【摘要】 目前对内燃机连杆轴承润滑性能的研究，一般将润滑油处理成牛顿流体，在润滑油使用中，经常加入少量高分子添加剂以改善摩擦副的润滑状况，这些高分子添加剂也会改变润滑油的流动状态，使其由牛顿流体转变为偶应力流体，同时考虑到内燃机设计要求的不断提高导致连杆轴承的工况愈加严苛，轴承表面形貌的影响也不可忽略。为了能更准确分析连杆轴承的润滑性能，应用了综合考虑轴承表面形貌和偶应力流体润滑影响的修正平均雷诺方程，以某四缸四冲程内燃机连杆轴承为研究对象，应用有限差分法和步进法进行数值求解，分析了不同表面粗糙度均方根、表面方向参数和偶应力参数下的连杆轴承润滑性能。结果表明：轴承的表面粗糙度均方根越大，轴颈摩擦功耗越大，与均匀粗糙表面轴承和横向粗糙表面轴承相比，纵向粗糙表面轴承有更小的轴颈摩擦功耗；偶应力流体润滑作用的效果明显，随着偶应力参数值的增大，轴颈摩擦功耗明显减小。因此，在相同轴承表面加工等级的情况下，将轴承加工出纵向粗糙表面和使用偶应力流体作润滑剂是降低轴颈摩擦功耗的有效措施。更多还原

【Abstract】 Lubricating oil is generally treated as a Newtonian fluid in current research on lubrication performance of connecting rod bearings for internal combustion engines. In practical applications of lubricating oil, small amounts of polymer additives are often added to improve the lubrication condition of friction pair. However, these polymer additives will change the flow state of lubricating oil from Newtonian fluid to couple stress fluid. At the same time, considering the continuously elevated design requirements for internal combustion engines that lead to more severe operating conditions for the bearings, the influence of bearing surface topography cannot be ignored. The modified average Reynolds equation that comprehensively considers the influence of bearing surface topography and couple stress fluid lubrication is applied to more accurately analyze the lubrication performance of the bearings. Taking connecting rod bearings for a four-cylinder four-stroke internal combustion engine as research objects, the finite difference method and step method are used for numerical calculation. The lubrication performances of the bearings under different RMS values of surface roughness, surface orientation parameters and couple stress parameters are analyzed. The results show that larger RMS values of surface roughness lead to greater frictional power loss of journal, the bearings with longitudinal rough surfaces have less frictional power loss of journal than bearings with uniform rough surfaces and transverse rough surfaces; the effect of couple stress fluid lubrication is obvious, with the increase of couple stress parameter value, the frictional power loss of journal decreases obviously. Therefore, in the case of same bearing surface processing level, machining longitudinal rough surfaces on bearings and using couple stress fluid as a lubricant are effective measures to reduce frictional power loss of journal.更多还原