A heat treatment method for large steel wire raceway bearing

Abstract

A large steel wire raceway bearing heat treatment method relates to the technical field of bearing heat treatment, and comprises the following steps: S1, the inner ring, the outer ring, two rows of steel balls and two steel wire raceways are assembled into a bearing assembly, and the bearing assembly is fixed on a rolling device; wherein the two steel wire raceways are clamped and fixed on the inner ring and the outer ring of the bearing assembly in a non-welding manner, each steel wire raceway is made of a steel wire bent into a ring, and a reserved gap is reserved between the two ends of the steel wire; S2, at least two groups of electromagnetic induction heaters are uniformly arranged on the outer side of the circumference of the bearing assembly. The heat treatment method realizes stress release and heat compensation by designing a special steel wire raceway structure, solves the problems of uneven heating of multi-material assembly, insufficient gap cooling, easy deformation and cracking, and stress concentration of integrated quenching, realizes overall quenching after assembly, eliminates soft belt from the source, and significantly improves hardness uniformity, quenching layer consistency, assembly precision and service life.

Description

Technical Field

[0001] This invention relates to the field of bearing heat treatment technology, specifically a heat treatment method for large steel wire raceway bearings. Background Technology

[0002] Wire raceway main bearings for CT scanners are core load-bearing components of rotary scanning systems, connecting the fixed frame to the rotary scanning mechanism. They must withstand combined axial, radial, and overturning moment loads, and their performance directly determines the scanning accuracy and operational stability of the CT scanner. These bearings typically consist of an inner ring, an outer ring, two rows of circumferentially arranged steel balls, an outer wire raceway, and an inner wire raceway, with diameters generally ranging from 2m to 5m. In the production of large wire raceway bearings, heat treatment is a crucial step in improving their mechanical properties. Quenching directly affects the bearing's hardness, wear resistance, and impact resistance, while the quality of quenching also determines the scanning accuracy, operational stability, and service life of the CT scanner.

[0003] The existing technology has the following insurmountable drawbacks:

[0004] Defects of step-by-step quenching process: Traditional process requires quenching the steel wire raceway, inner ring and outer ring separately before assembly, which requires multiple sets of tooling and multiple heating, making the process cumbersome, energy-intensive and time-consuming; the residual stress of the quenching of the parts is released during assembly, which can easily cause coaxiality deviation, reducing assembly accuracy and operational stability.

[0005] Open-loop rotary quenching has an unavoidable soft band: single-inductor scanning heating must reserve an unheated blind area, namely the "soft band". The soft band area has low hardness and poor impact resistance, which becomes a weak point of the bearing and seriously reduces the overall load-bearing capacity and safety reliability.

[0006] In summary, existing technologies cannot simultaneously meet the requirements of integrated quenching of the assembly, absence of soft strips, uniform cooling across the entire area, and high hardness uniformity. They also cannot solve the problems of stress concentration and uneven heat distribution caused by integrated quenching, making it difficult to adapt to the high precision, high reliability, and long service life requirements of CT machine main bearings. Summary of the Invention

[0007] The purpose of this invention is to propose a heat treatment method for large steel wire raceway bearings. By designing a special steel wire raceway structure, stress relief and heat compensation are achieved, which solves the problems of uneven heating of multi-material assemblies, insufficient gap cooling, easy deformation and cracking, and stress concentration in integrated quenching. It realizes overall quenching after assembly, eliminates soft bands from the source, and significantly improves hardness uniformity, hardened layer consistency, assembly accuracy and service life.

