Static pressure rotary table protection device based on bidirectional fluid-solid coupling analysis and design and optimization method thereof

Abstract

The invention provides a static pressure rotary table protection device based on bidirectional fluid-solid coupling analysis and a design and optimization method of the static pressure rotary table protection device in order to solve the problems that a traditional pressing plate is insufficient in rigidity, a hub deforms after being loaded and the precision of a rotary table system is influenced, and the static pressure rotary table protection device is characterized by comprising a bolt fastening area and a static pressure oil cavity area. The method mainly comprises the steps that structural parameters of the annular pressing plate are selected as design variables, hub deformation serves as an optimization target, simulation data are collected through bidirectional fluid-solid coupling analysis, and response surface analysis is constructed to obtain the optimal structural parameters of the annular pressing plate. The method not only considers the deformation generated by the action of the oil in the oil cavity on the hub part, but also considers the influence on the oil film thickness, pressure and the like of the oil in the oil cavity after the deformation of the solid domain. According to the invention, the deformation of the hub can be greatly reduced, and the transmission precision of turntable equipment is improved.

Description

Technical Field

[0001] The present invention relates to the field of static pressure turntable protection devices, and more particularly to a static pressure turntable protection device based on bidirectional fluid-solid coupling analysis and a design and optimization method thereof. Background Art

[0002] Hydrostatic turntables, with their advantages of averaged error, strong load-bearing capacity, excellent rigidity, and low-speed non-creep, have become a crucial component of large, heavy-duty CNC machine tools. Hydrostatic guideways provide support for hydrostatic turntables. However, due to uneven oil pipeline lengths and varying oil flow times between chambers, the turntable surface can tip over. Therefore, a turntable protection device is necessary to ensure safe and stable operation.

[0003] The prior art has the following problems:

[0004] Traditional block-type pressure plates suffer from insufficient rigidity. When the turntable is excessively lifted, the block-type pressure plate bears a heavy load, deforming and potentially coming into contact with the wheel hub, affecting transmission accuracy. Furthermore, when the turntable is unloaded, the oil film thickness of the traditional block-type pressure plate is extremely thin, and the oil chamber pressure is extremely high, causing wheel hub deformation and compromising turntable transmission accuracy. Summary of the Invention

[0005] The present invention provides a design and optimization method for a static pressure turntable protection device based on bidirectional fluid-solid coupling analysis, so as to solve the problem that a traditional block-shaped pressure plate causes hub deformation, thereby reducing the turntable machining accuracy.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A hydrostatic turntable protection device based on bidirectional fluid-solid coupling analysis includes a pressure plate fastening area and a hydrostatic oil chamber area. The pressure plate fastening area includes a plurality of bolt holes for fixing the pressure plate to the base; the hydrostatic oil chamber area includes a plurality of evenly distributed hydrostatic oil chambers for preventing excessive floating of the wheel hub and improving the anti-overturning ability of the turntable.

[0008] A design and optimization method for a static pressure turntable protection device based on bidirectional fluid-structure coupling analysis is provided, which is performed using the static pressure turntable protection device and specifically includes the following steps:

[0009] S1: Based on the original layout and structural dimensions of the hydrostatic turntable, a solid-fluid 3D coupled model of the platen oil film, wheel hub, and guide rail oil film was created and imported into the ANSYS fluid-solid coupling analysis module. In the software pre-processing module, appropriate model simplification was performed and boundaries were named.

[0010] S2: In the Fluent module, set the fluid model, boundary conditions, residual criteria, solution method, control coefficients, and other control parameters based on the actual working conditions and relevant knowledge of fluid mechanics. Set the physical parameters of the hydraulic oil according to the hydraulic oil type, perform fluid meshing and finite element simulation on the guide rail oil film and the pressure plate oil film, and obtain the pressure field of the hydrostatic turntable hub;

[0011] S3: The simulation results obtained in step S2 are imported into the wheel hub through the fluid-structure coupling interface to simulate the deformation field of the wheel hub; the simulation results of the fluid domain and the simulation results of the solid domain are imported into the System Coupling module for bidirectional fluid-structure coupling analysis;

[0012] S4: Post-process the coupling analysis results to extract the deformation δ of the hub outer ring. surface , the guide rail oil chamber oil pressure P1 and the pressure plate oil chamber oil pressure P2 data. Modify the pressure plate structural parameters, repeat the above steps, and collect simulation results.

