Gear gluing analysis method and device

Abstract

The invention provides a gear gluing analysis method and device, and relates to the technical field of data processing, and the method comprises the steps: simulating a gear transient meshing process based on a gear pair model, and obtaining mechanical parameters of gear meshing; based on the mechanical parameters, a gearbox temperature field and corresponding thermodynamic parameters are determined, and the thermodynamic parameters comprise lubricant viscosity and tooth surface deformation data; determining the minimum film thickness and the corresponding friction coefficient according to the mechanical parameters and the thermodynamic parameters; updating the three-dimensional gear pair model according to the tooth surface deformation data, and re-executing the transient meshing process of the simulated gear and subsequent steps based on the friction coefficient until convergence is achieved; and evaluating the gear gluing risk according to the tooth surface maximum contact stress, the tooth surface maximum temperature and the minimum film thickness during convergence. Therefore, through coupling analysis of mechanics, thermodynamics and lubrication, coupling analysis of multiple physical quantities is achieved, and the accuracy of gear gluing risk assessment is improved.

Description

Technical Field

[0001] This application relates to the field of data processing technology, and in particular to a method and apparatus for analyzing gear scuffing. Background Technology

[0002] Gear scuffing refers to a failure phenomenon in which the oil film between the gear teeth breaks down under conditions such as high speed, heavy load, or poor lubrication, resulting in direct contact and localized welding between the metal surfaces. Subsequently, the welded points are torn apart during relative motion, leading to grooves or tear marks on the gear teeth along the sliding direction.

[0003] Current gear scuff analysis often uses a single discipline (such as statics), which makes it difficult to accurately predict scuff risk. Summary of the Invention

[0004] In view of this, this application provides a method and apparatus for analyzing gear scuffing, aiming to improve the accuracy of gear scuffing analysis.

[0005] In a first aspect, this application provides a method for analyzing gear scuffing, including:

[0006] The transient meshing process of gears is simulated based on a gear pair model to obtain the mechanical parameters of gear meshing;

[0007] Based on the mechanical parameters, the gearbox temperature field and corresponding thermodynamic parameters are determined, including lubricant viscosity and tooth surface deformation data.

[0008] The minimum film thickness and the corresponding coefficient of friction are determined based on the mechanical and thermodynamic parameters.

[0009] The three-dimensional gear pair model is updated based on the tooth surface deformation data, and the simulated gear transient meshing process and subsequent steps are re-executed based on the friction coefficient until convergence is achieved.

[0010] The risk of gear scuffing is assessed based on the maximum contact stress on the tooth surface, the highest temperature on the tooth surface, and the minimum film thickness at the time of convergence.

[0011] Optionally, the mechanical parameters include the maximum contact stress of gear meshing and the sliding speed of the time step corresponding to the maximum contact stress;

[0012] The determination of the gearbox temperature field and corresponding thermodynamic parameters based on the mechanical parameters includes:

[0013] The frictional heat flux density at the time step is determined based on the maximum contact stress, the sliding speed, and the friction coefficient.

[0014] The temperature field inside the gearbox is solved by transient thermal analysis, based on the frictional heat flux density at the time step.

[0015] The lubricant viscosity is adjusted based on the maximum temperature of the tooth surface in the temperature field.

[0016] Based on the temperature field, determine the tooth surface deformation data caused by thermal expansion.

[0017] Optionally, the step of combining the frictional heat flux density to solve the internal temperature field of the gearbox via transient thermal analysis includes:

[0018] The frictional heat flux density is mapped to the mesh nodes of the tooth surface of the three-dimensional gear pair model as the boundary condition for the transient heat source;

[0019] Based on the transient heat source boundary conditions, the convective heat transfer coefficient between the gear tooth surface and the air, and the forced convective heat transfer coefficient of the lubricating oil inside the gearbox, the temperature field inside the gearbox is solved by transient thermal analysis.

[0020] Optionally, determining the minimum film thickness and corresponding coefficient of friction based on the mechanical and thermodynamic parameters includes:

[0021] The minimum film thickness is solved by combining the Reynolds equation and the film thickness equation based on the maximum contact stress, the lubricant viscosity, and the entrainment speed determined by the gear parameters and the sliding speed.

[0022] The film thickness ratio is determined based on the ratio of the minimum film thickness to the tooth surface roughness;

[0023] The lubrication state is determined based on the threshold range to which the film thickness ratio belongs, and the lubrication state includes full film lubrication, mixed lubrication and boundary lubrication;

[0024] The coefficient of friction is determined based on the lubrication condition.

[0025] Optionally, the transient meshing process of gears can be simulated based on a gear pair model to obtain the mechanical parameters of gear meshing, including:

[0026] A three-dimensional model of the gear pair is generated based on the gear data;

[0027] The tooth surfaces of the gears in the three-dimensional gear pair model are meshed;

[0028] The tooth surfaces of the meshing driving and driven gears in the three-dimensional gear pair model are set to frictional contact, and the corresponding friction coefficients are defined.

[0029] Set boundary constraints for the three-dimensional gear pair model;

[0030] An explicit dynamics solver is used to simulate the transient meshing process, obtaining the maximum contact stress and its distribution cloud map as a function of time, and the sliding speed as a function of time. This allows for the determination of the maximum contact stress during gear meshing and the sliding speed at the time step corresponding to the maximum contact stress.

[0031] Optionally, achieving convergence includes:

[0032] Calculate the difference between the minimum film thickness obtained by the current wheel performing the simulated gear transient meshing process and subsequent steps and the minimum film thickness obtained by the previous wheel performing the simulated gear transient meshing process and subsequent steps.

[0033] The ratio of the difference to the minimum film thickness obtained by the current wheel performing the simulated gear transient meshing process and subsequent steps is used as the convergence index;

[0034] If the convergence index is less than the preset value, then convergence is achieved.

