A wind power three-row column variable pitch bearing injection and drainage hole simulation analysis method

Abstract

The application discloses a kind of wind power three-row column variable pitch bearing injection and drainage hole simulation analysis method.For the problems of numerous variable pitch bearing injection and drainage holes, difficulty in meshing the overall finite element model and difficulty in convergence, the method first creates an overall mechanical analysis model without injection and drainage holes, uses spring element to equivalent rolling body, carries out overall finite element analysis, extracts the maximum load and inclination angle of roller;Then, according to the maximum load position, a submodel with injection and drainage holes is established, considering the profile modification and inclination angle of solid rollers, the grid of key parts is refined;Finally, the stress of injection and drainage holes and the contact stress of raceway are obtained through submodel analysis to evaluate the influence on bearing carrying capacity.The application avoids the problem of calculation divergence caused by global grid refinement, can effectively analyze the stress of injection and drainage holes, and provides reference for bearing structure design and optimization.

Description

Technical Field

[0001] This invention belongs to the field of bearing simulation analysis technology, and in particular, it is a simulation analysis method for the oil injection and drainage holes of a three-row column pitch bearing for wind power. Background Technology

[0002] This invention provides a simulation analysis method for the oil injection and drainage holes of a three-row column pitch bearing in wind turbines. Taking the three-row column pitch bearing as the research object, this invention further studies how to analyze the influence of the small internal structures such as the oil injection and drainage holes on the bearing race on the strength of key parts of the race. Typically, bearings have a large number of oil injection and drainage holes, making it difficult to divide the overall finite element analysis mesh, and the detailed analysis of key parts is not easy to converge. Usually, these structures are not analyzed in finite element analysis of bearings. This invention attempts to study a simulation analysis method for a three-row column pitch bearing with oil injection and drainage holes, which can be used to analyze the stress in the oil injection and drainage holes, providing a certain reference value for improving the evaluation of bearing load-bearing capacity. Summary of the Invention

[0003] In view of the above problems, the purpose of this application is to provide a simulation analysis method for the oil injection and drainage holes of a three-row column pitch bearing for wind power, which can evaluate the stress of the bearing with oil injection and drainage holes, and provide more reliable guidance for bearing structure design based on traditional bearing simulation analysis and calculation methods.

[0004] To achieve some or all of the above objectives or other objectives, this application provides the following technical solution: a simulation analysis method for the oil injection and drainage holes of a three-row column pitch bearing in wind turbines, comprising the following steps: Step 1: Create an overall mechanical analysis model of a three-row column pitch bearing without oil injection / drainage holes; Step 2: Set the relevant input parameters for the finite element analysis of the overall mechanical analysis model and perform finite element analysis preprocessing on the overall mechanical analysis model; Step 3: Define the load boundaries and applied loads for the overall mechanical analysis model, and perform finite element analysis on the overall mechanical analysis model; Step 4: Extract the overall mechanical analysis model and perform finite element analysis on the maximum load and tilt angle of the bearing rollers, including extracting the maximum load and corresponding tilt angle of the rollers on the blade side and hub side respectively, and determining whether it occurs on the blade side or the hub side. Step 5: Based on the location of the maximum load, create a finite element analysis sub-model of the three-row column pitch bearing with oil injection and drainage holes, and perform finite element analysis preprocessing, including creating a half-shaped cylindrical roller, inner and outer rings, and hub-side oil injection holes in Ansys Workbench to simulate the bearing outer ring being fixed to the hub, while the inner ring, due to the load transmitted from the blades, will generate relative displacement that is transmitted to the axial and radial rollers. Based on the tilt angle data corresponding to the maximum load on the blade side or hub side of the overall analysis, adjust the tilt angle of the rollers and inner ring relative to the outer ring accordingly. Step 6: Set the boundary conditions and loads for the finite element analysis sub-model of the three-row column pitch bearing with oil injection and drain holes. Perform finite element analysis on the finite element analysis sub-model of the three-row column pitch bearing with oil injection and drain holes, including setting the boundary constraints of the inner and outer rings and rollers, determining the maximum load loading position, and performing finite element analysis. Step 7: Based on finite element analysis, obtain the stress in the oil injection and drainage holes of the three-row column pitch bearing, and make a preliminary assessment of its impact on the bearing's load-bearing capacity.

[0005] Furthermore, the creation of the overall mechanical analysis model of the three-row column pitch bearing without oil injection and drainage holes in step one includes establishing a three-dimensional model of the three-row column pitch bearing using three-dimensional software based on the drawings. To simplify the analysis, the rolling elements are replaced by equivalent spring units. The overall mechanical analysis model of the assembly spindle-hub-bearing-blade system is then imported into the finite element software Ansysworkbench.

[0006] Furthermore, the finite element analysis related input parameters of the overall mechanical analysis model described in step two are used to perform finite element analysis preprocessing on the overall mechanical analysis model, including determining the load coordinate system, load spectrum, bearing material properties, element type and mesh generation, and bolt connection parameters.

[0007] Furthermore, in step three, the load boundaries and applied loads of the overall mechanical analysis model are set, and finite element analysis is performed on the overall mechanical analysis model, including applying full constraints to the end face of the spindle bearing and applying remote loads according to the load coordinate system.

[0008] Furthermore, step seven involves obtaining the stress in the oil injection and drainage holes of the three-row column pitch bearing based on finite element analysis, including extracting the stress in the oil injection and drainage holes and the contact stress of the adjacent raceways, and making a preliminary assessment of the impact on the bearing's load-bearing capacity.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a simulation analysis method for the oil injection and drainage holes of a three-row column pitch bearing in wind power. By using Ansys Workbench to establish a sub-model of the three-row column pitch bearing with oil injection and drainage holes, a series of issues such as solid roller shaping, roller tilt angle, and mesh refinement of key analysis parts are considered. This avoids the problem that the overall mechanical analysis model is not easy to converge after global mesh refinement. This method can preliminarily analyze the stress of the three-row column pitch bearing with oil injection and drainage holes and the contact stress of the adjacent raceways, providing certain reference value for improving the evaluation of bearing load capacity and optimizing the design of complex internal bearing structures. Attached Figure Description

[0010] Figure 1 This is a flowchart of the calculation process of the present invention; Figure 2 This is the finite element analysis model of the three-row column pitch bearing of the present invention; Figure 3This is the finite element analysis mesh model for the three-row column pitch bearing of the present invention; Figure 4 This is a schematic diagram of the bolt connection of the three-row column pitch bearing of the present invention; Figure 5 This is the coordinate system for defining the boundary and loading the load of the three-row column pitch bearing in this invention. Figure 6 This is a schematic diagram showing the relevant positions of the oil injection and drainage holes in the three-row column pitch bearing of the present invention; Figure 7 This is a model of the three-row column pitch bearing hub side (maximum stress side) with oil injection and drainage holes according to the present invention; Figure 8 Mesh generation for the sub-model of the three-row column pitch bearing hub side (with oil injection and drainage holes); Figure 9 This is an equivalent stress cloud diagram of the oil hole on the hub side (with oil injection and drainage holes) of the bearing outer ring of the present invention; Figure 10 This is a cloud diagram of the contact stress of the raceway on the hub side (without oil injection / drainage holes) of the outer ring of the bearing of the present invention; Figure 11 This is a cloud diagram of the contact stress of the raceway on the hub side (with oil injection and drainage holes) of the outer ring of the bearing of the present invention; In the diagram: 1. Main shaft, 2. Hub, 3. Bearing, 4. Flange, 5. Blade, 6. Bolt end face, 7. Bolt connection, 8. Blade side oil drain hole, 9. Hub side oil drain hole. Detailed Implementation

[0011] To make the structure and function of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0012] See appendix Figure 1-11 A simulation analysis method for the oil injection and drainage holes of a three-row column pitch bearing in wind turbines includes the following steps: Create an overall mechanical analysis model for a three-row column pitch bearing without oil injection / drainage holes. 1.1 The rolling elements are replaced by spring units. Due to the large number of rolling elements in the three-row column pitch bearing of wind turbines, solid analysis is difficult, so spring elements are used instead. The contact condition of the rolling bearing basically conforms to the Hertz assumption. In the simplified finite element model, the axial and radial rollers are divided into multiple spring elements. The nonlinear springs are only subjected to tension to simulate the load distribution of the rolling elements, where the contact deformation between the loaded rolling element and the inner and outer rings is δ. The pitch bearing with two raceways in line contact is calculated under load conditions of pure axial and radial displacement. The basic theory of load and deformation of the rolling elements in line contact is derived from the ISO / TS16281 formula using equations (1) and (2). (1) Wherein, the spring constant C, for steel contact parts... (2) In equations (1) and (2), Q It is the maximum load on the rolling element, calculated using the finite element method, and its unit is N. L It is the effective length of the roller. L , δ All units are mm.

[0013] 1.2 Establishment of 3D models for remaining parts See appendix Figure 2 Based on the bearing drawings, the small structures on the bearing, such as chamfers and fillets, are simplified. A simplified three-dimensional model of the bearing is established using three-dimensional software. The small structures on the given hub model are processed to build an overall mechanical analysis model of the main shaft 1-hub 2-bearing 3-blade 5 system, which is then imported into AnsysWorkbench finite element analysis software.

[0014] Set the relevant input parameters for the overall mechanical analysis model in the finite element analysis, and perform finite element analysis preprocessing on the overall mechanical analysis model. 2.1 Load Spectrum See appendix Figure 3-4 The load is located at the root of the blade. The load is established at the blade root to ensure that the load coordinate system is consistent with the given coordinate system.

[0015] 2.2 Bearing Material Properties Determine the material properties of the bearing and related connecting parts, including elastic modulus and Poisson's ratio, and input them into the material property settings in AnsysWorkbench.

[0016] 2.3 Element Types and Mesh Generation Element types: Solid elements such as hub 2, bearing 3, and blade 5 are represented by solid element 186; steel balls are equivalent to springs and are represented by spring element 39; bolts are equivalent to beams and are represented by beam element 188.

[0017] Local mesh processing: The surfaces of the bolt holes of bearing 3, hub 2, and blade 5 are refined; the surface of the bearing raceway is also refined.

[0018] 3. Define the load boundaries and applied loads for the overall mechanical analysis model, and perform finite element analysis on the overall mechanical analysis model. 3.1 Setting load boundary conditions See appendix Figure 4-5 X, Y, and Z refer to the coordinate system for the load on the three blades, used for load component orientation.

[0019] Full constraint on the end face of the spindle bearing ( UX = 0、 UY = 0、 UZ = 0、 ROTX = 0、 ROTY = 0、 ROTZ =0). UX, UY, and UZ represent the translational displacement of the constraint surface along the X, Y, and Z coordinate axes, respectively. A value of 0 indicates that the translation is restricted in the corresponding direction. ROTX, ROTY, and ROTZ represent the rotational angular displacement of the constraint surface around the X, Y, and Z coordinate axes, respectively. A value of 0 indicates that the rotation is restricted in the corresponding axis. When all six parameters are 0, a fully fixed constraint is applied to the mating surface between the spindle and the bearing.

[0020] 3.2 Apply preload to the inner and outer ring bolts of the bearing The outer ring of the bearing makes frictional contact with the hub 2, and the inner ring makes frictional contact with the flange blade 5 to establish a bolt connection. The bolt end face 6 and the bolt connection 7 are in binding contact to determine the magnitude of the preload.

[0021] Obtain the overall mechanical analysis model and perform finite element analysis on the maximum load and tilt angle of the bearing rollers. Extract the maximum load and corresponding tilt angle of the rolling element from the finite element calculation. The roller tilt angle is calculated by extracting the radial relative displacement of the spring node element and the roller length.

[0022] 5. Based on the location of the maximum load (hub side), create a finite element analysis sub-model of the three-row column pitch bearing with oil injection and drainage holes, and perform finite element analysis preprocessing. 5.1 Creating a Finite Element Analysis Submodel for a Three-Row Column Pitch Bearing with Injector and Drain Holes See appendix Figure 6 According to the bearing drawings, in Ansys Workbench, since the maximum load location during the overall finite element analysis is the hub side, a finite element analysis sub-model of the three-row column pitch bearing with oil injection and drainage holes is established as a sub-model of half a modified cylindrical roller, inner ring, outer ring, and hub-side oil injection hole 9. This simulates the bearing outer ring being fixed to the hub, while the inner ring, due to the load transmitted from the blades, will generate relative displacement that is transmitted to the axial and radial rollers. Based on the tilt angle data corresponding to the maximum load on the blade side or hub side in the overall analysis, the tilt angle of the rollers and inner ring relative to the outer ring is adjusted accordingly.

