Study On The Structure Of Flange Bit

Roller bit is the most main broken crag tool, with the increasing difficulty in exploitation of deep well, extradeep well and geothermal well, the teeth structure and fastening strength are being increasingly influenced by the downhole high temperature. Influenced by the downhole high temperature environment, strength of teeth structure decreased, teeth fastening ability abated, therefore, teeth are easy to take off, prone to reduce the service life of the roller bit. This thesis mainly researched on81/2tricone bit teeth arrangement and structure strength and teeth fastening, downhole high temperature environment when teeth arrangement and mount structure thermal stress change rule, different temperature change rule of teeth fastening ability, the results for roller bit teeth arrangement and mount structure design and improve roller bit life has very important significance.Through the experiment of cone body material in room temperature, we obtained the constitutive relation of cone body material; Using the elastic-plastic theory knowledge set up single tooth hole simplified finite element model, by using the finite element software ABAQUS, the mesh type, boundary conditions etc, determine the finite element analysis regulation, meanwhile, set up with maximum and average Mises stess, maximum and average contact pressure, teeth hole radius direction deformation, teeth press force as the index evaluation method; Teeth arrangement and mount structure parameter analysis, mainly involve teeth hole chamfer, teeth change interference fit design, teeth hole bottom cone angle, teeth root cone angle, teeth burial depth, teeth and teeth hole interference, teeth inlay order interference influence teeth change rule, seting up the main teeth ring double hole simplified three-dimensional model for coupled thermal-mechanical analysis; Under the condition of the downhole temperature (100℃,150℃,200℃,250℃,300℃,350℃,400℃), analyze the influence of the same interference for teeth arrangement and mount structure performance change, the distribution of thermal stress field, the teeth hole spacing and teeth fastening, determine the plastic area do not superposition minimum distance, teeth circle arrangement teeth density of cone, teeth fastening ability, teeth strength change rule.Through the study and analysis in this paper, obtained the rule how downhole high temperature influence the roller bit teeth arrangement and structure strength and teeth fastening strength, the results can guide roller bit design of the teeth arrangement and mount structure, increase the teeth fastening ability and the teeth circle arrangement teeth density, the thesis has great practical significance to develop roller bit which is suitable for high temperature environment.