JPS5846599B2 - Sealing device for rolls - Google Patents

Description

[Detailed description of the invention] A cylindrical shell is rotatably attached to a fixed shaft that is concentrically inserted through the cylindrical shell as a roll for applying pressure treatment such as rolling or calendering to a strip-shaped product such as paper. Alternatively, the shell can be forcedly rotated by interlocking with an appropriate power mechanism, and the cylindrical intermediate chamber formed between the inner circumferential surface of the shell and the outer circumferential surface of the shaft is rotated in the axial direction of the roll. It is known that the chamber is partitioned into two approximately semi-cylindrical chambers using a sealing device that shields and seals along the curve, and one of the intermediate chambers is configured as a pressurized chamber into which a pressure medium, that is, oil is pressurized. The invention relates to an improvement of the sealing device in a roll configured in this manner.

According to this type of roll, by adjusting the hydraulic pressure in the pressurizing chamber appropriately according to the degree of pressure received by the roll during pressure treatment of the strip-shaped article, this is applied to the shell portion facing the pressurizing chamber, that is, the strip-shaped article. The pressure-receiving part, which is normally subjected to pressure treatment by being pinched between rolls, can be held flat without causing concave deflections due to the pressure-receiving action of the pressure treatment, and can also be held in a convex shape as necessary. As a result, the pressure treatment of the belt-shaped article can always be performed satisfactorily depending on the treatment situation.

Therefore, for this type of roll, the important point is how to configure the sealing device to secure the pressurized chamber. Conventional sealing devices of this type are generally as shown in Fig. 1. As shown in FIG.
The shell 3 is supported by biting in the rotational direction of the shell 3, and the other edge is in contact with the inner circumferential surface 3a of the shell 3, and is arranged in an inclined manner so as to shield the circumferential end of the pressurizing chamber 4. A plate spring 6 fixedly supported in a support groove 2b formed on the outer peripheral surface of the shaft 2 via a spacer 5 presses and urges the seal body 1 in the direction of rotation of the shell 30, so that the other end edge of the seal body 1 is pressed. by pressing the part into pressure contact with the shell inner circumferential surface 3a,
It is configured.

By the way, in the roll, as the pressure received by the roll increases due to pressure treatment, the pressure in the pressurizing chamber 4 is increased accordingly, so that the sealing force by the sealing device, that is, the inner peripheral surface 3a of the shell of the seal body 1 is increased accordingly. It is necessary to make the pressure contact force more uniform, but according to the sealing device configured as above, when hydraulic pressure is applied to the pressurizing chamber 4,
In response to this oil pressure, the seal body 1, which is being pressed by the leaf spring 6, is more strongly pressed against the shell inner circumferential surface 3a, and therefore, the higher the oil pressure in the pressurizing chamber 4, the more the seal Since the pressing force of the body 1 against the inner circumferential surface 3a of the shell increases, a sealing effect corresponding to the oil pressure in the pressurizing chamber 4 can be expected.

However, if the hydraulic pressure in the pressurizing chamber 4 is made to act as it is as a pressing force on the shell inner circumferential surface 3a of the seal body 1, there will be little problem if the pressure in the pressurizing chamber 4 is not very high. However, when the pressure is high, the pressing force becomes larger than necessary, causing various problems.

That is, if the pressing force of the seal body 1 against the shell inner circumferential surface 3a becomes larger than necessary, the portion of the seal body 1 that presses against the shell inner circumferential surface 3a becomes severely worn, and during long-term use, the seal There is a risk that the body 1 will wear out to a large extent, and the seal body 1 will eventually be displaced to a state in which it cannot reliably receive the pressing action of the leaf spring 6 (the state shown by the chain line).

In such a state, when the injection of oil into the pressurizing chamber 4 is stopped, the seal body 1 is not pressed against the shell inner peripheral surface 3a by the leaf spring 6 and is in a free state.
Therefore, when hydraulic pressure is applied to the pressurizing chamber 4 again, oil leaks from the pressurizing chamber 4 between the seal body 1 and the shell inner peripheral surface 3a, and the sealing action can no longer be performed.

