Calender for producing very high line forces, and method for operating a calender

Abstract

The invention relates to a calender (100) for calendering sheet materials (10), preferably in order to produce electrodes, having a first roller (1) and a second roller (2). The rollers (1, 2) can be moved relative to each other in an axial direction (A), and the calender (100) has first actuation means (7) for bending the first roller (1) by the introduction of torque in a radial direction (R). The invention additionally relates to a method for operating a calender (100).

Description

[0001] Calender for generating highest line forces, method for operating a calender

[0002] The invention relates to a calender for calendering flat structures, preferably for producing electrodes, comprising a first roll and a second roll. Furthermore, the invention relates to a method for operating a calender.

[0003] A calender typically has at least two work rolls forming a nip, or nip, in which a fabric is processed. The fabric passes through the nip and is subjected to pressure by the two calender rolls.

[0004] Modern calender applications require the utmost precision in calender operation. Precise sizing of the roll gap is of utmost importance. Particular attention is paid to defined settings, particularly the consistency of the roll gap height across its entire width, i.e., along the axial directions of the calender rolls. Ensuring that the actual roll gap height—hereinafter also referred to as gap height—corresponds to the desired height is counteracted by operational challenges that regularly occur as a result of the inherent nature of the process. One example of a problem is the deflection of the rolls during calendering of a fabric. This deflection is typically due to deformation of the rolls when force is applied to the fabric. During calendering, the rolls deform due to the linear forces in the roll gap.However, especially when high levels of accuracy are required, other effects also become the focus of attention. For example, the rollers expand with increasing temperatures. A completely homogeneous temperature distribution is not possible, especially with heated rollers. Typically, the temperature of heated rollers drops at the edges, for example due to cooled bearings or a larger surface area through which heat can be dissipated. The inhomogeneous temperature distribution of heated rollers leads to inhomogeneous thermal expansion and thus also contributes to unwanted deviations in the gap height, which contributes to deflection in the sense of the present invention. Furthermore, undesirable effects occur in the roller gap at the edge of the calendered sheet, which contribute to deflection in the sense of the present invention.The force applied by the rollers to the calendered fabric causes the rollers to flatten in the areas in contact with the web. Outside of these areas, the rollers are not flattened by contact with the fabric. This creates shear stresses in the rollers at the edges of the calendered fabric, which deform the rollers and thus influence the roll gap. The effect described here reduces the gap height toward the edge of the calendered fabric, leading to an undesirable increase in the line force in the roll gap toward the edge of the calendered fabric.

[0005] State-of-the-art methods for dealing with, preventing, or compensating for roll deflection are known. One possibility is the use of ram-supported rolls, in which a device is provided inside the rolls that compensates for deflection of the roll shell by applying mechanical forces that counteract the deflection.

[0006] This technology becomes problematic in applications where extremely high precision is required while applying very high line forces. For example, the thin roll shells of ram-supported rolls cannot be manufactured with unlimited precision. Furthermore, ram-supported rolls are performance-limited in terms of the maximum line forces that can be applied. Finally, it is difficult to heat ram-supported rolls very evenly.

[0007] A constantly growing field of application for calenders is the production of electrodes for battery production. In this process, conductive foils are coated and then calendered. Calendering determines the density of the electrodes, their porosity, their adhesive strength, and, with these parameters, their conductivity and ultimately their electrochemical performance. Accuracies of 1 pm gap height relative to the roll gap are required across the entire width of the roll gap, with line forces ranging from over 500 N / mm to 10,000 N / mm.

[0008] Currently, calenders are used to produce electrodes with a web width typically not exceeding 800 mm. Larger web widths result in roll deflections that cannot be satisfactorily compensated for using conventional methods. For example, applying crowning to the rolls is inflexible, especially under varying line forces. Nevertheless, larger web widths are desirable because they significantly improve electrode production efficiency.

[0009] It is therefore an object of the present invention to provide a calender and a method for operating a calender which do not have the disadvantages of the prior art described, but offer the possibility of a very uniform adjustment of the roll gap at high line forces and large web widths.

[0010] This problem is solved by the features of claim 1 and claim 11.

[0011] The calender according to the invention for calendering sheet materials has a first roll and a second roll. The calender is preferably intended for calendering electrodes. The first roll and the second roll are working rolls of the calender. For example, it is conceivable that the first roll is an upper roll and the second roll a lower roll of the calender. However, it is also conceivable that the second roll is an upper roll and the first roll a lower roll of the calender. Furthermore, it is possible for the first roll and the second roll to be arranged next to one another and for the sheet material to be guided from above, from below, or obliquely between the first roll and the second roll. It is also conceivable for the first roll and the second roll to be inclined, i.e. for the axial directions of the rolls to be non-horizontal.Finally, it is conceivable that the rolls of the calender are aligned such that the nip plane is inclined, in particular not vertical. The present invention is not limited to a calender having only two rolls. In addition to the first roll and the second roll, the calender according to the invention can have additional rolls.

[0012] According to the invention, the first roller and the second roller can be displaced relative to one another along an axial direction. In particular, it is provided that, to displace the rollers relative to one another, either the first roller is moved along its axial direction, or the second roller is moved along its axial direction, or both the first roller and the second roller are moved along their respective axial directions. The axial direction refers to the axial direction of the first roller or the second roller, respectively, and is typically perpendicular to the direction in which the sheet is fed to the calender.

[0013] During operation, the respective roll rotates around its axial direction. A nip plane, as defined by the present invention, is the plane in which both axial directions lie. A radial direction, as defined by the present invention, is arranged orthogonally to the nip plane.

[0014] In addition, the calender according to the invention has first adjusting means for bending the first roll by applying torque in the radial direction.

[0015] The ability to bend the first roll with the first adjusting means by applying torque in a radial direction, i.e. by applying force parallel to the nip plane, makes it possible to adjust the gap height along the nip from one end of the roll gap, across the middle of the roll gap to the other end. If, for example, the roll gap is larger in the middle than at the ends, the first roll can be bent with the middle towards the second roll. The bending effect is greater in the middle of the first roll than at the ends. Particularly in combination with crowning of the roll barrel of the first roll or the roll barrels of both rolls, the bending can compensate for the deflection in the middle and at the ends. At the points between the middle and the outer ends, in particular after approx.However, at one eighth to one quarter of the roll gap, referred to here as quarter points, overcompensation typically occurs due to the bending of the first roll.

[0016] In order to avoid unwanted deviations in the gap height at the quarter points as well, the rolls are moved against each other along the axial direction. Moving the rolls changes the gap height profile along the axial direction. The combination of moving the rolls along the axial direction and thus adjusting the gap height profile by moving the profiles against each other and bending the first roll by applying a moment along the radial direction means that the gap height can be adjusted with high precision and reliably, even with very high line forces, even for very large web widths such as 1,500 mm or more. In particular, the combination of bending and moving along the axial direction also makes it possible to specifically compensate for unwanted deviations in the gap height caused by inhomogeneous roll temperatures.

[0017] Advantageous embodiments and further developments of the invention can be found in the dependent claims and the description with reference to the drawings.

[0018] According to a preferred embodiment of the present invention, the first roller has a first profile. The second roller has a second profile. The profiles of the rollers are surface topographies of the circumferential surfaces of the rollers and relate to the course of the extension of the rollers orthogonal to the respective axial direction along the respective axial direction. The profiles are preferably provided so that a desired course of the gap height, in particular a uniform gap height, of the roller gap between the rollers is generated by the displacement along the axial direction. It is preferably provided that the first profile and the second profile have an S-shape. Alternatively or additionally, it is preferably provided that the first profile and the second profile have a 0.5 S-shape or a multiple thereof, in particular a 1.5 S-shape.Alternatively or additionally, it is preferably provided that the first profile and the second profile have a double S shape. For this purpose, it is preferably provided that the first profile and the second profile have at least or exactly one, at least or exactly two or at least or exactly three turning points. The first and the second roller are therefore not cylindrical or frustoconical, but have regions of different pitch across the roller width. This results in different roller diameters along the roller widths, which have a non-linear profile along the axial direction. Non-linear preferably also includes a series of several non-parallel linear sections.Depending on the relative position of the rollers along the axial direction, the diameter deviations of the two rollers compensate for each other, so that, depending on the specific requirements, a desired, particularly uniform, gap height can be set without overcompensation. In addition to the explicitly mentioned 0.5-S, S, 1.5-S, and double-S shapes, other profiles are conceivable that include other numbers, especially larger numbers, of S shapes, for example, 1.75-S, 2.5-S, 3-S, and so on.

[0019] In particular, it is provided that the profiles each have a polynomial curve of at least or exactly third degree, or at least or exactly fourth degree, or at least or exactly fifth degree. It is conceivable that a crown is superimposed on the 0.5 S-shape, the S-shape, the 1.5 S-shape, and / or the double S-shape of the first roller. It is conceivable that, alternatively or additionally, a crown is superimposed on the S-shape, the 1.5 S-shape, and / or the double S-shape of the second roller.

[0020] During axial displacement, the areas in which compensation is applied can be freely selected by adjusting the profiles accordingly. By selecting appropriate profiles, a high degree of freedom is achieved to influence the roll gap in a highly customized manner, particularly with regard to the number of affected points, the locations of the influence within the roll gap, and the width of the affected areas.

