JPS61236921A - Static pressure bearing - Google Patents

Abstract

PURPOSE:To permit the stable high-speed revolution by arranging the pockets with the phase shifted in the circumferential direction between rows and offsetting the reaction force in the direction perpendicular to the direction of eccentricity between the pockets in each row. CONSTITUTION:Pressurized oil flows into the pockets 10-12 in each row through oil feeding holes 13-15, and a rotary shaft is supported by the pressurized oil. In this case, the pockets 10-12 between the pocket rows 10a-12a shift in the circumferential direction. Therefore, when shaft is set eccentric in the radial direction, the reaction force in the radial direction which is perpendicular to the above-described radial direction is offset between the pocket rows 10a-12a, and the reaction force is directed nearly in the radial direction in the initial state. Therefore, the stability of a bearing 9 can be improved markedly, and high speed revolution is permitted.

Description

【発明の詳細な説明】 〈産業上の利用分野〉 本発明は、回転軸を安定して支持する静圧軸受に関する
。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a hydrostatic bearing that stably supports a rotating shaft.

〈従来の技術〉 従来のポケット型静圧軸受の一例を表す第４図及びその
ｖ−■矢視断面形状を表す第５図に示すようｆこ、軸受
ｌの内面には円周方向に四つのポケット２が等間隔に形
成さｎており、こｎら各ポケット２には各ポケット２１
ζ夫々連通Ｔる給油孔３が開口している。そし“て、こ
の給油孔３には絞り４を介して高圧油供給ライン５から
の圧油が供給され、この給油孔３を通じてポケット２に
圧油が流入し。<Prior art> As shown in FIG. 4, which shows an example of a conventional pocket-type hydrostatic bearing, and FIG. Two pockets 2 are formed at equal intervals, and each pocket 2 has a pocket 21.
Oil supply holes 3 that communicate with each other are open. Then, pressurized oil is supplied to this oil supply hole 3 from a high pressure oil supply line 5 via a throttle 4, and the pressure oil flows into the pocket 2 through this oil supply hole 3.

この圧油によって回転軸６８支持するようにしている。The rotating shaft 68 is supported by this pressure oil.

（発明が解決しよう験する問題点〉 ポケット型静圧軸受１を高速回転で使用する場合１回転
軸６が第４図中、Ｘ方向に偏心しているご、偏心方向に
対して上流側のポケット２において回転軸６の回転方向
上流端における油膜隙間ｈ１の方が下流端における油膜
隙間　２よシ大きくなるため１回転流ｎに伴うポケット
２への流入ｉｔ力Ｓあり、逆に偏心方向ｌこ対して下流
側のポケット２では、上流漏の油ｍ隙間ｈｌ’よシも下
流端の油膜隙間ｈ２′が大きくなるため１回転流れに伴
うポケット２からの流出流量があることになる。このた
め、ポケット２の圧力は偏心方向に対して上流側の方が
下流側に比べて高くなる上、偏心方向と反対側の二つの
ポケット２についても、上記ご同様の理由で下流側が上
流側に狂ぺて高くなる。この結果、第４図Ｉこ示すｘｙ
座標でＸ方向に回転軸６が偏心した時、反力は−Ｘ方向
を向かずに＋ｙ軸方向の成分を必ず持つこととなる。(Problems to be solved by the invention) When the pocket-type hydrostatic bearing 1 is used at high speed rotation, the rotation shaft 6 is eccentric in the X direction in FIG. 4. 2, the oil film gap h1 at the upstream end in the rotation direction of the rotating shaft 6 is larger than the oil film gap 2 at the downstream end, so there is an inflow force S into the pocket 2 due to the one rotation flow n, and conversely, there is an inflow force S in the eccentric direction l. On the other hand, in the pocket 2 on the downstream side, the oil film gap h2' at the downstream end is larger than the oil film gap h1' of the upstream leak, so there is an outflow flow rate from the pocket 2 due to one rotation of the flow. , the pressure in pocket 2 is higher on the upstream side than on the downstream side in the eccentric direction, and for the two pockets 2 on the opposite side to the eccentric direction, the downstream side is distorted toward the upstream side for the same reason as above. As a result, xy shown in Figure 4
When the rotating shaft 6 is eccentric in the X direction of the coordinates, the reaction force will always have a component in the +y axis direction, not in the -X direction.

このため、この種の静圧軸受は必ずｋｙｘ＝＝２　Ｆｙ
　／２ｘ　＞　００はね定数を持つ。一般に、油で表わ
さｎるばね係数［ｋｉｊ　）及び減衰係数（ｃｉｊ）’
）持つが、軸受の安定性はこｎら係数の大きさや回転数
或いは軸質量等で決まる。For this reason, this type of hydrostatic bearing always has kyx==2 Fy
/2x > 00 has a spring constant. In general, the spring coefficient [kij) and the damping coefficient (cij)' expressed in oil are
), but the stability of the bearing is determined by the size of these coefficients, the rotation speed, the shaft mass, etc.

