A method and system for optimizing surface texture of a continuous-rotation electro-hydraulic servo motor

Abstract

A method and system for optimizing the surface texture of a continuous-rotating electro-hydraulic servo motor, relating to the field of electro-hydraulic servo motor optimization. The method solves the problem in the prior art that algorithm compensation cannot fundamentally reduce the friction and wear of the motor. The method includes: establishing a numerical solution model for circular, diamond-shaped, and special-shaped micro-textures on the blades of a continuous-rotating electro-hydraulic servo motor, as well as the oil film bearing capacity and leakage; using the NSGA‑II algorithm with the micro-texture oil film bearing capacity and leakage as the objective function to solve the optimal geometric morphology parameters of the micro-texture; performing finite element simulation based on the optimal geometric morphology parameters of the micro-texture and the three-dimensional model of the micro-texture oil film, obtaining the bearing capacity and leakage results of the oil film, and comparing and selecting the optimal geometric morphology parameters of the micro-texture to determine the texture shape applied to the friction pair on the surface of the blade of the continuous-rotating electro-hydraulic servo motor. The present invention improves the comprehensive performance of the key friction pair of the blades of the continuous-rotating electro-hydraulic servo motor.

Description

Technical Field

[0001] The present invention relates to the field of electro-hydraulic servo motor optimization, and in particular to a method for optimizing the surface texture of a continuous-rotation electro-hydraulic servo motor. Background Art

[0002] The friction mechanism of the friction pairs in a continuous-rotation electro-hydraulic servo motor is as follows: A continuous-rotation electro-hydraulic servo motor primarily consists of blades, a stator, a rotor, an oil distribution plate, an end cap, and a sleeve. The primary contact friction pairs exist between the blade tip and the inner surface of the stator, between the blade and the blade slot, between the blade end face and the oil distribution plate, and between the rotor end face and the oil distribution plate. For vane motors, the friction between the blade and the distribution plate is the dominant factor in determining the motor's friction performance. Furthermore, the blade-distribution friction pair consists of the blade end face friction surface and the stator distribution surface. Surface microtextures of varying morphologies are designed on the blade end face.

[0003] The blade-distributor friction pair is a key component in electro-hydraulic servo motors, impacting their performance and lifespan. Friction converts energy into heat, increasing system energy losses. This reduces system efficiency, requiring more energy input to achieve the same work. Furthermore, friction causes surface wear on components like the blades and distributor, which accumulates over time and can lead to component failure. Long-term high friction increases component fatigue and shortens the motor's lifespan. Friction also generates heat, raising the motor's operating temperature. Excessively high temperatures can affect system stability and reliability and may even cause component failure.

[0004] Existing technologies measure friction in real time and compensate for it in control algorithms. However, friction is difficult to measure accurately, and generally only a total resistance including friction and other factors can be collected. Moreover, algorithmic compensation cannot fundamentally reduce motor friction and wear, nor can it improve performance and reliability. Summary of the Invention

[0005] In view of the problem that algorithm compensation in the prior art cannot fundamentally reduce the friction and wear of the motor, the present invention proposes a method for optimizing the surface texture of a continuous rotation electro-hydraulic servo motor, the method comprising:

[0006] Establish a numerical model for the circular, diamond, and irregular micro-textures on the blades of a continuous-rotation electro-hydraulic servo motor, as well as the oil film bearing capacity and leakage rate;

[0007] The NSGA-II algorithm is used to solve the optimal geometric parameters of the micro-texture with the bearing capacity and leakage of the micro-texture oil film as the objective function;

[0008] Finite element simulation was performed based on the optimal geometric parameters of the microtexture and the three-dimensional model of the microtexture oil film to obtain the bearing capacity and leakage results of the oil film. The results were then compared with the optimal geometric parameters of the microtexture to determine the texture shape applied to the friction pair on the blade surface of the continuous rotation electro-hydraulic servo motor.

[0009] Furthermore, a preferred embodiment is proposed, in which the mathematical model of the circular texture is:

[0010]

[0011] Where r is the actual radius of the circular pit, (x c ,y c ) are the coordinates of the center of the computational domain, and (x,y) are the coordinates of the origin.

[0012] Furthermore, a preferred embodiment is proposed, wherein the diamond texture is composed of a single diamond-shaped pit located in the center of the calculation domain, and the shape is determined by the lengths of the two diagonal lines d1 and d2:

[0013] The two diagonals are obtained by calculating the ratio of the length of the computational domain side, D(1) and D(2), where the length of the computational domain side is L;

[0014] The four vertices of the diamond-shaped pit are located at:

[0015]

[0016] Where d1 = D(1)·L and d2 = D(2)·L are the actual lengths of the horizontal and vertical diagonals, respectively, and L is the side length of the computational domain.

