Patent Application
20070284072
The present application is a U.S. National Stage Application of International Application No. PCT/EP2005/051310 filed Mar. 22, 2005, which published as WO 2005/116331 A1 Dec. 8, 2005, the disclosure of which is expressly incorporated by reference herein in its entirety. Further, the present application claims priority under 35 U.S.C. §119 and §365 of German Application No. 10 2004 025 944.5 filed May 27, 2004.
1. Field of the Invention
The invention relates to a sheath for a pressing device, in particular a paper machine, the sheath surrounding the pressing device at least partially and the circumferential face of the sheath having substantially the shape of a cylinder circumferential face, the sheath being configured such that it is resilient in a spring-elastic manner. Furthermore, the invention relates to a pressing device having a sheath of this type.
2. Description of Background Information
In modern paper machines, rolls, between which the running material web is guided and is frequently also pressed under high pressure, are often surrounded with a flexible sheath which can follow the shape of a shoe press on its circumferential face.
For this purpose, the sheath has to be guided and mounted at its edge regions on the end sides of the roll, as a result of which these regions are loaded heavily.
In order to solve this problem, compliant shaped bodies are known which make mounting and force transmission possible on the sheath circumferential face from and to an axially mounted rigid carrier part of the roll.
They have the disadvantage that either the mounting and adjustment are very complicated and therefore expensive. Furthermore, it is disadvantageous that the known solutions absorb too much heat from the rolling action which occurs as a result of the shapes used and therefore have to be cooled in a complicated manner, as otherwise the service life is reduced considerably.
DE-A 197 03 218 A1 has disclosed a pressing device for a paper machine, in which a circulating roll sheath is mounted rotatably on a rigid carrier via a radial support device at the axial end regions. Here, the radial support device has a radially elastic hollow torus body, on which the roll sheath rests. Here, the torus body is connected fixedly to the rigid carrier via a flange by means of a clamping system. The torus body is configured separately from the roll sheath, and the roll sheath and torus body have to be mounted individually on the rigid carrier in a complicated mounting process and adjusted with respect to one another.
DE-A 101 38 526 A1 has disclosed a flexible pressing sheath with an embedded reinforcement and a shoe press roll with a pressing sheath of this type, in which the pressing sheath has an additional reinforcement at its end regions, via which the pressing sheath can be fastened to the outer face of a rotatable support element. This additional reinforcement has to be incorporated into the pressing sheath in additional complicated manufacturing steps. Furthermore, it is disadvantageous that the pressing sheath has to be fastened to the outer face of the rotatable support element in an additional mounting step, which makes accurate and complicated adaptation and adjustment necessary. Compliance of the edge region of the roll surface is not made possible, which has the consequence of more pronounced wear and contamination.
DE 35 46 650 C2 has disclosed a press roll sheath which can be clamped and fastened to the end side of the press roll by lugs which are formed integrally at its axial ends. In this previously known prior art, radial compliance is not possible at the axial edge region of the circumferential face, which limits the applicability of the proposed system, as only small pressing depths into the press roll surface are possible.
All the abovementioned solutions have the disadvantage that sealing problems occur at the transitions of circulating circumferential face and the end sides of the rolls as a result of the constructions which are used, which sealing problems can be eliminated only to a limited extent with high expenditure.
The invention is based on the aim of making a sheath for a pressing device and also a pressing device of this type possible, which sheath is improved over the prior art and in which the abovementioned disadvantages do not occur and, in particular, the service life is increased with respect to the known shapes of sheath.
The invention is directed to a sheath for a pressing device. The sheath surrounds the pressing device at least partially, the circumferential face of the sheath has substantially the shape of a cylinder circumferential face, and the sheath is configured such that it is resilient in a spring-elastic manner. The sheath is mounted on an annular bearing at at least one axial end, the radius of the annular bearing is smaller than the radius of the circumferential face, and the sheath extends at the at least one axial end via a bellows-shaped transition region to the annular bearing. Additionally, the invention is directed to a pressing device including the above-described sheath for a paper machine.
According to the invention, there is provision for the sheath to be mounted on an annular bearing at at least one axial end, the radius of the annular bearing being smaller than the radius of the circumferential face, the sheath extending at the at least one axial end via a bellows-shaped transition region to the annular bearing.
