JP2000291644A - Roll device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the reduction of an oil film thickness of a shoe end part by forming crowning on a shoe surface of a roll device whose inner face is supported through an oil film between a hydrostatic shoe and it and which rotates and has a hollow roll cell. SOLUTION: A shoe lubrication face in both end parts in the longitudinal direction of a hydrostatic shoe 2 is shaved off by a crowning amount δ1. A crowning shape is desirably a shape matching with a bending pattern of the shoe 2, but a shape close to a crowning shape like circular arc and taper may be used. The crowning amount is determined by pressure, bending rigidity, metal seal leak amount, etc., and the shoe 2 having low bending rigidity requires a large amount. Even if the shoe 2 is bent upward due to oil leakage in the end part, it is mutually cancelled with crowning to form a uniform clearance between an inner face of a hollow roll cell and it, ensure a proper oil film thickness, prevent the occurrence of burning accident, and increase the safety and reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll device having a hollow roll cell which is supported and rotated via an oil film by a static pressure shoe mounted on a core shaft.

[0002]

2. Description of the Related Art An outline of a conventional roll apparatus of this type will be described with reference to FIGS. FIG. 4 shows the entire view of the roll device. FIGS. 5 and 6 are axial sectional views of the roll device when the inclination angle of the core shaft is different, FIG. 7 is a top view of a static pressure shoe, and FIG. FIG. 9 shows the state of sealing at the end of the static pressure shoe, and FIG. 10 shows the state of the oil film due to deformation of the end of the static pressure shoe.

[0003] This type of roll device employed in a papermaking machine is such that a band such as paper or felt is applied at a predetermined pressure between the roll device and a pressure roll 5 or another pressure roll 51 forming a nip. By pressing and passing, the strip is dehydrated or molded.

[0004] The schematic structure of the roll device is as follows. The core shaft 1 having the central structure is supported by an external structure whose both ends are not shown, and the hollow roll cell 3 is rotatably supported by bearings 4 disposed at both left and right ends thereof.

[0005] The hollow roll cell 3 conveys the strip 8 while depressing or forming the strip 8 by pressing the strip 8 at a predetermined pressure with a nip formed by the outer surface and the pressure roll 5. As the roll 7, in addition to the pressure roll 5, another pressure roll 51 or the like is disposed, and a nip is formed between the roll 7 and the other pressure roll 51 to perform dehydration or molding of the belt-shaped body 8. They may be arranged.

The inner surface of the hollow roll cell 3 receives an oil film pressure generated between the hollow roll cell 3 and the static pressure shoe 2 attached to the core shaft 1 and opposes the pressing force of the pressure roll 5. The core shaft 1 has a substantially I-shaped cross section, and its mounting direction is such that the static pressure shoe 2 attached to the end is at an obliquely upper position as shown in FIG. 5, and as shown in FIG. There are various arrangements depending on the functions required for the roll device, the peripheral structure, and the arrangement, such as the arrangement in which the pressure shoe 2 is located straight upward or the arrangement in which the static pressure shoe 2 is directed downward (not shown). is there.

The static pressure shoe 2 has a piston 22 integrally formed at a lower portion thereof, and the piston 22 is provided with a metal seal 27 for lubricating oil sealing in a piston groove 23 formed at an upper portion of the core shaft 1. And can be moved in the radial direction of the hollow roll cell 3.

The upper surface of the static pressure shoe 2 has a shoe lubrication surface 2.
The shoe lubrication surface 21 is provided with a plurality of shoe pockets 24 for storing lubricating oil, and a throttle 25 is provided inside the static pressure shoe 2.

Lubricating oil is supplied to the piston groove 23 from an oil supply pipe 9 installed inside the core shaft 1, and the lubricating oil fills a shoe pocket 24 through a throttle 25, and a gap between the lubricating oil and the inner surface of the hollow roll cell 3. Causes oil film pressure. When the hollow roll cell 3 is stationary, a static pressure acts on the oil film pressure, and when the hollow roll cell 3 rotates, dynamic pressure is further applied.

In the static pressure shoe 2 configured as described above, in order for the pressing force to be stably generated between the pressure roller 5 and the hollow roll cell 3 when the hollow roll cell 3 rotates, the shoe lubrication surface 21 and the hollow roll cell 3 need It is necessary to maintain an oil film thickness of several tens μm to several hundreds μm between the inner surfaces.

The oil film thickness of the static pressure shoe 2 is determined by the shoe pocket 24, the throttle 25, the shoe lubrication surface 21, and the hollow roll cell 3.
The operating conditions such as the geometric shape of each part of the inner surface of the inner surface, the rotation speed of the roll device, the pressing force, the temperature of the supplied lubricating oil and the temperature of the shoe lubricating surface 21, the positional relationship with the pressing roll 5 and another pressing roll 51 The geometrical shape of each part such as the shoe pocket 24, the throttle 25, the shoe lubrication surface 21, and the inner surface of the hollow roll cell 3 is designed so as to satisfy the required operating conditions, since it is affected by various factors. I can decide.

