A method for calculating the allowance of a 20CrMnMo yaw output end integrated outer shell carburizing and quenching process

Abstract

The present application relates to wind power yaw gear box heat treatment process technical field, disclose a kind of 20CrMnMo integrated shell type part carburizing quenching process allowance calculation method, integrated outer shell is one integrated outer shell, inner gear ring and bearing raceway Large wall thickness difference rotary shell parts, based on its carburizing quenching deformation law, for three key processing positions of outer circle, inner hole, inner gear ring, with the ratio of corresponding site wall thickness and outer diameter as deformation coefficient, combined with outer diameter and axial length parameter to construct each site deformation amount quantitative calculation model, superimposed finishing datum allowance to obtain the machining process allowance before carburizing quenching, and the calculation model is verified and optimized by trial production detection.This application can accurately match the heat treatment deformation amount of each part to set allowance, ensure sufficient finishing allowance, meet the performance requirements of parts, compress redundant machining allowance, improve material utilization, reduce manufacturing cost, adapt to general heat treatment equipment, and have strong engineering practicability.

Description

Technical Field

[0001] This invention relates to the field of heat treatment technology for wind turbine yaw gearboxes, specifically to a method for calculating the allowance for the carburizing and quenching process of an integrated outer shell for the 20CrMnMo yaw output end. Background Technology

[0002] The yaw gearbox is a core transmission component of wind turbine generators. As the wind power industry moves towards lightweight and high torque density, the integration of yaw gearbox components continues to improve. The output structure is gradually adopting an integrated housing design, integrating multiple independent parts such as the traditional housing, bearing outer raceway, and internal gear ring into one unit to reduce the number of parts and the overall weight of the unit.

[0003] These integrated housings are typically made of 20CrMnMo low-carbon alloy carburizing steel. This material is suitable for heavy-load, alternating impact conditions in wind power yaw scenarios and is the mainstream material for such heavy-load integrated transmission components. However, 20CrMnMo has a high content of alloying elements such as Cr, Mn, and Mo. Its coefficient of thermal expansion, austenite stability, and martensite transformation characteristics during carburizing and quenching differ significantly from those of conventional carburizing steels such as 20Cr and 20CrMnTi. Consequently, the deformation trend and amount of deformation under the same structure exhibit obvious material specificity, making it impossible to directly apply the process allowance standards of other materials. Furthermore, these integrated housings are compact and highly integrated. During carburizing and quenching heat treatment, the differences in deformation trend and amount of deformation in different processed parts are already significant. Combined with the characteristics of 20CrMnMo material—high hardenability of large cross-sections and asynchronous microstructure transformation at different wall thicknesses—the deformation differences in various parts are further amplified, placing extremely high demands on the setting of pre-heat machining process allowances.

[0004] Currently, the industry lacks a systematic and precise method for calculating carburizing and quenching allowances for integrated shell parts made of 20CrMnMo material. Instead, it generally relies on common empirical standards to set process allowances. If the allowance is too large, material utilization is low and processing costs are high; if the allowance is too small, insufficient finishing allowances are likely, leading to a high risk of part scrap.

[0005] In existing publicly available technologies, some solutions provide localized profile compensation for the grinding allowance of a single cylindrical gear, while others improve heating uniformity through specialized heat treatment equipment. However, none of these solutions propose a quantitative calculation method for the allowance of the carburizing and quenching process covering all parts of 20CrMnMo shell-type parts with multiple integrated structures and large wall thickness differences. Consequently, they cannot accurately address the core issue of unreasonable allowance settings for such parts from the perspective of pre-heating process design. Summary of the Invention