この場合、ｋｙｘ〉０の特性を持つと安定限界が低くな
る。静圧軸受は、このｋｙｘ　＞　０という特性のため
に高速回転領域では通常の油膜軸受ξ同様の不安定ホワ
ールを発生し、使用できなくなる場合がある。In this case, if the characteristic is kyx>0, the stability limit becomes low. Due to this characteristic of kyx > 0, the hydrostatic bearing may generate unstable whirl similar to a normal oil film bearing ξ in a high-speed rotation region, and may become unusable.

本発明は従来の静圧軸受に関する上述した不具合に鑑み
てなされたもので、軸受の安定性を改善し、高速回転も
可能とする静圧軸受を提供することを目的とする。The present invention was made in view of the above-mentioned problems with conventional hydrostatic bearings, and an object of the present invention is to provide a hydrostatic bearing that improves the stability of the bearing and enables high-speed rotation.

一問題点を解決するための手段〉 上記目的を達成するための本発明の構成は、軸受内周面
にポケットを有し、このポケットと回転軸の外周面との
間に高圧油が供給さｎる静圧軸受において、前記ポケッ
トヲ内周方向に複数形成したポケット列を軸方向に複数
列形成すると共に各列間のポケットの位相を周方向にず
らしたことを特徴とするものである。Means for Solving a Problem> The configuration of the present invention to achieve the above object has a pocket on the inner circumferential surface of the bearing, and high pressure oil is supplied between the pocket and the outer circumferential surface of the rotating shaft. The static pressure bearing is characterized in that a plurality of pocket rows are formed in the inner circumferential direction of the pockets, and a plurality of pocket rows are formed in the axial direction, and the phases of the pockets between each row are shifted in the circumferential direction.

（作　　　用〉 各列での回転軸の偏心方向に対して向い合うポケット間
で回転軸の偏心方向と直角な方向の反力は相殺される結
果１反力は偏心方向にのみ向いて回転軸の安定な回転が
行わｎる。(Function) The reaction force in the direction perpendicular to the eccentric direction of the rotating shaft is canceled out between the pockets facing each other in the eccentric direction of the rotating shaft in each row. As a result, one reaction force is directed only in the eccentric direction of the rotating shaft. A stable rotation is performed.

く実　施　例〉 本発明による静圧軸受の一実施例の断面形状を表Ｔ第１
図及びそのｕ−■矢視断面形状を表す第２図に示Ｔよう
に、軸受９の内面には本実施例では三つのポケット列１
０　ａ、１１ａ。Embodiment Example The cross-sectional shape of an embodiment of the hydrostatic bearing according to the present invention is shown in Table T.
As shown in FIG. 2 and its cross-sectional shape in the direction of the u-■ arrow, there are three pocket rows 1 on the inner surface of the bearing 9 in this embodiment.
0a, 11a.

１２ａが軸方向に等間隔で形成さｎ、各ポケット列１０
ａ、ｌｌａ、１２ａには円周方向に等間隔でポケット１
０．１１．１２が本実施例では夫々四つ形成さｎている
。そして、各ポケット列ｔｅａ、ｆｌａｔ　　１２ａは
その展開形状を表す第３図に示すように、相互にポケッ
ト１０，１１．１２の位相が円周方向に３０＃釦ずｎる
ように臼装置さｎている。そして、軸受９のポケット列
１０　ａ、　　１１　ａ、１２ａの各ポケット１０，１
１．１２部分には、各ポケット１０．１１．１２に夫々
連通する給油孔１３，１４．１５が形成さｎている。こ
ｎら給油孔１３．１４．１５に夫々絞り４そ介して高圧
油供給ライン５から圧油が供給さｎ、こｎらの給油孔１
３，１４．１５％通じて各列のポケツ）　ｌ　Ｏ，ｌ　
１．　１２ｊこ圧油が流入し、この圧油によって図示し
ない回転軸を支持する。12a are formed at equal intervals in the axial direction, and each pocket row 10
There are pockets 1 at equal intervals in the circumferential direction on a, lla, and 12a.
In this embodiment, four 0.11.12 are formed respectively. Each pocket row tea, flat 12a is arranged in a mortar device so that the phases of the pockets 10, 11, and 12 are 30 # buttons in the circumferential direction, as shown in FIG. ing. Then, each pocket 10, 1 of the pocket rows 10a, 11a, 12a of the bearing 9
In the 1.12 portion, oil supply holes 13, 14.15 are formed which communicate with each pocket 10.11.12, respectively. Pressure oil is supplied to these oil supply holes 13, 14, and 15 from the high pressure oil supply line 5 through the throttle 4, respectively.
3, 14.15% through each row pocket) l O, l
1. 12j Pressure oil flows in, and a rotating shaft (not shown) is supported by this pressure oil.