[0017] Furthermore, a preferred embodiment is proposed, in which the polar coordinates of each point of the special-shaped micro-texture are determined by the ratio of the actual radial length to the side length of the calculation domain.

[0018] Furthermore, a preferred method is proposed, wherein the numerical solution model for the oil film bearing capacity and leakage is:

[0019] The Reynolds equation used in the numerical solution of oil film is:

[0020]

[0021] Where p represents the pressure distribution, h is the oil film thickness, μ represents the dynamic viscosity of the fluid, U is the relative velocity, x and y are the spatial coordinates in the plane, and t is the time;

[0022] The calculation formula of membrane bearing capacity is:

[0023]

[0024] Where W is the bearing capacity of the oil film, and p(x,y) is the pressure distribution on the oil film surface;

[0025] The flow rate of the oil film in the x and y directions is expressed by the following formulas:

[0026]

[0027]

[0028] Among them, Q x is the flow rate of oil film per unit width in the x direction, Q y is the flow rate of the oil film per unit width in the y direction, H is the thickness of the oil film, η is the dynamic viscosity of the fluid, and is the pressure gradient on the oil film surface;

[0029] When considering the leakage of the outlet in the x direction, by accumulating Q along the outlet boundary x To calculate:

[0030] leakage x =∑Q x (end)

[0031] Among them, leakage x is the leakage of the outlet in the x direction, and end is the outlet boundary.

[0032] Furthermore, a preferred method is proposed, wherein the method of solving the optimal geometric parameters of the microtexture includes:

[0033]

[0034] Where p(x,y) represents the pressure distribution on the oil film surface, ∑Q x (end)+∑Q y (end) indicates the leakage amount, g i (x,y) represents the constraints, and m is the number of constraints;

[0035] The load-bearing capacity W is integrated Indicates that the leakage Q is accumulated by the flow leakage on the boundary x =∑Q x (end)Calculated.

[0036] Based on the same inventive concept, the present invention also proposes a system for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor, the system comprising:

[0037] A solution construction unit is used to establish a numerical solution model for circular, diamond, and special-shaped micro-textures on the blades of a continuous-rotation electro-hydraulic servo motor, as well as the oil film bearing capacity and leakage;

[0038] A geometrical morphology parameter acquisition unit is used to solve the optimal geometrical morphology parameters of the micro-texture using the NSGA-II algorithm with the micro-texture oil film bearing capacity and leakage as the objective function;

[0039] The texture shape determination unit is used to perform finite element simulation based on the optimal geometric morphology parameters of the micro-texture and the three-dimensional model of the micro-texture oil film, obtain the bearing capacity and leakage results of the oil film, and compare and select the optimal geometric morphology parameters of the micro-texture to determine the texture shape applied to the friction pair of the blade surface of the continuous rotation electro-hydraulic servo motor.

[0040] Based on the same inventive concept, the present invention also proposes a computer device, including a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a method for optimizing the surface texture of a continuous rotating electro-hydraulic servo motor as described in any one of the above items.

[0041] Based on the same inventive concept, the present invention also proposes a computer-readable storage medium, which is used to store a computer program, and the computer program executes any one of the above-mentioned methods for optimizing the surface texture of a continuous rotation electro-hydraulic servo motor.

[0042] The present invention is beneficial in that:

[0043] Traditional algorithmic compensation methods struggle to fundamentally reduce motor friction and wear. However, this paper proposes a surface texture optimization method for continuous-rotation electro-hydraulic servo motors that directly reduces friction and wear by optimizing the surface microtexture, thereby addressing the problem at its source. Optimization using the NSGA-II algorithm allows for customized microtexture design based on specific application scenarios and requirements, balancing different objective functions. This improves motor performance and efficiency under specific operating conditions.

[0044] The present invention proposes a method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor. Through finite element simulation, the micro-texture design can be verified and optimized to ensure the effectiveness and reliability of the design, thereby improving the practicality and operability of the solution.

[0045] The present invention proposes a method for optimizing the surface texture of a continuous-rotation electro-hydraulic servo motor. This method takes the load-bearing capacity and leakage of the micro-textured oil film as objective functions, comprehensively considering the load-bearing capacity of the oil film and the influence of the micro-texture on leakage, thereby taking into account both motor performance and lubrication effect in the optimized design.