[0008] The technical solution adopted in this invention is: a heat treatment method for large steel wire raceway bearings, comprising the following steps:

[0009] S1. Assemble the inner ring, outer ring, two rows of steel balls and two steel wire raceways into a bearing assembly, and fix the bearing assembly on the rolling device; wherein, the two steel wire raceways are respectively clamped and fixed to the inner ring and outer ring of the bearing assembly in a non-welding manner, and each steel wire raceway is made by bending steel wire into a circle, with a reserved gap between the two ends of the steel wire;

[0010] S2. At least two sets of electromagnetic induction heaters are evenly arranged on the outer circumference of the bearing assembly. The rolling device is started to rotate the bearing assembly, and the electromagnetic induction heaters are started simultaneously to perform overall induction heating of the rotating bearing assembly to the quenching temperature.

[0011] During the heating process, the expansion and deformation of the steel wire raceway caused by high temperature is released through the reserved gap;

[0012] S3. After the heating in step S2 is completed, immediately turn off the electromagnetic induction heater and quickly move it away from the bearing assembly;

[0013] The bearing assembly is fully immersed in the quenching liquid by the lifting worktable. During the immersion process, the bearing assembly is kept rotating to provide synchronous convection cooling throughout the bearing assembly.

[0014] During the convection cooling process, the shrinkage deformation of the steel wire raceway is released through the reserved gap;

[0015] S4. After the convection cooling in step S3, the bearing assembly is subjected to tempering treatment, secondary stress relief, and quality inspection to obtain a bearing assembly that meets the requirements.

[0016] As a preferred option, in step S1, both ends of the steel wire are wedge-shaped structures.

[0017] As a preferred embodiment, the electromagnetic induction heaters are arranged in four groups, with the four groups of electromagnetic induction heaters evenly distributed at a 90° angle on the outer circumference of the bearing assembly, to achieve 360° full-area synchronous heating without blind spots.

[0018] As a preferred option, in step S2, the entire body is induction heated to 850-900℃ and held at that temperature for 15-25 minutes.

[0019] As a preferred embodiment, in step S2, during overall induction heating, the distance between the heating end face of the electromagnetic induction heater and the surface of the bearing assembly is 15-25mm; the power of a single electromagnetic induction heater is 50-80kW, and the rotation speed of the rolling device is set to 30-60r / min.

[0020] As a preferred embodiment, in step S2, the surface temperature is monitored in real time by no less than 8 infrared thermometers evenly distributed around the circumference of the bearing assembly, and the surface temperature is controlled to rise uniformly to 850-900℃, and kept at that temperature for 15-25 minutes, with temperature fluctuations controlled within ±10℃.

[0021] As a preferred embodiment, in step S3, the bearing assembly is fully immersed in the quenching liquid within 3-5 seconds, and the rolling device is kept running at a speed of 20-30 r / min during the immersion process.

[0022] As a preferred embodiment, in step S3, the electromagnetic induction heater moves away from the bearing assembly at a speed of not less than 0.5 m / s, and the distance away is not less than 100 mm.

[0023] As a preferred embodiment, in step S4, the tempering treatment involves holding the furnace at 180-220°C for 2-3 hours, followed by furnace cooling.

[0024] As a preferred embodiment, in step S4, after the tempering treatment is completed, the steel wire raceway of the bearing assembly is removed to achieve secondary elimination of the residual stress of the bearing assembly, and then the steel wire raceway is re-clamped onto the inner and outer rings.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. Integrated quenching process for bearing assemblies with stress relief and heat compensation. Unlike existing single-part quenching, this invention targets the overall quenching of complete assemblies containing specially structured wire raceways, steel balls, and inner and outer rings. Through the non-welded clamping structure of the wire raceways, wedge-shaped ends, and reserved gap design, it solves the problems of stress concentration and uneven heat distribution that exist in integrated quenching in the industry, breaks through the technical bottleneck of integrated quenching, and eliminates the need for separate quenching of multiple parts, multiple clamping, and multiple heating processes.

[0027] 2. Four sets of symmetrical full-area heating without soft strips. Unlike existing heat accumulation scanning heating and asymmetric multi-heat source heating, this invention uses four sets of 90° symmetrical inductors to achieve 360° blind-zone-free synchronous heating. It eliminates the need for reserved soft strips, heat compensation, and differences between initial and final quenching. Compared to existing multi-point heating, symmetrical full-area synchronous heating is not a simple layout adjustment, but rather achieves the technical effect of eliminating soft strips, overcoming the heating blind zone problem that still exists in existing multi-point heating.