[0035] Optionally, assessing the gear scuffing risk based on the maximum contact stress on the tooth surface, the highest temperature on the tooth surface, and the minimum film thickness at the time of convergence includes:

[0036] Calculate the first product of the maximum contact stress on the tooth surface and the highest temperature on the tooth surface;

[0037] The bonding risk index is obtained by calculating the ratio of the first product to the square of the minimum film thickness.

[0038] When the bonding risk index is greater than a preset critical value, there is a bonding risk.

[0039] Optionally, the method further includes:

[0040] For the gear pair model, the tooth surface modification parameters, gear parameters, and lubrication conditions are used as optimization variables. Through the optimization algorithm, the optimization parameters that minimize the scuffing risk index and maximize the transmission efficiency are obtained. The constraint condition of the optimization algorithm is that the tooth root bending strength is greater than or equal to the safety threshold, and the noise and vibration (NVH) index meets the industry standard.

[0041] Optionally, the method further includes:

[0042] Test parameters are obtained by testing the first gear corresponding to the unoptimized gear pair model and the second gear corresponding to the gear pair model after optimization of the optimized parameters using a gear fatigue testing bench.

[0043] The optimization degree of the first gear and the second gear on the first data is compared according to the test parameters. The first data includes the critical failure torque of scuffing, the tooth surface temperature rise curve and the wear morphology.

[0044] The first parameter is adjusted based on the degree of optimization. The first parameter includes the preset critical value, the tooth surface roughness, the convective heat transfer coefficient between the tooth surface and the air, and the forced convective heat transfer coefficient of the lubricating oil inside the gearbox.

[0045] Secondly, this application provides a gear scuffing analysis apparatus, the apparatus comprising:

[0046] The mechanical unit is used to simulate the transient meshing process of gears based on the gear pair model and obtain the mechanical parameters of gear meshing.

[0047] A thermodynamic unit is used to determine the gearbox temperature field and corresponding thermodynamic parameters based on the mechanical parameters, wherein the thermodynamic parameters include lubricant viscosity and tooth surface deformation data;

[0048] The lubrication unit is used to determine the minimum film thickness and the corresponding coefficient of friction based on the mechanical and thermodynamic parameters.

[0049] The processing unit is used to update the three-dimensional gear pair model according to the tooth surface deformation data, and re-execute the simulated gear transient meshing process and subsequent steps based on the friction coefficient until convergence is achieved;

[0050] The analysis unit is used to assess the risk of gear scuffing based on the maximum contact stress on the tooth surface, the highest temperature on the tooth surface, and the minimum film thickness at the time of convergence.

[0051] Thirdly, this application provides an apparatus comprising a memory and a processor, the memory for storing instructions or code, and the processor for executing the instructions or code to cause the apparatus to perform a gear scuffing analysis as described in any of the first aspects above.

[0052] Fourthly, this application provides a computer storage medium storing code, wherein when the code is executed, a device running the code implements a gear scuffing analysis as described in any of the first aspects above.

[0053] This application provides a method and apparatus for analyzing gear scuffing. When executing the method, firstly, the transient meshing process of the gears is simulated based on a gear pair model to obtain the mechanical parameters of the gear meshing, achieving a mechanical analysis of the gear meshing process. Then, based on the mechanical parameters, the gearbox temperature field and corresponding thermodynamic parameters are determined. The thermodynamic parameters include lubricant viscosity and tooth surface deformation data; that is, the temperature field inside the gearbox is analyzed based on the dynamic mechanical parameters of transient meshing, achieving a coupling of mechanics and thermodynamics. Next, the minimum film thickness and corresponding friction coefficient are determined based on the mechanical and thermodynamic parameters, achieving a coupled mechanical and thermodynamic analysis of lubrication. Furthermore, the three-dimensional gear pair model is updated based on the tooth surface deformation data, and the simulated transient meshing process and subsequent steps are re-executed based on the friction coefficient until convergence is achieved. That is, new mechanical parameters are obtained based on the tooth surface deformation data of the thermodynamic parameters and the friction coefficient determined by lubrication analysis, and the above-mentioned multiple cycles of coupled mechanical, thermodynamic, and lubrication analysis are continued until convergence. While performing mechanical analysis, the effects of heat accumulation and lubrication degradation during the gear meshing process are also considered, reducing the deviation between the results and actual working conditions, thereby improving the accuracy of evaluating gear scuffing. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings used in the description of the embodiment or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 A schematic flowchart illustrating a gear adhesion analysis method provided in this application embodiment;

[0056] Figure 2 This is a schematic diagram of a gear adhesion analysis device provided in an embodiment of this application. Detailed Implementation

[0057] Under heavy load, high speed, or poor lubrication conditions, instantaneous high temperatures are easily generated in the tooth contact area, leading to lubrication film failure and scuffing. Traditional gear design often relies on empirical formulas and single-discipline analysis (such as statics), making it difficult to accurately predict the risk of scuffing. In addition, current methods for optimizing gear design often consider gear geometry parameters or lubrication conditions in isolation, neglecting the coupling effects of multiple physical fields, resulting in insufficient optimization effects under actual operating conditions.

[0058] To address the aforementioned problems, this application provides a method and apparatus for analyzing gear scuffing. This application simulates the transient meshing process of gears using a gear pair model to obtain mechanical parameters. Then, based on these mechanical parameters, it obtains the gearbox temperature field and corresponding thermodynamic parameters (including lubricant viscosity and tooth surface deformation data) to achieve thermodynamic analysis. Furthermore, based on the mechanical and thermodynamic parameters, it solves for the minimum film thickness and the corresponding friction coefficient, thereby analyzing the gear lubrication situation. Further, the three-dimensional gear pair model is updated based on the tooth surface deformation data, and the simulated transient meshing process and subsequent steps are re-executed based on the friction coefficient. This yields new mechanical parameters based on the tooth surface deformation data from thermodynamic parameters and the friction coefficient determined by lubrication analysis. The coupled analysis of mechanics, thermodynamics, and lubrication is repeated until convergence. Thus, by analyzing the mechanical parameters of the transient meshing process to couple the analysis of the transient temperature rise temperature field, rather than relying on empirical formulas or static analysis, the accuracy of scuffing analysis is improved. Moreover, the influence of heat accumulation and lubrication degradation during gear meshing is considered simultaneously with the mechanical analysis, reducing the deviation between the results and actual operating conditions, further improving the accuracy of gear scuffing assessment.