[0046] The present invention proposes a method for optimizing the surface texture of a continuous-rotating electro-hydraulic servo motor, which uses a surface micro-texture optimization method to improve the electro-hydraulic servo motor. This method is different from the principles of the existing technology and proposes a different technical concept, which is expected to bring new development directions and solutions to the field of electro-hydraulic servo motors.

[0047] The present invention applies micro-texturing technology to the surface of the blades of a continuous-rotation electro-hydraulic servo motor to meet the application requirements of reducing friction while controlling leakage. A multi-objective optimization algorithm is used to optimize the morphological parameters of the micro-texture with the goal of maximizing the oil film bearing capacity and minimizing the leakage, so as to achieve the purpose of improving the motor performance.

[0048] The present invention designs a geometric design method for special-shaped textures to solve the problem of insufficient freedom in the design of micro-texture morphology. It can greatly expand the optimization range of the optimization algorithm and make the designed texture morphology have better comprehensive performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a flow chart of a method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor according to the first embodiment;

[0050] Figure 2 Schematic diagram of the continuous rotation electro-hydraulic servo motor according to embodiment 1;

[0051] Figure 3 Schematic diagram of circular texture according to the second embodiment, wherein p1 and p2 are the oil pressure in and out, AC is the long radius, BD is the short radius, and p g Oil pressure at the blade root;

[0052] Figure 4 This is a schematic diagram of the diamond texture described in the third embodiment;

[0053] Figure 5 Schematic diagram of the special-shaped texture described in the fourth embodiment;

[0054] Figure 6 Schematic diagram of the micro-textured oil film model according to the fifth embodiment, wherein h0 is the initial oil film thickness, h max is the pit thickness, Pit is the pit range;

[0055] Figure 7 This is a schematic diagram of the optimization result described in the sixth embodiment;

[0056] Figure 8 Schematic diagram of boundary condition settings for finite element simulation according to the tenth embodiment;

[0057] Figure 9 This is a pressure distribution diagram of the finite element simulation according to the tenth embodiment, wherein: Figure 9(a) CFD simulation pressure distribution diagram representing the first solution, Figure 9 (b) CFD simulation pressure distribution diagram representing the second solution, Figure 9 (c) represents the CFD simulation pressure distribution diagram of the third solution. Figure 9 (d) represents the CFD simulation pressure distribution diagram of the fourth solution. Figure 9 (e) represents the CFD simulation pressure distribution diagram of the fifth solution. Figure 9 (f) represents the CFD simulation pressure distribution diagram of the 6th solution. Figure 9 (g) represents the CFD simulation pressure distribution diagram of the 7th solution. Figure 9 (h) represents the CFD simulation pressure distribution diagram of the 8th solution. Figure 9 (i) represents the CFD simulation pressure distribution diagram of the 9th solution, Figure 9 (j) represents the CFD simulation pressure distribution diagram of the 10th solution. Figure 9 (k) represents the CFD simulation pressure distribution diagram of the 11th solution;

[0058] Figure 10 This is a comparison chart between the finite element simulation results and the MATLAB results described in the tenth embodiment. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0060] Implementation method 1, see Figure 1 and Figure 2 This embodiment describes a method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor, the method comprising:

[0061] Establish a numerical model for the circular, diamond, and irregular micro-textures on the blades of a continuous-rotation electro-hydraulic servo motor, as well as the oil film bearing capacity and leakage rate;

[0062] The NSGA-II algorithm is used to solve the optimal geometric parameters of the micro-texture with the bearing capacity and leakage of the micro-texture oil film as the objective function;

[0063] Finite element simulation was performed based on the optimal geometric parameters of the microtexture and the three-dimensional model of the microtexture oil film to obtain the bearing capacity and leakage results of the oil film. The results were then compared with the optimal geometric parameters of the microtexture to determine the texture shape applied to the friction pair on the blade surface of the continuous rotation electro-hydraulic servo motor.

[0064] Specifically, the method proposed in this embodiment first establishes micro-textures of different shapes such as circular, diamond, and special shapes on the blades of the continuous rotation electro-hydraulic servo motor, and establishes numerical solution models for the oil film bearing capacity and leakage. These models are used to evaluate the influence of different micro-texture shapes on the oil film performance. The NSGA-II (Non-dominated Sorting Genetic Algorithm II) algorithm is used as an optimization tool, and the micro-texture oil film bearing capacity and leakage are used as objective functions. Through this algorithm, the optimal geometric morphology parameters of the micro-texture can be found within the framework of multi-objective optimization to achieve the purpose of reducing friction and wear. According to the optimal geometric morphology parameters of the micro-texture, finite element simulation is performed on the three-dimensional model of the oil film. Through simulation, the bearing capacity and leakage of the oil film can be evaluated, and the simulation results can be compared with the optimal morphology parameters of the micro-texture for selection. Combining the simulation results and the optimization results, the optimal micro-texture shape suitable for the friction pair on the surface of the blade of the continuous rotation electro-hydraulic servo motor is determined.

