JPH109260A - Dynamic pressure type fluid bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a dynamic pressure type fluid bearing device at a low cost by supporting a sleeve by the spherical part and receive surface installed on this outer periphery and a pushpress spring rotatably and further posiotioning the center of the spherical part of the outer periphery of the sleeve on the center line of plural dynamic pressure generation grooves installed on the shaft. SOLUTION: The center of the spherical part of the outer periphery of a sleeve 11 is positioned on the center line of plural dynamic pressure generation grooves 15. Accordingly, as a force for adjusting the center of a clearance between the sleeve 11 and a shaft 14 generated when the shaft 14 is rotated 15 transmitted to the sleeve 11 effectively, the center adjustment is possible after assembly. Thereby, as a left outer frame 12 and a right outer frame 13 are replaced to a pressed part by a sheet plate with a bad accuracy but a low cost, a dynamic pressure type fluid bearing device with a low cost is possible. Further, when the center is adjusted once, a stable dynamic pressure fluid bearing device in which this state becomes hardly wrong extremely is obtained.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、モータの軸受など
に用いられる動圧型流体軸受装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrodynamic bearing device used for a motor bearing or the like.

【０００２】[0002]

【従来の技術】以下図面を参照しながら、上述した従来
の動圧型流体軸受装置の１例について説明する。図９は
従来の動圧型流体軸受装置の断面を示す。図９におい
て、１はスリーブ、２は左支持枠、３は右支持枠、４は
軸、５は軸４に設けられた複数の動圧発生溝、６は潤滑
油である。ここで、２つのスリーブ１はそれぞれ左支持
枠２と右支持枠３に、また左支持枠２は右支持枠３に、
それぞれがはめあい構造で位置決めされつつ、図示しな
いネジ等で固定されている。更にスリーブ１と軸４の隙
間には潤滑油６が注入されている。なお、軸４は図示し
ない回転手段により矢印Ａ方向へ回転可能に設けられて
いる。2. Description of the Related Art An example of the above-mentioned conventional hydrodynamic bearing device will be described with reference to the drawings. FIG. 9 shows a cross section of a conventional hydrodynamic bearing device. In FIG. 9, 1 is a sleeve, 2 is a left support frame, 3 is a right support frame, 4 is a shaft, 5 is a plurality of dynamic pressure generating grooves provided on the shaft 4, and 6 is lubricating oil. Here, the two sleeves 1 are on the left support frame 2 and the right support frame 3, respectively, and the left support frame 2 is on the right support frame 3,
Each of them is fixed by a screw or the like (not shown) while being positioned by the fitting structure. Further, a lubricating oil 6 is injected into a gap between the sleeve 1 and the shaft 4. The shaft 4 is provided so as to be rotatable in the direction of arrow A by rotating means (not shown).

【０００３】以上のように構成された従来の動圧型流体
軸受装置について、以下その動作について説明する。図
９において、図示しない回転手段により軸４が矢印Ａ方
向へ回転すると、軸４に設けた複数の動圧発生溝５によ
り潤滑油６が複数の動圧発生溝５の中央に集められよう
とするので、この中央部の潤滑油６の圧力が高まり、結
果軸４は左右のスリーブ１に対して非接触で回転するこ
ととなる。The operation of the conventional hydrodynamic bearing device configured as described above will be described below. In FIG. 9, when the shaft 4 is rotated in the direction of arrow A by rotating means (not shown), the lubricating oil 6 is likely to be collected at the center of the plurality of dynamic pressure generating grooves 5 by the plurality of dynamic pressure generating grooves 5 provided on the shaft 4. Therefore, the pressure of the lubricating oil 6 at the center increases, and as a result, the shaft 4 rotates without contact with the left and right sleeves 1.

【０００４】[0004]

【発明が解決しようとする課題】しかしながら上記のよ
うに構成された従来の動圧型流体軸受装置では、以下の
ような問題点があった。一般に動圧型流体軸受装置にお
ける軸４とスリーブ１との隙間は、この隙間が狭い方が
より大きな軸受負荷に耐えられることから、通常１０μ
ｍ前後で構成していた。またこの狭い隙間を確実に確保
するために、従来の動圧型流体軸受装置ではスリーブ
１、左支持枠２、右支持枠３を、それぞれのはめあい部
も含めて、施盤で高精度に加工することが不可欠であっ
た。すなわち従来の動圧型流体軸受装置は、施盤で各部
品を高精度に切削加工する必要性があったので、極めて
コストが高いという問題があった。However, the conventional hydrodynamic bearing device configured as described above has the following problems. Generally, the gap between the shaft 4 and the sleeve 1 in the hydrodynamic bearing device is usually 10 μm because a narrower gap can endure a larger bearing load.
m. In order to ensure this narrow gap, the sleeve 1, the left support frame 2, and the right support frame 3 are processed with high precision by a lathe in the conventional hydrodynamic bearing device, including the fitting portions thereof. Was indispensable. That is, the conventional hydrodynamic bearing device has a problem that the cost is extremely high because it is necessary to cut each component with high accuracy on a lathe.

【０００５】[0005]

【課題を解決するための手段】上記問題点を解決するた
めの本発明の第１の発明の動圧型流体軸受装置は、スリ
ーブを、この外周に設けた球面部と受け面、および押圧
バネで回転自在に支持し、更に軸に設けた複数の動圧発
生溝の中心線上にスリーブの外周の球面部の中心を位置
させた構成である。According to a first aspect of the present invention, there is provided a hydrodynamic bearing device for solving the above-mentioned problems, in which a sleeve is formed by a spherical portion provided on an outer periphery thereof, a receiving surface, and a pressing spring. The sleeve is rotatably supported, and the center of the spherical portion on the outer periphery of the sleeve is positioned on the center line of the plurality of dynamic pressure generating grooves provided on the shaft.