[0028] 3. Rotary Immersion Synergistic Cooling. Unlike existing spray cooling and static immersion cooling, this invention is the first to propose a forced convection cooling method that combines immersion and rotation. This allows the quenching liquid to flow fully in the raceway and between the steel balls, completely solving the problems of vapor film insulation, liquid accumulation in gaps, and uneven cooling. While immersion cooling has been partially disclosed, the synergistic cooling method combined with rotation is proposed for the first time. Furthermore, the integrated quenching gap structure achieves the technical effect of uniform cooling throughout the entire area.

[0029] 4. Precise temperature control system adaptable to multi-material assemblies. For differences in wire raceway, steel ball, inner and outer ring materials, and wall thickness, a multi-point temperature measurement, independent temperature control, and heat-insulated tooling collaborative control system is employed. This is not a conventional layout design, but a precise temperature control solution adapted to the structural characteristics and stress relief design of integrated quenching, avoiding localized overheating and burn-off, and improving quenching stability and finished product qualification rate.

[0030] 5. The large steel wire raceway of the bearing heat treatment using the present invention has uniform hardness and hardened layer height, which greatly optimizes production efficiency and cost, significantly improves assembly accuracy, greatly extends service life, and significantly improves the finished product qualification rate. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A schematic diagram of the shaft side structure of the steel wire raceway main bearing for a CT scanner;

[0033] Figure 2 This is a partial cross-sectional schematic diagram of the main bearing for a CT scanner using a steel wire raceway.

[0034] Figure 3 This is a schematic diagram of the steel wire raceway in this invention;

[0035] Figure 4 This is a schematic diagram of the quenching process of the present invention;

[0036] Figure 5 This is a schematic diagram of the quenching apparatus of the present invention.

[0037] Reference numerals in the attached drawings: 1. Bearing assembly; 101. Upper half of the outer ring of the bearing; 102. Lower half of the outer ring of the bearing; 103. Inner ring; 104. Steel wire raceway; 1041. End; 1042. Reserved clearance; 105. Steel ball; 106. Threaded hole one; 107. Threaded hole two; 108. Vibration damping pad; 2. Electromagnetic induction heater; 3. Rolling device; 4. Lifting worktable; 5. Quenching tank. Detailed Implementation

[0038] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0039] It should be noted that, unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "a," "an," or "the," etc., used in the specification and claims of this patent application do not express a limitation on quantity, but rather indicate the presence of at least one; the terms "first," "second," and "third," as used herein, should not be considered as a limitation on the order of components, but are merely for distinguishing different components; the terms "comprising," "including," etc., indicate that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same function.

[0040] To more clearly describe the heat treatment method for this large steel wire raceway bearing, in conjunction with the attached... Figure 1-5 Description of the embodiment:

[0041] like Figure 1-5 As shown, a heat treatment method for a large wire raceway bearing, taking the bearing shown as an example, includes an outer ring (upper half of the outer ring 101, lower half of the outer ring 102), an inner ring 103, wire raceways 104, steel balls 105, screw hole one 106, screw hole two 107, and vibration damping pad 108. The heat treatment method includes the following steps:

[0042] S1. Assemble the inner ring 103, outer ring, two rows of steel balls 105 and two steel wire raceways 104 into a bearing assembly 1, and fix the bearing assembly 1 to the rolling device 3 by means of a fixing clamp; wherein, the two steel wire raceways 104 (including the outer steel wire raceway and the inner steel wire raceway) are respectively clamped and fixed to the inner ring 103 and the outer ring of the bearing assembly in a non-welding manner. Each steel wire raceway 104 is made of steel wire bent into a circle. Both ends 1041 of the steel wire are wedge-shaped structures, and a reserved gap 1042 is left between the two ends;

[0043] The fixing clamp is made of high-temperature resistant alloy and its surface is uniformly coated with a high-temperature anti-oxidation coating.

