JP2007040527A - Fluid bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To positively prevent an oil leakage from a fluid bearing device. <P>SOLUTION: The fluid bearing device 1 comprises a shaft member 2 constituting a first seal part 14; a bearing member 17 with the shaft member 2 inserted in the inner periphery; a seal member 9 fixed to the bearing member 17 to constitute a second seal part 15; and a seal space S for preventing a leakage of lubricating oil. A recess 13 and an oil-repellent film 11 are formed at an upper end face 9c of the seal member 9, and the oil-repellent film 11 has the maximum thickness at a portion of the recess 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、流体軸受装置に関するものである。流体軸受装置は、情報機器、例えばＨＤＤ等の磁気ディスク装置、ＣＤ−ＲＯＭ、ＣＤ−Ｒ／ＲＷ、ＤＶＤ−ＲＯＭ／ＲＡＭ等の光ディスク装置、ＭＤ、ＭＯ等の光磁気ディスク装置等のスピンドルモータ用、レーザビームプリンタ（ＬＢＰ）のポリゴンスキャナモータ用、プロジェクタのカラーホイールモータ用、あるいは電気機器、例えば軸流ファンなどの小型モータ用の軸受装置として好適である。   The present invention relates to a hydrodynamic bearing device. Fluid bearing devices are used for spindle motors of information equipment such as magnetic disk devices such as HDD, optical disk devices such as CD-ROM, CD-R / RW, DVD-ROM / RAM, and magneto-optical disk devices such as MD and MO. It is suitable as a bearing device for a polygon scanner motor of a laser beam printer (LBP), a color wheel motor of a projector, or a small motor such as an electric device such as an axial fan.

上記各種モータには、高回転精度の他、高速化、低コスト化、低騒音化などが求められている。これらの要求性能を決定付ける構成要素の一つに当該モータのスピンドルを支持する軸受があり、近年では、この種の軸受として、上記要求性能に優れた特性を有する流体軸受装置の使用が検討され、あるいは実際に使用されている。   In addition to high rotational accuracy, the various motors are required to have high speed, low cost, low noise, and the like. One of the components that determine these required performances is a bearing that supports the spindle of the motor. In recent years, as this type of bearing, the use of a hydrodynamic bearing device having characteristics excellent in the required performance has been studied. Or actually used.

この種の流体軸受装置は、軸受隙間内の潤滑油に動圧を発生させるための動圧発生部を備えた動圧軸受と、動圧発生部を備えていない、いわゆる真円軸受（軸受断面が真円形状である軸受）とに大別される。   This type of hydrodynamic bearing device includes a hydrodynamic bearing provided with a dynamic pressure generating portion for generating dynamic pressure in the lubricating oil in the bearing clearance, and a so-called perfect bearing (bearing cross section) provided with no dynamic pressure generating portion. Are roughly divided into bearings having a perfect circle shape.

例えば、ＨＤＤ等のディスク装置用のスピンドルモータに組み込まれる流体軸受装置では、ラジアル方向およびスラスト方向の双方で軸部材を回転自在に非接触支持する動圧軸受が用いられる。この他、スラスト軸受部としては、軸部材を接触支持するピボット軸受が用いられる場合もある。これらの軸受装置では、内部に供給した潤滑油で軸受隙間が満たされる。ＨＤＤ等のディスク装置では製品の性質上、油（潤滑油）による汚染を極度に嫌うので、通常は、軸受隙間からの潤滑油の漏れ出しを防止するため、軸受部材の開口部にシール部材を設け、当該シール部材の内周面と軸部材の外周面との間に、毛細管力を利用して潤滑油を保持するシール空間を形成している（例えば、特許文献１参照）。
特開２００４−１７６８１５号公報 For example, in a hydrodynamic bearing device incorporated in a spindle motor for a disk device such as an HDD, a hydrodynamic bearing that rotatably supports a shaft member in both a radial direction and a thrust direction is used. In addition, a pivot bearing that contacts and supports the shaft member may be used as the thrust bearing portion. In these bearing devices, the bearing gap is filled with lubricating oil supplied to the inside. Since disk devices such as HDDs are extremely disliked by contamination due to oil (lubricating oil) due to the nature of the product, a sealing member is usually provided at the opening of the bearing member in order to prevent leakage of the lubricating oil from the bearing gap. A seal space for holding lubricating oil is formed between the inner peripheral surface of the seal member and the outer peripheral surface of the shaft member using a capillary force (see, for example, Patent Document 1).
JP 2004-176815 A

上記特許文献１に示す発明においては、潤滑油の漏れ出しを確実に防止するため、シール部材の端面等にフッ素樹脂等の撥油剤を塗布して撥油膜を形成している。この種の撥油剤は一般に濡れ性が良好であるため、固化後の撥油膜の膜厚は薄くなり易く、撥油剤成分である高分子の数層分（０．０１μｍ程度）の極薄膜となる場合もある。   In the invention shown in Patent Document 1, an oil repellent film is formed by applying an oil repellent such as a fluororesin to the end face of the seal member or the like in order to reliably prevent leakage of the lubricating oil. Since this type of oil repellent generally has good wettability, the film thickness of the oil repellent film after solidification tends to be thin, resulting in an ultrathin film for several layers (about 0.01 μm) of the polymer as the oil repellent component. In some cases.

このような極端に薄い撥油膜では、母材と被膜との密着強度が低下し、界面に油が浸透しやすくなって被膜の親油性が増す。また、母材には表面粗さが存在することから、母材表面を完全に撥油膜で被覆することが難しくなる。したがって、単に撥油膜を形成するだけでは、撥油効果が十分とは言えず、軸受装置の使用条件や設計仕様等によっては、油漏れを招くおそれがある。   In such an extremely thin oil-repellent film, the adhesion strength between the base material and the coating film decreases, and the oil easily penetrates into the interface, thereby increasing the lipophilicity of the coating film. Further, since the base material has surface roughness, it is difficult to completely cover the surface of the base material with the oil repellent film. Therefore, simply forming the oil-repellent film does not provide a sufficient oil-repellent effect, and there is a risk of oil leakage depending on the use conditions and design specifications of the bearing device.

また、極端に薄い撥油膜では、検査工程等において撥油膜の存在の有無を目視で識別することも難しくなる。識別性を改善するため、蛍光剤を含む撥油剤で撥油膜を形成し、その後の検査工程でＵＶ光を照射して撥油膜の有無を目視確認する手法も提案されているが、極薄膜であるが故に視認性が不十分で現状では必ずしも有効な判別方法とはいえない。   In addition, with an extremely thin oil repellent film, it is difficult to visually identify the presence or absence of the oil repellent film in an inspection process or the like. In order to improve discrimination, a method has been proposed in which an oil repellent film is formed with an oil repellent containing a fluorescent agent, and UV light is irradiated in the subsequent inspection process to visually check the presence or absence of the oil repellent film. Therefore, the visibility is insufficient and it is not always an effective discrimination method at present.

そこで、本発明は、油漏れを確実に防止することを第１の目的とする。また、撥油剤の存在の有無を容易に判別可能とすることを第２の目的とする。   Therefore, a first object of the present invention is to reliably prevent oil leakage. A second object is to make it possible to easily determine the presence or absence of an oil repellent.

前記課題を解決するため、本発明にかかる流体軸受装置は、軸部材と、ラジアル軸受隙間に形成した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、外気に開放され、一対のシール面を対向させて形成されたシール空間と、一方のシール面を有する第１シール部と、他方のシール面を有する第２シール部とを備えたものであって、第１シール部および第２シール部のうち、少なくとも何れか一方の表面に凹部と撥油膜とを形成し、かつ凹部で撥油膜を他所より厚く形成したことを特徴とするものである。   In order to solve the above problems, a hydrodynamic bearing device according to the present invention includes a shaft member, a radial bearing portion that supports the shaft member in a radial direction with an oil film formed in a radial bearing gap, and a pair of seal surfaces that are open to the outside air. And a first seal portion having one seal surface, and a second seal portion having the other seal surface, wherein the first seal portion and the second seal are provided. A recess and an oil repellent film are formed on at least one of the surfaces, and the oil repellent film is formed thicker than the other portions in the recess.

この流体軸受装置の具体的な構成例として、上記構成要素に加えて、
（１）内周に軸部材を挿入した軸受部材と、軸受部材に固定されたシール部材とを備え、軸部材で第１シール部を構成すると共に、シール部材で第２シール部を構成したもの：
（２）内周に軸部材を挿入した軸受部材を備え、軸部材で第１シール部を構成すると共に、軸受部材で第２シール部を構成したもの：
（３）軸部材に設けられた半径方向の突出部と、内周に軸部材を挿入した軸受部材とを備え、軸部材の突出部で第１シール部を構成すると共に、軸受部材で第２シール部を構成したもの：を挙げることができる。 As a specific configuration example of the hydrodynamic bearing device, in addition to the above components,
(1) A bearing member in which a shaft member is inserted on the inner periphery and a seal member fixed to the bearing member. The shaft member constitutes the first seal portion, and the seal member constitutes the second seal portion. :
(2) A bearing member in which a shaft member is inserted on the inner periphery, the shaft member constituting the first seal portion, and the bearing member constituting the second seal portion:
(3) A projecting portion in the radial direction provided on the shaft member and a bearing member having a shaft member inserted on the inner periphery thereof, and the projecting portion of the shaft member constitutes the first seal portion, and the bearing member is the second. What comprised the seal | sticker part: can be mentioned.

（１）の構成では、第１シール部となる軸部材の外周面、あるいは第２シール部となるシール部材の内周面や端面に撥油膜が形成され、（２）の構成では、第１シール部となる軸部材の外周面、あるいは第２シール部となる軸受部材の端面や内周面に撥油膜が形成され、（３）の構成では、第１シール部となる突出部の端面や内・外周面、あるいは第２シール部となる軸受部材の端面や内・外周面に撥油膜が形成される。なお、何れの構成においても、「軸受部材」は、それ自身が一体成形されている場合のみならず、二以上の部材を組み合わせた複合品である場合、例えば内周に軸部材を挿入した軸受スリーブと、軸受スリーブを収容したハウジングとで構成されている場合も含む概念である。   In the configuration of (1), an oil repellent film is formed on the outer peripheral surface of the shaft member serving as the first seal portion or the inner peripheral surface and the end surface of the seal member serving as the second seal portion, and in the configuration of (2), the first An oil repellent film is formed on the outer peripheral surface of the shaft member serving as the seal portion, or the end surface or inner peripheral surface of the bearing member serving as the second seal portion, and in the configuration of (3), the end surface of the projecting portion serving as the first seal portion An oil repellent film is formed on the inner and outer peripheral surfaces, or on the end surfaces and inner and outer peripheral surfaces of the bearing member to be the second seal portion. Note that, in any configuration, the “bearing member” is not only a case where the bearing member itself is integrally molded, but also a composite product in which two or more members are combined, for example, a bearing in which a shaft member is inserted on the inner periphery. It is a concept that includes a case in which a sleeve and a housing that houses a bearing sleeve are included.

