JP2010096200A - Fluid bearing device and its manufacturing method - Google Patents

Fluid bearing device and its manufacturing method Download PDF

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JP2010096200A
JP2010096200A JP2008265154A JP2008265154A JP2010096200A JP 2010096200 A JP2010096200 A JP 2010096200A JP 2008265154 A JP2008265154 A JP 2008265154A JP 2008265154 A JP2008265154 A JP 2008265154A JP 2010096200 A JP2010096200 A JP 2010096200A
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bearing
housing
peripheral surface
sleeve
outer peripheral
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Hiromichi Kunigome
広道 國米
Takaharu Inazuka
貴開 稲塚
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NTN Corp
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NTN Corp
NTN Toyo Bearing Co Ltd
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  • Injection Moulding Of Plastics Or The Like (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid bearing device excellent in high-rotation accuracy at a low cost. <P>SOLUTION: A housing 9 constituting the fluid bearing device 1 is molded by being inserted with a first bearing sleeve 81 and a second bearing sleeve 82 arranged in two positions which are axially separated from each other. The housing 9 integrally has a spacer 9c which is interposed between both the bearing sleeves 81, 82. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は流体軸受装置およびその製造方法に関するものである。   The present invention relates to a hydrodynamic bearing device and a manufacturing method thereof.

流体軸受装置は、軸受隙間に形成される油膜で軸部材を回転自在に支持するものである。この流体軸受装置は、高速回転、高回転精度、低騒音等の特徴を有するものであり、近年ではその特徴を活かして、情報機器をはじめ種々の電気機器に搭載されるモータ用の軸受装置として、より具体的には、ＨＤＤ等の磁気ディスク装置やＣＤ−ＲＯＭ、ＣＤ−Ｒ／ＲＷ、ＤＶＤ−ＲＯＭ／ＲＡＭ等の光ディスク装置等のスピンドルモータ、レーザビームプリンタ（ＬＢＰ）のポリゴンスキャナモータ、ＰＣ等のファンモータなどのモータ用軸受装置として好適に使用されている。   The hydrodynamic bearing device supports a shaft member rotatably with an oil film formed in a bearing gap. This hydrodynamic bearing device has characteristics such as high-speed rotation, high rotation accuracy, and low noise. In recent years, the hydrodynamic bearing device has been utilized as a motor bearing device for motors mounted on various electrical devices including information devices. More specifically, spindle motors for magnetic disk devices such as HDD, optical disk devices such as CD-ROM, CD-R / RW, DVD-ROM / RAM, etc., polygon scanner motors for laser beam printers (LBP), PCs It is suitably used as a motor bearing device such as a fan motor.

上記モータのうち、例えばディスク装置用のスピンドルモータに組み込んで使用される流体軸受装置として、例えば特開２００３−３３６６３６号公報（特許文献１）に記載のように、ハウジングと、ハウジングの内周に収容された軸受スリーブと、軸受スリーブの内周に挿入され、ハウジングおよび軸受スリーブに対して相対回転する軸部材とを主要な構成部材として備えるものが公知である。この流体軸受装置では、軸部材の回転に伴い、軸受スリーブの内周面と軸部材の外周面との間のラジアル軸受隙間に形成される油膜で軸部材をラジアル方向に支持するラジアル軸受部が形成される。   Among the motors, for example, as a hydrodynamic bearing device used by being incorporated in a spindle motor for a disk device, as described in, for example, JP-A-2003-336636 (Patent Document 1), a housing and an inner periphery of the housing are provided. A known bearing sleeve and a shaft member that is inserted into the inner periphery of the bearing sleeve and rotates relative to the housing and the bearing sleeve are known as main components. In this hydrodynamic bearing device, there is a radial bearing portion that supports the shaft member in the radial direction with an oil film formed in a radial bearing gap between the inner peripheral surface of the bearing sleeve and the outer peripheral surface of the shaft member as the shaft member rotates. It is formed.

ところで、ディスク装置の大容量化、高速回転化等に伴い、流体軸受装置には更なる回転精度の向上が求められている。回転精度向上のための一手段として、軸受剛性、特にモーメント剛性を高めることが考えられる。軸受剛性の向上には、ラジアル軸受部間のスパンを大きくするのが有効であり、そのため、上記特許文献１も含め、ラジアル軸受部を軸方向に離隔した複数箇所（一般的には２箇所）に設けた構成を採用するのが通例である。しかしながら、特に軸受スリーブを焼結金属製とした場合には、製作精度上の問題があることから、単一の軸受スリーブの内周側で、更なるラジアル軸受部間のスパンを拡大するのは容易ではない。そこで、例えば特開平１１−１５５２５４号公報（特許文献２）に記載のように、ハウジングの内周に、軸方向に離隔して複数の軸受スリーブを配置することが考えられる。この場合、ハウジングの内部空間に充填すべき油量の低減を目的として、スペーサ部材と称される（「間座」とも称される）部材が、軸方向で隣り合う軸受スリーブ間に配設されるのが通例である。
特開２００３−３３６６３６号公報 特開平１１−１５５２５４号公報 By the way, as the capacity of the disk device is increased and the rotation speed is increased, the hydrodynamic bearing device is required to further improve the rotation accuracy. As one means for improving the rotational accuracy, it is conceivable to increase the bearing rigidity, particularly the moment rigidity. In order to improve the bearing rigidity, it is effective to increase the span between the radial bearing portions. Therefore, including the above-mentioned Patent Document 1, a plurality of locations (generally two locations) in which the radial bearing portions are separated in the axial direction. Generally, the configuration provided in the above is adopted. However, especially when the bearing sleeve is made of sintered metal, there is a problem in manufacturing accuracy, so it is not possible to enlarge the span between the radial bearing portions on the inner circumference side of a single bearing sleeve. It's not easy. Therefore, for example, as described in Japanese Patent Application Laid-Open No. 11-155254 (Patent Document 2), it is conceivable to dispose a plurality of bearing sleeves on the inner periphery of the housing so as to be separated in the axial direction. In this case, for the purpose of reducing the amount of oil to be filled in the internal space of the housing, a member referred to as a spacer member (also referred to as a “spacer”) is disposed between axially adjacent bearing sleeves. It is customary.
JP 2003-336636 A JP-A-11-155254

しかしながら、上記特許文献２の構成では、ハウジング、複数の軸受スリーブ、およびスペーサ部材といった数多くの部材で軸部材を相対回転自在に支持する部材を構成する必要があるため、部品コストおよび製造コストが嵩むという問題がある。また、所期の軸受性能を発揮可能とするには、ハウジングに対する軸受スリーブおよびスペーサ部材の位置決めを精度良く行った上でこれらをハウジング内周に固定しなければならないが、工程や製造設備（治具等）がどうしても複雑となってしまうため、製造コストの高騰が特に問題となっている。   However, in the configuration of Patent Document 2, it is necessary to configure a member that supports the shaft member so as to be relatively rotatable with a large number of members such as a housing, a plurality of bearing sleeves, and a spacer member. There is a problem. In order to achieve the desired bearing performance, the bearing sleeve and spacer member must be accurately positioned with respect to the housing and then fixed to the inner periphery of the housing. In particular, the increase in manufacturing cost is a problem.

本発明の課題は、軸受剛性が高く、高い回転精度を誇る流体軸受装置を低コストに提供可能とすることにある。   An object of the present invention is to make it possible to provide a hydrodynamic bearing device having high bearing rigidity and high rotational accuracy at low cost.

上記課題を解決するため、本発明では、少なくとも一端が開口したハウジングと、ハウジングの内周に収容された軸受スリーブと、軸受スリーブの内周に挿入された軸部材と、軸受スリーブの内周面と軸部材の外周面との間のラジアル軸受隙間に形成される油膜で軸部材をラジアル方向に支持するラジアル軸受部とを備える流体軸受装置において、ハウジングが、軸方向に離隔して複数配置した軸受スリーブをインサートして型成形され、かつ、軸方向で隣り合う軸受スリーブ間に介在するスペーサ部を有することを特徴とする流体軸受装置を提供する。   In order to solve the above problems, in the present invention, a housing having at least one end opened, a bearing sleeve accommodated in the inner periphery of the housing, a shaft member inserted in the inner periphery of the bearing sleeve, and an inner peripheral surface of the bearing sleeve In a hydrodynamic bearing device including a radial bearing portion that supports a shaft member in a radial direction with an oil film formed in a radial bearing gap between the shaft member and an outer peripheral surface of the shaft member, a plurality of housings are arranged separately in the axial direction. Provided is a fluid dynamic bearing device which is molded by inserting a bearing sleeve and has a spacer portion interposed between adjacent bearing sleeves in the axial direction.

上記のように、本発明に係る流体軸受装置では、軸部材との間にラジアル軸受隙間を形成する軸受スリーブが軸方向に複数配置されることから、高いモーメント剛性を確保しつつ、個々の軸受スリーブの製作精度を高めて各ラジアル軸受部における支持能力を高めることができる。また、ハウジングが、複数の軸受スリーブをインサートして型成形され、かつ軸方向で隣り合う軸受スリーブ間に介在するスペーサ部を有するものであるから、スペーサ部を含めたハウジングの成形と、このハウジングに対する軸受スリーブの組み付けとを一工程で完了することができる。しかも、型精度を高めておくだけで、ハウジングに対する各軸受スリーブの相対的な位置決めは高精度に行い得る。   As described above, in the hydrodynamic bearing device according to the present invention, since a plurality of bearing sleeves that form radial bearing gaps between the shaft members are arranged in the axial direction, individual bearings are secured while ensuring high moment rigidity. The manufacturing accuracy of the sleeve can be increased to increase the support capability of each radial bearing portion. In addition, since the housing is formed by inserting a plurality of bearing sleeves and has a spacer portion interposed between adjacent bearing sleeves in the axial direction, molding of the housing including the spacer portion, and the housing The assembly of the bearing sleeve with respect to can be completed in one step. In addition, the relative positioning of each bearing sleeve with respect to the housing can be performed with high accuracy only by increasing the mold accuracy.

上記構成のハウジングは、例えば、軸方向に離隔して複数配置した軸受スリーブをインサート部品とし、軸方向で隣り合う軸受スリーブ間に配したゲートから溶融材料をキャビティ内に充填することにより成形することができる。これは、ハウジングが、その外周面のうち、スペーサ部の形成領域にゲート跡を有するものと換言することができる。このようにすれば、ゲートの軸方向両側に配される軸受スリーブを、キャビティ内に溶融材料を射出・充填するときの射出圧（射出・充填される溶融材料の流動力）でもって互いに離反する方向に移動させ、キャビティ（ハウジング）に対する軸方向の相対的な位置決めを行うことが可能となる。   The housing configured as described above is formed by, for example, using a plurality of bearing sleeves spaced apart in the axial direction as insert parts and filling the cavity with molten material from a gate disposed between adjacent bearing sleeves in the axial direction. Can do. In other words, the housing has a gate mark in the region where the spacer portion is formed on the outer peripheral surface thereof. In this way, the bearing sleeves arranged on both sides in the axial direction of the gate are separated from each other by the injection pressure (the flow force of the molten material to be injected / filled) when the molten material is injected / filled into the cavity. It is possible to perform relative positioning in the axial direction with respect to the cavity (housing).

具体的には、内型の外周面に各軸受スリーブを嵌合し、各軸受スリーブのうち、最も内型の基端側に位置する軸受スリーブの軸方向の位置決めを、内型に設けた段部に前記軸受スリーブを係合させることにより行うことができる。このようにすれば、成形金型に配置する段階で各軸受スリーブ間の芯出しを行うことができ、しかも金型へ軸受スリーブを配置段階では、各軸受スリーブの配置態様に格別の配慮を払う必要がない。そのため、高精度な成形品を低コストに製造することができる。   Specifically, each bearing sleeve is fitted to the outer peripheral surface of the inner mold, and the axial positioning of the bearing sleeve located closest to the proximal end of the inner mold among the bearing sleeves is provided on the inner mold. This can be done by engaging the bearing sleeve with the part. In this way, centering between the bearing sleeves can be performed at the stage of placing in the molding die, and in the stage of placing the bearing sleeve on the mold, special consideration is given to the manner of arrangement of the bearing sleeves. There is no need. Therefore, a highly accurate molded product can be manufactured at low cost.

上記方法を採用する場合に、軸受スリーブに付加される加圧力に対して内型と軸受スリーブとの間の摩擦抵抗力が過大であると、軸受スリーブを内型に沿って移動させることができないおそれがある他、軸受スリーブの内周面が損傷等してラジアル軸受部の軸受性能に悪影響が及ぶおそれがある。このような問題は、例えば、内型として、外周面に低摩擦処理が施されたものを用いる、あるいは、軸受スリーブを多孔質材料で形成し、この軸受スリーブを、その内部気孔に潤滑油を含浸させた状態で内型の外周面に嵌合することによって解消することができる。なお、低摩擦処理としては、ＤＬＣコーティング、めっき、フッ素コーティング等を採用することができる。   When the above method is employed, if the frictional resistance force between the inner mold and the bearing sleeve is excessive with respect to the pressure applied to the bearing sleeve, the bearing sleeve cannot be moved along the inner mold. In addition, there is a possibility that the inner peripheral surface of the bearing sleeve may be damaged and the bearing performance of the radial bearing portion may be adversely affected. Such a problem may be caused by, for example, using an inner die whose outer peripheral surface has been subjected to a low friction treatment, or forming a bearing sleeve from a porous material and applying lubricating oil to the inner pores of the bearing sleeve. This can be solved by fitting the outer peripheral surface of the inner mold in the impregnated state. In addition, as a low friction process, DLC coating, plating, a fluorine coating, etc. are employable.