[0013] S5: Use the Kriging function method to perform response surface analysis on the simulation data collected in step S4 to obtain the deformation δ of the outer ring of the hub surface The fitting function of the platen structural parameters; the overall deformation of the oil cover δ surface As the objective function, the platen structural parameters are used as design variables to establish a mathematical model for platen structural parameter optimization. The model is solved to obtain the optimal structural parameters of the static pressure platen.

[0014] The mathematical model for optimizing the platen structural parameters is shown in formulas (1) to (6):

[0015] Objective function:

[0016] f(x)={minf δ (x)} (1)

[0017] Design variables:

[0018] x=[x1,x2,x3,x4,x5,…,x n ] T (2)

[0019] Constraints:

[0020] minf δ (x)≤f' δ (x) (3)

[0021] 2Mpa≤f P1 (x)≤3Mpa (4)

[0022] 2Mpa≤f P2 (x)≤3Mpa (5)

[0023] a i ≤x i ≤b i (i=1,2,…,n) (6)

[0024] Among them, x i is the design variable, representing n typical platen structural parameter values; a i is the design variable x i The lower limit constraint represents the design variable x i The minimum value of b i is the design variable x i The upper limit constraint represents the design variable x i The maximum value of f δ (x), f' δ (x) are the hub deformation and the initial hub deformation respectively; f P1 (x) is the pressure value of the oil film in the guide rail oil chamber; f P2 (x) is the pressure value of the oil film in the pressure plate oil chamber.

[0025] The bidirectional fluid-structure interaction model of a large CNC hydrostatic turntable corresponding to step S1 is primarily composed of a pressure plate, a wheel hub, and a guide plate. The oil film is formed by the flow of hydraulic oil through the gaps between the oil chambers of the hydrostatic pressure plate or guide plate and the wheel hub. During meshing, each model component is divided into hexahedral meshes based on its characteristics, taking into account the model's complexity and the effectiveness of dynamic mesh generation, and each boundary surface is named.

[0026] The setting process of the coupled model fluid domain analysis in step S2 can be expressed as follows:

[0027] Step 2.1 Determine the fluid model in the oil cavity. The fluid model in the oil cavity can be determined according to formula (7).

[0028]

[0029] Where Re is the Reynolds number, ρ is the density of the hydraulic oil in the oil chamber, v is the flow velocity of the hydraulic oil in the oil chamber, d is the length of the pipeline, and μ is the viscosity coefficient of the hydraulic oil in the oil chamber;

[0030] Step 2.2 Set the fluid boundary conditions. Set the fluid inlet, fluid outlet, and fluid-solid coupling interface based on the oil cavity structure and oil film characteristics.

[0031] Step 2.3: Set the physical properties of the hydraulic oil. The physical properties include dynamic viscosity, density and other physical parameters.

[0032] Step 2.5 initializes the fluid domain and performs calculations to obtain the pressure distribution in the fluid domain of the static pressure plate / static pressure guide plate.

[0033] In step S3, the solid domain in the parametric coupling model of the large heavy-load hydrostatic turntable is analyzed using the statics analysis module in ANSYS. The pressure field simulation data of the oil cavity in step S2 is imported into the statics analysis module of ANSYS through the coupling interface to constrain the boundary conditions of the model. The solid solver is used to perform solution calculations to obtain the deformation of the wheel hub.

[0034] In step S3, the system coupling module is used to achieve data exchange between the fluid domain analysis and the solid domain. The pressure of the oil in the oil cavity acts on the wall of the solid domain, causing the solid domain wall to deform. The deformation of the solid domain wall further affects the pressure and flow of the oil in the oil cavity.

[0035] The modification of the static pressure plate structural parameters mentioned in step S4 includes but is not limited to modifying the pressure plate oil cavity shape, oil pad type, oil cavity installation position, oil cavity size parameters, and oil film thickness.

[0036] This invention not only considers the deformation caused by the oil in the oil chamber on the hub components, but also considers the impact of the deformation of the solid domain on the oil film thickness and pressure of the oil in the oil chamber. This invention can greatly reduce the deformation of the hub and improve the transmission accuracy of the turntable equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is an outline diagram of the annular pressure plate of the present invention;

[0038] Figure 2 This is an outline diagram of the turntable base of the present invention;

[0039] Figure 3 This is an outline diagram of the wheel hub assembly of the present invention;

[0040] Figure 4 This is a schematic diagram of the installation of the annular pressure plate of the present invention;

[0041] Figure 5 This is a diagram showing the deformation of the hub when the block pressure plate of the present invention is used;

[0042] Figure 6 This is a diagram showing the deformation of the hub when the annular pressure plate of the present invention is used;

[0043] Serial numbers in the figure: 1. Press plate fastening area; 2. Press plate static pressure oil chamber area; 3. Guide plate static pressure oil chamber area. DETAILED DESCRIPTION

[0044] The following is a combination of the embodiments of the present invention Figure 1-6, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0045] Example 1: This example provides a static pressure turntable protection device based on bidirectional fluid-solid coupling analysis, see Figure 1-4 , including a pressure plate fastening area 1 and a static pressure oil chamber area 2.

