Gearbox bearing manufacturing method based on surface strengthening

Abstract

The invention relates to the technical field of gear box bearing manufacturing, in particular to a gear box bearing manufacturing method based on surface strengthening, which comprises the following steps: annealing a blank subjected to upsetting, punching and ring rolling in sequence; rough turning of the blank and finish turning of a raceway and a chamfer are sequentially conducted, and then a bearing inner ring base material and a bearing outer ring base material are obtained; quenching, tempering and subzero treatment are conducted on the base material in sequence to complete heat treatment of the base material; marking the outer diameter surface of the bearing inner ring base material and the inner diameter surface of the bearing outer ring base material as raceway surfaces; performing induction quenching on the raceway surface to obtain an effective hardening depth, and preliminarily judging the qualification of surface heat treatment of the raceway surface according to the effective hardening depth; carrying out shot blasting treatment on the bearing qualified in surface heat treatment; judging the qualification of shot blasting treatment according to the characteristic value of the section defect; and under the condition that the shot blasting treatment is qualified, the rolling body is assembled after the rolling path surface of the bearing is ground to the preset size, so that the quality of the gear box bearing is improved.

Description

Technical Field

[0001] The present invention relates to Background Art

[0002] Gearbox bearings are key components in mechanical equipment for transmitting power and supporting rotating parts, and are widely used in fields such as wind power, rail transit, and industrial transmission. Since gearboxes usually operate under high rotational speeds, heavy loads, and complex alternating stresses, the raceway surfaces of bearings are prone to failure due to contact fatigue, wear, or microcrack propagation, resulting in a decrease in the overall life of the gearbox. Therefore, improving the fatigue strength, wear resistance, and dimensional stability of bearings has always been a key research direction in manufacturing technology.

[0003] Chinese Patent Application Publication No.: CN119260325A discloses a processing method for improving the residual compressive stress on the raceway surface of a bearing ring, which relates to the technical field of bearing processing. The steps are as follows: turning the bearing ring blank, and then quenching and tempering the processed part; shot peening and strengthening the raceway surface of the heat-treated ring; performing rough grinding on the raceway surface of the strengthened ring, and then performing additional tempering treatment; performing fine grinding on the raceway surface of the ring, and then performing finish grinding on the raceway surface of the ring; performing superfinishing on the raceway surface of the ring to complete. However, the following problems exist in the prior art: The surface strengthening in the prior art uses overall heat treatment technology, which easily leads to the risk of overall deformation or even cracking of the material due to temperature gradient or tissue transformation stress during the heating process. Summary of the Invention

[0004] Therefore, the present invention provides a manufacturing method for gearbox bearings based on surface strengthening to overcome the problems of material deformation and cracking easily caused by overall heat treatment for surface strengthening in the prior art.

[0005] To achieve the above object, the present invention provides a manufacturing method for gearbox bearings based on surface strengthening, including:

[0006] Step S1, annealing the blank that has been successively upset, punched, and ring rolled;

[0007] Step S2, using a lathe to successively perform rough turning on the blank, and finish turning on the raceway and chamfer to obtain the bearing inner ring substrate and the bearing outer ring substrate;

[0008] Step S3, successively performing quenching, tempering, and cryogenic treatment on the bearing inner ring substrate and the bearing outer ring substrate to complete the heat treatment of the substrate;

[0009] Step S4, marking the outer diameter surface of the bearing inner ring substrate and the inner diameter surface of the bearing outer ring substrate as the raceway surface;

[0010] In step S5, when the effective hardened depth is obtained after induction hardening of the raceway surface and it is preliminarily determined that the surface heat treatment of the raceway surface is unqualified, the reason for the unqualified surface heat treatment is determined according to the hardness gradient characteristic value, or the qualification of the surface heat treatment is re-determined according to the average grain size at the effective depth, where the hardness gradient characteristic value is the hardness difference between the interface hardness and the hardness at a preset depth point;

[0011] In step S6, shot peening is performed on the bearings with qualified surface heat treatment. The defect conditions on the surface and in the cross-section are obtained by taking the surface image and cross-section metallography of the bearings after shot peening, and the surface roughness and cross-section defect characteristic values are obtained;

[0012] In step S7, when it is determined that the shot peening is unqualified according to the cross-section defect characteristic value, the optimization strategy for the shot peening process is determined according to the surface roughness as increasing the shot peening duration or reducing the shot peening pressure;

[0013] In step S8, under the condition that the shot peening is qualified, the raceway surface of the bearing is ground to a preset size and then the rolling elements are assembled.

[0014] Further, in step S3, the quenching temperature range is 840°C to 860°C, the quenching medium is quenching oil, and the oil temperature is 80°C; the tempering temperature range is 150°C to 170°C, and the holding time is 2 hours; the cryogenic temperature is -150°C, and the soaking time in liquid nitrogen is 4 hours.

[0015] Further, the grinding in step S8 includes rough grinding and fine grinding. Among them, the rough grinding is processed by an efficient grinding process to a surface roughness of 0.8 to 1.6 μm; the fine grinding is processed by a precision ultra-finishing process to a surface roughness of 0.1 to 0.4 μm.

[0016] Further, the qualification of the surface heat treatment of the raceway surface is preliminarily determined according to the effective hardened depth. Among them, if the effective hardened depth is less than the first preset hardened depth, it is determined that the surface heat treatment is unqualified, and the reason for the unqualified surface heat treatment is determined according to the hardness gradient characteristic value;

[0017] If the effective hardened depth is greater than or equal to the first preset hardened depth and less than the second preset hardened depth, it is determined that the surface heat treatment is unqualified, and the qualification of the surface heat treatment is re-determined according to the average grain size at the effective depth;

[0018] If the effective hardened depth is greater than or equal to the second preset hardened depth, it is determined that the surface heat treatment is qualified, and the bearings are subjected to shot peening.

[0019] Further, determine the reason for the unqualified surface heat treatment based on the hardness gradient eigenvalue. Among them, if the hardness gradient eigenvalue is less than the preset hardness gradient eigenvalue, determine that the reason for the unqualified surface heat treatment is that the heating is not up to standard, and increase the induction quenching duration according to the difference between the preset hardness gradient eigenvalue and the hardness gradient eigenvalue;

[0020] If the hardness gradient eigenvalue is greater than or equal to the preset hardness gradient eigenvalue, determine that the reason for the unqualified surface heat treatment is that the interface hardness is not up to standard, and reduce the current density of induction quenching according to the ratio of the hardness gradient eigenvalue to the preset hardness gradient eigenvalue.

[0021] Further, re-determine the qualification of the surface heat treatment based on the average grain size at the effective depth. Among them, if the average grain size is less than the preset grain size, re-determine that the surface heat treatment is qualified, and perform shot peening on the bearing;

[0022] If the average grain size is greater than or equal to the preset grain size, re-determine that the surface heat treatment is unqualified, and increase the cooling rate of induction quenching according to the difference between the average grain size and the preset grain size.

[0023] Further, the current density of induction quenching is negatively correlated with the hardness gradient deviation rate, where the hardness gradient deviation rate is the ratio of the hardness gradient eigenvalue to the preset hardness gradient eigenvalue.

[0024] Further, there are several adjustment methods for the cooling rate of induction quenching, and the increase amplitude of each adjustment method for the cooling rate is different.

[0025] Further, determine the qualification of the shot peening treatment according to the cross-section defect eigenvalue. Among them, if the defect eigenvalue is less than the preset defect eigenvalue, determine that the shot peening treatment is qualified, and grind the bearing raceway surface to the preset size and then complete the assembly of the rolling elements;

[0026] If the defect eigenvalue is greater than or equal to the preset defect eigenvalue, determine that the shot peening treatment is unqualified, and determine the optimization strategy of the shot peening process according to the surface roughness;

[0027] The defect eigenvalue is jointly determined by the number of defect cracks and the average length.