Furthermore, as the pressure force of the seal body 1 against the shell inner circumferential surface 3a increases, the lubrication effect between the seal body 1 and the shell inner circumferential surface 3a cannot be performed well, and together with this, Smooth rotation of the shell 3 is greatly hindered by the seal body 1.

If such a braking phenomenon occurs, not only will good pressure processing not be carried out, but when the shell 3 is forcibly rotated by a power mechanism, an unnecessarily overload will be applied to this power mechanism, causing a failure. .

Moreover, due to the strong contact between the seal body 1 and the shell inner circumferential surface 3a, high heat is likely to be generated in the contact area, and this heat generation phenomenon deteriorates the properties such as the viscosity of the oil, further reducing the above-mentioned lubricating effect. , wear of seal body 1 and shell 3
The occurrence of the braking phenomenon is promoted.

Furthermore, the above-mentioned problems are likely to occur even when the pressure inside the pressurizing chamber 4 is not set to high pressure and when the shell 3 is rotated at high speed.

Therefore, the roll equipped with the conventional sealing device described above cannot be used as a roll that requires high pressure in the pressurizing chamber 4 and pressure treatment, such as a rolling roll for steel or aluminum. In addition, the shell 3 cannot be rotated at high speed to speed up the pressure treatment, and the actual situation is that its range of use is greatly limited.

In view of the above points, the present invention provides an improved sealing device that can perform a good sealing action over a long period of time even when the pressure in the pressurized chamber is set to high pressure or when the shell is rotated at high speed. This is intended to ensure that the pressure treatment of the strip-shaped article by the rolls can always be carried out well and quickly.

Hereinafter, one embodiment will be specifically described with reference to FIGS. 2 to 5.

In the figure, 11 is a roll, and this roll 11 is the second roll.
As shown in FIG. 3 and FIG. 3, an iron shaft 13 having an appropriate diameter smaller than the inner diameter is inserted concentrically into a cylindrical iron shell 12 made of a desired material, and both ends of the shell 120 are attached to the shaft 13. The shaft 71130 is supported rotatably and immovably in the axial direction via a bearing 14.14, and both ends of the shell 71130 are fixedly supported 15.15, so that a shaft 71130 is provided between the inner circumferential surface 12a of the shell 12 and the outer circumferential surface of the shaft 13. A cylindrical intermediate chamber 16 is formed, and at a suitable location of the intermediate chamber 16, which is divided into approximately two equal parts vertically in the circumferential direction,
A pair of sealing devices 17.17 capable of shielding and sealing the intermediate chamber 16 along the axial direction of the roll 11 is provided, and the intermediate chamber 16 is divided into two approximately semi-cylindrical upper and lower chambers by the sealing devices 17.17. A pair of sealing devices 18.18 capable of shielding and sealing the upper intermediate chamber 16 are provided at both ends in the axial direction of the upper intermediate chamber 16. The devices 17 and 18 provide a suitable number of oil supply passages which are tightly sealed regardless of the shell's 120 rotations, and which are connected to a suitable oil supply mechanism (not shown) to the shaft 13 and communicate with the upper intermediate chamber 16. 19.19, and an appropriate number of oil drain passages 20° 20 that are connected to a suitable oil drain mechanism (not shown) and communicate with the lower intermediate chamber 16. The intermediate chamber 16 portion of the lower intermediate chamber 16 is placed into a pressurizing chamber 16a into which oil as a pressure medium is injected under appropriate pressure by the oil feeding mechanism, and the lower intermediate chamber 16 portion is placed into a drain where oil can be drained to the oil draining mechanism. The oil chambers 16b are respectively configured.

According to the present invention, the valley sealing device 11 for shielding and sealing the circumferential end of the pressurizing chamber 16a along the axial direction is configured as follows.

That is, in this embodiment, as shown in FIGS. 3 and 4, a groove 21 is formed along the axial direction on the outer peripheral surface of the shaft 13, and the groove 21 has a longitudinal section extending in the axial direction. A support body 22 having a uniform U-shape is fitted with its opening projecting an appropriate amount from the outer circumferential surface of the shaft 13 and directly facing the shell inner circumferential surface 12a, and fixed by appropriate means. , the inside thereof is defined as a first pressure chamber 23, and the first pressure chamber 2
3, that is, the open end of the support body 22, there is a seal body 24 extending in the axial direction and having a uniform U-shaped vertical cross section, with its open end 24a in contact with the shell inner circumferential surface 12a. , are slidably inserted and supported in the radial direction (preferably in the axial direction) of the shell 12.

The interior of the seal body 24 is located at the shell inner circumferential surface 12.
The end surface of the seal body 24 facing the first pressure chamber 23, that is, the outer end surface 2 of the rear wall of the seal body 24 that closes the first pressure chamber 23, is a second pressure chamber 25 closed by a.
4b onto a surface perpendicular to the sliding direction of the seal body 24, and a second pressure receiving surface obtained by transparently projecting the second pressure chamber 25 onto a surface perpendicular to the sliding direction. It is configured to have an appropriately larger area than the surface.

Therefore, when the same hydraulic pressure is applied to each of the side pressure chambers 23 and 25, the seal body 24 is pressed against the shell inner circumferential surface 12a in the sliding direction by the entire pressure received by the first pressure receiving surface. On the other hand, the second pressure receiving surface tends to be separated from the shell inner circumferential surface 12a due to the total pressure applied to it, so that it acts on an area corresponding to the area difference between the first pressure receiving surface and the second pressure receiving surface. The entire pressure is applied to the inner circumferential surface 12a of the shell.

In this embodiment, the support body 22 forming the first pressure chamber 23 and the seal body 24 forming the second pressure chamber 25 are both configured in a U-shape with a uniform cross section. The pressure receiving surface is aligned with the outer end surface 24b of the rear wall of the seal body 24, and the second pressure receiving surface is aligned with the inner end surface 24c of the rear wall, and the difference in area is equal to the sum of the vertical cross-sectional areas of the upper and lower walls of the seal body 24. corresponds to

The support body 22 is made of a metal with excellent strength, such as steel, and the seal body 24 is made of a metal that is softer than the iron shell 12, such as copper, brass, bronze, or oil-free metal. It is molded from metal etc.

Furthermore, a first communication passage 26 is formed in the earthen wall portion of the support body 22 that protrudes from the outer circumferential surface of the shaft 13 to communicate from the pressurizing chamber 16a to the first pressure chamber 23. A second pressure chamber 25 is provided on the rear wall of the seal body 24 to communicate from the first pressure chamber 23 to the second pressure chamber 25.
A communication passage 27 is formed, and the second pressure chamber 25 is connected to the first pressure chamber 25.
It communicates with the pressurizing chamber 16a via the pressure chamber 23.

The communication passages 26 and 27 are formed in one or more appropriate sizes and shapes in the axial direction.

Therefore, when hydraulic pressure is applied to the pressurizing chamber 16a, the same hydraulic pressure is applied to the side pressure chambers 23 and 25.

Note that the first communicating path 26 is formed at a position where the first communicating path 26 is
It is located in such a position that it cannot be blocked by an earthen wall.

Further, an appropriate number of compression coil springs 28 (only the negative one is shown) are installed inside the first pressure chamber 23 at predetermined intervals in the axial direction, and the seal body 24 is pressed against the shell inner circumferential surface 12a by the springs 28. It's energizing.

Further, in this embodiment, each sealing device 18 for shielding and sealing both ends of the pressurizing chamber 16a in the axial direction has the same structure as the sealing device 17.

That is, as shown in FIG. 2 and FIG. At the same time, the seal receiver 2 is attached to the shaft 13.
An annular seal holder 30 is externally fitted and fixed to face 9.