このように、本発明では、第１シール部あるいは第２シール部の何れか一方または双方の表面に凹部を形成し、この凹部でフッ素樹脂等からなる撥油膜を他所よりも厚く形成している。そのため、撥油膜の厚い部分では接触面積の増大により母材に対する撥油膜の密着力を高めることができ、従って、界面への潤滑油の浸透を防止することが可能となる。また、少なくとも撥油膜の厚い部分では母材表面を完全に被膜で被覆することができる。以上の理由から、撥油膜の撥油性を高め、ラジアル軸受隙間からの油漏れを確実に防止することが可能となる。   Thus, in the present invention, a recess is formed on the surface of one or both of the first seal portion and the second seal portion, and an oil repellent film made of a fluororesin or the like is formed thicker than the other portions in the recess. . For this reason, in the thick part of the oil repellent film, the contact area can be increased to increase the adhesion of the oil repellent film to the base material, and therefore it is possible to prevent the penetration of the lubricating oil to the interface. Further, at least in the thick part of the oil repellent film, the surface of the base material can be completely covered with the film. For the above reasons, it is possible to improve the oil repellency of the oil repellent film and reliably prevent oil leakage from the radial bearing gap.

また、本発明のように撥油膜を部分的に厚くした場合、撥油膜の有無をより確認し易くなる。特に、撥油剤に蛍光剤を含有させると、厚い部分で蛍光作用が強まるため、検査工程等で母材表面にＵＶ光等を照射した際、撥油膜の有無を容易に目視確認することが可能となる。   Further, when the oil repellent film is partially thickened as in the present invention, it becomes easier to confirm the presence or absence of the oil repellent film. In particular, when a fluorescent agent is included in the oil repellent, the fluorescent action is enhanced at the thick part. Therefore, when the surface of the base material is irradiated with UV light or the like in the inspection process, the presence or absence of the oil repellent film can be easily visually confirmed. It becomes.

さらに、凹部は、表面に撥油剤を塗布して撥油膜を形成する際、余剰の撥油剤を堰き止める効果も有する。従って、凹部の形成位置を適宜定めることで、流動性に富む撥油剤の塗布した際、これが広がる範囲を規制し、意図しない箇所での撥油膜の形成を防止することができる。例えば、塗布した余剰の撥油剤が他部材との接着箇所に流れ込めば接着強度の低下を招くし、シール空間の油溜り部分に流れ込めば、その撥油性から油溜りに空気が進入し、これが潤滑油中に気泡として混入して軸受性能を低下させる恐れがあるが、凹部の形成位置を適切に設定することで、これらの不具合を防止することが可能となる。   Further, the recess has an effect of blocking excess oil repellent when an oil repellent is applied to the surface to form an oil repellent film. Therefore, by appropriately determining the formation position of the recesses, when an oil repellent with high fluidity is applied, the range in which the oil spreads can be restricted, and the formation of an oil repellent film at an unintended location can be prevented. For example, if the applied excess oil repellant flows into the adhesion area with other members, the adhesive strength is reduced, and if it flows into the oil reservoir portion of the seal space, air enters the oil reservoir from its oil repellency, Although this may be mixed as bubbles in the lubricating oil and deteriorate the bearing performance, it is possible to prevent these problems by appropriately setting the recess formation position.

本願発明者の検証によれば、以上の作用効果を得るためには、凹部の深さが３μｍ以上必要であることが判明した。従って、凹部の深さは、３μｍ以上、望ましくは１５μｍ以上に設定するのが望ましい。上記の効果を奏する上で凹部の深さに上限はないが、凹部が深すぎると撥油剤の使用量が増して不経済となり、また、凹部を形成した部材の強度にも悪影響を与える可能性があるので、かかる観点からは、凹部の深さを１ｍｍ以下とするのが望ましい。   According to the verification by the present inventor, it has been found that the depth of the concave portion is required to be 3 μm or more in order to obtain the above-described effects. Therefore, it is desirable that the depth of the recess is set to 3 μm or more, preferably 15 μm or more. There is no upper limit to the depth of the recess for achieving the above effect, but if the recess is too deep, the amount of the oil repellent used is increased and it is uneconomical, and the strength of the member having the recess may be adversely affected. Therefore, from such a viewpoint, it is desirable that the depth of the recess is 1 mm or less.

以上のように、本発明によれば、簡易な手段で撥油膜の撥油効果を高めることができ、油漏れを確実に防止することが可能となる。また、撥油膜の有無を容易に判別可能となり、製造ラインにおける検査工程を簡略化することができる。   As described above, according to the present invention, the oil repellent effect of the oil repellent film can be enhanced by simple means, and oil leakage can be reliably prevented. In addition, the presence or absence of the oil repellent film can be easily discriminated, and the inspection process in the production line can be simplified.

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、本発明の一実施形態に係る流体軸受装置を組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。この情報機器用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、流体軸受装置（動圧軸受装置）１と、流体軸受装置１の軸部材２に取り付けられたディスクハブ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、流体軸受装置１をモータに固定するためのブラケット６とを備えている。ステータコイル４はブラケット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ている。ディスクハブ３は、その外周に磁気ディスク等のディスクＤを一枚または複数枚保持する。ブラケット６の内周に流体軸受装置１のハウジング７が装着されている。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との間に発生する電磁力でロータマグネット５が回転し、それに伴ってディスクハブ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 a configuration example of a spindle motor for information equipment incorporating a hydrodynamic bearing device according to an embodiment of the present invention. This spindle motor for information equipment is used in a disk drive device such as an HDD, and includes a fluid dynamic bearing device (dynamic pressure bearing device) 1, a disk hub 3 attached to a shaft member 2 of the fluid dynamic bearing device 1, for example, The stator coil 4 and the rotor magnet 5 are opposed to each other with a gap in the radial direction, and the bracket 6 for fixing the hydrodynamic bearing device 1 to the motor. The stator coil 4 is attached to the outer periphery of the bracket 6, and the rotor magnet 5 is attached to the inner periphery of the disk hub 3. The disk hub 3 holds one or more disks D such as magnetic disks on the outer periphery thereof. A housing 7 of the hydrodynamic bearing device 1 is attached to the inner periphery of the bracket 6. When the stator coil 4 is energized, the rotor magnet 5 is rotated by an electromagnetic force generated between the stator coil 4 and the rotor magnet 5, and the disk D held by the disk hub 3 and the disk hub 3 is thereby moved to the shaft member 2. And rotate together.

図２に示すように、本実施形態にかかる流体軸受装置１は、軸受部材１７と、軸受部材１７の内周に挿入された軸部材２と、軸受部材１７に固定され、軸受部材１７の一端開口をシールするシール部材９と、軸受部材１７の他端開口を封口する蓋部材１０とを主要な構成部材として備える。なお、本実施形態において軸受部材１７は、内周に軸部材２を挿入した軸受スリーブ８と、当該軸受スリーブ８を収容したハウジング７とで構成されている。また、以下では、説明の便宜上、シール部材９の側を上側、これと軸方向反対側を下側として説明を行う。   As shown in FIG. 2, the hydrodynamic bearing device 1 according to the present embodiment is fixed to the bearing member 17, the shaft member 2 inserted into the inner periphery of the bearing member 17, and the bearing member 17. A seal member 9 that seals the opening and a lid member 10 that seals the other end opening of the bearing member 17 are provided as main constituent members. In this embodiment, the bearing member 17 includes a bearing sleeve 8 in which the shaft member 2 is inserted on the inner periphery, and a housing 7 in which the bearing sleeve 8 is accommodated. In the following description, for convenience of description, the seal member 9 side is described as the upper side, and the opposite side in the axial direction is described as the lower side.

軸部材２は、例えばステンレス鋼等の金属材料で形成された軸部２ａと、軸部２ａの外径側に張り出し、軸部２ａと一体又は別体のフランジ部２ｂとで構成される。また、軸部材２は金属部分と樹脂部分からなるハイブリッド構造とすることもできる（例えば、軸部２ａを金属材料で形成し、フランジ部２ｂの全体又はその両端面２ｂ１、２ｂ２のみを樹脂材料で形成する）。軸部２ａの外周面２ａ１は、動圧発生部としての動圧溝等を有さない真円状に形成される。また、フランジ部２ｂの両端面２ｂ１、２ｂ２は、動圧発生部としての動圧溝等を有さない平滑な平坦面に形成されている。   The shaft member 2 is composed of a shaft portion 2a formed of a metal material such as stainless steel, for example, and an outer diameter side of the shaft portion 2a, and a flange portion 2b that is integral with or separate from the shaft portion 2a. Moreover, the shaft member 2 can also have a hybrid structure composed of a metal portion and a resin portion (for example, the shaft portion 2a is formed of a metal material, and the entire flange portion 2b or only both end surfaces 2b1, 2b2 thereof are made of a resin material. Form). The outer peripheral surface 2a1 of the shaft portion 2a is formed in a perfect circle shape that does not have a dynamic pressure groove or the like as a dynamic pressure generating portion. Further, both end surfaces 2b1 and 2b2 of the flange portion 2b are formed as smooth flat surfaces having no dynamic pressure grooves or the like as dynamic pressure generating portions.

ハウジング７は、樹脂材料あるいは金属材料で両端を開口させた略円筒状に形成される。   The housing 7 is formed in a substantially cylindrical shape having both ends opened with a resin material or a metal material.

