Dynamical Simulation Analysis of Faulty Gearbox in Quay Crane Under Dynamic Load

Dynamics simulations with faults can elucidate fault vibration characteristics, yet the vibrational properties of the quay crane lifting gearboxes under dynamic load excitation remain unclear. Based on multi-body dynamics theory, a multi-body dynamical model of the quay crane gearbox is established, simulating dynamic load excitation caused by cables and containers during the operation of a quay crane. The vibration responses under various working conditions and load types of different gear states are analyzed, and the corresponding fault frequency features are extracted by envelope spectrum. Simulations indicate that local gear faults enlarge the amplitude of gearbox vibrations, inducing the phenomenon of gear mesh frequency and its harmonics modulated by gear fault frequency. Based on these studies, a testbed for the quay crane gearbox is constructed. The experiment verifies the accuracy of the dynamic model and reveals that the simulation signal of load-as-dynamic-load is more consistent with reality than static load. The results provide a basis for fault diagnosis of quay crane lifting gearboxes under dynamic load, and can offer simulation data support for intelligent diagnosis models lacking fault samples.