JPH0689779B2 - Shafts and bearings - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shaft and a bearing thereof that rotate or move in an axial direction about an axis and slide on each other, and particularly to the shaft and the bearing. The present invention relates to the improvement of lubrication performance for sliding surfaces due to the weight reduction.

[Conventional technology]

Conventionally, shafts and bearings that slide with each other as described above are
Especially in the case of a combination of a shaft and a bearing that slide continuously at high speed for a long time, for example, the shaft is made of steel or alloy steel, and the bearing is made of a copper-based sintered alloy or resin molded product. Then, a solid lubricant is dispersed and applied to these bearing surfaces or embedded therein to obtain excellent lubricating performance.

However, if the shaft is formed of a ferrous material such as steel having a large specific gravity as described above, it is preferable to use it for a member such as an industrial robot that should have a small moment of inertia of the rotating body, or for an aircraft or the like. Since it is unsuitable for a member that needs to be lightweight, such as a rotating shaft, the shaft formed of an aluminum alloy is anodized (hereinafter referred to as alumite treatment) to improve corrosion resistance,
Alternatively, measures are taken such as plating the outer peripheral surface with nickel, hard chrome, iron or the like.

[Problems to be solved by the invention]

Since the conventional aluminum-based alloy shaft as described above has poor wear resistance in the alumite treatment, it is not durable as a shaft that operates continuously at high speed for a long time, and the outer peripheral surface is plated with nickel or the like. The method requires plating undercoating on a substrate such as an aluminum-based material, which increases the cost of the plating process including this undercoating, and the high-speed and high-temperature severe conditions of an internal combustion engine, for example. When used, the plating layer may peel off during use due to thermal expansion or the like.

Further, generally, in order to suppress the friction between the metal surfaces that slide with each other due to rotation or the like, a lubricant is supplied between these metal surfaces regularly or continuously. There is a problem in that the peripheral substances are contaminated by the dispersion residue of the agent, and it is considered to be a problem especially in a device requiring a high degree of cleanliness such as medical equipment.

The present invention has been made in order to solve the above problems, and to form a shaft or a bearing from a lightweight metal such as a specific aluminum-based alloy, and to impart wear resistance and lubricity. The purpose is to obtain a shaft and a bearing that do not need to supply a lubricant such as oil.

[Means for solving problems]

The shaft and bearing according to the present invention are formed by using ultra-super duralumin-based, duralumin-based, or high-strength aluminum-based alloys equivalent to these as a raw material, and these are first anodized to form an alumite layer on the surface, and then in the layer. The micropores are filled with a lubricating substance, and this filling is filled with a fluororesin by electrophoresis, immersion in a hot bath or the like.

Examples of the fluororesin include tetrafluoroethylene resin, vinyl fluoride resin, tetrafluoroethylene and hexafluoropolypropylene copolymer resin, and polychlortolufluoroethylene resin.

〔Example〕

FIG. 1 is a diagram schematically showing a cross section of a shaft according to an embodiment of the present invention, and 1 is 2024,2014,2017,7003,7NO1,7075
Duralumin-based or super-duralumin-based alloys such as 60
61,6063,5052,5056, etc., a shaft formed of a high-strength aluminum alloy equivalent to the above duralumin-based or ultra-super duralumin-based alloy, 2 is an alumite layer formed on the surface of this shaft, 3 is this alumite layer Innumerable fine pores are formed together with the formation of.

After the alumite layer 2 is formed on the outer peripheral portion of the aluminum alloy as described above, the fluororesin is filled in the fine pores 3 as a slipping substance by electrophoresis, immersion in a hot bath, vacuum impregnation or the like. Since the material of the shaft 1 of the fluorine-based resin in the fine holes 3 is the specific aluminum-based alloy as described above, this shaft has a sufficiently high strength as compared with the conventional shaft material. Therefore, it is filled in the fine holes 3 with a strong fixing force and excellent slidability can be obtained.

The shaft processed and treated as described above is fitted with a bearing made of, for example, a lubricant-containing oil-containing copper-based sintered alloy or an oil-containing resin molding, so that the friction coefficient of this fitting portion is the same as that of conventional steel or hard chromium. Tests showing in the table below that a shaft according to the present invention has excellent lubricity and a combination of a shaft and a bearing having a small coefficient of friction value can be obtained when compared with a shaft plated or anodized with an aluminum alloy. The results proved.

FIG. 2 is a cross-sectional view showing the fitting between the shaft and the bearing used to obtain the test results, where 1 is a shaft, 5 is a bearing, 6 is a stop ring for supporting the bearing 5 in the thrust direction, and 7 is a bearing.
Is a flange into which the bearing 5 is press fitted. Also, axis 4
Has an outer diameter of 20.0 mm, an inner diameter of the bearing 6 is 20.1 mm, and surface roughnesses thereof are both 0.6 μm. Test No. 1 is a combination of a shaft and a bearing according to an example of the present invention, and Test No. 1 is the present invention. ,
2 to 4 are examples of a combination of a conventional shaft and a bearing for comparison with the present invention, NTN Lulon in the bearing material is a fluorine resin molded product containing a special filler made by Toyo Bearing, and OILES ^# 80 is an oil-containing acetal resin made by OILES. Solid lubricant dispersed in oilless cermet, solid lubricant dispersed in copper-based sintered alloy in the same way, Deflick Coat FH-2 is a solid lubricant in Kawamura Laboratory's organic binder, inorganic binder It is dispersed and applied, dried or baked.

In the above-mentioned embodiment, only the shaft was subjected to alumite treatment, and the example was described in which the fluorine-based resin was filled into the micropores after this treatment.
The above-mentioned specific aluminum-based alloy bearing may be subjected to the above-mentioned treatment to combine both objects, or the shaft and the bearing may be formed from the above-mentioned aluminum-based alloy and subjected to the above-mentioned treatment to combine them. Can also be used.

Further, in the above-mentioned embodiment, the example in which the shaft is formed of the above-mentioned specific aluminum-based alloy has been described. Although the same treatment as in the example may be performed, and the example in which the micropores 3 generated by the alumite treatment are filled with the fluororesin by hot bath impregnation, the fluororesin is subjected to electrophoresis or vacuum impregnation. Even if it is impregnated with and the fine holes 3 are filled with the same, the same effect as that of the above-described embodiment is obtained.

〔The invention's effect〕

As described above, according to the present invention, the sliding surface of the shaft or bearing formed of the aluminum alloy is alumite treated,
Since the fluorine-based resin is filled in the fine pores generated by the alumite treatment, there is an effect that it is possible to obtain a lubricating sliding surface having high wear resistance and dust-free.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a cross section of a shaft according to an embodiment of the present invention, and FIG. 2 is performed to compare the results of the present invention with the static friction coefficient of a conventional combination of a shaft and a bearing. FIG. 3 is a cross-sectional view of a shaft and bearing for an experiment. In the figure, 1 is a bearing, 2 is an alumite layer, and 3 is a fine hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Saruwatari 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. (72) Reiji Saito 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Densen Co., Ltd. (72) Inventor Rokuro Ito 3226-1, Toyohashi, Hamamatsu, Shizuoka Prefecture Miyaki Co., Ltd. (72) Inventor Kenichiro Ito 3226-1, Toyomachi, Hamamatsu, Shizuoka Prefecture ) Inventor Yoshio Koike 3226-1 Toyohmachi, Hamamatsu City, Shizuoka Miyauchi Co., Ltd. (56) References JP-A-49-65945 (JP, A) JP-A-47-3562 (JP, A)

Claims (1)

[Claims] Claim: What is claimed is: 1. A shaft and a bearing fitted to the shaft, which rotate or move in the axial direction about the shaft center and slide on each other, both the shaft and the bearing, or either the shaft or the bearing. One is formed from ultra-super duralumin, duralumin or a high-strength aluminum alloy equivalent to these as a raw material, and these are electrophoresed in the micropores in the oxide film generated by anodizing, immersion in a hot bath, Shafts and bearings characterized by being filled with fluorine-based resin as a slipping substance by vacuum impregnation, etc.