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往复式发动机中使用的滑动轴承在某些运行工况下会受到穴蚀腐蚀的影响。由于小气泡的产生和瞬间破灭而引起的高压脉冲会使轴承表面局部损坏。这种现象主要在提高发动机功率或改变轴承结构及其工作环境时发生。在环境保护法规的推动下,发动机设计师们正在努力提高小型和轻型发动机的效率和功率密度,因此会使整个曲柄机构和它的轴承座产生更大的弹性变形,从而使轴承的工作条件更加恶劣。尽管现在能用被广泛应用的 CFD 分析法成功模拟某些型式的穴蚀,但是轴承内的机油流动状态仍然太复杂,以致于无法用实体模型来描述。最常用的标准轴承评价方法是采用基于雷诺(Reynold)方程数值求解的弹性流体动力学模型。同时结合采用质量守恒算法能使润滑油更加均衡。而与曲柄机构机油流动可视化工具相结合能对大多数轴承穴蚀现象进行分析。论述了影响轴承初始穴蚀的主要因素。通过几个例子描述了最常见的穴蚀形态以及它们与模拟结果的相关性。然后列出了结构的影响因素,并提出了针对穴蚀的轴承设计工作流程。为了证明文中所述方法的优点,对新设计发动机的连杆大端轴承作了预防分析。最后对未来的发展作了简要论述和展望。
Sliding bearings used in reciprocating engines are subject to cavitation corrosion under certain operating conditions. High-pressure pulses due to the creation of small bubbles and instantaneous burst can cause localized damage to the bearing surface. This phenomenon occurs mainly when raising the engine power or changing the bearing structure and its working environment. Engineers are working to improve the efficiency and power density of small and light engines, driven by environmental regulations, thereby creating greater elastic deformation of the entire crank mechanism and its housings, allowing bearings to work more efficiently bad. Although some types of cavitation can now be successfully simulated with the widely used CFD analysis, the flow of oil within the bearing is still too complex to be characterized by a solid model. The most commonly used standard bearing evaluation method is the use of an elastic hydrodynamic model numerically solved based on the Reynold’s equation. At the same time with the use of conservation of mass conservation algorithm can make the oil more balanced. Combined with crank mechanism oil flow visualization tools, most bearing cavitation can be analyzed. Discussed the main factors affecting the initial bearing cavitation. A few examples describe the most common cavitation patterns and their correlation with simulation results. Then the influencing factors of the structure are listed, and the working process of bearing design for cavitation is proposed. In order to prove the advantages of the method described in the paper, preventive analysis was made on the big end bearing of the newly designed connecting rod of the engine. Finally, the development of the future made a brief exposition and outlook.