乏油状态下准双曲面齿轮传动润滑机理分析

Analysis on Lubrication Behavior of Hypoid Gears Under Starved Condition

在工程实际中,准双曲面齿轮不可避免地因润滑剂供给不足导致乏油问题,鉴于此,综合考虑了啮合区接触几何、粗糙形貌、入口区供油量、啮合界面速度矢量任意性等因素,建立了乏油状态下准双曲面齿轮传动界面任意速度矢量润滑分析模型,开展了乏油分析模型结果与文献实验数据的对比研究,数值分析了不同入口区供油量条件下准双曲面齿轮传动界面啮入点、啮合中点和啮出点的油膜演变规律,探讨了转速对不同供油量条件下传动界面润滑性能的影响。结果表明:乏油分析模型结果与文献实验数据取得了良好的一致性;随着入口区供油量的减小,3个啮合点油膜厚度的差异逐渐减小,当供油量减小到某一值时,3个啮合位置的油膜厚度基本一致;在不同的供油量下,转速对润滑状态的影响较为显著,油膜厚度随着转速的增加而升高,但是,转速升高到某一值时,乏油条件下的油膜厚度值将趋于稳定,而充分供油条件下的油膜厚度值将会继续增大。

In engineering practice,the starvation may occur due to insufficient supply of lubricant in hypoid gears.Therefore,a starved elastohydrodynamic lubrication model for hypoid gears was developed with the consideration of contact geometry,surface roughness,inlet oil layer thickness,and arbitrary entrainment velocity vector of interface.Model validation was executed by means of comparison between the obtained numerical results and the available starved EHL data found from some previous studies.A comprehensive analysis for the effect of inlet oil supply condition on film thickness at engaging-in,engaging-out and pitch point was conducted in a wide range of operating conditions.In addition,the influence of speed on lubrication performance under different inlet oil supply condition was obtained.The results showed that the comparison between numerical and experimental results demonstrates a good agreement.It was indicated that the difference of film thickness among the three meshing point are getting smaller when the amount of lubricant in the inlet decreased.If the inlet oil layer thickness is reduced down to a certain value,the film thickness of the three meshing points would be the same.Besides,the speed has significant effect on the lubrication behavior.The film thickness gradually increases with the increase of the speed,if the speed keeps getting greater,the film thickness would remain constant under starved condition while the film thickness would keep rising under fully flooded condition.