Research and implementation of automatic modeling

2022-08-13
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Research and implementation of automatic modeling of centrifuge permanent magnet bearing simulation system

centrifugal separation technology is a widely used purification method. To a certain extent, purity is closely related to the speed of centrifuge rotor. Due to the limitation of the mechanical properties of traditional rolling bearings, the speed of domestic centrifuges is currently no more than 22000 R/min. Permanent magnet bearings have excellent characteristics such as high speed, high precision, no wear, low power consumption and so on. They can meet the requirements of high-speed centrifuge separation and purification with rotor speed of r/min. They can also be widely used in biotechnology, aerospace, machining, rotor dynamic characteristics identification and testing and other fields, and have broad market application prospects. So far, many aspects of work have been done on the performance research of permanent magnet bearings. Its structural design and serialization are also a research problem for the application and promotion of permanent magnet bearings. The permanent magnet bearing model in the centrifuge permanent magnet bearing test simulation system studied in this paper is to design the structure of the bearing according to the action principle of the permanent magnet bearing, establish the parametric model of the permanent magnet bearing by using the three-dimensional design Software Solidworks, and then carry out the secondary development of SolidWorks by using VB language programming and API (Application Programming Interface) interface function, realizing the automatic establishment of the permanent magnet bearing model, It provides a three-dimensional simulation model for the finite element analysis of permanent magnet bearings

1 centrifuge rotor system

the purification accuracy of the centrifuge is limited by the rotor speed, and the bearing capacity is a bottleneck condition for the selection of high-performance power drive equipment. Due to the limited bearing capacity of the traditional rolling bearings, in order to achieve a higher speed of the centrifuge rotor system, using permanent magnet bearings to replace the traditional rolling bearings is a potential method to solve this problem. The centrifuge rotor spindle system supported by permanent magnet bearings is shown in Figure 1. The structure of permanent magnet bearing has two-way function of radial and thrust. According to the current research on magnetic materials at home and abroad, the stator and rotor of permanent magnet bearings are made of rare earth neodymium iron boron (NeFeB) high-strength permanent magnet materials

2 centrifuge permanent magnet bearing test simulation system

centrifuge permanent magnet bearing test simulation system is a simulation test system for the structural design and performance analysis of permanent magnet bearings in centrifuges. Using simulation technology and program design and development tools, the designed permanent magnet bearings are effectively tested and simulated, providing a basis for the design of permanent magnet bearings. The centrifuge magnetic bearing test simulation system includes four parts: human-computer interaction interface, structural design, simulation analysis, and result processing. The structure design includes three parts: parts design, assembly design and engineering drawing. The design of the simulation system takes the components and assemblies of permanent magnet bearing as the research object, and it is also the basis of finite element analysis and virtual prototype test. Therefore, the construction and assembly of bearing parts model is very important, which directly affects the static and dynamic characteristics analysis of permanent magnet bearings, and is the key technology of centrifuge permanent magnet bearing simulation system

the test simulation system has a good human-computer interaction interface, as shown in Figure 2. When entering the simulation system, the vertical tensile testing machine is applicable to the structural design module of plastic plates, pipes and profiles. Users only need to input the parameter coherence of the structure: number, and the system can automatically model, as shown in Figure 3

3 automatic modeling of permanent magnet bearing structure design

3.1 modeling process of permanent magnet bearing library

the modeling process of permanent magnet bearing library is the basic basis for modeling, guiding the successive steps of design to an optimized modeling process, which can make the design steps of permanent magnet bearing library clear and complete. In the permanent magnetic bearing library module of the test simulation system, the modeling adopts the modeling process in the form of tree branches. The magnetic bearing library is a tree root node. Three series of thrust bearings, centripetal bearings and centripetal thrust bearings are its level 1 branches, and various forms of bearings have two level 2 branches. When modeling with Solidworks software, each bearing model includes three parts: part drawing, engineering drawing and explosion action drawing as level 3 branches. The specific flow chart of modeling of the permanent magnet bearing library is shown in Figure 4. The ellipsis in the figure indicates that the branch content of this stage is the same as that of the same series of bearings

3.2 establish parametric model

first, establish the characteristic model of permanent magnet bearing in SolidWorks software environment. Based on the flow chart of permanent magnet bearing library modeling shown in Figure 4, the establishment process of parametric model is illustrated by taking centripetal thrust bearing as an example according to the steps of parts sketching, assembly drawing establishment and engineering drawing generation

parametric modeling is formed on the basis of feature modeling. By selecting "record" in SolidWorks [tools/macro operations], you can

generate macro files and applications for the process of generating models. According to the structure of permanent magnet bearing, the three-dimensional model of each part is established in turn, and then the assembly drawing of the part is established. Using the order from inside to outside, the assembly body can be generally divided into the suspension part with the permanent magnet bearing rotor as the main body and the fixed part with the stator as the main body to complete the virtual assembly model of the centripetal thrust bearing I. The rendered sectional view is shown in Figure 5. Finally, modify the dimension name marked by the feature model, and the dimension name should be meaningful expression as far as possible, so as to facilitate the use of variables in VB program during secondary development. Stop the macro file recording, the program code of macro recording, find out the key functions of the modeling process in the macro file, determine the key constants, figure out the influence of the change of the key constants on the solid model, replace the key constants with variables, delete the unnecessary operation process in the macro file, and a parameterized permanent magnet bearing model is established

3.3 realization of automatic modeling of permanent magnetic bearings in the simulation system

the automatic modeling of permanent magnetic bearings in the simulation system is realized by the secondary development of SolidWorks using VB language. First, in the VB integrated environment, check SolidWorks 2006 type library in the command [project/reference] dialog box to complete the reference of the type library, and then access the main objects provided by SolidWorks through ActiveX Automation. Modify the macro program in VB, use the principle of dimension driven method, regard the dimension of parts as variables, and generate part families with the same structure but different parameters through the change of dimension parameter values. As shown in Figure 5, part of the automatic modeling procedure of the permanent magnet bearing simulation model is as follows:

the above code is the basis for the implementation of automatic modeling and assembly. The specific example is shown in Figure 3. After the user enters the required parameters, you can preview the 3D model in the specified area. Package the secondary development application and make it into an executable file, which can be installed and run

4 Conclusion

in the structure module of the centrifuge permanent magnet bearing simulation system, the automatic assembly of parts is a key point. The combination of SolidWorks 3D design software and VB language programming is used to realize the automatic establishment of permanent magnet bearing model. At present, a lot of work has been done on the research of permanent magnet bearing performance, material and finite element analysis in China, but how to realize serial modeling of permanent magnet bearing structure needs to be solved. The research of this paper is not only the basis of the centrifuge permanent magnet bearing simulation system, but also enriches the research content of high-speed separation to ensure that unexpected problems will not appear when applied, and permanent magnet bearings. It provides a reference for the research on improving the speed of centrifuge rotor and exploring new design and analysis methods, and for this year's national reserve and crackdown on Mafia. (end)

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