Research On Optimization Of Key Parameters Of Heavy Vehicle Transmission Shaft Vibration

In recent years,the heavy-duty vehicle market has gradually shifted from an incremental market to a stock market.So in the fierce market competition,more and more manufacturers pay attention to the comfort of heavy vehicles.The transmission shaft of heavy truck is long and the torque transmitted is large.Therefore,there is a problem of vehicle comfort caused by transmission shaft vibration.This paper takes the transmission shaft of heavy vehicle as the research object,and based on the transmission shaft vibration mechanism,improves the transmission shaft vibration problem from the two aspects of transmission shaft vibration key parameter matching and transmission shaft unbalance optimization.The specific research content is as follows:(1)Analysis of the structure and layout of the transmission shaft of heavy vehicles.Do structural mechanics research on the intermediate support of the transmission shaft,and analyze the vibration isolation mechanism of the intermediate support of the transmission shaft.Analyze the cause of the centrifugal force of the transmission shaft and find out the relevant parameters of the unbalance.Provide theoretical support for the optimization of key parameters of transmission shaft vibration.(2)Analysis of external excitation factors of the drive shaft.Consider the coupled vibration of the engine,gearbox,rear axle and drive shaft in the transmission system.Summarize the three excitation modes of crankshaft reciprocating inertia moment to produce torque fluctuation,rear axle bounce to change the length and angle of the transmission shaft and the vibration of the final reducer gear.Lay a theoretical foundation for the vibration simulation of the transmission shaft.(3)Create a multi-parameter optimization model of transmission shaft based on RecurDyn.Taking the intermediate support stiffness,intermediate support damping,input speed,angle between shafts,shaft tube wall thickness and shaft tube outer diameter as the test parameters,and using the intermediate support weighted root mean square acceleration as the test index,141 sets of simulation orthogonal were run test.Find out the optimal horizontal combination scheme of key parameters of the transmission shaft,and analyze the primary and secondary relationship of the influence degree of the test index.And design verification experiments to ensure the correctness of the multi-parameter optimization model of the transmission shaft based on RecurDyn.(4)Based on the principle of on-site dynamic balance measurement of the transmission shaft,analyze common errors;for the problem of inaccurate acquisition of unbalanced signal amplitude and phase information caused by fluctuations in the transmission shaft speed,an unbalanced combination of EEMD and instantaneous frequency reconstruction unbalanced signal is proposed Signal acquisition method;and use this method to decompose the frequency-varying slow-simulation imbalanced signal containing noise signals,and use least squares method to calculate the amplitude and phase information to verify the effectiveness of the method...