JP2011140983A

JP2011140983A - Fluid bearing device

Info

Publication number: JP2011140983A
Application number: JP2010002040A
Authority: JP
Inventors: Akio Yogo; 秋男余語
Original assignee: YOGO GIKEN KK
Current assignee: YOGO GIKEN KK
Priority date: 2010-01-07
Filing date: 2010-01-07
Publication date: 2011-07-21

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid bearing device for a rotary apparatus endurable against high rotation with a simple structure. <P>SOLUTION: This fluid bearing device includes a shaft hole member 1 having a bearing surface 1a of a predetermined width in the axial direction on an inner peripheral surface for partitioning a shaft hole, a shaft member 2 having a shaft surface 2a opposed to the bearing surface rotatably held by the shaft hole and a fluid supply means for supplying fluid between the bearing surface and the shaft surface. Both the bearing surface and the shaft surface are a side peripheral surface shape of a truncated cone shape, and the fluid supply means supplies the fluid in the axial direction between the bearing surface and the shaft surface. The bearing surface and the shaft surface are the side peripheral surface shape of the truncated cone shape, and since the fluid is supplied in the axial direction in these clearances, the shaft member 2 is energized to the axis of the shaft hole member 1, and can receive a load in the radial direction and a load in the axial direction by one mechanism, and a structurally simple rotary apparatus can be realized. The shaft member 2 has a turbine 8 on the axis, and rotates by a jet from a nozzle 6 of the shaft hole member 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は流体軸受装置に関する。 The present invention relates to a hydrodynamic bearing device.

高速で回転する軸に砥石や工具を取り付け種々の加工に使用するリューター等の工作装置や、医科用、歯科用の器具（ハンドピース）などの回転機器に使用する軸受装置が知られている。このような回転機器では、駆動にモータを用いるものや、圧縮空気によりタービンを回転させるものがある。また、軸受にはボールベアリングのようなころがり軸受や、軸またはスリーブにヘリングボーン状やＶ字状に配置した動圧発生溝により、軸が回転する際に流体の圧力を発生させて軸を受ける動圧軸受、外部から圧縮空気を供給して軸を受ける静圧軸受などのすべり軸受がある。 2. Description of the Related Art There are known bearing devices for use in machine tools such as a luter that are used for various processes by attaching a grindstone or a tool to a shaft that rotates at high speed, and for rotating equipment such as medical and dental instruments (handpieces). Among such rotating devices, there are those that use a motor for driving and those that rotate a turbine by compressed air. Also, the bearing receives a shaft by generating a fluid pressure when the shaft rotates by a rolling bearing such as a ball bearing or a dynamic pressure generating groove arranged in a herringbone shape or a V shape on the shaft or sleeve. There are sliding bearings such as a hydrodynamic bearing and a hydrostatic bearing that receives a shaft by supplying compressed air from the outside.

一般に、砥石や工具を高速で回転させるほど研削や切削は容易となり、加工時の負荷を小さくでき、短時間で加工を終えることができる。このため高速で回転させるための考案がなされてきた。特許文献１はモータによって駆動する主軸をエアーで支持する構造を開示している。特許文献２は圧縮空気でタービンを回転させ、軸方向、半径方向を静圧軸受で受けるという構造を開示している。特許文献３は流体で回転するタービンの半径方向を静圧軸受で受け、軸方向を凸球面等と平面を接触させるという構造を開示している。 Generally, grinding and cutting become easier as the grindstone and tool are rotated at a higher speed, the processing load can be reduced, and processing can be completed in a short time. For this reason, devices for rotating at high speed have been devised. Patent Document 1 discloses a structure in which a main shaft driven by a motor is supported by air. Patent Document 2 discloses a structure in which a turbine is rotated with compressed air and axial and radial directions are received by a hydrostatic bearing. Patent Document 3 discloses a structure in which a radial direction of a turbine rotating with a fluid is received by a hydrostatic bearing, and a convex spherical surface or the like is brought into contact with a plane in the axial direction.

しかしながら、上記した従来例では、構造が複雑であったり（特許文献１、２）、寿命のきわめて短いもの（特許文献３）であったりするという問題がある。 However, the above-described conventional example has a problem that the structure is complicated (Patent Documents 1 and 2) or has a very short life (Patent Document 3).

特開平１１−１１７９３９号公報JP-A-11-117939 特開２００１−２０７０１号公報JP 2001-20701 A 特開平６−２９２６９０号公報JP-A-6-292690

先端に小さな刃先や砥石を取り付け、高速で回転する機器を片手で保持し、目視で対象を確認しながら細かな加工を施す用途には、簡単な構造で小型軽量であるものが求められてきた。現在でも上記のような用途、具体的にはガラス細工、金属加工後のバリ取り、加工後の面取り、趣味の工作、医科や歯科の治療用などの用途にこのような回転機器の要望が強い。 For applications where a small cutting edge or grindstone is attached to the tip, a machine that rotates at high speed is held with one hand, and fine processing is performed while visually checking the object, a simple structure that is small and lightweight has been required. . Even now, there is a strong demand for such rotating devices for the above-mentioned uses, specifically glasswork, deburring after metal processing, chamfering after processing, hobby work, medical and dental treatment. .

本発明の目的は、簡便な構造で、高回転にも耐える回転機器用の流体軸受装置を提供することである。 An object of the present invention is to provide a hydrodynamic bearing device for a rotating device that has a simple structure and can withstand high rotation.

上記課題を解決するため、本発明者は流体軸受について鋭意検討した結果、本発明に至った。本発明の流体軸受装置は、軸孔を区画する内周面に軸方向に所定幅の軸受面を持つ軸孔部材と、軸孔に回動自在に保持され軸受面に対向する軸面をもつ軸部材と、軸受面と軸面の間に流体を供給する流体供給手段とを有する流体軸受装置であって、軸受面及び軸面はいずれも円錐台形の側周面状であり、流体供給手段は軸受面及び軸面と間に軸方向に流体を供給するものであることを特徴とする。本発明の流体軸受装置の軸受面と軸面は円錐台形の側周面状であり、それらの間隙に流体が軸方向に供給されるので、軸部材が軸孔部材の軸心に付勢され、半径方向の荷重と、軸方向の荷重とを１つの機構で受けることができ、構造が簡単な回転機器が実現できる。 In order to solve the above-mentioned problems, the present inventor diligently studied a fluid bearing, and as a result, reached the present invention. The hydrodynamic bearing device of the present invention has a shaft hole member having a bearing surface having a predetermined width in the axial direction on an inner peripheral surface defining the shaft hole, and a shaft surface that is rotatably held in the shaft hole and faces the bearing surface. A fluid dynamic bearing device having a shaft member and a fluid supply means for supplying a fluid between the bearing surface and the shaft surface, both of the bearing surface and the shaft surface are in the shape of a frustoconical side surface, and the fluid supply means Is characterized by supplying fluid in the axial direction between the bearing surface and the shaft surface. The bearing surface and the shaft surface of the hydrodynamic bearing device of the present invention are frustoconical side surfaces, and fluid is supplied to the gap between them in the axial direction, so that the shaft member is biased to the shaft center of the shaft hole member. The load in the radial direction and the load in the axial direction can be received by one mechanism, and a rotating device with a simple structure can be realized.

軸孔部材は円錐の頂点方向が互いに逆方向となる２個１組の、少なくとも１組の軸受面を有し、軸部材は１組の軸受面とそれぞれ対向する、少なくとも１組の軸面を有するとよい。こうすれば、軸孔部材や軸部材の製作が容易となり、軸受装置の組立ても容易になる。 The shaft hole member has at least one set of bearing surfaces, each of which has a pair of two cones whose apex directions are opposite to each other. The shaft member has at least one set of shaft surfaces respectively opposed to the one set of bearing surfaces. It is good to have. If it carries out like this, manufacture of a shaft hole member and a shaft member will become easy, and it will also become easy to assemble a bearing device.

流体はガスであるとよい。高速回転を実現でき、特に加工物が酸化を嫌うものである場合適切なガスを選択することにより、排気による影響を避けることができる。 The fluid may be a gas. High speed rotation can be realized, and the influence of exhaust can be avoided by selecting an appropriate gas, particularly when the workpiece does not like oxidation.

ガスは空気であってもよい。コンプレッサーなどにより簡便に圧力流体を発生させることができる。 The gas may be air. A pressure fluid can be easily generated by a compressor or the like.

軸受面とこれに対向する軸面とが、軸方向の断面上において軸部材の軸方向に対しなす角度は相等しいことが望ましい。このような構造により良好な軸受を形成できる。 It is desirable that the angle formed between the bearing surface and the shaft surface facing the bearing surface with respect to the axial direction of the shaft member on the cross section in the axial direction is the same. With such a structure, a good bearing can be formed.

軸受面の最小内径は、前記軸面の最大外径より小さいことが望ましい。このような構成により軸受面、軸面の面積を大きくすることができ、単位面積当たりの荷重を小さくできるので、小型でも大きな荷重に耐えられる軸受装置とすることができる。 The minimum inner diameter of the bearing surface is preferably smaller than the maximum outer diameter of the shaft surface. With such a configuration, the areas of the bearing surface and the shaft surface can be increased, and the load per unit area can be reduced. Therefore, the bearing device can withstand a large load even with a small size.

軸受面と軸面は、軸方向にそれぞれ少なくとも４つ存在するとよい。こうすることによって、小型で、半径方向の荷重と軸方向の荷重とを１つの機構で受ける軸受装置とすることができる。 There may be at least four bearing surfaces and shaft surfaces in the axial direction. By carrying out like this, it can be set as a small bearing apparatus which receives the load of a radial direction, and the load of an axial direction with one mechanism.

軸部材は、同軸上に流体により駆動されるタービンを有し、軸孔部材は、該タービンに向けて流体を噴出するノズル口を持つものとすることができる。このような構造により容易に回転駆動装置が得られる。 The shaft member may have a turbine that is driven by a fluid on the same axis, and the shaft hole member may have a nozzle port that ejects fluid toward the turbine. With such a structure, a rotary drive device can be easily obtained.

流体軸受装置において、軸受面及び前記軸面はいずれも円錐台形の側周面状であるため、半径方向と軸方向の軸受を別途に設ける必要がなく、長寿命で簡単な構造とすることができる。 In the hydrodynamic bearing device, since both the bearing surface and the shaft surface are frustoconical side circumferential surfaces, there is no need to provide separate bearings in the radial direction and the axial direction, and a long-life and simple structure can be obtained. it can.

本発明の流体軸受装置を示す中心軸で切断した切断部端面図である。It is the cutting part end view cut by the central axis which shows the fluid dynamic bearing device of the present invention. 本発明の流体軸受装置を示す、ノズル部で切断した半径方向の断面図である。It is sectional drawing of the radial direction cut | disconnected by the nozzle part which shows the hydrodynamic bearing apparatus of this invention. 本発明の軸受装置にタービンを設けた様子を示す切断部端面図である。It is a cutting part end view which shows a mode that the turbine was provided in the bearing apparatus of this invention. タービンとノズルの関係を示すため図３のノズル部で切断した半径方向の断面図である。FIG. 4 is a radial cross-sectional view cut at the nozzle portion of FIG. 3 to show the relationship between the turbine and the nozzle. 本発明の別の実施例を示す切断部端面図である。It is a cutting part end view which shows another Example of this invention. 組み立てる様子を示す外輪と内輪の立体的な模式図である。It is a three-dimensional schematic diagram of an outer ring and an inner ring showing a state of assembling. タービンとノズルとサブノズルとの関係を示す、図５のノズル部で切断した半径方向の断面図である。（外輪用カラーは省略した）It is sectional drawing of the radial direction cut | disconnected by the nozzle part of FIG. 5, which shows the relationship between a turbine, a nozzle, and a sub nozzle. (The outer ring collar is omitted) 内輪に動圧発生溝を設けた様子を示す模式図である。It is a schematic diagram which shows a mode that the dynamic-pressure generation | occurrence | production groove | channel was provided in the inner ring. 動圧流体軸受とした別の実施例を示す切断部端面図である。It is a cutting part end view which shows another Example made into the dynamic pressure fluid bearing. 本発明の軸受を有する工作機械の例を示す模式図である。It is a schematic diagram which shows the example of the machine tool which has a bearing of this invention.

