JPH0833259A - Slide bearing - Google Patents

Abstract

PURPOSE:To increase the surface pressure of an oil film while suppressing the highest temperature by a structure wherein the oil is spread from the outlet of an oil groove made in the inner circumference of a bearing toward the breadthwise center of the bearing substantially in the axial direction. CONSTITUTION:The bearing metal of a slide bearing has a substantially cylindrical face and an oil groove 4 is made at a position where the oil film becomes thinnest. The oil groove 4 is elongated along the circumferential direction of the bearing while being bent toward the axial center of the bearing at the axial end thereof and the groove, serving as an oil outlet, becomes shallower gradually. Upon rotation of the shaft, the oil fed from an oil supply port 2 advances toward the bearing metal but the oil is collected partially in the oil groove 4 and the range of oil film for supporting the shaft effectively can be limited. Furthermore, the quantity of oil can be sustained constant because the oil groove prevents side flow of the oil and introduces the oil to the center of bearing. Consequently, the surface pressure can be increased while suppressing the temperature rise and the highest temperature can be lowered.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、回転機械のすべり軸受
装置、特にタービン発電機等の高速回転体を支承するす
べり軸受装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding bearing device for a rotary machine, and more particularly to a sliding bearing device for supporting a high speed rotating body such as a turbine generator.

【０００２】[0002]

【従来の技術とその課題】例えばタービン発電機に使わ
れるすべり軸受は、図３に示すようにその下半分１が単
純円筒面からなる軸受メタルにより作られ、上半分との
間に給油口２が形成される構造となっている。2. Description of the Related Art A sliding bearing used in, for example, a turbine generator, as shown in FIG. 3, has a lower half 1 made of a bearing metal having a simple cylindrical surface, and an oil filler port 2 between the upper half and the upper half. Is formed.

【０００３】この場合、図中右側の給油口２からの油は
軸受面に沿って周方向に図中左側に流れることになる
が、軸と軸受との隙間Ｃは大略図４に示すようになる。
すなわち時計方向回転の軸３は給油口２側でＣｉの隙間
があるが、Ａ点ではＣｏと狭くなる。一般的には給油量
Ｑは、Ｑ＝α・Ｒ・Ｎ・Ｃ・Ｌ（α：係数、Ｒ：メタル
内径、Ｎ：回転数、Ｃ：隙間、Ｌ：摺動長さ（軸受
幅））で示されるが、隙間Ｃｏが狭くなる分だけ油量が
サイドフローとなり、摺動面にて油膜の面圧を上げるよ
うになっていない。このため、高速回転時における油膜
自体の振動により外部エネルギを取り込むいわゆる自励
振動が発生しやすくなって安定性が良くない。In this case, the oil from the oil supply port 2 on the right side in the figure flows to the left side in the figure along the bearing surface in the circumferential direction, but the gap C between the shaft and the bearing is roughly as shown in FIG. Become.
That is, the clockwise rotation shaft 3 has a gap of Ci on the fuel filler port 2 side, but becomes narrower than Co at point A. Generally, the amount of lubrication Q is Q = α ・ R ・ N ・ C ・ L (α: coefficient, R: metal inner diameter, N: rotational speed, C: clearance, L: sliding length (bearing width)) However, the amount of oil becomes a side flow as the clearance Co becomes narrower, and the surface pressure of the oil film on the sliding surface is not increased. For this reason, the so-called self-excited vibration that takes in external energy is likely to occur due to the vibration of the oil film itself at the time of high speed rotation, and the stability is not good.

【０００４】また、図４のＡ点より進み回転側である例
えばＤ部では隙間は大きくなるものの、油量が少なくな
って油切れ状態となり温度上昇をもたらす。In addition, although the gap becomes larger on the rotation side, for example, the portion D, which advances from the point A in FIG. 4, the amount of oil decreases and the oil runs out, resulting in a temperature rise.

【０００５】本発明は、上述の問題に鑑み油膜を面圧を
上げしかも最高温度の上昇を抑えるようにしたすべり軸
受装置の提供を目的とする。The present invention has been made in view of the above problems, and an object thereof is to provide a plain bearing device in which the surface pressure of the oil film is raised and the rise of the maximum temperature is suppressed.

【０００６】[0006]

【課題を解決するための手段】上述の目的を達成する本
発明は軸が回転することにより軸受に供給される油の油
膜が最小となる付近の軸受内周に油溝を形成し、この油
溝は、この油溝の出口からの油が略軸方向に沿って軸受
幅中央に向うように形成したことを特徴とする。According to the present invention which achieves the above-mentioned object, an oil groove is formed in the inner circumference of the bearing near the point where the oil film of the oil supplied to the bearing due to the rotation of the shaft is minimized. The groove is characterized in that the oil from the outlet of the oil groove is formed so as to face the center of the bearing width along the substantially axial direction.

【０００７】[0007]

【作用】油溝の形成によりこの油溝付近の油膜の面圧が
上昇し高速回転時の自励振動が抑えられ、また、軸方向
の軸受幅方向中央に油が供給され、換言すれば軸受中心
へ油を供給することになって従来サイドフローとなる油
が前述した図４Ｄ部へ供給される。With the formation of the oil groove, the surface pressure of the oil film near the oil groove rises to suppress self-excited vibration during high-speed rotation, and oil is supplied to the center of the bearing width direction in the axial direction. The oil that becomes the conventional side flow when the oil is supplied to the center is supplied to the above-mentioned portion of FIG. 4D.

