JPS588979Y2 - fluid sliding bearing - Google Patents

Description

【考案の詳細な説明】 本案は流体すべり軸受の改良に関するものである。[Detailed explanation of the idea] This proposal relates to improvement of hydrodynamic sliding bearings.

従来回転機械特に立形の回転機械においては第１図Ａに
示す流体すべり軸受を使用している。Conventionally, a hydrodynamic sliding bearing shown in FIG. 1A has been used in a rotating machine, particularly a vertical rotating machine.

この流体すべり軸受は、潤滑流体が例えば水のように低
粘性の場合、軸受の負荷能力及び剛性が不足することが
多く、軸と軸受とが接触したり、軸振動が大きくなった
りして、軸受が早期に摩耗するという欠陥があった。In this fluid sliding bearing, when the lubricating fluid has low viscosity such as water, the bearing's load capacity and rigidity are often insufficient, and the shaft and bearing may come into contact or the shaft vibration may increase. The defect was that the bearings wore out prematurely.

多段ポンプ等の軸方向に流体圧力差を有する部分に設け
られる軸受において、高圧側に向って開口する軸断面コ
字状の切欠を設けた外部軸受と、該切欠の半径方向およ
び軸方向に指向する内壁面とそれぞれ所定間隙を存して
同切欠き内に遊嵌された内部軸受とを有し、前記両軸受
の半径方向間隙は軸方向での低圧側に向って狭くなる段
差を形成し、該内部軸受には前記外部軸受の半径方向に
指向する内壁面に当接する環状突起を設けると共に、同
環状突起に半径方向に貫通する孔を放射状に設けてなる
ことを特徴とする流体すべり軸受に係り、その目的とす
る処は、軸受剛性を高めることができて、軸と軸受との
接触或は軸振動を防止できる改良された流体すべり軸受
を供する点にある。In bearings installed in parts of multi-stage pumps that have a fluid pressure difference in the axial direction, an external bearing is provided with a notch with a U-shaped shaft cross section that opens toward the high pressure side, and the notch is oriented in the radial and axial directions. and an internal bearing loosely fitted in the notch with a predetermined gap therebetween, and the radial gap between the two bearings forms a step that narrows toward the low pressure side in the axial direction. , a fluid sliding bearing characterized in that the internal bearing is provided with an annular protrusion that contacts the radially oriented inner wall surface of the external bearing, and the annular protrusion is provided with holes that penetrate in the radial direction. The object of the present invention is to provide an improved fluid sliding bearing that can increase bearing rigidity and prevent contact between the shaft and the bearing or shaft vibration.

次に本考案の流体すべり軸受を第１，２図に示す一実施
例により説明する。Next, the fluid sliding bearing of the present invention will be explained with reference to an embodiment shown in FIGS. 1 and 2.

ｌず本案の流体すべり軸受の使用個所を第１図Ｂにより
説明すると、同流体すべり軸受は、多段ポンプ（なおａ
が各段のポンプインペラ、ｂが回転軸、Ｃがすべり流体
軸受）のように軸方向に圧力差が存在し且つ潤滑流体が
多段ポンプの作動流体と同じである回転機械の差圧存在
部分において回転軸すを支持するために使用される。The locations where the fluid sliding bearing of the present proposal is used are explained with reference to Fig. 1B.
is the pump impeller of each stage, b is the rotating shaft, and C is the sliding fluid bearing. Used to support rotating shafts.

従って以下の説明において、軸受の内部側（ＰＩ側）が
高圧側に、軸受の外部側（Ｐ２側）が低圧側に、それぞ
れ相当している。Therefore, in the following description, the inner side of the bearing (PI side) corresponds to the high pressure side, and the outer side of the bearing (P2 side) corresponds to the low pressure side.

