JPH1113748A - Thrust dynamic pressure bearing device - Google Patents
Thrust dynamic pressure bearing deviceInfo
- Publication number
- JPH1113748A JPH1113748A JP18058797A JP18058797A JPH1113748A JP H1113748 A JPH1113748 A JP H1113748A JP 18058797 A JP18058797 A JP 18058797A JP 18058797 A JP18058797 A JP 18058797A JP H1113748 A JPH1113748 A JP H1113748A
- Authority
- JP
- Japan
- Prior art keywords
- shaft
- thrust
- dynamic pressure
- thrust bearing
- annular member
- 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
- 239000000463 material Substances 0.000 claims abstract description 16
- 239000010687 lubricating oil Substances 0.000 claims description 46
- 230000002093 peripheral effect Effects 0.000 claims description 25
- 238000000926 separation method Methods 0.000 claims description 2
- 239000000843 powder Substances 0.000 abstract description 5
- 230000006866 deterioration Effects 0.000 abstract description 4
- 239000007779 soft material Substances 0.000 abstract description 4
- 238000005461 lubrication Methods 0.000 abstract description 2
- 238000011109 contamination Methods 0.000 abstract 1
- 239000003921 oil Substances 0.000 description 8
- 229910001220 stainless steel Inorganic materials 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000005086 pumping Methods 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 229910000906 Bronze Inorganic materials 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 2
- 239000010974 bronze Substances 0.000 description 2
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 2
- 239000011553 magnetic fluid Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Landscapes
- Sliding-Contact Bearings (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、潤滑油にスラスト
動圧を発生させ、そのスラスト動圧により軸部材とスラ
スト軸受部材とを相対的に回転自在に支持するように構
成したスラスト動圧軸受装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust dynamic pressure bearing in which a thrust dynamic pressure is generated in lubricating oil and the shaft member and the thrust bearing member are relatively rotatably supported by the thrust dynamic pressure. Related to the device.
【０００２】[0002]
【従来の技術】近年、モータ等の各種装置において、特
に高速回転に対応し得るようにオイル等の潤滑油の動圧
を利用した動圧軸受装置が種々検討され提案されてい
る。このうち、スラスト動圧軸受装置においては、軸部
材の軸端面側に設けられた動圧面に対して、スラスト軸
受部材側の動圧面が軸方向に所定の隙間を介して対向配
置されているとともに、これら両対向動圧面のうちの少
なくとも一方側にスラスト動圧発生用溝が形成されてお
り、上記軸部材とスラスト軸受部材との間の対向隙間内
に充填されたオイル等の潤滑油が、回転時にスラスト動
圧発生用溝のポンピング作用により昇圧されてスラスト
動圧を生じさせられ、このスラスト動圧によって、上記
軸部材とスラスト軸受部材とが、スラスト方向に所定量
相対浮上させられながら回転支持されるようになってい
る。2. Description of the Related Art In recent years, in various devices such as motors, various types of dynamic pressure bearing devices utilizing the dynamic pressure of lubricating oil such as oil have been studied and proposed so as to cope with high-speed rotation. Among these, in the thrust dynamic pressure bearing device, the dynamic pressure surface on the thrust bearing member side is disposed opposite to the dynamic pressure surface provided on the shaft end face side of the shaft member via a predetermined gap in the axial direction. A thrust dynamic pressure generating groove is formed on at least one side of these two opposing dynamic pressure surfaces, and lubricating oil such as oil filled in an opposing gap between the shaft member and the thrust bearing member is During rotation, the pressure is increased by the pumping action of the thrust dynamic pressure generating groove to generate thrust dynamic pressure, and the thrust dynamic pressure causes the shaft member and the thrust bearing member to rotate while being floated relative to each other by a predetermined amount in the thrust direction. It has become supported.
【０００３】このとき、上記スラスト動圧軸受装置にお
ける軸部材側の動圧面を、軸部材の軸端面のみから構成
すると、動圧面の面積が不十分となって十分なスラスト
動圧力が得られない場合がある。そこで、例えば特開平
７−２１７６４７号公報では、上記軸部材の外周側に対
して嵌着された抜け止め部材等からなる環状部材を動圧
面に形成することが行われている。この抜け止め部材等
の環状部材は、軸部材の外周面から半径方向に張り出す
ように設けられた円盤状部材からなり、その環状部材が
スラスト軸受部材側に対向する平坦表面を動圧面とする
ことによって、軸部材側における動圧面の面積を拡大
し、スラスト動圧を増大させている。[0003] At this time, if the dynamic pressure surface on the shaft member side in the thrust dynamic pressure bearing device is constituted only by the shaft end surface of the shaft member, the area of the dynamic pressure surface becomes insufficient and sufficient thrust dynamic pressure cannot be obtained. There are cases. Therefore, for example, in Japanese Patent Application Laid-Open No. Hei 7-217647, an annular member including a retaining member fitted to the outer peripheral side of the shaft member is formed on the dynamic pressure surface. The annular member such as the retaining member is a disk-shaped member provided so as to protrude in the radial direction from the outer peripheral surface of the shaft member, and the flat surface of the annular member facing the thrust bearing member side is a dynamic pressure surface. Thereby, the area of the dynamic pressure surface on the shaft member side is enlarged, and the thrust dynamic pressure is increased.
【０００４】上記軸部材としては、一般に、ステンレス
鋼を焼き入れしたもののような高硬度部材が用いられる
のに対して、抜け止め部材等の環状部材としては、比較
的軟らかい低硬度な材料が通常用いられている。これ
は、環状部材が軸部材に対して圧入で嵌着されること
や、動圧発生用溝をコイニング等の工法によって環状部
材に転写形成することが多いこと、等の理由による。As the shaft member, a high-hardness member such as a quenched stainless steel is generally used. On the other hand, a relatively soft and low-hardness material is generally used for an annular member such as a retaining member. Used. This is because the annular member is press-fitted to the shaft member, and the dynamic pressure generating groove is often transferred and formed on the annular member by a method such as coining.
【０００５】[0005]
【発明が解決しようとする課題】ところが、従来のスラ
スト動圧軸受構造では、動圧を生じていない回転停止時
や動圧が不十分な回転開始直後において、環状部材の表
面がスラスト軸受部材の表面に接触するように配置され
ており、軸部材の軸端面は、スラスト軸受部材から軸方
向にやや離れるようにして配置されているか、軽く接触
する配置関係になされている。そのため、回転の停止・
開始が頻繁に繰り返されると、抜け止め部材等の環状部
材の表面に摩耗が進行することとなり、動圧発生用溝の
溝深さが次第に減少して十分な動圧力が得られなくなっ
たり、摩耗粉が潤滑油に混入して潤滑油が劣化し易くな
る。However, in the conventional thrust dynamic pressure bearing structure, the surface of the annular member has the surface of the thrust bearing member at the time of rotation stop where no dynamic pressure is generated or immediately after the start of rotation where the dynamic pressure is insufficient. The shaft end surface of the shaft member is arranged so as to be slightly away from the thrust bearing member in the axial direction, or has a lightly contacting arrangement. Therefore, stop rotation
If the start is repeated frequently, the wear of the surface of the annular member such as the retaining member progresses, and the groove depth of the groove for generating dynamic pressure gradually decreases, so that sufficient dynamic pressure cannot be obtained, or The powder mixes with the lubricating oil, and the lubricating oil is easily deteriorated.
【０００６】そこで本発明は、簡易で低コストな構造
で、スラスト動圧力を長期にわたって安定的に得ること
ができるようにしたスラスト動圧軸受装置を提供するこ
とを目的とする。Accordingly, an object of the present invention is to provide a thrust dynamic pressure bearing device having a simple and low-cost structure and capable of stably obtaining a thrust dynamic pressure for a long period of time.
