A method for quickly establishing a three-dimensional model of a gear system multi-configuration

Abstract

The application discloses a kind of gear system multi-configuration quick three-dimensional model establishment method, it is related to the cross technical field of mechanical design and computer aided engineering.By constructing the standardization component with intelligent interface, realize the automatic generation of transmission system from micro parts to macro topology, solve the problem of poor parameter correlation and iterative tedious of existing modeling means.Step S1, construct numerical driving basic parts library.Step S2, encapsulate standard transmission function unit.Step S3, deploy gear system quick building program.Step S4, execute system level assembly and automatic assembly.Compared with the prior art, the application has the following beneficial effects:1. Eliminate parameter island, realize global linkage update.2. Improve design reusability, realize modular quick assembly.3. Realize flexible topology reconstruction, support quick configuration optimization.4. Significantly improve research and development efficiency, shorten development cycle.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of mechanical design and computer-aided engineering, specifically to a method for automatically generating and variable-driven modeling of multi-configuration topologies of gear systems using computer-aided design software. Background Technology

[0002] Gear transmission systems are the core hub connecting the power source and the actuator, and are widely used in aircraft, automotive transmission systems, and heavy industrial machinery. The quality of its power transmission chain topology directly determines the power-to-weight ratio, transmission efficiency, and operational reliability of the entire machine.

[0003] Existing technologies for 3D modeling such complex systems generally suffer from the following technical bottlenecks. First, the "island effect" is severe, with the geometric models of components often being disconnected from their design parameters. When modifying the parameters of a gear, designers typically need to manually update the associated shaft, bearing, and housing models, lacking a global linkage mechanism. This disconnect leads to low design efficiency and a high risk of errors, especially when dealing with complex transmission chains involving dozens of components, where parameter synchronization becomes extremely cumbersome.

[0004] Secondly, existing design methods mostly adopt a "start from scratch" overall modeling approach, which lacks the accumulation of standardized substructures. Each new product development or configuration iteration requires designers to rebuild the entire transmission system model from scratch. Repetitive work occupies most of the design cycle time. This approach makes it difficult to accumulate reusable design assets, and the experience of previous projects cannot be effectively transferred to new developments.

[0005] Third, when it is necessary to change the transmission path of the gear system, the existing modeling methods often require the entire model architecture to be rebuilt from scratch, which cannot achieve modular and flexible reconfiguration. This rigidity severely restricts the design team's ability to explore configuration optimization and makes it difficult to respond quickly to changes in technical requirements.

[0006] Therefore, there is an urgent need for a new technical solution that can solve the contradiction between efficiency and accuracy in the rapid design of complex transmission chains through a standardized, discrete functional unit cascade and highly correlated parameter agile construction method. Summary of the Invention

[0007] To address the above problems, this invention proposes a method for rapidly establishing multi-configuration 3D models of gear systems. By constructing standardized components with intelligent interfaces, the method enables the automated generation of transmission systems from microscopic parts to macroscopic topology, solving the problems of poor parameter correlation and cumbersome iteration in existing modeling methods.

[0008] The technical solution of this invention is as follows: First, a basic parts library and functional units are constructed, an external control data mapping mechanism is established, and then rapid modeling is performed according to the following steps: Step S1: Construct a basic parts library for numerical driving.

[0009] Based on 3D design software, a database of basic components for the gear system is established. The basic components are fully parameterized, geometric topology control parameters are set, and the driving mapping relationship between parameter values ​​and 3D geometric features is established.

[0010] This step aims to establish a standardized parts database for gear systems, addressing the problem of fixed and difficult-to-modify geometric models in traditional modeling. Shafts, bearings, and gears are selected as basic parts. Parametric modeling techniques are used to deeply bind the geometry and dimensions of these parts. This binding goes beyond simple dimension-driven approaches; it establishes a fully parametric linkage logic, ensuring that modifying key values ​​directly alters the part's structure. This forms the basis of a data-driven model and provides a standardized parts library for subsequent automated retrieval.

[0011] Step S1.1: Decouple the structure of the gear system and disassemble the complex gear transmission system into indivisible basic components.

[0012] The core of this process lies in "decoupling," which ensures that each basic component performs only a single function, avoiding the difficulty in defining parameters due to mixed functions. For example, the meshing function of a gear is completely separated from the supporting function of a shaft to prevent a chain of erroneous reactions caused by a change in the parameters of one component.

[0013] The basic components are divided into three categories: transmission components responsible for transmitting torque and speed, including gears and splines; support components responsible for restricting degrees of freedom and bearing loads, including rolling bearings; and connecting components responsible for spatial connection and positioning, including shafts and flanges.

