Hot rolling vertical roll bracket roller positioning shaft structure and maintenance method

Abstract

The invention relates to a hot rolling vertical roll bracket roller positioning shaft structure and a maintenance method, the hot rolling vertical roll bracket roller positioning shaft structure comprises a positioning shaft fixed on a bracket body and a roller assembled on the positioning shaft through a bearing, the positioning shaft comprises a shaft body part and a cylindrical wear-resistant sleeve independent of the shaft body part, and the wear-resistant sleeve is arranged on the shaft body part. The cylindrical wear-resistant sleeve sleeves and is fixed on a preset shaft section on the outer circumferential surface of the shaft body part; the outer circumferential surface of the cylindrical wear-resistant sleeve forms a mounting matching surface which is directly matched with the bearing inner ring; and the cylindrical wear-resistant sleeve is configured to be a component which can be independently detached from the shaft body part and replaced. The replaceable sleeve is arranged on the positioning shaft, and an easily-worn part is transferred to the sleeve, so that the quick and low-cost repair of the positioning shaft is realized, the maintenance time is remarkably shortened, the vicious circle of wear is broken, and the equipment operation rate and the product precision are improved.

Description

Technical Field

[0001] This invention relates to the field of metallurgical machinery and equipment technology, and more particularly to a hot rolling vertical roll support roller positioning shaft structure and maintenance method. Background Technology

[0002] In the hot-rolled strip steel production process, the vertical rolls of the roughing mill are the core equipment for achieving precise control of slab width. The vertical rolls move along fixed tracks via traveling rollers on their supports to adjust and set the roll gap. This area operates in an extremely harsh environment, constantly subjected to alternating impact loads during rolling, high-temperature radiation, steam and splashes from the high-pressure water descaling system, and corrosion from iron oxide scale dust. Under these conditions, the bearings inside the support rollers become the most vulnerable and susceptible to damage.

[0003] In existing technologies, such as Figure 3 , Figure 4 As shown, the positioning shaft of the roller typically adopts an integral structure (i.e., a single, smooth shaft), with the inner ring of the bearing directly mounted on the outer cylindrical surface of this positioning shaft. This traditional design has the following significant drawbacks:

[0004] Firstly, once the bearing fails due to fatigue, lubrication failure, or seal damage, the roller will seize. A seized roller will experience sliding friction with the track, causing severe wear on the surface of its positioning shaft and reducing its size. After replacing the roller (including the bearing), the worn positioning shaft creates an excessively large gap between the inner ring of the new bearing and the worn shaft surface, resulting in a non-ideal loose fit. This fit prevents the bearing from bearing evenly, causing impacts and uneven loading during operation, drastically shortening its lifespan and often leading to further failure within a short period. This creates a vicious cycle of bearing failure, shaft wear, and accelerated failure of the new bearing.

[0005] Because the positioning shaft is a single piece and securely installed inside the bracket body, which weighs tens of tons, replacement or repair is extremely inconvenient when its surface wears down. The existing maintenance process requires utilizing the annual overhaul window of the production line to lift the entire bracket out of the frame. Then, the old positioning shaft needs to be destructively removed using thermal cutting methods such as gas welding. When installing a new positioning shaft, due to the limited assembly space and the requirement for a high-precision interference fit, it is often necessary to cool the new shaft with liquid nitrogen before cold installation. The entire process of lifting, dismantling, installing, and adjusting is cumbersome, taking up to approximately 19 hours, severely restricting production rhythm, and can only be performed during long-term downtime.

[0006] When the roller bearings are damaged and jammed, the movement resistance of the vertical roller support increases or it becomes completely stuck, preventing the vertical roller gap from being accurately adjusted according to the set value. This directly causes inaccurate control of the slab width and results in warping or buckling during rolling due to uneven pressing on both sides. In extreme cases, enormous abnormal forces can be transmitted to the linkage mechanism of the vertical roller frame, posing a risk of link breakage, major equipment damage, and prolonged production interruption.

[0007] In summary, the existing integral positioning shaft design is the root cause of high maintenance costs, long downtime, and low equipment reliability in this area. Therefore, there is an urgent need for a positioning shaft structure and corresponding maintenance methods that enable rapid, low-cost, in-situ repair to break the wear cycle and improve equipment uptime. Summary of the Invention

[0008] To address the aforementioned technical problems, a structure and maintenance method for the positioning shaft of a hot-rolling vertical roll support roller are provided. This structure, by designing easily worn parts as independently replaceable sleeve assemblies, enables rapid and low-cost repair of the positioning shaft, fundamentally solving the vicious cycle of wear and significantly improving equipment availability and production economy.

