离散供油弹流润滑条件下油滴间距临界值的研究

Study on the critical value of oil droplet spacing distance under conditions of discrete droplet supply in elastohydrodynamic lubrication

在离散油滴供油条件下,建立了相应的简化弹流润滑模型,数值模拟了一列油滴通过点接触弹流接触区的全过程.结果表明:离散多油滴供油时,接触区润滑油膜厚度会经历3个阶段,即上升期、振荡期和稳定期;相邻油滴的间距影响到接触区润滑状态,过大的间距会导致接触区润滑失效.为保证接触区的连续有效润滑,油滴间距存在一个临界值,需保证离散油滴间距不应大于此临界值;卷吸速度、润滑油黏度和载荷都会影响到离散油滴的润滑成膜特性,进而改变油滴间距的临界值.

Based on the oil supply in the form of discrete droplets, a simplified model of elastohydrodynamic lubrication (EHL) has been established to simulate the whole process of a series of oil droplets passing through the point contact EHL zone. The results show that with discrete oil droplets supply, the lubrication film thickness of contact zone will experience three stages, that is, increase stage, oscillation stage and stablility stage. If the spacing distance between oil droplets changes, it will inevitably affect the lubrication state of contact zone, and there may be lubrication failure in some cases. In order to ensure that the contact zone is in a state of full lubrication, there is a critical value for the spacing distance between oil droplets. The actual droplet spacing distance must not be greater than this critical value. Entrainment speed, oil viscosity and load can significantly affect the lubrication film formation under oil droplets supply, and then change the critical value of droplet spacing distance.