Intelligent design method for surface strengthening process of transmission system based on gear bearing capacity evaluation

Abstract

The invention provides a transmission system surface strengthening process intelligent design method based on gear bearing capacity evaluation, which comprises the following steps: carrying out surface strengthening process treatment on a gear to obtain gear surface strengthening process parameters; measuring the surface integrity parameter of the gear to obtain the relationship between the gear surface strengthening process parameter and the surface integrity parameter; carrying out a gear bearing capacity test on the gear subjected to the surface strengthening process treatment to obtain a relationship between the surface integrity parameter prediction value and the gear bearing capacity; the performance of the transmission system under different surface strengthening processes is obtained; based on the actually measured gear bearing capacity and the transmission system performance, the importance degree of the gear bearing capacity to the transmission system performance is obtained; based on the importance degree, the relation between the gear bearing capacity predicted value and the transmission system performance is obtained, and intelligent design of the transmission system surface strengthening process based on gear bearing capacity evaluation is completed. According to the method, design-manufacturing integration of machining parameters and transmission system performance can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing and surface treatment, and specifically relates to an intelligent design method for a surface strengthening process of a transmission system based on gear load-bearing capacity evaluation. Background Art

[0002] Gears are important industrial basic parts, and their service performance directly determines the service performance of high-end equipment represented by aircraft engines. As the new generation of high-end equipment develops towards extreme service environments such as high speed, heavy load, and high temperature, the design of the gear transmission system usually takes meeting comprehensive performance indicators as the first requirement. However, due to the different application goals of gears in different equipment, the requirements for working conditions, load-bearing capacity, fatigue resistance, dynamic characteristics, etc. are also diversified. Therefore, design and manufacturing should be carried out in a coordinated and synchronous manner. However, the isolation of the existing gear processing, design, and manufacturing process has prevented the performance of the entire gear product from being further improved. The synergy between the design and manufacturing links cannot be fully utilized, making it difficult for the gear performance after processing and manufacturing to meet the high performance requirements of the design.

[0003] There is an obvious disconnect between the design and manufacture of existing high-end equipment gear transmission systems. On the design side, the transmission system is usually designed, strength checked, and the processing method is selected based on experience or design manuals, and the processing process parameters and effects cannot be considered temporarily, resulting in a lack of coordination between design and manufacturing. On the processing side, it is usually based on the rough requirements given by the design side, and the processing process parameters, processing steps, etc. cannot be further clarified. The vast majority of key processing parameters are selected based on processing experience and related processing manuals, and the corresponding parameters cannot be further given through design. As a result, the processing quality often cannot meet the design requirements, or the given design parameters cannot be used for actual processing. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides an intelligent design method for the surface strengthening process of the transmission system based on the gear load-bearing capacity evaluation, which breaks the barrier from process parameters to design performance evaluation and forms an integrated design and manufacturing collaboration.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The intelligent design method of transmission system surface strengthening process based on gear load-bearing capacity evaluation includes the following steps:

[0007] Perform surface strengthening process on the gear to obtain gear surface strengthening process parameters;

[0008] Measure the surface integrity parameters of the gear after surface strengthening process, and obtain the relationship between the gear surface strengthening process parameters and the surface integrity parameters;

[0009] Based on the relationship between the gear surface strengthening process parameters and the surface integrity parameters, the predicted values ​​of the surface integrity parameters under different gear surface strengthening processes are obtained;

[0010] The gear load capacity was tested on the gears after surface strengthening process, and the relationship between the predicted value of surface integrity parameters and the gear load capacity was obtained based on the data-driven method;

[0011] Based on the relationship between the predicted value of surface integrity parameters and the gear load capacity, the predicted value of gear load capacity under different gear surface strengthening processes is obtained;

[0012] Based on the measured gear load capacity and the working condition requirements of the gear transmission system, the structural parameters of the entire gear transmission system are designed to obtain the transmission system performance under different surface strengthening processes;

[0013] Based on the measured gear load capacity under different surface strengthening process conditions and the transmission system performance, the importance of the gear load capacity to the transmission system performance is obtained;

[0014] Based on the importance, the relationship between the predicted value of the gear load-bearing capacity and the transmission system performance is obtained, and the intelligent design of the transmission system surface strengthening process based on the gear load-bearing capacity evaluation is completed.

