A full-porous chevron groove gas radial bearing static performance design method

Abstract

The application discloses a full-porous chevron groove gas radial bearing static performance design method, which comprises the following steps: step 1, considering the influence of interface velocity slip effect, establishing a full-porous chevron groove gas radial bearing lubrication model, proposing a numerical calculation method, and calculating the gas film pressure distribution and bearing static performance parameters; step 2, carrying out full-porous chevron groove gas radial bearing static performance analysis; and step 3, carrying out full-porous chevron groove gas radial bearing static performance design to obtain as high bearing capacity as possible and as small deflection angle as possible. The analysis result shows that under certain working conditions, the static performance of the full-porous chevron groove gas radial bearing is superior to that of traditional pure hydrostatic and pure hydrodynamic bearings. The full-porous chevron groove gas radial bearing static performance design method provided by the application can greatly improve the precision and efficiency of performance design of the bearing, and provides an effective means for performance analysis and engineering design of the bearing.

Description

Technical Field

[0001] This invention relates to the field of gas bearing technology, specifically a static performance design method for a fully porous herringbone groove gas radial bearing. Background Technology

[0002] Porous gas radial bearings use gas as the lubricating medium and offer advantages such as high motion precision, low frictional power consumption, good high-speed stability, and oil-free operation, making them important in precision engineering fields such as high-speed electric spindles and turbines. Compared to partially porous throttling devices, fully porous throttling bearings have a more uniform pressure distribution, a larger high-pressure zone area, and higher hydrostatic load capacity. However, under high-speed operating conditions, the enhancement level of the dynamic pressure effect in traditional pure hydrostatic fully porous radial bearings is limited, restricting further improvement in bearing load capacity. Conversely, pure hydrostatic herringbone groove gas radial bearings, through the fluid pumping action generated by surface microstructures, can form a strong dynamic pressure effect in the gas film at high speeds, effectively improving bearing load capacity. However, the dynamic pressure effect of such bearings is entirely dependent on the operating speed; a complete lubricating gas film cannot be formed during start-up, shutdown, and low-speed operation, easily leading to localized contact and frictional wear problems. Therefore, by combining the hydrostatic support of the fully porous material with the dynamic support of the microstructure on the herringbone groove surface, a novel structure of a hydrostatically and statically pressure-type fully porous herringbone groove gas radial bearing is proposed, which is expected to improve the static performance of the bearing under different working conditions.

[0003] Under high-speed, micro-film conditions, the gas rarefaction effect and interfacial slip effect become more pronounced. For porous gas radial bearings, interfacial velocity slip mainly occurs at the interface between the porous material and the gas film, altering the interfacial flow distribution and the gas film pressure field, thus affecting static properties such as bearing capacity, offset angle, and static stiffness. Therefore, the influence of interfacial velocity slip needs to be considered when establishing a lubrication model for porous gas bearings. However, existing lubrication models for porous gas radial bearings are mostly designed for relatively simple porous bearings, making it difficult to accurately calculate the static performance of complex radial bearings with both porous throttling and herringbone groove dynamic pressure effects. The finite element method (FEM) is well-suited for handling complex flow field structures and irregular boundary conditions, but it is primarily used to solve the classical Reynolds equation and is ill-suited for complex bearing lubrication models that consider interfacial slip effects. Furthermore, when bearing structural parameters change, a new flow field model needs to be established and solved, resulting in low efficiency in bearing performance analysis. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a static performance design method for a fully porous herringbone groove gas radial bearing. This method considers the influence of interface velocity slippage, establishes a lubrication model for the fully porous herringbone groove gas radial bearing and a corresponding numerical calculation method, and proposes a static performance design method for this type of bearing, thereby improving the accuracy of bearing performance design and shortening the research and development cycle.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for static performance design of a fully porous herringbone groove gas radial bearing includes the following steps:

[0007] Step 1: Considering the influence of interfacial velocity slip effect, a fully porous herringbone groove gas radial bearing lubrication model is established, and a numerical calculation method is proposed to calculate the gas film pressure distribution and bearing static performance parameters;

[0008] Step 2: Based on the bearing lubrication model established in Step 1, conduct static performance analysis of the fully porous herringbone groove gas radial bearing;

[0009] Step 3: Based on the analysis results of Step 2, conduct static performance design of the fully porous herringbone groove gas radial bearing to obtain the highest possible load capacity and the smallest possible offset angle.

