The invention relates to a method in a reel-up of a paper web according to the preamble of claim 1.

The invention also relates to a device in a reel-up of a paper web according to the preamble of claim 8.

As prior art, we refer to EP patent specification 0369977 which presents a method and a device in a reel-up of a paper web, in which the roll is formed around a reeling shaft and/or on support of carrier rolls or carrier belts and, in which method and device, a reeling drum is used which forms a reeling nip with the roll to be produced. The deflection of the drum shell rotating around the central shaft of the reeling drum is adjusted with a load means, e.g. a hydraulic means, and, by means of adjusting the deflection, the distribution of the linear pressure in the reeling nip in the axial direction is controlled, e.g., kept substantially uniform.

As prior art, we also refer to EP patent specification 0912435 which presents a method and a reel-up for continuous reeling of a material web. The reel-up comprises a movable reeling drum which forms a reeling nip and, in which presented method, the line load in the reeling nip is controlled with the moving reeling drum. In the arrangement presented in the reference, the reeling drum moves horizontally or at an angle. As the reeling drum, e.g., a deflection- compensated reeling drum is used.

In embodiments known from prior art, when using a deflection-compensated reeling drum as the reeling drum of the reel-up, the aim has been to provide an even/desired nip-force profile in the reel-up and to eliminate problems caused by eccentric nip load. In addition, the aim has been to solve problems related to the

profile of paper in cross-direction and problems in the forming of the roll caused by air travelling along the paper web. With afore-described solutions known from prior art, it has not been possible to totally eliminate afore-described reeling problems. Furthermore, as known from prior art in connection with the reel-up, problems can be caused to nip force e.g. from changes in guide frictions which cannot be observed e.g. from the pressure measurements of hydraulic cylinders or from power sensors.

From prior art are also known reel-ups in which a crown has been turned on the outer surface of the shell of the reeling dram. A problem of these applications is, however, that the crown functions in as desired only at a certain diameter and nip- load level of the roll to be formed. Usually with crowns known from prior art, an ideal base for the roll to be formed is achieved but, with larger diameters of the roll, the crowns known from prior art are not adequate. When the diameter of the roll to be formed grows, the crown must be such that air travelling along the paper web will not be conducted inside the roll to be formed and, at the same time, the removal of air from inside the roll must be effective. In solutions known from prior art, the crown enables compensating the deflection of the nip with a certain constant nip load. One has tried to calculate the correct value of crowning by utilising several different types of parameters, but it is extremely difficult to provide an adequate nip form, e.g. linearity, for the whole line load area when the diameter of the roll changes.

The object of the present invention is to develop the reeling drum so that the afore-described disadvantages of solutions known from prior art will be eliminated or at least minimised.

Furthermore, an object of the invention is to develop the reeling drum so that its intended uses are more diverse and more reliable compared to solutions known from prior art.

An object of the invention is also to provide a deflection-adjustable reeling drum by means of which the problems related to the crown of the reeling dram of solutions known from prior art have will be eliminated or at least minimised.

To achieve the afore-mentioned objects and those which come out later, a method according to the invention is mainly characterised in what is presented in the characterising part of claim 1.

Again, a device according to the invention is mainly characterised in what is presented in the characterising part of claim 8.

In the method and the device according to the invention, the deflection of the roll shell rotating around the central shaft of the reeling dram is adjusted internally in the shell with loading provided with at least one load means for providing nip force and/or nip-force profile prevailing in the reeling nip at the same time as, in the method and the device, the nip force and/or nip-force profile prevailing in the reeling nip is adjusted with said at least one internal load means of the shell of the reeling drum. According to an advantageous embodiment of the invention, the nip force/nip-force profile prevailing in the reeling nip is also measured with the same said internal load means of the shell of the reeling drum from inside the roll shell. For measuring, it is possible to use measurement sensors placed below the bearing housings of the reeling dram or a pressure-sensitive measurement foil on the surface of the roll. Thus, according to the invention, nip-load level, nip-load profile are adjusted by means of the deflection-adjustable reeling dram and, according to an advantageous embodiment, the oscillation of the roll shell of the reeling dram is provided by using the same internal load means of the roll shell.

The deflection-adjustable reeling dram used in the method and the device according to the invention is, according to an advantageous embodiment, realised so that the roll shell of the reeling dram is movable so that the oscillation of the web is provided in relation to the roll to be produced by running the roll shell back

and forth askew in relation to the fixed central shaft of the reeling dram by means of load means, e.g. load and counter shoes, arranged inside the roll shell. When moving the shell of the deflection-adjustable roll, the web moves cross- directionally in relation to the roll to be produced. Thus, by means of the invention, the web can be deflected even with a small movement between the tending side and the driving side, whereby an advantage is achieved, inter alia, as the bearing of the reeling drum can be fixed because the oscillation movement is provided with the movement of the shell, and that the oscillation can be realised with the same means as the adjustment of the nip force and/or nip-force profile prevailing in the reeling nip.

The shell of the reeling dram used in connection with the method and the device according to the invention is advantageously of composite material, e.g., of fibreglass or carbon fibre, whereby an advantage is achieved in manufacturing costs as the manufacturing process is quick and simple and the manufacturing materials are inexpensive. Furthermore, the operation of the reel-up is more sensitive than that of reel-ups known from prior art because the deflection- adjustable roll with a composite shell is lighter, whereby a smaller friction affects it and it is more sensitive especially when using small forces, e.g., below 1 kN/m. When using composite material as the shell material of the deflection-adjustable roll, an adequate movement of the shell is provided with small load pressures for providing required nip force in the reeling nip.

