JP3623521B2 - Sintered metal oil-impregnated bearing - Google Patents
Sintered metal oil-impregnated bearing Download PDFInfo
- Publication number
- JP3623521B2 JP3623521B2 JP01193193A JP1193193A JP3623521B2 JP 3623521 B2 JP3623521 B2 JP 3623521B2 JP 01193193 A JP01193193 A JP 01193193A JP 1193193 A JP1193193 A JP 1193193A JP 3623521 B2 JP3623521 B2 JP 3623521B2
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- JP
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- Prior art keywords
- oil
- shaft body
- bearing
- face
- impregnated bearing
- 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.)
- Expired - Lifetime
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Description
【0001】
【産業上の利用分野】
本発明は、動圧スラスト軸受として使用される焼結含油軸受などの焼結金属製含油軸受に関する。
【0002】
【従来の技術】
含油軸受の多くは、粉末冶金法による焼結含油軸受である。焼結含油軸受は、多孔質の金属焼結体に潤滑油を含浸させたものである。そして、軸体の回転時には、含油軸受の気孔内に含まれた潤滑油が軸体と含油軸受との摺動部にしみ出して潤滑作用を行うものである。焼結含油軸受は、基本的にラジアルすべり軸受であり、筒状になっていて、内側に軸体を回転摺動自在に支持するものである。しかし、軸体に一体的に設けられた鍔が、含油軸受の端面へ軸方向の荷重を加える場合がある。摩擦熱などにより含油軸受の端面と軸体の鍔との間にも潤滑油はしみ出すが、含油軸受の端面が平坦であると潤滑油の誘出効果は薄い。しかも、含油軸受の端面と軸体の鍔との間の潤滑油は含油軸受の端面へ開口した気孔へ逃避しやすく、潤滑効果が下がる。これを防止するには、バニシングや研磨などにより含油軸受の端面の気孔を封孔することが考えられるが、ほとんど全ての気孔を封孔してしまえば、もとより潤滑油がしみ出さなくなる。いずれにせよ、含油軸受の端面が平坦であると、十分な潤滑効果が得られないが、潤滑効果が低ければ、抵抗も増大し、磨耗、損傷が生じやすくなる。
【0003】
これに対して、焼結含油軸受において、大きな軸方向の荷重に抗するために、従来より、端面にワッシャなどの補強材を固定する構造も採られている。しかし、これは、製造上、工数が増すとともに、部品点数も多くなり、コストアップを招く。また、軸体と軸受とは軸方向において直接接触するので、抵抗の増大、損傷の発生などの問題はやはり生じる。
【0004】
さらに、例えば特開平4−15311号公報などに記載されているように、良好な潤滑状態を保持するために、軸受の端面に多数のスパイラル状溝などからなる動圧発生溝を形成することも提案されている。しかし、このような動圧発生溝を形成したとしても、前述のように潤滑油が含油軸受の端面へ開口した気孔へ逃避してしまえば、十分な潤滑効果が得られなくなってしまう。
【0005】
【発明が解決しようとする課題】
前述のように、軸体の鍔などから大きな軸方向の荷重が加わる焼結含油軸受において、その平坦な端面に封孔処理を施さなくても、端面全体に封孔処理を施しても、潤滑油による十分な潤滑効果が得られず、抵抗の増大、磨耗、損傷の発生などの問題をきたす。また、大きな軸方向の荷重に抗するために、軸受の端面にワッシャなどの補強材を固定する前記従来の構造では、製造上不利であるとともに、やはり抵抗の増大、損傷の発生などの問題は解決できなかった。
【0006】
本発明は、このような問題点を解決しようとするもので、簡単な構造で確実に軸方向の荷重に抗することができるとともに、軸体の回転時の抵抗の増大や磨耗、損傷も生じない含油軸受を提供することを目的とする。
【0007】
【課題を解決するための手段】
本発明は、前記目的を達成するために、多孔質の金属焼結体の気孔に潤滑油を含侵させてなり軸体を回転自在に支持する筒状の焼結金属製含油軸受において、前記軸体から軸方向の加重を受ける端面に、内周および外周から前記軸体の回転方向へ向かって尖った楔状の凹部および凸部を前記回転方向に並べて交互に形成し、前記凹部に対する前記凸部の高さを、約3〜30μm程度とし、前記端面で凸部の表面のみを半分程度に封孔するように封孔処理してなるものである。
【0008】
【作用】
本発明の含油軸受は、筒状で、軸体を回転自在に支持するものであり、軸体の回転時、気孔内に含まれた潤滑油が軸体との摺動部にしみ出して潤滑作用を行う。特に、軸体から軸方向の荷重を受ける端面において、しみ出した潤滑油は、端面の内周および外周から軸体の回転方向へ向かって尖った楔状の凹部および凸部により、その尖った先端部の方へ案内され、凸部の先端部で油圧が高まり、その結果、この凸部と軸体との間に油膜が確実に介在し、軸受と軸体とが直接接触しない。しかも、軸受の端面で凸部の表面のみを半分程度に封孔するように封孔処理したことにより、凹部へ開口した気孔より十分な量の潤滑油がしみ出し、一方、軸体との間に油膜を生じるべき凸部では、気孔への潤滑油の逃避が抑えられることによって、よりいっそう確実に動圧が働く。
【0009】
【実施例】
以下、本発明の含油軸受の一実施例について、図面を参照しながら説明する。本実施例の含油軸受は、焼結含油軸受1であり、ほぼ円筒状に形成された金属焼結体の気孔に潤滑油を含浸させたものである。また、両端面2,3の内周部および外周部には、それぞれ面取り部4,5,6,7が形成されている。そして、本軸受1は、ファンモーターなどに利用され、内側に軸体11を回転摺動自在に支持するものであるが、この軸体11に一体的に設けられた鍔12から前記一端面2へ軸方向の荷重が加わるものである。この一端面2には、その内周および外周から軸体11の回転方向aへ向かって尖った楔状の凹部16および凸部17が前記回転方向aに並べて交互に形成されている。軸受1全体の長さが約12mm、外径が約8mmであるのに対して、凹部16に対する凸部17の高さは、約3〜30μm程度である。
【0010】
つぎに、前記軸受1の製造方法について、簡単に説明する。まず、原料粉末を粉末成形プレスにより圧縮して圧粉体を成形する(粉末成形工程)。ついで、この圧粉体を焼結炉で加熱して焼結する(焼結工程)。ついで、この焼結後の焼結体を矯正プレスにより再圧縮して、所定の寸法、形状に仕上げる(矯正工程)。この矯正工程において、前記凹部16および凸部17を形成する。すなわち、矯正用金型のパンチの端面に対応する凸部および凹部を形成しておくことにより、軸受1の端面2に凹部16および凸部17を形成する。ついで、軸受1の同端面2にバニシング加工を施す。すなわち、バニシ工具を軸受1の端面2の凸部17に当てて回転させることにより、この端面2を擦る。このバニシングにより、凸部17の表面へ開口した気孔は封孔される。ただし、凸部17の表面への気孔を全て封孔するのではなく、半分程度を封孔するようにする。これに対して、凹部16の表面へ開口した気孔は、封孔されない。さらに、軸受1の気孔内に潤滑油を含浸させる(含浸工程)。
