A Static Performance Design Method for High-Speed Heavy-Duty Tilt-Pad Journal Bearings

Abstract

The present invention discloses a static performance design method for a high-speed heavy-duty tilting pad journal bearing, which specifically includes the following steps: First, considering the coupling effects of multiple factors such as fluid turbulence effect, thermal effect, and elastic deformation, a lubrication model for the high-speed heavy-duty tilting pad journal bearing is established; based on the lubrication model, static performance analysis and calculation of the high-speed heavy-duty tilting pad journal bearing are carried out; and the design and optimization of the heavy-duty tilting pad journal bearing are guided according to the results of the static performance analysis. By using the static performance design method for the high-speed heavy-duty tilting pad journal bearing provided by the present invention, the accuracy of the static performance design of this type of bearing can be greatly improved, the bearing design risk can be reduced, and reference is provided for the performance analysis and engineering design of such bearings.

Description

Technical Field

[0001] The present invention relates to a static performance design method for a high-speed heavy-duty tilting pad journal bearing, belonging to the technical field of tilting pad journal bearing design. Background Art

[0002] In recent years, the technology of tilting pad journal bearings has attracted much attention at home and abroad. Since each pad of a tilting pad bearing can swing slightly around the journal, and each pad jointly bears the external load, making it easier to push the journal back to the center position of the bearing. Therefore, tilting pad journal bearings are widely used in rotating machinery. Although tilting pad journal bearings have high stability, the swing of each pad will generate additional degrees of freedom, so the prediction of the lubrication characteristics of such bearings will become more complex.

[0003] Under high-speed operating conditions, the turbulent flow phenomenon in tilting pad journal bearings is serious, which is a major challenge for the stable operation of the bearings; under heavy-load conditions, the pads will deform, affecting the thickness of the oil film and thus the lubrication characteristics of the bearings; in addition, as the temperature changes, the physical and chemical properties of the lubricating oil will change, further affecting the normal operation of the bearings. More importantly, effects such as turbulent flow effect, thermal effect, and elastic deformation of the pads will be coupled with each other, and the turbulent thermo-elastohydrodynamic coupling mechanism of the bearings is very complex. However, the existing lubrication theories are mainly established for the lubrication of low-speed, light-load, and small-sized bearings, and can no longer correctly describe the static performance of high-speed heavy-duty tilting pad journal bearings, with low calculation accuracy and unable to be applied to the static performance design of such bearings. Summary of the Invention

[0004] To solve the deficiencies of the prior art, the purpose of the present invention is to provide a static performance design method for a high-speed heavy-duty tilting pad journal bearing, providing a theoretical basis for improving the design accuracy of the performance of high-speed heavy-duty tilting pad journal bearings and shortening the R & D cycle.

[0005] To achieve the above objectives, the present invention adopts the following technical solutions:

[0006] A static performance design method for a high-speed heavy-duty tilting pad journal bearing includes the following steps:

[0007] Considering the coupling effect of multiple factors, establish a lubrication model for a high-speed heavy-duty tilting pad journal bearing, where the factors include turbulent flow effect, thermal effect, viscosity-temperature and viscosity-pressure effects, and elastic deformation of the pads;

[0008] Analyze and calculate the static performance of a high-speed heavy-duty tilting pad journal bearing;

[0009] Design the static performance of a high-speed heavy-duty tilting pad journal bearing.

[0010] Furthermore, the specific steps for establishing the lubrication model of a high-speed and heavy-duty tilting pad journal bearing by considering the coupling effect of multiple factors are as follows:

[0011] According to the geometric model of the tilting pad journal bearing, local coordinate systems of each pad are established under the global coordinate system, and the lubricating oil film thickness equation corresponding to any unfolding angle of each pad is established. The oil film thickness equation is:

[0012]

