JP2001012469A - Static pressure fluid bearing - Google Patents
Static pressure fluid bearingInfo
- Publication number
- JP2001012469A JP2001012469A JP17898199A JP17898199A JP2001012469A JP 2001012469 A JP2001012469 A JP 2001012469A JP 17898199 A JP17898199 A JP 17898199A JP 17898199 A JP17898199 A JP 17898199A JP 2001012469 A JP2001012469 A JP 2001012469A
- Authority
- JP
- Japan
- Prior art keywords
- guide surface
- fluid
- exhaust
- air supply
- exhaust groove
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
- F16C33/72—Sealings
- F16C33/74—Sealings of sliding-contact bearings
- F16C33/741—Sealings of sliding-contact bearings by means of a fluid
- F16C33/748—Sealings of sliding-contact bearings by means of a fluid flowing to or from the sealing gap, e.g. vacuum seals with differential exhaust
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C29/00—Bearings for parts moving only linearly
- F16C29/02—Sliding-contact bearings
- F16C29/025—Hydrostatic or aerostatic
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0603—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion
- F16C32/0614—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C2300/00—Application independent of particular apparatuses
- F16C2300/40—Application independent of particular apparatuses related to environment, i.e. operating conditions
- F16C2300/62—Application independent of particular apparatuses related to environment, i.e. operating conditions low pressure, e.g. elements operating under vacuum conditions
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Magnetic Bearings And Hydrostatic Bearings (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、２つの部材間に圧
縮流体を噴出して静圧流体層を形成するとともに、２つ
の部材間に供給された圧縮流体を回収し、外部へ漏洩さ
せることなく駆動させることが可能な回転運動や直線運
動に用いる静圧流体軸受に関するものであり、特に真空
中、その中でも１×１０-5Ｔｏｒｒ以上の超高真空中で
も使用可能な真空対応型の静圧流体軸受として好適なも
のである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of spraying a compressed fluid between two members to form a hydrostatic fluid layer, and recovering the compressed fluid supplied between the two members to leak the fluid to the outside. The present invention relates to a hydrostatic bearing used for rotary motion and linear motion that can be driven without any problem, and in particular, a vacuum-compatible static pressure that can be used in a vacuum, especially in an ultra-high vacuum of 1 × 10 −5 Torr or more. It is suitable as a fluid bearing.
【０００２】[0002]
【従来の技術】従来、滑らかな回転運動や直線運動をさ
せる手段として静圧流体軸受が用いられている。静圧流
体軸受は、固定部材と可動部材との微少隙間に圧縮流体
を噴出して静圧流体層を形成することにより、可動部材
を固定部材上に静圧支持するようになっており、２つの
部材同士が直接接触しないことから摩擦抵抗が極めて小
さく、可動部材を滑らかに回転運動や直線運動させるこ
とができるようになっている。2. Description of the Related Art Conventionally, hydrostatic bearings have been used as means for performing smooth rotational movement and linear movement. The hydrostatic fluid bearing supports the movable member on the fixed member by static pressure by ejecting a compressed fluid into a minute gap between the fixed member and the movable member to form a hydrostatic fluid layer. Since the two members do not directly contact each other, the frictional resistance is extremely small, and the movable member can be smoothly rotated or linearly moved.
【０００３】ところで、可動部材を固定部材上に静圧支
持するには、２つの部材間に供給された圧縮流体を外部
へ漏洩させる必要があるが、真空雰囲気下ではそのまま
使用することができず、本件出願人は例えば図９（ａ）
（ｂ）に示すような静圧流体軸受を先に提案している
（特公平８−１２１５号公報参照）。In order to support the movable member on the fixed member by static pressure, it is necessary to leak the compressed fluid supplied between the two members to the outside, but cannot be used as it is in a vacuum atmosphere. The applicant of the present application is, for example, as shown in FIG.
A hydrostatic bearing as shown in FIG. 1B has been proposed (see Japanese Patent Publication No. 8-1215).
【０００４】この静圧流体軸受は、両端が支持板２３，
２４により固定された柱状体であって、その外壁を第１
ガイド面２２とする第１部材２１と、該第１部材２１を
囲繞する筒状体であって、その内壁を第２ガイド面３２
とする第２部材３１とから成り、第２ガイド面３２に
は、ポケット３３と該ポケット３３と連通し、第１ガイ
ド面２２に向けて空気等の圧縮流体を噴出する給気孔３
４を有し、該給気孔３４から圧縮気体を噴出させ、ポケ
ット３３によって拡散させることで、第１ガイド面２２
との微少な隙間Ｓに静圧流体層を形成し、第２部材３１
を第１部材２１上に静圧支持するようになっていた。ま
た、第２部材３１と各支持板２３，２４との間には、第
１部材２１の外周を覆うように収縮性を持った、例えば
ネオプレンゴム等の如き外囲体２５，２６を気密に取着
してあり、第１部材２１と第２部材３１との隙間Ｓより
漏洩する流体を各支持板２３，２４に穿孔した排気孔２
３ａ，２４ａより真空雰囲気外へ放出することで真空環
境を維持するようになっていた。This hydrostatic bearing has a support plate 23 at both ends.
24, the outer wall of which is the first columnar body.
A first member 21 serving as a guide surface 22, and a cylindrical body surrounding the first member 21, the inner wall of which is a second guide surface 32
The second guide surface 32 has a pocket 33 and an air supply hole 3 which communicates with the pocket 33 and ejects a compressed fluid such as air toward the first guide surface 22.
4, the compressed gas is ejected from the air supply hole 34 and diffused by the pocket 33 so that the first guide surface 22
A static pressure fluid layer is formed in a small gap S between the second member 31
Is supported on the first member 21 by static pressure. Further, between the second member 31 and each of the support plates 23 and 24, an outer envelope 25, 26 made of, for example, neoprene rubber or the like having a contractive property so as to cover the outer periphery of the first member 21 is hermetically sealed. Exhaust holes 2 attached to each support plate 23, 24 to allow fluid leaking from the gap S between the first member 21 and the second member 31
The vacuum environment is maintained by releasing the gas from outside the vacuum atmosphere from 3a and 24a.
【０００５】そして、第２部材３１を移動させるには、
第１部材２１と平行に設置されたネジ軸４２に螺合する
ナット４３を第２部材３１と連結させ、モータ４４によ
ってネジ軸４２を回転させてナット４３を軸方向に移動
させることで、第２部材３１を第１部材２１に沿って移
動させるようになっていた。[0005] Then, in order to move the second member 31,
The nut 43 screwed to the screw shaft 42 installed in parallel with the first member 21 is connected to the second member 31, and the motor 44 rotates the screw shaft 42 to move the nut 43 in the axial direction. The two members 31 are moved along the first member 21.
【０００６】なお、第２部材３１を移動させる手段とし
ては、ボールネジ４１を介してのモータ４４駆動以外
に、ベルトを介してのモータ駆動や第２部材３１をエア
シリンダやリニアモータによって直接駆動させることも
行われていた。As means for moving the second member 31, besides driving the motor 44 via the ball screw 41, motor driving via a belt or direct driving of the second member 31 by an air cylinder or a linear motor. That was also done.