軸受スリーブ８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に潤滑油（または潤滑グリース）を含浸させた含油焼結金属の多孔質体で円筒状に形成される。この他、中実の金属材料、例えば黄銅等の軟質金属で軸受スリーブ８を形成することもできる。軸受スリーブ８の内周面８ａには、図３（ａ）に示すように、第１ラジアル軸受部Ｒ１と第２ラジアル軸受部Ｒ２のラジアル軸受面Ａとなる上下２つの領域が軸方向に離隔して設けられている。上記２つの離隔した領域には、動圧発生部として、例えばヘリングボーン状に配列された動圧溝８ａ１、８ａ２がそれぞれ形成され、各動圧溝８ａ１、８ａ２の間に背部（図中クロスハッチングで示す）が形成されている。上側の動圧溝８ａ１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。そのため、軸部材２の回転時、上側の動圧溝８ａ１による潤滑油の引き込み力（ポンピング力）は下側の対称形の動圧溝８ａ２に比べ相対的に大きくなる。   The bearing sleeve 8 is formed in a cylindrical shape with a porous body made of sintered metal, in particular, an oil-containing sintered metal porous body in which a sintered metal mainly composed of copper is impregnated with lubricating oil (or lubricating grease). The In addition, the bearing sleeve 8 can be formed of a solid metal material, for example, a soft metal such as brass. On the inner peripheral surface 8a of the bearing sleeve 8, as shown in FIG. 3A, two upper and lower regions serving as the radial bearing surfaces A of the first radial bearing portion R1 and the second radial bearing portion R2 are separated in the axial direction. Is provided. In the two separated regions, for example, dynamic pressure grooves 8a1 and 8a2 arranged in a herringbone shape are formed as dynamic pressure generating portions, respectively, and a back portion (cross hatching in the figure) is formed between the dynamic pressure grooves 8a1 and 8a2. Is formed). The upper dynamic pressure groove 8a1 is formed to be axially asymmetric with respect to the axial center m (the axial center of the upper and lower inclined groove regions), and the axial dimension X1 of the upper region is lower than the axial center m. It is larger than the axial dimension X2 of the region. Therefore, when the shaft member 2 rotates, the pulling force (pumping force) of the lubricating oil by the upper dynamic pressure groove 8a1 is relatively larger than that of the lower symmetrical dynamic pressure groove 8a2.

また、軸受スリーブ８の下側端面８ｂの一部環状領域は、第１スラスト軸受部Ｔ１のスラスト軸受面Ｂとなり、このスラスト軸受面Ｂには、例えば図３（ｂ）に示すようにスパイラル状に配列された複数の動圧溝８ｂ１が形成される。各動圧溝８ｂ１の間には背部（図中クロスハッチングで示す）が形成され、この背部の内径端は環状につながっている。なお、動圧溝形状としては、スパイラル状の他、ヘリングボーン状、あるいは放射状等にすることもできる。また、スラスト軸受面Ｂは、軸受スリーブ８の下側端面８ｂとスラスト軸受隙間を介して対向するフランジ部２ｂの上側端面２ｂ１に形成してもよい。   Further, a partial annular region of the lower end surface 8b of the bearing sleeve 8 becomes a thrust bearing surface B of the first thrust bearing portion T1, and the thrust bearing surface B has, for example, a spiral shape as shown in FIG. A plurality of dynamic pressure grooves 8b1 arranged in the same manner are formed. A back portion (indicated by cross hatching in the figure) is formed between the dynamic pressure grooves 8b1, and the inner diameter end of the back portion is connected in an annular shape. The dynamic pressure groove shape may be a herringbone shape, a radial shape, or the like in addition to a spiral shape. Further, the thrust bearing surface B may be formed on the upper end surface 2b1 of the flange portion 2b facing the lower end surface 8b of the bearing sleeve 8 via the thrust bearing gap.

そして、ハウジング７の内周に軸受スリーブ８を接着、圧入等適宜の手段で固定することにより軸受部材１７が形成される。   The bearing member 17 is formed by fixing the bearing sleeve 8 to the inner periphery of the housing 7 by an appropriate means such as bonding or press fitting.

軸受部材１７（ハウジング７）の下端開口には金属製の蓋部材１０が配置され、この蓋部材１０によってハウジング７の下端側開口が封口される。この蓋部材１０は、円筒状の側部１０ｂと、側部１０ｂの下端開口を封口する底部１０ａとを一体に備えた有底円筒状に形成される。底部１０ａの上側端面１０ａ１の一部環状領域は、第２スラスト軸受部Ｔ２のスラスト軸受面Ｃとなり、このスラスト軸受面Ｃには、図示は省略するが、例えばスパイラル状に配列された複数の動圧溝が形成される。もちろん、動圧溝形状はスパイラル状の他、上記のスラスト軸受面Ｂと同様にヘリングボーン状、あるいは放射状等にすることもできる。なお、スラスト軸受面Ｃは、蓋部材１０の上側端面１０ａ１とスラスト軸受隙間を介して対向するフランジ部２ｂの下側端面２ｂ２に形成してもよい。   A metal lid member 10 is disposed at the lower end opening of the bearing member 17 (housing 7), and the lower end side opening of the housing 7 is sealed by the lid member 10. The lid member 10 is formed in a bottomed cylindrical shape integrally including a cylindrical side portion 10b and a bottom portion 10a that seals a lower end opening of the side portion 10b. A partial annular region of the upper end surface 10a1 of the bottom portion 10a becomes a thrust bearing surface C of the second thrust bearing portion T2, and the thrust bearing surface C has a plurality of movements arranged in a spiral shape, for example, although not shown in the figure. A pressure groove is formed. Needless to say, the dynamic pressure groove shape may be a spiral shape or a herringbone shape or a radial shape as in the case of the thrust bearing surface B described above. The thrust bearing surface C may be formed on the lower end surface 2b2 of the flange portion 2b facing the upper end surface 10a1 of the lid member 10 via the thrust bearing gap.

上記構成の蓋部材１０は、ハウジング７の下端内周面に接着等の適宜の手段で固定される。このとき、軸部材２のフランジ部２ｂは、軸受スリーブ８の下側端面８ｂと蓋部材１０の底部１０ａの上側端面１０ａ１との間に形成された空間に収容される。蓋部材１０の側部１０ｂの上側端面１０ｂ１を軸受スリーブ８の下側端面８ｂに当接させることで、スラスト軸受隙間幅が高精度に管理される。   The lid member 10 having the above configuration is fixed to the inner peripheral surface of the lower end of the housing 7 by an appropriate means such as adhesion. At this time, the flange portion 2 b of the shaft member 2 is accommodated in a space formed between the lower end surface 8 b of the bearing sleeve 8 and the upper end surface 10 a 1 of the bottom portion 10 a of the lid member 10. By bringing the upper end surface 10b1 of the side portion 10b of the lid member 10 into contact with the lower end surface 8b of the bearing sleeve 8, the thrust bearing gap width is managed with high accuracy.

ハウジング７の上端開口部７ａには、金属材料や樹脂材料で形成された環状のシール部材９が配置され、例えば接着等の手段でハウジング７の内周に固定される。   An annular seal member 9 formed of a metal material or a resin material is disposed in the upper end opening 7a of the housing 7, and is fixed to the inner periphery of the housing 7 by means such as adhesion.

以上に述べた流体軸受装置１の内部空間は、微小幅のシール空間Ｓを介して外気に開放されている。流体軸受装置の組立完了後、その内部空間にシール空間Ｓを介して潤滑油が充満される。シール空間Ｓは、第１シール部１４に形成された一方のシール面と、第２シール部１５に形成された他方のシール面とを対向させることで形成される。図２に示す例では、軸部材２で第１シール部１４を構成し、軸部２ａに形成されたテーパ面２ａ２が一方のシール面となる。また、シール部材９で第２シール部１５を構成し、その内周面９ａが他方のシール面となる。   The internal space of the hydrodynamic bearing device 1 described above is open to the outside air through a very narrow seal space S. After the assembly of the hydrodynamic bearing device is completed, the internal space is filled with lubricating oil via the seal space S. The seal space S is formed by making one seal surface formed in the first seal portion 14 and the other seal surface formed in the second seal portion 15 face each other. In the example shown in FIG. 2, the shaft member 2 constitutes the first seal portion 14, and the tapered surface 2 a 2 formed on the shaft portion 2 a serves as one seal surface. Moreover, the 2nd seal | sticker part 15 is comprised with the sealing member 9, The inner peripheral surface 9a becomes the other sealing surface.

第１シール部１４を構成する軸部材２の軸部２ａの外周面には、上方を縮径させたテーパ面２ａ２が形成され、これによりシール空間Ｓには下方側を漸次縮径させたテーパ状の部分が形成される。このシール空間Ｓが奏する毛細管力で潤滑油がハウジング７の内部側に引き込まれ、外部への油の漏れ出しが防止される。図示のように、テーパ面２ａ２を回転側の軸部２ａに設けることで、このシール空間Ｓを、遠心力により潤滑油をハウジング７の内部側に押し込む遠心力シールとして機能させることもできる。遠心力シールとしての機能が不要である場合、テーパ面はシール部材９の内周面に形成してもよい。シール空間Ｓは、温度変化による潤滑油の容積変化量を吸収する機能（バッファ機能）をも有しており、そのため油面は軸受装置の運転状態（停止中もしくは回転中）を問わず、常時シール空間Ｓの範囲内に維持される。   On the outer peripheral surface of the shaft portion 2a of the shaft member 2 constituting the first seal portion 14, a taper surface 2a2 having a reduced diameter on the upper side is formed, whereby a taper in which the lower side is gradually reduced in diameter is formed in the seal space S. A shaped part is formed. Lubricating oil is drawn into the inside of the housing 7 by the capillary force exerted by the seal space S, and leakage of oil to the outside is prevented. As shown in the figure, by providing the tapered surface 2a2 on the shaft portion 2a on the rotation side, the seal space S can also function as a centrifugal force seal that pushes the lubricating oil into the housing 7 by centrifugal force. When the function as a centrifugal seal is not necessary, the tapered surface may be formed on the inner peripheral surface of the seal member 9. The seal space S also has a function (buffer function) that absorbs the volume change amount of the lubricating oil due to a temperature change. Therefore, the oil level is always maintained regardless of the operation state (stopped or rotating) of the bearing device. It is maintained within the range of the seal space S.