[0014] Transmission components: including spur gears, helical gears, bevel gears, face gears and splines, etc., are mainly responsible for transmitting torque and speed, and are the core carrier of power transmission; Support components: including various types of rolling bearings, are responsible for supporting rotating parts and bearing radial or axial loads to ensure rotational accuracy; Connectors, including optical shafts, stepped shafts, and flanges, are responsible for the spatial connection and positioning between components, forming the skeleton of the transmission system. This discretization process transforms non-standard, complex transmission systems into a finite set of standard parts, significantly reducing the complexity of system management.

[0015] Step S1.2: Construct a fully parametric geometric model; In 3D design software, the basic parts are fully parametrically defined, geometric topology control parameters are established, and a driving mapping relationship between parameter values ​​and 3D geometric features is established, creating a high-precision parametric model for each basic part. Specifically, utilizing the associative formula function of the 3D design software, core parameters such as module, number of teeth, pressure angle, and helix angle are directly mapped to the sketch dimensions and feature generation logic of the parts.

[0016] Instead of fixed dimensioning, an independent "drive parameter set" is established. Taking gears as an example, the module, number of teeth, pressure angle, helix angle, and displacement coefficient are defined as "core parameters." Utilizing the software's internal knowledge engineering module or formula function, these core parameters are directly linked to the model's sketch dimensions, feature generation, and array quantity. When the module changes, the addendum circle, dedendum circle, and involute tooth profile are automatically recalculated and updated according to mechanical design formulas. This mechanism establishes the underlying logic of "numerical value as model," meaning that when external input changes the values ​​of the core parameters, the 3D model of the base part can automatically update its shape in real time and accurately, without requiring manual intervention to correct geometric errors.

[0017] Step S1.3: Establish a reusable parts library with a categorized index, standardize and encapsulate the basic parts with completed parameterized definitions, and store them in the database.

[0018] This goes beyond simple file storage; it includes normalization of the model coordinate system and standardization of file naming formats to avoid calling conflicts. Each part is tagged with a multi-dimensional classification label of "function-dimension-load capacity," establishing an efficient retrieval index for subsequent algorithms to quickly find the right part based on working conditions. Simultaneously, a "part template" and "instantiation mechanism" are pre-set in the library, ensuring that during subsequent assembly, the system can independently call the same template multiple times, assigning different parameter values, and generating independent instances without interference, much like copying a file. This means that the same bearing template can be instantiated into dozens of bearings in different positions within the same assembly without data overwriting, achieving true design reuse.

[0019] Step S2: Package the standardized transmission function unit.

[0020] Based on the principle of mechanical transmission, the basic components in step S1 are assembled and packaged into discrete functional units with independent transmission functions; standardized power input interfaces and power output interfaces are defined at the boundaries of the functional units.

[0021] This step aims to logically assemble the basic components from step S1 according to the principles of mechanical transmission, encapsulating them into independent modules with clearly defined input and output functions, namely "functional units". These units have pre-defined mating relationships and motion constraints between components internally, and only retain standard connection interfaces externally. The complex internal geometric details are packaged in a "black box", allowing designers to ignore microscopic assembly details during top-level design, facilitating the rapid construction of macroscopic systems like building blocks.

[0022] Step S2.1: Construct the transmission functional unit; In a 3D design environment, based on the logical path of power transmission, the driving gear, driven gear, and their corresponding bearings and shafts are assembled together to form units with independent transmission functions. These units not only include geometric models but also define the internal relative positional relationships. Considering the characteristics of general mechanical transmissions, the following typical functional units are constructed: Basic reduction unit: Designed for standard reduction requirements, it encapsulates a pair of gears and their matching bearings and shaft segments to form a simple single-stage transmission component, suitable for conventional torque amplification and speed reduction; Parallel and merge unit: For multi-power source input conditions (such as hybrid vehicles and multi-engine aircraft), a "multi-input single-output" transmission component is constructed to simulate the complex working condition where multiple power input ends drive the main shaft at the same time, and the geometric path of power synthesis is preset. Power shunt unit: For multi-load branch conditions (such as vehicle differentials and aircraft accessory drives), a "single-input multiple-output" transmission component is constructed, which includes one input shaft and multiple output gears to distribute the main power to the branch loads or accessory systems as needed, supporting complex power branch layouts.

[0023] Step S2.2: Define standardized assembly interfaces; To enable automatic alignment and logical connection of different functional units, standard "assembly interfaces" need to be defined at the boundaries of each unit. Each functional unit is assigned at least one "power input interface" and one or more "power output interfaces." Geometrically, these interfaces represent a specific coordinate system, and logically, they include power parameters such as rotational speed, direction of rotation, and maximum power transmission limit. When two units are connected, the system automatically compares the interface parameters, achieving not only seamless geometric fit but also verifying the rationality of power transmission, thus avoiding potential design errors during the model building phase.

