| The scraper conveyor is one of the most important and indispensable machinery equipment in coal full-mining and mechanized mining. As higher performance of coal equipment is demanded, coal mining enterprises put more and more attention on the reliability of scraper conveyor. The scraper conveyor is a large and complex mechanical equipment, and the replacement caused by components'failure changes components'age structure of scraper conveyor, which make that the reliability calculation is very difficult and complex, so that the traditional methods to assess reliability are not suitable for the reliability of scraper conveyor. In this paper, the reliability of scraper conveyor is researched, which highlight include two aspects of work, the dynamic reliability modeling and the reliability simulation analysis to the typical parts of scraper conveyor undergoing maintenance and the key components of scraper conveyor, particular studies are as follows:1,The failure of key components influences the reliability of scraper conveyor. The failure is related to the strength and stress of key components, and the strength and stress varies with service time. According to the changing relationship between service time with strength and stress of key components, the reliability modeling is established by considering components'strength, stress and service time. The variation of parts'reliability with service time can be found out by the numerical simulation. The reliability of key components can be seen to running through decline, stability, wear processes from the simulation finding. Run-in processes should be given attention as the reliability of key components runs down too fast. During wearing processes, key components are easy to failure and need timely replacement with new components to avoid fault.2,The reliability of scraper typical parts undergoing maintenance is decided by reliability of system components and maintenance. Research from single component, the reliability mathematical modeling of typical parts undergoing maintenance is established by considering the failure distribution function of components. The variation of system reliability with the failure parameters of components and maintenance cycle is researched by simulation. From the simulation, we can see that the reliability of typical parts'system goes through oscillation and stability stages. The dramatic change and oscillation resulted from the big replacement rate of components during the early service of typical parts system should be given more attention in the system maintenance course. System'maintenance cycle influences the stability of system reliability, the shorter the maintenance cycle is, the bigger the fluctuations of system reliability is, but the bigger the system reliability during stability course is.3,Components of scraper conveyor may fail and need replace in the service process. Compared to the original components, replace components during to failure may have different failure characteristics, which can cause the change of the scraper conveyor original reliability modeling. According to the reliability logic relation of scraper system unit, such as series systems, parallel systems, voting systems and hybrid systems, the overall reliability of scrapers need to be comprehensively evaluated and re-researched. All kinds of reliability mathematical model of integrated machine system undergoing maintenance can be recited based on the logical relationship of each unit.4,In order to identify the failure of scraper components, the paper collects maintenance data from the field to establish scientific approach, which can provides scientific data for model simulation of scraper reliability. Finally, the reliability of scraper is obtained according to theoretical calculations, and the results is consistent with the actual service conditions.In this paper, the SGZ730/400 type scraper conveyor is used to research, whose reliability prediction problem undergoing maintenance has been solved. A scientific assessment to the reliability of complex mechanical and equipment is given out, and this new method has a good reference value for the assessment to the reliability of mechanical products. |
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