JPS6015596B2 - Mechanical seal sealing element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing element of a mechanical seal, and more particularly to a mechanical seal in which a sealing sliding ring and a seal base material are firmly joined.

Conventionally, alumina (
Single ceramic materials such as AI203) were rarely used.

The main reason for this is that it takes a lot of time and effort to bond and hold a single piece of ceramic material as a sealing sliding ring to a normal sealing base material made of metal such as stainless steel. That is, in the past, there have been sintered joining, O-ring mount joining (press-fitting), etc., and both require groove machining of the seal motherboard, highly accurate dimensions, or secondary parts such as O-rings. On the other hand, various ceramic materials have been attracting attention as being suitable as sealing fluid materials for mechanical seals, but it is difficult to obtain single ceramic molded bodies with high density and excellent material properties. It had been. However, in recent years, technological development has improved significantly, and in particular, various high-density ceramic molded products called "new ceramics," including high-density molded products of silicon carbide, have become the most productive. Now you can. The present invention was made against the background of the circumstances and situations described above, and is a simple structure in which a single silicon carbide material is simply and firmly joined to a seal base material made of stainless steel in order to be usable as a sealing sliding ring. It is intended to provide a sealing element for a mechanical seal.

Hereinafter, the present invention will be explained in detail based on embodiment figures.

FIG. 1 shows a sealing element of a mechanical seal according to the invention.

1 is a sealing sliding ring made of silicon carbide, 2 is a sealing base material made of stainless steel, and 3 is a brazing layer.

Then, the sealing ring 1 is connected to the sealing base material 2 through the brazing layer 3.
It is strongly connected with. As shown in FIG. 2, this sealing sliding ring 1 has a metal coating layer 6 formed on at least a portion of the surface other than the sealing sliding motion 4, that is, on the background 5 of the sealing sliding motion 4 in FIG. This metal coating layer 6 is obtained by applying so-called metallization, in which the back surface 5 made of ceramic is metallized, and is plated with a metal such as nickel.
Then, if a brazing layer 3 such as silver solder is placed between the metal coating layer 6 and the sealing base material 2 and heated to several hundred degrees Celsius, the brazing layer 3 will melt and the sealed tank will become visible as shown in FIG. The residual movement 1 and the seal base material 2 were joined by brazing, and a tightly integrated mechanical seal sealing element was obtained. In addition, the sealing sliding ring 1 includes:
It is a single unit consisting of a high-density silicon carbide molded body.

In addition to silver solder, yellow steel solder, phosphor steel solder, aluminum solder, etc. may be used for the brazing layer 3. The sealing element of a mechanical seal in which the sealed tank moving ring made of silicon carbide and the seal base material made of stainless steel are integrated in this way is sealed at the joint between the seal sliding ring and the seal base material as in the past. This is a sealing element of a mechanical seal in which a silicon carbide molded body, which is ideal as a sealing material, is disposed as a sealed tank moving ring, in addition to completely eliminating the possibility of secondary fluid leakage paths. Furthermore, in FIG. 3, as an alternative to forming the metal coating layer 6 by metallizing as shown in FIG. 2, a basic flux 7 with a low melting point is used.
The background of the sealing sliding ring 1 is etched, activated, and bonded to the sealing base material 2 via the brazing layer 3 as shown in FIG. The flux 7 used is a molten basic metal compound such as Na2C03 or K2C03, alone or in combination, and has a relatively low melting point of 300 to 900%. It is also preferable that the flux 7 is adhered to the back surface of the sealing ring 1 and then brazed to the base material 2. In addition, in FIG. 4, 1 is used as the sealing sliding ring 1'.
A metal coating layer 6 is formed by selecting a ceramic made of silicon carbide containing metallic silicon in a range of 25% to 25%, and metallizing the back surface 5 of the ceramic. Silicon carbide containing 1 to 25% silicon metal is inexpensive and easy to mass produce, and is particularly suitable for the sealing ring 1' of a general-purpose mechanical seal. In addition,
A sealing sliding ring made of silicon carbide is difficult to machine, such as cutting, as with other ceramics. For this reason, in the past, as described above, the seal base material was machined and the seal ring was competed to maintain the connection. In the present invention, as already shown in the embodiments, there is no need for any machining of the seal base material in order to join and hold the seal sliding ring, and the joint image of the seal base material is a flat surface. Good to have. Moreover, even if the sealed tank moving ring has a simple shape, it is fine.
In the past, the outer peripheral surface and back surface of the sealed tank moving ring were sometimes molded into a somewhat complicated shape in order to join it to the seal base material, but there was no need to do this at all. Since the sealing sliding ring was directly joined to the sealing base material through the brazing layer, a strong holding force was obtained. In the field of mechanical seals, conventionally, complicated joining methods have been used to join the seal base material and the sealing sliding ring, and the constituent material of the sealing sliding ring is tungsten carbide, which is easily obtained as a pseudo-cross body. The load capacity of the sealing element of such mechanical seals is generally 100
In contrast, the sealing element of the mechanical seal according to the present invention uses silicon carbide, which is ideal for the sealed tank sardine residue, in the sealed tank moving ring.
Moreover, since we are looking for a simple joining method, the load capacity can be increased four to five times compared to conventional methods.

[Brief explanation of drawings]

The drawings all show embodiments of the present invention; FIG. 1 is a sectional view of a sealing element of a mechanical seal, and FIGS. 2, 3, and 4 are sectional views of a sealing sliding ring. 1,1...Dense sliding ring, 2...Seal base material, 3...Brazing layer, 6...Metal coating layer, 7... ...Fluxing agent. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. Sealing of a mechanical seal in which a sealing sliding ring made of silicon carbide with a metal coating layer formed on at least a portion of the surface other than the sealing sliding motion is brazed to a sealing base material made of stainless steel. element. 2. A sealing element for a mechanical seal, in which at least a portion of the surface other than the sealing sliding motion is made of silicon carbide activated with a basic flux, and a sealing sliding ring is brazed to a sealing base material made of stainless steel.