A Digital-Based Vibration Characteristic Analysis Method for RV Reducers

Abstract

The present invention relates to the field of design methods for RV reducers, core components of industrial robots, and discloses a vibration characteristic analysis method for RV reducers based on digitization. The method includes the following steps: constructing parameter values ​​based on an analytical calculation method, designing a parametric model based on a size optimization guidance and a three-dimensional intelligent design method, automatically assembling the RV reducer based on a computer-aided design method, and analyzing the vibration characteristics of RV reducer parts based on a numerical analysis method. Among them, the size optimization guidance method is used for the allocation and constraint of parameter values; the three-dimensional intelligent design method is used for program-driven modeling; the computer-aided design method is used for the automatic assembly of RV reducers; and the numerical analysis method is used for the vibration characteristic analysis of RV reducers. The numerical analysis method based on the parametric model of the present invention analyzes the vibration characteristics, which can predict the vibration characteristics of the system under different conditions, and is of great significance for evaluating system performance and preventing vibration problems.

Description

Technical Field

[0001] The present invention relates to the field of design methods of RV reducers, which are core components of industrial robots, and in particular to a vibration characteristic analysis method of RV reducers based on digitization. Background Art

[0002] Industrial robots are an important driving force for the automation and intelligent upgrading of the manufacturing industry. RV reducers are one of the core components of industrial robots. Due to their advantages such as high precision, high stability, large load-bearing capacity, high efficiency, long life and compact size, they are widely used in load-bearing positions such as shoulders of industrial robots. However, traditional two-dimensional graphic digital design software (such as AutoCAD) has exposed many problems in the design process of RV reducers. For example, the workload is large, there are many repetitive labors, the design cycle is long, and the assembly process is complex and prone to errors. Designers need to rely on experience for manual assembly, which is easy to introduce errors and affect product performance. More importantly, since multiple modifications and adjustments are required during the design process, and traditional two-dimensional design software has limited support for modifications and adjustments, it is difficult to find and correct errors in the design in a timely manner, thereby increasing the development cycle and cost.

[0003] In order to cope with the challenges brought by the rapid development of industrial robot technology, a digital-based RV reducer vibration characteristic analysis method was invented. It only requires designers to input the key parameters of the parts, and through the secondary development of UG and OLE technology, convenient modification and automatic assembly of parts can be achieved. Combined with finite element analysis of vibration characteristics, it not only intuitively simulates assembly and vibration simulation effects, improves design accuracy, reduces the workload of designers, shortens the design cycle, and enhances the ability to find and correct errors, laying a solid foundation for the widespread application of RV reducers in the field of industrial robots. Summary of the invention

[0004] The purpose of the present invention is to shorten the design cycle of new products and provide a vibration characteristic analysis method of an RV reducer based on digitization.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A vibration characteristic analysis method of an RV reducer based on digitalization, comprising:

[0007] S101, constructing parameter values ​​based on analytical calculation method;

[0008] S102, selecting different parametric design methods based on the structural features of the parts, and then selecting the size optimization guidance method and the three-dimensional intelligent design method through variable assignment to generate a three-dimensional model of the parts, and automatically assembling the parts based on the structural features to obtain a three-dimensional digital model of the RV reducer;

[0009] S103. Select a numerical analysis method based on the three-dimensional digital model of the RV reducer, use Ansys finite element method to perform modal analysis on the RV reducer components, and obtain vibration simulation and vibration analysis results.

[0010] Furthermore, the step S101 specifically includes:

[0011] S201, determine the original data requirements, and set parameters according to the drive generation and constraint relationship of the component model features;

[0012] S202: Based on the determined parameter value range and constraint relationship, use an analytical calculation method to perform parameter calculation.

[0013] Furthermore, the parametric design method is based on UG secondary development, and the method includes using a macro recording function and an API function library, wherein the macro recording function refers to a function that comes with UG.

[0014] Furthermore, the API function library refers to that provided by UG software through OLE technology and implemented through VB calls.