A groove 31 is formed in the end surface of the seal holder 30, and a support 32 having a uniform U-shaped vertical cross section is inserted into the groove 31 so that its opening is directly exposed to the end surface 29a of the seal receiver 29. The interior of the first pressure chamber 33 is formed by fitting and fixing in the oriented state, and the opening of the first pressure chamber 33 is provided with a sealing body 34 having a uniform U-shaped vertical cross section. With the open end in contact with the end surface 29a of the seal receiver 29, it is fitted and supported so as to be slidable in the axial direction of the roll 11, that is, in the direction orthogonal to the end surface 29a.

Furthermore, a first communication passage 36 that communicates from the pressurizing chamber 16a through the seal holder 30 and the support body 32 to the first pressure chamber 33, and a first communication passage 36 that communicates from the first pressure chamber 33 through the rear wall of the seal body 34. A second communication passage 37 is formed in each case to communicate with the second pressure chamber 35 in the seal body 34.

The communication passages 36, 37 may be formed in the annular direction or may be formed at predetermined intervals.

Further, an appropriate number of compression coil springs 38 (only the negative one is shown) are disposed in the first pressure chamber 33 to urge the seal body 34 into pressure contact with the end surface 29a of the seal receiver 29.

Note that the sealing device 18, that is, the concave groove 31 which is a component thereof. The support body 32 and the seal body 34 are formed into a trapezoidal shape as shown in FIG. 3 in order to shield and seal the axial end of the pressurizing chamber 16a, considering the ease of manufacturing the groove 31 and the like. and is sealingly connected to each of the sealing devices 17 as in the customary case.

Further, the seal receiver 29 is made of the same material as the shell 12, the support body 32 is made of the same material as the support body 22, and the seal body 34 is made of the same material as the seal body 24.

Next, the sealing action of the sealing device 1γ will be explained with reference to the above embodiment. When no hydraulic pressure is applied to the pressurizing chamber 16a, the open end 24a of the sealing body 24 is pressed against the shell inner circumferential surface 12a by the spring 28. I'm being forced to do it.

From this state, when hydraulic pressure is applied to the pressurizing chamber 16a, the oil in the pressurizing chamber 16a is transferred from the first communication path 26 to the first pressure chamber 2.
3 and further into the second pressure chamber 25 from the second communication passage 27, and the respective chambers 16a.

The same hydraulic pressure acts on 23 and 25, respectively.

At this time, a pressing force in the direction toward the shell inner circumferential surface 12a is applied to the slidingly displaceable seal body 24 due to the total pressure acting on the outer end surface 24b of the rear wall, that is, the first pressure receiving surface 24b. On the other hand, due to the total pressure acting on the inner end surface 24c of the rear wall, that is, the second pressure receiving surface 24c, a non-pressing force acts in a direction away from the shell inner peripheral surface 12a.

However, the first pressure receiving surface 24b has a larger area than the second pressure receiving surface 24c, and the valley pressure receiving surface 24bt24
Since the oil pressures acting on c, that is, the pressure per unit area, are equal, the seal body 24 is pressed against the shell inner circumferential surface 12a with a force obtained by subtracting the non-pressing force from the pressing force.

That is, the seal body 24 acts as if the first pressure receiving surface 24
The pressure receiving surface having an area obtained by subtracting the area of the second pressure receiving surface 24c from the area b receives the hydraulic pressure of the pressurizing chamber 16a, and the shell inner peripheral surface 1
It will be pushed to 2a.

Therefore, even when the pressurizing chamber 16a is under high pressure, by appropriately setting the difference in area between the first pressure receiving surface 24b and the second pressure receiving surface 24c, the opening end 24a of the seal body 24 can be placed inside the shell. It is not pressed against the peripheral surface 12a more strongly than necessary, and a good sealing action can be performed for a long period of time without causing the problems mentioned at the beginning.