In such a situation, the characteristic of the static pressure shoe is that the aperture 25 of the shoe pocket 24 is located at each position in the width direction.
If sufficient oil is supplied, the same pocket pressure is generated and a uniform oil film thickness can be obtained.

[0013]

However, in this type of roll device, when the piston shape is rectangular as shown in FIG. 9, the metal seal 27 at the corner has a problem in sealing performance. Since there is a tendency that the oil leakage L in one part tends to be larger than that in the other part, there is a possibility that a case where a sufficient flow rate is not supplied to only the end part may occur.

In such a case, as shown in FIG. 10, a sufficient oil film pressure cannot be generated on the shoe lubrication surface 21 at the end, and the amount of oil supplied to the throttle in this portion is insufficient. The decrease M of the oil film becomes remarkable.

As a result, the end of the static pressure shoe 2 is bent upward in the y direction, as shown by the curve N of the shoe, and the oil film thickness is reduced as compared with the central portion. If it exceeds, the oil film thickness of the static pressure shoe 2 cannot be secured by a required amount, and there is a danger of causing an accident such as seizure.

If there is a temperature difference between the upper and lower surfaces of the static pressure shoe 2, when the temperature of the piston 22 becomes high, the end portion is deformed upward in the same manner as described above, which may lead to a seizure accident. .

The present invention solves such a problem in the conventional roll apparatus, and devises the shape of the static pressure shoe so as to provide a suitable static pressure shoe for preventing the oil film thickness from decreasing at the end of the static pressure shoe. An object of the present invention is to provide a roll device provided with the same.

[0018]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a static pressure shoe mounted on a core shaft having a fixed shaft end and movable in a radial direction. An object of the present invention is to provide a roll device having a hollow roll cell that rotates with its inner surface supported by an oil film between the pressure shoe and a pressure shoe, wherein a crowning is formed on the surface of the static pressure shoe.

That is, according to the present invention, since the hydrostatic shoe mounted on the core shaft has a crowning formed on the surface thereof, even if the end is bent upward due to oil leakage or the like at the end. The crowning is mutually canceled to form a uniform gap between the crowning and the inner surface of the hollow roll cell, so that an appropriate oil film thickness is ensured.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. In order to avoid redundant description, the same parts as those of the above-described conventional one are denoted by the same reference numerals in the drawings, and redundant description will be omitted as much as possible.

FIG. 1 shows a configuration in which a crowning is provided on a static pressure shoe in this embodiment, FIG. 2 shows a configuration in which no pressure is applied to the static pressure shoe and no load is applied, and FIG. 2 shows a state of the static pressure shoe when pressure is applied to the shoe.

In this embodiment, as shown in FIG. 1, a shoe lubrication surface 2 is provided at both longitudinal ends of the static pressure shoe 2.
1 adopts the crowning shape scraped off by crowning amount [delta] _1.

The crowning shape is desirably a shape that matches the y-direction bending pattern of the static pressure shoe. However, if a crowning effect is obtained, it is not always necessary to select a strict bending curve shape. Other shapes that approximate the crowning shape, such as an arc shape or a tapered shape, may be used.

Further, depending on the shape of the flexure, the crowning can be provided over the entire longitudinal direction in accordance with the shape, or can be provided only at the end where the conditions are particularly severe.

The magnitude of the crowning amount δ ₁ is determined depending on the pressure of the static pressure shoe 2, the bending rigidity of the static pressure shoe 2, the leakage amount of the metal seal, and the like. The larger the leak in the shoe 2, the larger the amount is required.

Since the seizure accident occurs when the oil film thickness of the static pressure shoe 2 becomes smaller than the allowable value, the crowning amount δ ₁ is always exactly equal to the bending amount of the static pressure shoe 2. It is not necessary, and it may be adjusted to such an extent that the amount of oil film reduction can be kept within an allowable range.

It is possible to provide a target which is strict in the operating conditions of the roll device, or it can be determined as appropriate such as by averaging the entire operating range.

As shown in FIG. 2, the static pressure shoe 2 having the crowning amount δ ₁ at both ends in the longitudinal direction has its piston 22 fitted into the piston groove 23 of the core shaft 1 via the metal seal 27.

The core shaft 1 is housed in the hollow roll cell 3 together with the integrated static pressure shoe 2 fitted in the piston groove 23.

FIG. 2 shows a no-load state. As described above, since both ends have a crowning shape, the gap between the surface of the static pressure shoe 2 and the hollow roll cell 3 in the no-load state is as follows. It is wide at the end.

