WO2025068104A1 - Calender for rolling a material web having a constant thickness, and corresponding method - Google Patents

Abstract

The invention relates to a calender for rolling a material web, which calender has at least two rollers which are arranged in parallel next to one another and between which a roller gap is formed, wherein each roller has a roller body as well as a first bearing journal and a second bearing journal axially opposite the first, by means of which journals each roller is mounted, wherein at least an inner bearing facing the roller body and an outer bearing facing away from the roller body are arranged axially next to one another at least on a first bearing journal of a first of the rollers and an adjacent first bearing journal of a second of the rollers, so that the inner bearings are arranged in a first bearing row and the outer bearings are arranged in a second bearing row, wherein the roller gap and/or a preload between the rollers is adjusted by clamping the inner bearings in alignment with one another or the outer bearings in alignment with one another and by diagonally clamping an inner bearing to an outer bearing. The invention also relates to a corresponding method.

Description

MATTHEWS INTERNATIONAL GMBH, Gutenbergstraße 1-3, 48691 Vreden, Germany

MATTHEWS INTERNATIONAL CORPORATION Two NorthShore Center 15212 Pittsburgh, USA

Calender for rolling a material web with a constant thickness and corresponding process

The invention is based on a calender for rolling a material web with a constant thickness, having at least two rolls arranged parallel to one another, between which a roll gap is formed, each roll having a roll barrel and a first and a second bearing journal axially opposite the first, via which the respective roll is mounted, at least on a first bearing journal of a first of the rolls and an adjacent first bearing journal of a second of the rolls, at least one inner bearing facing the roll barrel and an outer bearing facing away from the roll barrel are arranged axially next to one another, so that the inner bearings are arranged in a first bearing row and the outer bearings are arranged in a second bearing row.

Such a calender is known from the publication DE 10 2019 135 524 Ai. In this calender, two rolls are clamped against each other by cross-clamping two bearings of one roll with two bearings of the adjacent roll. The bearings of the second roll are in turn cross-clamped with the bearings of the next adjacent roll. The roll gap is controlled by regulating the tensile and compressive stress of the clamping. Furthermore, the gap between the rolls is adjusted by controlling the preload. The complexity of this design is prone to failure due to the high degree of interaction between the forces acting on the bearings and requires a high level of technical effort with regard to gap control. It is therefore the object of the invention to further develop a calender and a corresponding method in such a way that it has a lower complexity and susceptibility to failure with regard to gap control.

The problem is solved by the features of the independent claim. Advantageous embodiments of the invention are specified in the subclaims.

Accordingly, it is provided that the roll gap and/or a preload between the rolls is adjusted by means of aligned clamping of the inner bearings to one another or of the outer bearings to one another, on the one hand, and by diagonally clamping an inner bearing to an outer bearing, on the other hand. Bearings which can be assigned as essentially opposite a corresponding bearing of the adjacent roll are considered to be aligned within the meaning of the application. If a roll neck has a first inner bearing facing the roll barrel and a second bearing arranged axially adjacent to it and facing away from the roll barrel, and an adjacent roll neck of an adjacent roll likewise has a corresponding inner first bearing and an outer second bearing, then on the one hand the first bearings are assigned as essentially opposite one another and on the other hand the second bearings are assigned as essentially opposite one another. This can be continued for any number of bearings per roll neck. It is irrelevant whether the bearings are directly opposite each other, i.e. aligned in the strict mathematical sense, or have a certain axial offset from each other and, for example, are arranged to overlap each other only in sections in the axial direction of the rollers.

The advantage of the invention is that the preload of the bearings is not cross-aligned, and the individual control circuits for adjusting a roll gap between two rolls do not influence each other. The interaction occurs between the forces of the material web, the tensile forces or gap control forces, and the compressive forces or preload forces, and is limited to two rolls or one roll gap. It can be provided that the material web is fed into the first roll gap as a powder and rolled in this or the subsequent roll gaps of the calender into a material web of homogeneous thickness and width. The powder can, for example, be an electrode precursor material.

It can be provided that the calender further comprises a third roll which is arranged parallel to the second roll, with a further roll gap being formed between the second and third rolls. The third roll can, corresponding to the first and/or second roll, have at least one inner bearing facing the roll barrel and an outer bearing arranged axially adjacent to it and facing away from the roll barrel on a first bearing journal arranged adjacent to the first bearing journal of the second roll, so that the inner bearing is in the first row of bearings and the outer bearing is in the second row of bearings. It can be provided that the compressive forces acting diagonally between two rows of bearings are directed exclusively in the same direction or parallel to one another when there are more than two rolls. In other words, it can be provided that a compressive force is exerted on each bearing only on one side, so that maximum decoupling of the forces from one another is achieved.

In particular, it can be provided that the forces for aligned bracing and diagonal bracing are opposite to each other.

Thus, it can be provided that a tensile stress is generated between the aligned bearings. Furthermore, it is conceivable that the roll gap can be adjusted by regulating the distance between the aligned bearings. For this purpose, a device for generating a tensile stress, for example a pneumatic or hydraulic cylinder, can be arranged between the aligned bearings. Alternatively, it can be provided that a compressive stress is generated between the aligned bearings. In this case, it is conceivable that the roll gap can be adjusted by regulating the distance between the aligned bearings by arranging a device for generating a compressive stress, for example a pneumatic or hydraulic cylinder.