[0010] Furthermore, step 1 is specifically implemented through the following five steps 1a-1e:

[0011] Step 1a: Establishing the bearing structure and coordinate system:

[0012] A fully porous herringbone groove gas radial bearing consists of a bearing shell and a journal. The bearing shell is made of a porous material. Compressed gas from an external supply device is throttled through the porous bearing shell and enters the bearing clearance, thereby forming a static pressure effect in the gas film to bear the load. Several herringbone spiral grooves are machined on the outer surface of the journal or the inner surface of the bearing shell. When the journal rotates at high speed, the herringbone grooves pump gas from both ends of the bearing to the middle of the bearing, thereby forming a dynamic pressure effect in the gas film to bear the load. A rectangular coordinate system and a cylindrical coordinate system are established. The boundary fitting coordinate method is used to transform the physical coordinate system (θ, z) and the computational coordinate system (ξ, η). The transformation relationship between the two is as follows:

[0013] (1)

[0014] In equation (1): R is the bearing radius; β is the helix angle of the helical groove; L is the bearing length;

[0015] Step 1b: Establishment of the three-dimensional flow equation in porous materials:

[0016] According to Darcy's law, the three-dimensional flow equation in porous materials is:

[0017] (2)

[0018] In equation (2): p´ is the gas pressure in the porous region; r is the radial coordinate; z ξ rθ ξ z η and rθ η For inverse metric; J p For Jacobi determinant;

[0019] Step 1c: Establishing the equivalent modified Reynolds equation:

[0020] Based on the finite volume method, the equivalent modified Reynolds equation is:

[0021] (3)

[0022] In equation (3): subscripts 1-4 represent the divided regions in the finite control volume; mass flow rate Q ξ Q η and Q p It can be represented as:

[0023] (4)

[0024] In equation (4): p is the film pressure; ω is the angular velocity; μ is the gas dynamic viscosity; R g Where is the gas constant; T is the absolute temperature of the gas; γ 0 and γ 1 is the dimensionless velocity slip factor; h is the gas film thickness; k p Rθ is the permeability coefficient of the porous material. ξ and Rθ η J is the inverse metric; J is the Jacobian determinant.

[0025] Step 1d: Dimensionlessization of the system of equations

[0026] Introducing dimensionless quantities, the three-dimensional flow equations within porous materials are dimensionless as follows:

[0027] (5)

[0028] In equation (5): The pressure in the dimensionless porous region; h p The thickness of the porous bearing; , and It is a dimensionless inverse measure; It is a dimensionless Jacobian determinant; and Dimensionless coordinates;

[0029] The modified equivalent Reynolds equation is dimensionless as follows:

[0030] (6)

[0031] In equation (6): dimensionless mass flow rate , and It can be represented as:

[0032] (7)

[0033] In equation (7): The pressure is a dimensionless gas film pressure. Λ is the dimensionless gas film thickness; Λ is the compression number; p To provide parameters;

[0034] Step 1e: Set boundary conditions, use the finite difference method to discretize the equation system, use the over-relaxation iteration method to solve equation (5), use the Newton-Raphson method to solve equation (6), solve equations (5) and (6) simultaneously, and obtain the gas film pressure distribution, thereby obtaining the static performance parameters of the bearing.

[0035] Furthermore, in step 2, the static performance analysis of the fully porous herringbone groove gas radial bearing is based on the lubrication model and numerical calculation method of the fully porous herringbone groove gas radial bearing established in step 1. The sensitivity analysis of the bearing static performance (load capacity, offset angle) to design variables (compression number, feed parameters, slip coefficient, gas supply pressure, eccentricity, helix angle and groove depth ratio) is carried out systematically. The static performance of pure hydrostatic, pure hydrodynamic and hydrostatic bearings is compared and analyzed.

[0036] Furthermore, in step 3, the static performance design of the fully porous herringbone groove gas radial bearing is based on the sensitivity analysis results of the bearing static performance on the design variables in step 2 and the comparison results of the static performance of the three bearings. The design variables corresponding to the maximum load capacity and the minimum offset angle are obtained as the optimal values. The working conditions under which the static performance of the fully porous herringbone groove gas radial bearing is superior to the other two bearings are given.