[0021] A polynomial curve, or the characteristic that a profile has a polynomial of at least or exactly a certain order, is not to be understood in a slavishly mathematical sense. Rather, it should be viewed as a description of the essential form of the respective profile, as is sufficient for a person skilled in the art in everyday language. Thus, it is conceivable that in practice, the profiles are described not by mathematical functions but by tables of values ​​with disjoint extensions of the respective roller in the radial direction as a function of the axial direction. If the vast majority of the values ​​in the table of values ​​can be approximated within technical-practical error limits using a polynomial curve, then the respective profile, within the meaning of the present invention, corresponds precisely to this polynomial.If individual values ​​or smaller ranges of the value table are such that they cannot be approximated within the technical-practical error limits by the polynomial progression, this does not detract from what has been described above.

[0022] According to a further preferred embodiment of the present invention, two first roll necks of the first roll are mounted in first main bearings. The first adjusting means act on additional first bending bearings in which the first roll necks are also mounted. The distance along the axial direction between one of the first main bearings and the adjacent first bending bearing is at least 0.8 times, preferably at least 1 times, and particularly preferably at least 1.2 times the diameter of the first roll. This significantly reduces the load on the main bearings when the first roll is bent using the first adjusting means. The main bearings are preferably arranged in the axial direction between the bending bearings and the corresponding roll barrel. However, it is also conceivable for the bending bearings to be arranged along the axial direction between the main bearings and the corresponding roll barrel.For this purpose, it is conceivable that a difference is created between the force applied to the bending bearings and the main bearings in such a way that the rolls are bent away from each other in the middle of the roll gap. Depending on the moment applied to the bending bearings, a force can be provided on the rolls at the main bearings, pulling the rolls towards each other or pushing them away from each other. In this case, it is conceivable that a crowning of at least one of the rolls is provided. Typically, the crowning is designed for a certain line force or a certain material-related deflection. It is conceivable that the crowning is at least partially counteracted by bending, particularly during calendering with a lower line force than considered in the design of the crowning or with a material-related lower deflection than considered in the design of the crowning.

[0023] To adapt to the bending of the roll neck, it is conceivable that the first flexure bearings in particular, but also the first main bearings, comprise self-aligning bearings, for example, spherical roller bearings or self-aligning ball bearings, or cylindrical roller bearings with a spherical outer ring. It is conceivable that the first main bearings comprise cylindrical roller bearings. This makes it possible to safely absorb large forces and securely support the rolls. It is conceivable that the first flexure bearings also comprise cylindrical roller bearings. Due to the deflection or bending, the first main and first flexure bearings also move, at least in part.

[0024] In particular, it is provided that the first flexural bearings and the first main bearings comprise outer rings. Furthermore, it is particularly provided that the first main bearing and the first flexural bearing are kinematically decoupled from one another. In the context of the present invention, "kinematically decoupled" means that the outer ring of the first main bearing can adapt rotationally around the radial direction of a bend in the roll neck differently than the inner ring of the first flexural bearing and / or the first flexural bearing. In this regard, it is particularly conceivable for the first flexural bearings and the first main bearings to be arranged in separate housings.

[0025] It is conceivable that both the first main bearings and the first flexural bearings are cylindrical roller bearings. For this purpose, it is further provided in particular that the first main bearing and the first flexural bearing are kinematically decoupled from one another. Kinematically decoupled here means that the outer rings can adapt to different rotational directions around the radial direction of a bend in the roll neck. For this purpose, it is particularly conceivable that the first flexural bearings and the first main bearings are arranged in separate housings. It is preferably provided that the first adjusting means are intended to press the first roll necks along the nip plane away from the roll gap into the first main bearings. Alternatively or additionally, it is preferably provided that the first adjusting means are intended to press the first roll necks along the nip plane towards the roll gap into the first main bearings.It is conceivable that the first adjusting means are provided to press the first roll necks along the nip plane, away from the roll gap, into the first main bearings, using at least the weight of the first roll. This advantageously ensures that the first roll always sits snugly in the first main bearings and eliminates any bearing play in the first main bearings. This ensures extremely precise and stable adjustment of the roll gap when the calender is moved to the gap, particularly with varying thicknesses of the fabric fed to the calender. Those skilled in the art understand "moving to the gap" to mean that a specific gap height is specified. This gap height is maintained even with varying material parameters of the fabric and, for example, leads to changing line forces when the thickness of the fabric changes before calendering. Alternatively, the calender can be moved "to pressure."The line forces are kept constant.

[0026] According to a further preferred embodiment of the present invention, the first profile and the second profile are designed such that, in a relative position of the first or second roll, the roll gap has a uniform gap height along the axial direction when the adjusting means press the first roll necks along the nip plane away from the roll gap into the first main bearings. In other words, the shaping of the first profile and the second profile already takes into account that a bending of the first roll is caused by the first adjusting means. For example, it can be ensured that the first roll is pressed firmly into the first main bearings by the first adjusting means and that the resulting bending of the first roll is captured in the geometry of the first profile and the second profile when correcting the expected deflection during operation of the calender.For this purpose, it is preferably provided that the first profile and the second profile are designed such that in the relative position of the first and the second roller, the roller gap has a uniform gap height along the axial direction when the first adjusting means press the first roller necks with at least the weight force of the first roller in the radial direction away from the roller gap into the first main bearings.

[0027] In particular, it is provided that the calender has two first adjusting means, wherein the first adjusting means act on first roll necks of the first roll that are opposite in the axial direction. According to the embodiment described here, the two first adjusting means are intended to each act with different strengths on the opposite first roll necks. In other words, according to this preferred embodiment, it is provided that the first adjusting means act more strongly or less strongly at one axial end of the first roll than at the other axial end of the first roll. This results in the possibility of bending asymmetrically and thus compensating for asymmetric deflections of the first roll. During asymmetric bending, the maximum of the bending of the corresponding roll generated by the bending shifts from the center of the roll gap along or against the axial direction.

[0028] In addition to the first adjusting means for bending the first roll, it is preferably provided that the calender has second adjusting means for bending the second roll by applying torque along the radial direction. It is preferably provided that two second roll necks of the second roll are mounted in second main bearings, wherein the second adjusting means act on additional second bending bearings in which the second roll necks are mounted. It is particularly preferably provided that the second bending bearings and the second main bearings are spaced from each other by at least 0.8 times, very particularly preferably by at least 1 times and in particular by at least 1.2 times the diameter of the second roll. The possibility of additional bending of the second roll allows a significantly greater variety of compensation options to be used to produce a uniform roll gap.For example, by bending the second roller in addition to the bending of the first roller, a symmetrical compensation of the deflection or even an asymmetrical compensation can be carried out. All features, details, and advantages disclosed in connection with the bending of the first roller with the first adjusting means also relate to the bending of the second roller with the second adjusting means. It is conceivable that the second main bearings have cylindrical roller bearings. This makes it possible to safely absorb large forces and to securely mount the rollers. It is conceivable that the second bending bearings also have cylindrical roller bearings. Due to the deflection or bending, the second main and second bending bearings also move, at least in part.In order to adapt to the bending of the roll neck, it is conceivable that the second bending bearings in particular, but also the second main bearings, comprise self-aligning bearings, for example spherical roller bearings or self-aligning ball bearings, or cylindrical roller bearings with a spherical outer ring.

[0029] In particular, it is provided that the second flexural bearings and the second main bearings comprise outer rings that are kinematically decoupled from each other. In this regard, it is particularly conceivable that the second flexural bearings and the second main bearings are arranged in separate housings.

[0030] It is conceivable that the second adjusting means are preferably provided to press the second roll necks in the radial direction away from the roll gap, in particular with at least the weight force of the second roll, or towards the roll gap, into the second main bearings.

[0031] According to a further preferred embodiment of the present invention, it is provided that the first profile and the second profile are designed such that, in a relative position of the first or second roll during calendering, the roll gap has a desired and, in particular, uniform gap height along the axial direction when the first adjusting means press the first roll necks along the nip plane away from the roll gap or towards the roll gap into the first main bearings and the second adjusting means press the second roll necks along the nip plane away from the roll gap or towards the roll gap into the second main bearings. In other words, the shaping of the first profile and the second profile already takes into account that a bending of the first roll is brought about by the first adjusting means and a bending of the second roll is brought about by the second adjusting means.For example, it can be ensured that the rolls are pressed firmly into the main bearings by the respective adjusting means, and that the resulting bending of the rolls is captured in the geometry of the first profile and the second profile when correcting the expected deflection during operation of the calender. For this purpose, it is preferably provided that the first profile and the second profile are designed such that, in the relative position of the first and second rolls, the roll gap has a desired and, in particular, uniform gap height along the axial direction during calendering when the first adjusting means press the first roll necks into the first main bearings in the radial direction away from the roll gap with at least the weight of the first roll.

[0032] It is also conceivable for the calender to have two second adjusting means, wherein the two second adjusting means act on second roll necks of the second roll that are opposite in the axial direction. The two second adjusting means are designed to act on the opposite second roll necks with different strengths.

[0033] According to a preferred embodiment of the present invention, the deflection in the roll center is fully compensated by bending the first roll and / or the second roll through moment input along the radial direction, and the resulting overcompensation at the quarter points is balanced out by shifting the rolls relative to one another along the axial direction. For this purpose, it is preferably provided that the first profile and / or the second profile have a double S shape. For this purpose, it is provided, for example, that the first profile and / or the second profile correspond to a polynomial of at least or exactly the fifth degree.

[0034] If the deflection is compensated only by means of axial displacement, it is conceivable that the first profile and the second profile each have an S-shape and preferably correspond to a polynomial of at least or exactly third order.

[0035] Alternatively, the distribution of the roll gap correction to achieve the desired roll gap profile can also be chosen differently between bending and axial displacement. For example, it is conceivable that the deflection is only partially compensated, for example, two-thirds, by bending the first roll and / or the second roll, and the remaining compensation is achieved by axial displacement. It is conceivable that the first profile and / or the second profile only have an S-shape for this purpose. For this purpose, it is provided, for example, that the first profile and / or the second profile correspond to a polynomial of at least or exactly the third degree.