【０００６】また上記問題点を解決するための本発明の
第２の発明の動圧型流体軸受装置は、スリーブを、この
外周に設けた球面部と受け面、および押圧バネで回転自
在に支持し、更に軸に設けた複数の動圧発生溝の中心線
よりスリーブの球面部の中心位置をずらした構成であ
る。According to a second aspect of the present invention, there is provided a hydrodynamic bearing device in which a sleeve is rotatably supported by a spherical portion provided on an outer periphery thereof, a receiving surface, and a pressing spring. Further, the center position of the spherical portion of the sleeve is shifted from the center line of the plurality of dynamic pressure generating grooves provided on the shaft.

【０００７】本発明の第１の発明は、上記した構成によ
って、スリーブの調芯状態を狂わす力が発生せず調芯状
態を安定して維持することができるとともに、第２の発
明においてはスリーブの傾きを元へ戻そうとするトルク
が作用するため、軸とスリーブとの隙間を、部品精度で
はなく組立後の調整で確保できるので、高価な切削加工
部が減らせ、また支持枠等を低コストな板金プレス加工
品とすることもできるので、動圧型流体軸受装置を低コ
ストで実現できることになる。According to the first aspect of the present invention, with the above-described structure, the alignment state of the sleeve can be stably maintained without generating a force that disturbs the alignment state of the sleeve. The torque between the shaft and the sleeve can be secured by adjusting after assembly instead of component accuracy, so that expensive cutting parts can be reduced and the supporting frame etc. can be reduced. Since a cost-effective sheet metal pressed product can be used, a hydrodynamic bearing device can be realized at low cost.

【０００８】[0008]

【発明の実施の形態】以下本発明の第１の実施の形態に
ついて、図１を参照しながら説明する。図１において、
１１はスリーブである。１２は左外枠、１３は右外枠で
例えば板金のプレス加工で作られている。１４は軸、１
５は軸１４に設けられた複数の動圧発生溝で、この中心
とスリーブ１１の外周の球面の中心は一致して設けてい
る。１６は軸１４とスリーブ１１間の隙間に注油された
潤滑油で、１７は左外枠１２、右外枠１３にそれぞれ設
けられた受け面である。この受け面１７にはスリーブ１
１の外周の球面部が、図示しない例えばネジなどにより
左外枠１２、右外枠１３に固定された押圧バネ１８で押
圧されている。なお、押圧バネ１８も例えば板金のプレ
ス加工で作ることができる。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. In FIG.
Reference numeral 11 denotes a sleeve. Reference numeral 12 denotes a left outer frame, and 13 denotes a right outer frame, which is formed by, for example, pressing a sheet metal. 14 is the axis, 1
Reference numeral 5 denotes a plurality of dynamic pressure generating grooves provided on the shaft 14, the center of which is provided so as to coincide with the center of the spherical surface on the outer periphery of the sleeve 11. Reference numeral 16 denotes lubricating oil injected into a gap between the shaft 14 and the sleeve 11, and 17 denotes receiving surfaces provided on the left outer frame 12 and the right outer frame 13, respectively. This receiving surface 17 has a sleeve 1
A spherical portion on the outer periphery of 1 is pressed by a pressing spring 18 fixed to the left outer frame 12 and the right outer frame 13 by, for example, screws (not shown). The pressing spring 18 can also be made by, for example, pressing a sheet metal.

【０００９】以上のように構成された本発明の第１の実
施の形態における動圧型流体軸受装置について、図１〜
図６を用いてその動作を説明する。まず図１では軸１４
とスリーブ１１との隙間がすでに確保された状態を示し
ている。しかしながら特に本実施の形態における左外枠
１２、右外枠１３を板金のプレス加工で加工し、更に左
外枠１２と右外枠１３をはめあいに依らずに組み立てた
場合、組立直後は通常図２に示すような、軸１４とスリ
ーブ１１が擦れた状態となっているので、軸１４とスリ
ーブ１１との隙間を調整する必要がある。The hydrodynamic bearing device according to the first embodiment of the present invention configured as described above is shown in FIGS.
The operation will be described with reference to FIG. First, in FIG.
This shows a state where a gap between the sleeve 11 and the sleeve 11 has already been secured. However, in particular, when the left outer frame 12 and the right outer frame 13 in the present embodiment are processed by pressing a sheet metal, and the left outer frame 12 and the right outer frame 13 are assembled without depending on the fitting, a normal drawing immediately after the assembly is used. Since the shaft 14 and the sleeve 11 are rubbed as shown in FIG. 2, it is necessary to adjust the gap between the shaft 14 and the sleeve 11.