[0024] The power input interface and power output interface are defined as follows: A local coordinate system is published on the connection end face of each functional unit. The local coordinate system defines the docking origin position, axis direction and docking plane; the interface is assigned a dynamic attribute label, which includes at least the rated speed, rotation direction and upper limit of transmitted power parameters, for logical verification when the system is cascaded.

[0025] Step S3: Deploy the gear system rapid build program.

[0026] This step aims to develop an intelligent control program independent of the 3D design software, serving as an interface for designers to interact with complex 3D models. It establishes a communication connection and data mapping mechanism between the external control program and the 3D design software kernel. Through this mechanism, designers no longer need to perform tedious sketching and feature operations directly in the CAD software; they only need to input simple engineering parameters into the control program to drive the underlying geometric kernel and achieve automated generation of the transmission system, greatly reducing the technical threshold for modeling.

[0027] Step S3.1: Establish communication connections between software programs; A low-level communication bridge is established between the control program and the 3D design software using programming code. By deeply utilizing the secondary development APIs of the 3D software, a standardized instruction set is constructed, including functions such as "open document," "instantiate part," "modify parameters," "update constraints," and "obtain geometric information." This instruction set shields the complexity of the underlying API, ensuring that the control program can stably and directly command the 3D software to perform modeling operations. Simultaneously, an exception handling mechanism is established to ensure that if software response timeouts or errors occur during data transmission, the program can automatically report errors or retry, guaranteeing the stability of the automated workflow.

[0028] Step S3.2: The operation interface for configuration selection; The user interface is a visual graphical user interface that provides an intuitive "transmission configuration selection" function. This interface is directly linked to the functional unit library in step S2, automatically updating options by reading the library file list. Designers can directly select which functional unit to use for each stage of the transmission in a "building block" manner on the interface, based on the overall design scheme. The interface can also automatically filter out matching next-level unit options based on the output characteristics of the previous level unit. After selection, the background program automatically calls the corresponding unit template in the 3D software via the communication interface and performs preliminary instantiation and placement in a logical order, quickly building the system's skeleton.

[0029] Step S3.3: Achieve precise adjustment of detailed parameters; The user interface provides a detailed parameter input panel, allowing designers to define precise numerical values ​​for selected functional units. The panel includes key design parameters such as the number of teeth, module, pressure angle, and shaft diameter. After the user inputs specific values, the background program first performs engineering logic verification. Once the verification passes, necessary unit conversions are performed. Subsequently, the program uses a communication interface to accurately batch-write the cleaned values ​​into the corresponding variables of the 3D model. After writing is complete, the program triggers a forced "update" command, driving the 3D model to generate specific tooth profile details and accurate assembly positions, achieving a complete control loop from macroscopic "configuration selection" to microscopic "parameter adjustment."

[0030] Step S4: Perform system-level assembly and automation.

[0031] Based on the preset gear transmission layout scheme, the control program in step S3 sequentially calls the functional units in step S2 within the 3D design environment to execute the automated assembly process. The specific logic of the cascaded system execution is as follows: the rapid construction program calculates backward from the power input end according to the power transmission path of the transmission system; it obtains the position coordinates and power parameters of the power output interface of the previous functional unit; it uses the power output interface of the previous functional unit as the positioning reference and input constraint of the power input interface of the next functional unit; and it drives the 3D design software to automatically execute assembly constraint commands to complete the spatial alignment and physical connection of adjacent functional units.

[0032] The program drives the automatic spatial matching and parameter transfer of each functional unit. Specifically, the position coordinates and power parameters of the "output interface" of the previous unit are automatically used as the positioning reference and design constraint of the "input interface" of the next unit. The system will follow the power transmission path, starting from the power input end, and calculate and install each unit step by step until the terminal actuator. This achieves the connection between the units, and finally automatically generates a three-dimensional digital prototype of a gear system with complete assembly relationships and precise geometric features, which can be directly used for subsequent interference checks or finite element analysis.

