牙轮钻头滚动轴承弹流润滑的理论研究

根据钻头脂流变性能的试验结果，研究了牙轮钻头滚动轴承重载脂润滑弹流问题。利用Ｂｉｎｇｈａｍ流体Ｒｅｙｎｏｌｄｓ方程，并考虑轴承接触表面的粗糙度，建立了数学模型。采用多重网格方法进行数值求解，给出了典型工况下轴承滚子与滚道间的润滑膜厚度，确定了轴承的润滑状态，并分析了转速对润滑状态的影响。计算结果表明，钻头轴承处于边界润滑状态；低速不利于钻头轴承润滑，提高钻头转速能增加润滑膜厚度，改善轴承润滑状态。

Elasto-hydrodynamic lubrication of rolling bearing on cone bits

Based on the result of the test on the rheologic property of bit grease,the elasto-hydrodynamic lubrication problem of rolling bearing on a cone bit is investigated.By using the Reynolds equation of Bingham fluid,and considering the roughness of the contacting surface of the bearing, a mathematic model is established.The multigrid method is adopted to solve the numerical values,the thickness of the lubricant film between the roller and the race way under typical working conditions is given,the lubricating condition of the bearing is determined,and the influence of the rotary speed to the lubricating condition is analyzed.The result of the calculation shows that the lubrication of the bit's bearing is under a condition,low rotary speed is unfavourable to the lubrication of the bit's bearing,and the thickness of the lubricant film can be increased and the lubrication of the bearing can be improved by increasing the rotary speed of the bit.