Repairable roll and repair process

Abstract

The application discloses a repairable roller and a repairing process, and belongs to the technical field of roller repairing. The repairable roller comprises a roller shaft and a roller sleeve, the roller sleeve is arranged on the outer side of the roller shaft, the roller sleeve is connected with the roller shaft through interference fit, a fixing assembly is arranged on one side of the roller shaft, two fixing boxes are arranged on the outer side of the fixing assembly in a symmetrical manner, a threaded block is slidably connected in each fixing box, a supporting rod is arranged on the top of the threaded block, a positioning assembly is arranged on one side of the supporting rod, a circular clamping block is arranged on the top of the positioning assembly, the circular clamping block is rotationally connected with the roller shaft, the top of the circular clamping block is matched with the roller sleeve, and a dismounting assembly is arranged on the other side of the supporting rod. The application solves the problems of large quantity of traditional roller scrap, serious resource waste, long replacement cycle and influence on continuous operation of a production line.

Description

Technical Field

[0001] This invention relates to the field of roll repair technology, and in particular to a repairable roll and its repair process. Background Technology

[0002] Rolls and support rolls are key components in metallurgical and non-ferrous sheet rolling production lines, directly undertaking important tasks such as sheet rolling and pressure transmission. Their operating status directly affects the quality of rolled products and the stability of the entire production line. Currently, conventional rolls and support rolls in the industry are generally made of Cr3 and Cr5 materials. Due to rolling conditions, contact friction, and alternating loads, the hardened layer on the roll surface will continuously wear away during continuous operation. According to industry standards, when the cumulative steel throughput reaches 5,000 to 8,000 tons, the wear-resistant hardened layer on the roll surface is basically completely worn away, and the roll loses its original performance.

[0003] Currently, the industry mostly adopts the method of replacing worn-out rolls and support rolls as a whole, discarding the entire scrapped roll shaft and rendering it unusable. This approach results in the unnecessary loss of a large amount of metal raw materials, production energy, and labor costs, significantly increasing the company's equipment maintenance and spare parts procurement expenses. It also does not conform to the current production development concept of energy conservation, environmental protection, cost reduction, and efficiency improvement. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of existing rolls and support rolls being scrapped as a whole after surface wear, resulting in serious waste of resources and energy, high repair costs, long new roll preparation cycles, and reduced production efficiency. Therefore, this invention proposes a repairable roll and repair process.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A repairable roll includes a roll shaft and a roll sleeve. The roll sleeve is fitted onto the outside of the roll shaft and is connected to the roll shaft by an interference fit. A fixing component is fitted onto one side of the roll shaft. Two fixing boxes are provided on the outside of the fixing component. The two fixing boxes are arranged symmetrically vertically. A threaded block is slidably connected inside each fixing box. A support rod is provided on the top of the threaded block. A positioning component is fitted on one side of the support rod. A circular locking block is provided on the top of the positioning component. The circular locking block is rotatably connected to the roll shaft. The top of the circular locking block cooperates with the roll sleeve. A disassembly component is provided on the other side of the support rod.

[0006] In some embodiments, the fixing component includes two retaining sleeves, which are arranged symmetrically about the center line of the roller shaft. The retaining sleeves are fitted onto the outside of the roller shaft, and the two retaining sleeves are connected to each other by a plurality of first bolts.

[0007] In some embodiments, each of the fixed boxes is rotatably connected to a threaded rod, the outer side of the threaded rod is connected to a transmission bolt, the outer side of the threaded rod is threadedly connected to a threaded block, the inner side of each threaded rod is connected to a gear, the inner sides of two gears mesh together with a gear ring, and the inner side of the gear is rotatably connected to a roller shaft.

[0008] In some embodiments, the positioning component includes a first link, the bottom of which is rotatably connected to a support rod, and a first pin is hinged to the top of the first link. The inner side of the first pin is fixedly connected to a circular locking block, and the position of the first pin is higher than the center of the circular locking block.

[0009] In some embodiments, the end of the roller shaft is provided with two first grooves, which are arranged symmetrically about the center line of the roller shaft. The first grooves accommodate circular locking blocks. The end of the roller sleeve on the same side is provided with two second grooves, which are arranged symmetrically about the center line of the roller shaft.

[0010] In some embodiments, the top of the circular card block is provided with a first end and a second end, the first end abutting against the inner sidewall of the second groove, and the inner side of the second end abutting against the end of the roller sleeve.

[0011] In some embodiments, the disassembly assembly includes a bracket, the inner sides of which are interconnected by a second bolt and a roller, and the outer side of which is rotatably connected to a second connecting rod, the bottom of which is slidably connected to a support rod.

[0012] In some embodiments, a second pin is slidably connected to the top of the second connecting rod, a movable rod is fixedly connected to the outer side of the second pin, a vertical rod is connected through the inner side of the movable rod, the bottom of the vertical rod is fixedly connected to the bracket, a reversing rod is provided on the inner side of the movable rod, a clamping plate is fixedly connected to the inner side of the reversing rod, and a third groove is fitted on the inner side of the clamping plate, the third groove being located at the end of the roller sleeve.

[0013] A roll repair process includes the following steps: S1. Perform UT and magnetic particle testing on the scrapped rolls and support rolls to check for quality defects in the roll body; S2. The roller sleeve blank is made of mold steel and then subjected to forging, post-forging normalizing and tempering, rough machining, flaw detection, quenching and tempering, and precision machining. The roller sleeve is then quenched as a whole to the original design hardness of the roll. S3. Calculate and determine the assembly interference based on the roller sleeve length, inner and outer diameter dimensions, and transmitted torque parameters; S4. Heat the finished roller sleeve and heat-fit it onto the outside of the roller shaft to form an interference fit between the roller sleeve and the roller shaft, thus completing the repair operation.

[0014] In some embodiments, the roller sleeve material is selected from 5CrNiMo hot work die steel, which has excellent hardenability, toughness, thermal fatigue resistance and impact resistance, and is suitable for the working conditions of the support roller.

[0015] Compared with the prior art, the present invention provides a repairable roll and repair process, which has the following beneficial effects.

[0016] 1. This invention achieves efficient repair and recycling of waste rolls and support rolls, significantly reducing production and equipment maintenance costs. This invention abandons the traditional method of scrapping the entire roll after wear. By screening for intact old roll shafts through flaw detection, only the worn surface sleeve needs to be replaced to complete the repair, eliminating the need for re-forging a new roll. Simultaneously, the sleeve adopts a lightweight structural design, consuming only one-fifth of the material of the entire roll. Combined with an optimized integrated forging and heat treatment process, it greatly reduces raw material loss, processing energy consumption, and labor costs, shortening the roll production cycle. This effectively solves the problems of large scrap volumes, serious resource waste, long replacement cycles, and disruption to continuous production line operation associated with traditional rolls, resulting in energy conservation, environmental protection, and significant economic benefits.

[0017] 2. In this invention, the roll sleeve is made of 5CrNiMo hot work die steel. Compared with traditional Cr3 and Cr5 materials, this material has excellent hardenability and high toughness, and also has excellent thermal fatigue resistance and impact resistance, making it suitable for the harsh environment of heavy load, alternating impact, and continuous friction under rolling conditions. Combined with a complete set of heat treatment processes including forging, tempering, and overall quenching, the hardness and wear resistance of the roll sleeve meet the standards, effectively improving the overall service life of the roll.

[0018] 3. In this invention, the roller sleeve and the roller shaft are connected by a precisely calculated interference fit, ensuring smooth torque transmission. Simultaneously, a double-limiting structure consisting of a circular locking block and a locking plate constrains the roller sleeve axially and circumferentially, effectively preventing problems such as roller sleeve movement, offset, loosening, and slippage during high-speed rolling, thus ensuring continuous and stable rolling operations.

[0019] 4. This invention addresses the problems of small and medium-sized lightweight roller sleeves being lightweight, prone to jamming after heating, and difficult to detach naturally. This device uses a positioning component and a disassembly component together. First, a circular locking block is used to break the static friction of the mating surface. Then, a lever structure is used to amplify the pushing stroke. Combined with hoisting equipment, disassembly and assembly are completed, completely solving the drawbacks of traditional disassembly methods, such as low efficiency and easy jamming.

[0020] 5. The present invention is an external modular structure for the entire positioning and disassembly assembly components. It relies on the clamping and installation of split ferrules. Only a few assembly holes need to be opened in the local part of the roller shaft. There is no need to cut or modify the original roller shaft shape and base structure. It can be adapted and installed on both new and old specification rollers and support rollers. It has a wide range of applications and is convenient for on-site modification and assembly operations.

[0021] 6. This invention adopts a mechanical flexible pushing and step-by-step loosening operation method throughout the process, abandoning the operation methods of violent knocking and forced dragging, effectively avoiding surface scratches, deformation and cracking of the roller shaft and roller sleeve, and improving the yield of roller repair.

