JPH0729341Y2 - Box structure of gland packing - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a box structure of a gland packing used for shaft sealing of a fluid machine, in which the packing is held by a packing holder.

[Prior Art] As a box structure of a gland packing in a shaft sealing device using a gland packing, there are, for example, those shown in FIG. 3 and FIG.

FIG. 3 shows a shaft sleeve 102 externally fitted and fixed to a shaft 101, and a packing box 103 arranged on the outer peripheral side of the shaft sleeve 102.
Packing 104 is installed between the
04 is pressed in the axial direction by the packing presser 105 so that it is attached to the neck bush 106. As a result, the packing 104 fixed integrally with the packing box 103 and the packing retainer 105 and the shaft 10
Between the shaft sleeve 102 that rotates together with the shaft 1, the left side sealed fluid side A and the right side atmospheric side B are sealed in the figure.

When the sealed fluid has a high temperature and needs to be cooled in particular, a cooling jacket 107 is formed in the packing box 103 like the box structure of the gland packing as shown in FIG. A cooling jacket 108 is formed on the packing retainer 105 and cooling water is circulated to cool the heat generating portion, here, the sliding portion 109 between the packing 104 and the shaft sleeve 102.

On the other hand, in the box structure of the gland packing shown in FIG. 4, the packing 204 is provided between the shaft 201 and the packing box 203 arranged on the outer periphery of the shaft 201.
4 is made to be sandwiched between the packing press 205 and the neck bush 206, and the tightening jig 210 for pressing the packing press 205 and the neck bush 206 are fixed jigs 211,
It is fixed to the shaft 201 by 212, and thus the packing 204 is adapted to rotate with the shaft 201.

Even in the box structure of the gland packing as shown in FIG. 4, cooling of the heat generating portion, that is, the sliding portion 209 formed between the packing 204 and the packing box 203 is performed by forming a cooling jacket 207 on the packing box 203, for example. Then
This is done by circulating cooling water through the cooling jacket 207.

[Problems to be Solved by the Invention] However, the conventional gland packing box structure as described above has the following problems.

That is, in the structure as shown in FIG.
The largest frictional heat is generated on the inner peripheral side of the packing 104 due to the sliding of the inner peripheral surface of the outer peripheral surface of the shaft sleeve 102,
At this time, even if the cooling water is circulated through the cooling jacket 107 formed in the packing box 103 disposed on the outer peripheral side of the packing 104, the sliding portion 109 on the inner peripheral side of the packing 104 is used.
Since the packing 104 serving as a heat insulating material is interposed between the cooling jacket 107 and the cooling jacket 107, it is possible to directly cool the sliding portion 109 on the inner peripheral side of the packing 104 that generates the largest frictional heat. In addition, since the inner peripheral side of the packing 104, which is in a high temperature state due to frictional heat, rubs against the outer peripheral surface of the shaft sleeve 102, the amount of wear of the packing 104 is very large, its life, and eventually There was a problem that the predetermined shaft sealing performance deteriorates in a short period of time. Further, in the structure of FIG. 3, the shaft sleeve 102 has the shaft 1
Since it rotates integrally with 01, it is possible to form a cooling jacket on the shaft sleeve 102 so that the sliding portion 109, which is the inner peripheral side of the packing 104, can be directly cooled. In this case, since the jacket itself rotates, it is structurally very difficult to distribute the cooling water there.

On the other hand, in the structure shown in FIG. 4, since the sliding portion 209 can be adjacent to the cooling jacket 207, the cooling effect of the cooling water circulated in the cooling jacket 207 can be expected. However, in the case shown in FIG. 4, when the working fluid used for the sealed liquid side A has a high temperature, the shaft
There is a problem that the temperature of the packing 204 rises due to the heat conduction through the 201, and the heat generation of the sliding portion 209 is promoted. This also applies to the one shown in FIG.
The heat of the working fluid slides through the shaft 101 and the shaft sleeve 102.
It is transmitted to 109 and promotes heat generation of the sliding portion 109. In addition to this, in the one shown in FIG.
Since the diameter of is extremely larger than that of the sliding portion 109 shown in FIG. 3, there is also a problem that the sliding area also increases and the amount of heat generation increases accordingly.

