FI114034B - Slide shoe assembly for a roll in a paper/board machine has a loading element that is equipped with a mechanism to eliminate for a nip-load induced deflection of the roll shell and/or a deflection of the slide shoe - Google Patents

Abstract

A slide shoe assembly includes a loading element which is equipped with a mechanism to eliminate for a nip-load induced deflection of the roll shell and/or a deflection of the slide shoe that is caused by the pressure of a hydraulic medium. The element is provided to eliminate the harmful effects of deflections on an oil film between the loading shoe and a supported cylindrical surface. The slide shoe assembly comprises a stationary axle (4) mounted with a cylindrical roll shell (2). A clearance (5) is formed between the axle and an inner surface (3) of the roll shell. The roll shell is fitted with a loading elements (11) which are operated by a pressurized hydraulic fluid and provided with slide shoes (10). The slide shoes are loaded against the inner surface of the roll shell to control the distribution of a nip pressure in a nip. The loading element is equipped with a mechanism to eliminate or compensate for a nip-load induced deflection of the roll shell and/or a deflection of the slide shoe that is caused by the pressure of a hydraulic medium. The element is provided to eliminate the harmful effects of deflections on an oil film between the loading shoe and a supported cylindrical surface. An independent claim is also included for a loading shoe for a thin-shelled, deflection-compensated roll (1) in a paper/board machine. The loading shoe is fitted in a loading chamber formed along the roll axle which can be loaded by hydraulic medium present in the loading chamber. The shoe has its sliding surface provided with high-pressure chamber which is in line with the nip to eliminate a directed deformation in the shell.

Description

114034

Thin-skinned Compensated Roll Load Shoe for Paper / Cardboard or Post-Processing Machine

The present invention relates to a loading shoe for a thin-shell deflection-compensated roll of a paper / board machine or a finishing machine comprising a massive stationary roll shaft and a thin-walled roll-over load bearing shoe that is rotatable about the roll axis. by means of hydraulic medium towards the inner surface of the diaper to bring the sliding surface of the 10 shoes against the inner surface of the diaper, and which deflection compensated roll forms a nip with the counter roll.

The invention further relates to a method for eliminating or substantially reducing the radial deformation caused by nip loading in a roll jacket of a thin-shell deflection roll of a paper / board machine or a finishing machine, which roll includes a massive stationary roll axis; a thin-walled roller sheath rotatable about a roll axis; and a plurality of loading shoes disposed within the loading chambers formed on the roll shaft and the loading shoes being individually loadable or in groups of zones divided by a hydraulic medium in the loading chambers towards the inner surface of the shoe to prevent the sliding with a nip.

»I> 25 The use of thin-walled diapers having a thickness of the diaphragm, e.g., in the range of about 30 to about 60 mm, is advantageous in deflection compensated rolls, e.g.

for adjustability of the transverse property profile of the paper web.

: One problem with such thin-walled diapers is the inward deformation of the diaper due to the nip load »· ► ·, which causes the .1 1 30 thinning of the lubricating film between the diaper and the load shoe at the nip.

To solve this problem, for the zone-controlled roller, Fl application 880074 proposes a sliding shoe arrangement, where instead of the solid walls of the sliding chambers, flexible automatically adjusting walls are used instead of 2 114034 pan deformations. . However, this solution is relatively complex and expensive.

It is an object of the present invention to provide an improved solution for eliminating deformations due to nipple loading of a thin-walled flexural diaper, suitable for use with both individually adjustable and zone adjustable load shoes. To accomplish this goal, the loading shoe of the invention is characterized in that a high-pressure chamber is provided substantially on the sliding surface 10 of the shoe, substantially eliminating the radial deformation of the roll by the nip load.

The method according to the invention, in turn, is characterized in that in the method 15 a high pressure space is formed on the sliding surface of the shoe substantially at the nip which exerts a pressure effect against the nip load on the inner surface of the sheath.

The invention will now be described in more detail with reference to the accompanying drawings 20, in which: Figure 1 is a schematic cross-sectional view of a loading shoe according to the invention,: ': 25 shows another embodiment of a loading shoe according to the invention an embodiment from above. ton, and »; ··. 30 »· · *. Figure 4 shows yet another schematic cross-sectional view of a loading shoe according to the invention.

• · • · • · 114034 3

1-4, like parts are denoted by like reference numerals.

The deflection compensated roll of Fig. 1 includes a thin-walled jacket 5 1 rotatably arranged around a stationary massive shaft 10 which, together with the outer surface of the counter roll 6, forms a nip N in which the nip load FN tends to deform the jacket 1 in its radial direction. A loading chamber 7 is formed on the stationary shaft 10 to which hydraulic fluid is fed through a channel 12. A loading shoe 2 is disposed in this loading chamber 7 such that its sliding surface 10 a is directed towards the inner surface of the sheath 1. By the pressure of the hydraulic medium in the loading chamber 7, the shoe 2 can be loaded towards the inner surface of the sheath 1 to bring the shoe's sliding surface against that inner surface with the lubricating-oil film between said opposing surfaces. A high pressure chamber 15 3 is formed on the sliding surface of the loading shoe at nipple N, into which a high pressure hydraulic medium is introduced through channel 5.

On either side of this high pressure chamber 3, stabilizing chambers 4 are disposed in the circumferential direction of the diaper 1, to which hydraulic fluid is fed from the loading chamber 7 under low pressure. The function of these stabilization chambers 4 is to keep the shoe straight during the rotational movement of the diaper 1. Stabilization chambers 20 may be provided on each side of chamber 3 in two or more axial directions; In the embodiment of Figure 4, there are a total of four stabilization chambers.

»*, | By supplying the high pressure hydraulic medium to the high pressure chamber 3, radial deformation caused by the nip load FN in the diaper is substantially eliminated, thereby preventing the lubricating oil film from sliding between the loading shoe and the inner surface of the diaper. Such a solution achieves the advantageous use of thin-walled diapers in terms of adjustability of the transverse property profile of the material web to be treated.

30 »

The embodiment of Figs. 2 and 3 differs from the embodiment of Fig. 1 only in the arrangement of the channels 5 and 12. The channel 5 in this embodiment is preferably provided by a hose on the portion between the shaft 10 and the shoe 2.

114034 4

The embodiment of Figure 4 differs from the embodiments of Figures 1-3 in that, instead of the high pressure chamber 3, the high pressure space is formed by a relatively wide heel between the stabilization chambers 4 with inwardly sloping bevels 8 for hydrodynamically pressurizing the diaphragm. can be enhanced to provide a sufficiently high pressure to prevent deformation of the diaper. This head may also be provided with a supply of additional oil at a constant flow to enhance the hydrodynamically induced pressure increase without or in addition to said bevels.

t »1» »» 1 »♦ • • • • • I t I 1 •> ·>>» »· ·» · • · ·

Claims (9)

114034 5 A paper / board machine or a finishing machine, a thin jacket deflection compensated roll loading shoe (2), which roll includes a massive static-5 girder roll shaft (10) and a rotatably thin roll casing (1) rotatable about the roll axis, 2) disposed in a loading chamber (7) formed on a roll shaft (10) and loaded by hydraulic medium in the loading chamber towards the inner surface of the sheath (1) to bring the sliding surface of the shoe against the inner surface of the sheath; (N), wherein a pressure chamber (3, 8) is provided on the sliding surface (2a) of the shoe (2) in the region of the nip (3, 8) having on both sides further stabilization chambers (4) for lubricating oil from the loading chamber (7) at pressure in the loading chamber, characterized in that the pressure chamber (3, 8) is a high pressure chamber having a substantially high pressure. greater than the pressure of the loading chamber (7) and the stabilization chambers (4) to substantially eliminate the radial deformation caused by the nip load (FN) on the roll shell, and which pressure chamber is located substantially at the nip (N). Load shoe according to claim 1, characterized in that . there are two or more warping chambers (4) axially on either side of the high pressure chamber (3, 8). • «* Load shoe according to claim 1 or 2, characterized in that the high pressure chamber (3) is provided with a high pressure supply (5) separate from the load chamber (7). Load shoe according to one of Claims 1 to 3, characterized in that the high pressure chamber is formed by a wide heel in the hydrodynamic region of the sliding surface (2a) between the stabilization chambers (4), the pressure of which can be obtained hydrodynamically. the diaper (1) rotating with respect to the shoe (2). 114034 6 Load shoe according to claim 6, characterized in that an inwardly directed bevel (8) is formed in the heel to enhance the hydrodynamic pressure increase. Load shoe according to claim 4 or 5, characterized in that said heel is provided with a supply of additional oil at a constant flow. A method of eliminating or substantially reducing a radial deformation caused by a nip load in a roll jacket of a thin-shell deflection roll of a paper / board machine or a post-processing machine, the roll having a massive stationary roll axis (10); a thin-walled roll shell (1) arranged to rotate about a roll axis; and a plurality of loading shoes (2) disposed within the loading chambers (7) formed on the roller shaft (10) and the loading shoes being individually loadable 15 or grouped by hydraulic medium in the loading chambers towards the inner surface of the shoe inner surface through a lubricating oil film, and which deflection-compensated roll forms a nip (N) with the counter roll (6), characterized in that the method comprises forming a low pressure space substantially at the nip (N) against the nip load (FN). oriented printing; no effect on the inner surface of the jacket. t 1 A method according to claim 7, characterized in that the high-pressure space is formed by feeding a high-pressure hydraulic medium 25 to the sliding surface of the shoe in the chamber (3) formed at the nip (N). A method according to claim 7, characterized in that the high pressure space is formed by a sliding surface area in the hydrodynamic region at the nipple (N), which is formed with bevels to assist in the development of pressure and / or by feeding to said sliding surface. • · · add oil at constant flow. · 1 • · · 114034 7