铁路柴油机润滑油的流变学衰变研究

Research on the Rheological Change of Railroad Used Oil

使用中的铁路机车柴油机润滑油报废的主要原因是运动粘度超限。使用剪率控制型流变仪对使用中的铁路机车柴油机润滑油的流变学变化进行研究,测量不同剪率下润滑油剪应力,计算动力粘度。研究结果表明,柴油机润滑油在运用过程中由牛顿流体衰变为非牛顿流体,而且运动粘度值增加愈大,愈加偏离牛顿流体的特性。分析认为,运动粘度值不能真实的描述柴油机润滑油实际工作中的流变学特性。

The main reason to discard the lubricating oil in use for railway locomotive diesel engine lies in its kinematic viscosity beyond limiting value. The rheological change of the lubricating oil in use for railway locomotive diesel engine has been studied by rheometer controlled by shear ratio. The shear stress under different shear ratio was measured to calculate the kinematic viscosity. Results indicate that during the process of application, the lubricating oil used for diesel engine is disintegrated from Newtonian fluids to non-Newtownian.Moreover, the higher the increase of kinematic viscosity is, the more serious deviation is from the characteristics of Newtonian fluids. Analyses show that kinematic viscosity cannot truly reflect the actual rheological characteristics of the lubricating oil used for diesel engine.