JPH08159296A - Vertical type dry mechanical seal - Google Patents

Abstract

PURPOSE: To provide a vertical type dry mechanical seal which is devised to simplify structure and prevent wear of a seal surface and the generation of mechanical noise. CONSTITUTION: A reservoir forming ring 3 is fitted in a non-rotation ring 1 and a reservoir space P is formed between the reservoir forming ring 3 and a slide part 10. By filling the space with oil, an oil film is formed in a seal surface S, lubricity of the seal surface S is improved, and wear of the seal surface and mechanical noise are prevented from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical dry mechanical seal.

[0002]

2. Description of the Related Art In a vertical stirrer or the like, a rotary shaft is arranged in the vertical direction, and the rotary shaft is rotated by a motor provided above the stirrer to stir the inside of the stirrer. Since there is no sealing liquid in the shaft seal part of such a rotary shaft, a double mechanical seal is usually adopted to seal or circulate liquid higher than the pressure inside the agitator to lubricate the seal surface, or to use a dry mechanical seal. In general, the configuration is as follows.

[0003]

However, the double mechanical seal has a drawback that the cost of the seal unit is high, and if the seal becomes defective during operation, a considerable amount of the sealing liquid in the seal leaks into the machine. It is not suitable for equipment whose mixing is strictly limited. On the other hand, in the case of the dry mechanical seal, the above-mentioned drawbacks are not present, but the wear of the seal surface is severe, and abnormal noise is generated due to sliding of the seal surface, so-called mechanical squeal. The present invention aims to solve the above-mentioned problems of the prior art.

[0004]

In order to achieve the above object, a vertical dry mechanical seal of the present invention comprises a rotary ring mounted above a rotary shaft vertically arranged, and a rotary ring of the rotary ring. It is characterized in that it is provided with a non-rotating ring mounted below and a recess formed on the outer peripheral side of the sealing surface of the non-rotating ring for accumulating the lubricant. The lubricant stored in the recess penetrates into the seal surface to enhance the lubrication of the seal surface and reduce the wear, thereby suppressing the wear of the seal surface and the mechanical noise. As the lubricant, a lubricant such as oil is generally used, but a solid lubricant such as grease or wax, or a fine solid lubricant such as molybdenum disulfide can also be used. The recess is, in a preferred embodiment,
The sealing surface of the non-rotating ring is projected upward, and an annular projection protruding upward is provided on the outer peripheral portion of the non-rotating ring. Since such a ring-shaped projection makes it difficult to wrap the sealing surface of the non-rotating ring, the ring-shaped projection is formed separately from the non-rotating ring and fitted on the outer periphery of the non-rotating ring. Is desirable. This makes it possible to form an annular protrusion by fitting after lapping. Further, by arranging the upper surface of the lubricant stored in the concave portion to be located above the seal surface, the permeability of the lubricant into the seal surface is enhanced.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to a mechanical seal of a vertical stirrer will be described below with reference to the drawings. In FIG. 1, a rotating shaft R is arranged substantially vertically in the vertical direction, extends from the inside X of the machine to the atmosphere side, and is connected to rotational power of a motor or the like. The rotating shaft R is supported by a bearing B, and is sealed from a casing C by a sealing surface S formed by the non-rotating ring 1 and the rotating ring 2.

The rotary ring 2 has a rotary shaft R through an O-ring 20.
The sleeve 7 is fitted on the sleeve 7 provided on the shaft and rotates together with the rotary shaft R. The non-rotating ring 1 is located below the rotating ring 2, and is mounted on the casing C side via the fixed ring holding portion 4 with the sealing surface S thereof facing upward.
The fixed ring holding portion 4 has a structure integrated with the casing C. 40 is a spring and 41 is a rotation stop pin.

The non-rotating ring 1 is, as shown in FIGS. 1 and 2,
An annular sliding portion 10 protruding upward is provided, and this end surface contacts the end surface of the rotary ring 2 to form a sealing surface S. A pool forming ring 3 is fitted on the outer circumference of the non-rotating ring 1 via an O-ring 30.
An annular recess is formed between 0 and the pool forming ring 3, and this recess serves as a pool space P. As a lubricant, the reservoir space P is filled with a lubricating liquid such as oil,
The oil or the like permeates from the outer peripheral side to the inner peripheral side of the seal surface S by a capillary phenomenon to form an oil film on the inner surface of the seal surface S. When the inner side X has a negative pressure, the oil permeates not only by the capillary phenomenon but also by the pressure difference.

