Construction of lubrication diagnostic system supported by ultrasonic technique

为了能够从混合润滑的区域初期阶段到边界润滑阶段对润滑状态进行诊断，尝试构建了超声技术、摩擦学和声学分析相结合的新型润滑诊断系统，并采用了依赖于从滑动面反射的超声波脉冲幅度的面积指数进行润滑评价。然后，通过考虑1)无波形失真的1波长中心频率的面积指数和接触面的硬度，从而建立了方便的面积测量方法的基础，该方法可以估计固体接触面积比，而不受表面的粗糙度和地形的影响。2)从可以将超声波的入射区域限制在接触面部分的点焦点探头测量的局部场面积指数之间的差，知道滑动面上局部部分的摩擦，3)通过测量不通过油液传播的横波的反射率，阐明了定量估计混合润滑下载荷分担比的可能性。4)根据面状指数与摩擦的相关性，可以判断磨料在滑动表面的转移和氧化膜的形成条件。5)采用超声波法和声发射法相结合的UT-AE润滑诊断技术，实现了对摩擦表面接触状态的现场测量。通过与实测摩擦力的比较，可以对润滑面的风险进行评估。

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.