Examining the Modal Characteristics of the Prestressed Gearbox

The subject of the paper is to examine the modal characteristics of the conveyor gearbox. On gearbox were detected excessive vibrations during operation. Due to the fact that the gearbox operates in continuous operation, it was an unacceptable condition. For this reason, experimental measurements were made using the bump test to identify the cause of excessive vibrations. In addition, a finite element analysis was solved in the ANSYS Workbench software to compare results with experimental analysis results. Load was considered from torque on the input shaft, the mass, and inertia effects of the electric motor and prestressed bolt connections. This means, we solved modal analysis of prestressed system. This approach has enabled us to better understand the dynamic behavior of the gearbox under real operating loads. Output from the finite element analysis also confirmed the oscillation tendency occurs mainly on the input gear shaft at certain natural frequencies. From analyzes results, we can conclude that resonance is caused by the matching of gear mesh frequency of the input gear shaft with one of the natural frequencies of gearbox housing.