几何因素对牙轮钻头传动比的影响

在模拟钻井工况下，对由三排齿圈组成的实验牙轮，采用正交实验方法研究齿圈位置、各圈齿数和牙轮移轴距等诸因素对牙轮钻头传动比i值（牙轮转速／钻头转速）的影响。经分析得出：无齿（实际上相当于齿数为无穷大的极限情况）牙轮钻头的传动比是牙轮钻头传动比的最大值。随着牙轮各齿圈齿数的减少，i值下降，其中最外圈齿数影响最大，第二圈次之，第三圈齿数影响很小。当钻头基值和牙轮外形一定时，随着主锥上的齿圈向副锥上的齿圈靠近，i值下降；随着移轴距增大，i值增加。

Influence of geometric factor on transmission ratio of rock bit

Under the simulated working condition of drilling, by taking a cone with three tooth rows for experiment, and byadopting the orthogonal experiment method, the influence of the tooth row position, the tooth number of each row and thecutter offset on the transmission ratio i of a rock bit is studied. Analysis shows that the transmission ratio of the toothlessrock bit is the maximum value of the transmission ratio of rock bits. The value of i deereases with the decrease of thetooth number of each tooth row, and the influence of the first row is the greatest and that of the third row is very small.While the base value of the bit and the configuration of the cone are certain, the value of i decreases with the closing ofthe tooth row on the main taper to that on the accessory taper; and the value of i increases with the increase of the cutteroffset.