この場合、各ポケット列１０　ａ　＊　　ｌ　１　ａ　
１１２３間のポケット１０，１１．１２が円周方向にず
ｎていることにより、成る半径方向に軸が偏心した時、
各ポケット列１０ａ、１ｌａｅ１２ａ間でこの半径方向
ξ直角な半径方向の反力は相殺さｎ、反力はほぼ最初の
半径方向に向くようにな〕、第４図に示した従来の例ｒ
ａｋｙｘ＝０ごなる。条件によっては、　ｋ、Ｘ＜０の
領域ごなる場合もあり得る。このように。In this case, each pocket row 10 a * l 1 a
When the axis is eccentric in the radial direction due to the pockets 10, 11.12 between 1123 being offset in the circumferential direction,
The reaction force in the radial direction perpendicular to the radial direction ξ is canceled out between each pocket row 10a, 1lae 12a, and the reaction force is directed almost in the initial radial direction], as shown in the conventional example shown in FIG.
akyx=0. Depending on the conditions, there may be a region where k, X<0. in this way.

ｋｙｘミＯ又はｋｙｚ　＜　０となることによって軸受
９の安定性が大幅に改善さｎ、高速回転が可能ξなる。By satisfying kyxmiO or kyz<0, the stability of the bearing 9 is greatly improved, and high-speed rotation becomes possible.

なお１本実施例では円周方向ｔこポケット１１゜１２．
１３’）四個設けると共に軸方向に三列形成した例を示
したが、以上の効果はこの組合せに限定ざｎるものでは
ないことは勿論である。In this embodiment, the pockets are 11° and 12° in the circumferential direction.
13') Although an example has been shown in which four members are provided and three rows are formed in the axial direction, it goes without saying that the above effects are not limited to this combination.

〈発明の効果〉 本発明によｎば、ポケットを円周方向に複数形成したポ
ケット列を伜方向Ｉこ複数列形成すると共に、各列間の
ポケットの位相を円周方向にずらして配置したことｌこ
より、各列間のポケット間で回転軸の偏心方向と直角方
向の反力は相殺さｎ１反力は偏心方向にのみ向くように
なって軸受の安定性が増し、安定した高速回転も可能で
ある。<Effects of the Invention> According to the present invention, a plurality of pocket rows in which a plurality of pockets are formed in the circumferential direction are formed in the opposite direction, and the phases of the pockets between each row are shifted in the circumferential direction. Therefore, the reaction forces in the eccentric direction and the direction perpendicular to the rotating shaft are canceled out between the pockets between each row, and the n1 reaction force is directed only in the eccentric direction, increasing the stability of the bearing and allowing stable high-speed rotation. It is possible.

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

第１図は本発明の一実施例を示す断面図、第２図はその
■−■矢視断面図、第３図はその展開図、第４図は従来
例を示す断面図、第５図はそのｖ−■矢視断面図、であ
る。 又１図中の符号で４は佼９，５は高圧油供給ライｙ、６
／ｄＤｏ転軸、９は軸受、１０　ａｔ　１１ａ＃１２Ｊ
ｌ仁ポケット列、１０，１１．１２はポケット、１３，
１４．１５は給油孔である。Fig. 1 is a cross-sectional view showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line ■-■, Fig. 3 is a developed view thereof, Fig. 4 is a cross-sectional view showing a conventional example, and Fig. 5 is a sectional view taken along the line v-■. Also, in the symbols in Figure 1, 4 is 9, 5 is high pressure oil supply line y, and 6 is
/dDo rotating shaft, 9 is bearing, 10 at 11a #12J
l pocket row, 10, 11. 12 is pocket, 13,
14.15 is an oil supply hole.

Claims (1)

【特許請求の範囲】[Claims] 軸受内周面にポケットを有し、このポケットと回転軸の
外周面との間に高圧油が供給される静圧軸受において、
前記ポケットを円周方向に複数形成したポケット列を軸
方向に複数列形成すると共に各列間のポケットの位相を
前記周方向にずらしたことを特徴とする静圧軸受。In a hydrostatic bearing that has a pocket on the inner circumferential surface of the bearing and high pressure oil is supplied between the pocket and the outer circumferential surface of the rotating shaft,
A hydrostatic bearing characterized in that a plurality of pocket rows each having a plurality of pockets formed in the circumferential direction are formed in a plurality of rows in the axial direction, and the phases of the pockets between each row are shifted in the circumferential direction.