Further, the seal body 24 is slidable in the radial direction of the shell 12 (preferably in the diametrical direction, that is, in the direction perpendicular to the shell inner circumferential surface 12a), and is slidable in the direction of pressure contact with the shell inner circumferential surface 12a and in the direction of the spring. 28 coincides with the pressing direction of the seal body 24, even if the portion of the seal body 24 that is in pressure contact with the shell inner circumferential surface 12a is unexpectedly worn, when the pressurization of the hydraulic pressure into the pressurizing chamber 16a is stopped, The seal body 24 is reliably pressed against the shell inner peripheral surface 12a by the spring 28.

That is, unlike the conventional structure mentioned at the beginning, the seal body 24 is not displaced out of the pressing area of the /F screw 28 due to wear.

Furthermore, even when the seal body 24 is displaced due to wear of the seal structure, the state of pressure contact of the seal body 24 to the shell inner circumferential surface 12a does not change, and the sealing effect can be kept constant.

It goes without saying that the lubricating oil, that is, the drain oil that lubricates the space between the shell inner circumferential surface 12 a and the seal body 24 and accumulates in the oil drain chamber 16 b is drained from the oil drain path 20 .

Therefore, according to the seal device 17 according to the present invention, regardless of the size of the seal body 240 depending on the level of oil pressure in the pressurizing chamber 16a and the size of the roll 11, By appropriately setting the area difference between the outer end surface 24b of the rear wall and the second pressure receiving surface (the inner end surface 24c of the rear wall), an appropriate sealing force can be generated by the seal body 24, and this It is extremely easy to design something like this.

Furthermore, since the pressing force of the seal body 24 against the shell inner circumferential surface 12a does not become larger than necessary, the shell 12 can be rotated at high speed while maintaining a good sealing effect.

As can be understood from the above points, the roll 11 equipped with the sealing device 17 according to the present invention is a calender roll, a press roll, a wire bart press roll, etc. for paper manufacturing that keeps the pressure chamber 16a at a relatively low pressure. It goes without saying that it can be used as a back-up roll or two-stage roll for rolling steel, aluminum, etc. with large rolling blades that require high pressure in the pressurizing chamber 16a, and for skin passes, which could not withstand use in the past. It can also be used as a work roll of a rolling mill, and the shell 12 can be rotated at high speed to speed up pressure treatment.

Further, in the embodiment, the sealing device 18 for shielding and sealing the axial end of the pressurizing chamber 16a is also configured to provide the same sealing effect as the sealing device 17, so that the roll 11 has the above-mentioned advantages. becomes more prominent.

That is, the sealing action by the sealing device 18 is similar to the above-mentioned action, so the details are omitted, but the sealing body 34 is moved by the spring 38 to the seal receiver when no hydraulic pressure is applied to the pressurizing chamber 16a. It is pressed against the end surface 29a of 29.

When hydraulic pressure is applied to the pressurizing chamber 16a, the same pressure as in the pressurizing chamber 16a acts on the first pressure chamber 33 and the second pressure chamber 35 through the first communication passage 36 and the second communication passage 37. .

Therefore, the seal body 34 is moved to the seal receiver 29 with a force obtained by subtracting the total pressure that acts on the inner end surface 34b of the rear wall from the total pressure that acts on the outer end surface 34a of the rear wall of the seal body 34.
The seal body 34 is brought into pressure contact with the end surface 29a of the end surface 29a even when the pressure chamber 16a is brought into high pressure.
It will not be pressed more strongly than necessary.

Therefore, according to the sealing device 18, the axial end of the pressurizing chamber 16a can be maintained for a long period of time without causing various problems such as severe wear of the seal body 34 or interference with smooth rotation of the shell 12. Good shielding and sealing can be achieved over the entire area.

Note that the configuration of the sealing device 11 according to the present invention is not limited to the above-mentioned embodiment, and may be configured as follows, for example, and the same effects as in the above-described embodiment can be achieved.