【００１０】調整の具体的な手段として、複数の動圧発
生溝１５こそ無いが、ほぼ図１と同じ構成の外周に球面
部を有する焼結軸受の場合、軸１４が停止した状態で右
外枠１２、または左外枠１３を図示しないハンマ等で加
振する方法が用いられる。この方法は組立直後に軸１４
とスリーブ１１が強く接触している、すなわち大きな接
触力が発生している場合、この接触力と押圧バネ１８が
加振で瞬間緩むことでスリーブ１１が接触力が少なくな
る方へ微動し結果擦れの力が弱まるので、本来多数擦れ
ていても使える焼結軸受では有効であった。なおこの加
振方法は、軸１４とスリーブ１１との接触力が弱い場合
や、瞬間はあるが不均一な場合、スリーブ１１には調芯
するための力が何ら働いていないので、いくら加振して
もより均一な隙間は得られない。一方動圧型流体軸受装
置では、スリーブ１１に比較的焼き付き易い真鍮系の材
料を用いる場合が多いので、擦れの力を弱めるだけでな
く、軸１４をスリーブ１１に対して十分な隙間を保ちつ
つ非接触で回転させる、すなわちスリーブ１１と軸１４
を十分に調芯する必要がある。As a specific means of adjustment, there is no plurality of dynamic pressure generating grooves 15, but in the case of a sintered bearing having a spherical portion on the outer periphery having substantially the same configuration as that of FIG. A method of exciting the frame 12 or the left outer frame 13 with a hammer (not shown) or the like is used. This method uses the shaft 14 immediately after assembly.
When the sleeve 11 is in strong contact with the sleeve 11, that is, when a large contact force is generated, the contact force and the pressing spring 18 are momentarily loosened by the vibration, so that the sleeve 11 is slightly moved to a position where the contact force is reduced, resulting in rubbing. Therefore, a sintered bearing that can be used even if it originally rubs a lot was effective. In this vibration method, when the contact force between the shaft 14 and the sleeve 11 is weak, or when there is a moment but unevenness, no force for centering works on the sleeve 11, so Even so, a more uniform gap cannot be obtained. On the other hand, in a hydrodynamic bearing device, since a brass-based material that is relatively easy to seize is often used for the sleeve 11, not only the frictional force is reduced, but also the shaft 14 is secured while maintaining a sufficient clearance with respect to the sleeve 11. Rotate by contact, ie sleeve 11 and shaft 14
Needs to be fully aligned.

【００１１】以上のことから、動圧系流体軸受装置で
は、左外枠１２、右外枠１３、押圧バネ１８を単にプレ
ス加工で安く作ることだけでなく、どのような構造で軸
１４とスリーブ１１の調芯を確実に行うかが極めて重要
であり、本発明はこの点を考慮した発明である。より具
体的には、スリーブ１１の調芯を確実に行うために、軸
１４の回転と複数の動圧発生溝１５の効果で発生する潤
滑油１６の圧力を、スリーブ１１自体を調芯させる力と
して有効に利用できるよう考案したものであり、以下に
説明を続ける。As described above, in the hydrodynamic bearing device, not only the left outer frame 12, the right outer frame 13, and the pressing spring 18 can be formed cheaply by press working, but also by any structure, It is extremely important that the alignment of 11 is performed reliably, and the present invention has been made in consideration of this point. More specifically, in order to surely align the sleeve 11, the pressure of the lubricating oil 16 generated by the rotation of the shaft 14 and the effect of the plurality of dynamic pressure generating grooves 15 is reduced by the force for aligning the sleeve 11 itself. It has been devised so that it can be used effectively, and the description will be continued below.

【００１２】まず図１には、複数の動圧発生溝１５がス
リーブ１１の外周の球面部中心と対称に設けられ、かつ
軸１４とスリーブ１１の隙間が均一、すなわち軸１４と
スリーブ１１た調芯された状態が示されている。この状
態で軸１４が矢印Ａ方向へ回転すると、潤滑油１６には
複数の動圧発生溝１６の効果で圧力が発生する。この様
子を詳細に説明するために、図３に、図１のスリーブ１
１、軸１４の位置関係と潤滑油１６の圧力分布を重ねて
示す。図３に示すようなスリーブ１１と軸１４との隙間
が均一な場合の潤滑油１６の圧力分布は、動圧発生溝１
５の中心線に対して対称な分布となる。よって本実施の
形態のようにスリーブ１１の外周球面部の中心を複数の
動圧発生溝１５の中心線上に設けていれば、調芯された
後に軸１４を回転しても、スリーブ１１の調芯状態を狂
わす力が発生しない安定した動圧型流体軸受装置とな
る。First, in FIG. 1, a plurality of dynamic pressure generating grooves 15 are provided symmetrically with respect to the center of the spherical portion on the outer periphery of the sleeve 11, and the gap between the shaft 14 and the sleeve 11 is uniform, that is, the adjustment of the shaft 14 and the sleeve 11 is performed. The centered state is shown. When the shaft 14 rotates in the direction of arrow A in this state, pressure is generated in the lubricating oil 16 by the effect of the plurality of dynamic pressure generating grooves 16. In order to explain this situation in detail, FIG.
1. The positional relationship of the shaft 14 and the pressure distribution of the lubricating oil 16 are shown in an overlapping manner. When the gap between the sleeve 11 and the shaft 14 is uniform as shown in FIG.
5 has a symmetric distribution with respect to the center line. Therefore, if the center of the outer peripheral spherical portion of the sleeve 11 is provided on the center line of the plurality of dynamic pressure generating grooves 15 as in the present embodiment, even if the shaft 14 is rotated after the alignment, the adjustment of the sleeve 11 is performed. A stable hydrodynamic bearing device that does not generate a force that disturbs the core state is provided.

