Construction of lubrication diagnostic system supported by ultrasonic technique

为实现从区域混合润滑初始阶段到边界润滑阶段的润滑状态诊断，尝试构建超声技术、摩擦和a.e.相结合的新型润滑诊断系统。在润滑评价中，采用了依赖于滑面反射的超声波脉冲幅值的面指数。然后，从基于面指数变化的接触条件估计入手，阐明了以下事实。1)通过考虑无波形畸变的1波长中心频率的面积指数和接触面的刚度，建立了不考虑表面粗糙度和表面形貌而可以估计固体接触面积比的简便面积测量方法的基础。2)通过点焦点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面积限制在接触面部分，从而了解滑动面上局部部分的摩擦情况，并绘制摩擦分布图。3)通过测量未通过油液的横波反射率，阐明了在混合润滑条件下定量估计载荷分担比的可能性。4)根据面指数与摩擦力的关系，可以估计出磨损粉末的转移和滑动表面氧化膜的形成情况。5)采用超声法与声发射法相结合的UT-AE润滑诊断技术，使摩擦表面接触状态质量的现场测量成为可能。然后，通过与实测摩擦量的比较，对润滑表面进行风险评价。

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.