Retaining spherical pair is widely used in variable displacement axial piston pump with the feature of complex spatial relative motions.According to the kinematic relation and geometric feature of retaining spherical pair,a physical model based on the cylinder feature is proposed to study the process of oil lubrication between ball guide and retaining plate.And the lubricating film within retaining spherical pair is numerically investigated based on the modified Jakobsson-Floberg-Olsson (JFO) cavitation algorithm to consider the influence of shearing velocity.The relations among the distributions of shearing velocity,clearance shape,cavitation index and pressure under the conditions of three different tilting angles of swash plate are discussed.The research results show that the pressure distribution has the characteristics of double peak and double valley,which is depended on the hydrodynamic effect resulted from the clearance shape and the hydrostrictive effect due to shearing velocity.The hydrostrictive effect is positively correlated with the tilting angle of swash plate which plays an important role in eliminating the amount of load support.%回程球铰副是应用于轴向柱塞变量泵的机械结构,为研究其空间相对运动特征,结合回程球铰副的几何特征与相对运动关系,提出基于柱面特征的油膜润滑机理分析模型.通过拓展经典JFO空化算法以考虑复杂表面剪切速度影响因素,建立回程球铰副油膜润滑数值分析方法;对比分析斜盘倾角7.5°、12.5°与17.5° 3种典型工作条件下的润滑状态,以及摩擦副表面剪切速度分布、间隙形状分布、空化指数分布和压力分布之间的关系.研究结果表明:间隙形状引起的动压效应与表面剪切速度引起的伸缩效应共同决定油膜压力场具有“双峰双谷”的分布规律,伸缩效应与斜盘的倾斜程度呈正相关性,是导致润滑承载力下降的重要因素;回程球铰副润滑设计需综合考虑伸缩效应与动压效应对油液成膜过程的复合影响.
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