Taking the static transmission error and influence of rotor system into consideration

a dynamic model of helical pairs based on the expander subsystem is built.And then a lateral-torsional natural characteristic analysis of the rotor system considering the effect of mesh st iffness and helix angle is carried out according to a finite element model of a three parallel shaft gear pairs built afterwards.It is demonstrated that the vibration of the expander subsystem become intense and a coupling mode is excited due to the gear coupling

therefore the characterist ics of the system must be analyzed with the coupled method.It is also shown that change of bearing stiffness and helical angle contributes a lot to the dynamic meshing force on the meshing point of the gear

which even shifts the amplitude of the dynamic meshing force

and thus it can provide a better theory basis on confirming the bearing stiffness and gear design.