弹流润滑效应下直齿轮的接触疲劳寿命

Contact fatigue life on spur gear with consideration of elastohydrodynamic

将直齿轮的连续动态啮合过程用7个典型的啮合状态进行离散,得到7个不同啮合状态下弹流润滑油膜压力的精确数值解。通过有限元法,将此油膜压力转化为齿轮的接触应力。在综合考虑Goodman零均值应力转化公式、P-S-N曲线的横向影响因素以及Miner疲劳累积损伤理论的EM修正法则后,建立齿轮的P-S-N曲线,计算得到弹流润滑效应下直齿轮的接触疲劳寿命,其结果是干Hertz接触的3.91倍,是GB/T 3480—1997标准的10.4倍。对比结果表明:对高速传动直齿轮进行接触疲劳寿命的准确评估,有必要考虑弹流润滑效应,同时现行齿轮接触疲劳寿命评估方法偏于保守。

Continuous dynamic meshing process of spur gear was divided into seven typical meshing states. Accurate numerical solutions of elastohydrodynamic lubrication oil film pressure in different meshing states were obtained. Oil film pressure was converted to gear contact stress by finite element method. P-S-N curve of gear was established with the consideration of Goodman formula, influence factors of P-S-N curve and EM modify rule. Contact fatigue life of spur gear with consideration of elastohydrodynamic was calculated. The result is 3.91 times longer than that of dry Hertz contact, and 10.4 times than that of GB/T3480—1997. The results show that consideration of elastohydrodynamic is essential for an accurate contact fatigue life evaluation of high-speed gear, the present evaluation method of gear contact fatigue life is conservative.