【０００７】[0007]
【課題を解決するための手段】このような目的を達成す
るために、請求項１記載の発明では、軸部材と、この軸
部材の外周面から半径方向に張り出すようにして軸部材
に嵌着された環状部材と、これら軸部材及び環状部材の
それぞれに対して、軸方向に所定の隙間を介在して対向
するように配置されたスラスト軸受部材と、が設けられ
ているとともに、上記軸部材及び環状部材とスラスト軸
受部材との間の対向隙間内に潤滑油が充填され、かつ、
前記対向隙間を構成する環状部材及びスラスト軸受部材
の各対向平坦表面のうちの少なくとも一面に動圧発生用
溝が形成され、その動圧発生用溝の加圧作用により潤滑
油に生じさせられる動圧によって、前記軸部材及び環状
部材とスラスト軸受部材とが、軸方向に所定量Ｂだけ相
対浮上させられながら回転支持されるスラスト動圧軸受
装置において、回転停止時における上記環状部材とスラ
スト軸受部材との対向隙間の間隔Ａが、回転停止時にお
ける前記軸部材とスラスト軸受部材との対向隙間の間隔
である０より大きく、かつ回転駆動時における前記軸部
材及び環状部材とスラスト軸受部材との相対浮上量Ｂよ
り小さく設定されている。In order to achieve the above object, according to the first aspect of the present invention, the shaft member is fitted to the shaft member so as to protrude radially from the outer peripheral surface of the shaft member. The attached annular member, and a thrust bearing member disposed so as to face each of the shaft member and the annular member with a predetermined gap therebetween in the axial direction are provided, and Lubricating oil is filled in the opposing gap between the member and the annular member and the thrust bearing member, and
Grooves for generating dynamic pressure are formed on at least one of the opposed flat surfaces of the annular member and the thrust bearing member forming the opposed gap, and the dynamic force generated in the lubricating oil by the pressurizing action of the dynamic pressure generating grooves. In a thrust dynamic pressure bearing device in which the shaft member, the annular member, and the thrust bearing member are rotatably supported while being floated relative to each other in the axial direction by a predetermined amount B, the annular member and the thrust bearing member when rotation is stopped The gap A between the opposed gaps between the shaft member and the thrust bearing member during rotation is greater than 0, which is the interval between the opposed gaps between the shaft member and the thrust bearing member when the rotation is stopped, and It is set smaller than the flying height B.
【０００８】また、請求項２記載の発明では、上記請求
項１記載の軸部材における対向軸端面が、前記環状部材
の対向平坦表面から軸方向にスラスト軸受部材側に向っ
て所定量突出するように配置され、これら軸部材の対向
軸端面と環状部材の対向平坦表面との間の軸方向間隔
が、軸部材及び環状部材の浮上量より小さくなるように
設定されている。According to the second aspect of the present invention, the opposed shaft end surface of the shaft member according to the first aspect projects from the opposed flat surface of the annular member in the axial direction toward the thrust bearing member by a predetermined amount. And the axial distance between the opposed shaft end faces of these shaft members and the opposed flat surface of the annular member is set to be smaller than the floating amount of the shaft member and the annular member.
【０００９】さらに、請求項３記載の発明では、上記請
求項１記載の環状部材が、軸部材とスラスト軸受部材と
の軸方向における相対的な離脱を防止する抜け止め部材
からなる。Further, according to the third aspect of the present invention, the annular member according to the first aspect comprises a retaining member for preventing relative separation of the shaft member and the thrust bearing member in the axial direction.
【００１０】さらにまた、請求項４記載の発明では、上
記請求項１記載の軸部材の対向軸端面に、軸部材の一般
径より小さな外径で軸方向に突出するように形成され、
回転停止時及び回転開始直後にスラスト軸受部材の対向
平坦表面に接触する当接部が設けられている。Further, in the invention according to claim 4, the shaft member according to claim 1 is formed on the opposite shaft end face so as to project in the axial direction with an outer diameter smaller than the general diameter of the shaft member,
A contact portion is provided which comes into contact with the opposing flat surface of the thrust bearing member when the rotation stops and immediately after the rotation starts.
【００１１】また、請求項５記載の発明では、上記請求
項１記載の環状部材が、軸部材及びスラスト軸受部材よ
りも軟質な材料から形成されているとともに、当該環状
部材の対向平坦表面に動圧発生用溝が形成されている。According to the fifth aspect of the present invention, the annular member according to the first aspect is formed of a material softer than the shaft member and the thrust bearing member, and moves on the opposed flat surface of the annular member. A pressure generating groove is formed.
【００１２】このような各請求項記載の手段によれば、
動圧を生じていない回転停止時及び動圧力が不十分な回
転開始直後において、高硬度の材料から形成される軸部
材が、スラスト軸受部材側に接触することとなり、比較
的軟らかい材料から形成される抜け止め部材等の環状部
材は、スラスト軸受部材の表面から離間した状態で配置
される。したがって、従来のような抜け止め部材等の環
状部材における摩耗の発生はなくなり、その環状部材に
設けられた動圧発生用溝の溝深さを減少させることな
く、動圧力が長期にわたって安定して得られる。また、
環状部材からの摩耗粉が潤滑油に混入することもなくな
るので、潤滑油の粘度等の劣化が良好に防止されるよう
になっている。According to the means described in each claim,
At the time of rotation stop where no dynamic pressure is generated and immediately after the start of rotation where the dynamic pressure is insufficient, the shaft member formed of a high-hardness material comes into contact with the thrust bearing member side and is formed of a relatively soft material. An annular member such as a retaining member is disposed so as to be separated from the surface of the thrust bearing member. Therefore, wear of the annular member such as the retaining member as in the related art does not occur, and the dynamic pressure is stably maintained for a long period of time without reducing the groove depth of the dynamic pressure generating groove provided in the annular member. can get. Also,
Since wear powder from the annular member does not mix with the lubricating oil, deterioration of the viscosity and the like of the lubricating oil can be prevented well.
【００１３】このとき、特に請求項４記載の手段によれ
ば、上記作用に加えて、回転停止時及び回転開始直後に
おけるスラスト軸受部材側に対する軸部材の接触面積が
小さくなされるため、軸部材とスラスト軸受部材側とが
相対的に浮上して互いに離間するまでの接触時間が短時
間となり、その結果、軸部材側の摩耗量が極めて小さく
抑えられるようになっている。[0013] In this case, in particular, according to the means described in claim 4, in addition to the above-mentioned operation, the contact area of the shaft member with the thrust bearing member side at the time of rotation stop and immediately after the start of rotation is reduced. The contact time until the thrust bearing member side relatively floats and separates from each other is short, and as a result, the amount of wear on the shaft member side can be kept extremely small.
【００１４】[0014]
【発明の実施の形態】以下、本発明を、いわゆるＨＤＤ
スピンドルモータに適用した実施形態について図面によ
り詳細に説明する。まず、図１に示されたＨＤＤスピン
ドルモータは、いわゆる軸固定型であって、当該ＨＤＤ
スピンドルモータの全体は、固定部材としてのステータ
組１と、このステータ組１に対して図示上側から組み付
けられた回転部材としてのロータ組２とから構成されて
いる。このうちステータ組１は、図示省略した固定基台
側にネジ止めされるフレーム１１を有しているととも
に、このフレーム１１の略中央部分に設けられた中空円
筒状の支持ホルダー１２内に、固定軸１３が図示上方に
向かって延びるように固定されている。BEST MODE FOR CARRYING OUT THE INVENTION The present invention is hereinafter referred to as a so-called HDD.
An embodiment applied to a spindle motor will be described in detail with reference to the drawings. First, the HDD spindle motor shown in FIG.
The entire spindle motor is composed of a stator set 1 as a fixed member and a rotor set 2 as a rotating member assembled to the stator set 1 from above in the figure. The stator set 1 has a frame 11 screwed to a fixed base (not shown), and is fixed in a hollow cylindrical support holder 12 provided at a substantially central portion of the frame 11. The shaft 13 is fixed so as to extend upward in the figure.
【００１５】また、上記フレーム１１の支持ホルダー１
２の外周側には、ステータコア１４が嵌着されており、
このステータコア１４の突極部に、巻線１５が巻回され
ている。The support holder 1 for the frame 11
A stator core 14 is fitted on the outer peripheral side of 2.
A winding 15 is wound around the salient pole portion of the stator core 14.
【００１６】一方、前記ロータ組２は、複数段にわたっ
て配置される所定の記録媒体３を支持するためのハブ２
１を有しており、このハブ２１は、当該ハブ２１の中心
部分に固着された軸受スリーブ２２を介して、上記固定
軸１３の外周側に回転自在に支承されている。すなわ
ち、上記ハブ２１は、磁気ディスク等の磁気記録媒体３
を外周部に装着する略円筒形状の胴部２１ａを有してい
るとともに、この胴部２１ａの内周側に、バックヨーク
２１ｂを介して駆動マグネット２１ｃが環状に装着され
ている。この駆動マグネット２１ｃは、前述したステー
タコア１４の外周端面に対して環状に対向するように近
接配置されている。On the other hand, the rotor set 2 has a hub 2 for supporting a predetermined recording medium 3 arranged over a plurality of stages.