ところで、上記特許文献１にも記載のように、軸方向で隣り合うラジアル軸受部間には、軸受トルクの増大を抑制すべく、ラジアル軸受部のラジアル軸受隙間よりも隙間幅の大きい間隙部分が設けられる。この間隙部分は、互いに対向する軸受スリーブの内周面または軸部材の外周面に、逃げ部と称される凹状の部分を設けておくことによって形成することができる。上記本発明に係る流体軸受装置においては、ハウジングを構成するスペーサ部の内周面に、ハウジングの型成形後に生じる成形収縮を利用して逃げ部を形成することができる。このようにすれば、互いに対向する面の何れか一方に機械加工等で逃げ部を設ける必要がなくなるため、加工コストを低減することができる。   By the way, as described in Patent Document 1, a gap portion having a gap width larger than the radial bearing gap of the radial bearing portion is present between radial bearing portions adjacent in the axial direction in order to suppress an increase in bearing torque. Provided. This gap portion can be formed by providing concave portions called relief portions on the inner peripheral surface of the bearing sleeve or the outer peripheral surface of the shaft member facing each other. In the hydrodynamic bearing device according to the present invention, a relief portion can be formed on the inner peripheral surface of the spacer portion constituting the housing by utilizing molding shrinkage that occurs after molding of the housing. In this way, it is not necessary to provide a relief portion by machining or the like on any one of the surfaces facing each other, so that the processing cost can be reduced.

また、ハウジングの一端開口部には、ハウジングの内部空間に充満される潤滑油の漏れ出しを防止するためのシール空間が通常設けられる。本発明において、ハウジングには、複数の軸受スリーブのうち、最もハウジング開口側に位置する軸受スリーブの一端面（反スペーサ部側一端面）を被覆し、軸部材との間にシール空間を形成するシール部をさらに設けることができる。かかる構成とすれば、別途のシール部材をハウジングの開口部に設ける必要がなくなるので、部品点数および組立工数の更なる低減を図ることができる。また、最もハウジング開口側に位置する軸受スリーブの両端面をシール部およびスペーサ部で被覆することができるので、ハウジングに対する当該軸受スリーブの固定面積を増して固定強度を高めることが、ひいてはこの流体軸受装置の信頼性向上を図ることができる。   In addition, a seal space for preventing leakage of the lubricating oil filled in the internal space of the housing is usually provided at one end opening of the housing. In the present invention, the housing covers one end surface (one end surface on the side opposite to the spacer portion) of the bearing sleeve located closest to the housing opening among the plurality of bearing sleeves, and forms a seal space between the shaft member. A seal portion can be further provided. With such a configuration, it is not necessary to provide a separate seal member at the opening of the housing, so that the number of parts and the number of assembly steps can be further reduced. Further, since both end faces of the bearing sleeve located closest to the housing opening can be covered with the seal portion and the spacer portion, it is possible to increase the fixing strength by increasing the fixing area of the bearing sleeve with respect to the housing. The reliability of the apparatus can be improved.

また、ハウジングには、複数の軸受スリーブのうち、最も反ハウジング開口側に位置する軸受スリーブの一端面（反スペーサ部側一端面）を被覆し、軸部材との間にスラスト軸受隙間を形成するスラスト軸受隙間形成部をさらに設けることができる（図１０を参照）。このようにすれば、最も反ハウジング開口側に位置する軸受スリーブの一端面でスラスト軸受隙間を形成する場合（図２を参照）のように、軸方向に複数配置される軸受スリーブの形成態様をそれぞれ異ならせる必要がなくなり、使用する軸受スリーブを共通化することができる。そのため、製作すべき、また保有すべき軸受スリーブの種類を減じて軸受スリーブの製作コストや管理コストを減じることができる。また、ハウジング成形時（成形金型への配置時）における軸受スリーブの配置間違いを考慮する必要もなくなる。   In addition, the housing covers one end face (one end face on the side opposite to the spacer portion) of the bearing sleeve located closest to the housing opening side among the plurality of bearing sleeves, and forms a thrust bearing gap between the shaft member and the shaft member. A thrust bearing gap forming portion can be further provided (see FIG. 10). In this way, the formation mode of the bearing sleeves arranged in the axial direction is formed as in the case where the thrust bearing gap is formed on one end face of the bearing sleeve located closest to the housing opening side (see FIG. 2). It is not necessary to make each different, and the bearing sleeve to be used can be made common. Therefore, it is possible to reduce the manufacturing cost and management cost of the bearing sleeve by reducing the types of bearing sleeves to be manufactured and possessed. In addition, it is not necessary to take into account an arrangement error of the bearing sleeve at the time of molding the housing (at the time of arrangement in the molding die).

なお、スラスト軸受隙間形成部には、スラスト軸受隙間に流体動圧を発生させるためのスラスト動圧発生部を、ハウジングの射出成形と同時に型成形することができる。   A thrust dynamic pressure generating portion for generating a fluid dynamic pressure in the thrust bearing clearance can be molded at the same time as the injection molding of the housing.

また、ハウジングは、軸部材との間にスラスト軸受隙間を形成する補助スリーブをインサートして射出成形したものとすることもできる（図１１を参照）。かかる構成とすれば、ハウジングにスラスト軸受隙間形成部を設ける場合と同様の作用効果が得られる。   Further, the housing may be injection molded by inserting an auxiliary sleeve that forms a thrust bearing gap between the housing and the shaft member (see FIG. 11). With this configuration, the same effect as that obtained when the thrust bearing gap forming portion is provided in the housing can be obtained.

ハウジングを、他端も開口した円筒形態とした場合、当該他端開口は、ハウジングとは別体の蓋部材で閉塞することができるが、所期の軸受性能を安定維持可能とするためには、ハウジングに対する蓋部材の固定強度が問題となる。流体軸受装置の運転中等に衝撃荷重が加わると、軸部材の端部が蓋部材に突き当たり、この時の衝撃で蓋部材が脱落するおそれがあるからである。上記特許文献１の流体軸受装置のようにハウジングの内周面に蓋部材を固定する場合、蓋部材の肉厚を増せばハウジングに対する蓋部材の固定面積が拡大する分、ハウジングに対する蓋部材の固定強度を高めることができる。しかし、蓋部材の肉厚を増すと、軸受装置の軸方向寸法の長大化、あるいはラジアル軸受部の軸受スパンの縮小を招くため、蓋部材をむやみに厚肉化することはできない。   When the housing has a cylindrical shape with an opening at the other end, the opening at the other end can be closed with a lid member separate from the housing, but in order to maintain the desired bearing performance stably. The fixing strength of the lid member to the housing becomes a problem. This is because when an impact load is applied during operation of the hydrodynamic bearing device, the end of the shaft member hits the lid member, and the lid member may fall off due to the impact at this time. When the lid member is fixed to the inner peripheral surface of the housing as in the hydrodynamic bearing device of Patent Document 1, if the thickness of the lid member is increased, the fixing area of the lid member with respect to the housing is increased, so that the lid member is fixed to the housing. Strength can be increased. However, if the thickness of the lid member is increased, the axial dimension of the bearing device is increased or the bearing span of the radial bearing portion is reduced. Therefore, the lid member cannot be increased in thickness.

かかる事情に鑑みて、本発明に係る流体軸受装置では、ハウジングの外周面に蓋部材を固定することでハウジングの他端開口を閉塞するようにした。このようにすれば、蓋部材をハウジングの内周面に固定する場合に比べて、内周面と外周面の径差分だけ固定面積を増すことができる。蓋部材をハウジングの外周面に固定する場合、他端開口部を閉塞する円盤状の部分と、外周面に固定される筒状の部分とが必要となるが、ハウジングに対する固定面積を拡大するには、筒状部分の軸方向寸法を長大化すれば足り、蓋部材を厚肉化する必要がない。また、筒状部分を延ばしても軸受装置の全長寸法に影響は及ばない。以上から、軸受装置の軸方向寸法やラジアル軸受部の軸受スパンに影響を与えることなく蓋部材の耐抜け強度を高めることができ、所期の軸受性能を安定維持することが可能となる。   In view of such circumstances, in the hydrodynamic bearing device according to the present invention, the other end opening of the housing is closed by fixing a lid member to the outer peripheral surface of the housing. In this way, the fixed area can be increased by the difference in diameter between the inner peripheral surface and the outer peripheral surface as compared with the case where the lid member is fixed to the inner peripheral surface of the housing. When the lid member is fixed to the outer peripheral surface of the housing, a disk-shaped portion that closes the opening at the other end and a cylindrical portion that is fixed to the outer peripheral surface are required. It is sufficient to increase the axial dimension of the cylindrical portion, and it is not necessary to increase the thickness of the lid member. Further, even if the cylindrical portion is extended, the overall length of the bearing device is not affected. From the above, it is possible to increase the anti-slip strength of the lid member without affecting the axial dimension of the bearing device and the bearing span of the radial bearing portion, and the desired bearing performance can be stably maintained.

また、上記構成とすれば、ハウジングの外周面に固定した蓋部材をモータのベースとなる部材、例えばモータブラケットへの取り付け部として活用することができる。コスト面を考慮するとハウジングを樹脂の射出成形品とするのが有効であるが、これでは、通常金属製とされるモータブラケットに接着固定する場合に、必要とされる固定強度を確保することが難しくなる。一方、ハウジングを金属製とすれば、固定強度を満足することはできるものの、樹脂製とする場合に比べコスト高となることは否めない。これに対し、上記構成とすれば、蓋部材をモータブラケットとの接着性に富む金属材料で形成してモータブラケットに対する流体軸受装置の固定強度を満足しつつ、ハウジングを樹脂で形成してコスト低減の要求も満足することができる。   Moreover, if it is set as the said structure, the cover member fixed to the outer peripheral surface of a housing can be utilized as a member used as a base of a motor, for example, an attachment part to a motor bracket. Considering the cost, it is effective to make the housing an injection-molded product of resin, but with this, it is possible to secure the required fixing strength when bonding and fixing to a motor bracket that is usually made of metal. It becomes difficult. On the other hand, if the housing is made of metal, the fixing strength can be satisfied, but it cannot be denied that the cost is higher than when the housing is made of resin. On the other hand, with the above configuration, the lid member is made of a metal material that is highly adhesive to the motor bracket and satisfies the fixing strength of the hydrodynamic bearing device to the motor bracket, while the housing is made of resin to reduce costs. The requirements of

以上に示す本発明に係る流体軸受装置は、ステータコイルと、ロータマグネットとを備えるモータ、例えばＨＤＤ等、情報機器用のスピンドルモータに組み込んで好適に使用することができる。   The hydrodynamic bearing device according to the present invention described above can be suitably used by being incorporated in a spindle motor for information equipment such as a motor having a stator coil and a rotor magnet, such as an HDD.

以上より、本発明によれば、軸受剛性が高く、高い回転精度を誇る流体軸受装置を低コストに提供することができる。   As described above, according to the present invention, it is possible to provide a hydrodynamic bearing device having high bearing rigidity and high rotational accuracy at low cost.

以下、本発明の実施形態を図面に基づいて説明する。   Hereinafter, embodiments of the present invention will be described with reference to the drawings.

図１は、流体軸受装置を組み込んだ情報機器用スピンドルモータの一構成例を概念的に示している。このスピンドルモータは、ＨＤＤ等のディスク駆動装置に用いられるもので、軸部材２を回転自在に支持する流体軸受装置１と、軸部材２に固定されたディスクハブ３と、例えば半径方向のギャップを介して対向させたステータコイル４およびロータマグネット５と、ベース部材としてのモータブラケット６とを備えている。ステータコイル４はモータブラケット６の外周に取り付けられ、ロータマグネット５はディスクハブ３の内周に取り付けられる。流体軸受装置１のハウジング９は、モータブラケット６の内周に固定される。ディスクハブ３には磁気ディスク等のディスクＤが一又は複数枚（図示例は２枚）保持され、ディスクＤは図示しないクランプ機構でディスクハブ３に対して固定される。以上の構成において、ステータコイル４に通電すると、ステータコイル４とロータマグネット５との間の電磁力でロータマグネット５が回転し、それによって、ディスクハブ３およびディスクハブ３に保持されたディスクＤが軸部材２と一体に回転する。   FIG. 1 conceptually shows one configuration example of a spindle motor for information equipment incorporating a fluid dynamic bearing device. This spindle motor is used in a disk drive device such as an HDD, and has a hydrodynamic bearing device 1 that rotatably supports a shaft member 2, a disk hub 3 fixed to the shaft member 2, and a gap in the radial direction, for example. And a stator coil 4 and a rotor magnet 5 which are opposed to each other, and a motor bracket 6 as a base member. The stator coil 4 is attached to the outer periphery of the motor bracket 6, and the rotor magnet 5 is attached to the inner periphery of the disk hub 3. The housing 9 of the hydrodynamic bearing device 1 is fixed to the inner periphery of the motor bracket 6. One or a plurality (two in the illustrated example) of disks D such as magnetic disks are held on the disk hub 3, and the disks D are fixed to the disk hub 3 by a clamp mechanism (not shown). In the above configuration, when the stator coil 4 is energized, the rotor magnet 5 is rotated by the electromagnetic force between the stator coil 4 and the rotor magnet 5, whereby the disk hub 3 and the disk D held by the disk hub 3 are rotated. It rotates integrally with the shaft member 2.

