建立摆动工况下直齿轮的弹流润滑模型,解决因旋转方向改变导致的坐标系统不一致的问题;考虑时变效应,对以正弦规律摆动的直齿轮进行弹流润滑分析。结果表明:摆动工况下的中心油膜压力、中心膜厚、最小膜厚和最大压力均出现明显的波动变化,且都在旋转方向改变瞬时附近达到最小;摆动频率对压力和膜厚影响显著,在高频率摆动工况下的中心油膜压力、中心膜厚、最小膜厚和最大压力变化幅度更明显,且均高于低频摆动工况下相应的油膜压力和膜厚;摆动工况特别是高频摆动工况下的中心油膜压力和最大油膜压力会出现骤增和骤降现象,使啮合齿面应力循环频率加大,易导致齿面接触疲劳,因此要避免高频摆动。
Elastohydrodynamic lubrication(EHL) model of spur gears under oscillation conditions was established.The problem of coordinate system inconformity caused by variation of rotate direction was solved. Considering time-variant effect,EHL analysis of the spur gears with sine law swing was carried out.Resuhs show that there are evident fluctuations in centre film pressure, centre film thickness, minimum film thickness and maximum film pressure under oscillation conditions, moreover, they all reach the minimums nearby the transient that rotate direction varies.Oscillation frequency has obvious influence on film pressure and film thickness. Amplitude of variation of centre film pressure and maximum film pressure, centre film thickness and minimum film thickness are obvious under high frequency oscillation conditions, and their values are greater than those under low frequency oscillation conditions.The phenomenon of a surge and collapse in the centre film pressure and maximum film pressure under oscillation conditions, especially under high frequency oscillation conditions,which causes a remarkable increase in cycle frequency of meshing teeth surface stress and may lead to teeth contact failure.Therefore ,high frequency oscillation should be avoided.