上記構成の流体軸受装置１において、軸受部材１７と軸部材２とが相対回転すると（本実施形態では、軸部材２が回転する）、軸受スリーブ８の内周面８ａに形成されたラジアル軸受面Ａとなる上下２つの領域は、それぞれ軸部材２の外周面２ａ１とラジアル軸受隙間を介して対向する。軸部材２の回転に伴い、ラジアル軸受隙間を満たす潤滑油の動圧が発生し、ラジアル軸受隙間に形成される潤滑油の油膜によって軸部材２がラジアル方向に回転自在に非接触支持される。これにより、軸部材２をラジアル方向に回転自在に非接触支持する第１ラジアル軸受部Ｒ１と第２ラジアル軸受部Ｒ２とが形成される。   In the hydrodynamic bearing device 1 configured as described above, when the bearing member 17 and the shaft member 2 rotate relative to each other (in this embodiment, the shaft member 2 rotates), a radial bearing surface formed on the inner peripheral surface 8a of the bearing sleeve 8. The two upper and lower regions A are opposed to the outer peripheral surface 2a1 of the shaft member 2 via a radial bearing gap. As the shaft member 2 rotates, the dynamic pressure of the lubricating oil that fills the radial bearing gap is generated, and the shaft member 2 is supported in a non-contact manner in the radial direction by the oil film of the lubricating oil formed in the radial bearing gap. As a result, the first radial bearing portion R1 and the second radial bearing portion R2 that support the shaft member 2 in a non-contact manner so as to be rotatable in the radial direction are formed.

また、軸部材２が回転すると、軸受スリーブ８の下側端面８ｂに形成されたスラスト軸受面Ｂは、フランジ部２ｂの上側端面２ｂ１とスラスト軸受隙間を介して対向する。軸部材２の回転に伴い、スラスト軸受隙間を満たす潤滑油の動圧が発生し、スラスト軸受隙間に形成される潤滑油の油膜によって軸部材２がスラスト方向に回転自在に非接触支持される。これにより、軸部材２をスラスト方向に非接触支持する第１スラスト軸受部Ｔ１が形成される。同様に、蓋部材１０の底部１０ａの上側端面１０ａ１に形成されたスラスト軸受面Ｃは、フランジ部２ｂの下側端面２ｂ２とスラスト軸受隙間を介して対向する。軸部材２の回転に伴い、スラスト軸受隙間を満たす潤滑油の動圧が発生し、スラスト軸受隙間に形成される潤滑油の油膜によって軸部材２がスラスト方向に回転自在に非接触支持される。これにより、軸部材２をスラスト方向に回転自在に非接触支持する第２スラスト軸受部Ｔ２が形成される。   When the shaft member 2 rotates, the thrust bearing surface B formed on the lower end surface 8b of the bearing sleeve 8 faces the upper end surface 2b1 of the flange portion 2b via the thrust bearing gap. As the shaft member 2 rotates, dynamic pressure of lubricating oil that fills the thrust bearing gap is generated, and the shaft member 2 is supported in a non-contact manner in the thrust direction so as to be rotatable by an oil film of the lubricating oil formed in the thrust bearing gap. Thereby, the 1st thrust bearing part T1 which non-contact-supports the shaft member 2 in a thrust direction is formed. Similarly, the thrust bearing surface C formed on the upper end surface 10a1 of the bottom portion 10a of the lid member 10 faces the lower end surface 2b2 of the flange portion 2b via a thrust bearing gap. As the shaft member 2 rotates, dynamic pressure of lubricating oil that fills the thrust bearing gap is generated, and the shaft member 2 is supported in a non-contact manner in the thrust direction so as to be rotatable by an oil film of the lubricating oil formed in the thrust bearing gap. Thereby, the 2nd thrust bearing part T2 which non-contact-supports the shaft member 2 rotatably in a thrust direction is formed.

流体軸受装置１の運転中に、内部空間に満たされた潤滑油がその一部領域で負圧になると、気泡の発生や潤滑油の漏れ、あるいは振動の発生等の要因となる。かかる局所的な負圧の発生を防止するため、本発明では、上述のように上側のラジアル軸受面Ａの動圧溝形状を軸方向非対称として、軸部２ａの外周面２ａ１と軸受スリーブ８の内周面８ａとの間の半径方向隙間（ラジアル軸受隙間）を満たす潤滑油に軸方向下向きのポンピング能力を付与すると共に、下側に押し込まれた潤滑油を前記半径方向隙間の上端に戻す循環路１２を設け、潤滑油を流体軸受装置１の内部で強制的に循環させる構成を採用している。   During the operation of the hydrodynamic bearing device 1, if the lubricating oil filled in the internal space becomes a negative pressure in a part of the area, it may cause bubbles, leakage of the lubricating oil, or vibration. In order to prevent the occurrence of such a local negative pressure, in the present invention, the dynamic pressure groove shape of the upper radial bearing surface A is made axially asymmetric as described above, so that the outer peripheral surface 2a1 of the shaft portion 2a and the bearing sleeve 8 Circulation that gives axially downward pumping capability to the lubricating oil that fills the radial clearance (radial bearing clearance) between the inner circumferential surface 8a and returns the pushed-down lubricating oil to the upper end of the radial clearance. A structure is provided in which the passage 12 is provided and the lubricating oil is forcibly circulated inside the hydrodynamic bearing device 1.

図２に例示する循環路１２は、ハウジング７の内周面と軸受スリーブ８の外周面８ｄとの間に形成された軸方向流路１２ａと、シール部材９の下側端面９ｂと軸受スリーブ８の上側端面８ｃとの間に形成された第１の半径方向流路１２ｂと、蓋部材１０の上側端面１０ｂ１と軸受スリーブ８の下側端面８ｂとの間に形成された第２の半径方向流路１２ｃとで構成されている。図示例では、軸方向流路１２ａを軸受スリーブ８の外周面８ｄ、第１の半径方向流路１２ｂをシール部材９の下側端面９ｂ、第２の半径方向流路１２ｃを蓋部材１０の上側端面１０ｂ１に形成した場合をそれぞれ例示しているが、これらの流路１２ａ〜１２ｃは、その対向面（ハウジング７の内周面７ｂ、軸受スリーブの上下端面８ｃ、８ｂ）に形成しても構わない。   The circulation path 12 illustrated in FIG. 2 includes an axial flow path 12 a formed between the inner peripheral surface of the housing 7 and the outer peripheral surface 8 d of the bearing sleeve 8, the lower end surface 9 b of the seal member 9, and the bearing sleeve 8. The first radial flow path 12b formed between the upper end surface 8c of the first member and the second radial flow formed between the upper end surface 10b1 of the lid member 10 and the lower end surface 8b of the bearing sleeve 8. It is comprised with the path | route 12c. In the illustrated example, the axial flow path 12 a is the outer peripheral surface 8 d of the bearing sleeve 8, the first radial flow path 12 b is the lower end surface 9 b of the seal member 9, and the second radial flow path 12 c is the upper side of the lid member 10. Although the case where it forms in the end surface 10b1 is illustrated, respectively, these flow paths 12a-12c may be formed in the opposing surface (the inner peripheral surface 7b of the housing 7, and the upper and lower end surfaces 8c and 8b of a bearing sleeve). Absent.

このように、循環路１２を設けることで、流体軸受装置１の運転中には、スラスト軸受隙間→第２の半径方向流路１２ｃ→軸方向流路１２ａ→第１の半径方向流路１２ｂ→半径方向隙間の上端、という経路を経て軸受装置内部を潤滑油が循環する。これにより、軸受装置の内部空間における潤滑油の局所的な負圧発生を防止することができる。   Thus, by providing the circulation path 12, during the operation of the hydrodynamic bearing device 1, the thrust bearing gap → the second radial flow path 12c → the axial flow path 12a → the first radial flow path 12b → Lubricating oil circulates inside the bearing device through a path called the upper end of the radial clearance. Thereby, local negative pressure generation of the lubricating oil in the internal space of the bearing device can be prevented.

本実施形態において、第１シール部１４および第２シール部１５のうち、何れか一方の表面、例えば第２シール部１５を構成するシール部材９の上側端面９ｃには、凹部１３および撥油膜１１が形成される。このうち、凹部１３は例えば矩形状の断面形状をなし、上側端面９ｃの全周にわたって環状に形成されている。撥油膜１１は、予め凹部１３を形成した上側端面９ｃに、例えばスプレー塗布等の手段で撥油剤を塗布した後、これを固化させることにより帯状に形成される。図示のように上側端面９ｃの全面を撥油膜１１で被覆する他、少なくとも凹部１３を含む半径方向の一部環状領域のみを撥油膜１１で被服してもよい。凹部１３の形成方法は任意であり、例えばシール部材９の成形後に機械加工やプレス加工で凹部１３を形成し、あるいはシール部材９を樹脂等で射出成形する際には、その射出成形と同時に凹部１３を形成することもできる。   In the present embodiment, the concave portion 13 and the oil repellent film 11 are formed on any one surface of the first seal portion 14 and the second seal portion 15, for example, the upper end surface 9 c of the seal member 9 constituting the second seal portion 15. Is formed. Among these, the recessed part 13 comprises rectangular cross-sectional shape, for example, and is formed cyclically | annularly over the perimeter of the upper end surface 9c. The oil repellent film 11 is formed in a belt shape by applying an oil repellent to the upper end surface 9c in which the recess 13 has been previously formed by means of, for example, spray coating, and then solidifying the oil repellent. As shown in the figure, the entire upper end surface 9 c may be covered with the oil repellent film 11, and only a partial annular region in the radial direction including at least the recess 13 may be covered with the oil repellent film 11. The method of forming the concave portion 13 is arbitrary. For example, when the concave portion 13 is formed by machining or pressing after the sealing member 9 is molded, or when the sealing member 9 is injection-molded with resin or the like, the concave portion 13 is simultaneously formed with the injection molding. 13 can also be formed.

撥油膜１１を形成する際、上側端面９ｃに塗布した撥油剤は、その表面張力で半径方向中央部が盛り上がり、その内径側および外径側ほど薄くなった形態をとる。これがそのまま固化することにより、図２の拡大図に示す撥油膜１１が形成される（図２は理解の容易化のため、撥油膜１１の厚さの相違を誇張して描いている）。凹部１３は、撥油膜１１の幅方向（半径方向）中央部の最も盛り上がった部分の直下に形成されている。   When the oil repellent film 11 is formed, the oil repellent applied to the upper end surface 9c takes a form in which the central portion in the radial direction rises due to the surface tension, and the inner diameter side and the outer diameter side become thinner. When this is solidified as it is, the oil repellent film 11 shown in the enlarged view of FIG. 2 is formed (FIG. 2 exaggerates the difference in thickness of the oil repellent film 11 for easy understanding). The recess 13 is formed immediately below the most raised portion of the central portion in the width direction (radial direction) of the oil repellent film 11.