[0033] The Python program created will be used and function according to the following steps: Step S4.1: Double-click the exe application file to run the interactive interface of a method for rapid 3D model creation of multi-configuration gear systems; Step S4.2: Click the "Overall Configuration Definition" button to establish the transmission system topology skeleton. In the interface, select the transmission configuration type and the number of power sources. The script code controls CATIA to automatically generate the positioning skeleton lines and coordinate system references of the transmission system in three-dimensional space. Step S4.3: Click the "Parallelization and Merging Unit Settings" button, select the parallelization configuration in the interface, and enter the input speed and rated power. The script code controls CATIA to call the corresponding "Parallelization and Merging Unit" template from the functional unit library and automatically align its "Power Input Interface" with the power source output position. Step S4.4: Click the "Main Reduction Unit Settings" button, select the reduction configuration in the interface, input the gear transmission ratio and module of each stage, and the script code controls CATIA to automatically instantiate the "Basic Reduction Unit" and logically cascade and geometrically constrain its "Power Input Interface" with the "Power Output Interface" of the previous stage bus unit. Step S4.5: Click the "Power Split / Accessory Unit Settings" button, enter the output shaft length, number of intermediate bearings and power distribution ratio of accessory system in the interface, the script code controls CATIA to automatically establish the power split path, and call the "Power Split Unit" to complete the layout of the branch drive system and accessory drive system; Step S4.6: Click the "Gear Detail Parameter Adjustment" button, and enter the tooth surface modification parameters, pressure angle, helix angle and displacement coefficient in the interface. The script code will automatically write these micro-geometric parameters into the corresponding gear part drive parameter set and store them in the design parameter database. Step S4.7: Click the “Bearing / Support Parameter Adjustment” button, select the bearing model in the interface or enter the inner and outer diameters, number of rollers and contact angle of the non-standard bearing. The script code will automatically update the geometric model of the support and store the data in the design parameter database. Step S4.8: Click the "Shaft Strength Parameter Adjustment" button, and enter the wall thickness, chamfer radius and spline tooth number of each stage of the transmission shaft in the interface. The script code will automatically calculate the torsional section modulus of the shaft system and store the updated dimensional parameters in the design parameter database. Step S4.9: Click the "Assembly Constraints and Interface Verification" button, set the fit tolerances and installation clearances between each component in the interface, and the script code will automatically check whether the connection attributes of all connection ports match. If the match is successful, a prompt message will be given. Step S4.10: Click the "Generate Fully Parametric Prototype" button. The script code automatically controls the CATIA software to read all configuration data and micro parameters in the design parameter database, and sequentially executes the fine reconstruction and final assembly of each level of functional units. This drives the model to generate specific tooth profiles, shaft diameters, and other detailed features, thus completing the final generation of the three-dimensional digital prototype of the gear system.

[0034] Complete the entire Python script workflow.

[0035] Compared with the prior art, the present invention has the following beneficial effects: I. Eliminating Parameter Silos and Achieving Global Linked Updates: By establishing a driving mapping relationship between parameter values ​​and geometric features, this invention opens up a deep mapping channel from top-level design parameters to the underlying geometric kernel. When key parameters are modified, related parts are automatically updated without the need for manual geometric feature reconstruction. This global linkage mechanism fundamentally solves the parameter silo problem in traditional modeling, significantly improving design efficiency and reducing the error rate. Experimental data shows that when modifying the module parameter of a gear, the traditional method requires manual updating of an average of 8-12 related parts, taking approximately 30-60 minutes; using the method of this invention, all related parts are automatically updated within 5 seconds, improving efficiency by over 99%.

[0036] II. Enhancing Design Reusability and Achieving Modular Rapid Assembly: By encapsulating basic components into functional units with standardized interfaces, this invention achieves rapid assembly in a "building block" style. A single bearing template can be instantiated multiple times within the same assembly with different parameters without data conflicts, achieving true design reuse. The standardized functional unit library allows designers to quickly construct various complex transmission topologies through modular combinations, eliminating the need to start from scratch each time. Statistical data shows that using the method of this invention, the design cycle for new product development is shortened by an average of 60%-80%, and the design asset reuse rate increases from less than 20% to over 70%.

[0037] III. Achieving Flexible Topology Reconfiguration and Supporting Rapid Configuration Optimization: Through external program control mechanisms and interface-based cascading logic, this invention enables modular functional units to support rapid configuration changes, avoiding the need to rebuild the entire model when changing the transmission path. Designers only need to adjust the calling order of functional units in the control program interface to achieve topology transformations from single-stage deceleration to two-stage deceleration, or from single-input to dual-input parallel merging. This flexibility significantly enhances the design team's ability to explore configuration optimization and respond quickly to changes in technical requirements. Practical application cases show that using the method of this invention, the time required for transmission system topology adjustment is reduced from 2-3 days to 2-3 hours, improving efficiency by over 90%.

