A method and system for determining sliding bearing surface texture parameters

Abstract

This invention relates to the technical field of surface texture design for sliding bearings, specifically to a method and system for determining surface texture parameters of sliding bearings. The technical solution of this invention divides the radial clearance into a convergent clearance region and a diffused clearance region based on the operating speed and load of the shaft mounted within the sliding bearing. It then uses the Reynolds equation to analyze the oil film pressure distribution to obtain the cutoff position where the oil film overflows from the convergent clearance region to the diffused clearance region. To improve the oil film bearing capacity, multiple texture parameters are configured locally in the diffused clearance region from the cutoff position towards the maximum clearance position. The friction characteristics and oil film bearing capacity under each texture parameter are determined. Based on the oil film bearing capacity that satisfies the operating load, the friction characteristics are optimized to determine the texture parameter corresponding to the optimal friction characteristics as the target texture parameter for the sliding bearing. This solution improves the efficiency and accuracy of determining the target texture parameter for sliding bearings.

Description

Technical Field

[0001] This invention relates to the technical field of surface texture design for sliding bearings, and specifically to a method and system for determining surface texture parameters of sliding bearings. Background Technology

[0002] As a crucial supporting component of rotating machinery, sliding bearings directly impact the energy efficiency and lifespan of the equipment due to their frictional performance and oil film carrying capacity. To improve lubrication performance, textures (such as pits and microgrooves) need to be machined onto the surface of sliding bearings. These textures store lubricating oil, optimizing the hydrodynamic effect and frictional characteristics. However, texture parameters include multiple data points such as texture diameter and texture depth. The parameter selection process is complex and influenced by a combination of factors, including working load, width-to-diameter ratio, eccentricity, and offset angle, making it difficult to accurately determine suitable texture parameters. Existing methods largely rely on experience or limited experiments to set texture parameters, lacking a theoretically supported and efficient method for determination. This makes it difficult to achieve optimal frictional performance while meeting oil film carrying capacity requirements. Summary of the Invention

[0003] To address the technical problem of simultaneously optimizing oil film load capacity and friction when determining the texture parameters of sliding bearings, this invention aims to provide a method and system for determining the surface texture parameters of sliding bearings. This method can quickly and accurately determine the target texture parameters of the sliding bearing, ensuring that the oil film load capacity meets the working load while reducing friction. The specific technical solution adopted is as follows:

[0004] In a first aspect, embodiments of the present invention provide a method for determining the surface texture parameters of a sliding bearing, the method comprising:

[0005] Based on the operating speed and operating load of the shaft assembled in the sliding bearing, determine the convergence gap region and diffusion gap region divided by the maximum and minimum gap positions when the shaft is running, as well as the cross-sectional dataset characterizing the relative position of the sliding bearing and the shaft.

[0006] Based on the operating speed, operating load and cross-section data, the oil film pressure distribution is analyzed using the Reynolds equation to obtain the cutoff position of the oil film overflowing from the convergence gap region to the diffusion gap region.

[0007] Starting from the cutoff position, configure the local multi-structure parameters of the diffusion gap region in the direction of the maximum gap position, and determine the friction characteristics and oil film bearing capacity under each structure parameter. Each structure parameter includes the texture diameter, texture depth and texture area ratio.

[0008] The friction characteristics are optimized based on the oil film bearing capacity that meets the working load, and the texture parameters corresponding to the optimal friction characteristics are determined as the target texture parameters for the sliding bearing.

[0009] In an optional embodiment, before determining the convergence gap region and the diffusion gap region divided by the maximum gap position and the minimum gap position during shaft operation, the method further includes:

[0010] Obtain the initial eccentricity and initial offset angle between the sliding bearing and the shaft;

[0011] Estimate the current bearing capacity of the oil film based on the initial eccentricity and the initial offset angle;

[0012] If the current bearing capacity is less than or equal to the working load, modify the initial eccentricity and initial offset angle and re-estimate until the current bearing capacity is greater than the working load to obtain the target eccentricity and target offset angle.

[0013] Update the target eccentricity and target offset angle to the cross-section dataset.

[0014] In one optional embodiment, based on the operating speed, operating load, and cross-sectional data set, and in conjunction with the Reynolds equation, the oil film pressure distribution is analyzed to obtain the cutoff position where the oil film overflows from the convergence gap region to the diffusion gap region, including:

[0015] The Reynolds equation based on fluid lubrication theory is transformed into a dimensionless form. The working speed, working load and cross-section dataset are input into the dimensionless Reynolds equation, and the oil film pressure distribution in the convergence gap region is solved by the finite difference method.

[0016] The oil film overflow coefficient is obtained based on the surface roughness of the contact surface between the sliding bearing and the shaft, the operating speed, and the operating load.

[0017] Based on the oil film pressure distribution and oil film overflow coefficient in the convergence gap region, the cutoff position of the oil film overflowing from the convergence gap region to the diffusion gap region is determined.

[0018] In one optional embodiment, the oil film overflow coefficient is obtained based on the surface roughness of the contact surface between the sliding bearing and the shaft, the operating speed, and the operating load, including:

[0019] Based on the first surface roughness and first material hardness of the sliding bearing, and the second surface roughness and second material hardness of the rotating shaft, a first coefficient characterizing the degree of oil film overflow associated with the contact surface roughness is obtained.

[0020] The second and third coefficients are obtained based on the deviations between the operating speed and operating load and the reference speed and reference load set by the Reynolds equation, respectively.

[0021] The oil film overflow coefficient is obtained based on the first coefficient, the second coefficient, the third coefficient, and the overflow flow rate generated by the oil film under smooth conditions.

[0022] In one optional embodiment, configuring multiple tissue structure parameters locally in the diffusion gap region includes:

[0023] The first range of texture diameter is configured based on the oil film thickness and corresponding oil film tension at the cutoff position;

[0024] The second range of texture depth is configured according to the monotonically increasing segment of the depth bearing capacity curve, wherein the depth bearing capacity curve is the curve of texture depth as a function of oil film bearing capacity.

[0025] The first range is interval-valued according to a preset first interval value to obtain a first array of texture diameters;

[0026] The second range is interval-valued according to a preset second interval value to obtain a second array of texture depth, wherein the first interval value is greater than the second interval value;

[0027] Data are combined based on at least one set value of the first array, the second array, and the texture area ratio to obtain multiple texture parameters.

[0028] In an optional embodiment, before combining data based on at least one set value of the first array, the second array, and the texture area ratio to obtain multiple texture parameters, the method further includes:

[0029] Multiple dimensionless bearing capacity curves of the sliding bearing are obtained. Each dimensionless bearing capacity curve is a curve showing the change of the texture area ratio with the dimensionless oil film bearing capacity at a set texture depth.

[0030] The target area ratio is determined based on the monotonically increasing corresponding texture area ratio of each dimensionless bearing curve.

[0031] The set value of the fabric area ratio is determined based on the first set range formed by all target area ratios and the second set range that satisfies the fabric processing efficiency.

[0032] In one optional embodiment, friction characteristics are optimized based on the oil film bearing capacity that satisfies the working load, so as to determine the texture parameters corresponding to the optimal friction characteristics as the target texture parameters of the sliding bearing, including:

[0033] The combination of texture parameters whose oil film bearing capacity is greater than the working load is determined as the optional texture parameters;

[0034] All optional texture parameters are sorted in descending order based on a comprehensive score of friction characteristics and operating temperature rise;

[0035] The texture parameter combinations ranked at the top of the preset positions in descending order are used to evaluate the texture clogging risk, and the texture parameter combination with the lowest clogging risk is determined as the target texture parameter for the sliding bearing.

[0036] In an optional embodiment, the texture parameters further include a texture coverage angle extending from the cutoff position to the maximum gap position; before sorting all optional texture parameters in descending order according to a comprehensive score of frictional characteristics and operating temperature rise, the method further includes:

[0037] Based on the correlation between the frictional characteristics and oil film bearing capacity of the optional texture parameters under different texture coverage angles, the target coverage angle for each set of optional texture parameters is determined.

[0038] In one optional embodiment, the texture parameter combinations ranked at the top of the descending order are used to assess the texture clogging risk, and the texture parameter combination with the lowest clogging risk is determined as the target texture parameter for the sliding bearing, including:

[0039] Based on the oil film flow rate in the diffusion gap region and the pre-set texture parameters located at the top in descending order, the impurity deposition coefficient of each texture parameter combination in the pre-set texture parameters is determined.

[0040] The texture parameters corresponding to the smallest coefficient among all impurity deposition coefficients are combined to determine the target texture parameters for the sliding bearing.

[0041] Secondly, embodiments of the present invention also provide a system for determining the surface texture parameters of a sliding bearing. The system is used to implement any of the determination methods in the first aspect, and includes:

[0042] The first determining module is used to determine the convergence gap region and diffusion gap region divided by the maximum gap position and the minimum gap position when the shaft is running, based on the working speed and working load of the shaft assembled in the sliding bearing, as well as the cross-sectional dataset characterizing the relative position of the sliding bearing and the shaft.

[0043] The module is used to analyze the oil film pressure distribution based on the operating speed, operating load and cross-section dataset, combined with the Reynolds equation, so as to obtain the cutoff position of the oil film overflowing from the convergence gap region to the diffusion gap region.

[0044] The second determining module is used to configure multiple texture parameters of the local diffusion gap region from the cutoff position to the direction of the maximum gap position, and to determine the friction characteristics and oil film bearing capacity under each texture parameter. Each texture parameter includes texture diameter, texture depth and texture area ratio.

[0045] The third determining module is used to optimize the friction characteristics based on the oil film bearing capacity that meets the working load, so as to determine the texture parameters corresponding to the optimal friction characteristics as the target texture parameters of the sliding bearing.

[0046] The present invention has the following beneficial effects:

[0047] In determining the surface texture parameters of a sliding bearing, the technical solution of this invention divides the radial clearance into a convergent clearance region and a diffuse clearance region based on the operating speed and load of the shaft assembled inside the sliding bearing, and obtains a cross-sectional dataset characterizing the relative position of the sliding bearing and the shaft. It then analyzes the oil film pressure distribution using the Reynolds equation to obtain the cutoff position where the oil film overflows from the convergent clearance region to the diffuse clearance region. Since the oil film pressure is distributed in the convergent clearance region when the shaft rotates, to improve the oil film bearing capacity, multiple texture parameters are configured locally in the diffuse clearance region from the cutoff position towards the direction of the maximum clearance position. The friction characteristics and oil film bearing capacity under each texture parameter are determined, with each texture parameter including texture diameter, texture depth, and texture area ratio. Finally, friction characteristics are optimized based on the oil film bearing capacity that satisfies the operating load to determine the texture parameter corresponding to the optimal friction characteristics as the target texture parameter for the sliding bearing. This invention addresses the technical flaw that all textures in the gap convergence region not only reduce the load-bearing capacity but also increase the friction coefficient. By setting textures locally in the diffusion gap region and optimizing the friction characteristics, the oil film load-bearing capacity can be ensured to meet the working load while reducing friction when textures are arranged on the sliding bearing surface. This improves the efficiency and accuracy of determining the target texture parameters of the sliding bearing. Attached Figure Description

[0048] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 A flowchart illustrating a method for determining the surface texture parameters of a sliding bearing, as provided in an embodiment of the present invention;

[0050] Figure 2 This is a schematic diagram of the cross-sectional structure of a sliding bearing and a rotating shaft provided in one embodiment of the present invention;

[0051] Figure 3 This is a front view schematic diagram of a surface texture provided in one embodiment of the present invention;

[0052] Figure 4 This is a schematic diagram of the surface texture provided in a planar coordinate system according to an embodiment of the present invention;

[0053] Figure 5 The distribution cloud map of the dimensionless oil film thickness of a smooth bearing provided in one embodiment of the present invention;

[0054] Figure 6The distribution cloud map of dimensionless oil film pressure in a smooth bearing provided in one embodiment of the present invention;

[0055] Figure 7 A graph of dimensionless oil film pressure of a smooth bearing provided in an embodiment of the present invention;

[0056] Figure 8 A graph of a dimensionless load-bearing curve provided in one embodiment of the present invention;

[0057] Figure 9 The cloud map showing the distribution of dimensionless oil film thickness under a 200-360 degree texture is provided as an embodiment of the present invention.

[0058] Figure 10 The distribution cloud map of dimensionless oil film pressure under 200-360 degree texture provided in one embodiment of the present invention;

[0059] Figure 11 This is a structural diagram of a system for determining the surface texture parameters of a sliding bearing, provided in one embodiment of the present invention.

[0060] Explanation of reference numerals in the attached drawings: 1-sliding bearing, 2-rotating shaft, 3-texture. Detailed Implementation

[0061] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a method and system for determining the surface texture parameters of a sliding bearing according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0063] Experiments have shown that, under a fully textured structure with constant eccentricity between the sliding bearing and the shaft (i.e., texture is applied to the entire circumference of the sliding bearing's inner bore), regardless of variations in texture diameter and depth, the oil film bearing capacity remains lower than that of a smooth bearing, and this capacity gradually decreases with increasing depth. The presence of full texture, regardless of texture parameter configuration, reduces the friction between the sliding bearing and the shaft. This is because the increased oil film thickness in the textured area reduces the shear stress at the shaft-oil film interface, thus lowering friction. Although the friction of a fully textured structure is also lower than that of a smooth bearing, the greater reduction in oil film bearing capacity results in a correspondingly higher coefficient of friction, failing to improve the frictional performance between the sliding bearing and the shaft.

