Rolling mill drive connection structure and steel sheet rolling mill device

Abstract

The application provides a rolling mill transmission connection structure and a steel plate rolling mill device, and relates to the technical field of rolling mills. A shaft head in a cylindrical shape is arranged at the end of a rolling mill, the connection between the end head of the rolling mill and the inner hole of the round head sleeve is arranged as complete cylindrical interference fit connection, and the torque of the rotation of the rolling mill is entirely transmitted by the interference between the cylindrical end head and the inner hole of the round head sleeve. In the case that the diameters of the end heads of the rolling mills are the same, the interference between the cylindrical end head of the rolling mill and the round head sleeve can stably and reliably bear a torque force that exceeds the torque that can be transmitted by the flat head and the flat head sleeve, effectively improves the torque transmission stability, transmits the torque of the super heavy steel plate rolling mill, guarantees the safety and reliability, and solves the technical problem of insufficient bearing capacity of the sliding block type torque transmission mode in the prior art.

Description

Technical Field

[0001] This invention relates to the field of rolling mill technology, and in particular to a rolling mill transmission connection structure and a steel plate rolling mill device. Background Technology

[0002] In the field of steel rolling technology, the reliability and efficiency of the transmission system directly affect the production capacity and product quality of the rolling mill. As a key component connecting the drive shaft and the rolls, the design of the flat head sleeve has evolved from the traditional round hole keyway structure to a non-circular cross-section insert type structure. Early rolling mill transmission systems used universal joints or clamping joints. With the increasing demands for transmission efficiency and ease of roll changing in rolling processes, the bracket-type flat head sleeve structure integrated into the roll changing system gradually developed. This structure, through the non-circular cross-section cooperation between the flat head at the roll shaft end and the flat head sleeve at the drive shaft end, achieves the dual functions of torque transmission and axial sliding, while allowing a certain angle of runout to compensate for thermal expansion and installation errors during the rolling process.

[0003] The flat-head sleeve structure currently used in mainstream rolling mills can meet the operating requirements of roll diameters up to Ø1240mm and motor torques up to 2000KN·m. However, with the development of rolling processes towards higher loads, especially the widespread application of composite cast rolls, the traditional slide block torque transmission method has shown insufficient load-bearing capacity. In addition, the greater demand for a wider range of roll diameter variations in ultra-heavy rolling mills has severely limited the outer diameter of the flat-head sleeve. This not only restricts the improvement of the strength of transmission components but also causes stress concentration at the roll end at the slide block connection due to abrupt changes in cross-section, making it prone to fracture in the transition area. Summary of the Invention

[0004] The purpose of this invention is to provide a rolling mill drive connection structure and a steel plate rolling mill device to alleviate the technical problem of insufficient load-bearing capacity of the existing slider torque transmission method.

[0005] In a first aspect, the mill drive connection structure provided by the present invention includes: a rolling mill roll and a round head sleeve; One end of the roller is provided with a cylindrical shaft head; The round head sleeve is provided with an inner hole; The shaft head is interference-fitted to the inner hole so that the rotational torque of the roll is transmitted through the interference fit between the shaft head and the inner hole.

[0006] In an optional implementation, The shaft head is provided with a guide chamfer for guiding the shaft head into the inner hole.

[0007] In an optional implementation, The guide chamfer is set to 10mm~30mm*45°, or the guide chamfer is set to an arc chamfer with a length of 10mm~30mm.

[0008] In an optional implementation, The roll is made of composite cast iron, with the outer layer being a wear-resistant layer and the inner layer being ductile iron.

[0009] In an optional implementation, The wear-resistant layer contains at least one trace element selected from boron, magnesium, rare earth elements, and niobium.

[0010] In an optional implementation, The basic diameter of the shaft head that mates with the inner hole is 750mm~850mm, and the corresponding interference is 0.75mm~1.5mm.

[0011] In an optional implementation, The heating temperature of the round head sleeve in the heat treatment furnace is set to be 150°C to 250°C higher than room temperature.