[0028] Further, determine the optimization strategy of the shot peening process according to the surface roughness. Among them, if the surface roughness is less than the preset roughness, determine that the optimization strategy of the shot peening process is to increase the shot peening duration, and the shot peening duration is positively correlated with the first roughness difference, where the first roughness difference is the difference between the preset roughness and the surface roughness;

[0029] If the surface roughness is greater than or equal to the preset roughness, determine that the optimization strategy of the shot peening process is to reduce the shot peening pressure, and the shot peening pressure is positively correlated with the difference in the second roughness, where the difference in the second roughness is the difference when the surface roughness is greater than or equal to the preset roughness.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows. The present invention provides a method for manufacturing a gearbox bearing based on surface strengthening. After the heat treatment of the bearing inner ring substrate and the bearing outer ring substrate is completed by quenching, tempering, and cryogenic treatment in sequence, mark the outer diameter surface of the bearing inner ring substrate and the inner diameter surface of the bearing outer ring substrate as raceway surfaces and perform induction hardening on the raceway surfaces. By using local surface strengthening technology to replace traditional overall heat treatment, the problems of material deformation and cracking are effectively solved.

[0031] Furthermore, when the present invention preliminarily determines that the surface heat treatment of the raceway surface is unqualified according to the effective case depth, determine the reason for the unqualified surface heat treatment according to the hardness gradient characteristic value, or, re-determine the qualification of the surface heat treatment according to the average grain size at the effective depth. Through multi-dimensional determination of the effective case depth, hardness gradient characteristic value, and average grain size, accurately identify the reason for the surface heat treatment defect and adjust the induction hardening parameters accordingly, improving the process stability.

[0032] Furthermore, the present invention obtains the defect conditions of the surface and cross-section by photographing the surface image and cross-section metallography of the bearing after shot peening, and obtains the surface roughness and cross-section defect characteristic values. When it is determined that the shot peening treatment is unqualified according to the cross-section defect characteristic value, determine the optimization strategy of the shot peening process according to the surface roughness. Based on the dual determination of the defect characteristic value and the surface roughness, dynamically adjust the shot peening process, significantly improving the anti-fatigue performance of the bearing. Description of the Drawings

[0033] Figure 1 It is a flowchart of the method for manufacturing a gearbox bearing based on surface strengthening according to an embodiment of the present invention;

[0034] Figure 2 It is a flowchart of preliminarily determining the qualification of the surface heat treatment of the raceway surface according to an embodiment of the present invention;

[0035] Figure 3 It is a flowchart of determining the reason for the unqualified surface heat treatment according to an embodiment of the present invention;

[0036] Figure 4 It is a flowchart of determining the qualification of the shot peening treatment according to an embodiment of the present invention. Detailed Embodiments

[0037] To make the objectives and advantages of the present invention more clearly understood, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only for explaining the present invention and are not used to limit the present invention.

[0038] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0039] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 as shown, which are respectively the flowchart of the manufacturing method of the gearbox bearing based on surface strengthening according to the embodiment of the present invention; the flowchart of preliminarily determining the qualification of the surface heat treatment of the raceway surface according to the embodiment of the present invention; the flowchart of determining the reason for the unqualified surface heat treatment according to the embodiment of the present invention; the flowchart of determining the qualification of the shot peening treatment according to the embodiment of the present invention.

[0040] The manufacturing method of the gearbox bearing based on surface strengthening according to the embodiment of the present invention includes:

[0041] Step S1, annealing the blank that has been successively upset, punched, and ring-rolled.

[0042] Step S2, using a lathe to successively rough-turn the blank, and then finish-turn the raceway and chamfer to obtain the bearing inner ring substrate and the bearing outer ring substrate.

[0043] Step S3, successively quenching, tempering, and cryogenic treating the bearing inner ring substrate and the bearing outer ring substrate to complete the heat treatment of the substrate.

[0044] Step S4, marking the outer diameter surface of the bearing inner ring substrate and the inner diameter surface of the bearing outer ring substrate as the raceway surface.

[0045] Step S5, when the effective hardening depth is obtained after induction hardening of the raceway surface and it is preliminarily determined that the surface heat treatment of the raceway surface is unqualified according to the effective hardening depth, determine the reason for the unqualified surface heat treatment according to the hardness gradient characteristic value, or, re-determine the qualification of the surface heat treatment according to the average grain size at the effective depth, where the hardness gradient characteristic value is the hardness difference between the interface hardness and the hardness at a preset depth point.