【００１３】一方図２に示す、調芯される前の潤滑油１
６の圧力分布は、複数の動圧発生溝１５の中心線と対称
な圧力分布に、スリーブ１１と軸１４との隙間の効果を
加えた分布となる。なお隙間の効果を単純に説明すると
以下のようになる。図２において軸１４の矢印Ａ方向へ
回転すると、この回転方向へ潤滑油１６も流れる。この
時、一般に潤滑油１６は圧縮性のある油を用いるので、
潤滑油１６が軸１４とスリーブ１１との隙間の狭いとこ
ろを通ると潤滑油１６の圧力が上がり、隙間が広い所を
通過すると圧力が下がることになる。よって図２での潤
滑油１６の圧力分布は、図４に示すように軸１５とスリ
ーブ１１の隙間が狭い所で高く、隙間が広い所で低い、
複数の動圧発生溝１５の中心線に関し非対称な分布とな
る。この分布を図２のスリーブ１１に適応すると、この
非対称な潤滑油１６の圧力分布がスリーブ１１を複数の
動圧発生溝１５を中心に矢印Ｃ方向へ、すなわち隙間が
均等になる方向へ回転させる力として働くこととなる。
一方この力は、スリーブ１１の外周の球面部の中心が複
数の動圧発生溝１５の中心線上に位置しているので、直
接スリーブ１１を矢印Ｃ方向へ回そうとする力となるた
め、非対称の圧力分布が有効に活用されスリーブ１１を
回そうとする力となる。On the other hand, the lubricating oil 1 before alignment shown in FIG.
The pressure distribution 6 is a distribution obtained by adding the effect of the gap between the sleeve 11 and the shaft 14 to the pressure distribution symmetrical with the center line of the plurality of dynamic pressure generating grooves 15. The effect of the gap is simply described as follows. When the shaft 14 rotates in the direction of arrow A in FIG. 2, the lubricating oil 16 also flows in this direction of rotation. At this time, since the lubricating oil 16 generally uses a compressible oil,
When the lubricating oil 16 passes through a narrow space between the shaft 14 and the sleeve 11, the pressure of the lubricating oil 16 increases, and when the lubricating oil 16 passes through a wide space, the pressure decreases. Therefore, the pressure distribution of the lubricating oil 16 in FIG. 2 is high when the gap between the shaft 15 and the sleeve 11 is narrow as shown in FIG.
The distribution becomes asymmetric with respect to the center line of the plurality of dynamic pressure generating grooves 15. When this distribution is applied to the sleeve 11 of FIG. 2, this asymmetric pressure distribution of the lubricating oil 16 causes the sleeve 11 to rotate around the plurality of dynamic pressure generating grooves 15 in the direction of arrow C, that is, in the direction in which the gap becomes uniform. It will work as power.
On the other hand, since the center of the spherical portion on the outer periphery of the sleeve 11 is located on the center line of the plurality of dynamic pressure generating grooves 15, this force is a force for directly rotating the sleeve 11 in the direction of arrow C. The pressure distribution is effectively used to provide a force for rotating the sleeve 11.

【００１４】なお、特に本実施例の応用例として、軸１
４の正転、逆転の回転に対応可能な動圧型流体軸受を図
５に示す。なお、図５において図１と同機能部品に付い
ては同一番号に付している。また図５においては、軸１
４と外周に球面部をもつスリーブ１１、複数の動圧発生
溝１５、潤滑油１６のみを示している。図１からの具体
的な変形の内容は、軸１４が図示しない回転手段によ
り、矢印Ａ方向と矢印Ｄ方向へ回転する事と、複数の動
圧発生溝１５を溝Ｅ、溝Ｆ、溝Ｇ、溝Ｈで構成したこと
である。上記構成により、軸１４が矢印Ａ方向へ回転す
るときは溝Ｅと溝Ｆ、溝Ｇと溝Ｈの２箇所で、また軸１
４が矢印Ｄ方向へ回転するときは、溝Ｆと溝Ｇで、潤滑
油１６の圧力が高まるので、軸１４が矢印Ａ方向、矢印
Ｄ方向どちらへ回転しても、軸１４とスリーブ１１は非
接触で回転できる事になる。この図５に示すような動圧
発生溝１５に、第１の発明を適用するときは、単純にス
リーブ１１の外周の球面部中心を、溝Ｆと溝Ｇとの交点
を連ねた線上に位置させれば良い。これは軸１４が矢印
Ａ方向へ回転しても、矢印Ｄ方向へ回転しても、この溝
Ｆと溝Ｇの交点を中心に潤滑油１６の圧力が対称に発生
するためであり、この様な観点から、図５の構成は第１
の実施例の単純な変形といえる。In particular, as an application example of this embodiment, the shaft 1
FIG. 5 shows a hydrodynamic fluid bearing capable of coping with the forward and reverse rotations of No. 4. In FIG. 5, the same functional components as those in FIG. 1 are denoted by the same reference numerals. Also, in FIG.
4, only a sleeve 11 having a spherical portion on the outer periphery, a plurality of dynamic pressure generating grooves 15, and a lubricating oil 16 are shown. The specific contents of the deformation from FIG. 1 are that the shaft 14 is rotated in the directions of arrows A and D by rotating means (not shown), and the plurality of dynamic pressure generating grooves 15 are formed in the grooves E, F, and G. , Groove H. With the above configuration, when the shaft 14 rotates in the direction of the arrow A, the shaft 14 is rotated at two positions of the groove E and the groove F and the groove G and the groove H.
When the shaft 4 rotates in the direction of the arrow D, the pressure of the lubricating oil 16 increases in the groove F and the groove G, so that the shaft 14 and the sleeve 11 can be moved regardless of whether the shaft 14 rotates in the direction of the arrow A or the direction of the arrow D. It can be rotated without contact. When the first invention is applied to the dynamic pressure generating groove 15 as shown in FIG. 5, the center of the spherical portion on the outer periphery of the sleeve 11 is simply positioned on a line connecting the intersections of the groove F and the groove G. You can do it. This is because the pressure of the lubricating oil 16 is generated symmetrically around the intersection of the groove F and the groove G regardless of whether the shaft 14 rotates in the direction of arrow A or in the direction of arrow D. In view of the above, the configuration of FIG.
It can be said that this is a simple modification of the embodiment.

