Bearing box of rotating roller, cooling method of bearing box of rotating roller, continuous casting machine of steel, and continuous casting method of steel

Abstract

The present invention provides a bearing box of a rotating roller used in a high-temperature environment such as radiant heat, which can efficiently cool the entire width of the bearing and the oil seal using cooling water. The bearing box of the rotating roller of the present invention is provided with a bearing (2) and a sealing part (3, 4) inside, and the rotating roller is used to support or transport a high-temperature object. The bearing box (1) of the rotating roller (21) is characterized in that a cooling jacket (10) is provided on the outer peripheral side of the bearing box in a manner that includes at least a part of the axial range of the bearing and at least a part of the axial range of the sealing part. The cooling jacket has a cooling water inlet (11) and a cooling water outlet (12), and the bearing box is cooled by cooling water supplied from the cooling water inlet to the cooling jacket.

Description

Technical Field

[0001] The present invention relates to a bearing box of a rotating roll used in a high temperature environment such as radiant heat, such as a bearing box for rotating and supporting a casting support roll of a continuous casting machine, and a cooling method for the bearing box of the rotating roll. In addition, it also relates to a steel continuous casting machine having a rotating roll supported by the bearing box, and a steel continuous casting method using the continuous casting machine. Background Art

[0002] In a continuous casting machine for molten steel, molten steel in a tundish is poured into a mold, and a solidified shell is formed by the molten steel poured into the mold and contacting the mold, and a cast piece with unsolidified molten steel inside is continuously pulled out from the mold. The cast piece pulled out from the mold is supported by a cast piece support roller provided below the mold, and the surface of the cast piece is cooled by cooling water to solidify to the center of the thickness of the cast piece, and then cut into a predetermined length to produce a billet for hot rolling.

[0003] The surface temperature of the cast piece in the continuous casting machine is above 500°C, and even reaches above 900°C directly below the mold. Therefore, the bearing box that rotates and supports the cast piece support roller is exposed to a high temperature environment, so that the oil packing used to seal the lubricating oil inside the bearing box is damaged, and there is a risk of bearing damage. In other words, the damage of the oil packing causes the cast piece support roller to be unable to rotate. If the cast piece support roller cannot rotate, defects will occur on the surface of the cast piece, or the center segregation of the cast piece will worsen, and even burn-out of the cast piece will occur. In addition, if the roller bearing of the conveying roller in the rear section of the continuous casting machine is damaged, the cast piece cannot be removed, and the continuous casting operation has to be stopped.

[0004] Therefore, a method of cooling the bearing box to prevent damage to the bearing inside has been proposed. For example, Patent Document 1 proposes a method of providing a plurality of cooling water grooves on a portion of the outer peripheral surface of the bearing box shell, configuring a cover covering the cooling water grooves, and allowing cooling water to flow inside the cooling water grooves surrounded by the cover to cool the bearing box.

[0005] Patent Document 2 proposes a method of covering a bearing box of a roller table of a continuous casting machine with a jacket having an inlet and an outlet for cooling air, and introducing cooling air into the jacket to cool the bearing box.

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 10-274247

[0007] Patent Document 2: Japanese Patent Application Publication No. 2003-290891

[0008] However, the above-mentioned prior art has the following problems.

[0009] That is, in the method of Patent Document 1, a plurality of cooling water grooves are processed on the outer peripheral surface of the housing, and the cooling water grooves are covered with a cover. Therefore, the cooling water grooves can only be provided on the outer peripheral surface of the housing that can be covered with the cover, and the entire width of the bearing and the oil seal cannot be covered with the cooling water grooves. Therefore, when the entire outer periphery of the housing is subjected to radiant heat, the heat transferred to the bearing and the oil seal cannot be shielded, resulting in problems such as deterioration of the lubricating oil or damage to the oil packing.