[0064] The following description, in conjunction with the accompanying drawings, details the specific scheme of the method and system for determining the surface texture parameters of a sliding bearing provided by the present invention.

[0065] Please see Figure 1 , Figure 1 This is a flowchart illustrating a method for determining the surface texture parameters of a sliding bearing according to an embodiment of the present invention. This method can be applied to the design terminal of the sliding bearing; the design terminal can be a computer or server, as long as it can run the method. The determination method includes:

[0066] S11. Based on the operating speed and operating load of the shaft assembled inside the sliding bearing, determine the convergence gap region and diffusion gap region divided by the maximum and minimum gap positions when the shaft is running, as well as the cross-sectional dataset characterizing the relative position between the sliding bearing and the shaft.

[0067] For details, please refer to Figure 2 , Figure 2 This is a schematic diagram of the cross-sectional structure of a sliding bearing and a shaft, representing the cross-sectional structure of a textured rigid radial sliding bearing operating under steady-state conditions. A radial clearance exists between the sliding bearing and the shaft, which can be configured based on actual requirements. When the shaft is not rotating, it is located at the bottom of the sliding bearing; when the shaft rotates, the radial clearance causes it to deflect to one side. Figure 2 As shown in the figure, the shaft rotates clockwise. The position of the maximum clearance is the position of the sliding bearing A, and the position of the minimum clearance is the position of the sliding bearing B. Based on the line connecting points A and B, a convergence gap region and a diffusion gap region are divided. The convergence gap region is the area where the gap gradually decreases from point A to point B, and the diffusion gap region is the area where the gap gradually increases from point B to point A.

[0068] The cross-sectional dataset records the relative positions of the sliding bearing and the shaft, including offset angle and eccentricity. Multiple data items can be constructed based on the data required for analyzing the Reynolds equations, and each data item can be calculated or retrieved based on its name to obtain the cross-sectional dataset. When the shaft rotates, it carries lubricating oil into the convergence gap region, generating hydrodynamic pressure. The resultant force generated by the oil film pressure and the working load on the shaft... W The phases are in equilibrium, but the equilibrium position is biased to one side. e For the eccentricity, θ It is the offset angle. r The radius of the pivot is 1. R The radius of the sliding bearing is... c For the radius gap, c = R - r relative gap ψ = c / r , ω The rotational angular velocity of the shaft is given by [variable name], and the linear velocity is given by [variable name]. U = ωr express, x The axis represents the circumferential coordinate. y The axis represents the radial (oil film thickness) coordinate. z The axis represents the axial coordinate, and the width of the sliding bearing is represented by... L express, O 1 represents the center of the sliding bearing. O 2 is the center of the axis of rotation, in O 1 O The two lines have the largest gap at one end. h max = c + e The other end has a minimum gap h min = c - e Following the direction of rotation of the axis, from h max arrive h min Within a half-circle, the gap forms a converging wedge shape that gradually decreases in size; this is defined as the convergent gap region. And from... h min arrive h max Within a half-circle, the gap is a divergent wedge shape that gradually increases in size; this is defined as the diffusion gap region.

[0069] In the actual design of textures, due to fluctuations in process parameters, inhomogeneity of the surface material of parts, and adverse factors such as the surrounding environment, the size of these processed pits cannot be completely consistent, and their distribution will not be absolutely uniform. However, in theoretical analysis, these secondary factors are ignored, and it is assumed that the cylindrical pits are... x , z Uniformly distributed in direction, such as Figure 3 As shown, the radius of each pit is r p Depth is h p And each pit is located on an imaginary side of length . L x × L x The thickness of the oil film above the working surface of the sliding bearing at the center of the square unit is denoted as . h smooth Unfold the bearing surface along the plane, as follows: Figure 4 As shown, assuming the entire texture of the pits is located on the bearing surface and uniformly distributed, since the oil film thickness between the shaft and the sliding bearing is only on the order of micrometers, which is very small relative to the bearing diameter, the sliding bearing is unfolded into a plane along the circumference. Sp The ratio of the pit texture area to the surface texture of the bearing is given by: , L x Let be the side length of the square element in the axial direction.

[0070] It is understandable that during the rotation of the shaft within the sliding bearing, the shaft's axis relative to the bearing bore's axis will experience eccentric displacement due to the load. This eccentric displacement causes the oil film thickness of the sliding bearing to exhibit a non-uniform distribution in the circumferential direction, forming minimum and maximum clearance positions. Between these two extreme positions, the circumferential variation of the oil film thickness determines the convergence and diffusion characteristics of the flow field. The relative positions of the sliding bearing and the shaft under corresponding operating speeds and loads can be obtained through software simulation, thereby deriving the corresponding cross-sectional dataset.

[0071] In practical applications, the eccentricity and offset angle between the sliding bearing and the shaft directly affect the oil film bearing capacity, and thus the lubrication effect between the sliding bearing and the shaft. Therefore, when determining the texture parameters, it is necessary to prioritize determining the applicable eccentricity and offset angle.

[0072] Specifically, after obtaining the cross-sectional dataset, the current load-bearing capacity of the oil film is estimated based on the initial eccentricity and initial misalignment angle of the sliding bearing and the shaft. The eccentricity and misalignment angle can be derived from the initial design data of the sliding bearing and the shaft. For example, the initial eccentricity can be theoretically calculated using assembly tolerances, preload, and lubrication conditions; alternatively, the relative positions of the sliding bearing and the shaft under corresponding conditions can be obtained through simulation, thereby calculating the initial eccentricity and initial misalignment angle; or, of course, it can be calculated using a simplified model of the Reynolds equation or known empirical formulas. The current load-bearing capacity is the oil film load-bearing capacity corresponding to the initial eccentricity and initial misalignment angle. The oil film load-bearing capacity achieves non-contact support between the shaft and the sliding bearing through the dynamic pressure effect formed by the lubricating oil within the bearing clearance, avoiding direct metal-to-metal friction and thus reducing the risk of wear and ablation. The oil film load-bearing capacity characterizes the load-bearing capacity of the oil film under the current geometric state, and is measured in Newtons (N).

[0073] If the current bearing capacity is less than or equal to the working load, modify the initial eccentricity and initial offset angle and re-estimate them until the current bearing capacity is greater than the working load to obtain the target eccentricity and target offset angle. Modifications to the eccentricity and offset angle can be based on their relationship with the oil film bearing capacity. For example, a first relationship curve between eccentricity and oil film bearing capacity, and a second relationship curve between offset angle and oil film bearing capacity can be constructed. Modifications are then made based on the adjustment amounts represented by the first and second relationship curves to obtain the target eccentricity and target offset angle. The target eccentricity and target offset angle are then updated to the cross-sectional dataset.

