定制边界滑移平行轴承的挤压效应(英文)

Squeeze Effect of a Parallel Surface Bearing with Tailored Boundary Slippage

作者最近提出了一种利用滑块入口处的壁面滑移产生流体动压的新型轴承.笔者针对该类新轴承的油膜挤压问题,提出了基于滑移临界剪应力的数学模型,并给出了解析解.结果显示压力分布为分段光滑的抛物线,在滑移/非滑移边界,存在不连续的压力梯度.不同参数条件下的计算给出了不同的压力分布和壁面滑移类型.结果显示,对于代表滑块非浸润区长度的参数xt,最大压力并不总是随参数xt的减小而减小.存在一个参数xt的区间,在该区间内最大压力不变.与经典的挤压膜轴承类似,压力随膜厚的增加或趋进速度的减小而减小.笔者还发现临界剪应力的对挤压效应有重要的影响,揭示了此类新型轴承的一些内在的特性.

The authors recently proposed an approach to generating hydrodynamic lubrication by wall slippage in the inlet of the stationary bearing slider. In this paper, a mathematical model with a critical shear-stress criterion of slippage is presented to describe the squeeze film effect of this newly devised device, and an analytical solution is obtained. It is shown that the pressure distribution is a piecewise parabolic curve, and the pressure gradient can be discontinuous at the border of the slip and no-slip regions. Parametric studies show the variations of the pressure and the boundary slippage under different conditions. It is demonstrated that for the variation of the maximum pressure with the surface-tailored parameter xt which denotes the length of the hydrophobic region of the slider, there exists a range of act. where the pressure has no dependence on the surface-tailored parameter. Out of this range, the maximum pressure decreases with decreasing xt. Similar to the classical squeeze film bearing, the pressure decreases with the increase in the film thickness or the decrease in the approach velocity. The influences of the critical shear stress are also explored, and are found to significantly affect the squeeze behavior. Some intrinsic properties of this new type of parallel surface bearing are revealed.