【０００８】[0008]

【実施例】ここで、図１、図２を参照して本発明の実施
例を説明する。なお、図３と同一部分には同符号を付
す。図１は一実施例のすべり軸受の下半分１を示すもの
である。このすべり軸受の軸受メタルは略円筒面からな
るが、この軸受メタルの図４に示す油膜が最も薄くなり
すなわち隙間Ｃｏとなる位置に油溝４が形成される。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Now, an embodiment of the present invention will be described with reference to FIGS. The same parts as those in FIG. 3 are designated by the same reference numerals. FIG. 1 shows a lower half 1 of a slide bearing according to one embodiment. Although the bearing metal of this slide bearing is formed of a substantially cylindrical surface, the oil groove 4 is formed at a position where the oil film of this bearing metal shown in FIG.

【０００９】この油溝４は、軸受の周方向に沿って長溝
となるように形成され、軸回転が進む方向の端部では軸
受の軸方向中央に向うように折れ曲った溝となってい
る。そして、図２にも示す如く油の出口となるこの折れ
曲った溝は次第に浅くなるようになっている。The oil groove 4 is formed as a long groove along the circumferential direction of the bearing, and is a groove bent toward the center of the bearing in the axial direction at the end portion in the axial rotation direction. . Then, as shown in FIG. 2, the bent groove serving as an oil outlet is gradually shallowed.

【００１０】軸の回転と共に給油口２から供給された油
は軸受メタルを矢印方向に進むのであるが、油溝４では
油が部分的に溜まることになり、有効に軸を支持する油
膜の範囲を小さくできたので、この油溝付近では油の面
圧が上昇することになる。また、油溝４にてサイドフロ
ーしがちな油を軸受中央へ導くようにするため油量の減
少も防止することができる。このため、油の供給にて温
度上昇が抑制され最高温度が下げられる。While the oil supplied from the oil supply port 2 advances in the bearing metal in the direction of the arrow as the shaft rotates, the oil partially accumulates in the oil groove 4, and the range of the oil film that effectively supports the shaft is increased. Since the oil pressure can be reduced, the surface pressure of the oil increases near this oil groove. Further, since the oil that tends to flow sideways in the oil groove 4 is guided to the center of the bearing, it is possible to prevent a decrease in the amount of oil. Therefore, the temperature rise is suppressed by the oil supply, and the maximum temperature is lowered.

【００１１】上述の説明は図２に示す油溝について説明
したのであるが、油膜の面圧上昇と軸受中央への油の供
給ができれば良いため、油溝の形状も様々のものが考え
られ、油を回転周方向へ導くと共に軸受中央へ導く溝等
面圧を上げるものであれば良く、例えばハの字形の溝等
があげられる。The above description has been made with reference to the oil groove shown in FIG. 2. However, since it suffices if the surface pressure of the oil film can be increased and the oil can be supplied to the center of the bearing, various shapes of the oil groove are conceivable. Any groove may be used as long as it increases the surface pressure of the groove that guides the oil in the circumferential direction of the rotation and guides the oil to the center of the bearing, such as a V-shaped groove.

【００１２】[0012]

【発明の効果】以上説明したように本発明によれば、油
溝の形成により、油の逃がし溝となって軸を支持する油
膜の範囲が減少して面圧が高くでき、自励振動を防止で
き、また、油溝を通して油の供給ができて温度上昇が抑
制され最高温度が下げられるため、供給される油の温度
や軸受の平均温度が上昇しても問題なく冷却装置の省略
や小型過が図られ、また軸受の損失も減少することがで
きる。更に、油膜の平均温度が上昇した場合には、油の
粘度が低下して油膜が薄くなるので、オイルホイップ等
の振動の発生を抑制することができて、更なる高速運転
ができる。As described above, according to the present invention, the formation of the oil groove reduces the range of the oil film that serves as an oil relief groove and supports the shaft, and the surface pressure can be increased to cause self-excited vibration. In addition, the oil can be supplied through the oil groove to suppress the temperature rise and lower the maximum temperature.Therefore, even if the temperature of the oil supplied or the average temperature of the bearing rises, there is no problem and the cooling device can be omitted or the size can be reduced. And the loss of the bearing can be reduced. Further, when the average temperature of the oil film rises, the viscosity of the oil decreases and the oil film becomes thin, so that the occurrence of vibrations such as oil whip can be suppressed and further high speed operation can be performed.

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

【図１】本発明の実施例の軸受の下半分の斜視図。FIG. 1 is a perspective view of a lower half of a bearing according to an embodiment of the present invention.

【図２】油溝の一例の構成図。FIG. 2 is a configuration diagram of an example of an oil groove.

【図３】従来例の軸受の下半分の斜視図。FIG. 3 is a perspective view of a lower half of a conventional bearing.

【図４】軸と軸受の隙間、圧力分布の説明図。FIG. 4 is an explanatory diagram of a gap between a shaft and a bearing and pressure distribution.

【符号の説明】[Explanation of symbols]

１ 軸受の下半分 ３ 軸 ４ 油溝 1 Lower half of bearing 3 Shaft 4 Oil groove

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 軸が回転することにより軸受に供給され
る油の油膜が最小となる付近の軸受内周に油溝を形成
し、 この油溝は、この油溝の出口からの油が略軸方向に沿っ
て軸受幅中央に向うように形成したすべり軸受装置。1. An oil groove is formed on the inner circumference of the bearing in the vicinity of which the oil film of the oil supplied to the bearing due to the rotation of the shaft is minimized. A sliding bearing device formed so as to face the center of the bearing width along the axial direction.