【００１５】次に本発明の第２の実施の形態について、
図６を参照しながら説明する。図６において図１と同一
機能部品に付いては同一番号を付している。１１はスリ
ブ、１２は左外枠、１３は右外枠、１４は軸、１５は軸
１４に設けられた複数の動圧発生溝、１６は潤滑油、１
７は左外枠１２、右外枠１３それぞれに設けたスリーブ
１１の外周の球面部を支持する受け面、１８は押圧バネ
である。なお、図２に示した第１の実施形態と異なると
ころは、複数の動圧発生溝１５の中心線上にスリーブ１
１の外周の球面部中心を位置させていない点である。Next, a second embodiment of the present invention will be described.
This will be described with reference to FIG. 6, the same functional parts as those in FIG. 1 are denoted by the same reference numerals. 11 is a slab, 12 is a left outer frame, 13 is a right outer frame, 14 is a shaft, 15 is a plurality of dynamic pressure generating grooves provided on the shaft 14, 16 is lubricating oil,
Reference numeral 7 denotes a receiving surface that supports the spherical portion on the outer periphery of the sleeve 11 provided on each of the left outer frame 12 and the right outer frame 13, and 18 denotes a pressing spring. The difference from the first embodiment shown in FIG. 2 is that the sleeve 1 is placed on the center line of the plurality of dynamic pressure generating grooves 15.
1 is that the center of the spherical portion on the outer periphery is not located.

【００１６】以上のように構成された第２の実施形態に
ついて、図６〜図８を用いてその動作を説明する。図６
は第１の実施形態における図２に対応する断面図ある
が、基本的な動作は図２に示す場合と同じであるので、
第１の実施形態と異なる点を中心に説明する。第１の実
施形態と異なる点は、スリーブ１１の外周の球面部中心
が、軸１４に設けた複数の動圧発生溝１５の中心線上に
位置していない点にある。しかしながらこの様な構成で
も、軸１４が矢印Ａ方向へ回転すると、潤滑油１６の圧
力分布でスリーブ１１をその外周球面部で回転させる調
芯力が働く。この理由を図７を用いて説明する。スリー
ブ１１と軸１６との隙間が不均等な場合、潤滑油１６の
圧力分布は隙間が狭い方に圧力の中心位置が偏った非対
称な圧力分布となる事は既に第１の実施形態で示した
が、図７に於いても全く同じ現象が発生する。ここで圧
力分布による合成力をＩ、Ｊ、またスリーブ１１の外周
の球面部中心からＩ、Ｊまでの距離をＫ、Ｌとする。ま
ずＩとＪの大きさについては、軸１４とスリーブ１１と
の隙間が対称であることから、潤滑油１６の圧力分布は
複数の動圧発生溝１５の中心線に対して対称で方向だけ
が違う同じ大きさの圧力分布となるため、圧力分布によ
る合成力Ｉ、Ｊも当然同じ大きさとなる。一方スリーブ
１１を矢印Ｃ方向へ回転させようとするトルクはＩ×
Ｋ、逆方向へ回転させようとする力はＪ×Ｌとなるが、
Ｋ＞Ｌであるので、結果スリーブ１１には矢印Ｃ方向へ
回転させようとする力が働く。なお、このスリーブ１１
を回転させようとする力の大きさは、結果として第１の
実施形態における大きさと全く変わらない大きさとな
る。しかしながら第２の実施形態における構成は、第１
の実施形態における動圧発生溝１５の中心とスリーブ１
１の外周球面部の中心とを合致させるという制約条件が
無いことから、この動圧型流体軸受装置に例えば図示し
ないスラスト軸受や防塵、油溜まり等を設けようとする
とき、極めて自由度が高い構成といえる。The operation of the second embodiment configured as described above will be described with reference to FIGS. FIG.
Is a sectional view corresponding to FIG. 2 in the first embodiment, but since the basic operation is the same as that shown in FIG. 2,
The following description focuses on the differences from the first embodiment. The difference from the first embodiment is that the center of the spherical portion on the outer periphery of the sleeve 11 is not located on the center line of the plurality of dynamic pressure generating grooves 15 provided on the shaft 14. However, even in such a configuration, when the shaft 14 rotates in the direction of the arrow A, the pressure distribution of the lubricating oil 16 exerts a centering force for rotating the sleeve 11 at the outer peripheral spherical portion. The reason will be described with reference to FIG. When the gap between the sleeve 11 and the shaft 16 is unequal, the pressure distribution of the lubricating oil 16 becomes an asymmetric pressure distribution in which the center position of the pressure is biased toward the narrower gap as already described in the first embodiment. However, the same phenomenon occurs in FIG. Here, the combined forces due to the pressure distribution are I and J, and the distances from the center of the spherical portion on the outer periphery of the sleeve 11 to I and J are K and L. First, regarding the sizes of I and J, since the gap between the shaft 14 and the sleeve 11 is symmetric, the pressure distribution of the lubricating oil 16 is symmetric with respect to the center line of the plurality of dynamic pressure generating grooves 15 and only the direction is changed. Since the pressure distributions are different and have the same magnitude, the resultant forces I and J due to the pressure distribution naturally have the same magnitude. On the other hand, the torque for rotating the sleeve 11 in the direction of arrow C is I ×
K, the force to rotate in the opposite direction is J × L,
Since K> L, a force for rotating the sleeve 11 in the direction of the arrow C is applied. Note that this sleeve 11
As a result, the magnitude of the force to rotate is substantially the same as the magnitude in the first embodiment. However, the configuration in the second embodiment is the same as that of the first embodiment.
Of the dynamic pressure generating groove 15 and the sleeve 1 in the first embodiment.
Since there is no restriction condition that the center of the outer peripheral spherical portion 1 is matched with the center of the outer peripheral spherical portion, when a thrust bearing (not shown), dust proof, oil reservoir, etc. are provided in the hydrodynamic bearing device, the degree of freedom is extremely high. It can be said that.

