渐开线直齿轮瞬态微观热弹流润滑分析

考虑了瞬态效应、轮齿表面油膜温度场和轮齿表面纵向粗糙度等因素，对渐开线直齿圆柱齿轮的弹流润滑问题进行研究。载荷由双齿或单齿承担，根据实际载荷谱简化的轮齿载荷曲线，利用压力求解的多重网格法和弹性变形求解的多重网格积分法以及温度求解的逐列扫描技术，得到渐开线直齿轮瞬态微观热弹流润滑问题的完全数值解，讨论了轮齿间油膜的厚度、压力、温度沿啮合线的变化规律。数值计算结果表明，齿轮表面纵向粗糙度对轮齿间油膜的压力、膜厚、温升都有较大影响。考虑轮齿表面粗糙度后，油膜压力和温升明显增大，并随压力的增加而影响越来越显著，粗糙峰使油膜压力分布和温度分布产生振荡，轮齿表面的粗糙峰对摩擦因数影响较小，摩擦因数和最高温升在节点两侧最大。

TRANSIENT THERMAL MICRO-ELASTOHYDRODYNAMIC LUBRICATION ANALYSIS OF AN INVOLUTE SPUR GEAR

The clastohydrodynamic lubrication(EHL)of an involute spur gear is studied by considering the transient effect, thermal effect and the tooth surface longitudinal roughness. The load is first assumed to be carried by either two pairs of gear teeth or by only one pair, this transition is modeled as a step variation of the load by simplifying the experimental load spectrum. A full numerical solution to the problem of the time-dependent thermal line contact EHL with single asperities of an involute spur gear is obtained by using the multi-grid method for pressure, the multi-integration method for deformation and the column scanning method for temperature rise. The variation of the oil film thickness, pressure distribution and the temperature rise along the line the action between the contact teeth is discussed. Numerical results reveal that the existence of single asperities on the tooth surface can lead pressure and temperature to change drastically and film thickness to become thin in the vicinity of the asperities. The influences of the single asperities on the pressure, the film thickness and the temperature rise are investigated. The gear teeth surface longitudinal roughness has tiny influence on the friction coefficient. The maximum friction coefficient and the highest film temperature all occur in the vicinity of the pitch point.