JPH06307451A - Bearing system - Google Patents

Abstract

PURPOSE:To improve bearing rigidity so as to reduce fluid loss by providing a voltage source for applying an electric pole and electric potential thereto on a rotary part and a stationary part, and controlling an electric double layers for being generating on the rotary part or the interface of stationary part and lubricating liquid. CONSTITUTION:When an electric double layers 9 is generated on the interface of the shaft 1 and a bearing 2 by a voltage sources 4, 5, influence thereof appears on a position where the film thickness of lubricating liquid 3 in which the rotating shaft 1 and the bearing 2 are formed is most thin, namely on a position where pressure is highest, in largest value, so that respective electric double layers 9 are formed on the interface of the rotating shaft 1 and the bearing 2. In this case, bearing rigidity is maintained by electrostatic resiliency of both adjacent electric double layers 9, and electrostatic resiliency is increased at the inverse square of a distance, so that it is possible to exhibit supporting force corresponding to a load applied to a shaft at a position which is necessary for supporting force. Since the electric double layer 9 is formed as a solid protecting film, it is possible to prevent seizure of the shaft 1 and the bearing 2, and also reduce viscous abrasion.

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、潤滑液の界面の電気二
重層を制御する軸受システムに係り、特に、高速の小型
軸受システムに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing system for controlling an electric double layer at an interface of a lubricating liquid, and more particularly to a high speed small bearing system.

【０００２】[0002]

【従来の技術】レーザプリンタ等で用いられている軸受
システムは、高精度化，小型化及び高速化により、転が
り軸受から滑り軸受、それも磁性流体を応用した滑り軸
受や空気軸受へと発展をしてきた。しかし、さらに高速
化，高精度化及び小型化を図るにはこのシステムは、軸
受剛性を高める必要がある。軸受剛性を高めるには、潤
滑液の粘度を高める必要があるが、ただ粘度を高めただ
けでは、回転による流体損失が増大する。この矛盾する
要求は、マイクロアクチュエータ等でも、重大な課題で
ある。2. Description of the Related Art Bearing systems used in laser printers and the like have evolved from rolling bearings to sliding bearings, and also to sliding bearings and air bearings to which magnetic fluid is applied, due to higher precision, smaller size and higher speed. I've been However, in order to achieve higher speed, higher accuracy, and smaller size, this system needs to have higher bearing rigidity. To increase the bearing rigidity, it is necessary to increase the viscosity of the lubricating liquid, but simply increasing the viscosity increases the fluid loss due to rotation. This contradictory requirement is a serious problem even in microactuators and the like.

【０００３】[0003]

【発明が解決しようとする課題】上記従来技術の課題
が、本発明の目的、すなわち、高軸受剛性と低流体損失
の両者を満足させる軸受システムを提供することにあ
る。SUMMARY OF THE INVENTION It is an object of the above-mentioned prior art to provide a bearing system that satisfies both the object of the present invention, that is, high bearing rigidity and low fluid loss.

【０００４】[0004]

【課題を解決するための手段】上記目的を達成するに
は、粘度を上げないで軸受剛性を高める方法が必須とな
る。すなわち、潤滑液と回転部及び静止部との界面で発
生する電気二重層を制御または利用できるように電極を
設け電位を変化させるようにした。In order to achieve the above object, a method of increasing bearing rigidity without increasing viscosity is essential. That is, the electrodes are provided so that the electric double layer generated at the interface between the lubricating liquid and the rotating portion and the stationary portion can be controlled or utilized to change the potential.

【０００５】[0005]

【作用】このように構成することにより、回転部または
静止部に電極を設け、潤滑液と回転部または静止部との
界面に発生する電気二重層の厚さを制御して回転部と静
止部との間に働く静電力を制御するばかりでなく、回転
部または静止部の表面に付着する流体膜を形成すること
により、切れにくい潤滑膜を形成することにより高速化
に対応できる。また、静電気力は、表面力であるから体
積が小さいほど相対的に強くなるので、小型化するほど
有利となるばかりでなく、高速化にも対応する手段とな
る。With this structure, an electrode is provided on the rotating part or the stationary part, and the thickness of the electric double layer generated at the interface between the lubricating liquid and the rotating part or the stationary part is controlled to control the rotating part and the stationary part. In addition to controlling the electrostatic force that acts between and, the formation of a fluid film that adheres to the surface of the rotating portion or the stationary portion forms a lubricating film that is difficult to break, which makes it possible to cope with higher speeds. Further, since the electrostatic force is a surface force and becomes relatively stronger as the volume is smaller, it is not only advantageous as the size is made smaller, but also a means for coping with speeding up.

