EP0348711B1 - Device for axially shifting rolls in the stand of a rolling mill - Google Patents

Abstract

In the hitherto known devices, the axial shifting of rolls in the stand of a rolling mill is carried out on slideways, the sliding friction resistances of the hydraulic shifting machinery arranged externally on the roll stand which occur in the slideways having to be overcome by increased energy consumption. In addition, these roll-shifting devices are of complicated structure and are hard to get at and difficult to maintain owing to the pressure and lever elements which are arranged externally on the roll stand and project a long way outwards. According to the invention, these disadvantages are eliminated in a simple way by the fact that the inner bearing ring (5), fastened to the bearing journal (2) of the roll (1), of the radial bearing (3) in the form of a roller bearing is arranged so as to be axially moveable with respect to the outer bearing ring (7, 8) of the radial bearing (3), and that the shifting system is integrated in the axial bearing (4) as a hydraulic pressure system (16, 20, 22, 23).

Description

The invention relates to a device for the axial displacement of rolls in the stand of a rolling mill according to the preamble of claim 1; See GB-A 2 024 454.

In order to compensate or eliminate the undesirable and disadvantageous influences such as thermals, deflection of the work rolls or the set of rolls, wear, scoring on the roll surfaces etc. in order to achieve an optimally shaped rolled product, axial displacements of the rolls, especially the work rolls, are necessary . Therefore, as can be seen, for example, from DE-OS 35 21 180, a device for the axial displacement of rolls in roll stands has been designed, in which the rolls are held in special chocks via their radial and axial bearings, which in turn are held in the roll stands of the rolling stand arranged sliding guides and sliding carriages are slidably guided. For the axial displacement of the rollers are on the chocks hydraulic piston-cylinder units articulated, which are attached to the outside of the roll stand.

Since in this known device the axial displacement of the rollers takes place in so-called slideways, additional and relatively high axial forces have to be applied by the hydraulic piston-cylinder units due to the sliding friction which occurs, which is associated with increased energy and cost expenditure. Furthermore, this known shifting device of rollers is complicated in terms of its construction and is difficult to access and correspondingly difficult to maintain due to the hydraulic and mechanical shifting elements arranged on the outside of the roller stand and projecting outward to the outside.

Furthermore, from US Pat. No. 4,491,005 a device for axially displacing the work rolls in the stand of a rolling mill is known, in which the rolls with their bearings are arranged so as to be axially movable via chocks guided in slideways. Since the axial resistance of the rollers also has to overcome the frictional resistance in the slideways of the hydraulic displacement units, which are also arranged on the outside of the roll stand, by increased energy expenditure, this known roller displacement system also has the same disadvantages afflicted, such as the roller displacement device known from DE-OS 35 21 180.

From GB-A-2 024 454 a device for the axial displacement of rolls in the stand of a rolling mill is known, in particular the work rolls of a hot or cold rolling mill, the rolls being mounted in radial bearings at their ends designed as bearing journals and additionally provided with an axial bearing are over which a displacement system acts on the roller. In doing so
On the one hand, solutions were shown in which the rollers and their bearings are moved in chocks in the stand. On the other hand, FIG. 4 shows that the bearing chock is fixed in the frame and the inner bearing ring of the radial bearing, which is designed as a roller bearing and is attached to the bearing journal of the roller, is axially movable relative to the outer bearing ring of the radial bearing or vice versa. The thrust bearing is very complicated with a large number of individual actuators arranged within its housing, which leads to the fact that these, including the integrated displacement sensors, are extremely difficult to access and difficult to maintain.

Based on these known devices, the object of the invention is to provide a device for the axial displacement of rolls in a stand of a rolling mill, which is free from these known disadvantages mentioned above and is particularly characterized by its very simple construction and easy access to the hydraulic and mechanical components.

This object is achieved in a device for the axial displacement of rolls in the stand of a rolling mill according to the preamble of claim 1 with an embodiment according to the features specified in the characterizing part.