[0010] In the method of Patent Document 2, the installation range of the steam jacket for introducing cooling air is expanded, thereby cooling the entire width of the bearing and the oil seal. However, since the cooling medium is cooling air, there is a problem that sufficient cooling cannot be achieved. Summary of the invention

[0011] The present invention is made in view of the above situation, and its purpose is to provide a bearing box of a rotating roll and a cooling method of the bearing box of a rotating roll, which can efficiently cool the bearing and the oil seal by cooling water. In addition, a continuous casting machine for steel having a rotating roll supported by the bearing box and a continuous casting method for steel using the continuous casting machine are also provided.

[0012] The gist of the present invention for solving the above-mentioned problems is as follows.

[0013] [1] A bearing box of a rotating roller, wherein a bearing and a sealing portion are arranged inside the bearing box, and the rotating roller is used to support or transport a high-temperature object.

[0014] The bearing box of the rotating roller is characterized in that it is constructed as follows:

[0015] A cooling jacket is arranged on the outer peripheral side of the bearing box so as to include at least a portion of the axial range of the bearing and at least a portion of the axial range of the sealing portion.

[0016] The cooling jacket has a cooling water inlet and a cooling water outlet.

[0017] The bearing box is cooled by the cooling water supplied from the cooling water inlet to the cooling jacket.

[0018] [2] The bearing box for a rotating roller according to [1] above, characterized in that:

[0019] At least a portion of the cooling jacket disposed on the outer peripheral side of the axial range of the sealing portion is disposed radially inward of the cooling jacket disposed on the outer peripheral side of the axial range of the bearing.

[0020] [3] A method for cooling a bearing box of a rotating roller, wherein the bearing box of the rotating roller has a bearing and a sealing portion disposed therein, and the rotating roller is used to support or transport a high-temperature object.

[0021] The above-mentioned method for cooling the bearing box of the rotating roller is characterized in that:

[0022] A cooling jacket is arranged on the outer peripheral side of the bearing box so as to include at least a part of the axial range of the bearing and at least a part of the axial range of the sealing portion.

[0023] The bearing box is cooled by introducing cooling water into the cooling jacket from a cooling water inlet provided in the cooling jacket.

[0024] The cooling water having cooled the bearing box is discharged from a cooling water discharge port provided in the cooling jacket.

[0025] [4] The method for cooling a bearing box of a rotating roller according to [3] above, characterized in that:

[0026] At least a portion of the cooling jacket disposed on the outer peripheral side of the axial range of the sealing portion is disposed radially inward of the cooling jacket disposed on the outer peripheral side of the axial range of the bearing.

[0027] [5] A continuous casting machine for steel, characterized in that:

[0028] The cast piece is supported or guided using one or more rotating rollers supported by bearings provided in the bearing box of the rotating roller described in the above [1] or [2].

[0029] [6] A method for continuous casting of steel, characterized in that:

[0030] Steel slabs were continuously cast using the continuous casting machine for steel described in the above-mentioned [5].

[0031] According to the present invention, most of the outer circumference of the bearing box is covered with cooling water, so the transfer of radiant heat to the bearing and the sealing part can be blocked. Therefore, even if the bearing of the rotating roller is used in a high-temperature environment, there is no deterioration of the lubricating oil and the oil filler, thereby realizing the function of maintaining the bearing of the rotating roller. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic structural diagram of an example of cast slab support rolls arranged in a continuous casting machine.

[0033] Figure 2 yes Figure 1 An enlarged view of part A.

[0034] Figure 3This is a structural diagram showing an example of a bearing box proposed in Patent Document 1.

[0035] Figure 4 This is a diagram showing the results of measuring the temperature of a portion on the side casing side of an oil seal of a bearing box using a sheathed thermocouple during a continuous casting operation on a certain day. DETAILED DESCRIPTION

[0036] Hereinafter, the bearing box of the present invention for supporting or conveying a rotating roller of a high-temperature object will be described with reference to the accompanying drawings, taking as an example the case where it is applied to a bearing box for a cast sheet supporting roller arranged in a continuous casting machine in the steelmaking process of a steelmaking plant. Figure 1 This is a schematic structural diagram of an example of a cast slab support roll disposed in a continuous casting machine in a steelmaking process. Figure 2 yes Figure 1 An enlarged view of part A.