[0059] Furthermore, this application can simultaneously optimize multiple gear design variables through an optimization algorithm, obtaining the optimization parameters corresponding to minimizing the scuffing risk index and maximizing transmission efficiency under constraints. Thus, the objective function is to minimize the scuffing risk index based on multi-physical quantity coupling analysis and maximize transmission efficiency. Based on constraints such as strength and noise, multiple design variables are collaboratively optimized to determine the optimization parameters. In this way, while avoiding scuffing problems, strength, efficiency, and noise are simultaneously optimized, resulting in high robustness, reduced occurrence of other failure scenarios, and improved optimization effectiveness.

[0060] In addition, this application also uses bench tests and actual experimental data to analyze the optimization of gears before and after optimization, and optimizes and adjusts the relevant parameters of the multi-physical quantity coupling analysis of the scuffing risk index to obtain more accurate gear scuffing analysis results.

[0061] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0062] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0063] Unless otherwise stated, the term "multiple" means two or more. In embodiments of this disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B. The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0064] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0065] See Figure 1 , Figure 1 This application provides a schematic flowchart of a gear scuffing analysis method, which includes:

[0066] S101. Simulate the transient meshing process of gears based on the gear pair model to obtain the mechanical parameters of gear meshing.

[0067] The aforementioned gear pair model can be a three-dimensional model constructed based on gear data.

[0068] The aforementioned mechanical parameters can be relevant parameters of tooth surface contact stress during the transient meshing process of the gear. The mechanical parameters are obtained through mechanical analysis to facilitate coupling with subsequent thermodynamic and lubrication analyses.

[0069] S102. Based on the mechanical parameters, determine the gearbox temperature field and the corresponding thermodynamic parameters, including lubricant viscosity and tooth surface deformation data.

[0070] Based on the tooth surface contact stress determined during the transient meshing process, the transient temperature rise is analyzed to determine the gearbox temperature field, and thermodynamic analysis is performed. Then, the lubricant viscosity is corrected based on the gearbox temperature field, and the tooth surface deformation data is determined based on the thermal expansion. This achieves the coupling of mechanical analysis and thermodynamic analysis, simulating the transient temperature rise under dynamic load, rather than the analysis of a static model, thus improving the accuracy of scuff prediction.

[0071] S103. Determine the minimum film thickness and the corresponding friction coefficient based on the mechanical parameters and the thermodynamic parameters.

[0072] Lubrication analysis is performed by combining mechanical and thermodynamic parameters to determine the minimum film thickness and the corresponding coefficient of friction. This achieves the coupling of multiple physical quantities in mechanical, thermodynamic, and lubrication analysis.

[0073] S104. Update the three-dimensional gear pair model based on the tooth surface deformation data, and re-execute the simulated gear transient meshing process and subsequent steps based on the friction coefficient until convergence is achieved.

[0074] Cyclic multi-wheel and multi-physical quantity coupled analysis avoids the problems of heat accumulation and lubrication degradation during gear meshing that are ignored by single mechanical analysis, reducing the deviation between the results and actual working conditions. At the same time, the friction coefficient and heat flux density are updated in real time through cyclic coupled analysis, avoiding the problem that static model analysis cannot capture film thickness changes under transient loads, improving the accuracy of film thickness calculation, and thus improving the accuracy of gear scuffing assessment.

[0075] S105. Assess the risk of gear scuffing based on the maximum contact stress on the tooth surface, the highest temperature on the tooth surface, and the minimum film thickness at the time of convergence.

[0076] As described in steps S101-S105 above, this application first completes the mechanical analysis in step S101, then performs a thermodynamic analysis based on the mechanical parameters in step S102, and further analyzes the minimum lubrication film thickness and friction coefficient based on the parameters from the mechanical and thermodynamic analyses in step S103. The next round of mechanical analysis is performed based on the tooth surface deformation data obtained in step S102 and the friction coefficient determined in step S103. Thermodynamic and lubrication analyses are then performed based on the parameters from this next round of mechanical analysis, and this cycle continues until convergence. This multi-round cycle achieves multi-round coupled mechanical-thermodynamic-lubrication analysis, thus considering the effects of heat accumulation and lubrication degradation during gear meshing while performing mechanical analysis, reducing the deviation between the results and actual operating conditions, and improving the accuracy of gear scuff assessment.

[0077] Based on the above embodiments, in Figure 1 Before step S101, the following may also be included:

[0078] First, acquire gear data, which includes the gear's geometric parameters, material properties, operating conditions, and boundary conditions.

[0079] Optionally, the above geometric parameters may include gear module, number of teeth, helix angle, pressure angle, tooth tip modification amount, tooth profile modification curve, etc.; the above material properties may include the elastic modulus, Poisson's ratio, coefficient of thermal expansion, and thermal conductivity of the gear material; the above operating condition data may include input torque, speed range, lubricant viscosity-temperature characteristics, and load spectrum (such as periodic impact load); the above boundary conditions may include gearbox heat dissipation conditions (convective heat transfer coefficient) and lubricating oil supply pressure.

[0080] Then, the gear data is dimensionless. This ensures the compatibility of the processed gear data with the aforementioned coupled analysis of mechanics, thermodynamics, and lubrication.

[0081] In the embodiments of this application, the above Figure 1 There are several possible implementations of step S101, which will be described below. It should be noted that the implementations given below are merely illustrative examples and do not represent all implementations of the embodiments of this application.

[0082] In step S101 above, simulating the transient meshing process of gears based on the gear pair model to obtain the mechanical parameters of gear meshing may include:

[0083] Geometric modeling: Generate a three-dimensional model of the gear pair based on the gear data.

[0084] Optionally, an accurate 3D gear pair model is generated based on gear data (e.g., module, number of teeth, helix angle, etc.). Before the thermodynamic analysis in step S102, i.e., during the first round of mechanical-thermodynamic-lubrication coupling analysis, the 3D gear pair model remains unchanged. From the start of the second round of coupling analysis onwards, the tooth surface deformation data B caused by thermal expansion (dynamically updated) is obtained from the previous round of thermodynamic analysis, and the 3D gear pair model is corrected. The corrected 3D gear pair model then participates in the coupling analysis of that round.

[0085] Mesh generation: The tooth surfaces of the gears in the three-dimensional gear pair model are meshed.

[0086] Optionally, a high-density hexahedral mesh (unit size ≤ 0.1 mm) can be used to mark the tooth contact area, while tetrahedral meshes can be used in other areas (non-critical areas) to balance computational analysis efficiency.

[0087] Contact pair definition: The meshing tooth surfaces of the driving and driven gears in the three-dimensional gear pair model are defined as frictional contact, along with the corresponding friction coefficient.

[0088] Optionally, the coefficient of friction is assigned based on the lubrication state, which is divided into full film lubrication, boundary lubrication, and mixed lubrication.

[0089] Optionally, for full film lubrication, the friction coefficient μ = 0.03; for boundary lubrication, μ = 0.1; and for mixed lubrication, 0.03 < μ < 0.1. The specific value can be determined based on the film thickness ratio λ, and the calculation formula can be: μ = -0.035λ + 0.135. Before performing the lubrication analysis in step S103, i.e., during the first round of mechanical-thermodynamic-lubrication coupling analysis, a preset value for the friction coefficient can be set, for example, 0.065. From the start of the second round of coupling analysis, the film thickness ratio and the friction coefficient corresponding to the updated film thickness ratio are updated based on the ratio of the minimum film thickness to the tooth surface roughness from the previous round of lubrication analysis, to perform a new round of coupling analysis.

[0090] Set boundary conditions: Set boundary constraints for the three-dimensional gear pair model.

[0091] Optionally, the boundary conditions may include boundary constraints including fixing the axial degree of freedom of the driven wheel, applying a rotational speed and torque to the driving wheel, constraining the support points of the gearbox housing on the shafts of the driving and driven wheels, and assigning stiffness to the gearbox corresponding to the support points.

[0092] Solution: The transient meshing process is simulated using an explicit dynamic solver to obtain the time-varying maximum contact stress σ. max (t) and the distribution cloud map of contact stress, and the sliding velocity υ changing with time. s (t), determine the maximum contact stress σ during the entire gear meshing process. max and the sliding speed υ at the time step corresponding to the maximum contact stress. s .

[0093] The above analysis of tooth surface contact stress based on Hertz contact theory considers the dynamic load (stress) distribution during gear meshing, so as to facilitate the analysis of transient temperature field and thermoelastic deformation under dynamic load distribution in subsequent step S102. In this way, the analysis of temperature field during dynamic meshing process is combined to improve the accuracy of scuffing analysis and realize the coupling of mechanical analysis and thermodynamic analysis.

[0094] Based on the above embodiments, the above Figure 1 There are several possible implementations of step S102, which will be described below. It should be noted that the implementations given below are merely illustrative examples and do not represent all implementations of the embodiments of this application.

[0095] Step S102 above involves performing thermodynamic analysis based on the mechanical analysis results to obtain the thermodynamic analysis results. That is, based on the mechanical parameters, the gearbox temperature field and corresponding thermodynamic parameters are determined, which may include:

[0096] Based on the above mechanical analysis, the maximum contact stress σ during the entire gear meshing process is obtained. max and the sliding speed υ at the time step corresponding to the maximum contact stress. s The maximum contact stress and the sliding speed are used to determine the frictional heat flux density at that time step.

[0097] Optionally, calculate the friction coefficient and the aforementioned maximum contact stress σ. max And the aforementioned maximum contact stress σ max The sliding speed υ at the corresponding time step s The product of these three factors yields the frictional heat flux density at that time step.

[0098] By combining the frictional heat flux density at this time step, the temperature field inside the gearbox is solved by transient thermal analysis.

[0099] In one possible implementation, the frictional heat flux density is mapped to the mesh nodes of the tooth surface of the three-dimensional gear pair model as a transient heat source boundary condition. Based on the transient heat source boundary condition, the convective heat transfer coefficient between the tooth surface and the air, and the forced convective heat transfer coefficient of the lubricating oil inside the gearbox, the temperature field inside the gearbox is solved by transient thermal analysis to obtain the transient temperature distribution T inside the gearbox. L (x,y,z), determine the maximum temperature T on the tooth surface. L .

[0100] According to the maximum tooth surface temperature T of the temperature field L The lubricant viscosity η is modified and used in the lubrication analysis of step S103.

[0101] Based on the temperature field, a structural mechanical analysis of the gear is performed to determine the tooth surface deformation data B caused by thermal expansion. This tooth surface deformation data B is used for the next round of cyclic correction of the gear pair model.

[0102] Step S102 above can calculate the maximum contact stress σ based on the transient load (stress) distribution during the gear meshing process obtained in step S101. max The frictional heat flux density at the corresponding time step is calculated, and the internal temperature field and maximum tooth surface temperature of the gearbox are solved by transient thermal analysis. On the one hand, the lubricant viscosity is corrected to participate in subsequent lubrication analysis, realizing the coupled analysis of thermodynamics and lubrication. On the other hand, the gear pair model is corrected based on the tooth surface deformation data caused by thermoelastic deformation, thereby improving the accuracy of the next round of coupled analysis.

[0103] Based on the above embodiments, the above Figure 1 There are several possible implementations of step S103, which will be described below. It should be noted that the implementations given below are merely illustrative examples and do not represent all implementations of the embodiments of this application.

[0104] Step S103 involves further lubrication analysis based on the results of mechanical and thermodynamic analysis, specifically determining the minimum film thickness and corresponding coefficient of friction according to the mechanical and thermodynamic parameters, including:

[0105] First, based on the maximum contact stress σ max The viscosity η of the lubricant, and the sliding speed υ based on the gear data. s Given a fixed entrainment velocity U, solve for the minimum film thickness h by simultaneously applying the Reynolds equation and the film thickness equation. min ;

[0106] Then, based on the minimum film thickness h min The film thickness ratio λ is determined by the ratio of the film thickness to the tooth surface roughness Ra.

[0107] λ=h min ÷Ra, where Ra is the tooth surface roughness, usually taken as 0.4μm.

[0108] Furthermore, the lubrication state is determined based on the threshold range to which the film thickness ratio belongs, and the lubrication state includes full film lubrication, mixed lubrication, and boundary lubrication.

[0109] For example, the threshold range and the corresponding lubrication state can be set as follows: λ≥3 for full film lubrication (safe); 1<λ<3 for mixed lubrication (risk exists); λ≤1 for boundary lubrication (high risk).

[0110] Finally, the coefficient of friction is determined based on the lubrication condition.

[0111] For full film lubrication, the friction coefficient μ = 0.03; for boundary lubrication, μ = 0.1; and for mixed lubrication, 0.03 < μ < 0.1. The specific value can be determined based on the film thickness ratio λ, and the calculation formula is: μ = -0.035λ + 0.135. Before performing the lubrication analysis in step S103, i.e., during the first round of mechanical-thermodynamic-lubrication coupling analysis, a preset value for the friction coefficient can be set, for example, 0.065. From the start of the second round of coupling analysis, the film thickness ratio and the corresponding friction coefficient are updated based on the ratio of the minimum film thickness to the tooth surface roughness from the previous round of lubrication analysis, to perform a new round of mechanical analysis. This achieves the coupling of lubrication analysis and mechanical analysis.

[0112] Based on the above embodiments, the interaction relationship of the coupling parameters in the mechanical-thermodynamic-lubrication coupling analysis can be determined as follows:

[0113] The mechanical analysis transmits the maximum contact stress on the tooth surface and the sliding velocity at the time step corresponding to the maximum contact stress to the thermodynamic analysis, which is used to calculate the frictional heat source corresponding to that time step.

[0114] The mechanical analysis transmits the maximum contact stress and the sliding velocity at the time step corresponding to the maximum contact stress on the tooth surface to the lubrication analysis. At the same time, the thermodynamic analysis transmits the maximum temperature of the tooth surface to the lubrication analysis to correct the lubricant viscosity and calculate the minimum film thickness.

[0115] The lubrication analysis feeds back the friction coefficient corresponding to the current lubrication state to the mechanical analysis, updates the friction boundary conditions in the contact analysis, and simultaneously feeds back the thermal deformation (gear deformation data) to the mechanical analysis, updates the gear pair model, re-simulates the transient meshing process of the gear, and re-obtains the maximum contact stress on the tooth surface and the sliding speed at the time step corresponding to the maximum contact stress on the tooth surface, so as to achieve cyclic analysis.

[0116] Thus, this application integrates the coupled effects of multiple physical quantities—mechanics, thermodynamics, and lubrication—during gear meshing, avoiding the problems of heat accumulation and lubrication degradation that are ignored in single mechanical analysis, reducing the deviation between the results and actual working conditions, and thereby improving the accuracy of evaluating gear scuffing. Furthermore, this application avoids the problem that static model analysis cannot capture film thickness changes under transient loads, and improves the accuracy of film thickness calculation by updating the friction coefficient and heat flux density in real time through cyclic coupling analysis.

[0117] Based on the above embodiments, achieving convergence in step S104 can be as follows:

[0118] First, calculate the difference between the minimum film thickness obtained by the current wheel during the simulated gear transient meshing process and subsequent steps, and the minimum film thickness obtained by the previous wheel during the same process. Use the ratio of this difference to the minimum film thickness obtained by the current wheel during the same process as a convergence criterion. If the convergence criterion is less than a preset value, then convergence is achieved.

[0119] If the convergence point is defined as the Nth round of the mechanical-thermodynamic-lubrication coupling analysis, then the convergence index can be expressed as:

[0120]

[0121] Among them, h min (n) represents the minimum film thickness under the nth round of coupling analysis, h min(n-1) represents the minimum film thickness under the (n-1)th round of coupling analysis, and X is a preset value, which can be 1%-5%.

[0122] Based on the above embodiments, the assessment of gear scuffing risk in step S105, based on the maximum contact stress on the tooth surface, the highest temperature on the tooth surface, and the minimum film thickness at the time of convergence, can be as follows:

[0123] Calculate the first product of the maximum contact stress on the tooth surface and the highest temperature on the tooth surface; calculate the ratio of the first product to the square of the minimum film thickness to obtain the adhesive risk index.

[0124] Therefore, the formula for calculating the bonding risk index is:

[0125] S=(σ max ×T L )÷h min 2

[0126] Where σ max T represents the maximum contact stress on the tooth surface, measured in Pascals (Pa). L The highest temperature on the tooth surface, expressed in degrees Celsius (°C); h min The minimum film thickness is measured in millimeters (mm). S is the adhesion risk index, which has no unit. The larger the S value, the greater the likelihood and severity of adhesion risk.

[0127] The bonding risk index proposed in this application has a numerator σ. max ×T L Characterizing the synergistic effect of tooth surface stress and temperature, the superposition of high temperature and high stress accelerates lubricant film rupture; denominator h min 2 The inverse square ratio of the lubricating film thickness reflects the key role of film thickness in inhibiting adhesion. Thus, the traditional single-parameter analysis method is eliminated, and the adhesion risk index comprehensively represents the synergistic effect of tooth surface contact stress concentration, temperature rise effect and lubrication failure, thereby improving the accuracy of adhesion risk index in assessing adhesion failure.

[0128] Furthermore, when the bonding risk index is greater than a preset critical value, there is a bonding risk.

[0129] For example, when S > S c At that time, it was determined that there was a risk of adhesive bonding, among which S c It can be a preset critical value calibrated through experiments, typically 7 × 10⁻⁶. 3 Up to 8×10 3 between.

[0130] Based on the above embodiments, this application can further optimize the gear pair model by using an optimization algorithm to obtain optimization parameters, thereby optimizing and improving the design parameters of the gear pair model in multiple aspects, and obtaining an optimized gear pair model that comprehensively optimizes aspects such as scuffing risk, transmission efficiency, secondary gear strength, and noise. The specific method can be as follows:

[0131] For the gear pair model, tooth surface modification parameters, gear parameters, and lubrication conditions are used as optimization variables. Through optimization algorithms, optimization parameters that minimize the scuffing risk index S and maximize the transmission efficiency are obtained. The constraints of the optimization algorithm are that the tooth root bending strength is greater than or equal to the safety threshold, and the gear noise and vibration (NVH) index meets the industry standard.

[0132] For example, the tooth surface modification parameters mentioned above may include tooth tip modification amount (0 to 0.05 mm), tooth direction modification curve, etc.; the gear parameters mentioned above may include helix angle (25° to 40°), pressure angle (18° to 22°), etc.; the lubrication conditions mentioned above may be the lubricating oil viscosity grade (such as SAE 75W-90 compared with SAE 80W-140).

[0133] Optionally, the above optimization algorithm can be used to perform multi-objective optimization using NSGA-II (Non-dominated sorting genetic algorithm).

[0134] Optionally, the above noise and vibration (NVH) indicators meet the industry standards set by the industry for which the gears are applied, such as ≤75dB(A) for passenger car gearboxes.

[0135] Based on the above optimization algorithm analysis, optimization parameters are obtained. While avoiding glue problems, strength, efficiency and noise are optimized simultaneously. It has high robustness, reduces the occurrence of other failures, and improves the optimization effect.

[0136] Based on the above embodiments, the preset first data in the above method is optimized and adjusted by feedback from actual bench tests to improve the accuracy of the above coupling analysis. The specific method includes:

[0137] First, test parameters are obtained by testing the first gear corresponding to the unoptimized gear pair model and the second gear corresponding to the gear pair model after optimization of the parameters using a gear fatigue testing bench.

[0138] The aforementioned gear fatigue testing bench can simulate high torque, speed change and other operating conditions.

[0139] Then, the optimization degree of the first gear and the second gear on the first data is compared according to the test parameters. The first data includes the critical failure torque of scuffing, the tooth surface temperature rise curve, and the wear morphology.

[0140] Optionally, the above test parameters may include stepped loading of input torque (0 to 3500 N·m), monitoring of tooth surface temperature (infrared thermal imager), lubricating film thickness (capacitive sensor), and adhesion failure points (surface morphology analysis).

[0141] Thus, by comparing the critical load (failure torque) of scuffing before and after optimization, and analyzing the tooth surface temperature rise curve and wear morphology (SEM), we can analyze the improvement effect of the coupled analysis of the above mechanical analysis, thermodynamic analysis and lubrication analysis on avoiding scuffing failure in gear design.

[0142] Finally, the first parameter is adjusted based on the degree of optimization. The first parameter includes the preset critical value, the convective heat transfer coefficient between the tooth surface and the air, and the forced convective heat transfer coefficient of the lubricating oil inside the gearbox.

[0143] In this way, the actual data from the bench test is used to correct the data in the coupling analysis process (such as the convective heat transfer coefficient, tooth surface roughness, etc.) and the preset critical values ​​of the above-mentioned adhesive risk indicators, forming an iterative optimization process of "simulation-experiment-re-simulation".

[0144] The above describes some specific implementations of the gear scuffing analysis method provided in this application. Based on this, this application also provides a corresponding apparatus. The apparatus provided in this application will be described below from the perspective of functional modularity.

[0145] See Figure 2 The diagram shows a structural schematic of a gear scuffing analysis device. The device 200 includes:

[0146] Mechanical unit 201 is used to simulate the transient meshing process of gears based on the gear pair model and obtain the mechanical parameters of gear meshing;

[0147] Thermodynamic unit 202 is used to determine the gearbox temperature field and corresponding thermodynamic parameters based on the mechanical parameters, the thermodynamic parameters including lubricant viscosity and tooth surface deformation data;

[0148] The lubrication unit 203 is used to determine the minimum film thickness and the corresponding coefficient of friction based on the mechanical and thermodynamic parameters.

[0149] The processing unit 204 is used to update the three-dimensional gear pair model according to the tooth surface deformation data, and re-execute the simulated gear transient meshing process and subsequent steps based on the friction coefficient until convergence is achieved;

[0150] Analysis unit 205 is used to assess the risk of gear scuffing based on the maximum contact stress on the tooth surface, the highest temperature on the tooth surface, and the minimum film thickness at the time of convergence.

[0151] Based on the above device, it can be seen that the mechanical unit 201 transmits mechanical parameters to the thermodynamic unit 202 for calculating thermodynamic parameters; the mechanical unit 201 transmits mechanical parameters to the lubrication unit 203, and simultaneously, the thermodynamic unit 202 transmits thermodynamic parameters to the lubrication unit 203 for calculating the minimum film thickness, completing one cycle. Then, the processing unit 204 causes the lubrication unit 203 to feed back the friction coefficient μ corresponding to the current lubrication state to the mechanical unit 201, updating the friction boundary conditions in the contact analysis. At the same time, the thermodynamic unit 202 feeds back the thermal deformation amount (gear deformation data) to the mechanical unit 201 to update the gear geometric model, so as to perform a new round of mechanical analysis, recalculate the mechanical parameters, and perform a new round of coupled mechanical-thermodynamic-lubrication analysis until multiple cycles are completed and convergence is achieved. Then, the analysis unit 205 assesses the risk of gear scuffing. In this way, not only is the dynamic mechanics of the gear meshing process analyzed, but the effects of heat accumulation and lubrication degradation during the gear meshing process are also coupled and analyzed, reducing the deviation between the results and actual working conditions, thereby improving the accuracy of gear scuffing assessment.

[0152] In one possible implementation, the thermodynamic unit 202 is specifically used to determine the frictional heat flux density at the time step based on the maximum contact stress, the sliding speed, and the friction coefficient; to solve the internal temperature field of the gearbox by transient thermal analysis based on the frictional heat flux density at the time step; to correct the lubricant viscosity based on the maximum tooth surface temperature in the temperature field; and to determine the tooth surface deformation data caused by thermal expansion based on the temperature field.

[0153] Furthermore, the thermodynamic unit 202 is specifically used to map the frictional heat flux density to the mesh nodes of the tooth surface of the three-dimensional gear pair model as a transient heat source boundary condition;

[0154] Based on the transient heat source boundary conditions, the convective heat transfer coefficient between the gear tooth surface and the air, and the forced convective heat transfer coefficient of the lubricating oil inside the gearbox, the temperature field inside the gearbox is solved by transient thermal analysis.

[0155] In one possible implementation, the lubrication unit 203 is specifically used to solve for the minimum film thickness by simultaneously solving the Reynolds equation and the film thickness equation based on the maximum contact stress, the lubricant viscosity, and the entrainment speed determined based on the gear parameters and the sliding speed; to determine the film thickness ratio based on the ratio of the minimum film thickness to the tooth surface roughness; to determine the lubrication state based on the threshold range to which the film thickness ratio belongs, the lubrication state including full film lubrication, mixed lubrication, and boundary lubrication; and to determine the coefficient of friction based on the lubrication state.

[0156] In one possible implementation, the mechanical unit 201 is specifically used to generate a three-dimensional gear pair model based on gear data; to mesh the tooth surfaces of the gears in the three-dimensional gear pair model; to set the meshing tooth surfaces of the driving and driven gears in the three-dimensional gear pair model as frictional contact, and the corresponding friction coefficients; to set boundary constraints for the three-dimensional gear pair model; and to simulate the transient meshing process using an explicit dynamics solver to obtain the maximum contact stress and the distribution cloud map of the contact stress as a function of time, and the sliding speed as a function of time, thereby determining the maximum contact stress during gear meshing and the sliding speed at the time step corresponding to the maximum contact stress.

[0157] In one possible implementation, the processing unit 204 is specifically used to calculate the difference between the minimum film thickness obtained by the current wheel performing the simulated gear transient meshing process and subsequent steps and the minimum film thickness obtained by the previous wheel performing the simulated gear transient meshing process and subsequent steps; the ratio of the difference to the minimum film thickness obtained by the current wheel performing the simulated gear transient meshing process and subsequent steps is used as a convergence index; if the convergence index is less than a preset value, then convergence is achieved.

[0158] In one possible implementation, the analysis unit 205 is specifically used to calculate the first product of the maximum contact stress on the tooth surface and the highest temperature on the tooth surface; calculate the ratio of the first product to the square of the minimum film thickness to obtain the adhesive risk index; when the adhesive risk index is greater than a preset critical value, there is an adhesive risk.

[0159] In one possible implementation, the device further includes an optimization unit;

[0160] The optimization unit is used to optimize the gear pair model by using tooth surface modification parameters, gear parameters, and lubrication conditions as optimization variables, and by using an optimization algorithm to obtain optimization parameters that minimize the scuffing risk index and maximize the transmission efficiency. The constraint condition of the optimization algorithm is that the tooth root bending strength is greater than or equal to the safety threshold, and the noise and vibration (NVH) index meets the industry standard.

[0161] In one possible implementation, the device further includes a debugging unit;

[0162] The debugging unit is used to test the first gear corresponding to the unoptimized gear pair model and the second gear corresponding to the gear pair model after optimization of the optimized parameters through a gear fatigue test bench, and obtain test parameters; compare the optimization degree of the first gear and the second gear on the first data according to the test parameters, the first data including the critical failure torque of scuffing, the tooth surface temperature rise curve and the wear morphology; adjust the first parameters based on the optimization degree, the first parameters including the preset critical value, the tooth surface roughness, the convective heat transfer coefficient between the tooth surface and the air and the forced convective heat transfer coefficient of the lubricating oil inside the gearbox.

[0163] This application also provides corresponding devices and computer storage media for implementing the solutions provided in this application.

[0164] The device includes a memory and a processor. The memory is used to store instructions or code, and the processor is used to execute the instructions or code to enable the device to perform a gear scuffing analysis method according to any embodiment of this application.

[0165] The computer storage medium stores code, and when the code is run, the device running the code implements a gear scuffing analysis method according to any embodiment of this application.

[0166] In the embodiments of this application, the terms "first" and "second" (if they exist) are used only as name identifiers and do not represent the order of first and second.

[0167] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that all or part of the steps in the methods of the above embodiments can be implemented by means of software plus a general-purpose hardware platform. Based on this understanding, the technical solution of this application can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as a read-only memory (ROM) / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, a server, or a network communication device such as a router) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0168] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0169] The above description is merely an exemplary implementation of this application and is not intended to limit the scope of protection of this application.

