Construction of lubrication diagnostic system supported by ultrasonic technique

为了实现从混合润滑到边界润滑的区域初始阶段的润滑状态诊断，尝试构建了一种将超声技术、摩擦学技术和声电技术相结合的新型润滑诊断系统。然后，从基于面积指数变化的接触条件估计中澄清了以下事实。1）通过考虑无波形失真的1波长中心频率的面积指数和接触表面的刚度，建立了不受表面粗糙度和形貌影响而能估算固体接触面积比的简便面积测量方法的基础。利用点聚焦式探头测量的局部场面积指数的差异，可以将超声波的入射范围限定在接触面的一部分，从而了解滑动面局部的摩擦力，并绘制摩擦力分布图。3）通过测量不通过油膜传播的横波的反射率，4）根据摩擦系数与摩擦系数的相关性，可以判断磨损粉末的转移和滑动表面氧化膜的形成条件; 5）利用超声与声发射相结合的UT-AE润滑诊断技术，使摩擦表面接触质量的现场测量成为可能。然后，通过与测量的摩擦力进行比较，可以对润滑表面进行风险评估。

The construction of the new lubrication diagnostic system which combined ultrasonic technique, friction and A.E.was tried in order to enable the diagnosis of lubricated condition from the region initial stage of mixed lubrication to boundary lubrication.For the lubrication evaluation, the areal index which depended on pulse amplitude of ultrasonic wave reflected from sliding surface was used. Then, following fact clarified from the estimation of the contact condition based on the change of areal index.1) By the consideration of areal index for center frequency of the 1 wavelength without waveform distortion and of the stiffness of contacting surface, the base of convenient area measuring method which could estimate solid contact area ratio regardless of roughness and topography of the surface was able to be established.2) From the difference between local field areal index measured by the point focus type probe which could limit the incidence area of the ultrasonic wave to the part of contact surface, the friction in local part on the sliding surface was known, and the drawing of the friction distribution diagram became possible.3) From the measurement of the reflectivity of the transversal wave which does not propagate through the oil, the possibility of quantitatively estimation of load sharing ratio under the mixed lubrication was clarified.4) On the basis of the correlation between areal index and friction, transfer of the abrasion powder and formation condition of the oxide film on the sliding surface would be able to be estimated.5) By UT-AE lubrication diagnostic technique which combined ultrasonic method with the AE method, the in situ measurement of the quality of contact condition of friction surface became possible. Then, the risk evaluation of the lubricating surface by the comparison with measured friction was possible.