[0046] Step S6, performing shot peening on the bearing with qualified surface heat treatment, obtaining the defect conditions on the surface and cross-section by photographing the surface image and cross-section metallography of the bearing after shot peening, and obtaining the surface roughness and cross-section defect characteristic values.

[0047] In step S7, when it is determined that the shot peening treatment is unqualified according to the cross-sectional defect characteristic value, the optimization strategy for the shot peening process is determined according to the surface roughness as increasing the shot peening duration or reducing the shot peening pressure;

[0048] In step S8, under the condition that the shot peening treatment is qualified, the raceway surface of the bearing is ground to a preset size and then the rolling elements are assembled.

[0049] Specifically, in step S1, the blank is heated to 1200 °C, and upsetting, punching, and ring rolling are sequentially completed by a high-speed upsetting machine, a hydraulic punching machine, and a numerical control ring rolling machine. The optional range of the annealing temperature is 650 °C to 700 °C, and the optional range of the heat preservation duration is 2 to 4 hours. In this embodiment, the preferred annealing temperature is 670 °C, and the preferred heat preservation duration is 4 hours.

[0050] In the embodiment of the present invention, the blank is made of GCr15 bearing steel.

[0051] Specifically, in step S2, a machining allowance of 0.5 to 1 mm is left for rough turning, and the dimensional tolerance of finish turning is controlled within ±0.05 mm.

[0052] Specifically, in step S3, the quenching temperature range is 840 °C to 860 °C, the quenching medium is quenching oil, and the oil temperature is 80 °C; the tempering temperature range is 150 °C to 170 °C, and the heat preservation duration is 2 hours; the cryogenic temperature is -150 °C, and the soaking duration in liquid nitrogen is 4 hours.

[0053] Specifically, in step S6, the particle size range of the shot peening is 0.3 to 0.8 mm, the initial shot peening duration is set to 10 min, and the initial shot peening stress is set to 0.6 MPa.

[0054] Specifically, the grinding in step S8 includes rough grinding and fine grinding. Among them, the rough grinding is processed by an efficient grinding process to a surface roughness of 0.8 to 1.6 μm; the fine grinding is processed by a precision ultra-finishing process to a surface roughness of 0.1 to 0.4 μm.

[0055] Specifically, the qualification of the surface heat treatment of the raceway surface is preliminarily determined according to the effective hardening depth. Among them, if the effective hardening depth is less than the first preset hardening depth of 0.8 mm, it is determined that the surface heat treatment is unqualified, and the reason for the unqualified surface heat treatment is determined according to the hardness gradient characteristic value;

[0056] If the effective hardening depth is greater than or equal to the first preset hardening depth and less than the second preset hardening depth of 1.5 mm, it is determined that the surface heat treatment is unqualified, and the qualification of the surface heat treatment is re-determined according to the average grain size at the effective depth;

[0057] If the effective hardening depth is greater than or equal to the second preset hardening depth, it is determined that the surface heat treatment is qualified, and shot peening treatment is performed on the bearing.

[0058] In the embodiment of the present invention, the value of the first preset hardening depth is 0.8 mm, and the value of the second preset hardening depth is 1.5 mm. However, the above values are not limited to this, and those skilled in the art can adjust this value according to actual needs.

[0059] Specifically, the effective hardening depth is measured by the microhardness test method. By measuring the hardness values point by point in the vertical direction of the bearing raceway surface after induction hardening, a hardness gradient curve is drawn, and the depth at which the hardness drops to the preset hardness of 550 HV is determined as the effective hardening depth, where the value of the preset hardness is 550 HV.

[0060] Specifically, the reason for the unqualified surface heat treatment is determined according to the hardness gradient characteristic value. Among them, if the hardness gradient characteristic value is less than the preset hardness gradient characteristic value of 5 HRC, it is determined that the reason for the unqualified surface heat treatment is that the heating is not up to standard, and the duration of induction hardening is increased according to the difference between the preset hardness gradient characteristic value and the hardness gradient characteristic value;

[0061] If the hardness gradient characteristic value is greater than or equal to the preset hardness gradient characteristic value, it is determined that the reason for the unqualified surface heat treatment is that the interface hardness is not up to standard, and the current density of induction hardening is reduced according to the ratio of the hardness gradient characteristic value to the preset hardness gradient characteristic value.