[0022] Other advantages, objectives and features of the invention will be set forth in part in the description which follows; and in part will be apparent to those skilled in the art upon examination of the following description; or may be learned from practice of the invention. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention.

[0024] Figure 2 This is a schematic cross-sectional view of the structure of the present invention.

[0025] Figure 3 This is a schematic diagram of the first connecting rod and sleeve structure of the present invention.

[0026] Figure 4 This is a schematic diagram of the transmission bolt and circular locking block mating structure of the present invention.

[0027] Figure 5 This is a schematic diagram of the gear ring and gear mating structure of the present invention.

[0028] Figure 6 This is a schematic diagram of the circular card block structure of the present invention.

[0029] Figure 7 This is a schematic diagram of the threaded block and clamping plate mating structure of the present invention.

[0030] Figure 8 This is a schematic diagram of the planar structure of the threaded block and the clamping plate of the present invention.

[0031] Figure 9 This is a schematic diagram of the second and third groove structures of the present invention.

[0032] In the picture: 1. Roller sleeve; 2. Roller shaft; 3. First groove; 4. Second groove; 5. Sleeve; 6. First bolt; 7. Transmission bolt; 8. Threaded rod; 9. Fixing box; 10. Threaded block; 11. Support rod; 12. First connecting rod; 13. First pin; 14. Circular locking block; 15. Gear ring; 16. Gear; 17. First end; 18. Second end; 19. Bracket; 20. Second bolt; 21. Vertical rod; 22. Moving rod; 23. Reversing rod; 24. Clamping plate; 25. Second connecting rod; 26. Second pin; 27. Third groove. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0034] Example 1: Reference Figures 1-9The system includes a roller shaft 2 and a roller sleeve 1. The roller sleeve 1 is fitted onto the outside of the roller shaft 2 and coaxially fitted onto the outer surface of the roller shaft 2. The roller sleeve 1 and the roller shaft 2 are connected by an interference fit. The clamping force generated by the interference fit achieves the initial fixation of the roller sleeve 1 and the roller shaft 2, which can effectively transmit the torque during the rolling process and meet the high-strength rolling operation requirements of the rolls and support rolls. A fixing component is fitted onto one side of the roller shaft 2. This fixing component adopts a universal adaptable structure and can be directly snapped and fixed onto the existing roller shaft 2 without cutting, modifying or redesigning the original roller shaft 2 structure, which greatly reduces the equipment modification cost and has extremely strong adaptability and versatility. Two fixing boxes 9 are provided on the outside of the fixing component. The two fixing boxes 9 are symmetrically arranged vertically, and the structural layout is balanced and stable, which can ensure uniform clamping and positioning force. Each fixing box 9 has a threaded block 10 slidably connected inside. The threaded block 10 can slide inside the fixing box 9, and a support rod is provided on the top of the threaded block 10. 11. The threaded block 10 drives the support rod 11 to move. The support rod 11 is a round rod with high structural strength and strong resistance to compression and deformation. A positioning component is fitted on one side of the support rod 11. The top of the positioning component is equipped with a round locking block 14. The round locking block 14 is rotatably connected to the roller shaft 2 and can rotate flexibly against the outer wall of the roller shaft 2 without interfering with the normal rotation of the roller shaft 2. The top of the round locking block 14 cooperates with the roller sleeve 1. The axial and radial constraints on the roller sleeve 1 are achieved through multi-point contact and limiting. The positioning component can drive the round locking block 14 to rotate synchronously through its own adjustment structure, accurately fitting the assembly position of the roller sleeve 1. This effectively limits the axial movement, radial displacement, loosening and falling off of the roller sleeve 1 during the high-speed rotation of the roller shaft 2 and high-pressure rolling process. This greatly improves the stability and operational safety of the assembly of the roller sleeve 1 and the roller shaft 2, and extends the service life of the equipment. A disassembly component is provided on the other side of the support rod 11. The disassembly component can work in coordination with the positioning component. During the equipment assembly stage, the positioning component can be used to complete the precise alignment, clamping and fixing and limit locking of the roller sleeve 1, ensuring the assembly accuracy and firmness of the roller sleeve 1. During the disassembly stage of equipment maintenance and replacement of the roller sleeve 1, the disassembly component can provide auxiliary pushing and loosening force to release the limit constraint of the positioning component and reduce the disassembly difficulty of the interference fit roller sleeve 1.

