Metso Paper Inc.

Valmet Corporation

Valmet Paper Machinery Inc.

Juha Lahtinen

Pekka Kivioja

Kari Holopainen

Esa Lensu

Juhani Niskanen

Juha Ehrola

Jori Onnela

Ari Lehto

Esa Salavamaki

Aki Mikkola

Vesa Nokelainen

Matti Hulkkonen

Esa Salavam&auml;ki

Esa Salvamaki

A method for fitting a tubular roll shell () of a roll () in a paper or board machine. In the method, the roll shell () is supported on a stationary roll shaft () by means of hydrostatic slide bearing elements ('), acting on the roll shell () in radially opposite directions, at least in the direction of a plane co-directional with a first plane or a plane parallel to a primary loading (F) and in a plane substantially lateral to a plane co-directional with the primary loading (F). The slide bearing elements (&#x2032;) are loaded hydraulically by means of a pressure fluid. The lateral bearing elements (&#x2032;) acting in radially opposite directions have a hydrostatic pressure thereof adjusted by means of a regulator () having feedback connection with the main bearing elements (&#x2032;) acting in the direction of a plane co-directional with the primary loading (F) to comply at a predetermined ratio with the maximum hydrostatic pressure of the main bearing elements (&#x2032;) acting on the roll shell (). The invention relates further to an apparatus for applying the method.

Roll in a paper or board machine

The invention relates to a method for providing a roll ( ) for a paper machine with sliding bearings, the roll comprising a stationary roll axle ( ) and a tubular roll mantle ( ) arranged to revolve around it. In the method, the roll mantle ( ) is supported on the roll axle ( ) by means of hydraulic sliding bearing members ( ) which are arranged to accomplish radial fitting with bearings of the roll mantle in the loading direction and in the lateral direction with respect to it, and the axial fitting with bearings of the roll mantle. The sliding bearing members are loaded by means of a hydraulic medium, the feed of which to the sliding bearing members is controlled by means of control valves ( ). In the method relating to the invention, when loading (F) is applied to the sliding bearing member ( ) effective in the loading direction, the loading force applied to the sliding bearing member ( ) subject to an external load due to the loading is compensated for automatically, essentially immediately, without an external control instruction, by means of the movement of the control valve ( ) stem ( ) of the sliding bearing member ( ) subject to loading, the said control valve ( ) bringing about a rapid increase in the pressure of the hydraulic medium in the sliding bearing member ( ) subject to the external load, at the same time as the pressure of the medium supplied to the sliding bearing member ( ) located radially on the opposite side of the roll axle ( ) in the loading direction is adjusted to a certain minimum value, whereby the bearings of the roll mantle are rendered so as to be essentially without stroke. The invention also relates to a roll for a paper machine which is provided with sliding bearings.

Method for providing a roll for a paper machine with sliding bearings and a roll for a paper machine with sliding bearings

The invention relates to an arrangement for displacing a roll, which is hydrostatically journalled by its axle ( ) on support structures and positionable in its working position by means of a bearing, through a rapid movement of the bearing out of its said working position. The journalling comprises at each end of the roll at least one loading element ( ) pressurizable with a hydraulic medium and at least one support element ( ). The arrangement of the invention comprises a valve control piston ( ), delivering a hydraulic medium required for the pressurization of said at least one loading element ( ) and positioned in a valve cylinder ( ), said control piston ( ) being provided with a positioning valve ( ) on the face of the control piston ( ) pointing towards the loading element ( ), the face of the control piston ( ) opposite relative to the positioning valve ( ) being coupled with a pressure line (LP) of the hydraulic system for focusing a holding pressure on the control piston ( ).

Arrangement for rapid movement of a roll with hydrostatic bearings

Oil is pumped from a tank ( ) to points of service in the hydraulic roll control system of a papermaking machine, wherein the oil is pumped at least at one low pressure level such as is required for the lubrication of the roll bearings and/or drive gearbox and at least at one high pressure level such as is required for the pressure-loaded zones of a roll. The oil is filtered and if necessary cooled and the return circulation of oil is passed back to the tank ( ). The oil is pumped from the tank ( ) into a single low-pressure circuit by a pump or pumps ( ), with a capacity to meet overall demand of fluid flows delivered to the points of service. Supply lines form the circuit to desired points of service are passed through stages to stepwise elevate the line pressure to a desired high-pressure level.

Method in the hydraulic roll control system of a papermaking machine or the like and a multipressure hydraulic roll control system

Method and arrangement for automatic monitoring and correction of the regulation pressure of regulation valves in a regulation valve block in a variable-crown roll in a paper machine. The regulation pressure of the regulation valve in each regulation zone in the regulation valve block can be connected alternatingly to a reference pressure detector whose measurement signal is compared with the measurement signal of the actual value of the regulation pressure in the regulation zone concerned. The result of the comparison is stored on the page of monitoring of pressure detectors contained in the central computer system, on which page, in addition to this difference, set values and actual values of the regulation zone pressures as well as the value of the reference measurement are provided. In addition, a correction can be made to the actual value of the regulation pressure in the regulation zone concerned if the difference between the measurement signal of the reference pressure detector and the measurement signal of the actual value of the regulation pressure in the regulation zone concerned is higher than a predetermined value.

Method and arrangement for automatic monitoring and correction of the

Bearing control system for a roll with hydrostatic bearings

A method for providing a tubular roll mantle of a roll for a paper machine or equivalent with glide bearings and a roll including glide-bearings. The roll mantle is supported on a stationary roll axle by hydraulic glide-bearing members acting upon the roll mantle or upon the roll ends. The bearing members are loaded hydraulically by a pressure medium. The roll mantle is supported on the roll axle by at least one pair of glide-bearing members which acting radially and/or axially in opposite directions. When an outside force that shifts or attempts to shift the roll mantle in the direction transverse to the main loading direction and/or in the axial direction is applied to the roll mantle, the pressure in the glide-bearing member placed at the side of the higher loading is adjusted to a level higher than the pressure in the glide-bearing member acting in the opposite direction so that the outside forces are neutralized. In another embodiment, the roll mantle is permitted to be shifted over a certain distance in the main loading direction. When the roll mantle approaches its preset extreme position in this direction, the movement of the roll mantle is brake down, and finally the movement is stopped in its extreme position by the glide-bearing members.

Method for providing a roll mantle of a tubular roll for a paper machine

A method for providing a tubular roll mantle of a roll for a paper machine or equivalent with glide bearings and a roll including glide-bearings. The roll mantle is supported on a stationary roll axle by hydraulic glide-bearing members acting upon the roll mantle or upon the roll ends. The bearing members are loaded hydraulically by a pressure medium. The roll mantle is supported on the roll axle by at least one pair of glide-bearing members which acting radially and/or axially in opposite directions. When an outside force that shifts or attempts to shift the roll mantle in the direction transverse to the main loading direction and/or in the axial direction is applied to the roll mantle, the pressure in the glide-bearing member placed at the side of the higher loading is adjusted to a level higher than the pressure in the glide-bearing member acting in the opposite direction so that the outside forces are neutralized. In another embodiment, the roll mantle is permitted to be shifted over a certain distance in the main loading direction. When the roll mantle approaches its preset extreme position in this direction, the movement of the roll mantle is braked down, and finally the movement is stopped in its extreme position by the glide-bearing members.

Growing community of inventors

Jyväskylä, Finland

Juha Lahtinen