[0044] S2. At least two sets of cylinders are evenly arranged on the outer circumference of the bearing assembly. Each set of cylinders is equipped with an electromagnetic induction heater 2. The electromagnetic induction heater 2 does not rotate with the bearing assembly, but can move away from or close to the bearing assembly under the drive of the cylinder. The rolling device 3 is started to rotate the bearing assembly, and the electromagnetic induction heater 2 is started simultaneously to perform overall induction heating of the rotating bearing assembly to the quenching temperature.

[0045] Four sets of symmetrical inductors and process parameter debugging: Four sets of independently temperature-controlled electromagnetic induction heaters 2 are evenly arranged along the 90° circumference of the bearing assembly to achieve 360° full-area synchronous heating without blind spots; the distance between the heating end face of the electromagnetic induction heater 2 and the surface of the bearing assembly is 15-25mm; the power of a single electromagnetic induction heater 2 is 50-80kW, with independent temperature control and synchronous output; the rotation speed of the rolling device 3 is set to 30-60r / min. Water-based quenching liquid is injected into the quenching tank 5, and the liquid surface can completely immerse the bearing assembly 1. The temperature of the quenching liquid is 20-40℃. The quenching liquid contains 0.5-1.0% by mass of antioxidant and 0.3-0.5% by mass of defoamer. The antioxidant is a nitrite compound, and the defoamer is an organosilicon compound to reduce the oxidation reaction on the bearing surface and the foaming of the quenching liquid during the quenching process, ensuring the cooling effect.

[0046] Synchronous full-area induction heating without soft strips: After starting the rolling device 3 and stabilizing, four sets of electromagnetic induction heaters 2 are started simultaneously to provide 360° full-area heating; infrared thermometers with no less than 8 points evenly distributed around the circumference are used for real-time monitoring to control the surface temperature to rise uniformly to 850-900℃, maintain the temperature for 15-25 minutes, and control the temperature fluctuation within ±10℃ to ensure the uniformity of heating; during the heating process, the expansion and deformation of the steel wire roller 104 due to high temperature is released through the reserved gaps 1042 at both ends to achieve heat compensation and initial stress relief;

[0047] S3. After the heating in step S2 is completed, immediately turn off the electromagnetic induction heater 2 and move it away from the bearing assembly at a speed of not less than 0.5m / s by ≥100mm to avoid secondary heating of the bearing assembly and to prevent interference with the quenching process.

[0048] The lifting worktable 4 drives the bearing assembly to be fully immersed in the quenching liquid within 3-5 seconds. During the immersion process, the bearing assembly 1 is kept rotating (keeping the rolling device running at a speed of 20-30 r / min) to promote the flow of the quenching liquid on the bearing surface and avoid inconsistent local cooling rates, so as to achieve synchronous convection cooling of the bearing assembly throughout. Through this forced convection cooling, the vapor film is broken to ensure synchronous and uniform cooling throughout. During the cooling process, the shrinkage and deformation of the steel wire raceway are further released through the reserved gaps 1042 at both ends to avoid the generation of constraint stress between the inner and outer rings.

[0049] S4. After the convection cooling in step S3, the bearing assembly is subjected to tempering treatment, secondary stress relief and quality inspection to obtain a bearing assembly that meets the requirements.

[0050] After quenching, remove the bearing assembly and allow it to cool naturally to room temperature. Then, temper it at 180-220℃ for 2-3 hours, followed by furnace cooling to initially relieve stress. After tempering, remove the steel wire raceway 104 from the bearing assembly to achieve secondary stress relief of the bearing assembly. Then, re-clamp the steel wire raceway 104 onto the inner and outer rings. Finally, clean the bearing assembly (including removing surface oxide scale and residual quenching liquid). Then, use non-destructive testing equipment to test the hardness and hardened layer to ensure that there are no soft bands, the hardness uniformity is ≤0.5HRC, the hardened layer depth is 8-10mm, and the surface hardness is HRC58-63.

