基于承载因子理论的高转速齿轮润滑特性分析

考虑轮齿在啮合过程中温升及轮齿表面粗糙度的影响,应用Johnson的承载因子理论分析了渐开线圆柱齿轮在高速运动时,不同载荷下其承载油膜的膜厚、剪应力以及摩擦因数沿啮合方向的分布情况,并对比分析了粗糙度对上述参数产生的影响.数值结果表明:齿轮在高速运转时,仍不可避免有粗糙峰的接触;温升明显使膜厚减小,并且沿啮合线这种差别逐渐增加;剪切应力在单双齿啮合区的交替点发生突变,摩擦因数有阶跃变化.啮合节点处剪切应力骤降为0,摩擦因数在此处有波动.

Analysis of Lubricating Properties in Spur Gears with High Speed Based on Load-Sharing Concept

In the research of spur gears with high speed, the theory of Johnson's load-sharing concept was employed to analyze the influence of surface roughness and thermal effect on lubricating properties. The distribution of the lubricant film thickness, the shear stress, and the friction coefficient along line of action (LoA) were revealed. The solution result shows that the contact of asperities is still unavoidable even under high speed, the lubricant film thickness decreases obviously when thermal effect is considered, particularly at the point where the meshing is finished. Moreover, the shear stress of the film changes tremendously at the transition point where the engaged teeth shift from two pairs to one pair or on the contrary, and the friction coefficient has step change. The point where sliding to rolling ratio equals zero impels the shear stress to decrease instantaneously down to zero, and the friction coefficient fluctuates simultaneously.