[0009] The technical means employed in this invention are as follows: A hot-rolling vertical roll support roller positioning shaft structure includes a positioning shaft fixed to the support body, and a roller mounted on the positioning shaft via bearings, wherein... The positioning shaft includes a shaft body and a cylindrical wear-resistant sleeve independent of the shaft body. The cylindrical wear-resistant sleeve is sleeved and fixed on a preset shaft segment on the outer circumferential surface of the shaft body. The outer circumferential surface of the cylindrical wear-resistant sleeve forms an installation mating surface that directly mates with the inner ring of the bearing; The cylindrical wear-resistant sleeve is configured to be a component that can be removed and replaced separately from the shaft body.

[0010] Furthermore, the diameter of the shaft portion in the preset shaft section is set to be smaller than its original standard fit size; the cylindrical wear-resistant sleeve has an inner hole and an outer circle, the inner hole diameter matches the outer diameter of the shaft portion in the preset shaft section to form an interference fit, and the outer circle diameter is machined to the original standard fit size. The cylindrical wear-resistant sleeve and the shaft portion are fixedly connected in the circumferential and axial directions through the interference fit.

[0011] Furthermore, the interference fit is achieved by heating and expanding the cylindrical wear-resistant sleeve and then fitting it onto the shaft body, allowing it to cool and shrink.

[0012] Furthermore, the wall thickness of the cylindrical wear-resistant sleeve is set to be a thin-walled structure that is smaller than the radius of the shaft body.

[0013] Furthermore, the cylindrical wear-resistant sleeve is made of a metal material with higher wear resistance than the base material of the shaft body.

[0014] Furthermore, the wall thickness of the cylindrical wear-resistant sleeve is 4-6 mm.

[0015] The present invention also discloses a maintenance method for the hot rolling vertical roll support roller positioning shaft structure, comprising the following steps: Move the bracket carrying the positioning shaft structure to be repaired to the maintenance station; Release the axial lock of the roller relative to the positioning shaft, and remove the roller containing the damaged bearing from the positioning shaft to expose the cylindrical wear-resistant sleeve; Remove the worn or damaged cylindrical wear-resistant sleeve; Install and fix the new cylindrical wear-resistant sleeve to be replaced onto the preset shaft section of the shaft body to reconstruct the standard mounting mating surface; Install the rollers equipped with the new bearings onto the reconstructed mounting surface and restore their axial locking.

[0016] Furthermore, the step of removing the worn or damaged cylindrical wear-resistant sleeve specifically includes: cutting or splitting the cylindrical wear-resistant sleeve to release the interference fit between it and the shaft body, and then removing it from the shaft body.

[0017] Furthermore, the step of installing and fixing the new cylindrical wear-resistant sleeve is specifically achieved using a heat fitting process, that is, heating the new cylindrical wear-resistant sleeve to expand its inner hole, and then fitting it onto the shaft body.

[0018] Compared with the prior art, the present invention has the following advantages: 1. This invention designs the cylindrical wear-resistant sleeve as an independent, quickly detachable module. This transforms the main work object for maintenance personnel from a massive bracket weighing tens of tons and rigidly connected to the main structure to a single bushing component weighing only a few kilograms and connected via standardized interference fits. Consequently, the lifting capacity, working space, and process complexity required for maintenance are significantly reduced. As described in the background section, a project that previously required 19 hours of annual overhaul can be shortened to approximately 3 hours of routine maintenance, effectively reducing maintenance time and minimizing the impact on continuous production.

[0019] 2. This invention achieves hierarchical management of components through the functional separation design of the shaft body and bushing. The complex and costly shaft body is retained as a basic component, avoiding the waste of scrapping the entire part due to surface wear. Each maintenance only requires replacing the low-cost bushing and standard bearing. This directly saves on the procurement and processing costs of the overall positioning shaft spare parts, as well as the related costs of large-scale hoisting and special assembly.

[0020] 3. In traditional structures, journal wear is permanent, cumulative, and irreversible, directly leading to a continuous deterioration of bearing conditions. In this invention, the cylindrical wear-resistant sleeve serves as a resettable mating interface. Each replacement means that the bearing's mounting surface is restored to its initial geometric accuracy and surface quality at the factory, ensuring that each new bearing operates under the theoretically designed optimal mating condition, thereby achieving its expected fatigue life.

[0021] Because this invention enables rapid and low-cost preventative maintenance, equipment maintenance personnel can more proactively monitor and replace roller assemblies nearing the end of their lifespan, preventing them from developing into a completely jammed failure. This invention makes it easier to keep equipment in good condition, effectively preventing a series of serious equipment and quality accidents indirectly caused by roller jamming, such as slab misalignment, head warping, and even connecting rod overload breakage. This ensures production safety and improves quality indicators such as product width accuracy. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the assembly structure of the vertical roller bracket roller positioning shaft of the present invention.

[0024] Figure 2 This is a schematic diagram of the replaceable cylindrical wear-resistant sleeve of the present invention.