[0037] In a continuous casting machine (not shown) of a steelmaking process for continuously casting molten steel to produce steel slabs, slab support rolls 20, which are rotating rolls and are also called support rolls, guide rolls, pinch rolls, etc., are arranged in the casting direction and are relatively arranged with the slab 30 clamped therebetween, within a range from just below the mold to the machine end of the continuous casting machine. Figure 1 The slab support roll 20 of three-part type which is composed of three rolls, namely, an A roll 21, a B roll 22, and a C roll 23, used as guide rolls is shown.

[0038] A bearing box 1 having a bearing inside is provided at the roller bearing seat at both ends of each roller, and each bearing box 1 is fixed to the frame of the guide roller segment (not shown). That is, the A roller 21, the B roller 22, and the C roller 23 are supported by the bearing inside the bearing box 1, and are in contact with the casting 30 and thus rotate independently. In addition, Figure 1 The slab support roll 20 shown is a rotating roll of an internally water-cooled type.

[0039] The structure of the bearing box 1 will be described by taking the bearing box 1 provided on the left side of the A roller 21 as an example, but all the bearing boxes 1 have the same structure.

[0040] like Figure 2As shown, a bearing 2 composed of an outer ring 2a, a roller 2b, and an inner ring 2c is provided at the roller bearing seat 21a of the A roller 21. A surrounding shell 7 is provided on the outer periphery of the bearing 2, a side shell 8 is provided on one side of the bearing 2 (the side not facing the cross section of the A roller 21), and a fixed shell 9 is provided on the other side (the side facing the cross section of the A roller 21). The bearing 2 is fixed to a predetermined position of the roller bearing seat 21a by the above three shells. In addition, the surrounding shell 7 is configured to surround a part of the side of the bearing 2 on the side facing the cross section of the A roller 21, and the front end of the surrounding shell 7 surrounding the part of the above side of the bearing 2 is opposite to the fixed shell 9 at a predetermined interval.

[0041] An oil packing 3 is provided adjacent to the bearing 2 at a position surrounded by the surrounding housing 7 and the fixed housing 9 and facing the surrounding housing 7 and the fixed housing 9, and an oil seal 5 is formed by the oil packing 3. In addition, an oil packing 4 is provided adjacent to the bearing 2 at a position surrounded by the side housing 8 and the roller bearing seat 21a and facing the side housing 8 and the roller bearing seat 21a, and an oil seal 6 is formed by the oil packing 4. The bearing 2 is always wetted with lubricating oil by the oil packing 3 and the oil packing 4. Here, in this specification, the structure formed by the oil packing 3 and the oil seal 5 and the structure formed by the oil packing 4 and the oil seal 6 are referred to as "sealing portion".

[0042] As described above, the bearing housing 1 includes the bearing 2 , the surrounding housing 7 , the side housing 8 , the fixed housing 9 , the oil packing 3 , the oil packing 4 , the oil seal 5 , and the oil seal 6 . Figure 2 Reference numeral 20a in the figure denotes a flow path of roll cooling water for cooling the inside of the casting support roll 20, and 24 denotes a jig for supplying and draining the roll cooling water.

[0043] In the bearing box 1, a cooling jacket 10 is provided on the outer periphery of the surrounding housing 7, and the cooling jacket 10 covers the range where the bearing 2, the oil packing 3, the oil seal 5, the oil packing 4, and the oil seal 6 are provided, and a water passage 14 for flowing cooling water is formed in the cooling jacket 10. The material of the cooling jacket 10 does not need to be particularly specified, but since it is subjected to radiant heat, it is preferably formed of metal such as stainless steel and carbon steel.