[0015] Furthermore, the step S102 specifically includes:

[0016] S301. Use the skeleton line method to capture the main geometric features of the parts, select the appropriate digital design method for the parts, and define the secondary development interface API based on UG and link the software;

[0017] S302, assigning values ​​to the above parameters, and obtaining a three-dimensional model of the component according to a size optimization guidance method and a three-dimensional intelligent design method;

[0018] S303, using an assembly method based on computer-aided design to call the assembly relationship of parts and components for automatic assembly.

[0019] Furthermore, the step S103 specifically includes:

[0020] S401. Use UG and ANSYS Workbench to jointly simulate and select project modules, and import the whole machine model as the basis for finite element analysis;

[0021] S402, using ANSYS to perform modal analysis calculations to obtain a vibration model to achieve the purpose of vibration characteristic analysis.

[0022] Furthermore, the dimension optimization guidance method in step S302 is: based on the parameters obtained by the analytical calculation method, the secondary development of UG is used to add dimensions in the parametric design interface, thereby automatically generating a three-dimensional model of the component;

[0023] The specific three-dimensional intelligent design method is as follows: after clarifying the parameter range and constraints, the relationship between the parameters is described through programming scripts to construct a three-dimensional model of the RV reducer components.

[0024] Furthermore, the S303 is specifically as follows: using UG software to load the three-dimensional model of the parts into the memory, and then inserting the model into the assembly, obtaining the model part features, selecting appropriate model feature attributes and assembly types for automatic assembly, and obtaining the three-dimensional model of the RV reducer;

[0025] The procedure for loading components into memory is as follows:

[0026] retval=UG.OpenDoc6(filename, type, options, configuration, &Errors, &Warnings);

[0027] The procedure for inserting a part into an assembly is as follows:

[0028] retval=AssemblyDoc.AddComponent4(compName, configName, x, y, z).

[0029] The present invention has the following advantages:

[0030] 1. Practicality: Part of the work of a digital-based RV reducer vibration characteristic analysis method is completed in UG software, so a large amount of secondary development of the software is carried out, which greatly facilitates the user's use, avoids the difficulty of assembly and disassembly, and has strong practicality.

[0031] 2. Visualization: Based on UG software, designers can intuitively present and view the reducer model in a graphical way. This visualization capability helps designers better understand and evaluate the appearance, assembly and operation of the reducer.

[0032] 3. Data association: 3D digital modeling allows associations between different components, which means that when one parameter changes, other parameters and components associated with it will also be automatically adjusted. This data association helps ensure the consistency and correctness of the design and reduce errors and duplication of work.

[0033] 4. Efficiency: UG's secondary development is optimized using VB, which provides a large number of data types and a large number of internal functions, and uses a modular and structured programming language with the characteristics of clear structure, concise syntax, and easy to master.

[0034] 4. The assembly method based on computer-aided design can realize automated assembly and ensure the accurate positioning and connection of parts. Compared with manual assembly, automated assembly has higher precision and consistency, reducing errors and poor assembly during the assembly process.

[0035] 5. Analyzing vibration characteristics using numerical analysis methods based on parameterized models can predict the vibration characteristics of the system under different conditions, which is of great significance for evaluating system performance and preventing vibration problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic flow chart of a digital RV reducer vibration characteristic analysis method provided in an embodiment of the present invention;

[0037] Figure 2 A cycloid wheel closed curve provided by an embodiment of the present invention;

[0038] Figure 3 A cycloidal wheel design interface provided by an embodiment of the present invention;

[0039] Figure 4 A digital three-dimensional model of a cycloid wheel provided in an embodiment of the present invention;

[0040] Figure 5 A digitized three-dimensional model of a planetary gear provided in an embodiment of the present invention;

[0041] Figure 6 A digital three-dimensional model of a pinion housing provided in an embodiment of the present invention;

[0042] Figure 7 A digital three-dimensional model of a crankshaft provided in an embodiment of the present invention;

[0043] Figure 8 A schematic diagram of a computer-aided design process provided by an embodiment of the present invention;

[0044] Fig. 9 A schematic diagram of automated assembly provided by an embodiment of the present invention;

[0045] Fig.10 A three-dimensional assembly result diagram of the RV reducer provided in an embodiment of the present invention;

[0046] Fig.11 A schematic diagram of a digital RV reducer vibration characteristic analysis process provided by an embodiment of the invention;

