Reliability Research On Knotter Of Square Baler

With the development of my country's agriculture and animal husbandry,the application demand for square baler balers continues to increase.As the key component of the square bale baler,the performance of the knotter directly determines the knotting rate of the baler.At present,the knotter produced in our country generally has the problems of high failure rate and short life.Therefore,the research on the reliability and structure optimization of the knotter is of great significance to improve the reliability of the knotter,accelerate the development and application of the domestic knotter,and also promote the sustainable development of agricultural resources.The main research contents of this paper are as follows:(1)Based on the structure and working principle of knotter,this paper analyzes the common failure modes of knotter and the causes of knotter failure,establishes the knotter fault tree,and clearly expresses the relationship between the failure of each component and the whole knotter failure.The fault tree analysis method is used to solve the minimum cut set,and the structural importance of each component of the knotter is clarified.(2)The Bayesian network model of the knotter is established based on the knotter fault tree.Under the condition that the prior probability and the conditional probability Tab.are known,the Bayesian Network Toolbox(Full BNT)was used to conduct bidirectional reasoning on the knotter failure,and the reliability of the knotter was obtained.And through fault diagnosis,the weak parts of the knotter were determined,including: frame,drive gear disk,biting hook,etc.The research results are not only helpful for troubleshooting during the maintenance phase of the knotter,but also have important guiding significance for the structural optimization of the knotter.(3)Establish a three-dimensional model of the knotting jaws and analyze its working principle.For the vulnerable parts-biting hook,use ANSYS Workbench finite element analysis software for static analysis to obtain the stress,strain,and stress concentration place of the biting hook in the working process.Combined with the Miner linear fatigue cumulative damage theory,use the n Code Design Life software to perform fatigue life analysis of the biting hook,the analysis results show that the fatigue life of the biting hook is lower than the average life of the knotter.The above analysis results provide a reference for the optimal design of the biting hook.(4)The response surface method was used to optimize the structure of the biting hook,and the optimal size of the structure of the biting hook was determined.Strength analysis and fatigue life analysis of the optimized biting hook are carried out.The analysis results show that the structural optimization of the biting hook effectively reduces the maximum equivalent stress and total deformation,and at the same time improves the fatigue life.Finally,use the Six Sigma reliability analysis module in ANSYS Workbench software to analyze the structural reliability of the optimized biting hook.The analysis results show that the optimized reliability of the biting hook meets the reliability requirements of the key parts of agricultural and animal husbandry machinery,and has design reference value.