Furthermore, it can be provided that a compressive stress is generated between the diagonally clamped bearings to generate a preload. For this purpose, a device for generating a compressive stress, for example a pneumatic or hydraulic cylinder, can be arranged between the diagonally clamped bearings to generate the preload. Alternatively, it can be provided that a tensile stress is generated between the diagonally clamped bearings to generate a preload. For this purpose, a device for generating a tensile stress, for example a pneumatic or hydraulic cylinder, can be arranged between the diagonally clamped bearings to generate the preload. In particular, it can be provided that the diagonally clamped bearings are clamped in the opposite direction to the aligned clamped bearings.

To maintain a constant roll gap width between two adjacent rolls, the ratio between the pressing force of the material web acting in the roll gap, the tensile or compressive force of the aligned bearings, and the tensile or compressive force of the diagonally aligned bearings can be regulated. For example, the tensile or compressive force of the diagonally aligned bearings can be constant, and the pressing force of the material web can be compensated exclusively by the tensile or compressive force adjustable by the aligned bearings.

Thus, it can be provided that a tensile stress is generated between the inner bearing of the first roller and the inner bearing of the second roller, as well as between the inner bearing of the second roller and the inner bearing of the third roller, and a compressive stress is generated between the inner bearing of the first roller and the outer bearing of the second roller, and between the inner bearing of the second roller and the outer bearing of the third roller. Alternatively, it can be provided that a compressive stress is generated between the inner bearing of the first roller and the inner bearing of the second roller, as well as between the inner bearing of the second roller and the inner bearing of the third roller. a compressive stress is generated, and a tensile stress is generated between the inner bearing of the first roller and the outer bearing of the second roller, and a tensile stress is generated between the inner bearing of the second roller and the outer bearing of the third roller.

The rollers can be supported on a machine frame and arranged so that they can be displaced relative to one another perpendicular to the axial direction. The machine frame can, for example, have two opposing rails on which the rollers or roller bearings can be displaced horizontally perpendicular to the axial direction.

It can be provided that at least one further, third bearing is arranged on the bearing journals of the rollers, which is arranged axially next to the second bearing on the outside, so that the third bearings are arranged axially next to each other in a third bearing row next to the second bearing row.

The bearings of two of the three bearing rows can be clamped in alignment with each other and between two adjacent rollers one bearing of a remaining, non-aligned bearing row can be clamped diagonally with both aligned bearings of the adjacent roller.

Furthermore, it is conceivable that the bearings of the first row of bearings are clamped in alignment with one another and the bearings of the third row of bearings are clamped in alignment with one another and between two adjacent rollers a middle bearing of the second row of a roller is clamped diagonally with the first and third bearings of the adjacent roller.

Furthermore, at least one further, fourth bearing can be arranged on the bearing journals of the rollers, which bearing is arranged axially on the outside next to the third bearing, so that the fourth bearings are arranged in a fourth bearing row next to each other next to the third bearing row. If there are four bearings per bearing journal, the bearings of two of the four bearing rows can be clamped in alignment with one another, and between two adjacent rolls, a bearing of a first remaining, non-aligned bearing row can be clamped diagonally with a bearing of a first of the aligned bearing rows of the adjacent roll. Furthermore, a bearing of a second remaining, non-aligned bearing row can be clamped diagonally with a bearing of a second of the aligned bearing rows of the adjacent roll.

In a first configuration, the bearings of the second bearing row can be clamped in alignment with one another, and the bearings of the fourth bearing row can be clamped in alignment with one another. Between two rolls, a bearing of the first bearing row of a first of the adjacent rolls can be clamped diagonally with a bearing of the second bearing row of the adjacent roll, and furthermore, a bearing of the third bearing row of the first of the adjacent rolls can be clamped diagonally with a bearing of the fourth bearing row of the adjacent roll.

In a second configuration, the bearings of the first bearing row can be clamped in alignment with one another, and the bearings of the fourth bearing row can be clamped in alignment with one another. Furthermore, between two rolls, a bearing of the second bearing row of a first of the adjacent rolls can be clamped diagonally with a bearing of the first bearing row of the adjacent roll, and a bearing of the third bearing row of the first adjacent roll can be clamped diagonally with a bearing of the fourth bearing row of the adjacent roll.

The invention further relates to a method for controlling the gap width of a calender for producing a material web of constant thickness, preferably with a calender according to one of the preceding claims, comprising the steps:

Providing a calender with at least two rolls arranged parallel to one another, between which a roll gap is formed, each roll having a Roll barrel and a first and a second bearing journal axially opposite the first, via which the respective roll is mounted, wherein at least on a first bearing journal of a first of the rolls and an adjacent first bearing journal of a second of the rolls, at least one inner bearing facing the roll barrel and an outer bearing facing away from the roll barrel are arranged axially next to one another, so that the inner bearings are arranged in a first bearing row and the outer bearings in a second bearing row,

Adjusting a roll gap width and/or a preload between the rolls by aligning the inner bearings to each other or the outer bearings to each other on the one hand and by diagonally clamping an inner bearing to an outer bearing on the other hand;

Rolling a material web in the roll gap;

Control of a constant roll gap width by determining the pressing force of the material web acting in the gap, adjusting the preload force of the aligned bearings and/or the preload force of the diagonally clamped bearings depending on the determined pressing force of the material web.

It can be provided that the control of the constant roll gap width includes adjusting the preload force of the aligned bearings as a function of the determined pressing force of the material web, with the preload force of the diagonally aligned bearings being constant. It is conceivable that a tensile force is generated between the aligned bearings and a compressive force is generated between the diagonally aligned bearings. Alternatively, it is conceivable that a compressive force is generated between the aligned bearings and a tensile force is generated between the diagonally aligned bearings. At least one further, third bearing can be arranged on the first bearing journals of the rollers, which is arranged axially next to the second bearing on the outside, so that the third bearings are arranged axially next to each other in a third bearing row next to the second bearing row.

