三牙轮钻头滑动轴承失效分析

三牙轮钻头轴承的使用寿命直接决定了钻头的寿命。为了弄清三牙轮钻头轴承的失效形式、原因及机理，进一步提高三牙轮钻头轴承的寿命，分别对现场失效的三牙轮钻头轴承进行宏观和微观分析。结果表明，密封系统失效是轴承失效的主要原因之一。同时，轴承所受载荷过大且分布不均，温度过高导致材料表面金属强度和耐磨性降低，以及轴承与牙轮之间配合间隙过大，工作时晃动导致受力不均等原因也是造成牙轮钻头轴承的快速失效的主要原因。

THE FAILURE ANALYSIS OF THREE ROLLER BIT SLIDING BEARING

The life of drilling bit is directly determined by three roller bit bearing′s service life.In order to find out failure form,the failure causes and mechanism of three roller bit,and further improve the life of three roller bit,Macroscopic and microscopic analysis of failed three roller bit bearing are done in this article.The results show that failure of sealing system is one of the main reasons of the failure.Overload and unbalanced distributing loads and high temperature deteriorates wear resistance and strength of metal,big radial clearance between bearing and cutter,vibration in rotating are also the primary reason of three roller bit bearing failure.