根据单牙轮钻头的运动规律，首次提出了单牙轮钻头布齿面上存在牙齿与井底的永远接触区、轮换接触区和永不接触区，并从理论上对此三者作了准确的划分。在此基础上分别研究了各区牙齿在井底的工作区域，并讨论了单牙轮钻头的保径问题，提出了一级和二级保径方案。 According to the motion rule of single-cone bit, the permanent contact area, rotation contact area and never-contact area of ​​tooth and bottom hole of single-cone bit are presented for the first time, and the three are theoretically accurate The division. On this basis, the work area of ​​each tooth in the bottom of the well is studied respectively. The problem of the gage diameter of the single-cone bit is discussed. The primary and secondary gage protection schemes are proposed.