一、前言 本文主要从牙轮钻头轴承轴向结构的几何关系研究设计要求,并探讨保证设计要求的前提下,分析尺寸公差的配置规律及合理的尺寸基准,以期较合理地给定尺寸精度。具体讨论以下问题: I. Introduction In this paper, we mainly study the design requirements of the axial structure of roller bit bearings and discuss the configuration rules of dimensional tolerances and reasonable size references on the premise of ensuring the design requirements, in order to give a more reasonable size accuracy. Specifically discuss the following questions: