Design And Analysis On The Key Components Of High-speed Gear Fatigue Test Bench

The aero-engine is the jewel in the industrial crown.Its transmission system operates under high speed,high temperature,heavy load and other extreme conditions with long life and high reliability.The failure rate is as high as 15%.A large amount of data shows that the failure of the aero engine transmission system mainly comes from the unclear fatigue failure mechanism of the gear pair and the insufficient fatigue performance database.The design criteria deviate greatly from the actual working conditions,resulting in the design safety of the high-speed gear transmission system under extreme working conditions.Margin is difficult to control accurately for a long time.Therefore,the development of a high-speed gear fatigue test stand and the establishment of a real and reliable gear material basic database is one of the basic research work that is urgently needed to improve the reliability and durability of aeroengine gears.The thesis combines basic research on reliability and durability design of "twomachine special" transmission gear(J2019-Ⅳ-0001),and uses theoretical analysis,numerical calculation and finite element to test the fatigue basic data of high-speed gear transmission system in aero-engine The method of combining simulations to explore the high-speed gear test bench program provides a theoretical basis for the development of high-speed gear fatigue test bench.The main research contents are as follows:(1)Based on the conventional mechanical power closed fatigue test bench,a new high-speed gear fatigue strength test bench is proposed.Based on the principle of power seal power flow,the mechanically enclosed test bench is explained,the influence of different motor installation positions on the test bench power is analyzed,and the load characteristics of the gear fatigue strength test bench are described.(2)According to the characteristics of the high-speed gear fatigue test bench,design the liquid radial static pressure bearing and liquid static pressure thrust bearing of the new test gear box,and analyze the influence law of the static pressure bearing radius clearance parameter on the oil film stiffness,temperature rise and power consumption ratio,Use finite element software to simulate and analyze bearing oil film and temperature rise characteristics.(3)Based on Mathematics software and Python language NSGA-Ⅱ genetic algorithm program,analyze the influence of gear design parameters on gear contact fatigue strength and bending fatigue strength,optimize gear contact fatigue strength test parameters and gear bending fatigue strength test parameters;based on Pareto optimization Disaggregate,screen suitable test design parameters,and determine the center distance of the test gearbox.(4)Based on ANSYS workbench software,analyze the natural vibration characteristics of the gear spindle in the high-speed test gearbox,determine its natural vibration characteristics,calculate the critical speed of the spindle,explore the effect of the support stiffness on the spindle natural vibration characteristics,and use harmonic response analysis to study the amplitude of the spindle Frequency response characteristics,transient dynamic analysis of the structural state of the system during high-speed operation.