
軸受を構成するフランジ付シャフト１のスラストリング
３の上下面に、その溝深さが一定に保たれたスラスト動
圧発生溝が設けられた場合も、上述と同様に負圧が発生
する。A thrust dynamic pressure generating groove having a constant groove depth is provided on the upper and lower surfaces of the thrust ring 3 of the flanged shaft 1 which constitutes the fluid dynamic pressure bearing of the spindle motor shown in FIG. Also in this case, negative pressure is generated as described above.
【０００９】このような負圧を低く押えるためには、ス
ラストリング３に貫通孔を設ける等の対策が考えられる
が、このような対策はコストが高く実用的ではない。In order to suppress such negative pressure to a low level, measures such as providing a through hole in the thrust ring 3 may be considered, but such measures are costly and not practical.
【００１０】[0010]
【発明が解決しようとする課題】解決しようとする課題
は、スラストリング部と円柱部とを有するフランジ付シ
ャフトと、小径円筒部と大径円筒部と円筒状開放端部が
順に形成された片袋状段付スリーブと、前記スリーブの
円筒状開放端部に圧入固定される押えリングと、これら
軸受構成部材間に形成されたスラスト隙間を含む微小隙
間に封入された潤滑油とから構成された流体動圧軸受に
おいて、高いスラスト動圧を効率よく発生させると共
に、スラスト動圧発生溝の潤滑油の入口付近が負圧にな
らないようにすることである。The problem to be solved is to provide a flanged shaft having a thrust ring portion and a cylindrical portion, a small-diameter cylindrical portion, a large-diameter cylindrical portion, and a cylindrical open end formed in this order. It is composed of a bag-like stepped sleeve, a pressing ring press-fitted and fixed to the cylindrical open end of the sleeve, and lubricating oil enclosed in a minute gap including a thrust gap formed between these bearing constituent members. In a fluid dynamic pressure bearing, it is possible to efficiently generate a high thrust dynamic pressure and prevent negative pressure in the vicinity of the lubricating oil inlet of the thrust dynamic pressure generating groove.
【００１１】[0011]
【課題を解決するための手段】上記課題を解決するため
に、スラストリング部と円柱部とを有するフランジ付シ
ャフトと、小径円筒部と大径円筒部と円筒状開放端部が
順に形成された片袋状段付スリーブと、前記スリーブの
円筒状開放端部に圧入固定される押えリングと、これら
軸受構成部材間に形成されたスラスト隙間を含む微小隙
間に封入された潤滑油とから構成された流体動圧軸受に
おいて、前記スラスト隙間を形成する静止面と回転面の
いずれか一方に設けられたスパイラルパターンのスラス
ト動圧発生溝を、その溝深さが前記スラスト隙間を流れ
る潤滑油の流速が遅い側から速い側に向かって漸次深く
なるように形成した。In order to solve the above problems, a flanged shaft having a thrust ring portion and a cylindrical portion, a small diameter cylindrical portion, a large diameter cylindrical portion and a cylindrical open end portion are formed in order. It is composed of a one-bag stepped sleeve, a pressing ring press-fitted and fixed to the cylindrical open end of the sleeve, and lubricating oil sealed in a minute gap including a thrust gap formed between these bearing constituent members. In the fluid dynamic pressure bearing, the spiral dynamic pressure generating groove having a spiral pattern provided on one of the stationary surface and the rotating surface forming the thrust gap has a groove depth whose flow velocity of the lubricating oil flowing through the thrust gap. Was formed so that it gradually deepened from the slow side to the fast side.
【００１２】上記課題を解決するために、スラストリン
グ部と円柱部とを有するフランジ付シャフトと、小径円
筒部と大径円筒部と円筒状開放端部が順に形成された片
袋状段付スリーブと、前記スリーブの円筒状開放端部に
圧入固定される押えリングと、これら軸受構成部材間に
形成されたスラスト隙間を含む微小隙間に封入された潤
滑油とから構成された流体動圧軸受において、前記スラ
スト隙間を形成する静止面と回転面のいずれか一方に設
けられたヘリングボーンパターンのスラスト動圧発生溝
を、その溝深さがパターンの折り返し点より内周面側で
浅く、且つ外周側で深くなるように形成した。In order to solve the above-mentioned problems, a flanged shaft having a thrust ring portion and a cylindrical portion, a single bag-shaped stepped sleeve in which a small diameter cylindrical portion, a large diameter cylindrical portion and a cylindrical open end are formed in order. In a fluid dynamic pressure bearing comprising a pressing ring press-fitted and fixed to the cylindrical open end of the sleeve, and lubricating oil enclosed in a minute gap including a thrust gap formed between these bearing constituent members. , A thrust dynamic pressure generating groove of a herringbone pattern provided on one of the stationary surface and the rotating surface forming the thrust gap, the groove depth of which is shallower on the inner peripheral surface side than the turning point of the pattern, and on the outer peripheral surface. It was formed to be deep on the side.
