Introduction Faced with fierce market competition, every enterprise regards product design as its lifeline. Without innovative products that meet market demands, even the most advanced equipment and scientific management will lead to failure in the competition. The development and research of innovative products cannot be separated from advanced design technologies. CAD technology, as the core of advanced design technology, is evolving from traditional CAD to modern CAD. It can be said that market competition has promoted the development of CAD technology. Modern CAD technology is no longer merely a tool to replace manual drafting; it encompasses the entire process from product solution decision-making, structural design, performance analysis, functional simulation, to process design. It has evolved from two-dimensional drafting to today's feature-based three-dimensional parametric and variable modeling technology. Using three-dimensional design technology can better reflect the actual design, construction, and manufacturing process of products. Simultaneously, using CAD software to perform motion simulation and analysis of machines or mechanisms allows for the prediction and improvement of potential design problems, facilitating automated design, accelerating product updates, and enhancing the enterprise's market competitiveness. 1. Creation of 3D Models 1.1 Concept of Feature-Based Modeling Feature-based modeling is the development of geometric modeling technology. It provides a more intuitive and engineering-meaning comprehensive description of information such as part shape, size, process, and function. Feature-based modeling systems generally first store a large number of standard features or user-defined features in the database. During the design phase, features in the feature library are called as basic modeling units for modeling. Then, geometric information and process information are gradually input to establish the feature data model of the part and store it in the database. Feature-based modeling methods greatly improve design efficiency and quality. At the same time, designers can easily check the legality and relevance of features during the design process, which facilitates the organization of complex features. The feature modeling process is actually a series of feature accumulation processes. There are three main types of features in 3D modeling: (1) Solid features It is the basic unit and main design object for building 3D models. Solid features can be positive space features (such as the protruding parts of a solid) or negative space features (such as holes, slots, etc. on a solid). In Pro/E, based on the differences in modeling methods and principles, solid features are further divided into basic features and engineering features. Basic features are the starting point for 3D model design, including extrusion features, rotation features, sweep features, and hybrid features. Engineering features are additional features on top of basic features. Their creation depends on existing basic features and they are features with certain engineering application value, including hole features, rib features, chamfer features, and draft features. (2) Surface features are geometric features without mass or volume. The accurate description of surfaces is relatively complex. In current 3D modeling, "B-spline curves" are usually used as the basis. The curves are edited through curvature distribution diagrams to obtain high-quality surface models. Surface features are mainly used in product concept design, shape design, and reverse engineering. (3) Datum features refer to the datum points, datum axes, datum curves, datum planes, and coordinate systems of parametric design. Generally speaking, datum features are mainly used to assist in the creation of 3D models. 1.2 General Process of Pro/E Modeling Pro/E is an integrated CAD/CAM/CAE software developed by PTC (Parametric Technology Corporation) in the United States. This software integrates functions such as mechanical design, mold design, processing and manufacturing, sheet metal design, mechanism analysis, finite element analysis, and relational database management. It is currently the most widely used and powerful next-generation product modeling and dynamic simulation software among professional designers internationally. Modeling in Pro/E begins with a holistic study of the part to be modeled, analyzing its feature composition, clarifying the relationships and internal connections between different features, and determining the creation order of part features. Based on this, modeling and adding engineering features are then carried out. The construction of the three-dimensional solid model is achieved through tools such as rotation, extrusion, sweeping, and blending of two-dimensional planar sketches. The Pro/E 3D model organically combines wireframes, surfaces, and solids into a whole. The entire modeling process is a parametric design process based on features as the basic unit. These parameters include geometric parameters and dimensional parameters. Geometric parameters determine the fixed relationships of the basic positions of solid features, while dimensional parameters determine the product's appearance dimensions and relative distances. These parameters allow for precise control and modification of the established 3D model. The general process of Pro/E modeling is as follows: (1) Establish or select datum features as the datum for model space positioning: such as datum plane, datum axis and datum coordinate system. When establishing each solid feature, the datum feature must be used as a reference; (2) Establish basic solid features: extrusion, rotation, sweep, blending, etc.; (3) Establish engineering features: holes, chamfers, ribs, draft, etc.; (4) Modify features: feature array, feature copy and other editing operations; (5) Add materials and rendering. Figure 1 is a three-dimensional model of a gear oil pump part. Figure 1.3 Using family tables to realize part serialization design Serialization design refers to the design method of automatically generating new serialized parts by modifying parameters for some parts with similar basic shapes. Serialization design can save design time and improve design efficiency. The family table provided by Pro/E is actually an electronic spreadsheet, which consists of rows and columns. The parts established by the user in the family table are the basic parts (parent parts), and the parts generated by controlling parameters based on the basic parts are the family members (child parts). The collection of all basic parts and family members is the family table. Figure 2 shows the family table of ordinary bolts. Figure 2.2 Product Assembly All industrial products are assembled from varying numbers of parts and components. Pro/E's Assembly module is specifically designed for part assembly. Two common assembly methods are: ① Bottom-Top Assembly: This process is similar to actual assembly, using assembly constraints to determine the relative positions of geometric elements between parts, positioning and assembling all parts one by one until the entire product is assembled. ② Top-Down Assembly: This method is based on a top-down design philosophy, first establishing an assembly plan on a macro level, and then designing each part step-by-step according to the plan. This method is suitable for large projects completed collaboratively by a team. Because all Pro/E design modules use a single database, the design scheme can be adjusted at any time during the assembly process, changing part parameters as needed. These parameter changes will be reflected in all models. To display the structural relationships of the various parts of the product, exploded views can be generated while maintaining the constraints. Simulation animations of the assembly process can also be implemented, automatically creating dynamic video demonstrations of the assembly process through snapshots of each assembly state. Customers can understand the product's structure and assembly process by watching these video files. Figure 3 shows the assembly model of the gear oil pump. 3. Motion Simulation and Analysis After 3D modeling using Pro/E software, computer simulation systems can be used to simulate motion and functional characteristics in a real environment to verify the rationality of the design scheme, whether the motion and mechanical performance parameters meet the design requirements, and whether interference occurs between moving components. Motion simulation and analysis can promptly identify problems and continuously improve and refine the design, strictly ensuring design quality. The Mechanism module is a powerful module provided by Pro/E that integrates motion simulation and mechanism analysis. Once the parts are assembled into a complete mechanism through the assembly module, the mechanism motion analysis module can be accessed. In this module, the frame and the connections between the parts or components constituting the kinematic pairs are defined according to the design intent (note that the positioning constraints of the fixed constraints should be removed), and then the servo motors are defined. The function of a servo motor is to apply force or torque to a mechanism, providing it with specified motion. Finally, the motion is executed, and the results are analyzed. 4. Conclusion: The Pro/Engineer Wildfire version further improves the software's user interface and functionality, incorporating advanced international engineering design concepts and ideas, such as to-down design, parallel design, flexible design, and system sensitivity design technology. While further promoting and using Pro/E software, these advanced design technologies will also be introduced into industrial product styling design. Compared with other 3D modeling software, Pro/E has unique advantages in structural design. Applying Pro/E to all aspects of product styling and structural design will undoubtedly comprehensively promote the development and progress of product design, aligning it with the world's advanced computer-aided design technology.