Detection And Diagnosis Method About The Metallurgical Cranes Gear’s Fault

Recently, with the increase number of crane accidents, studies on safety of cranes have played important roles, as an important part of metallurgy crane, reducer will affect it directly and the failure of the reducer will make the cranes fail to work. Usually, there are four main modes of the failure of the reducer:Shafts, bearings, gears and a gearbox’s failure. The performance of gearbox’s failure is rupture which is easy to be observed; the gears’failure is most common but is most difficult to be monitored as well. Since gears is working all time and there is no any other good way to monitor it, Finding vibration signals based on gear’s characteristics through monitoring bearing is the only way to monitor gears.The gear failure generally can be divided into gear surface’s wear、 gear surface’s gluing、gear’s Macro crack and so on, the results of these failures eventually beak gear’s tooth. Among them, the gear’s Macro crack is the most common failure mode. Therefore, according to gear system theories research some Law that the crack’s extension influence meshing gears. This is helpful to probe signal characteristics and recognition technology before the gear reducer fail and prevent reducer failure. Moreover, this can provide a more effective means of support for the healthy operation of the crane safety. In connection with metallurgical crane reducer, the paper made the following main work:1、Based on studying on the design criteria, use and maintenance systems, inspection specification, according to analysis method of fault tree, considering the factors such as personnel, environment, management, a fault tree with reducer failure as the top event is set up.2、Based on dynamic theory, a gear equation is developed to understand the characteristics of gear meshing equation, a display dynamics analysis on a pair of gear meshing through ABAQUS dynamic analysis software is performed as well in order to find local stress concentration points when mesh which is known as prone to failure point.3、a gear system model is developed through SOLID WORKS and a dynamic simulation analysis is performed on gear system by employing ADAMS dynamic analysis software, meanwhile, a fault model with gear tooth crack is developed to simulate defective gears, by analyzing time domain and frequency domain maps, the effect rules of Crack depth of gear on verbal signals of gears during the changing is obtained.4、In order to validate the simulation results, an experiment on a ZQ500 metallurgic crane reducer is performed to get the time-frequency spectrum of both normal and fault gears, the shows are consistent with the simulation results; two experimental models of gear meshing was built to test the vibration of fault gears meshing in various degrees, whose outcomes are compared to the simulation results as well.