図２は、本発明の第１実施形態に係る流体軸受装置１を示すものである。この流体軸受装置１は、軸部材２と、軸部材２の外周に配置された第１および第２軸受スリーブ８１，８２と、両軸受スリーブ８１，８２を収容したハウジング９と、ハウジング９の一端開口を閉塞する蓋部材１０とを構成部材として備える。なお、以下では、便宜上、蓋部材１０が設けられた側を下側、その軸方向反対側を上側として説明を進める。   FIG. 2 shows the hydrodynamic bearing device 1 according to the first embodiment of the present invention. The hydrodynamic bearing device 1 includes a shaft member 2, first and second bearing sleeves 81 and 82 disposed on the outer periphery of the shaft member 2, a housing 9 housing both bearing sleeves 81 and 82, and one end of the housing 9. A lid member 10 that closes the opening is provided as a constituent member. In the following, for the sake of convenience, the description will be given with the side on which the lid member 10 is provided as the lower side and the opposite side in the axial direction as the upper side.

軸部材２は、軸部２ａとフランジ部２ｂとを有する。軸部２ａおよびフランジ部２ｂの双方は、耐摩耗性に富む金属材料、例えばステンレス鋼で形成される。軸部２ａの下端には小径部２ａ２が形成され、この小径部２ａ２を環状のフランジ部２ｂの内周に嵌合固定することで軸部材２が形成される。軸部２ａとフランジ部２ｂの固定方法は両者間に所定の固定強度を確保し得る限りにおいて任意であり、圧入、接着、溶接（特にレーザ溶接）等を採用することができる。軸部材２は、上記のように、個別に製作した軸部２ａおよびフランジ部２ｂを適宜の手段で一体化したものの他、両者を鍛造や切削等で一体的に設けたものを使用することもできる。   The shaft member 2 has a shaft portion 2a and a flange portion 2b. Both the shaft portion 2a and the flange portion 2b are made of a metal material having high wear resistance, such as stainless steel. A small diameter portion 2a2 is formed at the lower end of the shaft portion 2a, and the shaft member 2 is formed by fitting and fixing this small diameter portion 2a2 to the inner periphery of the annular flange portion 2b. The method of fixing the shaft portion 2a and the flange portion 2b is arbitrary as long as a predetermined fixing strength can be secured between them, and press-fitting, adhesion, welding (particularly laser welding) and the like can be employed. As described above, the shaft member 2 may be one in which the shaft portion 2a and the flange portion 2b manufactured individually are integrated by an appropriate means, or one in which both are integrally provided by forging, cutting, or the like. it can.

第１および第２軸受スリーブ８１，８２の双方は、焼結金属からなる多孔質体、特に銅を主成分とする焼結金属の多孔質体で円筒状に形成される。第１軸受スリーブ８１および第２軸受スリーブ８２の何れか一方又は双方は、焼結金属以外のその他の多孔質体、例えば多孔質樹脂で形成することもできるし、黄銅等の軟質金属で形成することもできる。   Both the first and second bearing sleeves 81 and 82 are formed in a cylindrical shape with a porous body made of sintered metal, in particular, a porous body made of sintered metal mainly containing copper. Either one or both of the first bearing sleeve 81 and the second bearing sleeve 82 can be made of a porous body other than a sintered metal, for example, a porous resin, or a soft metal such as brass. You can also.

図３に示すように、第１軸受スリーブ８１の内周面８１ａには、対向する軸部２ａの外周面２ａ１との間にラジアル軸受隙間を形成するラジアル軸受面Ａ１が設けられ、該ラジアル軸受面Ａ１には、ラジアル動圧発生部として、ヘリングボーン形状に配列された複数の動圧溝８１ａ１が形成される。また、第２軸受スリーブ８２の内周面８２ａには、対向する軸部２ａの外周面２ａ１との間にラジアル軸受隙間を形成するラジアル軸受面Ａ２が設けられ、該ラジアル軸受面Ａ２には、ラジアル動圧発生部として、ヘリングボーン形状に配列された複数の動圧溝８２ａ１が形成される。第１軸受スリーブ８１の動圧溝８１ａ１は、軸方向中心ｍ（上下の傾斜溝間領域の軸方向中央）に対して軸方向非対称に形成されており、軸方向中心ｍより上側領域の軸方向寸法Ｘ１が下側領域の軸方向寸法Ｘ２よりも大きくなっている。第２軸受スリーブ８２の動圧溝８２ａ１は軸方向対称に形成され、その上下領域の軸方向寸法は上記軸方向寸法Ｘ２と等しくなっている。なお、ラジアル動圧発生部は、対向する軸部２ａの外周面２ａ１に形成しても良い。   As shown in FIG. 3, a radial bearing surface A1 that forms a radial bearing gap between the inner peripheral surface 81a of the first bearing sleeve 81 and the outer peripheral surface 2a1 of the opposing shaft portion 2a is provided. A plurality of dynamic pressure grooves 81a1 arranged in a herringbone shape are formed on the surface A1 as radial dynamic pressure generating portions. Further, a radial bearing surface A2 that forms a radial bearing gap between the inner peripheral surface 82a of the second bearing sleeve 82 and the outer peripheral surface 2a1 of the opposed shaft portion 2a is provided, and the radial bearing surface A2 includes As the radial dynamic pressure generating portion, a plurality of dynamic pressure grooves 82a1 arranged in a herringbone shape are formed. The dynamic pressure groove 81a1 of the first bearing sleeve 81 is formed to be axially asymmetric with respect to the axial center m (the axial center of the region between the upper and lower inclined grooves), and the axial direction of the upper region from the axial center m The dimension X1 is larger than the axial dimension X2 of the lower region. The dynamic pressure grooves 82a1 of the second bearing sleeve 82 are formed symmetrically in the axial direction, and the axial dimensions of the upper and lower regions thereof are equal to the axial dimension X2. In addition, you may form a radial dynamic pressure generation | occurrence | production part in the outer peripheral surface 2a1 of the axial part 2a which opposes.

第２軸受スリーブ８２の下側端面８２ｂには、対向するフランジ部２ｂの上側端面２ｂ１との間に第１スラスト軸受隙間を形成するスラスト軸受面Ｂが設けられる。スラスト軸受面Ｂには、第１スラスト軸受隙間に動圧作用を発生させるためのスラスト動圧発生部が形成される。このスラスト動圧発生部は、図４に示すようにＶ字状に屈曲した動圧溝８２ｂ１と、これを区画する丘部８２ｂ２とを円周方向に交互に配列した構成をなし、全体としてヘリングボーン形状を呈する。なお、スラスト動圧発生部は、対向するフランジ部２ｂの上側端面２ｂ１に形成しても良い。   The lower end surface 82b of the second bearing sleeve 82 is provided with a thrust bearing surface B that forms a first thrust bearing gap with the upper end surface 2b1 of the opposing flange portion 2b. On the thrust bearing surface B, a thrust dynamic pressure generating portion for generating a dynamic pressure action in the first thrust bearing gap is formed. As shown in FIG. 4, the thrust dynamic pressure generating portion has a configuration in which dynamic pressure grooves 82b1 bent in a V shape and hill portions 82b2 partitioning the grooves are arranged alternately in the circumferential direction. Presents a bone shape. In addition, you may form a thrust dynamic pressure generation | occurrence | production part in the upper side end surface 2b1 of the flange part 2b which opposes.

ハウジング９は軸方向両端が開口した略円筒状をなし、両軸受スリーブ８１，８２を内周に保持した筒部９ａと、筒部９ａの上端内径側に設けられたシール部９ｂと、筒部９ａの軸方向略中央部から内径側に突出し、両軸受スリーブ８１，８２間に介在するスペーサ部９ｃとを一体に有する。筒部９ａは、その外周面が、軸方向で大径外周面９ａ１と小径外周面９ａ３とに区画された段付き形状とされる。両外周面９ａ１，９ａ３は軸線と直交する方向に延びる段差面９ａ２で繋がっている。   The housing 9 has a substantially cylindrical shape with both axial ends open, a cylindrical portion 9a that holds both bearing sleeves 81 and 82 on the inner periphery, a seal portion 9b that is provided on the upper inner diameter side of the cylindrical portion 9a, and a cylindrical portion. A spacer portion 9c that protrudes from the substantially central portion in the axial direction of 9a toward the inner diameter side and is interposed between the bearing sleeves 81 and 82 is integrally provided. The cylindrical portion 9a has a stepped shape with an outer peripheral surface partitioned into a large-diameter outer peripheral surface 9a1 and a small-diameter outer peripheral surface 9a3 in the axial direction. Both outer peripheral surfaces 9a1 and 9a3 are connected by a step surface 9a2 extending in a direction orthogonal to the axis.

シール部９ｂの内周面９ｂ１は、軸部２ａの外周面２ａ１との間にシール空間Ｓを形成する。シール部９ｂの内周面９ｂ１は下方に向けて漸次縮径したテーパ面状に形成される一方、軸部２ａの外周面２ａ１は径一定の円筒面状に形成されている。従い、シール空間Ｓは下方に向けて径方向寸法を漸次縮小させたテーパ形状を呈する。   A seal space S is formed between the inner peripheral surface 9b1 of the seal portion 9b and the outer peripheral surface 2a1 of the shaft portion 2a. The inner peripheral surface 9b1 of the seal portion 9b is formed in a tapered surface shape whose diameter is gradually reduced downward, while the outer peripheral surface 2a1 of the shaft portion 2a is formed in a cylindrical surface shape having a constant diameter. Accordingly, the seal space S has a tapered shape in which the radial dimension is gradually reduced downward.

スペーサ部９ｃは、上記のとおり、両軸受スリーブ８１，８２間に介在して、軸方向に離隔して配置された第１および第２軸受スリーブ８１，８２間に形成される空間を埋める役割を担う。スペーサ部９ｃの内周面９ｃ１の軸方向一部又は全部領域（図示例は全部領域）には、軸部２ａの外周面２ａ１との径方向離間距離を、両軸受スリーブ８１，８２の内周面８１ａ，８２ａと軸部２ａの外周面２ａ１との間の径方向離間距離よりも拡大させるための逃げ部Ｎが設けられる。図示例において、逃げ部Ｎ（スペーサ部９ｃの内周面９ｃ１）は、軸方向端部側ほど内径寸法を縮小させた円弧面状をなす。   As described above, the spacer portion 9c is interposed between the bearing sleeves 81 and 82, and fills the space formed between the first and second bearing sleeves 81 and 82 that are spaced apart in the axial direction. Bear. In a part or all of the axial direction of the inner peripheral surface 9c1 of the spacer portion 9c (all regions in the illustrated example), the radial distance from the outer peripheral surface 2a1 of the shaft portion 2a is set to the inner periphery of the bearing sleeves 81 and 82. An escape portion N is provided for enlarging the radial distance between the surfaces 81a, 82a and the outer peripheral surface 2a1 of the shaft portion 2a. In the illustrated example, the escape portion N (the inner peripheral surface 9c1 of the spacer portion 9c) has an arcuate surface shape whose inner diameter is reduced toward the end in the axial direction.

詳細は後述するが、以上の構成からなるハウジング９は、第１および第２軸受スリーブ８１，８２をインサート部品として樹脂材料で型成形（射出成形）される。従い、第１および第２軸受スリーブ８１，８２の表面のうち、キャビティに露出した面を除く面はハウジング９を形成する樹脂材料で被覆される。本実施形態では、第１軸受スリーブ８１は、その内周面８１ａおよび上端内周チャンファ８１ｆを除く面がハウジング９で被覆されており、第２軸受スリーブ８２は、その内周面８２ａ、下側端面８２ｂ、および下端内周チャンファを除く面がハウジング９で被覆されている。筒部９ａの大径外周面９ａ１のうち、スペーサ部９ｃの外径側、より詳細にはスペーサ部９ｃの軸方向中央部の外径側には、キャビティ内に樹脂を射出・充填するゲートを除去加工してなるゲート跡１２が、１８０°位相を異ならせた周方向の二箇所に形成されている。   Although details will be described later, the housing 9 having the above-described configuration is molded (injected) with a resin material using the first and second bearing sleeves 81 and 82 as insert parts. Accordingly, of the surfaces of the first and second bearing sleeves 81 and 82, the surfaces other than the surfaces exposed to the cavities are covered with the resin material that forms the housing 9. In the present embodiment, the first bearing sleeve 81 is covered with the housing 9 except for the inner peripheral surface 81a and the upper end inner peripheral chamfer 81f, and the second bearing sleeve 82 has an inner peripheral surface 82a and a lower side. The surface excluding the end face 82 b and the lower end inner peripheral chamfer is covered with the housing 9. Of the large-diameter outer peripheral surface 9a1 of the cylindrical portion 9a, a gate for injecting and filling resin into the cavity is provided on the outer diameter side of the spacer portion 9c, more specifically, on the outer diameter side of the central portion in the axial direction of the spacer portion 9c. Gate traces 12 formed by removal processing are formed at two places in the circumferential direction with different phases by 180 °.

