牙轮钻头超顶的运动分析

由于牙轮钻头在井底工作的复杂性 ,目前还没有从理论上建立牙轮钻头的定量运动与受力关系。在 4个基本假设的前提下 ,利用刚体运动的合成理论分析了牙轮钻头超顶布置时 ,牙轮在井底的运动规律。得出具有超顶布置钻头的牙轮在钻进过程中 ,从理论上可分解为牙轮钻头锥体绕着锥点处在井底的滚动和一个附加在锥体上的整体平动 ,前者对岩石产生压碎和冲击作用 ,后者对岩石产生剪切作用。由刚体运动合成理论得出的结论与以往的理论基本符合 ,牙轮与井底之间不存在纯滚动点

Motion analysis of bit with cone overhung

The quantitative relationship between the motion and force of cone bits has not been established up to now owing to the complexity of the work of the bits in bottom hole. Based on 4 assumptions, and by using the theory of rigid motion, the motion pattern of the overhung cones of a bit is analyzed. It is concluded that, the movement of the overhung cones can be divided into two kinds of motions, i.e. the rolling of the cone round the conical point and the bodily movement attached to the cone body, and which produces respectively an action of crush and impact and the shearing action on rocks. There are no pure rolling points between the bit cone and the bottom hole. The conclusion accords with previous relevant theory.