目的 针对滑动轴承等面接触机械器件，研究非线性剪切流速分布对滑块轴承承载力的影响。方法 采用荧光漂白恢复方法结合面接触润滑油膜测量系统，获得了润滑油膜受剪切时的流速分布。采用广义雷诺方程结合剪切流速分布，对面接触流体动压润滑的承载特性进行理论分析。采用Sigmoid函数对非线性流速分布进行拟合。结果 由于表观滑移或低黏度层的影响，微纳米间隙PAO8和PB450在膜厚较小时呈现非线性流速分布，且其非线性程度随膜厚变化，润滑油膜在厚度方向的黏度不是一个常量，在高膜厚时呈线性分布。非线性流速分布使广义雷诺方程中的黏度参量1/ηeff大于1，随着非线性程度的增加，黏度参量先迅速增加，然后缓慢上升，相应的最大无量纲承载量对应的收敛比大于经典计算值1.2，膜厚较高时，剪切流速呈现线性分布，理论值最大承载量对应的收敛比为1.2。通过与光干涉技术得到的无量纲承载量-收敛比实验结果进行对比，可知两者具有很好的一致性。结论 受剪切时的流速分布可以对机械器件的流体动压润滑特性进行理论预测。

The work aims to study the effect of nonlinear shear velocity distribution on load carrying capacity of pad bearings for mechanical devices such as sliding bearings in conformal contact. The velocity distribution of lubricating oil film was measured by fluorescence bleaching recovery method combined with the oil film measurement system. The theoretical analysis of the bearing capacity of hydrodynamic lubrication in conformal contact was carried out by the generalized Reynolds equation combined with the shear velocity distribution. Due to apparent slip or low viscosity layer, PAO8 and PB450 in micro-nano gap presented nonlinear velocity distribution when film thickness was small, and the degree of non-linearity changed with the film thickness. The viscosity of lubricant along the film thickness was not a constant, showing linear distribution at high thickness. The sigmoid function was used to fit the nonlinear velocity distribution. The nonlinear velocity profile made the viscosity parameter 1/ηeff greater than 1 in the generalized Reynolds equation. With the increase of the non-linearity degree, the viscosity parameter increased rapidly and then slowly. The corresponding convergence ratio of the maximum dimensionless bearing capacity was larger than that of the classical calculation value 1.2. When the film thickness was higher, there was a linear velocity distribution, and the corresponding convergence ratio of the theoretical maximum bearing capacity was 1.2. Compared with the experimental results of dimensionless bearing capacity-convergence ratio curves obtained by optical interferometry, there was a good consistency between theoretical and experimental results. Therefore, the shear velocity distribution can be used to predict the hydrodynamic lubrication characteristics of mechanical devices.