次に本案の流体すべり軸受を具体的に説明すると、１が
回転軸、２が外部軸受、３が軸受の内部側（Ｐｌ側）に
開口するように同外部軸受２に設けた切欠、２ａが同外
部軸受２の軸方向に沿う内周面、２ｂが同外部軸受２の
半径方向に沿う内側面（内孔３の奥部面）４が上記切欠
３に嵌挿した内部軸受、４ａが同内部軸受４の軸方向に
沿う外周面、４ｂが同内部軸受４の半径方向に沿う内側
面、４ｃが同内部軸受４の軸方向に沿う内周面で、前記
内周面２ａと前記外周面４ａとの間に隙間５が、また前
記内側面２ｂと前記内側面４ｂとの間に隙間６が、また
前記内周面４ｃと回転軸１との間に隙間１がそれぞれ形
成されている。Next, to specifically explain the fluid sliding bearing of the present invention, 1 is the rotating shaft, 2 is the external bearing, 3 is a notch provided in the external bearing 2 so as to open on the inside side (Pl side) of the bearing, and 2a is The inner circumferential surface of the outer bearing 2 along the axial direction, 2b is the inner surface of the outer bearing 2 along the radial direction (inner surface of the inner hole 3) 4 is the inner bearing fitted into the notch 3, and 4a is the inner circumferential surface of the outer bearing 2 along the axial direction. An outer circumferential surface of the internal bearing 4 along the axial direction, 4b an inner circumferential surface of the internal bearing 4 along the radial direction, 4c an inner circumferential surface of the internal bearing 4 along the axial direction, and the inner circumferential surface 2a and the outer circumferential surface 4a, a gap 6 between the inner surface 2b and the inner surface 4b, and a gap 1 between the inner peripheral surface 4c and the rotating shaft 1.

なおこの隙間１の大きさは、回転軸１の径の’／２５０
〜１／１０００程度である。The size of this gap 1 is '/250 of the diameter of the rotating shaft 1.
It is about 1/1000.

また上記隙間５の大きさは、隙間７と同じかそれよりも
小さい。Further, the size of the gap 5 is the same as or smaller than the gap 7.

また２ａ１が前記内周面２ａに設けた段差部で、前記隙
間５のうち軸受外部側の隙間が軸受内部側の隙間よりも
狭（なっている。Further, 2a1 is a stepped portion provided on the inner circumferential surface 2a, and the gap on the outside of the bearing in the gap 5 is narrower than the gap on the inside of the bearing.

また８が前記内側面４ｂから軸方向に突設して前記内側
面２ｂに当接した環状突起、９が同環状突起８を半径方
向に貫通する孔で、同環状突起８に放射状に設けられて
いる。Further, reference numeral 8 denotes an annular projection protruding from the inner surface 4b in the axial direction and abutting against the inner surface 2b, and reference numeral 9 denotes a hole passing through the annular projection 8 in the radial direction. ing.

なおこの孔９の径と数は、前記隙間５の大きさ、段差部
２ａｌの形状、軸方向差圧により決１す、一定でない。Note that the diameter and number of the holes 9 are determined by the size of the gap 5, the shape of the stepped portion 2al, and the differential pressure in the axial direction, and are not constant.

ｌた１０が前記内部軸受４に設けた溝、１１が間溝１０
内には１り込むように前記外部軸受２に固定したビンで
、内部軸受４の回転が同ピン１１により阻止されている
。10 is a groove provided in the internal bearing 4, and 11 is an intermediate groove 10.
The pin 11 is a pin fixed to the external bearing 2 so as to fit into the pin 11.

なお前記外部軸受２は軸受・・ウジング１２に固定され
ている。Note that the external bearing 2 is fixed to a bearing 12.

次に前記流体すべり軸受の作用を説明する。Next, the operation of the fluid sliding bearing will be explained.

回転軸１が回転すると、内部軸受４の内外面４ａ。When the rotating shaft 1 rotates, the inner and outer surfaces 4a of the internal bearing 4.

４ｂｔ４ｃが軸受になる。4bt4c becomes the bearing.

このとき隙間５の流体膜に回転軸１のすべり速度と回転
軸１の偏心とに応じた圧力が発生し、結果として負荷能
力が生じ、この部分の流体膜に剛性と減衰とをもたせる
ことができる。At this time, a pressure is generated in the fluid film in the gap 5 according to the sliding speed of the rotating shaft 1 and the eccentricity of the rotating shaft 1, and as a result, a load capacity is generated, and the fluid film in this part can be made to have rigidity and damping. can.

渣たこのとき流体膜絞シ作用により、隙間５の流体膜に
減衰を、ｌた差圧△Ｐ（軸受内部側の圧力Ｐ１は、軸受
外部側の圧力Ｐ２よりも高く、ＰｌからＰ２を差引いた
差圧△Ｐ）と、内部軸受４の半径方向への変位と、隙間
５のうち軸受外部側を軸受内部側よりも狭くしたことと
により、隙間５の流体膜にて定の剛性を、それぞれもた
せることができる。At this time, due to the fluid film throttling action, the fluid film in the gap 5 is damped and the differential pressure △P (pressure P1 on the inside of the bearing is higher than pressure P2 on the outside of the bearing, subtract P2 from Pl. Due to the differential pressure △P), the displacement of the internal bearing 4 in the radial direction, and the fact that the outside of the bearing is made narrower than the inside of the bearing, the fluid film in the clearance 5 has a certain rigidity. You can have each.

