Continuous casting machine fan-shaped section bearing dynamic clearance compensation mounting structure and control method

Abstract

The invention relates to the technical field of ferrous metallurgy continuous casting equipment, and particularly discloses a continuous casting machine fan-shaped section bearing dynamic clearance compensation installation structure and a control method. The continuous casting machine fan-shaped section bearing dynamic clearance compensation installation structure comprises a fan-shaped section roller and bearing seats, the fan-shaped section roller is installed between a bearing seat A and a bearing seat B, and the fan-shaped section roller is installed between a bearing seat C and a bearing seat D; a fan-shaped section roller is installed between the bearing seat E and the bearing seat F, annular grooves with the depth of 2 mm are machined in the inner sides of end covers of the bearing seat B, the bearing seat D and the bearing seat E which are arranged in the middle, and axial moving gaps are formed between the end covers and bearing outer rings; the bearing outer ring fixing mode and fit tolerance are optimized, dynamic balance of thermal expansion stress is achieved by improving the bearing outer ring fixing structure, the roller is allowed to move slightly in any direction during thermal expansion, single-side stress concentration is eliminated, and under the cold-state working condition, the bearing still keeps positioning precision through optimized tolerance fit, so that the service life of the bearing is prolonged. The shutdown maintenance time is shortened, and the maintenance cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of steel metallurgical continuous casting equipment, and in particular to a dynamic clearance compensation installation structure and a control method for a sector bearing of a continuous casting machine. Background Art

[0002] In the fan-shaped section of the continuous casting machine, bearing damage is the main factor affecting the life of the equipment. The traditional installation method uses one end of the bearing outer ring to be completely fixed, and the other end has a 5mm clearance, which causes the fixed end bearing to be frequently damaged due to unilateral force. Analysis shows that the axial force generated during thermal expansion exceeds the design bearing capacity of the bearing (for example, the axial load design value of the 24024 spherical roller bearing is 12.3 tons, and the actual force reaches 16 tons), causing fatigue damage. Although the existing technology attempts to extend the life by improving lubrication, cooling and assembly accuracy, it has not effectively solved the fundamental problem of excessive axial force. In addition, frequent replacement of bearings leads to increased continuous casting downtime and maintenance costs, and directly affects the surface quality of the ingot and the rolling yield. Therefore, a dynamic clearance compensation installation structure and control method for the fan-shaped section bearing of the continuous casting machine are designed to solve the problem of unilateral wear and fatigue failure of the bearing caused by thermal expansion stress concentration in the traditional installation structure. Summary of the invention

[0003] In view of the problems existing in the prior art, the purpose of the present invention is to provide a dynamic clearance compensation installation structure and control method for a continuous casting machine sector bearing, especially an axial stress compensation technology for double-row spherical roller bearings under high temperature and heavy load conditions. This technology solves the problems of unilateral wear and fatigue failure of bearings caused by thermal expansion stress concentration in traditional installation structures by optimizing the fixing method and fitting tolerance of the bearing outer ring.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a dynamic clearance compensation installation structure of a continuous casting machine fan-shaped segment bearing, including a fan-shaped segment roller and a bearing seat, the bearing seat including a coaxial bearing A seat, a bearing B seat, a bearing C seat, a bearing D seat, a bearing E seat, and a bearing F seat, a fan-shaped segment roller is installed between the bearing A seat and the bearing B seat, a fan-shaped segment roller is installed between the bearing C seat and the bearing D seat, and a fan-shaped segment roller is installed between the bearing E seat and the bearing F seat, and the inner sides of the end covers of the bearing B seat, the bearing D seat, and the bearing E seat arranged in the middle are all processed with an annular groove with a depth of 2mm, and the end cover forms an axial floating gap with the outer ring of the bearing.

[0005] Specifically, the width of the annular groove is increased by 4 mm according to the width of the bearing outer ring, so that the contact area between the end face of the bearing outer ring and the side wall of the annular groove during thermal expansion displacement is ≥ 75%.

