牙轮钻头滑动轴承混合润滑时的载荷计算

Load on cone bit journal bearing with composite lubrication

牙轮钻头滑动轴承实际工作时摩擦副之间处于混合润滑状态，此时金属微凸体和油膜一起承担载荷。文中给出了计算混合润滑时油膜和微凸体承载比例的计算方法，并以８１／２ＸＨＰ滑动轴承牙轮钻头为例，分析了钻头运转参数和最小油膜厚度对轴承摩擦副间载荷分配的影响，结果表明：钻头的运转参数直接影响轴承摩擦副间的润滑状况，在一定范围内，提高转速能够改善润滑状况。混合润滑时最小油膜厚度有一个下限门槛值，若低于此门槛值，则这种载荷分配计算方法不再适用。

The journal bearings of a cone bit in operation are in a condition of composite lubrication, the load on them is carried partly by the oil film and partly by the micro-protrusion of bearing metal. The method for calculating the distribution ratio between them is presented. Taking Model 81/2 XHP cone bit as an example,the influence of the bit's operating parameters and the thickness of the lubricant film on the distribution of load is analyzed, and result shows that the bit's operating parameters have direct influence on the lubrication condition, and it can be improved by increasing the rotary speed of the bit in a certain range.