The hub 21 is rotatably supported on the outer peripheral side of the fixed shaft 13 via a bearing sleeve 22 fixed to a center portion of the hub 21. That is, the hub 21 is used for the magnetic recording medium 3 such as a magnetic disk.
Is mounted on the outer periphery, and a drive magnet 21c is annularly mounted on the inner periphery of the body 21a via a back yoke 21b. The drive magnet 21c is disposed close to the outer peripheral end surface of the stator core 14 so as to annularly face the above-described outer peripheral end surface.
【００１７】上記軸受スリーブ２２の内周面と、前記固
定軸１３の外周面との間には、一対のラジアル動圧軸受
部２３，２４が、軸方向に所定間隔離して設けられてい
る。これらの各ラジアル動圧軸受部２３，２４における
軸受スリーブ２２の内周面と固定軸１３の外周面とは、
数μｍの隙間を介して対向配置されており、当該隙間内
には、オイルや磁性流体等からなる所定の潤滑油が介在
されている。Between the inner peripheral surface of the bearing sleeve 22 and the outer peripheral surface of the fixed shaft 13, a pair of radial dynamic pressure bearing portions 23 and 24 are provided at predetermined intervals in the axial direction. The inner peripheral surface of the bearing sleeve 22 and the outer peripheral surface of the fixed shaft 13 in each of the radial dynamic pressure bearing portions 23 and 24 are:
They are opposed to each other with a gap of several μm, and a predetermined lubricating oil made of oil, magnetic fluid, or the like is interposed in the gap.
【００１８】これら２箇所のラジアル動圧軸受部２３，
２４における潤滑油は、互いに連続した状態で充填され
ており、各ラジアル動圧軸受部２３，２４どうしの間部
分に設けられた油溜り２５内にも潤滑油が充填されてい
る。The two radial dynamic pressure bearing portions 23,
The lubricating oil in 24 is filled in a continuous state with each other, and the lubricating oil is also filled in an oil reservoir 25 provided between the radial dynamic pressure bearing portions 23 and 24.
【００１９】そして、上記軸受スリーブ２２と固定軸１
３との両対向面のうち、少なくとも一方側には、例えば
ヘリンボーン形状のラジアル動圧発生用溝が環状に並列
するように凹設されており、前記ハブ２１の回転時に、
当該ラジアル動圧発生用溝のポンピング作用によって潤
滑油が昇圧されて動圧が生じさせられ、この潤滑油の動
圧によって、ハブ２１がラジアル方向に軸支持されるよ
うに構成されている。The bearing sleeve 22 and the fixed shaft 1
For example, a herringbone-shaped radial dynamic pressure generating groove is recessed in at least one side of the two opposing surfaces with each other so as to be annularly arranged in parallel, and when the hub 21 rotates,
The lubricating oil is pressurized by the pumping action of the radial dynamic pressure generating groove to generate a dynamic pressure, and the hub 21 is axially supported in the radial direction by the dynamic pressure of the lubricating oil.
【００２０】一方、前記固定軸１３は、例えばステンレ
ス鋼を焼き入れした硬質材料から形成されており、当該
固定軸１３の先端側（図示上端側）に、リング状の環状
部材を構成する抜け止め部材１６が圧入により嵌着され
ている。この抜け止め部材１６は、上記固定軸１３の外
周面から半径方向に張り出すようにして嵌着された円盤
状の環状部材からなり、前記固定軸１３の材料よりも軟
質な材料、例えばリン青銅等の銅材料や、フェライト
系、オーステナイト系のステンレス鋼の生材料から形成
されている。On the other hand, the fixed shaft 13 is made of, for example, a hard material obtained by quenching stainless steel, and a tip end (upper end in the drawing) of the fixed shaft 13 is a retaining member forming a ring-shaped annular member. The member 16 is fitted by press fitting. The retaining member 16 is a disk-shaped annular member fitted so as to protrude from the outer peripheral surface of the fixed shaft 13 in the radial direction, and is made of a material softer than the material of the fixed shaft 13, for example, phosphor bronze. And the like, and a raw material of ferritic and austenitic stainless steel.
【００２１】そして、図２にも示されているように、前
述した軸受スリーブ２２の図示上端部分の内周部には、
環状に切り欠くようにしてスラスト軸受部ＳＢが凹設さ
れており、そのスラスト軸受部ＳＢ内に上記抜け止め部
材１６が収容されている。そして、この抜け止め部材１
６により軸受スリーブ２２が軸方向に係止されることに
よって、前記ハブ２１の軸方向への離脱が防止される構
成になされている。As shown in FIG. 2, the inner peripheral portion of the upper end of the bearing sleeve 22 shown in FIG.
The thrust bearing SB is recessed so as to be cut out in an annular shape, and the retaining member 16 is accommodated in the thrust bearing SB. And this retaining member 1
6, the bearing sleeve 22 is locked in the axial direction, so that the hub 21 is prevented from being detached in the axial direction.
【００２２】また、上記スラスト軸受部ＳＢを画成して
いる軸受スリーブ２２の環状外周壁部分には、当該軸受
スリーブ２２の図示上端面に対して、円盤状の部材から
なるスラスト軸受部材１７の外周部分が載置され固着さ
れている。このスラスト軸受部材１７は、前記固定軸１
３とほぼ同程度の硬度を有する硬質材料から形成されて
おり、上記抜け止め部材１６における軸方向外側（図示
上側）の平坦表面１６ａに対して、外側（図示上側）か
ら軸方向に近接対面するように配置されている。Further, on the annular outer peripheral wall portion of the bearing sleeve 22 defining the thrust bearing portion SB, a thrust bearing member 17 made of a disc-shaped member is formed with respect to the illustrated upper end surface of the bearing sleeve 22. The outer peripheral portion is placed and fixed. The thrust bearing member 17 is mounted on the fixed shaft 1.
3 is formed of a hard material having substantially the same hardness as that of the flat member 3, and faces the flat surface 16 a on the axially outer side (upper side in the figure) of the retaining member 16 in the axial direction from the outer side (upper side in the figure). Are arranged as follows.
【００２３】すなわち、上記スラスト軸受部材１７の図
示下側の平坦表面１７ａは、前記抜け止め部材１６の図
示上側の平坦表面１６ａに対して、所定の狭小隙間を介
在するように対向配置されており、これら両表面１７
ａ，１６ａの少なくとも一方側には、例えばヘリングボ
ーン形状の動圧発生用溝が形成され、これによって一対
のスラスト対向動圧面が構成されている。また、同様に
して上記抜け止め部材１６の図示下側の平坦表面１６ｂ
は、前述した軸受スリーブ２２のスラスト軸受部ＳＢを
画成している平坦表面２２ａに対して、所定の狭小隙間
を介在するように対向配置されており、そこにも一対の
スラスト対向動圧面が形成されている。That is, the lower flat surface 17a of the thrust bearing member 17 in the drawing is arranged to face the upper flat surface 16a of the retaining member 16 in the drawing so as to interpose a predetermined narrow gap. , These two surfaces 17
For example, a herringbone-shaped dynamic pressure generating groove is formed on at least one of the sides a and 16a, thereby forming a pair of thrust-facing dynamic pressure surfaces. Similarly, the lower flat surface 16b of the retaining member 16 as shown in the drawing.
Is disposed so as to face the flat surface 22a defining the thrust bearing portion SB of the bearing sleeve 22 so as to interpose a predetermined small gap, and a pair of thrust opposing dynamic pressure surfaces is also provided there. Is formed.
【００２４】そして、これらの各対向動圧面を構成して
いる対向隙間内、すなわち、上記固定軸１３の軸端面１
３ａとスラスト軸受部材１７の平坦表面１７ａとの間の
対向隙間内、前記抜け止め部材１６の平坦表面１６ａと
スラスト軸受部材１７の平坦表面１７ａとの間の対向隙
間内、並びに、上記抜け止め部材１６の平坦表面１６ａ
と軸受スリーブ２２の平坦表面２２ａとの間の対向隙間
内のそれぞれには、潤滑油が連続するようにして充填さ
れている。なおこの潤滑油は、上述したラジアル軸受側
の潤滑油から連続して注入されたものである。Then, in the facing gaps forming the respective facing dynamic pressure surfaces, that is, the shaft end face 1 of the fixed shaft 13
3a and a flat surface 17a of the thrust bearing member 17, an opposing gap between the flat surface 16a of the retaining member 16 and the flat surface 17a of the thrust bearing member 17, and the retaining member. 16 flat surfaces 16a
The lubricating oil is continuously filled in the opposing gaps between the bearing sleeve 22 and the flat surface 22a. This lubricating oil was continuously injected from the above-described lubricating oil on the radial bearing side.