In the above-described embodiment, the operation when the static pressure shoe 2 is incorporated into the core shaft 1 and a pressure is applied will be described with reference to FIG.

Hydrostatic shoe 2 having crowning amount δ ₁
The piston 22 can be moved up and down into a piston groove 23 provided at the upper part of the core shaft 1 through a metal seal 27 for lubricating oil sealing, and can be moved up and down. The lubrication surface 2 is on the upper part of the shoe 2.
1. Provide a plurality of pockets 24 for storing lubricating oil,
A throttle 25 is provided in the lower part of the piston 22.

When a hydraulic pressure is applied to the piston groove 23 in this state, the lubricating oil passes through the throttle 25 and
And an oil film pressure is generated between the inner surface of the hollow roll cell 3 and an appropriate oil film thickness.

However, in the case where the shape of the piston 22 is square, oil leakage in this part tends to be larger than that in other parts due to the problem of the sealing property of the metal seal 27 at the corner. In some cases, a sufficient flow rate of lubricating oil may not be supplied only to the ends.

In such a case, only the amount of oil in this portion is insufficient, and the end of the static pressure shoe 2 is bent upward (in the y direction), and the oil film thickness is reduced as compared with other portions. However, since the static pressure shoe 2 in the present embodiment is provided with a crowning, such a bend causes the hollow roll cell 3 at a position exactly balanced with the bending rigidity of the static pressure shoe 2. And a uniform gap is formed with the inner surface of the substrate.

Thus, according to the present embodiment, it is possible to prevent a seizure accident or the like that occurs when the oil film thickness is reduced only at the end of the static pressure shoe 2.

When a temperature difference occurs between the upper and lower surfaces of the static pressure shoe 2, when the temperature of the piston 22 becomes high, the end portion is deformed upward as described above. In this case, too, the oil film is formed due to the effect of crowning. It is possible to prevent the oil film from decreasing and maintain an appropriate oil film thickness.

Although the present invention has been described with reference to the illustrated embodiments, the present invention is not limited to such embodiments.
It goes without saying that various changes may be made to the specific structure within the scope of the present invention.

[0039]

As described above, according to the present invention, a static pressure shoe mounted on a core shaft having a fixed shaft end and movable in a radial direction is provided between the static pressure shoe and the static pressure shoe via an oil film. In a roll device having a hollow roll cell that rotates while being supported, a crowning is formed on the surface of the static pressure shoe, so that the static pressure shoe mounted on the core shaft has an oil at the end. Even if the same end is bent upward due to leakage, etc., it cancels each other with the crowning, forming a uniform gap between the inner surface of the hollow roll cell and ensuring an appropriate oil film thickness, seizure accident, etc. This has prevented the occurrence of cracks and provided a roll device with improved safety and reliability.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an outline of a static pressure shoe provided with a crowning in a roll device according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a configuration of the static pressure shoe shown in FIG. 1 in a no-load state.

FIG. 3 is an explanatory diagram showing a state when pressure is applied to the static pressure shoe shown in FIG. 1;

FIG. 4 is an explanatory view showing the entire appearance of a conventional roll device.

FIG. 5 is an explanatory diagram showing an example of an assembled state of a core shaft in the roll device of FIG. 5;

FIG. 6 is an explanatory view showing another example of a state where the core shaft is assembled in the roll device of FIG. 5;

FIG. 7 is an explanatory diagram showing a state where the static pressure shoe in the roll device of FIG. 5 is viewed from above.

FIG. 8 is an explanatory diagram showing a cross section of a static pressure shoe in the roll device of FIG. 5;

FIG. 9 is an explanatory diagram showing a sealing state at an end of a static pressure shoe in the roll device of FIG. 5;

10 is an explanatory diagram showing a state of an oil film due to deformation of an end of a static pressure shoe in the roll device of FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 core shaft 2 static pressure shoe 3 hollow roll cell 4 bearing 5 pressurizing roll 8 belt 9 oil supply pipe 10 oil drain pipe 21 shoe lubrication surface 22 piston 23 piston groove 24 shoe pocket 25 throttle 26 shoe lubrication surface exit side 27 metal seal 28 shoe Lubrication surface entry side 51 Pressure roll

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyoshi Nakano 5007 Itozakicho, Mihara City, Hiroshima Prefecture Mitsubishi Heavy Industries Mihara Works Co., Ltd. F term (reference) 3J103 AA02 AA24 CA51 DA02 FA02 FA26 GA02 GA13 GA32 4L055 CE72 CF41 CG12

Claims (1)

[Claims] 1. A static pressure shoe mounted on a core shaft having a fixed shaft end and movable in a radial direction, and a hollow roll cell which is rotated with its inner surface supported via an oil film between the static pressure shoe and the static pressure shoe. A crowning formed on a surface of the static pressure shoe.