Study On Evaluation Methods Of Chief Performance Parameters For Helicopter Main Reducer

Helicopter main reducer is the core part of the transmission system, and its performance has adirect impact on the helicopter. So to carry out the evaluation method of chief performance parametersfor the main reducer has an important theoretical and practical values.This paper assesses the helicopter main reducer transmission efficiency, introduces four factorsthat cause power loss in the transmission process, summarize the concrete measures to improve thehelicopter main reducer efficiency. Distribute the transmission ratio to acquire the smallest ofhelicopter main reducer volume by using the secondary sequential planning law. Then allocate thetransmission ratio based on the relationship between the gear volume and the transmission ratio in theideal constraint conditions. Comparing the results obtained by the two methods, one general methodof optimizing distribution of the helicopter main reducer transmission ratio is proposed. And then,using the safe life design method based on the gear’s structural and working condition, the paper sumsup a complete system of fatigue Life, analyses the factors that affect the aviation gear fatigue lifethrough given examples. Next, introduce the safe life design method into the rolling bearing fatiguelife assessment. Obtain the bearing’s fatigue life by calculating Hertz contact stress and using thefatigue life of the three-parameter power function curve, then compare it with the result based onLundburg and Palmgren’s classic fatigue life calculation methods, verify the feasibility of this method.Analyse how the speed affect the fatigue life for the high speed bearings in the main reducer. At last,combined the fatigue life of the crucial pieces, the paper calculates the life and reliability of the entirehelicopter main reducer.Based on the related theory and methods with Matlab software, the paper develops specializedsoftware for the evaluation method of chief performance parameters for the helicopter main reducer,such as: efficiency assessment, transmission ratio distribution, life evaluation and so on. Thus providea technical support for the study of helicopter main reducer.