【０００７】[0007]
【発明が解決しようとする課題】ところが、図９（ａ）
（ｂ）に示す静圧流体軸受を真空雰囲気下で使用できる
のは、真空度が１０-3Ｔｏｒｒ程度までであり、これ以
上の真空環境では、外囲体２５，２６の内部圧力と外部
圧力との圧力差が大きくなりすぎて外囲体２５，２６が
急激に膨張し、延いては破損に至るため、１×１０-3Ｔ
ｏｒｒを越える真空環境下では用いることができなかっ
た。However, FIG. 9 (a)
The hydrostatic bearing shown in (b) can be used in a vacuum atmosphere only when the degree of vacuum is up to about 10 −3 Torr. Is too large, the outer enclosures 25, 26 expand rapidly and eventually break, resulting in 1 × 10 −3 T
It could not be used in a vacuum environment exceeding orr.
【０００８】また、１×１０-3Ｔｏｒｒ以下の真空環境
下であっても、第２部材３１の移動に伴って収縮する外
囲体２５，２６の動きが抵抗となって第２部材３１の移
動が阻害されるため、第２部材３１の持つ滑らかな運動
性能が損なわれるといった課題もあった。Further, even in a vacuum environment of 1 × 10 −3 Torr or less, the movement of the outer enclosures 25 and 26 which contracts with the movement of the second member 31 becomes a resistance and the second member 31 There is also a problem that the smooth movement performance of the second member 31 is impaired because the movement is hindered.
【０００９】そこで、第２部材３１の滑らかな運動性能
を阻害する外囲体２５，２６を用いることなく、真空環
境下で使用可能な静圧流体軸受として、図１０（ａ）
（ｂ）に示すものが提案されている（特開昭６３−１９
２８６４号公報参照）。Therefore, as a hydrostatic bearing which can be used in a vacuum environment without using the outer enclosures 25 and 26 which impede the smooth movement performance of the second member 31, FIG.
(B) has been proposed (JP-A-63-19).
No. 2864).
【００１０】この静圧流体軸受は、円柱状体であって、
その外壁を第１ガイド面５２とする第１部材５１と、該
第１部材５１を囲繞する円筒体であって、その内壁を第
２ガイド面６２とする第２部材６１とから成り、第２ガ
イド面６２には、その中央で周方向に沿って形成された
ポケット６３と、該ポケット６３に連通し、第１ガイド
面５２へ向けて圧縮流体を噴出する給気孔６４と、前記
ポケット６３を挟んで両側に周方向に沿ってそれぞれ形
成された三重の排気溝６５，６６，６７と、各排気溝６
５，６６，６７とそれぞれ連通し、第１ガイド面５２と
第２ガイド面６２との微少な隙間Ｒより漏洩する気体を
強制的に排気する吸引孔６８，６９，７０を備えたもの
があった。そして、各排気溝６５，６６，６７の内壁
は、第２ガイド面６２に対してそれぞれ垂直に形成され
ていた。[0010] The hydrostatic bearing is a cylindrical body,
The first member 51 has an outer wall as a first guide surface 52 and a second member 61 which is a cylindrical body surrounding the first member 51 and has an inner wall as a second guide surface 62. The guide surface 62 has a pocket 63 formed at the center thereof along the circumferential direction, an air supply hole 64 communicating with the pocket 63 and ejecting a compressed fluid toward the first guide surface 52, and the pocket 63. Triple exhaust grooves 65, 66, 67 formed on each side of the exhaust groove along the circumferential direction;
5, 66, 67 respectively, and has suction holes 68, 69, 70 for forcibly exhausting gas leaking from a small gap R between the first guide surface 52 and the second guide surface 62. Was. The inner walls of the exhaust grooves 65, 66, and 67 were formed perpendicular to the second guide surface 62, respectively.
【００１１】なお、各吸引孔６８，６９，７０は、ホー
ス７１，７２，７３を介して不図示の吸引ポンプにより
真空吸引されるようになっており、また、給気孔６４
は、ホース７４を介して不図示の圧縮ポンプから圧縮流
体が供給されるようになっていた。Each of the suction holes 68, 69, 70 is designed to be vacuum-suctioned by a suction pump (not shown) via hoses 71, 72, 73, and the air supply holes 64 are provided.
The compressed fluid is supplied from a compression pump (not shown) via a hose 74.
【００１２】そして、この静圧流体軸受を作動させるに
は、第２部材６１の給気孔６４より圧縮気体を噴出さ
せ、ポケット６３で拡散させることにより、第１ガイド
面５２との微少な隙間Ｒに静圧流体層を形成し、第２部
材６１を第１部材５１上に静圧支持するとともに、第１
ガイド面５２と第２ガイド面６２との微少な隙間Ｒより
漏洩する流体を第１の排気溝６５、第２の排気溝６６、
第３の排気溝６７によって順次強制的に排気すること
で、外部（真空中）へ流体が漏洩することを防ぎ、真空
環境を維持するようになっていた。In order to operate the hydrostatic bearing, compressed gas is ejected from the air supply hole 64 of the second member 61 and diffused in the pocket 63, thereby forming a small gap R with the first guide surface 52. A static pressure fluid layer is formed on the first member 51, and the second member 61 is supported on the first member 51 by static pressure.
The fluid leaking from the minute gap R between the guide surface 52 and the second guide surface 62 is supplied to the first exhaust groove 65, the second exhaust groove 66,
By forcibly exhausting the gas sequentially through the third exhaust groove 67, the fluid is prevented from leaking to the outside (in vacuum), and the vacuum environment is maintained.
【００１３】ところが、図１０（ａ）（ｂ）に示す静圧
流体軸受でも真空度を低下させることなく作動させるこ
とができるのは、せいぜい１０-4Ｔｏｒｒ台〜１０-5Ｔ
ｏｒｒ台までであり、近年、半導体製造工程等で要求さ
れている１×１０-5Ｔｏｒｒを越える１０-6Ｔｏｒｒ
台、あるいはそれ以上の超高真空環境下では使用するこ
とができなかった。However, the hydrostatic bearing shown in FIGS. 10A and 10B can be operated without lowering the degree of vacuum at most on the order of 10 -4 Torr to 10 -5 T.
Torr level, and 10 -6 Torr exceeding 1 × 10 -5 Torr recently required in semiconductor manufacturing processes and the like.
It could not be used in a table or an ultra-high vacuum environment.