【０００６】[0006]

【実施例】本発明の実施例１を図１に示す。図１は、軸
受装置の横断面を示す。これは、つぎのものから構成さ
れる。回転する軸１，軸１を潤滑液３を介して支える軸
受２，軸１と軸受２を媒介する潤滑液３，軸受３に電位
を与える電圧源４及び軸１に電位を与える電圧源５。こ
れは、軸１及び軸受２の表面が電気の伝導体でできてい
る場合であり、絶縁体の場合は、図２に断面図で示すよ
うに軸受２に電極６，軸１に電極７を設ける。この場
合、電極６に電位を与える電圧源４，電極７に電位を与
える電圧源５を接続する。図３は、負荷時の潤滑液３に
掛かる圧力分布を示したもので、回転する軸１と軸受２
とが形成する潤滑液３の膜厚が最も薄い所で最も圧力が
高い。この圧力は、局所的でかつ薄い潤滑液３の膜で支
えられている。電気二重層９は、図４のように固体と液
体とが接触する界面に発生する。例えば、固体が正の電
位を持てば液体は負の電位を持つ。固体と液体との物性
の組み合わせによっては、この自然な状態で使用できる
が、通常は本発明のように外部から電位を与えないと軸
受システムを制御するのに十分な電気二重層９を発生さ
せられない。今、電圧源４及び５により、軸１及び軸受
２の界面に電気二重層９を発生させると、その影響が最
も大きく現われるのは、回転する軸１と軸受２とが形成
する潤滑液３の膜厚が最も薄い所、すなわち、最も圧力
が高い所であり、回転する軸１と軸受２の界面にはそれ
ぞれ電気二重層９が図５のように形成される。この場
合、軸受剛性は二つの近接する電気二重層９同士の静電
的反発力で保持できる。静電的反発力は、距離の二乗に
反比例して増大するから軸に掛かる負荷に対応できる支
持力を支持力の必要なこの部分で発揮できる。又、電気
二重層９は、図５の下の図に示したように固体の保護膜
となるから軸１と軸受２の焼き付きを防止することがで
きるし、膜と言っても固体ではないので、電気的に中立
な潤滑液３との境界面での剪断力は、固体に比べてかな
り緩和されるから、粘性摩擦も低減できる。図６は、本
実施例の静電的な関係を示したものである。今まで述べ
たように、距離の二乗に反比例する静電的反発力によ
り、図３に示した圧力分布をカバーできるため、電圧源
４及び５の出力の調整により、従来の軸受システムの小
型化、又、摩擦損失の低減ができる。EXAMPLE 1 Example 1 of the present invention is shown in FIG. FIG. 1 shows a cross section of a bearing device. It consists of: Bearing 2, which supports rotating shaft 1 and shaft 1 through lubricating liquid 3, lubricating liquid 3, which mediates shaft 1 and bearing 2, voltage source 4 which gives potential to bearing 3, and voltage source 5 which gives potential to shaft 1. This is a case where the surfaces of the shaft 1 and the bearing 2 are made of an electric conductor, and in the case of an insulator, an electrode 6 is provided on the bearing 2 and an electrode 7 is provided on the shaft 1 as shown in the sectional view of FIG. Set up. In this case, the voltage source 4 which gives a potential to the electrode 6 and the voltage source 5 which gives a potential to the electrode 7 are connected. FIG. 3 shows a pressure distribution applied to the lubricating liquid 3 under load. The rotating shaft 1 and the bearing 2 are shown in FIG.
The pressure is highest where the film thickness of the lubricating liquid 3 formed by and is the smallest. This pressure is supported locally and by a thin film of lubricating liquid 3. The electric double layer 9 is generated at the interface where the solid and the liquid come into contact with each other as shown in FIG. For example, if a solid has a positive potential, a liquid has a negative potential. Depending on the combination of physical properties of solid and liquid, it can be used in this natural state, but normally, when an electric potential is not externally applied as in the present invention, an electric double layer 9 sufficient to control the bearing system is generated. I can't. Now, when the electric double layer 9 is generated at the interface between the shaft 1 and the bearing 2 by the voltage sources 4 and 5, the most significant effect is that the lubricating liquid 3 formed by the rotating shaft 1 and the bearing 2 is formed. An electric double layer 9 is formed on the interface between the rotating shaft 1 and the bearing 2 as shown in FIG. 5, where the film thickness is the thinnest, that is, the pressure is the highest. In this case, the bearing rigidity can be maintained by the electrostatic repulsion between the two electric double layers 9 adjacent to each other. Since the electrostatic repulsive force increases in inverse proportion to the square of the distance, a supporting force capable of supporting the load applied to the shaft can be exerted in this portion where the supporting force is required. Further, the electric double layer 9 serves as a solid protective film as shown in the lower diagram of FIG. 5, so that seizure of the shaft 1 and the bearing 2 can be prevented, and even if it is called a film, it is not solid. Since the shearing force at the interface with the electrically neutral lubricating liquid 3 is considerably relaxed as compared with the solid, viscous friction can be reduced. FIG. 6 shows the electrostatic relationship of this embodiment. As described above, since the electrostatic repulsion force inversely proportional to the square of the distance can cover the pressure distribution shown in FIG. 3, the output of the voltage sources 4 and 5 can be adjusted to reduce the size of the conventional bearing system. Also, friction loss can be reduced.