【００１３】そして、最も浅い溝と最も深い溝の溝深さ
の比率は、０．６〜０．７の範囲で選定した。The ratio of the depth of the shallowest groove to the depth of the deepest groove was selected in the range of 0.6 to 0.7.
【００１４】[0014]
【発明の実施の形態】図１は、スラスト隙間とラジアル
隙間を含む微小隙間,及びスラスト動圧発生溝Ｇ２を誇
張して示した本発明の第１実施形態のスピンドルモータ
の断面図である。1 is a sectional view of a spindle motor according to a first embodiment of the present invention in which a minute gap including a thrust gap and a radial gap and a thrust dynamic pressure generating groove G2 are exaggeratedly shown.
【００１５】図１に示すスピンドルモータにおいて、ロ
ータは円筒状スカート部６ａとボス部６ｂを有するカッ
プ状ハブ６と、円筒状スカート部６ａの内周面に取りつ
けられたロータマグネット７を含む。また、ステータは
ベース基板９と、このベース基板９に立設された流体動
圧軸受のスリーブ４の外周面に取りつけられたステータ
コイル８を含む。In the spindle motor shown in FIG. 1, the rotor includes a cup-shaped hub 6 having a cylindrical skirt portion 6a and a boss portion 6b, and a rotor magnet 7 attached to the inner peripheral surface of the cylindrical skirt portion 6a. Further, the stator includes a base substrate 9 and a stator coil 8 attached to the outer peripheral surface of the sleeve 4 of the fluid dynamic bearing standing on the base substrate 9.
【００１６】前記ロータを前記ステータに回転自在に支
持する流体動圧軸受は、スラストリング３と円柱部２を
有するフランジ付シャフト１と、円筒状開放端部を有す
る片袋状段付スリーブ４と、片袋状段付スリーブ４の円
筒状開放端部に圧入固定される押えリング５とを主要構
成部材とするものである。A fluid dynamic bearing for rotatably supporting the rotor on the stator includes a shaft 1 with a flange having a thrust ring 3 and a cylindrical portion 2, and a stepped sleeve 4 having a cylindrical open end. The pressing ring 5 which is press-fitted and fixed to the cylindrical open end of the one-bag stepped sleeve 4 is a main constituent member.
【００１７】片袋状段付スリーブ４は、その閉塞端部側
に小径円筒部が形成され、且つ円筒状開放端部と前記小
径円筒部との間には大径円筒部が形成されている。片袋
状段付スリーブ４にフランジ付シャフト１を挿入する
と、小径円筒部の内周面にはフランジ付シャフト１の円
柱部２の下側の外周面が対向し、これらの面によってラ
ジアル隙間が形成される。ヘリングボーン溝の如きラジ
アル動圧発生溝Ｇ１は、フランジ付シャフト１の円柱部
２の下側の外周面に設けられている。The single-bag stepped sleeve 4 has a small diameter cylindrical portion formed on the closed end side thereof, and a large diameter cylindrical portion is formed between the cylindrical open end portion and the small diameter cylindrical portion. . When the flanged shaft 1 is inserted into the single-bag stepped sleeve 4, the lower outer peripheral surface of the cylindrical portion 2 of the flanged shaft 1 faces the inner peripheral surface of the small diameter cylindrical portion, and these surfaces form a radial gap. It is formed. A radial dynamic pressure generating groove G1 such as a herringbone groove is provided on the outer peripheral surface of the flanged shaft 1 below the cylindrical portion 2.