【００１４】また、図１０（ａ）（ｂ）に示す静圧流体
軸受は、その軸受剛性を維持するために必要な静圧領域
を確保したうえで、第１ガイド面５２と第２ガイド面６
２の微少な隙間Ｒから気体が漏洩することを防ぎ、作動
可能な前記真空環境を維持するためには、第２ガイド面
６２の両端に少なくとも低真空用、中真空用、高真空用
の３つの排気溝６５，６６，６７を必要とし、軸受剛性
を維持したまま第２部材６１を小型化することが難し
く、また、排気溝６５，６６，６７の数に合わせて３つ
の吸引ポンプ７１，７２，７３が必要となることから、
部品点数が多く構造が複雑となり、さらには各吸引ポン
プ７１，７２，７３と接続するホース７４，７５，７６
の数が多くなるため、第２部材６１が第１部材５１上を
直線運動するような場合、移動に伴うホース７４，７
５，７６の屈曲が抵抗となって第２部材６１の滑らかな
直線運動が阻害される恐れもあった。Further, in the hydrostatic bearing shown in FIGS. 10A and 10B, a first guide surface 52 and a second guide surface are provided after securing a static pressure region necessary for maintaining the bearing rigidity. 6
In order to prevent the gas from leaking from the small gap R and maintain the operable vacuum environment, at least both low-, medium-, and high-vacuum It requires two exhaust grooves 65, 66, 67, making it difficult to reduce the size of the second member 61 while maintaining the rigidity of the bearing. Since 72 and 73 are required,
The number of parts is large, the structure is complicated, and the hoses 74, 75, 76 connected to the suction pumps 71, 72, 73 are further provided.
When the second member 61 moves linearly on the first member 51, the hoses 74, 7 associated with the movement are increased.
There is also a risk that the bending of 5, 76 may cause resistance and hinder the smooth linear movement of the second member 61.
【００１５】[0015]
【課題を解決するための手段】そこで、本発明者は前記
課題に鑑み、排気溝を減らし、二重の排気溝でも１×１
０-5Ｔｏｒｒ以上の超高真空環境下で作動させることが
可能な静圧流体軸受について鋭意研究を重ねたところ、
少なくとも給気孔に近い排気溝の内壁を、開口部から外
側へ広がるように、ある角度をもって傾斜させることに
より、排気溝からの排気効率を格段に向上させることが
でき、もって二重の排気溝でも１×１０-5Ｔｏｒｒ以上
の超高真空環境下でも十分に作動し得ることを見出し、
本発明に至った。In view of the above-mentioned problems, the present inventor has reduced the number of exhaust grooves and has reduced the number of exhaust grooves to 1 × 1 even with double exhaust grooves.
After extensive research on hydrostatic bearings capable of operating in an ultra-high vacuum environment of 0 -5 Torr or higher,
At least the inner wall of the exhaust groove close to the air supply hole is inclined at an angle so as to spread outward from the opening, so that the exhaust efficiency from the exhaust groove can be remarkably improved. It has been found that it can operate sufficiently even in an ultra-high vacuum environment of 1 × 10 −5 Torr or more,
The present invention has been reached.
【００１６】即ち、本発明の静圧流体軸受は、第１ガイ
ド面を有する第１部材と、前記第１ガイド面に対し隙間
を設けて対向する第２ガイド面を有する第２部材とから
成り、前記第１ガイド面又は第２ガイド面には、前記隙
間に圧縮流体を噴出して静圧流体層を形成する給気孔
と、該給気孔の周囲に刻設され、前記圧縮流体を回収す
る二重の排気溝を備えるとともに、少なくとも内側に位
置する排気溝の内壁を、前記第１ガイド面又は第２ガイ
ド面に対して４０度〜６５度の範囲で外側に傾斜させた
ことを特徴とする。That is, the hydrostatic bearing of the present invention comprises a first member having a first guide surface, and a second member having a second guide surface opposed to the first guide surface with a gap provided therebetween. The first guide surface or the second guide surface has an air supply hole for ejecting a compressed fluid into the gap to form a hydrostatic fluid layer, and is engraved around the air supply hole to collect the compressed fluid. A double exhaust groove is provided, and at least an inner wall of the exhaust groove located inside is inclined outward in a range of 40 to 65 degrees with respect to the first guide surface or the second guide surface. I do.
【００１７】[0017]
【発明の実施の形態】以下、本発明の実施形態について
説明する。Embodiments of the present invention will be described below.
【００１８】図１は本発明の静圧流体軸受の一例を示す
斜視図、図２は図１のＸ−Ｘ線における主要部のみを示
す断面図、図３は図１の第２部材のみを示す一部を破断
した斜視図である。FIG. 1 is a perspective view showing an example of a hydrostatic bearing of the present invention, FIG. 2 is a cross-sectional view showing only a main part taken along line XX of FIG. 1, and FIG. 3 is a view showing only a second member of FIG. It is the perspective view which fractured | shown one part.
【００１９】この静圧流体軸受は、両端が支持板１３，
１４により固定された柱状体であって、その外壁を第１
ガイド面２とする第１部材１と、該第１部材１を囲繞す
る筒状体であって、その内壁を第２ガイド面４とする第
２部材３とから成り、第２ガイド面４には、ポケット５
と該ポケット５と連通し、第１ガイド面２に向けて空気
などの圧縮流体を噴出する給気孔６を有し、該給気孔６
から圧縮流体を噴出させ、ポケット５によって拡散させ
ることで、第１ガイド面２との微少な隙間Ｔに静圧流体
層を形成し、第２部材３を第１部材１上に静圧支持する
ようになっている。This hydrostatic bearing has a support plate 13 at both ends.
14 is a columnar body, the outer wall of which is the first
A first member 1 serving as a guide surface 2 and a second member 3 which is a tubular body surrounding the first member 1 and has an inner wall serving as a second guide surface 4 are provided. Is pocket 5
And an air supply hole 6 which communicates with the pocket 5 and ejects a compressed fluid such as air toward the first guide surface 2.
A static fluid layer is formed in a small gap T with the first guide surface 2 by spraying a compressed fluid from the first member 5 and diffusing the compressed fluid by the pocket 5, and the second member 3 is statically supported on the first member 1. It has become.
【００２０】また、第２ガイド面４には、前記ポケット
５（あるいは給気孔６）の周囲に刻設され、第１ガイド
面２との隙間Ｔに噴出された圧縮流体を回収する二重の
排気溝７，８を備え、内側に位置する排気孔７、即ち給
気孔６に近い排気溝７の内壁を、第２ガイド面４に対し
て４０度〜６５度の角度αで開口部から外側へ広がるよ
うに傾斜させるとともに、外側に位置する排気孔８、即
ち給気孔６より遠い排気溝８の内壁を、第２ガイド面４
に対して垂直に形成してある。The second guide surface 4 is provided with a double engraving formed around the pocket 5 (or the air supply hole 6) for recovering the compressed fluid injected into the gap T with the first guide surface 2. An exhaust hole 7, 8 is provided, and the inner wall of the exhaust hole 7 located inside, that is, the exhaust groove 7 close to the air supply hole 6, is disposed outside from the opening at an angle α of 40 to 65 degrees with respect to the second guide surface 4. And the inner wall of the exhaust groove 8 located outside, that is, the exhaust groove 8 farther from the air supply hole 6, is inclined toward the second guide surface 4.