[0074] S12. Based on the operating speed, operating load, and cross-sectional data set, and combined with the Reynolds equation, analyze the oil film pressure distribution to obtain the cutoff position where the oil film overflows from the convergence gap region to the diffusion gap region.

[0075] Specifically, finite difference calculations can be performed based on the Reynolds equation to obtain the oil film pressure distribution in the convergence gap and diffusion gap regions, and the cutoff position can be determined based on the oil film pressure in the convergence gap region. The general form of the Reynolds equation is as follows:

[0076] (Formula 1)

[0077] In the formula U , V They are respectively x Movement speed in the z-axis direction h For oil film thickness, ρ For the density of lubricating oil, η The viscosity of the lubricating oil. t For time.

[0078] when V When = 0 and the fluid is incompressible, it can be simplified to the form of a two-dimensional Reynolds equation:

[0079] (Formula 2)

[0080] The above equation is the steady-state Reynolds equation, which contains only one unknown: pressure. p This refers to the oil film pressure. Solving the above equation yields the pressure distribution of the lubricating oil film in the sliding bearing. For radial sliding bearings, using... The bearing's circumferential coordinates are represented using the vertical line above the bearing as the angular coordinates. Φ The origin, the axial tangential linear velocity is Substituting the following conditions into Formula 2, the formula becomes:

[0081] (Formula 3)

[0082] The research object of this invention is a cylindrical radial sliding bearing. For ease of calculation, the origin of the coordinate system can be taken at... h max At this point, the angular coordinates are used. express, ,because and All are dimensionless quantities. Similarly, the circumferential coordinates of the bearing can be represented. The formula is: (Formula 4)

[0083] in The interval is Based on the analysis of the Reynolds equations described above, the pressure distribution of the oil film can be obtained. Based on the oil film pressure in the convergence gap region, the overflow of the oil film from the convergence gap region to the diffusion gap region can be estimated, and thus the cutoff position of the oil film overflowing from the convergence gap region to the diffusion gap region can be obtained.

[0084] For example, step S12 specifically includes S12-1 to S12-3, which are described in detail below:

[0085] S12-1. The Reynolds equation, based on fluid lubrication theory, is transformed into a dimensionless form. The operating speed, operating load, and cross-section dataset are input into the dimensionless Reynolds equation, and the oil film pressure distribution in the convergence gap region is solved using the finite difference method. The Reynolds equation is a second-order partial differential equation. For finite-width radial sliding bearings, its analytical expression cannot be obtained; numerical methods are generally used. Dimensionalizing the Reynolds equation reduces the number of variables it deals with and ensures that the values ​​of these variables are not too large or too small, improving the stability of the calculation process and making the solution with dimensionless parameters more universal. The specific dimensionless transformation process is as follows:

[0086]

[0087] L This represents the axial length of the sliding bearing. h 0 represents the oil film thickness in the non-textured region. h p The thickness of the oil film in the textured region. p 0 represents the oil film pressure in the non-textured region. Assuming the viscosity of the lubricating oil remains constant along the oil film thickness direction and is unaffected by pressure, Equation 4 becomes dimensionless:

[0088] (Formula 5)

[0089] in d This indicates the diameter of the shaft. H Let be the dimensionless thickness of the oil film. The dimensionless form of the film thickness equation is:

[0090] (Formula 6)

[0091] In formula 6, Ω For the area where the texture is located, H(φ,λ) coordinates φ,λ The dimensionless thickness of the lower oil film; H 0 represents the dimensionless oil film thickness in the non-textured region; H pThe dimensionless oil film thickness characterizes the textured region. The finite difference method is used to solve for the pressure distribution. This involves dividing the oil film of the sliding bearing into many grids, using the pressure values ​​at each node to construct different order quotients, approximating the derivatives in the Reynolds equation, and transforming the equation into a set of algebraic equations. Solving for the pressure values ​​at each node yields a set of discrete pressure values, which approximates the pressure distribution within the oil film.

[0092] Please see Figure 5 and Figure 6 , Figure 5 Medium blue indicates a thinner oil film, while red indicates a thicker oil film. Figure 6 In the diagram, blue indicates lower oil film pressure, and red indicates higher oil film pressure. The graph shows that the dimensionless oil film thickness of a 360-degree finite-width radial sliding bearing is parabolic in the circumferential direction, with maximum thickness at 0 degrees. Since the 0-180 degree range is a convergence gap, the oil film thickness gradually decreases, reaching its minimum at 180 degrees. The 180-360 degree range is a diffusion gap, where the oil film thickness gradually increases, returning to its maximum at 360 degrees. Because pressure is generated only in the convergence gap, the three-dimensional pressure distribution approximates a continuous parabolic distribution. In the 0-360 degree region along the circumference, the dimensionless oil film pressure gradually increases to its maximum value, then drops sharply. The pressure drops to zero in the region ≥200 degrees. This indicates that the minimum oil film pressure does not drop to zero at the minimum gap, i.e., at 180 degrees, but rather the oil film can still maintain a portion of continuity after the gap narrows.

[0093] This invention establishes a film thickness equation applicable to surface-textured bearings. Based on boundary conditions considering all textures, the Reynolds equation is solved. Through dimensionless transformation, the oil film pressure distribution of smooth bearings and bearings with textures at different positions is numerically obtained using the finite difference method. To further illustrate the influence of textures at different circumferential positions on oil film pressure in sliding bearings, this invention prepares textures at different positions of the sliding bearing and calculates the corresponding oil film pressures. The obtained data are shown in Table 1.

[0094] Table 1:

[0095]

[0096] Table 1 shows that all texture types are not suitable for sliding bearings. The addition of texture reduces the local pressure gradient, thus flattening the local pressure field and reducing the average and maximum pressure values. Texture also causes a pressure decrease in the 0-180 degree range, indicating that texture actually reduces the average pressure and oil film bearing capacity in areas of pressure variation. Therefore, texture should be placed in areas where pressure is less affected. However, in the 180-360 and 200-360 degree textures, the texture pressure is essentially cavitation pressure, thus the texture parameters have a smaller impact on the pressure field.

[0097] S12-2. Obtain the oil film overflow coefficient based on the surface roughness of the contact surface between the sliding bearing and the shaft, the operating speed, and the operating load. The oil film overflow coefficient characterizes the ease with which the oil film overflows from the convergent gap region to the diffuser gap region under the corresponding dynamic operating conditions. The oil film overflow coefficient can be set to the range [0,1]. A larger oil film overflow coefficient indicates that the oil film can easily overflow from the convergent gap region to the diffuser gap region; conversely, a smaller oil film overflow coefficient indicates that it is more difficult for the oil film to overflow from the convergent gap region to the diffuser gap region. For example, the oil film overflow coefficient is calculated based on the following method.