The method may further comprise clamping the bearings of two of the three bearing rows in alignment and diagonally clamping one bearing of the remaining non-aligned bearing row with both aligned bearings of the adjacent roll.

Furthermore, the method can provide that the bearings of the first bearing row are clamped in alignment with one another and the bearings of the third bearing row are clamped in alignment with one another and between two rollers, a bearing of the second bearing row is clamped diagonally with the bearings of the first and third bearing rows of the adjacent roller.

In addition, at least one further, fourth bearing can be arranged on the first bearing journals of the rollers, which bearing is arranged axially on the outside next to the third bearing, so that the fourth bearings are arranged in a fourth bearing row next to each other next to the third bearing row.

It is also possible to provide for the aligned clamping of the bearings of two of the four bearing rows and the diagonal clamping of a bearing of one of the remaining, non-aligned bearing rows with a first of the aligned clamped bearings of the adjacent roll. Furthermore, it is possible to provide for the diagonal clamping of a bearing of the other remaining, non-aligned bearing row with a second of the aligned clamped bearings of the adjacent roll.

In a first configuration, the method may further comprise clamping the bearings of the second bearing row in alignment with one another and clamping the bearings of the fourth bearing row in alignment with one another. Furthermore, a diagonal clamping of one bearing of the first bearing row of a first of the adjacent rolls with a bearing of the second bearing row of the adjacent roll and a diagonal bracing of a bearing of the third bearing row of the first of the adjacent rolls with a bearing of the fourth bearing row of the adjacent roll.

Alternatively, in a second configuration, the method may further provide for the bearings of the first bearing row to be clamped in alignment with one another and the bearings of the fourth bearing row to be clamped in alignment with one another. For this purpose, a bearing of the second bearing row of a first of the adjacent rolls may be diagonally clamped with a bearing of the first bearing row of the adjacent roll, and a bearing of the third bearing row of the first of the adjacent rolls may be diagonally clamped with a bearing of the fourth bearing row of the adjacent roll.

It can be provided that the calender has a third roll arranged parallel to the second roll, with a further roll gap formed between the second and third rolls. Furthermore, the third roll can have at least one inner bearing facing the roll barrel and an outer bearing arranged axially adjacent to the first bearing journal of the second roll, facing away from the roll barrel, on a first bearing journal arranged adjacent to the first bearing journal of the second roll, so that the inner bearing is located in the first row of bearings and the outer bearing is located in the second row of bearings. Furthermore, the method can comprise the steps:

Driving adjacent rollers in opposite directions and/or guiding the material web first through the first roll gap and then through the second roll gap. By driving the rollers in opposite directions, the material to be rolled can first be fed into the first roll gap from a first direction. The resulting material web then circulates around the middle roller, for example, following the rotation of the roller, and is guided through the second roll gap in the opposite direction to the first direction. It can be provided that the third roller on the first roller neck further comprises a third bearing, which is arranged axially next to the side of the second bearing facing away from the roller barrel and is located in the third row of bearings. Furthermore, the third roller on the first roller neck can further comprise a fourth bearing, which is arranged axially next to the side of the third bearing facing away from the roller barrel and is located in the fourth row of bearings.

Further details of the invention are explained with reference to the following figures.

Fig. i shows a calender known from the prior art with representation of the force flow in rollers clamped together with two bearings;

Fig. 2 is a plan view of a calender with three rolls, each with two bearings, and the forces acting on the bearings according to a first embodiment of the invention;

Fig. 3 is a plan view of a calender with three rolls, each with three bearings, and the forces acting on the bearings according to a second embodiment of the invention;

Fig. 4 is a plan view of a calender with three rolls, each with four bearings, and the forces acting on the bearings according to a third embodiment of the invention;

Fig. 5 is a plan view of a calender with three rolls each with four bearings and the forces acting on the bearings according to a fourth embodiment of the invention;

Fig. 6 is a plan view of a calender with three rolls each with four bearings and the forces acting on the bearings according to a fifth embodiment of the invention; Fig. 7 is a plan view of a calender with three rolls, each with two bearings, and the forces acting on the bearings according to a sixth embodiment of the invention;

Fig. 8 is a plan view of a calender with three rolls, each with three bearings, and the forces acting on the bearings according to a seventh embodiment of the invention;

Fig. 9 is a plan view of a calender with three rolls each with four bearings and the forces acting on the bearings according to an eighth embodiment of the invention;

Fig. 10 is a plan view of a calender with three rolls each with four bearings and the forces acting on the bearings according to a ninth embodiment of the invention;

Fig. 11 is a plan view of a calender with three rolls, each with four bearings, and the forces acting on the bearings according to a tenth embodiment of the invention.