According to an embodiment of the invention, the deflection-adjustable reeling dram is realised so that the reeling dram has one zone on the area of the whole shell. This way, the adjustability of a bulge (crown) is provided by making, e.g. turning, the shell from inside as desired of its thickness profile in the cross- direction of the machine in connection with manufacturing. In connection with this embodiment of the invention, it is advantageous to use a shell thinner than usual or a composite shell, whereby it is possible to provide the bulge (crown) to the shell with small pressure. This kind of dram is applicable for use, in addition

to the reeling drum applications of reel-ups, as the nip rolls of paper and coating machines, e.g., in a press, a calender, in connection with coating stations etc. The drum according to this embodiment is inexpensive of its manufacturing costs, because no separate load shoes are required in deflection adjustment, but a desired profile form is provided by means of the different thickness of the shell as a function of pressure. The bulging of the shell is adjusted by adjusting the amount of pressure, whereby the cross-directional profile is created from the characteristics of the shell, i.e., according to the thickness profiles of the shell determined in connection with manufacturing; most advantageously is used a thin shell or one manufactured of composite material in which it is possible to achieve an adequate bulge (crown) even with small pressure, e.g. below 10 bar. Then an adjustable reeling dram/nip roll simple of its structure from the viewpoint of controlling deflection and nip linearity is provided. This kind of embodiment is especially useful in connection with replacement, whereby a normal deflection- adjustable drum is replaced on the site to be modernised by a drum according to the invention, in which drum, the shell, e.g. thicker from its edge areas of its thickness, is crowned by means of internal pressure to a desired shape.

In an embodiment of the method according to the invention, when using a deflection-adjustable reeling drum according to the invention, the nip-force profile of the reel-up is adjusted optimal in each operation phase of the reel-up e.g. so that a linear nip-force profile is used during threading and a linear or a centre- orientated nip-force profile is used during reeling.

The invention will now be described in more detail with reference to the figures of the accompanying drawing, to the details of which the invention is, however, by no means intended to be narrowly confined.

Fig. 1 schematically shows an embodiment of the invention in which the shell of the reeling drum is oscillated.

Fig. 2A schematically shows an embodiment of the invention with which the crown of the reeling drum is provided.

Fig. 2B schematically shows the deformation of the shell in the longitudinal direction of the shell depending on the thickness of the shell with some initial values.

Fig. 3 schematically shows an embodiment of the deflection-compensated reeling drum.

A reeling drum 10 and a web roll 11 to be formed, e.g. a machine roll, are schematically drawn in the embodiment of Fig. 1. However, in the figure, the situation in the reeling nip N is shown the reeling nip being open for the figure to be clearer. According to the figure, the shell 12 of the reeling drum, which is slide-bearing mounted on support of internal load and counter shoes of the shell 12, can be made to oscillate by moving the shell 12 in relation to its fixed central shaft (soul) by adjusting the place of the load and counter shoes as desired, whereby the shell 12 moves while the central shaft and bearings (not shown in figures) stay in place. The reeling drum 10 oscillates with a movement distance L e.g. ± 20 mm back and forth, whereby the machine roll 11 turns correspondingly, because the reeling nip N between the reeling drum 10 and the machine roll 11 being formed is closed and force-adjusted. In this situation, the web travelling via the reeling nip N oscillates in relation to the machine roll, whereby even with a very small oscillation movement, the deflection of the travel direction of the web in the reeling nip is provided in the shell of the reeling drum to a desired cross- direction in relation to the machine roll.

According to Fig. 2A, the reeling drum 10 is formed with one zone so that its internal space 13 can be pressurised, which is shown with arrow P. For providing a desired crown B, the roll shell 12 of the reeling drum 10 is formed in the manufacturing phase such of its thickness profile that the bulge (crown) B of the

shell 12 in the pressurisation situation is desired. The thickness of the wall of the shell 12 can vary e.g. so that the shell 12 is thicker of its edge areas and narrower of its central area, whereby it is possible to provide the bulge i.e. crown B outwards in the central area, such as is shown in the figure. The shape of the bulge is determined by the shape made to the shell 12 in the manufacturing phase to a standard shape and adjustably based on the pressure level of the internal space 13.

According to Fig. 2B, the shell 12 is deformed as the thickness of the shell 12 is designed in a way shown in Fig. 2A according to curve 21. For comparison, the situation is shown in the set of curves also when it is a question of a shell with uniform thickness, which has been marked with curve 22. In the example of the figure, the longitudinal direction of the shell from the edge of the shell to the centre of the shell is on the X axis and the deformation of the shell is on the vertical axis Y. The example curves 21, 22 of the figure are described in a situation when using the pressure of 10 bar as internal pressure.

The reeling dram used in connection with the invention according to Fig. 3 is a deflection-adjustable reeling dram 10 which comprises a stationary central shaft 14 which can be rotatable around its central shaft. Around the central shaft 14 is arranged to rotate a roll shell 12 so that a space 15 is left between the central shaft 14 and the shell 12. In the dram borings made to the central shaft 14 are arranged a set of load pistons 19 which load slide shoes 17 which form a sliding surface 16 with the inner surface of the shell 12. The sliding surfaces are oiled with the same hydraulic oil as load pistons 18 are loaded. The load pistons 19 are connected to an oil system 40. According to the advantageous embodiment of the invention, the roll shell 12 is of composite material, e.g. 20-50 mm of thickness, whereby the weight of the roll shell is light, because the density of composite materials (e.g. carbon fibre around 1,550 kg/m ² , fibreglass 2,000 kg/m ² ) is small compared to the density of steel (around 7,800 kg/m ³ ).

The invention was described above only referring to some of its advantageous embodiments, to the details of which the invention is, however, by no means intended to be narrowly confined.