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.
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.
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:
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.
Referring now to the drawings, and more particularly to
As is evident from
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
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
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
The extremities of the two eccentrics 30′, 30″ are therefore equally large.
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).
As can be seen from
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In the two cases mentioned in
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.
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
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.
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
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
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
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
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.
Number | Date | Country | Kind |
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10 2005 044 958.1 | Sep 2005 | DE | national |
This is a continuation of PCT application No. PCT/EP2006/064130, entitled “EXPANDER ROLLER”, filed Jul. 12, 2006, which is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/EP2006/064130 | Jul 2006 | US |
Child | 12050670 | US |