Investigation On Vibration Characteristics Of Helical Gear System

Compared to spur gear, the helical gear is one of comparatively complex transmission mode in all gear transmission systems which has compacte structure, better coincidence degreed and meshing performance. In order enhance the gear bearing capacity and insure transmission stability, wide helical gear pair is widely used especially when the load is heavy. Meshing procedure of the helical gear is a gradually entering and gradually withdrawing procedure, and its meshing impact to structures is much smaller compared to spur gear. In this thesis, the inner exciting mechanism is investigated. The vibration characteristics of the helical gear transmission system is also computed and tested.Firstly, the finite element model of the transmission shaft is built with Finite Element Analysis software, and based on the mode method; the bearing stiffness of the shafting is also optimized and identified.And then, in order to obtain the vibration transmission characteristics of the gear box accurately, based on the transmission system contained the inner structure and gear system, the finite element model of the helical gear system is built.In the end, based on Y. Cai's formulation, the helical gear stiffness stimulating model is built. Making use of the harmonic function the error excitation model is built. With the finite element method, the vibration response of the gear box under different load condition is obtained. Helical gear test experiment is designed, and LMS Virtual lab software is used to identify the system stimulation. The results of the experiment verified the rationality of stimulation model and vibration response calculation.