JPH11350091A - Bearing for motor and motor using this bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil-impregnated sintered bearing used for a small size motor which reduces friction resistance, restrains work hardening and reduces adhesive wear, and a motor using this bearing which has small friction resistance, high wear resistance and high accuracy. SOLUTION: In the sintered oilless bearing supported by inserting a shaft 4 through a bearing hole and composed of Fe alloy and/or Cu alloy as the bearing material, frit amorphous fine powder as vitreous molten material of thin state Fe-B-Si substantially individual-spotting with a low temp. burning is contained. This bearing is slidingly moved in contact with the shaft 4 through this thin state frit amorphous fine powder. The blending ratio of this fine powder in the bearing is made in the range of 2-25%. This major axis of this fine powder is made in the range of 20-150 μm and the thickness is made in the range of 5-20 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor bearing using a sintered oil-impregnated bearing alloy.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a motor in the field to which the present invention relates, and an improvement of a sintered oil-impregnated bearing 3 for supporting a shaft is the subject of the present invention. The sintered oil-impregnated bearing 4 is made of Fe
Alloys and / or Cu alloys are used. However, in order to suppress work hardening, reduce frictional resistance, and improve mechanical strength and wear resistance, for example, a conventional sintered oil-impregnated bearing is disclosed in Japanese Unexamined Patent Publication No. 8-177677. As described in Japanese Patent Application Publication No. H06-27139, compounding of PbO-containing compound fine particles and ceramic fine particles into a sintered oil-impregnated bearing suppresses work hardening, reduces frictional resistance,
The mechanical strength and wear resistance were improved.

[0003]

In general, when a shaft rotates, a sintered oil-impregnated bearing has a lubricating oil sucked by a "pump action" based on the rotation of the shaft on a bearing sliding surface and an expansion based on frictional heat. The oozed lubricating oil forms an oil film, and metal contact between the shaft and the sintered oil-impregnated bearing is avoided. When the shaft is stopped, it is cooled, and the excess lubricating oil present on the sliding surface is again absorbed in the original oil-impregnated hole by capillary action. That is, it can be said that the bearing is functionally a rational bearing having a characteristic that can be used without lubrication.

[0004] Such advantages are, of course, caused by pores in the sintered oil-impregnated bearing, but on the other hand, these pores also have inherent disadvantages as a bearing. For example, in a normal bearing without any holes, if ideal lubrication, that is, a method such as constant lubrication, is used, an oil film with hydraulic pressure will be generated on the sliding surface during operation, and the shaft will not contact the bearing. Fluid lubrication is used.On the other hand, in the case of sintered oil-impregnated bearings, even if oil pressure is generated there, lubricating oil leaks to the outside through holes and the oil pressure drops, so that the shaft makes local contact with the bearing, so-called boundary Lubrication is often performed. Therefore, the friction coefficient is 0.02 to 0.05 for ordinary bearings.
Whereas, in the case of the sintered oil-impregnated bearing, 0.07 to 0.15
And the temperature rise becomes relatively large.

[0005] However, the performance of a normal bearing is good when lubrication from the outside is ideally performed, and once lubrication is stopped, the lubricating oil is immediately depleted and there is a risk of seizure. In the case of a sintered oil-impregnated bearing, such concerns are extremely small due to the oil supply mechanism described above.

Among these, sintered oil-impregnated bearings containing melt particles have the advantageous characteristics of low frictional resistance and high wear resistance, but have the problem of low mechanical strength and easy work hardening. Had a point.

According to the present invention, in a sintered oil-impregnated bearing used for a small motor, mechanical strength is improved, frictional resistance is reduced, work hardening is suppressed, and cohesive wear is reduced. It is an object of the present invention to provide a motor bearing having low resistance and high wear resistance.

[0008]

SUMMARY OF THE INVENTION In a sintered oil-impregnated bearing having a bearing hole through which a shaft is inserted and supported, and the bearing material is made of an Fe alloy and / or a Cu alloy, the bearing is substantially individually scattered by low-temperature sintering. It contains frit amorphous fine powder, which is a vitreous melt of thin, leaf-like Fe-B-Si having a small coefficient of friction, and is slid into contact with a shaft via the thin, leaf-like Fe-B-Si frit amorphous fine powder.

Further, Fe-B- compounded in a sintered oil-impregnated bearing
The amount of Si frit amorphous fine powder is 2% or more 25
% Or less.

Further, a thin leaf-shaped F compounded in a sintered oil-impregnated bearing
e-B-Si frit amorphous fine powder long side is 20μ
m to 150 μm and a thickness of 5 μm to 20 μm.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION
It has a bearing hole for inserting and supporting the shaft, and the bearing material is F
A sintered oil-impregnated bearing made of an e-alloy and / or a Cu alloy contains frit amorphous fine powder, which is a vitreous melt of flaky Fe-B-Si substantially scattered independently by low-temperature sintering. Fe-B-Si frit amorphous fine powder is designed to slide in contact with the shaft. Fe-B-Si frit amorphous has a very small frictional resistance. -Friction resistance and cohesive wear are reduced by sliding in contact with the shaft via the amorphous silicon frit.

According to the invention of claim 2 of the present invention, the compounding amount of the Fe-B-Si frit amorphous fine powder compounded in the sintered oil-impregnated bearing is in the range of 2% to 25%. If the amount of Fe-B-Si frit amorphous fine powder is smaller than this, there is no effect. If the amount of Fe-B-Si frit amorphous fine powder is large, hard Fe-B-Si frit amorphous will cut the shaft during sliding.

[0013] The invention according to claim 3 of the present invention is characterized in that the long side of the thin leaf-like Fe-B-Si frit amorphous fine powder compounded in the sintered oil-impregnated bearing is in the range of 20 µm to 150 µm and the thickness is 5 µm or more. The range is 20 μm or less. If it is smaller than this, Fe-BS with low frictional resistance
The effect of the i-frit amorphous fine powder does not appear, and when the size is larger than this, the hard Fe-B-Si frit amorphous cuts the shaft during sliding.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a structural sectional view of a motor according to the present invention. 5 is a sintered oil-impregnated bearing, 4 is a shaft, 5 is a thrust plate, 6 is a substrate, 7 is a magnet, 8 is a rotor frame, 9 is a stator core, 10 is a coil, 11 is a drive pin, 12 is a housing, 13 Indicates a screw.

FIG. 3 is an overhead sectional view of a sintered oil-impregnated bearing according to the present invention. 4 shows a sintered oil-impregnated bearing.

FIG. 2 is a sectional view of a sintered oil-impregnated bearing according to the present invention. In FIG. 3, reference numeral 1 denotes thin-leafed Fe—B—Si fine powder substantially independently scattered by low-temperature firing, and reference numeral 2 denotes an Fe alloy and / or Cu alloy fine powder.

Further, the sintered oil-impregnated bearing is made to contain thin-leafed Fe-B-Si frit amorphous fine powder substantially scattered independently by low-temperature firing. Since the Fe-B-Si frit amorphous has a very small frictional resistance, the frictional resistance and the cohesive wear are reduced by contacting the shaft with the shaft through the Fe-B-Si frit amorphous having a small frictional resistance. .

FIG. 1 is an external view of a frit amorphous fine powder which is a vitreous melt of a thin leaf Fe-B-Si of the present invention.

[0020] The fact that the frit is substantially scattered independently by low-temperature firing means that the frit is made of an Fe alloy and / or a Cu alloy.
This refers to firing at a temperature low enough to uniformly disperse in the alloy fine powder or in the vicinity of the shaft contact surface and to prevent the frit from being deformed and altered or combined with the Fe alloy and / or Cu alloy fine powder to lose their properties. Even if the frit is combined, it is sufficient that the characteristics are exhibited, so that the shaft normally slides on both the frit and the Fe alloy and / or Cu alloy fine powder. The contact sliding with the shaft through the thin-leafed Fe-B-Si frit amorphous fine powder means at least sliding contact with the frit amorphous fine powder.

[0021]

The bearing for a motor according to the present invention has a bearing hole through which a shaft is inserted and supported, and in a sintered oil-impregnated bearing in which the bearing material is made of an Fe alloy and / or a Cu alloy, a thin-leafed bearing having a very small frictional resistance. Frit amorphous fine powder, which is a vitreous melt of Fe-B-Si, is substantially scattered and contained solely by low-temperature firing. The frictional resistance and cohesive wear are reduced by sliding the shaft through the Fe-B-Si frit amorphous having a small frictional resistance.

Fe-B-Si compounded in sintered oil-impregnated bearing
The amount of the frit amorphous fine powder is in the range of 2% or more and 25% or less. If the amount of Fe-B-Si frit amorphous fine powder is smaller than this, there is no effect, and Fe-B-Si frit is ineffective.
If there are many frit amorphous fine powders, hard Fe-BS
The i-frit amorphous cuts the shaft during sliding.

Thin leaf-like Fe-
The long side of the B-Si frit amorphous fine powder is in a range of 20 μm to 150 μm, and the thickness is 5 μm to 20 μm.
m or less. If smaller than this, Fe-B-S
The effect of the i-frit amorphous fine powder does not appear and the frictional resistance increases, and if it is larger than this, the hard Fe-B-Si frit amorphous cuts the shaft during sliding.

As described above, according to the present invention, in a sintered oil-impregnated bearing used for a small motor, reduction of frictional resistance,
The advantageous effects of suppressing the occurrence of work hardening and reducing cohesive wear and obtaining a motor with low frictional resistance and high wear resistance and high accuracy can be obtained.

[Brief description of the drawings]

FIG. 1 is an external view of a frit amorphous fine powder which is a vitreous melt of thin-leafed Fe—B—Si of the present invention.

FIG. 2 is a sectional view of a sintered oil-impregnated bearing of the present invention.

FIG. 3 is an overhead sectional view of a sintered oil-impregnated bearing of the present invention.

FIG. 4 is a structural sectional view of a motor using the sintered oil-impregnated bearing of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Frit amorphous fine powder which is a vitreous melt of thin leaf Fe-B-Si 2 Fe alloy and / or Cu alloy 3 Sintered oil-impregnated bearing 4 Shaft 5 Thrust plate 6 Substrate 7 Magnet 8 Rotor frame 9 Stator core 10 Coil 11 Drive pin 12 Housing 13 Screw

Claims (4)

[Claims] In a sintered oil-impregnated bearing having a bearing hole for supporting a shaft and having a bearing material made of an Fe alloy and / or a Cu alloy, a thin-leafed Fe-B substantially independently scattered by low-temperature sintering. Frit amorphous fine powder which is a vitreous melt of Si
-A motor bearing that slides in contact with a shaft via Si frit amorphous fine powder. 2. Fe-BS compounded in a sintered oil-impregnated bearing.
i-frit amorphous fine powder blending amount is 2% or more and 25%
The motor bearing according to claim 1, wherein the range is as follows. 3. Leaf-shaped Fe compounded in a sintered oil-impregnated bearing
-B-Si frit amorphous fine powder has a long side of 20 μm
In the range of not less than 150 μm and not more than 5 μm 2
2. The motor bearing according to claim 1, wherein the diameter of the motor bearing is not more than 0 μm. 4. A motor using the motor bearing according to claim 1.