【0011】
使用時、軸体11は、矢印aで示す方向へのみ回転する。この回転時、軸受1の気孔内に含まれた潤滑油が軸受1と軸体11との摺動部にしみ出して潤滑作用を行う。特に、軸体11の鍔12から軸方向の荷重を受ける端面2において、しみ出した潤滑油は、端面2の内周および外周から軸体11の回転方向aへ向かって尖った楔状の凹部16および凸部17により、その尖った先端部の方へ案内され、凸部17の先端部で油圧が高まる。こうして生じる動圧のために、凸部17と軸体11の鍔12との間に油膜が確実に介在し、軸受1と軸体11とが直接接触しない。このとき、潤滑油は、端面2において封孔されていない凹部16から主にしみ出し、ある程度の封孔がなされている凸部17においては、潤滑油が軸受1の気孔内に逃避してしまうことはほとんどない。
【0012】
以上のように、前記実施例の構成によれば、焼結含油軸受1における軸方向の荷重が加わる端面2に、軸体11の回転方向aへ向かって尖った楔状の凹部16および凸部17を形成したので、これら凹部16および凸部17による潤滑油の案内によって、確実に動圧を生じさせて、軸受1を軸体11の鍔12から軸方向において浮き上がらせることができる。しかも、凸部17の表面はバニシングによりある程度の封孔処理を施したのに対して、凹部16の表面は封孔していないので、この凹部16へ開口した気孔より十分な量の潤滑油がしみ出し、一方、鍔12との間に油膜を生じるべき凸部17では、気孔への潤滑油の逃避が抑えられることにより、よりいっそう確実に動圧が働く。したがって、軸体11の回転時の抵抗を低減できるとともに、磨耗、損傷の発生も抑えられる。また、製造上も、矯正工程において、軸受1の端面2に凹部16および凸部17を形成し、その後、同じ端面にバニシング加工を施すので、製造が容易であり、コストもかさまない。
【0013】
なお、本発明は、前記実施例に限定されるものではなく、種々の変形実施が可能である。例えば、凹部および凸部は、軸受の一方の軸方向端面にのみ形成してもよいし、あるいは、両方の軸方向端面に形成してもよい。軸受全体の形状も、前記実施例のものに限定されない。
【0014】
【発明の効果】
本発明によれば、含油軸受において、これが支持する軸体から軸方向の荷重を受ける端面に、内周および外周から軸体の回転方向へ向かって尖った楔状の凹部および凸部を前記回転方向に並べて交互に形成したので、凹部および前記凸部による潤滑油の案内によって動圧が確実に生じ、軸受の端面と軸体との直接接触を確実に防止でき、これにより、軸体の回転時の抵抗を低減できるとともに、磨耗、損傷の発生も抑えられる。また、構造が簡単で、製造も容易であり、コストもかさまない。さらに、前記凹部に対する前記凸部の高さを、約3〜30μm程度とし軸受の端面で凸部の表面のみを半分程度に封孔するように封孔処理したので、凹部へ開口した気孔より十分な量の潤滑油がしみ出し、一方、軸体との間に油膜を生じるべき凸部では、気孔への潤滑油の逃避が抑えられることにより、よりいっそう確実に動圧を働かせることができる。
【図面の簡単な説明】
【図1】本発明の含油軸受の一実施例を示す端面の正面図である。
【図2】同上図1のA−A断面図である。
【図3】同上全体の縦断面図である。
【符号の説明】
1 焼結含油軸受(含油軸受)
2 端面
11 軸体
16 凹部
17 凸部[0001]
[Industrial application fields]
The present invention relates to a sintered metal oil-impregnated bearing such as a sintered oil-impregnated bearing used as a dynamic pressure thrust bearing.