撥油膜１１を形成する撥油剤は、例えば撥油性を有する樹脂材料を主成分とし、これを有機溶媒に溶解させて生成される。撥油性を有する樹脂材料としては例えばフッ素系樹脂あるいはシリコーン系樹脂を使用することができる。フッ素系樹脂としては、例えばパーフルオロアクリレートを主成分とする重合体や非晶質パーフルオロ樹脂（例えば、旭硝子（株）社製 サイトップ（登録商標））等を、シリコーン系樹脂としては、例えば、シロキサンやアルコキシシラン等を使用することができる。なお、本実施形態で用いる撥油剤には蛍光剤を含有させている。蛍光剤としては、例えばＵＶ光を照射すると発光するタイプのもの等を使用することができる。   The oil repellent agent for forming the oil repellent film 11 is produced by, for example, using a resin material having oil repellency as a main component and dissolving it in an organic solvent. As the resin material having oil repellency, for example, a fluorine resin or a silicone resin can be used. Examples of the fluorine-based resin include a polymer mainly composed of perfluoroacrylate and an amorphous perfluoro resin (for example, Cytop (registered trademark) manufactured by Asahi Glass Co., Ltd.). Siloxane, alkoxysilane, etc. can be used. The oil repellent used in this embodiment contains a fluorescent agent. As the fluorescent agent, for example, a type that emits light when irradiated with UV light can be used.

本発明では、上記のように第２シール部１５を構成するシール部材９の上側端面９ｃに凹部１３を形成し、当該凹部１３を満たす形で撥油膜１１を形成しているので、少なくとも凹部１３では撥油膜１１が他所よりも厚くなる。そのため、当該凹部１３が形成された部分では、撥油膜１１との接触面積が増大するため、シール部材９に対する撥油膜１１の密着力を高めることができ、従って、界面への潤滑油の浸透を防止することができる。また、少なくとも凹部１３が形成された部分では、上側端面９ｃの表面粗さの影響を受けることなく、表面を完全に撥油膜１１で被覆することができる。以上の理由から、本発明によれば、撥油膜１１の撥油性能を高め、シール空間Ｓからの潤滑油の漏れ出しを確実に防止することができる。   In the present invention, the concave portion 13 is formed on the upper end surface 9c of the seal member 9 constituting the second seal portion 15 as described above, and the oil repellent film 11 is formed so as to fill the concave portion 13, so at least the concave portion 13 is formed. Then, the oil repellent film 11 becomes thicker than other places. Therefore, since the contact area with the oil repellent film 11 increases at the portion where the concave portion 13 is formed, the adhesion of the oil repellent film 11 to the seal member 9 can be increased, and therefore the penetration of the lubricating oil to the interface is prevented. Can be prevented. Further, at least in the portion where the recess 13 is formed, the surface can be completely covered with the oil repellent film 11 without being affected by the surface roughness of the upper end surface 9c. For the above reasons, according to the present invention, the oil-repellent performance of the oil-repellent film 11 can be enhanced, and leakage of the lubricating oil from the seal space S can be reliably prevented.

また、本発明によれば、例えば検査工程でＵＶ光を照射して撥油膜１１の存在有無を目視確認する場合でも、撥油膜１１の厚さは凹部１３が形成された幅方向領域で部分的に厚くなり、当該部分では蛍光作用が強まるので、撥油膜１１の有無を容易に目視確認することができる。   Also, according to the present invention, for example, even when UV light is irradiated in the inspection process to visually check the presence or absence of the oil repellent film 11, the thickness of the oil repellent film 11 is partially in the width direction region where the recess 13 is formed. Since the fluorescent action is enhanced in the portion, the presence or absence of the oil repellent film 11 can be easily visually confirmed.

これに加えて、本実施形態では、帯状に形成された撥油膜１１の幅方向中央部に凹部１３を形成することにより、撥油膜１１の盛り上がりが最大となる部分と凹部１３とを半径方向で一致した位置に形成しているので、より厚い膜厚を得ることができ、上記効果がより一層顕著に得られる。   In addition, in this embodiment, by forming the recess 13 in the central portion in the width direction of the oil-repellent film 11 formed in a band shape, the portion where the bulge of the oil-repellent film 11 is maximized and the recess 13 are formed in the radial direction. Since they are formed at the coincident positions, a thicker film thickness can be obtained, and the above effects can be obtained more remarkably.

ところで、本願発明者の検証によれば、凹部１３の深さが浅すぎる場合、例えば３μｍ未満であると、上記作用効果を得られなかった。一方、凹部１３の深さが深すぎる場合、例えば１ｍｍよりも深いと、撥油剤の使用量が増して不経済となり、また、シール部材９の強度にも悪影響を与える可能性があることが判明した。したがって、凹部１３の深さは３μｍ以上１ｍｍ以下、望ましくは１５μｍ以上１ｍｍ以下に設定するのが望ましい。   By the way, according to the verification by the inventors of the present application, when the depth of the concave portion 13 is too shallow, for example, when the depth is less than 3 μm, the above-described effect cannot be obtained. On the other hand, when the depth of the concave portion 13 is too deep, for example, if it is deeper than 1 mm, the amount of the oil repellent used is increased and it becomes uneconomical, and the strength of the seal member 9 may be adversely affected. did. Therefore, it is desirable that the depth of the recess 13 is set to 3 μm or more and 1 mm or less, preferably 15 μm or more and 1 mm or less.

なお、図２では、凹部１３および撥油膜１１（以下、「撥油膜等」という）を、シール部材９の上側端面９ｃに形成した場合を例示しているが、これ以外の箇所、例えばシール部材９の内周面９ａに撥油膜等を形成することもできる。また、第２シール部１５を構成するシール部材９のみならず、第１シール部１４を構成する軸部材２の軸部２ａにも撥油膜等を形成してもよい。この場合、撥油膜等は、図４に示すように、軸部２ａの外周面２ａ１のうち、例えばテーパ面２ａ２の上方に隣接した円筒状の隣接外周面２ａ３に形成することができる。このように第１シール部１４と第２シール部１５の双方に撥油膜等を形成することにより、さらに油漏れ防止効果が高まる。もちろん第１シール部１４を構成する軸部２ａの外周面２ａ１にのみ撥油膜等を形成しても構わない。   2 illustrates the case where the recess 13 and the oil repellent film 11 (hereinafter referred to as “oil repellent film”) are formed on the upper end surface 9c of the seal member 9, but other locations such as a seal member, for example, An oil repellent film or the like can also be formed on the inner peripheral surface 9a of 9. Further, an oil repellent film or the like may be formed not only on the seal member 9 constituting the second seal portion 15 but also on the shaft portion 2 a of the shaft member 2 constituting the first seal portion 14. In this case, as shown in FIG. 4, the oil repellent film or the like can be formed on, for example, a cylindrical adjacent outer peripheral surface 2a3 adjacent to the upper side of the tapered surface 2a2 in the outer peripheral surface 2a1 of the shaft portion 2a. Thus, by forming an oil repellent film etc. in both the 1st seal part 14 and the 2nd seal part 15, the oil leak prevention effect increases further. Of course, an oil repellent film or the like may be formed only on the outer peripheral surface 2a1 of the shaft portion 2a constituting the first seal portion 14.

凹部１３の形状として、断面矩形状を例示したが、凹部１３の断面形状は任意であり、これ以外にも例えば三角形状とすることもできる。また、図２では凹部１３を上側端面９ｃの一箇所にのみ形成する場合を例示しているが、母材表面を粗面化する等の手段で、上側端面９ｃに多数の凹部１３を分散状態で形成することもできる。   Although the cross-sectional rectangular shape was illustrated as a shape of the recessed part 13, the cross-sectional shape of the recessed part 13 is arbitrary and can also be made into triangular shape other than this, for example. In addition, FIG. 2 illustrates the case where the concave portion 13 is formed only at one location on the upper end surface 9c, but a number of concave portions 13 are dispersed on the upper end surface 9c by means such as roughening the surface of the base material. It can also be formed.

また、凹部１３は、余剰の撥油剤を堰き止める効果も有する。従って、凹部１３の形成位置を適宜定めることで、流動性に富む撥油剤を塗布した際、これが広がる範囲を規制し、意図しない箇所での撥油膜の形成を防止することができる。例えば、塗布した余剰の撥油剤がシール部材９の外周まで達し、ハウジング７の内周面７ｂとの接着箇所に流れ込めば、接着強度の低下を招く。あるいは、撥油剤がシール部材９の内周面９ａまで達し、シール空間Ｓを形成するシール面に撥油膜が形成されれば、その撥油性からシール空間Ｓの油溜り部分に空気が侵入し、これが潤滑油中に気泡として混入し、軸受性能を低下させる恐れがある。図５に示すように、シール部材９の上側端面９ｃの内径側および外径側に環状の凹部１３（図中にクロスハッチングで示す）を形成すると、この凹部１３で撥油剤が堰き止められ、上記のような不具合を防止することができる。尚、このシール部材９の上側端面９ｃの内径側および外径側に形成された環状の凹部１３のうち、何れか一方のみを形成することもできる。   Moreover, the recessed part 13 also has an effect which dams up excess oil repellent. Therefore, by appropriately determining the formation position of the recess 13, when an oil repellent with high fluidity is applied, the range in which it spreads can be restricted, and the formation of an oil repellent film at an unintended location can be prevented. For example, if the applied excess oil repellent reaches the outer periphery of the seal member 9 and flows into the bonding portion with the inner peripheral surface 7b of the housing 7, the adhesive strength is reduced. Alternatively, if the oil repellent reaches the inner peripheral surface 9a of the seal member 9 and an oil repellent film is formed on the seal surface forming the seal space S, air enters the oil reservoir portion of the seal space S due to its oil repellency, This may be mixed as bubbles in the lubricating oil, which may reduce the bearing performance. As shown in FIG. 5, when the annular recess 13 (shown by cross-hatching in the figure) is formed on the inner diameter side and the outer diameter side of the upper end surface 9c of the seal member 9, the oil repellent is blocked by the recess 13; The above problems can be prevented. Note that only one of the annular recesses 13 formed on the inner diameter side and the outer diameter side of the upper end surface 9c of the seal member 9 can be formed.

