Bench Test And Vibration Analysis On The Main Reducer Of The Helicopter

The transmission system of a helicopter is one of the most important parts.Transmission failure is the most important reason for a helicopter accident at the sametime.so study the helicopter transmission system, the main reducer in particular, isespecially important.Firstly, this paper introduces the transmission principle of the helicopter maingear box. Studies the characteristics of the planetary transmission, simplifies andextracts the model, establish its discrete model with the thought of lumped parameter,analyses the model and introduces the solutions related.Secondly, design the test bench based on the twist-only model of the planetarygear system; provide a basis for the analysis and experimental verification.Thirdly, set the parameters like the number of the gear system、modulus、thenumber of the planetary gears and so on in parameter files，then use the APDLlanguage and generate the finite model automatically including the model of the sungear, planetary gear, ring gear and the gear carrier. In the process of construction,according to the parameters of the planetary gear train and the assembly conditions,we can figure out the location and placement of the planetary gear and then the everypart are automatically constraint by the program.Finally, the gears’ pairs of the planetary gear train are defined on the planetarygear model built before. With the boundary conditions of planetary gear train which isdefined by the working condition, the planetary gear train is completely composed.Calculate the modal value of the gear train by means of modal solving method inANSYS and analyses the main mode.