Are formed perpendicular to.
【００２１】なお、第２部材３の内部には、各第２ガイ
ド面４に形成された給気孔６と連通する給気通路２１、
及び各第２ガイド面４に形成された排気溝７，８と連通
する吸引通路２２，２３を設けてあり、給気通路２１は
ホース２４を介して圧縮ポンプ１０と、各吸引通路２
２，２３はホース２５，２６を介して吸引ポンプ１１，
１２とそれぞれ接続してある。The inside of the second member 3 is provided with an air supply passage 21 communicating with the air supply hole 6 formed in each of the second guide surfaces 4.
And suction passages 22 and 23 communicating with the exhaust grooves 7 and 8 formed in the second guide surfaces 4. The air supply passage 21 is connected to the compression pump 10 via a hose 24 and the suction passages 2.
2, 23 are suction pumps 11 through hoses 25, 26,
12 respectively.
【００２２】また、この静圧流体軸受には、第１部材１
と平行にボールネジ１６のネジ軸１７を設置してあり、
該ネジ軸１７に螺合するナット１８を連結部材１９を介
して第２部材３と連結するとともに、ネジ軸１７の一端
にはモータ２０を連結してある。The hydrostatic bearing includes a first member 1
The screw shaft 17 of the ball screw 16 is installed in parallel with
A nut 18 screwed to the screw shaft 17 is connected to the second member 3 via a connecting member 19, and a motor 20 is connected to one end of the screw shaft 17.
【００２３】なお、図１では第２部材３を移動させる手
段として、ボールネジ１６を介したモータ２０による駆
動手段を示したが、ベルトを介してのモータ駆動や第２
部材３をエアシリンダやリニアモータによって直接駆動
させるようにしても良い。In FIG. 1, the driving means by the motor 20 via the ball screw 16 is shown as the means for moving the second member 3, but the motor driving via the belt or the second
The member 3 may be directly driven by an air cylinder or a linear motor.
【００２４】そして、この静圧流体軸受を用いて第２部
材３を移動させるには、まず、給気孔６より空気などの
圧縮流体を第１ガイド面２に向けて噴出する。この時、
ポケット５によって圧縮流体は拡散され、第１ガイド面
２との隙間Ｔに静圧流体層を形成して第２部材３を第１
部材１上に静圧支持する。そして、モータ２０によって
ネジ軸１７を回転させながらナット１８を軸方向に移動
させることにより、第２部材３は第１部材１と非接触で
あることから、この間での摺動抵抗は皆無であり、第２
部材３を第１部材１に沿って滑らかに移動させることが
できる。In order to move the second member 3 using this hydrostatic bearing, first, a compressed fluid such as air is jetted from the air supply hole 6 toward the first guide surface 2. At this time,
The compressed fluid is diffused by the pockets 5, and a static pressure fluid layer is formed in the gap T between the first guide surface 2 and the second member 3.
It is supported on the member 1 by static pressure. By moving the nut 18 in the axial direction while rotating the screw shaft 17 by the motor 20, the second member 3 is not in contact with the first member 1, so that there is no sliding resistance between them. , Second
The member 3 can be moved smoothly along the first member 1.
【００２５】また、第１ガイド面２と第２ガイド面４と
の隙間Ｔに供給された圧縮流体は、給気孔６の周囲に形
成された二重の排気溝７，８より吸引ポンプ１４，１５
によって回収し、第１ガイド面２と第２ガイド面４との
隙間Ｔより流体が漏れることを防止するのであるが、本
発明によれば、少なくとも内側に位置する排気溝７の内
壁を、第２ガイド面４に対して４０度〜６５度の角度α
で傾斜させてあるから、排気溝７により大部分の流体を
回収し、残存する流体を外側の排気溝８によって回収す
ることにより、第１ガイド面２と第２ガイド面４との隙
間Ｔより漏洩する流体量を極めて少なくすることができ
るため、１×１０-5Ｔｏｒｒを越える超高真空環境下で
もその真空度を低下させることなく作動させることがで
きる。The compressed fluid supplied to the gap T between the first guide surface 2 and the second guide surface 4 is supplied to the suction pump 14 by the double exhaust grooves 7 and 8 formed around the air supply hole 6. Fifteen
According to the present invention, at least the inner wall of the exhaust groove 7 located on the inner side is prevented from leaking through the gap T between the first guide surface 2 and the second guide surface 4. Angle α of 40 ° to 65 ° with respect to 2 guide surface 4
, The most part of the fluid is collected by the exhaust groove 7, and the remaining fluid is collected by the outer exhaust groove 8, so that the fluid can be removed from the gap T between the first guide surface 2 and the second guide surface 4. Since the amount of leaking fluid can be extremely reduced, it can be operated without reducing the degree of vacuum even in an ultra-high vacuum environment exceeding 1 × 10 −5 Torr.
【００２６】しかも、第１ガイド面２と第２ガイド面４
との隙間Ｔに噴出された流体の回収は、二重の排気溝
７，８によって達成することがきるため、三重の排気溝
を有する従来の静圧流体軸受と比較して、第２部材３を
小型化することができるとともに、第２部材３の重量を
小さくできるため、第２部材３を静圧支持するために給
気孔６より噴出させる圧縮流体量を少なくでき、経済的
である。Moreover, the first guide surface 2 and the second guide surface 4
The recovery of the fluid ejected into the gap T between the second member 3 and the second member 3 can be achieved by the double exhaust grooves 7 and 8 as compared with a conventional hydrostatic bearing having triple exhaust grooves. And the weight of the second member 3 can be reduced, so that the amount of compressed fluid ejected from the air supply holes 6 to support the second member 3 under static pressure can be reduced, which is economical.
【００２７】その上、二重の排気溝７，８としたことに
より、吸引ポンプ１１，１２も２つで済むため、構造を
簡略化できるとともに、各排気溝７，８と連通する吸引
通路２２，２３と吸引ポンプ１１，１２とをそれぞれ接
続するホース２５，２６の数を２本にできるため、第２
部材３の移動に伴うホース２５，２６の屈曲による抵抗
を低減することができ、滑らかな第２部材３の移動が阻
害されるのを抑制することができる。In addition, since the two exhaust grooves 7, 8 are used, only two suction pumps 11, 12 are required, so that the structure can be simplified and the suction passage 22 communicating with each of the exhaust grooves 7, 8 can be obtained. , 23 and the suction pumps 11, 12 can be reduced to two hoses 25, 26, respectively.
The resistance due to the bending of the hoses 25 and 26 accompanying the movement of the member 3 can be reduced, and the smooth movement of the second member 3 can be prevented from being hindered.
【００２８】ところで、このような効果を奏するために
は、前述したように、二重の排気溝７，８のうち、少な
くとも内側に位置する排気孔７の内壁を、第２ガイド面
４に対して４０〜６５度の角度αで開口部から外側へ広
がるように傾斜させることが重要である。By the way, in order to obtain such an effect, as described above, at least the inner wall of the exhaust hole 7 located inside of the double exhaust grooves 7 and 8 is It is important to incline so as to extend outward from the opening at an angle α of 40 to 65 degrees.
