弹流润滑条件下表面形貌对摩擦噪声的影响

研究了弹流润滑状态下表面形貌对摩擦噪声的影响.通过激光微加工方法在金属圆盘试件表面上制造了两种沟槽型织构表面形貌，在双盘摩擦磨损试验机上对不同表面形貌进行了摩擦噪声和摩擦特性试验，分析了线接触弹流润滑条件下不同工况和表面形貌影响摩擦噪声的机理，并结合有限元分析对结论加以验证.结果表明:载荷和转速的变化对线接触摩擦噪声有明显影响，由于线接触副工作在部分膜弹流润滑状态下，所以摩擦噪声的特性与干摩擦时类似，摩擦因数较大的表面会辐射出更强的摩擦噪声；特定结构的表面形貌能改善表面润滑特性，有效降低摩擦噪声声压级，沟槽型织构的存在可以打断接触区域应力分布，减轻接触面微凸体碰撞作用，从而降低了表面自激振动，同时合适的表面形貌结构也有利于润滑油膜的形成，减小了系统的摩擦能量，达到降低摩擦噪声的效果.

Effects of Surface Topography on Friction Noise Under Elastohydrodynamic Lubrication Condition

The effects of surface topography on the friction noise were studied under the elastohydrodynamic lubrication (EHL) condition.2 kinds of groove-textured surface topographies were fabricated by laser texturing on the surface of the metal disc specimen.Friction noises and friction characteristics of different surface topographies were tested on a modified JPM-1 2-disc tribo-tester.The effects of different operating conditions and surface topographies on the friction noise under line contact EHL conditions were analyzed,and the results were verified with the finite element analysis.The work shows that,variations of the load and the rotational speed have significant effects on the line contact friction noise.Since the line contact pairs usually work in a partial EHL condition,the friction noise characteristics are similar to those of dry friction:the surface with a larger friction coefficient will radiate stronger friction noise.Specific topographies can improve the lubrication characteristics of the surface,and effectively reduce the sound pressure level of the friction noise.The presence of groove textures can interrupt the stress distribution of the contact area and weaken the impact by surface asperities,thereby reducing the self-excited vibration.At the same time,the proper surface topography structure is also helpful in the formation of lubricating oil film,hence lowering the friction noise as well as the friction energy of the system.