[0035] It should be noted that the current industry standard for disassembling interference fit roll sleeves 1 typically involves heating the roll sleeve 1 as a whole and then hoisting it in place. This utilizes the thermal expansion of the heated roll sleeve 1 to eliminate the interference clamping force, and then relies on the roll sleeve 1's own weight combined with the hoisting pull to achieve natural separation between the roll sleeve 1 and the roll shaft 2. However, this disassembly method is only suitable for large-sized, heavy roll sleeves 1, and its specificity and applicability are limited. For small and medium-sized roll shafts 2 and lightweight roll sleeve 1 structures, because the roll sleeve 1 is relatively light and its own weight is insufficient to overcome the residual friction and structural adhesion forces, even with heating to expand its diameter and hoisting, the roll sleeve 1 is prone to jamming and failing to detach on its own. This not only makes disassembly difficult and inefficient, but also easily leads to surface scratches on the roll shaft 2 and deformation and damage to the roll sleeve 1 caused by forced hoisting. This can easily render the repaired roll shaft 2 unusable, significantly increasing equipment repair costs and severely impacting the roll maintenance and replacement schedule. Therefore, this invention sets up a dedicated disassembly component and positioning component to work together, and adopts a collaborative disassembly method of active assisted disassembly and passive hoisting and lifting. On the basis of traditional hoisting operations, the disassembly component provides active pushing and loosening force, which effectively overcomes the residual assembly friction of the lightweight roller sleeve 1, and completely solves the industry problem that the small roller shaft 2 and roller sleeve 1 cannot automatically fall off after heating and are stuck during disassembly and assembly. No violent disassembly is required, which effectively protects the base structure of the roller shaft 2 and roller sleeve 1, and greatly improves the disassembly efficiency and repair yield of roller sleeve 1.

[0036] The fixing assembly includes two retaining sleeves 5, which are symmetrically arranged about the center line of the roller shaft 2. The retaining sleeves 5 are fitted onto the outer side of the roller shaft 2, and the overall structure is a split, semi-enclosed design fitted onto the outer circumference of the roller shaft 2. This symmetrical retaining sleeve structure perfectly conforms to the outer contour of the roller shaft 2, ensuring uniform clamping force and avoiding problems such as localized compression deformation and stress concentration caused by single-point clamping. It also adapts to the existing standard roller shaft 2 outer diameter, requiring no processing or modification of the roller shaft 2 body, allowing for direct and rapid assembly and high versatility. The two retaining sleeves 5 are connected to each other by multiple first bolts 6, and the two sets of retaining sleeves 5 are locked together by multiple sets of evenly distributed first bolts 6. These first bolts 6 are evenly distributed on both sides of the retaining sleeves 5 at the mating positions, and the bolt tightening force ensures that the upper and lower retaining sleeves 5 tightly hug the outer wall of the roller shaft 2, ensuring no relative slippage or loosening between the retaining sleeves 5 and the roller shaft 2, significantly improving the overall assembly firmness and structural stability of the fixing assembly.

[0037] Inside the fixed box 9, threaded rods 8 are rotatably connected. Transmission bolts 7 are connected to the outer sides of the threaded rods 8, allowing rotation via an electric or manual wrench. The outer sides of the threaded rods 8 are threadedly connected to threaded blocks 10. Rotating the threaded rods 8 causes the threaded blocks 10 to slide linearly. A gear 16 is connected to the inner side of each threaded rod 8. The inner sides of two gears 16 mesh with a gear ring 15. The inner sides of the gears 16 are rotatably connected to the roller shaft 2. Gears 16 are fixed to the inner ends of the two threaded rods 8 respectively, and both gears 16 simultaneously mesh with the intermediate gear ring 15, allowing the gears 16 to rotate relative to the roller shaft 2. Through the meshing transmission of the gear ring 15, the two gears 16 can operate synchronously. The operator only needs to rotate any one of the transmission bolts 7 to achieve synchronous rotation of the two threaded rods 8, completing the linkage adjustment of the two side structures.

[0038] The positioning assembly includes a first connecting rod 12, the bottom of which is rotatably connected to a support rod 11. The support rod 11 and the first connecting rod 12 can freely deflect at an angle to ensure flexible and unhindered transmission. A first pin 13 is hinged to the top of the first connecting rod 12. The inner side of the first pin 13 is fixedly connected to a circular locking block 14. The position of the first pin 13 is higher than the center of the circular locking block 14. When the support rod 11 moves horizontally outward in sync with the threaded block 10, it will continuously pull the bottom end of the first connecting rod 12 outward, causing the first connecting rod 12 to tilt at an angle. The top end of the first connecting rod 12 is hinged with a first pin 13. The inner end of the first pin 13 is fixedly connected to the circular locking block 14 as an integral structure. The mounting position of the first pin 13 is higher than the center position of the circular locking block 14, forming an eccentric hinge transmission structure. The eccentricity can realize the mechanical transmission effect of small displacement driving large angle rotation, effectively improving the sensitivity of positioning adjustment. As the support rod 11 is pulled outward, the first connecting rod 12 swings and deflects outward and downward, which can pull the circular locking block 14 to rotate around the end of the roller shaft 2 as the rotation base point.

[0039] The end of the roller shaft 2 is provided with two first grooves 3. The two first grooves 3 are arranged symmetrically about the center line of the roller shaft 2. The first grooves 3 accommodate circular locking blocks 14. The groove size of the first groove 3 is adapted to the shape of the circular locking blocks 14, so that the circular locking blocks 14 can be stored, hidden and limited to avoid interference with the normal assembly and rotation of the roller sleeve 1. The end of the roller sleeve 1 on the same side is provided with two second grooves 4. The two second grooves 4 are arranged symmetrically about the center line of the roller shaft 2.

[0040] The top of the circular locking block 14 is provided with a first end 17 and a second end 18. The first end 17 abuts against the inner wall of the second groove 4, and the inner side of the second end 18 abuts against the end of the roller sleeve 1. In the assembly and positioning condition, the circular locking block 14 is driven to rotate forward by the support rod 11 and the connecting rod transmission, so that the first end 17 of the circular locking block 14 is tightly pressed against the inner wall of the second groove 4, completing the clamping and limiting structure. When it is necessary to disassemble the roller sleeve 1, the support rod 11 is adjusted in the opposite direction to retract inward, which drives the first connecting rod 12 to shift in the opposite direction, thereby driving the circular locking block 14 to rotate in the opposite direction. At this time, the second end 18 of the circular locking block 14 will actively push the end face of the roller sleeve 1, generating an axial pushing force, which can effectively break the static friction and adsorption clamping force between the interference fit between the roller sleeve 1 and the roller shaft 2, and realize the loosening and separation of the roller sleeve 1 in advance. Combined with traditional heating expansion and hoisting lifting methods, a collaborative disassembly mode of "mechanical active pushing + hoisting passive lifting" is formed, which solves the pain points of insufficient self-weight of small and lightweight roll sleeve 1, inability to automatically detach after heating, and jamming and difficult disassembly. It greatly reduces the difficulty of disassembling roll sleeve 1, avoids damage to roll shaft 2 and roll sleeve 1 caused by violent disassembly, and effectively improves the efficiency of roll repair and disassembly and the integrity rate of finished products.

[0041] Example 2: Based on Embodiment 1, and considering actual operating conditions, it is known that a gap is reserved between the first end 17 and the second end 18 of the circular locking block 14. This gap provides space for rotational clearance, which can prevent the locking block from being obstructed and the mechanism from being locked due to the complete clamping of the roller sleeve 1 at both ends. Since the circular locking block 14 moves along a circular arc trajectory, the axial pushing stroke of the second end 18 is limited. During operation, its short-stroke pushing force can be used to first break the static friction between the roller sleeve 1 and the roller shaft 2, and then the disassembly can be completed with hoisting. However, the short pushing distance will also reduce the disassembly and assembly efficiency. Therefore, the following technical solutions are proposed to solve the above problems.

[0042] Specifically, the disassembly assembly includes a bracket 19. The inner side of the bracket 19 is connected to the roller 2 via a second bolt 20. During assembly, only two mounting holes need to be machined at the corresponding positions on the roller 2. No changes need to be made to the overall structure and shape of the roller 2. The modification is simple and highly versatile. The outer side of the bracket 19 is rotatably connected to a second connecting rod 25. The bottom of the second connecting rod 25 is slidably connected to the support rod 11. Through-hole slots are opened at both the upper and lower ends of the second connecting rod 25. The bottom through-hole slot is slidably engaged with the support rod 11. The movement of the support rod 11 can drive the second connecting rod 25 to rotate.

