JPH0735859B2 - Manufacturing method of carbonaceous sliding material for mechanical seal - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a carbonaceous sliding material as a sealing sliding ring of a mechanical seal mounted on a shaft sealing portion of a rotating device.

[Conventional technology]

Carbon materials have been widely used for sealing sliding rings of mechanical seals. This is because the carbon material has excellent self-lubricating property and abrasion resistance and is extremely suitable as a sliding material.

Further, the sealing sliding surface of the sealing sliding ring may be machined to form fine spiral grooves. this is,
This is because the spiral groove causes a pumping action in the direction in which the fluid leakage is obstructed during rotation, thereby improving the sealing performance.

[Problems to be Solved by the Invention]

However, the conventional sealing slide ring made of carbon material has the following problems.

First of all, it means that a small fracture due to sliding may occur on the sliding surface. For example, when oil (viscous fluid) is to be sealed, sliding heat generation causes a blistering phenomenon called a blister on the sliding surface, which causes damage to the sliding surface and induces leakage. Of.

Secondly, the fine spiral groove formed by machining on the sliding surface disappears in a relatively short period of time due to wear, and the excellent sealing performance due to the pumping action of the spiral groove is impaired. Is.

In view of the above points, the present invention has been made for the purpose of obtaining a carbonaceous sliding material for a mechanical seal that has excellent mechanical strength and excellent sealing performance.

[Means for Solving the Problems]

In order to solve the above problems, the present invention, a first step of winding a carbon fiber spirally on the surface of a core portion formed into a ring of carbon in a required thickness, and a thermosetting resin between the carbon fibers. It is intended to provide a method for producing a carbonaceous sliding material for a mechanical seal, which comprises a second step of impregnation and a third step of heat-treating and thermosetting the thermosetting resin.

Further, in the above-mentioned manufacturing method, the carbon fiber wound in the first step may be replaced with the organic polymer fiber, and in the third step, the organic polymer fiber may be heat treated with a thermosetting resin to be carbonized.

[Action]

According to the production method of the present invention, a carbon-based sliding material having a structure in which the entire surface of the carbon-molded core portion is covered with a surface layer portion made of carbon fiber-carbon composite material is obtained, and the surface layer portion is a single layer. It has an extremely large mechanical strength as compared with a core material composed of only carbon of one composition, which improves the resistance of the sliding surface to microdestructive action.

Further, the carbon fiber has a matrix structure in which the surface layer portion has a spiral directional property, so that it is possible to generate a pumping action in the direction in which the leakage of the fluid is obstructed on the sliding surface by the rotation, and this spiral-shaped Since the tissue always appears on the sliding surface unless the surface layer part is completely worn away, the pump action can be exerted for a long period of time.

〔Example〕

Hereinafter, the present invention will be described with reference to the illustrated embodiment.

FIG. 1 schematically shows the structure of a carbonaceous sliding material for a mechanical seal manufactured by the method of the present invention. The carbonaceous sliding material 2 is a core of a single composition formed by molding carbon into an annular shape. Part 4
And a surface layer portion 6 having a required thickness that covers the surface of the core portion 4.

As shown in FIG. 2, the surface layer portion 6 has a first step of spirally winding the carbon fiber 8 around the entire circumference of the core portion 4 to a required thickness, and a layer of the carbon fiber 8 After the second step of impregnating a thermosetting resin such as phenol resin, furan resin, or epoxy resin and drying it sufficiently, as the third step, first, heat to about 300 ° C. at a heating rate of 2 ° C./hour. The carbon fiber 8 is obtained by heat treatment such as heating to about 600 ° C. at a heating rate of 5 ° C./hour, and further heating to a required high temperature T at a heating rate of 60 ° C./hour. A carbonized material in which the above-mentioned thermosetting resin that has entered between the layers due to the capillary phenomenon is carbonized and hardened by heat treatment.
Is composed of a carbon fiber-carbon composite material having a matrix structure in which are bonded and held.

The final temperature T in the heat treatment is about 1000 to 3000 ° C., and is determined by the desired degree of graphitization (the higher the temperature, the higher the degree of graphitization). The higher the lubricity, the higher the lubricity, and the lower the degree of graphitization, the higher the strength and hardness. In the first step, the core portion 4 is wrapped with an organic polymer fiber such as rayon-based material which is a material of the carbon fiber 8 and is heat-treated in the third step together with the thermosetting resin impregnated in the second step. Thus, even if the organic polymer fibers are carbonized, it is possible to obtain the surface layer portion 6 made of the carbon fiber-carbon composite material.

The carbonaceous sliding material 2 has one end surface as the sliding surface 2a, and the surface layer portion 6 forming the sliding surface 2a has the carbonized material 10 firmly held between the carbon fibers 8. Since it has a structure, it has high mechanical strength, and therefore has excellent abrasion resistance and also has excellent resistance to the phenomenon of minute damage to the surface due to blister or the like.

Further, on the sliding surface 2a, the carbon fiber 8 portion and the carbonized material 10 portion having different surface roughness are exposed with a spiral directionality, and rotation causes a pumping action on the fluid to be sealed, so that good sealing performance is obtained. In addition, this spiral structure is always present on the sliding surface 2a unless the surface layer portion 6 is worn away.

〔The invention's effect〕

As described above, the present invention provides a carbonaceous sliding material in which a surface layer portion including a sliding surface is composed of a carbon fiber-carbon composite material of a matrix structure having high mechanical strength formed by binding carbon fibers and a carbonaceous material. As a result, it is possible to prevent minute damage to the sliding surface due to the occurrence of prestars, and it is possible to exert a pumping action in the sealing direction during rotation for a long time due to the structure in which carbon fibers and carbonized materials are arranged in a spiral shape. It has an excellent effect that it can be done.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a carbonaceous sliding material obtained by a manufacturing method according to an embodiment of the present invention, and FIG. 2 is a schematic explanatory view showing a first step in the manufacturing method. . 2 carbonaceous sliding materials, 2a sliding surface, 4 cores, 6 surface layers, 8 carbon fibers, 10 carbonized materials

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Claims (2)

[Claims] 1. A first step in which carbon fibers are spirally wound around a surface of a core portion formed of carbon in an annular shape with a required thickness, and a second step in which a thermosetting resin is impregnated between the carbon fibers. And a third step of heat-treating the thermosetting resin to carbonize the thermosetting resin, the method for producing a carbonaceous sliding material for a mechanical seal. 2. The method according to claim 1, wherein the carbon fiber wound in the first step is replaced with an organic polymer fiber, and the organic polymer fiber is heat treated with a thermosetting resin in the third step to be carbonized. A method for producing a carbonaceous sliding material for a characteristic mechanical seal.