EP2858768B1 - Roll arrangement - Google Patents

Description

The invention relates to a roller assembly for use in metallurgical engineering, comprising a roller with a roll barrel and two roll neck, and at least one pin bushing for receiving one of the roll neck without radial play.

Roll arrangements are known from the prior art, in which the roll neck is received in a cylindrical or tapered pin bush. For example, oil film bearings are used in rolling mills to support back-up rollers that take over the rolling forces from pitching cylinders and transfer them to the work rolls. These are highly loaded plain bearings, which usually work in the high summer field number range, ie at a relatively low speed and under high load. At the very high pressures up to partially over 1500 bar, which form in the load zone, an elastic deformation or flattening of the pressure-loaded surfaces takes place. This flattening in the elastic region results in a larger pressure-effective surface counter to the effective direction of the external force, which is applied for example by the adjusting cylinder. The bearing can thus carry more load. This effect is called Elastohydrodynamic (EHD) increase in load capacity. To enhance this effect, so-called Morgoil KLX ^® bearings are used, which have a thin-walled, conical pin bushing as a tread, see also US 6,468,194 or EP 1 213 061 ,

From the publication " Newsletter 01/2009, SMS Group, 16th year, No .: 1, April 2009, pages 50 to 51 "Morgoil KLX ^® bearings for roller assembly are known in which a pin bushing is placed on a tapered roll neck.

For torque transmission, a feather key is disposed between the pin bushing and the roll neck.

The EP 1 651 876 B1 . US 2,955,002 (forms the basis for the preamble of claim 1) and FR 2 405 761 A describe an oil film storage for roll neck, which is mounted on it neck bushing surrounded by a bushing arranged in the bushing.

From the publication DE 603 03 052 D2 there is known an oil film bearing for use in rolling mills, comprising a cylindrical sleeve for rotatably supporting the journal surface of a roll neck, the sleeve being provided with recesses for receiving lubricant.

The DE 38 76 663 T2 describes a cylindrical bushing for supporting a rotating bearing on a hydrodynamic lubricant film.

Disadvantages of the previously known solutions are that for the transmission of very high loads a load adapted large dimensions of the storage is provided.

The invention has for its object to further increase the carrying capacity of a roller assembly, without increasing the size or the installation size of the roller assembly.

This object is achieved by the features of claim 1. The invention relates to a roller assembly for use in metallurgical engineering, comprising a roller with a roll barrel and two roll necks, and at least one pin bushing for non-rotatably receiving one of the roll neck without radial play. The roller arrangement is particularly characterized in that in the unloaded state, a circumferential cavity between the pin bushing and the roll neck is formed.

The cavity is precisely pre-dimensioned as a function of the maximum bearing force. The circumferential cavity is formed in the form of a rotationally symmetrical annular gap in the sense of a circumferential hollow profile in a plane perpendicular to the longitudinal axis of the roller assembly.

As a result of the cavity according to the invention, an enlarged clearance is created between the pin bushing and the roll neck, in which the pin bushing can locally flatten under load in the spatial region of the force effect. By flattening the pin bush, the pressure-effective surface is increased to absorb forces and the load capacity of the roller assembly significantly increased without having to increase their size. For details, see the chapter "Operation" at the end of the description.

According to a first embodiment it is provided that the cavity is enlarged and limited by a rotationally symmetrical concave expression on the lateral surface of the roll neck and / or on the inner circumferential surface of the neck bushing.

A further embodiment of the invention provides that the lateral surface of the roll neck and / or the inner surface of the neck bushing in the region of its concave expression - seen in longitudinal section of the roller assembly - at least in sections in the form of a straight line, a sine curve, a polygonal curve R (x) of the lowest degree or a combination of these. To ensure a stable bearing seat for the pin bushing on the roll neck without radial play, the pin bushing and the roll neck - adjacent to the cavity in the axial direction - on adjacent bearing surfaces.

It is further provided that the contour of the lateral surface of the roll neck or the contour of the inner circumferential surface of the pin bush in the region of its concave expression - seen in longitudinal section of the roller assembly - in Transition region between two adjacent profile sections is continuous and differentiable. Advantageously, smooth transitions are thus created without edges between the individual profile sections of the profiling, so as to avoid the formation of indents, for example grooves, on the mutually acting lateral surfaces of the journal bushing and the roll neck, especially in the case of loading. Advantageously, this also counteracts the disadvantages of a possible notch effect.

Furthermore, it is provided that the contour of the lateral surface of the roll neck or the contour of the inner surface of the pin bushing in the region of its concave expression - seen in longitudinal section of the roller assembly - correlates with the distribution of the bearing force in the axial direction, so that under load locally as large as possible Flattening of the pin bushing is achieved in its elastic range, which leads to an increased load capacity of the roller assembly with unchanged size.

Furthermore, the invention provides that the lateral surface of the roll neck frustoconical and the inner circumferential surface of the pin bushing are complementary frusto-conical. Advantageously, the pin bushing can be easily mounted on the roll neck via the cone or dismantled again.

In an alternative preferred embodiment of the arrangement according to the invention it is provided that the lateral surface of the roll neck are cylindrical in shape and the inner circumferential surface of the pin bushing are designed to be complementary cylindrical. Advantageously, in this case, the journal bush is shrunk onto the roll neck to produce a frictional connection without radial play.

Furthermore, the invention provides that the roll is a back-up roll or an intermediate roll or a work roll for use in a roll stand.

According to a further embodiment it is provided that the arrangement comprises at least one chock with a bearing bush in which the pin bushing is slidably mounted with the roll neck or with the roller using a bearing oil film between the bearing bush and the pin bushing.

Overall, with the arrangement according to the invention a simple and cost-effective way created to replace existing roller assemblies, for example, within a rolling mill by roller arrangements according to the invention or exchange, to create a lifting capacity or an increase in performance of the storage without having to change the existing installation space. The arrangement according to the invention is easy to assemble. In case of repair, a simple and quick replacement is possible.

Further advantages and details of the invention will become apparent from the dependent claims and from the following description in which the embodiments of the invention shown in the figures are explained in more detail. In addition to the combinations of features listed above, features alone or in other combinations are essential to the invention.

Description of the figures

• Figur 1 eine Walze mit profilierter zylindrischer Zapfenbuchse;
• Figur 2 eine Walze mit profilierter konischer Zapfenbuchse; und
• Figur 3a bis
• Figur 3c unterschiedliche Profilverläufe für die Mantelfläche des Walzenzapfens und/oder der inneren Mantelfläche der Zapfenbuchse.
• Figur 4 Darstellung der elastischen Verformung an der Zapfenbuchse - Schnittdarstellung im Bereich des maximalen Hohlraums.

The invention will be described below with reference to FIGS FIGS. 1 to 3 described in detail. Show it:

• FIG. 1 a roll with profiled cylindrical pin bushing;
• FIG. 2 a roller with profiled conical pin bushing; and
• FIG. 3a to
• Figure 3c different profile profiles for the lateral surface of the roll neck and / or the inner circumferential surface of the neck bushing.
• FIG. 4 Representation of the elastic deformation on the journal bushing - sectional view in the area of the maximum cavity.

In the FIG. 1 a roll assembly 100 is shown for use, for example in the field of metallurgical technology, with a roll with a roll barrel 11 and at least one cylindrical roll neck 10. The roll neck 10 is rotatably mounted in a complementary to the roll neck 10 receiving bore of the pin bushing 20 and at least without radial play , To produce a frictional connection without radial clearance, the journal bush 20 is shrunk onto the roll neck 10, for example. Advantageously, it is provided between the roll neck 10 and the pin bushing 20 to arrange at least one driver element 23, for example in the form of a feather key or a correspondingly specially designed sliding block.

The inner circumferential surface 21 of the pin bushing 20 and / or the outer surface of the roll neck are provided with a concave contour, hereinafter also referred to as profiling 40, which is produced for example by turning and / or grinding. The profiling 40 is in the region of its concave shape - seen in longitudinal section of the pin bushing 20 - at least partially contoured in the form of a straight line, a sine curve, a polygonal curve R (x) nth degree or a combination of these. The Profiling 40 can also describe a simple parabolic waveform.

Due to the concave curves or forms 10 recesses are formed on the pin bushing 20 or on the roll neck, which form a radially encircling rotationally symmetrical cavity 12 between the pin bushing 20 and the roll neck 10 with attached pin bushing 20 on the roll neck 10 in the unloaded state. The cavity 12 is designed in the form of an annular gap in the sense of a circumferential rotationally symmetrical hollow profile. The outer circumferential surface 22 of the pin bushing 20 and the lateral surface 13 of the roll neck 10 are shown in the illustration shown FIG. 1 designed as an example cylindrical.

It can be provided to arrange the above-described profiling 40 on the lateral surface 13 of the roll neck 10 and to form the inner circumferential surface 21 of the journal bush 20 in a cylindrical manner. The profilings 40 described above can also be formed simultaneously both on the inner circumferential surface of the journal bushing and on the outer circumferential surface of the roll neck, preferably opposite one another.

To limit the Aufschiebeposition the pin bushing 20 when pushed onto the roll neck 10, a spacer ring 28 is arranged with a stop 25 between the end face of the roll bale 11 and the pin bushing 20. Alternatively, the roll bale 11 may be provided with a projection (not shown) at the front end as a stop 25, which is formed integrally with the roll bale. The pin bushing 20 is stretched after being pushed onto the roll neck 10 with a pressure shoulder ring 17 via a thrust bearing, which is optionally arranged to support the roll neck 10, and a nut 18 in the axial direction x against the spacer ring 28 and secured against axial displacement, the Roll neck at its end for receiving the pressure shoulder ring 17 with a hub shoulder 26 and then with a threaded pin 27 is provided for receiving the nut 18. In the FIGS. 1 and 2 is merely schematically the axial bearing inner ring 16 between the pressure shoulder ring 17 and the nut 18 shown. The nut 18 may additionally be secured against loosening with an anti-twist device 19, for example a lock nut.

The depth t of the profiling 40 or the size of the resulting cavity 12 between the pin bushing 20 and the roll neck 10 is adjusted in dependence on the maximum occurring bearing force F and the modulus of elasticity of the pin bushing 20 so that the volume of the cavity 12 is greater is formed, the greater the maximum bearing force F in the loaded state, the deformation of the pin bushing 20 remains exclusively in the elastic range. The actual tread depths t are in the micrometer (μm) range, preferably up to 1000 μm.

The wall thickness d of the cylindrical pin bushing is between 10 mm to 75 mm without consideration of an optional rotationally symmetric concave characteristic described below.

In addition, it can be provided that at least one chock 50 is provided with a bearing bushing 51 for receiving the pin bushing 20 with the roll neck 10, wherein between the bearing bush 51 of the chock 50 and the outer circumferential surface 22 of the pin bushing 20, a supporting oil film 30 is provided. This arrangement is also referred to as oil film storage. In a preferred embodiment, the inner circumferential surface of the bearing bush 51 is coated with a bearing metal lining, for example with white metal.

In another embodiment as shown in FIG FIG. 2 it is provided that the roll neck 10 is frusto-conical. The inner circumferential surface 21 of the pin bushing 20 is formed complementary to the ideal line (without profiling) of the frusto-conical roll neck 10. It is As described above, a profiling 40 on the inner circumferential surface of the pin bushing 21 and / or on the outer circumferential surface of the roll neck 13 is provided.

In this variant, the pin bushing 20 is pushed onto the roll neck 10 until the radial clearance between the pin bushing 20 and roll neck 10 is eliminated. Subsequently, the pin bushing 20, as before for FIG. 1 described, biased and secured against displacement.

In order to ensure a stable bearing seat for the pin bushing 20 on the roll neck 10 without radial clearance, the pin bushing 20 and the roll neck 10 - adjacent in the axial direction on both sides of the cavity - adjacent bearing surfaces 14.

The wall thickness d of the conical bushing 20 is at its thin end between 10 mm and 75 mm.

In addition, a lubricating film 31 is disposed between the pin bushing 20 and the roll neck 10 to avoid micro-cold micro-welding. The profiles 40 on the roll neck 10 or on the pin bushing 20 are in this conical embodiment as before to the FIG. 1 described, executed.

The FIGS. 3a and 3b describe in principle the roller assembly 100 with the roller and at least one pin bushing 20 for play-free and rotationally fixed receiving one of the roll neck 10. Here, the lateral surface 13 of the roll neck 10 and the inner circumferential surface 21 of the pin bushing 20 may be cylindrical or frusto-conical, wherein the respective lateral surfaces 13th , 21 are complementary to each other and adjoin each other without radial play.

The profiles 40 of the inner circumferential surface 21 of the pin bushing 20 and / or the lateral surface 13 of the roll neck 10 as shown in the Figure 3c describe by way of example various possibilities of mathematical functions R (x) of the nth degree which, depending on the load case, can also be used in combination with other profilings. In order to ensure a uniform edge-free transition in profile sections combined with one another, the profiling 40 in the transition region between two adjacent profile sections is formed continuously and differentially. It should be mentioned that in the Figure 3c shown curves do not describe the actually practicable profilings. The illustrated plurality of curve or profile sections is merely a schematic representation of different possible Profilierungsvarianten.

functionality

The operation of the invention will be described below with reference to FIG. 4 described in more detail.

Due to the resulting from the profiling 40 rotationally symmetrical cavity 12 between the pin bushing 20 and the roll neck 10 is formed between the pin bushing 20 and the roll neck an enlarged space in which the pin bushing 20 can expand at the location of the force.

Specifically, in the rolling operation in a rolling stand, the at least substantially vertical upward rolling force F _{w is} exerted on the upper (supporting) roll, while at the same time exerting an at least substantially vertically downward rolling force F _w on the lower (supporting) roll becomes. These rolling forces are transmitted from the roll bales half on the Rolling pin, which presses down the roll pins in the upper chock and down in the lower chock.

The rolling forces are transmitted according to an action chain from the roll neck on the journal, the bearing oil film between the journal and bearing bush and the bearing bush on the chock. From the chock, the rolling forces are further derived in the rolling mill, in which the chock is stored.

The chock and also mounted in the chock bearing bush should ideally be regarded as relentless and incompressible to the rolling forces. That is, the chock and the bushing catch the acting on them each half rolling forces F _{w / 2} (Aktio) completely by holding each the same amount, but oppositely directed bearing forces F _L (Reactio).

Already a loading of a roll neck during the rolling operation with a low rolling force F _w causes the roll neck 10 presses with the pin bushing 20 in the direction of the rolling force F _w against the supporting oil film 30 and this against the bearing bush 51 and the chock; please refer FIG. 2 , However, the pin bushing 20 encounters the incompressible supporting oil film 30, which in turn is prevented from deflecting in the direction of the rolling force by the unyielding bushing 51 and the unyielding chock 50. As a result, the pin bushing is prevented from deflecting in the direction of the rolling force by the opposing bearing force F _L.

The pin bushing 20 itself, in conjunction with the cavity 12 according to the invention, towards the roll neck 10, is the weakest link in the above-described chain of effects of the (rolling) force.

Because the journal bushing 20 can not escape the rolling force, in the event of loading during elastic rolling operation, the journal bushing 20 elastically deforms. The journal bushing 20 is replaced by the rolling force F _{w / 2} or the opposing bearing force F _L into the original cavity 12 deformed into it and is flattened. The flattening takes place at the maximum extent until the pin bushing 20 presses on the roll neck 10 and is supported by this. The pin bushing 20 adapts locally elastically to the profiling 40 of the roll neck and deforms after discharge back into the original state. By flattening the pressure-effective area between the pin bushing 20 and the bearing bush 51 is increased. Between the pin bushing 20 and the bearing bush 51, the supporting oil film 30 is arranged, which forms a so-called hydrodynamic oil film storage. Due to the enlargement of the pressure-effective surface, the roller arrangement according to the invention leads to an increase in the load bearing capacity of the hydrodynamic oil film bearing between the journal bush and the bearing bush.

In reality, the rolling force or the bearing force is not punctiform or linear, but in the form of a force mountain. The power mountains have a surface extent in the circumferential direction and in the axial direction. Due to the flattening of the pin bushing and the associated enlargement of the pressure-effective surface a significant increase in load capacity of the roller assembly is achieved for the area extended power mountains.

The roller assembly according to the invention also carries significantly more compared to a roller assembly in which the pin bushing is already connected in the unloaded state non-positively with bias, for example by shrinking, with the roll neck. The force required for the elastic flattening of the pin bushing force is lower due to the cavity according to the invention as in constructions with bias between Bearing bush and pin. For prestressed structures, greater forces are required to achieve the same deformation of the pin bushing.

In other words:

Because of the relatively thin wall thickness of the pin bushing 20, the deformation under load on the inner circumferential surface 21 of the pin bushing 20 without change, that is in the same direction on the outer lateral surface 22 of the pin bushing 20, and thus leads to an increase / broadening of the force acting opposite This in turn leads to a more uniform distribution of the lubricating film pressure, so that a larger force is absorbed, and can be spread wider without the peak pressure in the supporting oil film 30, the limits of the material of the bearing bush or exceeds a bearing metal lining on the bearing bush. Consequently, the arrangement according to the invention leads to an increase in the carrying capacity of the hydrodynamic lubricating film or oil film bearing between the journal bush 20 and the bearing bush 51.

LIST OF REFERENCE NUMBERS

100

roll arrangement

10

roll neck

11

roll barrel

12

cavity

13

Lateral surface of the roll neck

14

level bearing surface

15

central axis

16

Thrust bearing inner ring

17

Pressure shoulder ring

18

mother

19

locknut

20

pin bush

21

Inner surface of the pin bushing

22

outer surface of the pin bushing

23

dogging

25

attack

26

hub extension

27

threaded pin

28

spacer

30

carrying oil film

31

filming

40

profiling

44

Pressure distribution - state of the art

46

optimized pressure distribution

50

chock

51

bearing bush

R (x)

Profiling as a mathematical function

x

Coordinate in the axial direction

_FW

rolling force

F _L

bearing force

t

tread depth

d

Wall thickness of the pin bushing

Claims (9)

1. Roll arrangement (100) for use in metallurgy, comprising:

   a roll with a roll barrel (11) and two roll pins (10) and

   at least one pin bush (20) for reception of one of the roll pins (10) to be secure against rotation relative thereto and without radial play,

   characterised in that

   in the unloaded state an encircling rotationally symmetrical cavity (12) is formed between the pin bush (20) and the roll pin (10) at least in a sub-region.
2. Arrangement according to claim 1, characterised in that the cavity (12) is bounded by a rotationally symmetrical - as seen in the longitudinal section of the roll arrangement (100) - concave shape of the circumferential surface (13) of the roll pin (10) and/or of the inner circumferential surface (21) of the pin bush (20).
3. Arrangement according to claim 2, characterised in that the circumferential surface of the roll pin (10) and/or the inner circumferential surface (21) of the pin bush (20) is contoured in the region of its concave shape - as seen in longitudinal section of the roll arrangement (100) - at least in a section in the form of a straight line, a sine curve, a polygonal curve (R(x)) of nth order or a combination thereof.
4. Arrangement according to claim 3, characterised in that the profiling (40) of the circumferential surface of the roll pin (10) and/or the inner circumferential surface (21) of the pin bush (20) in the region of its concave shape - as seen in longitudinal section of the roll arrangement (100) - is continuous and differentiable in the transition region between two adjacent sections.
5. Arrangement according to any one of the preceding claims, characterised in that the volume of the cavity (12) is formed to be greater the higher the maximum bearing load in the loaded state as long as the deformation of the pin bush (20) remains in the elastic region.
6. Arrangement according to any one of the preceding claims, characterised in that the circumferential surface (13) of the roll pin (10) and the inner circumferential surface (21) of the pin bush (20) are formed to be frusto-conical.
7. Arrangement according to any one of claims 1 to 5, characterised in that the circumferential surface (13) of the roll pin (11) and the inner circumferential surface (21) of the pin bush (20) are formed to be cylindrical.
8. Arrangement according to any one of the preceding claims, characterised in that the roll is a backing roll or an intermediate roll or a work roll for use in a roll stand.
9. Arrangement according to any one of the preceding claims, characterised in that the arrangement further comprises:

   at least one chock (50) with a bearing bush (51), in which the pin bush (20) together with the roll pin (10) or with the roll is slidingly mounted with use of a supporting oil film (30) between the bearing bush and the pin bush (20).

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