[0006] This invention aims to provide a method for calculating the allowance for carburizing and quenching of integrated shell housings for 20CrMnMo yaw output ends. This method addresses the problem that the allowance for carburizing and quenching of multi-structure integrated shell parts with large wall thickness differences relies on experience and lacks rationality. It achieves accurate quantitative design of the allowance for pre-heating processes, and while ensuring sufficient finishing allowance for each part and meeting the performance requirements of the parts, it reduces redundant machining allowance, improves material utilization, and lowers manufacturing costs.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a method for calculating the allowance of the carburizing and quenching process of an integrated shell housing for a 20CrMnMo yaw output end, wherein the integrated shell housing is a rotating shell part that integrates a shell structure, an internal gear ring structure, and a bearing outer raceway structure; the calculation method includes the following steps: S1: Based on the carburizing and quenching deformation law of the target part, determine the appropriate heat treatment process conditions. S2: For the three key machining parts of the part, namely the outer circle, inner hole and internal teeth, a quantitative calculation model for the carburizing and quenching deformation of each part is constructed for different axial structural sections of the part. Among them, the ratio of the wall thickness to the outer diameter of the corresponding part is used as the deformation coefficient. Combined with the outer diameter parameter and axial length parameter of the part, the carburizing and quenching deformation of the corresponding part is quantitatively calculated. S3: Based on the finishing allowance of each part, the carburizing and quenching deformation of the corresponding part is added to calculate the machining allowance of each part before carburizing and quenching. S4: Use the calculated process allowance for trial production, check the actual allowance and deformation of each part after carburizing and quenching, and verify and optimize the quantitative calculation model.

[0008] The principle and advantages of this solution are as follows: In practical applications, it uses deformation law recognition, quantitative prediction of different parts, precise accumulation of allowances, and closed-loop optimization of experiments as its core logic. For integrated shell parts with large wall thickness differences, it establishes a quantitative correlation between structural parameters such as wall thickness, outer diameter, and axial length and heat treatment deformation, realizing the transformation of allowance from empirical estimation to precise calculation. This solution can match corresponding allowances to the deformation differences of different parts, avoiding part scrapping caused by insufficient allowances in thin-walled parts and eliminating material waste caused by redundant allowances in thick-walled parts, directly achieving the core invention objectives of accurate allowances, improved utilization, and reduced costs.

[0009] Preferably, as an improvement, the inherent deformation trend of this type of structural part is clearly defined, which is the prerequisite for calculating allowances. This provides an accurate basis for the direction of allowance stacking, stacking shrinkage on the outer circle and expansion on the inner hole, avoiding the failure of allowance settings due to incorrect judgment of deformation trend. This ensures the reliability of the calculation method from the bottom up, which is a prerequisite for achieving accurate allowance design.

[0010] Preferably, as an improvement, the outer shell structure comprises three outer circle sections: an upper outer circle, a flange outer circle, and a lower outer circle. The internal gear ring structure is a straight-tooth internal gear ring, and the bearing raceway structure is a bearing outer raceway combining a spherical surface and a cylindrical surface. By anchoring the integrated structure of the three-section shell, internal gear ring, and bearing raceway, the calculation logic of the component modeling is made more targeted, ensuring the engineering practicality of the method and enabling direct implementation to solve the actual process pain points in the wind power gearbox industry.

[0011] Preferably, as an improvement, the deformation calculation is visualized as a directly calculable mathematical formula. Coefficients are fitted separately for the differences in wall thickness and rigidity in different axial sections, solving the problem that a unified formula cannot be adapted to structures with large wall thickness differences. By substituting structural parameters into the formula, the predicted deformation values ​​for each part can be quickly obtained without repeated trial and error, significantly improving the efficiency and accuracy of allowance design. This is the core technology for achieving the core objectives of quantitative calculation and precise allowance.

[0012] Preferably, as an improvement, the deformation calculation results are directly converted into process allowance parameters that can be executed in machining. The calculation logic corresponds one-to-one with the deformation trend, eliminating the need for secondary conversion. Process engineers can directly apply the formula to output the pre-heat machining dimensions. This completes the closed loop from deformation prediction to process output, allowing the calculation method to directly guide production and effectively achieve the goal of accurately setting allowances and improving machining efficiency.

[0013] Preferably, as an improvement, this method covers the standard product specification range of integrated yaw wind turbine housings, clearly defining the applicable boundaries of the calculation method. This ensures the accuracy of the calculation model's predictions within this parameter range and avoids calculation deviations caused by exceeding the applicable scope. While guaranteeing the method's universality, it maintains a minimum level of calculation accuracy, ensuring that the design goal of precise allowance can be achieved within the applicable range.

[0014] Preferably, as an improvement, the process parameters match the austenitizing and hardening characteristics of 20CrMnMo material, and are compatible with industry-standard box-type multi-purpose furnace equipment, without the need for new special equipment or modification of existing production lines; it can be directly applied under the existing production conditions of most gear processing enterprises, avoiding additional equipment investment caused by the method itself.

[0015] Preferably, as an improvement, an upper limit constraint is set on the finishing allowance of the carburized area from the perspective of the final quality target, so as to avoid excessive removal of the carburized layer and failure to meet the surface hardness due to excessive pursuit of reducing the allowance. This feature, while reducing redundant allowance, maintains the bottom line of the performance of the part, achieves a balance between "cost reduction" and "quality assurance", and fully meets the constraint of "ensuring the performance requirements of the part" in the purpose of the invention.

[0016] Preferably, as an improvement, K1 is controlled to be 0.05~0.06 and K2 to be 0.045~0.055. Within this range, the overall deformation of the parts is small and the uniformity of the allowance is good. This can reduce the number of early tests in the new product development stage, shorten the development cycle, and further improve the process stability of mass production. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a half-section of the integrated outer shell according to an embodiment of the present invention; Figure 2 The chart shows the process allowance before carburizing and quenching and the measured allowance after carburizing and quenching in the experimental cases of this invention.

[0018] The reference numerals in the accompanying drawings include: 1. Outer shell structure; 11. Upper outer circle; 12. Middle flange outer circle; 13. Lower outer circle; 14. Upper inner hole; 15. Lower inner hole; 2. Internal gear ring structure; 3. Bearing outer raceway structure. Detailed Implementation

[0019] The following detailed description illustrates the specific implementation method: Implementation, for example, attached Figure 1 As shown: A method for calculating the allowance of the carburizing and quenching process of the integrated shell of the 20CrMnMo yaw output end. The integrated shell is specifically the integrated shell of the wind power yaw output end, which is a one-piece molded rotating shell structure, consisting of shell structure 1, internal gear ring structure 2, and bearing outer raceway structure 3.

[0020] Reference Figure 1 The outer shell structure 1 is divided into three outer circular sections along the axial direction: an upper outer circle 11, a middle flange outer circle 12, and a lower outer circle 13. The diameters of the upper outer circle 11, the middle flange outer circle 12, and the lower outer circle 13 are D1, D2, and D3, respectively. The corresponding axial lengths are L1 for the upper outer circle 11, L2 for the middle flange outer circle 12, and L3 for the lower outer circle 13. An upper inner hole 14 and a lower inner hole 15 are correspondingly provided inside the shell, with diameters d1 and d2, respectively. An internal gear ring structure 2 is located in the upper part of the shell cavity. The internal gear ring structure 2 is a straight-tooth internal gear ring with a tooth width of B, a tooth profile pressure angle of α, and a module of 2mm to 6mm. The shell wall thickness at the upper stop is δ1, which is the radial wall thickness from the inner wall of the upper outer circle 11 to the tooth root circle. The bearing outer raceway structure 3 is located in the lower part of the inner cavity of the housing. The bearing outer raceway structure 3 is a combination of a spherical raceway surface and a cylindrical raceway surface. The housing wall thickness corresponding to the lower bearing raceway is δ2, which is the radial wall thickness from the inner wall of the lower outer circle 13 to the raceway surface.

[0021] In this embodiment, the material of the part is 20CrMnMo low-carbon alloy carburizing steel, and the performance requirements of the finished product are: the hardness of the inner gear ring tooth surface and the bearing raceway surface is ≥58HRC, the effective hardened layer depth is 1.0mm~2.5mm; the finishing allowance of the raceway in the carburizing area is ≤0.80mm, and the finishing allowance of the inner gear ring tooth surface is ≤0.70mm.

