Mechanical Analysis And Structure Optimization Of Lunar Soil Coring Mechanism

The goal of the third lunar exploration project is getting quality of bedding regolith samples.To achieve this goal,the device of coring lunar soil,coring mechanism is one of the important parts.On the basis of meeting space environment,the design of coring mechanism that will meeting low power consumption,high coring rate,high reliability and high level of bedding regolith is an urgent need to be solved.Needle in this regard,the design and optimization of the coring mechanism were discussed,the main research contents include the design of coring mechanism system,mechanical model,the analysis of discrete element simulation EDEM and the experimental study on the mechanism system.The soft bag lunar soil coring mechanism of turning inward type without sliding has the characteristics of simple structure,low power dissipation and well regolith bedding information-keeping.However,at the initial coring stage,the large pulling force and torque,which are resulted from the spiral movement of lunar soil around bit when it enters the holding-pipe,can consequently cause high power dissipation and bad regolith bedding information-keeping.In the paper,in order to achieve the goal of the minimum of pulling force and torque,a mechanical model representing the interaction of lunar soil on coring mechanism was established to analyze effects of structural parameters and drilling parameters on the pulling force and torque.The structural parameters of coring mechanism and drilling parameters were optimized.The results show that bag thickness and guide head radius have the greatest impact on the pulling force and on the torque respectively.When the guide head radius is 0.5mm and of the bag thickness is 0.2mm,the rope pulling force can reach its optimal value of 89 N,which can greatly reduce the degree of torsion in the process of coring.Coring experiments have verified the correctness of the theoretical analysis.According to the before and after optimization of lunar soil coring mechanism,its working state simulation using the discrete element software EDEM.Study in lunar soil into taking mechanism within the flow state and the soft bag in the inversion process smoothness of flip,and then verify that the regolith take heart agency theory to optimize the results.Finally,this paper takes the deep lunar soil sampling as the research object,according to the results of the theoretical analysis and software simulation.In actual work process to verify from mechanism system design rationality,and compared before and after optimization take power in the working process of the mechanism,heart rate,bedding retention.Ultimately determine the optimal slip soft bag coring mechanism,take heart body light weight,take heart of power consumption is low and took samples of bedding to maintain a good target requirement.