轴向柱塞泵滑靴副压力分布特性

Pressure distribution characteristics in slipper pad bearing of axial piston pump

为提高轴向柱塞泵滑靴工作可靠性,在充分考虑润滑流体在滑靴副间隙中流动特性的基础上,基于液压液阻原理提出等效液阻高度、构建流量模型,运用有限体积法对滑靴副油膜压力分布进行计算.从油膜挤压效应、供油压力、卷吸速度和油膜形状等方面对压力分布特性的影响进行分析,深入探讨了润滑油膜压力分布影响因素及变化规律.计算实例表明:在当前的数值计算方法下,动压和静压作用相对独立,相互影响较小;挤压效应对动压力影响显著;供油压力直接影响中心油腔压力,对动压几乎没有影响;卷吸速度对压力分布影响显著,不同的卷吸速度方向不但对动压力最大值影响很大,在膜厚较小区域压力分布呈现差异明显的变化规律,甚至在最大倾斜角附近会出现负压;油膜动压效应对中心膜厚和最大倾斜角非常敏感,在一定程度上,与中心膜厚相比,油膜动压效应对滑靴最大倾斜角更加敏感.

To improve the reliability in operation of slipper pad bearing in an axial piston pump,a flow model was proposed by using concept of height with equivalent flow resistance and by fully considering the flow features in the gap of bearing based on the flow resistance principle; then the pressure distribution was calculated by means of finite volume method. Besides,effects of squeezing,operation pressure,entrainment velocity,film thickness profile etc on the pressure distribution were analyzed. It was turned out that the dynamic and static pressures are relatively independent of each other and the squeezing effect can affect the dynamic pressure remarkably; the operation pressure can influence the pressure in the central recess of bearing directly but has little effect on the dynamic pressure. The entrainment velocity can alter the pressure profile considerably; the orientation of entrainment velocity can not only influence the maximum peak dynamic pressure but also induce a quite different pressure profile in the region with a thinner thickness in oil film,even a negative pressure can be resulted at the location with the biggest sloping angle in oil film thickness profile. The dynamic pressure is very sensitive to central oil film thickness and maximum sloping; in some degree,the pressure is more sensitive to the maximum sloping angle than to the thickness.