[0051] The following uses Figure 5 The quenching apparatus shown is described in detail below, and the technical solution of the present invention will be further explained in detail with reference to specific embodiments. However, the scope of protection of the present invention is not limited to the following embodiments.

[0052] Example 1

[0053] This embodiment is used for heat treatment of a large steel wire raceway main bearing for a CT scanner with a diameter of 2.5m. The specific heat treatment steps are as follows:

[0054] Step S1, Bearing pre-assembly and fixing:

[0055] According to the conventional assembly process, the outer steel wire raceway, inner steel wire raceway, inner ring and outer ring are assembled in sequence to form a bearing assembly; the bearing assembly is coaxially fixed to the rolling device 3 using a fixing fixture, the surface of the fixing fixture is coated with a high-temperature anti-oxidation coating, and the contact parts are wrapped with ceramic heat insulation material.

[0056] Step S2, Debugging and Layout of Quenching Equipment:

[0057] Four sets of 60kW electromagnetic induction heaters 2 were selected and evenly distributed on the outer circumference of the bearing assembly. The included angle between adjacent inductors was 90°, and the distance between the heating end face of the heater and the outer surface of the bearing was adjusted to 20mm. The rotation speed of the rolling device 3 was set to 45r / min. Water-based quenching liquid was injected into the quenching tank 5, and 0.8% by mass of nitrite antioxidant and 0.4% by mass of organosilicon defoamer were added. The temperature of the quenching liquid was controlled at 30℃, and the depth was ensured to completely immerse the bearing assembly.

[0058] Overall induction heating:

[0059] Start the rolling device 3. After the rotation speed stabilizes, start the four sets of electromagnetic induction heaters 2 simultaneously to perform overall induction heating on the bearing assembly. Monitor the surface temperature in real time through eight evenly distributed infrared thermometers, control the heating power to raise the bearing surface temperature to 880℃, keep it at that temperature for 20 minutes, and monitor the temperature fluctuation range in real time to keep it within ±8℃.

[0060] Step S3, Overall Immersion Hardening:

[0061] After the heat preservation is completed, the electromagnetic induction heater 2 is immediately turned off. The four sets of electromagnetic induction heaters 2 are driven by the cylinder to move away from the bearing assembly at a speed of 0.6m / s, with a distance of 120mm. Then, the lifting worktable 4 is started to immerse the bearing assembly in the quenching liquid within 4s. During the quenching process, the rolling device is kept running at a speed of 25r / min to ensure uniform cooling.

[0062] Step S4, Tempering and subsequent processing:

[0063] After quenching, the bearing assembly is removed and allowed to cool naturally to room temperature before being placed in a tempering furnace. The tempering temperature is set to 200℃ and held for 2.5 hours. The assembly is then cooled to room temperature in the furnace to initially eliminate stress. After tempering, the steel wire raceway 104 of the bearing assembly is removed to achieve secondary elimination of residual stress in the bearing assembly. The steel wire raceway 104 is then re-clamped onto the inner and outer rings. After tempering, the oxide scale on the bearing surface is cleaned using a sandblasting process. The internal quality is tested using an ultrasonic flaw detector, the surface hardness distribution is tested using a hardness tester, and the depth of the hardened layer is tested using a metallographic microscope.

[0064] The test results showed that the bearing surface had no soft bands, the hardness uniformity was 0.4 HRC, the hardened layer depth was 9 mm, and the surface hardness reached HRC60-HRC62, which met the requirements for use of CT machine main bearings.

[0065] Example 2

[0066] This embodiment describes the heat treatment of a large steel wire raceway main bearing for a CT scanner with a diameter of 4m. The specific steps are as follows:

[0067] Step S1, Bearing pre-assembly and fixing:

[0068] After the bearing assembly is assembled, it is coaxially fixed to the rolling device 3 using a fixing fixture.

[0069] Step S2, Debugging and Layout of Quenching Equipment:

[0070] Four sets of 75kW electromagnetic induction heaters were selected. The inductors were evenly distributed on the outer circumference of the bearing assembly, with an angle of 90° between adjacent inductors and a distance of 22mm between the heating end face and the outer surface of the bearing. The rotation speed of the rolling device 3 was set to 35r / min. Water-based quenching liquid was injected into the quenching tank, and 1.0% by mass of antioxidant and 0.5% by mass of defoamer were added. The temperature of the quenching liquid was controlled at 25℃.

[0071] Overall induction heating:

[0072] After the rolling device 3 is started and stabilized, four sets of electromagnetic induction heaters 2 are started. The temperature is monitored in real time by 10 infrared thermometers. The bearing surface temperature is controlled to rise to 890℃ and kept at that temperature for 22 minutes. The temperature fluctuation range is controlled within ±10℃.

[0073] Step S3, Overall Immersion Hardening:

[0074] After the heat preservation is completed, the electromagnetic induction heater 2 is turned off, and the cylinder drives the sensor to move away from the bearing assembly at a speed of 0.7 m / s. Then, the lifting worktable 4 is started to immerse the bearing assembly in the quenching liquid within 3.5 s. During the quenching process, the speed of the rolling device is maintained at 22 r / min.

[0075] Step S4, Tempering and subsequent processing:

[0076] After quenching, the bearing was naturally cooled to room temperature and then placed in a tempering furnace at 210℃ for 3 hours. It was then cooled to room temperature in the furnace to initially relieve stress. After the tempering process was completed, the steel wire raceway of the bearing assembly was removed and then re-clamped onto the inner and outer rings. Subsequent surface cleaning and quality inspection were carried out. The test results showed that there were no soft bands on the bearing surface, the hardness uniformity was 0.3HRC, the hardened layer depth was 9.5mm, and the surface hardness was HRC59-HRC63, which met the usage requirements.

[0077] Example 3

[0078] This embodiment is used for heat treatment of a large steel wire raceway main bearing for a CT scanner with a diameter of 3m. The specific steps are as follows:

[0079] Step S1, Bearing pre-assembly and fixing:

[0080] After the bearing assembly is assembled, it is fixed to the rolling device using a fixing fixture to ensure that the coaxiality error of the bearing assembly does not exceed 0.1mm.

[0081] Step S2, Debugging and Layout of Quenching Equipment:

[0082] Four sets of 65kW electromagnetic induction heaters are used, with a spacing of 90° between adjacent electromagnetic induction heaters and a distance of 18mm between the heating end face and the outer surface of the bearing; the speed of the rolling device is set to 50r / min.

[0083] The quenching fluid temperature is controlled at 35℃, and 0.6% by mass of antioxidant and 0.3% by mass of defoamer are added.

[0084] Overall induction heating: Start the rolling device 3 and electromagnetic induction heater 2, control the bearing surface temperature to rise to 870℃, keep it at that temperature for 18 minutes, and keep the temperature fluctuation within ±9℃.

[0085] Step S3, Overall Immersion Hardening:

[0086] After the heat preservation is completed, the electromagnetic induction heater 2 moves away quickly, and the bearing assembly is immersed in the quenching liquid within 4.5 seconds by the lifting worktable 4, while the rotation speed is maintained at 28 r / min.

[0087] Step S4, Tempering and subsequent processing:

[0088] After quenching, the bearing was naturally cooled to room temperature and then placed in a tempering furnace for tempering at 190℃ for 2 hours. After furnace cooling to room temperature, the stress was initially relieved. After tempering, the steel wire raceway of the bearing assembly was removed and then re-clamped onto the inner and outer rings. Subsequent surface cleaning and quality inspection were carried out. The test results showed that the bearing had no soft band, the hardness uniformity was 0.45HRC, the hardened layer depth was 8.5mm, and the surface hardness was HRC58-HRC61, which met the technical requirements.