ハウジング９の成形に用いる樹脂材料は射出成形可能であれば特段の限定はないが、本実施形態では液晶ポリマー（ＬＣＰ）をベース樹脂とし、これに要求特性に応じた各種充填材を配合しものとされる。もちろん、例えばポリフェニレンサルファイド（ＰＰＳ）に代表されるその他の結晶性樹脂、あるいはポリフェニルサルフォン（ＰＰＳＵ）、ポリエーテルサルフォン（ＰＥＳ）等の非晶性樹脂をベース樹脂とした樹脂材料を用いても良い。なお、後述するように、本実施形態においては蓋部材１０で導電性が確保されるので、樹脂材料中に導電性充填材を配合する必要はないが、ハウジング９の成形性等に悪影響を及ぼさず、かつコスト面でも支障がなければ、導電性充填材を配合しても良い。   The resin material used for molding the housing 9 is not particularly limited as long as it can be injection-molded. In this embodiment, a liquid crystal polymer (LCP) is used as a base resin, and various fillers are blended according to required characteristics. It is said. Of course, for example, other crystalline resins represented by polyphenylene sulfide (PPS), or resin materials based on amorphous resins such as polyphenylsulfone (PPSU) and polyethersulfone (PES) are used. Also good. As will be described later, in this embodiment, since the conductivity is ensured by the lid member 10, it is not necessary to add a conductive filler to the resin material, but the moldability of the housing 9 is adversely affected. If there is no problem in terms of cost, a conductive filler may be blended.

蓋部材１０は、ハウジング９（筒部９ａ）の小径外周面９ａ３に固定され、ハウジング９の下側開口を閉塞する。蓋部材１０は、導電性を有する金属材料で形成され、例えば金属板をプレス加工することにより、略円盤状のプレート部１０ａと、プレート部１０ａの外径端から上方に延びる円筒状の起立部１０ｂとを一体に有する有底筒状（コップ状）に形成される。起立部１０ｂは、第２軸受スリーブ８２のラジアル軸受面Ａ２の一部又は全部（本実施形態では一部）と軸方向でオーバーラップしている。   The lid member 10 is fixed to the small-diameter outer peripheral surface 9a3 of the housing 9 (cylinder portion 9a) and closes the lower opening of the housing 9. The lid member 10 is formed of a conductive metal material. For example, by pressing a metal plate, the substantially disk-shaped plate portion 10a and a cylindrical upright portion extending upward from the outer diameter end of the plate portion 10a. 10b is integrally formed with a bottomed cylindrical shape (cup shape). The upright portion 10b overlaps with a part or all of the radial bearing surface A2 of the second bearing sleeve 82 (a part in the present embodiment) in the axial direction.

プレート部１０ａの上側端面１０ａ１には、対向するフランジ部２ｂの下側端面２ｂ２との間に第２スラスト軸受隙間を形成するスラスト軸受面Ｃが設けられる。スラスト軸受面Ｃには、第２スラスト軸受隙間に動圧作用を発生させるためのスラスト動圧発生部が形成される。このスラスト動圧発生部は、図５に示すようにＶ字状に屈曲した動圧溝１０ａ１１と、これを区画する丘部１０ａ１２とを円周方向に交互に配列した構成をなし、全体としてヘリングボーン形状を呈する。このスラスト動圧発生部は、対向するフランジ部２ｂの下側端面２ｂ２に形成しても良い。   The upper end surface 10a1 of the plate portion 10a is provided with a thrust bearing surface C that forms a second thrust bearing gap with the lower end surface 2b2 of the opposing flange portion 2b. On the thrust bearing surface C, a thrust dynamic pressure generating portion for generating a dynamic pressure action in the second thrust bearing gap is formed. As shown in FIG. 5, the thrust dynamic pressure generating portion has a configuration in which dynamic pressure grooves 10a11 bent in a V-shape and hill portions 10a12 partitioning the grooves are arranged alternately in the circumferential direction, and as a whole herring Presents a bone shape. The thrust dynamic pressure generating portion may be formed on the lower end surface 2b2 of the opposing flange portion 2b.

蓋部材１０の起立部１０ｂの上側端面１０ｂ１とハウジング９の段差面９ａ２とは軸方向に対向し、後述するスラスト軸受隙間の幅設定後は、両面１０ｂ１，９ａ２間に隙間幅δ１の軸方向隙間１３が形成される。スラスト軸受隙間の幅設定後は、例えば接着剤により、軸方向隙間１３を完全に封止するようにしても良い。また、プレート部１０ａの上側端面１０ａ１とハウジング９の筒部９ａの下側端面９ａ４との間に隙間幅δ２の軸方向隙間が形成される。この軸方向隙間の隙間幅δ２は、軸受装置内部の保油量を減じるために極力小さくするのが望ましい。   The upper end surface 10b1 of the upright portion 10b of the lid member 10 and the stepped surface 9a2 of the housing 9 are opposed to each other in the axial direction, and after setting the width of the thrust bearing clearance described later, the axial clearance of the clearance width δ1 is set between both surfaces 10b1 and 9a2. 13 is formed. After setting the width of the thrust bearing gap, the axial gap 13 may be completely sealed with an adhesive, for example. Further, an axial gap having a gap width δ2 is formed between the upper end surface 10a1 of the plate portion 10a and the lower end surface 9a4 of the cylindrical portion 9a of the housing 9. The gap width δ2 of the axial gap is desirably as small as possible in order to reduce the amount of oil retaining in the bearing device.

以上の構成からなる流体軸受装置１において、軸部材２が回転すると、第１軸受スリーブ８１のラジアル軸受面Ａ１、および第２軸受スリーブ８２のラジアル軸受面Ａ２と、これらに対向する軸部２ａの外周面２ａ１との間にそれぞれラジアル軸受隙間が形成される。そして軸部材２の回転に伴い、両ラジアル軸受隙間の油膜圧力が動圧溝８１ａ１，８２ａ１の動圧作用によって高められる結果、軸部材２をラジアル方向に非接触支持するラジアル軸受部Ｒ１，Ｒ２が軸方向の二箇所に離隔形成される。これと同時に、第２軸受スリーブ８２のスラスト軸受面Ｂとフランジ部２ｂの上側端面２ｂ１との間、および、フランジ部２ｂの下側端面２ｂ２と蓋部材１０のスラスト軸受面Ｃとの間に、第１および第２スラスト軸受隙間がそれぞれ形成される。そして、軸部材２の回転に伴い、両スラスト軸受隙間の油膜圧力が、動圧溝８２ｂ１，１０ａ１１の動圧作用によって高められる結果、軸部材２をスラスト両方向に非接触支持する第１スラスト軸受部Ｔ１および第２スラスト軸受部Ｔ２が形成される。   In the hydrodynamic bearing device 1 having the above-described configuration, when the shaft member 2 rotates, the radial bearing surface A1 of the first bearing sleeve 81, the radial bearing surface A2 of the second bearing sleeve 82, and the shaft portion 2a opposed to them. Radial bearing gaps are formed between the outer peripheral surface 2a1 and each. As the shaft member 2 rotates, the oil film pressure in the radial bearing gaps is increased by the dynamic pressure action of the dynamic pressure grooves 81a1 and 82a1. As a result, the radial bearing portions R1 and R2 that support the shaft member 2 in the radial direction in a non-contact manner. Separately formed at two positions in the axial direction. At the same time, between the thrust bearing surface B of the second bearing sleeve 82 and the upper end surface 2b1 of the flange portion 2b, and between the lower end surface 2b2 of the flange portion 2b and the thrust bearing surface C of the lid member 10, First and second thrust bearing gaps are respectively formed. As the shaft member 2 rotates, the oil film pressure in the thrust bearing gaps is increased by the dynamic pressure action of the dynamic pressure grooves 82b1 and 10a11. As a result, the first thrust bearing portion that supports the shaft member 2 in a thrust non-contact manner. T1 and second thrust bearing portion T2 are formed.

また、シール空間Ｓが、下方（ハウジング９の内部側）に向かって径方向寸法を漸次縮小したテーパ形状を呈しているため、シール空間Ｓ内の潤滑油は毛細管力による引き込み作用によってハウジング９の内部側に向けて引き込まれる。また、シール空間Ｓは、ハウジング９の内部空間に充填された潤滑油の温度変化に伴う容積変化量を吸収するバッファ機能を有し、想定される温度変化の範囲内で潤滑油の油面を常にシール空間Ｓ内に保持する。これらの構成から、ハウジング９内部からの潤滑油漏れが効果的に防止される。   Further, since the seal space S has a tapered shape whose radial dimension is gradually reduced downward (inside the housing 9), the lubricating oil in the seal space S is pulled into the housing 9 by the capillary force. Pulled toward the inside. Further, the seal space S has a buffer function for absorbing the volume change amount accompanying the temperature change of the lubricating oil filled in the internal space of the housing 9, and the oil surface of the lubricating oil is kept within the range of the assumed temperature change. It is always held in the seal space S. From these configurations, lubricating oil leakage from the inside of the housing 9 is effectively prevented.

ところで本実施形態において、第１軸受スリーブ８１のラジアル軸受面Ａ１に設けた動圧溝８１ａ１は、軸方向中心ｍより上側領域の軸方向寸法Ｘ１が下側領域の軸方向寸法Ｘ２よりも大きくなっている。そのため、軸部材２の回転時、動圧溝８１ａ１による潤滑油の引き込み力は上側領域が下側領域に比べて相対的に大きくなる。このような引き込み力の差圧（ポンピング能力のアンバランス）により、第１軸受スリーブ８１の内周面８１ａと軸部２ａの外周面２ａ１との間の隙間に充満された潤滑油は下方に押し込まれる。この場合、軸受内部の閉塞側の空間、特に第２スラスト軸受隙間の内径側の空間（底面空間Ｐ、図６を参照）で圧力が高くなり、軸部材２に作用する上向きの浮上力が過剰となる結果、両スラスト軸受部Ｔ１，Ｔ２間でのスラスト支持力をバランスさせることが難しくなる。この点に鑑み、本実施形態に係る流体軸受装置１では、フランジ部２ｂに、その両端面２ｂ１，２ｂ２に開口した連通孔１１を設けている（図２および図６を参照）。これにより、連通孔１１を介して両スラスト軸受隙間間で潤滑油が行き来可能となるので、両スラスト軸受隙間間での圧力バランスの崩れを早期に解消し、両スラスト軸受部Ｔ１，Ｔ２間でのスラスト支持力をバランスさせることができる。   By the way, in this embodiment, the dynamic pressure groove 81a1 provided on the radial bearing surface A1 of the first bearing sleeve 81 has an axial dimension X1 in the upper region larger than the axial dimension X2 in the lower region from the axial center m. ing. Therefore, when the shaft member 2 rotates, the lubricating oil pulling force by the dynamic pressure groove 81a1 is relatively larger in the upper region than in the lower region. Due to the differential pressure of the pulling force (unbalanced pumping ability), the lubricating oil filled in the gap between the inner peripheral surface 81a of the first bearing sleeve 81 and the outer peripheral surface 2a1 of the shaft portion 2a is pushed downward. It is. In this case, the pressure increases in the space on the closed side inside the bearing, particularly the space on the inner diameter side of the second thrust bearing gap (bottom space P, see FIG. 6), and the upward levitation force acting on the shaft member 2 is excessive. As a result, it becomes difficult to balance the thrust support force between the thrust bearing portions T1, T2. In view of this point, in the hydrodynamic bearing device 1 according to the present embodiment, the flange portion 2b is provided with a communication hole 11 that opens to both end faces 2b1 and 2b2 (see FIGS. 2 and 6). As a result, the lubricating oil can go back and forth between the two thrust bearing gaps via the communication hole 11, so that the collapse of the pressure balance between the two thrust bearing gaps can be eliminated at an early stage, and the two thrust bearing portions T1 and T2 can be connected. The thrust support force can be balanced.

図６に示すように、本実施形態の連通孔１１は、両スラスト軸受面Ｂ，Ｃ（スラスト動圧発生部）の形成領域を避けてその内径側に開口させるため、径方向部１１ａと軸方向部１１ｂとで構成された屈曲形態をなす。より詳細には、径方向部１１ａの外径端が、フランジ部２ｂの上側端面２ｂ１、第２軸受スリーブ８２の下端内周チャンファ、および軸部２ａの下端に設けられたヌスミ部２ａ３とで形成される空間に開口し、径方向部１１ａの内径端に繋がった軸方向部１１ｂが軸部２ａの小径部２ａ２の外周面に沿って延び、第２スラスト軸受部Ｔ２の内径側に開口している。かかる構成は、円環状のフランジ部２ｂの内周面に軸方向溝を形成すると共に、フランジ部２ｂの上側端面２ｂ１に前記軸方向溝に通じる半径方向溝を形成し、その後、フランジ部２ｂの内周に軸部２ａの小径部２ａ２を嵌合することによって形成することができる。なお、連通孔１１は、円周方向の一箇所に設ける他、円周方向の複数箇所に設けることもできる。   As shown in FIG. 6, the communication hole 11 of the present embodiment avoids the formation area of both thrust bearing surfaces B and C (thrust dynamic pressure generating portions) and opens to the inner diameter side thereof. It forms a bent form composed of the direction portion 11b. More specifically, the outer diameter end of the radial direction portion 11a is formed by the upper end surface 2b1 of the flange portion 2b, the lower end inner peripheral chamfer of the second bearing sleeve 82, and the nose portion 2a3 provided at the lower end of the shaft portion 2a. The axial direction portion 11b connected to the inner diameter end of the radial direction portion 11a extends along the outer peripheral surface of the small diameter portion 2a2 of the shaft portion 2a, and opens to the inner diameter side of the second thrust bearing portion T2. Yes. In such a configuration, an axial groove is formed on the inner peripheral surface of the annular flange portion 2b, and a radial groove communicating with the axial groove is formed on the upper end surface 2b1 of the flange portion 2b. It can be formed by fitting the small diameter portion 2a2 of the shaft portion 2a to the inner periphery. In addition, the communication hole 11 can be provided in one place in the circumferential direction, or can be provided in a plurality of places in the circumferential direction.