Further, in the conventional gland packing box structure as shown in FIGS. 3 and 4, the sliding portion 109 or 2 is used.
If the bearing is disposed on the extension line of the leaking direction of the working fluid from the 09 (direction B on the atmosphere side in the drawing), if the amount of leakage from the sliding portion 109 or 209 is excessive, There was a risk that the bearing would be flooded with the leaked liquid.

The present invention has been made in view of the above circumstances, and it is possible to effectively suppress the heat generation of the sliding portion and extend the life of the packing, and to prevent the presence of leakage of the sealing fluid on the extension line of the rotating shaft. In addition to avoiding direct hits such as flooding, the bearing part can be easily handled for emergency maintenance work when leakage of the sealed fluid occurs due to wear of the shaft sliver, and replacement of packing It is an object of the present invention to provide a gland packing box structure that can greatly simplify the work.

[Means for Solving the Problems] In order to achieve the above object, the box structure of the gland packing according to the present invention has a cylindrical shape such that an annular gap is formed between the rotating shaft and the outer peripheral surface of the rotating shaft. -Shaped shaft sleeve is externally fitted, one end side of the shaft sleeve is fixed to a device casing through which the rotary shaft passes, and the rotary shaft at a position axially spaced from the other end of the shaft sleeve,
Cylindrical box body that faces the outer peripheral surface of the shaft sleeve, a ring-shaped connecting portion that is connected to one end of the box body, and a shaft-shaped portion of the ring-shaped connecting portion that can be fitted to the rotating shaft A packing box consisting of a cylindrical mounting portion is fixed, and a packing housing formed between the box body of the packing box and the shaft sleeve accommodates a packing whose inner peripheral surface is in sliding contact with the shaft sleeve. The packing retainer, which is abutted against one end of the packing and presses the packing in the axial direction, is opposed to the flange-shaped fastening portion formed on the opening end side of the box body of the packing box. Is provided so that it can be inserted from the opening end side of the box body to the inside of the box body via a fastener provided between the box-shaped fastening portion formed on the packing holding side. And at least the packing box, the packing retainer, and the packing constitute a cassette that can be moved and fixed in the axial direction integrally with the rotation shaft and is removable, and in a state where the cassette is mounted on the rotation shaft, It is configured to perform shaft sealing between the packing and the shaft sleeve.

[Operation] According to the present invention configured as described above, the sliding portion that generates the largest frictional heat forms an annular gap between the inner peripheral surface of the packing and the equipment casing, which is fixed to the rotating shaft. Since it is formed between the shaft sleeve and the outer peripheral surface of the shaft sleeve, a cooling jacket is formed on the shaft sleeve to allow the cooling water to flow, especially when the sealed fluid requires high temperature and active cooling. It is easy to have a configuration that allows
It is possible to directly cool the sliding part, the diameter of the sliding part does not become so large, and the heat generation area is made relatively small to suppress the heat generation of the sliding part and the accompanying wear of the packing. The shaft sealing performance can be kept good for a long period of time. In addition, the sealing fluid flows and stays in the annular gap formed between the rotary shaft and the shaft sleeve. Here, the heat conductivity λ of the metal constituting the rotating shaft, such as stainless steel, is 15 W / (m · k), whereas the heat conductivity λ of the sealed fluid, such as water, is 0.659 W / (m · k). Compared with stainless steel, it is about (1/27), and therefore, the sealing fluid retained in the annular gap can be regarded as a heat insulating material against the heat moving along the rotating shaft, and the sealing The heat transfer to the sliding portion when the fluid is at a high temperature can be extremely reduced, and the heat generation of the sliding portion can be avoided.

Further, even if the leak of the sealing fluid occurs, the leaking sealing fluid flows by being converted by 180 ° at one end side of the shaft sleeve, so that even if there is a bearing portion on the extension line of the rotating shaft, Leaking fluid is prevented from hitting the bearing section directly.

Furthermore, if the outer peripheral surface of the shaft sleeve, which is in sliding contact with the packing, is locally worn and fluid leakage occurs from the worn part, move the entire cassette in the axial direction to wear the packing and wear the shaft sleeve. By making sliding contact with the unused portion, it is possible to very easily perform emergency maintenance work such as temporarily preventing fluid leakage until the shaft sleeve is replaced with a new one.

Moreover, at least the packing box, the packing retainer, and the packing are formed into a cassette type that can be integrally attached to and removed from the rotary shaft, so that maintenance work including replacement of the packing can be greatly simplified. .

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention. In the figure, 15 is a fluid equipment casing, the inside of this equipment casing 15 is the sealed fluid side A, and the left side is the atmosphere side B.