[0013] where H i (φ i ) represents the oil film thickness corresponding to the i-th pad at the unfolding angle of φ i , ε = e / c is the eccentricity of the journal center, e is the eccentricity, c is the initial clearance, θ is the bearing offset angle, M is the bearing preload coefficient, ψ represents the clearance ratio, δ i is the swing angle of the i-th pad, β i is the fulcrum position angle of the i-th pad, φ i is the arbitrary unfolding angle of the i-th pad, i is the pad number, and Δ is the elastic deformation of the pad;

[0014] Establish a calculation and analysis model for the thermo-hydrodynamic lubrication characteristics of the bearing;

[0015] Realize the coupled calculation of the pressure field and the temperature field to obtain the pressure distribution P of the hydrodynamic oil film of the journal bearing;

[0016] Perform a thermo-fluid-solid multi-field coupling calculation considering the elastic deformation of the pads;

[0017] Respectively correct the initial preset values of the pads and recalculate until all convergence judgment conditions are met to ensure that the moment balance of each pad, the direction and magnitude of the oil film resultant force are the same as the external load.

[0018] Furthermore, the steps for establishing the calculation and analysis model for the thermo-hydrodynamic lubrication characteristics of the bearing are as follows:

[0019] Calculate the turbulence coefficient,

[0020]

[0021] where K φ 、K λ and τ c are the turbulence coefficients;

[0022] Effective Reynolds coefficient

[0023] where Re e is the effective Reynolds number, which can be obtained from the critical Reynolds number Re cTo determine three different flow regimes: laminar flow, mixed flow, and turbulent flow; H is the dimensionless oil film thickness; Re m =ρωRc / μ is the average Reynolds number, where ρ and μ are the lubricating oil density and viscosity respectively, ω is the bearing rotational speed, R is the bearing bore radius, and c is the initial clearance.

[0024] Construct the Reynolds equation, energy equation, and viscosity-temperature and viscosity-pressure equations considering the turbulent coefficient, and establish a calculation and analysis model for the thermo-hydrodynamic lubrication characteristics of the bearing.

[0025] The Reynolds equation can be expressed as:

[0026]

[0027] where P is the dimensionless oil film pressure; H is the dimensionless oil film thickness, D is the bearing diameter, L is the bearing width, and L / D is the bearing aspect ratio. is the dimensionless dynamic viscosity; φ and λ are the circumferential and axial coordinates of the bearing respectively.

[0028] The energy equation can be expressed as:

[0029]

[0030] where represents the dimensionless oil film temperature, T is the dimensional temperature, ρ is the lubricating oil density, C v is the specific heat capacity of the lubricating oil, and μ0 is the dynamic viscosity of the lubricating oil under standard atmospheric pressure at 40°C.

[0031] The viscosity-temperature and viscosity-pressure equation can be expressed as:

[0032]

[0033]

[0034] where μ represents the dynamic viscosity of the lubricating oil corresponding to the current temperature and pressure, μ0 is the dynamic viscosity of the lubricating oil under standard atmospheric pressure at 40°C, T0 is the initial temperature of the lubricating oil, A α and A β are two viscosity-temperature and viscosity-pressure coefficients respectively.

[0035] Furthermore, the specific steps for the aforementioned coupling calculation of the pressure field and temperature field to obtain the pressure distribution P of the hydrodynamic oil film of the tilting pad journal bearing include:

[0036] Write an algorithm program using the MATLAB computer language.

[0037] Determine the pressure boundary condition, energy boundary condition, and corresponding convergence judgment condition of the hydrodynamic oil film of the tilting pad journal bearing.

[0038] After coupling the Reynolds equation, the energy equation, and the viscosity-temperature and viscosity-pressure equations, and introducing the calculated actual Reynolds number, the above control equations are discretized using the finite difference method;

[0039] The point-by-point successive over-relaxation iteration method that is easy to converge is used to solve until the convergence criterion is met, and the pressure distribution at each node of the oil film is obtained.