【００１７】なお、第１の実施の形態とあえて比較する
と、次のような問題点がある。すなわち調芯が完了した
図６の状態で、軸１４の自重や図示しない例えば換気扇
の羽根重量などの軸受負荷は、単純に考えるとに動圧発
生溝１５の中央部で受けるので、この力に、複数の動圧
発生溝１５の中心からスリーブ１１の外周の球面部中心
までの距離を掛けたトルクがスリーブ１１の調芯状態を
狂わす力となる。しかしながら現実にはこの様な力が働
いても、押圧バネ１８の力を増大したり、スリーブ１１
の外周の球面部の半径を大きくする等で十分対策でき
る。In comparison with the first embodiment, there are the following problems. That is, in the state of FIG. 6 in which the alignment is completed, the bearing load such as the weight of the shaft 14 and the weight of the blades of the ventilation fan (not shown) is received at the central portion of the dynamic pressure generating groove 15 when simply considered. The torque obtained by multiplying the distance from the center of the plurality of dynamic pressure generating grooves 15 to the center of the spherical portion on the outer periphery of the sleeve 11 is a force that disturbs the alignment of the sleeve 11. However, in reality, even if such a force acts, the force of the pressing spring 18 is increased,
A sufficient measure can be taken, for example, by increasing the radius of the spherical portion on the outer periphery of the lens.

【００１８】なお、特に第２の実施の形態の変形とし
て、正転、逆転の回転に対応可能な動圧型流体軸受への
応用例を図８に示す。なお、図８において図６と同機能
部品に付いては同一番号を付している。また図８におい
ては、軸１４と外周が球面状のスリーブ１１、複数の動
圧発生溝１５、潤滑油１６のみを示している。図６から
の具体的な変形部位は、複数の動圧発生溝１５を、溝
Ｍ、溝Ｎ、溝Ｏで構成した点である。このことにより、
軸１４が矢印Ａ方向へ回転するときは溝Ｍと溝Ｎで、ま
た軸１４が矢印Ｄ方向へ回転するときは、溝Ｎと溝Ｏ
で、潤滑油１６の圧力が高まるので、軸１４が矢印Ａ方
向、矢印Ｄ方向どちらへ回転しても、軸１４とスリーブ
１１は非接触で回転できる事になる。しかしながら図８
では、軸１４の回転方向により複数の動圧発生溝１５の
実質的な中心位置が、溝Ｍと溝Ｎの交点、溝Ｎと溝Ｏの
交点の２箇所発生する。よってこの様な複数の動圧発生
溝１５の場合、第１の発明を適用する事はできない。一
方第２の発明によれば、例えば図８に示すように単純に
複数の動圧発生溝１５の中心線をスリーブ１１の外周の
球面の中心位置に合致させることができる。なお、図８
の固有の特徴を以下に簡単に説明する。軸１４の自重や
図示しない例えば換気扇の羽根重量などの軸受負荷は、
単純に考えると、軸１４が矢印Ａ方向へ回転するときは
溝Ｍと溝Ｎの交点、矢印Ｄ方向へ回転するときは溝Ｎと
溝Ｏの交点で受ける事になる。ここで受けた軸受負荷
に、スリーブ１１の外周の球面部中心までの距離を掛け
たトルクが、スリーブ１１と軸１４の隙間が調芯された
状態を崩そうとする力となる。図８の特徴は、軸１４が
矢印Ａ方向、矢印Ｄ方向いずれの方向へ回転する場合
も、調芯を狂わす力を最小にできることにある。FIG. 8 shows, as a modification of the second embodiment, an application to a dynamic pressure type fluid bearing capable of coping with forward rotation and reverse rotation. In FIG. 8, the same components as those in FIG. 6 are denoted by the same reference numerals. FIG. 8 shows only the shaft 14, the sleeve 11 having a spherical outer periphery, the plurality of dynamic pressure generating grooves 15, and the lubricating oil 16. A specific deformed portion from FIG. 6 is that a plurality of dynamic pressure generating grooves 15 are configured by grooves M, grooves N, and grooves O. This allows
When the shaft 14 rotates in the direction of the arrow A, the grooves M and N are used. When the shaft 14 rotates in the direction of the arrow D, the grooves N and O are used.
Since the pressure of the lubricating oil 16 increases, the shaft 14 and the sleeve 11 can rotate in a non-contact manner regardless of whether the shaft 14 rotates in the arrow A direction or the arrow D direction. However, FIG.
In this case, two substantial positions of the center of the plurality of dynamic pressure generating grooves 15 occur at the intersections of the grooves M and N and the intersections of the grooves N and O depending on the rotation direction of the shaft 14. Therefore, in the case of such a plurality of dynamic pressure generating grooves 15, the first invention cannot be applied. On the other hand, according to the second aspect, for example, as shown in FIG. 8, the center lines of the plurality of dynamic pressure generating grooves 15 can be simply made to coincide with the center positions of the spherical surfaces on the outer periphery of the sleeve 11. FIG.
The unique features of are described briefly below. The bearing load such as the weight of the shaft 14 and the weight of the fan (not shown) of the ventilation fan, for example,
To put it simply, when the shaft 14 rotates in the direction of the arrow A, it is received at the intersection of the groove M and the groove N, and when it rotates in the direction of the arrow D, it is received at the intersection of the groove N and the groove O. The torque obtained by multiplying the bearing load received here by the distance to the center of the spherical portion on the outer periphery of the sleeve 11 becomes a force for breaking the state where the gap between the sleeve 11 and the shaft 14 is aligned. The feature of FIG. 8 is that the force which disturbs the alignment can be minimized when the shaft 14 rotates in any of the directions of arrow A and arrow D.