[0036] In particular, it is conceivable that the quarter points are also specifically influenced. For this purpose, a different distribution of the compensation through bending and axial displacement is provided. For this purpose, an overlay of the S-shape with a double S shape of the first profile and the second profile is preferably provided. For this purpose, it is provided, for example, that the first profile and the second profile correspond to a polynomial of at least or exactly the fifth degree. If, for example, the roll gap is to be narrowed at the quarter points, the proportion of compensation through bending is increased and the proportion of compensation through axial displacement is reduced. If, on the other hand, the roll gap is to be narrowed less at the quarter points, the proportion of compensation through axial displacement is increased, while bending is reduced by moment input in the radial direction.

[0037] It is also conceivable that the deflection is compensated by bending until overcompensation, especially at the quarter points, just stops. The remaining deflection, especially the deflection in the center of the roll gap, is compensated by displacement along the axial direction. For this purpose, the first profile and / or the second profile has an S-shape. By changing the proportions of bending and axial displacement, the gap heights at the quarter points and in the roll center can also be influenced differently.

[0038] It is also conceivable that the deflection is deliberately overcompensated by bending in the center of the roll gap, so that the bending alone, i.e. without the influence of axial displacement, causes the roll gap height to vary only slightly and remain essentially constant from the center of the roll gap to the quarter points. To compensate at the edges of the roll gap, i.e. outside the quarter points, an S-shape with an elongated S extending over the length of the roll gap would be necessary. It is therefore possible to influence the roll gap in completely different ways by differently distributing the components of axial displacement and bending in the compensation of the deflection, thus taking into account technical conditions that otherwise could not have been considered in principle.The flexibility gained by the combination of axial displacement and bending is a clear advantage in extremely precise calendering with highest line forces, as is necessary in the calendering of electrodes.

[0039] This flexibility is further increased if, in addition to or as an alternative to axial displacement and bending, asymmetrical pressure is applied to the first roller and / or the second roller. It is conceivable that this will cause a tilting of at least one of the rollers. The asymmetrical pressure can be generated by applying unequal forces to the opposing main bearings of a roller, in particular by applying forces that are adjusted independently of each other at the opposing main bearings of a roller.

[0040] Roughly five zones of the roll gap can be influenced by a portion of symmetrical pressure, a portion of symmetrical bending (i.e., by applying the same moment to opposite roll necks of a roll), a portion of asymmetrical bending (i.e., by applying unequal moment to opposite roll necks of a roll), a portion of asymmetrical pressure, and a portion of axial displacement. These five zones are the two quarter points, the area of ​​the roll gap centers between the quarter points, and the edges of the roll gap (i.e., the areas between the quarter points and the roll necks). In particular, a combination of axial displacement, symmetrical and / or asymmetrical bending, and preferably also asymmetrical pressure can also influence the edges of the area of ​​the roll gap that is in contact with the fabric.This is particularly advantageous, as these areas are often among the critical areas during calendering, and the fabric outside the quarter points is often not calendered with satisfactory accuracy. A particular increase in flexibility is achieved through asymmetrical bending and asymmetrical printing. With only symmetrical printing or only symmetrical bending, the edges of the roll gap are affected equally. Likewise, with only symmetrical printing or symmetrical bending, the quarter points are affected equally.If the bending and / or compression is carried out asymmetrically, it is possible to influence the edges of the roll gap independently of each other and the quarter points independently of each other, to decouple the influence on the geometry of the roll gap at the edges, the quarter points and in the middle and thus to contribute an asymmetrical part to the compensation of the deflection by asymmetric bending and / or asymmetric compression.

[0041] Compensating for deflection by bending and axial displacement at the edge regions of the calendered sheet is particularly advantageous. These edge regions can be the edge regions of the calendered sheet on the outside in the roll gap. However, particularly when calendering electrodes, it is also common for the sheet to be coated not to be calendered across its entire width, but rather for longitudinal stripes to be provided on the sheet that are not coated. Longitudinal stripes can be arranged on the outside - relative to the roll gap - i.e., only border on one side an area with a coating to be calendered. Alternatively or additionally, longitudinal stripes can be arranged on the inside - also relative to the roll gap - i.e., both sides border on an area with a coating to be calendered.These uncoated areas can, for example, be used to make electrode contacts in a later production step. The longitudinal stripes extend transversely to the web path, i.e. along the roll gap, and their main direction of extension is along the web path, i.e. transversely to the roll gap. When calendering such a fabric with longitudinal stripes, the rollers are not in contact with the fabric in the area of ​​the longitudinal stripes, which means that edge regions of the calendered fabric are effectively also located at the longitudinal stripes. During calendering, the rollers are flattened in the areas where they are in direct contact with the calendered fabric by the force applied to the fabric. This flattening is similar to Hertzian pressure, with the difference that in the theory of Hertzian pressure, no fabric is arranged between the cylinders considered there.Outside the area of ​​the rollers in contact with the fabric, no force is applied to the fabric. In a transition zone between the flattening similar to Hertzian pressure and an area beyond the edge of the fabric that is not affected by this, the difference between the flattened and non-flattened shape of the rollers leads to shear stresses in the rollers. As a result, the roller gap narrows towards the edge area and the line force increases towards the edge area. Without internally arranged longitudinal stripes, but for example with the profile without externally arranged longitudinal stripes, compensation for the effect described here is possible solely with profiles that have a 0.5 S shape.If the fabric has the described longitudinal stripes, the axial displacement of the rollers with corresponding profiles can be used to specifically compensate for the proportion of deflection caused by shear stresses due to flattening of the rollers at the edge areas of the fabric. With two longitudinal stripes, i.e. three coated areas on the fabric, a 2.5 S-shape of the profiles would be necessary for this purpose. Since the rollers do not come into contact with the fabric in the area of ​​the longitudinal stripes, it is possible to provide a profile section here whose shape is not restricted by having to be suitable for calendering. For example, very steep profile gradients up to jump points can be provided. These areas not suitable for calendering are not part of the S-shapes and polynomial descriptions of the profiles within the meaning of the present invention.If, for example, discontinuities are provided in areas of the longitudinal stripes, for example to compensate for the height of the profile gradients, the profiles can be represented in the sense of the present invention, omitting the discontinuities, as already described above, using S-shaped shapes and / or polynomials. The discontinuities are equivalent to very steep areas that are at least functionally similar.

[0042] It should be emphasized that the design of the profiles can influence the number and location of the areas where the roll gap is influenced. The possibilities in profile design, the possibilities of asymmetric bending, and asymmetric printing thus provide a degree of freedom in influencing the geometry of the roll gap, which enables excellent results, especially when calendering electrodes.

[0043] It should be noted that the calender can be operated in compression and gap modes. The details presented throughout the disclosure refer to both compression and gap modes. In compression mode, the calender is operated such that a uniform pressure is maintained in the roll gap. In gap mode, the calender is operated such that a desired gap height is set and adjusted. In gap mode, as in compression mode, pressure is applied to the main bearings.

[0044] According to a further preferred embodiment of the present invention, the displacement of the first roll along the axial direction is accompanied by a displacement of the first roll necks by the first main bearings and preferably by the first flexural bearings. It is also conceivable that, alternatively or additionally, the displacement of the second roll along the axial direction is accompanied by a displacement of the second roll necks by the second main bearings and preferably by the second flexural bearings. In other words, at least parts of the main bearings or the flexural bearings remain fixed during the displacement of the rolls along the axial direction.

[0045] The displacement of the first roller along the axial direction preferably causes a displacement of an inner ring of at least one of the first main bearings. In particular, it is provided that rolling elements and / or an outer ring of the at least one of the first main bearings are not displaced when the first roller is displaced along the axial direction. Furthermore, it is preferably provided that an outer ring and / or rolling elements of the first flexural bearings are not displaced when the first roller is displaced along the axial direction. The displacement of the first roller along the axial direction preferably causes a displacement of an inner ring of at least one of the first flexural bearings. In particular, it is provided that rolling elements and / or an outer ring of the at least one of the first flexural bearings are not displaced when the first roller is displaced along the axial direction.It is conceivable that the rolling elements of the first main bearings and / or the first flexural bearings are guided only on the respective outer ring. This would prevent the rolling elements from moving. It is also conceivable that the rolling elements of the first main bearings and / or the first flexural bearings are guided only on the respective inner ring. This would cause the rolling elements to move. It is also conceivable that the inner ring of at least one of the first main bearings or first flexural bearings is formed by the first roll neck. For this purpose, the first roll neck is preferably hardened in the region of the respective bearing.

[0046] Preferably, spacing means are provided between the first main bearings of the first roll and the second main bearing of the second roll. It is conceivable that the spacing means are provided to set a defined distance between the first main bearing and the second main bearing, thereby influencing the roll gap. The spacing means can comprise, for example, spindles, wedges, or hydraulic cylinders.

[0047] Alternatively or additionally, it is further provided that the displacement of the second roller along the axial direction causes a displacement of an inner ring of at least one of the second main bearings. In particular, it is provided that rolling elements and / or an outer ring of the at least one of the second main bearings are not displaced when the second roller is displaced along the axial direction. Furthermore, it is preferably provided that an outer ring and / or rolling elements of the second flexural bearings are not displaced when the second roller is displaced along the axial direction. The displacement of the second roller along the axial direction preferably causes a displacement of an inner ring of at least one of the second flexural bearings. In particular, it is provided that rolling elements and / or an outer ring of the at least one of the second flexural bearings are not displaced when the second roller is displaced along the axial direction.It is conceivable that the rolling elements of the second main bearing and / or the second flexural bearing are guided only on the respective outer ring. This would prevent the rolling elements from moving. It is also conceivable that the rolling elements of the second main bearing and / or the second flexural bearing are guided only on the respective inner ring. This would cause the rolling elements to move. It is also conceivable that the inner ring of at least one of the second main bearings or second flexural bearings is formed by the second roll neck. For this purpose, the second roll neck is preferably hardened in the region of the respective bearing.