【００２５】一方、上述したように上記抜け止め部材１
６の軸方向両端の各平坦表面１６ａ，１６ｂには、例え
ばヘリングボーン形状をなすスラスト動圧発生用溝（図
示省略）が形成されており、このスラスト動圧発生用溝
の加圧作用により潤滑油に生じさせられるスラスト動圧
によって、前記スラスト軸受部材１７が、固定軸１３及
び抜け止め部材１６に対してスラスト方向（軸方向）に
所定量（図２中の符号「Ｂ」参照）浮上させられながら
スラスト方向に回転支持されるように構成されている。On the other hand, as described above, the retaining member 1
For example, a herringbone-shaped thrust dynamic pressure generating groove (not shown) is formed on each of the flat surfaces 16a and 16b at both axial ends, and lubrication is performed by the pressing action of the thrust dynamic pressure generating groove. Due to the thrust dynamic pressure generated in the oil, the thrust bearing member 17 floats in the thrust direction (axial direction) with respect to the fixed shaft 13 and the retaining member 16 by a predetermined amount (refer to the symbol “B” in FIG. 2). It is configured to be rotatably supported in the thrust direction while being rotated.
【００２６】このとき、特に図２に示されているよう
に、上記固定軸１３の対向軸端面（図示上端面）１３ａ
は、その中心部分がスラスト軸受部材１７側へ向って凸
となるように球面形状に形成されており、その球面の中
心部分が、当該固定軸１３の一般径より小さい凸状の当
接部になされている。すなわち、この固定軸１３の対向
軸端面（図示上端面）１３ａにおける球面凸状の当接部
は、回転停止時及び回転開始直後において、スラスト軸
受部材１７側へ接触するように形成されており、スラス
ト動圧の発生時には、浮上によって図２に示されている
ような状態に離間されるようになっている。At this time, as shown particularly in FIG. 2, the opposite shaft end surface (the upper end surface in the figure) 13a of the fixed shaft 13
Is formed in a spherical shape so that the central portion is convex toward the thrust bearing member 17 side, and the central portion of the spherical surface is in contact with a convex contact portion smaller than the general diameter of the fixed shaft 13. It has been done. That is, the spherical convex contact portion on the opposite shaft end surface (the upper end surface in the figure) 13a of the fixed shaft 13 is formed so as to come into contact with the thrust bearing member 17 when the rotation stops and immediately after the rotation starts. When the thrust dynamic pressure is generated, the thrust is separated from the state shown in FIG. 2 by floating.
【００２７】また、上記固定軸１３における球面状表面
の中心部分における突出部分は、前記抜け止め部材１６
の対向平坦表面（図示上側表面）１６ａから、スラスト
軸受部材１７側に向って軸方向に僅かな寸法「Ａ」だけ
突出するように配置されている。すなわち、上記固定軸
１３の軸端面１３ａと、抜け止め部材１６の平坦表面１
６ａとの間の軸方向間隔「Ａ」は、前述した固定軸１３
及び抜け止め部材１６に対するスラスト軸受部材１７側
の浮上量「Ｂ」よりやや小さくなるように設定されてい
る。The projecting portion at the center of the spherical surface of the fixed shaft 13 is provided with the retaining member 16.
Are arranged so as to protrude from the opposite flat surface (upper surface in the figure) 16a toward the thrust bearing member 17 by a small dimension "A" in the axial direction. That is, the shaft end surface 13 a of the fixed shaft 13 and the flat surface 1
6a is the same as the above-described fixed shaft 13
The height is set to be slightly smaller than the floating amount “B” on the thrust bearing member 17 side with respect to the retaining member 16.
【００２８】これを換言すれば、まず、回転停止時にお
いて固定軸１３側にスラスト軸受部材１７が接触するた
め、これら両部材１３，１７どうしの間隔が「０」とな
るとともに、上記抜け止め部材１６とスラスト軸受部材
１７との対向隙間の間隔が上述した寸法「Ａ」と等しく
なる。そして、このときの上記寸法「Ａ」は、回転停止
時において接触状態にある固定軸１３とスラスト軸受部
材１７との対向隙間の間隔である「０」より大きく設定
されているとともに（Ａ＞０）、スラスト軸受部におけ
る浮上量「Ｂ」より小さく設定されている（Ａ＜Ｂ）。In other words, first, the thrust bearing member 17 comes into contact with the fixed shaft 13 when the rotation is stopped, so that the distance between the two members 13 and 17 becomes "0" and the retaining member The space between the opposing gaps between the thrust bearing member 16 and the thrust bearing member 17 is equal to the above-mentioned dimension “A”. The dimension “A” at this time is set to be larger than “0”, which is the interval of the facing gap between the fixed shaft 13 and the thrust bearing member 17 in the contact state when the rotation is stopped (A> 0). ), And is set to be smaller than the floating amount “B” in the thrust bearing portion (A <B).
【００２９】なお、図２中の符号「Ｃ」は、スラスト軸
受部材１７に対する抜け止め部材１６の浮上量を表して
おり、上述した浮上量「Ｂ」とほぼ同じ隙間寸法（Ｃ≒
Ｂ）に設定されている。また、図２中の符号「Ｄ」は、
前述したラジアル軸受部２３，２４における隙間間隔を
表している。The symbol "C" in FIG. 2 represents the floating amount of the retaining member 16 with respect to the thrust bearing member 17, and the clearance dimension (C ≒) which is substantially the same as the floating amount "B" described above.
B). The symbol “D” in FIG.
It shows the gap between the radial bearings 23 and 24 described above.
【００３０】このような構成を有する本実施形態装置に
よれば、スラスト動圧を生じていない回転停止時及び動
圧力が不十分な回転開始直後において、高硬度の材料か
ら形成された固定軸１３が、スラスト軸受部材１７側に
接触することとなり、比較的軟らかい材料から形成され
た抜け止め部材１６は、スラスト軸受部材１７の表面か
ら離間した状態に配置される。その結果、従来のような
抜け止め部材１６の摩耗は完全になくなり、その抜け止
め部材１６に設けられたスラスト動圧発生用溝の溝深さ
を減少させることなく、スラスト動圧力が長期にわたっ
て安定して得られる。また、抜け止め部材１６からの摩
耗粉が潤滑油内に混入することもなくなるので、潤滑油
の粘度等の劣化も良好に防止されるようになっている。According to the apparatus of this embodiment having such a configuration, at the time of rotation stop where thrust dynamic pressure is not generated and immediately after the start of rotation where dynamic pressure is insufficient, the fixed shaft 13 made of a material of high hardness is used. However, it comes into contact with the thrust bearing member 17 side, and the retaining member 16 formed of a relatively soft material is arranged in a state separated from the surface of the thrust bearing member 17. As a result, the wear of the retaining member 16 as in the prior art is completely eliminated, and the thrust dynamic pressure is stable for a long time without reducing the depth of the thrust dynamic pressure generating groove provided on the retaining member 16. Is obtained. Further, since the wear powder from the retaining member 16 does not mix into the lubricating oil, deterioration of the viscosity and the like of the lubricating oil can be prevented well.
【００３１】また、特に本実施形態においては、固定軸
１３の軸端面１３ａに球面凸状の当接部が形成されてい
るため、上記作用に加えて、回転停止時及び回転開始直
後において、スラスト軸受部材１７側に対する固定軸１
３の接触面積が小さくなされる。したがって、スラスト
軸受部材１７が固定軸１３側から浮上して離間するまで
の接触時間は非常に短い時間となり、その結果、固定軸
１３側の摩耗量も極めて小さく抑えられることとなる。Further, in this embodiment, in particular, since a spherical convex contact portion is formed on the shaft end surface 13a of the fixed shaft 13, in addition to the above-described operation, the thrust can be obtained when the rotation is stopped and immediately after the rotation is started. Fixed shaft 1 for bearing member 17 side
3 is made small. Therefore, the contact time until the thrust bearing member 17 floats up from the fixed shaft 13 side and separates therefrom is very short, and as a result, the amount of wear on the fixed shaft 13 side is also extremely suppressed.