That is, in the embodiment, the first communication path 26 is
The pressure chamber 16a is formed to communicate directly with the first pressure chamber 23, and the second communication path 27 is formed so that the pressure chamber 16a communicates directly with the first pressure chamber 23.
a to the second pressure chamber 25 via the first pressure chamber 23, but as shown in FIG.
A communication passage 26 is formed in the rear wall of the seal body 24, and a second communication passage 27 is formed in the earthen wall of the seal body 24, so that the pressure chamber 16a is directly connected to the second pressure chamber 25 or the first pressure chamber 25. The pressure chamber 23 may be indirectly communicated with through the second pressure chamber 25.

Further, as shown in FIG. 7, the support body 22 and the seal body 24
The first communicating path 26 and the second communicating path 2γ may be formed in the earthen walls of the earth wall, respectively, and the pressurizing chamber 16a may be directly communicated with the pressure chambers 23 and 25, respectively.

Furthermore, communication passages 26' and 27' between the pressure chambers 23 and 25 may be formed as shown by chain lines in FIG.

Further, in each of the embodiments described above, the support body 22 is fitted and fixed in the groove 21 formed in the shaft 13, and the seal body 24 is slidably fitted and supported on the support body 22.
As shown in FIG. 8, the support body 22 is eliminated and the seal body 2 is
4 can also be directly slidably inserted into and supported by the groove 21.

In addition, in the previous stage of applying hydraulic pressure to the pressurizing chamber 16a, the elastic member such as the spring 28 in each of the above embodiments may be used as a means for holding the seal body 24 in pressure contact with the shell inner circumferential surface 12a. It is also possible to use a pressure medium.

For example, as shown in FIG. 9, when an oil feed passage 39 connected to an oil feed mechanism and communicating with the first pressure chamber 23 is formed on the shaft 13 and hydraulic pressure is applied to the pressurizing chamber 16a, first Oil may be press-fitted into the first pressure chamber 23 from the oil passage 39 to press the seal body 24 against the shell inner peripheral surface 12a.

In this case, from the first pressure chamber 23 to the first communication passage 26
In order to prevent oil from leaking into the pressurizing chamber 16a through the pressurizing chamber 16a, a valve (not shown) is provided in the first communication passage 26 to allow only oil to flow from the pressurizing chamber 16a into the first pressure chamber 23. However, since it is sufficient to keep the seal body 24 in pressure contact with the shell inner circumferential surface 12a for a very short time before the oil is pressurized into the pressurizing chamber 16a, it is not necessary to provide the valve as described above. It is not necessarily necessary to keep it.

After the oil is pressurized into the pressurizing chamber 16a, the pressurizing of oil from the oil feed path 39 is stopped, and the oil feed path 39 is closed with a valve or the like, and the first pressure is released from the pressurizing chamber 16a. Of course, it is necessary to prevent the oil pressurized into the chamber 23 from escaping from the oil feed path 39.

Furthermore, the configurations of the seal body 24 and the pressure chambers 23, 25 are arbitrary, and the point is that the first pressure receiving surface may be configured to have an appropriately larger area than the second pressure receiving surface.

In any case, as is clear from the above description, the sealing device for the roll of the present invention is such that the sealing body is slidably inserted in the first pressure chamber formed on the shaft side in the radial direction of the shell. a second pressure chamber closed by the inner peripheral surface of the shell is formed on the side of the seal body, and both pressure chambers are communicated with the pressurizing chamber via the first communication passage and the second communication passage. hand,
By applying hydraulic pressure within the pressurizing chamber, the same hydraulic pressure is applied within the side pressure chamber, and further, the end face of the seal body facing the first pressure chamber is orthogonal to the sliding direction of the seal body. The first pressure-receiving surface obtained by projecting onto the second
When the pressure chamber is set to have an appropriately larger area than the second pressure-receiving surface obtained by transparently projecting the pressure chamber onto a surface perpendicular to the sliding direction, and when hydraulic pressure is applied to the pressure chamber, the seal body Since the seal is configured to be brought into pressure contact with the inner circumferential surface of the shell with a pressure obtained by subtracting the total pressure acting on the second pressure receiving surface from the total pressure acting on the first pressure receiving surface, the conventional seal It goes without saying that the sealing force can be increased or decreased depending on the level of the oil pressure by using the oil pressure in the pressurizing chamber in the same way as the device, and while maintaining such a sealing effect, the first pressure receiving surface By setting the area difference between the first and second pressure-receiving surfaces as appropriate, the pressing force of the seal body against the inner peripheral surface of the shell is not excessively large, not only when the pressure inside the pressurizing chamber is low, but also when the pressure is high. It will never happen.

