WO2010105868A1 - Roller - Google Patents

Abstract

The invention relates to a roller (10) having a shell (12) rotatably mounted on the two ends thereof, wherein the roller shell has an external elastic material coating (16) at least in regions, the flexibility of which changes in the direction of the roller axis (18) when observed from the center region (20) of the roller to the two edge regions (22) of the roller. Alternatively, according to the invention, the roller shell can also have an external covering in regions the radial thickness thereof changing in the direction of the roller axis when observed from the center region of the roller to the two edge regions of the roller.

Description

 roller

The invention relates to a roller having a sleeve rotatably mounted at both ends thereof.

Such a roller is, for example, in the winding core, for example drum, for use in a winding machine on which a material web, in particular a paper or board web, is wound up. This winding core is preferably made of a hollow cylindrical winding core body and each attached to one of its two ends bearing journals with which it rests in operation in camps, which are usually supported on, for example, horizontal rails movable.

The winding process is of great importance both in material web production and in material web refinement, since there is sometimes the risk that a material web which has hitherto been produced immaculately during winding will be so affected by winding defects that parts of a manufactured winding roll are not to be sold. Among the well-known winding defects include the so-called shiny spots, wrinkles or Platzer. The resulting winding errors are generally greater, the faster the winding machines are operated and the larger the diameter and finished weights of the wound rolls are produced.

There are a variety of theories for the formation of, for example, glossy spots, the most common theory being that when the web is wound onto a winding core and the resulting winding roll gradually reaches its finished diameter, the high weight forces cause the winding core to deflect that ultimately have relative Slides of individual material web layers (axial displacements) in particular in the edge regions against each other causes. Adjacent web web layers glide on each other due to acting shear stresses under friction, which ultimately brings with it the unwanted highlights.

In order to counteract the edge inclination of the roller or winding core occurring during winding of a material web, such as, in particular, a paper or board web, EP 1 310 445 B1 discloses a deflection-reduced winding axis which is obtained through the use of tubular sleeves in the edge regions of the main cylinder body ,

For stiffening drums or other rolls whose deflection or edge inclination has technological influence, a fiber-reinforced casing of the relevant roll body has also been proposed.

In the usual standard designs of tambours a sufficiently high rigidity is achieved by appropriate diameters and wall thicknesses.

In order to improve or even out the nip pressure of roller pairs pressed against one another, the technique of so-called crowning is mostly used, that is to say a deviation from the cylindrical roller shape which is deliberately produced depending on the expected deflection as a result of the loading of the relevant roller.

Moreover, for demanding applications such as on calenders or for applications requiring a wide range of Niplast deflection deflection rolls employing a fixed yoke, an inner chamber pressurized with oil pressure and a rotating roll shell are used include, whose deformation is substantially compensated by the external load by means of the internal pressure.

The invention has for its object to provide an improved roller of the type mentioned, with the aforementioned problems are eliminated in a simpler and more reliable manner. In particular, the relief of selected zones, in particular edge zones of the roller used, for example, as a drum, or the equalization of the nip impression of, for example, press or calender rollers should be accomplished in the simplest possible and correspondingly cost-effective manner. In addition, in particular, the possibility should be created that the relief effect in question is dependent on the load occurring during operation or applied load.

According to the invention, this object is achieved in that the roll mantle is at least partially provided with an outer elastic material layer whose flexibility changes in the direction of the roll axis, starting from the center region of the roll to the edge regions of the roll.

Because of this design, the above-mentioned problems, such as in particular the tendency to edge when winding a material web, in particular paper or board web, or, for example, an uneven Nipabdrucks be met in a simpler and more cost-effective manner. Thus, for example, the rigidity of Tambourrohren whose currently required wall thickness go far beyond the requirements of strength, can be significantly reduced. In addition, the retrofitting of existing Tambouren is readily possible. For press rolls additionally results in the advantage that the previously optimized to a specific load case camber can be replaced by the inventive solution with a wide application window. The resilience of the elastic material layer preferably increases starting from the central region of the roller toward the two edge regions of the roller.

A preferred practical embodiment of the roller according to the invention is characterized in that the elastic material layer in the axial direction successive zones each one at least substantially the same

Has compliance and the flexibility of the elastic material layer changes from a central zone to the axially outer edge-side zones from zone to zone. It is advantageous if the resilience of the elastic material layer, starting from the middle zone to the edge side

Zones from zone to zone increases.

In the unloaded state, the roller may in particular have an at least substantially cylindrical shape.

Advantageously, the different resilience of the roll shell is selected as a function of the load occurring during operation of the roll in order to compensate, in particular, a corresponding deflection of the roll at least substantially.

The load of the roller during operation can be determined, for example, by the winding constructed on the roller or the winding core or drum, the weight of the roller and / or the like.

The roller can thus be designed for example as a winding core for winding a material web, in particular paper or board web. In this case, the resilience of the elastic material layer in the two edge regions of the roller is preferably higher than in the middle region of the roller. The roll may in particular also be designed as a press roll in order to form a press nip with a mating surface. The resilience of the elastic material layer in the two edge regions of the roller is preferably higher than in the middle region. In the case of a press roll, such a distribution of the differing flexibility over the roll axis is advantageous, in particular, when the roll is arranged at the bottom in the relevant press.

The roll may in particular also be designed as a calender roll.

Thus, according to the invention, in particular in individual zones, starting from the middle of the roll towards the edge, elastic material with different flexibility can be applied to the roll shell. In the unloaded state, a cylindrical shape of the roller is given. With a corresponding distribution of the different compliances in the axial direction, however, the edge region can be compressed more strongly than the central region under load, depending on the magnitude of the loading force, in order to reduce so-called edge inclination, which is advantageous in particular in connection with hubs or tambours, or To avoid excessive edge pressure, which is important for press rolls or calender rolls, for example.

According to the invention, the above-mentioned object is also achieved in that the roll mantle is provided at least in regions with an outer cover whose radial thickness, viewed in the direction of the roll axis, changes starting from the center region of the roll toward the two edge regions of the roll.

Preferably, the thickness of the outer cover, starting from the middle region of the roller, decreases towards the two edge regions of the roller. In this case, the thickness of the outer cover, starting from the central region of the roller to the two edge regions of the roller, in particular decrease continuously.

With this alternative second solution according to the invention, in particular, a wedge-shaped free position decreasing towards the center is possible in the edge region of the roll cover.

This second solution achieves a similar effect to the first solution.

The outer cover preferably consists of at least substantially incompressible material.

The outer cover can be applied directly to the roll shell.

In certain cases, however, it is also advantageous if the outer cover is deposited with compressible material.

Preferably, the roller provided with an outer cover of different thickness is designed as a winding core for winding up a material web, in particular a paper or board web. In principle, however, the roller may, for example, again be a press roll or calender roll.

In principle, a combination of the two approaches according to the invention is conceivable in that the cover has a different thickness and a variable compressibility in each case in the axial direction.

The invention will be explained in more detail below on the basis of exemplary embodiments with reference to the drawing; in this show: 1 is a schematic representation of an unloaded spool,

Fig. 2 is a schematic representation of the deformed by the paper load spool and

Fig. 3 is a schematic enlarged view of the left edge region of the reproduced in Fig. 2 loaded Tambours.

Fig. 1 shows a schematic representation of an unloaded roller 10, which in the present case, for example, a winding core or spool for winding a material web, in particular paper or board web, is.

The roller 10 comprises a jacket 12 which is rotatably mounted at both ends thereof. For pivotable mounting, for example, bearing journals 14 mounted on the two end faces of the roller or of the jacket may be provided.

The roller shell 12 is at least partially provided with an outer elastic material layer 16, the flexibility seen in the direction of the roller axis 18, starting from the central region 20 to the two edge regions 22 of the roller 10 changes out.

In this case, the resilience of the elastic material layer 16 starting from the middle region 20 of the roller 10 toward the two edge regions 22 of the roller 10 may increase in particular. The resilience of the elastic material layer can change continuously, for example increase, starting from the center region 20 towards the two edge regions 22.

However, it is also possible, in particular, for the elastic material layer 16 to have an at least substantially equal flexibility in successive zones in the axial direction, and for the elasticity of the elastic material layer 16 to change from zone to zone starting from a central zone towards the peripheral zones. In this case, the resilience of the elastic material layer 16 can increase again from zone to zone, starting from the central zone towards the peripheral zones.

As can be seen with reference to FIG. 1, the roller 10 has an at least substantially cylindrical shape in the unloaded state.

FIG. 2 shows, in a schematic representation, the roller or drum 10 deformed by the paper load, that is to say, in particular, the roll 24 produced on the roll or drum 10. The roll 10 or its sheath 12 is therefore bent downwards in the present case.

The different flexibility of the roll shell 12 can now be selected as a function of this occurring during operation load of the roller 10, in particular to compensate for a corresponding deflection of the roller 10 at least substantially.

As can be seen with reference to FIG. 2, it can be achieved that, despite the deflection of the roller 10 or of the roller shell 12, the upper contact line 26 extends at least substantially horizontally between the elastic material layer 16 and the winding 24 applied to the casing 12 , The corresponding deflection compensation takes place here in that the elastic see material layer 16 in the axial direction 18 is differentially substantially radially compressed.

For this purpose, in the present case, the resilience of the elastic material layer 16, in particular in the two edge regions 22 of the roller 10, may be higher than in the middle region 20.

FIG. 3 shows a schematic enlarged representation of the left edge region of the roller or drum 10 shown in FIG. 2.

As can be seen from this Fig. 3, the elastic material layer 16 in the axial direction 18 successive zones 28 - 32 each have an at least substantially equal flexibility, wherein the resilience of the elastic material layer 16 preferably from a central zone 28 to the axially outer peripheral zone 32 changes, here, for example, increases. As can be seen with reference to FIG. 3, an axially inner edge-side zone 30 can be provided between the central zone 28 and the axially outer edge-side zone.

In particular, the various layers 34 of the material web forming the winding 24, in particular paper or board web, can also be seen in FIG.

In addition, in this figure, the neutral axis 18 of the unloaded roller or drum 10 and the deformed axis 36 of the loaded roller or drum or spool 10 are shown.

In the present embodiment has the axially outer edge-side zone

32 a relatively high, the axially inner edge-side zone 30, a middle and the middle zone 28, a relatively low or the lowest compressibility. These three zones 28 to 32 are in the present case by the winding 24, that is especially deformed by its weight. In contrast, the unloaded, undeformed edge zone 38 can be seen in the lower area.

In the following, a concrete example or a preferred embodiment of the roller or the drum is given.

The aim of a corresponding design could be, for example, an increase of the permissible edge inclination of a spool by 1 mm / m. For this purpose, it would be necessary to select the compressibility and layer thickness of the elastic bedding or material layer such that in the edge region of about 500 mm a compression of at least 1 - 2 mm corresponding to a compression of the elastic material, for example 10 mm layer thickness of 10 up to 20%. Towards the center of the roll, the elastic bedding becomes zone-wise, preferably in each case 2 to 3 zones in the edge region, stiffer, as a result of which the bending line in the edge region is smoothed.

The cost of a spool with such reduced stiffness are about 10 - 15% lower than those of a comparable conventional spool. The additional costs for a layer according to the invention between the base body and the rubber cover of the spool should in any case be less than this saving.

If necessary, the outer diameter of the empty drum may also be smaller, which leads to greater flexibility in the design of the machine roller concerned.

Apart from that, as already mentioned, the possibility of retrofitting already existing, too weakly dimensioned drumming opens up.

The roller 10 may for example also be designed as a press roll to form a press nip with a counter surface. In this case, the resilience of the elastic material layer 16 in the two edge regions 22 of the roller 10th in particular be higher again than in the middle region 20 (cf., for example, once again FIG.

The roller 10 may for example also be designed as a calender roll.

The elastic material layer of different flexibility or compressibility can therefore also be provided, for example, for a deflection compensation on press and calender rolls. Depending on the application, the layer thickness, number of zones and width of the permissible inclination of the bending line or water surface can be varied.

In particular, such a dimensioning is preferably provided that the difference in compressibility between two adjacent zones does not become too great in order not to initiate excessive bending stresses on the externally applied material layer or roll cover. Optionally, the zone number can be increased, each with a small difference in compressibility in order to lower the bending AC voltage in the overlying reference below the allowable level.

LIST OF REFERENCE NUMBERS

10 roller, drum 12 coat

14 journal

16 material layer

18 roll axis, neutral axis, axial direction

20 center area 22 edge area

24 wraps

26 contact line

28 middle zone

30 axially inner edge zone 32 axially outer edge zone

34 location

36 deformed axis

38 unloaded, undeformed edge zone

Claims

Voith Patent GmbH File: HPL13318 WO89510 Heidenheim "Elastic Bedding" Claims 1. roller (10) having a rotatably mounted at both ends of its jacket (12), characterized in that the roll mantle (12) is at least partially provided with an outer elastic material layer (16), the flexibility of which is viewed in the direction of the roll axis (18) starting from the middle region (20) of the roller (10) to the two edge regions (22) of the roller (10) changes. 2. Roller according to claim 1, characterized g eken nze I net, that the resilience of the elastic material layer (16), starting from the central region (20) of the roller (10) to the two edge regions (22) of the roller (10) increases towards. 3. Roller according to claim 1 or 2, characterized g eken nze I n et that the elastic material layer (16) in the axial direction (18) successive zones (28 - 32) each have an at least substantially equal compliance and the flexibility of the elastic material layer (16), starting from a central zone (28) to the axially outer edge-side zones (32) out changes from zone to zone. 4. Roller according to claim 3, characterized g eken nze I n et, the flexibility of the elastic material layer (16) increases from zone to zone from the central zone (28) to the axially outer peripheral zones (30). 5. Roller according to one of the preceding claims, characterized g eken nze I n et that it has an at least substantially cylindrical shape in the unloaded state. 6. Roller according to one of the preceding claims, characterized g eken nze I n et that the different flexibility of the roll shell (12) is selected in dependence on the load occurring during operation of the roller (10), in particular a corresponding deflection of the roll ( 10) at least substantially compensate. 7. Roller according to claim 6, characterized g eken nze I n et et that the compliance of the elastic material layer in the two edge regions (22) of the roller (10) is higher than in the central region (20) of Roller. 8. roller with a rotatably mounted at both ends of coat, I think so n et that the roll shell is at least partially provided with an outer cover whose radial thickness viewed in the direction of the roll axis, starting from the central region of the roll to the two Edge of the roller changes. 9. Roller according to claim 8, By this, I would like to state that the thickness of the outer covering starts from the center of the Roller decreases toward the two edge regions of the roller. 10. Roller according to claim 9, characterized in that the thickness of the outer cover starts from the middle region of the outer cover Roller continuously decreases towards the two edge regions of the roller. 11. Roller according to one of claims 8 to 10, characterized g eken nze I n et that the outer cover consists of at least substantially non-compressible siblem material. 12. Roller according to one of claims 8 to 11, characterized g eken nze I net, that the outer cover is applied directly to the roll shell. 13. Roller according to one of claims 8 to 12, characterized g eken nze I n et et that the outer cover is deposited with compressible material. 14. Roller according to one of claims 1 to 13, characterized g eken nze I N et that the roll shell (12) is at least partially provided with an outer elastic material layer (16), the flexibility of which in the direction of the roll axis (18) considered starting from the central region (20) of the roller (10) to the two edge regions (22) of the roller (10) out changes and the roll shell (12) is provided, at least in regions, with an outer cover (16) whose radial thickness, viewed in the direction of the roll axis (18), starts from the center region (20) of the roll (10) to the two edge regions (22) of the roll (10) changes. 15. Roller according to one of claims 1 to 14, characterized in that it serves as a winding core for winding a material web, as a press roller in a press section for pressing a material web, as an application roller in a coating unit for applying a medium to a material web, as a smoothing roll in one Calender or calender or as a balancer roll.