低速大偏心滑动轴承润滑状态转变及特性分析

Lubrication State Transformation and Characteristic Analysis of Sliding Bearing under Low Rotary Speed and High Eccentric

以动压滑动轴承为研究对象,建立了完全流体润滑模型和混合润滑模型。采用有限差分法进行数值求解,得到摩擦阻力、摩擦因数、承载力和端泄油温升等特性参数;通过膜厚比和摩擦因数判断轴承所处润滑状态,分析润滑状态转变后表面粗糙度对轴承特性的影响;并基于M2000型摩擦磨损实验机进行了混合润滑状态摩擦副跑合实验。结果表明,低转速下增大偏心率,轴承润滑状态从完全流体润滑转变为混合润滑,且综合表面粗糙度越大,润滑状态转变所需偏心率越小;混合润滑状态粗糙峰接触可以提高承载力,但导致轴承摩擦阻力和端泄油温升迅速升高;大偏心下实验结果与混合润滑理论计算结果基本一致。

Taking hydrodynamic sliding bearing as the research object,models of hydrodynamic lubrication and mixed lubrication are established.The characteristic parameters such as friction force,friction coefficient,load-carrying capacity and temperature rise of lubricating oil are obtained by finite difference method for numerical solution,then lubrication state of bearing could be judged by friction coefficient and film thickness ratio,the influence of surface roughness on bearing characteristics after lubrication state transformation is analyzed,and the running-in experiment of mixed lubrication friction pair is carried out under mixed lubrication based on M2000 friction and wear tester.The results show that as the eccentric ratio increase,the lubrication state of the bearing will transform to mixed lubrication from hydrodynamic lubrication at low rotary speed;the rough peak contact in mixed lubrication state can improve load-carrying capacity,but lead to rapidly increase of bearing friction force and oil temperature;the experimental results are consistent with the theoretical results of mixed lubrication under high eccentric ratio.