JPH0237449Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Field of Application> The present invention relates to a backup bearing for a roller leveler that can increase load capacity.

<Prior Art> FIG. 2 shows a broken cross-sectional view of a four-layer hot roller leveler. The hot roller leveler has a plurality of upper and lower leveling rolls 1, 1 and 2 disposed above and below the material A to be straightened. The material to be straightened A is made into a flat plate by repeatedly bending it between two parts. In this hot roller leveler, if the straightening load is supported only by the leveling roll bearings that support the upper and lower leveling rolls 1 and 2, the load capacity cannot be sufficiently large. 2 is supported by back-up rolls 3 and 4, that is, a four-layer roller leveler type is adopted.

By the way, since the temperature of the material to be straightened in a hot roller leveler is generally as high as 500 to 1000°C, the leveling roll and back-up roll are cooled with cooling water. For this reason, the material of the back-up roll is stainless steel, which has high corrosion resistance and wear resistance.
The hardness of the outer circumferential surface of the back up roll, which is the contact surface with the leveling roll, is set to Shore hardness H _S =about 50 to 60 (equivalent to Rockwell C scale hardness H _R C = around 40) to prevent thermal cracks.

Here, the structure of a conventional back-up roll bearing is shown in FIGS. 3 to 7. Bearing 6 shown in Figure 3
is a rolling bearing that rotatably supports both ends of a back-up roll 5 of a shaft-rotating type. The load of the back-up roll 5 is received as a correction reaction force by a bearing stand 7 that supports the back-up roll 5 via a bearing 6.

The bearing 6 shown in FIG. 4 is the same as the one shown in FIG. We are working to improve its corrosion resistance and abrasion resistance. In this case as well, the load of the backup roll 8 is supported by the bearing stand 7 via the bearing 6.

Further, the bearing 10 shown in FIG. 5 is a rolling bearing, and is interposed between a fixed shaft 11 installed between both bearing stands 12 and a hollow stainless steel back-up roll 9. . The back-up roll 9 is rotatable around the fixed shaft 11 via the bearing 10, and the load is carried by the bearing 10,
It is supported by a bearing stand 12 via a fixed shaft 11.
The bearing 10 shown in FIG. 6 is also similar to that shown in FIG.
In No. 3, a stainless steel weld overlay 13a is applied to the outer circumferential surface of the base metal of a chromium-molybdenum alloy steel to improve its corrosion resistance and wear resistance. In this case too,
The load of the backup roll 13 is supported by a bearing stand 12 via a bearing 10 and a fixed shaft 11.

By the way, the shaft fixed type bearing shown in FIG. 7 is thought to be able to increase the load capacity the most among conventional bearings, and as shown in the figure, this is because the bearing outer ring 15 and cylindrical rollers 16 are made of bearing steel. It consists of
The fixed shaft 17 also serves as the inner ring of the bearing. Therefore, the size of the cylindrical rollers 16 can be increased, and the load capacity can be increased accordingly. The hollow stainless steel back-up roll 14 is rotatably supported by a fixed shaft 17 via a bearing, and the load is transferred via the bearing, that is, the bearing outer ring 15 and cylindrical rollers 16, and the fixed shaft 17. It is supported by a bearing stand 18.

<Problems to be solved by the invention> Incidentally, in recent years, there has been a demand for high-load hot roller levelers, but conventional back-up roll bearings as shown in Figs. However, there was a problem in that the load capacity could not be increased to the maximum.

Therefore, an object of the present invention is to provide a backup bearing for a roller leveler that can maximize the load capacity.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention provides a back-up bearing for a roller leveler comprising a roller bearing that rotatably supports a hollow back-up roll on a fixed shaft. The roll itself also serves as the outer ring of the bearing, with the outer circumference having low hardness and the inner circumference having high hardness.

<Function> In this way, no special parts are provided as the bearing outer ring,
By making the back-up rolls double as the bearing outer ring, the bearing roller dimensions can be increased by the size of the bearing outer ring, which was previously required as a dedicated part, and this allows the bearing's load capacity to be maximized. can. In addition, the outer periphery of the back-up roll has a low hardness, which helps prevent thermal cracks.
Since the inner peripheral side has high hardness, the load capacity can be further increased.

<Example> An example of the present invention will be described below based on FIG. 1.

FIG. 1 is a broken cross-sectional view showing a backup roll according to the present invention. In the figure, 21 is a fixed shaft installed between both bearing stands 22, and this has a plurality of (four in the illustrated example) a fixed shaft. A hollow backup roll 19 is rotatably supported via rollers 20.
That is, in this case, the back-up roll 19 also serves as the outer ring of the bearing, and the fixed shaft 21 also serves as the inner ring of the bearing. Therefore, the dimensions of the rollers 20 can be increased by the size that the inner and outer rings of the bearing occupy between the fixed shaft 21 and the back-up roll 19, which was required in the past, and the load capacity is correspondingly increased, making it more suitable for the roller levelers of recent years. Can meet load demands. On the other hand, in the one shown in FIG. 7, which seems to have the largest load capacity among conventional back-up bearings, the back-up roll 14 and the bearing outer ring 15 are separate parts (different materials), so the rollers 16 Due to the limited dimensions of the bearing, it was not possible to maximize the bearing load capacity.

Furthermore, in the back-up bearing structure according to the present invention, the back-up roll 19 also serves as the outer ring of the bearing.
The hardness of the outer circumferential side, that is, the contact surface with the leveling roll (not shown) is reduced to prevent the occurrence of thermal cracks, and the hardness of the inner circumferential side, that is, the rolling surface of the roller 20 is increased. We are trying to increase the load capacity. In the conventional backup bearing shown in FIG. 7, the material of the backup roll 14 is stainless steel with low hardness (about H _R C = 40) to prevent thermal cracking, and the material of the bearing outer ring 15 is The bearing steel (SUJ) with high hardness (H _R C = approximately 60) is used to increase the bearing load capacity.

As mentioned above, Backup Prowl 19 is:
A hardness difference is provided on the outer circumference side, and the manufacturing method is as follows. That is, first of all, Backup Prowl 19
The whole is tempered by heat treatment such as quenching and tempering, and its hardness is set to H _S =40 to 50 (H _R C = about 32). Next, the outer peripheral surface of the back-up roll 19 is induction hardened to have a hardness of _HS = 50 to 60 (H _R C = 40).
Finally, the inner circumferential surface is induction hardened to a hardness of about H _R C = 60.

In the above embodiment, the fixed shaft 21 also serves as the bearing inner ring, but a bearing outer ring independent of the fixed shaft 21 may be separately attached. however,
In this case, the load capacity is lower than that of the embodiment. Further, the rollers 20 may be of various types other than cylindrical rollers, such as tapered rollers and needle rollers. Furthermore,
Various materials can be considered for the rollers 20 and the fixed shaft 21, such as bearing steel (SUJ) and stainless steel (SUS), but not limited to these, any material can be used.

<Effects of the invention> As is clear from the above description, according to the present invention, in a roller leveler backup bearing comprising a roller bearing that rotatably supports a hollow backup roll on a fixed shaft, the backup roll itself The roller leveler back-up bearing also serves as the outer ring of the bearing, and the outer circumferential side thereof has a low hardness and the inner circumferential side has a high hardness, so that the load capacity of the roller leveler backup bearing can be increased.

[Brief explanation of the drawing]

FIG. 1 is a broken sectional view showing a backup bearing according to the present invention, FIG. 2 is a broken sectional view of a roller leveler, and FIGS. 3 to 7 are broken sectional views showing a conventional backup bearing structure. In the drawings, 19 is a back-up roll, 20 is a roller, 21 is a fixed shaft, and 22 is a bearing stand.

Claims (1)

[Scope of utility model registration request] A roller bearing in which a hollow back-up roll is rotatably supported on a fixed shaft, the back-up roll itself serving as the outer ring of the bearing, and its outer circumferential side has a low hardness and its inner circumferential side has a high hardness. A back-up bearing for roller levelers featuring: