Roll neck fixing structure

Abstract

The application discloses a roll ring fixing structure and belongs to the technical field of steel rolling equipment. The structure comprises a roll shaft, a hard alloy roll ring and a pressing plate. An arc surface key groove is arranged on the end surface of the shaft shoulder of the roll shaft, and an arc surface key with an outward convex arc surface is arranged in the groove. The corresponding end surface of the hard alloy roll ring is provided with an inner concave arc surface groove which is engaged with the arc surface key. The pressing plate is connected with the roll shaft through screw threads and applies axial pressure to the roll ring, so that the arc surface key is tightly combined with the arc surface groove. The application transmits rolling torque through mechanical engagement of the arc surface key and the arc surface groove, avoids the problem of sharp corner stress concentration of the traditional key groove, does not need to rely on friction force generated by huge pressure, and can be disassembled and assembled only through a conventional wrench without professional hydraulic tools. The application has the advantages of simple structure, convenient disassembly and assembly, stable torque transmission and protection of the strength of the roll ring, can effectively improve the steel rolling production efficiency and prolong the service life of the roll ring.

Description

Technical Field

[0001] This utility model belongs to the field of steel rolling equipment technology, and in particular relates to a roll ring fixing structure. Background Technology

[0002] In steel rolling production, cemented carbide roll rings are widely used in the rolling mill industry due to their high strength and hardness, which significantly increase the steel rolling yield. However, cemented carbide roll rings have inherent defects such as poor toughness, fragility, and susceptibility to cracking, making them unable to withstand significant impacts and vibrations.

[0003] In existing technologies, there are two main methods for fixing cemented carbide roll rings: one is to tightly adhere them to the shoulder of the roll shaft from the end face, and the other is to tighten them outwards using a tensioning sleeve within the inner hole. Both methods rely on friction generated by high pressure to transmit rolling torque, and their common advantage is that no structure affecting strength needs to be machined on the roll ring body. However, they also have significant drawbacks: because a huge pressure is required to maintain friction, the disassembly and assembly process must rely on specialized hydraulic roll disassembly and assembly tools, which is not only complex and time-consuming but also increases equipment investment and maintenance costs. Furthermore, the method of relying on friction to transmit torque is prone to pressure attenuation due to vibration during long-term use, posing a risk of unstable torque transmission and affecting rolling accuracy.

[0004] Traditional alloy steel roller rings are fixed using a keyway and key combination method. However, this method requires machining a rectangular keyway in the inner hole of the roller ring. The sharp corners of the keyway will cause severe stress concentration, which can easily lead to breakage for cemented carbide roller rings with poor toughness. Therefore, it cannot be directly applied to the fixing of cemented carbide roller rings. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a film unwinding mechanism for a film packaging machine that automatically cuts the film after packaging, thus solving the problems of the prior art.

[0006] This invention provides the following technical solution:

[0007] A roller ring fixing structure includes a roll shaft, a cemented carbide roller ring, and a pressure plate. One end of the roll shaft is provided with a shoulder, and at least one set of arc-shaped keyways are uniformly formed along the circumferential direction on the end face of the shoulder. An arc-shaped key is adapted to be installed in the arc-shaped keyway, and the outer surface of the arc-shaped key is an outwardly convex arc surface that protrudes from the end face of the shoulder. The cemented carbide roller ring is sleeved on the roll shaft, and its end face near the shoulder is provided with arc-shaped grooves that correspond one-to-one with the arc-shaped keys. The arc-shaped grooves are concave arc surfaces and mesh with the outwardly convex arc surfaces of the arc-shaped keys.

[0008] Preferably, the outer periphery of the end of the roll shaft away from the shoulder is provided with an external thread, the pressure plate is threaded to the external thread through an internal thread hole, and the end face of the pressure plate near the cemented carbide roll ring abuts against the cemented carbide roll ring to apply axial pressure.

[0009] Preferably, the arc-shaped key and the arc-shaped keyway are fixed by a transition fit.

[0010] Preferably, the number of the arc-shaped keys is 1-6 sets, which are evenly distributed on the end face of the shoulder.

[0011] Preferably, the radius of the convex arc surface of the arc key is 1.5-3 times the radius of the inner hole of the cemented carbide roller ring.

[0012] Preferably, the depth of the arc groove is 3-15mm.

[0013] Preferably, an elastic gasket is provided between the pressure plate and the hard alloy roller ring, and the elastic gasket is made of spring steel.

[0014] Preferably, the arc-shaped key is made of high-strength alloy steel with a surface hardness of HRC35-45.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention provides a roller ring fixing structure that is easy to assemble and disassemble, reducing costs. It transmits rolling torque through the meshing of the arc-shaped key and the arc-shaped groove, and applies axial pressure through the threaded connection of the pressure plate. It does not rely on the frictional force generated by huge pressure. Therefore, the assembly and disassembly process does not require professional hydraulic tools and can be completed with just a conventional wrench, which significantly improves the efficiency of assembly and disassembly and reduces equipment investment and maintenance costs.

[0017] To protect the strength of the roller ring and extend its service life, both the arc-shaped key and the arc-shaped groove adopt an arc-shaped design, avoiding the sharp corner structure of the traditional rectangular keyway and greatly reducing stress concentration. At the same time, the arc-shaped groove is shallow, which has minimal impact on the overall strength of the cemented carbide roller ring, effectively solving the problem of the cemented carbide roller ring being easily broken and extending the service life of the roller ring.

[0018] The torque transmission is stable and reliable. It uses a mechanical meshing method to transmit torque, which is more efficient and stable than the traditional friction transmission method. It is less prone to torque attenuation due to vibration and other factors, thus ensuring rolling accuracy. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a cross-sectional view of the present invention.

[0021] Figure 2 This is a top view of the present invention.

[0022] Figure 3 This is a schematic diagram of the hard alloy roller ring structure of this utility model.

[0023] Figure 4 This is a schematic diagram of the arc-shaped key structure of this utility model. Detailed Implementation

[0024] 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 a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0026] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions and features of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this invention.

[0027] refer to Figure 1-4 A roller ring fixing structure includes a roller shaft 1, a carbide roller ring 2, and a pressure plate 3. The left end of the roller shaft 1 has a shoulder 11, and the right end face of the shoulder 11 has a set of arc-shaped key slots 4 evenly spaced along the circumference. Each set of arc-shaped key slots 4 contains an arc-shaped key 4 installed through a transition fit. The arc-shaped key 4 is made of 40Cr alloy steel, and after quenching and tempering, its surface hardness is HRC40. Its outer surface is a convex arc surface, the radius of which is a multiple of the inner radius of the carbide roller ring 2, and the convex arc surface protrudes 0.3 mm beyond the right end face of the shoulder 11.

[0028] The carbide roller ring 2 is fitted onto the roll shaft 1. Its left end face (the end face near the shoulder 11) has a circumferentially formed arc-shaped groove 21 that corresponds one-to-one with the arc-shaped key 4. The arc-shaped groove 21 is a concave arc surface, and its curvature perfectly matches the curvature of the convex arc surface of the arc-shaped key 4. The depth of the arc-shaped groove 21 is 10mm. During assembly, the arc-shaped groove 21 and the arc-shaped key 4 are fully engaged.

[0029] The right end of the roll shaft 1 has an external thread, and the center of the pressure plate 3 has an internal thread hole that matches the external thread. The pressure plate 3 is screwed onto the right end of the roll shaft 1 via a threaded connection. An elastic washer made of spring steel is provided between the left end face of the pressure plate 3 and the right end face of the carbide roll ring 2. After the pressure plate 3 is tightened, the elastic washer is compressed, applying axial pressure to the carbide roll ring 2, so that the arc groove 21 and the arc key 4 fit tightly together, ensuring reliable engagement.

[0030] During the rolling process, the rolling torque is transmitted to the arc key 4 through the shoulder 11 of the roll shaft 1, and then to the carbide roll ring 2 through the meshing of the arc key 4 and the arc groove 21, thus achieving stable torque transmission. When it is necessary to replace the carbide roll ring 2, simply loosen the pressure plate 3 in the reverse direction with a wrench, remove the elastic washer and the old roll ring, replace the new roll ring, and then tighten the pressure plate 3 again. The operation is simple and quick.

[0031] As one possible implementation, the arc-shaped key is made of 40CrNiMo alloy steel, which is quenched and tempered (hardness HRC38-42) and then nitrided (nitriding layer depth 0.3-0.5mm) to improve wear resistance. The inner surface of the arc-shaped key is a concave arc surface (radius R50mm) adapted to the arc-shaped keyway, and the outer surface is a convex arc surface (radius R300mm, twice the radius φ150mm of the inner hole of the carbide roll ring in this embodiment). The thickness of the arc-shaped key is 10mm (radial along the roll shaft), the width is 25mm (consistent with the width of the keyway), and the length is 40mm (circumferential along the shoulder). After assembly, the convex arc surface of the arc-shaped key protrudes 0.3mm from the right end face of the shoulder, ensuring pre-contact with the arc-shaped groove of the roll ring. The arc-shaped key and the arc-shaped keyway adopt an H7 / j s6 transition fit, which ensures assembly stability and avoids stress concentration on the shoulder caused by interference fit.

[0032] The carbide roll ring is made of WC-Co carbide (8% Co content), with an overall hardness of HRA90-92, ensuring wear resistance during rolling. The inner diameter of the roll ring is φ300mm, and the clearance between it and the roll shaft is 0.02-0.05mm (using H8 / f7 clearance fit) for easy installation. On the left end face of the roll ring (the end face near the shoulder), there is a circular groove that corresponds one-to-one with the arc-shaped key. The center diameter of the groove distribution circle is consistent with the arc-shaped keyway (φ200mm). The arc-shaped groove is a concave arc surface, and its radius of curvature perfectly matches the convex arc surface of the arc-shaped key (R300mm). The groove depth is 1mm (depth error ≤ ±0.05mm), and the groove width is 26mm (1mm larger than the width of the arc-shaped key, reserving assembly clearance). The arc-shaped groove is machined using a special forming grinding wheel, and the groove edge is rounded with R0.5mm to avoid stress concentration caused by sharp corners.

[0033] Assembly Method: 1. Pre-install the arc-shaped key: Embed the two arc-shaped keys into the arc-shaped keyways on the shoulder of the roll shaft, ensuring that the convex arc surface of the key protrudes evenly from the end face of the shoulder. Use a dial indicator to check that the protrusion error is ≤0.02mm; 2. Install the roll ring: Slide the carbide roll ring onto the right end of the roll shaft and slowly push it to the shoulder. Rotate the roll ring to fully engage the arc-shaped groove and the arc-shaped key (you can confirm by hand that there is no jamming). At this time, the gap between the left end face of the roll ring and the right end face of the shoulder is ≤0.1mm; 3. Install the elastic shim: Slide the elastic shim onto the roll shaft, tightly against the right end face of the carbide roll ring; 4. Screw the pressure plate into the roll shaft through the threaded connection. Use a torque wrench to tighten it evenly in three stages (50 N·m for the first time, 100 N·m for the second time, and 150 N·m for the third time), ensuring that the elastic shim is compressed evenly. At this time, the contact rate of the engagement surface between the arc-shaped key and the arc-shaped groove is ≥90%.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations; any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A roller ring fixing structure, characterized in that, The device includes a roll shaft (1), a carbide roll ring (2), and a pressure plate (3). One end of the roll shaft (1) is provided with a shoulder (11). At least one set of arc-shaped keyways are uniformly opened along the circumferential direction on the end face of the shoulder (11). An arc-shaped key (4) is adapted to be installed in the arc-shaped keyway. The outer surface of the arc-shaped key (4) is an outwardly convex arc surface and protrudes from the end face of the shoulder (11). The carbide roll ring (2) is sleeved on the roll shaft (1). An arc-shaped groove corresponding to the arc-shaped key (4) is opened on its end face near the shoulder (11). The arc-shaped groove is an inwardly concave arc surface and meshes with the outwardly convex arc surface of the arc-shaped key (4).

2. The roll ring fixation structure according to claim 1, characterized by The outer periphery of the end of the roll shaft (1) away from the shoulder (11) is provided with an external thread. The pressure plate (3) is threadedly connected to the external thread through an internal thread hole. The end face of the pressure plate (3) near the hard alloy roll ring (2) abuts against the hard alloy roll ring (2) to apply axial pressure.

3. The roller ring fixing structure according to claim 1, characterized in that, The arc-shaped key (4) and the arc-shaped keyway are fixed by a transition fit.

4. The roller ring fixing structure according to claim 1, characterized in that, The number of the arc-shaped keys (4) is 1-6 sets, which are evenly distributed on the end face of the shoulder (11).

5. The roller ring fixing structure according to claim 1, characterized in that, The radius of the convex arc surface of the arc key (4) is 1.5-3 times the radius of the inner hole of the cemented carbide roller ring (2).

6. The roller ring fixing structure according to claim 1, characterized in that, The depth of the arc groove (21) is 3-15mm.

7. The roller ring fixing structure according to claim 1, characterized in that, An elastic gasket is provided between the pressure plate (3) and the hard alloy roller ring (2), and the elastic gasket is made of spring steel.

8. The roller ring fixing structure according to claim 1, characterized in that, The arc-shaped key (4) is made of high-strength alloy steel.

Images