Fig. i shows a calender 1 known from the prior art, with three rolls 3 arranged parallel to one another, between each of which a roll gap 4, 4.2 is formed. Each of the rolls 3 has a roll barrel 5 and a first and a second bearing journal 6, 7 axially opposite the first, via which the respective roll 3 is mounted. On the bearing journals 6, 7, an inner bearing 8 facing the roll barrel 5 and an outer bearing 9 facing away from the roll barrel 5 are provided, wherein the bearings 8, 9 are arranged axially next to one another, such that the inner bearings 8 are arranged in a first bearing row A and the outer bearings 9 are arranged in a second bearing row B. The rolls are clamped against one another by cross-clamping two bearings 8, 9 of one roll 3 with two bearings 8, 9 of the adjacent roll 3. The bearings 8, 9 of the second roller 3 are in turn clamped crosswise with the bearings 8, 9 of the next adjacent roller 3. As can be seen, the inner bearing 8 of a left Roller 3 is clamped to the outer bearing 9 of a roller 3 located to the right of roller 3 via compressive stress. At the same time, the outer bearing 9 of a left-hand roller 3 is clamped to the inner bearing 8 of the roller 3 located to the right of roller 3 via tensile stress. This makes it clear that in order to control each roll gap 4, 4.2 and the preload provided therein, a large number of forces must be taken into account and that there is a significant interaction between the forces, whereby the forces occurring in the roll gaps 4, 4.2, which are generated by the rolling of the material web 2, must also be taken into account. Accordingly, the complexity of this structure is prone to failure due to the high degree of interaction between the forces acting on the bearings and requires a high level of technical effort with regard to gap control.

Figure 2 shows a first embodiment of the calender 1 according to the invention. In this arrangement, each roll 3 is equipped with two bearings 8, 9 on the roll neck 6, 7. The rolling of a material web 2 is shown as an example, which is rolled in the roll gap 4 and exerts the pressing force FP on it. The same applies to the second roll gap 4.2 as soon as the material web 2 is passed through it (not shown). As can be seen, the inner bearings 8 are aligned, i.e., clamped together in row A, with a tensile stress Fz being generated between the individual bearings 8. In contrast, the inner bearing 8 of the left roll 3 is clamped diagonally to the outer bearing 9 of the middle roll 3 via a compressive stress _FD , and the inner bearing 8 of the middle roll 3 is clamped diagonally to the outer bearing 9 of the right roll 3 via a compressive stress FD. The outer bearing 9 of the left roller 3 is not subjected to any force from the middle roller 3. A corresponding arrangement (not shown) is provided on the opposite roller journals 7. The roller distance is adjusted via the inner bearings 8 and the associated forces Fz and counteracts the force of the material web. The preload between the left roller 3 and the middle roller 3 is generated via a hydraulic cylinder (not shown) between the inner bearing 8 of the left roller 3 and the outer bearing 9 of the middle roller. A corresponding arrangement is found between the middle and right rollers 3. Bearings that are subjected to compressive stress are each subjected to a compressive stress FD from only one side, so that maximum force decoupling is achieved. The inner bearing 8 of the left roller 3 and the inner bearing 8 of the middle roller 3 are only pressurized from the right, while the outer bearing 9 of the middle roller 3 and the outer bearing 9 of the right roller 3 are correspondingly only pressurized from the left. This means that the preload is not generated crosswise, so that the individual control circuits of the different rollers do not influence each other. The interaction occurs only between the forces of the material web Fp, the tensile stress Fz or gap control, and the compressive stress FD or preload, and is limited to two rollers 3 or one roll gap 4, 4.2. This complexity can be further reduced by operating the preload at a constant force and compensating the force FP of the material web 2 by the gap control Fz. This allows a material web 2 with a constant thickness to be produced.

The second embodiment of the invention shown in Figure 3 has the essential difference from the arrangement in Figure 1 that three bearings 8, 9, 10 are provided for each roll neck 6, 7, which bearings have a different bracing configuration. This forms an inner bearing row A, a middle bearing row B and an outer bearing row C. In the three-bearing arrangement, the gap force or gap width is regulated by aligned bracing (tensile force Fz) of the outer and inner bearings 8, 10 or the bearing rows A and C. The middle bearing 9 is connected on one side (shown here on the left) to the outer and inner bearings 8, 10 of the adjacent roll (left) and builds up the preload (compressive force FD) relative to these bearings. The middle bearing 9 of the left roll 3 is free from any force applied by the middle roll 3. Bearings that are subjected to compressive stress are each subjected to a compressive stress FD from only one side, so that maximum force decoupling is achieved. The inner bearings 8 and outer bearings 10 of the left and middle rolls 3 are only subjected to pressure from the right, and the middle bearings 9 of the middle and right rolls 3 are correspondingly only subjected to pressure from the left. With the three-bearing arrangement, an imbalance arises in the roll neck 6, 7, since two bearings 8, 10 are preloaded in one direction and one bearing 9 in the opposite direction. This leads to an additional load on the middle bearing 9. To avoid this additional load, a four- or more-bearing arrangement is conceivable. Figures 4 and 5 show a third and a fourth embodiment of the invention, which has a 4-bearing arrangement, so that four bearings 8, 9, 10, 11 arranged axially next to one another are provided on each bearing journal 6, 7, wherein the inner bearings 8 are arranged in a first bearing row A, the second bearings from the inside 9 in a second bearing row B, the third bearings from the inside 10 in a third bearing row 10 and the outer (fourth bearing from the inside) bearings 11 in a bearing row D. The third and fourth embodiments differ again in that the clamping configuration of the bearings 8, 9, 10, 11 is different. In the third embodiment, the bearing rows B and D are clamped in alignment with one another (tensile force Fz). In contrast, the first bearings 8 are diagonally preloaded with a second bearing 9 of the left-adjacent roller 3 by a compressive force FD, and the third bearings 10 are diagonally preloaded with a fourth bearing 11 of the left-adjacent roller 3 by a compressive force _FD . The first and third bearings 8, 10 of the left roller 3 are not subjected to any such force. Bearings that are subjected to compressive stress are each subjected to a compressive stress FD from only one side, so that maximum force decoupling is achieved. The second bearings 9 and outer bearings 11 of the left and middle rollers 3 are only subjected to pressure from the right, while the first bearings 8 and third bearings 10 of the middle and right rollers 3 are correspondingly only subjected to pressure from the left.