[0006] Specifically, the fit tolerance between the inner hole of the bearing housing and the outer ring of the bearing is adjusted from an interference fit of H7 / m6 to a clearance fit of H7 / g6, and the clearance is controlled within 0.02 - 0.05 mm to ensure cold-state positioning accuracy and radial adjustment of the outer ring in the hot state.

[0007] A control method for the dynamic clearance compensation installation structure of the segment bearings of a continuous casting machine includes the following steps:

[0008] 1) Pre-installation inspection: Install the modified bearing housing on the non-driving side of the segment roller shaft, namely bearing housing B, bearing housing D, and bearing housing E.

[0009] 2) Clearance adjustment: Insert a 2-mm standard feeler gauge between the outer ring of the fixed-end bearing and the annular groove of the end cover, and lock the clearance by adjusting the torque of the end cover bolts to 120 ± 5 N·m.

[0010] 3) Dynamic verification: Start the continuous casting machine to run without load, use an infrared thermal imager to monitor the temperature rise rate of the roller surface, and when the temperature reaches the equilibrium state, use a displacement sensor to detect the axial displacement of the outer ring of the bearing.

[0011] Specifically, after the installation of the bearing housing in step 1), use a laser alignment instrument to detect that the deviation of the axis line of the segment roller is ≤ 0.1 mm / m.

[0012] Specifically, the temperature at the equilibrium state in step 3) is 180 - 220 °C.

[0013] Specifically, the axial displacement in step 3) is controlled such that the unilateral floating amount ≤ 1.8 mm and the total reciprocating displacement in both directions ≤ 3.5 mm.

[0014] The present invention has the following beneficial effects:

[0015] The dynamic clearance compensation installation structure and control method for the segment bearings of the continuous casting machine designed by the present invention process a 2-mm axial clearance groove at the end cover of the fixed-end bearing housing to ensure that the outer ring can freely move during the thermal expansion process, optimize the fixing method and fit tolerance of the outer ring of the bearing, achieve dynamic balance of the thermal expansion stress by improving the fixing structure of the outer ring of the bearing, allow the roller to have a small amount of displacement in any direction during thermal expansion, eliminate unilateral stress concentration, and in the cold-state working condition, the bearing still maintains the positioning accuracy through the optimized tolerance fit, reduce the shutdown maintenance time, and lower the maintenance cost.

[0016] The dynamic clearance compensation installation structure and control method for the segment bearings of the continuous casting machine designed by the present invention are widely applied to scenarios such as the three-roll system of the segment of a slab continuous casting machine and the support roll group of a heavy plate continuous casting machine, and at the same time provide a technical reference for the bearing positioning design of other high-temperature transmission components in the metallurgical industry. Description of the Drawings

[0017] Figure 1 It is a schematic diagram of the assembly structure of the segment bearing housing of a continuous casting machine.

[0018] Figure 2 It is a sectional view of the assembly of the segment bearing housing of a continuous casting machine.

[0019] In the figure: 1 - Bearing housing A; 2 - Bearing housing B; 3 - Bearing housing C; 4 - Bearing housing D; 5 - Bearing housing E; 6 - Bearing housing F; 7 - Segment roll; 8 - End cover; 9 - Bearing outer ring. Specific implementation mode

[0020] The following will further clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] As Figure 1 - Figure 2 shown, a dynamic clearance compensation installation structure for the segment bearings of a continuous casting machine includes a segment roll 7 and a bearing housing. The bearing housing includes coaxial bearing housings A 1, B 2, C 3, D 4, E 5, and F 6. A segment roll 7 is installed between bearing housings A 1 and B 2, a segment roll 7 is installed between bearing housings C 3 and D 4, and a segment roll 7 is installed between bearing housings E 5 and F 6. Annular grooves with a depth of 2 mm are machined on the inner sides of the end covers 8 of the bearing housings B 2, D 4, and E 5 located in the middle, and an axial floating clearance is formed between the end cover 8 and the bearing outer ring 9.

