Research On Fault Diagnosis Of The Crawler Drive Gearbox Of Electric Shovel

Excavator is used widely in international and domestic engineering construction and mining performance. With the rapid development of national economy, the growth of elemental construction program, the demand for excavator will be increased. Electric shovel, whether its lifting mechanism, rotation mechanism, or mobile mechanism, uses for gear transmission equipment to transmit. Gear is the important part that is extensively used in the mechanical equipment, its damage and failure often cause trouble of transmission system or complete equipment .Thus lead the great incident. The gear, the core of power transmission, its condition monitoring and fault diagnosis has received more and more attention. How to detection of incipient faults of gear transmission system, and arrange maintenance time of equipment in order to avoid the equipment breakdown is of great significance. Crawler drive mechanism is a important part of excavator. Once the Crawler drive mechanism has a breakdown, the entire excavator equipment will not work properly. So fault diagnosis on Crawler drive mechanism, as well as on Crawler drive gearbox is very necessary. By gear condition monitoring and fault diagnosis, can achieve fundamental change from maintenance after accidence or periodical maintenance to real-time maintenance. Reduces unnecessary economic losses, and therefore creates greater economic and social benefit. The existing mechanical fault diagnosis technology is not effective enough to solve the early gear fault diagnosis. For this reason, this paper presents an early fault diagnosis method based on virtual prototyping technology. Numerical model is the is the basis for virtual prototype technique . With Pro/E ,a 3-D model of mobile gear reducer is set up,Then sets Models under different failure mode. Two different methods to model the helical gear are proposed in this paper. Gear modeling is convenient using the method. Using pro/program to carry on the parameter modeling of the involute cylinder gear, this model can generate helical gear in a flexible way. Through intuitionistic suggestion input method of parameter can generate models. Inputting some basic parameters can generate the corresponding 3D model while using. it reduces the tedious and repeated work in the design.The whole machine of 3D model and the virtual assembles are finished with PRO/Engineer software, and through interface of ADAMS, the virtual prototype of this machine is built, and the kinematics simulation was performed, which proved the new Virtual Prototyping was feasible In process of simulation, needs to adjust collision parameter constantly .Finally, through the analysis of simulation results, we can judge the simulation process of the reducer accord with its real work process. By this, proves the correctness of the Virtual Prototyping.This paper focus on how to carry on fault recognition early. So Wavelet transformation is used . Wavelet transformation a time_frequency signal analysis. it has many desirable properties, and has been widely applied in many fields of engineering. First prototype model is set to different fault, and then simulations are performed. Introduction simulation results and data into Matlab software to complete the fault signal acquisition. Actual gear translation often contain noise interference ,which makes fault signal become abundance, and frequency component become complexity. But as ideal simulation software, ADAMS's simulation results do not exist noise. To make the simulation result much more actual and credible, flat noise is added to Simulation results. Finally toolbox of wavelet in Matlab is used to decomposition fault signals. Based on analysis of wavelet decomposition, the reducer's fault can be judged easily. thus verify the correctness of the wavelet decomposition. In the traditional gear drive fault diagnosis process, the data is based on actual results of the physical model and test bed。This test method needs testing equipment with higher accuracy. And there may be some wrong using this method, such as missed diagnosis, Diagnostic Errors and so on.。The test time is longer, more costly and requires a great amount of manpower and resources. Fault diagnosis method based on virtual prototype technology, as well as based on numerical model, can save lots of apparatus such as physical prototype, experiment table and data acquisition equipment, thus saving the cost of fault diagnosis. To simulate the real fault signal, all sorts of possible noise interference is added to Adams's simulation results. Wavelet analysis is used for fault diagnosis.Finally, feasibility of this method is demonstrated through an illustration. use virtual prototyping technology for the early gearbox fault diagnosis is a new type of fault diagnosis. We believe that the new technology will be wide concerned. after further study, this economic and efficient diagnostic methods can be a practical and effective method.