偏心单牙轮钻头井底破岩轨迹研究

偏心单牙轮钻头有一个球形牙轮，牙轮旋转中心线与钻头中心线相交于一点，该交点与牙轮球心之间有偏移距离。针对偏心单牙轮钻头的结构和运动特点，利用复合圆柱坐标系统的基本原理，建立了偏心单牙轮钻头几何学基本方程和牙齿对岩石的吃入条件。在此基础上以楔形齿为对象研究了偏心单牙轮钻头井底破岩轨迹的形成，并编制了井底轨迹图仿真软件以模拟牙齿的凿岩轨迹。通过台架试验，所得仿真井底轨迹图与实际井底轨迹非常吻合，表明关于偏心单牙轮钻头的基本理论的研究是正确的，编制的仿真软件是可信的。

The Research on Rock-Disintegrating Track of Offset Mono-Cone Bit

Offset mono-cone bit has a spherical cone, the rotation centre line of cone intersects the rotation centre line of bit at a point, and there is a distance between this point and spherical cone centre. According to the structure and motion characteristics of the spherical offset mono-cone bit, compound cylindrical coordinates were set up, and basic geometric equations and the conditions of teeth to penetrate rock for the bit were presented. The formation of the bottom hole rock-disintegrating track of the mono-cone bit with wedge teeth was studied, and simulation software for the track pattern was developed. By bench test, we can find that simulation track pattern obtained accords with the actual bottom hole disintegrated by a test bit. So study results on offset mono-cone bit are correct and the simulation software is validated.