[0022] Reference Figure 1 The calculation method for allowance in the carburizing and quenching process of integrated outer shell includes the following steps: S1: Based on the carburizing and quenching deformation characteristics of the target part, determine the appropriate heat treatment process conditions. Based on traditional process allowance standards and statistical analysis of deformation from batch process tests of parts with the same structure and material, the deformation pattern of this type of 20CrMnMo integrated shell after carburizing and quenching was clarified as follows: the outer diameters of the parts exhibit overall shrinkage deformation after carburizing and quenching, while the inner holes and internal gear rings exhibit overall expansion deformation. Simultaneously, due to uneven circumferential cooling and axial wall thickness differences, each machined part is accompanied by varying degrees of elliptical distortion and taper deformation. Therefore, when determining the machining allowance, the shrinkage of the outer diameters is mainly considered, while the expansion deformation of the inner holes and internal gears is mainly considered. Based on the above deformation patterns and the heat treatment characteristics of 20CrMnMo material, suitable heat treatment process conditions were determined: a box-type multi-purpose furnace with a loading capacity of 1.0~5.0 tons was used for carburizing and quenching treatment, with the carburizing temperature set at 900℃~950℃ and the quenching temperature set at 820℃~860℃. The process parameters are matched with the austenitizing temperature and hardening characteristics of 20CrMnMo material, which can control the overall deformation within a predictable range while ensuring the depth of the carburized layer and the surface hardness.

[0023] S2: Constructing a quantitative calculation model for carburizing and quenching deformation in different parts. For three key machining areas of a part—outer diameter, inner hole, and internal gear ring—different axial structural sections are identified. A quantitative calculation model for deformation is constructed based on the outer diameter, axial length, and wall thickness parameters of each area. A deformation coefficient K = δ / D is introduced, where δ is the shell wall thickness at the corresponding location, and D is the outer diameter at the corresponding location. This coefficient characterizes the structural rigidity and cooling uniformity of the area. A smaller K value indicates a thinner wall, weaker structural rigidity, and greater heat treatment deformation.

[0024] The specific calculation formulas for the deformation of each part are as follows: (1) Reduction of the outer circle The reduction in the outer circle 11D1 at the top end = L1 × (1 + 2K1) / D1, where K1 = δ1 / D1; The reduction in diameter of the outer circle of the intermediate flange is 12D2 = D2 / 1000; The reduction in the outer circle at the lower end is 13D3 = L3 × (2 + 4K2) / D3, where K2 = δ2 / D3.

[0025] (2) Excessive expansion at the inner hole The expansion amount of the upper inner hole 14d1 = L1×(1+8K1) / D1, where K1=δ1 / D1; The expansion amount of the lower inner hole 15d2 is = L3×(2+6K2) / D3, where K2=δ2 / D3.

[0026] (3) Excessive expansion in the internal gear ring area The expansion amount in the common normal direction of the internal gear ring = L1×(1+4K1)×sinα / D1, where K1=δ1 / D1.

[0027] In the above formula, δ1 is the shell wall thickness at the upper stop, δ2 is the shell wall thickness corresponding to the lower bearing raceway, L1 is the axial length of the upper outer circle 11, L3 is the axial length of the lower outer circle 13, and α is the tooth profile pressure angle of the internal gear ring. The deformation of the internal gear ring is calculated according to the common normal direction, which can be directly matched with the allowance measurement and machining datum of the gear grinding process without additional conversion.

[0028] S3: Calculate the machining allowance for each part before carburizing and quenching. Based on the finishing allowance of each part, the corresponding carburizing and quenching deformation amount is added to obtain the machining allowance before carburizing and quenching of each part: the outer circle part needs to add the shrinkage amount on the finishing allowance because the size shrinks after heat treatment; the inner hole and internal gear ring part need to add the expansion amount on the finishing allowance because the size expands after heat treatment, so as to ensure that each part still has sufficient and uniform finishing allowance after heat treatment.

[0029] The specific calculation formulas for the process allowances for each part are as follows: Upper outer diameter 11D1 allowance = outer diameter finishing datum allowance Z1 + upper outer diameter 11D1 reduction amount; The allowance for the outer diameter 12D2 of the intermediate flange = the allowance for finishing the outer diameter Z1 + the reduction amount for the outer diameter 12D2 of the intermediate flange; Lower outer diameter 13D3 allowance = outer diameter finishing datum allowance Z1 + lower outer diameter 13D3 reduction amount; The allowance for the upper inner hole 14d1 = the allowance for finishing the inner hole Z2 + the expansion amount of the upper inner hole 14d1; 15d2 allowance for lower inner hole = Z2 allowance for inner hole finishing + 15d2 expansion amount of lower inner hole; The allowance for the common normal of the internal gear ring = the machining allowance for the internal gear ring Z3 + the expansion amount in the direction of the common normal of the internal gear ring.

[0030] In the formula, Z1 is the datum allowance for finishing the outer circle, Z2 is the datum allowance for finishing the inner hole, and Z3 is the datum allowance for finishing the internal gear ring. These allowances can be reasonably selected according to the precision grade of the parts and the precision of the machining equipment. The datum allowances for non-mating surfaces can be adjusted as needed to further improve material utilization. In this embodiment, the datum allowance Z1 for finishing the outer circle ranges from 0.4 to 0.6 mm, the datum allowance Z2 for finishing the inner hole ranges from 0.2 to 0.4 mm, and the datum allowance Z3 for finishing the internal gear ring ranges from 0.2 to 0.4 mm.

[0031] S4: Trial Production Verification and Model Optimization The parts are pre-heat machined using the process allowances calculated above, followed by carburizing and quenching treatment according to the determined heat treatment process conditions. After heat treatment, the actual dimensions, remaining allowances, ellipticity, and taper deformation of each part are checked. The deviation between the actual deformation and the calculated deformation is compared, and the coefficients of the quantitative calculation model are corrected and optimized to improve the accuracy of subsequent calculations.

[0032] Through multiple batches of testing and verification, for this type of 20CrMnMo wind turbine yaw output integrated housing, when K1 is controlled to be 0.05~0.06 and K2 to be 0.045~0.055, the comprehensive carburizing and quenching deformation of the parts can be effectively controlled, ensuring uniform finishing allowance in each part, and taking into account both material utilization and machining qualification rate.

[0033] Reference Figure 1 In this embodiment, a specific 20CrMnMo yaw output end integrated housing is used for calculation and experimental verification. The structural parameters of the part are as follows: D1=429mm, D2=515mm, D3=438mm; L1=203mm, L2=37mm, L3=80mm; K1=0.05, K2=0.045; internal gear pressure angle α=20°. The tooth width of the internal gear ring is B=183mm. The Z1 of D1 and D3 is uniformly 0.5mm. D2 is a non-mating surface, so the allowance is reduced separately, and the allowance is even lower, taking 0.3mm. The Z2 of the two inner holes is uniformly 0.3mm. The internal tooth is separately taken according to the tooth surface requirements, with Z3=0.4mm, which fully conforms to the design rules of the original text.

[0034] 1. Calculation of Deformation Substitute the values ​​into the formula from step S2 to calculate the heat treatment deformation of each part: (1) Reduction in outer diameter The reduction in size of the upper outer circle 11D1 is approximately 0.52 mm (203 × (1 + 2 × 0.05) / 429). The reduction in diameter of the outer circle of the intermediate flange (12D2) is 515 / 1000 = 0.51 mm. The reduction in the outer diameter of the lower end (13D3) is approximately 0.40 mm (80 × (2 + 4 × 0.045) / 438).

[0035] (2) Expansion of the inner hole The expansion amount of the upper inner hole 14d1 is approximately 0.65 mm (203 × (1 + 8 × 0.05) / 429). The expansion amount of the lower inner hole 15d2 is approximately 0.41 mm (80 × (2 + 6 × 0.045) / 438).

[0036] (3) Expansion of the common normal of the internal gear ring: Expansion of the common normal of the internal gear ring = 203 × (1 + 4 × 0.05) × sin20 / 421≈0.20mm.

