单牙轮钻头布齿方案的综合评价

Comprehensive evaluation on teeth arrangement of mono-cone bits

在给出单牙轮钻头对井底的切削均匀性和覆盖率定义的基础上，以切削均匀性和覆盖率为衡量单牙轮钻头切削效果的依据，探讨了不同布齿方案的优劣。为此建立了综合评价不同布齿方案的欧氏距离评价原则，并按这一原则对直径为２１６ｍｍ、共设置３０枚楔形齿的单牙轮钻头的四种不同布齿方案作了综合评价。按所作的分析和综合评价结果可得出如下结论：（１）单牙轮钻头对井底的切削均匀性和覆盖率是检验牙齿分布设计是否合理的两个重要指标；（２）可用欧氏距离评价原则对牙齿分布进行优化设计；（３）圈状螺旋布齿方案显著优于两种困状辐射布齿方案，也优于螺旋状布齿方案。

After defining the cutting uniformity and bottomhole coverage rate of a mono-cone bit, and taking them as a base for evaluating the cutting effect of the bit, the advantages and disadvantages of various teeth arrangement schemes are investigated, thereafter a criterion for comprehensively evaluating various teeth arrangement schemes is established,and a comprehensive evaluation on four kinds of teeth arrangement schemes of a mono-cone bit is made according to the criterion.