JPH054624Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shaft sealing device for sealing a rotating shaft portion of a device containing a fluid that is corrosive to metals.

[Conventional technology]

Conventionally, as this type of shaft sealing device, one having a structure as shown in FIG. 2 has been known.

That is, a fixed ring 2 made of ceramic is tightly fitted and fixed to the inner periphery of the stuffing box 1, while a rotating ring 6 made of carbon is fixed to the small diameter portion 3 of the stepped rotating shaft 3.
A collar 10 is fixed to a sleeve 4 externally attached to the sleeve 1 with a set screw 11, a spring 9 whose rear end is in contact with the collar 10, and a retainer 8 disposed at the tip of the spring 9 are supported. This rotary ring 6, which rotates integrally with the shaft 3, comes into sliding contact with the fixed ring 2 oppositely due to the urging force of a spring 9, and a space A is located on the back side of the fixed ring 2, which is a space communicating with the inner diameter of this sliding contact part. This prevents the corrosive fluid contained in the space B from leaking into the space B on the left side in the figure. Note that the large diameter portion 32 of the stepped rotating shaft 3 that comes into contact with the corrosive fluid in the space A is
A glass lining (not shown) is provided to prevent corrosion, and the tip 4a of the sleeve 4
A wedge ring 5 is interposed between the step portion 3a of the stepped rotating shaft 3 and the step portion 3a.

[The problem that the idea aims to solve]

However, the shaft sealing device having the conventional structure described above has the following problems.

That is, since the corrosive fluid in the space A to be sealed reaches the front surface of the shaft packing 7 made of PTFE that seals the inner circumference of the rotating ring 6, from the viewpoint of preventing corrosion of the sleeve 4, the stepped rotating shaft is used. Step part 3 of 3
a must be located behind the shaft packing 7, that is, toward the space B side, that is, the rotating ring 6
It is necessary to isolate the sleeve 4 from the corrosive fluid in the space A by setting the shaft packing 7 on the inner circumference thereof to the large diameter portion 32 side of the stepped rotating shaft 3.

Therefore, it is possible to assemble the collar 10 and the spring 9 integrally with the sleeve 4 in advance in the unattached state, but since the rotating ring 6 protrudes greatly due to the expansion of the spring 9, it is possible to assemble the collar 10 and the spring 9 integrally with the sleeve 4 in advance. It is difficult to keep the rotation ring 6 and the shaft packing 7 on the inner circumference of the shaft on the shaft circumference, and furthermore, it is difficult to push the rotary ring 6 and the shaft packing 7 on the inner circumference of the stepped rotary shaft 3 toward the large diameter portion 32 side beyond the stepped portion 3a of the stepped rotary shaft 3. Therefore, there was a risk that the shaft packing 7 and the rotating ring 6 would be damaged by galling with the stepped portion 3a, and the sealing performance would be impaired.

In view of these points, the present invention provides a seal structure in which a group of rotary-side seal parts including a rotary ring can be integrated, and is not damaged when installed around the shaft.

[Means to solve the problem]

In order to solve the above problems, the shaft sealing device according to the present invention includes: a rotating ring that slides on a fixed ring having a stepped rotating shaft inserted through the inner periphery; a retainer on the back surface of the rotating ring;
A group of rotating side seal parts includes a spring that biases the rotating ring toward the fixed ring via this retainer, a collar that supports the rear end of this spring, and a shaft packing that seals the inner circumference of the rotating ring. Protection consisting of a clamping part interposed between the tip of the sleeve that is placed on the small diameter part of the rotary shaft and the stepped part of the stepped rotary shaft, and a cylindrical part that covers the outer diameter surface near the tip of the sleeve. The structure is such that it is assembled around the outer circumference of the packing.

[Effect]

According to the present invention, the tip of the sleeve that is sheathed on the small diameter portion of the stepped rotating shaft and the outer diameter surface near the tip are protected from corrosive fluid by the clamping portion and the cylindrical portion of the protective packing. Even if a portion of the sleeve is located closer to the corrosive fluid than the shaft packing on the inner periphery of the rotating ring, the sleeve will not be corroded. Therefore, it is not necessary to position the rotating ring on the large diameter side of the stepped rotating shaft as in the conventional case.

〔Example〕

Hereinafter, the shaft sealing device of the present invention will be explained with reference to an embodiment shown in FIG. In this embodiment, parts having the same structure as those of the conventional example shown in FIG.

