表面微织构对球盘点接触润滑摩擦性能的影响

基于统一Reynolds方程系统模型开展了富油点接触工况下微织构表面润滑摩擦性能的数值模拟研究.在通过实验标定数值模拟中润滑剂流变参数的基础上,系统分析了微织构表面摩擦系数周期变化的全过程,初步揭示了微织构的减摩机理.结果表明：数值模拟结果与实验结果有较好的吻合;瞬时摩擦系数达到最小值时,微坑单元一般处于名义Hertz接触区域的前边界;当微坑运动到Hertz接触区域内时,微坑前沿局部膜厚减小,而微坑后边沿膜厚局部增大,形成局部膜厚增大区;局部膜厚增大区的大小对微织构的润滑摩擦性能有较大影响,其面积越大,减摩效果越好.

Effect of Surface Texturing on Lubrication Performance of Ball-on-Disc Point Contacts

The numerical simulations of surface textures in fully flooded point-contact lubrication were conducted based on the unified Reynolds equation model. The friction reducing mechanism was demonstrated by systemically analyzing the periodic change of friction coefficients of surface textures. The lubricant rheological parameters used in the simulations were calibrated by experiments. The numerical results show good agreements with experimental results, i.e. friction coefficient reached its minimum value when the dent moved to the front boundary of the Hertzian contact region. Also, the local film thickness reduction in front of the dent and enhancement in the back were observed. Local film enhancement region was formed when the dent moved to the Hertzian contact region. The influence of local film enhancement region on the characteristics of textures was significant i.e. the bigger the area, the lower the friction coefficient.