[0023] 5.2 Mesh Generation See appendix Figure 8 The grid size of key parts such as oil grooves, contact areas between rollers and raceways, and oil injection / drainage holes is refined; the grid size of other parts can be increased accordingly to facilitate analysis and calculation.

[0024] 6. Set the boundary conditions and applied loads for the finite element analysis sub-model of the three-row column pitch bearing with oil injection and drain holes, and perform finite element analysis on the sub-model. See appendix Figure 7 The bottom surface of the outer ring of the finite element analysis sub-model of the three-row column pitch bearing with oil filling and drain holes is fixed to the hub mating surface, which restricts the normal displacement of the inner and outer ring sides and the axial displacement of the roller middle surface. Since only half of the roller and inner and outer ring models are drawn, half of the maximum load on the bearing hub side bearing of the entire bearing ANSYS finite element calculation result is applied to the upper surface of the inner ring of the finite element analysis sub-model of the three-row column pitch bearing with oil filling and drain holes.

[0025] 7. Based on finite element analysis, the stress in the oil injection and drainage holes of the three-row column pitch bearing was obtained, and its impact on the bearing's load-bearing capacity was preliminarily assessed. See appendix Figure 9-11 After calculation and analysis in AnsysWorkbench, the stress with and without the oil drain hole, the contact stress of the adjacent raceway, and the contact stress of the adjacent raceway are extracted. Based on the allowable contact stress of the bearing raceway, the static safety factor formula for the bearing raceway is calculated. The preliminary assessment of the impact of the oil injection / drainage holes on the bearing load capacity is shown in Table 1.

[0026] Table 1. Oil hole stress and raceway contact stress of the three-row column bearing sub-model

Claims

1. A simulation analysis method for the oil injection and drainage holes of a three-row column pitch bearing in wind turbines, characterized in that: Includes the following steps: Step 1: Create an overall mechanical analysis model of the three-row column pitch bearing without oil injection and drainage holes. This includes creating a three-dimensional model of the three-row column pitch bearing using 3D software based on the drawings. To simplify the analysis, the rolling elements are replaced with equivalent spring units. Assemble the overall mechanical analysis model of the main shaft-hub-bearing-blade system and import it into the finite element software Ansys Workbench. Step 2: Set the relevant input parameters for the finite element analysis of the overall mechanical analysis model, and perform finite element analysis preprocessing on the overall mechanical analysis model, including determining the load coordinate system, load spectrum, bearing material properties, element type and mesh generation, and bolt connection parameters; Step 3: Set the load boundaries and applied loads of the overall mechanical analysis model, and perform finite element analysis on the overall mechanical analysis model, including applying full constraints to the spindle bearing end face and applying remote loads according to the load coordinate system; Step 4: Extract the overall mechanical analysis model and perform finite element analysis on the maximum load and tilt angle of the bearing rollers, including extracting the maximum load and corresponding tilt angle of the rollers on the blade side and hub side respectively, and determining whether it occurs on the blade side or the hub side. Step 5: Based on the location of the maximum load, create a finite element analysis sub-model of the three-row column pitch bearing with oil injection and drainage holes, and perform finite element analysis preprocessing, including creating a half-shaped cylindrical roller, inner and outer rings, and hub-side oil injection holes in Ansys Workbench to simulate the bearing outer ring being fixed to the hub, while the inner ring, due to the load transmitted from the blades, will generate relative displacement that is transmitted to the axial and radial rollers. Based on the tilt angle data corresponding to the maximum load on the blade side or hub side of the overall analysis, adjust the tilt angle of the rollers and inner ring relative to the outer ring accordingly. Step 6: Set the boundary conditions and loads for the finite element analysis sub-model of the three-row column pitch bearing with oil injection and drain holes. Perform finite element analysis on the finite element analysis sub-model of the three-row column pitch bearing with oil injection and drain holes, including setting the boundary constraints of the inner and outer rings and rollers, determining the maximum load loading position, and performing finite element analysis. Step 7: Based on finite element analysis, obtain the stress in the oil injection and drainage holes of the three-row column pitch bearing, including extracting the stress in the oil injection and drainage holes and the contact stress of the adjacent raceways, and make a preliminary assessment of the impact on the bearing's load-bearing capacity.

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