EP4247573A1

EP4247573A1 - Roll device for rolling metal strips, roll arrangement for use in such a roll device, and method for converting a roll device

Info

Publication number: EP4247573A1
Application number: EP21782464.8A
Authority: EP
Inventors: Edgar Filk; Markus GÜMPEL
Original assignee: SMS Group GmbH
Current assignee: SMS Group GmbH
Priority date: 2020-11-17
Filing date: 2021-09-20
Publication date: 2023-09-27
Also published as: JP2023550065A; WO2022106093A1; US20230415211A1; DE102020214383A1; CN116457116A

Abstract

The invention relates to a roll device (1) for rolling metal strips, comprising at least a first and a second work roll (4, 6, 6') which define a roll gap (W) therebetween, and at least a first and a second support roll (11, 12), wherein: in a common rolling stand (2), at least one work roll (4, 6') is mounted in work roll chocks (5, 9') and the support rolls (11, 12) are mounted in support roll chocks (13, 14); the work roll chocks (5, 9') are designed such that the first and/or the second work roll (4, 6') can each be replaced by a roll arrangement (10) having a work roll (6) with a smaller diameter and at least one additional roll (8); and the work roll (6) with the smaller diameter is supported via the additional roll (8), the additional roll is mounted in additional roll chocks (7), and the work roll with the smaller diameter is situated in work roll bearings (9) of the additional roll chocks (7). The invention also relates to a roll arrangement (10) for use in such a roll device (1), and to a method for converting a roll device (1).

Description

Rolling device for rolling metal strips, roll arrangement for use in such a rolling device and method for converting a rolling device

The invention relates to a rolling device for rolling metal strips, comprising at least a first and a second work roll, which define a roll gap between them, and at least a first and a second back-up roll, the work rolls being mounted in work roll chocks and the back-up rolls being mounted in back-up roll chocks in a common roll stand are.

For the cold rolling of high-strength and thin metal strips with high reduction in thickness, roll stands in a convertible 18-HS or 20-HS design with 18 or 20 rolls are often used. These roll stands include relatively small work rolls, but are technically complex and require a lot of maintenance. Converting from a 4-roller configuration to a multi-roller configuration is expensive.

High-strength and thin strips made of special alloys are niche products, so the use of special multi-roll stands, such as those in the Sendzimir design, is often not economical.

Common to all these roll stand designs is that the small work rolls are built into the roll stand without their own bearings and the vertical and lateral fixing and guidance is provided by additional devices, in particular by support rollers. In the prior art, the small work rolls without bearings are manually inserted into and removed from the roll stand.

The invention is therefore based on the object of providing a rolling device of the type mentioned, which with relatively simple means that high-strength and thin metal strips can be rolled with a high reduction in thickness.

The invention is also based on the object of providing a rolling device that can be converted relatively easily for different requirements.

The object on which the invention is based is achieved with the features of the independent claims. Advantageous configurations of the invention result from the dependent claims.

One aspect of the invention relates to a rolling apparatus for rolling metal strips comprising at least a first and a second work roll, which define a roll gap between them, and at least a first and a second back-up roll, wherein at least one work roll in work roll chocks and the back-up rolls in back-up roll chocks in one common roll stand, the work roll chocks being designed in such a way that the first and/or the second work roll can each be exchanged for a roll arrangement which has a work roll with a smaller diameter and at least one additional roll, the work roll with the smaller diameter being above the additional roll the back-up roll is supported in back-up roll chocks, and the smaller diameter work roll is disposed in work-roll bearings of the back-up roll chocks.

According to the invention, it is proposed to design the rolling device in such a way that a given pair of work rolls of the roll stand with larger roll diameters can be converted in such a way that one and/or both work rolls can be replaced by a work roll with a smaller diameter and an additional roll. As a result, various configurations of the rolling device can be implemented. In a variant of Rolling device, in which both the first and the second work roll are replaced by a roll arrangement with a work roll with a smaller diameter and an additional roll, a symmetrical work roll pairing with smaller work rolls is thereby achieved overall, with which a relatively high thickness reduction can already be achieved.

Due to the independent mounting of the roll with the smaller diameter in associated work roll bearings, the position of this work roll can be precisely defined both axially and vertically in relation to the additional roll and/or in relation to the work roll interacting with it to form the roll gap. As a result, particularly stable rolling conditions are established. Due to the positional stability not only during rolling, but also when changing the rolls, the pairing of the working rolls can be set particularly easily. In this respect, the invention is also particularly suitable for modernizing an existing plant to expand the product range.

The position of the work roll bearings within the roll arrangement is preferably adjustable and thus also the position of the work roll with the smaller diameter. According to the invention, the work roll bearings fulfill the function of smaller “work roll chocks” that can be displaced within the additional roll chocks and with them.

The position of the work roll bearings is particularly preferably adjustable axially and/or transversely to the longitudinal extent of the roll gap.

This ensures that the position of the axis of rotation of the work roll in the roller arrangement can be adjusted or adjusted relative to the position of the axis of rotation of the additional roll. Such an adjustment can be necessary, for example, to set a so-called offset. This is understood to mean an axial center offset or offset of the longitudinal center axis of the additional roll on the one hand and the longitudinal center axis of the work roll on the other hand, which is intended to improve the stability of the arrangement against horizontal deflection. In principle, an offset can be set by means of wear plates or shims of different thicknesses, which are provided in pockets or recesses in the work roll chocks of the roll arrangement. Alternatively, hydraulic piston-cylinder arrangements can be provided for this.

The work roll bearings may be supported on viscoelastic buffers which lift the work roll of the roll assembly from the back-up roll once unloaded, thereby avoiding surface contact between the work roll and the back-up roll of the roll assembly during assembly and disassembly of the roll assembly.

In a favorable and preferred variant of the rolling device according to the invention, either the first or the second work roll is replaced by a roll arrangement with a work roll with a smaller diameter and an additional roll. According to the invention, a rolling device is particularly preferably provided which comprises a first, upper work roll with a relatively large diameter and a lower roll arrangement with a work roll with a smaller diameter. This asymmetrical configuration of the work rolls with a first upper work roll with a relatively large diameter and a second lower work roll with a relatively small diameter has proven to be particularly favorable with regard to the reduction in thickness to be achieved. Such a diameter ratio of the work rolls is advantageous in that a rolling result can be achieved that corresponds to a pass with a pair of work rolls in which the diameter of each work roll corresponds to the arithmetic mean of the diameters of a larger and a smaller work roll. The additional roll preferably has a larger diameter than the working roll of the roll arrangement.

In a preferred and expedient variant of the rolling device according to the invention, it is provided that the first or the second work roll is designed as a work roll with a smaller or larger diameter and that the work roll with the smaller diameter has a diameter that is less than or equal to half the diameter of the large work roll.

The rolling device according to the invention is expediently designed such that the additional roll chocks of the roll arrangement have an outer contour which approximately corresponds to the outer contour of the work roll chocks for a single work roll with a larger diameter. This configuration ensures, in particular, that the rolling device can be easily converted. It can thus be ensured that the additional roll chocks of the roll arrangement can be exchangeably accommodated in the installation space of the work roll chocks within the roll stand of the rolling device. No conversion work is required within the scaffolding area.

In an advantageous exemplary embodiment of the rolling device according to the invention, it is provided that the first or second work roll is mounted in pockets or recesses on the side of the additional roll chocks of the roll arrangement that faces the roll gap in the installed position. This ensures that no further adjustment of any bending or balancing devices provided for the work rolls and/or back-up rolls is required.

The inventive configuration of the roller assembly, which is designed as an independent functional unit, can be a roll change that is also a configuration change at the same time, can be implemented quickly and easily using conventional means, preferably fully automated.

