JPH03144109A - Backup roll bearing - Google Patents

Abstract

PURPOSE:To improve wear resistance and corrosion resistance and impart long-time stable quality and function by flame-coating the outer periphery of a roll with ceramic composite material to give the inner periphery of the roll by high frequency quenching and thus local surface hardening into a raceway surface. CONSTITUTION:A backup roll bearing comprises a roll 10, a needle bearing 30, a deep groove ball bearing 40 and a cover 50. For the roll 10, the outer periphery of a base material 12 is flame-coated with ceramic composite mateiral 14. The inner periphery 18 of the roll 10 is formed as a direct raceway surface. The roll 10 has the inner periphery 18 given high frequency quenching in a preset range and thus hardening. It is thus possible to improve wear resistance and corrosion resistance and provide long-time stable quality and function.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bearing for a bank-up roll of a scale breaker device for steel equipment.

[Conventional technology]

A scale breaker device is a device that cold-straightens a rolled plate material to improve its flatness to a certain level.

The third example of a long type backup roll bearing
Referring to the figure, a needle roller with cage (3) is interposed between the roll (1) and the shaft (2), and the inner circumferential surface of the roll (1) and the outer circumferential surface of the shaft (2) are directly orbited. It is a face. The roll (1) is made of bearing steel or the like, and the raceway surface portion of the inner peripheral surface and the outer peripheral surface are hardened by heat treatment.

[Problem to be solved by the invention]

The working atmosphere of the scale breaker equipment is such that the plate material rusts,
The conditions are extremely poor, including the contamination of foreign matter, the use of a large amount of water, and the corrugated shape of the planks. Therefore, even though the roll is made of bearing steel, the roll undergoes dimensional changes and deformation due to corrosion, wear, etc. in a very short period of time, and becomes unusable. Here, a short period of time depends on the conditions, but generally it is about 1f for the roll diameter from 20 days of operation to 1 month.
It wears out quickly, around i. Naturally, as a countermeasure to this, it is necessary to replace the roll, remanufacture it, or replace it with a new one, which requires a huge amount of cost and time to maintain the device.

Therefore, an object of the present invention is to improve the wear resistance and corrosion resistance of a scale breaker device backup roll bearing so that it can exhibit stable quality and function over a long period of time.

[Means to solve the problem]

This invention has solved this problem by thermally spraying a ceramic composite material that has both wear resistance and corrosion resistance onto the outer peripheral surface of the bank ambrol.

An example of such a ceramic composite material is a composite material of carbide ceramics+Cr-Ni-Fe alloy. Steel or iron such as 535C1SUJ2 can be used as the roll base material.

As a thermal spraying method, a welding overlay method can be adopted in which the base material is brought into a molten state and the Hesera-based composite material is overlaid thereon.

[Effect]

The ceramic composite material has a hardness of Hs80 to 85 and is excellent in heat resistance, corrosion resistance, and wear resistance. By adopting the weld build-up method for thermal spraying of ceramic-based composite materials, the adhesion strength to the base material is high, and there is no problem of peeling like with ordinary thermal sprayed materials. The finish of the sprayed surface can be polished with a general grindstone, so desired dimensions and accuracy can be easily achieved.

However, since the temperature of the roll base material reaches around 1000° C. during thermal spraying of the ceramic composite material, the roll base material cannot be heat treated. This is because the structure changes due to the temperature increase during thermal spraying, impairing the effect of heat treatment. Further, even if heat treatment is performed after thermal spraying, it will affect the welding strength and the like of the ceramic composite material.

〔Example〕

As mentioned above, since the roll base material cannot be heat treated,
In carrying out the present invention, different embodiments may be considered regarding the type of raceway surface to be provided on the inner diameter side of the roll. This will be explained below with reference to the drawings. In the drawings, the same reference numerals indicate substantially the same members or parts throughout the drawings.

First, the backup roll bearings shown in Fig. 1 include a roll (10), a shaft (20), and a needle bearing (30).
, deep groove ball bearing (40) and cover (50)
This is an assembly with a rotating outer ring.

The roll (10) has improved wear resistance and corrosion resistance by thermally spraying a ceramic composite material (14) on the outer peripheral surface of a base material (12). Ceramink composite material (14
) is carbide ceramic 60% + Cr-Ni- in this case.
It is a composite material of 40% Fe alloy and has a wall thickness of 2f1 or more. Roll (the outer diameter shape of 10 is 16 mm without missing on both sides passed as a scale breaker device backup roll)
), and the ceramic composite material (step 4) is welded to the entire length of the roll.

The roll base material (12) is not subjected to heat treatment, and a separate bearing ring (36) is press-fitted into the inner peripheral surface. A needle roller (32) with a retainer (34) is inserted between the bearing ring (36>) and the shaft (20), forming a needle bearing (30).The main load M (radial load) is The load is applied by needle rollers (32), and the induced thrust is received by deep groove ball bearings (40) located on both sides.
40) has a structure that does not receive radial loads.

Seal (42) and cover (50) of deep groove ball bearing (40)
> to provide a sealing effect, and a predetermined amount of grease that has passed the characteristics of the backup roll is sealed inside.

Next, in the backup roll bearing shown in FIG. 2, the inner circumferential surface (18) of the roll (10) is directly used as the raceway surface. That is, this bank-up roll bearing includes a roll (10), a shaft (20), a needle roller (32) with a cage (34), a deep groove ball bearing (40), and a seal (4).
2) An assembly whose main components are a cover (50), and a retaining ring (44), which is used in an outer ring rotation format.

The roll (10) has an inner peripheral surface (
18) The predetermined area is hardened by induction hardening.

In terms of quality and functionality, it is important for bank-up roll bearings to be manufactured with extremely high dimensional accuracy and rotational accuracy as a bearing device.
In the illustrated embodiment, the roll (10) and the separate bearing ring (
Due to the dimensional accuracy and rotational accuracy of each of the needle bearings (30) including 36), it is necessary to assemble them while carrying out a lot of management such as selection and combination of uneven thickness. Therefore, production efficiency and dimensional accuracy as a bearing device There are problems in ensuring that In this respect, as shown in Fig. 2, by directly using the inner circumferential surface (18) of the roll (10) as the raceway surface without using a separate raceway, the press-fitting process can be performed with the upper pressure hole of the selected combination. There is no need for management, and since there is no bearing ring, there is greater freedom in design, making it possible to design a needle roller with cage that is optimal for the usage conditions, and increasing the rated load. In addition, since a separate bearing ring is not used, it is possible to achieve a high level of stable quality in terms of dimensional accuracy, and production efficiency is dramatically improved.

〔Effect of the invention〕

The bearing for bank-up rolls of this invention has wear resistance due to the fact that a cera-main ivy composite material is thermally sprayed on the outer peripheral surface of the roll.
Corrosion resistance is improved and stable quality and functionality can be demonstrated over a long period of time. Therefore, according to the present invention, there is no need to replace the rolls as frequently as in the past, and maintenance is simplified, making it possible to significantly reduce running costs.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view of a backup roll bearing showing an embodiment of the present invention, FIG. 2 is a half-sectional view of a backup roll bearing showing another embodiment, and FIG. 3 is a half-sectional view of a conventional backup roll bearing. It is a half sectional view. 10: Roll 12: Base material 14: Ceramic composite material 18: Inner circumferential surface (raceway surface) 20: Shaft 32: Needle roller patent application Artificial Nutie Co., Ltd. Agent Shogo Ebara

Claims (2)

[Claims] (1) In a backup roll bearing consisting of a roll, a shaft, and a needle roller with a cage interposed between the two, the inner peripheral surface of the roll is coated with high frequency A backup roll bearing characterized by having a raceway surface that is locally hardened by quenching. (2) The backup roll bearing according to claim 1, wherein the outer bearing ring is fitted onto the inner circumferential surface of the roll.