Research On Design Of Sand Removal Scheme And Optimization Of Sand Collection Structure In Orbital Sand Removal Vehicles

China has a vast territory and its land area is in the forefront of the world.The climate and geographical environment from south to north are quite different.The larger area of Inner Mongolia in the northern part of China is covered by desert.Perennial wind and sand disasters pose a great threat to the railway cargo transportation and the safety of personnel.On the basis of unique orbital conditions and topography,the development of a self-powered orbital sand removal vehicle can clean up the sand on the track surface and the inner side of the track,reducing the secondary coverage of the sand return to the track formation.In this paper,the development of orbital sand removal vehicle and the dynamic analysis of its key structures are the main research objects.The discrete element analysis of sand is carried out,and the main mechanical structure is designed and calculated.The sand particle motion and the force curve of interaction between sand particles and mechanical mechanism were analyzed by the co-simulation of the discrete element analysis software and the dynamic analysis software.The following research work were carried out specifically:(1)The two major links of the track and sand removal vehicle were analyzed.According to the characteristics of dry sand with strong fluidity,the mature bulk material conveying scheme was chosen to select a reasonable sand collecting and sand discharging scheme.The hopper lifting structure as a sand collecting scheme and the belt conveying structure as a sand discharging scheme were calculated and checked respectively.(2)The experiment was carried out by sampling sand in the experimental area.The sand was sampled and classified by a high frequency vibrating screen and a standard sieve.The morphology of the sand particles was observed and recorded by an electronic imager.And 3D model was built based on the measurements and observations.A 1:1 contour model was established and the measurements of the stacking angle were repeated according to the classical sidewall collapse method.The process and results of the simulation experiment were analyzed by orthogonal experiment method,and the calibration of the sand particle experimental simulation parameters were completed.The particle size was enlarged properly.(3)The model of the sand particle bed was built in the discrete element software according to the parameters of the previous chapter calibration.The mechanical structure was built by the multi-body dynamics software.The co-simulation relationship was established.The recycling process and the unloading process of the sand in the hopper were analyzed.The motion law of sand was studied.The rationality of the existing cover structure was verified.The structural optimization scheme was proposed.The relative relationship between the sand trajectory and the drive sprocket was analyzed.The basis for the optimization of sand collection structure was provided.The stress situation in the hopper clearing process and the concentrated force parts were found and the structural optimization plan was proposed.(4)Through the co-simulation of discrete element software and dynamics software,the influence of particle motion on the chain system was studied under the condition of the flexible chain system.Through the comparison of the cleaning effects under different speed combination conditions,the optimal speed combination was determined.By recording the relationship between the link and the sprocket speed,the deformation range of the chain during the co-simulation was determined.