In the fourth embodiment (Figure 5), in contrast, the first bearing row A and the fourth bearing row D are clamped in alignment (tensile force F _z ), whereas the second bearing 9 of a roller 3 is clamped to the first bearing 8 of the roller 3 located to the left of it, and the third bearing 10 of the roller 3 is clamped to the fourth bearing 11 of the roller to the left of it (compressive force FD). Bearings that are subjected to compressive stress are each only subjected to compressive stress FD from one side, so that maximum force decoupling is achieved. The first bearing 8 and fourth bearing 11 of the left and middle roller 3 are only subjected to pressure from the right, while the second bearing 9 and third bearing 10 of the middle and right roller 3 are correspondingly only subjected to pressure from the left. The fourth embodiment has the advantage that the resulting force of the preload in the axial direction X is zero, since the compressive forces FD described above cancel each other out in the axial direction X. These bearing arrangements are suitable for any number of Bearings per roll neck as well as for calenders with any number of rolls.

Figure 6 shows a fifth embodiment of the invention, which differs from the fourth embodiment of Figure 5 only in that the bearing 8 of the middle roller 3 is displaced axially inwards and the bearing 11 of the middle roller 3 is displaced axially outwards, with respect to the adjacent inner and outer bearings 8 and 11 of the adjacent rollers. Nevertheless, the bearings 8 of the first bearing row A and the bearings 11 of the fourth bearing row D each form an alignment with one another within the meaning of the application, since they are essentially opposite one another and are functionally associated with one another. The bearings 8 of the bearing row A and the bearings 11 of the bearing row D are therefore each clamped in alignment with one another.

Figure 7 shows a sixth embodiment of the calender 1 according to the invention. In this arrangement, each roll 3 is equipped with two bearings 8, 9 on the roll neck 6, 7. The rolling of a material web 2 is shown as an example, which is rolled in the roll gap 4 and exerts the pressing force FP on it. The same applies to the second roll gap 4.2 as soon as the material web 2 is passed through it (not shown). As can be seen, the inner bearings 8 are aligned, i.e., clamped together in row A, with a compressive stress FD being generated between the individual bearings 8. In contrast, the inner bearing 8 of the left roll 3 is clamped diagonally to the outer bearing 9 of the middle roll 3 via a tensile stress F _z , and the inner bearing 8 of the middle roll 3 is clamped diagonally to the outer bearing 9 of the right roll 3 via a tensile stress F _z . The outer bearing 9 of the left roller 3 is not subjected to any force from the middle roller 3. A corresponding arrangement (not shown) is provided on the opposite roller journals 7. The roller distance is adjusted via the inner bearings 8 and the associated forces FD and counteracts the force of the material web. The pretension between the left roller 3 and the middle roller 3 is generated via a (not shown) hydraulic cylinder between the inner bearing 8 of the left roller 3 and the outer bearing 9 of the middle roller. A corresponding arrangement is found between the middle and right rollers 3. Bearings which are subjected to tensile stress are each only supported on one side by a Tensile stress Fz is applied so that maximum force decoupling is achieved. The inner bearing 8 of the left roller 3 and the inner bearing 8 of the middle roller 3 are only subjected to tensile stress from the right, while the outer bearing 9 of the middle roller 3 and the outer bearing 9 of the right roller 3 are correspondingly only subjected to tensile stress from the left. This means that the preload is not generated crosswise, so that the individual control circuits of the different rollers do not influence one another. The interaction only occurs between the forces of the material web Fp, the compressive stress FD or gap control and the tensile stress Fz or preload and is limited to two rollers 3 or one roll gap 4, 4.2. This complexity can be further reduced by operating the preload at a constant force and compensating the force FP of the material web 2 by the gap control FD. This makes it possible to produce a material web 2 with a constant thickness.

The seventh embodiment of the invention shown in Figure 8 has the essential difference from the arrangement in Figure 1 that three bearings 8, 9, 10 are provided for each roll neck 6, 7, which bearings have a different bracing configuration. This forms an inner bearing row A, a middle bearing row B and an outer bearing row C. In the three-bearing arrangement, the gap force or gap width is regulated by aligned bracing (compressive force FD) of the outer and inner bearings 8, 10 or the bearing rows A and C. The middle bearing 9 is connected on one side (shown here on the left) to the outer and inner bearings 8, 10 of the adjacent roll (left) and builds up the preload (tensile force Fz) with respect to these bearings. The middle bearing 9 of the left roll 3 is free from any force applied by the middle roll 3. Bearings that are subjected to tensile stress are each subjected to a tensile stress Fz from only one side, so that maximum force decoupling is achieved. The inner bearings 8 and outer bearings 10 of the left and middle rolls 3 are only subjected to tensile stress from the right, while the middle bearings 9 of the middle and right rolls 3 are correspondingly only subjected to tensile stress from the left. With a three-bearing arrangement, an imbalance arises in the roll neck 6, 7, since two bearings 8, 10 are preloaded in one direction and one bearing 9 in the opposite direction. This leads to an additional load on the middle bearing 9. To avoid this additional load, a four- or more-bearing arrangement is conceivable. Figures 9 and 10 show an eighth and a ninth embodiment of the invention, which has a 4-bearing arrangement, so that four bearings 8, 9, 10, 11 arranged axially next to one another are provided on each bearing journal 6, 7, wherein the inner bearings 8 are arranged in a first bearing row A, the second bearings from the inside 9 in a second bearing row B, the third bearings from the inside 10 in a third bearing row 10 and the outer (fourth bearing from the inside) bearings 11 in a bearing row D. The third and fourth embodiments differ again in that the clamping configuration of the bearings 8, 9, 10, 11 is different. In the third embodiment, the bearing rows B and D are clamped in alignment with one another (compressive force FD). In contrast, the first bearings 8 are diagonally preloaded with a second bearing 9 of the left-adjacent roller 3 by a tensile force Fz, and the third bearings 10 are diagonally preloaded with a fourth bearing 11 of the left-adjacent roller 3 by a tensile force _Fz . The first and third bearings 8, 10 of the left roller 3 are not subjected to any such force. Bearings that are subjected to tensile stress are each subjected to a tensile stress Fz from only one side, so that maximum force decoupling is achieved. The second bearings 9 and outer bearings 11 of the left and middle rollers 3 are only subjected to tensile stress from the right, while the first bearings 8 and third bearings 10 of the middle and right rollers 3 are correspondingly only subjected to tensile stress from the left.