[0043] The top of the second connecting rod 25 is slidably connected to a second pin 26. A movable rod 22 is fixedly connected to the outside of the second pin 26. A vertical rod 21 is connected through the inside of the movable rod 22. The vertical rod 21 guides and limits the movable rod 22, allowing it to move only in a straight line in the horizontal direction. The second connecting rod 25 is rotatably connected to the bottom of the bracket 19. Therefore, the second connecting rod 25 is a lever that requires effort to operate. Relying on the lever transmission characteristics, a small displacement of the support rod 11 can drive the top of the second connecting rod 25 to produce a large stroke. The vertical rod 21 is fixedly connected to the bracket 19 at its bottom. The inner side of the moving rod 22 is provided with a reversing rod 23. The reversing rod 23 can be manually turned or automatically driven by a geared motor to adapt to different working scenarios. The inner side of the reversing rod 23 is fixedly connected with a clamping plate 24. The inner side of the clamping plate 24 is fitted with a third groove 27. The third groove 27 is located at the end of the roller sleeve 1. The internal cavity space has sufficient clearance to provide clearance space for the rotation of the clamping plate 24. During operation, the clamping plate 24 is first inserted into the third groove 27, and then the reversing rod 23 is controlled to rotate the clamping plate 24 by 90 degrees, so that the clamping plate 24 and the third groove 27 form a locking fit, thereby realizing a reliable locking connection between the clamping plate 24 and the roller sleeve 1. A sensor can be added at a certain point of the disassembly assembly to monitor the movement of the roller sleeve 1. When the clamping plate 24 is detected to be in contact with the side wall of the third groove 27, the geared motor can be actively controlled to rotate, so that the clamping plate 24 rotates and completes the connection with the roller sleeve 1.

[0044] During assembly, the roller sleeve 1 is first heated, and the roller shaft 2 is placed into the roller sleeve 1 using hoisting equipment. When the sensor detects that the clamping plate 24 is in contact with the end of the roller sleeve 1 and the roller sleeve 1 is close to being assembled, the control reversing rod 23 drives the clamping plate 24 to rotate 90 degrees, so that the clamping plate 24 is locked into the third groove 27 at the end of the roller sleeve 1 to complete the initial locking. Then, the transmission bolt 7 is rotated, and the gear 16 and gear ring 15 drive the threaded rods 8 on both sides to rotate, driving the threaded block 10 and the support rod 11 to move. On the one hand, the support rod 11 drives the positioning component to move, so that the circular clamping block 14 rotates in the forward direction, and its first end 17 abuts against the inner side wall of the second groove 4 of the roller sleeve 1. On the other hand, the clamping plate 24 cooperates to pull the roller sleeve 1 to fine adjust its position. Finally, the circular clamping block 14 and the clamping plate 24 form a bidirectional limit, and the circular clamping block 14 and the clamping plate 24 form a bidirectional locking constraint from the axial and circumferential directions, respectively, completely restricting the displacement of the roller sleeve 1. The entire assembly operation is completed.

[0045] The disassembly operation is performed in reverse order of assembly: First, the reversing rod 23 is operated to rotate and reset the clamping plate 24, aligning it with the opening of the third groove 27, thus releasing the clamping constraint of the clamping plate 24 and facilitating the removal of the roller sleeve 1. Then, the threaded rod 8 is driven in the reverse direction, causing the support rod 11 to retract, causing the circular clamping block 14 to rotate in the opposite direction. With the help of its second end 18, it pushes against the end face of the roller sleeve 1, breaking the static friction generated by the interference fit between the roller sleeve 1 and the roller shaft 2. At the same time, the lever amplification effect of the second connecting rod 25 is used to drive the clamping plate 24 to apply a long-stroke axial thrust to the roller sleeve 1. Combined with traditional hoisting operations, the roller sleeve 1 is quickly separated from the roller shaft 2, completing the disassembly.

[0046] Example 3: A roll repair process includes the following steps: S1. Perform UT and magnetic particle testing on the scrapped rolls and support rolls 2 to check for quality defects in the roll body 2; S2. The roller sleeve blank is made of mold steel and then subjected to forging, post-forging normalizing and tempering, rough machining, flaw detection, quenching and tempering, and precision machining. The roller sleeve is then quenched as a whole to the original design hardness of the roll. S3. Calculate and determine the assembly interference based on the roller sleeve length, inner and outer diameter dimensions, and transmitted torque parameters; S4. Heat the processed roller sleeve and heat-fit it onto the outside of the roller shaft 2 to form an interference fit between the roller sleeve and the roller shaft 2, thus completing the repair operation.

[0047] The roller sleeve material is 5CrNiMo hot work die steel, which has excellent hardenability, toughness, thermal fatigue resistance and impact resistance, and is suitable for the working conditions of the support roller.

