Lightweight Design And Dynamic Analysis Of Turbine Gear Transmission System

As an important mechanical element for transmitting power and torque,gears have the advantages of high transmission efficiency,compact structure,and a large constant speed range of transmission ratios.They play an irreplaceable role in the fields of automobiles and aerospace.In the process of gear transmission,due to the weight of the gear itself,the power of the gear will be lost during operation,and the equipment equipped with the gear box will consume more energy,so all kinds of gears are developing in the direction of light weight;On the one hand,with the light weight of the gear,the dynamic performance of the gear will be deteriorated,which will affect the stability of the gear transmission and generate a lot of noise.This paper takes the turbine gear transmission system as the research object,and carries out parameter optimization,structural optimization and analysis of the dynamic performance of the lightweight gear for the gear transmission system.The research contents of this paper are as follows:(1)For the gear transmission system,according to the parameters of the gear and shaft,the mathematical model of the transmission system is established,and the multi-objective optimization algorithm NSGAIII is used to optimize the parameters of the gear transmission system to meet the strength constraints of the gear and the shaft.As the goal,the optimal parameter solution that satisfies the strength constraint is selected by means of the multi-objective decision-making methods,and the purpose of reducing the weight of the gear body through the parameter optimization method is achieved.(2)Taking the large-scale general finite element software Hypermesh as the analysis platform,and using the "Optimization" function of the Optistruct module,a three-dimensional calculation model of topology optimization of a single large gear in the gear transmission system is established.The goal is to minimize the flexibility of the gear,and a modal The frequency and volume are the constraint responses,the gear structure topology optimization is carried out,the optimal density arrangement of the gear spoke parts satisfying the strength and modal constraints is analyzed,and the modal analysis is carried out on the results obtained from the optimization,and the results of the modal analysis are compared.The frequency and amplitude changes,and the reasons for the changes were analyzed.This work laid the foundation for the lightweight design of the gear spoke structure.(3)The results of topology optimization are approximately re-modeled,and the model is optimized by the interface of ANSYS Workbench and NX software to optimize the spoke area and the size of the weight-reducing hole.Firstly,the modal analysis and transient dynamics analysis are carried out on the gear of topology optimization,and the modal frequency in the optimization result and the stress and displacement in the transient dynamics are parameterized,and constraints are set on the result to The minimization of the transmission system volume is the goal to optimize the parameters,and then through the design experiment,select the appropriate experimental sample points for experimental simulation,and then perform numerical fitting according to the parameters and result characteristics of the sample points,create an approximate response surface model,and finally use the response surface.Based on the model,the size of the gear transmission system is optimized,and the modal and transient dynamic performance of the size optimization results are compared and analyzed,which provides a feasible idea for the lightweight design of gears.(4)Based on the above topology optimization results,the lightened gear is remodeled,and the dynamic performance and running stability of the lightened gear are analyzed.Use Workbench to mesh the gear and import the dynamic analysis software LSDYNA to analyze the strength and dynamic performance of the lightweight gear to simulate the real situation.The simulation results show that compared with the original gear,the vibration amplitude of the lightweight gear is higher There is a small increase,the running stability is slightly worse than that of the original gear,and the spoke area of the gear bears part of the stress,so that the material of the spoke part can be fully utilized.This work provides a strong basis for verifying the dynamic performance of the gear before and after the weight reduction.(5)In order to verify the reliability and authenticity of the finite element simulation,an analogy test was carried out to verify the gear transmission system,and the same type of gear transmission system as the optimal design was used for the test.Process the vibration data,extract the main frequency of vibration,analyze the test vibration amplitude and stability of the gear transmission system,and compare the test and simulation results to verify the reliability of the finite element simulation.