【００２９】即ち、第１ガイド面２と第２ガイド面４と
の隙間Ｔに噴出された圧縮流体を効率良く回収するため
には、排気溝７の内壁をできるだけ傾斜させた方が良い
のであるが、第２ガイド面４に対する角度αが４０度未
満では、これ以上傾斜させても流体の回収効率を高める
ことができず、しかも、三重の排気溝を有する従来の静
圧流体軸受と比較して第２部材３を小型化することがで
きないからであり、逆に、第２ガイド面４に対する角度
αが６５度を越えると、流体の回収効率が悪く、二重の
排気溝７，８では隙間Ｔから漏洩する流体量が多くなり
すぎるために、１×１０-5Ｔｏｒｒを越える超高真空環
境下ではその真空度を低下させることなく動作させるこ
とができないからである。なお、好ましくは第２ガイド
面４に対して４０〜４５度の角度αで開口部から外側へ
広がるように傾斜させることが良い。That is, in order to efficiently collect the compressed fluid jetted into the gap T between the first guide surface 2 and the second guide surface 4, it is better to make the inner wall of the exhaust groove 7 as inclined as possible. However, if the angle α with respect to the second guide surface 4 is less than 40 degrees, it is not possible to increase the fluid recovery efficiency even if the angle is further inclined, and moreover, compared with a conventional hydrostatic fluid bearing having a triple exhaust groove. On the other hand, if the angle α with respect to the second guide surface 4 exceeds 65 degrees, the efficiency of fluid recovery is poor, and the double exhaust grooves 7 and 8 cannot be used. This is because the amount of fluid leaking from the gap T becomes too large, so that it cannot be operated without lowering the degree of vacuum in an ultra-high vacuum environment exceeding 1 × 10 −5 Torr. Preferably, the second guide surface 4 is inclined so as to spread outward from the opening at an angle α of 40 to 45 degrees.
【００３０】また、排気溝７，８による流体の回収効率
を高めるためには、内側に位置する排気溝７の溝幅Ｌ
を、外側に位置する排気溝８の溝幅Ｎの２倍以上とする
とともに、排気溝７と排気溝８との間隔Ｍを、外側に位
置する排気溝８の溝幅Ｎと同等あるいはそれ以上長くす
ることが好ましい。これは、内側に位置する排気溝７の
溝幅Ｌが、外側に位置する排気溝８の溝幅Ｎの２倍未満
では、溝幅Ｌが狭いために排気溝７にて回収できる流体
量をそれほど多くすることができないからであり、ま
た、排気溝７と排気溝８との間隔Ｍが、外側に位置する
排気溝８の溝幅Ｎ未満であると、両者間の間隔Ｍが短す
ぎるため、この間を通過する流体の流量が大きく、排気
溝８に流れ込む流体量が増大し、二重の排気溝７，８に
よる流体の回収効率が低下するからである。In order to increase the efficiency of fluid recovery by the exhaust grooves 7, 8, the groove width L of the inner
Is twice or more the groove width N of the exhaust groove 8 located on the outside, and the interval M between the exhaust grooves 7 and 8 is equal to or greater than the groove width N of the exhaust groove 8 located on the outside. Preferably, it is longer. When the groove width L of the exhaust groove 7 located on the inner side is less than twice the groove width N of the exhaust groove 8 located on the outer side, the amount of fluid that can be collected in the exhaust groove 7 is small because the groove width L is small. If the distance M between the exhaust groove 7 and the exhaust groove 8 is smaller than the groove width N of the exhaust groove 8 located on the outside, the distance M between the two is too short. This is because the flow rate of the fluid passing through the gap is large, the amount of fluid flowing into the exhaust groove 8 is increased, and the efficiency of fluid recovery by the double exhaust grooves 7 and 8 is reduced.
【００３１】なお、図２では、給気孔６に近い排気溝７
の内壁のみを傾斜させた例を示したが、外側の排気溝８
の内壁も排気溝７と同様の条件で傾斜させても良く、よ
り効率的に流体を回収することができる。In FIG. 2, the exhaust grooves 7 near the air supply holes 6 are shown.
The example in which only the inner wall of the outer exhaust groove 8 is inclined is shown.
May be inclined under the same conditions as the exhaust groove 7, so that the fluid can be collected more efficiently.
【００３２】また、本実施形態では、第１部材１が第２
部材３によって囲繞され、第２部材３が第１部材１上に
静圧支持された状態で直線運動する構造の静圧流体軸受
について示したが、必ずしも第１部材１が第２部材３に
よって囲繞されている必要性はなく、平板状の第１部材
と平板状の第２部材との隙間に圧縮流体を噴出して静圧
支持するようにした静圧流体軸受についても本発明を適
用できることは言うまでもない。In this embodiment, the first member 1 is the second member.
Although the hydrostatic bearing has a structure in which the second member 3 is linearly moved in a state where the second member 3 is supported on the first member 1 by static pressure, the first member 1 is not necessarily surrounded by the second member 3. It is not necessary that the present invention is applicable to a hydrostatic bearing in which a compressed fluid is jetted into a gap between a first plate-shaped member and a second plate-shaped member to support the hydrostatic pressure. Needless to say.
【００３３】さらに、本発明は直線運動する静圧流体軸
受だけに限定されるものではなく、第１部材が第２部材
によって囲繞され、第１部材が第２部材内で回転運動す
る構造の静圧流体軸受にも適用することができ、同様の
効果を奏することができることは言うまでもない。Further, the present invention is not limited to a hydrostatic bearing that linearly moves. The static member having a structure in which a first member is surrounded by a second member and the first member rotates in the second member. Needless to say, the present invention can be applied to a pressure fluid bearing, and the same effect can be obtained.
【００３４】[0034]
【実施例】（実施例１）ここで、本発明の静圧流体軸受
と従来の静圧流体軸受による流体の回収効率を確認する
ため、本発明として、図４（ａ）に示すように、平板４
０と対設したガイド面４２に二重の排気溝４４，４５を
備えた部材４１を５μｍの間隔を設けて設置したもの
と、従来として、図４（ｂ）に示すように、平板４０と
対設したガイド面４７に三重の排気溝４９，５０，５１
を有する部材４６を５μｍの間隔を設けて設置したもの
とをそれぞれ用意し、図５に示す実験装置の真空容器５
２内で、平板４０と各部材４１，４６との隙間に圧縮空
気を噴出させた時の図４（ａ）に示す二重の排気溝４
４，４５と図４（ｂ）に示す三重の排気溝４９，５０，
５１による空気の回収効率を、真空容器５２内における
真空度の低下具合を調べることにより確認した。(Embodiment 1) Here, in order to confirm the efficiency of fluid recovery by the hydrostatic fluid bearing of the present invention and the conventional hydrostatic fluid bearing, as shown in FIG. Flat plate 4
A member 41 provided with a double exhaust groove 44, 45 on a guide surface 42 opposite to a member 0 is provided at an interval of 5 μm, and a member 40, as shown in FIG. Triple exhaust grooves 49, 50, 51 are provided on the opposed guide surface 47.
