Establishment of method to observe EHL film thickness and its behavior in commercial steel rolling bearing by ultrasonic interference method

为了保证滚动轴承在恶劣条件下的稳定运行，观察弹流润滑油膜厚度及其在轻微固体接触条件下的行为是非常重要的。因此，仅靠常规的光学观察是不够的，必须弄清实际滚动轴承弹流润滑区域的润滑条件。本研究的目的是提出一种新的超声脉冲反射法测量小于100 nm弹流润滑油膜厚度的方法，并建立一种新的测量系统来观察商用钢轴承的弹流润滑油膜厚度及其行为。用50 MHz探头在大气压下测量超声波的反射特性，油膜厚度与在超声波辐照区域进行平均回波高度的理论结果之间的关系。此外，还提出了一种新的测量系统，该系统可用于工业钢轴承弹流润滑油膜厚度的测量测量了已知薄膜厚度时的回波高度关系。…绘制了更多的红色和校准曲线。用该定标曲线对静态条件下的薄膜厚度进行估计，可以得到小于100 nm的薄膜厚度估计。用由光学玻璃和钢球组成的单细胞式弹流润滑装置用超声波法观测到的回波高度的形状分布与光干涉法观察到的弹流润滑薄膜的形状定性地吻合。当用钢盘进行类似的实验时，可以观察到通常用光干涉法观察到的马蹄形油膜。此外，速度和载荷对弹流润滑油膜形成的影响符合一般趋势，证实了用超声波法测量弹流润滑油膜厚度的可能性，并观察了油膜厚度与推力轴承装置直接固体接触启动前的行为，该装置具有停止滚珠旋转的功能，可以评估商业滚动轴承的润滑状况。结果表明，商用轴承的弹流润滑油膜厚度分布规律与平板钢盘的观测结果基本一致，证实了用超声波方法评价商用轴承弹流润滑状态的可能性，为技术开发奠定了基础。较少

For the stable operation of a roll bearing operated with severe condition, it is important to observe an EHL film thickness and its behavior under the condition that solid contact slightly occurs. Therefore, it is insufficient only by conventional optical observation and must clarify the lubrication conditions of EHL region for real roll bearing which does not transmit the light.The purposes of this study were proposal of a new measurement method of oil film thickness for the EHL film less than 100 nm by ultrasonic pulse reflection method, and establishment of the new measurement system which can observe the EHL film thickness and its behavior for commercial steel bearing.Relations of reflection characteristic of ultrasonic wave, measured under atmospheric pressure with 50MHz probe, and the oil film thickness accord with the theory result which is made echo height average in ultrasonic wave irradiation area.In addition, the relations of echo height for a known film thickness were measu … More red and calibration curves were made. When the estimation of a film thickness under the static condition with this calibration curve was done, it became clear that film thickness estimation of less than 100nm can be possible.The distribution of the shape in echo height observed by a ultrasonic wave method with the monocyte type EHL apparatus, which consisted of optical glass and a steel ball, agreed with the shape of EHL film observed by light interference method qualitatively. When the similar experiment using steel disc was performed, the horseshoe-shaped oil film, which is generally observed by light interference method, was able to observe. In addition, the influence of speed and load for the formation of the EHL film accorded with a general tendency, and the possibility of the EHL film thickness measurement by a ultrasonic wave method was confirmed.Furthermore, the behavior of a film thickness until direct solid contact start with a thrust bearing apparatus, which has a function stopping the revolution of balls and can evaluate lubrication conditions of a commercial roll bearing, was observed. As a result, it was confirmed that the behavior of EHL film thickness distribution of a commercial bearing was same with the behavior observed by a flat steel disc.As mentioned above, the possibility of the evaluation of EHL lubrication conditions for the commercial bearing by an ultrasonic wave method was confirmed, and the base for technology development was established. Less