【００３２】また、図３に示された実施形態では、固定
軸１３’の図示上端部分に潤滑油の循環通路１８が設け
られている。この潤滑油循環通路１８は、固定軸１３’
の中心部分を軸方向に延在して図示上側の軸端面１３’
ａに開口するように設けられており、当該潤滑油循環通
路１８の開口部分の外周を取り囲むようにして、凸状当
接部１３’ｂが環状に形成されている。この凸状当接部
１３’ｂは、上述した実施形態における球面当接部の替
りに設けられたものであって、当該凸状当接部１３’ｂ
が、回転停止時及び回転開始直後において、スラスト軸
受部材１７に当接する構成になされている。In the embodiment shown in FIG. 3, a lubricating oil circulation passage 18 is provided at the upper end of the fixed shaft 13 'in the figure. This lubricating oil circulation passage 18 is
Extends axially in the center portion of the shaft end surface 13 'on the upper side in the figure.
The lubricating oil circulation passage 18 has a convex contact portion 13 ′ b formed in an annular shape so as to surround the outer periphery of the opening portion of the lubricating oil circulation passage 18. The convex contact portion 13'b is provided in place of the spherical contact portion in the above-described embodiment, and is provided with the convex contact portion 13'b.
However, when the rotation is stopped and immediately after the rotation is started, the thrust bearing member 17 is abutted.
【００３３】このように本実施形態においては、上記固
定軸１３’が、当該固定軸１３’の一般径より小さな径
に形成されたスラスト軸受部材１７への凸状当接部１
３’ｂを有しており、その凸状当接部１３’ｂにおける
軸端面が、前記抜け止め部材１６におけるスラスト軸受
部材１７への対向平坦表面（図示上平坦表面）１６ａか
ら、図示上側であるスラスト軸受部材１７側に向って軸
方向に僅かな寸法「Ａ」だけ突出するように配置されて
いる。この固定軸１３における凸状当接部１３’ｂの軸
端面と、抜け止め部材１６の平坦表面１６ａとの間の軸
方向間隔「Ａ」は、回転時における抜け止め部材１６の
スラスト方向への浮上量「Ｂ」よりやや小さくなるよう
に設定されている。すなわち、回転停止時において固定
軸１３’とスラスト軸受部材１７とが接触したときの上
記抜け止め部材１６とスラスト軸受部材１７との対向隙
間の間隔「Ａ」が「０」より大きく（Ａ＞０）、かつ回
転駆動時における浮上量「Ｂ」より小さく設定されてい
る（Ａ＜Ｂ）。このような実施形態によっても、前述し
た実施形態と同様な作用・効果を得ることができる。As described above, in the present embodiment, the fixed shaft 13 ′ has a convex contact portion 1 with the thrust bearing member 17 having a smaller diameter than the general diameter of the fixed shaft 13 ′.
3'b, and the shaft end face of the convex contact portion 13'b is located on the upper side in the figure from the flat surface (the upper flat surface in the figure) 16a of the retaining member 16 facing the thrust bearing member 17. It is arranged so as to protrude toward the certain thrust bearing member 17 side by a small dimension “A” in the axial direction. The axial distance “A” between the axial end surface of the convex contact portion 13 ′ b of the fixed shaft 13 and the flat surface 16 a of the retaining member 16 is determined by the axial direction “A” of the retaining member 16 in the thrust direction during rotation. It is set to be slightly smaller than the flying height "B". That is, when the fixed shaft 13 'and the thrust bearing member 17 come into contact with each other when the rotation is stopped, the gap "A" of the opposing gap between the retaining member 16 and the thrust bearing member 17 is larger than "0"(A> 0). ), And is set to be smaller than the flying height “B” during the rotation drive (A <B). According to such an embodiment, the same operation and effect as those of the above-described embodiment can be obtained.
【００３４】さらに、図４に示されている実施形態で
は、固定軸１３の図示上端部分を凸状球面とするため
に、当該固定軸１３に設けられた潤滑油循環通路１８’
を中心軸に対して傾斜するように配置したものである。
すなわち、前述した図３にかかる実施形態のように、潤
滑油循環通路１８を軸方向に延ばして球面の中心部に開
口させた場合には、その潤滑油循環通路１８の開口縁部
がスラスト軸受部材１７の表面に対してエッジ状に接触
し、摩耗を促進させてしまうこととなる。そこで、本実
施形態では、潤滑油循環通路１８’を傾斜配置すること
によって、当該潤滑油循環通路１８’の上端開口部を、
固定軸１３がスラスト軸受部材１７の表面からやや離間
した部分に配置している。これにより、上記潤滑油循環
通路１８’の開口部は、スラスト軸受部材１７の表面に
対して非接触状態になされている。Further, in the embodiment shown in FIG. 4, in order to make the illustrated upper end portion of the fixed shaft 13 a convex spherical surface, a lubricating oil circulation passage 18 'provided in the fixed shaft 13 is provided.
Are arranged so as to be inclined with respect to the central axis.
That is, when the lubricating oil circulation passage 18 is extended in the axial direction and is opened at the center of the spherical surface as in the embodiment according to FIG. 3 described above, the opening edge of the lubricating oil circulation passage 18 has a thrust bearing. It comes into contact with the surface of the member 17 in an edge-like manner, which promotes abrasion. Therefore, in the present embodiment, by arranging the lubricating oil circulation passage 18 'at an angle, the upper end opening of the lubricating oil circulation passage 18' is
The fixed shaft 13 is disposed at a portion slightly separated from the surface of the thrust bearing member 17. Thus, the opening of the lubricating oil circulation passage 18 ′ is in a non-contact state with the surface of the thrust bearing member 17.
【００３５】一方、図５に示されている実施形態は、い
わゆる軸回転型のＨＤＤスピンドルモータに本発明を適
用したものであって、ステータ組５は、図示省略した固
定基台側にネジ止めされるフレーム５１を有していると
ともに、このフレーム５１の略中央部分に設けられた中
空円筒状の支持ホルダー５２内に、軸受スリーブ５３を
介して、ロータ組６の回転軸６１が図示上方に向かって
延びるように回転支持されている。On the other hand, in the embodiment shown in FIG. 5, the present invention is applied to a so-called shaft-rotating HDD spindle motor, and the stator set 5 is screwed to a fixed base (not shown). And a rotating shaft 61 of the rotor set 6 is disposed upward through a bearing sleeve 53 in a hollow cylindrical support holder 52 provided at a substantially central portion of the frame 51. It is rotatably supported so as to extend toward it.
【００３６】また、上記フレーム５１の支持ホルダー５
２の外周側には、ステータコア５４が嵌着されており、
このステータコア５４の突極部に、巻線５５が巻回され
ている。The support holder 5 of the frame 51
A stator core 54 is fitted on the outer peripheral side of 2.
A winding 55 is wound around the salient pole portion of the stator core 54.
【００３７】一方、前記ロータ組６は、複数段にわたっ
て配置される所定の記録媒体７を支持するためのハブ６
２を有している。このハブ６２の中心部分は、上記回転
軸６１の図示上端部分に固着されており、回転軸６１と
ともに回転するように支承されている。すなわち、上記
ハブ６２は、磁気ディスク等の磁気記録媒体７を外周部
に装着する略円筒形状の胴部６１ａを有しているととも
に、この胴部６１ａの内周側に、バックヨーク６１ｂを
介して駆動マグネット６１ｃが環状に装着されている。
この駆動マグネット６１ｃは、前述したステータコア５
４の外周端面に対して環状に対向するように近接配置さ
れている。On the other hand, the rotor set 6 has a hub 6 for supporting a predetermined recording medium 7 arranged over a plurality of stages.
Two. The center portion of the hub 62 is fixed to the upper end of the rotary shaft 61 in the figure, and is supported so as to rotate with the rotary shaft 61. That is, the hub 62 has a substantially cylindrical body 61a for mounting the magnetic recording medium 7 such as a magnetic disk on the outer periphery, and a back yoke 61b on the inner periphery of the body 61a. The driving magnet 61c is annularly mounted.
The driving magnet 61c is connected to the stator core 5 described above.
4 are arranged close to each other so as to face the outer peripheral end face in a ring shape.
【００３８】上記軸受スリーブ５３の内周面と、前記回
転軸６１の外周面との間には、一対のラジアル動圧軸受
部６３，６４が、軸方向に所定間隔離して設けられてい
る。これらの各ラジアル動圧軸受部６３，６４における
軸受スリーブ５３の内周面と回転軸６１の外周面とは、
数μｍの隙間を介して対向配置されており、当該隙間内
には、オイルや磁性流体等からなる所定の潤滑油が介在
されている。A pair of radial dynamic pressure bearings 63 and 64 are provided between the inner peripheral surface of the bearing sleeve 53 and the outer peripheral surface of the rotary shaft 61 at predetermined intervals in the axial direction. The inner peripheral surface of the bearing sleeve 53 and the outer peripheral surface of the rotary shaft 61 in each of the radial dynamic pressure bearing portions 63 and 64 are:
They are opposed to each other with a gap of several μm, and a predetermined lubricating oil made of oil, magnetic fluid, or the like is interposed in the gap.
【００３９】これら２箇所のラジアル動圧軸受部６３，
６４における潤滑油は、互いに連続した状態で充填され
ており、各ラジアル動圧軸受部６３，６４どうしの間に
設けられた油溜り６５内にも潤滑油が充填されている。The two radial dynamic pressure bearings 63,
The lubricating oil at 64 is filled in a continuous state with each other, and the lubricating oil is also filled in an oil sump 65 provided between the radial dynamic pressure bearing portions 63 and 64.
【００４０】そして、上記軸受スリーブ５３と回転軸６
１との両対向面のうち、少なくとも一方側には、例えば
ヘリンボーン形状のラジアル動圧発生用溝が環状に並列
するように凹設されており、前記ハブ６２の回転時に、
当該ラジアル動圧発生用溝のポンピング作用によって潤
滑油が昇圧されて動圧が生じ、この潤滑油に生じさせら
れた動圧によって、ハブ６２がラジアル方向に軸支持さ
れるように構成されている。The bearing sleeve 53 and the rotating shaft 6
For example, a herringbone-shaped radial dynamic pressure generating groove is concavely provided in at least one side of the two opposing surfaces with each other so as to be annularly parallel to each other.
The lubricating oil is pressurized by the pumping action of the radial dynamic pressure generating groove to generate a dynamic pressure, and the dynamic pressure generated by the lubricating oil causes the hub 62 to be axially supported in the radial direction. .
【００４１】一方、前記回転軸６１は、前述した実施形
態と同様に、ステンレスの焼き入れ鋼等のような硬質材
料から形成されており、当該回転軸６１の先端側（図示
下端側）に、リング状の環状部材を構成する抜け止め部
材６６が圧入により嵌着されている。この抜け止め部材
６６は、上記回転軸６１の外周面から半径方向に張り出
すようにして嵌着された円盤状の環状部材から形成され
ており、前記回転軸６１の材料よりも軟質な材料、例え
ばリン青銅等の銅材料や、フェライト系、オーステナイ
ト系のステンレス鋼の生材料から形成されている。On the other hand, the rotating shaft 61 is made of a hard material such as hardened stainless steel, as in the above-described embodiment, and is provided at the tip end (the lower end in the drawing) of the rotating shaft 61. A retaining member 66 constituting a ring-shaped annular member is fitted by press fitting. The retaining member 66 is formed of a disk-shaped annular member fitted so as to protrude in the radial direction from the outer peripheral surface of the rotating shaft 61, and is made of a material softer than the material of the rotating shaft 61, For example, it is formed from a raw material of a copper material such as phosphor bronze or a ferritic or austenitic stainless steel.
【００４２】そして、上記抜け止め部材６６が、軸受ス
リーブ５３の図示下端部分の内周部に環状に切り欠くよ
うにして凹設されたスラスト軸受部内に収容されている
ことによって、当該抜け止め部材６６により回転軸６１
が軸方向に係止され、前記ハブ６２の軸方向への離脱が
防止されるようになっている。The retaining member 66 is accommodated in a thrust bearing portion which is recessed so as to be annularly notched in the inner peripheral portion of the lower end portion of the bearing sleeve 53 in the drawing, so that the retaining member 66 is provided. The rotation shaft 61 by 66
Are locked in the axial direction to prevent the hub 62 from being detached in the axial direction.
【００４３】また、上記軸受スリーブ５３の図示下端側
外周壁部分には、中実円盤状部材からなるスラスト軸受
部材５７が固着されている。このスラスト軸受部材５７
は、前記回転軸６１とほぼ同程度の硬度を有する硬質材
料から形成されており、上記抜け止め部材６６における
軸方向外側（図示下側）の平坦表面に対して軸方向に対
面するように配置されている。A thrust bearing member 57 made of a solid disk is fixed to the outer peripheral wall of the bearing sleeve 53 at the lower end in the figure. This thrust bearing member 57
Are formed of a hard material having substantially the same hardness as the rotation shaft 61 and are disposed so as to face the flat surface on the axially outer side (the lower side in the figure) of the retaining member 66 in the axial direction. Have been.
【００４４】すなわち、上記スラスト軸受部材５７の図
示上側の平坦表面は、前記回転軸６１の軸端面、及び抜
け止め部材６６の図示下側の平坦表面に対して、所定の
隙間を介在するように対向配置されることによりスラス
ト動圧面を構成しており、そのスラスト動圧面間におけ
る隙間内に潤滑油が注入されている。同様に、上記抜け
止め部材６６の図示下側の平坦表面は、前述した軸受ス
リーブ５３の平坦表面に対して、所定の隙間を介在する
ように対向配置されることによりスラスト動圧面を構成
しており、そのスラスト動圧面間における隙間内に潤滑
油が、連続的に注入されている。これらの潤滑油は、上
述したラジアル軸受側の潤滑油から連続して注入されて
いる。That is, the upper flat surface of the thrust bearing member 57 in the drawing is provided such that a predetermined gap is interposed between the shaft end surface of the rotary shaft 61 and the lower flat surface of the retaining member 66 in the drawing. The thrust dynamic pressure surfaces are formed by being arranged to face each other, and lubricating oil is injected into a gap between the thrust dynamic pressure surfaces. Similarly, the flat surface on the lower side in the figure of the retaining member 66 constitutes a thrust dynamic pressure surface by being disposed so as to face the flat surface of the bearing sleeve 53 with a predetermined gap therebetween. The lubricating oil is continuously injected into the gap between the thrust dynamic pressure surfaces. These lubricating oils are continuously injected from the above-described lubricating oil on the radial bearing side.
【００４５】一方、上記抜け止め部材６６の軸方向両端
における各平坦表面には、例えばヘリンボーン形状をな
すスラスト動圧発生用溝（図示省略）が形成されてお
り、このスラスト動圧発生用溝の加圧作用により潤滑油
に生じさせられるスラスト動圧によって、前記スラスト
軸受部材１７に対して、回転軸６１及び抜け止め部材６
６が、軸方向に所定量浮上させられながら、スラスト方
向に回転支持されるように構成されている。On the other hand, on each flat surface at both axial ends of the retaining member 66, for example, a herringbone-shaped thrust dynamic pressure generating groove (not shown) is formed. By the thrust dynamic pressure generated in the lubricating oil by the pressurizing action, the rotation shaft 61 and the retaining member 6 are applied to the thrust bearing member 17.
6 is configured to be rotatably supported in the thrust direction while being floated in the axial direction by a predetermined amount.
【００４６】このとき、上記回転軸６１の対向軸端面
（図示下端面）６１ａは、中心部分がスラスト軸受部材
５７へ向って凸となる球面形状に形成されており、その
回転軸６１の中心部分における突出表面が、前記抜け止
め部材６６の対向平坦表面（図示上平坦表面）から、軸
方向（図示下側方向）に向って僅かな寸法（図２中の符
号「Ａ」参照）だけ突出するように配置されている。す
なわち、上記回転軸６１の軸端面６１ａと、抜け止め部
材６６の平坦表面との間の軸方向間隔（図２中の符号
「Ａ」参照）は、前述した回転軸６１及び抜け止め部材
６６のスラスト方向への浮上量（図２の符号「Ｂ」参
照）よりやや小さくなるように設定されている。At this time, the opposite shaft end face (the lower end face in the figure) 61a of the rotary shaft 61 is formed in a spherical shape whose central portion is convex toward the thrust bearing member 57. Is protruded from the opposing flat surface (upper flat surface in the drawing) of the retaining member 66 by a small dimension (refer to the symbol “A” in FIG. 2) in the axial direction (lower direction in the drawing). Are arranged as follows. That is, the axial distance between the shaft end surface 61a of the rotating shaft 61 and the flat surface of the retaining member 66 (see reference numeral "A" in FIG. 2) is different from that of the rotating shaft 61 and the retaining member 66 described above. The flying height is set to be slightly smaller than the flying height in the thrust direction (see reference numeral “B” in FIG. 2).