[0098] The first step is to obtain a first coefficient characterizing the degree of oil film overflow associated with the surface roughness of the contact surfaces, based on the first surface roughness and first material hardness of the sliding bearing, and the second surface roughness and second material hardness of the shaft. The first and second surface roughness can be derived from the actual machining process roughness. Sliding bearings are mostly made of brass, so the first material hardness can be derived from the hardness of brass; shafts are mostly made of tempered steel, so the second material hardness can be derived from the hardness of tempered steel. The greater the roughness, the larger the microscopic oil film channels, and the more lubricating oil overflows; conversely, the less lubricating oil overflows. The ease of oil film overflow can be analyzed based on the first surface roughness, first material hardness, second surface roughness, and second material hardness to determine the corresponding weights of each parameter. All weights are summed to 1, and a weighted calculation is performed to obtain the first coefficient. Alternatively, a calculation model can be proposed based on the correspondence between the parameters and the first coefficient, and the first coefficient can be obtained based on the calculation results of the model.

[0099] The second step involves obtaining the second and third coefficients based on the deviations between the operating speed and operating load and the reference speed and reference load set by the Reynolds equation. Similarly, the operating speed and operating load also affect the ease with which the oil film overflows. Higher speeds make it easier for the oil film to overflow from the convergence gap region to the diffusion gap region; conversely, lower speeds make it more difficult for the oil film to overflow. Stronger compression can create a higher pressure gradient in the convergence region, thus the third coefficient can also be derived based on the deviation between the operating load and the reference load.

[0100] The third step involves obtaining the oil film overflow coefficient based on the first, second, and third coefficients and the overflow flow rate generated by the oil film under smooth conditions. It can be understood that the higher the roughness and hardness corresponding to the first coefficient, the larger the gap between the sliding bearing and the rotating shaft contact surface, and the stronger the oil film overflow; conversely, the oil film overflow weakens. Under the second coefficient, a greater increase in rotational speed leads to stronger oil film overflow; conversely, a greater decrease in rotational speed leads to weaker oil film overflow. The relationship between the third coefficient and the oil film overflow flow rate is non-linear. A corresponding curve can be obtained through calibration experiments, and then the accurate third coefficient can be calculated. The oil film overflow coefficient can be obtained based on the product of the first, second, and third coefficients and the overflow flow rate. The calculated result of the product can be normalized to obtain the accurate oil film overflow coefficient.

[0101] S12-3. Based on the oil film pressure distribution and oil film overflow coefficient in the convergence gap region, determine the cutoff position where the oil film overflows from the convergence gap region to the diffusion gap region. Calibration experiments or software simulations can be performed based on the oil film pressure distribution, oil film overflow coefficient, and cutoff position to derive the relationship between the three, and then determine the cutoff position. The cutoff position characterizes the pressure generated by the oil film under the current operating conditions, and the location where the oil film permeates from the convergence gap region to the diffusion gap region; at this position, the oil film has not ruptured axially in the sliding bearing.

[0102] This invention configures the calculation parameter as the shaft diameter. d =20mm, width-to-diameter ratio L / d =1, radial clearance c =0.019mm, lubricating oil viscosity η =0.01275 Pa·s, eccentricity =0.6. Please refer to [link / reference]. Figure 7 , Figure 7 The graph shows the dimensionless oil film pressure. It can be seen from the graph that the maximum oil film pressure is located at 150 degrees circumferentially, and the pressure approaches zero at 200-210 degrees circumferentially. 200 degrees can be regarded as the cutoff position for the oil film to overflow from the convergence gap region to the diffusion gap region.

[0103] S13. Starting from the cutoff position, configure the local multi-structure parameters of the diffusion gap region in the direction of the maximum gap position, and determine the friction characteristics and oil film bearing capacity under each structure parameter. Each structure parameter includes the texture diameter, texture depth and texture area ratio.

[0104] For details, please continue reading. Figure 2If point C is the cutoff point, then the texture is processed from point C towards point A. The area containing the processed texture is defined as the texture region. Multiple sets of texture parameters are configured for this region, based on differences in texture diameter, texture depth, and texture area ratio. Under different texture parameters, friction characteristics and oil film bearing capacity change accordingly. Friction characteristics can be characterized based on friction force and / or friction coefficient. Multiple texture parameters can be configured based on the experience of technicians, or by setting selection ranges for each parameter, using software tools to take values ​​at intervals within each parameter's selection range, and then combining them to obtain multiple texture parameters.

[0105] It should be noted that, in order to improve the feasibility of texture verification, each texture parameter can be configured as a multi-row structure, that is, a texture with multiple rows of pits along the axial direction of the sliding bearing. The number of rows can be configured based on the actual situation, such as 3-8 rows, to improve the feasibility of calculating the friction characteristics and oil film bearing capacity of the sliding bearing. Of course, a fixed coverage angle of the texture can also be set, such as covering 100 degrees from the cutoff position to the maximum gap position.

[0106] It is understood that the oil film bearing capacity and friction characteristics of sliding bearings are important indicators for evaluating texture performance. This invention calculates the dimensionless pressure using the over-relaxation iterative method, and then obtains the dimensionless bearing capacity, dimensionless friction force, and dimensionless friction coefficient of the bearing under different texture parameters through integration. Simultaneously, these can be converted into the oil film pressure of a specific bearing as needed, thereby calculating the oil film bearing capacity, friction force, and friction coefficient of the actual sliding bearing. The friction coefficient is the ratio of friction force to oil film bearing capacity. The influence of parameters such as texture diameter, texture depth, and area ratio on the bearing lubrication tribological characteristics under a fixed eccentricity is analyzed.

[0107] It should be noted that when calculating the oil film bearing capacity, the oil film pressure over the entire sliding bearing surface can be integrated; the result of the integration is the oil film bearing capacity. The frictional force exerted by the oil film on the shaft surface can be obtained by integrating the shear stress in the fluid layer in contact with the surface along the entire lubrication film. To obtain the frictional force acting on the two friction surfaces, the first shear force on the bearing surface and the second shear force on the shaft surface can be derived based on the expression for shear force. Integrating the first and second shear forces yields the frictional force. The ratio of the frictional force to the oil film bearing capacity is the coefficient of friction.

[0108] The following section will describe in detail the configuration process of local multiple tissue parameters in the diffusion gap region, including:

[0109] S13-1. Configure the first range of texture diameter based on the oil film thickness and corresponding oil film tension at the cutoff position. In texture design, an excessively large texture diameter may disrupt the oil film continuity, leading to localized cavitation or flow turbulence; while an excessively small texture diameter will struggle to create effective pressure disturbance, limiting its effect on improving lubrication performance. Therefore, the texture diameter value can be set by combining the oil film thickness and oil film tension at the cutoff position.