Claims

1. A method for analyzing gear scuffing, characterized in that, include: The transient meshing process of gears is simulated based on a gear pair model to obtain the mechanical parameters of gear meshing; Based on the mechanical parameters, the gearbox temperature field and corresponding thermodynamic parameters are determined, including lubricant viscosity and tooth surface deformation data. The minimum film thickness and the corresponding coefficient of friction are determined based on the mechanical and thermodynamic parameters. The three-dimensional gear pair model is updated based on the tooth surface deformation data, and the simulated gear transient meshing process and subsequent steps are re-executed based on the friction coefficient until convergence is achieved. The risk of gear scuffing is assessed based on the maximum contact stress on the tooth surface, the highest temperature on the tooth surface, and the minimum film thickness at the time of convergence.

2. The method according to claim 1, characterized in that, The mechanical parameters include the maximum contact stress of gear meshing and the sliding speed of the time step corresponding to the maximum contact stress; The determination of the gearbox temperature field and corresponding thermodynamic parameters based on the mechanical parameters includes: The frictional heat flux density at the time step is determined based on the maximum contact stress, the sliding speed, and the friction coefficient. The temperature field inside the gearbox is solved by transient thermal analysis, based on the frictional heat flux density at the time step. The lubricant viscosity is adjusted based on the maximum temperature of the tooth surface in the temperature field. Based on the temperature field, determine the tooth surface deformation data caused by thermal expansion.

3. The method according to claim 2, characterized in that, The method of combining the frictional heat flux density to solve the internal temperature field of the gearbox via transient thermal analysis includes: The frictional heat flux density is mapped to the mesh nodes of the tooth surface of the three-dimensional gear pair model as the boundary condition for the transient heat source; Based on the transient heat source boundary conditions, the convective heat transfer coefficient between the gear tooth surface and the air, and the forced convective heat transfer coefficient of the lubricating oil inside the gearbox, the temperature field inside the gearbox is solved by transient thermal analysis.

4. The method according to claim 2, characterized in that, The step of determining the minimum film thickness and the corresponding coefficient of friction based on the mechanical and thermodynamic parameters includes: The minimum film thickness is solved by combining the Reynolds equation and the film thickness equation based on the maximum contact stress, the lubricant viscosity, and the entrainment speed determined by the gear parameters and the sliding speed. The film thickness ratio is determined based on the ratio of the minimum film thickness to the tooth surface roughness; The lubrication state is determined based on the threshold range to which the film thickness ratio belongs, and the lubrication state includes full film lubrication, mixed lubrication and boundary lubrication; The coefficient of friction is determined based on the lubrication condition.

5. The method according to claim 1, characterized in that, Based on the gear pair model, the transient meshing process of gears is simulated to obtain the mechanical parameters of gear meshing, including: A three-dimensional model of the gear pair is generated based on the gear data; The tooth surfaces of the gears in the three-dimensional gear pair model are meshed; The tooth surfaces of the meshing driving and driven gears in the three-dimensional gear pair model are set to frictional contact, and the corresponding friction coefficients are defined. Set boundary constraints for the three-dimensional gear pair model; An explicit dynamics solver is used to simulate the transient meshing process, obtaining the maximum contact stress and its distribution cloud map as a function of time, and the sliding speed as a function of time. This allows for the determination of the maximum contact stress during gear meshing and the sliding speed at the time step corresponding to the maximum contact stress.

6. The method according to claim 1, characterized in that, The convergence includes: Calculate the difference between the minimum film thickness obtained by the current wheel performing the simulated gear transient meshing process and subsequent steps and the minimum film thickness obtained by the previous wheel performing the simulated gear transient meshing process and subsequent steps. The ratio of the difference to the minimum film thickness obtained by the current wheel performing the simulated gear transient meshing process and subsequent steps is used as the convergence index; If the convergence index is less than the preset value, then convergence is achieved.

7. The method according to any one of claims 1-6, characterized in that, The assessment of gear scuffing risk based on the maximum contact stress, highest temperature, and minimum film thickness at convergence includes: Calculate the first product of the maximum contact stress on the tooth surface and the highest temperature on the tooth surface; The bonding risk index is obtained by calculating the ratio of the first product to the square of the minimum film thickness. When the bonding risk index is greater than a preset critical value, there is a bonding risk.

8. The method according to claim 7, characterized in that, The method further includes: For the gear pair model, the tooth surface modification parameters, gear parameters, and lubrication conditions are used as optimization variables. Through the optimization algorithm, the optimization parameters that minimize the scuffing risk index and maximize the transmission efficiency are obtained. The constraint condition of the optimization algorithm is that the tooth root bending strength is greater than or equal to the safety threshold, and the noise and vibration (NVH) index meets the industry standard.

9. The method according to claim 8, characterized in that, The method further includes: Test parameters are obtained by testing the first gear corresponding to the unoptimized gear pair model and the second gear corresponding to the gear pair model after optimization of the optimized parameters using a gear fatigue testing bench. The optimization degree of the first gear and the second gear on the first data is compared according to the test parameters. The first data includes the critical failure torque of scuffing, the tooth surface temperature rise curve and the wear morphology. The first parameter is adjusted based on the degree of optimization. The first parameter includes the preset critical value, the tooth surface roughness, the convective heat transfer coefficient between the tooth surface and the air, and the forced convective heat transfer coefficient of the lubricating oil inside the gearbox.

10. A gear scuffing analysis device, characterized in that, The device includes: The mechanical unit is used to simulate the transient meshing process of gears based on the gear pair model and obtain the mechanical parameters of gear meshing. A thermodynamic unit is used to determine the gearbox temperature field and corresponding thermodynamic parameters based on the mechanical parameters, wherein the thermodynamic parameters include lubricant viscosity and tooth surface deformation data; The lubrication unit is used to determine the minimum film thickness and the corresponding coefficient of friction based on the mechanical and thermodynamic parameters. The processing unit is used to update the three-dimensional gear pair model according to the tooth surface deformation data, and re-execute the simulated gear transient meshing process and subsequent steps based on the friction coefficient until convergence is achieved; The analysis unit is used to assess the risk of gear scuffing based on the maximum contact stress on the tooth surface, the highest temperature on the tooth surface, and the minimum film thickness at the time of convergence.

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