【００４７】これを換言すれば、回転停止時における上
記抜け止め部材６６とスラスト軸受部材５７との対向隙
間の間隔「Ａ」が、回転停止時における前記回転軸６１
とスラスト軸受部材５７との対向隙間の間隔である
「０」より大きく（Ａ＞０）、かつ回転駆動時における
浮上量「Ｂ」より小さく設定されていることとなる（Ａ
＜Ｂ）。In other words, the interval “A” between the opposing gaps between the retaining member 66 and the thrust bearing member 57 when the rotation is stopped depends on the rotation shaft 61 when the rotation is stopped.
(A> 0), which is the distance between the opposing gaps between the bearing and the thrust bearing member 57 (A> 0), and is set to be smaller than the flying height "B" during rotational driving (A).
<B).
【００４８】この実施形態装置のように、本発明は、軸
回転型のＨＤＤスピンドルモータに対しても同様に適用
することができるものであり、同様な作用・効果を得る
ことができる。As in the apparatus of this embodiment, the present invention can be similarly applied to a shaft-rotating HDD spindle motor, and similar operations and effects can be obtained.
【００４９】さらに、図６に示されている実施形態で
は、潤滑油の循環通路５８が、ラジアル軸受部に設けら
れた油溜り部６５から軸受スリーブ５３内を半径方向外
側に向って延びている。この場合の回転軸６１の構成、
及びスラスト動圧軸受部の構成は、上述した実施形態と
同様であって、この実施形態においても、上述した各実
施形態と同様な作用・効果を得ることができる。Further, in the embodiment shown in FIG. 6, the lubricating oil circulation passage 58 extends radially outward in the bearing sleeve 53 from the oil reservoir 65 provided in the radial bearing. . The configuration of the rotating shaft 61 in this case,
The configuration of the thrust dynamic pressure bearing portion is the same as that of the above-described embodiment. In this embodiment, the same operation and effect as those of the above-described embodiments can be obtained.
【００５０】以上、本発明者によってなされた発明の実
施形態を具体的に説明したが、本発明は上記実施形態に
限定されるものではなく、その要旨を逸脱しない範囲で
種々変形可能であるというのはいうまでもない。The embodiment of the invention made by the inventor has been specifically described above. However, the present invention is not limited to the above embodiment, and can be variously modified without departing from the gist of the invention. Needless to say.
【００５１】例えば、上記各実施形態においては、環状
部材として抜け止め部材を兼用させているが、環状部材
はこれに限定されるものではなく、抜け止め部材以外の
環状部材を同様にして用いることも可能である。For example, in each of the above embodiments, the retaining member is also used as the annular member. However, the annular member is not limited to this, and the annular member other than the retaining member may be used in the same manner. Is also possible.
【００５２】また、上記各実施形態では、軸部材の軸端
面を環状部材から軸方向に突出させているが、スラスト
軸受部材に所定の凹凸形状を形成することによって、軸
部材と環状部材との凹凸関係を、上述した各実施形態と
は逆の凹凸関係に設定することも可能である。Further, in each of the above embodiments, the shaft end face of the shaft member protrudes in the axial direction from the annular member. However, by forming a predetermined uneven shape on the thrust bearing member, the shaft member and the annular member can be separated from each other. It is also possible to set the unevenness relationship opposite to the above-described embodiments.
【００５３】さらに本発明は、上述したＨＤＤモータ以
外に用いられる動圧軸受装置に対しても同様に適用する
ことができる。Further, the present invention can be similarly applied to a dynamic pressure bearing device used other than the HDD motor described above.
【００５４】[0054]
【発明の効果】以上述べたように本発明は、軸部材側に
嵌着された環状部材とスラスト軸受部材との対向隙間の
間隔を、軸部材とスラスト軸受部材との対向隙間の間隔
より大きく、かつスラスト浮上量より小さく設定するこ
とにより、スラスト動圧を生じていない回転停止時及び
動圧力が不十分な回転開始直後において、通常高硬度の
材料から形成される軸部材をスラスト軸受部材側に接触
させ、比較的軟らかい材料から形成される抜け止め部材
等の環状部材をスラスト軸受部材の表面から離間させる
ように構成したものであるから、従来のような環状部材
の摩耗を完全になくして、動圧力を長期にわたって安定
して得ることができるとともに、環状部材からの摩耗粉
が潤滑油に混入することを防止して潤滑油の粘度等の劣
化を良好に防止することができ、スラスト動圧軸受装置
の信頼性を向上させることができる。As described above, according to the present invention, the gap between the opposed gap between the annular member fitted to the shaft member and the thrust bearing member is made larger than the gap between the opposed gap between the shaft member and the thrust bearing member. By setting the thrust floating amount to be smaller than the thrust floating amount, the shaft member, which is usually formed of a high-hardness material, is moved to the thrust bearing member side at the time of rotation stop where no thrust dynamic pressure is generated and immediately after the start of rotation where the dynamic pressure is insufficient. , So that the annular member such as a retaining member formed of a relatively soft material is separated from the surface of the thrust bearing member, thereby completely eliminating the wear of the conventional annular member. In addition, the dynamic pressure can be stably obtained over a long period of time, and the deterioration of the viscosity and the like of the lubricating oil can be well prevented by preventing wear powder from the annular member from being mixed into the lubricating oil. It can, it is possible to improve the reliability of the thrust dynamic pressure bearing device.
【００５５】このとき、請求項４記載の手段は、軸部材
の対向軸端面に、回転停止時及び回転開始直後にスラス
ト軸受部材の対向平坦表面に接触する小さな外径の当接
部を設けることにより、スラスト軸受部材側に対する軸
部材の接触面積を小さくし、環状部材を軸部材側に嵌着
する際の直角度に多少の誤差を生じていた場合であって
も、軸部材とスラスト軸受部材との接触時間を短時間と
して軸部材側の摩耗量を小さく抑えるように構成したも
のであるから、上述した効果をさらに高めることができ
る。また、小さい径とした当接部の直角度を、容易に出
すことができるため、生産性を向上させることもでき
る。At this time, in the means according to the fourth aspect, a small outer diameter contact portion which comes into contact with the opposed flat surface of the thrust bearing member when the rotation is stopped and immediately after the rotation is started is provided on the opposed shaft end face of the shaft member. Accordingly, the contact area of the shaft member with the thrust bearing member side is reduced, and even if a slight error occurs in the perpendicularity when the annular member is fitted to the shaft member side, the shaft member and the thrust bearing member Since the contact time with the shaft member is set to be short and the amount of wear on the shaft member side is suppressed to be small, the above-described effect can be further enhanced. Further, since the perpendicularity of the contact portion having a small diameter can be easily obtained, productivity can be improved.
【図１】本発明の一実施形態にかかるスラスト動圧軸受
装置を備えた軸固定型のＨＤＤスピンドルモータの一例
を表した横断面説明図である。FIG. 1 is an explanatory cross-sectional view showing an example of a fixed-shaft HDD spindle motor including a thrust dynamic pressure bearing device according to an embodiment of the present invention.
【図２】図１におけるスラスト動圧軸受部を拡大して表
した部分横断面説明図である。FIG. 2 is a partial cross-sectional explanatory view showing a thrust dynamic pressure bearing portion in FIG. 1 in an enlarged manner.
【図３】図２に対応する本発明の他の実施形態における
スラスト動圧軸受部の部分拡大横断面説明図である。FIG. 3 is a partially enlarged cross-sectional explanatory view of a thrust dynamic pressure bearing portion according to another embodiment of the present invention corresponding to FIG. 2;
【図４】図２及び図３に対応する本発明のさらに他の実
施形態におけるスラスト動圧軸受部の部分拡大横断面説
明図である。FIG. 4 is a partially enlarged cross-sectional explanatory view of a thrust dynamic pressure bearing portion according to still another embodiment of the present invention corresponding to FIGS. 2 and 3;
【図５】本発明にかかるスラスト動圧軸受装置を備えた
軸回転型のＨＤＤスピンドルモータの一例を表した横断
面説明図である。FIG. 5 is a cross-sectional explanatory view showing an example of a shaft rotation type HDD spindle motor provided with a thrust dynamic pressure bearing device according to the present invention.