[0015] Preferably, the surface strengthening process treatment includes carburizing, quenching and grinding treatment, single shot peening treatment with different shot peening intensities, shot peening coverage rates and shot diameters, and secondary shot peening treatment with different shot peening passes, shot peening intensities, shot peening coverage rates and shot diameters.

[0016] Preferably, the surface integrity parameters of the gear include residual compressive stress on the gear surface, gear surface roughness and gear surface hardness gradient.

[0017] Preferably, the gear load-bearing capacity test includes testing the contact fatigue strength, bending fatigue strength and bonding limit temperature of the gear after surface strengthening process.

[0018] Preferably, the method for obtaining the relationship between the predicted value of the surface integrity parameter and the gear load capacity is:

[0019] Based on the gear surface roughness and the gear surface hardness gradient, the gear contact fatigue strength is obtained;

[0020] Based on the gear surface hardness gradient and the gear surface residual compressive stress value, the gear bending fatigue strength is obtained;

[0021] The gear bonding limit temperature is obtained based on the gear surface hardness gradient, gear surface roughness and gear surface aspect ratio.

[0022] Preferably, the method for obtaining the importance of gear load capacity to transmission system performance is:

[0023] Different safety performance indicators are obtained based on different surface strengthening processes for gears;

[0024] Based on the different safety performance indicators, the SHAP machine learning model interpretation method is used to obtain the importance of the contact fatigue strength, bending fatigue strength and bonding limit temperature of the gear to the comprehensive safety performance of the transmission system.

[0025] Preferably, the comprehensive safety performance of the transmission system includes the reliability and weight of the gears under different surface strengthening process conditions.

[0026] Preferably, the method for obtaining the relationship between the predicted value of the gear load capacity and the performance of the transmission system is:

[0027] Based on the importance of contact fatigue strength, bending fatigue strength and bonding limit temperature to the comprehensive safety performance of the transmission system, the least squares method is used to perform polynomial regression analysis to fit the comprehensive safety performance of the transmission system under different gear load capacities, and the relationship between the predicted value of the gear load capacity and the performance of the transmission system is obtained.

[0028] Compared with the prior art, the beneficial effects of the present invention are: building a bridge from gear load-bearing capacity to transmission system performance direct evaluation, forming an active evaluation formula of "surface strengthening process parameters-surface integrity-gear load-bearing capacity-transmission system performance", breaking through the barrier from process parameters to design performance evaluation, and forming integrated design and manufacturing collaboration. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 This is a flow chart of an intelligent design method for a transmission system surface strengthening process based on gear load-bearing capacity evaluation according to an embodiment of the present invention;

[0031] Figure 2 This is a test of the bending, contact and gluing load-bearing capacity of the gears in the embodiment of the present invention;

[0032] Figure 3 The safety comparison of the embodiments of the present invention after carburizing grinding, shot peening and secondary shot peening treatment;

[0033] Figure 4The importance of the gear load-bearing capacity such as contact fatigue limit, bending fatigue limit, and bonding limit temperature to the safety performance of the embodiment of the present invention;

[0034] Figure 5 The comparison effect between the comprehensive safety factor calculated for the embodiment of the present invention and the actual safety factor is shown in the figure. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Embodiment 1

[0038] like Figure 1 As shown, the transmission system surface strengthening process intelligent design method based on gear load-bearing capacity evaluation is formed. This embodiment takes the shot peening and secondary shot peening of 16Cr3NiWMoVNbE aviation gear as an example, and takes the 230kW-class turbofan engine accessory case gear transmission system as the design object, and forms a transmission system surface strengthening process intelligent design method based on gear load-bearing capacity evaluation, which specifically includes the following steps:

[0039] S1: performing surface strengthening process treatment on the gear to obtain gear surface strengthening process parameters; a further implementation method is that the surface strengthening process treatment sequentially includes carburizing quenching grinding treatment, single shot peening treatment with different shot peening intensities, shot peening coverage rates, and shot diameters, and secondary shot peening treatment with different shot peening passes, shot peening intensities, shot peening coverage rates, and shot diameters.

[0040] S2: Measure the surface integrity parameters of the gear after the surface strengthening process, and obtain the relationship between the gear surface strengthening process parameters and the surface integrity parameters; based on the relationship between the gear surface strengthening process parameters and the surface integrity parameters, obtain the predicted values ​​of the surface integrity parameters under different gear surface strengthening processes; a further implementation method is that the surface integrity parameters of the gear include residual compressive stress on the gear surface, gear surface roughness and gear surface hardness gradient.

[0041] Specifically, the relationship between gear surface strengthening process parameters and surface integrity parameters is as follows:

[0042] Calculation formula between single shot peening process parameters and surface integrity:

[0043] I: represents the shot peening intensity, the unit is mmA;

[0044] C: represents the shot peening coverage, in %;

[0045] D: represents the diameter of the projectile, in mm;

[0046] Surface hardness: SH = 54.11 × I + 0.0201 × C + 23.83 × D + 733.5

[0047] Surface residual compressive stress: SR = 435.6 × I-0.53872 × C + 110.2 × D-1017.2

[0048] Maximum residual compressive stress: MR = -485.2 × I-8.385 × e -6 ×C 2 -6.149×D 2.68 -1179

[0049] Surface roughness parameter Sa: Sa = 0.4247 × I + 1.964 × 10 -5 ×C+0.1232×D+0.2993

[0050] The aspect ratio Str of the gear surface is: Str = 0.4778 × I + 2 × 104 × C + 0.076 × D + 0.6534.

[0051] Among them, the aspect ratio of the gear surface is a surface roughness parameter.

[0052] Calculation formula between secondary shot peening process parameters and surface integrity:

[0053] Surface hardness: SH = 28.41 × (I1 + I2) + 0.0106 × (C1 + C2) + 12.51 × (D1 + D2) + 770.2

[0054] Surface residual compressive stress: SR = 252.65 × (I1 + I2) - 0.3124 × (C1 + C2) + 63.92 × (D1 + D2) - 1180

[0055] Maximum compressive residual stress:

[0056] R=-271.7×(I1+I2)-4.69×e -6 ×(C1 2 +C2 2 )-3.44×(D1 2.68 +D2 2.68 )-1320

[0057] Surface roughness parameter Sa:

[0058] Sa=0.1699×(I1+I2)+7.856×10 -9 ×(C1+C2)+0.04928×(D1+D2)+0.2394

[0059] Surface roughness parameter Str:

[0060] Str=0.2532×(I1+I2)+1.06×10 -6 ×(C1+C2)+0.04028×(D1+D2)+0.6926

[0061] S3: Conducting a gear load-bearing capacity test on the gears that have been treated with the surface strengthening process, and obtaining the relationship between the predicted value of the surface integrity parameter and the gear load-bearing capacity based on a data-driven method; obtaining the predicted value of the gear load-bearing capacity under different gear surface strengthening processes based on the relationship between the predicted value of the surface integrity parameter and the gear load-bearing capacity; a further implementation method is that the gear load-bearing capacity test includes conducting contact fatigue strength, bending fatigue strength and bonding limit temperature tests on the gears that have been treated with the surface strengthening process.

[0062] In this embodiment, a pulsating cycle loading tester is used to test the bending fatigue strength of a gear with a module of 3 and 24 teeth after carburizing grinding, shot peening and secondary shot peening. A Strama gear contact fatigue tester is used to test the gear contact fatigue limit of a gear pair with a module of 4.5 and 28 teeth and a module of 4.5 and 27 teeth. A standard FZG gear tester is used to test the gear bonding limit temperature of a gear pair with a module of 4.5 and 24 teeth and a module of 4.5 and 16 teeth. Figure 2 As shown, the contact fatigue limit (strength), bending fatigue limit and bonding limit temperature of the gears in the carburized grinding state, shot peening state and after secondary shot peening treatment are obtained.

[0063] Specifically, this embodiment measures the contact fatigue strength limit, bending fatigue strength limit and bonding limit temperature of the gear in the carburizing and grinding state, the shot peening state and the secondary shot peening state, and measures the surface integrity parameters of the gear in these three process states, as shown in Table 1.

[0064] Table 1

[0065]

[0066] Through the data-driven method in the prior art "Study on the relationship between surface integrity and contact fatigue of carburized gears", the relationship between the predicted value of the surface integrity parameter of the 16Cr3NiWMoVNbE gear and the gear load-bearing capacity in this embodiment is obtained.

[0067] A further embodiment is that the method for obtaining the relationship between the predicted value of the surface integrity parameter and the gear load capacity is:

[0068] Based on the gear surface roughness and the gear surface hardness gradient, the gear contact fatigue strength is obtained;

[0069] Specific:

[0070] σ Hlim =455.745×Sa -0.105 +1.868×SH+164.614×e -0.0003MR -257.833

[0071] Based on the gear surface hardness gradient and the residual compressive stress value on the gear surface, the gear bending fatigue strength is obtained; specifically, σ Flim =0.809×SH-0.049×SR+28.95

[0072] Based on the gear surface hardness gradient, gear surface roughness and gear surface aspect ratio, the gear bonding limit temperature is obtained. Specifically, T Sint =0.430×SH+9.9×Sa-60.969×Str

[0073] Among them, σ Hlim is the gear contact fatigue strength; σ Flim is the gear bending fatigue strength; T Sint is the gear bonding limit temperature; Sa is the gear surface roughness; SH represents the gear surface hardness gradient (gear surface microhardness); MR is the maximum residual compressive stress value of the gear subsurface; SR is the residual compressive stress value of the gear surface; Str represents the aspect ratio of the gear surface.

[0074] S4: Based on the measured gear load-bearing capacity and the working condition requirements of the gear transmission system, the structural parameters of the entire gear transmission system are designed to obtain the transmission system performance under different surface strengthening processes; a further implementation method is that the comprehensive safety performance of the transmission system includes the gear reliability and weight under different surface strengthening process conditions.

[0075] This embodiment is based on the 230kW-class turbofan engine accessory casing as the research object. According to the working conditions and design parameter requirements of the aero-engine gear transmission, the structural parameters of the entire gear transmission are designed for the gear transmission system after carburizing grinding, shot peening and secondary shot peening. The transmission gears of the aero-engine accessory casing are all designed with involute cylindrical gears. The preliminary design and strength verification of the gear geometric structure parameters are carried out according to the design requirements such as the transmission ratio and the gear center distance. The pressure angle of the aviation involute cylindrical spur gears involved in this embodiment is selected as a 25° pressure angle, and the gear module is selected as 2.5mm. The tooth width is calculated according to the strength after different process treatments, so as to determine the safety performance of the gear set in its transmission system.

[0076] This embodiment takes the calculation of its safety performance as an example and evaluates the safety performance by using the comprehensive safety factor method.

[0077] Comprehensive safety factor method assessment process:

[0078]

[0079] Among them, S I represents the comprehensive safety factor;

[0080] w i It represents the evaluation weight of the safety factor by various methods. The present invention mainly adopts entropy evaluation weight, fuzzy comprehensive evaluation weight, CRITIC weight, independence weight and information weight; s i It represents the minimum contact, bending and gluing safety factor in the gear transmission system.

[0081] The distribution of the influence weights of the minimum contact, bending, and bonding safety factors calculated by the entropy value evaluation method and other five methods is shown in Table 2. It can be found that the weights of the contact, bending, and bonding safety factors obtained by the entropy value evaluation weight method are 0.1612, 0.716, and 0.1228, respectively, and the weight of the bending safety factor accounts for the largest proportion; in addition, the safety factor weights calculated by the fuzzy comprehensive evaluation weight, CRITIC weight, and information weight method are all greater than the contact and bonding safety factor weights. The bonding safety factor weight calculated by the independence weight method is the largest, reaching 0.4655; while the contact safety factor weight and the bending safety factor weight are almost the same, 0.2675 and 0.267, respectively. The minimum contact, bending and bonding safety factors were calculated by five methods, namely entropy evaluation weight, fuzzy comprehensive evaluation weight, CRITIC weight, independence weight and information weight. The comprehensive safety assessment weights were 0.1723, 0.62072 and 0.20698 respectively. The weight coefficients can be used to comprehensively evaluate the safety factors of contact, bending and bonding, providing a method for efficiently evaluating the safety performance of aero-engine transmission systems.

[0082] Table 2

[0083]

[0084]

[0085] The comprehensive safety factor of the gear transmission system after shot peening and secondary shot peening treatment is increased by 3.23% and 21.68% respectively compared with the carburized grinding state. Figure 3 As shown in the figure, secondary shot peening has a more obvious effect on improving the comprehensive safety performance. Therefore, the reliability of the gear transmission system can be improved through secondary shot peening, and the human-machine safety of aircraft engines and pilots can be improved.

[0086] S5: Based on the measured gear load capacity and transmission system performance under different surface strengthening process conditions, the importance of gear load capacity to transmission system performance is obtained;

[0087] A further implementation method is that the method for obtaining the importance of the gear load capacity to the transmission system performance is:

[0088] Different safety performance indicators are obtained based on different surface strengthening processes for gears;

[0089] Based on different safety performance indicators, the SHAP machine learning model interpretation method is used to obtain the importance of contact fatigue strength, bending fatigue strength and bonding limit temperature of gears to the comprehensive safety performance of the transmission system.

[0090] SHAP machine learning model interpretation method:

[0091] The SHapleyAdditive exPlanations (SHAP) model interpretation method used in this invention is widely used to interpret various machine learning and deep learning models. Its basic idea is to interpret various black box models by calculating the marginal contribution of each feature when it is added to the model, thereby realizing the influence weight of different parameters. The SHAP value is calculated as follows:

[0092]

[0093] In the formula, is the model's predicted value for the i-th sample; y base Predict the mean for all samples; m is the number of input features of the i-th sample; x ij is the jth input feature of the i-th sample; f(x ij ) is the sample feature x ij SHAP value. When f(x ij)>0, the feature has a positive impact on the model evaluation results, otherwise it means that the feature has a negative impact on the model evaluation results. By obtaining the SHAP values ​​of all features of n samples, the importance of m features is calculated respectively. The calculation formula for the importance of feature j is:

[0094]

[0095] Among them, I(x j ) is the influence weight on a certain feature parameter.

[0096] This embodiment uses the SHAP machine learning model interpretation method to evaluate the importance of the load-bearing capacity of aviation gears based on the carburizing grinding, shot peening, and secondary shot peening of a typical 230kW-class accessory casing to obtain different safety performance indicators. The SHAP model interpretation method is used to evaluate the minimum safety factor of the aero-engine transmission system based on different contact, bending, and bonding load-bearing capacity data, so as to actively design the aero-engine transmission system to improve its safety.

[0097] Based on the SHAP machine learning model, the importance of gear contact fatigue limit, bending fatigue limit and bonding limit temperature to the comprehensive safety performance of the gear transmission system is 36.73%, 32.65% and 30.62% respectively. Figure 4 As shown in the figure, it can be found that the importance of contact, bending and bonding to the safety performance of gears is almost the same. Therefore, when designing the transmission system, it is necessary to comprehensively consider their corresponding safety performance to ensure that the transmission system can operate stably and reliably.

[0098] S6: Based on the importance, the relationship between the predicted value of gear load capacity and the performance of the transmission system is obtained, and the intelligent design of the surface strengthening process of the transmission system based on the gear load capacity evaluation is completed.

[0099] A further implementation method is that the method for obtaining the relationship between the predicted value of the gear load capacity and the transmission system performance is:

[0100] Based on the importance of contact fatigue strength, bending fatigue strength and bonding limit temperature to the comprehensive safety performance of the transmission system, the least squares method was used for polynomial regression analysis to fit the comprehensive safety performance of the transmission system under different gear load capacities, and the relationship between the predicted value of gear load capacity and the performance of the transmission system was obtained.

[0101] In this embodiment, a polynomial regression analysis is performed using the least squares method to fit the formula for the comprehensive performance of the aero-engine transmission system, and the comprehensive safety factor under different gear load capacities is obtained by evaluating the gear load capacity data under different process conditions against the comprehensive safety factor.

[0102] The expression of the comprehensive safety factor obtained by the least squares method in this embodiment is as follows. It can be found that it has a linear relationship with the contact fatigue limit, bending fatigue strength limit, bonding limit temperature, etc. of the gear.

[0103] S I =0.00639×σ Hlim -0.00682×σ Flim +0.00607×T Sint -5.833

[0104] Among them, S I Represents the comprehensive safety performance of the transmission system, σ Hlim Gear contact fatigue limit; σ Flim Gear contact fatigue limit; T Sint Gear bonding limit temperature. The comparison between the comprehensive safety factor calculated by this expression and the actual safety factor is as follows: Figure 5 As shown, it can be found that the prediction error is 1% under carburizing and grinding state, 1.68% under shot peening state, and 1.20% under secondary shot peening process state. The maximum prediction error can be controlled within 1.7%, which shows the prediction accuracy of the formula.