また、上記のように、本実施形態に係る流体軸受装置１では、底面空間Ｐの圧力が高くなる傾向にある。この場合に第２スラスト軸受部Ｔ２を形成する動圧溝１０ａ１１を、従来多用されてきたポンプインタイプのスパイラル形状に配列すると、第２スラスト軸受隙間内に充満された潤滑油が内径側に押し込まれるため、底面空間Ｐの圧力増大を助長することとなる。これに対し、第２スラスト軸受部Ｔ２を形成する動圧溝１０ａ１１を、図５に示すようにヘリングボーン形状に形成（配列）すれば、この問題を回避することができ、望ましい。一方、第１スラスト軸受部Ｔ１では、この種の問題が生じないので、動圧溝８２ｂ１を、図４に示すヘリングボーン形状ではなく、ポンプインタイプのスパイラル形状に形成しても良い。   Further, as described above, in the hydrodynamic bearing device 1 according to the present embodiment, the pressure in the bottom space P tends to increase. In this case, when the dynamic pressure grooves 10a11 forming the second thrust bearing portion T2 are arranged in a pump-in type spiral shape that has been widely used in the past, the lubricating oil filled in the second thrust bearing gap is pushed into the inner diameter side. Therefore, the pressure increase in the bottom space P is promoted. On the other hand, if the dynamic pressure groove 10a11 forming the second thrust bearing portion T2 is formed (arranged) in a herringbone shape as shown in FIG. 5, this problem can be avoided, which is desirable. On the other hand, since this type of problem does not occur in the first thrust bearing portion T1, the dynamic pressure groove 82b1 may be formed in a pump-in type spiral shape instead of the herringbone shape shown in FIG.

次に、以上の構成からなる流体軸受装置１の製造方法について、ハウジング９の成形工程およびハウジング９に対する蓋部材１０の組み付け工程を中心に、以下説明を行う。   Next, the manufacturing method of the hydrodynamic bearing device 1 having the above-described configuration will be described below with a focus on the molding process of the housing 9 and the assembly process of the lid member 10 to the housing 9.

図７〜図９は、ハウジング９の型成形（射出成形）工程を示すものである。図７に示すように、当該成形工程に用いられる成形金型２０は、内型２２を有する第１金型２１と、第１金型２１と衝合する第２金型２３と、第２金型２３の内周に配置され、内型２２（の先端）を内周に収容可能な孔部２４ａを有する第３金型２４とで主要部が構成される。第１金型２１の１８０°位相を異ならせた周方向の二箇所にはゲート２５が設けられる。   7 to 9 show a molding (injection molding) process of the housing 9. As shown in FIG. 7, a molding die 20 used in the molding process includes a first die 21 having an inner die 22, a second die 23 that abuts with the first die 21, and a second die. The main part is composed of the third mold 24 which is disposed on the inner periphery of the mold 23 and has a hole 24a capable of accommodating the inner mold 22 (the tip thereof) on the inner periphery. Gates 25 are provided at two locations in the circumferential direction where the 180 ° phase of the first mold 21 is different.

内型２２は、小径部２２ａと大径部２２ｂとを有する段付き軸状をなす。小径部２２ａの外周面は、ハウジング９のスペーサ部９ｃを成形する成形面として機能する他、インサート部品として金型２０内に供給配置される第１および第２軸受スリーブ８１，８２を保持する保持部としても機能する。小径部２２ａの外径寸法は、軸受スリーブ８１，８２が小径部２２ａの外周面に沿って軸方向移動可能で、かつ、嵌合後の軸受スリーブ８１，８２が自重で脱落しない程度に設定される。内型２２のうち、少なくとも小径部２２ａの外周面には、摩擦力を減じるための被膜２７が形成されている。なお、当該被膜２７は、例えばＤＬＣコーティング、めっき、フッ素コーティング等によって形成される。後述するように、小径部２２ａと大径部２２ｂとの間に介在する段部２２ｃは、第１軸受スリーブ８１の上端内周チャンファ８１ｆと係合して、当該内型２２に対する第１軸受スリーブ８１の軸方向の位置決めを行う。従い、段部２２は、第１軸受スリーブ８１の上端内周チャンファ８１ｆに倣ったテーパ面状に形成される。   The inner mold 22 has a stepped shaft shape having a small diameter portion 22a and a large diameter portion 22b. The outer peripheral surface of the small-diameter portion 22a functions as a molding surface for molding the spacer portion 9c of the housing 9, and also holds the first and second bearing sleeves 81 and 82 supplied and arranged in the mold 20 as insert parts. It also functions as a part. The outer diameter of the small-diameter portion 22a is set such that the bearing sleeves 81 and 82 can move in the axial direction along the outer peripheral surface of the small-diameter portion 22a and the fitted bearing sleeves 81 and 82 do not fall off due to their own weight. The A coating 27 for reducing the frictional force is formed on at least the outer peripheral surface of the small diameter portion 22a in the inner mold 22. The film 27 is formed by, for example, DLC coating, plating, fluorine coating, or the like. As will be described later, a stepped portion 22c interposed between the small diameter portion 22a and the large diameter portion 22b engages with an upper end inner peripheral chamfer 81f of the first bearing sleeve 81, so that the first bearing sleeve for the inner mold 22 is engaged. 81 is positioned in the axial direction. Accordingly, the step portion 22 is formed in a tapered surface shape following the upper end inner peripheral chamfer 81 f of the first bearing sleeve 81.

以上の構成からなる成形金型２０において、まず、図７に示すように、内型２２の小径部２２ａ外周に第１軸受スリーブ８１と第２軸受スリーブ８２とを嵌合する。これにより、両軸受スリーブ８１，８２間の芯出しが行われる。このとき、両軸受スリーブ８１，８２の軸方向の位置決めを厳密に行う必要はないが、同図にも示すように、第１軸受スリーブ８１をゲート２５よりも上方に配置する一方、第２軸受スリーブ８２をゲート２５よりも下方に配置する。   In the molding die 20 having the above configuration, first, the first bearing sleeve 81 and the second bearing sleeve 82 are fitted to the outer periphery of the small diameter portion 22a of the inner mold 22 as shown in FIG. Thereby, the centering between both bearing sleeves 81 and 82 is performed. At this time, it is not necessary to strictly position the both bearing sleeves 81 and 82 in the axial direction. However, as shown in the figure, the first bearing sleeve 81 is disposed above the gate 25, while the second bearing sleeve 81, 82 is positioned in the second bearing. The sleeve 82 is disposed below the gate 25.

次いで、図８に示すように、第１金型２１を下降させ、内型２２の下端を第３金型２４の孔部２４ａに収容すると共に、型締めを行って各型２１〜２４でキャビティ２６を画成する。その後、ゲート２５からキャビティ２６内に溶融材料Ｊ（ここでは溶融樹脂）を射出・充填する。ゲート２５と両軸受スリーブ８１，８２の配置態様とから、溶融材料Ｊがキャビティ２６内に射出されると、溶融材料Ｊの射出圧（流動力）によって第１軸受スリーブ８１には上向きの加圧力が付加され、第１軸受スリーブ８１は、その上端内周チャンファ８１ｆが内型２２の段部２２ｃに係合するまで小径部２２ａの外周面に沿って上方に移動する。これと同時に、第２軸受スリーブ８２には下向きの加圧力が付加され、第２軸受スリーブ８２は、その下側端面８２ｂが第３金型２４の上側端面２４ｂに当接するまで小径部２２ａの外周面に沿って下方に移動する。これにより、キャビティ２６への溶融材料Ｊの充填と同時に、キャビティ２６内における両軸受スリーブ８１，８２の位置決め（ハウジング９に対する両軸受スリーブ８１，８２の位置決め）が完了する。   Next, as shown in FIG. 8, the first mold 21 is lowered, the lower end of the inner mold 22 is accommodated in the hole 24 a of the third mold 24, and the molds are clamped to form cavities in the molds 21 to 24. 26 is defined. Thereafter, the molten material J (here, molten resin) is injected and filled from the gate 25 into the cavity 26. From the arrangement of the gate 25 and the bearing sleeves 81 and 82, when the molten material J is injected into the cavity 26, upward pressure is applied to the first bearing sleeve 81 by the injection pressure (fluid force) of the molten material J. Is added, and the first bearing sleeve 81 moves upward along the outer peripheral surface of the small diameter portion 22a until the upper end inner peripheral chamfer 81f engages with the step portion 22c of the inner mold 22. At the same time, a downward pressing force is applied to the second bearing sleeve 82, and the second bearing sleeve 82 has an outer periphery of the small-diameter portion 22 a until the lower end surface 82 b abuts the upper end surface 24 b of the third mold 24. Move down along the surface. Thereby, the positioning of the bearing sleeves 81 and 82 in the cavity 26 (positioning of the bearing sleeves 81 and 82 with respect to the housing 9) is completed simultaneously with the filling of the molten material J into the cavity 26.

以上のようにすれば、成形金型２０に両軸受スリーブ８１，８２を配置する段階で両軸受スリーブ８１，８２間の芯出しを行うことができ、しかも配置精度に格別の配慮を払うことなく、キャビティ２６（ハウジング９）に対する両軸受スリーブ８１，８２の軸方向の位置決めを正確に行うことができる。但し、以上のようにして両軸受スリーブ８１，８２の位置決めを行うに際しては、内型２２と軸受スリーブ８１，８２との間の摺動抵抗が問題となる。すなわち、軸受スリーブ８１，８２に付加される加圧力に対して両者間の摩擦抵抗力が過大であると、軸受スリーブ８１，８２を内型２２に沿って移動させることができないおそれがある他、軸受スリーブ８１，８２のラジアル軸受面Ａ１，Ａ２が損傷等してラジアル軸受部Ｒ１，Ｒ２の軸受性能に悪影響が及ぶおそれがある。これに対し、本発明では、軸受スリーブ８１，８２を保持する内型２２の小径部２２ａの外周面に、低摩擦処理を施した（摩擦力を減じるための被膜２７を形成した）ので、前述の問題は効果的に解消される。   In this way, centering between the two bearing sleeves 81 and 82 can be performed at the stage of arranging the two bearing sleeves 81 and 82 in the molding die 20, and without paying special consideration to the arrangement accuracy. The axial positioning of the bearing sleeves 81 and 82 with respect to the cavity 26 (housing 9) can be performed accurately. However, the sliding resistance between the inner mold 22 and the bearing sleeves 81 and 82 becomes a problem when the bearing sleeves 81 and 82 are positioned as described above. That is, if the frictional resistance between the two is excessive with respect to the pressure applied to the bearing sleeves 81 and 82, the bearing sleeves 81 and 82 may not be moved along the inner mold 22. There is a possibility that the radial bearing surfaces A1 and A2 of the bearing sleeves 81 and 82 may be damaged and adversely affect the bearing performance of the radial bearing portions R1 and R2. On the other hand, in the present invention, the low-friction process is performed on the outer peripheral surface of the small-diameter portion 22a of the inner mold 22 that holds the bearing sleeves 81 and 82 (the coating 27 for reducing the frictional force is formed). This problem is effectively solved.

なお、以上では、内型２２と軸受スリーブ８１，８２との間の摺動抵抗を減じるべく、内型２２の外周面に被膜２７を形成するようにしたが、軸受スリーブ８１，８２が焼結金属製とされる本実施形態においては、予め内部気孔に潤滑油を含浸させた軸受スリーブ８１，８２を、内型２２（小径部２２ａ）の外周に嵌合させるようにしても良い。   In the above, the coating 27 is formed on the outer peripheral surface of the inner die 22 in order to reduce the sliding resistance between the inner die 22 and the bearing sleeves 81 and 82. However, the bearing sleeves 81 and 82 are sintered. In the present embodiment, which is made of metal, bearing sleeves 81 and 82 in which internal pores are previously impregnated with lubricating oil may be fitted to the outer periphery of the inner mold 22 (small diameter portion 22a).

