JPH0627884Y2 - mechanical seal - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a mechanical seal for sealing the shaft circumference of a device,
In particular, it relates to a mechanical seal having improved slurry resistance.

[Conventional technology]

Conventionally, as a kind of mechanical seal, as shown in FIG. 3, a spring is supported by an annular metal case 102 having a substantially U-shaped cross section that is tightly fitted to the housing 107 side so as to be axially movable and non-rotatable. 103 is pressed and urged in the direction of coming out of the metal case 102,
A carbon resin seal ring (stationary side seal ring) 101, which is kept airtight from the metal case 102 by a rubber bellows 104, and a gasket 10 on the rotary shaft 108 side.
6 is equipped with an alumina ceramic mating ring (rotating side sealing ring) 105, and both rings 101, 105 are brought into close contact with each other so that the liquid A to be sealed on the outer peripheral side is exposed to the atmosphere B. Mechanical seals that prevent leakage to the side are widely used as shaft sealing devices for equipment such as pumps.

[Problems to be solved by the device]

However, the conventional mechanical seal described above is
When the slurry is contained therein, both rings 101, 10
5, the slurry enters between the sliding surfaces 101a and 105a, so that the seal ring 101 made of carbon resin is formed.
The sliding surface 101a of No. 1 caused surface roughness or abnormal wear, resulting in deterioration of sealing performance.

The present invention has been made in view of the above points and has an object to improve the slurry resistance of the mechanical seal.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the mechanical seal according to the present invention is such that one of the sliding surfaces of the rotating-side sealing ring and the stationary-side sealing ring, which are in close contact with each other, has one sliding surface on the inner peripheral side. Formed of a carbon material having a property and a copper alloy on the outer peripheral side,
Further, the other sliding surface is formed of an alumina ceramic on the inner peripheral side facing the carbon material and a high-purity alumina ceramic on the outer peripheral side facing the copper alloy.

[Action]

According to the above-mentioned present invention, the sliding surfaces of both sealing rings are made of carbon resin and alumina ceramic on the inner peripheral side and copper alloy and high-purity alumina ceramic on the outer peripheral side. On the outer peripheral side of the sliding surface, the liquid to be sealed penetrates closely in a good lubrication state with an appropriate lubricating liquid film interposed, and prevents the slurry from entering, combining copper alloy and high-purity alumina ceramic. Due to this, the foreign matter wear resistance is improved. Further, since the inner peripheral side of the sliding surface is in contact with the atmosphere, it is difficult to form a lubricating liquid film of sufficient thickness, but the carbon resin and alumina ceramic have a good compatibility as a sliding material and a good self-lubricating effect. Provides lubricity.

〔Example〕

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

In the embodiment shown in FIG. 1, reference numeral 1 denotes a stationary side which is supported by a metal case 2 which is tightly fitted to the housing side in a state where it is movable in the axial direction and is prevented from rotating and is urged in the axial direction by a spring 3. Seal ring 4 as a seal ring,
A mating ring as a rotary seal ring mounted on the rotary shaft side via a gasket 5, both rings 1 and 4 closely slide on opposing sliding surfaces 1a and 4a.

The seal ring 1 is formed of a carbon material 11 having excellent self-lubricating property, and a copper alloy 12 is embedded and joined to the outer peripheral portion of the end portion on the sliding surface 1a side, that is, the sliding surface 1a is It is composed of the surface of the carbon material 11 on the inner peripheral side and the surface of the copper alloy 12 on the outer peripheral side. Further, the mating ring 4 is formed by joining the alumina ceramic 41 on the inner peripheral side and the high-purity alumina ceramic 42 on the outer peripheral side, that is, the sliding surface 4a has the surface of the alumina ceramic 41 at the inner peripheral portion thereof made of the carbon material. 11 surface, and the high-purity alumina ceramic 42 surface in the outer peripheral part slides on the copper alloy 12 surface.

Therefore, between the surface of the copper alloy 12 and the surface of the high-purity alumina ceramic 42 on the outer peripheral portions of the sliding surfaces 1a and 4a on the liquid A side to be sealed, a lubricating film of the liquid A to be sealed is present for good fluid lubrication. In addition, the resistance to the slurry in the liquid A to be sealed is increased, and the sliding surfaces 1a and 4a on the atmosphere B side, which are likely to be in a dry state.
The surface of the carbon material 11 and the surface of the alumina ceramic 41 in the inner peripheral portion have a good compatibility as a sliding material, and surface roughness and abnormal wear are less likely to occur.

Next, in the embodiment shown in FIG. 2, in addition to the structure shown in FIG. 1, a copper alloy 12 and a carbon material 1 are provided on the sliding surface 1a of the seal ring 1.
By forming the annular groove 6 at the boundary of No. 1 and filling the annular groove 6 with the liquid A to be sealed, the inside of the carbon material 11 on the atmosphere B side and the surface of the alumina ceramic 41 are also sealed. The lubricity is improved by interposing a lubricating film of the target liquid A.

[Effect of device]

As described above, according to the present invention, on the outer peripheral side of the sliding surface, the foreign material wear resistance is improved by the combination of the copper alloy and the high-purity alumina ceramic, and on the inner peripheral side of the sliding surface, the compatibility with the sliding material is good. It has a combination of carbon resin and alumina ceramics, and because the copper alloy and high-purity alumina ceramics on the outer peripheral side prevent the slurry from entering from the outer periphery, it has good lubricity, and therefore sealability and durability. It has an excellent effect that the property is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part showing a first embodiment of the present invention, FIG. 2 is a sectional view of a main part showing a second embodiment, and FIG. 3 is a half-cut sectional view showing a conventional example. 1 ... Seal ring, 1a, 4a ... Sliding surface 4 ... Mating ring, 11 ... Carbon material 12 ... Copper alloy, 41 ... Alumina ceramic 42 ... High-purity alumina ceramic

Claims (1)

[Scope of utility model registration request] 1. A rotary side sealing ring and a stationary side sealing ring, of which sliding surfaces are in close contact with each other, one sliding surface has a self-lubricating carbon material on the inner peripheral side and an outer peripheral side carbon material. It is formed of a copper alloy, and the other sliding surface is formed of an alumina ceramic on the inner peripheral side facing the carbon material and a high-purity alumina ceramic on the outer peripheral side facing the copper alloy. Mechanical seal to do.