Design And Optimization Of Cow Bedding Material Spreader

With the improvement of people’s living standards in China,demand for dairy products is increasing rapidly.Bedding made of sand can improve mastitis and hoof disease,and ensure milk yield and quality.At present,workers need to spread sand on the bedding every day and make it smooth,so the labor intensity is high.In order to solve the problems of lack of special working machinery,poor working environment,low working efficiency and high labor intensity,a cow bedding material spreader was designed.The main research contents and conclusions are as follows:(1)In view of the lack of special working machinery for spreading sand in China at present,the whole design scheme of the cow bedding material spreader was determined according to the actual pasture conditions and production process requirements.The spreader is mainly composed of a light truck chassis,a spiral conveying mechanism,a bedding material dispersing mechanism and a hydraulic transmission system.It can complete the transportation and spreading of sand at one time,and can meet the requirements of about 5 m width of bedding.(2)The structure design and parameter calculation of the key components of the cow bedding material spreader were carried out.The driving mode and working principle of spiral conveying mechanism and bedding material spreading mechanism were determined.The spiral conveying mechanism is driven by the hydraulic system,and the sand is pushed to the discharge port by driving the spiral blade and the dial to rotate.The bedding material spreading mechanism is also driven by the hydraulic system,and the hydraulic motor drives the spreading spindle and hammer to rotate to spread out the sand,so as to ensure the uniformity of sand spreading.(3)Through the combination of the actual test and virtual test,the static friction coefficient and dynamic friction coefficient of sand are calibrated to ensure that the real flow process of sand is simulated.The discrete element simulation analysis was carried out on the bedding material spreading mechanism,and the single factor tests were carried out on the spreading speed,opening angle of the upper baffle,spreading tangent angle and length of the upper baffle,with a total of 16 groups.The factors and levels of follow-up simulation are obtained by analyzing the thickness curve of ground particles,the spreading velocity map of particles and the distribution map of particles at the discharge port,and the theoretical basis is provided for it.(4)The response surface test based on the Box-Behnken design principle was carried out on the bedding material dispersing mechanism.The response surface analysis and parameter optimization of the test results were carried out by Design-Expert 8.0.6,and the optimal parameter combination of the bedding material dispersing mechanism was obtained.The simulation test was carried out under the optimal parameters and the relevant data were counted.The result shows that the spreading width is 5.4 m,the spreading thickness is 21.25 mm,and the coefficient of variation of spreading uniformity is 26.55%,which is close to the predicted value.The accuracy of the optimized model is verified.(5)According to the design scheme of the whole machine and the design of the key components,the cow bedding material spreader was trial-produced and tested.The test data show that under the optimized parameters,the spreading width is 5.322 m,the spreading thickness is 23.16 mm,and the coefficient of variation of spreading uniformity is 29.702%,which is basically consistent with the simulation data.It shows that it is feasible to optimize and study the bedding material dispersing mechanism by using the research method of discrete element analysis combined with response surface test,and the main indexes meet the operation requirements of bedding material spreading.