[0037] The beneficial effects of this invention are:

[0038] 1. This invention provides a static performance design method for a fully porous herringbone groove gas radial bearing. Considering the influence of interface velocity slip effect, a lubrication model for a fully porous herringbone groove gas radial bearing with complex structures is established, and a corresponding numerical solution method is proposed. This provides an effective means for the static performance analysis and design of fully porous herringbone groove gas radial bearings, and can significantly improve the accuracy and efficiency of the performance design of this type of bearing.

[0039] 2. This invention systematically conducts sensitivity analysis of bearing static performance (load capacity and offset angle) on design variables (compression coefficient, feed parameters, slip coefficient, gas supply pressure, eccentricity, helix angle, and groove depth ratio), obtaining the design variables corresponding to the maximum load capacity and minimum offset angle as the optimal values. At the same time, it comprehensively compares and analyzes the static performance of three types of gas radial bearings: pure hydrostatic, pure dynamic, and hydrostatic. It provides the operating conditions under which the static performance of the hydrostatic type fully porous herringbone groove gas radial bearing is superior to the other two traditional bearings, thus providing a theoretical basis for the selection and design of such bearings. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the geometry and coordinate system of a fully porous herringbone groove gas radial bearing. (a) is the front view, and (b) is the left view.

[0041] Figure 2 It controls the flow balance within the volume;

[0042] Figure 3 This is a flowchart of the bearing static performance calculation.

[0043] Figure 4 These are the main steps and contents of the design method of the present invention;

[0044] Figure 5 These are the curves showing the variation of bearing capacity and offset angle with compression number under different slip coefficients. (a) is the curve showing the variation of bearing capacity with compression number, and (b) is the curve showing the variation of offset angle with compression number.

[0045] Figure 6 These are the curves showing the variation of bearing capacity and offset angle with supply parameters under different slip coefficients. (a) is the curve showing the variation of bearing capacity with supply parameters, and (b) is the curve showing the variation of offset angle with supply parameters.

[0046] Figure 7 These are the curves showing the variation of bearing capacity and misalignment angle with compression number for three types of bearings under different supply parameters. (a) is the curve showing the variation of bearing capacity with compression number, and (b) is the curve showing the variation of misalignment angle with compression number.

[0047] Figure 8 The curves showing the variation of bearing capacity and offset angle with supply parameters for two types of bearings under different compression numbers are shown. (a) is the curve of bearing capacity with supply parameters, and (b) is the curve of offset angle with supply parameters.

[0048] Figure 9 These are the curves showing the variation of bearing capacity with compression number and supply parameters for three types of bearings under different air supply pressures. (a) is the curve showing the variation of bearing capacity with compression number, and (b) is the curve showing the variation of bearing capacity with supply parameters.

[0049] Figure 10 These are the curves showing the variation of bearing capacity with compression number and supply parameters for two types of bearings under different eccentricities. (a) is the curve showing the variation of bearing capacity with compression number, and (b) is the curve showing the variation of bearing capacity with supply parameters.

[0050] Figure 11 These are the curves showing the variation of bearing capacity and deviation angle with helix angle and groove depth ratio under different supply parameters. (a) shows the curves showing the variation of bearing capacity and deviation angle with helix angle, and (b) shows the curves showing the variation of bearing capacity and deviation angle with groove depth ratio.

[0051] Figure 12 Table 1 details the geometric and operating parameters of a fully porous herringbone groove gas radial bearing. Detailed Implementation

[0052] The following section, in conjunction with the accompanying drawings, provides a more detailed explanation of a static performance design method for a fully porous herringbone groove gas radial bearing.

[0053] Figure 4 The present invention provides a detailed method for static performance design of a fully porous herringbone groove gas radial bearing, comprising the following steps:

[0054] Step 1: Considering the Beavers-Joseph velocity-slip boundary conditions at the gas film-porous interface, a fully porous herringbone groove gas radial bearing lubrication model is established. A numerical calculation method is proposed to calculate the gas film pressure distribution and bearing static performance parameters, which can be achieved through the following five steps 1a-1e:

[0055] Step 1a: Establishment of bearing structure and coordinate system

[0056] The geometry of a fully porous herringbone groove gas radial bearing is as follows: Figure 1 As shown, a fully porous herringbone groove gas radial bearing consists of a bearing shell and a journal; wherein, the bearing shell remains stationary, is made of porous material, has herringbone spiral grooves machined on its inner surface, and is sealed at both ends to prevent gas leakage from the ends; the journal rotates at an angular velocity ω and has a smooth surface; the external gas supply pressure is p. s High-pressure gas enters the bearing clearance after being throttled through the porous bearing bush; the gas film pressure and the gas pressure in the porous region are represented by p and p', respectively. The static pressure effect generated by the porous throttling and the dynamic pressure effect generated by the herringbone groove work together to form a novel type of radial gas bearing with dynamic and static pressure. The bearing dimensional parameters include: bearing radius R, bearing length L, and porous bearing bush thickness h. p The parameters for the herringbone groove include: helix angle β, bearing clearance c, and groove depth h. g , slot width b g Platform width b r And number of slots Ng The established coordinate system is as follows: Figure 1 As shown, the boundary fitting coordinate method is used to transform the physical coordinate system (θ, z) and the computational coordinate system (ξ, η). The transformation relationship between the two is as follows:

[0057] (1)

[0058] Step 1b: Establishment of the three-dimensional flow equation in porous materials

[0059] Based on Darcy's law, the continuity equation for compressible fluids, and the ideal gas law, the three-dimensional flow equation in porous media is derived:

[0060] (2)

[0061] In equation (2): r is the radial coordinate; the inverse metric and Jacobian determinant can be expressed as:

[0062] , , , ,

[0063] Step 1c: Establishing the equivalent modified Reynolds equation

[0064] like Figure 2 As shown, based on the flow balance within a finite control volume, the equivalent modified Reynolds equation is derived:

[0065] (3)

[0066] In equation (3): subscripts 1-4 represent the divided regions in the finite control volume; mass flow rate Q ξ Q η and Q p It can be represented as:

[0067] (4)

[0068] In equation (4): μ is the gas dynamic viscosity; R g Where is the gas constant; T is the absolute temperature of the gas; γ 0 and γ 1 is the dimensionless velocity slip factor; h is the gas film thickness; k p The permeability coefficient of the porous material; the inverse metric and Jacobian determinant can be expressed as:

[0069] , ,

[0070] Step 1d: Dimensionlessization of the system of equations

[0071] Define the following dimensionless quantities:

[0072] , , , , , , , , , , , , ,

[0073] The three-dimensional flow equation in porous materials can be expressed in dimensionless form:

[0074] (5)

[0075] The modified equivalent Reynolds equation is dimensionless as follows:

[0076] (6)

[0077] In equation (6): dimensionless mass flow rate , and It can be represented as:

[0078] (7)

[0079] In equation (7): Λ is the dimensionless gas film thickness; Λ is the compression number; p To provide parameters.

[0080] Dimensionless gas film thickness It can be represented as:

[0081] (8)

[0082] In equation (8): and These are the eccentricities along the x and y directions, respectively; and These are the journal tilt angles about the x and y axes, respectively; the groove depth ratio. For the tank area, =1, and for the substation area, =0.

[0083] The dimensionless velocity slip factors γ0 and γ1 can be expressed as:

[0084] , (9)

[0085] In equation (9): α is the slip coefficient.

[0086] Step 1e: Set boundary conditions, use the finite difference method to discretize the equation system, use the over-relaxation iteration method to solve equation (5), use the Newton-Raphson method to solve equation (6), solve equations (5) and (6) simultaneously, and obtain the gas film pressure distribution, thereby obtaining the static performance parameters of the bearing.

[0087] Boundary conditions for the dimensionless three-dimensional flow equation (5) in porous materials:

[0088] (10)

[0089] Boundary conditions for the dimensionless modified equivalent Reynolds equation (6):

[0090] (11)

[0091] The specific solution process for the static performance parameters of the bearing is as follows: Figure 3 As shown. The dimensionless three-dimensional flow equation (5) in the porous mass is a linear equation, which is solved by the over-relaxation iteration method; the dimensionless modified equivalent Reynolds equation (6) is a nonlinear equation, which is solved by the Newton-Raphson method. The equations (5) and (6) are discretized using a second-order precision finite difference scheme; the first and second derivatives at the grid nodes inside the solution domain are discretized using the central difference scheme; the first derivatives at the boundary nodes are discretized using the second-order upwind scheme. It is assumed that the gas film pressure in the grid cell is linearly distributed. In order to ensure the convergence of the iterative algorithm under high compressibility, the estimated initial gas film pressure value should be as close as possible to or higher than the pressure value of the corresponding pure hydrodynamic bearing. The iterative convergence accuracy of the pressure distribution is 10. -5 The computational domain is meshed using a three-dimensional mesh, with the number of meshes set to 128×40×16. It can meet both the requirements of computational accuracy and efficiency.

[0092] Dimensionless bearing capacity components along the x and y directions:

[0093] (12)

[0094] In equation (12): F x and F y These are the load-bearing capacity components along the x and y directions, respectively.

[0095] Dimensionless bearing capacity and offset angle:

[0096] (13)

[0097] Step 2: Based on the bearing lubrication model established in Step 1, conduct static performance analysis of the fully porous herringbone groove gas radial bearing.

[0098] The geometric and operating parameters of a fully porous herringbone groove gas radial bearing are shown in Table 1. When determining the influence of a certain design variable on the static and dynamic performance of the bearing, other variables remain constant. Based on the bearing lubrication model and numerical calculation method established in step 1, the influence of design variables such as compression coefficient, feed parameters, slip coefficient, gas supply pressure, eccentricity, helix angle, and groove depth ratio on the static performance of the fully porous herringbone groove gas radial bearing is systematically analyzed. The static performance of pure hydrostatic, pure dynamic, and hydrostatic bearings is compared and analyzed. The calculation results are shown in Table 1. Figures 5-11 As shown.

[0099] The calculation results show that when considering the interface velocity slip effect, both the bearing capacity and the offset angle decrease, but the maximum decrease is less than 10% and 4.5 deg, respectively. With the increase of compression number, supply pressure, and eccentricity, and the decrease of slip coefficient, the influence of velocity slip effect on the bearing capacity increases. With the increase of supply parameters, the influence of velocity slip effect on the bearing capacity first increases and then decreases, reaching a certain level at Λ... p The effect is strongest at point 2. Design variables such as compression coefficient, feed parameters, slip coefficient, air supply pressure, eccentricity, helix angle, and groove depth ratio are all important parameters affecting the static performance of bearings.

[0100] Step 3: Based on the analysis results of Step 2, conduct static performance design of the fully porous herringbone groove gas radial bearing to obtain the highest possible load capacity and the smallest possible offset angle.

[0101] Based on the analysis results of step 2, the following design criteria are derived:

[0102] (1) In terms of bearing type comparison: when the compression number Λ>15 and the supply parameter Λ p When Λ < 2, the load-carrying capacity of the hydrostatic bearing is significantly higher than that of the pure hydrostatic bearing; however, when Λ < 5, the load-carrying capacity of the hydrostatic bearing will be lower than that of the pure hydrostatic bearing. When the compression number is less than a certain value, the static performance of the hydrostatic bearing is significantly better than that of the pure hydrostatic bearing; moreover, as the supply parameters and supply pressure increase, the advantages of the hydrostatic bearing become more obvious.

[0103] (2) Regarding bearing parameter optimization: When the supplied parameters are relatively small, the optimal helix angle and groove depth ratio corresponding to the maximum load capacity are respectively β =36 deg and =1.4; the optimal helix angle and groove depth ratio corresponding to the minimum offset angle are respectively β =40 deg and =0.6-0.8. When the supply parameters are large, the optimal helix angle and groove depth ratio corresponding to the maximum bearing capacity are respectively 0.6-0.8. β =40 deg and =1.2; the optimal helix angle and groove depth ratio corresponding to the minimum offset angle are respectively β =20 deg and =0.4.

[0104] It will be understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for designing the static performance of a fully porous herringbone groove gas radial bearing, characterized in that: It includes the following three steps: Step 1: Considering the Beavers-Joseph velocity slip boundary condition at the gas film-porous interface, a fully porous herringbone groove gas radial bearing lubrication model is established, and a numerical calculation method is proposed to calculate the gas film pressure distribution and bearing static performance parameters. Step 2: Conduct static performance analysis of the fully porous herringbone groove gas radial bearing; Step 3: Conduct static performance design of the fully porous herringbone groove gas radial bearing to obtain the highest possible load capacity and the smallest possible offset angle.

2. The static performance design method for a fully porous herringbone groove gas radial bearing according to claim 1, characterized in that: Step 1 includes the following five steps: Step 1a: Establishing the bearing structure and coordinate system: A fully porous herringbone groove gas radial bearing consists of a bearing shell and a journal. The bearing shell is made of a porous material, and the outer surface of the journal or the inner surface of the bearing shell is machined with several herringbone spiral grooves. A boundary fitting coordinate method is used to transform the physical coordinate system (θ, z) and the computational coordinate system (ξ, η). The transformation relationship between the two is as follows: (1) In equation (1): R is the bearing radius; β is the helix angle of the helical groove; L is the bearing length; Step 1b: Establishment of the three-dimensional flow equation in porous materials: The three-dimensional flow equation in porous materials is: (2) In equation (2): p´ is the gas pressure in the porous region; r is the radial coordinate; z ξ rθ ξ z η and rθ η For inverse metric; J p For Jacobi determinant; Step 1c: Establishing the equivalent modified Reynolds equation: The equivalent modified Reynolds equation is: (3) In equation (3): subscripts 1-4 represent the divided regions in the finite control volume; mass flow rate Q ξ Q η and Q p It can be represented as: (4) In equation (4): p is the film pressure; ω is the angular velocity; μ is the gas dynamic viscosity; R g Where is the gas constant; T is the absolute temperature of the gas; γ 0 and γ 1 is the dimensionless velocity slip factor; h is the gas film thickness; k p Rθ is the permeability coefficient of the porous material. ξ and Rθ η J is the inverse metric; J is the Jacobian determinant. Step 1d: Dimensionlessization of the system of equations: Define the following dimensionless quantities: , , , , , , , , , , , , , The three-dimensional flow equation in a dimensionless porous mass is: (5) The dimensionless modified equivalent Reynolds equation is: (6) In equation (6): dimensionless mass flow rate , and It can be represented as: (7) Dimensionless gas film thickness for: (8) In equation (8): and These are the eccentricities along the x and y directions, respectively; and These are the journal tilt angles about the x and y axes, respectively; the groove depth ratio. For the tank area, =1, and for the substation area, =0; Dimensionless velocity slip factor γ 0 and γ 1 is: ， (9) In equation (9): α is the slip coefficient; Step 1e: Set boundary conditions, discretize the equation system using the finite difference method, solve equation (5) using the over-relaxation iteration method, solve equation (6) using the Newton-Raphson method, solve equations (5) and (6) simultaneously to obtain the gas film pressure distribution, and then obtain the static performance parameters of the bearing: Boundary conditions for the dimensionless three-dimensional flow equation (5) in porous materials: (10) Boundary conditions for the dimensionless modified equivalent Reynolds equation (6): (11) The dimensionless three-dimensional flow equation (5) in the porous mass is a linear equation, solved by the over-relaxation iterative method; the dimensionless modified equivalent Reynolds equation (6) is a nonlinear equation, solved by the Newton-Raphson method; equations (5) and (6) are discretized using a second-order precision finite difference scheme; the first and second derivatives at the grid nodes inside the solution domain are discretized using the central difference scheme; the first derivatives at the boundary nodes are discretized using the second-order upwind scheme; it is assumed that the gas film pressure in the grid cell is linearly distributed; in order to ensure the convergence of the iterative algorithm under high compressibility, the estimated initial gas film pressure value should be as close as possible to or higher than the pressure value of the corresponding pure hydrodynamic bearing; the iterative convergence accuracy of the pressure distribution is 10. -5 The computational domain is meshed using a three-dimensional mesh, with the number of meshes set to 128×40×16. It can meet both the requirements of computational accuracy and efficiency.

3. The static performance design method for a fully porous herringbone groove gas radial bearing according to claim 1, characterized in that: Step 2, the static performance analysis of the fully porous herringbone groove gas radial bearing, is based on the lubrication model and numerical calculation method of the fully porous herringbone groove gas radial bearing established in Step 1. It systematically conducts a sensitivity analysis of the bearing's static performance to design variables; it compares and analyzes the static performance of three types of bearings: pure hydrostatic, pure hydrodynamic, and hydrostatic. The bearing's static performance includes load capacity and offset angle; the design variables include compression coefficient, feed parameters, slip coefficient, gas supply pressure, eccentricity, helix angle, and groove depth ratio.

4. The static performance design method for a fully porous herringbone groove gas radial bearing according to claim 1, characterized in that: The static performance design of the fully porous herringbone groove gas radial bearing in step 3 is based on the sensitivity analysis results of the bearing static performance to the design variables in step 2 and the comparison results of the three bearing static performances, to obtain the design variables corresponding to the maximum load capacity and the minimum offset angle as the optimal values. The operating conditions under which the static performance of the fully porous herringbone groove gas radial bearing is superior to that of the other two types of bearings are given.

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