Characterized in that the inner bearing ring of the roller bearing designed as a roller bearing is axially movable relative to the outer bearing ring, practically no sliding friction occurs when the roller is axially displaced, since the axial movement of the inner bearing ring relative to the outer bearing ring of the between the Bearing rings located bearing bodies is compensated for by their rolling movements. It comes with
the axial displacement of the roller at most to a low bearing roller friction in the radial bearings of the roller, the overcoming of which, however, hardly requires any significant axial forces. The axial forces to be applied by the displacement system for axially displacing the roller can therefore be kept lower in the bearing system on which the invention is based in comparison with roller displacement devices with axially displaceable chocks, and energy and costs can thereby be saved, in particular if, as in the arrangement on which the invention is based, the displacement system as a hydraulic pressure system in Thrust bearing is integrated.

According to the invention, a further improvement and simplification is achieved in that the hydraulic pressure system integrated in the axial bearing consists of a double-acting piston-cylinder unit, the outer bearing ring of the axial bearing is designed as a piston and the bearing housing surrounding it is designed as a cylinder.

Through this design and arrangement of the hydraulic pressure system in the axial bearing, an immediate, direct and almost smooth transmission of the compressive forces acting in the axial direction from the pressure system to the roller is achieved in a particularly simple manner, and a structurally simple, particularly compact and closed to the outside Roll shifting system presented, which is not only more easily accessible and easier to maintain than the previously known roll shifting devices, but is also dynamically faster and safer in its operation.

In a further embodiment of the invention, the outer bearing ring designed as a piston and the bearing housing of the axial bearing designed as a cylinder are made in several parts. In this way, the maintenance and replacement of the bearing or the hydraulic pressure system or parts thereof considerably relieved.

In order to be able to safely and permanently absorb the pressure loads emanating from the rollers during operation of the rolling mill, which often act on the radial bearings with strongly fluctuating intensity, the radial bearings are, according to a further advantageous embodiment of the invention, with several, in rows in the axial direction at a distance bearing bodies arranged from each other. It is also particularly expedient to use a cylindrical roller bearing or a radial bearing designed as a needle roller bearing.

The device for the axial displacement of rolls in the stand of a rolling mill according to the invention is explained in more detail below with reference to an embodiment shown schematically in the drawing.

The drawing shows a section of a roller (1) of a rolling mill with a bearing journal (2) which is tapered in a step-like manner at the left end and is mounted in a radial bearing (3) and an axial bearing (4) shown in longitudinal section. The right end of the roller (1), which is not shown in the drawing, is provided with a single-stage bearing journal which is mounted in a radial bearing of the same design as the radial bearing (3).

These radial bearings (3) consist of an inner, relatively long, attached to the bearing journal (2) trained bearing ring (5) and two outer bearing rings (7, 8) arranged in the stand (6) of the rolling mill and from the intermediate bearing bodies (9) arranged in four rows at a distance from one another. This inventive design of the radial bearing (3) very advantageously allows an axial displacement (arrows 10) of the roller (1) together with the inner bearing ring (5) relative to the outer, two-part bearing ring (7, 8) without it to the undesirably disadvantageous, energy-consuming sliding friction between the bearing rings (5) and (7, 8), since the axial movement of the inner bearing ring (5) relative to the outer bearing ring (7, 8) is absorbed by the bearing bodies (9) and into one Rolling motion is converted from very little friction. The radial bearings (3) are expediently designed as cylindrical roller bearings in order to be able to reliably absorb and compensate for the high loads occurring on the rollers during operation of the rolling mill. Of course, other roller bearings such as needle roller bearings, barrel roller bearings, etc. in a single or multi-row arrangement can also advantageously be used as radial bearings.

For the axial displacement of the roller (1) in the stand (6) of the rolling mill, according to the invention, the axial bearing (4) with integrated hydraulic bearings, which is also shown in longitudinal section in the drawing and is arranged on the left-hand side and is firmly connected to the stepped bearing journal (2) Printing system provided. This axial bearing (4) consists of an inner bearing ring (11) attached to the bearing journal (2), which counteracts axial displacement on the journal (2) is secured by support and retaining rings (12, 13, 14, 15), and from an outer bearing ring (16) with intermediate support rings (17) and bearing rollers (18). The outer bearing roller support ring (17) is supported in the axial direction by a ring (19) with a flange which is firmly connected to the outer bearing ring (16). The outer bearing ring (16) of the axial bearing (4) is provided on the outside with an annular extension (20) with a sealing ring (21) which is slidably guided in an axially movable manner in a cylindrical recess (22) of the bearing housing (23). On the outer end face of the bearing housing (23), which in turn is attached to the roll stand (6), an annular disc (24) with a sealing ring (25) is attached, which seals the cylindrical recess (22) in the bearing housing (23) to the outside in a pressure-tight manner. The outer bearing ring (16) with the ring-shaped extension (20) and the bearing housing (23) with ring washer (24) together form the double-acting piston-cylinder unit of the hydraulic pressure system, the ring-shaped extension (20) functioning as the piston and the recess ( 22) in the bearing housing (23) performs the function of the cylinder.

In the bearing housing (23) for the supply of the hydraulic pressure medium in this double-acting piston-cylinder unit holes (26, 27) are arranged, which open on both sides of the annular extension (20) in the recess (22) of the outer bearing ring (23) . Pressure pipes (28, 29) are connected to these bores (26, 27) on the outside Interposition of a slide control (30) with a pump unit, not shown in the drawing, and via which the hydraulic double-acting piston-cylinder unit is pressurized with pressure medium and moves the roller (1) in the axial direction. This functionally known, electromagnetically operating slide control (30) is connected via electrical lines (31, 32) to a displacement sensor (33) which is attached to an annular cover (34) arranged on the bearing housing (23).

With the aid of the travel sensor (33), the axial displacement path of the roller (1), which in practice lies between about 0 and 400 mm, can be easily monitored and adjusted and / or adjusted at any time even during the rolling operation. To protect the bearings, bearing parts and the hydraulic pressure system from dust or other contamination, the bearing housing (23) is sealed to the outside by an end cover (35) and between the roller body (1) and the roll stand (6) there is a rubber for this -elastic cuff (36) arranged.

In addition, the device designed according to the invention can be used not only very advantageously for the axial displacement of work rolls and backup rolls in the stand of a hot or cold rolling mill, but also in rolling mills, for. B. for crushing hard materials or the like. The device according to the invention is particularly characterized by its very simple and compact, after externally closed, easily accessible, easy to assemble or disassemble and easy to maintain design that can be retrofitted to existing rolling mills at any time. In addition, the roller shifting device according to the invention can be used very advantageously in duo, four-high, six-high and special rolling mills.

The measures according to the invention are not limited to the exemplary embodiment shown in the drawing figure. For example, without departing from the scope of the invention as drawn by the claims, the radial bearings can have any shape, for example several radial bearings can also lie one above the other. The respective structural design is left to the person skilled in the art to adapt to the specific use.

Claims (4)

1. Device for the axial displacing of rolls (1) in the stand (6) of a rolling mill, particularly of the working rolls of a hot or cold rolling mill, wherein the rolls are mounted at their ends, which are preferably constructed as bearing pins (2), in radial bearings (3) and are additionally provided at one end with an axial bearing (4), by way of which a displacing system engages at the roll (1), wherein the inner bearing ring (5), which is fastened to the bearing pin (2) of the roll (1), of the radial bearing (3) constructed as roller bearing is arranged to be axially movable relative to the outer bearing ring (7, 8) of the radial bearing (3) or conversely and the displacement system is integrated as hydraulic pressure system (16, 20, 22, 23) in the axial bearing (4), characterised thereby that the hydraulic pressure system (16, 20, 22, 23) integrated in axial bearing (4) consists of a double-acting piston-cylinder unit (20, 23), wherein the outer bearing ring (16) of the axial bearing (4) is constructed as piston (20) and the bearing housing (23) surrounding it as cylinder (22).
2. Device according to claim 1, characterised thereby that the outer bearing ring (16) constructed as piston (20) and the bearing housing (23) constructed as cylinder (22) of the axial bearing (4) are constructed to be multi-part.
3. Device according to claim 1 or 2, characterised thereby that the radial bearing (3) is constructed as cylinder roller bearing or needle roller bearing.
4. Device according to one or several of the preceding claims, in particular according to claim 1, characterised thereby that the radial bearings (3) are equipped with several bearing bodies (9) arranged spaced-apart in rows.

Images