また、シール部材９の上側端面９ｃの内径側および外径側に形成された環状の凹部１３の両方に跨るように撥油剤を塗布しておけば、両凹部１３で撥油膜の存在を確認することにより、撥油膜が凹部１３で挟まれた領域、すなわちシール部材９の上側端面９ｃのほぼ全面に形成されているか否かが判別可能となる。同様の効果は、図６に示すように、端面に放射状の凹部１３を形成した場合、図７に示すように、端面に螺旋状の凹部１３を形成した場合、図８に示すように、複数のスパイラル状の凹部１３を形成した場合にも得られる。   Further, if an oil repellent agent is applied so as to straddle both of the annular recesses 13 formed on the inner diameter side and the outer diameter side of the upper end surface 9 c of the seal member 9, the presence of the oil repellent film is confirmed at both the recesses 13. As a result, it is possible to determine whether or not the oil repellent film is formed in a region sandwiched between the recesses 13, that is, almost the entire upper end surface 9 c of the seal member 9. Similar effects are obtained when a radial recess 13 is formed on the end face as shown in FIG. 6, or when a spiral recess 13 is formed on the end face as shown in FIG. 7, as shown in FIG. This is also obtained when the spiral recess 13 is formed.

以上、本発明の一実施形態を説明したが、本発明は、この実施形態に限定されるものではなく、以下示すような流体軸受装置１においても好ましく用いることができる。なお、以下の説明では、図２に示す実施形態と同一機能を有する部材および要素には共通の参照番号を付して重複説明を省略する。   As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this Embodiment, It can use preferably also in the hydrodynamic bearing apparatus 1 as shown below. In the following description, members and elements having the same functions as those in the embodiment shown in FIG.

図９に示す流体軸受装置１は、図２に示す流体軸受装置１において、ハウジング７および軸受スリーブ８を一体化して軸受部材１７を構成したものである。この場合、ラジアル軸受部Ｒ１、Ｒ２のラジアル軸受面Ａは、例えば軸受部材１７の内周面１７ａに形成され、第１スラスト軸受部Ｔ１のスラスト軸受面Ｂは、例えば軸受部材１７の下側端面１７ｂに形成される。この軸受部材１７は、樹脂材料や金属材料の射出成形、あるいは金属材料（焼結金属も含む）の塑性加工によって形成することができる。   A hydrodynamic bearing device 1 shown in FIG. 9 is obtained by integrating a housing 7 and a bearing sleeve 8 in the hydrodynamic bearing device 1 shown in FIG. In this case, the radial bearing surface A of the radial bearing portions R1 and R2 is formed, for example, on the inner peripheral surface 17a of the bearing member 17, and the thrust bearing surface B of the first thrust bearing portion T1 is, for example, the lower end surface of the bearing member 17 17b. The bearing member 17 can be formed by injection molding of a resin material or a metal material, or plastic processing of a metal material (including a sintered metal).

図９に示す流体軸受装置１では、軸受部材１７のうち、ハウジング７に相当する部分の上端開口部に第２シール部１５を構成するシール部材９が固定される。この第２シール部１５としてのシール部材９の内周面９ａ（他方のシール面）と、第１シール部を構成する軸部材２の軸部２ａのテーパ面２ａ２（一方のシール面）との間にシール空間Ｓが形成される。この場合も、第１シール部の表面（例えば軸部２ａの外周面）と第２シール部の表面（例えばシール部材９の内周面９ａや上側端面９ｃ）の何れか一方または双方に上記撥油膜等を形成することにより、図２に示す実施形態と同様に、撥油効果を高め、さらには撥油膜１１の有無の視認性向上を図ることができる。   In the hydrodynamic bearing device 1 shown in FIG. 9, the seal member 9 constituting the second seal portion 15 is fixed to the upper end opening of the bearing member 17 corresponding to the housing 7. An inner peripheral surface 9a (the other seal surface) of the seal member 9 as the second seal portion 15 and a tapered surface 2a2 (one seal surface) of the shaft portion 2a of the shaft member 2 constituting the first seal portion. A seal space S is formed between them. Also in this case, the above-described repellent property is applied to one or both of the surface of the first seal portion (for example, the outer peripheral surface of the shaft portion 2a) and the surface of the second seal portion (for example, the inner peripheral surface 9a and the upper end surface 9c of the seal member 9). By forming the oil film or the like, the oil repellency effect can be enhanced and the visibility of the presence or absence of the oil repellant film 11 can be improved as in the embodiment shown in FIG.

図１０に示す流体軸受装置１は、図９に示す流体軸受装置１において、さらにシール部材９を軸受部材１７に一体化したものである。この流体軸受装置１では、軸受部材１７のうち、シール部材９に相当する部分が第２シール部１５を構成する。この第２シール部１５のテーパ状の内周面１５ａ（他方のシール面）と、第１シール部１４を構成する軸部材２の軸部２ａの外周面２ａ１（一方のシール面）との間にシール空間Ｓが形成されている。この場合も、第１シール部１４の表面（例えば軸部２ａの外周面）と、第２シール部１５の表面（例えば軸受部材１７のシール部材に相当する部分の内周面や上側端面１７ｃ）の何れか一方または双方に上記撥油膜等を形成することにより、同様の効果を得ることができる。この他、図２に示す流体軸受装置１において、軸受スリーブ８とシール部材９に相当する部分のみを一体化して軸受部材１７を構成した場合（ハウジング７に相当する部分を軸受部材１７とは別体に構成した場合）にも、第１シール部１４の表面（例えば軸部２ａの外周面）と、軸受部材１７のうち、第２シール部１５の表面（例えばシール部材９に相当する部分の内周面）とに撥油膜等を形成することができる。   The hydrodynamic bearing device 1 shown in FIG. 10 is obtained by further integrating the seal member 9 with the bearing member 17 in the hydrodynamic bearing device 1 shown in FIG. In the hydrodynamic bearing device 1, a portion corresponding to the seal member 9 of the bearing member 17 constitutes the second seal portion 15. Between the tapered inner peripheral surface 15a (the other seal surface) of the second seal portion 15 and the outer peripheral surface 2a1 (one seal surface) of the shaft portion 2a of the shaft member 2 constituting the first seal portion 14. A seal space S is formed at the bottom. Also in this case, the surface of the first seal portion 14 (for example, the outer peripheral surface of the shaft portion 2a) and the surface of the second seal portion 15 (for example, the inner peripheral surface and the upper end surface 17c of the portion corresponding to the seal member of the bearing member 17). The same effect can be obtained by forming the oil repellent film or the like on one or both of the above. In addition, in the hydrodynamic bearing device 1 shown in FIG. 2, when only the portion corresponding to the bearing sleeve 8 and the seal member 9 is integrated to form the bearing member 17 (the portion corresponding to the housing 7 is different from the bearing member 17). (When the body is configured), the surface of the first seal portion 14 (for example, the outer peripheral surface of the shaft portion 2a) and the surface of the second seal portion 15 (for example, the portion corresponding to the seal member 9) of the bearing member 17 An oil repellent film or the like can be formed on the inner peripheral surface.

図１１に示す流体軸受装置１は、軸部材２に、フランジ状の突出部１９、２０を軸方向に離隔させて設けている。突出部１９の下側端面１９ｂおよび突出部２０の上側端面２０ｃは、それぞれ軸受スリーブ８の上下端面８ｃ、８ｂと対向し、第１および第２のスラスト軸受部Ｔ１、Ｔ２の各スラスト軸受隙間を形成する。例えば軸受スリーブ８の上下端面８ｃ、８ｂに、第１および第２スラスト軸受部Ｔ１、Ｔ２の各スラスト軸受面Ｂ、Ｃが形成される。   In the hydrodynamic bearing device 1 shown in FIG. 11, flange-shaped protrusions 19 and 20 are provided on the shaft member 2 so as to be spaced apart in the axial direction. The lower end surface 19b of the projecting portion 19 and the upper end surface 20c of the projecting portion 20 face the upper and lower end surfaces 8c and 8b of the bearing sleeve 8, respectively, and each thrust bearing gap of the first and second thrust bearing portions T1 and T2 is provided. Form. For example, the thrust bearing surfaces B and C of the first and second thrust bearing portions T1 and T2 are formed on the upper and lower end surfaces 8c and 8b of the bearing sleeve 8, respectively.

図１１に示す流体軸受装置１では、突出部１９、２０が第１シール部１４を構成し、ハウジング７のうち、突出部１９と対向する上下の端部が第２シール部１５を構成する。突出部１９、２０の外周面１９ａ、２０ａ（一方のシール面）とハウジング７の内周面７ｂ（他方のシール面）との間に、それぞれシール空間Ｓ１、Ｓ２が形成される。この場合も、第１シール部１４の表面、例えば突出部１９の外周面１９ａ、２０ａや外気開放側の端面１９ｃ、２０ｂと、第２シール部１５の表面、例えばハウジング７の内周面７ｂや上下の端面７ｃ、７ｄの何れか一方または双方に上記撥油膜等を形成することにより、上記と同様の効果を得ることができる。この実施形態では、軸部材２に軸方向に離隔する二つの突出部１９、２０を設けることにより、軸受装置１の軸方向両端にシール空間Ｓを形成した場合を例示しているが、一方の突出部で軸方向の一端部にのみシール空間Ｓを形成すると共に、他端部では、図２に示す実施形態と同様にハウジング７の開口部を蓋部材１０で封口した軸受装置においても同様の構成を採用することができる。また、図９に示す実施形態と同様に、ハウジング７と軸受スリーブ８を一体化して軸受部材１７を構成することもできる。   In the hydrodynamic bearing device 1 shown in FIG. 11, the protruding portions 19 and 20 constitute the first seal portion 14, and the upper and lower ends of the housing 7 that face the protruding portion 19 constitute the second seal portion 15. Seal spaces S1 and S2 are formed between the outer peripheral surfaces 19a and 20a (one seal surface) of the protrusions 19 and 20 and the inner peripheral surface 7b (the other seal surface) of the housing 7, respectively. Also in this case, the surface of the first seal portion 14, for example, the outer peripheral surfaces 19 a and 20 a of the protruding portion 19, the end surfaces 19 c and 20 b on the open side, and the surface of the second seal portion 15, for example, the inner peripheral surface 7 b of the housing 7 By forming the oil repellent film or the like on one or both of the upper and lower end faces 7c and 7d, the same effect as described above can be obtained. In this embodiment, the case where the seal space S is formed at both axial ends of the bearing device 1 by providing the shaft member 2 with two projecting portions 19 and 20 that are separated in the axial direction is illustrated. In the bearing device in which the seal space S is formed only at one end portion in the axial direction with the protruding portion, and the opening portion of the housing 7 is sealed with the lid member 10 at the other end portion as in the embodiment shown in FIG. A configuration can be employed. Similarly to the embodiment shown in FIG. 9, the bearing member 17 can be configured by integrating the housing 7 and the bearing sleeve 8.