【０００７】[0007]

【発明の効果】本発明によれば、軸受システムに電気二
重層を利用することにより距離の二乗に反比例する静電
的反発力を使えるので軸受剛性を高くできるし、また、
電気的に中立な潤滑液との境界面での剪断力は、固体に
比べてかなり緩和されるから軸受損失もできるので高速
化，小型化及び軽量化が図れる。According to the present invention, the use of the electric double layer in the bearing system allows the electrostatic repulsion force inversely proportional to the square of the distance to be used, so that the bearing rigidity can be increased.
Since the shearing force at the interface with the electrically neutral lubricating liquid is considerably relaxed compared to solids, bearing loss can also be achieved, so speedup, downsizing and weight reduction can be achieved.

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

【図１】本発明の一実施例の軸受の回路図。FIG. 1 is a circuit diagram of a bearing according to an embodiment of the present invention.

【図２】本発明の第二の実施例の軸受の回路図。FIG. 2 is a circuit diagram of a bearing according to a second embodiment of the present invention.

【図３】軸受の一般的な圧力分布の説明図。FIG. 3 is an explanatory diagram of a general pressure distribution of a bearing.

【図４】電気二重層の説明図。FIG. 4 is an explanatory diagram of an electric double layer.

【図５】電気二重層による軸受作用の説明図。FIG. 5 is an explanatory diagram of a bearing action by the electric double layer.

【図６】電気二重層による軸受作用の説明図。FIG. 6 is an explanatory view of a bearing action by the electric double layer.

【符号の説明】[Explanation of symbols]

１…軸、２…軸受、３…潤滑液、４，５…電圧源。 1 ... Shaft, 2 ... Bearing, 3 ... Lubricating liquid, 4, 5 ... Voltage source.

Claims (5)

【特許請求の範囲】[Claims] 【請求項１】回転部，静止部と潤滑液から成る軸受にお
いて、前記回転部または前記静止部に電極と前記電極に
電位を与える電圧源とを設け、前記回転部または前記静
止部と潤滑液との界面に発生する電気二重層を制御でき
るようにしたことを特徴とする軸受システム。1. A bearing comprising a rotating part, a stationary part and a lubricating liquid, wherein the rotating part or the stationary part is provided with an electrode and a voltage source for applying an electric potential to the electrode, and the rotating part or the stationary part and the lubricating liquid. The bearing system is characterized in that the electric double layer generated at the interface with is controlled. 【請求項２】請求項１において、前記回転部または前記
静止部に電極に両者に共通する同じ符号の電位を掛け
て、前記回転部または前記静止部と潤滑液との界面に発
生する電気二重層同士の反発する静電力を利用して軸受
剛性を可変に制御できるように前記電極の電位を与える
可変電圧源を設けた軸受システム。2. An electric generator generated at the interface between the rotating part or the stationary part and the lubricating liquid by applying an electrode having the same sign common to both electrodes to the rotating part or the stationary part. A bearing system provided with a variable voltage source for applying the electric potential of the electrode so that the bearing rigidity can be variably controlled by utilizing the repulsive electrostatic force between the multiple layers. 【請求項３】請求項２において、潤滑液中に電極を設け
て前記回転部または静止部と潤滑液との界面に発生する
電気二重層同士の反発する静電力を利用して軸受剛性を
可変に制御できるように前記電極の電位を与える可変電
圧源を設けた軸受システム。3. The bearing rigidity is varied according to claim 2, wherein an electrode is provided in the lubricating liquid, and electrostatic force repulsive between the electric double layers generated at the interface between the rotating portion or the stationary portion and the lubricating liquid is utilized. A bearing system provided with a variable voltage source for applying the electric potential of the electrode so as to be controlled. 【請求項４】請求項２において、潤滑液の圧力，温度ま
たは前記回転部の振動または回転数を検知する検知器と
前記検知器の出力により前記電圧源を制御する制御器を
設けた軸受システム。4. A bearing system according to claim 2, further comprising a detector for detecting the pressure and temperature of the lubricating liquid, vibration or rotation speed of the rotating portion, and a controller for controlling the voltage source by the output of the detector. . 【請求項５】請求項１において、前記電極に白金，白金
黒または炭素のような電気二重層容量の大きい材質を用
いた軸受システム。5. The bearing system according to claim 1, wherein the electrode is made of a material having a large electric double layer capacity such as platinum, platinum black or carbon.