[0047] Fig.12 A schematic diagram of a modal analysis module provided for an embodiment of the invention;

[0048] Fig.13 A schematic diagram of adding material property parameters in ANSYS provided by an embodiment of the invention;

[0049] Fig.14 A schematic diagram of grid division provided for an embodiment of the invention;

[0050] Fig.15 Provide a total deformation cloud diagram of the overall random vibration simulation of the RV reducer for the embodiment of the invention;

[0051] Fig.16 Provide an equivalent strain cloud diagram of the overall random vibration simulation of the RV reducer for the embodiment of the invention;

[0052] Fig.17 An equivalent stress cloud diagram of the overall random vibration simulation of the RV reducer is provided for the embodiment of the invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the following is a further detailed description of a digital-based RV reducer vibration characteristic analysis method described in the present invention, taking the RV40E model as an example, and referring to the accompanying drawings in combination with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] The following is combined with Figure 1-Figure 17 The present invention will be further described.

[0055] A vibration characteristic analysis method of an RV reducer based on digitalization includes the following steps:

[0056] S101, constructing parameter values ​​based on analytical calculation method;

[0057] S102. Select different parametric design methods based on the structural features of the parts, and then select the dimension optimization guidance method and the three-dimensional intelligent design method through variable assignment to generate a three-dimensional model of the parts. At the same time, automatically assemble the parts based on the structural features to obtain a three-dimensional digital model of the RV reducer.

[0058] S103. Select a numerical analysis method to perform modal analysis based on the three-dimensional digital model of the RV reducer, and then use data sharing to perform vibration simulation and vibration characteristics analysis.

[0059] Specifically, the method for constructing parameter values ​​based on the analytical calculation method in step S101 includes the following steps:

[0060] (1) Determine the original data requirements and set the transmission ratio and number of teeth according to the structure and working principle of the model RV40E reducer;

[0061] (2) Based on the determined parameter values ​​and constraint relationships, the analytical calculation method is used to calculate the parameters and obtain the motor model, speed, power, torque, and transmission ratio.

[0062] The parameterized RV reducer three-dimensional digital modeling method in step S102 includes:

[0063] (1) Use the skeleton line method to capture the main geometric features of the cycloid gear, planetary gear, pinion housing, and crankshaft, select the appropriate digital design method for the components, and use UG to define the secondary development interface API and link the software;

[0064] (2) Assign values ​​to the above parameters and obtain the three-dimensional model of the component based on the size optimization guidance method and the three-dimensional intelligent design method.

[0065] In the RV reducer, most parts such as the pinion housing and crank shaft adopt the size optimization guidance method; while the cycloid gear and planetary gear adopt the three-dimensional intelligent design method.

[0066] Combination Figure 1 Shown is a flow chart of the digital design of each part, illustrating the design process of some parts of the RV reducer.

[0067] (1) Parametric design of cycloid wheel: Based on the parameters obtained by analytical calculation method, a visual design platform is constructed. VB is used to encapsulate the program and parameters into an object in a visual way. Then, the parametric modeling method of the cycloid wheel is selected based on the skeleton method, that is, the three-dimensional intelligent design method. The cycloid wheel modeling must first draw the cycloid contour curve. From the existing parameter chain, it can be known that the equation curve formula is:

[0068] In the formula, =z4 / z5 is the relative transmission ratio between the cycloid wheel and the pinion gear; It is the rotation angle of the rotating arm relative to the center vector of a certain needle tooth.

[0069] At the same time, convert the formula into a program that can be used in VB, the program is as follows:

[0070]

[0071] Since UG cannot directly recognize the formula with parameters in VB, 20 points are selected in the cycloid equation and the corresponding coordinates are obtained. Then the 20 points are connected by the program to basically get the cycloid curve. The specific program is as follows:

[0072] Combination Figure 2 , Figure 3As shown, the two endpoints of the curve are then used to draw arcs to form a closed curve. Draw a tooth on the closed curve, and complete the drawing of all the teeth of the cycloid wheel in an array manner. Finally, only the circular hole of the cycloid wheel needs to be cut off to obtain the design interface.