キャビティ２６内への溶融材料Ｊの射出・充填が完了し、さらには充填された溶融材料Ｊの固化後、図９に示すように、第１金型２１を上昇させて型開きを行うのと同時に成形品内周から内型２２を抜き取る。内型２２の小径部２２ａ外周には摩擦力を減じるための被膜２７が形成されていることから、成形品内周からの内型２２の抜き取りはスムーズに行うことができる。次いで、第２金型２２と第３金型２３とを軸方向に相対移動させ、軸受スリーブ８１，８２およびハウジング９が一体となった成形品と、第２および第３金型２２，２３と分離する。このとき、成形されたハウジング９のうち、スペーサ部９ｃは他所に比べて厚肉に形成されていることから、図９の拡大断面図に示すように、成形収縮に伴ってスペーサ部９ｃの内周面９ｃが外径側に後退して逃げ部Ｎが形成される。   After the injection and filling of the molten material J into the cavity 26 is completed, and after the filled molten material J is solidified, as shown in FIG. 9, the first mold 21 is raised and the mold is opened. At the same time, the inner mold 22 is extracted from the inner periphery of the molded product. Since the coating 27 for reducing the frictional force is formed on the outer periphery of the small-diameter portion 22a of the inner mold 22, the inner mold 22 can be smoothly extracted from the inner periphery of the molded product. Next, the second mold 22 and the third mold 23 are moved relative to each other in the axial direction, and a molded product in which the bearing sleeves 81 and 82 and the housing 9 are integrated, and the second and third molds 22 and 23, To separate. At this time, since the spacer portion 9c of the molded housing 9 is formed thicker than other portions, as shown in the enlarged sectional view of FIG. The peripheral surface 9c retreats to the outer diameter side, and the relief portion N is formed.

以上のようにして製造された成形品（ハウジング９および軸受スリーブ８１，８２）の内周に軸部材２を挿入する。次いで、ハウジング９の小径外周面９ａ３、および蓋部材１０の起立部１０ｂの内周面の何れか一方又は双方に接着剤を塗布し、小径外周面７ａ３に蓋部材１０の起立部１０ｂの内周面を嵌合する。そのままハウジング９と蓋部材１０とを軸方向に相対移動させ、フランジ部２ｂの上側端面２ｂ１を第２軸受スリーブ８２の下側端面８２ｂに当接させると共に、フランジ部２ｂの下側端面２ｂ２を蓋部材１０のプレート部１０ａの上側端面１０ａ１に当接させる（すなわち、両スラスト軸受隙間の隙間幅をそれぞれ０の状態にする）。このとき、蓋部材１０の起立部１０ｂの上側端面１０ｂ１とハウジングの段差面７ａ２とが接触しないように各部材の寸法を設定しておく。次いで、両スラスト軸受隙間の隙間幅の合計量分だけ蓋部材１０とハウジング９とを軸方向に相対移動させ、その後、接着剤を固化させることにより、ハウジング９に対する蓋部材１０の組み付けと、スラスト軸受隙間の幅設定とが同時に完了し、図２に示す流体軸受装置１の組立が完了する。その後、流体軸受装置１の内部空間に、潤滑流体としての潤滑油を充満する。以上のような組立手順であれば、蓋部材１０の移動量でスラスト軸受隙間の幅設定を行うことができるので、各部材の加工精度を緩和して、加工コストを低減することができる。   The shaft member 2 is inserted into the inner periphery of the molded product (housing 9 and bearing sleeves 81 and 82) manufactured as described above. Next, an adhesive is applied to one or both of the small-diameter outer peripheral surface 9a3 of the housing 9 and the inner peripheral surface of the standing portion 10b of the lid member 10, and the inner periphery of the standing portion 10b of the lid member 10 is applied to the small-diameter outer peripheral surface 7a3. Mates the surfaces. The housing 9 and the lid member 10 are moved relative to each other in the axial direction, the upper end surface 2b1 of the flange portion 2b is brought into contact with the lower end surface 82b of the second bearing sleeve 82, and the lower end surface 2b2 of the flange portion 2b is covered with the lid. The member 10 is brought into contact with the upper end surface 10a1 of the plate portion 10a (that is, the gap widths of both thrust bearing gaps are set to 0). At this time, the dimension of each member is set so that the upper end surface 10b1 of the standing portion 10b of the lid member 10 and the stepped surface 7a2 of the housing do not contact each other. Next, the lid member 10 and the housing 9 are moved relative to each other in the axial direction by the total amount of the clearance widths of the thrust bearing gaps, and then the adhesive is solidified, thereby assembling the lid member 10 to the housing 9 and the thrust. The setting of the width of the bearing gap is completed at the same time, and the assembly of the hydrodynamic bearing device 1 shown in FIG. 2 is completed. Thereafter, the internal space of the hydrodynamic bearing device 1 is filled with lubricating oil as a lubricating fluid. With the assembly procedure as described above, the width of the thrust bearing gap can be set by the amount of movement of the lid member 10, so that the processing accuracy of each member can be relaxed and the processing cost can be reduced.

なお、上述のように、本実施形態に係る流体軸受装置１では、ハウジング９が樹脂製、蓋部材１０が金属製とされ、かつこの蓋部材１０の起立部１０ｂは、第２軸受スリーブ８２のラジアル軸受面Ａ２の一部と軸方向でオーバーラップしている。このような場合に、圧入を伴う手法（圧入、圧入接着等）で蓋部材１０をハウジング９に固定したのでは、圧入に伴うハウジング９の変形が第２軸受スリーブ８２のラジアル軸受面Ａ２にも及び、ラジアル軸受隙間の幅精度、ひいてはラジアル方向の回転精度に悪影響が及ぶおそれがある。このような悪影響を回避すべく、本実施形態では、蓋部材１０の起立部１０ｂの内周面とハウジング９の小径外周面９ａ３との間に微小な径方向隙間を介在させ、この径方向隙間を満たす接着剤で両者が接着固定される（隙間接着）。   As described above, in the hydrodynamic bearing device 1 according to the present embodiment, the housing 9 is made of resin, the lid member 10 is made of metal, and the standing portion 10b of the lid member 10 is formed by the second bearing sleeve 82. It overlaps with a part of radial bearing surface A2 in the axial direction. In such a case, if the lid member 10 is fixed to the housing 9 by a method involving press-fitting (press-fitting, press-fitting adhesion, etc.), deformation of the housing 9 due to press-fitting is also applied to the radial bearing surface A2 of the second bearing sleeve 82. In addition, the width accuracy of the radial bearing gap, and thus the rotational accuracy in the radial direction, may be adversely affected. In order to avoid such an adverse effect, in the present embodiment, a minute radial gap is interposed between the inner peripheral surface of the standing portion 10b of the lid member 10 and the small-diameter outer peripheral surface 9a3 of the housing 9, and this radial gap Both are bonded and fixed with an adhesive that satisfies the conditions (gap bonding).

以上では、蓋部材１０をハウジング９に固定する際、ハウジング９の小径外周面９ａ３や蓋部材１０の起立部１０ｂの内周面に予め接着剤を塗布するようにしたが、蓋部材１０とハウジング９とを嵌合してスラスト軸受隙間の幅設定を行った後に、軸方向隙間１３から接着剤を供給し、ハウジング９の小径外周面９ａ３と起立部１０ｂの内周面との間の径方向隙間の毛細管力を利用して接着剤を引き込むことで両者を接着固定してもよい。   In the above description, when the lid member 10 is fixed to the housing 9, the adhesive is applied in advance to the small-diameter outer peripheral surface 9 a 3 of the housing 9 and the inner peripheral surface of the upright portion 10 b of the lid member 10. 9 is fitted and the width of the thrust bearing gap is set, and then an adhesive is supplied from the axial gap 13, and the radial direction between the small-diameter outer peripheral surface 9a3 of the housing 9 and the inner peripheral surface of the upright portion 10b. Both may be bonded and fixed by drawing the adhesive using the capillary force of the gap.

以上の構成からなる流体軸受装置１は、蓋部材１０の起立部１０ｂの外周面、およびハウジング９の大径外周面９ａ１を、アルミ合金等の金属材料で形成されたモータブラケット６（図１を参照）の内周面に例えば接着固定することでモータに組み込まれる。このとき、ハウジング９と蓋部材１０の外径寸法を等しくしておけば、これらをモータブラケット６の内周面に確実に固定することができる。またこのとき、モータブラケット６の内周面をハウジング９の大径外周面９ａ１よりもある程度大径に形成しておけば、両者間に形成される径方向隙間に充填した接着剤で両者を接着固定することができる（隙間接着）。このようにすれば、ハウジング９をモータブラケット６の内周に挿入する際にハウジング９のゲート跡１２がモータブラケット６に接触せず、かつ両者の固定後にはゲート跡１２が接着剤で被覆されるので、ゲート跡１２の除去処理を入念に行う必要はない。そして、蓋部材１０とモータブラケット６は何れも金属製とされるから、流体軸受装置１はモータブラケット６に対して高い接着強度でもって固定することができる。   In the hydrodynamic bearing device 1 having the above configuration, the motor bracket 6 (see FIG. 1) formed of a metal material such as an aluminum alloy on the outer peripheral surface of the standing portion 10 b of the lid member 10 and the large-diameter outer peripheral surface 9 a 1 of the housing 9. For example, it is incorporated in the motor by being fixedly bonded to the inner peripheral surface of the motor. At this time, if the outer diameters of the housing 9 and the lid member 10 are made equal, they can be securely fixed to the inner peripheral surface of the motor bracket 6. At this time, if the inner peripheral surface of the motor bracket 6 is formed to be somewhat larger in diameter than the large-diameter outer peripheral surface 9a1 of the housing 9, the two are bonded with an adhesive filled in a radial gap formed between them. Can be fixed (gap adhesion). In this way, when the housing 9 is inserted into the inner periphery of the motor bracket 6, the gate trace 12 of the housing 9 does not contact the motor bracket 6, and the gate trace 12 is covered with the adhesive after both are fixed. Therefore, it is not necessary to carefully perform the removal process of the gate trace 12. Since the lid member 10 and the motor bracket 6 are both made of metal, the hydrodynamic bearing device 1 can be fixed to the motor bracket 6 with high adhesive strength.

なお、蓋部材１０とモータブラケット６との間で十分な接着強度を確保できるのであれば、ハウジング９をモータブラケット６に対して必ずしも接着固定する必要はない。但し、ハウジング９をモータブラケット６に接着固定しないのであれば、ゲート跡１２の処理工数を減じる観点から、ハウジング９の外径寸法を蓋部材１０の外径寸法よりも小さくしておくのが望ましい。   Note that the housing 9 does not necessarily need to be bonded and fixed to the motor bracket 6 as long as sufficient adhesive strength can be secured between the lid member 10 and the motor bracket 6. However, if the housing 9 is not bonded and fixed to the motor bracket 6, it is desirable to make the outer diameter of the housing 9 smaller than the outer diameter of the lid member 10 from the viewpoint of reducing the man-hour for processing the gate mark 12. .

上述のように、本発明では、軸部材２の軸部２ａとの間にラジアル軸受隙間を形成する軸受スリーブが軸方向に複数配置されることから、軸受スパンを拡大して高いモーメント剛性を確保しつつ、個々の軸受スリーブ８１，８２の製作精度を高めて各ラジアル軸受部Ｒ１，Ｒ２における支持能力を高めることができる。また、ハウジング９が、複数の軸受スリーブ８１，８２をインサートして射出成形され、かつ軸方向で隣り合う軸受スリーブ８１，８２間に介在するスペーサ部９ｃを有するものであるから、スペーサ部９ｃを含めたハウジング９の成形と、このハウジング９に対する軸受スリーブ８１，８２の組み付けとを一工程で完了することができる。しかも、型精度を高めておくだけで、ハウジング９に対する各軸受スリーブ８１，８２の相対的な位置決めを高精度に行い得る。以上のことから、軸受剛性、特にモーメント剛性が高く、高い回転精度を誇る流体軸受装置１を低コストに提供することができる。   As described above, in the present invention, since a plurality of bearing sleeves that form radial bearing gaps between the shaft member 2 and the shaft portion 2a are arranged in the axial direction, the bearing span is expanded to ensure high moment rigidity. However, it is possible to increase the manufacturing accuracy of the individual bearing sleeves 81 and 82 and increase the support capability of the radial bearing portions R1 and R2. Since the housing 9 is injection-molded by inserting a plurality of bearing sleeves 81 and 82 and has a spacer portion 9c interposed between the bearing sleeves 81 and 82 adjacent in the axial direction, the spacer portion 9c is The molding of the housing 9 including the assembly and the assembly of the bearing sleeves 81 and 82 to the housing 9 can be completed in one step. Moreover, the relative positioning of the bearing sleeves 81 and 82 with respect to the housing 9 can be performed with high accuracy only by increasing the mold accuracy. From the above, it is possible to provide the hydrodynamic bearing device 1 having high bearing rigidity, particularly moment rigidity, and high rotational accuracy at low cost.

