JPH0229310Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to shaft sealing technology, and relates to a mechanical seal that provides stable sealing performance.

[Conventional technology]

Conventionally, mechanical seals have been used in which a primary seal surface that slides airtight is formed by a rotating ring supported on the rotating shaft side and a fixed ring supported on the machine casing side, and the sealed sliding surface has a smooth finish. In,
Seals leakage from the rotating shaft.

[Problem that the invention attempts to solve]

For this reason, this type of mechanical seal generates heat on the sealing sliding surface due to the circumferential speed of the rotating shaft and the contact pressure of the sealing sliding surface due to fluid pressure.
In the case of severe usage conditions such as high pressure and high temperature, the above-mentioned sealing sliding surface may be deformed due to heat generation, or wear may become significant, resulting in leakage.

The present invention was developed in view of the above-mentioned problems, and it is an object of the present invention to provide a mechanical seal that can provide stable sealing performance even in a high temperature atmosphere.

[Means for solving problems]

The mechanical seal of the present invention forms a hollow part continuous in the circumferential direction inside the stationary sliding ring that is airtightly attached to the inner periphery of the machine casing. It is filled with refrigerant liquid.

[Effect]

This invention transfers and removes heat from the sliding surface side by utilizing the transfer of latent heat when the refrigerant liquid sealed inside the fixed side sliding ring undergoes a phase change. Since the refrigerant is rotated, the saturated vapor pressure at the liquid level of the refrigerant in the hollow portion does not increase due to centrifugal force, that is, the amount of evaporation is not affected by centrifugal force.

〔Example〕

Hereinafter, one embodiment of the mechanical seal of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a rotating ring that is airtightly supported on a liner 3 that is inserted and fixed to the shaft sealing portion of the rotating shaft 2. The seal is made by closely contacting the annular sliding protrusion 8 of the fixed ring 7, which is airtightly inserted into the shaft hole of the machine casing 5 via O-rings 6, 6, with respect to the sliding surface 4 of the rotating ring 1. It forms a sealing surface. The fixed ring 7 has an annular inner cavity 9 formed therein, and the inner cavity 9 contains chlorofluorocarbons, water, diphenyl heat transfer oil, benzene, methanol, acetone, etc.
It is filled and sealed with a refrigerant liquid 10 such as ammonia.

When filling the refrigerant liquid 10, as shown in FIG.
Adhesive method (a) in which the lid member 12 is attached and fixed by adhesive, and O-ring method (a) in which the lid member 12 is fastened and fixed to the small hole 11 made in one wall of the fixed ring 7 via an O-ring 13. There are various methods such as (b) and (c) a driving method in which a caulking member 14 such as a pin or a ball is driven into a small hole 11 formed in one wall of the fixed ring 7.

When the mechanical seal having the above structure is used in operation, the sliding friction between the sliding surface 4 of the rotating ring 1 and the annular sliding projection 8 of the stationary ring 7 causes the annular sliding projection 8 to become a heated part A, and The outer periphery and rear end surface of the ring 7 serve as a cooling section B. Therefore, the refrigerant liquid 10 sealed in the annular bore 9 of the fixed ring 7 is heated and vaporized in the heating section A, becomes a vapor flow H1, flows to the cooling section B, and is condensed by heat radiation in the cooling section B. , becomes reflux H2 and circulates back to the heating section A, thereby cooling the annular sliding protrusion 8 and controlling the heat generation of the sliding surface.

[Effect of idea]

As mentioned above, the mechanical seal of the present invention removes sliding heat by using a thermal cycle caused by the phase change of the refrigerant sealed inside the fixed side sliding ring, and the fixed side sliding ring is Because of the rotation, the saturated vapor pressure at the liquid level increases due to centrifugal force and evaporation of the refrigerant is not hindered, and the sliding heat is actively transported and removed, preventing wear of the parts. It has the feature of being able to eliminate leakage, and the practical effects of the present invention are extremely large.

[Brief explanation of drawings]

Fig. 1 is a front sectional view cut in half showing an embodiment of the mechanical seal of the present invention, Fig. 2 is an explanatory diagram showing the principle of the mechanical seal, and Fig. 3 a, b, and c are the refrigerant liquid sealing structures, respectively. FIG. 1... Rotating ring, 2... Rotating shaft, 4... Sliding surface,
5... Machine housing, 7... Fixed ring, 8... Annular sliding protrusion, 9... Annular lumen, 10... Refrigerant liquid.

Claims (1)

[Scope of utility model registration request] A circumferentially continuous hollow part is formed inside the stationary sliding ring that is airtightly attached to the inner periphery of the machine casing, and an appropriate amount of refrigerant liquid is sealed in the hollow part to reach a saturated vapor amount by vaporization. Features mechanical seal.