[0048] Non-destructive testing of roll shaft 2: First, scrapped rolls and support rolls 2 with worn hardened layers and acceptable steel throughput but intact substrates after on-site use were selected. A comprehensive inspection of roll shaft 2 was conducted using both UT ultrasonic testing and magnetic particle testing. Ultrasonic testing was used to detect internal defects such as cracks, porosity, inclusions, and fatigue damage within the roll shaft 2 substrate. Magnetic particle testing focused on detecting micro-cracks and fatigue lines on the surface and near-surface of roll shaft 2, which are difficult to detect with the naked eye. By comprehensively assessing the quality of the roll shaft 2 substrate through dual testing, only roll shafts with intact structure, no cracks, deformation, or fatigue damage, and only worn wear layers on the roll surface, were retained as repair substrates. This ensured the overall structural strength and operational safety of the repaired roll from the source, eliminating unqualified rolls with internal hidden dangers and avoiding production risks such as roll breakage or failure after repair.

[0049] Customized processing and heat treatment of high-performance roll sleeves: This process differs from traditional Cr3 and Cr5 ordinary material roll sleeves. It selects 5CrNiMo hot work die steel as the raw material for roll sleeve preparation. This material has excellent hardenability, high strength, high toughness, excellent heat fatigue resistance and impact resistance. It can effectively resist alternating loads, instantaneous impact loads and high temperature friction conditions during the rolling process. It is very suitable for the long-term pressure bearing, fatigue resistance and wear resistance of support rolls, and greatly improves the service life of repair rolls. After the roll sleeve blank is formed, it undergoes multiple precision machining and heat treatment processes in sequence: First, forging is performed to break up the as-cast structure, refine the metal grains, and improve the material density and comprehensive mechanical properties; after forging, post-forging normalizing and tempering is carried out to completely eliminate forging internal stress and prevent deformation and cracking during subsequent processing and use; then, rough machining is performed to remove the blank allowance and initially form the roll sleeve structure; after rough machining, non-destructive testing is performed again to check for internal defects in the machined blank and ensure that the blank quality is qualified; then, quenching and tempering is performed to further stabilize the metallographic structure and improve the material strength and toughness matching; after quenching and tempering, fine machining is carried out to strictly ensure the accuracy of key dimensions such as the inner and outer diameters, length, and end face flatness of the roll sleeve; finally, the roll sleeve is subjected to overall quenching treatment, and the quenching process parameters are precisely controlled to make the overall hardness of the roll sleeve match the original equipment roll design hardness standard, ensuring that the wear resistance and rolling load-bearing capacity of the roll sleeve meet the standards.

[0050] Precise Interference Calculation and Parameter Verification: Before assembling the roll sleeve and roll shaft 2, the interference fit is precisely designed based on the actual operating parameters of the repaired roll. Combining the actual length, inner diameter, outer diameter, and wall thickness of the roll sleeve, as well as core parameters such as the rated torque, rolling load, operating speed, and thermal expansion / contraction variables that the roll needs to transmit during operation, theoretical calculations are performed using mechanical interference fit calculation formulas. These calculations are then verified and optimized using data from multiple on-site repair tests to ultimately determine a reasonable, safe, and suitable interference fit. Precise calculation avoids issues such as roll sleeve slippage, loosening, and movement during rolling due to insufficient interference, while also preventing problems like difficulty in hot fitting, roll sleeve cracking, and extrusion damage to roll shaft 2 caused by excessive interference, ensuring assembly accuracy and long-term stability.

[0051] Hot-fitting assembly and repair molding: The processed, heat-treated, and dimensionally verified roll sleeves are uniformly heated to increase the inner diameter of the roll sleeve through the principle of thermal expansion and contraction, eliminating assembly interference. During heating, uniform heating of the entire roll sleeve is ensured to prevent localized overheating that could alter material properties. After the roll sleeve expands to the assembly size, specialized hoisting equipment is used to precisely align and quickly heat-fit it onto the outside of the pre-treated roll shaft 2. As the roll sleeve cools naturally, it gradually shrinks, forming a high-strength interference fit with the outer wall of the roll shaft 2. The clamping force of the mating surfaces ensures stable torque transmission, fully meeting the load-bearing and transmission requirements of rolling conditions. After the roll sleeve has completely cooled and stabilized, the overall roll dimensions, coaxiality, and fit are re-inspected. Once the re-inspection is passed, the repair of the entire roll and support roll is complete, and the repaired roll can be reused on the production line.