[0089] The parts not described in detail in the above embodiments are existing technologies.

[0090] It should be noted that although the present invention has been described through the above embodiments, the present invention may have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and modifications to the present invention, but all such changes and modifications should fall within the scope of protection of the appended claims and their equivalents.

Claims

1. A heat treatment method for large steel wire raceway bearings, characterized in that, Includes the following steps: S1. Assemble the inner ring, outer ring, two rows of steel balls, and two steel wire raceways into a bearing assembly, and fix the bearing assembly to the rolling device; wherein, the two steel wire raceways are respectively clamped and fixed to the inner ring and outer ring of the bearing assembly in a non-welding manner, each steel wire raceway is made by bending steel wire into a circle, a reserved gap is left between the two ends of the steel wire, and both ends of the steel wire are wedge-shaped structures; S2. At least two sets of electromagnetic induction heaters are evenly arranged on the outer circumference of the bearing assembly. The rolling device is started to rotate the bearing assembly, and the electromagnetic induction heaters are started simultaneously to perform overall induction heating of the rotating bearing assembly to the quenching temperature. During the heating process, the expansion and deformation of the steel wire raceway caused by high temperature is released through the reserved gap; S3. After the heating in step S2 is completed, immediately turn off the electromagnetic induction heater and quickly move it away from the bearing assembly; The bearing assembly is fully immersed in the quenching liquid by the lifting worktable. During the immersion process, the bearing assembly is kept rotating to provide synchronous convection cooling throughout the bearing assembly. During the convection cooling process, the shrinkage deformation of the steel wire raceway is released through the reserved gap; S4. After the convection cooling in step S3, the bearing assembly is subjected to tempering treatment, secondary stress relief and quality inspection to obtain a bearing assembly that meets the requirements. In step S2, during overall induction heating, the distance between the heating end face of the electromagnetic induction heater and the surface of the bearing assembly is 15-25mm; the power of a single electromagnetic induction heater is 50-80kW, and the rotation speed of the rolling device is set to 30-60r / min; the surface temperature is monitored in real time by no less than 8 infrared thermometers evenly distributed in the circumferential direction of the bearing assembly, and the surface temperature is controlled to rise uniformly to 850-900℃, held for 15-25min, and the temperature fluctuation is controlled within ±10℃. In step S3, the bearing assembly is fully immersed in the quenching liquid within 3-5 seconds, and the rolling device is kept running at a speed of 20-30 r / min during the immersion process; the electromagnetic induction heater moves away from the bearing assembly at a speed of not less than 0.5 m / s, and the distance away is not less than 100 mm.

2. The heat treatment method for a large steel wire raceway bearing according to claim 1, characterized in that: In step S2, the electromagnetic induction heaters are arranged in four groups, with the four groups of electromagnetic induction heaters evenly distributed at a 90° angle on the outer circumference of the bearing assembly to achieve 360° full-area synchronous heating without blind spots.

3. The heat treatment method for a large steel wire raceway bearing according to claim 1, characterized in that: In step S2, the entire unit is induction heated to 850-900℃ and held at that temperature for 15-25 minutes.

4. The heat treatment method for a large steel wire raceway bearing according to claim 1, characterized in that: In step S4, the tempering process involves holding the furnace at 180-220°C for 2-3 hours, followed by furnace cooling.

5. The heat treatment method for a large steel wire raceway bearing according to claim 1, characterized in that: In step S4, after the tempering process is completed, the steel wire raceway of the bearing assembly is removed to achieve a secondary elimination of the residual stress in the bearing assembly. Then, the steel wire raceway is re-clamped onto the inner and outer rings.

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