【図６】図２、図３及び図４に対応する本発明の他の実
施形態におけるスラスト動圧軸受部の部分拡大横断面説
明図である。FIG. 6 is a partially enlarged cross-sectional explanatory view of a thrust dynamic pressure bearing portion according to another embodiment of the present invention corresponding to FIGS. 2, 3, and 4;
１３ 固定軸 １３ａ 固定軸の軸端面 １６ 抜け止め部材（環状部材） １６ａ，１６ｂ 抜け止め部材の平坦表面 １７ スラスト軸受部材 １７ａ スラスト軸受部材の平坦表面 ２１ ハブ ２２ 軸受スリーブ ２２ａ 軸受スリーブの平坦表面 ２３，２４ ラジアル動圧軸受部 ＳＢ スラスト軸受部 Ａ 固定軸の軸端面と抜け止め部材の対向平坦表面との
間の間隔 Ｂ 固定軸及び抜け止め部材に対するスラスト軸受部材
の浮上量 １３’ 固定軸 １３’ａ 固定軸の軸端面 １３’ｂ 凸状当接部 １８，１８’ 潤滑油循環通路 ５３ 軸受スリーブ ５７ スラスト軸受部材 ５８ 潤滑油循環通路 ６１ 回転軸 ６１ａ 回転軸の軸端面 ６２ ハブ ６３，６４ ラジアル動圧軸受部 ６６ 抜け止め部材（環状部材）Reference Signs List 13 fixed shaft 13a shaft end surface of fixed shaft 16 retaining member (annular member) 16a, 16b flat surface of retaining member 17 thrust bearing member 17a flat surface of thrust bearing member 21 hub 22 bearing sleeve 22a flat surface of bearing sleeve 23, 24 Radial dynamic pressure bearing part SB Thrust bearing part A The distance between the shaft end face of the fixed shaft and the opposing flat surface of the retaining member B The floating amount of the thrust bearing member with respect to the fixed shaft and the retaining member 13 'Fixed shaft 13'a Shaft end face 13'b Convex contact portion 18, 18 'Lubricating oil circulation passage 53 Bearing sleeve 57 Thrust bearing member 58 Lubricating oil circulation passage 61 Rotating shaft 61a Shaft end surface of rotating shaft 62 Hub 63, 64 Radial dynamic pressure Bearing 66 Retaining member (annular member)
Claims (5)
方向に張り出すようにして軸部材に嵌着された環状部材
と、これら軸部材及び環状部材のそれぞれに対して、軸
方向に所定の隙間を介在して対向するように配置された
スラスト軸受部材と、が設けられているとともに、 上記軸部材及び環状部材とスラスト軸受部材との間の対
向隙間内に潤滑油が充填され、かつ、前記対向隙間を構
成する環状部材及びスラスト軸受部材の各対向平坦表面
のうちの少なくとも一面に動圧発生用溝が形成され、 その動圧発生用溝の加圧作用により潤滑油に生じさせら
れる動圧によって、前記軸部材及び環状部材とスラスト
軸受部材とが、軸方向に所定量Ｂだけ相対浮上させられ
ながら回転支持されるスラスト動圧軸受装置において、 回転停止時における上記環状部材とスラスト軸受部材と
の対向隙間の間隔Ａが、回転停止時における前記軸部材
とスラスト軸受部材との対向隙間の間隔である０より大
きく、かつ回転駆動時における前記軸部材及び環状部材
とスラスト軸受部材との相対浮上量Ｂより小さく設定さ
れていることを特徴とするスラスト動圧軸受装置。A shaft member, an annular member fitted to the shaft member so as to protrude radially from an outer peripheral surface of the shaft member, and an axial direction with respect to each of the shaft member and the annular member. A thrust bearing member arranged to face each other with a predetermined gap therebetween, and lubricating oil is filled in an opposing gap between the shaft member and the annular member and the thrust bearing member, Further, a dynamic pressure generating groove is formed on at least one of the opposing flat surfaces of the annular member and the thrust bearing member constituting the opposing gap, and the lubricating oil is generated by the pressurizing action of the dynamic pressure generating groove. In the thrust hydrodynamic bearing device in which the shaft member and the annular member and the thrust bearing member are rotatably supported while being floated relative to each other by a predetermined amount B in the axial direction by the applied dynamic pressure, The gap A between the facing gap between the annular member and the thrust bearing member is larger than 0 which is the spacing between the facing gap between the shaft member and the thrust bearing member when rotation is stopped, and the gap between the shaft member and the annular member during rotational driving. A thrust dynamic pressure bearing device, wherein the relative floating height B with respect to a thrust bearing member is set to be smaller.
面が、前記環状部材の対向平坦表面から軸方向にスラス
ト軸受部材側に向って所定量突出するように配置され、 これら軸部材の対向軸端面と環状部材の対向平坦表面と
の間の軸方向間隔が、軸部材及び環状部材の浮上量より
小さくなるように設定されていることを特徴とするスラ
スト動圧軸受装置。2. The shaft member according to claim 1, wherein the opposed shaft end face is arranged so as to protrude from the opposed flat surface of the annular member in the axial direction toward the thrust bearing member by a predetermined amount, and the opposed shaft members are opposed to each other. A thrust dynamic pressure bearing device, wherein an axial distance between a shaft end surface and an opposed flat surface of an annular member is set to be smaller than a floating amount of the shaft member and the annular member.
ラスト軸受部材との軸方向における相対的な離脱を防止
する抜け止め部材であることを特徴とするスラスト動圧
軸受装置。3. The thrust dynamic pressure bearing device according to claim 1, wherein the annular member is a retaining member for preventing relative separation of the shaft member and the thrust bearing member in the axial direction.
軸部材の一般径より小さな外径で軸方向に突出するよう
に形成され、回転停止時及び回転開始直後にスラスト軸
受部材の対向平坦表面に接触する当接部が設けられてい
ることを特徴とするスラスト動圧軸受装置。4. The shaft member according to claim 1, wherein
The thrust bearing member is formed so as to protrude in the axial direction with an outer diameter smaller than the general diameter of the shaft member, and is provided with a contact portion that comes into contact with the opposed flat surface of the thrust bearing member at the time of rotation stop and immediately after the start of rotation. Thrust hydrodynamic bearing device.
スラスト軸受部材よりも軟質な材料から形成されている
とともに、 当該環状部材の対向平坦表面に動圧発生用溝が形成され
ていることを特徴とするスラスト動圧軸受装置。5. The annular member according to claim 1, wherein the annular member is formed of a material softer than the shaft member and the thrust bearing member, and a dynamic pressure generating groove is formed on the opposed flat surface of the annular member. A thrust hydrodynamic bearing device characterized by the above-mentioned.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18058797A JPH1113748A (en) | 1997-06-21 | 1997-06-21 | Thrust dynamic pressure bearing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18058797A JPH1113748A (en) | 1997-06-21 | 1997-06-21 | Thrust dynamic pressure bearing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1113748A true JPH1113748A (en) | 1999-01-22 |
Family
ID=16085880
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18058797A Pending JPH1113748A (en) | 1997-06-21 | 1997-06-21 | Thrust dynamic pressure bearing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1113748A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SG111931A1 (en) * | 2001-03-05 | 2005-06-29 | Sankyo Seiki Seisakusho Kk | Fluid dynamic pressure bearing apparatus |
| JP2007192369A (en) * | 2006-01-20 | 2007-08-02 | Jtekt Corp | Performance determining method of dynamic pressure bearing and dynamic pressure bearing |
-
1997
- 1997-06-21 JP JP18058797A patent/JPH1113748A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SG111931A1 (en) * | 2001-03-05 | 2005-06-29 | Sankyo Seiki Seisakusho Kk | Fluid dynamic pressure bearing apparatus |
| US6962443B2 (en) | 2001-03-05 | 2005-11-08 | Sankyo Seiki Mfg. Co., Ltd. | Fluid dynamic pressure bearing apparatus |
| JP2007192369A (en) * | 2006-01-20 | 2007-08-02 | Jtekt Corp | Performance determining method of dynamic pressure bearing and dynamic pressure bearing |
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