Reference numeral 1 denotes a rotary shaft that penetrates the equipment casing 15. On the outer wall surface of the equipment casing 15, a cylindrical shaft sleeve 2 which is concentrically fitted on the rotary shaft 1 is fixed by bolting a flange portion 2a formed on one end side. . The inner peripheral diameter of the shaft sleeve 2 is larger than the outer peripheral diameter of the rotary shaft 1, so that an annular gap 16 is formed between the inner peripheral surface of the shaft sleeve 2 and the outer peripheral surface of the rotary shaft 1.

A packing box 3 has a cylindrical box main body 3a whose inner peripheral surface faces the outer peripheral surface of the shaft sleeve 2, and a box connected to one end of the box main body 3a via a ring-shaped connecting portion 3c. It comprises a cylindrical attachment part 3b having a smaller diameter than the main body 3a. The inner diameter of the box body 3a is the same as the shaft sleeve 2
The packing 4 is designed to have a diameter such that a packing 4 described later can be interposed between the packing box 3 and the shaft sleeve 2, and a packing accommodating portion 23 is formed between the packing box 3 and the shaft sleeve 2. . On the other hand, the inner diameter of the attachment portion 3b is formed to substantially match the outer diameter of the rotary shaft 1. The attachment portion 3b is detachably fitted to the rotary shaft 1 at a position spaced from the free end of the shaft sleeve 2 so as to be movable and fixed in the axial direction via a screw 21. It is fixed. Reference numeral 20 is an O-ring that seals between the rotating shaft 1 and the mounting portion 3b of the packing box 3.

As described above, the packing housing portion 23 between the shaft sleeve 2 and the box body 3a of the packing box 3 has a packing 4 whose inner peripheral surface is in sliding contact with the outer peripheral surface of the shaft sleeve 2.
Is stored.

A ring-shaped neck bush 6 having an outer diameter substantially equal to the inner diameter of the packing box 3 is disposed between one end surface of the packing 4 and the connecting portion 3c of the packing box 3.
On the other hand, a packing retainer 5 is in contact with the other end surface of the packing 4. The packing retainer 5 is formed at one end of the retainer body 5a, which is insertable from one end of the packing box 3 into the inside of the box body 3a and has an inner diameter larger than the outer diameter of the shaft sleeve 2. And a collar-shaped fastening portion 5b. The fastening portion main body is formed by fastening the fastening portion 5b and the collar-shaped fastening portion 3d formed at one end of the packing box 3 with a bolt 19 as a fastener.
The packing box 3 and the packing retainer 5, the packing 4 and the neck bush 6 are attached to the rotary shaft 1 such that the packing 4 is sandwiched between the neck 5 and the neck bush 6.
It has a cassette type that can be attached and detached as a unit.

As described above, the packing box 3, the packing retainer 5, the neck bush 6 and the packing 4 constitute a cassette which can be moved and fixed in the axial direction with respect to the rotary shaft 1 and which is detachable. In the mounted state of the cassette, the packing 4 is sandwiched between the packing box 3 and the packing retainer 5 and rotates together with the rotating shaft 1 so as to slide on the outer peripheral surface of the shaft sleeve 2 to seal the shaft. 9 is formed.

Therefore, if the fluid on the sealing liquid side A has a low temperature, the shaft sleeve 2 is cooled by this sealing fluid, and the sliding portion 9 is directly cooled by the shaft sleeve 2 thus cooled.

Further, the fluid leaking from the sealed liquid side A leaks from the sliding portion 9 toward the device casing 15 side through the gap 16 between the rotary shaft 1 and the shaft sleeve 2. Therefore, even if a bearing portion is provided on the atmosphere side B, the leakage fluid does not hit the bearing portion directly.

In the embodiment shown in FIG. 1, the shaft sleeve 2, the packing box 3, the packing 4, the packing retainer 5, the neck bush 6 and the O-ring 20 are constructed as a cassette type which can be integrally attached to and detached from the rotary shaft. Worn packing 4
Is easy to replace.

Next, FIG. 2 shows another embodiment of the present invention. In this embodiment, the parts other than the shaft sleeve 2'are exactly the same as those in the embodiment of FIG. 1, so that the description will be omitted here and only the shaft sleeve 2'will be described.

The shaft sleeve 2'is formed integrally with the equipment casing 15 and also serves as a cooling jacket having a cooling water flow passage 17 formed therein. The cooling water flow passage 17 is formed so that the cooling water flowing from the cooling water inlet 17a is circulated in the shaft sleeve 2'and discharged from the cooling water outlet 17b.

By thus forming the shaft sleeve 2'as a cooling jacket, the sliding portion 9 is cooled more effectively. Also,
Even if the sealing fluid has a high temperature, since the gap 16 is provided between the shaft 1 and the shaft sleeve 2, heat is not transmitted to the sliding portion 9 via the shaft 1.

[Advantage of the Invention] As described above, according to the present invention, when the sealed fluid requires high temperature and positive cooling, the shaft sleeve is fixed, so that a cooling jacket is formed on the shaft sleeve. It is easy to have a structure in which cooling water is circulated.
It is possible to directly cool the sliding portion, suppress the amount of heat generated in the sliding portion and the amount of wear of the packing that accompanies it, and maintain good shaft sealing performance for a long time.

Further, even if the sealing fluid has a high temperature, the sealing fluid is retained in the annular gap formed between the rotary shaft and the shaft sleeve,
This retained sealing fluid can be made to function as a heat insulating material against the heat that moves along the rotating shaft having a high thermal conductivity, so that the heat transfer to the sliding portion when the sealing fluid is at a high temperature can be extremely reduced. The promotion of heat generation in the moving part can also be avoided.

Furthermore, because the leak direction of the leaking fluid changes 180 °,
It is also possible to prevent the leakage fluid from directly hitting the bearing portion provided on the atmosphere side and inundating the bearing portion. Furthermore, since the sliding portion is formed on the inner peripheral side of the packing, the diameter of the sliding portion does not become so large, and it is possible to suppress an increase in the amount of heat generated as the sliding area increases.

In addition, the packing box, packing retainer, and packing make it a cassette type that can be moved and fixed in the axial direction with respect to the rotating shaft and is removable, so that the outer peripheral surface of the shaft sleeve with which the packing makes sliding contact is localized. In case that fluid is leaked from the worn part, the entire cassette is moved in the axial direction and the packing is slidably contacted with the undamaged part of the shaft sleeve.
Not only can temporary maintenance work such as temporarily preventing fluid leakage until the shaft sleeve is replaced with a new one, it is extremely easy to perform, and maintenance work including replacement of packing can be significantly performed. The effect that it can be simplified is exhibited.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention, FIG. 2 is a vertical sectional view showing another embodiment, FIG. 3 is a sectional explanatory view of a conventional example, and FIG. 4 is another conventional example. FIG. 1 …… Rotary shaft 2,2 ′ …… Shaft sleeve 3,3 ″ …… Packing box 3a …… Box body 3b …… Cylindrical attachment part 3c …… Ring-shaped connection part 4 …… Packing 5 …… Packing retainer 15 …… Equipment casing 23 …… Packing storage

Claims (1)

[Scope of utility model registration request] 1. A cylindrical shaft sleeve is externally fitted to a rotary shaft so as to form an annular gap between the rotary shaft and an outer peripheral surface of the rotary shaft, and one end of the shaft sleeve is attached to an equipment casing through which the rotary shaft penetrates. A fixed side, and a cylindrical box body facing the outer peripheral surface of the shaft sleeve and one end of the box body, which is connected to the rotary shaft at a position axially spaced from the other end of the shaft sleeve. A ring-shaped connecting portion and a packing box including a cylindrical attachment portion that is continuously provided in the axial center portion of the ring-shaped connecting portion and that can be fitted to the rotary shaft are fixed, and the box body of the packing box and the A packing housing formed between the shaft sleeve and the shaft sleeve accommodates a packing whose inner circumferential surface is in sliding contact with the shaft sleeve, and abuts on one end of the packing to press the packing in the axial direction. A fastener provided with a packing holder provided between a collar-shaped fastening portion formed on the opening end side of the box body of the packing box and a collar-shaped fastening portion formed on the packing holding side so as to oppose thereto. Is provided so that it can be inserted into the inside of the box body from the opening end side of the box body via at least the packing box, the packing presser and the packing, and can be moved and fixed integrally in the axial direction with respect to the rotating shaft, A box structure of a gland packing, characterized in that a detachable cassette is constructed, and a shaft is sealed between the packing and the shaft sleeve when the cassette is mounted on a rotary shaft.