航空齿轮泵滑动轴承接触状态流体润滑特性

Lubrication characteristics in contact state of journal bearings inside aero gear pump

针对航空齿轮泵处于高负荷状态齿轮轴-轴瓦润滑间隙的润滑问题,将CFD仿真与齿轮轴刚性模型相结合实现了基于CFD径向运动分析的瞬时润滑计算。得到了齿轮泵瞬态场影响下的齿轮轴径向微动情况,在此基础上基于轴承三维热流体润滑计算模型和微凸体接触模型实现了对润滑油膜在高偏心接触状态的特性分析。结果表明:齿轮泵CFD仿真结果与试验结果的误差小于10%,而仿真得到的内流场的瞬变性将通过改变齿轮轴所受径向载荷的波动形状从而影响到轴承的润滑特性。通过对轴承润滑模型的数值计算发现:相比于非接触状态,轴承处于高偏心接触状态时介质的高温、低黏现象加剧。

In order to solve the problem of aero-gear pump gear-shaft/bearing gap lubrication under high load condition,CFD simulation and gear-shaft rigid model were combined to realize the transient lubrication calculation based on the CFD radial motion coupled analysis.The bearings film three-dimensional thermohydrodynamic lubrication calculation model and rough surface micro-asperity contact model were established.On the basis of calculation of the gear-shaft radial motion orbit on the gear pump transient field influence,the model was used to achieve the analysis of the characteristics under high eccentricity/contact condition.Results showed that:the error between gear pump simulation results and experimental results was less than 10%.And the transient behavior of pressure distribution caused by gear pump transient field had an impact on the fluctuation shape of gear shaft radial load,leading to the change of bearings lubrication characteristics.By the numerical calculation for bearings lubrication model,it was found that:compared with non-contact condition,journal bearings lubrication state was more serious on the contact condition,with the higher temperature and lower viscosity.