[0046] The pressure plate fastening area includes several bolt holes for fixing the pressure plate to the base; the static pressure oil chamber area includes several evenly distributed static pressure oil chambers for preventing excessive floating of the wheel hub and improving the turntable's anti-overturning ability.

[0047] In the specific implementation process, the static pressure oil chamber area 2 of the annular pressure plate contacts the upper surface of the hub assembly, and the static pressure oil chamber area 3 of the base surface guide plate contacts the lower surface of the hub. Figure 4 shown.

[0048] During operation, the hydraulic station delivers hydraulic oil to the inlet of the static oil chamber. The oil then flows back through the oil seal to the oil return tank, from which it is discharged back to the hydraulic station, completing the cycle. A static oil film forms between the oil seal on the guide rail surface, the oil seal on the pressure plate, and the wheel hub, buoying the moving guide rail surface and maintaining a pure liquid friction state between the guide rail surface, pressure plate, and wheel hub, significantly reducing frictional resistance and power consumption.

[0049] Embodiment 2: This embodiment provides an optimization method for a static pressure turntable protection device based on bidirectional coupling analysis, specifically comprising the following steps:

[0050] S1: Based on the original layout and structural dimensions of the hydrostatic turntable, a solid-fluid 3D coupled model of the platen oil film, wheel hub, and guide rail oil film was created and imported into the ANSYS fluid-solid coupling analysis module. In the software pre-processing module, appropriate model simplification was performed and boundaries were named.

[0051] S2: In the Fluent module, set the fluid model, boundary conditions, residual criteria, solution method, control coefficients, and other control parameters based on the actual working conditions and relevant knowledge of fluid mechanics. Set the physical parameters of the hydraulic oil according to the hydraulic oil type, perform fluid meshing and finite element simulation on the guide rail oil film and the pressure plate oil film, and obtain the pressure field of the hydrostatic turntable hub;

[0052] S3: The simulation results obtained in step S2 are imported into the wheel hub through the fluid-structure coupling interface to simulate the deformation field of the wheel hub; the simulation results of the fluid domain and the simulation results of the solid domain are imported into the System Coupling module for bidirectional fluid-structure coupling analysis;

[0053] S4: Post-process the coupling analysis results to extract the deformation δ of the hub outer ring. surface , the guide rail oil chamber oil pressure P1 and the pressure plate oil chamber oil pressure P2 data. Modify the pressure plate structural parameters, repeat the above steps, and collect simulation results.

[0054] S5: Use the Kriging function method to perform response surface analysis on the simulation data collected in step S4 to obtain the deformation δ of the outer ring of the hub surface The fitting function of the platen structural parameters; the overall deformation of the oil cover δ surface As the objective function, the platen structural parameters are used as design variables to establish a mathematical model for platen structural parameter optimization. The model is solved to obtain the optimal structural parameters of the static pressure plate. The hub deformation of the annular platen and the block platen is as follows: Figure 5 、 6 As shown in the figure, the hub deformation is reduced from 0.089mm to 0.003mm, a reduction of about 96%.

[0055] The mathematical model for optimizing the platen structural parameters is shown in formulas (1) to (6):

[0056] Objective function:

[0057] f(x)={minf δ (x)} (1)

[0058] Design variables:

[0059] x=[x1,x2,x3,x4,x5,…,x n ] T (2)

[0060] Constraints:

[0061] minf δ (x)≤f′ δ (x) (3)

[0062] 2Mpa≤f P1 (x)≤3Mpa (4)

[0063] 2Mpa≤f P2 (x)≤3Mpa (5)

[0064] a i ≤x i ≤b i (i=1,2,…,n) (6)

[0065] Among them, x i is the design variable, representing n typical platen structural parameter values; a i is the design variable x iThe lower limit constraint represents the design variable x i The minimum value of b i is the design variable x i The upper limit constraint represents the design variable x i The maximum value of f δ (x), f' δ (x) are the hub deformation and the initial hub deformation respectively; f P1 (x) is the pressure value of the oil film in the guide rail oil chamber; f P2 (x) is the pressure value of the oil film in the pressure plate oil chamber.