[0040] Furthermore, the specific steps of the above-mentioned thermal-fluid-solid multi-field coupling calculation considering the elastic deformation of the pad include:

[0041] Use ANSYS software to construct a three-dimensional tilting pad bearing pad model and perform mesh generation, and apply the oil film pressure P as a load on each corresponding node of the solid domain;

[0042] Use the MATLAB computer language to write an algorithm program to read the oil film force on the pad surface, and calculate the displacement increment of the pad according to the oil film force;

[0043] Add this displacement increment to the grid node position coordinates after the end of the previous cycle calculation. When the displacement increment obtained from the cycle calculation meets the elastic deformation convergence determination condition, the update of the node position coordinates is completed;

[0044] Store the updated grid node position coordinate information.

[0045] Furthermore, the above-mentioned separately correcting the initial preset value of the pad and recalculating until all the convergence conditions in the convergence determination conditions are met include:

[0046]

[0047] |Fx / Fy|≤0.001

[0048]

[0049] where M P represents the moment of each pad, L is the bearing width, μ0 is the dynamic viscosity of the lubricating oil under standard atmospheric pressure at 40 °C, ω is the bearing speed, ψ represents the clearance ratio, R is the bearing hole radius, φ is the expansion angle, β is the fulcrum position angle, Fx is the resultant force of the oil film in the x direction, Fy is the resultant force of the oil film in the y direction, and Fw is the external load.

[0050] Furthermore, the above-mentioned method for analyzing and calculating the static performance of a high-speed and heavy-load tilting pad journal bearing includes:

[0051] Based on the established lubrication model of a tilting pad journal bearing for high-speed and heavy-load applications, a sensitivity analysis of the static performance of the tilting pad journal bearing to operating parameters is carried out. Assuming that one design variable remains unchanged, the influence of the change of another design variable on the static performance of the tilting pad journal bearing is calculated and analyzed. The static performance includes oil film pressure, oil film thickness, eccentricity, and oil film temperature, and the design variables include the magnitude of the external load and the rotational speed.

[0052] Furthermore, the method for designing the static performance of the tilting pad journal bearing for high-speed and heavy-load applications described above includes:

[0053] Based on the sensitivity analysis results of the static performance of the tilting pad journal bearing to the design variables, taking the design variables corresponding to the maximum oil film pressure, the minimum oil film thickness, and the minimum eccentricity as the optimal values, the oil film temperature rise is obtained.

[0054] The beneficial effects achieved by the present invention:

[0055] Adopting the method for designing the static performance of the tilting pad journal bearing for high-speed and heavy-load applications provided by the present invention provides an effective means for the analysis and design of the static performance of the tilting pad journal bearing for high-speed and heavy-load applications. At the same time, it can greatly improve the accuracy of the performance design of this type of bearing and shorten the R & D cycle. Description of the Drawings

[0056] Figure 1 is the test piece model of the present invention;

[0057] Figure 2 is the schematic diagram of the geometric model of the test piece of the present invention;

[0058] Figure 3 is the schematic diagram of the oil film expansion in the present invention;

[0059] Figure 4 is the schematic diagram of the fluid-structure interaction calculation of the present invention;

[0060] Figure 5 is the algorithm flow chart of the present invention;

[0061] Figure 6 is the model verification result of the present invention;

[0062] Figure 7 is the dimensionless oil film pressure distribution under different journal speeds of the present invention;

[0063] Figure 8 is the dimensionless oil film thickness distribution under different journal speeds of the present invention;

[0064] Figure 9 is the oil film temperature distribution under different journal speeds of the present invention;

[0065] Figure 10It is the calculation result of the bearing eccentricity under different journal speeds of the present invention;

[0066] Figure 11 It is the dimensionless oil film pressure distribution under different external loads of the present invention;

[0067] Figure 12 It is the dimensionless oil film thickness distribution under different external loads of the present invention;

[0068] Figure 13 It is the oil film temperature distribution under different external loads of the present invention;

[0069] Figure 14 It is the calculation result of the bearing eccentricity under different external loads of the present invention. Specific embodiments

[0070] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and should not be used to limit the protection scope of the present invention.