【００１９】以上のように本発明の第１の実施の形態に
よれば、複数の動圧発生溝１５の中心線上にスリーブ１
１の外周の球面部の中心を位置させているので、軸１４
を回転させる時に発生するスリーブ１１と軸１４間との
隙間を調芯させる力が有効にスリーブ１１に伝わるので
組立後に調芯が可能となる。これにより左外枠１２、右
外枠１３等を精度に悪いがコストが安い板金のプレス加
工品に置き換えられるので、低コストの動圧型流体軸受
装置が可能となる。更に一旦調芯されると、その状態が
極めて狂いにくい安定した動圧型流体軸受装置となる。As described above, according to the first embodiment of the present invention, the sleeve 1 is placed on the center line of the plurality of dynamic pressure generating grooves 15.
1 is located at the center of the spherical portion on the outer periphery of
Since the force for aligning the gap between the sleeve 11 and the shaft 14 that is generated when the shaft is rotated is effectively transmitted to the sleeve 11, the alignment can be performed after the assembly. As a result, the left outer frame 12, the right outer frame 13 and the like can be replaced with a stamped product made of a sheet metal having low accuracy but low cost, so that a low-cost hydrodynamic bearing device can be realized. Further, once the alignment is performed, a stable dynamic pressure type hydrodynamic bearing device in which the state is hardly deviated is obtained.

【００２０】また本発明の第２の実施の形態によれば、
動圧発生溝１５の中心線上にスリーブ１１の外周の球面
部の中心を位置させていないが、軸１４を回転させる時
に発生するスリーブ１１と軸１４間との隙間を調芯させ
る力が有効にスリーブ１１に伝わるので組立後に調芯が
可能となる。これにより左外枠１２、右外枠１３等を精
度は悪いがコストが安い板金のプレス加工品に置き換え
られるので、低コストの動圧型流体軸受装置が可能とな
り、更に動圧型流体軸受装置を各種商品に適用するとき
の、設計の自由度が極めて高くなる。更に第１の実施の
形態に比べて極めて設計の自由度が高い動圧型流体軸受
装置となる。According to a second embodiment of the present invention,
Although the center of the spherical portion on the outer periphery of the sleeve 11 is not located on the center line of the dynamic pressure generating groove 15, the force generated when the shaft 14 is rotated to align the gap between the sleeve 11 and the shaft 14 is effectively used. Since it is transmitted to the sleeve 11, alignment can be performed after assembly. As a result, the left outer frame 12, the right outer frame 13 and the like can be replaced with a sheet metal stamped product with low accuracy but low cost, so that a low-cost hydrodynamic bearing device can be realized. When applied to products, the degree of freedom in design becomes extremely high. Further, the hydrodynamic bearing device has a very high degree of freedom in design as compared with the first embodiment.

【００２１】なお、第１の実施の形態、第２の実施の形
態では、複数の動圧発生溝１５を軸１４に設けたが、ス
リーブ１１に設けても良い。また複数の動圧発生溝を構
成する各溝の軸方向長さは同じ長さで示したが、長さを
変えても良い。また、スリーブ１１の外周全面を球面部
として示したが、受け面１７の大きさに調芯範囲を加え
た最小範囲としても良い。またスリーブ１１の外周と受
け面１７は共に球面の一部として示したが、スリーブ１
１が略球面内で回転自在に支持できるような他の支持方
法を用いても良い。また押圧バネ１７は板バネで示した
が、コイルバネ等の他の手段を用いても良い。更にスリ
ーブ１１を調芯させる力は動圧型流体軸受が本質的に持
っている潤滑油１６の圧力を活用しているので、この力
だけで調芯される場合もあるが、不足する場合もある。
よってより確実な調芯方法として、軸１４を回転させた
状態で、図示しないハンマ等による加振を併用しても良
い。また加振の手段は、ハンマ以外の、例えば圧電素子
等を用いても良い。In the first and second embodiments, the plurality of dynamic pressure generating grooves 15 are provided on the shaft 14, but they may be provided on the sleeve 11. Although the axial length of each of the plurality of dynamic pressure generating grooves is the same, the length may be changed. Further, although the entire outer periphery of the sleeve 11 is shown as a spherical portion, it may be a minimum range obtained by adding the centering range to the size of the receiving surface 17. Although the outer periphery of the sleeve 11 and the receiving surface 17 are both shown as part of a spherical surface, the sleeve 1
Other support methods that allow the 1 to be rotatably supported within a substantially spherical surface may be used. Further, although the pressing spring 17 is shown as a leaf spring, other means such as a coil spring may be used. Further, since the force for aligning the sleeve 11 utilizes the pressure of the lubricating oil 16 inherently possessed by the hydrodynamic bearing, the sleeve 11 may be aligned by itself, but may be insufficient. .
Therefore, as a more reliable alignment method, vibration with a hammer (not shown) may be used in combination with the shaft 14 being rotated. Further, as the vibration means, for example, a piezoelectric element or the like other than the hammer may be used.