In the ninth embodiment (Figure 10), in contrast, the first bearing row A and the fourth bearing row D are clamped in alignment (compressive force FD), whereas the second bearing 9 of a roller 3 is clamped to the first bearing 8 of the roller 3 located to its left, and the third bearing 10 of the roller 3 is clamped to the fourth bearing 11 of the roller to its left (tensile force Fz). Bearings that are subjected to tensile stress are each subjected to tensile stress Fz from only one side, so that maximum force decoupling is achieved. The first bearing 8 and fourth bearing 11 of the left and middle rollers 3 are subjected to tensile stress only from the right, while the second bearing 9 and third bearing 10 of the middle and right rollers 3 are correspondingly subjected to tensile stress only from the left. The ninth embodiment has the advantage that the resulting force of the preload in the axial direction X is zero, since the tensile forces Fz described above in the axial direction X cancel each other out. These bearing arrangements are applicable for any number of bearings per roll neck and for calenders with any number of rolls.

Figure 11 shows a tenth embodiment of the invention, which differs from the ninth embodiment of Figure 10 only in that the bearing 8 of the middle roller 3 is displaced axially inwards and the bearing 11 of the middle roller 3 is displaced axially outwards, with respect to the adjacent inner and outer bearings 8 and 11 of the adjacent rollers. Nevertheless, the bearings 8 of the first bearing row A and the bearings 11 of the fourth bearing row D each form an alignment with one another within the meaning of the application, since they are essentially opposite one another and are functionally associated with one another. The bearings 8 of the bearing row A and the bearings 11 of the bearing row D are therefore each clamped in alignment with one another.

The features of the invention disclosed in the above description, in the drawings and in the claims may be essential for the realization of the invention both individually and in any combination.