Are provided at intervals of 5 μm, and the vacuum vessel 5 of the experimental apparatus shown in FIG. 5 is prepared.
In FIG. 4, when the compressed air is blown into the gap between the flat plate 40 and each of the members 41 and 46, the double exhaust groove 4 shown in FIG.
4, 45 and the triple exhaust grooves 49, 50, shown in FIG.
The efficiency of air recovery by 51 was confirmed by examining the degree of decrease in the degree of vacuum in the vacuum vessel 52.
【００３５】なお、図４（ａ）（ｂ）において、４３，
４８は平板４０に対して圧縮空気を噴出する各部材４
１，４６に設けた給気孔である。また、図５は図４
（ａ）の平板４０と部材４１を真空容器５２内に設置し
た状態を示したもので、平板４０と部材４１との隙間の
うち３辺は封止部材５３，５４，８５にて閉じ、残る一
辺のみを開放してある。ただし、５６は真空容器５２内
を真空にするための排気ポンプ、５７は真空容器５２内
の圧力変動を測定するための真空ゲージ、５８は部材４
１の給気孔４３へ圧縮空気を供給するためのホース、５
９，６０は各部材４１の排気溝４４，４５より回収した
空気を不図示の吸引ポンプへ送るためのホースである。In FIGS. 4A and 4B, reference numerals 43,
Numeral 48 denotes each member 4 for ejecting compressed air to the flat plate 40.
These are the air supply holes provided in the first and second air intakes 46. FIG. 5 is FIG.
3A shows a state in which the flat plate 40 and the member 41 are set in the vacuum vessel 52, and three sides of the gap between the flat plate 40 and the member 41 are closed by the sealing members 53, 54, and 85 and remain. Only one side is open. Here, 56 is an exhaust pump for evacuating the vacuum vessel 52, 57 is a vacuum gauge for measuring pressure fluctuation in the vacuum vessel 52, and 58 is a member 4
A hose for supplying compressed air to the first air supply hole 43,
9 and 60 are hoses for sending air collected from the exhaust grooves 44 and 45 of each member 41 to a suction pump (not shown).
【００３６】また、図４（ａ）では、給気孔４３に近い
排気溝４４の溝幅を２０ｍｍ、外側の排気溝４５の溝幅
を１０ｍｍ、排気溝４４，４５の間隔を１０ｍｍとし、
かつ排気溝４４の内壁を、ガイド面４２に対して４５度
の角度βで開口部から外側へ向けて傾斜させるととも
に、排気溝４５の内壁を、ガイド面４２と垂直に形成
し、図４（ｂ）では、給気孔４８に近い排気溝４９の溝
幅を１０ｍｍ、次の排気溝５０の溝幅を１０ｍｍ、外側
の排気溝５１の溝幅を１０ｍｍ、排気溝４９，５０，５
１の間隔を１０ｍｍとし、かつ各排気溝４９，５０，５
１の内壁をいずれもガイド面４７と垂直に形成した。In FIG. 4A, the width of the exhaust groove 44 close to the air supply hole 43 is 20 mm, the width of the outer exhaust groove 45 is 10 mm, and the interval between the exhaust grooves 44, 45 is 10 mm.
Further, the inner wall of the exhaust groove 44 is inclined outward from the opening at an angle β of 45 degrees with respect to the guide surface 42, and the inner wall of the exhaust groove 45 is formed perpendicular to the guide surface 42, as shown in FIG. In b), the groove width of the exhaust groove 49 near the air supply hole 48 is 10 mm, the groove width of the next exhaust groove 50 is 10 mm, the groove width of the outer exhaust groove 51 is 10 mm, and the exhaust grooves 49, 50, and 5 are provided.
1 is 10 mm, and each exhaust groove 49, 50, 5
Each of the inner walls was formed perpendicular to the guide surface 47.
【００３７】そして、この実験装置により空気の回収効
率を確認するには、真空容器５２内の空気を排気ポンプ
５６により排気して５×１０-6Ｔｏｒｒの真空度とした
あと、各部材４１（４６）の給気孔４３（４８）より平
面４０に対して２リットル／ｍｉｎの圧縮空気を噴出さ
せた状態で排気溝４４，４５（４９，５０，５１）によ
り空気を回収し、その時の真空ゲージ５７の真空度を確
認した。In order to confirm the efficiency of air recovery using this experimental apparatus, the air in the vacuum vessel 52 is evacuated by the exhaust pump 56 to a degree of vacuum of 5 × 10 −6 Torr, and then each member 41 ( Air is collected by the exhaust grooves 44, 45 (49, 50, 51) in a state where compressed air of 2 liter / min is jetted from the air supply hole 43 (48) of the 46) to the plane 40, and the vacuum gauge at that time is collected. The degree of vacuum of 57 was confirmed.
【００３８】この結果、図４（ｂ）は、排気溝４９，５
０，８５の内壁がいずれもガイド面４７に対して垂直に
形成されているために空気の回収効率が悪く、平板４０
と部材４６と隙間からの空気の漏れ量が多いため、真空
容器５２内の真空度は１０-5Ｔｏｒｒ台まで低下した。As a result, FIG. 4B shows the exhaust grooves 49 and 5.
Since the inner walls 0, 85 are formed perpendicular to the guide surface 47, the efficiency of air recovery is poor, and
The degree of vacuum in the vacuum vessel 52 has been reduced to the order of 10 -5 Torr due to a large amount of air leaking from the gap between the member 46 and the gap.
【００３９】これに対し、図４（ａ）は、排気溝４４の
内壁をガイド面４２に対して４５度の角度βで開口部か
ら外側へ向けて傾斜させてあることから、二重の排気溝
４４，４５であるものの、空気の回収性に優れ、平板４
０と部材４１との隙間からの空気の漏れ量が極めて少な
いために、真空容器５２内の真空度が１×１０-5Ｔｏｒ
ｒを下回ることがなく、超高真空下でも使用可能であっ
た。On the other hand, FIG. 4A shows a double exhaust because the inner wall of the exhaust groove 44 is inclined outward from the opening at an angle β of 45 ° with respect to the guide surface 42. Even though the grooves 44 and 45 are provided, the flat plate 4
Since the amount of air leaking from the gap between the zero and the member 41 is extremely small, the degree of vacuum in the vacuum vessel 52 is 1 × 10 −5 Torr.
r and could be used even under ultra-high vacuum.
【００４０】そこで、図４（ａ）の構造において、排気
溝４４の内壁をガイド面４２に対して３０度、４５度、
６５度、７５度の角度βで傾斜させる以外は同様の条件
にて空気の回収効率について測定した。Therefore, in the structure of FIG. 4A, the inner wall of the exhaust groove 44 is set at 30 °, 45 ° with respect to the guide surface 42,
The air recovery efficiency was measured under the same conditions except for inclining at an angle β of 65 degrees and 75 degrees.