[0071] This embodiment discloses a static performance design method for a high-speed heavy-duty tilting pad journal bearing, including the following steps:

[0072] Step 1: Considering the coupling effects of multiple factors, including turbulent effect, thermal effect, viscosity-temperature and viscosity-pressure effects, and the elastic deformation of the pad, establish a lubrication model for a high-speed heavy-duty tilting pad journal bearing. The specific process is as follows:

[0073] The first step is to derive the equation for the lubricating oil film thickness corresponding to any unfolding angle of each pad. Specifically: As Figure 2 shown, according to the geometric model of a three-pad tilting pad journal bearing, establish the local coordinate system of each pad in the overall coordinate system, and the film thickness equation is expressed as:

[0074]

[0075] Among them, H i (φ i ) represents the oil film thickness corresponding to the i-th pad at the unfolding angle of φ i , ε = e / c is the journal center eccentricity, e is the eccentricity, c is the initial clearance, θ is the bearing offset angle, M is the bearing preload coefficient, ψ represents the clearance ratio, δ i is the swing angle of the i-th pad, β i is the fulcrum position angle of the i-th pad, φ i is the arbitrary unfolding angle of the i-th pad, i is the pad number, and Δ is the elastic deformation of the pad.

[0076] Step 2: Establish a calculation and analysis model for the thermal fluid lubrication characteristics of the bearing. Based on the formation mechanism of the hydrodynamic oil film, establish the Reynolds equation, energy equation, and viscosity-temperature and viscosity-pressure equations of the hydrodynamic oil film; introduce the turbulence coefficient into each control equation to consider the flow regime under complex working conditions. Specifically,

[0077] Calculate the turbulence coefficient:

[0078]

[0079] where Re e is the effective Reynolds number, which is the basis for judging the flow regime of the lubricating oil and represents the relative relationship between the fluid inertial force and the viscous force; K φ , K λ and τ c are the turbulence coefficients.

[0080] Three different flow regimes can be determined according to the effective Reynolds number: laminar flow, mixed flow, and turbulent flow.

[0081]

[0082] where H is the dimensionless oil film thickness; Re e is the effective Reynolds number, and three different flow regimes: laminar flow, mixed flow, and turbulent flow can be determined by the critical Reynolds number Re c ; Re m =ρωRc / μ is the average Reynolds number, ρ and μ are the density and viscosity of the lubricating oil respectively, ω is the bearing speed, R is the bearing hole radius, and c is the initial clearance.

[0083] Construct the Reynolds equation, energy equation, and viscosity-temperature and viscosity-pressure equations considering the turbulence coefficient. Specifically:

[0084] The Reynolds equation based on the hydrodynamic effect can be expressed as:

[0085]

[0086] where P is the dimensionless oil film pressure; H is the dimensionless oil film thickness, D is the bearing diameter, L is the bearing width, L / D is the bearing width-diameter ratio; K φ and K λ are the turbulence coefficients; is the dimensionless dynamic viscosity; φ and λ are the circumferential and axial coordinates of the bearing respectively.

[0087] The energy equation can be expressed as:

[0088]

[0089] In the formula, represents the dimensionless temperature of the oil film, T is the dimensional temperature, ρ is the density of the lubricating oil, Cv is the specific heat capacity of the lubricating oil, and μ0 is the dynamic viscosity of the lubricating oil under standard atmospheric pressure when it is 40°C.

[0090] The viscosity-temperature-viscosity-pressure equation can be expressed as:

[0091]

[0092] Among them, μ represents the dynamic viscosity of the lubricating oil corresponding to the current temperature and pressure, μ0 is the dynamic viscosity of the lubricating oil under standard atmospheric pressure at 40°C, and T0 is the initial temperature of the lubricating oil. Z and S are obtained by the following formula:

[0093]

[0094] Among them, A α and A β are the two viscosity-temperature-viscosity-pressure coefficients respectively.

