三牙轮钻头切削结构：很长的间隔较宽，凿形刀片和相当大锥轴偏移量对位的中心线确保很高的普及率。 为了确保从直径损失该位，保径镶已经得到了更短的长度和顶部的更大的角度。 阵型：长的时间间隔很软很差压实的页岩，砂岩，粘土，盐和软mestones的。 大小和IADC可供选择：2 7/8至26 IADC 114 117 216 217 317 321 417 437 517 537 617 637等。

该系统的总设计。 三牙轮钻头的参数化绘图系统采用模块化程序设计方法; 整个系统被分成四个功能模块：用户界面管理模块，齿面的结构设计模块，数据库管理模块和参数化绘图模块的位。 的用户界面使用VBA，这是嵌入在AutoCAD中，牙轮钻头设计的性能，实现第二个工具的开发。 通过三个牙轮钻头设计用户接口模块输入相关参数的用户，实现人机对话。 位齿构造设计模块的主要功能是根据三个牙轮钻头3位数据的理论为复杂计算的设计而设计的。 数据库管理模块是由Access 2003中从建立数据库的数据。

三牙轮钻头是石油钻井的重要工具，它的性能是否好坏将直接影响到钻井，钻井效率和钻井成本的质量。 三牙轮钻头的设计，在传统的实践经验为基础，结合试验和错误，反复设计计算的方法中，所以设计的精度低，周期长，并且难以提高设计的质量。 而每次计算的设计只能是一个位和低效率。 因此，制定一套三颗牙齿轮钻头CAD系统，实现三牙轮钻头参数化绘图是非常必要的。

Tricone bit Cutting structure: very long widely spaced , chisel-shaped inserts and considerable cone axis offset against center line of bit ensure very high penetration rate . To secure the bit from diameter loss, the gage protection inserts have got shorter length and greater angle of the top. Formations: long intervals of very soft poorly compacted shale, sandstone, clays, salts and soft mestones. Size and IADC available: 2 7/8 to 26 IADC 114 117 216 217 317 321 417 437 517 537 617 637 and so on.

Total design of the system. The parametric drawing system of three teeth wheel drill adopts the modular programming method; the whole system is divided into four functional modules: user interface management module, the bit of tooth surface structure design module, database management module and parametric drawing module. The performance of roller cone bit design of user interface use VBA, which is embedded in AutoCAD, to realize second tools development. The user through the user interface module input relevant parameters of three cone bit design to realize the man-machine communication. The main function of the bit teeth structure design module is designed according to the theory of three cone bit three bit data for the design of complex calculations. Database management module is composed of Access 2003 as a data from the establishment of the database.

Three cone bit is the important tool in oil drilling, whether its performance is good or bad will directly affect the quality of drilling, drilling efficiency and drilling cost. Three cone bit's design in the traditional is based on practical experience and combined with the method of trial and error, repeated design and calculation, so the accuracy of design is low, the cycle is long and it is difficult to improve the quality of design. And the design of each calculation can only be a bit and with low efficiency. Therefore, to develop a set of three teeth wheel drill bit CAD system and realize parametric drawing of three cone bit are very necessary.