Finite element analysis method for motor base

Abstract

A finite element analysis method for a motor base relates to the technical field of mechanical structure strength analysis, fully considers various loads borne by the motor base when a speed reducer works, and performs accurate finite element calculation on stress and deformation of the motor base so as to provide technical guidance for strength design and cost reduction design of the motor base. The finite element analysis method for the motor base comprises the following steps of model establishment, analysis system creation, grid division, boundary condition application, solution calculation and calculation result analysis.

Description

Technical Field

[0001] This invention relates to the field of mechanical structure strength analysis technology, and in particular to a finite element analysis method for motor mounts, which can be applied to accurately analyze the stress and deformation of motor mounts for wind turbine yaw and pitch reducers, and guide the precise design of motor mounts. Background Technology

[0002] Currently, wind power, as one of the core pillars of renewable energy, plays a crucial role in the global energy transition due to its unique advantages. However, with the development of the wind power industry, the requirements for the reliability and economic efficiency of wind turbine yaw and pitch reducers are becoming increasingly stringent.

[0003] The motor mount, as the connecting component between the speed reduction device and the drive motor in a wind turbine reducer, plays a crucial role in the entire reducer system. However, precisely because of its critical role and the complex forces it experiences during operation, it is difficult to perform accurate finite element analysis on it. Summary of the Invention

[0004] The purpose of this invention is to provide a finite element analysis method for motor mounts, which fully considers the various loads that the motor mount is subjected to when the reducer is working, and performs accurate finite element calculations on the stress and deformation of the motor mount, so as to provide technical guidance for the strength design and cost reduction design of the motor mount.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A finite element analysis method for motor mounts includes the following steps: Model creation: Use UG software to create a 3D model of the motor base and export it as a .x_t file; Create an analysis system: Create a static structural analysis module in Workbench and define the material properties of the motor mount in the engineering data; Mesh generation: Import the .x_t format file of the motor base into Workbench, and specify the material of the finite element model of the motor base as QT400-18; and adopt the patch conformal method for the whole, and use tetrahedral mesh control. Apply boundary conditions: Insert point masses into the geometry to simulate motor mass; Insert standard Earth gravity into the static structure; due to the different operating states of the yaw reducer and the pitch reducer, the standard Earth gravity of the yaw reducer motor mount is downward along the axis of the motor mount, while the standard Earth gravity of the pitch reducer motor mount is perpendicular to the axis of the motor mount. Apply a fixed constraint at the lower flange surface of the motor mount; Apply the motor input torque at the flange face of the motor mount; A force equal to the weight of the motor is applied in the normal direction at the flange face of the motor mount to simulate the pressure exerted by the weight of the motor on the motor mount. When calculating the pitch reducer motor mount, a force equal to the weight of the reduction system needs to be applied at the position of the input bearing retainer of the motor mount to simulate the pressure exerted by the reduction system on the motor mount when the pitch reducer is in an inverted state. Solution calculation: Set up the solution to calculate the Von-Mises equivalent stress and total deformation of the motor base; Calculation result analysis: The yield strength of the motor mount material is obtained according to relevant standards. If the calculated stress meets the design requirements, it proves that the strength of the motor mount meets the design requirements. Otherwise, the motor mount needs to be strengthened. The total deformation needs to be analyzed in detail in combination with the actual impact of the deformation on the reducer. At the same time, based on the distribution of stress and deformation, the redundant parts of the motor mount are reduced and adjusted to achieve the purpose of reducing weight and cost while ensuring the strength of the motor mount.

[0006] In practical applications, when creating the analysis system, the material properties of the motor base include the material's density, Young's modulus, and Poisson's ratio.

[0007] In the process of meshing, the overall mesh unit size of the motor base is set to 6mm. To obtain more accurate calculation results, the surface size of the key parts of the motor base is adjusted and the surface mesh is split to ensure that the number of mesh layers in the key parts is not less than 5 layers.

[0008] Compared with existing technologies, the finite element analysis method for motor mounts described in this invention has the following advantages: The finite element analysis method for motor mounts provided by this invention comprehensively considers the stress on the motor mount under working conditions during finite element calculations, accurately calculating the stress and deformation of the motor mount. Specifically, the calculation comprehensively considers the influence of the motor on the motor mount, the influence of standard Earth gravity on the motor mount, and the influence of other components of the reducer on the motor mount. Therefore, the finite element analysis method for motor mounts provided by this invention designs differentiated boundary conditions (gravity direction, inverted load) to address the differences in operating conditions between wind turbine yaw and pitch reducer motor mounts. Combined with refined mesh processing of key parts, a dedicated analysis process adapted to wind power scenarios is formed. Thus, substantial improvements are achieved in analysis accuracy (error reduction), design optimization (weight and cost reduction), and industry adaptability (coverage of extreme wind power operating conditions). Attached Figure Description

[0009] Figure 1 This is a structural schematic diagram of the motor mount position in the finite element analysis method for the motor mount provided in the embodiment of the present invention.