図１は本発明の１実施例を示す切断端面図である。本実施例の流体軸受装置は、両端部の内周側に傾斜面１ａをもち、中央部にノズル６を有する円筒状の軸孔部材１と、軸孔部材１の内側に、軸３と、径方向に突出し軸方向の一方側が円錐台形状（または切頭円錐形状）をなす第１フランジ４、第２フランジ５とを有して回動自在に設けられた軸部材２とからなる。 FIG. 1 is a cut end view showing an embodiment of the present invention. The hydrodynamic bearing device of the present embodiment has a cylindrical shaft hole member 1 having an inclined surface 1a on the inner peripheral side of both end portions and a nozzle 6 at the center portion, a shaft 3 inside the shaft hole member 1, The shaft member 2 includes a first flange 4 and a second flange 5 that protrude in the radial direction and have a truncated cone shape (or frustoconical shape) on one side in the axial direction.

軸孔部材１の傾斜面１ａは、軸部材２のフランジ部の円錐台形状の円錐凸面に対応するように円錐台形状の円錐凹面を有する。本実施例では、軸孔部材１の円錐台形状の側周面状（円錐凹面）の部分が本発明の軸受面に該当し、軸受面に対向する軸部材２の円錐台形状の側周面状の部分が本発明の軸面に該当する。したがって、図１では軸受面１ａと軸面２ａの数はそれぞれ２つあることになる。また、軸受面１ａと軸面２ａとは、断面上で軸部材２の軸方向に対し同一の角度を持つ。実施例１ではその角度を３０度としたが、小さな角度では軸方向の荷重を支える効果が薄れ、大きな角度では半径方向の荷重を支える効果が薄れるという関係がある。用途に応じて１０度から８０度の範囲で選択するのが好ましい。なお、圧縮空気が供給されていない場合、軸受面１ａと軸面２ａは一部が接触する場合があるが、各図は圧縮空気が供給されている状態を表わしているものである。 The inclined surface 1 a of the shaft hole member 1 has a truncated conical concave surface so as to correspond to the truncated conical convex surface of the flange portion of the shaft member 2. In this embodiment, the frustoconical side circumferential surface (conical concave surface) portion of the shaft hole member 1 corresponds to the bearing surface of the present invention, and the frustoconical side circumferential surface of the shaft member 2 facing the bearing surface. The shape portion corresponds to the axial surface of the present invention. Therefore, in FIG. 1, there are two bearing surfaces 1a and two shaft surfaces 2a. The bearing surface 1a and the shaft surface 2a have the same angle with respect to the axial direction of the shaft member 2 on the cross section. In the first embodiment, the angle is set to 30 degrees, but there is a relationship that the effect of supporting the load in the axial direction is reduced at a small angle, and the effect of supporting the load in the radial direction is reduced at a large angle. It is preferable to select in the range of 10 to 80 degrees depending on the application. In addition, when compressed air is not supplied, although the bearing surface 1a and the shaft surface 2a may partly contact, each figure represents the state by which compressed air is supplied.

流体軸受装置には、軸孔部材１のノズル６を通して外部から圧縮空気が供給される。図１では簡略化して示したが、図２に示すようにノズル６はその延長が軸孔部材１の中心を通らないよう、ずれて設けられている。よって圧縮空気は軸孔部材１の内周にガイドされ軸孔部材１と軸部材２の間の空間を回転する。軸方向においては、圧縮空気は先端側と後端側に分かれ、図１で軸孔部材１と軸３が平行になって対向する空間を通り、軸孔部材１の軸受面１ａと軸部材２の軸面２ａとからなる狭小な空間に達する。このとき軸受面１ａと軸面２ａの互いの中心がずれて一部が近接すれば、軸受面１ａと軸面２ａは、断面において曲率が異なるので、近接部分近傍の空間はくさび状となり、前述した軸部材２の周りを回転している圧縮空気が導かれ、軸受面１ａと軸面２ａを分離するよう作用する。結果として軸部材２の中心は軸孔部材１の中心とほぼ一致する位置に付勢され、圧縮空気の圧力は周方向に渡ってほぼ等しくなり、安定して保持される。図２では均等に配置された４つのノズル６があるが、軸部材２の中心が軸孔部材１の中心に付勢されればよく、数や配置を限定するものではない。本実施例の流体軸受装置は、ノズル６を通して圧縮空気を供給することにより軸部材２は軸孔部材１の軸心に付勢される。軸部材２が回動していなくとも軸部材２は軸孔部材１と非接触となるため手で軸部材２を回動させると、軸部材２は相当長く回転を続ける。 The hydrodynamic bearing device is supplied with compressed air from the outside through the nozzle 6 of the shaft hole member 1. Although simplified in FIG. 1, as shown in FIG. 2, the nozzle 6 is offset so that its extension does not pass through the center of the shaft hole member 1. Therefore, the compressed air is guided by the inner periphery of the shaft hole member 1 and rotates in the space between the shaft hole member 1 and the shaft member 2. In the axial direction, the compressed air is divided into a front end side and a rear end side, and passes through a space in which the shaft hole member 1 and the shaft 3 are parallel and opposed in FIG. 1, and the bearing surface 1 a of the shaft hole member 1 and the shaft member 2. A narrow space consisting of the axial surface 2a is reached. At this time, if the bearing surface 1a and the shaft surface 2a are displaced from each other and partly close to each other, the bearing surface 1a and the shaft surface 2a have different curvatures in cross section. The compressed air rotating around the shaft member 2 is guided and acts to separate the bearing surface 1a and the shaft surface 2a. As a result, the center of the shaft member 2 is urged to a position substantially coincident with the center of the shaft hole member 1, and the pressure of the compressed air becomes substantially equal in the circumferential direction and is stably held. In FIG. 2, there are four nozzles 6 that are equally arranged, but the center of the shaft member 2 may be urged toward the center of the shaft hole member 1, and the number and arrangement are not limited. In the hydrodynamic bearing device of the present embodiment, the shaft member 2 is biased to the shaft center of the shaft hole member 1 by supplying compressed air through the nozzle 6. Even if the shaft member 2 is not rotating, the shaft member 2 is not in contact with the shaft hole member 1. Therefore, when the shaft member 2 is rotated by hand, the shaft member 2 continues to rotate considerably long.