[0095] The third step is the coupled calculation of pressure field and temperature field. Specifically:

[0096] The algorithm program is written in MATLAB computer language to determine the pressure boundary conditions, energy boundary conditions and corresponding convergence judgment conditions of the dynamic pressure oil film of the tilting pad radial sliding bearing. After introducing the actual Reynolds number calculated by combining the Reynolds equation, energy equation and viscosity-temperature-viscosity-pressure equation, the finite difference method is used to discretely solve the Reynolds equation and the energy equation. The steady-state Reynolds equation adopts the central difference format, and the energy equation adopts the upwind difference format. The point-by-point super-relaxation iteration method that is easy to converge is used to solve until the convergence criterion is met to obtain the pressure distribution at each node of the oil film. Figure 3 As shown in the figure, the oil film is extended from the ring to the plane along the circumferential direction, and the viscosity-temperature-viscosity-pressure relationship is introduced to realize the coupled calculation of the pressure field and the temperature field, and the pressure distribution P of the dynamic pressure oil film of the sliding bearing is obtained.

[0097] The fourth step is to calculate the thermal-fluid-solid multi-field coupling taking into account the elastic deformation of the tile. Specifically:

[0098] like Figure 4 As shown, a three-dimensional tilting pad bearing pad model is constructed and meshed using ANSYS software, and the oil film pressure P is applied as a load to each corresponding node in the solid domain;

[0099] The 3D tilting pad bearing pad model was constructed and meshed using ANSYS software, and the oil film pressure P was applied as a load to each corresponding node in the solid domain.

[0100] The algorithm program is written using the MATLAB computer language to read the oil film force on the surface of the tile, and the displacement increment of the tile is calculated based on the oil film force;

[0101] Add the displacement increment to the grid node position coordinates after the end of the previous loop calculation. When the displacement increment obtained from the loop calculation meets the elastic deformation convergence determination condition, complete the update of the node position coordinates;

[0102] Store the updated grid node position coordinate information.

[0103] Step 5: Ensure the moment balance of each pad, and the direction and magnitude of the oil film resultant force are the same as the external load. Specifically:

[0104] The moment of each pad is expressed by the following formula:

[0105]

[0106] It is necessary to satisfy that the moment of each pad is 0, otherwise, re-correct the preset value of the pad swing angle. Here, L is the bearing width, μ0 is the dynamic viscosity of the lubricating oil under standard atmospheric pressure at 40°C, ω is the bearing rotation speed, ψ represents the clearance ratio, R is the bearing hole radius, φ is the developed angle, and β is the fulcrum position angle.

[0107] The balance condition for the direction of the oil film resultant force is:

[0108] |Fx / Fy|≤0.001

[0109] where Fx is the resultant force of the oil film in the x direction and Fy is the resultant force of the oil film in the y direction. If this balance condition is not satisfied, re-correct the preset value of the bearing offset angle.

[0110] The balance condition for the magnitude of the oil film resultant force is:

[0111]

[0112] where Fw is the external load. If this balance condition is not satisfied, re-correct the preset value of the bearing eccentricity.

[0113] Step 2: Static performance analysis and calculation of a high-speed heavy-duty tilting pad journal bearing;

[0114] Based on the lubrication model and numerical calculation method of the high-speed heavy-duty tilting pad journal bearing established in Step 1, systematically conduct a sensitivity analysis of the static performance of the tilting pad journal bearing to operating parameters. Assuming that one design variable remains unchanged, calculate and analyze the influence of the change of another design variable on the static performance of the tilting pad journal bearing.

[0115] The static performance includes oil film pressure, oil film thickness, eccentricity, and oil film temperature, and the design variables include the magnitude of the external load and the rotation speed.

[0116] Step 3: Static performance design of a high-speed heavy-duty tilting pad journal bearing to predict the operating conditions of the bearing under different operating parameters.

[0117] Based on the sensitivity analysis results of the design variables for the static performance of the tilting pad journal bearing in Step 2, the design variables corresponding to the maximum oil film pressure, the minimum oil film thickness, and the minimum eccentricity are taken as the optimal values, and as low an oil film temperature rise as possible is obtained, thereby providing a theoretical basis for the engineering design of such bearings.