【００２２】[0022]

【発明の効果】以上のように本発明の第１の発明は、複
数の動圧発生溝の中心線上にスリーブの外周の球面部中
心を位置させた構成により組立後の調芯ができるので、
支持枠等の低コスト化が可能な、かつ調芯後は調芯状態
が狂いにくい動圧型流体軸受装置が実現できる。As described above, according to the first aspect of the present invention, since the center of the outer peripheral surface of the sleeve is located on the center line of the plurality of dynamic pressure generating grooves, the centering after assembly can be performed.
It is possible to realize a hydrodynamic bearing device in which the cost of the support frame and the like can be reduced and the alignment state after alignment is less likely to be out of order.

【００２３】また本発明の第２の発明は、複数の動圧発
生溝の中心線上よりスリーブの外周の球面部中心をずら
した構成により組立後の調芯ができるので、支持枠等の
低コスト化が可能な、かつ設計の自由度が高い動圧型流
体軸受装置が実現できる。Further, according to the second aspect of the present invention, the center of the outer periphery of the sleeve is shifted from the center line of the plurality of dynamic pressure generating grooves with respect to the center of the sleeve. A hydrodynamic bearing device that can be manufactured and has a high degree of freedom in design can be realized.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の第１の発明の実施例における断面図FIG. 1 is a sectional view of a first embodiment of the present invention.

【図２】本発明の第１の発明の実施例における調芯前の
断面図FIG. 2 is a cross-sectional view before alignment in an embodiment of the first invention of the present invention.

【図３】図１における潤滑油の圧力分布の説明図FIG. 3 is an explanatory diagram of a lubricating oil pressure distribution in FIG. 1;

【図４】図２における潤滑油の圧力分布の説明図FIG. 4 is an explanatory diagram of a lubricating oil pressure distribution in FIG. 2;

【図５】本発明の第１の発明の変形例における断面図FIG. 5 is a sectional view of a modification of the first invention of the present invention.

【図６】本発明の第２の発明の実施例における断面図FIG. 6 is a sectional view of a second embodiment of the present invention.

【図７】図６における潤滑油の圧力分布の説明図FIG. 7 is an explanatory diagram of a pressure distribution of lubricating oil in FIG. 6;

【図８】本発明の第２の発明の変形例における断面図FIG. 8 is a sectional view of a modification of the second invention of the present invention.

【図９】従来の動圧型流体軸受装置の断面図FIG. 9 is a sectional view of a conventional hydrodynamic bearing device.

【符号の説明】[Explanation of symbols]

１、１１ スリーブ ２、１２ 左支持枠 ３、１３ 右支持枠 ４、１４ 軸 ５、１５ 複数の動圧発生溝 ６、１６ 潤滑油 １７ 受け面 １８ 押圧バネ 1, 11 Sleeve 2, 12 Left support frame 3, 13 Right support frame 4, 14 Shaft 5, 15 Plural dynamic pressure generating grooves 6, 16 Lubricating oil 17 Receiving surface 18 Press spring

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 軸と、スリーブと、このスリーブの外周
に設けた球面部と、この球面部を回転自在に受ける受け
面と、この受け面を有する支持枠と、前記スリーブの球
面部を前記受け面に押圧する押圧バネと、前記軸もしく
は前記スリーブに設けた複数の動圧発生溝とを有する動
圧型流体軸受装置において、前記複数の動圧発生溝の中
心線上に前記スリーブの前記球面部の中心を位置させた
動圧型流体軸受装置。1. A shaft, a sleeve, a spherical portion provided on an outer periphery of the sleeve, a receiving surface rotatably receiving the spherical portion, a support frame having the receiving surface, and a spherical portion of the sleeve. In a hydrodynamic bearing device having a pressing spring that presses against a receiving surface and a plurality of dynamic pressure generating grooves provided on the shaft or the sleeve, the spherical portion of the sleeve is provided on a center line of the plurality of dynamic pressure generating grooves. Hydrodynamic bearing device in which the center of is located. 【請求項２】 軸と、スリーブと、このスリーブの外周
に設けた球面部と、この球面部を回転自在に受ける受け
面と、この受け面を有する支持枠と、前記スリーブの球
面部を前記受け面に押圧する押圧バネと、前記軸もしく
は前記スリーブに設けた複数の動圧発生溝とを有する動
圧型流体軸受装置において、前記複数の動圧発生溝の中
心線上より、前記スリーブの前記球面部の中心位置をず
らして設けた動圧型流体軸受装置。A shaft, a sleeve, a spherical portion provided on an outer periphery of the sleeve, a receiving surface rotatably receiving the spherical portion, a support frame having the receiving surface, and a spherical portion of the sleeve. In a hydrodynamic bearing device having a pressing spring that presses against a receiving surface, and a plurality of dynamic pressure generating grooves provided on the shaft or the sleeve, the spherical surface of the sleeve is positioned from a center line of the plurality of dynamic pressure generating grooves. Hydrodynamic bearing device provided with the center of the part shifted.