また、ノズル６は両端の２つの軸受面１ａと軸面２ａのほぼ中央に設けられているので、半径方向と同時に軸方向に対しても両端部の軸受面１ａと軸面２ａの間隔が均等になるように作用する。このように本発明の流体軸受は、半径方向の荷重と軸方向の荷重を１つの機構で支持するものである。特に、軸方向を点接触支持するものに比べ耐久性に優れたものとなる。 Further, since the nozzle 6 is provided substantially at the center between the two bearing surfaces 1a and the shaft surface 2a at both ends, the distance between the bearing surface 1a and the shaft surface 2a at both ends is equal in the axial direction as well as in the radial direction. Act to be. Thus, the hydrodynamic bearing of the present invention supports a radial load and an axial load by a single mechanism. In particular, it is superior in durability compared to the one that supports point contact in the axial direction.

さらに上記軸受装置を回転駆動装置に適用することができる。軸３にタービン８を設けた様子を切断端面図である図３に示し、図３の中央部の半径方向の断面図を図４に示す。なお、図４はわかりやすくするために図３とは比例関係を変えてある。また、ノズル６は、その延長が軸部材の中心を通らないようずれて設けられているが、図３では簡略化して示した。タービン８は半径流タービンであり、タービン８とノズル６の関係を図４のようにすれば、タービン８を回転させることができる。 Furthermore, the bearing device can be applied to a rotational drive device. A state in which the turbine 8 is provided on the shaft 3 is shown in FIG. 3 which is a cut end view, and a radial sectional view of the central portion of FIG. 3 is shown in FIG. Note that the proportional relationship of FIG. 4 is different from that of FIG. The nozzle 6 is provided so that its extension does not pass through the center of the shaft member, but is shown in a simplified manner in FIG. The turbine 8 is a radial flow turbine. If the relationship between the turbine 8 and the nozzle 6 is as shown in FIG. 4, the turbine 8 can be rotated.

タービン８を回転させた排気は、先端側と後端側に分かれ、図３で軸孔部材１と軸３が平行になって対向する空間を通り、軸孔部材１の軸受面１ａと軸部材２の軸面２ａとからなる狭小な空間に達する。排気はこの断面上互いに平行な軸受面１ａと軸面２ａを半径方向で均等に分離するよう作用し、流体軸受を形成し、排出口７から外部へ排出される。各部品を図３のように配置することにより、軸受面１ａと軸面２ａの間で両面を分離する流体と、タービン８を回転させる流体とが、共通のノズル６と排出口７を持つ回転駆動装置が得られる。このようにすることにより、専用のノズルや排気口の加工を省略でき、回転駆動装置全体として配管の構造を簡単にでき小型化に寄与することができる。軸部材２はタービン８と共に回転するので、先端側に不図示のコレットチャック等を設け、工具や砥石などを取り付ければ、所定の用途を達成することができる。 Exhaust gas that has rotated the turbine 8 is divided into a front end side and a rear end side, passes through a space in which the shaft hole member 1 and the shaft 3 are parallel to each other in FIG. 3, and the bearing surface 1 a of the shaft hole member 1 and the shaft member. It reaches a narrow space composed of two axial surfaces 2a. The exhaust gas acts to separate the bearing surface 1a and the shaft surface 2a, which are parallel to each other in this cross section, in the radial direction, forms a fluid bearing, and is discharged from the discharge port 7 to the outside. By arranging each component as shown in FIG. 3, a fluid that separates both surfaces between the bearing surface 1 a and the shaft surface 2 a and a fluid that rotates the turbine 8 are rotated with a common nozzle 6 and a discharge port 7. A drive device is obtained. By doing in this way, processing of a dedicated nozzle or exhaust port can be omitted, and the structure of the piping can be simplified as a whole of the rotary drive device, contributing to miniaturization. Since the shaft member 2 rotates together with the turbine 8, a predetermined application can be achieved by providing a collet chuck (not shown) on the tip side and attaching a tool, a grindstone, or the like.

以上のように構成すれば、軸受装置を流体軸受としたため軸受部での発熱の心配がなく、さらに駆動に流体を使うため、モータを使うもののように駆動部の発熱の問題がない回転駆動装置を提供できる。 With the above configuration, since the bearing device is a fluid bearing, there is no fear of heat generation in the bearing portion, and since a fluid is used for driving, there is no problem of heat generation in the driving portion as in the case of using a motor. Can provide.

組立方法の一例としては、両端部の内面に軸受を加工した円筒状の軸孔部材１に、あらかじめ所定の方法で軸３にタービン８と第１フランジ４を固定したものを挿入し、ついで第２フランジ５を軸３に挿入し、ロックナット９で軸３の端部に設けられた不図示のねじ部で締結、固定する、というものであるが、特に限定するものではない。 As an example of the assembling method, a cylindrical shaft hole member 1 whose bearings are machined on the inner surfaces of both ends is inserted in advance with a shaft 3 fixed with a turbine 8 and a first flange 4 by a predetermined method. The two flanges 5 are inserted into the shaft 3 and fastened and fixed with a screw portion (not shown) provided at the end of the shaft 3 with a lock nut 9, but this is not particularly limited.

図１、３では軸部材２のうち、軸３と第１フランジ４、第２フランジ５が別体であったが、このうち軸３と第１フランジ４が一体に形成されてもよい。軸部材２を作る際に第１フランジ４も同時に作ることができ、第１フランジ４を固定する工数を削減できるという利点がある。なお、材質については特に限定しない。 In FIGS. 1 and 3, the shaft 3, the first flange 4, and the second flange 5 are separate from each other in the shaft member 2, but the shaft 3 and the first flange 4 may be integrally formed. When the shaft member 2 is made, the first flange 4 can be made at the same time, and there is an advantage that the number of steps for fixing the first flange 4 can be reduced. The material is not particularly limited.