[0048] According to a further preferred embodiment of the present invention, the calender is provided with a first axial adjusting means for displacing the first roll along the axial direction. It is conceivable that the first axial adjusting means comprises a first annular cylinder. This advantageously ensures that the axial force required for this purpose acts centrally during displacement along the axial direction. A corresponding axial bearing is thus evenly loaded, which further leads to even loading of the roll. Finally, the centric application of the axial force and the resulting even loading prevent any unwanted influence on the bending line, i.e. the geometry of the roll gap.

[0049] According to a further preferred embodiment of the present invention, the first annular cylinder comprises a first expansion chamber, which is intended to be filled with an expansion medium, preferably with hydraulic oil. This advantageously makes it possible to move the first annular cylinder by introducing the expansion medium. The use of hydraulic oil is particularly advantageous because hydraulic oil, as a liquid, is virtually incompressible, and the expansion path of the first expansion chamber is thus highly defined.

[0050] It is preferably provided that the first expansion chamber is closed off by a stationary first part and a first annular piston that is movable along the axial direction. By introducing the expansion medium, the first expansion chamber is enlarged along the axial direction. In this case, the first annular piston is displaced along the axial direction. The use of a stationary first part and the first annular piston, which is movable in a defined manner along the axial direction, allows the introduction of the expansion medium into the first expansion chamber to be converted very precisely into a movement of the first axial actuating means. It is preferably provided that the stationary first part and the first annular piston each have an L-shaped part with respect to a sectional plane in which the axial direction lies.One leg of the L-shaped part of the movable first part can be displaced along one leg of the L-shaped part of the first annular piston. The first expansion chamber formed between the L-shaped parts is preferably sealed to the outside with seals.

[0051] For this purpose, it is preferably provided that the first annular piston is operatively connected to the first roller, in particular to one of the first roll necks, in order to absorb axially acting forces. In other words, axially acting forces are transmitted from the first annular piston to the first roller, in particular to one of the first roll necks. This advantageously makes it possible for a movement of the first annular piston to be directly converted into a movement of the first roller. It is preferably provided that the first annular piston is mounted on the first roll neck via a first axial bearing. In particular, it is provided that the first axial bearing is a rolling bearing, particularly preferably an axial cylindrical roller bearing. This enables smooth running of the first roller.

[0052] According to a further preferred embodiment of the present invention, the calender comprises a further first axial adjusting means for displacing the first roll counter to the axial direction. The further first axial adjusting means comprises a further first annular cylinder, wherein the further first annular cylinder preferably comprises a further first expansion chamber, which is intended to be filled with the expansion agent. The expansion agent is, in particular, a hydraulic oil. This advantageously makes it possible to displace the first roll not only along the axial direction, but also counter to it, and to allow the axial force required for this to act centrally.It is also conceivable that both the first expansion chamber and the further first expansion chamber are filled under pressure, so that the axial position of the first roller can be held by the first axial adjusting means and the further first axial adjusting means.

[0053] It is conceivable that the further first axial adjusting means is arranged on the same first roll neck of the first roll on which the first axial adjusting means is also arranged. The further first expansion chamber is closed off by a further stationary first part and a further first annular piston that is movable counter to the axial direction. The further first expansion chamber is enlarged counter to the axial direction by introducing the expansion means, whereby the further first annular piston is displaced counter to the axial direction. The further first annular piston is operatively connected to the first roll neck to absorb axially acting forces. Preferably, the further first annular piston is mounted on the first roll neck via a further first axial bearing, in particular a rolling bearing. In other words, the further first axial adjusting means is arranged on the same roll neck as the first axial adjusting means.Thus, the axial adjustment of the first roller can be effected from just one side in an advantageously simple manner, enabling technical synergy effects, for example, regarding the provision of control or supply lines. It is conceivable that the first axial bearing and the second axial bearing have a common ring, over one side of which rolling elements of the first axial bearing run, and over the other side of which rolling elements of the second axial bearing run, and which is firmly connected to the roll neck along the axial direction.

[0054] Alternatively, it is provided that the further first axial adjusting means is arranged on the first roll neck of the first roll, on which the first axial adjusting means is not arranged. Both first roll necks of the first roll are located opposite one another. The further first expansion chamber is closed off by a stationary further first part and a further first annular piston that is movable counter to the axial direction. By introducing the expansion means, the further first expansion chamber is enlarged counter to the axial direction, wherein the further first annular piston is displaced counter to the axial direction. The further first annular piston is operatively connected to the first roll neck to absorb axially acting forces, wherein the further first annular piston is preferably mounted on the first roll neck via a further first axial bearing, in particular a rolling bearing.In other words, the first axial adjusting means is arranged on one side of the first roll and the further first axial adjusting means is arranged on the other side of the first roll. The embodiment described here has the advantage that the calender is constructed symmetrically, which is simpler to design and offers the possibility of designing the first axial adjusting means and the second axial adjusting means at least partially identical. Furthermore, arranging the axial adjusting means on different sides of the roll offers the advantage that the calender is less wide overall. However, it is also conceivable that the first axial adjusting means and / or the second axial adjusting means and / or the further first axial adjusting means and / or the further second axial adjusting means act on axial bearings of the main bearings and / or on axial bearings of the flexural bearings. For this purpose, it is conceivable that the main bearings and / or the flexural bearings have combined radial-axial bearings.It is conceivable that the main bearings and / or the flexure bearings comprise angular contact ball bearings, tapered roller bearings, and / or spherical roller bearings. It is also conceivable that the axial adjustment means effect the axial displacement of the rollers via the housings of the main bearings and / or the flexure bearings. To apply the axial force for axial displacement, the axial adjustment means can comprise, for example, spindles, pneumatic means, electric motors, and / or hydraulic means.

[0055] According to a further preferred embodiment of the present invention, the stationary first part is supported on a first main bearing counter to the axial direction. The first main bearing is intended to support the first roll neck of the first roll. The first main bearing is capable of absorbing the axially acting forces of the first axial adjusting means. This results in an advantageously simple way of fixing the stationary first part. It is conceivable that the first main bearing comprises a cylindrical roller bearing. This makes it possible to reliably absorb large forces and to securely support the rolls. The divisions of the deflection compensation described here also relate to the inventive method described further below.

[0056] According to a further preferred embodiment of the present invention, the calender comprises means for tempering the first roller and / or the second roller. The tempering means make it possible to heat or cool the first or second roller. During calendering, particularly during the calendering of electrodes, there are often optimal temperature ranges within which calendering takes place. Depending on the temperature of the sheet material entering the calender, the calendering temperature must be raised or lowered. To achieve the optimal temperature range directly in the calendering area, heat can be dissipated from the sheet material to the rollers, thus cooling the sheet material. Furthermore, heat can be transferred from the rollers to the sheet material. To generate this heat flow, a temperature difference between the sheet material and the roller surface is necessary.The heat output transferred depends on the temperature difference, which can be adjusted by tempering the first and / or the second roller, i.e. by raising or lowering the temperature of the roller surface of the first or second roller as required. To raise the temperature, the first and / or the second roller are heated, and to lower the temperature, the first and / or the second roller are cooled. It is conceivable that the first and / or the second roller are heated to introduce heat into the sheet-like structure. It is also conceivable that the first and / or the second roller are heated to dissipate heat from the sheet-like structure. This is the case, for example, if the temperature difference between the surfaces of the rollers and the sheet-like structure is so great that excessive heat would be dissipated from the sheet-like structure without heating the rollers.It is also conceivable that the first and / or second rollers are cooled to dissipate heat from the fabric. It is also conceivable that the first and / or second rollers are cooled to transfer heat from the rollers into the fabric. This is the case when the rollers are warmer than the fabric and the temperature difference is so great that it would lead to excessive heat being transferred into the fabric.

[0057] Preferably, the first roller and / or the second roller of the calender are heated to raise the temperature of the respective roller surface. This makes the calender even more suitable for use in the manufacture of electrodes. The first roller and / or the second roller can, for example, be heated electrically or inductively via induction coils. However, it is also conceivable for the first and / or the second roller to be heated with steam, which is guided, for example, through a central bore or through peripheral bores. It is preferred that the first roller and / or the second roller are provided for heating with an oil which flows through the first or second roller via peripheral bores. The roller surfaces of the first roller and / or the second roller are preferably heated to at least 80°C and very particularly preferably to at least 100°C.It is also conceivable that electrical heating elements are provided to heat the roller surface of the first roller and / or the second roller, for example in peripheral bores of the first and / or second rollers, respectively. Preferably, the first roller and / or the second roller of the calender are cooled to lower the temperature of the respective roller surface. This makes the calender even more suitable for use in the production of electrodes, which must be calendered within a specific temperature range. If the sheet to be calendered is supplied at a temperature above the temperature range, the temperature can be lowered to the optimal range via the cooled rollers.

[0058] The first roller and / or the second roller can be cooled, for example, with a coolant which is preferably guided through a central bore or through peripheral bores.