【００４１】結果は図６に示す通りである。The results are as shown in FIG.
【００４２】この結果、角度βが４５度を越えると真空
容器５２内の真空度が徐々に低下し、６５度を越えると
１×１０-5Ｔｏｒｒを下回り、１０-6Ｔｏｒｒ台を維持
することができなくなった。ただし、角度βが４０度よ
り小さいと、部材４１が大型化して好ましくなかった。As a result, when the angle β exceeds 45 degrees, the degree of vacuum in the vacuum vessel 52 gradually decreases, and when the angle β exceeds 65 degrees, it falls below 1 × 10 −5 Torr and is maintained at a level of 10 −6 Torr. Is no longer possible. However, if the angle β is smaller than 40 degrees, the member 41 becomes large, which is not preferable.
【００４３】よって、二重の排気溝４４、４５のうち、
給気孔４３に近い排気溝４４の内壁は、ガイド面４２に
対して４０度〜６５度の角度βで開口部から外側へ広が
るように傾斜させることにより、二重の排気溝４４，４
５でも高い空気の回収効率が得られ、１×１０-5Ｔｏｒ
ｒ以上の真空度を維持できることが判る。Therefore, of the double exhaust grooves 44 and 45,
By inclining the inner wall of the exhaust groove 44 near the air supply hole 43 so as to spread outward from the opening at an angle β of 40 to 65 degrees with respect to the guide surface 42, the double exhaust groove 44, 4 is formed.
5, a high air recovery efficiency can be obtained, and 1 × 10 −5 Torr
It turns out that the degree of vacuum of r or more can be maintained.
【００４４】（実施例２）次に、図４（ａ）の構造にお
いて、給気孔４３に近い排気溝４４の溝幅を異ならせた
時の空気の回収効率について、実施例１と同様の条件に
て測定を行った。なお、実験にあたり、排気溝４４の内
壁の傾斜角度βは４５度、排気溝４４，４５間の間隔は
１０ｍｍ、排気溝４５の溝幅は１０ｍｍとした。(Embodiment 2) Next, in the structure of FIG. 4A, the same conditions as in Embodiment 1 are applied to the air recovery efficiency when the width of the exhaust groove 44 near the air supply hole 43 is changed. Was measured. In the experiment, the inclination angle β of the inner wall of the exhaust groove 44 was 45 degrees, the interval between the exhaust grooves 44, 45 was 10 mm, and the groove width of the exhaust groove 45 was 10 mm.
【００４５】結果は図７に示す通りである。The results are as shown in FIG.
【００４６】この結果、供気孔４３に近い排気溝４４の
溝幅を、もう一方の排気溝４５の溝幅の２倍以上とする
ことにより、空気の回収効率を高め、真空容器５２内の
真空度を１×１０-5Ｔｏｒｒ以上とすることができた。As a result, by setting the groove width of the exhaust groove 44 close to the air supply hole 43 to be at least twice the groove width of the other exhaust groove 45, the efficiency of recovering air is increased, and the vacuum in the vacuum vessel 52 is increased. The degree could be 1 × 10 −5 Torr or more.
【００４７】この結果、給気孔４３に近い排気溝４４の
溝幅は、もう一方の排気溝４５の溝幅の２倍以上とすれ
ば良いことが判る。As a result, it is found that the width of the exhaust groove 44 close to the air supply hole 43 should be at least twice the width of the other exhaust groove 45.
【００４８】（実施例３）さらに、図４（ａ）の構造に
おいて、排気溝４４，４５の間隔を異ならせた時の空気
の回収効率について、実施例１と同様の条件にて測定を
行った。(Embodiment 3) Further, in the structure shown in FIG. 4A, the air recovery efficiency when the interval between the exhaust grooves 44 and 45 is changed is measured under the same conditions as in Embodiment 1. Was.
【００４９】なお、実験にあたり、排気溝４４の内壁の
傾斜角度βは４５度、排気溝４４の溝幅は２０ｍｍ、排
気溝４５の溝幅は１０ｍｍとした。In the experiment, the inclination angle β of the inner wall of the exhaust groove 44 was 45 degrees, the groove width of the exhaust groove 44 was 20 mm, and the groove width of the exhaust groove 45 was 10 mm.
【００５０】結果は図８に示す通りである。The results are as shown in FIG.
【００５１】この結果、排気溝４４，４５の間隔は、外
側の排気溝４５の溝幅と同等以上の長さとすることによ
り、真空容器５２内の真空度を１×１０-5Ｔｏｒｒ以上
とすることができた。As a result, the degree of vacuum in the vacuum vessel 52 is set to 1 × 10 −5 Torr or more by setting the interval between the exhaust grooves 44 and 45 to be equal to or longer than the groove width of the outer exhaust groove 45. I was able to.
【００５２】この結果、排気溝７４，４５の間隔は、外
側の排気溝４５の溝幅と同等以上とすれば良いことが判
る。As a result, it is understood that the interval between the exhaust grooves 74 and 45 should be equal to or greater than the width of the outer exhaust groove 45.
【００５３】[0053]
【発明の効果】以上のように、本発明の静圧流体軸受に
よれば、第１ガイド面を有する第１部材と、前記第１ガ
イド面に対し隙間を設けて対向する第２ガイド面を有す
る第２部材とから成り、前記第１ガイド面又は第２ガイ
ド面には、前記隙間に圧縮流体を噴出して静圧流体層を
形成する給気孔と、該給気孔の周囲に刻設され、前記圧
縮流体を回収する二重の排気溝を備えるとともに、少な
くとも内側に位置する排気溝の内壁を、前記第１ガイド
面又は第２ガイド面に対して４０度〜６５度の範囲で排
気溝の開口部から外側に傾斜させたことにより、二重の
排気溝でも第１ガイド面と第２ガイド面との隙間に噴出
された流体の大部分を回収し、第１ガイド面と第２ガイ
ド面との隙間より外部へ漏洩する流体量を極めて少なく
することができるため、１×１０-5Ｔｏｒｒ以上という
超高真空環境下でもその真空度を低下させることなく作
動させることができる。As described above, according to the hydrostatic bearing of the present invention, the first member having the first guide surface and the second guide surface facing the first guide surface with a gap provided therebetween are provided. And a second member having an air supply hole formed on the first guide surface or the second guide surface to eject a compressed fluid into the gap to form a hydrostatic fluid layer, and engraved around the air supply hole. And a double exhaust groove for recovering the compressed fluid, wherein at least the inner wall of the exhaust groove located at the inner side is formed in a range of 40 to 65 degrees with respect to the first guide surface or the second guide surface. Of the fluid ejected into the gap between the first guide surface and the second guide surface even in the double exhaust groove, the first exhaust surface and the second guide surface are inclined. The amount of fluid leaking to the outside from the gap with the surface can be extremely reduced Because, 1 × can also be operated without reducing the degree of vacuum under ultra-high vacuum environment of 10 -5 Torr or more.