【００１８】片袋状段付スリーブ４にフランジ付シャフ
ト１を挿入し、更に片袋状段付スリーブ４の円筒状開放
端部に押えリング５を圧入固定すると、フランジ付シャ
フト１のスラストリング３の上面と押えリング５の下面
が対向し、これらの面によって第１スラスト隙間が形成
される。また、スラストリングの下面と前記大径円筒部
と前記小径円筒部の境界面である段部の表面は対向し、
これらの面によって第２スラスト隙間を形成している。
スラスト動圧発生溝Ｇ２は、回転面であるスラストリン
グ３の上下の表面に設けられている。The flanged shaft 1 is inserted into the one-bag shaped stepped sleeve 4, and the pressing ring 5 is press-fitted and fixed to the cylindrical open end of the one-bag shaped stepped sleeve 4 to form the thrust ring 3 of the flanged shaft 1. And the lower surface of the pressing ring 5 face each other, and these surfaces form a first thrust gap. The lower surface of the thrust ring, the surface of the step portion which is the boundary surface of the large-diameter cylindrical portion and the small-diameter cylindrical portion face each other,
These surfaces form the second thrust gap.
The thrust dynamic pressure generating groove G2 is provided on the upper and lower surfaces of the thrust ring 3 which is a rotating surface.
【００１９】そして、フランジ付シャフト１、片袋状段
付スリーブ４、押えリング５の主要な軸受構成部材間に
形成されたラジアル隙間と第１スラスト隙間と第２スラ
スト隙間を含む微小隙間、及び押えリングの内周面とカ
ップ状ハブ６のボス部６ｂの外周面の間に形成された微
小隙間には潤滑油が封入されている。Then, a small gap including the radial gap, the first thrust gap and the second thrust gap formed between the main bearing constituent members of the shaft with flange 1, the stepped sleeve 4 in the shape of a bag and the pressing ring 5, and Lubricating oil is filled in a minute gap formed between the inner peripheral surface of the pressing ring and the outer peripheral surface of the boss portion 6b of the cup-shaped hub 6.
【００２０】スラストリング３の上面と下面に、切削や
エッチングによって設けられたスラスト動圧発生溝Ｇ２
は、図３（Ａ）に示す如きスパイラルパターン溝、又は
図３（Ｂ）に示す如きヘリングボーン溝である。そし
て、その溝深さはスラスト隙間を流れる潤滑油の流速が
遅い側が浅く、速い側が深くなるように形成されてい
る。A thrust dynamic pressure generating groove G2 provided on the upper surface and the lower surface of the thrust ring 3 by cutting or etching.
Is a spiral pattern groove as shown in FIG. 3 (A) or a herringbone groove as shown in FIG. 3 (B). The groove depth is formed such that the side where the flow velocity of the lubricating oil flowing through the thrust gap is slow is shallow and the side where it is fast is deep.
【００２１】即ち、本発明における流体動圧軸受の構成
部材であるスラストリング３の表面に形成されたスラス
ト動圧発生溝Ｇ２は、スパイラルパターン溝の場合は図
２（Ａ）に部分断面図で示す如く、その溝深さはスラス
ト隙間を流れる潤滑油の流速が遅い側から速い側に向か
って漸次深くなるように形成されている。That is, when the thrust dynamic pressure generating groove G2 formed on the surface of the thrust ring 3 which is a constituent member of the fluid dynamic pressure bearing of the present invention is a spiral pattern groove, FIG. As shown in the drawing, the groove depth is formed so as to gradually increase from the slow flow speed side to the fast flow speed side of the lubricating oil flowing through the thrust gap.
【００２２】また、本発明における流体動圧軸受の構成
部材であるスラストリング３の表面に形成されたスラス
ト動圧発生溝Ｇ２は、ヘリングボーンパターン溝の場合
は図２（Ｂ）に部分断面図で示す如く、その溝深さはパ
ターンの折り返し点Ｒより内周面側で浅く、且つ外周面
側で深くなるように形成されている。Further, the thrust dynamic pressure generating groove G2 formed on the surface of the thrust ring 3 which is a constituent member of the fluid dynamic pressure bearing of the present invention is a partial cross-sectional view of FIG. 2B in the case of a herringbone pattern groove. As shown by, the groove depth is formed such that it is shallower on the inner peripheral surface side and deeper on the outer peripheral surface side than the pattern turning point R.
【００２３】ところで、スラスト動圧発生溝の溝深さ
は、最も浅いもので５μm、最も深いもので２０μm程度
である。そこで、最も浅い溝と最も深い溝の溝深さの比
率、即ち(最も浅い溝深さ)／(最も深い溝深さ)を０〜
２．０の範囲で変えて、最大圧力とフランジ径方向圧力
をシュミレーションしてみると、図６に示す如くとな
る。即ち、最大圧力は溝深さ比が０〜１．４までは正の
圧力で、溝深さ比が１．４を超えると負の圧力となる。
溝深さ比が０．７で最大値１４５ｋＰａを示している。By the way, the depth of the thrust dynamic pressure generating groove is about 5 μm at the shallowest and about 20 μm at the deepest. Therefore, the ratio of the depth of the shallowest groove to the depth of the deepest groove, that is, (the shallowest groove depth) / (the deepest groove depth) is 0 to
When the maximum pressure and the pressure in the radial direction of the flange are simulated while changing the range of 2.0, the result is as shown in FIG. That is, the maximum pressure is a positive pressure when the groove depth ratio is 0 to 1.4, and is a negative pressure when the groove depth ratio exceeds 1.4.
The groove depth ratio is 0.7 and the maximum value is 145 kPa.
【００２４】一方、フランジ径方向圧力は溝深さ比が０
〜２．０までの範囲で変わると、−３０ｋＰａ〜１４０
ｋＰａの範囲で変化している。そして、溝深さ比が０．
７〜１．８の範囲にあるときは、フランジ径方向圧力は
負圧となっている。On the other hand, the flange radial pressure has a groove depth ratio of 0.
-30kPa-140 when changing in the range of up to 2.0
It changes within the range of kPa. The groove depth ratio is 0.
When it is in the range of 7 to 1.8, the pressure in the radial direction of the flange is a negative pressure.
【００２５】本発明におけるスラスト動圧発生溝は、図
６に示した特性図、即ち本発明における流体動圧軸受に
おけるスラスト軸受部の最大圧力とフランジ径方向圧力
が、溝深さ比によってどのように変化するかを示した特
性図に基づいて、その溝深さ比が選定されるものであ
る。即ち、本発明におけるスラスト動圧発生溝は、その
溝深さ比は、０．６〜０．７を最適値とするものであ
る。この溝深さ比０．６〜０．７であれば、スラスト軸
受部のフランジ径方向圧力は正の小さな値であって、且
つその最大圧力は１４０ｋＰａ〜１４５ｋＰａとなるか
らである。The thrust dynamic pressure generating groove of the present invention is the characteristic diagram shown in FIG. 6, that is, the maximum pressure of the thrust bearing portion and the pressure in the radial direction of the flange in the fluid dynamic pressure bearing of the present invention are determined by the groove depth ratio. The groove depth ratio is selected based on the characteristic diagram showing whether the groove depth changes. That is, the thrust dynamic pressure generating groove in the present invention has a groove depth ratio of 0.6 to 0.7 as an optimum value. This is because if the groove depth ratio is 0.6 to 0.7, the pressure in the radial direction of the flange of the thrust bearing portion is a small positive value, and the maximum pressure is 140 kPa to 145 kPa.
【００２６】上述の如きスラスト動圧発生溝が形成され
たスラストリング３を備えた本発明に係る流体動圧軸受
のスラスト軸受の動圧は、シャフトの両側に高いスラス
ト動圧が上下方向に分布するが、フランジ径方向の圧力
負圧にならず、殆どゼロである。The dynamic pressure of the thrust bearing of the fluid dynamic pressure bearing according to the present invention having the thrust ring 3 having the thrust dynamic pressure generating groove as described above is such that the high thrust dynamic pressure is vertically distributed on both sides of the shaft. However, the pressure in the radial direction of the flange does not become negative and is almost zero.
【００２７】[0027]
【発明の効果】本発明により、スラストリング部と円柱
部とを有するフランジ付シャフトと、小径円筒部と大径
円筒部と円筒状開放端部が順に形成された片袋状段付ス
リーブと、前記スリーブの円筒状開放端部に圧入固定さ
れる押えリングと、これら軸受構成部材間に形成された
スラスト隙間を含む微小隙間に封入された潤滑油とから
構成された流体動圧軸受において、高いスラスト動圧を
効率よく発生させると共に、スラスト動圧発生溝の潤滑
油の入口付近が負圧にならないようにすることができ
た。According to the present invention, a flanged shaft having a thrust ring portion and a cylindrical portion, a single bag shaped stepped sleeve in which a small diameter cylindrical portion, a large diameter cylindrical portion and a cylindrical open end are formed in order, In a fluid dynamic pressure bearing including a holding ring press-fitted and fixed to the cylindrical open end of the sleeve, and lubricating oil enclosed in a minute gap including a thrust gap formed between these bearing components, It was possible to efficiently generate thrust dynamic pressure and prevent negative pressure near the lubricating oil inlet of the thrust dynamic pressure generation groove.
【００２８】従って、本発明に係る流体動圧軸受を備え
たスピンドルモータにおいては、負圧に起因するＮＲＲ
Ｏ等の大きな振れが発生しなくなった。Therefore, in the spindle motor provided with the fluid dynamic bearing according to the present invention, the NRR caused by the negative pressure is
Large shakes such as O no longer occur.
【図１】本発明に係る流体動圧軸受を備えたスピンドル
モータの一実施形態の断面図である。FIG. 1 is a sectional view of an embodiment of a spindle motor having a fluid dynamic bearing according to the present invention.
【図２】溝深さを誇張して示したスラストリングの部分
断面図で、（Ａ）はスラスト動圧発生溝がスパイラルパ
ターンの場合、（Ｂ）はスラスト動圧発生溝がヘリング
ボーンパターンの場合である。FIG. 2 is a partial cross-sectional view of the thrust ring exaggeratedly showing the groove depth. (A) shows a thrust dynamic pressure generating groove having a spiral pattern, and (B) shows a thrust dynamic pressure generating groove having a herringbone pattern. This is the case.
【図３】スラストリング３の平面図で、（Ａ）はスラス
ト動圧発生溝がスパイラルパターンの場合、（Ｂ）はス
ラスト動圧発生溝がヘリングボーンパターンの場合であ
る。3A and 3B are plan views of the thrust ring 3, where FIG. 3A is a case where the thrust dynamic pressure generating groove has a spiral pattern, and FIG. 3B is a case where the thrust dynamic pressure generating groove is a herringbone pattern.
【図４】本発明に係る流体動圧軸受におけるスラスト動
圧分布パターンを示す。FIG. 4 shows a thrust dynamic pressure distribution pattern in the fluid dynamic bearing according to the present invention.
【図５】従来の流体動圧軸受におけるスラスト動圧分布
パターンを示す。FIG. 5 shows a thrust dynamic pressure distribution pattern in a conventional fluid dynamic bearing.
【図６】本発明における流体動圧軸受におけるスラスト
軸受部の最大圧力とフランジ径方向圧力が、溝深さ比に
よってどのように変化するかを示した特性図である。FIG. 6 is a characteristic diagram showing how the maximum pressure in the thrust bearing portion and the pressure in the flange radial direction in the fluid dynamic bearing according to the present invention change depending on the groove depth ratio.
【図７】従来の流体動圧軸受におけるスラスト軸受部の
最大圧力とフランジ径方向圧力が、溝深さによってどの
ように変化するかを示した特性図である。FIG. 7 is a characteristic diagram showing how the maximum pressure in the thrust bearing portion and the pressure in the radial direction of the flange in the conventional fluid dynamic bearing change depending on the groove depth.
１ フランジ付シャフト ２ 円柱部 ３ スラストリング ４ 片袋状段付スリーブ ５ 押えリング ６ カップ状ハブ ６ａ 円筒状スカート部 ６ｂ ボス部 ７ ロータマグネット ８ ステータコイル ９ ベース基板 １０ チャッキングマグネット Ｇ１ ラジアル動圧発生溝 Ｇ２ スラスト動圧発生溝 Ｒ ヘリングボーンパターンの折り返し点 1 Shaft with flange 2 column 3 thrust ring 4 Single bag step sleeve 5 Presser ring 6 cup-shaped hub 6a Cylindrical skirt part 6b Boss 7 rotor magnet 8 Stator coil 9 Base substrate 10 chucking magnet G1 radial dynamic pressure generating groove G2 thrust dynamic pressure generating groove R Herringbone pattern turning point
フロントページの続き (72)発明者 米山 良治 千葉県千葉市美浜区中瀬１丁目８番地 セ イコーインスツルメンツ株式会社内 Ｆターム(参考） 3J011 AA07 BA06 CA03 JA02 KA02 KA03 MA03 5H019 AA04 CC04 DD01 FF03 5H605 BB05 BB09 BB10 BB19 CC04 EB06 EB15 5H607 BB01 BB07 BB09 BB17 BB25 CC01 DD16 GG12 GG15 KK10 5H621 GA01 HH01 JK19 Continued front page (72) Inventor Ryoji Yoneyama 1-8 Nakase, Nakase, Mihama-ku, Chiba City, Chiba Prefecture Ico Instruments Co., Ltd. F term (reference) 3J011 AA07 BA06 CA03 JA02 KA02 KA03 MA03 5H019 AA04 CC04 DD01 FF03 5H605 BB05 BB09 BB10 BB19 CC04 EB06 EB15 5H607 BB01 BB07 BB09 BB17 BB25 CC01 DD16 GG12 GG15 KK10 5H621 GA01 HH01 JK19
Claims (4)
ランジ付シャフトと、小径円筒部と大径円筒部と円筒状
開放端部が順に形成された片袋状段付スリーブと、前記
スリーブの円筒状開放端部に圧入固定される押えリング
と、これら軸受構成部材間に形成されたスラスト隙間を
含む微小隙間に封入された潤滑油とから構成された流体
動圧軸受において、前記スラスト隙間を形成する静止面
と回転面のいずれか一方に設けられたスパイラルパター
ンのスラスト動圧発生溝が、その溝深さが前記スラスト
隙間を流れる潤滑油の流速が遅い側から速い側に向かっ
て漸次深くなるように形成されていることを特徴とする
流体動圧軸受。1. A flanged shaft having a thrust ring portion and a cylindrical portion, a single bag shaped stepped sleeve in which a small diameter cylindrical portion, a large diameter cylindrical portion and a cylindrical open end are formed in order, and a cylinder of the sleeve. A thrust ring is formed in a fluid dynamic pressure bearing composed of a holding ring press-fitted and fixed to the open end and a lubricating oil enclosed in a minute gap including a thrust gap formed between these bearing constituent members. The spiral dynamic pressure generating groove of the spiral pattern provided on either the stationary surface or the rotating surface gradually becomes deeper from the slower flow speed side of the lubricating oil flowing through the thrust gap to the faster speed side. A fluid dynamic bearing characterized by being formed in the following manner.
ランジ付シャフトと、小径円筒部と大径円筒部と円筒状
開放端部が順に形成された片袋状段付スリーブと、前記
スリーブの円筒状開放端部に圧入固定される押えリング
と、これら軸受構成部材間に形成されたスラスト隙間を
含む微小隙間に封入された潤滑油とから構成された流体
動圧軸受において、前記スラスト隙間を形成する静止面
と回転面のいずれか一方に設けられたヘリングボーンパ
ターンのスラスト動圧発生溝が、その溝深さがパターン
の折り返し点より内周面側で浅く、且つ外周側で深くな
るように形成されていることを特徴とする流体動圧軸
受。2. A flanged shaft having a thrust ring portion and a cylindrical portion, a single bag shaped stepped sleeve in which a small diameter cylindrical portion, a large diameter cylindrical portion and a cylindrical open end are formed in order, and a cylinder of the sleeve. A thrust ring is formed in a fluid dynamic pressure bearing composed of a holding ring press-fitted and fixed to the open end and a lubricating oil enclosed in a minute gap including a thrust gap formed between these bearing constituent members. The thrust dynamic pressure generating groove of the herringbone pattern provided on either the stationary surface or the rotating surface is such that the groove depth is shallower on the inner peripheral surface side and deeper on the outer peripheral side than the turning point of the pattern. A fluid dynamic bearing characterized by being formed.
は、０．６〜０．７の範囲で選定されることを特徴とす
る請求項１又は２の流体動圧軸受。3. The fluid dynamic bearing according to claim 1, wherein the ratio of the groove depths of the shallowest groove and the deepest groove is selected in the range of 0.6 to 0.7.