[0105] By directly inputting the process parameters of shot peening or secondary shot peening, the comprehensive safety performance of the aero-engine gear transmission system can be obtained, providing the designed safety performance for the processing parameters; the best combination of process parameters can also be obtained by giving a comprehensive safety factor, providing processing parameters for the designed performance; this method can realize the design-manufacturing integration of processing parameters-transmission system performance.

[0106] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An intelligent design method for transmission system surface strengthening process based on gear load-bearing capacity evaluation, characterized in that: The following steps are involved: Perform surface strengthening process on the gear to obtain gear surface strengthening process parameters; Measure the surface integrity parameters of the gear after surface strengthening process, and obtain the relationship between the gear surface strengthening process parameters and the surface integrity parameters; Based on the relationship between the gear surface strengthening process parameters and the surface integrity parameters, the predicted values ​​of the surface integrity parameters under different gear surface strengthening processes are obtained; The gear load capacity was tested on the gears after surface strengthening process, and the relationship between the predicted value of surface integrity parameters and the gear load capacity was obtained based on the data-driven method; Based on the relationship between the predicted value of surface integrity parameters and the gear load capacity, the predicted value of gear load capacity under different gear surface strengthening processes is obtained; Based on the measured gear load capacity and the working condition requirements of the gear transmission system, the structural parameters of the entire gear transmission system are designed to obtain the transmission system performance under different surface strengthening processes; Based on the measured gear load capacity under different surface strengthening process conditions and the transmission system performance, the importance of the gear load capacity to the transmission system performance is obtained; Based on the importance, the relationship between the predicted value of the gear load-bearing capacity and the transmission system performance is obtained, and the intelligent design of the transmission system surface strengthening process based on the gear load-bearing capacity evaluation is completed.

2. The intelligent design method for transmission system surface strengthening process based on gear load-bearing capacity evaluation according to claim 1 is characterized in that: The surface strengthening process treatments include carburizing, quenching and grinding treatments, single shot peening treatments with different shot peening intensities, shot peening coverages and shot diameters, and secondary shot peening treatments with different shot peening passes, shot peening intensities, shot peening coverages and shot diameters.

3. The intelligent design method for transmission system surface strengthening process based on gear load-bearing capacity evaluation according to claim 1 is characterized in that: The surface integrity parameters of gears include residual compressive stress on the gear surface, gear surface roughness, and gear surface hardness gradient.

4. The intelligent design method for transmission system surface strengthening process based on gear load-bearing capacity evaluation according to claim 1 is characterized in that: The gear load-bearing capacity test includes testing the contact fatigue strength, bending fatigue strength and bonding limit temperature of the gears after surface strengthening process.

5. The intelligent design method for transmission system surface strengthening process based on gear load-bearing capacity evaluation according to claim 4 is characterized in that: The method for obtaining the relationship between the predicted value of the surface integrity parameter and the gear load capacity is: Based on the gear surface roughness and the gear surface hardness gradient, the gear contact fatigue strength is obtained; Based on the gear surface hardness gradient and the gear surface residual compressive stress value, the gear bending fatigue strength is obtained; The gear bonding limit temperature is obtained based on the gear surface hardness gradient, gear surface roughness and gear surface aspect ratio.

6. The intelligent design method for transmission system surface strengthening process based on gear load-bearing capacity evaluation according to claim 5 is characterized in that: The method to obtain the importance of gear load capacity to the transmission system performance is: Different safety performance indicators are obtained based on different surface strengthening processes for gears; Based on the different safety performance indicators, the SHAP machine learning model interpretation method is used to obtain the importance of the contact fatigue strength, bending fatigue strength and bonding limit temperature of the gear to the comprehensive safety performance of the transmission system.

7. The intelligent design method for transmission system surface strengthening process based on gear load-bearing capacity evaluation according to claim 6 is characterized in that: The comprehensive safety performance of the transmission system includes the reliability and weight of gears under different surface strengthening process conditions.

8. The intelligent design method for transmission system surface strengthening process based on gear load-bearing capacity evaluation according to claim 1 is characterized in that: The method for obtaining the relationship between the gear load capacity prediction value and the transmission system performance is: Based on the importance of contact fatigue strength, bending fatigue strength and bonding limit temperature to the comprehensive safety performance of the transmission system, the least squares method is used to perform polynomial regression analysis to fit the comprehensive safety performance of the transmission system under different gear load capacities, and the relationship between the predicted value of the gear load capacity and the performance of the transmission system is obtained.

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