In the figure, 20 is a protective gasket made of PTFE.
A rotating side seal parts group S including a rotating ring 6, a shaft packing 7, a retainer 8, a spring 9, and a collar 10 is assembled on the outer periphery of the rotating ring 6. It receives the biasing force of the spring 9 and is in sliding contact with the non-rotating fixed ring 2.

The protection gasket 20 protects the sleeve 4 from corrosive fluids, and includes a clamping portion 20a interposed between the tip 4a of the sleeve 4 and the stepped portion 3a of the stepped rotating shaft 3, and a clamping portion 20a interposed between the tip 4a of the sleeve 4 and the stepped portion 3a of the stepped rotating shaft 3, and a portion near the tip of the sleeve 4. The pin-shaped inner end 11a of the set screw 11 that fixes the collar 10 is made up of a cylindrical portion 20b that covers the outer diameter surface, and the pin-shaped inner end 11a of the set screw 11 is connected to the cylindrical portion 20b of the protective gasket 20.
It is adapted to radially penetrate through the sleeve 4 and engage with the sleeve 4. Note that 21 is a glass lining for anticorrosion provided on the outer diameter surface of the large diameter portion 32 of the stepped rotating shaft 3 that comes into contact with the corrosive fluid in the space A.

That is, in the shaft sealing device of the above embodiment, by attaching the rotating ring 6 and the shaft packing 7 on the inner circumference thereof to the large diameter portion 32 side of the stepped rotating shaft 3, the sleeve 4 is protected against corrosive fluid. By covering the tip 4a of the sleeve 4 and the outer circumferential surface of the vicinity thereof with a protective packing 20,
The structure is such that the corrosive fluid in the space A between the protective gasket 20 and the rotating ring 6 attached to its outer periphery, which reaches the front surface of the shaft gasket 7, does not come into contact with the sleeve 4.

Therefore, when the shaft sealing device is assembled around the shaft, the shaft packing 7 is damaged as in the conventional case due to pushing the rotating ring 6 over the stepped portion 3a of the stepped rotating shaft 3 toward the large diameter portion 32. There is no rotating ring 6,
The rotary-side seal parts group S including the shaft packing 7, retainer 8, spring 9, and collar 10 is assembled on the outer periphery of the protective packing 20 attached to the sleeve 4 in advance, so that the sleeve 4 can be attached to the stepped rotating shaft. By inserting it into the small diameter portion 31 of No. 3, the entire rotating side seal parts group S can be assembled at once.

[Effect of idea]

As described above, according to the present invention, there is no need to isolate the sleeve from the corrosive fluid by pushing the rotating ring and the shaft packing on its inner circumference toward the large diameter side of the stepped rotating shaft, so that it is not necessary to assemble it around the shaft. The shaft packing will not be damaged by galling with the stepped portion of the stepped rotating shaft, and the entire rotating side seal parts including the rotating ring can be integrally held on the outer periphery of the protective packing, making handling easier. It has excellent effects such as ease of assembly.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view showing an embodiment of the shaft sealing device according to the present invention in an installed state, and FIG. 2 is a half-cut sectional view showing a conventional shaft sealing device in an installed state. 2... Fixed ring, 3... Stepped rotating shaft, 3a... Stepped part, 31... Small diameter part, 4... Sleeve, 4a...
...Tip, 6...Rotating ring, 7...Shaft seal, 8...
... Retainer, 9 ... Spring, 10 ... Collar, 20 ... Protective gasket, S ... Rotating side seal parts group.

Claims (1)

[Scope of utility model registration request] A rotating ring that slides on a fixed ring with a stepped rotating shaft inserted through its inner periphery, the back surface of this rotating ring and a retainer, a spring that biases the rotating ring toward the fixed ring via this retainer, and a rear surface of this spring. A rotary-side seal parts group including a collar that supports the end and a shaft gasket that seals the inner periphery of the rotary ring is attached to the tip of the sleeve that is sheathed on the small diameter portion of the stepped rotary shaft and the stepped portion of the stepped rotary shaft. A shaft sealing device, characterized in that the shaft sealing device is assembled to the outer periphery of a protective packing consisting of a clamping portion interposed between the sleeve and a cylindrical portion covering the outer diameter surface near the tip of the sleeve.