よってロータがステータに回転自在に支持されたスピン
ドルモータ。4. A spindle motor in which a rotor is rotatably supported by a stator by the fluid dynamic pressure bearing according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001237366A JP2003049828A (en) | 2001-08-06 | 2001-08-06 | Fluid dynamic pressure bearing and spindle motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001237366A JP2003049828A (en) | 2001-08-06 | 2001-08-06 | Fluid dynamic pressure bearing and spindle motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003049828A true JP2003049828A (en) | 2003-02-21 |
Family
ID=19068460
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001237366A Pending JP2003049828A (en) | 2001-08-06 | 2001-08-06 | Fluid dynamic pressure bearing and spindle motor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003049828A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004084382A1 (en) * | 2003-03-19 | 2004-09-30 | Seiko Instruments Inc. | Motor for information recording and reproducing device, and information recording and reproducing device using the same |
| WO2004084381A1 (en) * | 2003-03-19 | 2004-09-30 | Seiko Instruments Inc. | Motor and recording medium drive device |
| JP2006170338A (en) * | 2004-12-16 | 2006-06-29 | Hitachi Global Storage Technologies Netherlands Bv | Magnetic disc device |
| JP2006329321A (en) * | 2005-05-26 | 2006-12-07 | Tokyo Univ Of Science | Foil bearing |
| JP2014105870A (en) * | 2012-11-22 | 2014-06-09 | Seagate Technology Llc | Fluid bearing with non-uniform grooves |
| US20140294330A1 (en) * | 2010-10-06 | 2014-10-02 | Eagle Industry Co., Ltd. | Sliding component |
| CN105114446A (en) * | 2015-09-15 | 2015-12-02 | 武汉理工大学 | Changeable stepped damping thrust bearing |
| CN108757721A (en) * | 2018-05-15 | 2018-11-06 | 袁虹娣 | All there is the energy saving ladder bearing of interface sliding at entire moving surface and at inlet region static surface |
-
2001
- 2001-08-06 JP JP2001237366A patent/JP2003049828A/en active Pending
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004084381A1 (en) * | 2003-03-19 | 2004-09-30 | Seiko Instruments Inc. | Motor and recording medium drive device |
| WO2004084382A1 (en) * | 2003-03-19 | 2004-09-30 | Seiko Instruments Inc. | Motor for information recording and reproducing device, and information recording and reproducing device using the same |
| CN100350721C (en) * | 2003-03-19 | 2007-11-21 | 精工电子有限公司 | Motor and recording medium drive device |
| US7307364B2 (en) | 2003-03-19 | 2007-12-11 | Seiko Instruments Inc. | Motor and recording medium drive device |
| JP4616632B2 (en) * | 2004-12-16 | 2011-01-19 | ヒタチグローバルストレージテクノロジーズネザーランドビーブイ | Magnetic disk unit |
| JP2006170338A (en) * | 2004-12-16 | 2006-06-29 | Hitachi Global Storage Technologies Netherlands Bv | Magnetic disc device |
| JP2006329321A (en) * | 2005-05-26 | 2006-12-07 | Tokyo Univ Of Science | Foil bearing |
| JP4669323B2 (en) * | 2005-05-26 | 2011-04-13 | 学校法人東京理科大学 | Foil thrust bearing and small blower equipped with the foil thrust bearing |
| US20140294330A1 (en) * | 2010-10-06 | 2014-10-02 | Eagle Industry Co., Ltd. | Sliding component |
| US9470267B2 (en) * | 2010-10-06 | 2016-10-18 | Eagle Industry Co., Ltd. | Sliding component |
| US9850953B2 (en) | 2010-10-06 | 2017-12-26 | Eagle Industry Co., Ltd. | Sliding component |
| JP2014105870A (en) * | 2012-11-22 | 2014-06-09 | Seagate Technology Llc | Fluid bearing with non-uniform grooves |
| CN105114446A (en) * | 2015-09-15 | 2015-12-02 | 武汉理工大学 | Changeable stepped damping thrust bearing |
| CN108757721A (en) * | 2018-05-15 | 2018-11-06 | 袁虹娣 | All there is the energy saving ladder bearing of interface sliding at entire moving surface and at inlet region static surface |
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