[0022] During the assembly of the segment roll 7, the rigid limit structure of the original fixed-end bearing housing end cover 8 is transformed into a stepped compensation groove. An annular groove with a depth of 2 mm is machined on the inner side of the end cover 8 to form an axial floating clearance with the bearing outer ring 9. The width of the annular groove is increased by 4 mm according to the width of the bearing outer ring 9, so that the contact area between the end face of the bearing outer ring 9 and the side wall of the annular groove is ≥ 75% during thermal expansion displacement, avoiding local stress concentration.

[0023] The fit tolerance between the inner hole of the bearing housing and the bearing outer ring is adjusted from an interference fit of H7 / m6 to a clearance fit of H7 / g6, and the clearance is controlled within 0.02 - 0.05 mm, which not only ensures the cold-state positioning accuracy but also allows radial fine adjustment of the outer ring under hot conditions.

[0024] The original completely fixed design of the fixed-end bearing outer ring 9 is changed to a reserved thermal expansion movement clearance of 2 mm, and at the same time, the fit tolerance of the bearing outer ring 9 is adjusted from H7 / m6 to H7 / g6. This design allows the segment roll 7 to displace slightly in any direction during thermal expansion, eliminating unilateral stress concentration. Under cold-state working conditions, the bearing still maintains the positioning accuracy through the optimized tolerance fit.

[0025] During implementation, a 2-mm axial clearance groove is machined at the fixed-end bearing housing end cover 8 to ensure that the outer ring can freely move during the thermal expansion process. Taking the three-roll system as an example, when the roll body expands due to heat, the outer rings 9 of the bearings at both ends can synchronously compensate for the axial displacement, enabling the two rows of rollers of the double-row self-aligning roller bearing to evenly bear the load. Through finite element analysis verification, the axial load of the improved bearing drops within the design allowable range (<12.3 tons), thus avoiding premature failure caused by overload of a single row of rollers.

[0026] A control method for the dynamic clearance compensation installation structure of the bearings in the segment of a continuous casting machine includes the following steps:

[0027] 1. Pre-installation detection: Install the modified bearing housing on the non-driving side of the segment roll shaft, namely bearing housing B 2, bearing housing D 4, and bearing housing E 5; after the installation of the bearing housing is completed, use a laser alignment instrument to detect that the deviation of the axis line of the segment roll is ≤0.1 mm / m.

[0028] 2. Clearance adjustment: Insert a 2-mm standard feeler gauge between the annular groove of the outer ring 9 of the fixed-end bearing and the end cover 8, and lock the clearance by adjusting the torque of the end cover bolts to 120 ± 5 N·m.

[0029] 3. Dynamic verification: Start the continuous casting machine to run without load, use an infrared thermal imager to monitor the temperature rise rate of the roll surface, when the temperature reaches the equilibrium state, the temperature at the equilibrium state is 180 - 220 °C, use a displacement sensor to detect the axial displacement of the outer ring 9 of the bearing, and control the axial displacement within the unilateral floating amount ≤1.8 mm and the total bidirectional displacement ≤3.5 mm.

[0030] Implementation case.

[0031] Implement this solution on the SA-2 segment of the SEG5 segment of the 4# continuous casting machine in a certain iron and steel company:

[0032] Parameter setting, taking the 24024 self-aligning roller bearing as an example, the key parameter configuration is as follows.

[0033] Axial load threshold: ≤12.3 tons (monitored in real time by a pressure sensor, triggering an alarm when exceeding the limit);

[0034] Thermal expansion compensation coefficient: 0.15 mm / °C (calculated based on the thermal expansion coefficient of the roll material);

[0035] Minimum contact stress: ≥8 MPa (verify the strength of the groove contact surface through finite element analysis).

[0036] (1) Remove the original FAG bearing end cover and install a new end cover with a 2-mm compensation groove (material ZG270-500, surface high-frequency quenching treatment).

[0037] (2) Use a three - coordinate measuring instrument to calibrate the inner hole tolerance of the bearing housing to H7 / g6 (the measured hole diameter is φ240 +0.04 / -0.01 mm).

[0038] (3) Monitoring data during the hot commissioning stage shows that when the roller 7 of the segment heats up to 205 °C, the outer ring of the bearing displaces 1.2 mm towards the drive side and 0.6 mm towards the non - drive side, and the deviation of the double - row roller load drops from 63% before the transformation to 11%.

[0039] (4) After disassembling and inspecting after continuous production for 2158 hours, the wear amount of the outer ring of the bearing is only 0.13 mm (the wear amount of the original structure reached 0.82 mm during the same period), and the steel - passing capacity is increased to 5 million tons.

[0040] This invention was put into use in the No. 4 continuous caster of the steelmaking plant of a certain iron and steel company in September 2024. Through production verification, the average steel - passing capacity of the two transformed segments SA - 2 and SA - 8 is 5 million tons, which is significantly increased compared with the average steel - passing capacity of 3 million tons of the 5th and 6th segments of the original No. 4 machine.

[0041] This invention is not limited to the above - mentioned implementation manners. Anyone should know that structural changes made under the inspiration of this invention, as long as they have the same or similar technical solutions as this invention, fall within the protection scope of this invention.

[0042] The technologies, shapes, and structures not described in detail in this invention are all well - known technologies.

Claims

1. A dynamic clearance compensation installation structure for the segment bearings of a continuous casting machine, characterized in that, It includes segment rolls and bearing seats. The bearing seats include concentric bearing seat A, bearing seat B, bearing seat C, bearing seat D, bearing seat E, and bearing seat F. Segment rolls are installed between bearing seat A and bearing seat B, between bearing seat C and bearing seat D, and between bearing seat E and bearing seat F. Annular grooves with a depth of 2 mm are machined on the inner sides of the end covers of bearing seat B, bearing seat D, and bearing seat E located in the middle, and an axial floating clearance is formed between the end covers and the outer rings of the bearings.

2. The dynamic clearance compensation installation structure of the segment bearing of the continuous casting machine according to claim 1, wherein, The width of the annular groove is increased by 4 mm according to the width of the outer ring of the bearing, so that the contact area between the end face of the outer ring of the bearing and the side wall of the annular groove is ≥ 75% during thermal expansion displacement.

3. The dynamic clearance compensation installation structure of the segment bearing of the continuous casting machine according to claim 1, characterized in that, The fit tolerance between the inner hole of the bearing seat and the outer ring of the bearing is adjusted from an interference fit of H7 / m6 to a clearance fit of H7 / g6, and the clearance is controlled within 0.02 - 0.05 mm to ensure the cold-state positioning accuracy and the radial adjustment of the outer ring under hot conditions.

4. The control method of the dynamic clearance compensation installation structure of the sector segment bearing of the continuous casting machine according to any one of claims 1-3, characterized in that, It includes the following steps: 1) Pre-assembly inspection: Install the modified bearing seat on the non-driving side of the segment roll shaft, that is, bearing seat B, bearing seat D, and bearing seat E. 2) Clearance adjustment: Insert a 2-mm standard feeler gauge between the outer ring of the fixed-end bearing and the annular groove of the end cover, and lock the clearance by adjusting the torque of the end cover bolts to 120 ± 5 N·m. 3) Dynamic verification: Start the continuous caster to run without load, use an infrared thermal imager to monitor the surface temperature rise rate of the roll, and when the temperature reaches the equilibrium state, use a displacement sensor to detect the axial displacement of the outer ring of the bearing.

5. The control method of the dynamic clearance compensation installation structure of the segment bearing of the continuous casting machine according to claim 4, characterized in that, After the installation of the bearing seat in step 1), use a laser alignment instrument to detect that the deviation of the axis line of the segment roll is ≤ 0.1 mm / m.

6. The control method of the dynamic clearance compensation installation structure of the continuous casting machine segment bearing according to claim 4, characterized in that The temperature at the equilibrium state in step 3) is 180 - 220 °C.

7. The control method of the dynamic clearance compensation installation structure of the segment bearing of the continuous casting machine according to claim 4, characterized in that, The axial displacement in step 3) is controlled such that the unilateral floating amount ≤ 1.8 mm and the total bidirectional displacement ≤ 3.5 mm.

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