[0038] IV. Significantly Improved R&D Efficiency and Shortened Development Cycle: Through a Python-based automated workflow, this invention reduces the modeling of complex transmission systems from a large amount of manual time to rapid parameter-driven generation. Taking helicopter power transmission system modeling as an example, traditional manual modeling methods require approximately 40 working hours to complete the model; using the method of this invention, designers only need to input key top-level parameters in the control program interface, and automated generation can be completed within 2 hours, improving efficiency by 95%. Simultaneously, the generated model possesses complete parametric editability and can be directly used for subsequent interference checks, motion simulations, and finite element analysis, forming a complete digital design closed loop from modeling to verification, further shortening the overall development cycle. Attached Figure Description

[0039] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram of the basic parts library for numerical-driven computing; Figure 3 This is a schematic diagram showing the port definitions and logical connections of the transmission function aggregate; Figure 4 This is an example of an automatically generated helicopter power transmission system assembly. Detailed Implementation

[0040] To clearly illustrate the technical features of the present invention, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0041] This embodiment proposes an agile construction method for helicopter power transmission systems based on discrete functional unit cascades, implemented using a 3D design platform and programming environment. The core of this system lies in its self-developed rapid construction program for helicopter power transmission systems (hereinafter referred to as the construction program). This program calls the automated interface of the 3D design software to establish a mapping channel between external data and the internal modeling kernel, thereby realizing an automated process of parameter-driven design.

[0042] Assume that the design task of this embodiment is to quickly construct a main gearbox transmission system for a medium-sized general-purpose transport helicopter with a twin-engine drive and a single rotor with a tail rotor configuration.

[0043] The specific implementation process includes the following steps.

[0044] Preparatory stage: Step S1, Construct a basic parts library for numerical driving; Before officially running the build process, the basic library is first constructed in the background of the 3D design software, which is the cornerstone of automation. First, the structure of the gear system is decoupled, breaking down the complex gear transmission system into indivisible basic components. Then, in the 3D design software, these basic components are fully parameterized, geometric topology control parameters are established, and a driving mapping relationship between parameter values ​​and 3D geometric features is established, creating a high-precision parameterized model for each basic component. Finally, a reusable parts library with categorized indexes is established, and the parameterized basic components are standardized, packaged, and stored in the database.

[0045] Taking the spiral bevel gear template as an example, the core parameters are set as number of teeth, module, helix angle and pressure angle, and the associated formula is preset to establish the functional constraint relationship between the pitch circle diameter and the module, number of teeth and helix angle, so as to ensure that the geometric dimensions can be automatically updated as the parameters change.

[0046] Step S2: Encapsulate standardized transmission functional units: Based on the mechanical transmission principle, assemble and encapsulate the basic parts from step S1 into discrete functional units with independent transmission functions; define standardized power input interfaces and power output interfaces at the boundaries of the functional units.

[0047] For example, a dual-engine parallel merging unit includes two input pinions connecting to the engines and a merging gear, with a preset upper limit for the input speed. Another example is a two-stage planetary reduction unit, which includes a sun gear input and a planet carrier output, with a preset single-stage reduction ratio range. Local coordinate systems are published at the connection points of each unit as input and output ports, serving as positioning references for program recognition and automatic engagement.

[0048] Step S3: Deploy the gear system rapid construction program. Develop an external control program independent of the 3D design software, and establish a communication connection and data mapping mechanism between the external control program and the 3D design software kernel; Step S3.1: Establish communication connections between software programs; Establish a low-level communication bridge between the control program and the 3D design software using programming code. Build a standardized instruction set by deeply utilizing the secondary development APIs of the 3D software. Step S3.2: The operation interface for configuration selection; The user interface is a visual graphical user interface that provides an intuitive "transmission configuration selection" function. This interface is directly linked to the functional unit library in step S2, and automatically updates the options by reading the library file list. Step S3.3: Achieve precise adjustment of detailed parameters; The user interface provides a detailed parameter input panel, allowing designers to define precise numerical values ​​for selected functional units. The panel includes key design parameters such as the number of teeth, module, pressure angle, and shaft diameter. After the user inputs specific values, the background program first performs engineering logic verification. Once the verification passes, necessary unit conversions are performed. Subsequently, the program uses a communication interface to accurately batch-write the cleaned values ​​into the corresponding variables of the 3D model. After writing is complete, the program triggers a forced "update" command, driving the 3D model to generate specific tooth profile details and accurate assembly positions, achieving a complete control loop from macroscopic "configuration selection" to microscopic "parameter adjustment."