[0062] In the embodiment of the present invention, the value of the preset hardness gradient characteristic value is 5 HRC. However, the above value is not limited to this, and those skilled in the art can adjust this value according to actual needs.

[0063] Specifically, the duration of induction hardening is increased according to the difference between the preset hardness gradient characteristic value and the hardness gradient characteristic value. Among them, if the hardness gradient difference is less than the first preset hardness gradient difference of 0.5 HRC, the first duration adjustment coefficient of 1.2 is used to increase the duration of induction hardening to the corresponding value;

[0064] If the hardness gradient difference is greater than or equal to the first preset hardness gradient difference and less than the second preset hardness gradient difference of 1.0 HRC, the second duration adjustment coefficient of 1.5 is used to increase the duration of induction hardening to the corresponding value;

[0065] If the hardness gradient difference is greater than or equal to the second preset hardness gradient difference, the third duration adjustment coefficient of 1.8 is used to increase the duration of induction hardening to the corresponding value;

[0066] The hardness gradient difference is the difference between the preset hardness gradient characteristic value and the hardness gradient characteristic value.

[0067] In the embodiment of the present invention, the initial duration of induction hardening is 15 s, the first preset hardness gradient difference is 0.5 HRC, and the second preset hardness gradient difference is 1.0 HRC. However, the above values are not limited to this, and those skilled in the art can adjust these values according to actual needs.

[0068] Specifically, the qualification of surface heat treatment is re-determined according to the average grain size at the effective depth. Among them, if the average grain size is less than the preset grain size of 10 μm, the surface heat treatment is re-determined to be qualified, and shot peening treatment is performed on the bearing.

[0069] If the average grain size is greater than or equal to the preset grain size, the surface heat treatment is re-determined to be unqualified, and the cooling rate of induction hardening is increased according to the difference between the average grain size and the preset grain size.

[0070] Specifically, the average grain size is obtained by taking an image of the effective depth with a metallographic microscope and using image analysis software. In the embodiment of the present invention, the preset grain size is 10 μm. However, the above value is not limited to this, and those skilled in the art can adjust this value according to actual needs.

[0071] Specifically, the current density of induction hardening is negatively correlated with the hardness gradient deviation rate. Among them, if the hardness gradient deviation rate is less than the first preset deviation rate of 0.95, the first current adjustment coefficient of 0.86 is used to reduce the current density to the corresponding value.

[0072] If the hardness gradient deviation rate is greater than or equal to the first preset deviation rate and less than the second preset deviation rate of 0.9, the second current adjustment coefficient of 0.92 is used to reduce the current density to the corresponding value.

[0073] If the hardness gradient deviation rate is greater than or equal to the second preset deviation rate, the third current adjustment coefficient of 0.97 is used to reduce the current density to the corresponding value.

[0074] The hardness gradient deviation rate is the ratio of the hardness gradient characteristic value to the preset hardness gradient characteristic value.

[0075] In the embodiment of the present invention, the initial current density of induction hardening is 20 A / mm 2 , the first preset deviation rate is 0.95, and the second preset deviation rate is 0.9. However, the above values are not limited to this, and those skilled in the art can adjust these values according to actual needs.

[0076] Specifically, there are several adjustment methods for setting the cooling rate of induction hardening, and each adjustment method has a different increase range for the cooling rate. Among them, if the grain size difference is less than the first preset grain size difference of 2 μm, the cooling rate is increased to the corresponding value using the first rate adjustment coefficient of 1.3;

[0077] If the grain size difference is greater than or equal to the first preset grain size difference and less than the second preset grain size difference of 5 μm, the cooling rate is increased to the corresponding value using the second rate adjustment coefficient of 1.6;

[0078] If the grain size difference is greater than or equal to the second preset grain size difference, the cooling rate is increased to the corresponding value using the third rate adjustment coefficient of 2.0;

[0079] The grain size difference is the difference between the average grain size and the preset grain size.

[0080] In the embodiment of the present invention, the initial cooling rate of induction hardening is taken as 150 °C / s, the first preset grain size difference is taken as 2 μm, and the second preset grain size difference is taken as 5 μm. However, the above values are not limited thereto, and those skilled in the art can adjust these values according to actual needs.

[0081] Specifically, the qualification of shot peening is determined according to the cross-section defect characteristic value. Among them, if the defect characteristic value is less than the preset defect characteristic value of 0.98, it is determined that the shot peening is qualified, and the bearing raceway surface is ground to the preset size and then the assembly of the rolling elements is completed;

[0082] If the defect characteristic value is greater than or equal to the preset defect characteristic value, it is determined that the shot peening is unqualified, and the optimization strategy of the shot peening process is determined according to the surface roughness;

[0083] The defect characteristic value is jointly determined by the number of defect cracks and the average length.

[0084] Specifically, the defect characteristic value is the ratio of the product of the number of defect cracks and the average length to the defect threshold. Among them, the unit of the average length is mm, the defect threshold is taken as 10 mm, and the preset defect characteristic value is taken as 0.98. However, the above values are not limited thereto, and those skilled in the art can adjust these values according to actual needs.

[0085] Specifically, the optimization strategy of the shot peening process is determined according to the surface roughness. Among them, if the surface roughness is less than the preset roughness of 2.0 μm, the optimization strategy of the shot peening process is determined to be increasing the shot peening duration, and the shot peening duration is positively correlated with the first roughness difference, where the first roughness difference is the difference between the preset roughness and the surface roughness;

[0086] If the surface roughness is greater than or equal to the preset roughness, it is determined that the optimization strategy of the shot peening process is to reduce the shot peening pressure, and the shot peening pressure is positively correlated with the second roughness difference, where the second roughness difference is the difference between the surface roughness being greater than or equal to the preset roughness.

[0087] Specifically, the adjustment range of the shot peening duration is 5 - 10 min, and the adjustment range of the shot peening pressure is 0.3 - 0.6 MPa.

[0088] In the embodiment of the present invention, the value of the preset roughness is 2.0 μm, but the above value is not limited thereto, and those skilled in the art can adjust this value according to actual needs.

[0089] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0090] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a gearbox bearing based on surface strengthening, characterized in that: include: Step S1, annealing the blank that has been subjected to upsetting, punching and rolling in sequence; Step S2, using a lathe to sequentially perform rough turning of the blank, and fine turning of the raceway and chamfer to obtain a bearing inner ring substrate and a bearing outer ring substrate; Step S3, sequentially performing quenching, tempering and cryogenic treatment on the bearing inner ring substrate and the bearing outer ring substrate to complete heat treatment of the substrate; Step S4, marking the outer diameter surface of the bearing inner ring substrate and the inner diameter surface of the bearing outer ring substrate as raceway surfaces; Step S5, after induction quenching the raceway surface, obtaining the effective hardening depth and preliminarily determining that the surface heat treatment of the raceway surface is unqualified according to the effective hardening depth, determining the cause of the unqualified surface heat treatment according to the hardness gradient characteristic value, or secondarily determining the eligibility of the surface heat treatment according to the average grain size at the effective depth, wherein the hardness gradient characteristic value is the difference between the interface hardness and the hardness at the preset depth point; Step S6, performing shot peening on the bearings that have passed the surface heat treatment, obtaining the surface and cross-sectional defect conditions by photographing the surface image and cross-sectional metallographic structure of the bearings after shot peening, and obtaining the surface roughness and cross-sectional defect characteristic values; Step S7, when the shot peening process is judged to be unqualified according to the cross-sectional defect characteristic value, the optimization strategy of the shot peening process is determined according to the surface roughness to increase the shot peening time, or reduce the shot peening pressure; Step S8, under the condition that the shot peening is qualified, the raceway surface of the bearing is ground to a preset size and then the rolling element is assembled.

2. The method for manufacturing a gearbox bearing based on surface strengthening according to claim 1, characterized in that: In step S3, the quenching temperature range is 840°C to 860°C, the quenching medium is quenching oil, and the oil temperature is 80°C; the tempering temperature range is 150°C to 170°C, and the insulation time is 2 hours; the cryogenic temperature is -150°C, and the liquid nitrogen immersion time is 4 hours.