[0044] The cooling jacket 10 is provided with a cooling water inlet 11 and a cooling water outlet 12, and the outer periphery of the surrounding housing 7 is cooled by cooling water introduced from a cooling water supply pipe (not shown) into the cooling water inlet 11, flowing through the water path 14 and discharged from the cooling water outlet 12. As described above, it is configured so that the radiation heat of the casting 30 is not transmitted to the bearing 2, the oil packing 3, the oil seal 5, the oil packing 4 and the oil seal 6.

[0045] For the cooling jacket 10, if Figure 2As shown, the portion covering the axial range of the seal portion composed of the oil packing 3 and the oil seal 5 is arranged radially inward of the portion covering the axial range of the bearing 2 in accordance with the cross-sectional shape of the end of the A roller 21 .

[0046] The cooling water discharged from the cooling water outlet 12 may flow down the outer periphery of the cooling jacket 10 as it is, or may be discharged to a cooling water outlet pipe (not shown). By flowing down the outer periphery of the cooling jacket 10 as it is, the cooling jacket 10 is also cooled from the outer periphery, which is more preferable in terms of blocking the radiant heat of the cast slab 30.

[0047] exist Figure 2 In the illustrated bearing box 1, the installation range of the cooling jacket 10 includes the entire axial range of the bearing 2 and the entire axial range of the sealing portion, but is not limited to this method. That is, the installation range of the cooling jacket 10 only needs to be arranged on the outer peripheral side of the bearing box 1 in a manner that includes at least a portion of the axial range of the bearing 2 and at least a portion of the axial range of the sealing portion.

[0048] In addition, Figure 2 In the illustrated bearing box 1, the cooling water inlet 11 and the cooling water outlet 12 are directly connected to the cover 13 forming the outer periphery of the cooling jacket 10, but the arrangement of the cooling water inlet 11 and the cooling water outlet 12 to the cooling jacket 10 is not limited to this arrangement. For example, the cooling water may be supplied and discharged via a water channel formed inside the bearing box 1.

[0049] As described above, according to the bearing box of a rotating roller and the cooling method of the bearing box of a rotating roller of the present invention, most of the outer periphery of the bearing box 1 is covered with cooling water, so that the transmission of radiant heat to the bearing 2 and the oil seals 5 and 6 can be blocked. Therefore, even if the bearing 2 is used in a high temperature environment, there is no deterioration of the lubricating oil and the oil packings 3 and 4, so that the function of maintaining the bearing 2 can be achieved.

[0050] In addition, the above description takes the case where the present invention is applied to the bearing box 1 of the cast sheet support roll 20 of the continuous casting machine as an example, but the present invention can be applied to any bearing box of a rotating roll exposed to a high temperature environment due to radiant heat, etc., and is not limited by the use of the bearing box. In addition, the internal structure of the bearing box is not limited to the above description, and the present invention can be applied to any bearing box having a so-called "bearing".

[0051] Example

[0052] [Example 1]

[0053] In the bearing box of the slab support roller (guide roller) of the continuous casting machine that manufactures steel slabs by continuous casting, a test was conducted to cool the bearing box by cooling water. The specifications of the continuous casting machine used are a vertical bending type slab continuous casting machine with a vertical section of 3.0m, 10-point bending (upper bending zone), a bending radius of 10.5m, 6-point correction (lower correction zone), and a machine length of 49.2m. It can manufacture slabs with a thickness of 220mm and a width of 675 to 2100mm. The bearing box of the test object is a bearing box of the slab support roller that supports the slab with a surface temperature of 700 to 900°C. The bearing box is provided with a bearing (rolling bearing) with an outer diameter of 170mm, an inner diameter of 110mm, and a width of 43mm.

[0054] The test was set up Figure 2 The bearing box of the present invention shown above and the bearing box proposed in Patent Document 1 for comparison were compared by measuring the temperature of the bearing box during continuous casting.

[0055] Figure 3 An example of a bearing box proposed in Patent Document 1 is shown. Figure 3 As shown, the bearing box 1A proposed in Patent Document 1 is a structure in which a plurality of cooling water grooves 16 are provided on the periphery of the surrounding housing 7, and a cover 15 covering the cooling water grooves 16 is provided, so that cooling water flows inside the cooling water grooves 16 surrounded by the cover 15 to water-cool the periphery of the surrounding housing 7. In addition, Figure 3 Other structures of the bearing housing 1A shown are Figure 2 The bearing box 1 shown has the same structure, and the same parts are denoted by the same reference numerals, and the description thereof will be omitted.

[0056] Relative to Figure 2 The bearing box 1 of the present invention (hereinafter also referred to as "the present invention example") and Figure 3 The bearing box 1A for comparison (hereinafter, also referred to as "the prior art") shown in the figure has 15 L of cooling water per minute introduced into the water path 14 and the cooling water tank 16 for each bearing box, thereby cooling the bearing box 1 and the bearing box 1A. The cooling water after cooling the bearing box 1 and the bearing box 1A remains unchanged and flows down the outer periphery of the bearing box in both the bearing box 1 of the present invention and the bearing box 1A as the prior art.

[0057] Figure 4 Indicates the continuous casting operation on a certain day through the armored thermocouple Figure 2 as well as Figure 3 The temperature of the oil seal 6 at the side of the housing 8 indicated by the reference symbol "P" is measured. Figure 4The period during which the temperature is locally lowered is a period during which continuous casting is not performed between continuous casting operations, and the other period is a period during which molten steel is continuously cast (continuous casting).

[0058] like Figure 4 As shown, it can be confirmed that in the present invention example, the temperature of the oil seal 6 during continuous casting is 20 to 40° C. lower than that in the conventional example, and the influence of the radiation heat from the cast piece on the oil seal 6 can be reduced.

[0059] In the conventional example, the oil seal 5 is not covered by the cover 15, whereas in the present invention, the oil seal 5 is also covered by the cooling jacket 10. As a result of obtaining the temperature of the portion through temperature analysis, it can be confirmed that the temperature of the oil seal 5 in the present invention is also about 70 to 80°C lower than that in the conventional example.

[0060] [Example 2]

[0061] The vertical bending slab continuous casting machine used in Example 1 was used to cast steel whose ductility showed a minimum value when the surface temperature of the slab was between 700°C and 900°C, especially at 800°C, i.e., steel that was prone to cracking on the surface of the slab. The slab width of the manufactured slab was the maximum width of the continuous casting machine, i.e., 2100 mm. In the lower correction belt of the slab continuous casting machine, the bearing box at the end of the slab width direction from the upstream side of the pull rope toward the downstream side near the left side became Figure 3 The bearing box (conventional type) proposed in Patent Document 1 shown in FIG. 1 is a bearing box at the end of the slab width direction near the right side toward the downstream side. Figure 2 The bearing box of the present invention is shown. In addition, in the lower correction zone of the vertical bending type slab continuous casting machine, there are cases where deformation is applied to the surface of the cast piece and cracks are generated on the surface of the cast piece.

[0062] The bearing box was arranged as described above, and in the continuous casting operation of level A, the amount of secondary cooling water until reaching the lower correction zone was adjusted so that the surface temperature of the cast piece became a surface temperature of 700°C to 900°C, including 800°C, which is a temperature at which the above-mentioned surface cracks are easily generated. On the other hand, in the continuous casting operation of level B, the amount of secondary cooling water until reaching the lower correction zone was adjusted so that the surface temperature of the cast piece in the lower correction zone became a range of 900°C to 1000°C.