本構造は、排出された流体の経路を確保すれば、流体がオイルや水や不凍液などのような液体の場合にも適用できる。たとえば、魚用の水槽にポンプで水を循環させる場合、水槽内の経路に上記軸孔部材１を透明な樹脂で形成した本回転駆動装置を設置すれば、タービン８の回転を目視確認することにより、水の循環を確認でき、装飾にもなる。また、水力発電機への適用も可能である。 This structure can also be applied to a case where the fluid is a liquid such as oil, water, or antifreeze, as long as the path of the discharged fluid is secured. For example, in the case where water is circulated by a pump in a fish tank, the rotation of the turbine 8 is visually confirmed if the rotary drive device in which the shaft hole member 1 is formed of a transparent resin is installed in the path in the tank. By this, you can check the circulation of water and you can also decorate it. Moreover, application to a hydroelectric generator is also possible.

軸受面と軸面の数を増やし大きな荷重に耐えられる軸受装置を持った回転駆動装置の実施例を述べる。この実施例の切断端面図を図５に示す。軸孔部材１はハウジング１０とハウジング１０に固定され軸受面１ａをもつ外輪１１とからなり、軸部材２は軸３と軸３に固定される内輪１２、端部用内輪１３とからなる。軸３に固定されたタービン８の先端側、後端側に外輪１１と内輪１２とが交互に配置される。 An embodiment of a rotary drive device having a bearing device capable of withstanding a large load by increasing the number of bearing surfaces and shaft surfaces will be described. A cut end view of this embodiment is shown in FIG. The shaft hole member 1 includes a housing 10 and an outer ring 11 fixed to the housing 10 and having a bearing surface 1a. The shaft member 2 includes a shaft 3, an inner ring 12 fixed to the shaft 3, and an end inner ring 13. Outer rings 11 and inner rings 12 are alternately arranged on the front end side and rear end side of the turbine 8 fixed to the shaft 3.

図５と、立体的な模式図である図６からわかるように、軸受面１ａは外輪１１の傾斜面であり、軸面２ａは内輪１２、端部用内輪１３の傾斜面である。いずれも円錐台形の側周面状であることや、軸受面１ａが円錐凹面であり、軸面２ａが円錐面（円錐凸面）となっていることは実施例１と同様である。本実施例では、外輪１１の内輪１２に対向していない面を除く円錐台形状の側周面状（円錐凹面）の部分が本発明の軸受面に該当し、軸受面に対向する内輪１２、端部用内輪１３の円錐台形状の側周面状（円錐凸面）の部分が軸面に該当する。したがって、図５では、軸受面１ａと軸面２ａの数はそれぞれ１０あることになるが、数を限定するものではなく、全体の寸法等に応じ増減が可能である。 As can be seen from FIG. 5 and FIG. 6, which is a three-dimensional schematic diagram, the bearing surface 1 a is an inclined surface of the outer ring 11, and the shaft surface 2 a is an inclined surface of the inner ring 12 and the end inner ring 13. As in the first embodiment, each of them has a frustoconical side surface shape, the bearing surface 1a is a conical concave surface, and the shaft surface 2a is a conical surface (conical convex surface). In this embodiment, the frustoconical side circumferential surface (conical concave surface) portion excluding the surface of the outer ring 11 that does not face the inner ring 12 corresponds to the bearing surface of the present invention, and the inner ring 12 that faces the bearing surface, A portion of the end-side inner ring 13 that has a truncated cone-shaped side circumferential surface (conical convex surface) corresponds to an axial surface. Therefore, in FIG. 5, the number of the bearing surfaces 1a and the shaft surfaces 2a is ten, but the number is not limited, and can be increased or decreased according to the overall dimensions and the like.

内輪１２は図６のように、大きさを無視するとそろばんの珠に似た形状であり、外輪１１は内輪１２を軸方向に２つ並べたときの空間を埋めるような形状となっている。なお、図５からわかるように端部用内輪１３は内輪１２を軸方向に半分にした形状であり、外径や傾斜面の角度等は内輪１２と同じである。図５、図６からわかるように、外輪１１のもっとも小さい部分、すなわち軸受面１ａの最小内径は、内輪１２、端部用内輪１３のもっとも大きな部分、すなわち軸面２ａの最大外形より小さいという関係になっている。このような構成により軸受面１ａ、軸面２ａの面積を大きくすることができ、単位面積当たりの荷重を小さくできるので、小型で大きな荷重に耐えられる軸受装置が得られる。 As shown in FIG. 6, the inner ring 12 has a shape similar to an abacus bead when the size is ignored, and the outer ring 11 has a shape that fills a space when two inner rings 12 are arranged in the axial direction. As can be seen from FIG. 5, the end inner ring 13 has a shape in which the inner ring 12 is halved in the axial direction, and the outer diameter and the angle of the inclined surface are the same as those of the inner ring 12. As can be seen from FIGS. 5 and 6, the smallest inner diameter of the outer ring 11, that is, the minimum inner diameter of the bearing surface 1a is smaller than the largest part of the inner ring 12 and the inner ring 13 for the end, that is, the maximum outer shape of the shaft surface 2a. It has become. With such a configuration, the areas of the bearing surface 1a and the shaft surface 2a can be increased, and the load per unit area can be reduced. Therefore, a bearing device that can withstand a large load can be obtained.

外輪１１、内輪１２はいずれも２つの傾斜面をもっており、端部用内輪１３は１つの傾斜面をもっている。本実施例では外輪１１、内輪１２、端部用内輪１３の傾斜面の角度を断面上、軸方向に対し４５度としたが、用途に応じて１０度から８０度の角度を適宜選択するのが好ましい。なお、本実施例では１つの外輪１１、内輪１２のもつ２つの傾斜面は互いに等しい角度としたが、対向する軸受面１ａと軸面２ａとが相等しい角度であれば、２つの傾斜面の角度は互いに異なっていてもよく、１０度から８０度の角度を適宜選択するものとする。 Both the outer ring 11 and the inner ring 12 have two inclined surfaces, and the end inner ring 13 has one inclined surface. In the present embodiment, the angles of the inclined surfaces of the outer ring 11, the inner ring 12, and the end inner ring 13 are set to 45 degrees with respect to the axial direction in the cross section, but an angle of 10 degrees to 80 degrees is appropriately selected depending on the application. Is preferred. In this embodiment, the two inclined surfaces of the outer ring 11 and the inner ring 12 have the same angle. However, if the bearing surface 1a and the shaft surface 2a facing each other have the same angle, The angles may be different from each other, and an angle of 10 to 80 degrees is appropriately selected.

組立方法の一例を述べる。まず固定用フランジ１４のついた軸３に端部用内輪１３を入れ、固定用フランジ１４に突き当てる。これを先端側になるようにハウジング１０に入れ、続いて外輪１１をハウジング１０の突き当て部まで入れる。つぎに内輪１２と外輪１１を後端側から所定数、交互に入れ、寸法調整用の内輪用カラー１５を入れ、次いでタービン８、内輪用カラー１５、外輪用カラー１６を入れ、再び外輪１１と内輪１２を所定数、交互にセットしていき、端部用内輪１３、固定用フランジ１４を入れロックナット９で軸３の端部に設けた不図示のねじ部で締結し固定する。外輪１１は固定リング１７をハウジング１０の端部に設けた不図示のねじ部で締結し固定する。それぞれの外輪１１同士、内輪１２同士は相互に突き当たることにより位置が決まる。 An example of an assembly method will be described. First, the end inner ring 13 is inserted into the shaft 3 with the fixing flange 14 and abuts against the fixing flange 14. This is placed in the housing 10 so as to be on the front end side, and then the outer ring 11 is inserted to the abutting portion of the housing 10. Next, a predetermined number of inner rings 12 and outer rings 11 are alternately inserted from the rear end side, an inner ring collar 15 for adjusting dimensions is inserted, then a turbine 8, an inner ring collar 15 and an outer ring collar 16 are inserted, and the outer ring 11 and again are inserted. A predetermined number of inner rings 12 are alternately set, and an inner ring 13 for an end and a fixing flange 14 are inserted and fastened with a screw nut (not shown) provided at the end of the shaft 3 with a lock nut 9 and fixed. The outer ring 11 is fixed by fastening the fixing ring 17 with a screw portion (not shown) provided at the end of the housing 10. The positions of the outer rings 11 and the inner rings 12 are determined by abutting each other.

つぎに動作の様子を述べる。まずサブノズル１８から圧縮空気を送ると、軸３が回転する。このサブノズル１８による回転は、図７からわかるように圧縮空気がタービン８の羽根に当たる角度が小さいことと、図５からわかるようにサブノズル１８がタービン８の幅方向の中央から離れた位置に配置されているため、タービン８の羽根を効率よく回転させるわけではなく、比較的ゆっくりした回転となる。この回転を予備回転と呼ぶ。この予備回転を確認することにより、軸受面１ａと軸面２ａが分離し流体軸受が形成されたことを確認することができる。次いでノズル６から圧縮空気を送ると、ノズル６は図５からわかるようにタービン８の幅方向中央部に配されていることと、図７からわかるように圧縮空気はタービン８の羽根に大きな角度で当たり、効率よくタービン８を回転させるため、予備回転の力に打ち勝って、タービン８は予備回転とは逆方向に回転し出す。この回転を主回転と呼ぶ。なお、図５ではノズル６とサブノズル１８は同位相の位置にあるように表わしたが、両ノズルの位相は図７のようにずれていてもよい。主回転が始まったのちサブノズル１８からの圧縮空気の供給は停止してよい。 Next, the operation will be described. First, when compressed air is sent from the sub nozzle 18, the shaft 3 rotates. The rotation by the sub-nozzles 18 is such that the angle at which the compressed air strikes the blades of the turbine 8 is small as can be seen from FIG. Therefore, the blades of the turbine 8 are not efficiently rotated, and the rotation is relatively slow. This rotation is called preliminary rotation. By confirming this preliminary rotation, it can be confirmed that the bearing surface 1a and the shaft surface 2a are separated to form a fluid bearing. Next, when the compressed air is sent from the nozzle 6, the nozzle 6 is arranged at the center in the width direction of the turbine 8 as can be seen from FIG. 5, and the compressed air has a large angle at the blades of the turbine 8 as can be seen from FIG. 7. In order to efficiently rotate the turbine 8, the power of the preliminary rotation is overcome and the turbine 8 starts to rotate in the direction opposite to the preliminary rotation. This rotation is called main rotation. In FIG. 5, the nozzle 6 and the sub nozzle 18 are shown to be in the same phase position, but the phases of both nozzles may be shifted as shown in FIG. After the main rotation starts, the supply of compressed air from the sub nozzle 18 may be stopped.

回転を停止するときは、ノズル６からの圧縮空気の供給を停止すると同時にサブノズル１８から圧縮空気を送るようにするか、または、サブノズル１８から圧縮空気を供給した後、ノズル６からの供給を停止する。圧縮空気が供給されなくなれば、外輪１１と内輪１２等とを非接触に保つことができなくなり、高速で回転していた場合には両者が焼き付いて破損し用をなさなくなってしまうことがあるが、サブノズル１８からの圧縮空気により、外輪１１と内輪１２等が接触することを防止できる。さらにサブノズル１８からの圧縮空気は、前述のようにノズル６からの圧縮空気による主回転とは逆方向に回転させるよう向きであるため、ブレーキとして作用し、停止に要する時間を短縮できる。このサブノズル１８による予備回転は、上記したようにゆっくりした回転なので、予備回転になってから圧縮空気を停止しても傷つきにくい。さらに、外輪１１や内輪１２、端部用内輪１３が金属製であれば、表面にめっきやＣＶＤ、電着塗装などで硬質の被膜や潤滑性のある被膜を設けるとよい。 When stopping the rotation, the supply of compressed air from the nozzle 6 is stopped, and at the same time, the compressed air is sent from the sub nozzle 18, or the compressed air is supplied from the sub nozzle 18 and then the supply from the nozzle 6 is stopped. To do. If the compressed air is not supplied, the outer ring 11 and the inner ring 12 cannot be kept in a non-contact state, and when rotating at a high speed, both of them may be seized and damaged. The outer ring 11 and the inner ring 12 can be prevented from coming into contact with the compressed air from the sub nozzle 18. Furthermore, since the compressed air from the sub nozzle 18 is directed to rotate in the direction opposite to the main rotation by the compressed air from the nozzle 6 as described above, it acts as a brake and the time required for stopping can be shortened. Since the preliminary rotation by the sub nozzle 18 is a slow rotation as described above, even if the compressed air is stopped after the preliminary rotation, it is not easily damaged. Furthermore, if the outer ring 11, the inner ring 12, and the end inner ring 13 are made of metal, a hard film or a lubricating film may be provided on the surface by plating, CVD, electrodeposition coating, or the like.

ノズル６、サブノズル１８は軸方向にわずかな傾きを持たせると排気がスムーズとなる。この場合先端側に傾くものと、後端側に傾くものの角度と数を等しくするとよい。 When the nozzle 6 and the sub nozzle 18 are slightly inclined in the axial direction, the exhaust becomes smooth. In this case, it is preferable that the angle and the number of the one inclined to the front end side and the one inclined to the rear end side are equal.

流体の供給源は特に限定しないが、本実施例の場合は圧縮空気を不図示のコンプレッサーで供給し、コンプレッサーとノズルの間にフィルター付きのレギュレータを配置しオイルミストを除去し、圧力の変動が小さくなるようにした。 The fluid supply source is not particularly limited, but in the case of this embodiment, compressed air is supplied by a compressor (not shown), a regulator with a filter is arranged between the compressor and the nozzle to remove oil mist, and the pressure fluctuation is reduced. I tried to make it smaller.

なお、被加工物が酸化を嫌うものである場合や、水蒸気による弊害が懸念される場合は、排気による影響を考えて、圧縮空気ではなく、窒素ガスなどの適切なガスを使用するものとする。 If the workpiece does not like oxidation or if there are concerns about the harmful effects of water vapor, use an appropriate gas such as nitrogen gas instead of compressed air in consideration of the effects of exhaust. .

以上のような回転駆動装置を適用した工作装置の一例を図１０に示した。コレットチャック２４に軸付きの砥石２５が装着され、内部にノズル６、サブノズル１８への配管（不図示）を施し後端側にサブノズル用配管２６とノズル用配管２７が接続されている。 An example of a machine tool to which the above rotary drive device is applied is shown in FIG. A grindstone 25 with a shaft is attached to the collet chuck 24, pipes (not shown) to the nozzle 6 and the sub nozzle 18 are provided inside, and a sub nozzle pipe 26 and a nozzle pipe 27 are connected to the rear end side.

別の実施例として図８に示すような、周知の動圧発生溝１９を設けた動圧発生用内輪２０や同様な動圧発生用端部用内輪２１を使い、回転駆動装置を構成してもよい。本実施例では、外輪１１の動圧発生用内輪２０に対向していない面を除く円錐台形状の側周面状（円錐凹面）の部分が本発明の軸受面に該当し、軸受面に対向する動圧発生用内輪２０、動圧発生用端部用内輪２１の円錐台形状の側周面状（円錐凸面）の部分が軸面に該当する。また、図８では内輪２０に動圧発生溝１９が設けられているが、動圧発生溝は内輪または外輪の少なくともいずれか一方に設けることとする。これらの場合、切断端面図である図９に示すように、ハウジング１０に適切に設けたタービン用排気口２３から圧縮空気を排出するようにし、圧縮空気が軸受面１ａや軸面２ａの動圧に影響を与えないようにする。 As another embodiment, as shown in FIG. 8, a dynamic pressure generating inner ring 20 provided with a known dynamic pressure generating groove 19 or a similar inner ring 21 for generating dynamic pressure is used to constitute a rotary drive device. Also good. In the present embodiment, the frustoconical side circumferential surface (conical concave surface) portion of the outer ring 11 excluding the surface not facing the dynamic pressure generating inner ring 20 corresponds to the bearing surface of the present invention and faces the bearing surface. The portions of the frustoconical side circumferential surface (conical convex surface) of the inner ring 20 for generating dynamic pressure and the inner ring 21 for generating dynamic pressure correspond to the shaft surface. Further, in FIG. 8, the dynamic pressure generating groove 19 is provided in the inner ring 20, but the dynamic pressure generating groove is provided in at least one of the inner ring and the outer ring. In these cases, as shown in FIG. 9 which is a cut end view, the compressed air is discharged from the turbine exhaust port 23 appropriately provided in the housing 10, and the compressed air is subjected to dynamic pressure on the bearing surface 1a and the shaft surface 2a. Do not affect.

タービン８の駆動には圧縮空気を使うが、この圧縮空気は軸受部には使われない。すなわち、タービン８により軸部材２に回転が生じ、軸受面１ａと軸面２ａとの相対的運動によって軸面に設けられた動圧発生溝１９により空気に発生する圧力で軸受面１ａと軸面２ａを分離する。流体としてオイルを使う場合には、別途オイル漏れ防止の方策を採るものとする。このときタービン８の駆動に圧縮空気を使い、軸受の流体としてオイルを使うことができる。圧縮空気が軸受部に使われないため、低圧でも高回転が得られる。 Compressed air is used to drive the turbine 8, but this compressed air is not used for the bearing portion. That is, the shaft member 2 is rotated by the turbine 8, and the bearing surface 1a and the shaft surface are generated by the pressure generated in the air by the dynamic pressure generating groove 19 provided in the shaft surface by the relative movement between the bearing surface 1a and the shaft surface 2a. Separate 2a. When oil is used as the fluid, measures to prevent oil leakage shall be taken separately. At this time, compressed air can be used to drive the turbine 8 and oil can be used as a bearing fluid. Since compressed air is not used for the bearing, high rotation can be obtained even at low pressure.