3. The method for manufacturing a gearbox bearing based on surface strengthening according to claim 1, characterized in that: The grinding in step S8 includes coarse grinding and fine grinding, wherein the coarse grinding adopts a high-efficiency grinding process to process the surface roughness to 0.8-1.6 μm; the fine grinding adopts a precision superfinishing process to process the surface roughness to 0.1-0.4 μm.

4. The method for manufacturing a gearbox bearing based on surface strengthening according to claim 1, characterized in that: Preliminarily determining the eligibility of the surface heat treatment of the raceway surface according to the effective hardening depth, wherein if the effective hardening depth is less than the first preset hardening depth, the surface heat treatment is determined to be unqualified, and the reason for the unqualified surface heat treatment is determined according to the hardness gradient characteristic value; If the effective hardening depth is greater than or equal to the first preset hardening depth and less than the second preset hardening depth, the surface heat treatment is judged to be unqualified, and the qualification of the surface heat treatment is secondarily judged according to the average grain size at the effective depth; If the effective hardening depth is greater than or equal to the second preset hardening depth, the surface heat treatment is determined to be qualified, and the bearing is shot peened.

5. The method for manufacturing a gearbox bearing based on surface strengthening according to claim 4, characterized in that: Determining the reason for the unqualified surface heat treatment according to the hardness gradient characteristic value, wherein if the hardness gradient characteristic value is less than a preset hardness gradient characteristic value, determining that the reason for the unqualified surface heat treatment is that the heating does not meet the standard, and increasing the duration of induction quenching according to the difference between the preset hardness gradient characteristic value and the hardness gradient characteristic value; If the hardness gradient characteristic value is greater than or equal to the preset hardness gradient characteristic value, it is determined that the reason for the failure of the surface heat treatment is that the interface hardness does not meet the standard, and the current density of induction quenching is reduced according to the ratio of the hardness gradient characteristic value to the preset hardness gradient characteristic value.

6. The method for manufacturing a gearbox bearing based on surface strengthening according to claim 4, characterized in that: Secondarily judging the eligibility of the surface heat treatment according to the average grain size at the effective depth, wherein if the average grain size is less than the preset grain size, the second judging that the surface heat treatment is qualified is performed, and the bearing is shot peened; If the average grain size is greater than or equal to the preset grain size, the surface heat treatment is secondarily determined to be unqualified, and the cooling rate of induction quenching is increased according to the difference between the average grain size and the preset grain size.

7. The method for manufacturing a gearbox bearing based on surface strengthening according to claim 5, characterized in that: The current density of induction hardening is negatively correlated with the hardness gradient deviation rate, wherein the hardness gradient deviation rate is the ratio of the hardness gradient characteristic value to the preset hardness gradient characteristic value.

8. The method for manufacturing a gearbox bearing based on surface strengthening according to claim 6, characterized in that: There are several adjustment methods for the cooling rate of induction quenching, and each adjustment method increases the cooling rate by a different amount.

9. The method for manufacturing a gearbox bearing based on surface strengthening according to claim 1, characterized in that: The eligibility of the shot peening treatment is determined according to the cross-sectional defect characteristic value, wherein if the defect characteristic value is less than a preset defect characteristic value, the shot peening treatment is determined to be qualified, and the bearing raceway surface is ground to a preset size before the rolling element is assembled; If the defect characteristic value is greater than or equal to the preset defect characteristic value, the shot peening process is judged to be unqualified, and an optimization strategy for the shot peening process is determined according to the surface roughness; The defect characteristic value is determined by the number and average length of the defect cracks.

10. The method for manufacturing a gearbox bearing based on surface strengthening according to claim 9, characterized in that: Determining an optimization strategy for the shot peening process according to the surface roughness, wherein if the surface roughness is less than a preset roughness, determining that the optimization strategy for the shot peening process is to increase the shot peening time, the shot peening time is positively correlated with the first roughness difference, wherein the first roughness difference is the difference between the preset roughness and the surface roughness; If the surface roughness is greater than or equal to the preset roughness, the optimization strategy for the shot peening process is determined to be to reduce the shot peening pressure, and the shot peening pressure is positively correlated with the second roughness difference, wherein the second roughness difference is the difference when the surface roughness is greater than or equal to the preset roughness.

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