図１２に示す流体軸受装置１は、軸部材２に設けられた突出部としてのディスクハブ３が回転側の第１シール部１４を、また、ハウジング７が固定側の第２シール部１５を構成する。ディスクハブ３は、ハウジング７の上側開口部を覆う円盤部３ａ及び円盤部３ａの外径端から下方へ延びた円筒部３ｂを有する。第１シール部１４としてのディスクハブ３の円筒部３ｂの内周面３ｂ１（一方のシール面）と、第２シール部１５としてのハウジング７の外周面に形成されたテーパ面７ｄ（他方のシール面）との間にシール空間Ｓを形成する。この場合も、第１シール部１４の表面、例えばディスクハブ３の円筒部３ｂの内周面と、第２シール部１５の表面、例えばハウジング７の外周面のテーパ面７ｄの何れか一方または双方に上記撥油膜等を形成することにより、上記と同様の効果を得ることができる。なお、この実施形態では、第２のスラスト軸受部Ｔ２が、ディスクハブ３を構成する円盤部３ａの下側端面３ａ１と、ハウジング７の上側端面７ｃとの間に形成される。また、図５に示す実施形態と同様に、ハウジング７と軸受スリーブ８を一体化して軸受部材１７を構成することもできる。   In the hydrodynamic bearing device 1 shown in FIG. 12, the disk hub 3 as a projecting portion provided on the shaft member 2 constitutes the first seal portion 14 on the rotating side, and the housing 7 constitutes the second seal portion 15 on the fixed side. To do. The disk hub 3 has a disk part 3 a that covers the upper opening of the housing 7 and a cylindrical part 3 b that extends downward from the outer diameter end of the disk part 3 a. A tapered surface 7d (the other seal) formed on the inner peripheral surface 3b1 (one seal surface) of the cylindrical portion 3b of the disk hub 3 as the first seal portion 14 and the outer peripheral surface of the housing 7 as the second seal portion 15. A seal space S is formed between the first and second surfaces. Also in this case, either or both of the surface of the first seal portion 14, for example, the inner peripheral surface of the cylindrical portion 3 b of the disc hub 3, and the surface of the second seal portion 15, for example, the tapered surface 7 d of the outer peripheral surface of the housing 7. By forming the oil repellent film or the like, the same effects as described above can be obtained. In this embodiment, the second thrust bearing portion T2 is formed between the lower end surface 3a1 of the disk portion 3a constituting the disk hub 3 and the upper end surface 7c of the housing 7. Similarly to the embodiment shown in FIG. 5, the housing 7 and the bearing sleeve 8 can be integrated to constitute the bearing member 17.

また、以上の説明では、ラジアル軸受部Ｒ１、Ｒ２を構成する軸受として、へリングボーン状やスパイラル状に配列された複数の動圧溝からなる動圧発生部を有する軸受を例示しているが、動圧発生部の構成はこれに限定されるものではない。   Moreover, in the above description, the bearing having the dynamic pressure generating portion including a plurality of dynamic pressure grooves arranged in a herringbone shape or a spiral shape is illustrated as a bearing constituting the radial bearing portions R1 and R2. The configuration of the dynamic pressure generator is not limited to this.

例えば、ラジアル軸受部Ｒ１、Ｒ２として、円周方向複数箇所でラジアル軸受隙間を円周方向の一方又は双方にくさび状に縮小させた形状とした、いわゆる多円弧軸受や非真円軸受の他、軸方向に延びる動圧溝を円周方向等間隔に配した、いわゆるステップ軸受を採用しても良い。   For example, as radial bearing portions R1, R2, in addition to so-called multi-arc bearings and non-circular bearings in which radial bearing gaps are reduced in a wedge shape in one or both directions in the circumferential direction at multiple locations in the circumferential direction, A so-called step bearing in which dynamic pressure grooves extending in the axial direction are arranged at equal intervals in the circumferential direction may be employed.

図１３は、ラジアル軸受部Ｒ１、Ｒ２の一方又は双方を多円弧軸受で構成した場合の一例を示している。この例では、軸受スリーブ８の内周面８ａのラジアル軸受面となる領域が、３つの円弧面８ａ３、８ａ４、８ａ５で構成されている（いわゆる３円弧軸受）。３つの円弧面８ａ３、８ａ４、８ａ５の曲率中心は、それぞれ、軸受スリーブ８の軸中心Ｏから等距離オフセットされている。３つの円弧面８ａ３、８ａ４、８ａ５で区画される各領域において、ラジアル軸受隙間は、円周方向の両方向に対して、それぞれ楔状に漸次縮小した形状を有している。そのため、軸受スリーブ８と軸部２ａとが相対回転すると、その相対回転の方向に応じて、ラジアル軸受隙間内の潤滑流体が楔状に縮小した最小隙間側に押し込まれて、その圧力が上昇する。このような潤滑流体の動圧作用によって、軸受スリーブ８と軸部２ａとが非接触支持される。尚、３つの円弧面８ａ３、８ａ４、８ａ５の相互間の境界部に、分離溝と称される、一段深い軸方向溝を形成しても良い。   FIG. 13 shows an example of a case where one or both of the radial bearing portions R1 and R2 are configured by multi-arc bearings. In this example, the region that becomes the radial bearing surface of the inner peripheral surface 8a of the bearing sleeve 8 is configured by three arc surfaces 8a3, 8a4, and 8a5 (so-called three arc bearings). The centers of curvature of the three arcuate surfaces 8a3, 8a4, 8a5 are offset from the axial center O of the bearing sleeve 8 by an equal distance. In each region defined by the three arcuate surfaces 8a3, 8a4, and 8a5, the radial bearing gap has a shape that is gradually reduced in a wedge shape in both circumferential directions. For this reason, when the bearing sleeve 8 and the shaft portion 2a rotate relative to each other, the lubricating fluid in the radial bearing gap is pushed into the minimum gap side reduced in a wedge shape in accordance with the direction of the relative rotation, and the pressure rises. The bearing sleeve 8 and the shaft portion 2a are supported in a non-contact manner by the dynamic pressure action of the lubricating fluid. A deeper axial groove called a separation groove may be formed at the boundary between the three arcuate surfaces 8a3, 8a4, 8a5.

図１４は、ラジアル軸受部Ｒ１、Ｒ２の一方又は双方を多円弧軸受で構成した場合の他の例を示している。この例においても、軸受スリーブ８の内周面８ａのラジアル軸受面となる領域が、３つの円弧面８ａ６、８ａ７、８ａ８で構成されているが（いわゆる３円弧軸受）、３つの円弧面８ａ６、８ａ７、８ａ８で区画される各領域において、ラジアル軸受隙間は、円周方向の一方向に対して、それぞれ楔状に漸次縮小した形状を有している。このような構成の多円弧軸受は、テーパ軸受と称されることもある。また、３つの円弧面８ａ６、８ａ７、８ａ８の相互間の境界部に、分離溝と称される、一段深い軸方向溝８ａ９、８ａ１０、８ａ１１が形成されている。そのため、軸受スリーブ８と軸部２ａとが所定方向に相対回転すると、ラジアル軸受隙間内の潤滑流体が楔状に縮小した最小隙間側に押し込まれて、その圧力が上昇する。このような潤滑流体の動圧作用によって、軸受スリーブ８と軸部２ａとが非接触支持される。   FIG. 14 shows another example in the case where one or both of the radial bearing portions R1 and R2 are constituted by multi-arc bearings. In this example as well, the region that becomes the radial bearing surface of the inner peripheral surface 8a of the bearing sleeve 8 is configured by three arc surfaces 8a6, 8a7, and 8a8 (so-called three arc bearings), but the three arc surfaces 8a6, In each region divided by 8a7 and 8a8, the radial bearing gap has a shape gradually reduced in a wedge shape with respect to one direction in the circumferential direction. The multi-arc bearing having such a configuration may be referred to as a taper bearing. Further, deeper axial grooves 8a9, 8a10, 8a11 called separation grooves are formed at boundaries between the three arcuate surfaces 8a6, 8a7, 8a8. Therefore, when the bearing sleeve 8 and the shaft portion 2a are relatively rotated in a predetermined direction, the lubricating fluid in the radial bearing gap is pushed into the minimum gap side reduced in a wedge shape, and the pressure rises. The bearing sleeve 8 and the shaft portion 2a are supported in a non-contact manner by the dynamic pressure action of the lubricating fluid.

図１５は、ラジアル軸受部Ｒ１、Ｒ２の一方又は双方を多円弧軸受で構成した場合の他の例を示している。この例では、図１４に示す構成において、３つの円弧面８ａ６、８ａ７、８ａ８の最小隙間側の所定領域θが、それぞれ、軸受スリーブ８の軸中心Ｏを曲率中心とする同心の円弧で構成されている。従って、各所定領域θにおいて、ラジアル軸受隙間（最小隙間）は一定になる。このような構成の多円弧軸受は、テーパ・フラット軸受と称されることもある。   FIG. 15 shows another example in the case where one or both of the radial bearing portions R1 and R2 are configured by multi-arc bearings. In this example, in the configuration shown in FIG. 14, the predetermined regions θ on the minimum gap side of the three circular arc surfaces 8 a 6, 8 a 7, 8 a 8 are each configured by concentric arcs with the axis O of the bearing sleeve 8 as the center of curvature. ing. Therefore, in each predetermined area θ, the radial bearing gap (minimum gap) is constant. The multi-arc bearing having such a configuration may be referred to as a tapered flat bearing.