[0002]
[Prior art]
Most oil-impregnated bearings are sintered oil-impregnated bearings by powder metallurgy. The sintered oil-impregnated bearing is obtained by impregnating a porous metal sintered body with lubricating oil. During rotation of the shaft body, the lubricating oil contained in the pores of the oil-impregnated bearing exudes to the sliding portion between the shaft body and the oil-impregnated bearing and performs a lubricating action. Sintered oil-impregnated bearings are basically radial slide bearings, are cylindrical, and support a shaft body in a freely slidable manner inside. However, the rod provided integrally with the shaft body may apply an axial load to the end face of the oil-impregnated bearing. Although the lubricating oil oozes out between the end face of the oil-impregnated bearing and the shaft flange due to frictional heat or the like, if the end face of the oil-impregnated bearing is flat, the effect of attracting the lubricating oil is small. Moreover, the lubricating oil between the end face of the oil-impregnated bearing and the shaft flange easily escapes to the pores opened to the end face of the oil-impregnated bearing, and the lubricating effect is reduced. In order to prevent this, it is conceivable to seal the pores at the end face of the oil-impregnated bearing by burnishing or polishing. However, if almost all the pores are sealed, the lubricating oil will not exude. In any case, if the end face of the oil-impregnated bearing is flat, a sufficient lubricating effect cannot be obtained. However, if the lubricating effect is low, the resistance increases, and wear and damage are likely to occur.
[0003]
On the other hand, in the case of a sintered oil-impregnated bearing, a structure in which a reinforcing material such as a washer is fixed to an end surface has been conventionally employed in order to resist a large axial load. However, this increases the number of man-hours in manufacturing and increases the number of parts, leading to an increase in cost. Further, since the shaft body and the bearing are in direct contact with each other in the axial direction, problems such as an increase in resistance and occurrence of damage still occur.
[0004]
Furthermore, as described in, for example, JP-A-4-15311, a dynamic pressure generating groove including a large number of spiral grooves may be formed on the end face of the bearing in order to maintain a good lubrication state. Proposed. However, even if such a dynamic pressure generating groove is formed, a sufficient lubricating effect cannot be obtained if the lubricating oil escapes to the pores opened to the end face of the oil-impregnated bearing as described above.
[0005]
[Problems to be solved by the invention]
As described above, in a sintered oil-impregnated bearing to which a large axial load is applied due to shaft wrinkles or the like, lubrication is possible even if the flat end surface is not sealed or the entire end surface is sealed. A sufficient lubricating effect due to oil cannot be obtained, causing problems such as increased resistance, wear, and damage. In addition, the conventional structure in which a reinforcing material such as a washer is fixed to the end face of the bearing in order to resist a large axial load is disadvantageous in terms of manufacturing, and problems such as increased resistance and occurrence of damage are also caused. It could not be solved.
[0006]
The present invention is intended to solve such problems, and can withstand a load in the axial direction with a simple structure, and also causes an increase in resistance, wear and damage during rotation of the shaft body. The object is to provide a non-oil-impregnated bearing.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a cylindrical sintered metal oil-impregnated bearing comprising a porous metal sintered body impregnated with lubricating oil and rotatably supporting a shaft body. Wedge-shaped concave portions and convex portions sharpened from the inner periphery and outer periphery toward the rotational direction of the shaft body are alternately formed on the end surface receiving the axial load from the shaft body in the rotational direction, and the convex portions with respect to the concave portion are formed. The height of the part is about 3 to 30 μm, and the end face is sealed so that only the surface of the convex part is sealed about half.
[0008]
[Action]
The oil-impregnated bearing of the present invention is cylindrical and supports the shaft body rotatably. When the shaft body rotates, the lubricating oil contained in the pores exudes into the sliding portion with the shaft body and lubricates. Perform the action. In particular, at the end face that receives the axial load from the shaft body, the lubricating oil that oozes out is caused by the wedge-shaped concave and convex portions sharpened from the inner periphery and outer periphery of the end face toward the rotation direction of the shaft body. The oil pressure is increased at the tip of the convex portion, and as a result, an oil film is reliably interposed between the convex portion and the shaft body, and the bearing and the shaft body are not in direct contact with each other. In addition, a sufficient amount of lubricating oil oozes out from the pores opened to the recesses by the sealing treatment so that only the surface of the projections is sealed in half at the end face of the bearing. In the convex portion where an oil film is to be formed, the escape of the lubricating oil to the pores is suppressed, so that the dynamic pressure works more reliably.