[0063] Both Level A and Level B continuously cast molten steel having a chemical composition of 0.03-0.05 mass% [C], 0.25-0.35 mass% [Si], 1.3-1.4 mass% [Mn], 0-0.015 mass% [P], and 0-0.002 mass% [S] in ten furnaces each. The mass of molten steel per furnace is 245 tons.

[0064] After continuous casting, the entire surface of the cast piece was scarfed to a thickness of 2 mm, and the number of surface cracks (3 mm or longer) on the cast piece was counted. Under level A, 3.4 surface cracks occurred per 1 m of the cast piece, while under level B, there were no surface cracks with a length of 3 mm or longer.

[0065] On the other hand, the appearance of the bearing box of the lower correction zone was inspected shortly after the above-mentioned continuous casting test was performed. As a result, no particular abnormality was found in the bearing box of the present invention, but discoloration due to temperature rise was found on the surface of the bearing box of the conventional example, and there was also a bearing box with scales generated on the cast piece adhered.

[0066] Description of reference numerals:

[0067] 1…bearing box; 1A…bearing box; 2…bearing; 2a…outer ring; 2b…roller; 2c…inner ring; 3…oil packing; 4…oil packing; 5…oil seal; 6…oil seal; 7…surrounding shell; 8…side shell; 9…fixed shell; 10…cooling jacket; 11…cooling water inlet; 12…cooling water outlet; 13…cover; 14…water path; 15…cover; 16…cooling water trough; 20…casting sheet support roller; 20a…roller cooling water flow path; 21…A roller; 21a…roller bearing seat of A roller; 22…B roller; 23…C roller; 30…casting sheet.

Claims

1. A bearing box of a rotating roller, wherein a bearing and a sealing part are arranged inside, wherein the rotating roller is used to support or transport a high-temperature object. The bearing box of the rotating roller is characterized in that it is constructed as follows: A cooling jacket is arranged on the outer peripheral side of the bearing box so as to include at least a portion of the axial range of the bearing and at least a portion of the axial range of the seal portion. The cooling jacket has a cooling water inlet and a cooling water outlet. The bearing box is cooled by the cooling water supplied from the cooling water inlet to the cooling jacket. The rotating roller is composed of a plurality of roller components, the bearing boxes are provided at both ends of the roller components, and the outer surface of the bearing box is configured to be located radially inward of the outer surface of the roller component. Corresponding to the shape of the end of the roller member, at least a portion of the outer circumference of the cooling jacket arranged on the outer circumference side of the axial range of the seal portion is arranged radially inward of at least a portion of the outer circumference of the cooling jacket arranged on the outer circumference side of the axial range of the bearing.

2. A method for cooling a bearing box of a rotating roller, wherein: The bearing box of the rotating roller is internally provided with a bearing and a sealing part, and the rotating roller is used to support or transport high-temperature objects. The method for cooling the bearing box of the rotating roller is characterized in that: A cooling jacket is arranged on the outer peripheral side of the bearing box so as to include at least a part of the axial range of the bearing and at least a part of the axial range of the sealing portion. The bearing box is cooled by introducing cooling water into the cooling jacket from a cooling water inlet provided in the cooling jacket, The cooling water after cooling the bearing box is discharged from a cooling water discharge port provided in the cooling jacket, The rotating roller is composed of a plurality of roller components, the bearing boxes are provided at both ends of the roller components, and the outer surface of the bearing box is configured to be located radially inward of the outer surface of the roller component. Corresponding to the shape of the end of the roller member, at least a portion of the outer circumference of the cooling jacket arranged on the outer circumference side of the axial range of the seal portion is arranged radially inward of at least a portion of the outer circumference of the cooling jacket arranged on the outer circumference side of the axial range of the bearing.

3. A continuous casting machine for steel, characterized in that: The cast piece is supported or guided by one or more rotating rollers supported by the bearings provided in the bearing box of the rotating roller according to claim 1 .

4. A continuous casting method for steel, characterized in that: The steel continuous casting machine according to claim 3 is used to continuously cast steel slabs.

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