[0065] This embodiment can reduce the friction and wear between the blades and the distribution plate by optimizing the shape of the micro-texture, thereby improving the efficiency and life of the motor. The NSGA-II algorithm can balance multiple objectives, thereby realizing micro-texture design for specific application scenarios and improving the degree of customization of the design. Through finite element simulation, the effectiveness of the micro-texture design can be verified, and the micro-texture shape can be further optimized based on the simulation results to ensure the accuracy and reliability of the design. The design principle of micro-texture is based on the theory of oil film lubrication and the foundation of surface engineering. By introducing tiny concave and convex structures on the surface of the blade, the formation and distribution of the oil film can be changed, thereby regulating friction and wear. The goal of optimizing the shape of the micro-texture is to minimize friction while ensuring sufficient oil film bearing capacity to ensure good lubrication and contact performance between the blade and the distribution plate. As a multi-objective optimization algorithm, the NSGA-II algorithm can effectively explore the design space and find the optimal micro-texture shape to balance the contradiction between friction and oil film bearing capacity.

[0066] Implementation method 2, see Figure 3 This embodiment further defines the method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor described in the first embodiment. The mathematical model of the circular texture is:

[0067]

[0068] Where r is the actual radius of the circular pit, (x c ,y c ) are the coordinates of the center of the computational domain, and (x,y) are the coordinates of the origin.

[0069] Circular dimples are used as a microtexture. Through a specific mathematical model, the shape and size of the microtexture can be more accurately designed and controlled, thereby optimizing friction and lubrication performance. As a simple yet effective microtexture, circular dimples are suitable for a variety of electro-hydraulic servo motor applications. This type of microtexture offers great versatility, meeting the friction and lubrication requirements of various operating conditions.

[0070] Implementation method three, see Figure 4 This embodiment further defines the method for optimizing the surface texture of a continuous-rotation electro-hydraulic servo motor described in Embodiment 1. The diamond texture is composed of a single diamond-shaped pit located at the center of the computational domain, and its shape is determined by the lengths of two diagonal lines d1 and d2:

[0071] The two diagonals are obtained by calculating the ratio of the length of the computational domain side, D(1) and D(2), where the length of the computational domain side is L;

[0072] The four vertices of the diamond-shaped pit are located at:

[0073]

[0074] Where d1 = D(1)·L and d2 = D(2)·L are the actual lengths of the horizontal and vertical diagonals, respectively, and L is the side length of the computational domain.

[0075] Compared with circular texture, diamond texture has more geometric shape variations because the boundary of the diamond is composed of two diagonal lines, and diamonds of different shapes can be achieved by adjusting the length ratio of the diagonal lines. This makes the design of micro-texture more flexible and can be customized according to the needs of specific application scenarios. By adjusting the length ratio of the diagonal lines, the shape and size of the diamond pits can be precisely controlled. This precise controllability makes it possible to better optimize the friction and lubrication properties of the micro-texture, thereby improving the efficiency and performance of the electro-hydraulic servo motor. The design of the diamond pits can provide a more optimized surface contact shape to a certain extent, thereby improving the friction characteristics and lubrication performance. This optimization may lead to lower energy loss and longer equipment life, which is particularly important for equipment such as electro-hydraulic servo motors that require efficient operation and long-term stability.

[0076] Implementation method 4, see Figure 5 This embodiment further defines the method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor described in the first embodiment. The polar coordinates of each point of the irregular micro-texture are determined by the ratio of the actual radial length to the side length of the calculation domain R1, R2, R3...R n Sure.

[0077] In this embodiment, L is the side length of the calculation domain, and the number of R is n. These two can be adjusted in the preset parameters to meet different needs. For example, if you want the texture to be less difficult to process and reduce the computational cost of the optimization algorithm, you can lower the value of n. Adjusting the texture density can be achieved by adjusting L. Moreover, it is easy to modify the program through proportion, without redesigning the upper and lower limits of R, thus simplifying the design process.