各実施例の本発明の流体軸受を利用する場合、上記ハウジング１０または軸孔部材１をさらに外装用円筒に収め、先端側に砥石や刃等の工具を固定するためのコレットチャック等を設けたり、配管等を固定したりするようにするとよい。また、各実施例では先端側、後端側に排気するようにしたが、対象によっては、排気がかからないように適宜排出路を設けるものとする。 When the hydrodynamic bearing of the present invention of each embodiment is used, the housing 10 or the shaft hole member 1 is further housed in an exterior cylinder, and a collet chuck or the like for fixing a tool such as a grindstone or a blade is provided on the tip side. It is better to fix the pipes. In each embodiment, exhaust is performed to the front end side and the rear end side. However, depending on the target, a discharge path is appropriately provided so that exhaust is not performed.

１軸孔部材
１ａ斜面、軸受面
２軸部材
２ａ軸面
３軸
４第１フランジ
５第２フランジ
６ノズル
７排出口
８タービン
９ロックナット
１０ハウジング
１１外輪
１２内輪
１３端部用内輪
１４固定用フランジ
１５内輪用カラー
１６外輪用カラー
１７固定リング
１８サブノズル
１９動圧発生溝
２０動圧発生用内輪
２１動圧発生用端部用内輪
２２カラー
２３タービン用排気口
２４コレットチャック
２５砥石
２６サブノズル用配管
２７ノズル用配管 DESCRIPTION OF SYMBOLS 1 Shaft hole member 1a Slope, bearing surface 2 Shaft member 2a Shaft surface 3 Shaft 4 1st flange 5 2nd flange 6 Nozzle 7 Outlet 8 Turbine 9 Lock nut 10 Housing 11 Outer ring 12 Inner ring 13 End part inner ring 14 Fixing flange 15 inner ring collar 16 outer ring collar 17 fixing ring 18 sub nozzle 19 dynamic pressure generating groove 20 dynamic pressure generating inner ring 21 inner ring for dynamic pressure generating end 22 collar 23 turbine exhaust port 24 collet chuck 25 grindstone 26 sub nozzle piping 27 Nozzle piping

Claims

軸孔を区画する内周面に軸方向に所定幅の軸受面を持つ軸孔部材と、
該軸孔に回動自在に保持され該軸受面に対向する軸面をもつ軸部材と、
該軸受面と該軸面の間に流体を供給する流体供給手段と、
を有する流体軸受装置であって、
前記軸受面及び前記軸面はいずれも円錐台形の側周面状であり、かつ前記流体供給手段は該軸受面及び該軸面の間に軸方向に流体を供給するものであることを特徴とする流体軸受装置。 A shaft hole member having a bearing surface of a predetermined width in the axial direction on the inner peripheral surface defining the shaft hole;
A shaft member rotatably held in the shaft hole and having a shaft surface facing the bearing surface;
Fluid supply means for supplying fluid between the bearing surface and the shaft surface;
A hydrodynamic bearing device comprising:
Both the bearing surface and the shaft surface are frustoconical side surfaces, and the fluid supply means supplies fluid in the axial direction between the bearing surface and the shaft surface. Fluid bearing device.

前記軸孔部材は、円錐の頂点方向が互いに逆方向となる２個１組の少なくとも１組の前記軸受面を有し、
前記軸部材は、前記１組の前期軸受面とそれぞれ対向する、少なくとも１組の前記軸面を有する請求項１記載の流体軸受装置。 The shaft hole member has at least one set of the bearing surfaces in a set of two in which the apex directions of the cones are opposite to each other.
2. The hydrodynamic bearing device according to claim 1, wherein the shaft member has at least one set of the shaft surfaces respectively opposed to the one set of the preceding bearing surfaces.

前記流体はガスである請求項１または２に記載の流体軸受装置。 The hydrodynamic bearing device according to claim 1, wherein the fluid is a gas.

前記ガスは空気である請求項３に記載の流体軸受装置。 The hydrodynamic bearing device according to claim 3, wherein the gas is air.

前記軸受面とこれに対向する前記軸面とが、軸方向の断面上において前記軸部材の軸方向に対しなす角度は相等しい請求項１から４のいずれか１項に記載の流体軸受装置。 5. The hydrodynamic bearing device according to claim 1, wherein the bearing surface and the shaft surface facing the shaft surface have the same angle with respect to the axial direction of the shaft member on an axial cross section.

前記軸受面の最小内径は、前記軸面の最大外径より小さい請求項１から５のいずれか１項に記載の流体軸受装置。 The hydrodynamic bearing device according to claim 1, wherein a minimum inner diameter of the bearing surface is smaller than a maximum outer diameter of the shaft surface.

前記軸受面と前記軸面は、軸方向にそれぞれ少なくとも４つ存在する請求項１から６のいずれか１項に記載の流体軸受装置。 The hydrodynamic bearing device according to claim 1, wherein there are at least four of the bearing surface and the shaft surface in the axial direction.

軸孔を区画する内周面に軸方向に所定幅の軸受面を持つ軸孔部材と、
該軸孔に回動自在に保持され該軸受面に対向する軸面をもつ軸部材と、
該軸受面と該軸面の間に流体を供給する流体供給手段とを有し、
前記軸受面及び前記軸面はいずれも円錐台形の側周面状であり、かつ前記流体供給手段は該軸受面及び該軸面の間に軸方向に流体を供給する流体軸受装置と、
前記軸部材に同軸上に形成された流体により駆動されるタービンと前記軸孔部材に形成された該タービンに向けて流体を噴出するノズル口とを持つ駆動部と、
を有することを特徴とする回転駆動装置。 A shaft hole member having a bearing surface of a predetermined width in the axial direction on the inner peripheral surface defining the shaft hole;
A shaft member rotatably held in the shaft hole and having a shaft surface facing the bearing surface;
Fluid supply means for supplying fluid between the bearing surface and the shaft surface;
The bearing surface and the shaft surface are both frustoconical side surfaces, and the fluid supply means supplies a fluid in the axial direction between the bearing surface and the shaft surface;
A drive unit having a turbine driven by a fluid coaxially formed in the shaft member and a nozzle port for ejecting fluid toward the turbine formed in the shaft hole member;
A rotary drive device comprising: