摘要
利用力学平衡方程与流体力学方程并结合楔形模型,建立无界面滑移、单边界面滑移以及双边界面滑移状态下的力学模型,采用有限元方法对表面织构分布位置及不同界面滑移对滑移速度与摩擦力的作用规律进行研究。研究表明:油膜发生界面滑移时,在升压区和降压区油膜滑移速度分别表现为非线性的凹形和凸形变化规律;油膜在上表面和下表面发生滑移时,最大剪切力分别发生在油膜上表面和下表面;而上、下表面均发生界面滑移时,油膜最大剪切应力发生在上、下表面,且二者最大剪切应力数值相同,此时摩擦力显著减小且仅为无滑移时的4%~17%;相比表面织构布置在入口与中部位置的模型,表面织构在出口处的模型呈现出优异的承载和减摩效果。表面织构轴承界面滑移产生的机制主要是润滑油具有牛顿流体的黏滞特性。
The mechanical models of no interface slip,single interface slip and double interface slip were established by using mechanical equilibrium equation and hydrodynamic equation combined with wedge model.The effects of the surface textured distribution and different interface slip on the sliding velocity and friction force were studied by finite element method.The results show that when the interface slip occurs,the slip velocities of oil film in boost region and decompression region show nonlinear concave and convex variation laws,respectively.When the interface slip occurs on the upper surface and the lower surface of oil film,the maximum shear stress occurs on the upper surface and the lower surface respectively.When the interface slip occurs on both upper and lower surfaces,the maximum shear stress of oil film occurs on both upper and lower surfaces,and the values of the maximum shear stress are the same,while the friction force is significantly reduced by 4%~17% compared with the friction force of no interface slip.The model with surface texture distributed at the exit exhibits excellent effect of load bearing and friction reducing compared with the models with surface texture distributed the atentrance and the middle.The mechanism of interfacial slip of surface texture hydrodynamic journal bearing is that the lubricating oil has viscous property of Newtonian fluid.
引文
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