List of reference symbols

1 calender

2 material web

3 rollers

4 Roll gap

4.2 second roll gap

5 roller bales

6 first bearing journal

7 second bearing journal

8 inner (first) bearing

9 outer (second) bearing

10 third camp

11 fourth camp

A first row of bearings

B second bearing row

C third bearing row

D fourth bearing row

FD compressive stress

F _z tensile stress

F _P Press force material web

X Axial direction

Claims

Claims 1. Calender (1) for rolling a material web (2) with a constant thickness, comprising at least two rolls (3) arranged parallel to one another, between which a roll gap (4) is formed, wherein each roll (3) has a roll barrel (5) and a first and a second bearing journal (6, 7) axially opposite the first, via which the respective roll (3) is mounted, wherein at least on a first bearing journal (6) of a first of the rolls (3) and an adjacent first bearing journal (6) of a second of the rolls (3), at least one inner bearing (8) facing the roll barrel (5) and an outer bearing (9) facing away from the roll barrel (5) are arranged axially next to one another, so that the inner bearings (8) are arranged in a first bearing row (A) and the outer bearings (9) are arranged in a second bearing row (B), characterized in that the roll gap (4) and/or a preload between the rolls (3) is aligned clamping of the inner bearings (8) to one another or of the outer bearings (9) to one another on the one hand and by diagonal clamping of an inner bearing (8) with an outer bearing (9) on the other hand. 2. Calender (1) according to claim 1, which further comprises a third roll (3) which is arranged parallel next to the second roll (3), wherein a further roll gap (4) is formed between the second and third rolls (3), wherein the third roll (3) has at least one inner bearing (8) facing the roll barrel (5) and an outer bearing (9) arranged axially next to it and facing away from the roll barrel (5) on a first bearing journal (6) arranged adjacent to the first bearing journal (6) of the second roll (3), so that the inner bearing (8) is located in the first bearing row (A) and the outer bearing (9) is located in the second bearing row (B). 3- Calender according to one of claims 1 or 2, in which the forces for aligned clamping and for diagonal clamping are opposite to each other. 4. Calender according to one of claims 1 to 3, in which a tensile stress or a compressive stress (Fz, FD) is generated between the aligned bearings (8, 9). 5. Calender according to one of claims 1 to 4, in which the roll gap (4) is adjustable by regulating the distance between the bearings (8, 9) which are clamped in alignment with one another. 6. Calender (1) according to claim 4 or 5, wherein a device (12) for generating a tensile or compressive stress (Fz, FD), for example a pneumatic or hydraulic cylinder, is arranged between the bearings (8, 9) clamped in alignment with one another. 7. Calender (1) according to one of claims 1 to 6, wherein a compressive or a tensile stress (Fz, FD) is generated between the diagonally braced bearings (8, 9) to generate a prestress, or the diagonally braced bearings (8, 9) are braced in the opposite direction with respect to the aligned braced bearings (8, 9). 8. Calender (1) according to claim 7, wherein a device (13) for generating a tensile or compressive stress (FD), for example a pneumatic or hydraulic cylinder, is arranged between the diagonally braced bearings (8, 9) for generating a prestress. 9. Calender (1) according to one of the preceding claims, in which, in order to set a constant roll gap width between two adjacent rolls (3), the ratio between a pressing force (Fp) of the material web (2) acting in the roll gap (4), the pretensioning force (Fz) of the aligned clamped Bearings and the preload force (FD) of the diagonally clamped bearings (3) is regulated. 10. Calender (i) according to claim 9, wherein the pre-tensioning force (F _D ) of the diagonally clamped bearings (3) is constant and the pressing force (F _P ) of the material web (2) is compensated by the pre-tensioning force (Fz) adjustable by means of the aligned clamped bearings (8, 9). 11. Calender (1) according to one of claims 7 to 10, in which a tensile or compressive stress (Fz) is generated between the inner bearing (8) of the first roll (3) and the inner bearing (8) of the second roll (3) and the inner bearing (8) of the second roll (3) and the inner bearing (3) of the third roll (3), and a tensile or compressive stress (FD) is generated between the inner bearing (8) of the first roll (3) and the outer bearing (9) of the second roll (3), and a tensile or compressive stress (FD) is generated between the inner bearing (8) of the second roll (3) and the outer bearing (9) of the third roll (3). 12. Calender (1) according to one of the preceding claims, in which the rollers (3) are supported on a machine frame (14) and are arranged to be displaceable relative to one another perpendicular to the axial direction (X). 13. Calender (1) according to one of the preceding claims, in which at least one further, third bearing (10) is arranged on the bearing journals (6, 7) of the rolls, which bearing journal is arranged on the outside axially next to the second bearing (9), so that the third bearings (10) are arranged in a third bearing row (C) axially next to each other next to the second bearing row (B). 14. Calender according to claim 13, wherein the bearings (8, 9, 10) of two of the three bearing rows (A, B, C) are clamped in alignment with one another and wherein between two adjacent rolls (3) a bearing (8, 9, 10) of a remaining, non-aligned bearing row (A, B, C) is clamped diagonally with both aligned bearings (8, 9, 10) of the adjacent roll (3). 15- Calender (i) according to claim 14, wherein the bearings (8) of the first bearing row (A) are clamped in alignment with one another and the bearings (10) of the third bearing row (C) are clamped in alignment with one another and between two adjacent rollers (3) a middle bearing (9) of the second row (B) of a roller (3) is clamped diagonally with the first and third bearings (8, 10) of the adjacent roller (3). 16. Calender (1) according to one of claims 14 to 15, in which at least one further, fourth bearing (11) is arranged on the bearing journals (6, 7) of the rolls (3), which bearing is arranged axially on the outside next to the third bearing (10), so that the fourth bearings (11) are arranged in a fourth bearing row (D) next to one another next to the third bearing row (C). 17. Calender (1) according to claim 16, in which the bearings (8, 9, 10, 11) of two of the four bearing rows (A, B, C, D) are clamped in alignment with one another and wherein between two adjacent rolls (3) in each case a bearing (8, 9, 10, 11) of a first remaining, non-aligned bearing row (A, B, C, D) is clamped diagonally with a bearing (8, 9, 10, 11) of a first of the aligned bearing rows (A, B, C, D) of the adjacent roll (3) a bearing (8, 9, 10, 11) of a second remaining, non-aligned bearing row (A, B, C, D) is clamped diagonally with a bearing (8, 9, 10, 11) of a second of the aligned bearing rows (A, B, C, D) of the adjacent roll (3). 18. Calender (1) according to claim 17, wherein the bearings (9) of the second bearing row (B) are clamped in alignment with one another and the bearings (11) of the fourth bearing row (D) are clamped in alignment with one another and between two rollers (3) a bearing (8) of the first bearing row (A) of a first of the adjacent rollers (3) is clamped diagonally with a bearing (9) of the second bearing row (B) of the adjacent roller (3) and a bearing (10) of the third bearing row (C) of the first of the adjacent rollers (3) is clamped diagonally with a bearing (11) of the fourth bearing row (D) of the adjacent roller (3). 19- Calender (i) according to claim 17, in which the bearings (8) of the first bearing row (A) are clamped in alignment with one another and the bearings (11) of the fourth bearing row (D) are clamped in alignment with one another and between two rolls (3) in each case a bearing (9) of the second bearing row (B) of a first of the adjacent rolls (3) is clamped diagonally with a bearing (8) of the first bearing row (A) of the adjacent roll (3) and a bearing (10) of the third bearing row (C) of the first adjacent roll (3) is clamped diagonally with a bearing (11) of the fourth bearing row (D) of the adjacent roll (3). 20. A method for controlling the gap width of a calender (1) for producing a material web (2) of constant thickness, preferably with a calender (1) according to one of the preceding claims, comprising the steps: Providing a calender (1) with at least two rolls (3) arranged parallel to one another, between which a roll gap (4) is formed, wherein each roll (3) has a roll barrel (5) and a first and a second bearing journal (6, 7) axially opposite the first, via which the respective roll (3) is mounted, wherein at least on a first bearing journal (6) of a first of the rolls (3) and an adjacent first bearing journal (6) of a second of the rolls (3), at least one inner bearing (8) facing the roll barrel (5) and an outer bearing (9) facing away from the roll barrel (5) are arranged axially next to one another, so that the inner bearings (8) are arranged in a first bearing row (A) and the outer bearings (9) are arranged in a second bearing row (B). Adjusting a roll gap width and/or a preload between the rolls (3) by clamping the inner bearings (8) in alignment with one another or the outer bearings (9) in alignment with one another on the one hand and by diagonally clamping an inner bearing (8) with an outer bearing (9) on the other hand; Rolling a material web (2) in the roll gap (4); Regulating a constant roll gap width by determining the pressing force (F _P ) of the material web (2) acting in the gap, adjusting the pre-tensioning force (F _z ) of the bearings (8, 9) clamped in alignment with one another and/or the pre-tensioning force (F _D ) of the bearings (8, 9) clamped diagonally with one another as a function of the determined pressing force (Fp) of the material web (2). 21. The method according to claim 20, wherein the control of the constant roll gap width comprises adjusting the pretensioning force (Fz) of the bearings (8, 9) clamped in alignment with one another as a function of the determined pressing force (FP) of the material web (2), wherein the pretensioning force (FD) of the bearings (8, 9) clamped diagonally with one another is constant. 22. Method according to claim 21, wherein a tensile or compressive force (Fz) is generated between the aligned bearings (8, 9) and a tensile or compressive force (FD) is generated between the diagonally aligned bearings (8, 9), wherein the diagonally aligned bearings (8, 9) are biased in the opposite direction with respect to the aligned bearings (8, 9). 23. Method according to one of claims 20 to 22, in which at least one further, third bearing (10) is arranged on the first bearing journals (6) of the rollers (3), which bearing is arranged on the outside axially next to the second bearing (9), so that the third bearings (10) are arranged in a third bearing row (C) axially next to one another next to the second bearing row (B). 24. The method according to claim 23, further comprising clamping the bearings (8, 9, 10) of two of the three bearing rows (A, B, C) in alignment and diagonally clamping one bearing (8, 9, 10) of the remaining non-aligned bearing row (A, B, C) with both aligned bearings (8, 9, 10) of the adjacent roller (3). 25- Method according to claim 24, in which the bearings (8) of the first bearing row (A) are clamped in alignment with one another and the bearings (10) of the third bearing row (C) are clamped in alignment with one another and between two rollers (3) a bearing (9) of the second bearing row (B) is clamped diagonally with the bearings (8, 10) of the first and third bearing rows (A, C) of the adjacent roller (3). 26. Method according to one of claims 20 to 25, in which at least one further, fourth bearing (11) is arranged on the first bearing journals (6) of the rollers (3), which bearing is arranged axially on the outside next to the third bearing (10), so that the fourth bearings (11) are arranged in a fourth bearing row (D) next to one another next to the third bearing row (C). 27. The method according to claim 26, further comprising clamping the bearings (8, 9, 10, 11) of two of the four bearing rows (A, B, C, D) in alignment and diagonally clamping a bearing (8, 9, 10, 11) of one of the remaining non-aligned bearing rows (A, B, C, D) with a first of the aligned bearings (8, 9, 10, 11) of the adjacent roll and diagonally clamping a bearing (8, 9, 10, 11) of the other remaining non-aligned bearing row (A, B, C, D) with a second of the aligned bearings (8, 9, 10, 11) of the adjacent roll (3). 28. The method according to claim 27, further comprising clamping the bearings (9) of the second bearing row (B) in alignment with one another and clamping the bearings (11) of the fourth bearing row (D) in alignment with one another and diagonally clamping a bearing (8) of the first bearing row (A) of a first of the adjacent rolls (3) with a bearing (9) of the second bearing row (B) of the adjacent roll (3) and diagonally clamping a bearing (10) of the third bearing row (C) of the first of the adjacent rolls (3) with a bearing (11) of the fourth bearing row (D) of the adjacent roll (3). 29- Method according to claim 27, further comprising clamping the bearings (8) of the first bearing row (A) in alignment with one another and clamping the bearings (11) of the fourth bearing row (D) in alignment with one another and diagonally clamping a bearing (9) of the second bearing row (B) of a first of the adjacent rolls (3) with a bearing (8) of the first bearing row (A) of the adjacent roll (3) and diagonally clamping a bearing (10) of the third bearing row (C) of the first of the adjacent rolls (3) with a bearing (11) of the fourth bearing row (D) of the adjacent roll (3). 30. The method according to any one of claims 20 to 29, wherein the calender (1) has a third roll (3) which is arranged parallel to the second roll (3), wherein a further roll gap (4.2) is formed between the second and third rolls (3), wherein the third roll (3) has at least one inner bearing (8) facing the roll barrel (5) and an outer bearing (9) arranged axially adjacent to it and facing away from the roll barrel (5) on a first bearing journal (6) arranged adjacent to the first bearing journal (6) of the second roll (3), so that the inner bearing (8) is located in the first bearing row (A) and the outer bearing (9) is located in the second bearing row (B), the method further comprising the step; Counter-rotating driving of adjacent rollers (3); Guide the material web (2) first through the first roll gap (4) and then through the second roll gap (4.2). 31. The method according to claim 30, wherein the third roll (3) on the first roll neck further comprises a third bearing (11) which is arranged axially adjacent to the side of the second bearing (10) facing away from the roll barrel (5) and lies in the third bearing row (C). 32. The method according to claim 31, wherein the third roll (3) on the first roll neck further comprises a fourth bearing (11) which is axially adjacent to the roll barrel (5) opposite side of the third bearing (n) and is located in the fourth row of bearings (D).