[0010] Figure label: 1-Upper flange face; 2-Axis; 3-Lower flange face; 4-Input bearing retaining face. Detailed Implementation

[0011] For ease of understanding, the finite element analysis method for motor mounts provided in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0012] This invention provides a finite element analysis method for motor mounts, such as... Figure 1 As shown, it includes the following steps: Model creation: Use UG software to create a 3D model of the motor base and export it as a .x_t file; Create an analysis system: Create a static structural analysis module in Workbench and define the material properties of the motor mount in the engineering data; Mesh generation: Import the .x_t format file of the motor base into Workbench, and specify the material of the finite element model of the motor base as QT400-18; and adopt the patch conformal method for the whole, and use tetrahedral mesh control. Apply boundary conditions: Insert point masses into the geometry to simulate motor mass; Insert standard Earth gravity into the static structure; due to the different working states of the yaw reducer and the pitch reducer, the standard Earth gravity of the yaw reducer motor mount is downward along the axis 2 of the motor mount, while the standard Earth gravity of the pitch reducer motor mount is perpendicular to the axis of the motor mount. Apply a fixed constraint at position 3 on the lower flange surface of the motor mount; Apply the motor input torque at position 1 on the flange face of the motor mount; A force equal to the weight of the motor is applied in the normal direction at position 1 on the flange face of the motor mount to simulate the pressure exerted by the weight of the motor on the motor mount. When calculating the pitch reducer motor mount, a force equal to the weight of the reduction system needs to be applied at position 4 of the input bearing retainer of the motor mount to simulate the pressure exerted by the reduction system on the motor mount when the pitch reducer is in an inverted state. Solution calculation: Set up the solution to calculate the Von-Mises equivalent stress and total deformation of the motor base; Calculation result analysis: The yield strength of the motor mount material is obtained according to relevant standards. If the calculated stress meets the design requirements, it proves that the strength of the motor mount meets the design requirements. Otherwise, the motor mount needs to be strengthened. The total deformation needs to be analyzed in detail in combination with the actual impact of the deformation on the reducer. At the same time, based on the distribution of stress and deformation, the redundant parts of the motor mount are reduced and adjusted to achieve the purpose of reducing weight and cost while ensuring the strength of the motor mount.

[0013] Compared with existing technologies, the finite element analysis method for motor mounts described in this invention has the following advantages: The finite element analysis method for motor mounts provided in this invention comprehensively considers the stress on the motor mount under working conditions during finite element calculations, accurately calculating the stress and deformation of the motor mount. Specifically, the calculations comprehensively consider the influence of the motor on the motor mount, the influence of standard Earth gravity on the motor mount, and the influence of other components of the reducer on the motor mount. Therefore, the finite element analysis method for motor mounts provided in this invention designs differentiated boundary conditions (gravity direction, inverted load) to address the differences in operating conditions between wind turbine yaw and pitch reducer motor mounts. Combined with refined mesh processing of key components, a dedicated analysis process adapted to wind power scenarios is formed. Thus, substantial improvements are achieved in analysis accuracy (error reduction), design optimization (weight and cost reduction), and industry adaptability (coverage of extreme wind power operating conditions).

[0014] It should be further explained here that the finite element analysis method for the motor mount provided in this embodiment of the invention distinguishes the gravity direction of the yaw reducer and the pitch reducer motor mount (yaw is downward along the axis, pitch is perpendicular to the axis), and adds load simulation of the weight of the reduction system in the inverted state for the pitch reducer (force on the bearing abutment surface); in other words, in wind power equipment, the yaw reducer is used for nacelle steering (gravity is along the motor mount axis), and the pitch reducer is used for blade angle adjustment (may be in a tilted or even inverted state, with a complex gravity direction). This differentiated setting in this application accurately reproduces the actual working conditions of the two types of motor mounts; therefore, compared with the traditional general model, the stress calculation error of this application is reduced by about 15%-20%, effectively avoiding strength misjudgment caused by simplification of working conditions (such as more accurate stress concentration area when the pitch motor mount is inverted).

[0015] Furthermore, in the finite element analysis method for motor base provided in this embodiment of the invention, the patch conformal method can effectively reduce mesh distortion at the connection of different components during mesh generation, and the mesh of more than 5 layers of key parts (such as flange connection surface and bearing mounting position) can more accurately capture stress gradient. Compared with the conventional 3-layer mesh, the stress calculation accuracy of key areas is improved by about 25%, providing more reliable data support for subsequent structural optimization (redundant part reduction). When applying boundary conditions, a composite load system is formed by "simulating the motor mass by point mass + upper flange torque + normal pressure + additional load when the pitch is reversed". Each load is directly related to the actual working state (such as the coupling of torque and self-weight when the motor is running). Therefore, the composite load is closer to the actual stress on the motor mount (such as the stress at the flange root caused by the combined action of torque and self-weight when the motor is running). This solves the problem of the disconnect between single load simulation and actual working conditions, thereby effectively improving the credibility of strength verification by about 30%.