【００５４】また、二重の排気溝によって流体の回収を
行うことができるため、三重の排気溝を有する従来の静
圧流体軸受と比較して、給気孔を有する部材を小型化す
ることができるとともに、重量を小さくできるため、給
気孔より噴出させる圧縮流体量を少なくでき、経済的で
ある。Further, since the fluid can be recovered by the double exhaust grooves, the member having the air supply hole can be reduced in size as compared with the conventional hydrostatic fluid bearing having the triple exhaust grooves. At the same time, since the weight can be reduced, the amount of compressed fluid ejected from the air supply hole can be reduced, which is economical.
【００５５】さらに、気体を回収するための吸引ポンプ
も２つで済むため構造を簡略化できるとともに、各排気
溝と連通する吸引孔と吸引ポンプとをそれぞれ接続する
ホースの数も２本で済むため、排気溝を備えた部材が移
動する場合、ホースの屈曲による抵抗を低減することが
でき、静圧流体軸受の滑らかな移動を維持することがで
きる。Further, since only two suction pumps are required for recovering the gas, the structure can be simplified, and the number of hoses connecting the suction holes and the suction pumps communicating with the respective exhaust grooves can be reduced to two. Therefore, when the member provided with the exhaust groove moves, the resistance due to the bending of the hose can be reduced, and the smooth movement of the hydrostatic bearing can be maintained.
【図１】本発明に係る静圧流体軸受の一例を示す斜視図
である。FIG. 1 is a perspective view showing an example of a hydrostatic bearing according to the present invention.
【図２】図１のＸ−Ｘ線における主要部のみを示す断面
図である。FIG. 2 is a cross-sectional view showing only a main part along line XX in FIG.
【図３】図１における第２部材のみを示す一部を破断し
た斜視図である。FIG. 3 is a partially broken perspective view showing only a second member in FIG. 1;
【図４】（ａ）は実験における二重の排気溝を備えた部
材を示す断面図、（ｂ）は実験における三種の排気溝を
備えた部材を示す断面図である。FIG. 4A is a cross-sectional view illustrating a member having a double exhaust groove in an experiment, and FIG. 4B is a cross-sectional view illustrating a member having three types of exhaust grooves in an experiment.
【図５】実験装置を示す概略図である。FIG. 5 is a schematic view showing an experimental apparatus.
【図６】給気孔に近い排気溝の内壁の傾斜角度と真空容
器内の真空度との関係を示すグラフである。FIG. 6 is a graph showing a relationship between an inclination angle of an inner wall of an exhaust groove close to an air supply hole and a degree of vacuum in a vacuum vessel.
【図７】給気孔に近い排気溝の溝幅と真空容器内の真空
度との関係を示すグラフである。FIG. 7 is a graph showing a relationship between a groove width of an exhaust groove close to an air supply hole and a degree of vacuum in a vacuum vessel.
【図８】二重の排気溝の間隔と真空容器内の真空度との
関係を示すグラフである。FIG. 8 is a graph showing a relationship between an interval between double exhaust grooves and a degree of vacuum in a vacuum vessel.
【図９】（ａ）は従来の静圧流体軸受の一例を示す斜視
図、（ｂ）は（ａ）のＹ−Ｙ線断面図である。9A is a perspective view showing an example of a conventional hydrostatic bearing, and FIG. 9B is a sectional view taken along line YY in FIG. 9A.
【図１０】（ａ）は従来の静圧流体軸受の他の例を示す
斜視図、（ｂ）は（ａ）のＺ−Ｚ線断面図である。10A is a perspective view showing another example of the conventional hydrostatic bearing, and FIG. 10B is a sectional view taken along line ZZ of FIG. 10A.
１：第１部材 ２：第１ガイド面 ３：第２部材 ４：
第２ガイド面 ５：ポケット ６：給気孔 ７，８：排気溝 １０：圧縮ポンプ １
１，１２：吸引ポンプ １３，１４：支持部材 １６：ボールネジ １７：ネジ
軸 １８：ナット １９：連結部材 ２０：モータ Ｌ，Ｎ：排気溝の溝幅 Ｔ：第１部材と第２部材との隙
間 Ｍ：二重の排気溝間の間隔 α：ガイド面に垂直な平面
に対する排気溝内壁の傾斜角度1: First member 2: First guide surface 3: Second member 4:
Second guide surface 5: Pocket 6: Air supply hole 7, 8: Exhaust groove 10: Compression pump 1
1, 12: suction pump 13, 14: support member 16: ball screw 17: screw shaft 18: nut 19: connecting member 20: motor L, N: groove width of exhaust groove T: gap between first member and second member M: Spacing between double exhaust grooves α: Incline angle of the exhaust groove inner wall with respect to a plane perpendicular to the guide surface
Claims (1)
１ガイド面に対し隙間を設けて対向する第２ガイド面を
有する第２部材とから成り、前記第１ガイド面又は第２
ガイド面は、前記隙間に圧縮流体を噴出して静圧流体層
を形成する給気孔と、該給気孔の周囲に形成され、前記
圧縮流体を回収する二重の排気溝を備えており、かつ少
なくとも内側に位置する排気溝の内壁が、前記第１ガイ
ド面又は第２ガイド面に対し外側に４０度〜６５度傾斜
していることを特徴とする静圧流体軸受。A first member having a first guide surface; and a second member having a second guide surface opposed to the first guide surface with a gap provided between the first member and the second member.
The guide surface includes an air supply hole for ejecting a compressed fluid into the gap to form a static pressure fluid layer, and a double exhaust groove formed around the air supply hole to collect the compressed fluid, and A hydrostatic bearing wherein at least an inner wall of an exhaust groove located inside is inclined at an angle of 40 to 65 degrees outward with respect to the first guide surface or the second guide surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17898199A JP3659308B2 (en) | 1999-06-24 | 1999-06-24 | Hydrostatic fluid bearing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17898199A JP3659308B2 (en) | 1999-06-24 | 1999-06-24 | Hydrostatic fluid bearing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001012469A true JP2001012469A (en) | 2001-01-16 |
| JP3659308B2 JP3659308B2 (en) | 2005-06-15 |
Family
ID=16058039
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17898199A Expired - Fee Related JP3659308B2 (en) | 1999-06-24 | 1999-06-24 | Hydrostatic fluid bearing |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3659308B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101047812B1 (en) * | 2007-07-11 | 2011-07-08 | 스미도모쥬기가이고교 가부시키가이샤 | Hydrostatic Bearings |
-
1999
- 1999-06-24 JP JP17898199A patent/JP3659308B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101047812B1 (en) * | 2007-07-11 | 2011-07-08 | 스미도모쥬기가이고교 가부시키가이샤 | Hydrostatic Bearings |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3659308B2 (en) | 2005-06-15 |
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