[0059] According to a further preferred embodiment of the present invention, a region is provided in the roll nip through which the sheet to be calendered is guided and calendered, and which is also referred to as the calendering region in the context of this disclosure. Furthermore, it is provided that the calender has means for cooling the roll surface of the first roll and / or means for cooling the roll surface of the second roll, which act on the rolls, preferably from outside the rolls, and cool the roll surface outside this region (here also referred to as the non-calendering region) and preferably partially within this region. The non-calendering regions also include, in particular, regions in which the longitudinal strips described above pass through the roll nip.In addition to heat dissipation through the air, the roller surfaces of the heated rollers dissipate heat to the calendered fabric, while the roller surfaces of the heated rollers to the left and right of the calendering areas only dissipate heat to the air. This effect is further amplified with rollers heated by means of peripheral bores. To the left and right of the fabric, the roller surface temperature can be significantly higher than in the areas of the rollers that come into contact with the fabric due to a deflection of the heating medium arranged in this area of ​​the roller. This can therefore lead to undesirable changes in the roller geometry, particularly at the edge areas of the fabric, and thus to an undesirable influence on the roller gap and, consequently, to a falsification of the line force.In order to prevent the areas of the rollers that do not come into contact with the fabric from expanding so much due to excessive heating that this leads to undesirable effects in the roller nip, even to the point of contact between the first roller and the second roller outside the area through which the fabric is passed, the cooling means cool the heated rollers in these critical areas. Furthermore, the cooling ensures that the temperature profile in the roller nip is constant, and that in particular the rollers in the edge areas of the fabric are not hotter than in the middle of the roller nip. The axial displacement of the rollers relative to one another further increases the temperature gradient and the associated negative effects. The part of a roller that extends further beyond the fabric to be calendered heats up more.This is due to the fact that the area of ​​the roller into which heat is introduced but not absorbed by the fabric is larger here than on the opposite side. The part of the roller that protrudes less gets less hot. In particular, this also creates a temperature difference between the first roller and the second roller at points opposite each other in the roller gap. To prevent unwanted influences on the geometry of the roller gap, it is preferably provided that the cooling means can be adjusted independently of one another in terms of their respective cooling performance and, in particular, can be operated asymmetrically. This allows the problem described to be addressed directly and cooling can be provided as needed. Furthermore, it is conceivable that the cooling means can each be moved independently of one another along the axial direction.This allows the cooling means to be individually and precisely positioned at the points where heat needs to be dissipated from the rollers. Finally, it is conceivable that by varying the cooling intensity, for example, by cooling both sides of a roller to different degrees and / or by cooling the first and second rollers differently, the temperature distribution of the rollers and thus also the geometry of the roller gap can be specifically influenced.

[0060] It is also conceivable for the calender to have means for heating the roll surface of the first roll and / or means for heating the roll surface of the second roll, which act on the rolls, preferably from outside the rolls, and heat the roll surface in the non-calendering region and preferably partially within the calendering region. The non-calendering regions also include, in particular, regions in which the longitudinal strips described above pass through the roll gap. Cooled rolls absorb heat from the air as well as the calendered fabric, while the roll surfaces of the cooled rolls to the left and right of the calendering regions only absorb heat from the air. This effect is further enhanced with rolls cooled by means of peripheral bores.To the left and right of the fabric, the roller surface temperature can be significantly lower than in the areas of the rollers that come into contact with the fabric due to a coolant deflection arranged in this area of ​​the roller. This can lead to undesirable changes in the roller geometry, particularly at the edge areas of the fabric, and thus to an undesirable influence on the roller gap and, consequently, to a distortion of the line force. To prevent the areas of the rollers that do not come into contact with the fabric from becoming so severely deformed by greater cooling that unwanted effects occur in the roller gap, the heating means heat the cooled rollers in these critical areas.Furthermore, the heating ensures that the temperature profile in the roll nip is constant, and that in particular the rolls in the edge areas of the fabric are not cooler than, for example, in the middle of the roll nip. The axial displacement of the rolls relative to one another further intensifies the temperature gradient and the associated negative effects. The part of a roll that extends further beyond the fabric to be calendered cools down more quickly. This is because the area of ​​the roll from which heat is taken but not introduced by the fabric is larger here than on the opposite side. The part of the roll that extends less far gets less cold. In particular, this also creates a temperature difference between the first roll and the second roll at points opposite each other in the roll nip.In order to prevent unwanted influences on the geometry of the roll gap, it is preferably provided that the heating means can be adjusted independently of one another in terms of their respective heating output and, in particular, can be operated asymmetrically. This allows the problem described to be addressed directly and reheated as needed. Furthermore, it is conceivable that the heating means can each be moved independently of one another along the axial direction. This allows the heating means to be individually and precisely positioned at the points where heat must be dissipated from the rolls. Finally, it is conceivable that the temperature distribution of the rolls and thus also the geometry of the roll gap can be specifically influenced by heating to different intensities, for example by heating both sides of a roll to different intensities and / or by heating the first and second rolls differently.It is conceivable, for example, that the heating means are intended for inductive heating of the roller surfaces.

[0061] According to a further preferred embodiment of the present invention, the first profile is introduced by grinding the surface of the first roll, wherein the first roll is heated during grinding to the temperature intended for operation of the first roll. This makes it possible to achieve an extremely high accuracy of the first profile during operation of the calender. Temperature-related changes in the roll geometry can thus be at least partially compensated for. It is also conceivable that the second profile is introduced by grinding the surface of the second roll, wherein the second roll is heated during grinding to the temperature intended for operation of the second roll. In particular, the hot grinding described here can compensate for a polygon effect that occurs when the first roll is heated by means of peripheral bores.The temperature gradient of the roll between the points near the peripheral holes and the points farther away from the peripheral holes leads to different heat-induced expansions of the roll barrel, which forms the calendering area. Hot grinding makes it possible to grind the roll in such a way that the different heat-induced expansions during operation of the ground roll lead to the desired peripheral shape and, in particular, to the avoidance of the polygon effect.

[0062] It is particularly preferred that the surfaces of the roll barrels of the first roll and / or the second roll be hard-chrome-plated. It is also conceivable that the surfaces of the roll barrels of the first roll and / or the second roll be tungsten carbide coated. Furthermore, it is preferably additionally or alternatively provided that the surfaces of the roll barrels of the first roll and / or the second roll are inductively surface-hardened.

[0063] A further object for achieving the object posed at the outset is a method for operating a calender, in particular a calender according to the invention. Deflections of the first roll, in particular deflections occurring during operation of the calender, are compensated for by shifting the rolls along the axial direction and bending the first roll by applying torque along the radial direction by means of first adjusting means, such that the roll gap of the calender has a defined height profile along the axial direction. The method according to the invention advantageously enables sheet-like structures, for example in the production of electrodes, to be calendered with high precision using very high line forces across a wide web width. Even with web widths of significantly more than one meter, the gap height can be adjusted across the entire web width with an accuracy of 1 pm or less and, at the same time, with line forces of up to 10.000 N / mm calendered.

[0064] For this purpose, it is preferably provided that the first roll necks are pressed into the first main bearings by the first adjusting means along the roll gap or towards the roll gap in such a way that a bearing play of the first main bearing is suppressed and / or that the second roll necks are pressed into the second main bearings by the second adjusting means along the radial direction away from the roll gap or towards the roll gap in such a way that a bearing play of the second main bearing is suppressed.

[0065] The features, details and advantages mentioned above in connection with the calender according to the invention also relate to the method according to the invention.

[0066] According to a further preferred embodiment of the present invention, it is provided that, in addition to the deflection, temperature-induced deformations of the first roll and / or the second roll of the calender are compensated for by shifting the rolls along the axial direction and bending the first roll or the second roll by introducing torque along the radial direction by the first adjusting means or by the second adjusting means such that the roll gap has the desired gap height profile along the axial direction. In particular, it can be provided that by shifting the rolls along the axial direction and bending the rolls by introducing torque along the radial direction, deformations of the rolls that arise due to locally different temperatures of the rolls and thus locally different thermal expansion of the rolls are compensated for.

[0067] Further details, features, and advantages of the invention will become apparent from the drawings and the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the scope of the invention.

[0068] They show:

[0069] Fig. 1 : a schematic view of a calender according to an exemplary embodiment of the present invention for carrying out a method according to an exemplary embodiment of the present invention in an unloaded state,

[0070] Fig. 2: a schematic view of a calender according to another exemplary embodiment of the present invention for carrying out a method according to an exemplary embodiment of the present invention,

[0071] Fig. 3: a schematic view of a calender according to another exemplary embodiment of the present invention for carrying out a method according to an exemplary embodiment of the present invention,

[0072] Fig. 4: schematic views of the first roller and the second

[0073] Roll of a calender according to an exemplary embodiment of the present invention in different relative positions along the axial direction,

[0074] Fig. 5: a schematic view of a calender according to another exemplary embodiment of the present invention for carrying out a method according to an exemplary embodiment of the present invention in an unloaded state,

[0075] Fig. 6 (a)-(d): schematic views of a main bearing of a calender according to an exemplary embodiment of the present invention,

[0076] Fig. 7: a schematic view of a detail of a calender according to another exemplary embodiment of the present invention,

[0077] Fig. 8 is a schematic view of a detail of a calender according to another exemplary embodiment of the present invention,

[0078] Fig. 9: a schematic view of a detail of a calender according to another exemplary embodiment of the present invention,

[0079] Fig. 10 (a)-(b) Detailed representations of a calender from the prior art and

[0080] Fig. 11 (a)-(c) Detailed views of calenders according to different exemplary embodiments of the present invention.

