JPS6230624Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to improvement of carbon sliding materials.

Usually, the sliding member of a mechanical seal consists of a ring member a on the fixed side that has a relatively wide sliding surface and high hardness, and a sliding protrusion that has a relatively narrow sliding surface and low hardness, as shown in Figure 1. The ring member b on the rotation side having the ring member b is configured to be in sliding contact with each other, and both sliding surfaces are finished with extremely precise flat surfaces so as to slide smoothly and to prevent fluid from leaking across the sliding surfaces. However, in actual use, the sliding surface becomes distorted and leaks easily due to the effects of pressure, temperature, etc. Therefore, in general, even if one ring member a is slightly distorted, the sliding surface of ring member b is made of a soft (low Young's modulus) material such as carbon so that the other ring member b follows that of ring member a. However, when the mechanical seal is used, for example, in a water pump for cooling an automobile engine, the molding sand from the casting of the engine remains in the sealing fluid, and therefore the ring member b, which is made of carbon material, is As shown in the figure, it has the disadvantage of significant wear on the sealed fluid side of the sliding surface.

In view of the above points, the present invention consists of a ring member with an outer layer made of a carbon material that is relatively harder than the internal carbon material, and is a mechanical seal that maintains the sealing effect and has excellent wear resistance. The purpose is to provide carbon sliding materials.

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 3. 1 is a mechanical seal that comes into sliding contact in the axial direction with a hard ring member 2 made of ceramic, metal, hardened metal, etc. In the carbon sliding material constituting the moving member, the entire surface of the carbon sliding material 1 excluding the sliding surface 3 is formed with an outer layer portion 1b made of a carbon material having a relatively higher hardness than the internal carbon material 1a. has been done. This outer layer 1b has a thickness of about 1 mm and prevents the sealing fluid containing slurry from gradually entering from the outer periphery of the sliding surface 3 and abrading the sealed fluid side of the sliding surface 3. .

Next, FIG. 4 shows another embodiment of the present invention. To explain only the parts that are different from the first embodiment, the outer layer is made of a carbon material having a relatively higher hardness than the inner carbon material 1a. The portion 1b is formed only on the sealing fluid side circumferential surface of the sliding protrusion 4 of the carbon sliding material 1. As mentioned above, this outer layer 1b is intended to prevent the sliding surface 3 from being worn out by the slurry contained in the sealing fluid, and is located at a position to protect the sealing fluid side of the sliding surface 3. If it is formed, the effect can be fully exhibited.

As explained above, in the carbon sliding material of the present invention, the outer layer portion made of a carbon material that is relatively harder than the internal carbon material forming the sliding surface forms a sliding portion on the sealed fluid side of the sliding surface. Therefore, if the sealing fluid contains molding sand or the like, the sealing fluid side of the sliding surface will not be easily worn away by the molding sand or the like. Therefore, it is possible to effectively prevent the sliding surface from being sequentially worn from the sealed fluid side to the inside by molding sand or the like. Furthermore, since the sliding surface is made of a normal carbon material with low hardness, the ability to follow the ring member will not be reduced and the sealing effect will not be reduced. The practical effects of this invention are extremely large.

[Brief explanation of the drawing]

The drawings show an embodiment of the carbon sliding material of the present invention. Figure 1 is a half-cut sectional view showing the sliding member of a conventional mechanical seal, Figure 2 is an enlarged front sectional view of the same essential part, and Figure 3 is an enlarged front sectional view of the same main part. 4 is an enlarged front sectional view of the main part showing the carbon sliding material of the present invention, and FIG. 4 is an enlarged front sectional view of the same main part showing another embodiment. 1...Carbon sliding material, 1a...Internal carbon material, 1b...Outer layer part, 2...Hard ring member,
3...Sliding surface, 4...Sliding protrusion.

Claims (1)

[Scope of utility model registration request] In the carbon sliding material that constitutes the sliding member of a mechanical seal that comes into sliding contact in the axial direction with a hard ring member such as ceramic, a sliding surface is provided on the circumferential surface of the carbon sliding material on the sealed fluid side. An outer layer portion made of a carbon material having a relative hardness than the inner carbon material to be formed is formed, the outer layer portion forming a sliding portion on the sealing fluid side of the sliding surface, and sealing the sliding surface. A carbon sliding material that prevents wear on the fluid side.