[0073] Combination Figure 4 As shown, after entering the corresponding parameters, UG will automatically generate the corresponding cycloid wheel model.

[0074] (2) Parametric design of planetary gears: The design method of planetary gears is similar to that of cycloid gears. A program is written based on the equation curve formula of the planetary gear to calculate the coordinate points of the tooth profile curve. Then, interpolation and fitting are used to generate a closed tooth profile curve. Then, the tooth stretching and array are completed to quickly generate the entire tooth surface of the planetary gear. The same design method is used to complete the drawing of the internal spline.

[0075] Combination Figure 5 As shown, the design interface of the planetary gear is designed on the UG software, and the planetary gear model can be obtained by inputting corresponding parameters and adding constraints.

[0076] Planetary gear parameter design:

[0077] (3) Parametric design of the pinion housing: Based on the parameter values ​​obtained by analytical calculation, and using the parametric design interface of UG, the three-dimensional model of the pinion housing can be generated by inputting the corresponding data in the dimension part of the drawing on the interface.

[0078] In the digitization process, according to the structural characteristics of the RV40E parts, the simplest modeling method is selected. The large frame of the pinion gear housing is a revolved part, so the section is directly drawn and then the general frame of the pinion gear housing is drawn by rotation, and then the hole is stretched and cut on the front reference plane to complete the modeling process.

[0079] Combination Figure 6 As shown, the three-dimensional model of the needle tooth shell is finally obtained.

[0080] (4) Parametric design of crankshaft: Based on the link between VB and UG, a program is written in the software to create a new blank part file. Parameters are set according to the drive generation and constraint relationship of the component model features, and parameter calculations are performed in the parametric design program interface.

[0081] Combination Figure 7 As shown, the involute spline part is drawn based on the parameters and API functions, and the modeling function of UG is used to draw and create the other parts of the crankshaft, so as to obtain a three-dimensional model of the crankshaft.

[0082] Based on the three-dimensional model of the crank shaft, constraint relationships are set in UG to ensure the accuracy of the model. At the same time, simple collision and interference checks are performed to ensure that the model is correct.

[0083] The procedure for creating a new part is:

[0084] Combination Figure 8 The schematic diagram showing the computer-aided design process illustrates the automatic assembly process of the RV40E reducer.

[0085] (1) Using the API interface of UG secondary development, write a program to automatically load the 3D models of each component into the memory environment of UG software. This process is implemented through functions such as OpenDoc6 to ensure that the model can be correctly recognized and processed by the software. The program is as follows:

[0086] retval=UG.OpenDoc6(filename, type, options, configuration, &Errors, &Warnings);

[0087] (2) After the model is loaded, the UG software is used to perform feature recognition, including identifying the geometric features of the parts, such as points, lines, and surfaces, as well as the potential assembly relationships between them. At the same time, an assembly strategy is formulated to determine the features that will be used for alignment, positioning, and fixing during the assembly process.

[0088] (3) Based on the identified features and assembly strategies, the program is used to automatically add assembly relationships that ensure the correct position and relative movement between parts.

[0089] Combination Fig. 9 and Fig.10 As shown, by repeating this process, multiple parts can be gradually combined into a complete RV40E reducer assembly.

[0090] retval=UG.OpenDoc6(filename, type, options, configuration, &Errors, &Warnings);

[0091] In the program, use the AddMate3 function to load parts.

[0092] (4) After completing the preliminary assembly, collision detection and interference analysis are performed, which is a key step to ensure that the assembly is physically feasible and free of conflict. If collision or interference is found, you can go back and adjust the assembly strategy or modify the part model until the design requirements are met.

[0093] (5) After resolving all collision and interference issues, the assembly is optimized, including adjusting the position of parts, improving the assembly sequence, and adopting a more efficient assembly method. In addition, motion simulation and performance analysis can be performed to verify the functionality and reliability of the assembly.

[0094] Combination Fig.11 The figure shows a schematic diagram of the numerical analysis process based on the digital model, which illustrates the process of using ANSYS finite element analysis to analyze vibration characteristics.

[0095] (1) Create a solid model module in ANSYS, then import the solid model, select the modal analysis module, and share the model through a shared connection.