[0081] Figures 1, 2, 3, 5, 9, and 10 each show calenders 100 according to different embodiments of the present invention. The calenders 100 shown will be described jointly below as far as features and details are concerned, which are implemented both in the calender 100 shown in Figure 1 and in the calenders 100 shown in Figures 2, 3, 5, and 9. The differences between the calenders 100 shown will be discussed further below. For the sake of clarity, the calenders 100 shown in Figure 11 are shown with less detail in order to draw attention to the details highlighted there. Therefore, Figure 11 will be described separately below. Nevertheless, the same features and details apply to the calenders 100 of Figure 11 as are discussed below with reference to Figures 1, 2, 3, 5, and 9.

[0082] Figure 1 shows the calender 100 of Figure 2 in an unloaded state. The calender 100 is intended for calendering a sheet-like structure 10, in particular for the production of electrodes. For this purpose, the calender 100 has a first roll 1 and a second roll 2. It is conceivable that the calender 100 has additional rolls. However, the following description will be limited to the first roll 1 and the second roll 2, which form the working rolls of the embodiments shown.

[0083] The first roll 1 is supported by first roll necks 3 in first main bearings 5. The first main bearings 5 ​​can comprise, for example, rolling bearings, in particular cylindrical roller bearings. The rolls 1, 2 are heated in the embodiments shown here.

[0084] During the calendering of electrodes, a coated, conductive foil is rolled to a thickness of 40 to 400 pm using line forces ranging from 500 N / millimeter to 10,000 N / millimeter. Accuracy plays a key role in the electrode's subsequent performance. For example, the porosity of the electrode is determined by calendering. Even gap height deviations of 2 to 3 pm result in inaccuracies in the electrode manufacturing process that are barely acceptable. The calender and method according to the invention enable the compensation of unwanted deflection with deviations of 1 pm or better.

[0085] If the coated films are calendered between the first roller 1 and the second roller 2, deformation of the rollers 1, 2 inevitably occurs. The rollers 1, 2 bend. The rollers 1, 2 also deform due to temperature differences that occur along the rollers. Temperature inhomogeneities of just a few degrees Celsius can lead to deviations in the gap height, which should be avoided. During calendering, particularly with larger web widths, this leads to deviations in the gap height that can no longer be tolerated. In order to compensate for these deviations and achieve a desired, in particular uniform, gap height, the calender 100 has first adjusting means 7 for bending the first roller 1 while applying torque along a radial direction R. Furthermore, the calender 100 shown here has second adjusting means 8 for bending the second roller 2 while applying torque along the radial direction R.The first adjusting means 7 engage the first bending bearings.

[0086] 11 and apply a force to them along a nip plane, which in the illustrated embodiments lies in the paper plane. The second adjusting means 8 act on second bending bearings 12 and also apply a force to them along the nip plane. Figure 2 shows the calender 100 of Figure 1 in a state in which deflection is compensated. For clarity, the effect of the bending is greatly exaggerated. The first roll 1, with its first roll neck 3, is supported in the first bending bearings 11 in addition to the first main bearings 5. The second roll 2, with its second roll neck 4, is supported in the second bending bearings 12 in addition to the second main bearings 6. The bending bearings 11, 12 are spaced from the main bearings 5, 6 along an axial direction A by at least 0.8 times the roll diameter. Furthermore, outer rings (see Fig. 6, 7, 8) of the bending bearings 11,

[0087] 12 and the main bearings 5, 6 are kinematically decoupled. Here, the main bearings 5, 6 are arranged in the axial direction A between the flexural bearings 7, 8 and the corresponding roll barrel (not labeled). However, it is also conceivable that the flexural bearings 11, 12 are arranged along the axial direction A between the main bearings 5, 6 and the corresponding roll barrel.

[0088] Figures 6 (a) to (d) show a section of a calender 100, in which one of the first main bearings 5 ​​can be seen. The first main bearing 5 is designed here as a cylindrical roller bearing with an outer ring 5.1, an inner ring 5.2 and rolling elements 5.3. In the embodiments shown in Figs. 6 (a) and (b), the rolling elements 5.3 are laterally guided by a rolling element guide 5.4, which is connected to the outer ring 5.1. When the roll neck 3 is displaced along the axial direction A by a first axial adjusting means 13 (see Figs. 1, 7, 8), the inner ring 5.2 is also displaced, but the rolling elements 5.3 are held in position by the rolling element guide 5.4 with respect to the axial direction A and are fixed to the outer ring 5.1. Fig. 6 (c) shows an exemplary embodiment in which the rolling element guide 5.4 is attached to the inner ring 5.2. With a displacement of the inner ring 5.2 along the axial direction A, the rolling elements 5 are also displaced.3 displaced. Fig. 6 (d) shows an exemplary embodiment in which the inner ring 5.2 is formed by the roll neck 3 itself. For this purpose, the roll neck 3 is surface-hardened. The rolling element guide 5.4 is again attached to the outer ring 5.1, whereby the rolling elements 5.4 are not displaced in the axial direction A. The details of the first main bearing 5 shown here also apply to the second main bearings 6, whose inner rings are displaced with or without rolling elements, and preferably to the first and second flexural bearings 11, 12.

[0089] In the embodiments illustrated here, the first adjusting means 7 and the second adjusting means 8, via the corresponding bending bearings 11, 12, apply a moment along the radial direction R and push the rollers 1, 2 away from the roller gap 9. The force applied by the adjusting means 7, 8 is indicated by arrows on the corresponding adjusting means 7, 8. This force application bends the rollers 1, 2 in such a way that the height of the roller gap 9 in the center of the rollers 1, 2 is reduced.

[0090] In addition to the effect that plays a role in adjusting the roll gap 9, the bending of the rolls 1, 2 by the adjusting means 7, 8 has a further positive effect on the quality of the calendering process. The force applied by the adjusting means 7, 8 to the bending bearings 11, 12, preferably at least equal to the weight of the respective roll 1, 2, ensures that the roll necks 3, 4 sit snugly in the main bearings 5, 6 and that bearing play is suppressed. The force acting on the main bearings 5, 6 is indicated by arrows. Especially when calendering flat structures 10, which are provided with alternating layer thicknesses prior to calendering, suppressing the bearing play when operating the calender 100 in the gap mode leads to significantly higher-quality results.

[0091] By bending the rolls 1, 2 along the radial direction R, the shape of the roll gap 9 is influenced, whereby the unwanted deviation is typically overcompensated by compensating for unwanted deviations in the gap height in the middle of the roll gap at points between the middle and the outer ends. In order to be able to eliminate this overcompensation, the first roll 1 is provided with a first profile PI and the second roll 2 with a second profile P2. The profiles Pl, P2 are ground into the roll barrels of the respective rolls 1, 2 and are shaped in such a way that different roll diameters are achieved along the axial direction A. The illustrations show the profiles Pl, P2 greatly enlarged. Preferably, the profiles Pl, P2 are hot-ground, i.e.that when grinding the profiles Pl, P2, the respective roller is heated to a temperature which corresponds to the temperature at which it is to be operated in the calender 100.

[0092] In the embodiment shown here, the profiles Pl, P2 have different pitches and display three inflection points. By moving the first roller 1 and the second roller 2 against each other along the axial direction A, the profile of the height of the roller gap 9 can be adjusted along the axial direction. This is shown in Figure 4. In Figure 4, the first roller 1 and the second roller 2 can be seen in three different relative positions along the axial direction A. In the relative position shown at the top, the profiles Pl, P2 run parallel to each other without load, i.e. without calendering a sheet-like structure 10. As soon as a sheet-like structure 10 is calendered, this changes due to the force introduced which occurs when the sheet-like structure 10 is rolled. To compensate for this, the first roller 1 and the second roller 2 can be moved against each other in the axial direction A.

[0093] The setting of a desired roll gap 9 with compensation for the deflection is therefore achieved through a combination of bending and axial displacement. It is conceivable that the deflection is fully compensated by bending the first roll 1 and the second roll 2 through moment input along the radial direction R, and that the resulting overcompensation at the quarter points is balanced out by shifting the rolls 1, 2 against each other along the axial direction A. For this purpose, the first profile PI and the second profile P2 each have a double S shape in the form of a fifth-degree polynomial. Another possibility for setting a desired roll gap 9 is that the deflection is only partially compensated, for example, by 2 / 3, by bending the first roll 1 and the second roll 1, and the remaining compensation is achieved by shifting along the axial direction A.For this purpose, profiles Pl, P2 would be provided, which only have an S-shape in the form of a third-degree polynomial.

[0094] Furthermore, it is also possible to specifically influence the quarter points through axial displacement. For this purpose, the deflection compensation components, which are due partly to axial displacement and partly to bending, can be varied. Such combinations could include superimposing the S-shape with a double S-shape of the first profile PI and superimposing the S-shape with a double S-shape of the second profile P2, with the first profile PI and the second profile P2 having the shape of a fifth-degree polynomial.

[0095] Overall, the combination of symmetrical pressure application in the main bearings 5, 6, axial displacement, and bending results in a very flexible way of adjusting the desired roll gap 9. In addition, it is also possible to influence the roll gap 9 through asymmetrical pressure application. For this purpose, for example, different amounts of force can be applied to the opposing main bearings 5, 6 of a roll 1, 2.Depending on the selected distribution of the deflection compensation between axial displacement, symmetrical and asymmetrical bending and symmetrical and asymmetrical pressure application, the zones of the roll gap 9, i.e. in particular the areas between roll necks 3, 4 and the quarter points, the quarter points and the area between the quarter points, can be adjusted in a targeted manner and taking into account further effects of the axial displacement and bending, such as more or less pressure in the main bearings 5, 6 due to stronger or weaker bending.