[0110] For example, the oil film thickness at the cutoff point is used as the physical lower limit of the texture diameter, ensuring that the texture size cannot be less than the local oil film thickness, otherwise the oil film will rupture; the stable range corresponding to the oil film tension is used as the upper limit, ensuring that the texture diameter will not be so large as to destroy the overall flow field structure of the oil film; under these two constraints, a reasonable diameter variation range is established, and by coupling with the physical state at the cutoff point, it is ensured that the range design of the texture diameter meets the stability requirements of the lubricating oil film, avoiding calculation errors or redundancy caused by unreasonable geometric parameters.

[0111] S13-2. The second range of texture depth is configured based on the monotonically increasing segment of the depth-bearing capacity curve, where the depth-bearing capacity curve represents the variation of texture depth with oil film bearing capacity. Texture depth also significantly affects oil film bearing capacity; as texture depth increases, a local pressure enhancement effect occurs, thereby increasing oil film bearing capacity. However, when the depth exceeds a certain critical value, excessively deep textures disrupt the fluid pressure distribution, leading to a decrease in oil film bearing capacity. The depth-bearing capacity curve can be obtained through calibration experiments, and a reasonable value range can be determined based on this curve. The depth-bearing capacity curve describes the relationship between texture depth and oil film bearing capacity: in the initial stage, the curve monotonically increases with depth; after exceeding the critical point, the curve exhibits a decreasing characteristic. The monotonically increasing segment of the depth-bearing capacity curve is extracted as the effective range of texture depth and defined as the second range.

[0112] S13-3. The first range is interval-valued according to a preset first interval value to obtain a first array of texture diameters. The interval value can discretize the first range to reduce the amount of computation in the texture parameter optimization process.

[0113] S13-4. The second range is interval-selected according to a preset second interval value to obtain a second array of texture depths. The first interval value is greater than the second interval value, and the absolute value of the difference between adjacent data in the second array is less than the absolute value of the difference between adjacent data in the first array. Since texture depth is generally more sensitive to oil film pressure distribution and friction performance than texture diameter, a denser interval is needed to ensure the accuracy of the optimization results. However, the texture diameter's effect on oil film load-bearing performance is relatively gradual within a certain range, and using a larger interval will not significantly affect the results. This processing method can effectively reduce the total number of combinations and lower computational complexity.

[0114] S13-5. Combine data according to at least one set value of the first array, the second array, and the texture area ratio to obtain multiple texture parameters. Combine the first array representing the texture diameter with the second array representing the texture depth in pairs to form a set containing two parameters; based on this, combine with the pre-set texture area ratio (which can be a single value or multiple values) to expand it into a set containing three parameters, each set being a texture parameter.

[0115] Setting the texture area ratio using empirical values ​​may lead to insufficient accuracy. Therefore, in one specific embodiment, before combining data based on at least one set value of the first array, the second array, and the texture area ratio to obtain multiple texture parameters, the method further includes:

[0116] Multiple dimensionless load-bearing curves of the sliding bearing are obtained. Each curve represents the variation of the texture area ratio with the dimensionless oil film load-bearing capacity at a given texture depth. These curves determine how the dimensionless oil film load-bearing capacity changes with the texture area ratio at a corresponding texture depth. Please refer to [link to relevant documentation]. Figure 8 The horizontal axis represents the texture area ratio, and the vertical axis represents the dimensionless bearing capacity. The dimensionless texture depths are 1, 2, 5, 10, 15, and 20, respectively.

[0117] The target area ratio is determined based on the monotonically increasing corresponding texture area ratio of each dimensionless bearing capacity curve. Figure 8 It can be seen that when the dimensionless bearing capacity curve is monotonically increasing, the dimensionless bearing capacity increases with the increase of the texture area ratio. The selected texture area ratio is positive and is therefore determined as the target area ratio.

[0118] The set value of the fabric area ratio is determined based on a first set range comprised of all target area ratios and a second set range that satisfies fabric processing efficiency. From... Figure 8 As can be seen, the target area ratio is between 2 and 6, therefore the first setting range is 2-6. However, under localized texture conditions, the coefficient of friction decreases as the area ratio increases. Considering that the area ratio is large, such as exceeding 50.27%, the spacing between textures is small and difficult to process. Therefore, a second setting range can be determined. The setting value of the area ratio is obtained by the intersection of the two setting ranges, and the setting value can be configured to 50.27%.

[0119] Please see Figure 9 and 10 , Figure 9 The blue area indicates a thinner oil film, while the red area indicates a thicker oil film. As can be seen from the figure, the oil film thickness gradually increases from the radial gap of the diffusion gap region, and the oil film covers the entire gap diffusion region. Figure 10 Medium blue indicates lower oil film pressure, while red indicates higher oil film pressure. It can be seen that the oil film pressure is higher in the gap convergence zone and lower in the gap diffusion zone. Therefore, configuring the local texture of the diffusion gap zone from the cutoff position towards the maximum gap position is more reasonable.

[0120] S14. Optimize the friction characteristics based on the oil film bearing capacity that meets the working load, and determine the texture parameters corresponding to the optimal friction characteristics as the target texture parameters of the sliding bearing.

[0121] Specifically, the lubrication design of sliding bearings must ensure the oil film's load-bearing capacity—that is, the oil film can resist the working load without direct contact or wear—while also pursuing optimal frictional characteristics to reduce energy consumption, lower temperature rise, and extend equipment lifespan. Frictional force can be calculated based on the texture parameters corresponding to all oil film load-bearing capacities greater than the working load, and the texture parameter with the minimum frictional force can be selected as the target texture parameter. The target texture parameter determined based on the above parameters is the texture diameter. d p =2mm, texture depth h p =c=0.019mm, texture area ratio S p =50.27%.

[0122] Those skilled in the art will understand that, since the sliding bearing is a circular rotating body, and the texture is machined on the bore wall of the sliding bearing, to ensure the relative position between the texture and the rotating shaft, the texture machining can be performed based on the target texture parameters after they are determined, and a horizontal assembly line can be machined on the outer cylindrical end face of the sliding bearing. During the installation of the sliding bearing, the horizontal assembly line is calibrated using a level to ensure that the sliding bearing is installed in the target position.

[0123] For example, step S14 includes sub-steps S14-1 to S14-3, which are described in detail below:

[0124] S14-1. Texture parameter combinations whose oil film bearing capacity is greater than the working load are determined as optional texture parameters. The oil film bearing capacity of the optional texture parameters meets the requirements of the working load, and the oil film will not rupture prematurely under the working load, thus ensuring the lubrication effect of the sliding bearing and the shaft.

[0125] Furthermore, the texture parameters also include the texture coverage angle extending from the cutoff position to the maximum gap position; please refer to [link to relevant documentation]. Figure 2The texture coverage angle is the central angle extending from point C to point A. The determination method also includes: determining the target coverage angle for each set of optional texture parameters based on the correlation between different texture coverage angles and the frictional characteristics and oil film bearing capacity of the optional texture parameters. The target coverage angle is the texture coverage angle among the optional texture parameters where the oil film bearing capacity meets the working load, and the corresponding frictional characteristics are optimal or second-optimal.

[0126] Similarly, the size of the texture coverage angle affects both frictional characteristics and oil film load-bearing capacity. The texture coverage angle determines whether the texture is in the region that effectively regulates the oil film. By anchoring the coverage angle at the oil film cutoff position and extending it towards the direction of maximum gap, it is possible to ensure that the texture effect occurs in the critical diffusion zone of the oil film, thereby improving frictional performance while maintaining the necessary load-bearing capacity.

[0127] The angular region between the cutoff position and the maximum clearance position can be considered as the effective arrangement area of ​​the texture. Within this region, the coverage angle is gradually extended according to different combinations of texture parameters, and friction performance is evaluated. During the evaluation process, analysis is first performed based on fluid lubrication theory and the Reynolds equation to confirm that the oil film's load-bearing capacity at the selected coverage angle meets the requirements of the actual working load. Further screening is conducted among multiple coverage angles that meet the load-bearing conditions to select the texture parameter combination with superior friction characteristics. If an excessively large coverage angle leads to a high texture area ratio, negatively impacting processing feasibility and load-bearing stability, the texture coverage angle is appropriately reduced to ensure a reasonable selection.

[0128] S14-2. All optional texture parameters are sorted in descending order based on a comprehensive score of friction characteristics and operating temperature rise. Friction characteristics are usually directly related to the shaft surface temperature, but due to differences in oil film thickness under different texture parameters, the operating temperature rise cannot be derived solely from friction characteristics. The operating temperature rise characterizes the temperature increase between the sliding bearing and the shaft as the operating time increases under the corresponding optional texture parameters. Especially at higher operating speeds, excessive temperature rise may lead to a decrease in lubricating oil viscosity, thereby reducing the oil film's load-bearing capacity.

[0129] It should be noted that during operation, the oil film of a sliding bearing is subjected to shearing action by the rotating shaft, resulting in viscous friction within the oil film and thus frictional power consumption. Frictional power consumption can be estimated by multiplying the frictional force by the operating speed; alternatively, it can be calculated by integrating the distribution of viscous shear dissipation in the oil film, thereby yielding the operating temperature rise. A weighted score can be calculated based on friction characteristics and operating temperature rise. For example, the friction characteristics and operating temperature rise can be normalized using the minimum-maximum method, with a friction weight of 0.7 and a temperature rise weight of 0.3. The weighted calculation yields a comprehensive score, which is then sorted in descending order.

[0130] S14-3. Assess the texture blockage risk of the texture parameter combinations ranked first in descending order using a preset position, and determine the texture parameter combination with the lowest blockage risk as the target texture parameter for the sliding bearing. The preset position can be determined based on the total number of calculation results; for example, if the total number is greater than 10, set the preset position to 5. Assess the texture blockage risk of the 5 texture parameter combinations.

[0131] When a shaft operates within a sliding bearing, the lubricating oil mixes with impurities generated by friction to form sludge. This sludge can clog the texture of the pit structure. Therefore, conducting a texture clogging risk assessment on the texture parameters can reduce poor lubrication caused by sludge clogging. The trend assessment of texture clogging can be based on the experience of technicians; alternatively, calibration experiments can be conducted based on the influencing factors of texture clogging to obtain corresponding experimental data. A neural network model can then be trained based on this data. After training, the model can be used to assess the clogging risk, and the texture parameter with the lowest clogging risk among the preset combinations of texture parameters can be determined as the target texture parameter.

[0132] For example, sub-step S14-3 includes:

[0133] The first step is to determine the impurity deposition coefficient for each combination of texture parameters in the preset order, based on the oil film flow rate in the diffusion gap region and the pre-defined texture parameters in descending order. The flow rate of the oil film in the diffusion gap region reflects the fluid's ability to scour the textured area. If the flow rate is low, suspended impurity particles are more likely to deposit in the texture, leading to a risk of clogging. The impurity deposition coefficient for each parameter combination can be calculated based on the texture diameter, texture depth, texture area ratio, and the corresponding oil film flow rate. The smaller the coefficient, the stronger the oil film's ability to carry impurities through the texture, and the lower the likelihood of clogging; conversely, a larger coefficient indicates that the texture is prone to becoming an impurity retention point, posing a potential clogging risk during operation. Similarly, a calculation model can be formulated based on the relationship between texture parameters, oil film flow rate, and impurity deposition coefficient. For example, a hydrodynamic model or risk index model can be formulated for calculation to predict the corresponding impurity deposition coefficient; no specific restrictions are imposed here.

[0134] The second step involves determining the texture parameter combination corresponding to the smallest coefficient among all impurity deposition coefficients as the target texture parameter for the sliding bearing. These coefficients are compared, and the texture parameter combination corresponding to the smallest value is selected. This combination satisfies the working load requirements and friction characteristic optimization conditions while also having the lowest risk of texture clogging, thus balancing lubrication performance and long-term operational reliability.

[0135] Based on the same technical concept as the determination method, embodiments of the present invention also provide a system for determining the surface texture parameters of a sliding bearing, the system being used to implement any of the determination methods described above. Please refer to... Figure 11 The system includes a first determining module 101, an obtaining module 102, a second determining module 103, and a third determining module 104.

[0136] The first determining module 101 is used to determine, based on the operating speed and operating load of the shaft assembled inside the sliding bearing, the convergent gap region and the diffuse gap region divided by the maximum gap position and the minimum gap position during the operation of the shaft, as well as the cross-sectional dataset characterizing the relative position of the sliding bearing and the shaft.

[0137] The module 102 is used to analyze the oil film pressure distribution based on the operating speed, operating load and cross-section dataset, combined with the Reynolds equation, so as to obtain the cutoff position of the oil film overflowing from the convergence gap region to the diffusion gap region.

[0138] The second determining module 103 is used to configure multiple texture parameters of the local diffusion gap region from the cutoff position to the direction of the maximum gap position, and to determine the friction characteristics and oil film bearing capacity under each texture parameter. Each texture parameter includes texture diameter, texture depth and texture area ratio.

[0139] The third determining module 104 is used to optimize the friction characteristics based on the oil film bearing capacity that meets the working load, so as to determine the texture parameters corresponding to the optimal friction characteristics as the target texture parameters of the sliding bearing.