[0078] In this implementation, the parameter n is fixed at 5, which reduces the computational complexity. This is because determining the polar coordinates of each point on the irregular microtexture requires only the ratio of the actual radial length to the computational domain side length, eliminating the need for additional complex calculations. This simplified calculation process improves algorithm execution efficiency, reduces computation time, and ultimately results in faster optimization results.

[0079] By fixing n to 5, a balance between accuracy and computational efficiency is achieved. Smaller values ​​of n may reduce the accuracy of the calculations, but for practical applications, this loss of accuracy may be acceptable, especially when the computational effort is significantly reduced. Therefore, this approach takes into account the need to minimize computational cost while ensuring the quality of the results. Fixing n to 5 ensures consistent results in different situations. This consistency is crucial for repeatability and stability in design and production processes because it ensures that microtextures obtained under different conditions have similar performance characteristics, thereby reducing risks and uncertainties in practical applications.

[0080] Implementation method five, see Figure 6 This embodiment further defines the method for optimizing the surface texture of a continuous rotation electro-hydraulic servo motor described in Embodiment 1. The numerical solution model for the oil film bearing capacity and leakage is:

[0081] The Reynolds equation used in the numerical solution of oil film is:

[0082]

[0083] Where p represents the pressure distribution, h is the oil film thickness, μ represents the dynamic viscosity of the fluid, U is the relative velocity, x and y are the spatial coordinates in the plane, and t is the time;

[0084] The calculation formula of membrane bearing capacity is:

[0085]

[0086] Where W is the bearing capacity of the oil film, and p(x,y) is the pressure distribution on the oil film surface;

[0087] The flow rate of the oil film in the x and y directions is expressed by the following formulas:

[0088]

[0089]

[0090] Among them, Q x is the flow rate of oil film per unit width in the x direction, Q y is the flow rate of the oil film per unit width in the y direction, H is the thickness of the oil film, η is the dynamic viscosity of the fluid, and is the pressure gradient on the oil film surface;

[0091] When considering the leakage of the outlet in the x direction, by accumulating Q along the outlet boundary x To calculate:

[0092] leakage x =∑Q x (end)

[0093] Among them, leakage x is the leakage of the outlet in the x direction, and end is the outlet boundary.

[0094] This implementation utilizes fluid mechanics principles such as the Reynolds equation to establish numerical models for the oil film's load-bearing capacity and leakage. These equations account for factors such as pressure distribution, oil film thickness, and dynamic viscosity, and can more accurately describe the oil film's behavior on the blade surface. By employing the NSGA-II algorithm and using oil film load-bearing capacity and leakage as objective functions, this method achieves multi-objective optimization of the optimal geometric parameters of the microtexture. This approach not only considers maximizing the oil film's load-bearing capacity but also minimizing leakage, making the texture design more comprehensive and rational.

[0095] After determining the optimal microtexture parameters, finite element simulation can be used to verify the oil film's load-bearing capacity and leakage under actual operating conditions. This simulation helps confirm the effectiveness of the optimal microtexture parameters, thereby improving the reliability and feasibility of the design. This implementation also considers oil film leakage at the outlet, calculating the leakage at the outlet boundary by cumulatively calculating the leakage. This consideration makes the model more realistic and enhances the comprehensiveness and practicality of the design.

[0096] Implementation method six, see Figure 7 This embodiment further defines the method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor described in Embodiment 1, wherein the method for determining the optimal geometric parameters of the micro-texture includes:

[0097]

[0098] Where p(x,y) represents the pressure distribution on the oil film surface, ∑Q x (end)+∑Q y (end) indicates the leakage amount, g i (x,y) represents the constraints, and m is the number of constraints;

[0099] The load-bearing capacity W is integrated Indicates that the leakage Q is accumulated by the flow leakage on the boundary x =∑Q x (end)Calculated.

[0100] This embodiment is described in conjunction with the fifth embodiment. Using the NSGAII algorithm, the micro-texture morphology parameters are optimized with the oil film bearing capacity and leakage as the target, and several optimal texture morphologies are obtained. Figure 7 In order to optimize the results, comparative analysis and screening were carried out to obtain the optimal geometric morphology parameters of the microtexture.

[0101] This embodiment takes into account factors such as the pressure distribution and leakage on the oil film surface, and the method can comprehensively consider the impact of multiple key factors on the performance of the microtexture. Such comprehensive consideration can ensure that the designed microtexture achieves the optimal level of performance in all aspects. By adjusting the number of constraints, the design of the microtexture can be flexibly controlled. This flexibility makes the design process more controllable and can meet the needs of different application scenarios. Since factors such as the pressure distribution and leakage on the oil film surface are taken into account, this method is applicable to different types of continuous rotation electro-hydraulic servo motors, and is not limited to motors of specific types or specifications.

