Research On Fault Simulation Method Based On Gear Dynamics

In the process of operation,the gears often appear gear fracture,tooth surface pitting,tooth surface gluing,tooth surface wear and other failure forms.The existence of these faults will increase the vibration of the system and force the system to produce noise.Then,the vibration signal can be used as one of the main parameters to monitor the operating condition of the gear.Currently,gearbox vibration signals are widely used in gear fault diagnosis.This method needs to separate the gear vibration signals from the complex components of the box vibration signal.But because the early fault of gear vibration signal is very weak,and from the source to the vibration box test point transmission path of the gear vibration signal caused serious distortion,and the vibration signal of the composition is very complicated,resulting in the body vibration signal testing method is very difficult to find the early fault feature of gear.1)Using ANSYS parametric design language(APDL)and interface operation method,we set up two sets of gear finite element models of normal tooth surface and peeling fault.2)Use ANSYS software to simulate the twist angle of a meshing period with different rotation angles,so as to calculate the meshing stiffness of normaland failure gears in a meshing period.The meshing stiffness of the gear is reduced by the analysis of the peeling failure.3)Based on the study of gear dynamics,the in fluence of the exfoliation on the gear running condition is studied mainly from the two aspects of the meshing force and the vibration acceleration signal.The simulation results show that the peeling makes a significant increase in the amplitude of the meshing force and the vibration acceleration signal of the gear,and the simulation results are in accordance with the theory.4)In order to better locate the location of the peeling fault,the simulation signals of the gear Circumferential 6 nodes are compared with the experimental signals.According to the deferred character of the distance and the circumferential signal,the peeling position is well located.5)The frequency spectrum analysis of the normal and fault gear vibration acceleration signals of the test is carried out.It is analyzed that the vibration signals of the normal gear are mainly manifested in the frequency and the meshing frequency of the rotating shaft in the frequency domain.The amplitude of fault signal except in the shaft frequency and the meshing frequency is large,mainly in the two times frequency,three times frequency in the frequency for the carrier,the rotating frequency FM sidebands.