[0140] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0141] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for determining the surface texture parameters of a sliding bearing, characterized in that, The method includes: Based on the operating speed and operating load of the shaft assembled in the sliding bearing, determine the convergence gap region and diffusion gap region divided by the maximum gap position and the minimum gap position when the shaft is running, as well as the cross-sectional data set characterizing the relative position of the sliding bearing and the shaft; Based on the operating speed, the operating load, and the cross-sectional dataset, the oil film pressure distribution is analyzed using the Reynolds equation to obtain the cutoff position where the oil film overflows from the convergence gap region to the diffusion gap region; this includes: converting the Reynolds equation, which is based on fluid lubrication theory, into a dimensionless form; inputting the operating speed, the operating load, and the cross-sectional dataset into the dimensionless Reynolds equation; and using the finite difference method to solve for the oil film pressure distribution in the convergence gap region. The oil film overflow coefficient is obtained based on the surface roughness of the contact surface between the sliding bearing and the rotating shaft, the operating speed, and the operating load. Based on the oil film pressure distribution in the convergence gap region and the oil film overflow coefficient, determine the cutoff position where the oil film overflows from the convergence gap region to the diffusion gap region; Starting from the cutoff position, configure the local multi-structure parameters of the diffusion gap region in the direction of the maximum gap position, and determine the friction characteristics and oil film bearing capacity under each structure parameter. Each structure parameter includes the texture diameter, texture depth and texture area ratio. The friction characteristics are optimized based on the oil film bearing capacity that satisfies the working load, so that the texture parameters corresponding to the optimal friction characteristics are determined as the target texture parameters of the sliding bearing. The step of obtaining the oil film overflow coefficient based on the surface roughness of the contact surface between the sliding bearing and the rotating shaft, the operating speed, and the operating load includes: Based on the first surface roughness and first material hardness of the sliding bearing, and the second surface roughness and second material hardness of the rotating shaft, a first coefficient characterizing the degree of oil film overflow associated with the contact surface roughness is obtained; The second and third coefficients are obtained based on the deviations between the operating speed and the operating load and the reference speed and reference load set by the Reynolds equation, respectively. The oil film overflow coefficient is obtained based on the first coefficient, the second coefficient, the third coefficient, and the overflow flow rate generated by the oil film under smooth conditions.

2. The method for determining the surface texture parameters of a sliding bearing according to claim 1, characterized in that, Before determining the convergence gap region and diffusion gap region divided by the maximum and minimum gap positions during the operation of the rotating shaft, the method further includes: Obtain the initial eccentricity and initial offset angle between the sliding bearing and the rotating shaft; Estimate the current bearing capacity of the oil film based on the initial eccentricity and the initial offset angle; If the current bearing capacity is less than or equal to the working load, the initial eccentricity and initial offset angle are modified and re-estimated until the current bearing capacity is greater than the working load, so as to obtain the target eccentricity and target offset angle. Update the target eccentricity and the target offset angle to the cross-sectional dataset.

3. The method for determining the surface texture parameters of a sliding bearing according to claim 1, characterized in that, Configuring the local multi-structure parameters of the diffusion gap region includes: The first range of the texture diameter is configured based on the oil film thickness and corresponding oil film tension at the cutoff position; The second range of the texture depth is configured according to the monotonically increasing segment of the depth bearing capacity curve, wherein the depth bearing capacity curve is the curve of the texture depth as a function of the oil film bearing capacity. The first range is interval-valued according to a preset first interval value to obtain a first array of texture diameters; The second range is interval-valued according to a preset second interval value to obtain a second array of texture depths, wherein the first interval value is greater than the second interval value; The data is combined based on at least one set value of the first array, the second array, and the texture area ratio to obtain the multi-texture parameters.

4. The method for determining the surface texture parameters of a sliding bearing according to claim 3, characterized in that, Before combining data based on at least one set value of the first array, the second array, and the texture area ratio to obtain the multi-texture parameters, the method further includes: Multiple dimensionless bearing curves of the sliding bearing are obtained. Each dimensionless bearing curve is a curve showing the change of the texture area ratio with the dimensionless oil film bearing capacity at a set texture depth. The target area ratio is determined based on the monotonically increasing corresponding texture area ratio of each dimensionless bearing curve. The set value of the fabric area ratio is determined based on a first set range consisting of all target area ratios and a second set range that satisfies the fabric processing efficiency.

5. The method for determining the surface texture parameters of a sliding bearing according to claim 1, characterized in that, The step of optimizing friction characteristics based on the oil film bearing capacity that satisfies the working load, and determining the texture parameters corresponding to the optimal friction characteristics as the target texture parameters of the sliding bearing, includes: The combination of texture parameters whose oil film bearing capacity is greater than the working load is determined as optional texture parameters; All optional texture parameters are sorted in descending order based on a comprehensive score of friction characteristics and operating temperature rise; The texture parameter combinations ranked at the top of the descending order are evaluated for texture blockage risk, and the texture parameter combination with the lowest blockage risk is determined as the target texture parameter of the sliding bearing.

6. The method for determining the surface texture parameters of a sliding bearing according to claim 5, characterized in that, The texture parameters also include a texture coverage angle extending from the cutoff position to the maximum gap position; before sorting all optional texture parameters in descending order according to a comprehensive score of friction characteristics and operating temperature rise, the method further includes: Based on the correlation between the frictional characteristics and oil film bearing capacity of the optional texture parameters under different texture coverage angles, the target coverage angle for each set of optional texture parameters is determined.

7. The method for determining the surface texture parameters of a sliding bearing according to claim 5, characterized in that, The step of evaluating the texture blockage risk of the texture parameter combinations ranked in descending order and determining the texture parameter combination with the lowest blockage risk as the target texture parameter of the sliding bearing includes: Based on the texture parameters at the top of the preset order in descending order and the oil film flow rate in the diffusion gap region, the impurity deposition coefficient of each texture parameter combination in the preset order is determined. The texture parameters corresponding to the smallest coefficient among all impurity deposition coefficients are combined to determine the target texture parameters of the sliding bearing.

8. A system for determining the surface texture parameters of a sliding bearing, characterized in that, The system is used to implement the determining method according to any one of claims 1-7, and the system comprises: The first determining module is used to determine, based on the operating speed and operating load of the rotating shaft assembled in the sliding bearing, the convergence gap region and the diffusion gap region divided by the maximum gap position and the minimum gap position when the rotating shaft is running, as well as the cross-sectional data set characterizing the relative position of the sliding bearing and the rotating shaft; The module is used to analyze the oil film pressure distribution based on the operating speed, the operating load and the cross-sectional dataset, combined with the Reynolds equation, so as to obtain the cutoff position of the oil film overflowing from the convergence gap region to the diffusion gap region. The second determining module is used to configure multiple texture parameters of the diffusion gap region in the direction from the cutoff position to the maximum gap position, and to determine the friction characteristics and oil film bearing capacity under each texture parameter. Each texture parameter includes texture diameter, texture depth and texture area ratio. The third determining module is used to optimize the friction characteristics based on the oil film bearing capacity that satisfies the working load, so as to determine the texture parameters corresponding to the optimal friction characteristics as the target texture parameters of the sliding bearing.

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