[0118] In this embodiment, a three-pad tilting pad journal bearing is taken as an example to specifically elaborate on the present invention. As Figure 1 shown, the orifice diameter of the tilting pad bearing is 416 mm, the pad thickness is 40 mm, the elastic modulus is 204 GPa, the Poisson's ratio is 0.3, and the density is 7850 kg / m 3 . The selected lubricating oil is ISO VG32, the preload coefficient is 0.3, the clearance ratio is 0.003, the initial oil inlet temperature is 40 °C, the spindle speed is 500 rpm, and the external load is 150 kN.

[0119] As Figure 5 shown, the calculation of this embodiment includes the following steps:

[0120] (a) Parameter presetting.

[0121] Input the bearing operating parameters and the preset values of the swing angle of each pad, the preset value of the offset angle, and the preset value of the eccentricity.

[0122] (b) Calculating the oil film thickness and the viscosity of the lubricating oil at the inlet.

[0123] Calculate the oil film thickness of each pad according to the oil film thickness equation, and calculate the viscosity of the lubricating oil at an initial temperature of 40 °C and a pressure of standard atmospheric pressure according to the viscosity-temperature and viscosity-pressure equations.

[0124] (c) Calculating the turbulence coefficient.

[0125] (d) Calculating the oil film pressure and temperature distribution.

[0126] (e) Calculating the elastic deformation of the pad.

[0127] (f) Ensure that the moment balance of each pad, the direction and magnitude of the oil film resultant force are the same as the external load.

[0128] (g) End the calculation and output the characterization parameters of the lubrication characteristics of the tilting pad journal bearing.

[0129] In this example, the static performance of the tilting pad journal bearing under different operating conditions is simulated. And the simulation results of the present invention are compared with the simulation results of the CFD method, as Figure 6 shown; it can be seen that the calculation results of the present invention are basically consistent with the simulation results of the CFD method, and the maximum pressure difference is only 0.3%.

[0130] Figures 7 - 10Calculation results of dimensionless pressure, dimensionless film thickness, temperature, and eccentricity of each pad at different main shaft speeds. From Figure 7 It can be seen that as the speed increases from 500 rpm to 2500 rpm, the dimensionless pressure will drop rapidly, while when the speed exceeds 2500 rpm, the pressure change is small. As Figure 8 shown, when the speed increases, the change in oil film thickness is opposite. This is because as the speed increases, the journal center gradually moves towards the bearing center, and the oil film thickness increases accordingly. When the shaft speed increases to a certain value, the main shaft center gradually stabilizes, and the oil film thickness stops changing. When the shaft speed increases from 500 rpm to 4500 rpm, the oil film temperature inside each pad is as Figure 9 shown. The temperature increases with the increase of the shaft speed, which is due to the increase in energy dissipation caused by the increase in shear rate. Generally speaking, the eccentricity is closely related to the film thickness. As Figure 10 shown, as the speed increases, the journal position gradually rises, the hydrodynamic effect increases, the eccentricity gradually decreases, and the stability of the tilting pad journal bearing is significantly improved.

[0131] Figures 11 - 14 Calculation results of dimensionless pressure, dimensionless film thickness, temperature, and eccentricity of each pad under different external loads. From Figure 11 it can be known that as the external load gradually increases, the oil film pressure borne by the pad gradually increases. As Figure 12 shown, when the load increases, the change in oil film thickness is opposite. When the external load increases from 150 kN to 350 kN, the oil film temperature inside the pad is as Figure 13 shown, and the temperature increases with the increase of the shaft load. As Figure 14 shown, as the load increases, the hydrodynamic effect increases, the eccentricity gradually decreases, and the stability of the tilting pad journal bearing is significantly improved.