As described above, a lubricating liquid such as oil is generally used as the lubricant, but solid substances such as grease and wax can also be used. in this case,
The sliding heat of the seal surface S melts the grease or wax to wet the seal surface S, so that the same effect as the lubricating liquid can be obtained. Further, as the lubricant, a fine solid lubricant such as molybdenum disulfide can be used.

It is desirable that the end surface 31 of the pool forming ring 3 is located above the level of the seal surface S, and the level of the lubricant in the pool space P is equal to or higher than the level of the seal surface S. In this embodiment as well, the end face 31 is projected more than the sealing surface S, but in the case of such a configuration, the sealing surface S
Since the end face 31 becomes a hindrance during the lapping process, the pool forming ring 3 is configured as a separate body, is detachable, and is fitted to the non-rotating ring 1 via the O-ring 30 after the lapping process. .

As shown in FIG. 1, the casing C is provided with a monitoring hole 5 for supplying a lubricant to the reservoir space P and for monitoring the level of the lubricant in the reservoir space P.
The monitoring hole 5 is normally closed by a plug 50.

A receiving portion 6 is formed below the fixed ring holding portion 4. The receiving portion 6 is provided with an annular partition wall 60 provided along the rotation axis R so as to prevent a liquid or an individual leaking from the seal surface S from entering the inside X of the machine. Further, the receiving portion 6 is communicated with the discharge hole 61,
The foreign matter accumulated in the receiving portion 6 is discharged to the outside of the system.

In the above structure, if the reservoir space P formed between the sliding portion 10 and the reservoir forming ring 3 is filled with a lubricant such as oil to a level greater than the seal surface S, the lubricant will be applied to the seal surface S. And the friction of the seal surface S is reduced, and wear and mechanical noise can be suppressed. Even if the lubricant leaks from the seal surface S, the amount thereof is very small, and since it accumulates in the receiving portion 6, there is no fear of contaminating the inside X of the machine.

[0013]

As described above, the vertical dry mechanical seal of the present invention is provided with a rotary ring mounted above the rotary shaft arranged in the vertical direction and a non-rotary ring mounted below the rotary ring. And a concave portion for accumulating the lubricant formed on the outer peripheral side of the seal surface of the non-rotating ring, the lubricant accumulated in the concave portion enters the seal surface to lubricate the seal surface. It can be increased to reduce wear and suppress wear of the seal surface and mechanical squeal. When the annular projection for forming the recess is formed separately from the non-rotating ring and is fitted on the outer periphery of the non-rotating ring, the lapping process of the sealing surface of the non-rotating ring is hindered. Never. Further, when the upper surface of the lubricant stored in the recess is located above the seal surface, the permeability of the lubricant into the seal surface is increased.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a half sectional view showing the sectional view of FIG. 1 in a partially enlarged manner.

[Explanation of symbols]

1: non-rotating ring, 2: rotating ring, 3: pool forming ring, 4: fixed ring holding part, 5: monitoring hole, 6: receiving part, 7: sleeve, 1
0: sliding part, 20: O-ring, 30: O-ring, 31:
End face, 40: spring, 41: anti-rotation pin, 50:
Plug, 60: partition wall, 61: discharge hole.

Claims (4)

[Claims] 1. A rotating ring mounted above a rotating shaft arranged in the up-down direction, a non-rotating ring mounted below the rotating ring, and formed on the outer peripheral side of a sealing surface of the non-rotating ring. In addition, a vertical dry mechanical seal characterized by having a recess for storing the lubricant. 2. The vertical dry member according to claim 1, wherein a sealing surface of the non-rotating ring is projected upward, and an annular projection protruding upward is provided on an outer peripheral portion of the non-rotating ring to form the recess. mechanical seal. 3. The vertical dry mechanical seal according to claim 2, wherein the annular protrusion is a ring body fitted around the outer periphery of the non-rotating ring. 4. The vertical dry mechanical seal according to claim 1, wherein an upper surface of the lubricant accumulated in the recess is located above the sealing surface.