Therefore, regardless of the oil pressure in the pressurizing chamber and the rotational speed of the shell, the part of the seal body that presses against the inner peripheral surface of the shell will always be severely worn, or the pressure contact action of the seal body will prevent the smooth rotation of the shell. In addition, high heat is generated at the contact area between the seal body and the inner circumferential surface of the shell, which deteriorates the viscosity and other properties of the oil used as the pressure welding medium. A good sealing effect can be achieved throughout.

Therefore, the roll equipped with the sealing device of the present invention can be used as a pressure treatment roll for steel, aluminum, etc., which has a large reduction blade and requires a high pressure in the pressurization chamber. The pressure treatment of all kinds of strip-shaped products can be carried out well while fully utilizing the functions of the rolls, and the shell can be rotated at high speed to speed up the pressure treatment.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing a conventional sealing device (showing the same parts as FIG. 4), and FIGS. 2 to 5 show an embodiment of a roll equipped with a sealing device according to the present invention. Figure 2 is a vertical side view (the cross section is along the line ■-■ in Figure 3), and Figure 3 is a vertical front view (the cross section is along the line 1ll-[
[along the line], FIG. 4 is an enlarged view of the main part of FIG. 3, FIG. 5 is an enlarged view of the main part of FIG. FIG. 5 is an enlarged view similar to FIG. 4 showing another embodiment of the device; 11...Roll, 12...Shell, 1
2a...Inner peripheral surface, 13...Shaft,
16a... Pressure chamber, 17... Sealing device, 23... First pressure chamber, 24... Seal body, 24b... Outer end surface (first pressure receiving surface), 2
4c...Inner end surface (second pressure receiving surface), 25...
...Second pressure chamber, 26, 26'...First communication passage,
2T, 27'...Second communication path.

Claims (1)

[Claims] 1 A cylindrical shell is rotatably supported by a fixed shaft inserted concentrically through the shell, and a pressurizing chamber extending in the axial direction into which a pressure medium is press-fitted is defined between the opposing surfaces of the two. A sealing device for shielding and sealing both circumferential ends of the pressurizing chamber along the axial direction in the roll provided, the sealing device extending in the axial direction and opening toward the inner circumferential surface of the shell on the shaft side. A first pressure chamber is provided, and a seal body extending in the axial direction and in contact with the inner circumferential surface of the shell is fitted and supported in the opening of the first pressure chamber so as to be slidable in the radial direction of the shell. A first pressure chamber is closed by a sealing body, a second pressure chamber is formed in the sealing body, and the second pressure chamber is closed by the inner peripheral surface of the shell, and the sealing body has an end face of the sealing body facing the first pressure chamber. The first pressure receiving surface obtained by projecting the second pressure chamber onto a surface perpendicular to the sliding direction of the seal body is more appropriately than the second pressure receiving surface obtained by projecting the second pressure chamber onto a surface perpendicular to the sliding direction. and a first communication path that communicates from the pressurizing chamber directly or indirectly through a second pressure chamber, and from the pressurizing chamber to the first pressure chamber. 1. A sealing device for a roll, characterized in that a second communication path is provided to communicate with the second pressure chamber directly or indirectly via the first pressure chamber.