JPS6073122A - Friction and wear part - Google Patents

Abstract

PURPOSE:To greatly improve the mechanical loss, the seizure phenomenon and the wear phenomenon by applying graphite scattered ceramics as the material of a mechanical element part sliding against a bearing and by treating a part of the surface of said part with fluorine gas. CONSTITUTION:Ceramics 2 in which graphite 3 is scattered is used as the material of a mechanical element part sliding against a bearing, and a part of the surface of the ceramics 2 is treated with fluorine gas to selectively change graphite contained in a layer 3 into graphite fluoride 3. The mechanical element part sliding against the bearing may be easily substituted by the fluorinated part of graphite compound ceramics having the characteristics of low friction and low wear, hence attaining reduction of the mechanical loss increased with increase in coefficent of friction, prevention of seizure caused by heating and improvement of reliability on the resistance against wear, which all occur on the friction face with the bearing.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to mechanical components with bearing sliding parts such as compressors, and particularly relates to a graphite-dispersed ceramic composite suitable for reducing mechanical loss due to frictional wear. Regarding materials.

[Background of the invention]

Conventional ceramic bearing sliding parts are made of silicon carbide.

Silicon nitride, zirconia, alumina, sialon, etc. are made of a single component of highly hard crystal grains 1 as shown in Figure 1, and are used by precision machining after firing, but solid contact is not possible. Under the accompanying boundary lubrication conditions, if the surface roughness of the sliding surface is poor, it will bite into the mating ceramic or metal like abrasive grains, increase mechanical loss due to frictional resistance and frictional heat generation, and reduce product reliability due to seizure phenomenon 5 wear phenomenon. This has the disadvantage of lowering the efficiency of compression work in products such as rotary compressors.

[Purpose of the invention]

The purpose of the present invention is to form a fluorinated graphite layer with excellent self-lubricating properties by reacting a portion of Table 1m of graphite composite ceramics with graphite exposed on the entire surface or a portion of the surface by fluorine gas treatment. The purpose of this invention is to provide bearing sliding parts with low wear and low friction.

[Summary of the invention]

Silicon carbide, silicon nitride, zirconia, alumina.

Mechanical components with sliding bearings are made by blending appropriate amounts of ceramic materials such as Sialon and graphite powder, pressure sintering, molding, and finishing into the desired shape through precision machining, using fluorine gas or diluted fluorine. We have discovered that by selectively reacting the surface graphite layer in gas to form a fluorinated graphite layer with self-lubricating properties, it is possible to manufacture bearing sliding parts with low friction and low wear. The reaction rate between fluorine gas and graphite can be controlled by temperature, a degree, pressure conditions, etc.If you want to selectively treat only the sliding surfaces of the bearings of the mechanical components, this part can be treated with high frequency heating, laser heating, or electronic heating. It is possible to partially accelerate the reaction by beam heating, radiation heating, etc.

Although the graphite fluorinated by this method expands slightly, it is only in the 5 surface layer and is much softer than the ceramic layer, so it does not pose any problem in terms of dimensional accuracy, but rather improves conformability during assembly. It has an improving effect.

The bearing sliding parts obtained using this method have high strength.

A high hardness ceramic layer and a soft self-lubricating fluorinated graphite layer have the effect of significantly improving friction and wear characteristics.

In addition, since graphite fluoride and ceramics are chemically stable, when used in rotary compressors that compress Freon or air, it is possible to reduce mechanical loss and improve product reliability such as wear and burnout phenomena. Become.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. Figure 2 shows a cross section of the sliding movement of a mechanical component, where 2 is a ceramic crystal grain, 3 is a graphite layer, and 4 is a fluorinated graphite layer that is a fluorinated compound exposed on the surface. +1i1. A high-strength, high-hardness ceramic layer is used to withstand the load strength of friction and sliding.

The fluorinated graphite layer, which has self-lubricating properties, is responsible for the low coefficient of friction and amount of wear, and the composite characteristics of each layer exhibit excellent friction and wear characteristics with low friction and low wear.

An application example of the present invention will be explained with reference to a sectional view of a rotary compressor shown in Fig. 3. 5 is a vane that moves up and down, 6 is a rotating roller, 7 is a rotating shaft, 8 is a cylinder, 9 is a spring, and 10 is a suction A port 11 indicates a discharge port. Suction gas flows in from the suction port 10, is compressed in the space between the roller 6, the cylinder 8, and the vane 5 due to the eccentric rotation of the rotating shaft 7 and the roller 6, and then flows into the discharge port 11. The structure is such that the gas is discharged as a compressed gas, and each part exhibits frictional sliding behavior with its neighboring parts. Among these frictional sliding parts, the tips of the roller 6 and vane 5 are in point contact, so the surface pressure is high, and the oil supply runs out, resulting in a boundary 11'8 sliding area due to solid contact. However, there were major problems such as increased friction coefficient and frictional heat generation, which caused mechanical loss and seizure phenomenon, and abrasion of sliding surfaces, which significantly impaired reliability. By using this for one or both of the vanes 5 and rollers 6, the conventional defects such as mechanical loss, seizure phenomenon, and wear phenomenon can be significantly improved.

〔Effect of the invention〕

According to the present invention, mechanical components that involve sliding bearings can easily be replaced with fluorine-treated graphite composite ceramics that have low friction and low wear characteristics. It is effective in reducing mechanical loss due to increased friction coefficient, preventing seizure due to heat generation, and improving reliability due to wear.
Especially the rotary.

Boundary lubrication areas such as vanes and rollers of engraving machines.

The effect is particularly large for expected parts1.
This greatly contributes to improving compression work efficiency and product reliability by reducing mechanical loss.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the conventional sliding movement of fired ceramics, Figure 2
The figure is a cross-sectional view of the sliding movement according to the present invention, and FIG. 3 is a cross-sectional view of a rotary compressor sliding part. 1... Ceramic crystal grain, 2... Ceramic crystal grain. 3...graphite, 4...fluorinated graphite, 5...vane, 6
...Roller, 7...Rotating shaft, 8...Cylinder,
9...Spring, 10...Suction port, 11...Discharge port.ノ/-)

Claims (1)

[Claims] 1. Friction and wear parts that use graphite-dispersed ceramics for mechanical components that involve sliding bearings, and partially treat the surface with fluorine gas to selectively convert the graphite layer exposed on the surface into fluorinated graphitization.