[0066] The bidirectional fluid-structure interaction model of a large CNC hydrostatic turntable corresponding to step S1 is primarily composed of a pressure plate, a wheel hub, and a guide plate. The oil film is formed by the flow of hydraulic oil through the gaps between the oil chambers of the hydrostatic pressure plate or guide plate and the wheel hub. During meshing, each model component is divided into hexahedral meshes based on its characteristics, taking into account the model's complexity and the effectiveness of dynamic mesh generation, and each boundary surface is named.

[0067] The setting process of the coupled model fluid domain analysis in step S2 can be expressed as follows:

[0068] Step 2.1 Determine the fluid model in the oil cavity. The fluid model in the oil cavity can be determined according to formula (7).

[0069]

[0070] Where Re is the Reynolds number, ρ is the density of the hydraulic oil in the oil chamber, v is the flow velocity of the hydraulic oil in the oil chamber, d is the length of the pipeline, and μ is the viscosity coefficient of the hydraulic oil in the oil chamber;

[0071] Step 2.2 Set the fluid boundary conditions. Set the fluid inlet, fluid outlet, and fluid-solid coupling interface based on the oil cavity structure and oil film characteristics.

[0072] Step 2.3: Set the physical properties of the hydraulic oil. The physical properties include dynamic viscosity, density and other physical parameters.

[0073] Step 2.5 initializes the fluid domain and performs calculations to obtain the pressure distribution in the fluid domain of the static pressure plate / static pressure guide plate.

[0074] In step S3, the solid domain in the parametric coupling model of the large heavy-load hydrostatic turntable is analyzed using the statics analysis module in ANSYS. The pressure field simulation data of the oil cavity in step S2 is imported into the statics analysis module of ANSYS through the coupling interface to constrain the boundary conditions of the model. The solid solver is used to perform solution calculations to obtain the deformation of the wheel hub.

[0075] In step S3, the system coupling module is used to achieve data exchange between the fluid domain analysis and the solid domain. The pressure of the oil in the oil cavity acts on the wall of the solid domain, causing the solid domain wall to deform. The deformation of the solid domain wall further affects the pressure and flow of the oil in the oil cavity.

[0076] The modification of the static pressure plate structural parameters mentioned in step S4 includes but is not limited to modifying the pressure plate oil cavity shape, oil pad type, oil cavity installation position, oil cavity size parameters, and oil film thickness.

[0077] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A static pressure turntable protection device based on bidirectional fluid-solid coupling analysis, characterized in that: It includes a pressure plate fastening area and a static pressure oil chamber area. The pressure plate fastening area includes a plurality of bolt holes for fixing the pressure plate to the base; the static pressure oil chamber area includes a plurality of evenly distributed static pressure oil chambers for preventing the wheel hub from floating excessively and improving the turntable's anti-overturning ability.

