Design Of Tooth Profile And Analysis Of Rock - Breaking Efficiency Of Special Single - Cone Drum

In the area of petroleum drilling engineering, special single—cone bit has good prospects of application in many fields as the new one. It differs from the common three—cone bit, PDC bit and the single—cone bit both in pressure and motion in the procession of work, so it is still unclear that how is the rock-breaking efficiency and how to improve it. As the executive component of erosion, teeth’s efficiency will directly affect the bit’s rock breaking efficiency, while the breaking efficiency is mainly subject to the effect of shape of crown, and different combination of teeth row and shape can maximize its rock breaking efficiency, so it needs to choose proper teeth for the different tooth row on the cone.Aiming at the above-mentioned problems, the paper chooses the best shape for every tooth row in the existing tooth shape through researching special single-cone bit’s motion characteristics, experiencing the rock breaking in the single teeth row’s compound motion of existing teeth shapes and comparing the special single-cone bit’s breaking efficiency with the different teeth shapes by finite element simulation technology, at the same time,some more effective tooth have been designed. During this research:1) Based on rock mechanical analysis, settles model JOHNSON-HOLMQUIST-CONCRETE as the rock model and discusses the bit’s motion and pressure in the process of rock breaking.2) LS-DYNA is chosen as the simulation software for its functional characteristics. In the selection process, some special parameter of rock model is determined through "trial and error method"; under the condition of introducing the contact boundary and the failure criterion, the LS-DYNA is used to the finite element simulation of the rock breaking process using; the breaking experiments of single teeth rows’ compound motion are finished, and those results test the result of simulation very well.3) In the analysis process, the volume of rock breaking, the depth of the hole after breaking, the area of breaking and the maximum stresses ed. are all taken into consideration; the three teeth shapes are all evaluated by fuzzy comprehensive evaluation; and the paper chooses the best teeth shape for every teeth row.4) The three new tooth are presented which are designed based on the teeth’s movement orbits and the stress during the process of simulation experiment.