また、ハウジング９は、軸部材２との間にシール空間Ｓを形成するシール部９ｂをも有するものであるから、ハウジング９の上端開口部にシール空間Ｓを形成するための別部材を配置する必要がない。そのため、部品点数および組立工数を減じて流体軸受装置１の低コスト化を図ることができる。また、シール部９ｂによって、ハウジング９の上端開口側に位置する第１軸受スリーブ８１の上側端面が被覆される。これにより、第１軸受スリーブ８１のハウジング９に対する固定面積を増して第１軸受スリーブ８１の固定強度を高めることができ、当該流体軸受装置１の信頼性向上を図ることができる。なお、両軸受スリーブ８１，８２が焼結金属の多孔質体で形成される本実施形態においては、ハウジング９成形時の溶融材料Ｊがインサート部品として金型２０内に配置される軸受スリーブ８１，８２の表面開孔に入り込んでアンカー効果を発揮する。そのため、ハウジング９に対する軸受スリーブ８１，８２の固定強度は十分に確保される。但し、更なる固定強度の向上（例えば、回り止め）を目的として、軸受スリーブ８１，８２の外周面や端面に溝を設けた軸受スリーブ８１，８２を用いるようにしても良い。   In addition, since the housing 9 also has a seal portion 9 b that forms a seal space S between the housing 9 and the shaft member 2, another member for forming the seal space S is disposed in the upper end opening of the housing 9. There is no need. Therefore, it is possible to reduce the cost of the hydrodynamic bearing device 1 by reducing the number of parts and the number of assembly steps. The upper end surface of the first bearing sleeve 81 located on the upper end opening side of the housing 9 is covered with the seal portion 9b. Thereby, the fixed area with respect to the housing 9 of the 1st bearing sleeve 81 can be increased, the fixed strength of the 1st bearing sleeve 81 can be raised, and the reliability improvement of the said hydrodynamic bearing apparatus 1 can be aimed at. In the present embodiment in which both bearing sleeves 81 and 82 are formed of a sintered metal porous body, the bearing sleeve 81, in which the molten material J at the time of molding the housing 9 is disposed in the mold 20 as an insert part. It enters the surface opening of 82 and exhibits an anchor effect. Therefore, the fixing strength of the bearing sleeves 81 and 82 with respect to the housing 9 is sufficiently ensured. However, for the purpose of further improving the fixing strength (for example, detent), the bearing sleeves 81 and 82 having grooves on the outer peripheral surfaces and end surfaces of the bearing sleeves 81 and 82 may be used.

また、第１ラジアル軸受部Ｒ１のラジアル軸受隙間と第２ラジアル軸受部Ｒ２のラジアル軸受隙間との間には、ラジアル軸受隙間よりも隙間幅の大きい間隙部分を設け、トルク増大を極力防止するようにしている。上記特許文献１では軸部材の外周面の一部を凹状（小径）に形成することにより前記間隙部分を形成するようにしているが、これは軸部材に機械加工等の後加工を施すことによって形成されるため、加工コストを高騰させる一因となる。これに対し本発明では、ハウジング９成形後の成形収縮を利用して逃げ部Ｎ（凹状の部分）を両軸受スリーブ８１，８２間に介在するスペーサ部９ｃの内周面９ｃ１に形成するようにしたので、機械加工等で逃げ部を形成する手間を省いて加工コストの更なる低廉化を図ることができる。   Further, a gap portion having a gap width larger than the radial bearing gap is provided between the radial bearing gap of the first radial bearing portion R1 and the radial bearing gap of the second radial bearing portion R2, so as to prevent an increase in torque as much as possible. I have to. In Patent Document 1 described above, the gap portion is formed by forming a part of the outer peripheral surface of the shaft member in a concave shape (small diameter), but this is performed by performing post-processing such as machining on the shaft member. Since it is formed, it becomes a cause of increasing the processing cost. On the other hand, in the present invention, the relief portion N (concave portion) is formed on the inner peripheral surface 9c1 of the spacer portion 9c interposed between the bearing sleeves 81 and 82 by utilizing the molding shrinkage after the housing 9 is molded. Therefore, it is possible to further reduce the machining cost by eliminating the trouble of forming the relief portion by machining or the like.

また、蓋部材１０をハウジング９の外周面（筒部９ａの小径外周面９ａ３）に固定しているので、従来のように蓋部材をハウジングの内周面に固定する場合に比べ、内周面と外周面の径差分だけ両部材間の固定面積を増すことができる。また、ハウジング９の筒部９ａのうち、大径外周面９ａ１を有する部分の軸方向寸法を短縮する一方、小径外周面９ａ３を有する部分の軸方向寸法を長大化することにより、蓋部材１０の起立部１０ｂの軸方向寸法を増すことができるので、固定面積の更なる増大、すなわち固定強度の更なる向上も容易に達成できる。しかも、これに伴って蓋部材１０を厚肉化する必要がなく、さらに、蓋部材１０は接着性の良好な金属材料で形成されている。従って、流体軸受装置１の軸方向寸法やラジアル軸受部Ｒ１，Ｒ２の軸受スパンに影響を与えることなく蓋部材１０の耐抜け強度を高めることができるので、所期の軸受性能が安定的に維持される。   Further, since the lid member 10 is fixed to the outer peripheral surface of the housing 9 (small-diameter outer peripheral surface 9a3 of the cylindrical portion 9a), the inner peripheral surface is compared with the case where the lid member is fixed to the inner peripheral surface of the housing as in the prior art. And the fixed area between both members can be increased by the difference in diameter between the outer peripheral surfaces. Moreover, while the axial dimension of the part which has the large diameter outer peripheral surface 9a1 is shortened among the cylinder parts 9a of the housing 9, while the axial dimension of the part which has the small diameter outer peripheral surface 9a3 is lengthened, the cover member 10 of FIG. Since the axial dimension of the upright portion 10b can be increased, further increase in the fixing area, that is, further improvement in the fixing strength can be easily achieved. Moreover, it is not necessary to increase the thickness of the lid member 10 along with this, and the lid member 10 is made of a metal material having good adhesiveness. Accordingly, the anti-slip strength of the lid member 10 can be increased without affecting the axial dimensions of the hydrodynamic bearing device 1 and the bearing spans of the radial bearing portions R1 and R2, so that the desired bearing performance can be stably maintained. Is done.

また、蓋部材１０は金属材料で形成されているので、ディスクＤが回転することによって帯電した静電気を、軸部材２→蓋部材１０→モータブラケット６という経路を介して確実に接地側に放電することができる。但し、蓋部材１０とモータブラケット６とを接着固定した本実施形態においては、接着剤（通常は絶縁体）によって導電経路が遮断されるおそれがある。かかる事態を防止するため、必要に応じて蓋部材１０の下端外径端部とモータブラケット６の下端内径端部とにまたがって適当な導電材を塗布し、両者間での導電経路を確保しておくのが望ましい。   Further, since the lid member 10 is made of a metal material, the static electricity charged by the rotation of the disk D is surely discharged to the ground side via the path of the shaft member 2 → the lid member 10 → the motor bracket 6. be able to. However, in the present embodiment in which the lid member 10 and the motor bracket 6 are bonded and fixed, the conductive path may be blocked by an adhesive (usually an insulator). In order to prevent such a situation, an appropriate conductive material is applied over the lower end outer diameter end portion of the lid member 10 and the lower end inner diameter end portion of the motor bracket 6 as necessary to secure a conductive path between the two. It is desirable to keep it.

このように蓋部材１０で導電経路を構成すれば、ハウジング９の導電性を考慮せずとも足りるため、ハウジング９の成形材料を検討する際に材料選択の余地が広がり、流体軸受装置１の設計自由度が増す。樹脂製としたハウジング９に導電性を持たせる場合には樹脂材料中に高価な導電性充填材を配合する必要があるが、本発明では、この種の導電性充填材の配合を不要とし、あるいは配合量を少なくすることができるので、材料コストの高騰を抑制することができる。   If the conductive path is configured by the lid member 10 in this way, it is not necessary to consider the conductivity of the housing 9, so that the room for material selection is widened when examining the molding material of the housing 9, and the design of the hydrodynamic bearing device 1. Increased freedom. In order to give conductivity to the housing 9 made of resin, it is necessary to blend an expensive conductive filler in the resin material, but in the present invention, the blending of this type of conductive filler is unnecessary, Or since a compounding quantity can be decreased, the rise in material cost can be suppressed.

図１０は、本発明の第２実施形態に係る流体軸受装置１を示すものである。同図に示す流体軸受装置１が図２に示すものと異なる主な点は、ハウジング９が、第２軸受スリーブ８２の下側端面８２ｂを被覆し、軸部材２のフランジ部２ｂとの間に第１スラスト軸受隙間（第１スラスト軸受部Ｔ１）を形成するスラスト軸受隙間形成部９ｄをさらに有する点にある。スラスト軸受隙間形成部９ｄの下側端面９ｄ１には、図５に示すような動圧溝を有するスラスト軸受面Ｂがハウジング９を成形するのと同時に型成形されている。その他の構成は、図２に示す流体軸受装置１と実質的に同一であるから共通の参照番号を付して重複説明を省略する。   FIG. 10 shows a hydrodynamic bearing device 1 according to a second embodiment of the present invention. The main difference of the hydrodynamic bearing device 1 shown in FIG. 2 from that shown in FIG. 2 is that the housing 9 covers the lower end surface 82b of the second bearing sleeve 82 and is between the flange portion 2b of the shaft member 2. A thrust bearing gap forming portion 9d that forms a first thrust bearing gap (first thrust bearing portion T1) is further provided. A thrust bearing surface B having dynamic pressure grooves as shown in FIG. 5 is molded on the lower end surface 9 d 1 of the thrust bearing gap forming portion 9 d at the same time as the housing 9 is molded. Since the other configuration is substantially the same as that of the hydrodynamic bearing device 1 shown in FIG.

図１１は、本発明の第３実施形態に係る流体軸受装置１を示すものである。同図に示す流体軸受装置１が図２に示すものと異なる主な点は、ハウジング９が、さらに、軸部材２のフランジ部２ｂとの間に第１スラスト軸受隙間（第１スラスト軸受部Ｔ１）を形成する補助スリーブ８３をインサート部品として型成形されたものである点にある。補助スリーブ８３の下側端面８３ｂには、図５に示すような動圧溝を有するスラスト軸受面Ｂが設けられている。第２軸受スリーブ８２の下側端面８２ｂと補助スリーブ８３の上側端面とは当接状態にある。これは、ハウジング９の成形工程において、第２軸受スリーブ８２の軸方向の位置決めを行うためである。なお、補助スリーブ８３の内周面８３ａと軸部２ａの外周面２ａ１との間にラジアル軸受隙間（ラジアル軸受部）を形成しても良いし形成しなくても良い。   FIG. 11 shows a hydrodynamic bearing device 1 according to a third embodiment of the present invention. The main difference of the hydrodynamic bearing device 1 shown in FIG. 2 from that shown in FIG. 2 is that the housing 9 is further provided between the flange portion 2b of the shaft member 2 and the first thrust bearing gap (first thrust bearing portion T1). ) Is formed as an insert part. A thrust bearing surface B having dynamic pressure grooves as shown in FIG. 5 is provided on the lower end surface 83b of the auxiliary sleeve 83. The lower end surface 82b of the second bearing sleeve 82 and the upper end surface of the auxiliary sleeve 83 are in contact with each other. This is because the second bearing sleeve 82 is positioned in the axial direction in the molding process of the housing 9. A radial bearing gap (radial bearing portion) may or may not be formed between the inner peripheral surface 83a of the auxiliary sleeve 83 and the outer peripheral surface 2a1 of the shaft portion 2a.

図１０および図１１にそれぞれ示す実施形態では、第１軸受スリーブ８１と第２軸受スリーブ８２の軸方向寸法を異ならせているが、上記構成とすれば第２軸受スリーブ８２の下側端面８２ｂにスラスト軸受面Ｂを形成する必要がなくなり、両軸受スリーブ８１，８２を同一のもので構成することが可能となる。そのため、製作すべき、また保有すべき軸受スリーブの種類を減じて軸受スリーブの製作コストや管理コストを減じることができる。また、成形金型２０（内型２２）に第１および第２軸受スリーブ８１，８２を配置する際の配置間違いを考慮する必要もなくなる。   In the embodiments shown in FIGS. 10 and 11, the axial dimensions of the first bearing sleeve 81 and the second bearing sleeve 82 are different. However, with the above configuration, the lower end face 82b of the second bearing sleeve 82 is provided. It is not necessary to form the thrust bearing surface B, and both the bearing sleeves 81 and 82 can be formed of the same thing. Therefore, it is possible to reduce the manufacturing cost and management cost of the bearing sleeve by reducing the types of bearing sleeves to be manufactured and possessed. In addition, it is not necessary to consider an arrangement error when the first and second bearing sleeves 81 and 82 are arranged in the molding die 20 (inner mold 22).

以上に示す各実施形態では、軸方向の二箇所に離隔配置した軸受スリーブ８１，８２をインサートしてハウジング９を型成形した構成としているが、軸方向の三箇所以上に離隔配置した軸受スリーブをインサートしてハウジング９を型成形することも可能である。   In each of the embodiments described above, the housing 9 is molded by inserting the bearing sleeves 81 and 82 spaced apart at two axial positions, but the bearing sleeves spaced apart at three or more axial positions are formed. It is also possible to insert and mold the housing 9.

また、以上に示す各実施形態では、ハウジング９の成形材料として樹脂を使用しているが、コスト面等で問題がなければ、例えば、マグネシウム合金やアルミニウム合金等の低融点金属材料を使用してハウジング９を型成形することも可能である。また、ハウジング９を、いわゆるＭＩＭ成形品とすることも可能である。但し、ハウジング７を金属材料の型成形品（射出成形品）とする場合には、インサート部品として金型内に供給配置される軸受スリーブ８１，８２を、溶融材料よりも高融点の材料で形成しておくのが肝要である。   Moreover, in each embodiment shown above, although resin is used as the molding material of the housing 9, if there is no problem in terms of cost or the like, for example, a low melting point metal material such as a magnesium alloy or an aluminum alloy is used. It is also possible to mold the housing 9. The housing 9 can also be a so-called MIM molded product. However, in the case where the housing 7 is a metal material molded product (injection molded product), the bearing sleeves 81 and 82 supplied and arranged in the mold as insert parts are formed of a material having a higher melting point than the molten material. It is important to keep it.