なおこれらの減衰と剛性とについては後に詳述する。Note that these damping and rigidity will be explained in detail later.

またこのとき内部軸受４の内側面４ｂに設けた環状突起
８を外部軸受２の内側面２ｂＫ当接する一方、同環状突
起８に貫通孔９を設けたので、貫通孔９の径及び数を適
当に選定すれば、隙間６の圧力を軸受内部側の圧力Ｐ１
と軸受外部側の圧力Ｐ２の略中間に設定できる。Also, at this time, the annular protrusion 8 provided on the inner surface 4b of the internal bearing 4 is brought into contact with the inner surface 2bK of the external bearing 2, and the annular protrusion 8 is provided with a through hole 9, so the diameter and number of the through holes 9 can be adjusted appropriately. If the pressure in the gap 6 is selected as the pressure inside the bearing P1
and the pressure P2 on the outside of the bearing.

そのため内部軸受４に作用する軸方向スラスト（第２図
の矢印Ａ参照）を軽減できて、環状突起８の半径方向変
位に対する摩擦力を小さくできるとともに同摩擦力によ
る減衰をこの部分にもたせることができる。Therefore, the axial thrust (see arrow A in FIG. 2) acting on the internal bearing 4 can be reduced, and the frictional force against the radial displacement of the annular protrusion 8 can be reduced, and the damping due to the frictional force can be provided to this part. can.

次に前記隙間５での減衰と剛性とについて説明する。Next, damping and rigidity in the gap 5 will be explained.

第４図に示すように２つの平面間に矢印■方向の相対速
度がある場合、同各平面間の流体膜には第５図に示すよ
うに搬物線状に圧力が発生する。As shown in FIG. 4, when there is a relative velocity between two planes in the direction of the arrow {circle around (2)}, pressure is generated in the fluid film between the two planes in the shape of a carrier line, as shown in FIG.

前記隙間５の流体膜に減衰をもたせることができるのは
、上記圧力（流体膜絞り作用）に基づいている。The reason why the fluid film in the gap 5 can be damped is based on the pressure (fluid film throttling effect).

また第６図に示すように軸方向に差圧があり、軸受に段
圧部があっても、軸と軸受とが同心状態ならば、軸方向
の圧力分布が概ね第７図のようになる。Also, as shown in Figure 6, even if there is a differential pressure in the axial direction and there is a step pressure part in the bearing, if the shaft and bearing are concentric, the pressure distribution in the axial direction will be approximately as shown in Figure 7. .

同第７図において△Ｐｉ１は流体が軸受端から隙間に流
入するときの加速に基づく動圧降下分、△Ｐｌ工は流体
が軸受端から段差部の手前１で流れる間、即ち、広い隙
間のｒｅｇｉｏｎｌを旅れる間の粘性抵抗による圧力降
下分、△Ｐｉ２は流体が段差部から狭い隙間に流入する
ときの加速に基づく圧力降下分、△ＰＡｚは流体が狭い
隙間のｒｅｇｉｏｎ２ を流れる間の粘性抵抗による圧
力降下分である。In Fig. 7, △Pi1 is the dynamic pressure drop based on acceleration when the fluid flows from the bearing end into the gap, and △Pl is the dynamic pressure drop during the fluid flowing from the bearing end 1 before the step, that is, in the wide gap. △Pi2 is the pressure drop caused by the acceleration when the fluid flows into the narrow gap from the step, △PAz is the viscous resistance while the fluid flows through the narrow gap in region 2. This is the pressure drop due to

上記同心状態から軸が半径方向に変位して第８図のよう
に偏心すれば、偏心方向の隙間と反対方向の隙間との大
きさが異って（るので、それぞれでは軸方向の流速と粘
性抵抗が異ってきて、軸方向の圧力分布が、偏心方向の
隙間では第９図の一点鎖線のように、渣た反対方向の隙
間では第９図の破線のようＫなり、流体膜が剛性をもつ
ことになる。If the shaft is displaced in the radial direction from the above-mentioned concentric state and becomes eccentric as shown in Fig. 8, the size of the gap in the eccentric direction and the gap in the opposite direction will be different, so the flow velocity in the axial direction will differ in each case. The viscous resistance changes, and the pressure distribution in the axial direction becomes K as shown in the dashed line in Figure 9 in the gap in the eccentric direction, and as shown in the dashed line in Figure 9 in the gap in the opposite direction, and the fluid film is formed. It will have rigidity.

以上第６図乃至第９図の説明において軸が内部軸受４に
、軸受が外部軸受２に、隙間が隙間５に、それぞれ相当
している。In the above description of FIGS. 6 to 9, the shaft corresponds to the internal bearing 4, the bearing corresponds to the external bearing 2, and the gap corresponds to the gap 5, respectively.

隙間５の流体膜に剛性をもたせることができるのは上記
の理由に基づいている。The reason why the fluid film in the gap 5 can be made rigid is based on the above reason.

本案のすべり軸受は前記の作用をもつので、従来の流体
すべり軸受に比べると軸受全体で考えた剛性（減衰も加
えた複素インピーダンスの絶対値）を高めることができ
て、軸と軸受との接触或は軸の振動を効果的に防「Ｅで
きるものである。Since the proposed sliding bearing has the above-mentioned effect, it is possible to increase the rigidity (absolute value of complex impedance including damping) of the bearing as a whole compared to conventional hydrodynamic sliding bearings, and the contact between the shaft and the bearing can be increased. Alternatively, it can effectively prevent shaft vibration.

なお前記第１，２図の実施例では段差部２ａｘを外部軸
受２の内周面２ａに設けているが、内部軸受４の外周面
４ａに設けてもよい。In the embodiment shown in FIGS. 1 and 2, the stepped portion 2ax is provided on the inner circumferential surface 2a of the external bearing 2, but it may be provided on the outer circumferential surface 4a of the internal bearing 4.

またこの段差部２ａ１を内周面２ａまた外周面４ａの全
体に設けずに一部に設けてもよい。Further, the stepped portion 2a1 may be provided on a portion of the inner circumferential surface 2a or the outer circumferential surface 4a instead of being provided on the entirety thereof.

會たこの段差部２ａ１をテーパにかえても同様の効果を
達成できる。The same effect can be achieved even if the stepped portion 2a1 of the octopus is replaced with a taper.

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

第１図Ａは従来の流体すべり軸受を示す縦断側面図、第
２図Ｂは流体すべり軸受の使用個所の一例を示す説明図
、第２図は本考案に係る流体すべり軸受の一実施例を示
す縦断側面図、第３図は第２図矢視線■−■線に沿う縦
断正面図、第４図乃至第９図は本案流体すべり軸受の作
用説明図である。 ２・・・外部軸受、３・・・内孔、４・・・内部軸受、
４ｂ・・・内部軸受４の半径方向に沿う内側面、５・・
・軸方向に沿う隙間、６・・半径方向に沿う隙間、８・
・・環状突起、９・・・半径方向に貫通する孔、Ｐｌ・
・・軸受の内部側、Ｐ２・・・軸受の外部側。Fig. 1A is a vertical side view showing a conventional hydrodynamic sliding bearing, Fig. 2B is an explanatory view showing an example of a location where the hydrodynamic sliding bearing is used, and Fig. 2 shows an example of the hydrodynamic sliding bearing according to the present invention. 3 is a vertical sectional side view taken along the arrow line ■-■ in FIG. 2... External bearing, 3... Inner hole, 4... Internal bearing,
4b... Inner surface along the radial direction of the internal bearing 4, 5...
・Gap along the axial direction, 6.・Gap along the radial direction, 8.
... Annular projection, 9... Hole penetrating in the radial direction, Pl.
...Inner side of the bearing, P2...Outer side of the bearing.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 多段ポンプ等の軸方向に流体圧力差を有する部分に設け
られる軸受において、高圧側に向って開口する軸断面コ
字状の切欠を設けた外部軸受と、該切欠の半径方向およ
び軸方向に指向する内壁面とそれぞれ所定間隙を存して
同切欠き内に遊嵌された内部軸受とを有し、前記両軸受
の半径方向間隙は軸方向での低圧側に向って狭くなる段
差を形成し、該内部軸受には前記外部軸受の半径方向に
指向する内壁面に当接する環状突起を設けると共に、同
環状突起に半径方向に貫通する孔を放射状に設けてなる
ことを特徴とする流体すべり軸受。In bearings installed in parts of multi-stage pumps that have a fluid pressure difference in the axial direction, an external bearing is provided with a notch with a U-shaped shaft cross section that opens toward the high pressure side, and the notch is oriented in the radial and axial directions. and an internal bearing loosely fitted in the notch with a predetermined gap therebetween, and the radial gap between the two bearings forms a step that narrows toward the low pressure side in the axial direction. , a fluid sliding bearing characterized in that the inner bearing is provided with an annular protrusion that abuts the radially oriented inner wall surface of the outer bearing, and the annular protrusion is provided with holes that penetrate in the radial direction. .