[0012] In an optional implementation, The heating temperature of the round head sleeve in the heat treatment furnace is set to be 180°C to 200°C higher than room temperature.

[0013] In an optional implementation, The round head sleeve is kept at a temperature of more than 10 minutes in the heat treatment furnace.

[0014] Secondly, the steel plate rolling mill device provided by the present invention includes the rolling mill transmission connection structure.

[0015] The mill transmission connection structure provided by this invention features a cylindrical shaft end at the end of the roll. The connection between the roll end and the inner hole of the round head sleeve is configured as an interference fit between a complete cylinder and the inner hole. The torque of the roll rotation is transmitted entirely through the interference fit between the cylindrical end and the inner hole of the round head sleeve. When the roll end diameter is the same, the torque force that the cylindrical end and the round head sleeve can reliably and stably bear exceeds the torque that the flat end and the flat head sleeve can transmit. This effectively improves the stability of torque transmission, enabling the transmission of the roll torque of ultra-heavy steel plate rolling mills, while ensuring safety and reliability. It also alleviates the technical problem of insufficient load-bearing capacity in the existing slider-type torque transmission method. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific 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 from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the mill drive connection structure provided in an embodiment of the present invention from a frontal view. Figure 2 This is a top view of the structure of the rolling mill drive connection structure provided in an embodiment of the present invention.

[0018] Icons: 100-roll; 110-shaft head; 120-guide chamfer; 200-round head sleeve; 210-inner hole. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0023] like Figures 1 to 2 As shown, the mill drive connection structure provided in this embodiment includes a roll 100 and a round head sleeve 200. One end of the roll 100 is machined into a continuous, smooth, keyless, or non-circular cylindrical shaft head 110. The shaft head 110 extends a certain length along the axial direction, and its surface roughness and roundness accuracy meet the interference fit assembly requirements. One end of the round head sleeve 200 has an opening, and the inner wall of the opening end of the round head sleeve 200 is machined into a cylindrical inner hole 210 that strictly matches the diameter and tolerance of the shaft head 110. The surface of the inner hole 210 is precision turned, ground, or honed to ensure uniform contact. The connection method is characterized by the absence of any intermediate force transmission elements between the shaft head 110 and the inner hole 210. The power of the active motor is transmitted through the radial force generated by the mechanical interference to the shaft head 110 via the transmission shaft (not shown) and the rotating round head sleeve 200. The torque generated by the rotation of the shaft head 110 is transmitted to the cylindrical inner hole 210 completely, continuously, and without gaps. This connection method completely eliminates the non-circular interlocking structure between the traditional flat head and the flat head sleeve, and changes the torque transmission path from discrete surface contact to full circumferential continuous surface contact, which significantly improves the uniformity of load distribution and connection rigidity.

[0024] The shaft head 110 has a guide chamfer 120 at the edge where the cylindrical surface and the end face meet. This chamfer is located at the foremost end of the shaft head 110 in the insertion direction. Its function is to provide guidance in the initial stage of hot assembly, so that the inner hole 210 of the round head sleeve 200 can slide naturally along the chamfered surface and automatically center itself. This avoids the difficulty in alignment caused by slight coaxiality deviations or inconsistent thermal deformation between the shaft head 110 and the inner hole 210, which can lead to time-consuming assembly, or the shaft head sleeve cooling down, reducing or eliminating the gap due to excessive assembly time, which may require reheating. It may even cause difficulties such as the shaft sleeve being partially fitted into the shaft head, while the remaining part is stuck in the middle due to the small gap, making it impossible to remove. This greatly reduces the time required for manual alignment and improves on-site assembly efficiency and first-time success rate.

[0025] There are two possible structures for the guide chamfer 120: The first is a straight chamfer, in which a plane is cut at a 45° angle to the axis along the generatrix direction at the end of the shaft head 110. The axial extension of this plane is 10mm to 30mm, and its width increases synchronously with the increase of the diameter of the shaft head 110, ensuring sufficient guiding depth throughout the entire chamfer range; The second is an arc chamfer, in which a circular arc surface with its center on the axis is formed by smoothly transitioning along both the axial and radial directions from the edge of the end of the shaft head 110. The arc length of this circular arc surface is 10mm to 30mm, ensuring smooth guidance and avoiding excessive reduction of the cross-sectional area at the root of the shaft head 110 due to an excessively large arc, which would affect the bending stiffness.