[0132] Based on the calculation results in step 2, the following design criteria can be obtained:

[0133] (1) High-speed and heavy-load conditions will cause a large temperature rise, so cooling measures need to be increased to avoid sudden changes in the properties of the lubricating oil caused by excessive temperature.

[0134] (2) Appropriately increasing the speed and external load helps to improve the system stability.

[0135] (3) It is advisable to adopt hydrodynamic lubrication to avoid large power losses and frictional wear during the start-stop stage or at low speeds.

[0136] Through the present invention, the effects of turbulent flow effect, thermal effect, viscosity-temperature and viscosity-pressure effects, and the elastic deformation of the pad on the lubrication performance of the tilting pad bearing can be comprehensively considered. By using the static performance design method of the high-speed and heavy-duty tilting pad radial sliding bearing provided by the present invention, an effective means is provided for the static performance analysis and design of the high-speed and heavy-duty tilting pad radial sliding bearing. At the same time, the accuracy of the performance design of this type of bearing can be greatly improved, and the R & D cycle can be shortened.

[0137] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A static performance design method for a high-speed heavy-duty tilting pad journal bearing, characterized in that, The steps include: Considering the coupling effect of multiple factors, a lubrication model of high-speed and heavy-load tilting pad radial sliding bearing is established. The factors include turbulence effect, thermal effect, viscosity-temperature-viscosity effect and elastic deformation of pads. Analyze and calculate the static performance of high-speed and heavy-load tilting pad radial sliding bearings; Design the static performance of high-speed and heavy-load tilting pad radial plain bearings; The specific steps of establishing the lubrication model of the high-speed and heavy-loaded tilting pad radial sliding bearing by considering the coupling effect of multiple factors include: According to the geometric model of the tilting pad radial sliding bearing, the local coordinate system of each pad is established in the global coordinate system, and the lubricating oil film thickness equation corresponding to any expansion angle of each pad is established; Establish a calculation and analysis model for the thermal fluid lubrication characteristics of bearings; Realize the coupled calculation of pressure field and temperature field, and obtain the pressure distribution P of the dynamic pressure oil film of the sliding bearing; Thermal-fluid-solid multi-field coupling calculation taking into account the elastic deformation of tiles; Correct the initial preset values ​​of the pads and recalculate until all convergence conditions are met to ensure that the moment of each pad is balanced and the direction and magnitude of the oil film resultant force are the same as the external load; The step of establishing a calculation and analysis model for the thermal fluid lubrication characteristics of the bearing comprises: Calculate the turbulence coefficient; The Reynolds equation, energy equation, and viscosity-temperature-viscosity-pressure equation taking into account the turbulence coefficient are constructed, and a calculation and analysis model for the thermal fluid lubrication characteristics of bearings is established.

2. The static performance design method for a high-speed heavy-duty tilting pad journal bearing according to claim 1, characterized in that, The oil film thickness equation is: ， Among them, represents the oil film thickness corresponding to the when the expansion angle of the th block of tile is The eccentricity of the journal center, is the eccentricity, is the initial clearance, is the bearing offset angle, represents the clearance ratio, For the swing angle of the th block of tile, is the fulcrum position angle of the th block of tile, is the arbitrary expansion angle of the th block of tile, is the elastic deformation of the tile.

3. The static performance design method for a high-speed heavy-duty tilting pad journal bearing according to claim 2, characterized in that, The turbulence coefficient is calculated as follows: ， Among them, , and are turbulence coefficients; The effective Reynolds number is as follows: ， Among them, is the effective Reynolds number, and three different flow regimes: laminar flow, mixed flow, and turbulent flow can be determined by the critical Reynolds number ; is the dimensionless oil film thickness; is the average Reynolds number, and are the lubricating oil density and viscosity respectively, is the bearing rotational speed, is the bearing hole radius, is the initial clearance; The Reynolds equation is expressed as: ， Among them, is the dimensionless oil film pressure; is the dimensionless oil film thickness, is the bearing diameter, is the bearing width, is the bearing aspect ratio; is the dimensionless dynamic viscosity; and are the circumferential and axial coordinates of the bearing, respectively; The energy equation is expressed as: ， Among them, represents the dimensionless temperature of the oil film, , is the dimensional temperature, is the density of the lubricating oil, is the specific heat capacity of the lubricating oil, is the dynamic viscosity of the lubricating oil under standard atmospheric pressure at 40°C; The viscosity-temperature-viscosity-pressure equation is expressed as: ， Among them, represents the dynamic viscosity of the lubricating oil corresponding to the current temperature and pressure, is the dynamic viscosity of the lubricating oil under standard atmospheric pressure at 40°C, is the initial temperature of the lubricating oil, and are the two viscosity-temperature and viscosity-pressure coefficients respectively.

4. The static performance design method for a high-speed heavy-duty tilting pad journal bearing according to claim 3, characterized in that, The specific steps of realizing the coupled calculation of the pressure field and the temperature field and obtaining the pressure distribution P of the dynamic pressure oil film of the sliding bearing include: Use MATLAB computer language to write algorithm programs; Determine the pressure boundary conditions, energy boundary conditions and corresponding convergence judgment conditions of the hydrodynamic oil film of the tilting pad radial sliding bearing; The Reynolds equation, energy equation and viscosity-temperature-viscosity-pressure equation are combined, and after introducing the actual Reynolds number obtained by calculation, the finite difference method is used to discretize the above control equations. The point-by-point super-relaxation iteration method which is easy to converge is used to solve the problem until the convergence criterion is met, and the pressure distribution at each node of the oil film is obtained.

5. A static performance design method for a high-speed heavy-duty tilting pad journal bearing according to claim 4, characterized in that, The specific steps of the thermal-fluid-solid multi-field coupling calculation taking into account the elastic deformation of the tile include: The 3D tilting pad bearing pad model was constructed and meshed using ANSYS software, and the oil film pressure P was applied as a load to each corresponding node in the solid domain. The algorithm program is written using the MATLAB computer language to read the oil film force on the surface of the tile, and the displacement increment of the tile is calculated based on the oil film force; The displacement increment is added to the mesh node position coordinates after the last cycle calculation. When the displacement increment obtained by the cycle calculation meets the elastic deformation convergence judgment condition, the node position coordinates are updated. Stores updated grid node position coordinate information.

6. A static performance design method for a high-speed heavy-duty tilting pad journal bearing according to claim 5, characterized in that, The step of respectively correcting the initial preset values ​​of the tiles and recalculating until all the convergence conditions in the convergence judgment conditions are met includes: ， ， ， in, represents the moment of each tile, is the bearing width, is the dynamic viscosity of the lubricating oil at standard atmospheric pressure at 40°C, is the bearing speed, represents the gap ratio, is the bearing hole radius, is the expansion angle, is the fulcrum position angle, Oil film Direction force, Oil film Direction force, For external load.

7. A static performance design method for a high-speed heavy-duty tilting pad journal bearing according to claim 2, characterized in that, The method for analyzing and calculating the static performance of the high-speed and heavy-loaded tilting pad radial sliding bearing comprises: Based on the established lubrication model of the high-speed and heavy-duty tilting pad journal bearing, the sensitivity analysis of the static performance of the tilting pad journal bearing to operating parameters is carried out. Assuming that a certain design variable remains unchanged, the influence of the change of another design variable on the static performance of the tilting pad journal bearing is calculated and analyzed. The static performance includes oil film pressure, oil film thickness, eccentricity and oil film temperature, and the design variables include the magnitude of the external load and the rotational speed.

8. A static performance design method for a high-speed heavy-duty tilting pad journal bearing according to claim 7, characterized in that, The method for designing the static performance of the high-speed and heavy-duty tilting pad journal bearing includes: Based on the sensitivity analysis results of the static performance of the tilting pad journal bearing to the design variables, taking the design variables corresponding to the maximum oil film pressure, the minimum oil film thickness and the minimum eccentricity as the optimal values, the oil film temperature rise is obtained.

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