また、以上の実施形態では、ヘリングボーン形状等の動圧溝による動圧作用により動圧軸受からなるラジアル軸受部Ｒ１，Ｒ２を構成した場合について説明を行ったが、いわゆる多円弧軸受、ステップ軸受、および波型軸受等、公知のその他の動圧軸受でラジアル軸受部を構成することもできる。また、ラジアル軸受隙間を介して対向する軸受スリーブ８１，８２の内周面８１ａ，８２ａ、および軸部２ａの外周面２ａ１の双方を円筒面とした、いわゆる真円軸受でラジアル軸受部を構成することもできる。   Further, in the above embodiment, the case where the radial bearing portions R1 and R2 including the dynamic pressure bearing are configured by the dynamic pressure action by the dynamic pressure groove having a herringbone shape or the like has been described. The radial bearing portion can also be configured by other known hydrodynamic bearings such as a wave bearing and the like. Further, the radial bearing portion is constituted by a so-called circular bearing in which both the inner peripheral surfaces 81a and 82a of the bearing sleeves 81 and 82 and the outer peripheral surface 2a1 of the shaft portion 2a facing each other through the radial bearing gap are cylindrical surfaces. You can also.

また、以上の実施形態では、ヘリングボーン形状、スパイラル形状等の動圧溝による動圧作用により動圧軸受からなるスラスト軸受部Ｔ１，Ｔ２を構成した場合について説明を行ったが、いわゆるステップ軸受や波型軸受等、公知のその他の動圧軸受でスラスト軸受部Ｔ１，Ｔ２の何れか一方又は双方を構成することもできる。また、スラスト軸受部は、軸部材２の一端を接触支持する、いわゆるピボット軸受で構成することもできる。   Further, in the above embodiment, the case where the thrust bearing portions T1 and T2 including the dynamic pressure bearings are configured by the dynamic pressure action by the dynamic pressure grooves such as the herringbone shape and the spiral shape has been described. Any one or both of the thrust bearing portions T1 and T2 can be configured by other known dynamic pressure bearings such as a wave bearing. Further, the thrust bearing portion can be constituted by a so-called pivot bearing that contacts and supports one end of the shaft member 2.

ディスク装置用のスピンドルモータを概念的に示す断面図である。It is sectional drawing which shows notionally the spindle motor for disk apparatuses. 本発明の第１実施形態に係る流体軸受装置を示す断面図である。It is sectional drawing which shows the hydrodynamic bearing apparatus which concerns on 1st Embodiment of this invention. ハウジングおよび軸受スリーブの断面図である。It is sectional drawing of a housing and a bearing sleeve. 第２軸受スリーブの下側端面を示す図である。It is a figure which shows the lower end surface of a 2nd bearing sleeve. 図２に示す流体軸受装置の要部拡大断面図である。It is a principal part expanded sectional view of the hydrodynamic bearing apparatus shown in FIG. 蓋部材のプレート部の上側端面を示す図である。It is a figure which shows the upper side end surface of the plate part of a cover member. ハウジングの型成形工程を示す断面図である。It is sectional drawing which shows the mold forming process of a housing. ハウジングの型成形工程を示す断面図である。It is sectional drawing which shows the mold forming process of a housing. ハウジングの型成形工程を示す断面図である。It is sectional drawing which shows the mold forming process of a housing. 本発明の第２実施形態に係る流体軸受装置を示す断面図である。It is sectional drawing which shows the hydrodynamic bearing apparatus which concerns on 2nd Embodiment of this invention. 本発明の第３実施形態に係る流体軸受装置を示す断面図である。It is sectional drawing which shows the hydrodynamic bearing apparatus which concerns on 3rd Embodiment of this invention.

符号の説明Explanation of symbols

１ 流体軸受装置
２ 軸部材
２ａ 軸部
６ モータブラケット
９ ハウジング
９ｂ シール部
９ｃ スペーサ部
９ｄ スラスト軸受隙間形成部
１０ 蓋部材
１２ ゲート跡
２０ 成形金型
２２ 内型
２５ ゲート
８１ 第１軸受スリーブ
８２ 第２軸受スリーブ
８３ 補助スリーブ
Ａ１、Ａ２ ラジアル軸受面
Ｂ、Ｃ スラスト軸受面
Ｎ 逃げ部
Ｓ シール空間
Ｒ１、Ｒ２ ラジアル軸受部
Ｔ１、Ｔ２ スラスト軸受部 DESCRIPTION OF SYMBOLS 1 Fluid dynamic bearing apparatus 2 Shaft member 2a Shaft part 6 Motor bracket 9 Housing 9b Seal part 9c Spacer part 9d Thrust bearing gap formation part 10 Lid member 12 Gate trace 20 Molding die 22 Inner mold 25 Gate 81 First bearing sleeve 82 Second Bearing sleeve 83 Auxiliary sleeve A1, A2 Radial bearing surface B, C Thrust bearing surface N Relief part S Seal space R1, R2 Radial bearing part T1, T2 Thrust bearing part

Claims (11)

少なくとも一端が開口したハウジングと、ハウジングの内周に収容された軸受スリーブと、軸受スリーブの内周に挿入された軸部材と、軸受スリーブの内周面と軸部材の外周面との間のラジアル軸受隙間に形成される油膜で軸部材をラジアル方向に支持するラジアル軸受部とを備える流体軸受装置において、
ハウジングが、軸方向に離隔して複数配置した軸受スリーブをインサートして型成形され、かつ、軸方向で隣り合う軸受スリーブ間に介在するスペーサ部を有することを特徴とする流体軸受装置。 A housing having at least one open end, a bearing sleeve housed in the inner periphery of the housing, a shaft member inserted in the inner periphery of the bearing sleeve, and a radial between the inner peripheral surface of the bearing sleeve and the outer peripheral surface of the shaft member In a hydrodynamic bearing device including a radial bearing portion that supports a shaft member in a radial direction with an oil film formed in a bearing gap,
A hydrodynamic bearing device, characterized in that the housing is molded by inserting a plurality of axially spaced bearing sleeves and is interposed between axially adjacent bearing sleeves. ハウジングの外周面のうち、スペーサ部の形成領域にゲート跡を有する請求項１記載の流体軸受装置。   The hydrodynamic bearing device according to claim 1, wherein a gate mark is formed in a region where the spacer portion is formed on the outer peripheral surface of the housing. 型成形後に生じる成形収縮により、スペーサ部の内周面に逃げ部が形成された請求項１記載の流体軸受装置。   The hydrodynamic bearing device according to claim 1, wherein a relief portion is formed on the inner peripheral surface of the spacer portion due to molding shrinkage that occurs after molding. ハウジングが、複数の軸受スリーブのうち、最もハウジング開口側に位置する軸受スリーブの一端面を被覆し、軸部材との間にシール空間を形成するシール部をさらに有する請求項１記載の流体軸受装置。   2. The hydrodynamic bearing device according to claim 1, wherein the housing further includes a seal portion that covers one end face of the bearing sleeve located closest to the housing opening among the plurality of bearing sleeves and forms a seal space with the shaft member. . ハウジングが、複数の軸受スリーブのうち、最も反ハウジング開口側に位置する軸受スリーブの一端面を被覆し、軸部材との間にスラスト軸受隙間を形成するスラスト軸受隙間形成部をさらに有する請求項１記載の流体軸受装置。   2. The housing further includes a thrust bearing gap forming portion that covers one end surface of the bearing sleeve that is located closest to the housing opening side among the plurality of bearing sleeves and that forms a thrust bearing gap with the shaft member. The hydrodynamic bearing device described. ハウジングが、軸部材との間にスラスト軸受隙間を形成する補助スリーブをインサートして型成形された請求項１記載の流体軸受装置。   The hydrodynamic bearing device according to claim 1, wherein the housing is molded by inserting an auxiliary sleeve that forms a thrust bearing gap between the housing and the shaft member. ハウジングの他端を開口させ、該他端開口をハウジングの外周面に固定した蓋部材で閉塞した請求項１記載の流体軸受装置。   2. The hydrodynamic bearing device according to claim 1, wherein the other end of the housing is opened, and the other end opening is closed with a lid member fixed to the outer peripheral surface of the housing. 少なくとも一端が開口したハウジングと、ハウジングの内周に収容された軸受スリーブと、軸受スリーブの内周に挿入された軸部材と、軸受スリーブの内周面と軸部材の外周面との間のラジアル軸受隙間に形成される油膜で軸部材をラジアル方向に支持するラジアル軸受部とを備える流体軸受装置の製造方法において、
軸方向に離隔して複数配置した軸受スリーブをインサート部品とし、軸方向で隣り合う軸受スリーブ間に配したゲートから溶融材料をキャビティ内に充填することにより、ハウジングを型成形する工程を含むことを特徴とする流体軸受装置の製造方法。 A housing having at least one open end, a bearing sleeve housed in the inner periphery of the housing, a shaft member inserted in the inner periphery of the bearing sleeve, and a radial between the inner peripheral surface of the bearing sleeve and the outer peripheral surface of the shaft member In a manufacturing method of a hydrodynamic bearing device comprising a radial bearing portion that supports a shaft member in a radial direction with an oil film formed in a bearing gap,
Including a step of molding a housing by using a plurality of axially spaced bearing sleeves as insert parts and filling the cavity with molten material from a gate disposed between adjacent axially adjacent bearing sleeves. A method for manufacturing a hydrodynamic bearing device. 内型の外周面に各軸受スリーブを嵌合し、各軸受スリーブのうち、最も内型の基端側に位置する軸受スリーブの軸方向の位置決めを、内型に設けた段部に前記軸受スリーブを係合させることにより行う請求項８記載の流体軸受装置の製造方法。   Each bearing sleeve is fitted to the outer peripheral surface of the inner mold, and among the bearing sleeves, the bearing sleeve positioned in the proximal end side of the inner mold is positioned in the axial direction. The method for manufacturing a hydrodynamic bearing device according to claim 8, wherein the hydrodynamic bearing device is engaged with each other. 内型として、外周面に低摩擦処理が施されたものを用いる請求項９記載の流体軸受装置の製造方法。   The method for manufacturing a hydrodynamic bearing device according to claim 9, wherein an inner die whose outer peripheral surface is subjected to low friction treatment is used. 軸受スリーブを多孔質材料で形成し、この軸受スリーブを、その内部気孔に潤滑油を含浸させた状態で内型の外周面に嵌合する請求項９記載の流体軸受装置の製造方法。   10. The method of manufacturing a hydrodynamic bearing device according to claim 9, wherein the bearing sleeve is formed of a porous material, and the bearing sleeve is fitted to the outer peripheral surface of the inner mold in a state where the internal pores are impregnated with lubricating oil.
JP2008265154A 2008-10-14 2008-10-14 Fluid bearing device and its manufacturing method Pending JP2010096200A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015098921A (en) * 2013-11-20 2015-05-28 Ntn株式会社 Fluid dynamic pressure bearing device and manufacturing method thereof
JP2017101593A (en) * 2015-12-01 2017-06-08 トヨタ紡織株式会社 Motor and electric supercharger with the same
WO2020175351A1 (en) * 2019-02-28 2020-09-03 株式会社ダイヤメット Insert bearing and manufacturing method therefor, sintered bearing suitable for insert bearing, sintered insert component and manufacturing method therefor, and sintered component suitable for sintered insert component
CN113396025A (en) * 2019-02-28 2021-09-14 大冶美有限公司 Insert bearing and method for manufacturing the same, sintered bearing used in the insert bearing, insert sintered member and method for manufacturing the same, and sintered member used in the insert sintered member

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015098921A (en) * 2013-11-20 2015-05-28 Ntn株式会社 Fluid dynamic pressure bearing device and manufacturing method thereof
JP2017101593A (en) * 2015-12-01 2017-06-08 トヨタ紡織株式会社 Motor and electric supercharger with the same
WO2020175351A1 (en) * 2019-02-28 2020-09-03 株式会社ダイヤメット Insert bearing and manufacturing method therefor, sintered bearing suitable for insert bearing, sintered insert component and manufacturing method therefor, and sintered component suitable for sintered insert component
CN113396025A (en) * 2019-02-28 2021-09-14 大冶美有限公司 Insert bearing and method for manufacturing the same, sintered bearing used in the insert bearing, insert sintered member and method for manufacturing the same, and sintered member used in the insert sintered member
CN113396025B (en) * 2019-02-28 2023-12-01 大冶美有限公司 Insert bearing and method for manufacturing same, sintered bearing applied to insert bearing, insert sintered part and method for manufacturing same, and sintered part applied to insert sintered part
CN113396025B9 (en) * 2019-02-28 2024-04-12 大冶美有限公司 Insert bearing and method for manufacturing same, sintered bearing applied to insert bearing, insert sintered part and method for manufacturing same, and sintered part applied to insert sintered part

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