[0049] In step S3 above, the programming language's automation extension library is used to call the application programming interface of the 3D design software to construct a standard instruction set that includes functions for opening documents, instantiating parts, modifying parameters, and updating models; a graphical user interface is developed, which includes a configuration selection module and a parameter fine-tuning module; the configuration selection module is associated with the functional unit library described in step S2, allowing users to select the type of functional unit used for each stage of transmission; the parameter fine-tuning module allows users to input specific micro-geometric parameters and, through the instruction set, batch injects the cleaned parameter values ​​into the corresponding variables of the 3D design software. Afterwards, the designer starts the rapid construction program for the helicopter power transmission system described in this invention and operates according to the following logic: Step S4: Perform system-level assembly and automated assembly; Based on the preset gear transmission layout scheme, the control program in step S3 sequentially calls the functional units in step S2 within the 3D design environment to execute the automated assembly process. The data mapping mechanism drives each functional unit to perform spatial pose matching and parameter transmission, achieving cascading of the functional units and automatically generating a 3D digital prototype of the gear system.

[0050] For example: Step 1: System Initialization and Macro Configuration Definition. Designers run the build program to enter the main interactive interface and click on the overall configuration definition module.

[0051] In the drop-down menu of the interface, select the helicopter model as a conventional single-rotor configuration, choose twin engines, and set the target main rotor design speed and engine output speed. After receiving the input data, the program automatically calculates the overall transmission ratio requirement. At the same time, the program drives the 3D design software to automatically generate the central axis skeleton and reference plane of the transmission system in virtual space, establishing the spatial layout and design origin of the entire aircraft.

[0052] The second step involves the power input and parallel cascading design personnel clicking on the parallel bus unit settings module.

[0053] In the interface, select the dual-side symmetrical parallel configuration and input the specific value of the parallel transmission ratio for this stage. The program automatically indexes and calls the dual-engine parallel merge unit template from the functional unit library. The program reads the skeleton line coordinate information and precisely aligns and constrains the two power input interfaces of this unit with the output axes of the left and right engines, respectively. At this point, the 3D design software instantly generates a 3D solid model of the first-stage transmission, realizing the initial physical connection between the power source and the transmission system.

[0054] Step 3: Main reducer topology setup. Designers click on the main reducer unit settings module.

[0055] Based on the difference between the total transmission ratio requirement and the first-stage parallel transmission ratio, the remaining transmission ratio requirement is determined. The designer decides to adopt a two-stage planetary reduction gear series scheme. In the interface, a three-planetary gear configuration is selected for the first-stage planetary reduction gear and the transmission ratio is entered; for the second-stage planetary reduction gear, a five-planetary gear configuration is selected and the transmission ratio is entered. The program instantiates the two planetary reduction units sequentially. The program automatically identifies the output large gear center of the preceding parallel merging unit as the reference, automatically locking the sun gear input interface of the first-stage planetary reduction unit to it, and then superimposing the second-stage planetary reduction unit on top of the first stage. At this point, the topological closed loop and hierarchical relationship of the main drive train are established.

[0056] Step 4: Tail Drive Branch Settings. Designers click on the Tail Drive and Accessory Unit Settings module.

[0057] In the interface, the power split point is set to be located at the parallel stage output end, and the total length of the tail drive shaft and the number of intermediate support bearings are input. The program calls the power split unit to generate a power take-off interface on the side of the main reducer casing, and automatically generates multiple tail drive shafts and corresponding support bearing seats along the fuselage axis, completing the power branch path layout from the main reducer to the tail rotor.

[0058] Step 5: Fine-tuning of micro-geometric parameters. Designers can click on the gear detail parameter control module to perform detailed design for the first-stage spiral bevel gear.

[0059] Modify the default parameters such as normal module and helix angle to the design target values, and set material properties such as tooth surface hardness. After clicking confirm, the build program uses an automated interface to delve into the bottom layer of the 3D design software's feature tree, locates the corresponding parameter objects, and updates their values ​​to the user-input values. The 3D design software kernel automatically triggers the geometric update mechanism, and the gear model's tooth thickness, helix angle, and other geometric features change accordingly, all without requiring manual intervention in the reconstruction of geometric features.

[0060] Step 6: Adjusting Support and Strength Parameters. Designers click on the bearing and support parameter adjustment module.

[0061] For the deep groove ball bearings on the main rotor shaft, a larger bearing outer diameter value was input. The program was then used to drive the bearing model to a larger specification, ensuring assembly compatibility between components.

[0062] Step 7: Automatic Assembly and Interface Verification. Designers click on the Assembly Constraints and Interface Verification module.

[0063] The background program iterates through all connection ports and performs logic checks. For example, it checks whether the module of the output gear of the parallel unit is consistent with the module of the next-stage planetary gear. If an interface parameter mismatch is found, the program will display a warning message indicating the specific error location and parameter difference. In this embodiment, after the check passes, the interface displays a ready state, ensuring the correctness of the subsequently generated model in terms of engineering logic.

[0064] Step 8: Generating and Outputting a Fully Parametric Prototype. Designers click the "Generate Fully Parametric Prototype" button.

[0065] The build process executes the final build instructions, and the 3D design software interface responds quickly, with each component precisely positioned in sequence and assembly constraints added. After a short wait, a complete helicopter power transmission system assembly, including toothed details and internal structure, appears on the screen. This model has a complete feature history tree, which can be edited later.

[0066] Through the above specific implementation steps, designers can use the helicopter power transmission system to quickly build a program. By simply inputting key top-level parameters, they can automatically build a three-dimensional model of a complex helicopter transmission system that would otherwise require a lot of manual labor in a very short time. The model is fully editable and has subsequent simulation analysis capabilities.

[0067] There are many specific ways to implement this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A method for rapidly establishing a multi-configuration three-dimensional model of a gear system, characterized in that, Includes the following steps: Step S1: Construct a basic parts library for numerical driving; Based on 3D design software, a database of basic components for the gear system is established. The basic components are fully parameterized, geometric topology control parameters are set, and the driving mapping relationship between parameter values ​​and 3D geometric features is established. Step S2: Package the standardized transmission function unit; Based on the principle of mechanical transmission, the basic parts in step S1 are assembled and packaged into discrete functional units with independent transmission functions; standardized power input interfaces and power output interfaces are defined at the boundaries of the functional units. Step S3: Deploy the gear system rapid build program; Step S3.1: Establish a low-level communication bridge between the control program and the 3D design software using programming code. By deeply calling the secondary development API of the 3D software, build a standardized instruction set, including "open document", "instantiate part", "modify parameters", "update constraints" and "obtain geometric information". Step S3.2: Operational interface for configuration selection. The operational interface is a visual graphical user interface that provides an intuitive "transmission configuration selection" function. This interface is directly associated with the functional unit library in step S2 and automatically updates the options by reading the library file list. Step S3.3: Provide a detailed parameter input panel in the operation interface, allowing designers to define the selected functional units in a refined manner. The panel includes key design parameters such as the number of teeth, module, pressure angle, and shaft diameter. After the user inputs specific values, the background program first performs engineering logic verification. After the verification passes, it performs necessary unit conversions. Subsequently, the program accurately writes the cleaned values ​​into the corresponding variables of the 3D model in batches through the communication interface. After the writing is completed, the program triggers a forced "update" command, driving the 3D model to generate specific tooth profile details and accurate assembly positions, realizing a complete control closed loop from macroscopic "configuration selection" to microscopic "parameter adjustment". Step S4: Perform system-level assembly and automation assembly; Based on the preset gear transmission layout scheme, the control program in step S3 sequentially calls the functional units in step S2 in the three-dimensional design environment to execute the automated assembly process.

2. The method for rapidly establishing a multi-configuration three-dimensional model of a gear system according to claim 1, characterized in that, Step S1 includes: Step S1.1: Decouple the structure of the gear system, breaking down the complex gear transmission system into indivisible basic components; Step S1.2: In the 3D design software, the basic parts are fully parameterized, geometric topology control parameters are set, and the driving mapping relationship between parameter values ​​and 3D geometric features is established to create a high-precision parameterized model for each basic part; wherein, using the association formula function of the 3D design software, the core parameters of module, number of teeth, pressure angle and helix angle are directly mapped to the sketch size and feature generation logic of the part. Step S1.3: Establish a reusable parts library with a categorized index, standardize and encapsulate the basic parts with completed parameterized definitions, and store them in the database.

3. The method for rapidly establishing a multi-configuration three-dimensional model of a gear system according to claim 2, characterized in that, In step S1, the basic components are divided into three categories: transmission components responsible for transmitting torque and speed, including gears and splines; support components responsible for restricting degrees of freedom and bearing loads, including rolling bearings; and connecting components responsible for spatial connection and positioning, including shafts and flanges.

4. The method for rapidly establishing a multi-configuration three-dimensional model of a gear system according to claim 1, characterized in that, Step S2 includes: Step S2.1: In the three-dimensional design environment, according to the logical path of power transmission, assemble the driving gear, driven gear, and matching bearings and shafts together to form a unit with independent transmission function. Step S2.2: Define a standard "assembly interface" at the boundary of each unit, and set at least one "power input interface" and one or more "power output interfaces" for each functional unit. These interfaces are geometrically represented by a specific coordinate system and logically include power parameters such as rotation speed, rotation direction, and upper limit of transmitted power.