2. A design and optimization method for a static pressure turntable protection device based on bidirectional fluid-solid coupling analysis, characterized in that: The static pressure turntable protection device is used to carry out the process, which specifically includes the following steps: S1: According to the original layout and structural dimensions of the hydrostatic turntable, a solid and fluid three-dimensional coupling model of the pressure plate oil film, wheel hub and guide rail oil film is established and imported into the ANSYS fluid-solid coupling analysis module. In the software pre-processing module, appropriate model simplification is performed and the boundaries are named; S2: In the Fluent module, set the fluid model, boundary conditions, residual standard, solution method, control coefficient and other control parameters according to the actual working conditions and relevant knowledge of fluid mechanics. Set the physical parameters of the oil according to the model of the hydraulic oil, perform fluid meshing and finite element simulation on the guide rail oil film and the pressure plate oil film, and obtain the pressure field of the hydrostatic turntable hub; S3: The simulation results obtained in step S2 are imported into the wheel hub through the fluid-solid coupling interface to simulate the deformation field of the wheel hub; the simulation results of the fluid domain and the simulation results of the solid domain are imported into the System Coupling system coupling module to perform bidirectional fluid-solid coupling analysis; S4: Post-process the coupling analysis results to extract the deformation δ of the hub outer ring. surface , guide rail oil chamber oil pressure P1 and pressure plate oil chamber oil pressure P2 data. Modify the pressure plate structure parameters, repeat the above steps, and collect simulation results. S5: Use the Kriging function method to perform response surface analysis on the simulation data collected in step S4 to obtain the deformation δ of the outer ring of the hub surface The fitting function of the platen structural parameters; the overall deformation of the oil cover δ surface As the objective function, the platen structural parameters are taken as design variables, and a mathematical model for optimizing the platen structural parameters is established. The model is solved to obtain the optimal structural parameters of the static pressure platen. The mathematical model for optimizing the platen structural parameters is shown in formulas (1) to (6): Objective function: f(x)={minf δ (x)} (1) Design variables: x=[x1,x2,x3,x4,x5,…,x n ] T (2) Constraints: minf δ (x)≤f′ δ (x) (3) 2Mpa≤f P1 (x)≤3Mpa (4) 2Mpa≤f P2 (x)≤3Mpa (5) a i ≤x i ≤b i (i=1,2,…,n) (6) Among them, x i is the design variable, representing n typical platen structural parameter values; a i is the design variable x i The lower limit constraint represents the design variable x i The minimum value of b i is the design variable x i The upper limit constraint represents the maximum value of the design variable xi; f δ (x), f′ δ (x) are the hub deformation and the initial hub deformation respectively; f P1 (x) is the pressure value of the oil film in the guide rail oil chamber; f P2 (x) is the pressure value of the oil film in the pressure plate oil chamber.

3. The optimization method of a static pressure turntable protection device based on bidirectional fluid-solid coupling analysis according to claim 2 is characterized in that: The bidirectional fluid-solid coupling model of the large CNC hydrostatic turntable corresponding to step S1 is mainly composed of a pressure plate, a wheel hub and a guide plate; wherein the oil film is formed by the flow of hydraulic oil in the gap between the oil chambers of the hydrostatic pressure plate or the guide plate and the wheel hub. When meshing, the parts of the model are divided into hexahedral meshes according to the characteristics of each part of the model, taking into account the complexity of the model and the effect of dynamic mesh generation, and each boundary surface is named.

4. The optimization method of a static pressure turntable protection device based on bidirectional fluid-solid coupling analysis according to claim 2 is characterized in that: The setup process of the coupled model fluid domain analysis in step S2 can be expressed as follows: Step 2.1 Determine the fluid model in the oil cavity. The fluid model in the oil cavity can be determined according to formula / 7). Where Re is the Reynolds number, ρ represents the density of the hydraulic oil in the oil chamber, v represents the flow velocity of the hydraulic oil in the oil chamber, d represents the length of the pipeline, and μ represents the viscosity coefficient of the hydraulic oil in the oil chamber; Step 2.2 Set the boundary conditions of the fluid. Set the fluid inlet, fluid outlet and fluid-solid coupling interface according to the oil cavity structure and oil film characteristics. Step 2.3 sets the physical performance parameters of the hydraulic oil. The physical performance parameters include dynamic viscosity, density and other physical parameters; Step 2.5 initializes the fluid domain and performs calculations to obtain the pressure distribution of the fluid domain of the static pressure plate / static pressure guide plate.

5. The optimization method of a static pressure turntable protection device based on bidirectional fluid-solid coupling analysis according to claim 2 is characterized in that: In step S3, the statics analysis module in ANSYS is used to analyze the solid domain in the parametric coupling model of the large heavy-load hydrostatic turntable. The pressure field simulation data of the oil cavity in step S2 is imported into the statics analysis module of ANSYS through the coupling interface to constrain the boundary conditions of the model. The solid solver is used to perform solution calculations to obtain the deformation of the wheel hub.

6. The optimization method of a static pressure turntable protection device based on bidirectional fluid-solid coupling analysis according to claim 2 is characterized in that: In step S3, the system coupling module is used to realize the data exchange between the fluid domain analysis and the solid domain. The pressure of the oil in the oil cavity acts on the wall of the solid domain to deform the wall of the solid domain, and the deformation of the wall of the solid domain further affects the pressure and flow of the oil in the oil cavity.

7. The optimization method of a static pressure turntable protection device based on bidirectional fluid-solid coupling analysis according to claim 2 is characterized in that: The modification of the static pressure plate structural parameters mentioned in step S4 includes but is not limited to modifying the shape of the pressure plate oil cavity, the oil pad type, the oil cavity installation position, the oil cavity size parameters, and the oil film thickness.

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