[0102] Embodiment 7: A system for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor according to this embodiment, the system comprises:

[0103] A solution construction unit is used to establish a numerical solution model for circular, diamond, and special-shaped micro-textures on the blades of a continuous-rotation electro-hydraulic servo motor, as well as the oil film bearing capacity and leakage;

[0104] A geometrical morphology parameter acquisition unit is used to solve the optimal geometrical morphology parameters of the micro-texture using the NSGA-II algorithm with the micro-texture oil film bearing capacity and leakage as the objective function;

[0105] The texture shape determination unit is used to perform finite element simulation based on the optimal geometric morphology parameters of the micro-texture and the three-dimensional model of the micro-texture oil film, obtain the bearing capacity and leakage results of the oil film, and compare and select the optimal geometric morphology parameters of the micro-texture to determine the texture shape applied to the friction pair of the blade surface of the continuous rotation electro-hydraulic servo motor.

[0106] Embodiment 8. A computer device described in this embodiment includes a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a method for optimizing the surface texture of a continuous rotation electro-hydraulic servo motor as described in any one of Embodiments 1 to 6.

[0107] Embodiment 9. A computer-readable storage medium described in this embodiment is used to store a computer program, and the computer program executes the method for optimizing the surface texture of a continuous rotation electro-hydraulic servo motor described in any one of embodiments 1 to 6.

[0108] Implementation Method 10: See Figure 8 、 Figure 9 and Figure 10 This embodiment provides a specific example of the method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor described in the first embodiment, and is also used to explain the second to sixth embodiments. Specifically:

[0109] Step 1: To examine the performance characteristics of different texture morphologies, considering the reciprocating motion of the motor blades, different symmetrical morphologies were considered for comparison. Circular, diamond, and irregular microtextures were created on the blades of the continuous-rotation electro-hydraulic servo motor, and a numerical solution model for the oil film load-bearing capacity and leakage was established.

[0110] The mathematical model of circular texture can be expressed as:

[0111]

[0112] Where r = R·L is the actual radius of the circular pit, (x c ,y c ) is the coordinate of the center of the computational domain, set to (0,0).

[0113] The diamond texture consists of a single diamond-shaped pit located in the center of the computational domain. The diamond is a symmetrical shape, and its shape is determined by the lengths of the two diagonals d1 and d2. For the convenience of calculation, the two diagonals are calculated by the ratio D(1) and D(2) of the length of the computational domain side, and the length of the computational domain side is L. The four vertices of the diamond pit are located at: Where d1 = D(1)·L and d2 = D(2)·L are the actual lengths of the horizontal and vertical diagonals, respectively.

[0114] In order to solve the problem of insufficient freedom in texture design, this embodiment establishes a morphology design method for special-shaped textures. The polar coordinates of each point are determined by the ratio of the actual radial length to the side length L of the calculation domain R1, R2, R3...R nIn this embodiment, n is fixed to 5 to balance the accuracy and computational complexity and to ensure the consistency between the micro-texture morphology obtained in actual engineering applications and the results of the multi-objective optimization algorithm.

[0115] Before calculating the oil film pressure distribution, it is necessary to establish the corresponding film thickness equation, mainly considering the location of increasing the oil film thickness. The basic setting of the oil film thickness can be expressed as:

[0116]

[0117] The oil film thickness in the micro-texture area is adjusted to:

[0118]

[0119] Where h0 is the initial oil film thickness. The initial oil film thickness of the friction pair of the continuous rotary electro-hydraulic servo motor is 10 μm. H is the oil film thickness array. is the thickness of the oil film added in the micro-texture area, which is set to 10 μm for quantitative analysis in this study and is also the depth of the pit, while H inpit Indicates the thickness of the oil film in the pit.

[0120] The Reynolds equation used in the numerical solution of oil film is:

[0121]

[0122] Where p represents the pressure distribution, h is the oil film thickness, μ represents the dynamic viscosity of the fluid, U is the relative velocity, x and y are the spatial coordinates in the plane, and t is time.

[0123] We use the Reynolds equation to numerically solve the oil film. By integrating the pressure distribution across the entire computational domain, we can calculate the bearing capacity of the oil film surface. After numerically solving the Reynolds equation, we obtain the pressure distribution p(x,y) at each point on the oil film surface. The oil film bearing capacity is calculated by integrating the entire pressure distribution over the oil film surface area. This can be considered the sum of the bearing capacities of all small areas on the oil film. Therefore, the formula for calculating the oil film bearing capacity can be expressed as:

[0124]

[0125] In the above formula, W is the bearing capacity of the oil film, p(x,y) is the pressure distribution on the oil film surface, and L is the side length of the oil film calculation domain, which is 1000μm in this study. The bearing capacity value can be obtained by integrating the entire pressure field using the trapezoidal rule. When expressing the trapezoidal rule mathematically, the one-dimensional integral can be approximated as:

[0126]

[0127] Where x i+1 -x i is the interval between adjacent points, and It is the average of the function values ​​of two adjacent points, representing the area under the original function approximated by the area of ​​the trapezoid in each small interval.

[0128] Based on the pressure distribution p(x,y) obtained by solving the Reynolds equation, the calculation of oil film leakage first requires determining the pressure gradient and These gradients represent the rate of change of pressure on the oil film surface and are key factors in determining the direction and rate of fluid flow. The flow rate of the oil film in the x and y directions is expressed by the following formulas:

[0129]

[0130]

[0131] Where Q x and Q y are the flow rates of the oil film per unit width in the x and y directions, H is the oil film thickness, η is the dynamic viscosity of the fluid, and is the pressure gradient on the oil film surface.

[0132] When considering the leakage of the outlet in the x direction, it can be achieved by accumulating Q along the outlet boundary. x To calculate:

[0133] leakage x =∑Q x (end) (9)

[0134] Step 2: Using the NSGA-II algorithm and Matlab software, the optimal geometric parameters of the micro-texture are solved with the bearing capacity and leakage of the micro-texture oil film as the objective function;

[0135] For each texture morphology, the optimization problem can be expressed in the following general form:

[0136] min{-F load (·),Q leak (·)}

[0137] stg i (·)≤0,i=1,2,…,m (10)

[0138] In the formula, · represents the corresponding design parameters, g i (·) represents the constraints, and m is the number of constraints.

[0139] Combined with the mathematical model of bearing capacity and leakage established in the first step, it can be expressed as:

[0140]

[0141] Where p(x,y) represents the pressure distribution on the oil film surface, ∑Q x (end)+∑Q y (end) indicates the leakage amount, g i (x,y) represents the constraints, m is the number of constraints,

[0142] Bearing capacity W, available points Leakage Q is expressed by accumulating the flow leakage on the boundary x =∑Q x (end)Calculated.

[0143] Matlab software is required to design the NSGA-II algorithm. The population size is set to 100 and the maximum number of generations is 100, which determines the number of iterations of the algorithm and the scale of parallel search. After optimization, the geometric parameters of different texture morphology design methods can be obtained.

[0144] Step 3: Based on the obtained micro-texture geometric parameters, the Space Claim module in Ansys software was used to establish a three-dimensional model of the micro-textured oil film. Fluent Meshing was used to mesh the micro-textured oil film. Based on the actual working conditions of the continuous rotary electro-hydraulic servo motor, the corresponding boundary conditions were applied, and finite element simulation analysis was performed using Fluent to obtain the bearing capacity and leakage results of the oil film. The results were compared with the optimization results calculated by Matlab to determine the texture shape applied to the friction pair of the blade surface of the continuous rotary electro-hydraulic servo motor.

[0145] Several morphologies with excellent performance were selected for modeling, and finite element simulation analysis was performed using Fluent software. The boundary conditions were set as shown in Table 1, and the following results were obtained: Figure 8 and Figure 9 The simulation results are compared with the optimization results. Figure 10 Compare and analyze to verify whether the simulation results are consistent with the optimization results, and screen the optimal solution.

[0146] Table 1 Parameters of special-shaped texture morphology and their corresponding Fluent simulation results

[0147]

[0148] Although preferred embodiments of the present disclosure have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present disclosure. Obviously, those skilled in the art may make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if such changes and modifications of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is also intended to include such changes and modifications.

[0149] Those skilled in the art will appreciate that embodiments of the present disclosure may be provided as methods, systems, or computer program products. Thus, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0150] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including the instruction device, which implements the function specified in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure and are not intended to limit its scope of protection. Although the present disclosure has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present disclosure, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the disclosed claims.

