# Patent

## Title
Expander roller

## Abstract

A roller, in particular an expander roller, for a web-processing machine, has a support core, which is braced in the region of both its ends via a respective bearing arrangement, and an outer covering, which in its axially central region is braced in a radially fixed manner in relation to the support core and in the region of its two ends is braced in a radially displaceable manner in relation to the support core by a respective additional bearing arrangement, whereby the radially extending center plane of both the support core bearing arrangement and the outer covering bearing arrangement lies axially within the outer covering. Preferably the outer covering is displaceable in this case in the region of its two ends respectively by an actuator arranged within the outer covering.

## Background
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of PCT application No. PCT/EP2006/064130, entitled “EXPANDER ROLLER”, filed Jul. 12, 2006, which is incorporated herein by reference.


BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a roller, in particular an expander roller, for a web-processing machine.
2. Description of the Related Art
Expander rollers are used on web-processing machines in order to prevent fold formation or sagging on a running material web by expanding the material web. Also, expander rollers are used to guide apart material webs that are arranged side by side and parallel with each other. Material webs arranged side by side and parallel with each other can be produced by slitting a wide material web for example.
Expander rollers of the type initially referred to are known for example from DE 199 27 897 A1 and DE 10 2004 045 407 A1.
The newest expander roller versions based on high-performance plastics have optimized curvatures. The disadvantage of said versions is however that the constructions in question are not torque-free mounted, meaning that the support of the machine in question, for example a paper machine, is loaded in undesirable manner. In the case of new plants, account must be given to the torques arising, which requires cost-intensive reinforcements. In the case of existing plants, even more expensive auxiliary structures are required.
What is needed in the art is an improved roller, in particular an improved expander roller, of the type initially referred to, with which the previously mentioned problems are eliminated. In particular the torques introduced into the support should also be reduced to a minimum in this case.
SUMMARY OF THE INVENTION
The present invention provides a roller, in particular an expander roller, for a web-processing machine, said roller having a support core, which is braced in the region of both its ends via a respective bearing arrangement, and an outer covering, which in its axially central region is braced in a radially fixed manner in relation to the support core and in the region of its two ends is braced in a radially displaceable manner in relation to the support core by a respective additional bearing arrangement, whereby the radially extending center plane of both the support core bearing arrangement and the outer covering bearing arrangement lies axially within the outer covering. Preferably the outer covering is displaceable in this case in the region of its two ends respectively by an actuator arranged within the outer covering.
As a result of this construction, the torque introduced into the support is reduced to a minimum, whereby it can be reduced even to zero in the optimum case. The fact that the actuator is also arranged within the outer covering results in a compact adjusting device which enables the forces for the adjustment to be reduced and the forces arising to be contained.
The actuator is advantageously arranged radially between the support core bearing arrangement and the outer covering bearing arrangement.
On a practical embodiment of the inventive roller, the actuator is braced on the support.
Advantageously the actuator includes at least one eccentric, whereby preferably two inter-mounted eccentrics are provided.
Expediently the two eccentrics are adjustable jointly and/or separately.
With such an eccentric arrangement, the position of the curvature height or magnitude of curvature and/or the position of the curvature plane can be adjusted in each case separately or jointly or simultaneously.
With a view to as torque-free a bearing arrangement as possible, it is an advantage for the respectively radially extending center planes of the support core bearing arrangement and the outer coating bearing arrangement to coincide at least essentially. Advantageously provision is made therefore for an aligned or symmetrical arrangement of the support core bearings and the outer covering bearings.
A practical embodiment of the inventive roller is characterized in that the support core bearing arrangement and the outer covering bearing arrangement include respectively only one bearing and in that the support core bearing and the outer covering bearing are arranged at least essentially in a common radial plane.
Advantageously it is also possible for the support core bearing arrangement and/or the outer covering bearing arrangement to include respectively two or more bearings.
If the outer covering bearing arrangement includes two or more bearings, then the radially extending center plane of said outer covering bearing arrangement expediently coincides at least essentially with the radially extending center plane of the support core bearing arrangement. If the support core bearing arrangement is formed by only one bearing, then said support core bearing can be arranged at least essentially in the radially extending center plane of the outer covering bearing arrangement.
In principle it is also possible however for the support core bearing arrangement to include two or more bearings. In this case the bearings of the outer covering bearing arrangement and the bearings of the support core bearing arrangement are advantageously arranged respectively symmetrically with regard to a radial plane common to the two bearing arrangements.
If the support core bearing arrangement includes two or more bearings, then the radially extending center plane of said support core bearing arrangement expediently coincides at least essentially with the radially extending center plane of the outer covering bearing arrangement.
If the outer covering bearing arrangement includes only one bearing in this case, then said outer covering bearing can be arranged at least essentially in the radially extending center plane of the support core bearing arrangement.
If the outer covering bearing arrangement also includes two or more bearings, then the bearings of the support core bearing arrangement and the bearings of the outer covering bearing arrangement are again advantageously arranged respectively symmetrically with regard to a radial plane common to both bearing arrangements.
Through the corresponding arrangement of the bearings and/or the actuator there results a very rigid construction which is particularly insensitive to vibrations. Vibrations which arise nevertheless can at least be reduced by suitable damping elements. On a practical embodiment provision is made for example for damping ways between the support core bearing arrangement and the outer covering bearing arrangement. In this case a viscous liquid can be inserted into the hollow space between the support core bearing arrangement and the outer covering bearing arrangement.
It is also possible for example to provide a membrane in the region between the support core bearing arrangement and the outer covering bearing arrangement.
Alternatively or in addition it is an advantage for the roller to be fastened via vibration-damping elements on the support. Alternatively or in addition it can also be fastened in particular via actively damping hydraulic elements on the support.
Due to the small construction space it may be necessary to use small bearings and preferably bearings which unite the bearing function and an angle-compensating function in one. The support core bearing arrangement and/or the outer covering bearing arrangement respectively can include at least one angle-compensating bearing.
In particular in the case of high forces, the support core bearing arrangement and/or the outer covering bearing arrangement include preferably in particular at least one tapered-roller bearing, cylindrical-roller bearing or spherical-roller bearing which, because they permit no angle adjustment, must be mounted such that an angle adjustability of the outer covering axis and/or the support core axis is guaranteed.
On a practical embodiment of the inventive roller, the support core is rotatable jointly with the outer covering. In this case the outer covering can be non-rotatably connected to the support core.
Also possible in principle, however, are for example such versions on which the support core is non-rotatable about its longitudinal axis and the outer covering is mounted so that it can rotate about its longitudinal axis relative to the support core.
It is also an advantage in particular for the support core to have, looking in the axial direction, a different cross-sectional shape at least in some sections. In this case the support core can have, in particular at least in some sections, a cross-sectional shape which tapers conically towards its ends.
On the inventive roller the force flow, which is caused by the corresponding construction and the loads arising, is thus transferred as directly as possible and without auxiliary structures between the two bearing arrangements.



BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic representation in longitudinal section of an expander roller with an assigned support;
FIG. 2 is a schematic representation in cross section of an actuator, which includes a double eccentric, in the zero position;
FIG. 3 is a schematic representation in cross section of an actuator, which includes a double eccentric, in a setting for effecting a maximum displacement;
FIG. 4 is a schematic representation in cross section of a roller end with an assigned support core bearing arrangement, outer covering bearing arrangement and actuator, and with a worm gear assigned to the actuator;
FIG. 5 shows a schematic side view in partial section of the roller end according to FIG. 4;
FIG. 6 shows a simplified schematic representation in cross section of a roller end with an assigned actuator compared to the outer covering position in the region of the web center at different settings of the actuator;
FIG. 7 is a schematic representation in longitudinal section of a roller end according to FIG. 1, whereby the support core bearing arrangement and the outer covering bearing arrangement include respectively only one bearing;
FIG. 8 shows a representation comparable with that from FIG. 7, whereby however the support core bearing arrangement includes two bearings; and
FIG. 9 shows a representation comparable with that from FIG. 7, whereby however the outer covering bearing arrangement includes two bearings.



Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to FIG. 1, there is shown in a schematic representation in longitudinal section an expander roller 10 with an assigned support 12. Said expander roller 10 can be used in particular on a web-processing machine, in particular a paper machine.
As is evident from FIG. 1, the expander roller 10 has a support core 16, which is braced in the region of its two ends by way of a respective bearing arrangement 14, and an outer covering 18.
In its axially central region 20 the outer covering 18 is mounted in a radially fixed manner in relation to the support core 16 and in the region of its two ends is braced in a radially displaceable manner in relation to the support core 16 by a respective additional bearing arrangement 22.
As can be seen in FIG. 1, the radially extending center plane 26 and 28 of respectively the support core bearing arrangement 14 and the outer covering bearing arrangement 22 lie within the outer covering.
In the region of its two ends, the outer covering 18 is adjustable respectively by an actuator 30 which is arranged within the outer covering 18 radially between the support core bearing arrangement 14 and the outer covering bearing arrangement 22. Said actuator 30 is braced on the support 12 and is variably adjustable by way of a pivot gear, in particular a worm gear 32 (described in more detail in the following).
Also evident from FIG. 1 is a material web 34 which is passed over the expander roller 10; said web can be for example a paper web, paperboard web or tissue web.
Said material web 34 is accompanied by a corresponding web tension and hence a steady load 36 which results solely in a small tilting torque which is introduced into the support 12.
The actuator 30 includes two inter-mounted eccentrics which can be adjusted jointly or separately.
In the state shown, the expander roller is curved. For this purpose the support core is displaced by the actuator including the two eccentrics. The force for lifting the support core is introduced in the inner eccentric. The outer covering is curved with the force and braces itself on the outer covering bearing arrangements. Because said bearing arrangements lie in one plane, no torque arises. The precondition for this are pivotable bearings.
For the expander roller to adopt its non-curved neutral position, the actuator must be adjusted such that the eccentricity of the inner eccentric is displaced by 180° in relation to the eccentricity of the outer eccentric.
In the case in question the bearing arrangements provided are for example self-aligning roller bearings etc. As is evident from FIG. 1, the outer covering bearing arrangement provided on the left-hand roller end is a floating bearing and the outer covering bearing arrangement provided on the right-hand roller end is a fixed bearing. The support tube bearing arrangements are formed respectively by a floating bearing.
FIG. 2 shows in a schematic representation in cross section the actuator 30, which includes the two eccentrics 30′, 30′′, in a zero position in which the maximum eccentric of the inner eccentric 30′ coincides with the minimum eccentricity of the outer eccentric 30′′. Hence the axis 38 of the circular cylindrical interface 40 between the two eccentrics 30′, 30′′ is displaced here upwards by an amount “e” in relation to the axis 42 of the support core bearing arrangement 14, thus resulting also in a corresponding positioning of the outer covering bearing arrangement 22 and hence of the roller covering end in question.
FIG. 3 shows a representation comparable with FIG. 2, whereby in the case in question the actuator 30 including the two eccentrics 30′, 30′′ is adjusted such that a maximum displacement results. In this case the extremities of the two eccentrics 30′, 30′′ coincide. Accordingly the axis 38 of the circular cylindrical interface 40 between the two eccentrics 30′, 30′′ is displaced here for example to the left by the amount “2e” in relation to the axis 42 of the support core bearing arrangement 14, thus resulting again in a corresponding displacement of the outer covering bearing arrangement 22 and hence of the roller covering end in question.
The extremities of the two eccentrics 30′, 30′′ are therefore equally large.
FIG. 4 shows in a schematic representation in cross section a roller end with assigned support core bearing arrangement 14, outer covering bearing arrangement 22, actuator 30 and a double pivot mechanism (cf. also FIG. 5) for adjusting the two eccentricities 30′, 30′′ of the actuator 30.
In view of the small construction space available, use is made of in particular small bearing arrangements, preferably bearings, for example self-aligning bearings, which unite the bearing function and the angle-compensating function in one. Possible in addition are tapered-roller bearings, cylindrical-roller bearings or spherical-roller bearings (also several).
FIG. 5 shows the roller end in a schematic side view in partial section.
As can be seen from FIGS. 4 and 5, the two eccentrics 30′, 30′′ are connected respectively via an eccentric shaft 44′, 44′′ to a worm gear 46′, 46′′, to which is assigned a respective worm shaft 48′, 48′′, by way of which the two eccentrics 30′, 30′′ are jointly or separately rotatable.
As is best evident from FIG. 4, turning the eccentrics 30′, 30′′ results in a corresponding adjustment of the eccentricity and position of the roller end in question.
FIG. 6 shows in a simplified schematic representation in cross section a roller end with an assigned actuator 30 compared to the outer covering position in the region of the web center at different settings of the actuator 30.
In said FIG. 6, the neutral line of the outer covering 18 has the reference number “50”. Also evident in the various sections a) to d), in addition to the two eccentrics 30′, 30′′ of the actuator 30, are the support core 16 and the outer covering 18, whereby 18′ represents the position of the outer covering 18 at a respective roller end and 18′′ the position of the outer covering 18 in the web center.
According to FIG. 6a), the two eccentrics 30′, 30′′ are adjusted such that the maximum curvature of the outer covering 18 points downwards and the outer covering 18 in the region of the two roller ends is displaced upwards.
According to FIG. 6b), the two eccentrics 30′, 30′′ are adjusted such that the maximum curvature of the outer covering 18 points upwards and the outer covering 18 at the roller ends is displaced downwards.
According to FIG. 6c), the two eccentrics 30′, 30′′ are adjusted such that no curvature of the covering arises and the outer covering is displaced downwards.
According to FIG. 6d), the two eccentrics 30′, 30′′ are adjusted such that no curvature of the covering arises and the outer covering 18 is displaced upwards.
In the two cases mentioned in FIGS. 6c and 6d, the outer covering 18 is without curvature and oblique relative to the support core 16. As the result it is also possible to realize a guide function with the expander roller.
Of course it is also possible for the outer covering 18 to be simultaneously curved relative to the support core 16 and oblique relative to the support core 16.
FIG. 7 shows in a schematic representation in longitudinal section one end of the expander roller 10 according to FIG. 1.
In this case the support core bearing arrangement 14 and the outer covering bearing arrangement 22 include respectively only one bearing. In this case the support core bearing and the outer covering bearing are arranged in a common radial plane. The outer covering bearing in the embodiment in question has larger dimensions than the support core bearing. In this case the respectively radially extending center planes 26 and 28 of the support core bearing arrangement 14 and the outer covering bearing arrangement 22 coincide. Also evident again in said FIG. 7 are the outer covering 18, the support core 16 and the actuator 30.
With some versions of bearings it is possible that the normally more powerful outer tube bearing is converted by smaller rollers etc. to the approximately same load capacity as the inner tube bearing. Hence with a small curvature, the two bearings have an approximately identical minimum load, which results in rolling of the inner tube bearing and the outer tube bearing, meaning that sliding of the rolling bearings and its destructive effect on the bearings are reduced or largely prevented.
The result is a favorable arrangement because direct bracing leads to a reduction of the load on the intermediate sleeves and eccentrics and enables a very rigid low-vibration construction.
Said arrangement can be realized only if the outer diameter of the support core bearing resulting from the roller diameter and the size of the outer covering bearing is still possible for bearings with corresponding load ratings.
FIG. 8 shows a representation comparable with that from FIG. 7, whereby however in the case in question the support core bearing arrangement 14 includes two axially spaced bearings 14′, 14′′. Here too the outer covering bearing arrangement 22 is again formed by only one bearing.
While the right-hand bearing 14′′ of the support core bearing arrangement 14 is arranged within the outer covering 18, the left-hand bearing 14′ lies outside said outer covering 18. However, the center plane 26 of said support core bearing arrangement 14 still lies clearly within the outer covering 18. The bearing of the outer covering bearing arrangement 22 is again larger than the bearings 14′, 14′′ of the support core bearing arrangement 14.
As is evident from FIG. 8, the radially extending center plane 26 of the support core bearing arrangement 14 coincides with the radially extending center plane 28 of the outer covering bearing arrangement 22.
Here too the actuator including the two eccentrics 30′, 30′′ is arranged radially between the support core bearing arrangement, which includes the two bearings 14′, 14′′, and the outer covering bearing arrangement 22.
When using differently sized bearings, the axial distances x and y can differ in order to obtain a load distribution proportional to the load capacity of the bearings.
Given an oblique position of the roller, a corresponding oblique position of the bearings must be enabled in order to obtain a torque-free state. This can be effected either directly by selecting an angle-adjustable bearing or, as is required for a twin arrangement, by way of a seat in the plane of force introduction which permits an oblique position, as is the case for example with a spherical seat.
The arrangement of the outer covering bearing 22 represented in FIG. 8 can also be realized by two or more bearings. Similarly, the number of support core bearings is not limited to two bearings. When using two or more bearings per axis of rotation, the direct bracing and adjustment of the double eccentric bearing arrangement shown by way of example must be effected by accordingly powerful bearing housings which divert internally the force onto two or more bearings and are loaded therefore by an internal torque.
FIG. 9 shows a representation comparable with that from FIG. 7, whereby however in the case in question the outer covering bearing arrangement 22 includes two bearings 22′, 22′′.
The bearings 22′, 22′′ of the outer coating bearing arrangement 22 are larger in the case in question than the support core bearing arrangement 14, which again is formed by only one bearing.
In the case in question, both the support core bearing arrangement 14 and the outer covering bearing arrangement 22 lie respectively completely within the outer covering 18.
As previously mentioned, the support core bearing arrangement 14 in the case in question includes only one bearing. As is evident from FIG. 9, said support core bearing is arranged in the radially extending center plane 28 of the outer covering bearing arrangement 22. Here too the radially extending center plane 28 of the outer covering bearing arrangement 22 again coincides therefore with the radially extending center plane 26 of the support core bearing arrangement 14.
Also possible in principle are such versions on which both the support core bearing arrangement 14 and the outer covering bearing arrangement 22 include respectively of two or more bearings. Such designs with respectively two or more bearings are used in order to achieve a higher overall bearing load capacity and/or they are used in cases in which the radially available construction space is not sufficient for an arrangement of radially nested bearings.
The support core 16 can be rotatable jointly with the outer covering 18. In this case the outer covering 18 can be non-rotatably connected to the support core 16. Also possible in principle, however, are such versions on which the support core 18 is non-rotatable about its longitudinal axis.
As is evident from FIG. 1, the support core 16 can have, looking in the axial direction, a different cross-sectional shape at least in some sections. In the case in question, said support core 16 has, at least in some sections, a cross-sectional shape which tapers conically towards its ends.
While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
LIST OF REFERENCE NUMERALS


    
    
        10 Expander roller
        12 Support
        14 Support core bearing arrangement
        14′ Bearing
        14′′ Bearing
        16 Support core
        18 Outer covering
        20 Center region
        22 Outer covering bearing arrangement
        26 Center plane of the support core bearing arrangement
        28 Center plane of the outer covering bearing arrangement
        30 Actuator
        30′ Eccentric
        30′′ Eccentric
        32 Pivot gear, worm gear
        34 Material web
        36 Steady load
        38 Axis
        40 Circular cylindrical interface
        42 Axis of the support core bearing arrangement
        44′ Eccentric shaft
        44′′ Eccentric shaft
        46′ Worm gear
        46′′ Worm gear
        48′ Worm shaft
        48′′ Worm shaft
        50 Neutral line of the outer covering

## Claims

1. A roller for a machine which processes a web of fibrous material, said roller comprising:
two support core bearing arrangements;
a support core including two end regions each of which is braced respectively by one of said support core bearing arrangements, each of said support core bearing arrangements defining a radially extending center plane;
two outer covering bearing arrangements;
an outer covering including an axially central region and two end regions, said outer covering being braced, in said axially central region, in a radially fixed manner relative to said support core, each of said end regions of said outer covering being braced in a radially displaceable manner relative to said support core respectively by one of said outer covering bearing arrangements, each of said outer covering bearing arrangements defining a radially extending center plane, said radially extending center plane of each of said support core bearing arrangements and said radially extending center plane of each of said outer covering bearing arrangements lying axially within said outer covering; and
two actuators arranged within said outer covering, each of said end regions of said outer covering being displaceable respectively by one of said actuators, each of said actuators being arranged radially between one of said support core bearing arrangements and one of said outer covering bearing arrangements, each of said end regions of said supporting core being configured for being supported on a respective roller support by way of said actuators.

2. The roller according to claim 1, wherein the roller is an expander roller.

3. The roller according to claim 1, wherein each of said actuators includes at least one eccentric.

4. The roller according to claim 1, wherein each of said actuators includes two inter-mounted eccentrics.

5. The roller according to claim 4, wherein said two inter-mounted eccentrics of each of said actuators are at least one of adjustable jointly and adjustable separately.

6. The roller according to claim 1, wherein said radially extending center plane of each of said support core bearing arrangements and said radially extending center plane of each of said outer covering bearing arrangements respectively coincide at least essentially.

7. The roller according to claim 1, wherein each of said support core bearing arrangements includes only one bearing and each of said outer covering bearing arrangements includes only one bearing, said bearing of each of said support core bearing arrangements and said bearing of each of said outer covering bearing arrangements being arranged respectively at least essentially in a common radial plane.

8. The roller according to claim 1, wherein at least one of a) each of said support core bearing arrangements and b) each of said outer covering bearing arrangements includes respectively at least two bearings.

9. The roller according to claim 8, wherein each of said outer covering bearing arrangements includes at least two bearings, each said radially extending center plane of said outer covering bearing arrangements and each said radially extending center plane of said support core bearing arrangements respectively coinciding at least essentially.

10. The roller according to claim 9, wherein each of said support core bearing arrangements includes only one bearing, said bearing of each of said support core bearing arrangements being arranged respectively at least essentially in said radially extending center plane of said outer covering bearing arrangements.

11. The roller according to claim 9, wherein each of said support core bearing arrangements includes at least two bearings.

12. The roller according to claim 11, wherein said bearings of each of said outer covering bearing arrangements and said bearings of each of said support core bearing arrangements are arranged respectively symmetrically with regard to a radial plane common to corresponding ones of said support core bearing arrangements and said outer covering bearing arrangements.

13. The roller according to claim 8, wherein each of said support core bearing arrangements includes at least two said bearings, said radially extending center plane of each of said support core bearing arrangements respectively coinciding at least essentially with said radially extending center plane of each of said outer covering bearing arrangements.

14. The roller according to claim 13, wherein each of said outer covering bearing arrangements includes only one said bearing, said bearing of each of said outer covering bearing arrangements being arranged respectively at least essentially in said radially extending center plane of each of said support core bearing arrangements.

15. The roller according to claim 13, wherein each of said outer covering bearing arrangements includes at least two said bearings.

16. The roller according to claim 15, wherein said bearings of each of said support core bearing arrangements and said bearings of each of said outer covering bearing arrangements are arranged respectively symmetrically with regard to a radial plane common to corresponding ones of said support core bearing arrangements and said outer covering bearing arrangements.

17. The roller according to claim 1, further including a damping device between a respective one of said support core bearing arrangements and a respective one of said outer covering bearing arrangements.

18. The roller according to claim 17, further including a viscous liquid, each of said support core bearing arrangements and each of said outer covering bearing arrangements respectively defining a hollow space therebetween, said viscous liquid being in said hollow space.

19. The roller according to claim 17, further including a membrane, each of said support core bearing arrangements and each of said outer covering bearing arrangements respectively defining a region therebetween, said membrane being in said region.

20. The roller according to claim 1, further including a support and a plurality of vibration-damping elements, the roller being fastened via said plurality of vibration-damping elements on said support.

21. The roller according to claim 1, further including a support and a plurality of actively damping hydraulic elements, the roller being fastened via said plurality of actively damping hydraulic elements on said support.

22. The roller according to claim 1, wherein at least one of a) each of said support core bearing arrangements and b) each of said outer covering bearing arrangements includes respectively one angle-compensating bearing.

23. The roller according to claim 1, wherein at least one of a) each of said support core bearing arrangements and b) each of said outer covering bearing arrangements includes respectively at least one self-aligning bearing.

24. The roller according to claim 1, wherein at least one of a) each of said support core bearing arrangements and b) each of said outer covering bearing arrangements includes respectively one of at least one tapered-roller bearing, at least one cylindrical-roller bearing, and at least one spherical-roller bearing.

25. The roller according to claim 1, wherein said support core is rotatable via said support core bearing arrangements about a longitudinal axis of said support core.

26. The roller according to claim 25, wherein said support core is rotatable jointly with said outer covering.

27. The roller according to claim 25, wherein said outer covering is non-rotatably connected to said support core.

28. The roller according to claim 1, wherein said support core is non-rotatable about a longitudinal axis of said support core.

29. The roller according to claim 1, wherein said support core has, in an axial direction of said support core, a different cross-sectional shape at least in some sections of said support core.

30. The roller according to claim 29, wherein said support core includes a plurality of ends and has, at least in some sections of said support core, a cross-sectional shape which tapers conically towards said plurality of ends.