[0096] Combination Fig.12 As shown, UG software and ANSYS Workbench are used for joint simulation.

[0097] (2) Set materials based on RV reducer components. In the project module, add and modify material properties, and then define materials for each part in ANSYS.

[0098] Combination Fig.13 As shown, ANSYS is used to add various material properties to the database.

[0099] (3) Use no separation and bonding to set the contact relationship of each component, and set the boundary conditions at the same time. Use the shell to fix and the output disk to output, and set fixed constraints on the holes on the shell.

[0100] (4) The finite element method is used to mesh the entire assembly system of the RV reducer. Since the sizes of the various components of the reducer are different and the number of surfaces is different, in addition to meshing the entire assembly, the key parts should also be encrypted locally. The overall method adopted is mainly based on tetrahedrons.

[0101] Combination Fig.14 As shown, the mesh division model and mesh number of the RV reducer overall assembly are obtained.

[0102] (5) The modal calculation of the RV reducer is performed using numerical analysis methods. Then the first ten natural frequencies of the RV reducer and the corresponding vibration mode cloud diagram are obtained.

[0103] (6) Based on modal analysis, random vibration simulation of RV reducer is carried out, and ANSYS is used to introduce the model, divide the mesh and set the boundary conditions, and then modal analysis is carried out.

[0104] Combination Fig.15 , Fig.16 and Fig.17As shown, the random vibration analysis results of the RV reducer assembly are obtained.

[0105] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person skilled in the art, several modifications, improvements and substitutions can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A digital-based RV reducer vibration characteristic analysis method, characterized in that: include: S101, constructing parameter values ​​based on analytical calculation method; S102, selecting different parametric design methods based on the structural features of the parts, and then selecting the size optimization guidance method and the three-dimensional intelligent design method through variable assignment to generate a three-dimensional model of the parts, and automatically assembling the parts based on the structural features to obtain a three-dimensional digital model of the RV reducer; The step S102 specifically includes: S301. Use the skeleton line method to capture the main geometric features of the parts, select the appropriate digital design method for the parts, and define the secondary development interface API based on UG and link the software; S302, assigning values ​​to the above parameters, and obtaining a three-dimensional model of the parts according to a size optimization guidance method and a three-dimensional intelligent design method; the size optimization guidance method is: based on the parameters obtained by the analytical calculation method, using UG secondary development and adding dimensions in the parametric design interface to automatically generate a three-dimensional model of the parts; the three-dimensional intelligent design method is specifically: after clarifying the parameter range and constraint conditions, describing the correlation between the parameters through a programming script to construct a three-dimensional model of the RV reducer parts; S303, using an assembly method based on computer-aided design, calling the assembly relationship of parts for automatic assembly, specifically: using UG software to load the three-dimensional model of the parts into memory, and then inserting the model into the assembly, obtaining model features, selecting appropriate model feature attributes and assembly types for automatic assembly, and obtaining a three-dimensional model of the RV reducer; wherein, the procedure for loading parts into memory is as follows: retval1=UG.OpenDoc6(filename, type, options, configuration, &Errors, &Warnings); The procedure for inserting a part into an assembly is as follows: retval2=AssemblyDoc.AddComponent4(compName, configName, x, y, z); S103. Select a numerical analysis method based on the three-dimensional digital model of the RV reducer, use Ansys finite element method to perform modal analysis on the RV reducer components, and obtain vibration simulation and vibration analysis results.

2. A digital-based RV reducer vibration characteristic analysis method according to claim 1, characterized in that: The parametric design method is based on UG secondary development, and the method includes using a macro recording function and an API function library, wherein the macro recording function refers to a function provided by UG.

3. A digital-based RV reducer vibration characteristic analysis method according to claim 2, characterized in that: The API function library refers to the one provided by UG software through OLE technology and is implemented through VB calls.

4. A digital-based RV reducer vibration characteristic analysis method according to claim 1, characterized in that: The step S103 specifically includes: S401. Use UG and ANSYS Workbench to jointly simulate and select project modules, and import the whole machine model as the basis for finite element analysis; S402, using ANSYS to perform modal analysis calculations to obtain a vibration model to achieve the purpose of vibration characteristic analysis.

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