[0025] Figure 3 This is the original vertical roller support roller assembly drawing.

[0026] Figure 4 This is a diagram of the original vertical roller support roller positioning pin.

[0027] In the diagram: 1. Bracket body; 2. Positioning shaft; 3. Roller; 4. Bushing; 5. Pressure plate; 6. Bolt; 7. Cylindrical wear-resistant sleeve; 8. Bearing. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0031] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0032] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0033] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0034] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0035] like Figure 1 As shown, this embodiment of the invention discloses a hot rolling vertical roll support roller positioning shaft structure, including a positioning shaft 2 fixed to the support body 1, and a roller 3 assembled on the positioning shaft 2 via a bearing 8, wherein... The positioning shaft 2 includes a shaft body and, as shown in the figure, Figure 2 The cylindrical wear-resistant sleeve 7 shown is independent of the shaft body and is sleeved and fixed on a preset shaft section on the outer circumferential surface of the shaft body. The outer circumferential surface of the cylindrical wear-resistant sleeve 7 forms an installation mating surface that directly mates with the inner ring of the bearing 8; The cylindrical wear-resistant sleeve 7 is configured to be a component that can be removed and replaced separately from the shaft body.

[0036] Furthermore, the diameter of the shaft portion in the preset shaft section is set to be smaller than its original design standard fit size; the cylindrical wear-resistant sleeve 7 has an inner hole and an outer circle, the inner hole diameter matches the outer diameter of the shaft portion in the preset shaft section to form an interference fit, and the outer circle diameter is machined to the original design standard fit size. The cylindrical wear-resistant sleeve 7 and the shaft portion are fixedly connected in the circumferential and axial directions through the interference fit.

[0037] Furthermore, the interference fit is achieved by heating and expanding the cylindrical wear-resistant sleeve 7 and then fitting it onto the shaft body, allowing it to cool and shrink.

[0038] Furthermore, the wall thickness of the cylindrical wear-resistant sleeve 7 is set to be a thin-walled structure that is smaller than the radius of the shaft body.

[0039] Furthermore, the cylindrical wear-resistant sleeve 7 is made of a metal material with higher wear resistance than the base material of the shaft body.

[0040] Furthermore, the wall thickness of the cylindrical wear-resistant sleeve 7 is 4-6 mm.

[0041] The present invention also discloses a maintenance method for the hot rolling vertical roll support roller positioning shaft structure, comprising the following steps: Move the bracket carrying the positioning shaft structure to be repaired to the maintenance station; Remove the pressure plate 5 and bolts 6 used to fix the roller 3 to release the axial lock of the roller 3 relative to the positioning shaft, and remove the roller 3 containing the damaged bearing 8 from the positioning shaft to expose the cylindrical wear-resistant sleeve 7; Remove the worn or damaged cylindrical wear-resistant sleeve 7; Install and fix the new cylindrical wear-resistant sleeve 7 to be replaced onto the preset shaft section of the shaft body to rebuild the standard mounting mating surface; Install the roller 3, which is equipped with the new bearing 8, onto the reconstructed mounting surface, and reinstall the pressure plate 5 and bolts 6 to restore its axial locking.

[0042] Furthermore, the step of removing the worn or damaged cylindrical wear-resistant sleeve 7 specifically includes: cutting or splitting the cylindrical wear-resistant sleeve 7 to release the interference fit between it and the shaft body, and then removing it from the shaft body.

[0043] Furthermore, the step of installing and fixing the new cylindrical wear-resistant sleeve 7 is specifically achieved by a heat fitting process, that is, heating the new cylindrical wear-resistant sleeve 7 to expand its inner hole, and then fitting it onto the shaft body.

[0044] Example 1 This embodiment provides detailed specifications for the aforementioned hot-rolling vertical roll support roller positioning shaft structure and maintenance method. Specifically, A hot-rolled vertical roll support roller positioning shaft structure includes a positioning shaft 2 fixed on the support body 1, and a roller 3 assembled on the positioning shaft 2 via a bearing 8.

[0045] In practical implementation, for modifying existing equipment or manufacturing new equipment, the following preferred solutions can be adopted: Shaft body (i.e. base shaft) design: The diameter of the preset shaft segment that mates with the bearing 8 on the positioning shaft 2 is reduced by 8-12mm (preferably 10mm) compared to the original integral design size, forming a base shaft with a smaller diameter.

[0046] Cylindrical wear-resistant sleeve design: The cylindrical wear-resistant sleeve 7 is made of a material with better wear resistance than the base material of the shaft body (such as 42CrMo alloy steel). Its wall thickness is 4-6mm (preferably 5mm), which is a thin-walled structure. Its inner hole and the outer diameter of the machined base shaft adopt an interference fit tolerance design of H7 / s6 level, and the outer circle is machined to the standard fit size of the original design.

[0047] Assembly and fixing: The cylindrical wear-resistant sleeve 7 is fixed to the shaft body by a heat fitting process, that is, it is heated to about 200°C to expand its inner hole, and then quickly fitted into the corresponding position of the base shaft. After cooling, a firm interference fit is formed, realizing circumferential and axial fixation.

[0048] The specific maintenance method is as follows: when bearing 8 is damaged, causing wear of the cylindrical wear-resistant sleeve 7, it is not necessary to disassemble the bracket body 1. The maintenance steps are as follows: Move the vertical roller to the maintenance position and slightly raise the bracket to unload roller 3.

[0049] Remove the pressure plate 5 and bolts 6, lift out the damaged roller assembly 3, and expose the worn sleeve 7.

[0050] Remove the old sleeve by cutting or cutting the old sleeve 7.

[0051] Install the new sleeve and heat-fit the new sleeve 7 onto the positioning shaft 2.

[0052] Reinstall the roller 3 with the new bearing and tighten the pressure plate 5.

[0053] Through the aforementioned structure and method, the annual overhaul, which previously required disassembling the bracket and took approximately 19 hours, can be transformed into online maintenance that only takes about 3 hours, saving more than 84% of the operation time. Simultaneously, it ensures the ideal fit between bearing 8 and the standard-sized mating surface, breaking the vicious cycle of wear. Practical application shows that this solution effectively improves the product width control accuracy, increasing it from 97.70% to 98.03%, and eliminates major equipment accidents caused by roller jamming.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hot-rolled vertical roll support roller positioning shaft structure, characterized in that, It includes a positioning shaft fixed to the bracket body, and a roller mounted on the positioning shaft via a bearing, wherein... The positioning shaft includes a shaft body and a cylindrical wear-resistant sleeve independent of the shaft body. The cylindrical wear-resistant sleeve is sleeved and fixed on a preset shaft segment on the outer circumferential surface of the shaft body. The outer circumferential surface of the cylindrical wear-resistant sleeve forms an installation mating surface that directly mates with the inner ring of the bearing; The cylindrical wear-resistant sleeve is configured to be a component that can be removed and replaced separately from the shaft body.

2. The hot-rolled vertical roll support roller positioning shaft structure according to claim 1, characterized in that, The diameter of the shaft body in the preset shaft section is set to be smaller than its original standard fit size; the cylindrical wear-resistant sleeve has an inner hole and an outer circle, the inner hole diameter matches the outer diameter of the shaft body in the preset shaft section to form an interference fit, and the outer circle diameter is machined to the original standard fit size. The cylindrical wear-resistant sleeve and the shaft body are fixedly connected in the circumferential and axial directions through the interference fit.

3. The hot-rolled vertical roll support roller positioning shaft structure according to claim 2, characterized in that, The interference fit is achieved by heating and expanding the cylindrical wear-resistant sleeve, then fitting it onto the shaft body, and allowing it to cool and shrink.

4. The hot-rolled vertical roll support roller positioning shaft structure according to claim 1, characterized in that, The wall thickness of the cylindrical wear-resistant sleeve is set to be a thin-walled structure that is smaller than the radius of the shaft body.

5. The hot-rolled vertical roll support roller positioning shaft structure according to claim 1, characterized in that, The cylindrical wear-resistant sleeve is made of a metal material with higher wear resistance than the base material of the shaft body.

6. The hot-rolled vertical roll support roller positioning shaft structure according to claim 1, characterized in that, The wall thickness of the cylindrical wear-resistant sleeve is 4-6 mm.

7. A method for overhauling the hot-rolled vertical roll support roller positioning shaft structure according to any one of claims 1 to 6, characterized in that, Includes the following steps: Move the bracket carrying the positioning shaft structure to be repaired to the maintenance station; Release the axial lock of the roller relative to the positioning shaft, and remove the roller containing the damaged bearing from the positioning shaft to expose the cylindrical wear-resistant sleeve; Remove the worn or damaged cylindrical wear-resistant sleeve; Install and fix the new cylindrical wear-resistant sleeve to be replaced onto the preset shaft section of the shaft body to reconstruct the standard mounting mating surface; Install the rollers equipped with the new bearings onto the reconstructed mounting surface and restore their axial locking.

8. The method according to claim 7, characterized in that, The step of removing the worn or damaged cylindrical wear-resistant sleeve specifically includes: cutting or splitting the cylindrical wear-resistant sleeve to release the interference fit between it and the shaft body, and then removing it from the shaft body.

9. The method according to claim 7, characterized in that, The step of installing and fixing the new cylindrical wear-resistant sleeve is specifically achieved by a heat fitting process, that is, heating the new cylindrical wear-resistant sleeve to expand its inner hole, and then fitting it onto the shaft body.

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