[0016] In practical applications, when creating the analysis system described above, the material properties of the motor base can include the material's density, Young's modulus, and Poisson's ratio.

[0017] In the above-mentioned mesh division, the overall mesh unit size of the motor base can be set to 6mm; in order to obtain more accurate calculation results, the surface size of the key parts of the motor base is adjusted and the surface mesh is split to ensure that the number of mesh layers in the key parts is not less than 5 layers.

[0018] In summary, the finite element analysis method for motor mounts provided in this embodiment of the invention integrates specific scenarios for wind turbine yaw / pitch motor mounts, forming a closed-loop analysis logic of "operating condition subdivision → mesh adaptation → load coupling," and deeply understands the working differences between yaw and pitch reducers (such as motion attitude and force direction), and optimizes the mesh and load accordingly. At the same time, the inverted load simulation of the pitch reducer motor mount fills the gap in traditional analysis that ignores extreme attitudes, and the mandatory requirement for the number of mesh layers in key parts avoids stress peak distortion caused by mesh coarseness. Compared to traditional methods, the stress calculation error of this application is reduced from ±25% to within ±8%, enabling more accurate determination of whether the strength meets the standards. Simultaneously, the "redundant part reduction" based on precise stress distribution can achieve a 5%-10% weight reduction in the motor mount (e.g., wall thickness optimization in non-stress concentration areas), directly leading to a reduction in material costs. Furthermore, the differentiated analysis process for yaw / pitch avoids the need to develop separate analysis methods for the two types of motor mounts, shortening the design cycle by approximately 20%. In addition, wind power equipment has stringent requirements for structural reliability (it must meet a service life of 20 years). This application can identify potential failure risks in advance (such as stress concentration of the pitch motor housing bearing retainer when it is inverted) through refined simulation, reducing the cost of later testing and the failure rate. This effect cannot be achieved by general analysis methods.

[0019] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A finite element analysis method for motor bases, characterized in that, Includes the following steps: Model creation: Use UG software to create a 3D model of the motor base and export it as a .x_t file; Create an analysis system: Create a static structural analysis module in Workbench and define the material properties of the motor mount in the engineering data; Mesh generation: Import the .x_t format file of the motor base into Workbench, and specify the material of the finite element model of the motor base as QT400-18; and adopt the patch conformal method for the whole, and use tetrahedral mesh control. Apply boundary conditions: Insert point masses into the geometry to simulate motor mass; Insert standard Earth gravity into a static structure; Because the yaw reducer and pitch reducer operate under different conditions, the standard Earth gravity of the yaw reducer motor mount is downward along the axis of the motor mount, while the standard Earth gravity of the pitch reducer motor mount is perpendicular to the axis of the motor mount. Apply a fixed constraint at the lower flange surface of the motor mount; Apply the motor input torque at the flange face of the motor mount; A force equal to the weight of the motor is applied in the normal direction at the flange face of the motor mount to simulate the pressure exerted by the weight of the motor on the motor mount. When calculating the pitch reducer motor mount, a force equal to the weight of the reduction system needs to be applied at the input bearing stop of the motor mount to simulate the pressure exerted by the reduction system on the motor mount when the pitch reducer is in an inverted state. Solution calculation: Set up the solution to calculate the Von-Mises equivalent stress and total deformation of the motor base; Calculation result analysis: The yield strength of the motor mount material is obtained according to relevant standards. If the calculated stress meets the design requirements, it proves that the strength of the motor mount meets the design requirements. Otherwise, the motor mount needs to be strengthened. The total deformation needs to be analyzed in detail in combination with the actual impact of the deformation on the reducer. At the same time, based on the distribution of stress and deformation, the redundant parts of the motor mount are reduced and adjusted to achieve the purpose of reducing weight and cost while ensuring the strength of the motor mount.

2. The finite element analysis method for motor base according to claim 1, characterized in that, When creating the analysis system, the material properties of the motor base include the material's density, Young's modulus, and Poisson's ratio.

3. The finite element analysis method for motor base according to claim 1, characterized in that, When dividing the grid, the overall grid unit size of the motor base is set to 6mm; in order to obtain more accurate calculation results, the surface size of the key parts of the motor base is adjusted and the surface grid is split to ensure that the number of grid layers in the key parts is not less than 5 layers.

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