In principle, it can be provided that the work roll with the smaller diameter is supported along at least part of the roll barrel on one side or on both sides. Smaller diameter work rolls tend to bow transversely to the direction of strip travel across the barrel length transverse to its longitudinal axis.

According to the invention, this can be taken into account in that the first or second work roll is movably mounted in the additional roll chocks of the roll arrangement transversely to the axis of rotation and is supported on at least one side parallel to the axis of rotation over at least part of its length by means of at least one hydrostatic support bearing. The offset can also be adjusted using the hydrostatic support bearing.

In this variant, the hydrostatic support bearing has a dual function. It compensates for the deflection of the small work roll and adjusts the axial position of the axis of rotation of the work roll relative to the axis of rotation of the auxiliary roll.

The hydrostatic support bearing preferably comprises at least one support shell which extends over a substantial part of the barrel length of the work roll of the roll arrangement. The support shell is preferably sealed at each end on the steady seat of the work roll of the roll arrangement. Alternatively, the supporting shell can be sealed against spacers in the region of the bearing of the work roll of the roll arrangement.

A lateral seal of the bearing shell serves the purpose of ensuring a constant pressure of the hydraulic medium between the bearing shell and the work roll to maintain. For example, the rolling emulsion or rolling oil usually used for roll cooling and roll lubrication can be considered as the hydraulic medium.

In an advantageous embodiment of the rolling device according to the invention, it is provided that the supporting shell is set and/or held against the work roll by at least one, preferably hydraulic, setting device. The adjusting device can be provided as an additional device or external device on the rolling device.

For example, at least one guide element provided on the rolling device or in the rolling train for the rolling stock can be provided or designed as the adjusting device.

In a particularly advantageous embodiment of the rolling device according to the invention, it is provided that at least one adjusting device is provided in a movable table or belt deflector assigned to the rolling device and arranged on the inlet and/or outlet side. It makes sense to integrate a screwdown device in each control table for the rolling stock.

The adjusting device can comprise a multiplicity of adjusting cylinders which act on the supporting shell with adjusting elements.

The additional roll chock of the roll arrangement and/or at least one work roll bearing of the roll arrangement can comprise at least one media coupling for lubricant and/or coolant and/or another hydraulically active medium.

The invention further relates to a roll arrangement for use in a rolling device for rolling metal sheets of the type described above. The roll arrangement comprises at least one additional roll and at least one work roll, the auxiliary roll in

Additional roll chocks is mounted and the work roll in

Work roll bearings of the additional roll chocks is arranged.

The auxiliary roll preferably has a larger diameter than the work roll.

To ensure that the roll arrangement has a configuration that roughly corresponds to the configuration of a work roll to be replaced, the invention provides that the work roll bearings are arranged in pockets on the side of the additional roll chocks that faces the roll gap in the installed position.

The work roll can, for example, be movably mounted in the work roll bearings transversely to the longitudinal extent of the roll gap and supported on at least one side parallel to the axis of rotation over at least part of its length by means of at least one hydrostatic support bearing.

The working roll can be adjustable transversely and/or vertically with respect to the additional roll.

For this purpose, it can be provided that the work roll bearings in the additional roll chock can be adjusted transversely and/or vertically.

At least one of the additional roll chocks and/or at least the work roll bearing, preferably both, is expediently provided with at least one media coupling or a media connection for introducing a hydraulic medium. Lubricants and/or rolling emulsion for cooling and lubricating the work rolls and as a medium for maintaining the hydrostatic pressure within the hydrostatic support bearing can be considered as hydraulic media. The roll arrangement according to the invention preferably has one or more of the features disclosed above in connection with the rolling device according to the invention.

Finally, the invention relates to a method for retrofitting a rolling device for rolling metal strips, which comprises at least a first and a second work roll, which define a roll gap between them and which further comprises at least a first and a second back-up roll, the work rolls in work roll chocks and the back-up rolls are mounted in back-up roll chocks in a common roll stand, the first and/or second work roll being replaced by a roll arrangement which comprises an additional roll which supports the work roll arranged in work roll bearings, the diameter of the work roll of the roll arrangement being smaller than the diameter of the work roll to be replaced and the external dimensions of the additional roll chocks of the roll arrangement largely correspond to those of the work roll chocks of the work roll to be replaced.

The invention is explained below with reference to an embodiment shown in the figures.

Show it:

Figure 1 is a schematic and simplified representation of a rolling device according to the invention,

FIG. 2A shows a conventional pair of work rolls,

FIG. 2B shows a roller arrangement according to the invention, FIG. 3 shows an enlarged representation of the bearing of the work roll of the roll arrangement according to FIG. 2B,

Figure 4 is a perspective view of the roller assembly according to the invention,

FIG. 5 shows a perspective view of the rolling device according to FIG. 4 viewed from the drive side,

FIG. 6 shows a perspective representation of a control table for guiding the rolling stock with a positioning device according to the invention and

FIG. 7 shows a further perspective representation of the control table according to FIG.

The rolling device 1 according to the invention comprises a roll stand 2 with a roll stand 3, within which an upper (large) work roll 4 is mounted in upper work roll chocks 5 and a lower (small) work roll 6 in and an additional roll 8. A roll gap W is formed between the work rolls 4.6, through which the rolling stock, not shown, is passed in the form of a metal strip.

The rolling device 1 comprises, in a known manner, both bending cylinders and balancing cylinders, with which bending of the work rolls and the weight of the back-up rolls can be compensated. For reasons of simplification, these devices are not shown in the drawings. Furthermore, the rolling device according to the invention comprises means for the axial displacement of the work rolls 4,6, which are also not shown in the drawings for reasons of simplification. An axial displacement or adjustment within the meaning of this patent application is to be understood as a displacement in the direction of the longitudinal axis of the rolls in question. A vertical displacement or adjustment within the meaning of this patent application is to be understood as an adjustment transverse to the longitudinal extent of the roll gap W.

In the vertical direction, the upper work roll 4 is supported against an upper backup roll 11, whereas the lower work roll 6 is supported against a lower auxiliary roll 8. The additional roller 8 is supported against a lower support roller 12 . The upper backup roller 11 is in upper

Back-up roll chocks 13 and the lower back-up roll 12 mounted in lower back-up roll chocks 14. The combination of the below

Work roll 6 and the additional roll 8 form a roll arrangement 10 within the meaning of the present invention. The roll arrangement 10 comprises an additional roll chock 7 in which the lower work roll 6 with a smaller diameter is mounted. The work roll 6 is supported by work roll bearings 9 of the additional roll chocks 7 .

The work rolls 4, 6 bring about a reduction in the thickness of the rolling stock in a manner known per se. The rolling device 1 according to the invention is preferably designed as a device for cold-rolling metal strips and designed for a relatively large reduction in thickness.

To stabilize the entire set of rolls, both the upper backup roll chock 13 and the lower backup roll chock 14 are subjected to a force parallel to their longitudinal center axes within the roll stand 3 by means of known pusher cylinders 15, which counteracts a lateral deflection of the backup rolls 11, 12. Such stabilization is particularly advantageous because of the odd number of rolls in the set of rolls. By means of the pusher cylinders 15, an offset (longitudinal center offset) of the longitudinal center axes of the support rollers 11, 12 can be adjusted in a known manner to the longitudinal center axes of the work rolls 4, 6 set. Due to the possible variable offset directions, the directions of action of the pusher cylinders 15 must be recalculated for each application and load case. This takes place via a control unit S of the rolling device 1 .

In the configuration of the rolling device 1 shown in FIG. 1, it is provided that the lower work roll 6 has approximately half the diameter of the upper work roll 4 . The diameter of the additional roll 8 is slightly smaller than the diameter of the upper work roll 4. As will be described later, the rolling device 1 according to the invention can be converted between different configurations with different pairs of rolls. This has the advantage that a rolling device 1 with a pair of rollers for rolling less strong strips with a relatively small reduction in thickness can be converted with simple means if higher-strength and thinner strips made of special alloys or with a greater reduction in thickness are to be rolled.

The configuration of the various pairs of rollers of the rolling device can be seen in particular from FIGS. 2A and 2B. Figure 2A shows an end view of a conventional work roll pair, which comprises a first upper work roll 4 and a second lower work roll 6', the upper work roll 4 being mounted in an upper work roll chock 5 and the lower work roll 6' being mounted in a lower work roll chock 9' are. Both work rolls 4,6' have the same diameter and accordingly form a symmetrical pair of work rolls.

The invention provides that the rolling device 1 according to the invention can be converted in such a way that either the upper work roll 4 with the associated upper work roll chocks 5 or the lower work roll 6 'with the associated lower work roll chocks 9' against the Roller assembly 10 is replaced according to Figure 2B. This configuration is shown in FIG.

The roll arrangement 10 according to FIG. 2B comprises additional roll chocks 7, the external dimensions and geometry of which correspond approximately to the geometry of the work roll chocks 4, 6′ of the conventional work roll pairing according to FIG. 2A. This is made possible in particular by the fact that the additional roll 8, whose diameter corresponds approximately to the diameter of the upper work roll 4 or is slightly smaller, is mounted in the lower additional roll chocks 7 corresponding to the upper work roll 4 in the upper work roll chocks. The lower work roll 6 is mounted in work roll bearings 9 which are each arranged in pockets 26 on the upper side of the additional roll chocks 7 facing the roll gap W.

In the variant of the rolling device 1 according to FIG. 1, it is provided that the position of the axis of rotation of the lower work roll 6 can be adjusted by means of replaceable wear plates 16 .

In the variant of the roll arrangement 10 shown in FIG. 2B, it is provided that the lower work roll 6 is movably mounted transversely to its longitudinal axis and is centered within the pockets 26 by means of a hydrostatic bearing 17 .

As can be seen in particular from FIG. 3, which shows a detailed view from FIG. The hydrostatic bearing 17 is charged with cooling/lubricant, for example rolling emulsion, via media connections described below, so that it is ensured that the support shells 18 enclose the work roll 6 between them in such a way that they do not rest on the surface of the work roll 6 . In addition, one not shown lateral seal of the support shells 18 is provided, which is supported on the bezel seat of the lower work roll 6, so that it is ensured that the support shells 18 do not rest against the work roll 6 when no media pressure is built up.

The additional roll chock 7 also has receptacles for viscoelastic buffers 27 in the lower area of the pocket 26, which lift the small work roll 6 with the associated work roll bearings 9 as soon as they are free of load. This ensures that when the rolls are changed, there is no surface contact between the work roll 6 and the additional roll 8 that could impair the surface quality of the smaller work roll 6 .

In the exemplary embodiment described, the small work roll 6 has two hydrostatic bearings 17 , one each on the entry side and one on the exit side of the rolling device 1 . Loading of the supporting shells 18 on one or both sides can optionally be provided. In other exemplary embodiments, a one-sided arrangement can also be provided.

Figure 4 shows a perspective view of the roller assembly 10 according to the invention. The additional roll chocks 7 of the roll arrangement are provided with first media couplings 24 for supplying pressure to the hydrostatic bearing 17 and with second media couplings 25 for providing a coolant and/or lubricant to the roller bearings of the lower work roll 6 and the additional roll 8 .

The rolling emulsion can, for example, be circulated through the hydrostatic bearing 17 with a volume flow of approx. 1000 l/min as a medium for pressure supply. As can be seen from FIG. 5, the rolling device 1 according to the invention comprises, at least on one side, a guide table 19 for guiding the rolling stock. The guide level of the control table 19 extends approximately at the height of the lateral surface of the lower work roll 6. According to the invention, means for adjusting and/or centering a support shell 18 of the hydrostatic bearing 17 in the form of a control beam 20 are provided on the control table 19, which can be moved relatively by means of feed cylinders 21 to the control table 19 is slidably arranged.

The control table 19 is shown in perspective in FIGS. 6 and 7 in an enlarged form. The adjusting beam 20 can be positioned in relation to a supporting shell 18 with feed cylinders 21 which are arranged on the underside of the control table 19 (see FIG. 7). The adjusting beam 20 also includes a large number of adjusting cylinders 22 which act on the relevant supporting shell 18 of the hydrostatic bearing 17 with tappets 23 . The back pressure on the supporting shell 18 of the hydrostatic bearing 17 can be adjusted over the entire length of the barrel of the lower work roll 6 by means of the adjusting cylinders 22 . In the case of the rolling device 1 according to the invention, a control table 19 can be provided both on the entry side and on the exit side.

The setting of the supporting shells 18 of the hydrostatic bearing 17 is effected with the adjusting beams fastened to the control table 19, so that additional adjusting means to be provided on the roller arrangement 10 are unnecessary. The roller arrangement 10 can thus be made compact and without additional adjusting means.

Reference List

1 rolling device

2 roll stand

3 roller stands

4 upper stripper

5 upper work roll chock

6 bottom stripper

6' lower work roll of a conventional work roll pairing

7 Additional roll chock

8 additional roller

9 work roll bearings

9' lower work roll chock

10 reel arrangement

11 upper support roller

12 lower support roller

13 upper backup roll chock

14 lower back-up roll chock

15 pusher cylinders

16 wear plates

17 hydrostatic bearings

18 support shells

19 control desk

20 setting bars

21 feed cylinder

22 adjusting cylinder

23 rams

24 first media clutch

25 second media clutch

26 pockets

27 viscoelastic buffers S control device

W nip

0 offset

Claims

patent claims

1. Rolling device (1) for rolling metal strips, comprising at least a first and a second work roll (4,6,6') which define a roll gap (W) between them and at least a first and a second back-up roll (11,12) , wherein at least one work roll (4, 6') is mounted in work roll chocks (5, 9') and the back-up rolls (11, 12) are mounted in back-up roll chocks (13, 14) in a common roll stand (2), the work roll chocks (5, 9') are designed such that the first and/or the second work roll (4,6') can each be exchanged for a roll arrangement (10) which has a work roll (6) with a smaller diameter and at least one additional roll (8). wherein the work roll (6) with the smaller diameter is supported via the auxiliary roll (8), the auxiliary roll is mounted in auxiliary roll chocks (7) and the work roll with the smaller diameter is arranged in work roll bearings (9) of the auxiliary roll chocks (7).

2. Rolling device (1) according to claim 1, characterized in that the position of the work roll bearing (9) within the roll arrangement (10) is adjustable.

3. Rolling device (1) according to claim 2, characterized in that the position of the work roll bearings is adjustable axially and/or transversely to the longitudinal extent of the roll gap (W).

4. Rolling device (1) according to one of claims 1 to 3, characterized in that the additional roll (8) has a larger diameter than the working roll (6) of the roll arrangement (10). Rolling device (1) according to one of Claims 1 to 4, characterized in that the first or the second work roll (4,6,6') is designed as a work roll with a smaller or larger diameter and that the work roll (6) with the smaller diameter has a diameter that is less than or equal to half the diameter of the large-diameter work roll (4, 6'). Rolling apparatus (1) according to Claim 5, characterized in that the diameter of the auxiliary roll (8) is smaller than or equal to the diameter of the large-diameter work roll (4, 6'). Rolling device (1) according to one of Claims 1 to 6, characterized in that the additional roll chocks (7) of the roll arrangement (10) have an outer contour which corresponds to the outer contour of the work roll chocks (5, 9') for a single work roll (4, 6'). ) with larger diameter corresponds approximately. Rolling device (1) according to one of Claims 1 to 7, characterized in that the work roll bearings (9) are arranged in pockets (26) on the side of the additional roll chocks (7) facing the roll gap (W) in the installed position. Rolling device (1) according to one of Claims 1 to 8, characterized in that the working roll (6) of the roll arrangement (10) is supported on at least one side parallel to its axis of rotation over at least part of its length by means of at least one hydrostatic support bearing (17). Rolling device (1) according to any one of claims 1 to 9, characterized in that the position of the axis of rotation of the work roll (6) in the Work roll bearings (9) of the roll arrangement (10) is adjustable relative to the position of the axis of rotation of the additional roll (8).

11. Rolling device (1) according to one of claims 9 or 10, characterized in that the work roll (6) is movably mounted in the work roll bearings (9) of the roll arrangement (10) transversely to its axis of rotation and with the aid of a support shell (18) of the hydrostatic Support bearing (17) can be positioned.

12. Rolling device (1) according to any one of claims 9 to 11, characterized in that the support shell extends over a substantial part of the barrel length of the work roll (6).

13. Rolling device (1) according to one of claims 11 or 12, characterized in that the supporting shell (18) is set and/or held against the work roll (6) via at least one, preferably hydraulic, setting device.

14. Rolling device (1) according to claim 13, characterized in that at least one guide element for the rolling stock is provided as the adjusting device.

15. Rolling device (1) according to one of claims 13 or 14, characterized in that the adjusting device comprises a plurality of adjusting cylinders (22) which act on the supporting shell (18) with adjusting elements (23).

16. Rolling device (1) according to one of claims 1 to 15, characterized in that at least one roll chock (7) and/or at least one work roll bearing (9) of the roll arrangement (10) comprises at least one media coupling (24,25). Roll arrangement (10) for use in a rolling device (1) with one of the features of claims 1-16, comprising at least one additional roll (8) and at least one working roll (6), the additional roll (8) being mounted in additional roll chocks (7). and the work roll (6) is arranged in work roll bearings (9) of the auxiliary roll chocks (7). Roll arrangement (10) according to Claim 17, characterized in that the additional roll (8) has a larger diameter than the working roll (6). Roll arrangement (10) according to one of claims 17 or 18, characterized in that the work roll bearings (9) are arranged in pockets (26) on the side of the additional roll chocks (9) facing the roll gap (W) in the installed position. Roll arrangement (10) according to one of Claims 17 to 19, characterized in that the work roll (6) is supported on at least one side parallel to the axis of rotation over at least part of its length by means of at least one hydrostatic support bearing (17). Roll arrangement (10) according to one of Claims 19 or 20, characterized in that the work roll bearings (9) are movably mounted in the pockets (26) of the additional roll chocks (7). Roll arrangement (10) according to one of Claims 17 to 21, characterized in that at least one additional roll chock and/or at least one work roll bearing (9) has at least one media coupling (24, 25) or a media connection.

21 Method for converting a rolling device for rolling metal strips, comprising at least one first and one second work roll (4,6') which define a roll gap between them and at least one first and one second back-up roll (11,12), wherein at least one work roll ( 4,6') in work roll chocks (5,9') and the back-up rolls (11,12) are mounted in back-up roll chocks (13,14) in a common roll stand (2), characterized in that the first and/or second work roll ( 4,6') is replaced by a roll arrangement (10) comprising an additional roll (8) supporting the work roll (6) arranged in work roll bearings (9), the diameter of the work roll (6) of the roll arrangement (10) being smaller is as the diameter of the work roll (6') to be replaced and the outer dimensions of the additional roll chocks (7) of the roll arrangement (10) are those of the work roll chocks (5) of the work roll (6') to be replaced equals. Method according to Claim 23, characterized by the use of a roller arrangement having one or more features of Claims 17 to 22.

22