Research On Penetrating Mechanism Of Drilling&Coring Device For Lunar Soil Sampling

This article comes from China’s3r dLunar Exploration Programme.Because ofthe low gravity of the lunar surface, the drill sampling device can not afford enoughdrilling pressure,which is essencial for the drilling process. In order to solve theproblem,based on the overall design requirements of the drilling&coring device oflunar soil, this paper puts forward a penetrating driving device, which is light,low-power,and has high-reiability.Based on the fully understanding of the extraterrestrial sampling techniques,this paper compares the advantages and the disadvantages of a variety of programswhich can provide the penetrating pressure for the drilling mechine, the rope-drivingpenetrating mechanism program is chosen as the research target.Combined with the overall configuration of the lander, the layout of the ropedrive penetrating mechanism device is completed. For the key points of the ropedrive designing, i.e. the drive reel of the penetrating mechanis m, the paper putsforward three design proposals, design is. According to the friction Euler’s formulafor flexible body, a mathematical model is established based on the friction betweenthe wire rope and the winding reel.Combined with the load forecast experimentresults, the related parametres of the penetrating system are designed in detail. Thenaccomplishes the structural design of the three design proposals, and anslyses theimit working ability, working feasibility, luanr environment adaptation ability andthe advantages and disadvantages of the proposals. Finally the control system anddata acquisition for the penetrating device is completed.The capacity and the reliability of the penetrating device is the key factor toensure the completion of the lunar soil drilling and coring and lunar soil samplingtask. In order to analyze the penetrating drive characteristics of the system,thetesting bed for the penetrating driving system is designed and set up, and a series oftests are conducted for the analysis of the system.The equivalent coeffic ient of friction between the rope and drive wheel iscalculated based on the test results. Then Analyzes the relationship between thepenetrating driving force and the relevant parameters, such as the penetrating rate，the penetrating preload and the winding round number of the wire rope. Comparedthe experiment results of deformation with the ideal assumption conditions, andcombined with the fitting data results, proposed the correct calculation formula forpenetrating driving force under multi-round winding conditions, and the referencecorrect distortion coefficient, which meets the actual situation,verifies thecorrectness of the mathematical model. Then accomplishes the testing experiments for the working force stability and repeatability of the device, tests the mechanicalperformance of the wire rope which was the transmission parts of the penetratingmechanis m, and the change of the mechanical properties under high-lowtemperature environments. Finally this paper provides a theoretical reference anddesign guidance for the lunar drilling and sampling system.