Rolling contact bearing arrangement for rollers in continuous casting plants

Abstract

A rolling contact bearing arrangement for two axially adjacent rollers, e.g. for use in a continuous casting plant. The rollers are each mounted via two rolling contact bearings, wherein the two central adjacent rolling contact bearings are arranged within the hollows at the inner ends of the rollers. The rotating bearing outer ring bearing the roller and the stationary bearing inner ring being supported by a common axle journal for both bearings, which is held in a supporting block. This arrangement enables the distance between two axially adjacent rollers to be minimized and the cast material or slab may sag less at this point.

Description

FIELD OF THE INVENTION

[0001] The invention relates to the rolling contact mounting of rollers for continuous casting plants.

BACKGROUND OF THE INVENTION

[0002] In continuous casting plants, the cast strand (the slab) has to be well supported by rollers during casting in order that the slab does not sag. To support the slab, therefore, thin rollers are used, which are spaced apart at short intervals in the direction of flow of the slab, to support the slab. To reduce the sag of the thin rollers in the radial direction (that is, perpendicular to the direction of flow of the slab), the rollers are additionally supported. The thin rollers in the axial direction of the rollers across the slab are separated in the axial direction into two axially adjacent rollers. The rollers usually are provided on both axial sides with a journal in which the rollers are mounted in a bearing block via rolling contact bearings. At the point at which the two central journals of axially adjacent rollers are supported in rolling contact bearings or bearing blocks located beside one another, the slab cannot be guided. This produces a problem that during the casting process, the slab may sag between two axially adjacent rollers.

[0003] However, there are also designs in which the two axially adjacent rollers are produced from one piece. In order to mount this roller, radially divisible rolling contact bearings are used. The problem with a continuous roller, of one piece, is that this roller is more complicated to fabricate, and special rolling contact bearings are required for mounting the central bearing point.

SUMMARY OF THE INVENTION

[0004] Objects of the invention are to provide a mount for rollers of continuous casting plants which are simple to produce and in which the free space between two axially adjacent rollers is as small as possible.

[0005] The objects are achieved by the invention which improves the journals between two axially adjacent rollers, improves the supporting connection and improves the cooling thereof.

[0006] The essential element of the invention is that the rolling contact mounting between axially adjacent rollers is displaced into the roller. In this application, the outer ring then rotates with the roller and the inner ring is arranged on the axle journal. The interspace between two axially adjacent rollers is therefore reduced to the width of a supporting block in which the axle journal is supported.

[0007] A countercurrent cooling system is used, which comprises two separate spiral or helical cooling ducts. In the first cooling duct, the cooling flow takes place and the return flow takes place in the second cooling duct. The two cooling ducts are connected to each other on one axial side of the roller, in order that the cooling medium can flow from the first cooling duct into the second cooling duct. Owing to the flat design of the two ducts, the rolling contact bearing within the roller can be designed with a large external diameter. A further advantage of this countercurrent cooling system is that the temperature differences along and within the roller should be small.

[0008] Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 shows an arrangement of rollers in a continuous casting plant in the prior art.

[0010] FIG. 2 shows a roller mounting according to the invention with countercurrent cooling.

[0011] FIG. 3 shows the functioning of the countercurrent cooling.

DETAILED DESCRIPTION OF THE INVENTION

[0012] FIG. 1 shows an arrangement of rollers for a continuous casting plant in the prior art. An upper row of rollers is illustrated. The cast material or the slab 14 is located under this row. The rollers 1, 1a in the continuous casting plants have to support the slab 14 over short intervals between rollers (in the direction of flow of the slab). For this reason, the roller diameters are kept small. Because of their small diameter, the rollers are divided along the axial direction 1, 1a and are mounted intermediate their length, at 15, in order that these rollers 1, 1a not sag excessively in a radial direction (perpendicular to the direction of flow of the slab). In this arrangement, the two rollers have journals 2 at both ends of each roller. These end journals 2 are mounted in rolling contact bearings 9, 15. At the points where the rolling contact bearings 15 are arranged, the slab 14 cannot be supported and may sag. Adjacent sets of rollers have the intermediate mounting 15 placed at different points along the roller axes, in order that the slab not always sag at the same axial point across the arrangement.

[0013] FIG. 2 illustrates the inventive roller 1, 1a with rolling contact mountings 9, 11, 12. The rolling contact bearings are arranged inside the hollow of the rollers near their axial ends at the central bearing points 11, 12. There is an axle journal 13 through the central bearing block 10 which supports the journal 13. The first and second central rolling contact mountings (self-adjusting roller bearings or cylindrical roller bearings) 11, 12 are supported on the journal. The outer ring of the rolling contact bearings 11, 12 rotates with the respective rollers 1, 1a.

[0014] Cooling of the axially outer roller 1 is shown in the section view. From the feed 3, cooling liquid flows into the spiral (helical or thread-like) first duct 4 in the outer region of the roller 1 and then out the second outlet duct 5. The ducts are just below the shell of the roller. At the opposite end of the roller 1, there is a connection 6 between the first and the second cooling ducts. After the cooling medium has flowed through the connection 6, it flows back through the second spiral helical cooling duct 5. The arrow tips and arrow ends identify the directions of flow within the cooling ducts. The cooling principle corresponds to the countercurrent cooling principle (for equalization of the temperature along the roller axis). The cooling medium then flows out of the roller 1 through an annular duct 7. The ducts define a flat, spiral cooling system 4, 5, which enables the rolling contact mountings in the rollers to be large in their external diameters. The outer bearing blocks 8 and the central supporting block 10 are cooled by respective separate cooling circuits 8a, 10a. The inlet and outlet of the cooling medium, and also the outer rolling contact mounting of the second roller 1a of all of these cooling circuits, are not illustrated but correspond to the principle of the first roller 1.

[0015] FIG. 3 illustrates the countercurrent cooling principle showing the two cooling ducts 4, 5 arranged spirally in countercurrent relation to each other. On one side of the rollers 1, 1a, the two spiral cooling ducts 4, 5 are connected to each other via a connecting piece 6. On the opposite side, the feed 3 and the outlet 7 of the cooling medium are provided (but not shown). The arrows show the direction of flow of the cooling medium within the first 4 and the second 5 cooling duct.

[0016] Although the present invention has been described in relation to a particular embodiment thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.

Claims

1. A rolling contact bearing arrangement for two axially adjacent rollers, comprising:

each roller has a respective outward end opposite and away from the adjacent roller and each outward end is supported for rotation, each roller has an inward end toward the inward end of the adjacent roller, the adjacent rollers being hollow at least toward their inward ends;

a respective rolling contact bearing located in each of the hollows in the inner ends of the adjacent rollers, each contact bearing having an outer ring bearing the respective roller and rotating therewith, and each bearing having an inner ring inward of the outer ring, and bearing elements between the inner and outer rings allowing for relative rotation;

a common axle journal disposed inside and supporting both of the inner rings of the adjacent rollers.

2. The bearing arrangement of claim 1, further comprising a supporting block supporting the common axle journal.

3. The bearing arrangement of claim 1, wherein each of the contact bearings is near the axially inward end of the respective rollers.

4. A rolling contact bearing arrangement for a continuous casting plant, comprising:

a plurality of sets of two axially adjacent rollers, each set of axially adjacent rollers being spaced apart from adjacent sets of the rollers in a radial direction and the roller sets being adapted to support a slab being cast;

each of the sets of axially adjacent rollers includes two axially adjacent rollers and a respective rolling contact bearing arrangement according to claim 1 for the two axially adjacent rollers.

5. The bearing arrangement of claim 1, wherein the rollers have an outer surface and a cooling device at the outer surface of the roller.

6. The bearing arrangement of claim 5, wherein the cooling device comprises a first helical, thread-like cooling duct for in feed of coolant and a second thread-like cooling duct for discharge of coolant, and the ducts being arranged parallel to each other, and the first duct being connected to the second duct to define a flow circuit of coolant.

7. The bearing arrangement of claim 6, wherein the first duct is connected for in feed and the second duct is connected for discharge of coolant at the outer end of the rollers and the first and second ducts are connected to each other toward the inner ends of the rollers, so that cooling medium can flow from the first duct into the second cooling duct and along the axially length of each of the rollers.

8. The bearing arrangement of claim 7, wherein the rollers have outer shells and the cooling ducts are radially inside the outer shells thereof.