基于转动定律的钻头轮头速比仿真模型

在牙轮钻头的破岩过程中,影响牙轮转速的因素非常复杂,因此,研究牙轮钻头的轮头速比对岩石破碎机理研究和钻头设计都有重要的指导作用。总结了国内外以力矩平衡、最小功原理等为代表的几种牙轮钻头轮头速比模型的建模理论及其优缺点。通过分析台架试验数据,发现影响轮头速比的主要因素是外齿圈和次外齿圈的齿数、每颗触底齿与岩石的相互作用力、钻压及岩石的硬度。在此基础上,假设牙轮是对称结构、牙轮轴心线为牙轮中心惯性主轴,考虑影响轮头速比的钻头结构参数、钻压和岩石硬度等主要因素,建立了一种基于转动定律的牙轮钻头轮头速比仿真模型。采用数学回归方法对台架试验数据进行处理,求得了所建仿真模型的相关系数。对比分析发现,所建仿真模型的计算结果与台架实物试验结果相对误差较小,说明所建仿真模型可以用来计算实际钻头或仿真钻头的轮头速比,为牙轮钻头破岩机理分析和建立钻进仿真模型奠定了基础。 

A New Simulation Model about Ratio of Velocity between Cone and Bit Based on Law of Rotation

The factors affecting the rotation speed of cone are very complex during the drilling,therefore,the study about ratio of velocity between cone and bit plays an important guiding role to the rock breaking mechanism and bit design.The modeling theory of ratio of velocity between cone and bit such as torque balance and minimum work,and its advantage and disadvantage have been summed up in this paper.Based on the analysis of staging testing results,the main factors affecting the ratio of velocity between cone and bit include:structural parameters of bit,weight on bit(WOB) and rock hardness.Based on the above research,it is assumed that the cone structure is symmetrical and the cone axis is the central major axis of inertia.Under the assumption,a new simulation model about ratio of velocity between cone and bit based on law of rotation has been created,taking into account the main factors such as the structural parameters of the bit,WOB,and rock hardness.By using mathematical regression method for processing the test result,the correlation coefficient of the simulation model built has been obtained.Based on comparative analysis,the result has been achieved that the error between the calculation result of simulation model and the actual test result is small.So,the built simulation model can be used to calculate the ratio of velocity between cone and bit and to lay a foundation for the analysis of cone bit rock breaking mechanism and the establishment of a drilling simulation model.