以上の各例における多円弧軸受は、いわゆる３円弧軸受であるが、これに限らず、いわゆる４円弧軸受、５円弧軸受、さらに６円弧以上の数の円弧面で構成された多円弧軸受を採用しても良い。   The multi-arc bearings in the above examples are so-called three-arc bearings, but are not limited to this, and so-called four-arc bearings, five-arc bearings, and multi-arc bearings composed of more than six arc surfaces are adopted. You may do it.

上記のラジアル軸受部Ｒ１、Ｒ２の一方又は双方は、ステップ軸受で構成することもできる（図示省略）。ステップ軸受は、例えば軸受スリーブ８の内周面８ａのラジアル軸受面Ａとなる領域に、複数の軸方向溝形状の動圧溝を円周方向所定間隔に設けたものである。   One or both of the radial bearing portions R1 and R2 may be configured by step bearings (not shown). In the step bearing, for example, a plurality of axial groove-shaped dynamic pressure grooves are provided at predetermined intervals in the circumferential direction in a region that becomes the radial bearing surface A of the inner peripheral surface 8 a of the bearing sleeve 8.

なお、以上の説明では、ラジアル軸受部を、ラジアル軸受部Ｒ１、Ｒ２のように、軸方向２箇所に離隔して設けた構成を例示しているが、軸方向の上下領域に亘って１つのラジアル軸受部を設けた構成としても良い。また、ラジアル軸受部を軸方向３箇所以上に離隔して設けることもできる。   In the above description, a configuration in which the radial bearing portion is provided separately in two axial directions as in the radial bearing portions R1 and R2 is illustrated. However, one radial bearing portion is provided over the upper and lower regions in the axial direction. It is good also as a structure which provided the radial bearing part. Further, the radial bearing portions can be provided apart from each other in three or more axial directions.

また、図示は省略するが、スラスト軸受部Ｔ１およびＴ２のうち何れか一方又は双方は、例えば、スラスト軸受面となる領域に、複数の半径方向溝形状の動圧溝を円周方向所定間隔に設けた、いわゆるステップ軸受、いわゆる波型軸受（ステップ型が波型になったもの）等で構成することもできる。   Although illustration is omitted, either one or both of the thrust bearing portions T1 and T2 has, for example, a plurality of radial groove-shaped dynamic pressure grooves at predetermined intervals in the circumferential direction in the region that becomes the thrust bearing surface. It can also be configured by a so-called step bearing provided, a so-called corrugated bearing (the step type is a corrugated type), or the like.

また、以上の説明では、ラジアル軸受隙間に流体動圧を発生させるための動圧発生部を、軸受スリーブ８の内周面８ａ（軸受部材１７の内周面１７ａ）に形成する形態を例示したが、動圧発生部はラジアル軸受隙間を介して対向する軸部２ａの外周面２ａ１に、例えば切削加工、プレス加工、印刷等の手段を用いて形成することもできる。   Moreover, in the above description, the form which forms the dynamic-pressure generation | occurrence | production part for generating fluid dynamic pressure in a radial bearing clearance in the internal peripheral surface 8a (internal peripheral surface 17a of the bearing member 17) of the bearing sleeve 8 was illustrated. However, the dynamic pressure generating portion can also be formed on the outer peripheral surface 2a1 of the shaft portion 2a that is opposed via the radial bearing gap by using means such as cutting, pressing, and printing.

また、以上の説明では、ラジアル軸受部Ｒ１、Ｒ２を動圧軸受で構成した場合を例示したが、これ以外の軸受で構成することもできる。例えば図示は省略するが、軸受スリーブ８の内周面８ａを動圧溝や円弧面を有さない真円状内周面に形成すると共に、この内周面とラジアル軸受隙間を介して対向する軸部２ａの外周面２ａ１を真円状外周面とすることで、いわゆる真円軸受を構成することもできる。   Moreover, although the case where radial bearing part R1, R2 was comprised with the dynamic pressure bearing was illustrated in the above description, it can also comprise with bearings other than this. For example, although not shown, the inner peripheral surface 8a of the bearing sleeve 8 is formed as a perfect circular inner peripheral surface that does not have a dynamic pressure groove or an arc surface, and faces the inner peripheral surface via a radial bearing gap. By making the outer peripheral surface 2a1 of the shaft portion 2a into a perfect circular outer peripheral surface, a so-called perfect circle bearing can be configured.

また、以上の説明では、スラスト軸受部を動圧軸受で構成した場合を例示したが、スラスト軸受部を、いわゆるピボット軸受で構成することもできる。   Moreover, although the case where the thrust bearing part was comprised with the dynamic pressure bearing was illustrated in the above description, a thrust bearing part can also be comprised with what is called a pivot bearing.

流体軸受装置を組み込んだスピンドルモータの一例を示す断面図である。It is sectional drawing which shows an example of the spindle motor incorporating the hydrodynamic bearing apparatus. 本発明の構成を有する流体軸受装置の断面図である。It is sectional drawing of the hydrodynamic bearing apparatus which has a structure of this invention. （ａ）図は軸受スリーブの縦断面図、（ｂ）図は軸受スリーブの下側端面を示す図である。(A) is a longitudinal sectional view of the bearing sleeve, and (b) is a view showing a lower end surface of the bearing sleeve. 本発明の構成を示す要部拡大断面図である。It is a principal part expanded sectional view which shows the structure of this invention. 他の例の凹部１３が形成されたシール部９の上面図である。It is a top view of the seal | sticker part 9 in which the recessed part 13 of the other example was formed. 他の例の凹部１３が形成されたシール部９の上面図である。It is a top view of the seal | sticker part 9 in which the recessed part 13 of the other example was formed. 他の例の凹部１３が形成されたシール部９の上面図である。It is a top view of the seal | sticker part 9 in which the recessed part 13 of the other example was formed. 他の例の凹部１３が形成されたシール部９の上面図である。It is a top view of the seal | sticker part 9 in which the recessed part 13 of the other example was formed. 本発明の構成を有する流体軸受装置の他の形態を示す断面図である。It is sectional drawing which shows the other form of the hydrodynamic bearing apparatus which has a structure of this invention. 本発明の構成を有する流体軸受装置の他の形態を示す断面図である。It is sectional drawing which shows the other form of the hydrodynamic bearing apparatus which has a structure of this invention. 本発明の構成を有する流体軸受装置の他の形態を示す断面図である。It is sectional drawing which shows the other form of the hydrodynamic bearing apparatus which has a structure of this invention. 本発明の構成を有する流体軸受装置の他の形態を示す断面図である。It is sectional drawing which shows the other form of the hydrodynamic bearing apparatus which has a structure of this invention. ラジアル軸受部の他の形態を示す断面図である。It is sectional drawing which shows the other form of a radial bearing part. ラジアル軸受部の他の形態を示す断面図である。It is sectional drawing which shows the other form of a radial bearing part. ラジアル軸受部の他の形態を示す断面図である。It is sectional drawing which shows the other form of a radial bearing part.

符号の説明Explanation of symbols

１ 流体軸受装置
２ 軸部材
２ａ 軸部
３ ディスクハブ
７ ハウジング
８ 軸受スリーブ
９ シール部材
１１ 撥油膜
１２ 循環路
１３ 凹部
１４ 第１シール部
１５ 第２シール部
１７ 軸受部材
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 3 Disc hub 7 Housing 8 Bearing sleeve 9 Seal member 11 Oil-repellent film 12 Circulation path 13 Recess 14 First seal part 15 Second seal part 17 Bearing member S Seal space R1, R2 Radial bearing T1, T2 Thrust bearing

Claims (6)

軸部材と、ラジアル軸受隙間に形成した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、外気に開放され、一対のシール面を対向させて形成されたシール空間と、一方のシール面を有する第１シール部と、他方のシール面を有する第２シール部とを備えた流体軸受装置であって、
第１シール部および第２シール部のうち、少なくとも何れか一方の表面に凹部と撥油膜とを形成し、かつ凹部で撥油膜を他所より厚く形成したことを特徴とする流体軸受装置。 A shaft member, a radial bearing portion that supports the shaft member in the radial direction with an oil film formed in a radial bearing gap, a seal space that is open to the outside air and is formed by facing a pair of seal surfaces, and one seal surface A hydrodynamic bearing device comprising a first seal portion having a second seal portion having the other seal surface,
A hydrodynamic bearing device, wherein a recess and an oil repellent film are formed on at least one surface of the first seal part and the second seal part, and the oil repellent film is formed thicker than the other part by the recess. さらに、内周に軸部材を挿入した軸受部材と、軸受部材に固定されたシール部材とを備え、軸部材で第１シール部を構成すると共に、シール部材で第２シール部を構成する請求項１記載の流体軸受装置。   Furthermore, it is provided with the bearing member which inserted the shaft member in the inner periphery, and the sealing member fixed to the bearing member, and while comprising a 1st seal part with a shaft member, a 2nd seal part is comprised with a seal member. The hydrodynamic bearing device according to 1. さらに、内周に軸部材を挿入した軸受部材を備え、軸部材で第１シール部を構成すると共に、軸受部材で第２シール部を構成する請求項１記載の流体軸受装置。   2. The hydrodynamic bearing device according to claim 1, further comprising a bearing member in which a shaft member is inserted on an inner periphery, wherein the shaft member constitutes the first seal portion and the bearing member constitutes the second seal portion. さらに、軸部材に設けられた半径方向の突出部と、内周に軸部材を挿入した軸受部材とを備え、軸部材の突出部で第１シール部を構成すると共に、軸受部材で第２シール部を構成する請求項１記載の流体軸受装置。   Furthermore, a radial projection provided on the shaft member and a bearing member having a shaft member inserted on the inner periphery thereof, the first seal portion is constituted by the projection portion of the shaft member, and the bearing member is provided with the second seal. The hydrodynamic bearing device according to claim 1, constituting a part. 請求項２〜４の何れかに記載した軸受部材が、内周に軸部材を挿入した軸受スリーブと、軸受スリーブを収容したハウジングとからなる流体軸受装置。   A hydrodynamic bearing device, wherein the bearing member according to any one of claims 2 to 4 comprises a bearing sleeve having a shaft member inserted into an inner periphery thereof and a housing containing the bearing sleeve. 凹部の深さが３μｍ以上である請求項１記載の流体軸受装置。   The hydrodynamic bearing device according to claim 1, wherein the depth of the recess is 3 μm or more.

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