不同压力角下自由端面对渐开线直齿轮弹流润滑性能的影响

区别于基于半空间理论的传统直齿轮弹流润滑模型，本文基于有限长空间解建立考虑轮齿自由端面影响的渐开线直齿轮有限长弹流润滑模型. 采用叠加法构造自由端面，矩阵法和半解析法求解自由端面的影响，快速傅里叶变换算法加速齿面弹性变形计算；采用统一Reynolds方程法求解油膜压力和油膜厚度. 以啮合节点为特征位置，分析比较不同压力角下自由端面对直齿轮弹流润滑的影响. 结果表明:与半空间模型比较，考虑自由端面后端面峰值压力降低，压力分布更均匀，最小油膜厚度增大；增大轮齿压力角，节点压力水平减小，油膜厚度增大；当压力角不同时，自由端面对齿轮弹流润滑压力峰值的影响基本相当，对最小膜厚的影响较大. 

The Influence of Free End Surfaces on Elastohydrodynamic Lubrication of Involute Spur Gears with Different Pressure Angles

A finite-length elastohydrodynamic lubrication (EHL) model of involute spur gears with consideration of free end surfaces was established based on the solution to the finite-length space, which was different from the conventional EHL model of spur gears based on half-space theory. The overlapping method was used to construct the free end surfaces. Matrix formulation and semi-analytical method were utilized to solve the effect of free end surfaces and FFT algorithm was utilized to speed up the calculation of the elastic deformation. The unified Reynolds equation method was used to obtain the oil film pressure and thickness. The effect of free end surfaces on EHL of involute spur gears with different pressure angles was analyzed and compared at the pitch point. The results showed that, compared with the conventional half-space model, the free end surfaces reduced the peak pressure, homogenized the distribution of pressure and increased the minimum oil film thickness. The level of pressure decreased and the film thickness increased as the pressure angle increased. When different pressure angles were adopted, the influence of free end surfaces on the peak pressure of the EHL of involute spur gears was approximately identical and that on the minimum film thickness was significant.