[0026] The roll 100 is made of composite cast iron. The composite cast iron has a double-layer structure: the outer layer is a high-chromium, high-hardness, wear-resistant layer, and the inner layer is ductile iron. The ductile iron is preferably QT450-10. Its matrix structure is mainly ferrite, and the graphite is in a uniformly distributed spherical shape. It has good plasticity, toughness and impact fatigue resistance, and is used to support the outer layer and bear the combined axial and torsional loads.

[0027] The outer wear-resistant layer of composite cast iron contains at least one trace element selected from boron, magnesium, rare earth elements and niobium; this alters the spherical shape of graphite, eliminates the carbide network structure, and refines the solidification structure, significantly improving its resistance to hot cracking and wear resistance.

[0028] The basic diameter of the fit between the shaft head 110 and the inner hole 210 of the round head sleeve 200 is set in the range of 750mm to 850mm. The interference fit corresponding to this basic diameter is controlled between 0.75mm and 1.5mm. This interference fit is the difference between the maximum limit size of the shaft head 110 and the minimum limit size of the inner hole 210. It is calculated based on the material's elastic modulus, the fit length, and the expected maximum working torque. When the interference fit is less than 0.75mm, the interface is prone to micro-movement under alternating torque and vibration load, which may cause the fit to loosen. When it exceeds 1.5mm, it will cause excessive circumferential stress on the inner wall of the round head sleeve 200, resulting in irreversible plastic deformation or even circumferential cracking.

[0029] Before assembly, the round head sleeve 200 needs to be heated in a heat treatment furnace. The heating temperature is set to be 150°C to 250°C higher than the ambient temperature. The diameter of the inner hole 210 will increase by 1.4mm to 2.4mm. This temperature rise range ensures that a sufficient assembly gap is formed between the diameter of the inner hole 210 and the outer diameter of the shaft head 110 after heating. This avoids insufficient expansion due to low temperature, which would prevent assembly, and also prevents material deterioration or severe oxidation caused by high temperature.

[0030] The heating temperature of the round head sleeve 200 in the heat treatment furnace is further preferably 180°C to 200°C higher than the room temperature. Within this temperature range, the thermal expansion of the inner hole 210 is stably in the range of 1.7mm to 2.2mm, which not only fully covers the interference requirement of 0.75mm to 1.5mm, but also leaves a reasonable margin to compensate for factors such as furnace temperature uniformity deviation, temperature measurement lag and heat dissipation during furnace loading.

[0031] After the round head sleeve 200 reaches the target heating temperature, it must be kept at a constant temperature in the heat treatment furnace for more than 10 minutes. This holding time ensures that the heat is fully conducted from the outer surface of the round head sleeve 200 to the inside, eliminating the problem of dimensional instability and reliability caused by the inconsistency between the inner and outer temperatures, making the temperature of the entire cylinder wall section tend to be uniform, and meeting the thermal condition consistency requirements of precision interference assembly.

[0032] The steel plate rolling mill integrates the aforementioned rolling mill transmission connection structure. The roll 100 is connected to the main drive through the interference fit between the cylindrical shaft head 110 and the inner hole 210 of the round head sleeve 200. The other end of the round head sleeve 200 retains the original fork head structure and is slidably hinged to the drive shaft through a crescent-shaped slider. This structure transforms the original auxiliary positioning function into the sole and dominant torque transmission mechanism, thereby breaking through the load-bearing bottleneck of the traditional flat head structure under ultra-large diameter and ultra-high torque conditions. It provides a new transmission interface solution with engineering feasibility for ultra-heavy steel plate rolling mills with work roll specifications of 1250mm to 1500mm.

[0033] The diameter of roll 100 can be 1250mm, 1260mm, 1270mm, 1280mm, 1290mm, 1300mm, 1310mm, 1320mm, 1330mm, 1340mm, 1350mm, 1360mm, 1370mm, 1380mm, 1390mm, 1400mm, 1410mm, 1410~30mm, 1430mm, 1440mm, 1450mm, 1460mm, 1470mm, 1480mm, 1490mm, or 1500mm, or any value between 1250mm and 1500mm for any steel plate rolling mill.

[0034] In another preferred embodiment, the diameter of the roll 100 is 1350 mm. A roll 100 shaft end 110 is provided at the right end of the roll 100, and a round head sleeve 200 inner hole 210 is provided at the left end of the round head sleeve 200. The roll 100 shaft end 110 and the round head sleeve 200 inner hole 210 are connected by an interference fit. The interference fit adopts a hole-basis system, with a basic fit dimension of 750 mm in diameter and an interference amount of 0.75~0.80 mm. The head is equipped with a guide chamfer of 120°, with the guide chamfer size set to 20mm*45°; the roll 100 is a composite cast iron made of an outer high-chromium, high-hardness, wear-resistant hard layer and an inner ductile cast iron layer that is relatively flexible. The inner layer of the roll 100, including the end material, is all made of QT450-10, and the round head sleeve 200 is made of 42CrMo quenched and tempered steel; during assembly, the round head sleeve 200 is placed in an intermediate frequency coil and heated to 180°C above room temperature, held for 15 minutes, and then assembled.

[0035] As another preferred embodiment, the roller 100 shaft head 110 and the inner hole 210 of the round head sleeve 200 have a basic size of 830mm in diameter and an interference fit of 1.2~1.3mm. The guide chamfer 120 is set as an arc chamfer of R20mm. During assembly, the round head sleeve 200 is placed in the intermediate frequency coil and heated to 210°C higher than the room temperature, kept warm for 20 minutes, and then assembled.

[0036] 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 rolling mill drive connection structure, characterized in that, include: Roll (100) and round head sleeve (200); One end of the roller (100) is provided with a cylindrical shaft head (110). The round head sleeve (200) is provided with an inner hole (210); The shaft head (110) is interference-fitted with the inner hole (210) so that the rotational torque of the roller (100) is transmitted by the interference fit between the shaft head (110) and the inner hole (210).

2. The rolling mill drive connection structure according to claim 1, characterized in that, The shaft head (110) is provided with a guide chamfer (120) for guiding the shaft head (110) into the inner hole (210).

3. The rolling mill drive connection structure according to claim 2, characterized in that, The guide chamfer (120) is set to 10mm~30mm*45°, or the guide chamfer (120) is set to an arc chamfer with a length of 10mm~30mm.

4. The rolling mill drive connection structure according to claim 1, characterized in that, The material of the roll (100) is set as composite cast iron, the outer layer of the composite cast iron is a wear-resistant layer, and the inner layer of the composite cast iron is ductile iron.

5. The rolling mill drive connection structure according to claim 4, characterized in that, The wear-resistant layer contains at least one trace element selected from boron, magnesium, rare earth elements, and niobium.

6. The rolling mill drive connection structure according to claim 1, characterized in that, The basic diameter of the shaft head (110) and the inner hole (210) is 750mm~850mm, and the corresponding interference is 0.75mm~1.5mm.

7. The rolling mill drive connection structure according to claim 6, characterized in that, The heating temperature of the round head sleeve (200) in the heat treatment furnace is set to be 150°C to 250°C higher than room temperature.

8. The mill drive connection structure according to claim 7, characterized in that, The heating temperature of the round head sleeve (200) in the heat treatment furnace is set to be 180°C to 200°C higher than room temperature.

9. The rolling mill drive connection structure according to claim 8, characterized in that, The round head sleeve (200) is kept at a temperature of more than 10 minutes in the heat treatment furnace.

10. A steel plate rolling mill apparatus, characterized in that, Includes the mill drive connection structure as described in any one of claims 1-9.

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