[0009]
【Example】
Hereinafter, an embodiment of the oil-impregnated bearing of the present invention will be described with reference to the drawings. The oil-impregnated bearing of the present embodiment is a sintered oil-impregnated bearing 1 in which pores of a sintered metal body formed in a substantially cylindrical shape are impregnated with lubricating oil. Further, chamfered
[0010]
Next, a method for manufacturing the bearing 1 will be briefly described. First, the raw material powder is compressed by a powder forming press to form a green compact (powder forming step). Next, the green compact is heated and sintered in a sintering furnace (sintering process). Next, the sintered body after the sintering is recompressed by a correction press to finish to a predetermined size and shape (correction process). In the straightening process, the
[0011]
In use, the shaft 11 rotates only in the direction indicated by the arrow a. During this rotation, the lubricating oil contained in the pores of the bearing 1 oozes out to the sliding portion between the bearing 1 and the shaft body 11 to perform a lubricating action. In particular, on the
[0012]
As described above, according to the configuration of the above-described embodiment, the wedge-shaped
[0013]
In addition, this invention is not limited to the said Example, A various deformation | transformation implementation is possible. For example, the concave portion and the convex portion may be formed only on one axial end surface of the bearing, or may be formed on both axial end surfaces. The shape of the entire bearing is not limited to that of the above embodiment.
[0014]
【The invention's effect】
According to the present invention, in the oil-impregnated bearing, wedge-shaped concave portions and convex portions that are pointed from the inner periphery and the outer periphery toward the rotation direction of the shaft body are formed on the end surface that receives the axial load from the shaft body supported by the oil-impregnated bearing. Since the lubricating oil is guided by the concave portions and the convex portions, dynamic pressure is surely generated, and direct contact between the bearing end surface and the shaft body can be reliably prevented. Resistance can be reduced, and wear and damage can be suppressed. Moreover, the structure is simple, the manufacture is easy, and the cost is not increased. Furthermore, since the height of the convex portion with respect to the concave portion is about 3 to 30 μm and the sealing process is performed so that only the surface of the convex portion is sealed about half at the end face of the bearing, it is more sufficient than the pores opened to the concave portion. On the other hand, in the convex portion where an oil film oozes out and a film of oil is to be formed between the shaft body and the escape of the lubricating oil to the pores is suppressed, the dynamic pressure can be exerted more reliably.
[Brief description of the drawings]
FIG. 1 is a front view of an end face showing an embodiment of an oil-impregnated bearing of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA in FIG.
FIG. 3 is a longitudinal sectional view of the whole of the above.
[Explanation of symbols]
1 Sintered oil-impregnated bearing (oil-impregnated bearing)
2 End face
11 Shaft
16 recess
17 Convex
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP01193193A JP3623521B2 (en) | 1993-01-27 | 1993-01-27 | Sintered metal oil-impregnated bearing |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP01193193A JP3623521B2 (en) | 1993-01-27 | 1993-01-27 | Sintered metal oil-impregnated bearing |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH06221324A JPH06221324A (en) | 1994-08-09 |
JP3623521B2 true JP3623521B2 (en) | 2005-02-23 |
Family
ID=11791427
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP01193193A Expired - Lifetime JP3623521B2 (en) | 1993-01-27 | 1993-01-27 | Sintered metal oil-impregnated bearing |
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Country | Link |
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JP (1) | JP3623521B2 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3599886B2 (en) * | 1996-03-08 | 2004-12-08 | 日立粉末冶金株式会社 | Hydrodynamic thrust porous bearing |
JP2000350408A (en) | 1999-03-29 | 2000-12-15 | Nippon Densan Corp | Motor for driving recovering disk |
JP4573349B2 (en) * | 2004-10-21 | 2010-11-04 | 日立粉末冶金株式会社 | Manufacturing method of hydrodynamic bearing |
-
1993
- 1993-01-27 JP JP01193193A patent/JP3623521B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPH06221324A (en) | 1994-08-09 |
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