Claims

1. A method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor, characterized in that: The method comprises: Establish a numerical solution model for circular, diamond, and special-shaped micro-textures on the blades of a continuous-rotation electro-hydraulic servo motor, as well as the oil film bearing capacity and leakage rate; The NSGA-II algorithm is used to solve the optimal geometric parameters of the micro-texture with the bearing capacity and leakage of the micro-texture oil film as the objective function; Finite element simulation was performed based on the optimal geometric parameters of the micro-texture and the three-dimensional model of the micro-texture oil film to obtain the bearing capacity and leakage of the oil film. The results were then compared with the optimal geometric parameters of the micro-texture to determine the texture shape for the friction pair on the blade surface of the continuous rotation electro-hydraulic servo motor. The numerical solution model for the oil film bearing capacity and leakage is: The Reynolds equation used in the numerical solution of oil film is: in, represents the pressure distribution, is the oil film thickness, represents the dynamic viscosity of the fluid, is the relative velocity, and is the spatial coordinate in the plane, For time; The calculation formula of membrane bearing capacity is: in, is the bearing capacity of the oil film, is the pressure distribution on the oil film surface; Oil film and The flow rates in the directions are expressed by the following formulas: in, The oil film per unit width is Traffic in the direction, The oil film per unit width is Traffic in the direction, is the oil film thickness, is the dynamic viscosity of the fluid, and is the pressure gradient on the oil film surface; Considering When leakage occurs in the outlet direction, the accumulated To calculate: in, for Leakage from the outlet, is the export boundary; Solve the optimal geometric parameters of the microtexture, including: in, represents the pressure distribution on the oil film surface, Indicates the leakage amount; Carrying capacity Use points Leakage By accumulating the flow on the boundary Calculated.

2. The method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor according to claim 1, characterized in that: The mathematical model of the circular texture is: in, is the actual radius of the circular pit, are the coordinates of the center of the computational domain, is the origin coordinate.

3. The method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor according to claim 1, characterized in that: The diamond texture consists of a single diamond-shaped pit located in the center of the computational domain, and its shape is composed of two diagonal lines. and The length is determined by: The two diagonals are determined by the ratio of the lengths of the computational domain sides. and The calculation domain side length is ; The four vertices of the diamond-shaped pit are located at: ， ， ， ， in, and are the actual lengths of the horizontal and vertical diagonals, respectively, is the side length of the computational domain.

4. The method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor according to claim 1, characterized in that: The polar coordinates of each point of the special-shaped micro-texture are determined by the ratio of the actual radial length to the side length of the calculation domain.

5. A system for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor, characterized in that: The system comprises: A solution construction unit is used to establish a numerical solution model for circular, diamond, and special-shaped micro-textures on the blades of a continuous-rotation electro-hydraulic servo motor, as well as the oil film bearing capacity and leakage; A geometrical morphology parameter acquisition unit is used to solve the optimal geometrical morphology parameters of the micro-texture using the NSGA-II algorithm with the micro-texture oil film bearing capacity and leakage as the objective function; The texture shape determination unit is used to perform finite element simulation based on the optimal geometric morphology parameters of the micro-texture and the three-dimensional model of the micro-texture oil film to obtain the bearing capacity and leakage results of the oil film, and then compare and select the optimal results with the optimal geometric morphology parameters of the micro-texture to determine the texture shape applied to the friction pair of the blade surface of the continuous rotation electro-hydraulic servo motor; The numerical solution model for the oil film bearing capacity and leakage is: The Reynolds equation used in the numerical solution of oil film is: in, represents the pressure distribution, is the oil film thickness, represents the dynamic viscosity of the fluid, is the relative velocity, and is the spatial coordinate in the plane, For time; The calculation formula of membrane bearing capacity is: in, is the bearing capacity of the oil film, is the pressure distribution on the oil film surface; Oil film and The flow rates in the directions are expressed by the following formulas: in, The oil film per unit width is Traffic in the direction, The oil film per unit width is Traffic in the direction, is the oil film thickness, is the dynamic viscosity of the fluid, and is the pressure gradient on the oil film surface; Considering When leakage occurs in the outlet direction, the accumulated To calculate: in, for Leakage from the outlet, is the export boundary; Solve the optimal geometric parameters of the microtexture, including: in, represents the pressure distribution on the oil film surface, Indicates the leakage amount; Carrying capacity Use points Leakage By accumulating the flow on the boundary Calculated.

6. A computer device, characterized in that: The invention comprises a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a method for optimizing the surface texture of a continuous rotary electro-hydraulic servo motor as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium is used to store a computer program, and the computer program executes the method for optimizing the surface texture of a continuous rotation electro-hydraulic servo motor according to any one of claims 1 to 4.

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