[0037] 2. Process allowance setting and test results Based on the machining requirements of the parts, a finishing allowance was selected. Combined with the aforementioned deformation, a pre-heat treatment allowance was set. A batch carburizing and quenching test was conducted on 12 parts of the same specification. After heat treatment, the remaining machining allowance at each location was measured. The test data are statistically analyzed as follows: Figure 2 As shown in the table, (the extreme differences in circumferential allowances are caused by the combined effects of pre-heat machining roundness deviation and uneven deformation during heat treatment. This scheme uses the average allowance to verify the accuracy of the calculation, the minimum allowance to ensure the machining baseline, and the maximum allowance as an accompanying indicator, which does not affect the rationality of the process), the core results are as follows: Upper outer circle 11D1: Preheat allowance 1.0mm, average remaining allowance after heat treatment 1.01mm, minimum remaining allowance 0.4mm, which is greater than or equal to the minimum value of the outer circle finishing datum allowance Z1 of 0.4mm, and the allowance meets the finishing requirements. The outer diameter of the intermediate flange 12D2: the allowance before heat treatment is 0.8mm, the average remaining allowance after heat treatment is 0.78mm, the minimum remaining allowance is 0.36mm, which is greater than or equal to the minimum value of the finishing allowance Z1 of the outer diameter of the non-mating surface, which is 0.3mm. The allowance of the non-mating surface is sufficient. The lower outer diameter 13D3: the allowance before heat treatment is 0.9mm, the average remaining allowance after heat treatment is 0.94mm, the minimum remaining allowance is 0.41mm, which is greater than or equal to the minimum value of the outer diameter finishing datum allowance Z1 of 0.4mm, and the deformation control is stable. Upper inner hole 14d1: 1.2mm allowance before heat treatment, 1.24mm average remaining allowance after heat treatment, 0.42mm minimum remaining allowance. It is greater than or equal to the minimum value of the inner hole finishing datum allowance Z2 of 0.2mm. The allowance meets the finishing requirements. The common normal of the internal gear ring is 0.60mm before heat treatment, 0.64mm on average after heat treatment, and 0.39mm on minimum. It is greater than or equal to the minimum value of the finishing allowance Z3 of the internal gear ring, which is 0.2mm, to meet the requirements of finishing of the tooth surface and depth of carburized layer. The lower inner hole 15d2: the allowance before heat treatment is 0.80mm, the average remaining allowance after heat treatment is 0.87mm, and the minimum remaining allowance is 0.26mm. The allowance is greater than or equal to the minimum value of the inner hole finishing allowance Z2 of 0.2mm, which meets the finishing requirements.

[0038] Experimental results show that by using the calculation method of this invention to set the pre-heating process allowance, sufficient finishing allowance is maintained in all parts after carburizing and quenching. The deviation between the actual deformation and the calculated value is within the allowable range for engineering. The accuracy and reliability of the method can meet the needs of mass production. Compared with the traditional empirical allowance design, this method can compress the average machining allowance of parts, significantly improve material utilization, reduce machining time and manufacturing costs, and avoid part scrap due to insufficient allowance.

[0039] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for calculating the allowance for the carburizing and quenching process of the integrated outer shell of the 20CrMnMo yaw output end, characterized in that: The integrated outer shell is a rotating shell part that integrates an outer shell structure (1), an internal gear ring structure (2), and a bearing outer raceway structure (3); the calculation method includes the following steps: S1: Based on the carburizing and quenching deformation law of the target part, determine the appropriate heat treatment process conditions. S2: For the three key machining parts of the part, namely the outer circle, inner hole and internal teeth, a quantitative calculation model for the carburizing and quenching deformation of each part is constructed for different axial structural sections of the part. Among them, the ratio of the wall thickness to the outer diameter of the corresponding part is used as the deformation coefficient. Combined with the outer diameter parameter and axial length parameter of the part, the carburizing and quenching deformation of the corresponding part is quantitatively calculated. S3: Based on the finishing allowance of each part, the carburizing and quenching deformation of the corresponding part is added to calculate the machining allowance of each part before carburizing and quenching. S4: Use the calculated process allowance for trial production, check the actual allowance and deformation of each part after carburizing and quenching, and verify and optimize the quantitative calculation model.

2. The method for calculating the allowance for carburizing and quenching process of the integrated outer casing of the 20CrMnMo yaw output end according to claim 1, characterized in that: The deformation pattern of carburizing and quenching is as follows: after carburizing and quenching, the outer diameter of each part shrinks as a whole, while the inner hole and the inner gear ring expand as a whole, and each part is accompanied by elliptical distortion and taper deformation.

3. The method for calculating the allowance for carburizing and quenching process of the integrated outer shell of the 20CrMnMo yaw output end according to claim 1, characterized in that: The outer shell structure (1) includes three outer circle structures: the upper outer circle (11), the middle flange outer circle (12), and the lower outer circle (13). The internal gear ring structure (2) is a straight internal gear ring. The bearing outer raceway structure (3) is a bearing outer raceway composed of a spherical raceway surface and a cylindrical raceway surface.

