Balance Characteristic Calculation And Structure Optimization Of Balanced Vibration Reduction Gear In Three-cylinder Engine

Balanced vibration reduction gear of three cylinder engine is the core part of the engine to achieve the balance function.Its balance characteristics directly affect the engine performance.Therefore,it must be guaranteed to have good quality to meet the functional requirements of engine vibration and noise reduction.The balance characteristic calculation and structural optimization of balanced vibration reduction gear are investigated.The main contents are as follows:(1)On basis of analyzing the framework of balanced vibration reduction gear components,the balance calculation index theory such as mass,moment of inertia and unbalance is applied to derive and establish the balance characteristic index of balanced vibration reduction gear weight gain/reduction component,elastic components and entire gear.The reliability of the balance characteristic index calculation model is verified through application example.(2)Aiming at the problem of structural parameters involved in the balance characteristic index calculation model of balanced vibration reduction gear,the orthogonal experimental design method is adopted to analyze the balance characteristic index calculation data.The main factors and secondary factors affecting balanced vibration reduction gear are defined,as the input variables that establish the mapping relation of each balance characteristic index and the basic parameter range is given.(3)The input data sample points are selected based on the optimal Latin hypercube test design method and the sensitivity of the input is analyzed.Based on the principle of radial basis function,the response mapping model is established by applying ISIGHT platform.In order to improve the prediction accuracy of balanced vibration reduction gear balance characteristic index under the change of key structural parameters,the validity of the established mapping model is verified through the relative root mean square error,relative mean error,relative maximum error and decision coefficient R~2.(4)the dimensional constraints of each structural parameter and the geometric constraints among each other are established by applying the Gaussian radial basis function mapping function model corresponding to the balance characteristic index of each key structural parameter and mass,unbalance quantity and moment of inertia.Multi-objective optimization function of key structural parameters is obtained.The NSGA-II multi-objective genetic algorithm is selected to solve the design optimization mathematical model.By inputting the optimized result to the simulation software,the detected balance index conforms the balance performance requirements and the correctness of the multi-objective optimization model is verified.The work of this dissertation provides a theoretical basis for the control of balanced vibration reduction gear balance characteristic index and the structural parameter design of the three-cylinder engine,which is beneficial to improve the processing quality of balanced vibration reduction gear and ensure the balance performance of the three-cylinder engine.