Research On Process Parameters For Nozzles Of Freight Train Bearing Cleaning Equipments

The safe operation of railway wagons is an important prerequisite for the development of Chinese railways to realize the heavy-load and high-speed targets.In order to ensure and improve the safety of railway truck transportation,it is necessary to clean and maintain the truck bearings regularly.With the development of technology,the requirements for the cleaning effect of bearing cleaning equipment are getting higher and higher.As the main execution component of the bearing cleaning equipment,the performance of the nozzle affects the cleaning effect of the bearings directly.Jet process parameter models of cylindrical nozzles and fan-shaped nozzles are created using software named Creo.Meshing models are developed using software named Gambit.After checking the mesh quality and defining the boundary constraints,the MESH file is imported into software named ANSYS FLUENT.The VOF two-phase flow model and the Realizable k-ε turbulence model are set according to the actual working condition.The parameters of boundary conditions are set.Finally,the data are initialized and simulated.The single-factor analyses of process parameters are performed for two nozzles.The analysis results state that there is a coupling relationship among the jet process parameters which affect the axial dynamic pressure of the impact surface.An orthogonal optimization design of jet process parameters is executed.The finite element analysis is carried out according to the orthogonal optimization data for nozzles.The optimal jet process parameter combinations is obtained for the two types of nozzles.Based on the optimal jet process parameters combinations of the two kinds of nozzles,the internal structure parameters of the two types of nozzles are optimized using orthogonal optimization design.The prototypes of two types of nozzles having the optimal internal structural parameters are fabricated using three-dimensional printing method.In order to verify the optimization resulte,cleaning experiments are performed in the factory.Because the experimental results could not meet the desired requirements,the laboratory experimental equipment are designed and manufactured.The optimal process parameters of two types of nozzles obtained from the orthogonal optimization design are verified using the laboratory experiments.The final experimental results showed that the theoretical simulation data of the optimal nozzles are basically consistent with the experiment results.In the end,the research methods of multi-nozzle layout are analyze.The objective function,optimization variables and optimization methods are determined.An example analysis of cylindrical multi-nozzle layout is performed.The results showed that the research method of multi-nozzle layout is feasible.The results above provide a theoretical foundation for further research on the cleaning effect of the nozzles and the theoretical reference data for the study of other cleaning equipments.