[0052] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A repairable rolling mill roll, comprising a roll shaft (2) and a roll sleeve (1), characterized in that, The roller sleeve (1) is fitted on the outside of the roller shaft (2). The roller sleeve (1) and the roller shaft (2) are connected by an interference fit. A fixing component is fitted on one side of the roller shaft (2). Two fixing boxes (9) are provided on the outside of the fixing component. The two fixing boxes (9) are arranged symmetrically up and down. A threaded block (10) is slidably connected inside each fixing box (9). A support rod (11) is provided on the top of the threaded block (10). A positioning component is provided on one side of the support rod (11). A circular locking block (14) is provided on the top of the positioning component. The circular locking block (14) is rotatably connected to the roller shaft (2). The top of the circular locking block (14) cooperates with the roller sleeve (1). A disassembly component is provided on the other side of the support rod (11).

2. The repairable roll according to claim 1, characterized in that, The fixing assembly includes two sleeves (5), which are arranged symmetrically about the center line of the roller shaft (2). The sleeves (5) are fitted onto the outside of the roller shaft (2), and the two sleeves (5) are connected to each other by a plurality of first bolts (6).

3. A repairable roll according to claim 1, characterized in that, The fixed box (9) is rotatably connected to a threaded rod (8). The outer side of the threaded rod (8) is connected to a transmission bolt (7). The outer side of the threaded rod (8) is threadedly connected to a threaded block (10). The inner side of each threaded rod (8) is connected to a gear (16). The inner sides of the two gears (16) mesh together with a gear ring (15). The inner side of the gear (16) is rotatably connected to the roller shaft (2).

4. A repairable roll according to claim 1, characterized in that, The positioning component includes a first connecting rod (12), the bottom of which is rotatably connected to a support rod (11), and a first pin (13) is hinged to the top of the first connecting rod (12). The inner side of the first pin (13) is fixedly connected to a circular locking block (14), and the position of the first pin (13) is higher than the center of the circular locking block (14).

5. A repairable roll according to claim 4, characterized in that, The end of the roller (2) is provided with two first grooves (3), the two first grooves (3) are arranged symmetrically about the center line of the roller (2) and the first grooves (3) accommodate circular blocks (14). The end of the roller sleeve (1) on the same side is provided with two second grooves (4), the two second grooves (4) are arranged symmetrically about the center line of the roller (2) and the two second grooves (4) are arranged symmetrically about the center line of the roller (2).

6. A repairable roll according to claim 5, characterized in that, The top of the circular card block (14) is provided with a first end (17) and a second end (18). The first end (17) abuts against the inner wall of the second groove (4), and the inner side of the second end (18) abuts against the end of the roller sleeve (1).

7. A repairable roll according to claim 1, characterized in that, The disassembly assembly includes a bracket (19), the inner side of which is connected to the roller (2) by a second bolt (20), and the outer side of which is rotatably connected to a second connecting rod (25), the bottom of which is slidably connected to a support rod (11).

8. A repairable roll according to claim 7, characterized in that, The top of the second connecting rod (25) is slidably connected to a second pin (26), and a moving rod (22) is fixedly connected to the outside of the second pin (26). A vertical rod (21) is connected through the inside of the moving rod (22), and the bottom of the vertical rod (21) is fixedly connected to the bracket (19). A reversing rod (23) is provided on the inside of the moving rod (22), and a clamping plate (24) is fixedly connected on the inside of the reversing rod (23). A third groove (27) is fitted on the inside of the clamping plate (24), and the third groove (27) is located at the end of the roller sleeve (1).

9. A roll repair process, characterized in that, Repairing the roll sleeve (1) using a repairable roll as described in claim 1 includes the following steps: S1. Perform UT and magnetic particle testing on the scrapped rolls and support rolls (2) to check whether there are quality defects in the roll body (2); S2. The roller sleeve blank is made of mold steel and then subjected to forging, post-forging normalizing and tempering, rough machining, flaw detection, quenching and tempering, and precision machining. The roller sleeve is then quenched as a whole to the original design hardness of the roll. S3. Calculate and determine the assembly interference based on the roller sleeve length, inner and outer diameter dimensions, and transmitted torque parameters; S4. Heat the finished roller sleeve and heat-fit it to the outside of the roller shaft (2) so that the roller sleeve and the roller shaft (2) form an interference fit and complete the repair operation.

10. A roll repair process according to claim 9, characterized in that, The roller sleeve material is 5CrNiMo hot work die steel, which has excellent hardenability, toughness, thermal fatigue resistance and impact resistance, and is suitable for the working conditions of the support roller.

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