4. The method for calculating the allowance for carburizing and quenching process of the integrated outer shell of the 20CrMnMo yaw output end according to claim 3, characterized in that: In step S2, the specific formulas for quantifying the deformation of each part include: The reduction of the outer circle at the top (11) D1 is L1×(1+2K1) / D1, where K1=δ1 / D1; The reduction amount of the outer diameter of the intermediate flange (12) D2 = D2 / 1000; The reduction of the lower outer circle (13)D3 = L3×(2+4K2) / D3, where K2=δ2 / D3; The expansion amount of the upper inner hole (14) d1 = L1 × (1 + 8K1) / D1, where K1 = δ1 / D1; The expansion amount of the lower inner hole (15) d2 = L3×(2+6K2) / D3, where K2=δ2 / D3; The expansion amount in the direction of the common normal of the internal gear = L1×(1+4K1)×sinα / D1, where K1=δ1 / D1; In the formula, δ1 is the wall thickness at the upper stop, δ2 is the wall thickness of the housing corresponding to the lower bearing raceway, L1 is the axial length of the upper outer circle (11), L3 is the axial length of the lower outer circle (13), and α is the internal tooth pressure angle.

5. The method for calculating the allowance for carburizing and quenching process of the integrated outer casing of the 20CrMnMo yaw output end according to claim 4, characterized in that: In step S3, the specific formulas for calculating the machining allowance for each part before carburizing and quenching include: Upper outer circle (11) D1 allowance = outer circle finishing allowance Z1 + upper outer circle (11) D1 reduction allowance; The allowance for the outer diameter (12)D2 of the intermediate flange = the finishing allowance for the outer diameter Z1 + the reduction allowance for the outer diameter (12)D2 of the intermediate flange; Lower outer circle (13)D3 allowance = outer circle finishing allowance Z1 + lower outer circle (13)D3 reduction allowance; The allowance for the upper inner hole (14)d1 = the inner hole finishing allowance Z2 + the expansion amount of the upper inner hole (14)d1; The allowance for the lower end inner hole (15) d2 = the inner hole finishing allowance Z2 + the expansion amount of the lower end inner hole (15) d2; Internal gear ring common normal allowance = internal gear finishing allowance Z3 + internal gear ring common normal direction expansion amount; In the formula, Z1 is the datum allowance for finishing the outer circle, Z2 is the datum allowance for finishing the inner hole, and Z3 is the datum allowance for finishing the internal gear ring.

6. The method for calculating the allowance for carburizing and quenching process of the integrated outer shell of the 20CrMnMo yaw output end according to claim 4, characterized in that: The structural parameters of the parts satisfy the following: 300mm≤D1≤500mm, 400mm≤D2≤600mm, 300mm≤D3≤500mm; 150mm≤L1≤250mm, 30mm≤L2≤60mm, 50mm≤L3≤150mm, where L2 is the axial length of the outer circle of the flange; the tooth width B of the internal gear ring satisfies 0.7×L1≤B≤0.9×L1, and the module of the internal gear ring is 2mm~6mm; 0.04×D1≤δ1≤0.08×D1,0.04×D2≤δ2≤0.1×D2。 7. The method for calculating the allowance for carburizing and quenching process of the integrated outer casing of the 20CrMnMo yaw output end according to claim 1, characterized in that: The heat treatment process conditions determined in step S1 are as follows: a box-type multi-purpose furnace with a loading capacity of 1.0 to 5.0 tons is used; the carburizing temperature is 900℃ to 950℃; and the quenching temperature is 820℃ to 860℃.

8. The method for calculating the allowance for carburizing and quenching process of the integrated outer shell of the 20CrMnMo yaw output end according to claim 1, characterized in that: The finished product performance requirements for the internal gear ring and bearing raceway are as follows: surface hardness ≥ 58HRC, effective hardened layer depth 1.0mm~2.5mm; raceway machining allowance ≤ 0.80mm in the carburized area, and internal gear ring tooth surface machining allowance ≤ 0.70mm.

9. The method for calculating the allowance for carburizing and quenching process of the integrated outer casing of the 20CrMnMo yaw output end according to claim 3, characterized in that: In step S4, controlling K1 to a value of 0.05~0.06 and K2 to a value of 0.045~0.055 can effectively control the overall carburizing and quenching deformation of the parts and ensure uniform finishing allowance in each part.

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