[0096] Furthermore, it is possible for the deflection to be compensated by bending until no overcompensation occurs, particularly at the quarter points. The remaining deflection, particularly in the middle of the roll gap 9, is compensated by displacement along the axial direction A. For this purpose, the profiles P1, P2 have an S-shape. In the relative position shown in the middle, the first roll 1 is shifted to the left and the second roll 2 to the right. Shown below is a relative position in which the first roll 1 is shifted to the right and the second roll 2 to the left. The relative positions shown here clearly show how the profile of the height of the roll gap 9 changes as a result of displacement along the axial direction A. In particular, this can influence the areas of the roll gap 9 between the outer ends and the middle.

[0097] The position of the first roller 1 and / or the second roller 2 along the axial direction A is preferably monitored and adjusted in case of a deviation from a target value.

[0098] In the embodiment of the calender 100 shown in Figure 2, the rolls 1,

[0099] 2 are additionally provided with a camber. By superimposing the polynomial shape of the profiles Pl, P2 for the effect shown in Figure 4 with a camber, the rollers 1, 2 can be perfectly adapted to the expected loads and the resulting deflections, especially at high line forces. Such a superposition is shown in Figure

[0100] 3. The profiles P1, P2 of rolls 1, 2 exhibit a crowning in addition to their double S shape. To suppress the crowning, the adjusting elements 7, 8 correct the deflections by applying force along the nip plane so that the roll gap 9 has the desired gap height profile.

[0101] What all of the embodiments shown have in common is that they have a first axial adjusting means 13, which is shown in detail in Figures 7 and 8 according to different embodiments of the present invention. The first axial adjusting means 13 is provided to displace the first roll 1 along the axial direction A. For this purpose, the first axial adjusting means 13 has a first annular cylinder 31. The first annular cylinder 31 has a first expansion chamber 32, which can be filled with an expansion medium, for example with hydraulic oil. The first annular cylinder 31 is arranged along the entire circumference of the first roll neck 3 of the first roll 1. By introducing the expansion medium into the first expansion chamber 32, a first annular piston 34 is displaced along the axial direction A.The first annular piston 34 presses in the axial direction A against a first axial bearing 35, which here is designed in the form of a rolling bearing, against whose ring on the roll barrel side the first annular piston 34 rests. The ring of the first axial bearing 35 facing away from the roll barrel is firmly connected to the first roll neck 3. Thus, a movement of the first annular piston 34 along the axial direction A leads to a movement of the first roll neck 3 along the axial direction A. The arrangement of the first expansion chamber 32 along the entire circumference of the first roll neck 5 enables a centric application of the axial force for displacing the first roll 1 along the axial direction A, resulting in a uniform load on the first axial bearing 35 and thus a uniform load on the first roll 1. Furthermore, an undesirable influence on the roll gap 9 due to a non-centric application of the axial force is avoided.

[0102] Figure 7 shows that the stationary first part 33 is supported on the first main bearing 5 opposite to the axial direction A. The first expansion chamber 32 is formed by a gap between the stationary first part 33 and the first annular piston 34. To prevent leaks through which the expansion medium could escape, the first expansion chamber 32 is sealed with circumferential seals 36.

[0103] In the exemplary embodiment shown in Figure 7, the first axial adjusting means 13 is arranged between the first main bearing 5 and the first bending bearing 11. Not visible is the further first axial adjusting means 13', which in the exemplary embodiment shown in Figure 7 is located on the opposite side of the first roll 1 on the other first roll neck 3 and can cause a displacement of the first roll 1 counter to the axial direction A. According to this exemplary embodiment, the further first axial adjusting means 13' is designed to be completely mirror-symmetrical to the first axial adjusting means 13, which is why a pictorial representation is omitted here.

[0104] In contrast to the exemplary embodiment shown in Figure 7, in the exemplary embodiment shown in Figure 8, both the first axial adjusting means 13 and the further first axial adjusting means 13' are arranged on the same first roll neck 3 of the first roll 1. Both the first axial adjusting means 13 and the further first axial adjusting means 13' are arranged here between the first main bearing 5 and the first bending bearing 11. The fixed first part 33 of the first axial adjusting means 13 is supported on the first main bearing 5 opposite to the axial direction A. Furthermore, the fixed first part 33 forms a side wall of the first expansion space 32 as well as an upper wall of the expansion space 32 and an upper wall of the wide expansion space 32' of the further first axial adjusting means 13'. The fixed first part 33 thus spans the first axial adjusting means 13 and, at least partially, also the further first axial adjusting means 13'.In addition to the first expansion chamber 32 of the first axial adjusting means 13, the further first expansion chamber 32' of the further first axial adjusting means 13' can also be seen. Like the first expansion chamber 32, the further first expansion chamber 32' is intended to be filled with the expansion medium. When the expansion medium is introduced into the further first expansion chamber 32', a movable further first annular piston 34' of the further first axial adjusting means 3' moves counter to the axial direction A. The further first annular piston 34' presses counter to the axial direction A against a further first axial bearing 35', the roll barrel-side ring of which is firmly connected to the first roll neck 5. Filling the further first expansion chamber 32' thereby causes the first roll 1 to move counter to the axial direction A.The roll barrel-side ring of the further first axial bearing 35' and the ring of the first axial bearing 35, which faces away from the roll barrel of the first roll 1, are integrally connected to each other. However, it is also conceivable that these rings are separate.

[0105] In the exemplary embodiment of the present invention shown in Figure 8, the stationary further first part 33' forms at least part of a housing of the first flexural bearing 11. The stationary first part 33 and the stationary further first part 33' are screwed together. In order to achieve kinematic decoupling between the first flexural bearing 11 and the first main bearing 5, the stationary first part 33 is connected in an oscillating manner to the first main bearing 5. Thus, a movement of the first flexural bearing 11 along the radial direction R is not transmitted via the first axial adjusting means 13 to the first main bearing 6. Not shown are the details of the second axial adjusting means 14 and the further second axial adjusting means 14', which correspond completely to the details of the first axial adjusting means 13 and the further first axial adjusting means 13' shown here and have a second orfurther second annular cylinders with a second expansion chamber or further second expansion chamber, which is formed between a fixed second part and a movable second annular piston or between a fixed further second part and a movable further second annular piston. The movable second part of the second axial actuating means 14 is supported on a second axial bearing. The movable further second part of the further second axial actuating means 14' is supported on a further second axial bearing.

[0106] The axial position of the first roller 1 and the second roller 2 is controlled servo-hydraulically. For this purpose, the axial positions of the first roller 1 and the second roller 2 are measured, and the pressures in the expansion chambers 32, 32' are regulated so that the axial positions correspond to target values.

[0107] The rollers 1, 2 are temperature-controlled, particularly for calendering electrodes. For this purpose, the rollers 1, 2 are heated, for example, by means of peripheral bores (not shown) in which a heating medium is arranged or passed. The heating medium can be, for example, oil, steam, or the like. It is also conceivable for electrical heating elements to be provided in the peripheral bores or for the rollers 1, 2 to be heated inductively. The heat introduced by the heating is, on the one hand, dissipated by the roller surfaces into the ambient air, but, on the other hand, is also absorbed by the calendered sheet material 10. This results in a temperature gradient on the rollers 1, 2 between an area in which the roller surfaces of the rollers 1, 2 come into contact with the sheet material 10, the so-called calendering areas 92, and the areas to the left and right of these areas, the so-called non-calendering areas 93.This temperature gradient can be further increased by diverting the peripheral bores at the outer ends of the roll barrels in 180° turns, thus allowing more heat to be transferred from the heating medium to the rolls 1, 2. Due to the different thermal expansions of the rolls 1, 2 along the axial direction A, the temperature gradient influences the geometry of the rolls 1, 2 and thus also the geometry of the roll gap 9 and the bending line, and can lead to undesirable effects, such as a deviation from the intended geometry of the roll gap 9, or even contact between the first roll 1 and the second roll 2 outside the area in which the sheet 10 is calendered.

[0108] To prevent this, means 15 for cooling the first roller 1 and the second roller 2 are provided outside the rollers 1, 2, as can be seen in Figures 1, 2, 3 and 5. The cooling means 15 are arranged such that they absorb heat from the roller surfaces of the rollers 1, 2 in the areas that do not come into contact with the sheet material 10 and, at the same time, also absorb heat from the areas of the roller surface of the rollers 1, 2 that come into direct contact with the sheet material 10. For this purpose, the cooling means 15 can be displaced along the axial direction A. The heat absorption by the cooling means 15 makes it possible to even out the temperature of the roller surfaces of the rollers 1, 2 along the roller gap 9 and thus prevent undesirable effects caused by temperature gradients.By cooling, it is even possible to specifically influence the thermal expansion of the rollers 1, 2 and to actively change the geometry of the roller gap 9.

[0109] It is also conceivable, however, that the rolls 1, 2 are cooled. This is particularly advantageous if the sheet 10 is fed to the calender 100 at a temperature which is above the optimal temperature for calendering the sheet 10. The cooling can be effected, for example, by means of peripheral bores (not shown) in which a coolant is arranged or passed through. The heat dissipated by the cooling is partially re-introduced into the rolls 1, 2 by the calendered sheet 10 during calendering. This results in a temperature gradient on the rolls 1, 2 between the calendering regions 92 and the non-calendering regions 93. The temperature gradient can be further increased by diverting the peripheral bores for cooling at the outer ends of the roll barrels in 180° turns, so that more heat can be absorbed by the coolant there.Due to the different thermal expansions of the rollers 1, 2 along the axial direction A, the temperature gradient influences the geometry of the rollers 1, 2 and thus also the geometry of the roller gap 9 and the bending line and can lead to undesirable effects, such as a deviation from the intended geometry of the roller gap 9.

[0110] To prevent this, means for heating the first roller 1 and the second roller 2 (not shown, analogous to reference numeral 15) are provided outside the rollers 1, 2. The heating means are arranged such that they introduce heat from the roller surfaces of the rollers 1, 2 into the areas that do not come into contact with the sheet material 10 and, at the same time, also introduce heat into the area of ​​the roller surface of the rollers 1, 2 that comes into direct contact with the sheet material 10. For this purpose, the heating means can be displaced along the axial direction A. By adding heat via the heating means, it is possible to even out the temperature of the roller surfaces of the rollers 1, 2 along the roller gap 9 and thus prevent undesirable effects caused by temperature gradients.By heating, it is even possible to specifically influence the thermal expansion of the rollers 1, 2 and actively change the geometry of the roller gap 9. It is conceivable that the heating means are inductive heating means.

[0111] Figures 10 (a) and (b) depict an effect that occurs during calendering at the edge regions 95 of the calendered fabric 10. In the calendering region 92 of the rollers 1, 2, i.e., the region of the rollers 1, 2 that is in direct contact with the fabric 10 during calendering, the rollers 1, 2 are flattened by the application of force. Further out to the left and right of the calendering regions 92, in non-calendering regions 93, no flattening occurs due to the application of force. This difference leads to shear stresses in the rolls 1, 2. As a result, the roll gap 9 narrows in a transition area 94 between the calendering area 92 and the non-calendering area 93 towards the edge area 95 and there is an increase in the line force 91 (shown here as arrows) in the direction of the edge area 95. The described effect does not only occur at the left and right edges of the roll gap 9.If the sheet 10 includes thinner regions, for example, regions without a coating, non-calendering regions 93 are also present in these regions. Figures 11 (b) and (c) show a sheet 10 with three such regions, which are represented as longitudinal stripes on the sheet 10. Shear stresses also occur in the edge regions 95 of the sheet 10, which border the longitudinal stripes, and thus lead to deformations of the rollers 1, 2.

[0112] Without longitudinal stripes in the fabric 10, compensation for the effect described here is possible solely by profiles P1, P2, which have a 0.5 S shape. This is illustrated in Figure 11 (a). By axially displacing the rolls 1, 2 with the illustrated profiles P1, P2, the narrowing of the roll gap 9 in the transition region 94 between the calendering region 92 and the non-calendering region 93, caused by the flattening, can be compensated.

[0113] If the sheet material 10 has the described longitudinal stripes, the axial displacement of the rollers 1, 2 with corresponding profiles P1, P2 can be used to specifically compensate for the portion of the deflection caused by shear stresses due to flattening of the rollers 1, 2 at the edge regions 95 of the sheet material 10. This is illustrated by way of example in Figures 11 (b) and (c). The sheet material 10 illustrated in Figure 11 (b) has three coated regions and thus (in addition to the uncoated regions of the sheet material 10 at its outer edges) two longitudinal stripes. To compensate for the effect caused by the shear stresses, a 2.5-S shape of the profiles P1, P2 is provided here. The special shape of the profiles P1, P2 in the exemplary embodiment in Figure 11 (b) results in the coated regions being offset from one another along the direction of the line force.

[0114] This can be prevented by discontinuities 96 in the profiles P1, P2, as shown in Figure 11(c). The discontinuities 96 are incorporated into the profiles P1, P2 in the non-calendering regions 93. Here, the roll surfaces do not come into contact with the calendered fabric 10, so that the height differences between the calendering regions 92, as shown in Figure 11(b), can be compensated.

[0115] Reference list:

[0116] 1 first roller

[0117] 2 second roller

[0118] 3 first roll neck

[0119] 4 second roll neck

[0120] 5 first main camp

[0121] 5.1 Outer ring

[0122] 5.2 Inner ring

[0123] 5.3 Rolling elements

[0124] 5.4 Rolling element guidance

[0125] 6 second main camp

[0126] 7 first setting medium

[0127] 8 second adjusting agent

[0128] 9 Roller gap

[0129] 10 surface structures

[0130] 11 first bending bearing

[0131] 12 second bending bearing

[0132] 13 first axial adjusting means

[0133] 13' further first axial adjusting means

[0134] 14 second axial adjusting means

[0135] 14' further second axial adjusting means

[0136] 15 cooling remedies

[0137] 31 first ring cylinder

[0138] 31' further first ring cylinder

[0139] 32 first expansion room

[0140] 32' additional first expansion space

[0141] 33 fixed first part

[0142] 33' fixed further first part

[0143] 34 first ring piston

[0144] 34' further first ring piston

[0145] 35 first thrust bearing

[0146] 35' additional first axial bearing

[0147] 36 Seal

[0148] 91 Line force 92 Calendering area

[0149] 93 non-calendering area

[0150] 94 Transition area

[0151] 95 Edge area 96 Jump point

[0152] 100 calenders

[0153] A axial direction PI first profile

[0154] P2 second profile

[0155] R radial direction

Claims

Patent claims:

1. Calender (100) for calendering flat structures (10), preferably for producing electrodes, comprising a first roller (1) and a second roller (2), wherein the rollers (1, 2) can be displaced relative to one another along an axial direction (A), wherein the calender (100) has first adjusting means (7) for bending the first roller (1) by applying torque along a radial direction (R).

2. Calender (100) according to claim 1, characterized in that the first roll (1) has a first profile (PI) and the second roll (2) has a second profile (P2), wherein the first profile (PI) has a 0.5 S shape or a multiple of a 0.5 S shape, preferably a 1.0 or 1.5 S shape, particularly preferably a double S shape, very particularly preferably a 2.5 S shape and the second profile (P2) has a 0.5 S shape or a multiple of a 0.5 S shape, preferably a 1.0 or 1.5 S shape, particularly preferably a double S shape, very particularly preferably a 2.5 S shape.

3. Calender (100) according to one of the preceding claims, characterized in that two first roll necks (3) of the first roll (1) are mounted in first main bearings (5), wherein the first adjusting means (7) act on additional first bending bearings (11) in which the first roll necks (3) are mounted, wherein the first bending bearings (11) and the first main bearings (5) are preferably spaced apart by at least 0.8 times, particularly preferably by at least 1 times and in particular by at least 1.2 times the diameter of the first roll (1).

4. Calender (100) according to claim 3, characterized in that the first adjusting means (7) are provided to press the first roll necks (3) in the radial direction (R) away from the roll gap (9) into the first main bearings (5) or to press them towards the roll gap (9) into the first main bearings (5), wherein the first adjusting means (7) are preferably provided to press the first roll necks (3) with at least the weight of the first roller (1) in the radial direction (R) away from the roller gap (9) into the first main bearings (5).

5. Calender (100) according to one of claims 3 to 4, characterized in that the first profile (PI) and the second profile (P2) are designed such that, in a relative position of the first and the second roll (1, 2), the roll gap (9) has a uniform gap height along the axial direction (A) when the adjusting means (7) press the first roll necks (3) in the radial direction (R) away from the roll gap (9) into the first main bearings (5), wherein the first profile (PI) and the second profile (P2) are preferably designed such that, in the relative position of the first and the second roll (1, 2), the roll gap (9) has a uniform gap height along the axial direction (A) when the first adjusting means (7) press the first roll necks (3) in the radial direction (R) away from the roll gap (9) into the first main bearings (5).

6. Calender (100) according to one of the preceding claims, characterized in that the calender (100) has two first adjusting means (7), wherein the two first adjusting means (7) act on first roll necks (3) of the first roll (1) which are opposite in the axial direction (A), wherein the two first adjusting means (7) are provided to act with different strengths on the opposite first roll necks (3).

7. Calender (100) according to one of the preceding claims, characterized in that the calender (100) has second adjusting means (8) for bending the second roll (2) along the radial direction (R), wherein preferably two second roll necks (4) of the second roll (2) are mounted in second main bearings (6), wherein the second adjusting means (8) act on additional second bending bearings (12) in which the second roll necks (4) are mounted, wherein the second bending bearings (12) and the second main bearings (6) are particularly preferably spaced apart from one another by at least 0.8 times, very particularly preferably by at least 1 times and in particular by at least 1.2 times the diameter of the second roll (2).

8. Calender (100) according to one of claims 3 to 7, characterized in that the displacement of the first roll (1) along the axial direction (A) is accompanied by a displacement of the first roll necks (3) by the first main bearings (5) and preferably by the first bending bearings (11).

9. Calender (100) according to claim 8, characterized in that the first bending bearings (11) are rolling bearings, preferably cylindrical roller bearings, wherein the displacement of the first roller (1) along the axial direction (A) is brought about by a displacement of an inner ring of at least one of the first bending bearings (11), wherein it is provided in particular that rolling elements and / or an outer ring of the at least one of the first bending bearings (11) are not displaced when the first roller (1) is displaced along the axial direction (A).

10. Calender (100) according to one of the preceding claims, characterized in that the first roller (1) and / or the second roller (2) are heated.

11. Method for operating a calender (100), in particular a calender (100) according to one of the preceding claims, wherein a deflection of the first roll (1) of the calender (100) is compensated by a displacement of the rolls (1, 2) along the axial direction (A) and a bending of the first roll (1) by moment input along the radial direction (R) by the first adjusting means (8) such that the roll gap (9) has a desired gap height profile along the axial direction (A).

12. The method according to claim 11, wherein the first roll necks (3) are pressed into the first main bearings (5) by the first adjusting means (7) away from the roll gap (9) or towards the roll gap (9) in such a way that a bearing play of the first main bearing (5) is suppressed.

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