The invention proposes to make a deformation of the sheath, for example when used in a shoe press, reversible in, above all, the radial direction by the fact that the circumferential face of the sheath is mounted in a reversibly deformable manner and as a result of the bellows-shaped transition region on the annular bearing. For this purpose, the bellows-shaped transition region is configured with a flexibly deformable bulge which absorbs the mechanical relative movement between the circumferential face of the sheath and the annular bearing.
According to one preferred refinement of the invention, there is provision for the bellows-shaped transition region to be configured in one piece with the circumferential face.
One advantageous refinement of the invention provides for the annular bearing to be formed by the support face of a circular end disk which is mounted axially on the rotating pressing device.
According to one advantageous variant of the invention, there is provision for the transition region to merge into individual tabs which are fastened individually to the annular bearing.
A filler body is advantageously provided in the bellows-shaped bulge of the transition region between this end of the circumferential face which adjoins it and the annular bearing.
The filler body is preferably formed by a torus which is halved in the radial direction with regard to its center point.
One advantageous refinement of the invention provides for the filler body to seal the inner region of a pressing device which is enclosed by the sheath, in the region of the transition region.
According to one particularly preferred refinement of the invention, the filler body is formed by a pressurized tube.
According to one likewise very advantageous variant of the invention, there is provision for the filler body to be formed by a spring-elastic torus body of solid configuration.
Accordingly, the filler body can be of the open-pore configuration, as a result of which a dissipation of heat is ensured in it as a result of ventilation, which increases the service life.
The pressing device is advantageously filled in the interior with a filler medium at a preselected pressure.
A laid fabric layer is advantageously formed in the sheath, which laid fabric layer extends over the circumferential face and over the transition region to the annular bearing.
One variant of the invention provides for the laid fabric layer which extends over the circumferential face to be formed in the sheath. Accordingly, an additional laid fabric layer is provided which overlaps with the laid fabric layer of the circumferential face and extends over the transition region to the annular bearing.
One advantageous development of the invention provides for the additional laid fabric layer to be spliced onto the laid fabric layer of the circumferential face in the overlapping region.
The circumferential face and the transition region are advantageously manufactured from the same material.
The transition region is preferably cast onto or adhesively bonded to the circumferential face.
The radial compliance of the transition region and the circumferential face advantageously corresponds at most to 90% of the difference in radius between the circumferential face and the annular bearing.
Further advantages, special features and expedient developments of the invention result from the further subclaims or their sub-combinations.
In the following text, the invention will be explained further using the drawings, in which, in detail and in a diagrammatic illustration:
The designations in the figures denote identical or identically acting elements.
The sheath 1 merges at its axial ends 17 from the circumferential face 11 with a bellows-shaped transition region 3 into the annular bearing 7 which is formed by a support on the axially (A) mounted end disk 6 of the press roll 2.
The radius R2 of the annular bearing 7 is smaller than the radius R1 of the circumferential face 11. As a result, a bulge 32 is formed in the profile of the bellows-shaped transition region 3.
At one end, the bellows-shaped transition region 3 is integrally formed onto the circumferential face 11 of the sheath 1 and, at its other end, is clamped on the support face 71 in the annular bearing 7 on the end disk 6.
As the inner region of the press roll which is shown is filled with a gas under pressure, the sheath cannot spring back again into its original shape after passing through the deforming shoe press region (see
Here, the radial compliance of the transition region 3 and the circumferential face 11 is at most 90% of the difference in radius (R1−R2) between the circumferential face 11 and the annular bearing 7.
The filler body 5 (tube 52) seals the inner region 21 of the pressing device 2 in a gastight manner between the sheath 1 and the end disk 6 at the bellows-shaped transition region 3. The restoring force of the circumferential face counter to the deformation at the press shoe can therefore be set by gas pressure which can be regulated in the interior.
In a modification of
Within the context of the invention, an above-described sheath 1 or a pressing device 2 can be used at all locations of the paper machine, at which rolls or guides are provided.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2004 025 944.5 | May 2004 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP05/51310 | 3/22/2005 | WO | 4/25/2007 |