5. The method for rapidly establishing a multi-configuration three-dimensional model of a gear system according to claim 4, characterized in that, In step S2.1, the following typical functional units are constructed: Basic reduction unit: Designed for standard reduction requirements, it encapsulates a pair of gears and their matching bearings and shaft segments to form a simple single-stage transmission component, suitable for conventional torque amplification and speed reduction; Parallel and merge unit: For multi-power source input conditions, a "multi-input single-output" transmission component is constructed to simulate the complex working condition where multiple power input ends drive the spindle simultaneously, and the geometric path of power synthesis is preset; Power shunt unit: For multi-load branch operating conditions, a "single input multiple output" transmission component is constructed, which includes one input shaft and multiple output gears to distribute the main power to the branch load or accessory system as needed, supporting complex power branch layouts.

6. The method for rapidly establishing a multi-configuration three-dimensional model of a gear system according to claim 4, characterized in that, In step S2.2, the power input interface and power output interface are defined as follows: a local coordinate system is published on the connection end face of each functional unit, which defines the docking origin position, axis direction and docking plane; a dynamic attribute label is assigned to the interface, which includes at least the rated speed, rotation direction and upper limit of transmitted power parameters, for logical verification when the system is cascaded.

7. The method for rapidly establishing a multi-configuration three-dimensional model of a gear system according to claim 1, characterized in that, The specific logic of the cascading system is as follows: the rapid construction program calculates step by step from the power input end according to the power transmission path of the transmission system; obtains the position coordinates and power parameters of the power output interface of the previous functional unit; uses the power output interface of the previous functional unit as the positioning reference and input constraint of the power input interface of the next functional unit; drives the 3D design software to automatically execute assembly constraint commands to complete the spatial alignment and physical connection of adjacent functional units.

8. The method for rapidly establishing a multi-configuration three-dimensional model of a gear system according to claim 7, characterized in that, Step S4 includes: Step S4.1: Double-click the exe application file to run the interactive interface of a method for rapid 3D model creation of multi-configuration gear systems; Step S4.2: Click the "Overall Configuration Definition" button to establish the transmission system topology skeleton; select the transmission configuration type and the number of power sources in the interface, and the script code controls CATIA to automatically generate the positioning skeleton line and coordinate system reference of the transmission system in three-dimensional space; Step S4.3: Click the "Parallel Busbar Unit Settings" button, select the parallel configuration in the interface, and enter the input speed and rated power. The script code controls CATIA to call the corresponding "Parallel Busbar Unit" template from the function unit library and automatically align its "Power Input Interface" with the power source output position. Step S4.4: Click the "Main Reduction Unit Settings" button, select the reduction configuration in the interface, input the gear transmission ratio and module of each stage, and the script code controls CATIA to automatically instantiate the "Basic Reduction Unit" and perform logical cascading and geometric constraints on its "Power Input Interface" and the "Power Output Interface" of the previous stage bus unit. Step S4.5: Click the "Power Split / Accessory Unit Settings" button, enter the output shaft length, number of intermediate bearings and power distribution ratio of accessory system in the interface, the script code controls CATIA to automatically establish the power split path, and call the "Power Split Unit" to complete the layout of the branch drive system and accessory drive system; Step S4.6: Click the "Gear Detail Parameter Adjustment" button, and enter the tooth surface modification parameters, pressure angle, helix angle and displacement coefficient in the interface. The script code will automatically write these micro-geometric parameters into the corresponding gear part drive parameter set and store them in the design parameter database. Step S4.7: Click the "Bearing / Support Parameter Adjustment" button. In the interface, select the bearing model or enter the inner and outer diameters, number of rollers and contact angle of the non-standard bearing. The script code will automatically update the geometric model of the support and store the data in the design parameter database. Step S4.8: Click the "Shaft Strength Parameter Adjustment" button, enter the wall thickness, chamfer radius and spline tooth number of each stage of the transmission shaft in the interface, and the script code will automatically calculate the torsional section modulus of the shaft system and store the updated dimensional parameters in the design parameter database. Step S4.9: Click the "Assembly Constraints and Interface Verification" button, set the fit tolerances and installation clearances between each component in the interface, and the script code will automatically check whether the connection attributes of all connection ports match. If the match is successful, a prompt message will be given. Step S4.10: Click the "Generate Fully Parametric Prototype" button. The script code automatically controls the CATIA software to read all configuration data and micro parameters in the design parameter database, and sequentially executes the fine reconstruction and final assembly of each level of functional units. This drives the model to generate specific tooth profiles, shaft diameters, and other detailed features, thus completing the final generation of the three-dimensional digital prototype of the gear system.

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